已按“实验成绩独立管理”完成修改。

每个实验项目独立建成绩单，支持评分项、参与状态、补做次数、安全违规、报告地址和教师评语。
流程为：录入 → 学院审核 → 教务发布；学生只能查看已发布成绩。
自主预约实验支持同步有效预约名单，已评分记录不会被误删。
课程成绩可将已发布实验成绩汇总为快照导入指定分项；导入后锁定，不能手工篡改。
实验项目成绩不完整时，对应课程分项保持空白，不按 0 分处理。
一级“实验管理”菜单下增加“项目与场次”“实验成绩”；学生端增加“实验安排”“实验成绩”。
已生成 MySQL 正式迁移及 SQLite 开发迁移，尚未操作生产数据库。
界面采用“实验项目 → 独立评分 → 审核发布”工作台设计。

src/Jiaowu.Api/Controllers/ExperimentGradesController.cs

@@ -0,0 +1,945 @@
+using System.ComponentModel.DataAnnotations;
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Grades;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Jiaowu.Api.Infrastructure.Teaching;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Controllers;
+
+[ApiController]
+[Authorize]
+[Route("api/experiment-grades")]
+public sealed class ExperimentGradesController(
+    AppDbContext db,
+    ICurrentUserDataScope currentUserDataScope) : ControllerBase
+{
+    private const string Managers =
+        SystemRoles.SuperAdmin + "," +
+        SystemRoles.AcademicAdmin + "," +
+        SystemRoles.CollegeAdmin + "," +
+        SystemRoles.Teacher;
+
+    private const string Reviewers =
+        SystemRoles.SuperAdmin + "," +
+        SystemRoles.AcademicAdmin + "," +
+        SystemRoles.CollegeAdmin;
+
+    private const string Publishers =
+        SystemRoles.SuperAdmin + "," +
+        SystemRoles.AcademicAdmin;
+
+    [HttpGet("management")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> GetManagement(
+        Guid? academicTermId,
+        ExperimentGradeSheetStatus? status,
+        CancellationToken cancellationToken)
+    {
+        var source = ScopedProjects().AsNoTracking()
+            .Where(x =>
+                x.Status == ExperimentProjectStatus.Published ||
+                x.Status == ExperimentProjectStatus.Closed);
+        if (academicTermId.HasValue)
+            source = source.Where(x =>
+                x.TeachingTask!.AcademicTermId == academicTermId);
+        if (status.HasValue)
+            source = source.Where(x =>
+                x.GradeSheet != null &&
+                x.GradeSheet.Status == status.Value);
+
+        return Ok(await source
+            .OrderByDescending(x => x.TeachingTask!.AcademicTerm!.StartDate)
+            .ThenBy(x => x.TeachingTask!.TaskNumber)
+            .ThenBy(x => x.Code)
+            .Select(x => new
+            {
+                x.Id,
+                x.Code,
+                x.Name,
+                x.ArrangementMode,
+                ProjectStatus = x.Status,
+                x.TeachingTaskId,
+                x.TeachingTask!.TaskNumber,
+                TaskName = x.TeachingTask.Name,
+                AcademicTermId = x.TeachingTask.AcademicTermId,
+                TermName = x.TeachingTask.AcademicTerm!.Name,
+                CourseCode = x.TeachingTask.Course!.Code,
+                CourseName = x.TeachingTask.Course.Name,
+                CollegeName = x.TeachingTask.Course.College!.Name,
+                TeacherNames = x.TeachingTask.Teachers
+                    .OrderByDescending(item => item.IsPrimary)
+                    .Select(item => item.Teacher!.Name),
+                Sheet = x.GradeSheet == null
+                    ? null
+                    : new
+                    {
+                        x.GradeSheet.Id,
+                        x.GradeSheet.Status,
+                        x.GradeSheet.ContributionWeight,
+                        x.GradeSheet.PassScore,
+                        ItemCount = x.GradeSheet.Items.Count,
+                        StudentCount = x.GradeSheet.Records.Count,
+                        CompletedCount = x.GradeSheet.Records.Count(record =>
+                            record.ParticipationStatus !=
+                                ExperimentParticipationStatus.Pending),
+                        ScoredCount = x.GradeSheet.Records.Count(record =>
+                            record.TotalScore != null),
+                        PassedCount = x.GradeSheet.Records.Count(record =>
+                            record.IsPassed == true),
+                        x.GradeSheet.SubmittedAt,
+                        x.GradeSheet.ReviewedAt,
+                        x.GradeSheet.PublishedAt
+                    }
+            })
+            .ToListAsync(cancellationToken));
+    }
+
+    [HttpGet("mine")]
+    [Authorize(Roles = SystemRoles.Student)]
+    public async Task<ActionResult> GetMine(CancellationToken cancellationToken)
+    {
+        var student = await CurrentStudentAsync(cancellationToken);
+        if (student is null)
+            return ConflictProblem("当前账号未关联有效学生档案。");
+
+        return Ok(await db.ExperimentGradeRecords.AsNoTracking()
+            .Where(x =>
+                x.StudentId == student.Id &&
+                x.ExperimentGradeSheet!.Status ==
+                    ExperimentGradeSheetStatus.Published)
+            .OrderByDescending(x =>
+                x.ExperimentGradeSheet!.PublishedAt)
+            .ThenBy(x =>
+                x.ExperimentGradeSheet!.ExperimentProject!.Code)
+            .Select(x => new
+            {
+                x.Id,
+                x.ExperimentGradeSheetId,
+                ProjectId = x.ExperimentGradeSheet!.ExperimentProjectId,
+                ProjectCode =
+                    x.ExperimentGradeSheet.ExperimentProject!.Code,
+                ProjectName =
+                    x.ExperimentGradeSheet.ExperimentProject.Name,
+                x.ExperimentGradeSheet.ExperimentProject.ArrangementMode,
+                CourseCode = x.ExperimentGradeSheet.ExperimentProject
+                    .TeachingTask!.Course!.Code,
+                CourseName = x.ExperimentGradeSheet.ExperimentProject
+                    .TeachingTask.Course.Name,
+                TermName = x.ExperimentGradeSheet.ExperimentProject
+                    .TeachingTask.AcademicTerm!.Name,
+                x.ExperimentGradeSheet.PassScore,
+                x.ParticipationStatus,
+                x.TotalScore,
+                x.IsPassed,
+                x.SafetyViolation,
+                x.AttemptNumber,
+                x.SubmissionReference,
+                x.SubmittedAt,
+                x.IsLate,
+                x.TeacherComment,
+                Items = x.ItemScores
+                    .OrderBy(score =>
+                        score.ExperimentGradeItem!.SortOrder)
+                    .Select(score => new
+                    {
+                        score.ExperimentGradeItemId,
+                        score.ExperimentGradeItem!.Name,
+                        score.ExperimentGradeItem.Kind,
+                        score.ExperimentGradeItem.Weight,
+                        score.Score,
+                        score.Comment
+                    }),
+                x.ExperimentGradeSheet.PublishedAt
+            })
+            .ToListAsync(cancellationToken));
+    }
+
+    [HttpPost("sheets")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> CreateSheet(
+        ExperimentGradeSheetRequest request,
+        CancellationToken cancellationToken)
+    {
+        var items = BuildItems(request.Items);
+        if (!ExperimentGradeCalculator.AreWeightsValid(
+                request.ContributionWeight,
+                request.PassScore,
+                items))
+            return ValidationProblem(
+                "实验评分项至少设置一项、权重合计 100%，项目贡献权重应大于 0。");
+
+        var project = await ScopedProjects()
+            .Include(x => x.TeachingTask)
+            .ThenInclude(x => x!.Teachers)
+            .ThenInclude(x => x.Teacher)
+            .FirstOrDefaultAsync(x =>
+                x.Id == request.ExperimentProjectId,
+                cancellationToken);
+        if (project is null) return NotFound();
+        if (project.Status is not (
+                ExperimentProjectStatus.Published or
+                ExperimentProjectStatus.Closed))
+            return ConflictProblem("只有已发布或已关闭实验项目可以建立成绩单。");
+        if (!CanInitialize(project.TeachingTask!)) return Forbid();
+        if (await db.ExperimentGradeSheets.AnyAsync(x =>
+                x.ExperimentProjectId == project.Id,
+                cancellationToken))
+            return ConflictProblem("该实验项目已经建立成绩单。");
+
+        var participants = await LoadParticipantsAsync(
+            project,
+            cancellationToken);
+        if (participants.Count == 0)
+            return ConflictProblem("实验项目当前没有可评分学生。");
+
+        var sheet = new ExperimentGradeSheet
+        {
+            ExperimentProjectId = project.Id,
+            ContributionWeight = request.ContributionWeight,
+            PassScore = request.PassScore,
+            Items = items,
+            Records = participants.Select(participant =>
+                new ExperimentGradeRecord
+                {
+                    StudentId = participant.StudentId,
+                    ExperimentSessionId = participant.SessionId,
+                    ItemScores = items.Select(item =>
+                        new ExperimentGradeItemScore
+                        {
+                            ExperimentGradeItemId = item.Id
+                        }).ToList()
+                }).ToList()
+        };
+        db.ExperimentGradeSheets.Add(sheet);
+        await db.SaveChangesAsync(cancellationToken);
+        return Created(string.Empty, new { sheet.Id });
+    }
+
+    [HttpGet("sheets/{id:guid}")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> GetSheet(
+        Guid id,
+        int recordPage = 1,
+        int recordPageSize = 50,
+        string? studentKeyword = null,
+        CancellationToken cancellationToken = default)
+    {
+        recordPage = Math.Max(1, recordPage);
+        recordPageSize = Math.Clamp(recordPageSize, 10, 100);
+        studentKeyword = string.IsNullOrWhiteSpace(studentKeyword)
+            ? null
+            : studentKeyword.Trim();
+
+        var sheet = await ScopedSheets().AsNoTracking()
+            .Where(x => x.Id == id)
+            .Select(x => new
+            {
+                x.Id,
+                x.ExperimentProjectId,
+                ProjectCode = x.ExperimentProject!.Code,
+                ProjectName = x.ExperimentProject.Name,
+                x.ExperimentProject.ArrangementMode,
+                x.ExperimentProject.TeachingTaskId,
+                x.ExperimentProject.TeachingTask!.TaskNumber,
+                TaskName = x.ExperimentProject.TeachingTask.Name,
+                AcademicTermId =
+                    x.ExperimentProject.TeachingTask.AcademicTermId,
+                TermName = x.ExperimentProject.TeachingTask
+                    .AcademicTerm!.Name,
+                CourseCollegeId = x.ExperimentProject.TeachingTask
+                    .Course!.CollegeId,
+                CourseCollegeName = x.ExperimentProject.TeachingTask
+                    .Course.College!.Name,
+                CourseCode =
+                    x.ExperimentProject.TeachingTask.Course.Code,
+                CourseName =
+                    x.ExperimentProject.TeachingTask.Course.Name,
+                TeacherNames = x.ExperimentProject.TeachingTask.Teachers
+                    .OrderByDescending(item => item.IsPrimary)
+                    .Select(item => item.Teacher!.Name),
+                x.ContributionWeight,
+                x.PassScore,
+                Items = x.Items.OrderBy(item => item.SortOrder)
+                    .Select(item => new
+                    {
+                        item.Id,
+                        item.Name,
+                        item.Kind,
+                        item.Weight
+                    }),
+                x.Status,
+                x.ReviewComment,
+                x.SubmittedAt,
+                x.ReviewedAt,
+                x.PublishedAt,
+                x.CreatedAt,
+                x.UpdatedAt
+            })
+            .FirstOrDefaultAsync(cancellationToken);
+        if (sheet is null) return NotFound();
+
+        var recordsSource = db.ExperimentGradeRecords.AsNoTracking()
+            .Where(x => x.ExperimentGradeSheetId == id);
+        if (studentKeyword is not null)
+            recordsSource = recordsSource.Where(x =>
+                x.Student!.StudentNumber.Contains(studentKeyword) ||
+                x.Student.Name.Contains(studentKeyword) ||
+                x.Student.AdministrativeClass!.Name.Contains(studentKeyword));
+        var recordTotal = await recordsSource.CountAsync(cancellationToken);
+        var records = await recordsSource
+            .OrderBy(x => x.Student!.StudentNumber)
+            .Skip((recordPage - 1) * recordPageSize)
+            .Take(recordPageSize)
+            .Select(x => new
+            {
+                x.Id,
+                x.StudentId,
+                x.Student!.StudentNumber,
