Organic complex of divalent Europium with deep blue emission

Undergraduate Scientific Research Program

What’s undergraduate scientific research program?

The undergraduate scientific research program is a project conducted by Peking University. One that majors in science could join this program. By joining the program, the undergraduates could get in touch with frontiers from various fields. Every attendant would be required to perform experiments for one year(specific working hours) under the guidance of a professor and corresponding graduate student. Two reports are required respectively in the midterm and the final of the research period.

My Progress

My undergraduate research program would come to an end in Nov., 2021. Details of my research content could not be provided for all of the works belongs to the intellectual properties of the school.

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DIY:3D Printed RFID Doorgate

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我拿出了尘封多年的芯片，找到了MFRC-522模组，查阅了一下Documentation之后简单接了一下线，码了几十行代码，接上Arduino。

The serial contact seems worked, and the rfid cards could be read as expected.

The S70 type of card has uuid with 4 bytes, just the same as the campus id card.

随后我用一台老古董示波器观察了芯片之间的串口通讯。基础电路就装好啦！由于年代久远，加上当时忘记拍照，所以没有初步成型的电路照片。我们还使用了金属舵机。确认原型电路工作良好之后，我们把这个带面包板的原型部署在了门上。然后又根据门锁设计了一个502淬火的瓦楞纸壳。将舵机装进去，并且设计了一个单向传动轴，既可以电动开门也可以手动开门。找不到传动轴的照片了，不过还是可以从其他照片看到它的样子（三层瓦楞纸加上一支废旧的笔，502伺候）。

We first decided to use the chargable power banks as the power supplier. The first generation of the door gate system is literally working! (ugly as it is though)

The first generation costs me about a week to finish, which stills results in large electricity consumption for the power bank. What’s more, the appearance is ugly and fragile and the mechanical parts are not designed carefully, leading to bad performances and bugs.

After days of research and discussion, I worked up an 3D sketch in solidworks and printed it with my 3D printer.

看到成品的那一瞬间特别开心，因为组件精度和结构强度都超乎我的想象（PLA聚乳酸）。 加上之前的充电宝供电问题，我们改用了市电供电电源，这样就不用换充电宝啦！ After optimization in codes, the door gate now consumes 50% energy less than the prototype. The power is so low that the power bank would halt when the door gate is idle.

Then we find the servo motor is always encountering serious lack of energy when operated by the chip, which would lead to failure of door opening. 我的初步估计是面包板的电阻对VCC的5V电压不可忽略，舵机的连接入口离电源太远，导致电位降大，供电不足。将舵机电源直接接到Micro USB输入口针脚上有效的解决了这个问题。

The picture shows the Arduino Uno developing board, and we can see that nearly all digital ports are used.

After several practices, we found that smart devices with NFC(e.g. Apple Watch)could also be read by the door gate. So I modified the code, making it compatible for phones and watches. The door gate is much more safer than using merely keys, according to my observation. For cracking the rfid encryption is much more diffcult than simply breaking the lock.

The exposed wires gave me a sense of danger. So I decided to pack the wires up. By using rfid chips with larger power, I can completely clear the wires and the chips outside the door.

Secondly, Arduino Uno is a demo chip for development, which would lead to higher energy consumption and less stabilities. 还有一点是我们需要缩小芯片的体积，于是我们选择了Arduino Nano Pro芯片代替，体积仅为Uno的1/6，功耗也更低，是成品芯片的不二选择。

于是买来了Nano芯片。本来想通过焊接代替暂时的杜邦线连接以增强电路稳定性，然并卵，反而体现了我的渣焊锡技术（ORZ）。

接下来要做的第一件事情是把新的主机外壳设计出来。已经经过一个月Solidworks软件探索得我，掌握了熟（lā）练（jī）的画图技巧（说出来可能要被学建筑的笑死）

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Intermediate Physical Chemistry Lab

The manufacture and optimization of microscopic Raman spectrometer and its application in measuring surface enhanced raman spectroscopy.

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Geek: A Simple COVID-19 Kinetic Simulation Model

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Original Passage in Chinese

我的小破号已经死了一个多月了，除了一些照片分享就没再发过一些新奇好玩而荒谬的事情，现在终于有机会啦！

这本是一篇放了一个多月的推送草稿。早在2月初，我就已经开始给病毒传播进行动力学建模了。但当时正值疫情最严重的的时候，放出一系列“令人堪忧”的预测数据就算连手动狗头也不能保命了，而且当时数据也相当不够，还有非常多问题没有解决，不过，当时确实成功提前12天预测到了中国疫情的高峰。现在，疫情在全球范围内传播，这又给了我很多新的数据，于是我决定重启这个计划。

Setting up of the mathematical model

Let’s devide the population into several parts: sustainable, exposed, infected, recovered and dead. This is the so-called SEIRD kinectic model.

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DIY: Build Your Own Font

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• Date: January 2017
• Client: Explore
• Category: Graphic Design

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Wechat Wordcloud

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Coming Soon!

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The Record Player

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Use this area to describe your project. Lorem ipsum dolor sit amet, consectetur adipisicing elit. Est blanditiis dolorem culpa incidunt minus dignissimos deserunt repellat aperiam quasi sunt officia expedita beatae cupiditate, maiores repudiandae, nostrum, reiciendis facere nemo!

• Date: January 2017
• Client: Explore
• Category: Graphic Design

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Big Data Analysis of Structures of Rare-Earth Coordination Compounds

Published as the third author in Univ. Chem.

Use this area to describe your project. Lorem ipsum dolor sit amet, consectetur adipisicing elit. Est blanditiis dolorem culpa incidunt minus dignissimos deserunt repellat aperiam quasi sunt officia expedita beatae cupiditate, maiores repudiandae, nostrum, reiciendis facere nemo!

• Date: January 2017
• Client: Explore
• Category: Graphic Design

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Contract Photographer of Creativity: Visual China Group

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Check here for full photography exhibition.

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Original Scientific Macro Video: Phamton of Chemistry

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3D-Printing Projects

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