研究笔记 · Research Note
Undergraduate Research @ Peking University & Caltech/UCR
Undergraduate Research @ Peking University & Caltech/UCR
相关页面: 本页只记录科研项目 (umbrella pointer page)。本科期间的 班长 / 学生会 / 支教 / 爱心社 / 棒垒队 等 leadership & service 经历见 PKU-Leadership-and-Service; 所有奖项荣誉 见 Academic-Honors-PKU。
基本信息
- 时间: 2018.09 — 2022.06 (本科 4 年)
- 角色: 本科独立研究 (4 independent projects across 3 labs / 3 institutions)
- 组织: 北京大学物理学院 (李婧 / 胡永云 / 聂绩 教授) + Caltech / UC Riverside (Yuk Yung / King-Fai Li)
- 地点: 北京 / 远程
- 资助: PKU President Fellowship + 本科生科研训练项目
4 Projects Overview (按时间顺序, 每个独立 page 见 pointer)
1. Walker/Hadley Circulation Response Under Global Warming (2019.10 — 2020.05, Ji-Nie-聂绩) → 独立页面: PKU-Walker-Hadley-Response-Research → TL;DR: 本科大二秋季 first project, 计算不同 CO₂ level 下 Walker/Hadley 强度变化 + 贡献分解。2019-11-04 first long report 43 slides 已 demonstrate 3-method Walker strength 并列对比 (velocity potential / integral / precip+850hPa) — 是 Zhenyu multi-method comparison discipline 的 earliest evidence (比 PhD SWTG 早 6 年)。包含 Ji Nie 组 onboarding + 4-advisor evaluation selection ([four PKU faculty across quantitative-biology / optics / quantum-materials / climate]) + 2 个 reading club 跨 monsoon/BL/Walker/Hadley/ENSO ~30+ papers in 2 months + 2020-09 全员大组会 Walker metric (ω@500mb WEP-EEP diff) = Walker paper v6 §3.1 metric 完全 identical, 早 1 年 7 个月 already articulated。
2. Walker Circulation Width Dependence (2020.11 — 2021.10, Ji-Nie-聂绩 + )
→ 独立页面: PKU-Walker-Circulation-Research
→ TL;DR: 本科大三秋到大四秋 (12 months), CAM3 aqua-planet 10 cases × 30-yr runs (D60-D180 step 20° + Wonly/Conly/Aqua)。2021-07-13 breakthrough Zhenyu 自己提出 Linear Superposition framework + Ji Nie 当场 endorsement (4-field corr 0.83-0.93 validation); paper draft v6 (3663 words, 11 refs, 2021-10-22) 未投稿 (Ji Nie 当时 private context (held until 2026-06-10))。27,882 MATLAB+NCL lines + 20 NCAR CAM3 .F90 source mods (含 somoce MLDANN 50→30m key dep) + Tianhe-II (undergraduate Tianhe-II account) 48-PE 并行 + 5-stage HPC pipeline。
3. MCMC Retrieval Methods (2021.03 — 2022.03, Yuk-Yung + King-Fai-Li, Caltech / UCR 远程) → 独立页面: Caltech-DSCOVR-Research → TL;DR: 本科大三春到大四春, DSCOVR 单点光曲线反演地球陆海分布。4 项原创贡献: (a) Hansen σ² vs σ⁴ 80× bug catch (Hansen 教材数值实现 bug); (b) Pre-whitening L-curve (L-Curve Curvature / GCV / Morozov 4 方法系统对比); (c) Hardened Balancing Principle 90-paragraph writeup (Sep 2021 被 Siteng Fan 点名); (d) Direction of Noise Vector discovery (Sep 2021 Zhenyu 自己发现的 ill-posed structure)。5 种 programming languages (IDL / MATLAB / Python / Mathematica / R) + 29 group_meeting pptx。自学 Hansen Discrete Inverse Problems + Bishop PRML + Golub 1979 GCV 原始论文并逐一复现数值实验。Repo: 。
4. MODIS+CALIPSO Joint Aerosol Retrieval (Senior Thesis) (2021.12 — 2022.06, Jing-Li-李婧) → 独立页面: PKU-Aerosol-Senior-Thesis → TL;DR: 本科大四春 senior thesis。First iteratively-coupled MODIS+CALIPSO joint retrieval (用 CALIPSO 反演 aerosol extinction 廓线替换 MODIS lookup table + MODIS AOD 作 CALIPSO 反演 boundary condition, 迭代直至收敛)。CALIPSO L2 -10⁴ non-physical bug catch + 4 Beijing case study (abs ↓ 0.011-0.032, rel ↓ 3-20%) + 9-version thesis auto-diff (316→1350 words in 27 days) + 4-person lab scaffolding (Jing-Li-李婧 + Chang-Liang-常亮 + Li-Chong-李充 + Dong-Yueming-董悦明 + Caltech bridge)。
Early Exploration Prequel Phase (2019.04 — 2019.10, 前 Ji Nie onboarding)
本科 research 并非从 2019.10 Ji Nie first project 启动就开始, 前面有 18 个月 prequel phase:
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Phase 0.A: 2019-03-17 物理学院本研分享会 (7 senior PPTs covering HEP / Quantum / Biology / ML / Galaxy / Planetary Climate) + 4-advisor candidate evaluation across quantitative-biology / optics / quantum-materials / climate, 最终 selected Ji Nie ([Moment 1 of Independent Judgment narrative — held until 2026-06-10])
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Phase 0.B: 2019 春期间撰写的关于本科生科研体制的 critical reflection note (private),影响后续 advisor 选择 (selected 李婧 + 聂绩 都属于主动 deemphasize 自己 credit 的 minority)。
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Phase 0.C-G: 2 group reading club (BL 8 papers + monsoon 6 papers) + 首次 CAM5 aqua-planet 实验 (2020-04 → 2020-05,
data_summary_big_picture.pptx22 slides) + 2020-09 全员大组会 Walker/Hadley metric establish (Walker paper v6 metric 早 1 年 7 个月 source-of-truth) + 2020-09-27 Zhenyu first appearance in Hu group (28 slides)
使用的技能
- Python-科学计算
- 气候物理与大气科学
- 卫星遥感与数据处理
- MCMC-贝叶斯反演
- 数值模式源代码修改 (Walker 20 NCAR CAM3 .F90 mods, aggregate)
- 高性能计算-HPC (Tianhe-II (undergraduate Tianhe-II account) → (undergraduate Tianhe-II account) → (undergraduate Tianhe-II account) 跨 3 个 lab account)
相关页面
- PKU-Walker-Hadley-Response-Research — Project 1 独立 page
- PKU-Walker-Circulation-Research — Project 2 独立 page
- Caltech-DSCOVR-Research — Project 3 独立 page
- PKU-Aerosol-Senior-Thesis — Project 4 独立 page
- PKU-Leadership-and-Service — 非科研 leadership/service experiences
- Academic-Honors-PKU — 本科奖项荣誉
- Ji-Nie-聂绩 + + Jing-Li-李婧 + Yuk-Yung + King-Fai-Li — 本科 advisors
- Independent Judgment narrative (held until 2026-06-10) — Moment 1 + 2 (4-advisor + 18 岁 critical reflection)
- PKU advisor methodology companion (private) — 李婧 + 聂绩 advisor methodology (private) narrative spine
- Multi-Method-Comparison-Spine — 3-method Walker strength 并列对比 root evidence (2019-11-04)
- 2019 critical reflection note (private) — 大二春季 critical reflection source