+                x.Student.Name,
+                ClassName = x.Student.AdministrativeClass!.Name,
+                x.ExperimentSessionId,
+                Session = x.ExperimentSession == null
+                    ? null
+                    : new
+                    {
+                        x.ExperimentSession.SessionDate,
+                        x.ExperimentSession.StartPeriod,
+                        x.ExperimentSession.PeriodCount,
+                        ClassroomName =
+                            x.ExperimentSession.Classroom!.Name
+                    },
+                x.ParticipationStatus,
+                x.TotalScore,
+                x.IsPassed,
+                x.SafetyViolation,
+                x.AttemptNumber,
+                x.SubmissionReference,
+                x.SubmittedAt,
+                x.IsLate,
+                x.TeacherComment,
+                ItemScores = x.ItemScores
+                    .OrderBy(score =>
+                        score.ExperimentGradeItem!.SortOrder)
+                    .Select(score => new
+                    {
+                        score.ExperimentGradeItemId,
+                        score.ExperimentGradeItem!.Name,
+                        score.Score,
+                        score.Comment
+                    }),
+                x.UpdatedAt
+            })
+            .ToListAsync(cancellationToken);
+
+        var task = await db.TeachingTasks.AsNoTracking()
+            .Include(x => x.Teachers)
+            .ThenInclude(x => x.Teacher)
+            .SingleAsync(
+                x => x.Id == sheet.TeachingTaskId,
+                cancellationToken);
+        var canReview = CanReviewCollege(sheet.CourseCollegeId) &&
+                        sheet.Status ==
+                            ExperimentGradeSheetStatus.Submitted;
+        return Ok(new
+        {
+            Sheet = new
+            {
+                sheet.Id,
+                sheet.ExperimentProjectId,
+                sheet.ProjectCode,
+                sheet.ProjectName,
+                sheet.ArrangementMode,
+                sheet.TeachingTaskId,
+                sheet.TaskNumber,
+                sheet.TaskName,
+                sheet.AcademicTermId,
+                sheet.TermName,
+                sheet.CourseCollegeName,
+                sheet.CourseCode,
+                sheet.CourseName,
+                sheet.TeacherNames,
+                sheet.ContributionWeight,
+                sheet.PassScore,
+                sheet.Items,
+                sheet.Status,
+                sheet.ReviewComment,
+                sheet.SubmittedAt,
+                sheet.ReviewedAt,
+                sheet.PublishedAt,
+                RecordTotal = recordTotal,
+                RecordPage = recordPage,
+                RecordPageSize = recordPageSize,
+                Records = records,
+                sheet.CreatedAt,
+                sheet.UpdatedAt
+            },
+            CanEdit = CanEdit(task) &&
+                sheet.Status is
+                    ExperimentGradeSheetStatus.Draft or
+                    ExperimentGradeSheetStatus.Returned,
+            CanReview = canReview,
+            CanPublish = IsPublisher() &&
+                sheet.Status == ExperimentGradeSheetStatus.Approved
+        });
+    }
+
+    [HttpPut("sheets/{id:guid}/settings")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> UpdateSettings(
+        Guid id,
+        ExperimentGradeSettingsRequest request,
+        CancellationToken cancellationToken)
+    {
+        var replacementItems = BuildItems(request.Items);
+        if (!ExperimentGradeCalculator.AreWeightsValid(
+                request.ContributionWeight,
+                request.PassScore,
+                replacementItems))
+            return ValidationProblem(
+                "实验评分项至少设置一项、权重合计 100%，项目贡献权重应大于 0。");
+
+        var sheet = await ScopedSheets()
+            .Include(x => x.Items)
+            .Include(x => x.Records)
+            .ThenInclude(x => x.ItemScores)
+            .Include(x => x.ExperimentProject)
+            .ThenInclude(x => x!.TeachingTask)
+            .ThenInclude(x => x!.Teachers)
+            .ThenInclude(x => x.Teacher)
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+        if (sheet is null) return NotFound();
+        if (!CanEdit(sheet.ExperimentProject!.TeachingTask!)) return Forbid();
+        if (sheet.Status is not (
+                ExperimentGradeSheetStatus.Draft or
+                ExperimentGradeSheetStatus.Returned))
+            return ConflictProblem("当前状态不能修改实验评分方案。");
+
+        sheet.ContributionWeight = request.ContributionWeight;
+        sheet.PassScore = request.PassScore;
+        db.ExperimentGradeItems.RemoveRange(sheet.Items);
+        foreach (var record in sheet.Records)
+        {
+            record.ItemScores.Clear();
+            record.TotalScore = null;
+            record.IsPassed = null;
+        }
+        sheet.Items = replacementItems;
+        foreach (var record in sheet.Records)
+            foreach (var item in replacementItems)
+                record.ItemScores.Add(new ExperimentGradeItemScore
+                {
+                    ExperimentGradeItemId = item.Id
+                });
+        await db.SaveChangesAsync(cancellationToken);
+        return NoContent();
+    }
+
+    [HttpPut("sheets/{id:guid}/records")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> UpdateRecords(
+        Guid id,
+        ExperimentGradeRecordsRequest request,
+        CancellationToken cancellationToken)
+    {
+        var sheet = await ScopedSheets()
+            .Include(x => x.Items)
+            .Include(x => x.Records)
+            .ThenInclude(x => x.ItemScores)
+            .Include(x => x.ExperimentProject)
+            .ThenInclude(x => x!.TeachingTask)
+            .ThenInclude(x => x!.Teachers)
+            .ThenInclude(x => x.Teacher)
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+        if (sheet is null) return NotFound();
+        if (!CanEdit(sheet.ExperimentProject!.TeachingTask!)) return Forbid();
+        if (sheet.Status is not (
+                ExperimentGradeSheetStatus.Draft or
+                ExperimentGradeSheetStatus.Returned))
+            return ConflictProblem("成绩单提交后不能继续修改。");
+
+        var records = sheet.Records.ToDictionary(x => x.Id);
+        if (request.Records.Select(x => x.Id).Distinct().Count() !=
+                request.Records.Count ||
+            request.Records.Any(x => !records.ContainsKey(x.Id)))
+            return ValidationProblem("包含无效或重复的实验成绩记录。");
+        var itemIds = sheet.Items.Select(x => x.Id).ToHashSet();
+        foreach (var item in request.Records)
+        {
+            if (item.AttemptNumber is < 1 or > 20)
+                return ValidationProblem("实验尝试次数应在 1—20 次之间。");
+            if (item.ItemScores.Select(x => x.ExperimentGradeItemId)
+                    .Distinct().Count() != item.ItemScores.Count ||
+                item.ItemScores.Any(x =>
+                    !itemIds.Contains(x.ExperimentGradeItemId) ||
+                    !ValidScore(x.Score)))
+                return ValidationProblem("包含无效、重复或超出 0—100 分的评分项。");
+
+            var record = records[item.Id];
+            record.ParticipationStatus = item.ParticipationStatus;
+            record.SafetyViolation = item.SafetyViolation;
+            record.AttemptNumber = item.AttemptNumber;
+            record.SubmissionReference =
+                Normalize(item.SubmissionReference);
+            record.SubmittedAt = item.SubmittedAt;
+            record.IsLate = item.IsLate;
+            record.TeacherComment = Normalize(item.TeacherComment);
+            var scores = record.ItemScores.ToDictionary(
+                x => x.ExperimentGradeItemId);
+            foreach (var score in item.ItemScores)
+            {
+                var target = scores[score.ExperimentGradeItemId];
+                target.Score = score.Score;
+                target.Comment = Normalize(score.Comment);
+            }
+            Recalculate(sheet, record);
+        }
+        await db.SaveChangesAsync(cancellationToken);
+        return NoContent();
+    }
+
+    [HttpPost("sheets/{id:guid}/sync-participants")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> SyncParticipants(
+        Guid id,
+        CancellationToken cancellationToken)
+    {
+        var sheet = await ScopedSheets()
+            .Include(x => x.Items)
+            .Include(x => x.Records)
+            .ThenInclude(x => x.ItemScores)
+            .Include(x => x.ExperimentProject)
+            .ThenInclude(x => x!.TeachingTask)
+            .ThenInclude(x => x!.Teachers)
+            .ThenInclude(x => x.Teacher)
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+        if (sheet is null) return NotFound();
+        if (!CanEdit(sheet.ExperimentProject!.TeachingTask!)) return Forbid();
+        if (sheet.Status is not (
+                ExperimentGradeSheetStatus.Draft or
+                ExperimentGradeSheetStatus.Returned))
+            return ConflictProblem("成绩单提交后不能同步参与学生。");
+
+        var expected = await LoadParticipantsAsync(
+            sheet.ExperimentProject,
+            cancellationToken);
+        var expectedByStudent = expected.ToDictionary(x => x.StudentId);
+        var existingByStudent = sheet.Records.ToDictionary(x => x.StudentId);
+        var added = 0;
+        var removed = 0;
+        var retained = 0;
+        var recordsToRemove = new List<ExperimentGradeRecord>();
+        var recordsToAdd = new List<ExperimentGradeRecord>();
+
+        foreach (var participant in expected)
+        {
+            if (existingByStudent.TryGetValue(
+                    participant.StudentId,
+                    out var record))
+            {
+                if (record.ParticipationStatus ==
+                        ExperimentParticipationStatus.Pending &&
+                    record.ItemScores.All(x => !x.Score.HasValue))
+                    record.ExperimentSessionId = participant.SessionId;
+                retained++;
+                continue;
+            }
+
+            var newRecord = new ExperimentGradeRecord
+            {
+                ExperimentGradeSheetId = sheet.Id,
+                StudentId = participant.StudentId,
+                ExperimentSessionId = participant.SessionId
+            };
+            db.ExperimentGradeRecords.Add(newRecord);
+            recordsToAdd.Add(newRecord);
+            added++;
+        }
+
+        foreach (var record in sheet.Records
+                     .Where(x => !expectedByStudent.ContainsKey(x.StudentId))
+                     .ToList())
+        {
+            if (record.ParticipationStatus !=
+                    ExperimentParticipationStatus.Pending ||
+                record.ItemScores.Any(x => x.Score.HasValue))
+            {
+                retained++;
+                continue;
+            }
+
+            db.ExperimentGradeItemScores.RemoveRange(record.ItemScores);
+            recordsToRemove.Add(record);
+            removed++;
+        }
+
+        if (recordsToRemove.Count > 0 || recordsToAdd.Count > 0)
+        {
+            await db.SaveChangesAsync(cancellationToken);
+            foreach (var record in recordsToRemove)
+                sheet.Records.Remove(record);
+            db.ExperimentGradeRecords.RemoveRange(recordsToRemove);
+        }
+        foreach (var record in recordsToAdd)
+            foreach (var item in sheet.Items)
+                record.ItemScores.Add(new ExperimentGradeItemScore
+                {
+                    ExperimentGradeItemId = item.Id
+                });
+        await db.SaveChangesAsync(cancellationToken);
+        return Ok(new
+        {
+            Added = added,
+            Removed = removed,
+            Retained = retained,
+            Total = await db.ExperimentGradeRecords.CountAsync(
+                x => x.ExperimentGradeSheetId == sheet.Id,
+                cancellationToken)
+        });
+    }
+
+    [HttpPost("sheets/{id:guid}/submit")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> Submit(
+        Guid id,
+        CancellationToken cancellationToken)
+    {
+        var sheet = await LoadForWorkflowAsync(id, cancellationToken);
+        if (sheet is null) return NotFound();
+        if (!CanEdit(sheet.ExperimentProject!.TeachingTask!)) return Forbid();
+        if (sheet.Status is not (
+                ExperimentGradeSheetStatus.Draft or
+                ExperimentGradeSheetStatus.Returned))
+            return ConflictProblem("只有草稿或已退回实验成绩单可以提交。");
+        if (sheet.Records.Count == 0)
+            return ConflictProblem("实验成绩单没有学生记录。");
