2025-07-30
40 篇热帖
2. Our $100M Series B (oxide.computer)
Raising our Series B round of financing
3. Try the Mosquito Bucket of Death (www.energyvanguard.com)
The Mosquito Bucket of Death is a safe and environmentally sound way to rid your yard of mosquitoes. Here's how you make them.
4. M8.7 earthquake in Western Pacific, tsunami warning issued (earthquake.usgs.gov)
5. URL-Driven State in HTMX (www.lorenstew.art)
Build stateful HTMX applications using URL parameters as your state store, creating naturally bookmarkable and shareable interfaces
6. The HTML Hobbyist (2022) (www.htmlhobbyist.com)
Learning HTML to build your website, fanzine, or personal site.
7. Weather Model based on ADS-B (obrhubr.org)
Each second thousands of planes send messages about their location and flight data - in ADS-B messages. These are intended to prevent mid-air collisions, but we can exploit the aggregated data to map out atmospheric conditions. By deriving the wind speed from the broadcast flight data, we can model wind speed and direction.
8. Online Collection of Keygen Music (keygenmusic.tk)
Online chiptune music player. Charged with music from keygens. Streams directly in your browser
9. Sleep all comes down to the mitochondria (www.science.org)
10. Problem solving often a matter of cooking up an appropriate Markov chain (2007) (math.uchicago.edu)
马尔可夫链技巧概述（2007年）
本文档是一份关于马尔可夫链构造技巧的技术材料，旨在展示如何通过设计合适的马尔可夫链来解决问题，特别是在概率计算和随机过程建模方面。文档内容包含理论推导、证明示例和具体应用方法。
核心内容
文档主要探讨了在不同场景下构造马尔可夫链的策略，重点强调了构造“合适”的马尔可夫链对于高效解决问题的关键作用。内容涉及：
- 目的：介绍在问题求解中，如何有目的地设计马尔可夫链的转移概率和结构。
- 方法论：展示了多种构造技巧，包括状态空间的选取、转移矩阵的设计以及保持平稳分布或目标性质的约束条件。
- 理论证明：包含了一系列数学推导和证明，用于验证所构造马尔可夫链的有效性和正确性，例如确保其具有唯一的平稳分布或满足特定的收敛性。
- 应用示例：文档中可能包含将理论技巧应用于具体问题（如抽样、优化或模拟）的案例，尽管部分内容因文本编码问题难以完全辨识。
结构与格式
- 格式：PDF文档（版本1.2）。
- 结构：材料以分页形式呈现，包含大量的数学公式、推导步骤和文字说明。内容按逻辑顺序组织，从基本概念逐步深入到复杂技巧和应用。
- 关键技术要素：
- 状态空间与转移矩阵：详细讨论了如何根据问题特性定义马尔可夫链的状态和转移规则。
- 平稳分布：构造过程的核心目标之一是使马尔可夫链收敛到一个已知或所需的平稳分布。
- 可逆性与细致平衡：许多构造技巧依赖于满足细致平衡条件，以简化设计并保证良好的性质。
- 收敛速度：部分讨论可能涉及所构造链的混合时间或收敛速率。
总结
该文档是一份侧重技术实践的参考资料，系统地阐释了“构造马尔可夫链”作为一种主动的问题求解工具。它超越了被动地分析给定链，转向主动地设计链以满足特定计算或建模需求。文档的价值在于提供了一套实用的理论框架和技巧集合，适用于需要利用马尔可夫链进行模拟、抽样或算法设计的研究人员和学生。尽管部分内容因原始文本编码问题导致显示异常，但其核心思想和主要技术脉络是清晰的。
11. Show HN: I built an AI that turns any book into a text adventure game (www.kathaaverse.com)
KathaaVerse: Transform Any Book Into your own Interactive Adventure
12. Maru OS – Use your phone as your PC (maruos.com)
Maru is a context-aware, lightweight, and open operating system that unites mobile and desktop computing.
13. I launched 17 side projects. Result? I'm rich in expired domains
14. Learning basic electronics by building fireflies (a64.in)
From missing real fireflies to learning basic electronics and building my own blinking "fireflies"
15. Microsoft bans LibreOffice developer's account without warning, rejects appeal (www.neowin.net)
16. A major AI training data set contains millions of examples of personal data (www.technologyreview.com)
Personally identifiable information has been found in DataComp CommonPool, one of the largest open-source data sets used to train image generation models.
