KS－1型双功能控湿仪的研制

ＫＳ－１型控湿仪由集成运算放大器、５５５时基电路、固态继电器等先进的电子器件组成，具有双功能、自动控制灵敏、结构简单、使用方便、经济实用等特点。本文介绍了该控湿仪的设计思想、基本原理和性能特点，并对５５５集成芯片组成的单稳、控时电路作了具体的分析     

KS－1型双功能控湿仪的研制

ＫＳ－１型控湿仪由集成运算放大器、５５５时基电路、固态继电器等先进的电子器件组成，具有双功能、自动控制灵敏、结构简单、使用方便、经济实用等特点。本文介绍了该控湿仪的设计思想、基本原理和性能特点，并对５５５集成芯片组成的单稳、控时电路作了具体的分析     

复杂非线性电阻电路小信号分析法的研究

利用小信号分析法，对复杂线性电阻网络与数个非线性电阻元件联接的电路进行了分析求解，进而得出了复杂非线性电阻电路的一般分析方法。     

Closed system anaesthesia in dogs using liquid sevoflurane injection; evaluation of the square-root-of-time model and the influence of CO2 absorbent

Objective To determine whether predictable alveolar concentrations of sevoflurane are reliably produced in dogs when liquid sevoflurane is injected into closed circuit breathing systems, as calculated by Lowe's square‐root‐of‐time anaesthetic uptake model, and to confirm the validity of the model using soda lime and calcium hydroxide lime. Study design Prospective clinical study. Animals Eleven healthy dogs with a mean body mass of 34 ± 9 kg scheduled for pelvic limb orthopaedic surgery. Materials and methods Following pre‐anaesthetic medication, anaesthesia was induced with propofol and maintained with sevoflurane in a closed circle system. Epidural anaesthesia was performed with morphine and bupivacaine. Liquid sevoflurane was injected into the circuit by syringe, using dosages and time intervals derived from Lowe's square‐root‐of‐time anaesthetic uptake model. The target alveolar concentration chosen was 1.1 × MAC (2.6% end‐tidal sevoflurane). Either soda lime (group S; n = 6) or calcium hydroxide lime (Amsorb; group A; n = 5) were used for CO₂ absorption. Sevoflurane concentration and the respiratory gas composition were measured with an infrared gas analyser. Results End‐tidal sevoflurane concentrations were close to the predicted value of 2.6% at 9 minutes (2.53 ± 0.1% group S; 2.60 ± 0.26% group A) and 16 minutes (2.55 ± 0.30 group S; 2.52 ± 0.28% group A) but declined thereafter to reach 50% (group S) and 64% (group A) of the predicted value at 121 minutes. There was a constant trend towards higher end‐tidal sevoflurane concentrations in group A but the difference was not statistically significant. Conclusions The square‐root‐of‐time model leads to significantly lower alveolar concentrations than expected, suggesting that the rate of sevoflurane uptake in dogs declines less rapidly than predicted. The use of Amsorb tends to reduce the deviation from predicted concentrations. Clinical relevance The model used in this study provided only an approximate guide to the volume of liquid sevoflurane required. Consequently, the definitive dose schedule must be based on measured anaesthetic concentrations and clinical monitoring.     

舰用塑壳断路器电磁脱扣器的优化

针对普通工频断路器用于400Hz条件下的舰船上不能通断问题,采用了基于磁路和基于磁场的分析方法,对额定工作电流为25A的断路器的脱扣器进行了研究。建立了脱扣器的三维模型,在有限元分析软件ANSYS中进行静态电磁仿真分析计算,找出了工频脱扣器不能正常脱扣的因素,并根据影响因素和实际工作经验,对原有的脱扣器进行了优化设计,仿真的结果得到了实验验证。     

YN型快速土壤肥料养分测定仪的研制

介绍了ＹＮ型土壤肥料养分测定仪的结构及工作原理,利用集成电子技术的设计的土壤肥料养分快速测定仪工作可靠,快速简便,重现性好,测试精度高,试验结果表明,速测的土壤中Ｎ,Ｐ,Ｋ的结果与常规测定呈极显著相关关系,其Ｎ,Ｐ,Ｋ的相关系数分别为０．８８７０,０．９８９７,０．９７６３。     

基于压电效应的简易型细胞力学测试仪

针对传统的细胞力学研究方法的非无损性,不能对细胞力学参数连续、长期监测的特点,研制出一种基于石英晶体压电效应的简易型细胞力学测试仪。该测试仪以STM32 103C8 为核心,设计有石英晶体在液相环境下的起振电路、稳定振荡电路,采用了频率/电压转换电路。系统实现了对石英晶体频率变化的高精度采集,对与传感器耦合的界面层（细胞）的质量、粘弹性和表面应力多参数敏感,能对细胞黏附过程和细胞力学性能进行动态监测。通过整机在细胞培养液环境下的实验,验证了测试仪系统的可行性与稳定性。     

生物育种用无极调频可变磁场发生器的研究

装置分为输出磁场的磁路部分、激励磁场的电路部分,以及以DSP为控制核心的控制部分。磁路部分设计为带气隙的环回形,励磁线圈中配有铁氧体磁芯可以大大增强装置输出的磁场强度,交变磁场产生于气隙即为实验区。电路部分采用的是桥式拓扑结构,控制部分采用改进的锁相环使得逆变器工作在小感性的准谐振状态,确保整个装置安全、稳定、高效的运行。最后通过仿真验证了装置的可行性,实验结果表明:该交变磁场发生装置能够连续地调节磁场频率和场强,育种效果得到认可。     

水果分选机称重模块调理电路设计

为了满足水果外观品质和质量综合分选的实际需要,可以在水果机器视觉分选机上加上称重模块。为了提高称重模块的精度,基于AD7195芯片,利用比率测量和交流激励的方法,设计出了水果分选机称重模块的调理电路。同时,详细描述了该调理电路的理论基础、硬件构成以及输出结果的软件补偿等,得到了质量与其A/D转换值之间的关系式,并对调理电路的精度进行了实验验证。实验结果表明,该调理电路具有很高的测量精度,且具有线性度、重复性好等特点,可以满足大多数水果称重分选的要求。     

无线遥控变压器保护开关的制作

无线遥控以其传输距离远、抗干扰能力强、无方向性等优点,被应用于许多领域。本文详细介绍了以小型无线遥控发射模块TWH9236和无线接收模块TWH9238作为遥控开关的执行元件取代了保护变压器的断路器手动合闸手柄,使产品具有操作方便、可靠性、保密性强等优点,提高了产品档次,增加了该产品的市场竞争力。