+
+        foreach (var record in sheet.Records) Recalculate(sheet, record);
+        if (sheet.Records.Any(x =>
+                x.ParticipationStatus ==
+                    ExperimentParticipationStatus.Pending))
+            return ConflictProblem("仍有学生未登记实验参与状态。");
+        if (sheet.Records.Any(x =>
+                x.ParticipationStatus is
+                    ExperimentParticipationStatus.Completed or
+                    ExperimentParticipationStatus.Makeup &&
+                !x.TotalScore.HasValue))
+            return ConflictProblem("仍有已完成或补做学生缺少必填评分项。");
+
+        sheet.Status = ExperimentGradeSheetStatus.Submitted;
+        sheet.SubmittedAt = DateTime.UtcNow;
+        sheet.ReviewComment = null;
+        await db.SaveChangesAsync(cancellationToken);
+        await NotificationService.SendToRoleAsync(
+            db,
+            SystemRoles.CollegeAdmin,
+            "实验成绩待审核",
+            $"“{sheet.ExperimentProject!.Name}”实验成绩已提交，请及时审核。",
+            sheet.ExperimentProject.TeachingTask!.Course!.CollegeId,
+            "/experiment-grades",
+            cancellationToken,
+            NotificationCategory.Grade);
+        return NoContent();
+    }
+
+    [HttpPost("sheets/{id:guid}/approve")]
+    [Authorize(Roles = Reviewers)]
+    public async Task<ActionResult> Approve(
+        Guid id,
+        CancellationToken cancellationToken)
+    {
+        var sheet = await LoadForWorkflowAsync(id, cancellationToken);
+        if (sheet is null) return NotFound();
+        var collegeId = sheet.ExperimentProject!.TeachingTask!.Course!.CollegeId;
+        if (!CanReviewCollege(collegeId)) return Forbid();
+        if (sheet.Status != ExperimentGradeSheetStatus.Submitted)
+            return ConflictProblem("只有待审核实验成绩单可以通过审核。");
+
+        sheet.Status = ExperimentGradeSheetStatus.Approved;
+        sheet.ReviewedAt = DateTime.UtcNow;
+        sheet.ReviewComment = null;
+        await db.SaveChangesAsync(cancellationToken);
+        await NotifyTeachersAsync(
+            sheet.ExperimentProject.TeachingTaskId,
+            "实验成绩审核通过",
+            $"“{sheet.ExperimentProject.Name}”实验成绩已通过学院审核。",
+            cancellationToken);
+        return NoContent();
+    }
+
+    [HttpPost("sheets/{id:guid}/return")]
+    [Authorize(Roles = Reviewers)]
+    public async Task<ActionResult> Return(
+        Guid id,
+        ExperimentGradeReviewRequest request,
+        CancellationToken cancellationToken)
+    {
+        var sheet = await LoadForWorkflowAsync(id, cancellationToken);
+        if (sheet is null) return NotFound();
+        var collegeId = sheet.ExperimentProject!.TeachingTask!.Course!.CollegeId;
+        if (!CanReviewCollege(collegeId)) return Forbid();
+        if (sheet.Status != ExperimentGradeSheetStatus.Submitted)
+            return ConflictProblem("只有待审核实验成绩单可以退回。");
+        if (string.IsNullOrWhiteSpace(request.Comment))
+            return ValidationProblem("退回时必须填写修改意见。");
+
+        sheet.Status = ExperimentGradeSheetStatus.Returned;
+        sheet.ReviewedAt = DateTime.UtcNow;
+        sheet.ReviewComment = request.Comment.Trim();
+        await db.SaveChangesAsync(cancellationToken);
+        await NotifyTeachersAsync(
+            sheet.ExperimentProject.TeachingTaskId,
+            "实验成绩被退回",
+            $"“{sheet.ExperimentProject.Name}”实验成绩被退回：{sheet.ReviewComment}",
+            cancellationToken);
+        return NoContent();
+    }
+
+    [HttpPost("sheets/{id:guid}/publish")]
+    [Authorize(Roles = Publishers)]
+    public async Task<ActionResult> Publish(
+        Guid id,
+        CancellationToken cancellationToken)
+    {
+        var sheet = await LoadForWorkflowAsync(id, cancellationToken);
+        if (sheet is null) return NotFound();
+        if (!IsPublisher()) return Forbid();
+        if (sheet.Status != ExperimentGradeSheetStatus.Approved)
+            return ConflictProblem("只有审核通过的实验成绩单可以发布。");
+
+        sheet.Status = ExperimentGradeSheetStatus.Published;
+        sheet.PublishedAt = DateTime.UtcNow;
+        await db.SaveChangesAsync(cancellationToken);
+        var userIds = await db.ExperimentGradeRecords
+            .Where(x => x.ExperimentGradeSheetId == sheet.Id)
+            .Select(x => x.Student!.UserId)
+            .Where(x => x != null)
+            .Select(x => x!.Value)
+            .Distinct()
+            .ToListAsync(cancellationToken);
+        await NotificationService.SendToUserIdsAsync(
+            db,
+            userIds,
+            "实验成绩已发布",
+            $"“{sheet.ExperimentProject!.Name}”实验成绩已发布。",
+            "/experiment-grades",
+            cancellationToken,
+            NotificationCategory.Grade);
+        return NoContent();
+    }
+
+    private async Task<ExperimentGradeSheet?> LoadForWorkflowAsync(
+        Guid id,
+        CancellationToken cancellationToken)
+    {
+        if (!await ScopedSheets().AnyAsync(
+                x => x.Id == id,
+                cancellationToken))
+            return null;
+        return await db.ExperimentGradeSheets
+            .Include(x => x.Items)
+            .Include(x => x.Records)
+            .ThenInclude(x => x.ItemScores)
+            .Include(x => x.ExperimentProject)
+            .ThenInclude(x => x!.TeachingTask)
+            .ThenInclude(x => x!.Course)
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+    }
+
+    private async Task<List<ExperimentParticipantSeed>> LoadParticipantsAsync(
+        ExperimentProject project,
+        CancellationToken cancellationToken)
+    {
+        if (project.ArrangementMode ==
+            ExperimentArrangementMode.Centralized)
+        {
+            return await TeachingTaskRosterQuery
+                .ForTask(db, project.TeachingTaskId)
+                .AsNoTracking()
+                .OrderBy(x => x.StudentNumber)
+                .Select(x => new ExperimentParticipantSeed(x.Id, null))
+                .ToListAsync(cancellationToken);
+        }
+
+        return await db.ExperimentBookings.AsNoTracking()
+            .Where(x =>
+                x.ExperimentProjectId == project.Id &&
+                x.Status == ExperimentBookingStatus.Booked &&
+                x.Student!.Status == StudentStatus.Active)
+            .OrderBy(x => x.Student!.StudentNumber)
+            .Select(x => new ExperimentParticipantSeed(
+                x.StudentId,
+                x.ExperimentSessionId))
+            .ToListAsync(cancellationToken);
+    }
+
+    private static List<ExperimentGradeItem> BuildItems(
+        IReadOnlyCollection<ExperimentGradeItemRequest>? requests) =>
+        requests?.Select((item, index) => new ExperimentGradeItem
+        {
+            Name = item.Name.Trim(),
+            Kind = item.Kind,
+            Weight = item.Weight,
+            SortOrder = index
+        }).ToList() ?? [];
+
+    private static void Recalculate(
+        ExperimentGradeSheet sheet,
+        ExperimentGradeRecord record)
+    {
+        record.TotalScore = ExperimentGradeCalculator.CalculateTotal(
+            record,
+            sheet.Items.ToList());
+        record.IsPassed = record.TotalScore.HasValue
+            ? record.TotalScore.Value >= sheet.PassScore &&
+              !record.SafetyViolation
+            : null;
+    }
+
+    private IQueryable<TeachingTask> AccessibleTeachingTasks()
+    {
+        var source = db.TeachingTasks.AsQueryable();
+        var scope = currentUserDataScope.Current;
+        if (scope.Scope == DataScope.All) return source;
+        if (scope.Scope == DataScope.College)
+            return source.Where(x =>
+                x.Course!.CollegeId == scope.RestrictedCollegeId);
+        if (scope.IsInRole(SystemRoles.Teacher))
+            return source.Where(x => x.Teachers.Any(item =>
+                item.Teacher!.UserId == scope.UserId));
+        return source.Where(_ => false);
+    }
+
+    private IQueryable<ExperimentProject> ScopedProjects()
+    {
+        var taskIds = AccessibleTeachingTasks().Select(x => x.Id);
+        return db.ExperimentProjects.Where(x =>
+            taskIds.Contains(x.TeachingTaskId));
+    }
+
+    private IQueryable<ExperimentGradeSheet> ScopedSheets()
+    {
+        var projectIds = ScopedProjects().Select(x => x.Id);
+        return db.ExperimentGradeSheets.Where(x =>
+            projectIds.Contains(x.ExperimentProjectId));
+    }
+
+    private bool CanInitialize(TeachingTask task) =>
+        currentUserDataScope.Current.IsInRole(SystemRoles.SuperAdmin) ||
+        currentUserDataScope.Current.IsInRole(SystemRoles.AcademicAdmin) ||
+        currentUserDataScope.Current.IsInRole(SystemRoles.CollegeAdmin) ||
+        IsAssignedTeacher(task);
+
+    private bool CanEdit(TeachingTask task) =>
+        currentUserDataScope.Current.IsInRole(SystemRoles.SuperAdmin) ||
+        IsAssignedTeacher(task);
+
+    private bool IsAssignedTeacher(TeachingTask task) =>
+        task.Teachers.Any(x =>
+            x.Teacher?.UserId == currentUserDataScope.Current.UserId);
+
+    private bool CanReviewCollege(Guid collegeId)
+    {
+        var scope = currentUserDataScope.Current;
+        if (!scope.IsInRole(SystemRoles.SuperAdmin) &&
+            !scope.IsInRole(SystemRoles.AcademicAdmin) &&
+            !scope.IsInRole(SystemRoles.CollegeAdmin))
+            return false;
+        return scope.Scope == DataScope.All ||
+               scope.RestrictedCollegeId == collegeId;
+    }
+
+    private bool IsPublisher() =>
+        currentUserDataScope.Current.IsInRole(SystemRoles.SuperAdmin) ||
+        currentUserDataScope.Current.IsInRole(SystemRoles.AcademicAdmin);
+
+    private Task<Student?> CurrentStudentAsync(
+        CancellationToken cancellationToken) =>
+        db.Students.FirstOrDefaultAsync(x =>
+            x.UserId == currentUserDataScope.Current.UserId &&
+            x.Status == StudentStatus.Active,
+            cancellationToken);
+
+    private async Task NotifyTeachersAsync(
+        Guid teachingTaskId,
+        string title,
+        string content,
+        CancellationToken cancellationToken)
+    {
+        var userIds = await db.TeachingTaskTeachers
+            .Where(x => x.TeachingTaskId == teachingTaskId)
+            .Select(x => x.Teacher!.UserId)
+            .Where(x => x != null)
+            .Select(x => x!.Value)
+            .Distinct()
+            .ToListAsync(cancellationToken);
+        await NotificationService.SendToUserIdsAsync(
+            db,
+            userIds,
+            title,
+            content,
+            "/experiment-grades",
+            cancellationToken,
+            NotificationCategory.Grade);
+    }
+
+    private static bool ValidScore(decimal? score) =>
+        !score.HasValue || score.Value is >= 0 and <= 100;
+
+    private static string? Normalize(string? value) =>
+        string.IsNullOrWhiteSpace(value) ? null : value.Trim();
+
+    private ActionResult ConflictProblem(string detail) =>
+        Conflict(new ProblemDetails
+        {
+            Title = "无法完成实验成绩操作",
+            Detail = detail,
+            Status = StatusCodes.Status409Conflict
+        });
+
+    private sealed record ExperimentParticipantSeed(
+        Guid StudentId,
+        Guid? SessionId);
+}
+
+public sealed record ExperimentGradeSheetRequest(
+    Guid ExperimentProjectId,
+    [Range(typeof(decimal), "0.1", "100")] decimal ContributionWeight,
+    [Range(typeof(decimal), "0", "100")] decimal PassScore,
+    IReadOnlyCollection<ExperimentGradeItemRequest> Items);
+
+public sealed record ExperimentGradeSettingsRequest(
+    [Range(typeof(decimal), "0.1", "100")] decimal ContributionWeight,
+    [Range(typeof(decimal), "0", "100")] decimal PassScore,
+    IReadOnlyCollection<ExperimentGradeItemRequest> Items);
+
+public sealed record ExperimentGradeItemRequest(
+    [Required, MaxLength(60)] string Name,
+    ExperimentGradeItemKind Kind,
+    [Range(typeof(decimal), "0.1", "100")] decimal Weight);
+
+public sealed record ExperimentGradeRecordsRequest(
+    IReadOnlyCollection<ExperimentGradeRecordRequest> Records);
+
+public sealed record ExperimentGradeRecordRequest(
+    Guid Id,
+    ExperimentParticipationStatus ParticipationStatus,
+    bool SafetyViolation,
+    [Range(1, 20)] int AttemptNumber,
+    [MaxLength(500)] string? SubmissionReference,
+    DateTime? SubmittedAt,
+    bool IsLate,
+    [MaxLength(500)] string? TeacherComment,
+    IReadOnlyCollection<ExperimentGradeItemScoreRequest> ItemScores);
+
+public sealed record ExperimentGradeItemScoreRequest(
+    Guid ExperimentGradeItemId,
+    decimal? Score,
+    [MaxLength(300)] string? Comment);
+
+public sealed record ExperimentGradeReviewRequest(
+    [MaxLength(500)] string? Comment);