17. More honey bees dying, even as antibiotic use halves (news.uoguelph.ca)
Despite tighter restrictions on antibiotics used in Canadian beekeeping, honey bee death rates are still rising. A new study led by University of Guelph…
18. Launch HN: Hyprnote (YC S25) – An open-source AI meeting notetaker
19. RIP Shunsaku Tamiya, the man who made plastic model kits a global obsession (japanesenostalgiccar.com)
Japanese Nostalgic Car
20. How the brain increases blood flow on demand (hms.harvard.edu)
大脑血流调节机制
大脑根据神经活动需求动态调整局部血流量，这一过程称为神经血管耦合。其核心机制包括神经调节和代谢调节两条主要途径，两者协同确保活跃脑区获得充足的氧气和葡萄糖。
1. 神经调节途径
- 起源于脑干：脑干中的蓝斑核（释放去甲肾上腺素）和缝际核（释放血清素）发出神经纤维，广泛支配大脑血管。
- 双重控制：
- 交感神经（主要来自蓝斑核）：在整体应激或血压升高时收缩血管，维持稳定的脑血流。
- 副交感神经和三叉神经：释放乙酰胆碱、血管活性肠肽（VIP）等，引起血管舒张，可能参与快速的局部调节。
- 局部中间神经元：大脑皮层内的特定神经元（如释放一氧化氮的中间神经元）可直接作用于邻近血管，实现精准的快速调节。
2. 代谢调节途径
- 局部活动触发：神经元活动增加导致局部代谢产物积累，如CO₂、H⁺（pH下降）、腺苷和钾离子（K⁺）。
- 直接效应：这些代谢产物直接作用于小动脉的平滑肌细胞，引起血管舒张，增加血流。
- 星形胶质细胞的关键作用：
- 星形胶质细胞的终足包裹脑血管，充当代谢传感器。
- 它们感知神经元释放的谷氨酸等信号，通过钙离子波传递信息。
- 最终在终足释放前列腺素、**一氧化氮（NO）**等血管活性物质，精确调节局部血管直径。
3. 一氧化氮（NO）的核心作用
- 由神经元和内皮细胞产生。
- 它是强大的血管舒张剂，通过激活平滑肌细胞内的信号通路使其松弛。
- 在神经血管耦合中起关键中介作用，连接神经活动与血管反应。
4. 结构基础：血脑屏障
- 脑血管内皮细胞连接紧密，形成血脑屏障。
- 星形胶质细胞终足与周细胞、内皮细胞共同构成神经血管单元。
- 该结构不仅控制物质进出，更是血流调节信号传递的功能平台。
总结
大脑通过多层次的精密系统实现按需供血：脑干神经提供全局性背景调节；局部神经元和星形胶质细胞对突触活动产生的代谢信号做出快速响应；一氧化氮等分子作为关键信使介导血管舒张。神经调节和代谢调节途径相互整合，确保大脑在不同功能状态下维持匹配的血流供应，这对维持正常认知功能和预防缺血损伤至关重要。
21. Elements of System Design (github.com)
A Periodic Table of System Design Principles. Contribute to jarulraj/periodic-table development by creating an account on GitHub.
22. Writing memory efficient C structs (tomscheers.github.io)
A struct in C is the best way to organize your data so that you can easily use the data later in your program. However, there are a few caveats to C structures, mainly how their memory works. Note that I’m making a lot of assumptions about type sizes and standards. These can differ between systems and ABI’s, so for example, the alignment value of an int isn’t strictly 4, meaning some sizes differ from mine.
23. LangExtract: Python library for extracting structured data from language models (github.com)
A Python library for extracting structured information from unstructured text using LLMs with precise source grounding and interactive visualization. - google/langextract
24. Linux 6.16: faster file systems, improved confidential memory, more Rust support (www.zdnet.com)
Linux continues to grow bigger and better. Here's what's new and notable in the 6.16 release, plus what you need to know about 6.17.
25. A month using XMPP (using Snikket) for every call and chat (2023) (neilzone.co.uk)
For the last month, I've been using XMPP (using Snikket) for every call and chat between me and my wife Sandra, at least.
26. Big Tech Killed the Golden Age of Programming (www.taylor.gl)
27. U.S. intelligence intervened with DOJ to push HPE-Juniper merger (www.axios.com)
28. Oscar-Winning 'No Other Land' Awdah Hathaleen Killed by Israeli Settler (www.latimes.com)
Awdah Hathaleen, a Palestinian activist and consultant on the Oscar-winning documentary 'No Other Land,' died Monday after he was shot dead by an Israeli settler in the occupied West Bank.
29. Programmers aren’t so humble anymore, maybe because nobody codes in Perl (www.wired.com)
Perl is a messy, maddening programming language, the “duct tape of the internet.” But at least you can tell it was made by humans.
30. Blog series on creating an OS in Rust (os.phil-opp.com)
This blog series creates a small operating system in the Rust programming language. Each post is a small tutorial and includes all needed code.
31. Launch HN: Lucidic (YC W25) – Debug, test, and evaluate AI agents in production
32. ACM Transitions to Full Open Access (www.acm.org)
33. Mezzano, an operating system written in Common Lisp (github.com)
An operating system written in Common Lisp. Contribute to froggey/Mezzano development by creating an account on GitHub.
34. Webflow Down for >31 Hours (status.webflow.com)
Welcome to Webflow's home for real-time and historical data on system performance.
35. Someone made a 128k line PR to OpenCut (github.com)
The open-source CapCut alternative. Contribute to OpenCut-app/OpenCut development by creating an account on GitHub.
36. Fixing Ctrl+C in Rust terminal apps: Child process management (www.fiveonefour.com)
37. Two Birds with One Tone: I/Q Signals and Fourier Transform (wirelesspi.com)
When a new member arrives at the Signal Processing Club, this is what they find at the club gate: I/Q signals. Perhaps a secret plot to keep most people out of the party?
38. A short post on short trains (shakeddown.substack.com)
The lesser urbanism hack
39. Show HN: Open-source alternative to ChatGPT Agents for browsing (github.com)
state of the art browsing agent (WebArena 72.7%). Contribute to trymeka/agent development by creating an account on GitHub.
40. Show HN: Sourcebot – Self-hosted Perplexity for your codebase (github.com)
Sourcebot is a self-hosted tool that helps humans and agents understand your codebase. - Release v4.6.0 · sourcebot-dev/sourcebot