Design of pH Control System for Electrodialysis Water Treatment

电渗析技术以其独特优势,在水处理、食品和化工等领域有着广泛的应用。针对电渗析水处理系统出水酸碱度可调的应用需求,利用STM32F407RET6单片机开发了一套基于PID算法的pH值控制系统,运用PWM方式完成了电渗析电源电压的快速控制,实现电渗析水处理系统出水pH值的快速调节,调节时间小于30s。所述酸碱度控制系统的开发,有助于提升水处理系统的响应速度,提高水质监控水平。To meet the requirement of adjustable water pH for electrodialysis water treatment system,a pH value control system based on PID algorithm is developed using STM32F407RET6 microcontraller.Then to realize rapid water pH adjust- ment of the electrodialysis water treatment system,the PWM method is utilized for fast control of the electrodialysis power supply voltage,which makes the adjusting time less than 30s.The development of pH value control system contributes to im- proving the response speed of the water treatment system.国家自然科学基金（51405408）; 厦门南方海洋研究中心项目（15GHS019HJ03）; 厦门市科技计划项目（3502Z20163005）; 福建省中青年教师教育科研项目（JAT160002

Study on Portable Ion Concentration Detection System Based on Electrochemical Principles

近年来，水、食品、土壤的安全问题越来越成为威胁人类健康的关注焦点，本文针对水质安全标准中重点关注的硝酸盐、重金属以及微生物指标，开展基于电化学的便携式微传感器离子浓度检测系统研究，以开发适用于个人、工厂和医院的快速、便携式水质测量仪器。 基于电化学检测硝酸盐溶液浓度、重金属离子浓度以及微生物的原理，设计了以STM32F405为核心的便携式离子浓度检测系统和杯式智能水质监测仪的硬件电路以及基于CC2540蓝牙通讯模块电路；开发了嵌入式系统程序、CC2540蓝牙通讯程序和基于PC机的特征值提取及去噪等算法程序。 利用本文设计的离子浓度检测系统，通过提取特征值的方法拟合溶液浓度函数，实现中性条件...In recent years, the safety of water, food and soil has become the focus of attention to human health. Based on the nitrate, heavy metal and microbial indicators in water quality safety standards, study on portable ion concentration detection system based on electrochemical principles was present to design water quality measuring instruments suitable for individuals, factories and hospitals. Base...学位：工学硕士院系专业：航空航天学院_电气检测技术及仪器学号：1992014115289

Research on the Finite Element Simulation of the Adaptive Compensation to the Distortion of the Reflecting Mirror

针对射频板条CO2激光器所采用的非稳-波导混合腔反射镜热变形问题。利用有限元分析法仿真得出了反射镜的热变形和温度分布,并提出了一种背面多热丝同步加热自适应补偿方法。结果表明,加热补偿方法可将反射镜的曲率变形从0.16%降低到0.02%以内,并获得了不同激光功率下的补偿曲线。Aiming to the distortion of the reflecting mirror in the unstable waveguide mixing resonator on the radio-frequency stimulated slab CO2 laser,a method of synchronously heating compensation for the mirror was established by simulating and analyzing the temperature distribution and distortion of the reflecting mirror using the method of finite element analysis.The curvature rate distortion was reduced from 0.16%to less than 0.02%.And the relation curve of the synchronously heating compensation with the variation of the laser power was obtained.福建省自然科学基金资助项目(项目编号:2011J01334

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^