src/Jiaowu.Api/Controllers/GradesController.cs

@@ -101,7 +101,9 @@ public sealed class GradesController(
                         {
                             item.Id,
                             item.Name,
-                            item.Weight
+                            item.Weight,
+                            item.SourceType,
+                            item.SourceSnapshotAt
                         }),
                         StudentCount = sheet.Records.Count,
                         CompletedCount = sheet.Records.Count(record =>
@@ -220,7 +222,9 @@ public sealed class GradesController(
                 {
                     item.Id,
                     item.Name,
-                    item.Weight
+                    item.Weight,
+                    item.SourceType,
+                    item.SourceSnapshotAt
                 }),
                 x.Status,
                 x.ReviewComment,
@@ -408,7 +412,7 @@ public sealed class GradesController(
             request.Records.Any(x => !records.ContainsKey(x.Id)))
             return ValidationProblem("包含无效或重复的成绩记录。");
 
-        var itemIds = sheet.Items.Select(item => item.Id).ToHashSet();
+        var itemsById = sheet.Items.ToDictionary(item => item.Id);
         foreach (var item in request.Records)
         {
             if (!ValidScore(item.RegularScore) ||
@@ -428,8 +432,19 @@ public sealed class GradesController(
                 {
                     if (!ValidScore(scoreEntry.Score))
                         return ValidationProblem("分项成绩必须在 0—100 分之间。");
-                    if (scoreMap.TryGetValue(scoreEntry.GradeItemId, out var existing))
-                        existing.Score = scoreEntry.Score;
+                    if (!itemsById.TryGetValue(
+                            scoreEntry.GradeItemId,
+                            out var gradeItem) ||
+                        !scoreMap.TryGetValue(
+                            scoreEntry.GradeItemId,
+                            out var existing))
+                        continue;
+                    if (gradeItem.SourceType ==
+                            GradeItemSourceType.ExperimentSummary &&
+                        existing.Score != scoreEntry.Score)
+                        return ConflictProblem(
+                            $"“{gradeItem.Name}”来自实验成绩快照，不能手工修改；请重新导入实验成绩。");
+                    existing.Score = scoreEntry.Score;
                 }
             }
 
@@ -438,6 +453,66 @@ public sealed class GradesController(
         return await SaveAsync(id, false, cancellationToken);
     }
 
