大学化学 >> 2026, Vol. 41 >> Issue (4): 302-309.doi: 10.12461/PKU.DXHX202506103

科普 上一篇    

化影成形——从信号采集到图谱呈现的奇妙旅程

吴晶1, 兰景凤2, 王威1, 李莲花2, 曲昭玮1, 梅凡1, 蒲巧生1   

  1. 1 兰州大学化学化工学院, 甘肃 兰州 730000;
    2 化学国家级实验教学示范中心(兰州大学), 甘肃 兰州 730000
  • 收稿日期:2025-06-27 录用日期:2025-08-28 发布日期:2026-04-24
  • 通讯作者: 蒲巧生 E-mail:puqs@lzu.edu.cn Qiaosheng Pu
  • 基金资助:
    感谢兰州市科学技术局科技计划项目(2024-2-27)；甘肃省教育厅2023年高等教育教学成果培育项目(PX-48232713)；兰州大学教育教学改革研究项目(202212)；教育部化学“101计划”——化学测量学实验课程建设项目；教育部第三批虚拟教研室建设试点——“101计划”化学测量学实验课程虚拟教研室对本工作的支持。

From shadow to shape: the fascinating journey from signal acquisition to spectrum display

Jing Wu1, Jingfeng Lan2, Wei Wang1, Lianhua Li2, Zhaowei Qu1, Fan Mei1, Qiaosheng Pu1   

  1. 1 College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, Gansu Province, China;
    2 National Demonstration Center for Experimental Chemistry Education (Lanzhou University), Lanzhou 730000, Gansu Province, China
  • Received:2025-06-27 Accepted:2025-08-28 Published:2026-04-24
  • Contact: Qiaosheng Pu E-mail:puqs@lzu.edu.cn

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摘要： 在使用现代分析仪器时，许多学生虽能解释实验原理，却不清楚样品进入仪器后为何能“变成”图谱。其实，这背后经历了一场信号的“旅程”：看不见的光、电、化学变化，先由探测器“感知”变成“电”(模拟信号)，再通过信号放大器将微弱电流转为电压信号并放大，随后被整形、转化为计算机能理解的数字信号，最终绘制成图像。这一过程中涉及一连串电子模块和概念，如跨阻放大器、模数转换器、采样频率及分辨率。本文通过一系列通俗类比串联起信号处理的各个关键步骤，帮助学生梳理从信号到数据的全过程，使他们不再只是停留在“按按钮或点鼠标看结果”的阶段，而是能真正理解谱图背后的信号处理流程，更好地使用分析仪器。

关键词: 模拟信号, 滤波器, 跨阻放大器, 模数转换, 数字信号

Abstract: While chemistry students can clearly explain the experimental principles behind modern analytical instruments, many remain unclear about a crucial intermediate step: how a sample is transformed into a spectral output after entering the instrument. This conversion involves a sophisticated signal processing cascade: initially, subtle changes in optical, electrical, or chemical properties are detected and converted into analog electrical signals by a transducer. These weak current signals are converted into voltage signals via amplification, conditioned, and digitized, ultimately yielding computer-readable data displayed as a visual spectrum. This intricate process incorporates multiple electronic modules and fundamental concepts, including transimpedance amplifiers, analog-to-digital converters (ADCs), sampling frequency, and resolution. Through intuitive analogies that elucidate key signal processing stages, this article enhances students' comprehension of the complete pathway from raw signal acquisition to interpretable spectral data. It moves beyond the reductive “button-pressing” paradigm, cultivating a deeper appreciation for the underlying signal processing that generates each spectrum, thereby transforming analytical instruments from opaque “black boxes” into transparent and comprehensible tools.

Key words: Analog signal, Filter, Transimpedance amplifier, Analog-to-digital conversion, Digital signal