+    [HttpPost("sheets/{id:guid}/import-experiment-scores")]
+    [Authorize(Roles = SheetUsers)]
+    public async Task<ActionResult> ImportExperimentScores(
+        Guid id,
+        ImportExperimentScoresRequest request,
+        CancellationToken cancellationToken)
+    {
+        var sheet = await AccessibleSheets()
+            .Include(x => x.Items)
+            .Include(x => x.Records)
+            .ThenInclude(x => x.ItemScores)
+            .Include(x => x.TeachingTask)
+            .ThenInclude(x => x!.Teachers)
+            .ThenInclude(x => x.Teacher)
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+        if (sheet is null) return NotFound();
+        if (!CanEditScores(sheet.TeachingTask!)) return Forbid();
+        if (sheet.Status is not (
+                GradeSheetStatus.Draft or
+                GradeSheetStatus.Returned))
+            return ConflictProblem("成绩单提交后不能导入实验成绩。");
+
+        var targetItem = sheet.Items.FirstOrDefault(x =>
+            x.Id == request.GradeItemId);
+        if (targetItem is null)
+            return ValidationProblem("请选择当前成绩单中的有效分项。");
+
+        var aggregate = await ExperimentGradeAggregationService.CalculateAsync(
+            db,
+            sheet.TeachingTaskId,
+            sheet.Records.Select(x => x.StudentId).ToArray(),
+            cancellationToken);
+        if (aggregate.PublishedProjectCount == 0)
+            return ConflictProblem(
+                "该教学任务尚无已发布的实验项目成绩，无法导入。");
+
+        var imported = 0;
+        var missing = 0;
+        foreach (var record in sheet.Records)
+        {
+            var targetScore = record.ItemScores.First(x =>
+                x.GradeItemId == targetItem.Id);
+            targetScore.Score = aggregate.Scores[record.StudentId];
+            if (targetScore.Score.HasValue) imported++;
+            else missing++;
+            Recalculate(sheet, record);
+        }
+        targetItem.SourceType = GradeItemSourceType.ExperimentSummary;
+        targetItem.SourceSnapshotAt = DateTime.UtcNow;
+        await db.SaveChangesAsync(cancellationToken);
+        return Ok(new
+        {
+            aggregate.PublishedProjectCount,
+            aggregate.Projects,
+            ImportedCount = imported,
+            MissingCount = missing,
+            targetItem.SourceSnapshotAt
+        });
+    }
+
     [HttpPost("sheets/{id:guid}/submit")]
     [Authorize(Roles = SheetUsers)]
     public async Task<ActionResult> Submit(Guid id, CancellationToken cancellationToken)
@@ -998,5 +1073,7 @@ public sealed record GradeItemScoreRequest(
     Guid GradeItemId,
     decimal? Score);
 
+public sealed record ImportExperimentScoresRequest(Guid GradeItemId);
+
 public sealed record GradeReviewRequest(
     [MaxLength(500)] string? Comment);

src/Jiaowu.Api/Domain/Academic/ExperimentEntities.cs

@@ -19,6 +19,7 @@ public sealed class ExperimentProject : EntityBase
     public DateTime? ClosedAt { get; set; }
     public ICollection<ExperimentSession> Sessions { get; set; } = [];
     public ICollection<ExperimentBooking> Bookings { get; set; } = [];
+    public ExperimentGradeSheet? GradeSheet { get; set; }
 }
 
 public sealed class ExperimentSession : EntityBase

src/Jiaowu.Api/Domain/Academic/ExperimentGradeEntities.cs

@@ -0,0 +1,92 @@
+using Jiaowu.Api.Domain.Common;
+
+namespace Jiaowu.Api.Domain.Academic;
+
+public sealed class ExperimentGradeSheet : EntityBase
+{
+    public Guid ExperimentProjectId { get; set; }
+    public ExperimentProject? ExperimentProject { get; set; }
+    public decimal ContributionWeight { get; set; } = 1;
+    public decimal PassScore { get; set; } = 60;
+    public ExperimentGradeSheetStatus Status { get; set; } =
+        ExperimentGradeSheetStatus.Draft;
+    public string? ReviewComment { get; set; }
+    public DateTime? SubmittedAt { get; set; }
+    public DateTime? ReviewedAt { get; set; }
+    public DateTime? PublishedAt { get; set; }
+    public ICollection<ExperimentGradeItem> Items { get; set; } = [];
+    public ICollection<ExperimentGradeRecord> Records { get; set; } = [];
+}
+
+public sealed class ExperimentGradeItem : EntityBase
+{
+    public Guid ExperimentGradeSheetId { get; set; }
+    public ExperimentGradeSheet? ExperimentGradeSheet { get; set; }
+    public required string Name { get; set; }
+    public ExperimentGradeItemKind Kind { get; set; } =
+        ExperimentGradeItemKind.Other;
+    public decimal Weight { get; set; }
+    public int SortOrder { get; set; }
+    public ICollection<ExperimentGradeItemScore> Scores { get; set; } = [];
+}
+
+public sealed class ExperimentGradeRecord : EntityBase
+{
+    public Guid ExperimentGradeSheetId { get; set; }
+    public ExperimentGradeSheet? ExperimentGradeSheet { get; set; }
+    public Guid StudentId { get; set; }
+    public Student? Student { get; set; }
+    public Guid? ExperimentSessionId { get; set; }
+    public ExperimentSession? ExperimentSession { get; set; }
+    public ExperimentParticipationStatus ParticipationStatus { get; set; } =
+        ExperimentParticipationStatus.Pending;
+    public decimal? TotalScore { get; set; }
+    public bool? IsPassed { get; set; }
+    public bool SafetyViolation { get; set; }
+    public int AttemptNumber { get; set; } = 1;
+    public string? SubmissionReference { get; set; }
+    public DateTime? SubmittedAt { get; set; }
+    public bool IsLate { get; set; }
+    public string? TeacherComment { get; set; }
+    public ICollection<ExperimentGradeItemScore> ItemScores { get; set; } = [];
+}
+
+public sealed class ExperimentGradeItemScore
+{
+    public Guid ExperimentGradeRecordId { get; set; }
+    public ExperimentGradeRecord? ExperimentGradeRecord { get; set; }
+    public Guid ExperimentGradeItemId { get; set; }
+    public ExperimentGradeItem? ExperimentGradeItem { get; set; }
+    public decimal? Score { get; set; }
+    public string? Comment { get; set; }
+}
+
+public enum ExperimentGradeSheetStatus
+{
+    Draft = 1,
+    Submitted = 2,
+    Approved = 3,
+    Published = 4,
+    Returned = 5
+}
+
+public enum ExperimentGradeItemKind
+{
+    Operation = 1,
+    Report = 2,
+    Result = 3,
+    Defense = 4,
+    Attendance = 5,
+    Safety = 6,
+    Other = 7
+}
+
+public enum ExperimentParticipationStatus
+{
+    Pending = 1,
+    Completed = 2,
+    Absent = 3,
+    Excused = 4,
+    Makeup = 5,
+    Exempt = 6
+}

src/Jiaowu.Api/Domain/Academic/GradeEntities.cs

@@ -24,6 +24,9 @@ public sealed class GradeItem : EntityBase
     public required string Name { get; set; }
     public decimal Weight { get; set; }
     public int SortOrder { get; set; }
+    public GradeItemSourceType SourceType { get; set; } =
+        GradeItemSourceType.Manual;
+    public DateTime? SourceSnapshotAt { get; set; }
     public ICollection<GradeItemScore> Scores { get; set; } = [];
 }
 
@@ -68,3 +71,9 @@ public enum GradeExamStatus
     Exempt = 4,
     Makeup = 5
 }
+
+public enum GradeItemSourceType
+{
+    Manual = 1,
+    ExperimentSummary = 2
+}

src/Jiaowu.Api/Infrastructure/Grades/ExperimentGradeAggregationService.cs

@@ -0,0 +1,88 @@
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Infrastructure.Grades;
+
+public static class ExperimentGradeAggregationService
+{
+    public static async Task<ExperimentGradeAggregateResult> CalculateAsync(
+        AppDbContext db,
+        Guid teachingTaskId,
+        IReadOnlyCollection<Guid> studentIds,
+        CancellationToken cancellationToken)
+    {
+        var sheets = await db.ExperimentGradeSheets.AsNoTracking()
+            .Where(x =>
+                x.Status ==
+                    Domain.Academic.ExperimentGradeSheetStatus.Published &&
+                x.ExperimentProject!.TeachingTaskId == teachingTaskId)
+            .OrderBy(x => x.ExperimentProject!.Code)
+            .Select(x => new PublishedExperimentSheet(
+                x.Id,
+                x.ExperimentProject!.Code,
+                x.ExperimentProject.Name,
+                x.ContributionWeight,
+                x.Records.Select(record => new PublishedExperimentScore(
+                    record.StudentId,
+                    record.TotalScore)).ToList()))
+            .AsSplitQuery()
+            .ToListAsync(cancellationToken);
+
+        var scores = new Dictionary<Guid, decimal?>();
+        foreach (var studentId in studentIds.Distinct())
+        {
+            decimal weightedTotal = 0;
+            decimal totalWeight = 0;
+            var complete = sheets.Count > 0;
+            foreach (var sheet in sheets)
+            {
+                var score = sheet.Scores.FirstOrDefault(x =>
+                    x.StudentId == studentId);
+                if (score?.TotalScore is not decimal totalScore)
+                {
+                    complete = false;
+                    break;
+                }
+                weightedTotal += totalScore * sheet.ContributionWeight;
+                totalWeight += sheet.ContributionWeight;
+            }
+            scores[studentId] = complete && totalWeight > 0
+                ? Math.Round(
+                    weightedTotal / totalWeight,
+                    1,
+                    MidpointRounding.AwayFromZero)
+                : null;
+        }
+
+        return new ExperimentGradeAggregateResult(
+            sheets.Count,
+            sheets.Select(x => new ExperimentGradeAggregateProject(
+                x.Id,
+                x.Code,
+                x.Name,
+                x.ContributionWeight)).ToList(),
+            scores);
+    }
+
+    private sealed record PublishedExperimentSheet(
+        Guid Id,
+        string Code,
+        string Name,
+        decimal ContributionWeight,
+        List<PublishedExperimentScore> Scores);
+
+    private sealed record PublishedExperimentScore(
+        Guid StudentId,
+        decimal? TotalScore);
+}
+
+public sealed record ExperimentGradeAggregateResult(
+    int PublishedProjectCount,
+    IReadOnlyList<ExperimentGradeAggregateProject> Projects,
+    IReadOnlyDictionary<Guid, decimal?> Scores);
+
+public sealed record ExperimentGradeAggregateProject(
+    Guid Id,
+    string Code,
+    string Name,
+    decimal ContributionWeight);

src/Jiaowu.Api/Infrastructure/Grades/ExperimentGradeCalculator.cs

@@ -0,0 +1,45 @@
+using Jiaowu.Api.Domain.Academic;
+
+namespace Jiaowu.Api.Infrastructure.Grades;
+
+public static class ExperimentGradeCalculator
+{
+    public static bool AreWeightsValid(
+        decimal contributionWeight,
+        decimal passScore,
+        IEnumerable<ExperimentGradeItem> items)
+    {
+        var itemList = items.ToList();
+        return contributionWeight is > 0 and <= 100 &&
+               passScore is >= 0 and <= 100 &&
+               itemList.Count > 0 &&
+               itemList.All(item => item.Weight is > 0 and <= 100) &&
+               itemList.Sum(item => item.Weight) == 100;
+    }
+
+    public static decimal? CalculateTotal(
+        ExperimentGradeRecord record,
+        IReadOnlyCollection<ExperimentGradeItem> items)
+    {
+        if (record.SafetyViolation ||
+            record.ParticipationStatus == ExperimentParticipationStatus.Absent)
+            return 0;
+        if (record.ParticipationStatus is
+            ExperimentParticipationStatus.Pending or
+            ExperimentParticipationStatus.Excused or
+            ExperimentParticipationStatus.Exempt)
+            return null;
+
+        var scores = record.ItemScores.ToDictionary(
+            x => x.ExperimentGradeItemId);
+        decimal total = 0;
+        foreach (var item in items)
+        {
+            if (!scores.TryGetValue(item.Id, out var score) ||
+                !score.Score.HasValue)
+                return null;
+            total += score.Score.Value * item.Weight / 100;
+        }
+        return Math.Round(total, 1, MidpointRounding.AwayFromZero);
+    }
+}

src/Jiaowu.Api/Infrastructure/Persistence/AppDbContext.cs

@@ -47,6 +47,14 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
     public DbSet<ExperimentProject> ExperimentProjects => Set<ExperimentProject>();
     public DbSet<ExperimentSession> ExperimentSessions => Set<ExperimentSession>();
     public DbSet<ExperimentBooking> ExperimentBookings => Set<ExperimentBooking>();
+    public DbSet<ExperimentGradeSheet> ExperimentGradeSheets =>
+        Set<ExperimentGradeSheet>();
+    public DbSet<ExperimentGradeItem> ExperimentGradeItems =>
+        Set<ExperimentGradeItem>();
+    public DbSet<ExperimentGradeRecord> ExperimentGradeRecords =>
+        Set<ExperimentGradeRecord>();
+    public DbSet<ExperimentGradeItemScore> ExperimentGradeItemScores =>
+        Set<ExperimentGradeItemScore>();
     public DbSet<CourseSelectionRound> CourseSelectionRounds =>
         Set<CourseSelectionRound>();
     public DbSet<CourseSelectionRoundGrade> CourseSelectionRoundGrades =>
@@ -608,6 +616,75 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
                 .OnDelete(DeleteBehavior.Restrict);
         });
 
+        builder.Entity<ExperimentGradeSheet>(entity =>
+        {
+            entity.Property(x => x.ContributionWeight).HasPrecision(5, 1);
+            entity.Property(x => x.PassScore).HasPrecision(5, 1);
+            entity.Property(x => x.ReviewComment).HasMaxLength(500);
+            entity.HasIndex(x => x.ExperimentProjectId).IsUnique();
+            entity.HasOne(x => x.ExperimentProject)
+                .WithOne(x => x.GradeSheet)
+                .HasForeignKey<ExperimentGradeSheet>(
+                    x => x.ExperimentProjectId)
+                .OnDelete(DeleteBehavior.Cascade);
+        });
+
+        builder.Entity<ExperimentGradeItem>(entity =>
+        {
+            entity.Property(x => x.Name).HasMaxLength(60);
+            entity.Property(x => x.Weight).HasPrecision(5, 1);
+            entity.HasIndex(x => new
+            {
+                x.ExperimentGradeSheetId,
+                x.SortOrder
+            });
+            entity.HasOne(x => x.ExperimentGradeSheet)
+                .WithMany(x => x.Items)
+                .HasForeignKey(x => x.ExperimentGradeSheetId)
+                .OnDelete(DeleteBehavior.Cascade);
+        });
+
+        builder.Entity<ExperimentGradeRecord>(entity =>
+        {
+            entity.Property(x => x.TotalScore).HasPrecision(5, 1);
+            entity.Property(x => x.SubmissionReference).HasMaxLength(500);
+            entity.Property(x => x.TeacherComment).HasMaxLength(500);
+            entity.HasIndex(x => new
+            {
+                x.ExperimentGradeSheetId,
+                x.StudentId
+            }).IsUnique();
+            entity.HasOne(x => x.ExperimentGradeSheet)
+                .WithMany(x => x.Records)
+                .HasForeignKey(x => x.ExperimentGradeSheetId)
+                .OnDelete(DeleteBehavior.Cascade);
+            entity.HasOne(x => x.Student).WithMany()
+                .HasForeignKey(x => x.StudentId)
+                .OnDelete(DeleteBehavior.Restrict);
+            entity.HasOne(x => x.ExperimentSession).WithMany()
+                .HasForeignKey(x => x.ExperimentSessionId)
+                .OnDelete(DeleteBehavior.Restrict);
+        });
+
+        builder.Entity<ExperimentGradeItemScore>(entity =>
+        {
+            entity.HasKey(x => new
+            {
+                x.ExperimentGradeRecordId,
+                x.ExperimentGradeItemId
+            });
+            entity.Property(x => x.Score).HasPrecision(5, 1);
+            entity.Property(x => x.Comment).HasMaxLength(300);
+            entity.HasOne(x => x.ExperimentGradeRecord)
+                .WithMany(x => x.ItemScores)
+                .HasForeignKey(x => x.ExperimentGradeRecordId)
+                .OnDelete(DeleteBehavior.Cascade);
+            entity.HasOne(x => x.ExperimentGradeItem)
+                .WithMany(x => x.Scores)
+                .HasForeignKey(x => x.ExperimentGradeItemId)
+                .OnDelete(DeleteBehavior.Cascade);
+        });
+
         builder.Entity<CourseSelectionRound>(entity =>
         {
             entity.Property(x => x.Name).HasMaxLength(120);
@@ -687,6 +764,8 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
         {
             entity.Property(x => x.Name).HasMaxLength(60);
             entity.Property(x => x.Weight).HasPrecision(5, 1);
+            entity.Property(x => x.SourceType)
+                .HasDefaultValue(GradeItemSourceType.Manual);
             entity.HasIndex(x => new { x.GradeSheetId, x.SortOrder });
             entity.HasOne(x => x.GradeSheet)
                 .WithMany(x => x.Items)

src/Jiaowu.Api/Infrastructure/Persistence/DevelopmentSqliteMigrator.cs

@@ -72,6 +72,8 @@ public sealed class DevelopmentSqliteMigrator(
         "20260728_38_exam_publish_jobs";
     private const string ExperimentManagementMigration =
         "20260728_39_experiment_management";
+    private const string ExperimentGradeManagementMigration =
+        "20260728_40_experiment_grade_management";
 
     public async Task MigrateAsync(CancellationToken cancellationToken = default)
     {
@@ -543,6 +545,32 @@ public sealed class DevelopmentSqliteMigrator(
             ExperimentManagementMigration,
             experimentProjectsExist ? [] : ExperimentManagementStatements,
             cancellationToken);
+
+        var gradeItemSourceExists = await db.Database
+            .SqlQueryRaw<int>(
+                """
+                SELECT COUNT(*) AS "Value"
+                FROM pragma_table_info('GradeItems')
+                WHERE name = 'SourceType'
+                """)
+            .AnyAsync(value => value > 0, cancellationToken);
+        var experimentGradeSheetsExist = await db.Database
+            .SqlQueryRaw<int>(
+                """
+                SELECT COUNT(*) AS "Value"
+                FROM sqlite_master
+                WHERE type = 'table' AND name = 'ExperimentGradeSheets'
+                """)
+            .AnyAsync(value => value > 0, cancellationToken);
+        await ApplyMigrationAsync(
+            ExperimentGradeManagementMigration,
+            (gradeItemSourceExists
+                    ? []
+                    : ExperimentGradeItemSourceStatements)
+                .Concat(experimentGradeSheetsExist
+                    ? []
+                    : ExperimentGradeManagementStatements),
+            cancellationToken);
     }
 
     private async Task ApplyMigrationAsync(
@@ -2511,4 +2539,133 @@ public sealed class DevelopmentSqliteMigrator(
         );
         """
     ];
+
+    private static readonly string[] ExperimentGradeItemSourceStatements =
+    [
+        """
+        ALTER TABLE "GradeItems"
+        ADD "SourceType" INTEGER NOT NULL DEFAULT 1;
+        """,
+        """
+        ALTER TABLE "GradeItems"
+        ADD "SourceSnapshotAt" TEXT NULL;
+        """
+    ];
+
+    private static readonly string[] ExperimentGradeManagementStatements =
+    [
+        """
+        CREATE TABLE "ExperimentGradeSheets" (
+            "Id" TEXT NOT NULL
+                CONSTRAINT "PK_ExperimentGradeSheets" PRIMARY KEY,
+            "ExperimentProjectId" TEXT NOT NULL,
+            "ContributionWeight" TEXT NOT NULL,
+            "PassScore" TEXT NOT NULL,
+            "Status" INTEGER NOT NULL,
+            "ReviewComment" TEXT NULL,
+            "SubmittedAt" TEXT NULL,
+            "ReviewedAt" TEXT NULL,
+            "PublishedAt" TEXT NULL,
+            "CreatedAt" TEXT NOT NULL,
+            "UpdatedAt" TEXT NOT NULL,
+            CONSTRAINT "FK_ExperimentGradeSheets_ExperimentProjects_ExperimentProjectId"
+                FOREIGN KEY ("ExperimentProjectId")
+                REFERENCES "ExperimentProjects" ("Id")
+                ON DELETE CASCADE
+        );
+        """,
+        """
+        CREATE UNIQUE INDEX "IX_ExperimentGradeSheets_ExperimentProjectId"
+        ON "ExperimentGradeSheets" ("ExperimentProjectId");
+        """,
+        """
+        CREATE TABLE "ExperimentGradeItems" (
+            "Id" TEXT NOT NULL
+                CONSTRAINT "PK_ExperimentGradeItems" PRIMARY KEY,
+            "ExperimentGradeSheetId" TEXT NOT NULL,
+            "Name" TEXT NOT NULL,
+            "Kind" INTEGER NOT NULL,
+            "Weight" TEXT NOT NULL,
+            "SortOrder" INTEGER NOT NULL,
+            "CreatedAt" TEXT NOT NULL,
+            "UpdatedAt" TEXT NOT NULL,
+            CONSTRAINT "FK_ExperimentGradeItems_ExperimentGradeSheets_ExperimentGradeSheetId"
+                FOREIGN KEY ("ExperimentGradeSheetId")
+                REFERENCES "ExperimentGradeSheets" ("Id")
+                ON DELETE CASCADE
+        );
+        """,
+        """
+        CREATE INDEX "IX_ExperimentGradeItems_ExperimentGradeSheetId_SortOrder"
+        ON "ExperimentGradeItems" ("ExperimentGradeSheetId", "SortOrder");
+        """,
+        """
+        CREATE TABLE "ExperimentGradeRecords" (
+            "Id" TEXT NOT NULL
+                CONSTRAINT "PK_ExperimentGradeRecords" PRIMARY KEY,
+            "ExperimentGradeSheetId" TEXT NOT NULL,
+            "StudentId" TEXT NOT NULL,
+            "ExperimentSessionId" TEXT NULL,
+            "ParticipationStatus" INTEGER NOT NULL,
+            "TotalScore" TEXT NULL,
+            "IsPassed" INTEGER NULL,
+            "SafetyViolation" INTEGER NOT NULL,
+            "AttemptNumber" INTEGER NOT NULL,
+            "SubmissionReference" TEXT NULL,
+            "SubmittedAt" TEXT NULL,
+            "IsLate" INTEGER NOT NULL,
+            "TeacherComment" TEXT NULL,
+            "CreatedAt" TEXT NOT NULL,
+            "UpdatedAt" TEXT NOT NULL,
+            CONSTRAINT "FK_ExperimentGradeRecords_ExperimentGradeSheets_ExperimentGradeSheetId"
+                FOREIGN KEY ("ExperimentGradeSheetId")
+                REFERENCES "ExperimentGradeSheets" ("Id")
+                ON DELETE CASCADE,
+            CONSTRAINT "FK_ExperimentGradeRecords_Students_StudentId"
+                FOREIGN KEY ("StudentId") REFERENCES "Students" ("Id")
+                ON DELETE RESTRICT,
+            CONSTRAINT "FK_ExperimentGradeRecords_ExperimentSessions_ExperimentSessionId"
+                FOREIGN KEY ("ExperimentSessionId")
+                REFERENCES "ExperimentSessions" ("Id")
+                ON DELETE RESTRICT
+        );
+        """,
+        """
+        CREATE UNIQUE INDEX "IX_ExperimentGradeRecords_ExperimentGradeSheetId_StudentId"
+        ON "ExperimentGradeRecords" ("ExperimentGradeSheetId", "StudentId");
+        """,
+        """
+        CREATE INDEX "IX_ExperimentGradeRecords_StudentId"
+        ON "ExperimentGradeRecords" ("StudentId");
+        """,
+        """
+        CREATE INDEX "IX_ExperimentGradeRecords_ExperimentSessionId"
+        ON "ExperimentGradeRecords" ("ExperimentSessionId");
+        """,
+        """
+        CREATE TABLE "ExperimentGradeItemScores" (
+            "ExperimentGradeRecordId" TEXT NOT NULL,
+            "ExperimentGradeItemId" TEXT NOT NULL,
+            "Score" TEXT NULL,
+            "Comment" TEXT NULL,
+            CONSTRAINT "PK_ExperimentGradeItemScores"
+                PRIMARY KEY (
+                    "ExperimentGradeRecordId",
+                    "ExperimentGradeItemId"
+                ),
+            CONSTRAINT "FK_ExperimentGradeItemScores_ExperimentGradeRecords_ExperimentGradeRecordId"
+                FOREIGN KEY ("ExperimentGradeRecordId")
+                REFERENCES "ExperimentGradeRecords" ("Id")
+                ON DELETE CASCADE,
+            CONSTRAINT "FK_ExperimentGradeItemScores_ExperimentGradeItems_ExperimentGradeItemId"
+                FOREIGN KEY ("ExperimentGradeItemId")
+                REFERENCES "ExperimentGradeItems" ("Id")
+                ON DELETE CASCADE
+        );
+        """,
+        """
+        CREATE INDEX "IX_ExperimentGradeItemScores_ExperimentGradeItemId"
+        ON "ExperimentGradeItemScores" ("ExperimentGradeItemId");
+        """
+    ];
 }

src/Jiaowu.Api/Infrastructure/Persistence/Migrations/MySql/20260728134931_ExperimentGradeManagement.cs

@@ -0,0 +1,208 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
+{
+    /// <inheritdoc />
+    public partial class ExperimentGradeManagement : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<DateTime>(
+                name: "SourceSnapshotAt",
+                table: "GradeItems",
+                type: "datetime(6)",
+                nullable: true);
+
+            migrationBuilder.AddColumn<int>(
+                name: "SourceType",
+                table: "GradeItems",
+                type: "int",
+                nullable: false,
+                defaultValue: 1);
+
+            migrationBuilder.CreateTable(
+                name: "ExperimentGradeSheets",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "char(36)", nullable: false),
+                    ExperimentProjectId = table.Column<Guid>(type: "char(36)", nullable: false),
+                    ContributionWeight = table.Column<decimal>(type: "decimal(5,1)", precision: 5, scale: 1, nullable: false),
+                    PassScore = table.Column<decimal>(type: "decimal(5,1)", precision: 5, scale: 1, nullable: false),
+                    Status = table.Column<int>(type: "int", nullable: false),
+                    ReviewComment = table.Column<string>(type: "varchar(500)", maxLength: 500, nullable: true),
+                    SubmittedAt = table.Column<DateTime>(type: "datetime(6)", nullable: true),
+                    ReviewedAt = table.Column<DateTime>(type: "datetime(6)", nullable: true),
+                    PublishedAt = table.Column<DateTime>(type: "datetime(6)", nullable: true),
+                    CreatedAt = table.Column<DateTime>(type: "datetime(6)", nullable: false),
+                    UpdatedAt = table.Column<DateTime>(type: "datetime(6)", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_ExperimentGradeSheets", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_ExperimentGradeSheets_ExperimentProjects_ExperimentProjectId",
+                        column: x => x.ExperimentProjectId,
+                        principalTable: "ExperimentProjects",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                })
+                .Annotation("MySQL:Charset", "utf8mb4");
+
+            migrationBuilder.CreateTable(
+                name: "ExperimentGradeItems",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "char(36)", nullable: false),
+                    ExperimentGradeSheetId = table.Column<Guid>(type: "char(36)", nullable: false),
+                    Name = table.Column<string>(type: "varchar(60)", maxLength: 60, nullable: false),
+                    Kind = table.Column<int>(type: "int", nullable: false),
+                    Weight = table.Column<decimal>(type: "decimal(5,1)", precision: 5, scale: 1, nullable: false),
+                    SortOrder = table.Column<int>(type: "int", nullable: false),
+                    CreatedAt = table.Column<DateTime>(type: "datetime(6)", nullable: false),
+                    UpdatedAt = table.Column<DateTime>(type: "datetime(6)", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_ExperimentGradeItems", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_ExperimentGradeItems_ExperimentGradeSheets_ExperimentGradeSh~",
+                        column: x => x.ExperimentGradeSheetId,
+                        principalTable: "ExperimentGradeSheets",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                })
+                .Annotation("MySQL:Charset", "utf8mb4");
+
+            migrationBuilder.CreateTable(
+                name: "ExperimentGradeRecords",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "char(36)", nullable: false),
+                    ExperimentGradeSheetId = table.Column<Guid>(type: "char(36)", nullable: false),
+                    StudentId = table.Column<Guid>(type: "char(36)", nullable: false),
+                    ExperimentSessionId = table.Column<Guid>(type: "char(36)", nullable: true),
+                    ParticipationStatus = table.Column<int>(type: "int", nullable: false),
+                    TotalScore = table.Column<decimal>(type: "decimal(5,1)", precision: 5, scale: 1, nullable: true),
+                    IsPassed = table.Column<bool>(type: "tinyint(1)", nullable: true),
+                    SafetyViolation = table.Column<bool>(type: "tinyint(1)", nullable: false),
+                    AttemptNumber = table.Column<int>(type: "int", nullable: false),
+                    SubmissionReference = table.Column<string>(type: "varchar(500)", maxLength: 500, nullable: true),
+                    SubmittedAt = table.Column<DateTime>(type: "datetime(6)", nullable: true),
+                    IsLate = table.Column<bool>(type: "tinyint(1)", nullable: false),
+                    TeacherComment = table.Column<string>(type: "varchar(500)", maxLength: 500, nullable: true),
+                    CreatedAt = table.Column<DateTime>(type: "datetime(6)", nullable: false),
+                    UpdatedAt = table.Column<DateTime>(type: "datetime(6)", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_ExperimentGradeRecords", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_ExperimentGradeRecords_ExperimentGradeSheets_ExperimentGrade~",
+                        column: x => x.ExperimentGradeSheetId,
+                        principalTable: "ExperimentGradeSheets",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "FK_ExperimentGradeRecords_ExperimentSessions_ExperimentSessionId",
+                        column: x => x.ExperimentSessionId,
+                        principalTable: "ExperimentSessions",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "FK_ExperimentGradeRecords_Students_StudentId",
+                        column: x => x.StudentId,
+                        principalTable: "Students",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Restrict);
+                })
+                .Annotation("MySQL:Charset", "utf8mb4");
+
+            migrationBuilder.CreateTable(
+                name: "ExperimentGradeItemScores",
+                columns: table => new
+                {
+                    ExperimentGradeRecordId = table.Column<Guid>(type: "char(36)", nullable: false),
+                    ExperimentGradeItemId = table.Column<Guid>(type: "char(36)", nullable: false),
+                    Score = table.Column<decimal>(type: "decimal(5,1)", precision: 5, scale: 1, nullable: true),
+                    Comment = table.Column<string>(type: "varchar(300)", maxLength: 300, nullable: true)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_ExperimentGradeItemScores", x => new { x.ExperimentGradeRecordId, x.ExperimentGradeItemId });
+                    table.ForeignKey(
+                        name: "FK_ExperimentGradeItemScores_ExperimentGradeItems_ExperimentGra~",
+                        column: x => x.ExperimentGradeItemId,
+                        principalTable: "ExperimentGradeItems",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "FK_ExperimentGradeItemScores_ExperimentGradeRecords_ExperimentG~",
+                        column: x => x.ExperimentGradeRecordId,
+                        principalTable: "ExperimentGradeRecords",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                })
+                .Annotation("MySQL:Charset", "utf8mb4");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ExperimentGradeItems_ExperimentGradeSheetId_SortOrder",
+                table: "ExperimentGradeItems",
+                columns: new[] { "ExperimentGradeSheetId", "SortOrder" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ExperimentGradeItemScores_ExperimentGradeItemId",
+                table: "ExperimentGradeItemScores",
+                column: "ExperimentGradeItemId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ExperimentGradeRecords_ExperimentGradeSheetId_StudentId",
+                table: "ExperimentGradeRecords",
+                columns: new[] { "ExperimentGradeSheetId", "StudentId" },
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ExperimentGradeRecords_ExperimentSessionId",
+                table: "ExperimentGradeRecords",
+                column: "ExperimentSessionId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ExperimentGradeRecords_StudentId",
+                table: "ExperimentGradeRecords",
+                column: "StudentId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ExperimentGradeSheets_ExperimentProjectId",
+                table: "ExperimentGradeSheets",
+                column: "ExperimentProjectId",
+                unique: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "ExperimentGradeItemScores");
+
+            migrationBuilder.DropTable(
+                name: "ExperimentGradeItems");
+
+            migrationBuilder.DropTable(
+                name: "ExperimentGradeRecords");
+
+            migrationBuilder.DropTable(
+                name: "ExperimentGradeSheets");
+
+            migrationBuilder.DropColumn(
+                name: "SourceSnapshotAt",
+                table: "GradeItems");
+
+            migrationBuilder.DropColumn(
+                name: "SourceType",
+                table: "GradeItems");
+        }
+    }
+}

src/Jiaowu.Api/Infrastructure/Persistence/Migrations/MySql/AppDbContextModelSnapshot.cs

@@ -2043,6 +2043,176 @@ namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
                     b.ToTable("ExperimentBookings");
                 });
 
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.ExperimentGradeItem", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("char(36)");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.Property<Guid>("ExperimentGradeSheetId")
+                        .HasColumnType("char(36)");
+
+                    b.Property<int>("Kind")
+                        .HasColumnType("int");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(60)
+                        .HasColumnType("varchar(60)");
+
+                    b.Property<int>("SortOrder")
+                        .HasColumnType("int");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.Property<decimal>("Weight")
+                        .HasPrecision(5, 1)
+                        .HasColumnType("decimal(5,1)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("ExperimentGradeSheetId", "SortOrder");
+
+                    b.ToTable("ExperimentGradeItems");
+                });
+
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.ExperimentGradeItemScore", b =>
+                {
+                    b.Property<Guid>("ExperimentGradeRecordId")
+                        .HasColumnType("char(36)");
+
+                    b.Property<Guid>("ExperimentGradeItemId")
+                        .HasColumnType("char(36)");
+
+                    b.Property<string>("Comment")
+                        .HasMaxLength(300)
+                        .HasColumnType("varchar(300)");
+
+                    b.Property<decimal?>("Score")
+                        .HasPrecision(5, 1)
+                        .HasColumnType("decimal(5,1)");
+
+                    b.HasKey("ExperimentGradeRecordId", "ExperimentGradeItemId");
+
+                    b.HasIndex("ExperimentGradeItemId");
+
+                    b.ToTable("ExperimentGradeItemScores");
+                });
+
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.ExperimentGradeRecord", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("char(36)");
+
+                    b.Property<int>("AttemptNumber")
+                        .HasColumnType("int");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.Property<Guid>("ExperimentGradeSheetId")
+                        .HasColumnType("char(36)");
+
+                    b.Property<Guid?>("ExperimentSessionId")
+                        .HasColumnType("char(36)");
+
+                    b.Property<bool>("IsLate")
+                        .HasColumnType("tinyint(1)");
+
+                    b.Property<bool?>("IsPassed")
+                        .HasColumnType("tinyint(1)");
+
+                    b.Property<int>("ParticipationStatus")
+                        .HasColumnType("int");
+
+                    b.Property<bool>("SafetyViolation")
+                        .HasColumnType("tinyint(1)");
+
+                    b.Property<Guid>("StudentId")
+                        .HasColumnType("char(36)");
+
+                    b.Property<string>("SubmissionReference")
+                        .HasMaxLength(500)
+                        .HasColumnType("varchar(500)");
+
+                    b.Property<DateTime?>("SubmittedAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.Property<string>("TeacherComment")
+                        .HasMaxLength(500)
+                        .HasColumnType("varchar(500)");
+
+                    b.Property<decimal?>("TotalScore")
+                        .HasPrecision(5, 1)
+                        .HasColumnType("decimal(5,1)");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("ExperimentSessionId");
+
+                    b.HasIndex("StudentId");
+
+                    b.HasIndex("ExperimentGradeSheetId", "StudentId")
+                        .IsUnique();
+
+                    b.ToTable("ExperimentGradeRecords");
+                });
+
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.ExperimentGradeSheet", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("char(36)");
+
+                    b.Property<decimal>("ContributionWeight")
+                        .HasPrecision(5, 1)
+                        .HasColumnType("decimal(5,1)");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.Property<Guid>("ExperimentProjectId")
+                        .HasColumnType("char(36)");
+
+                    b.Property<decimal>("PassScore")
+                        .HasPrecision(5, 1)
+                        .HasColumnType("decimal(5,1)");
+
+                    b.Property<DateTime?>("PublishedAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.Property<string>("ReviewComment")
+                        .HasMaxLength(500)
+                        .HasColumnType("varchar(500)");
+
+                    b.Property<DateTime?>("ReviewedAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.Property<int>("Status")
+                        .HasColumnType("int");
+
+                    b.Property<DateTime?>("SubmittedAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("ExperimentProjectId")
+                        .IsUnique();
+
+                    b.ToTable("ExperimentGradeSheets");
+                });
+
             modelBuilder.Entity("Jiaowu.Api.Domain.Academic.ExperimentProject", b =>
                 {
                     b.Property<Guid>("Id")
@@ -2176,6 +2346,14 @@ namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
                     b.Property<int>("SortOrder")
                         .HasColumnType("int");
 
+                    b.Property<DateTime?>("SourceSnapshotAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.Property<int>("SourceType")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int")
+                        .HasDefaultValue(1);
+
                     b.Property<DateTime>("UpdatedAt")
                         .HasColumnType("datetime(6)");
 
@@ -4812,6 +4990,73 @@ namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
                     b.Navigation("Student");
                 });
 
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.ExperimentGradeItem", b =>
+                {
+                    b.HasOne("Jiaowu.Api.Domain.Academic.ExperimentGradeSheet", "ExperimentGradeSheet")
+                        .WithMany("Items")
+                        .HasForeignKey("ExperimentGradeSheetId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("ExperimentGradeSheet");
+                });
+
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.ExperimentGradeItemScore", b =>
+                {
+                    b.HasOne("Jiaowu.Api.Domain.Academic.ExperimentGradeItem", "ExperimentGradeItem")
+                        .WithMany("Scores")
+                        .HasForeignKey("ExperimentGradeItemId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("Jiaowu.Api.Domain.Academic.ExperimentGradeRecord", "ExperimentGradeRecord")
+                        .WithMany("ItemScores")
+                        .HasForeignKey("ExperimentGradeRecordId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("ExperimentGradeItem");
+
+                    b.Navigation("ExperimentGradeRecord");
+                });
+
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.ExperimentGradeRecord", b =>
+                {
+                    b.HasOne("Jiaowu.Api.Domain.Academic.ExperimentGradeSheet", "ExperimentGradeSheet")
+                        .WithMany("Records")
+                        .HasForeignKey("ExperimentGradeSheetId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("Jiaowu.Api.Domain.Academic.ExperimentSession", "ExperimentSession")
+                        .WithMany()
+                        .HasForeignKey("ExperimentSessionId")
+                        .OnDelete(DeleteBehavior.Restrict);
+
+                    b.HasOne("Jiaowu.Api.Domain.Academic.Student", "Student")
+                        .WithMany()
+                        .HasForeignKey("StudentId")
+                        .OnDelete(DeleteBehavior.Restrict)
+                        .IsRequired();
+
+                    b.Navigation("ExperimentGradeSheet");
+
+                    b.Navigation("ExperimentSession");
+
+                    b.Navigation("Student");
+                });
+
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.ExperimentGradeSheet", b =>
+                {
+                    b.HasOne("Jiaowu.Api.Domain.Academic.ExperimentProject", "ExperimentProject")
+                        .WithOne("GradeSheet")
+                        .HasForeignKey("Jiaowu.Api.Domain.Academic.ExperimentGradeSheet", "ExperimentProjectId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("ExperimentProject");
+                });
+
             modelBuilder.Entity("Jiaowu.Api.Domain.Academic.ExperimentProject", b =>
                 {
                     b.HasOne("Jiaowu.Api.Domain.Academic.TeachingTask", "TeachingTask")
@@ -5550,10 +5795,29 @@ namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
                     b.Navigation("SeatAssignments");
                 });
 
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.ExperimentGradeItem", b =>
+                {
+                    b.Navigation("Scores");
+                });
+
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.ExperimentGradeRecord", b =>
+                {
+                    b.Navigation("ItemScores");
+                });
+
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.ExperimentGradeSheet", b =>
+                {
+                    b.Navigation("Items");
+
+                    b.Navigation("Records");
+                });
+
             modelBuilder.Entity("Jiaowu.Api.Domain.Academic.ExperimentProject", b =>
                 {
                     b.Navigation("Bookings");
 
+                    b.Navigation("GradeSheet");
+
                     b.Navigation("Sessions");
                 });