电阻阵列辐射输出特性评估

电阻阵列是一种出射式动态红外场景投射器件,它通过控制流经电阻元的电流使电阻发热产生红外辐射,达到成像目的.由于非均匀性校正等需求,需要使用红外成像探测器测试单个电阻元的辐射特性.由于输入电流和输出红外辐射之间复杂的非线性关系,电阻阵列的辐射输出特性主要通过测试数据拟合来获取.基于典型的光学系统配置,给出了电阻元辐射亮度与探测器辐射照度之间的关系式,分析了光轴上及轴外电阻元辐射亮度的测试方法;通过对硅桥和悬浮薄膜电阻阵列电阻元的分析,给出了实际温度与等效黑体温度之间的对应关系,对电阻阵列辐射输出特性的测试具有一定的理论参考价值.     

印制板中炭黑类埋置电阻喷墨打印油墨的制作及性能研究

文章讲述了印制电路板中炭黑类埋置电阻喷墨打印油墨。制作的油墨黏度经黏度计测得0.087 Pa＆#183;s。TGA（热重分析）的分析结果显示油墨的固化条件为180℃、4 h。研究了固化后的埋置电阻油墨性能,包括电阻性能,玻璃化温度Tg,电阻温度系数TCR和热膨胀系数CTE等。该性能参数说明了固化后的埋置电阻油墨能够很好地与市面上大部分的印制电路板的兼容。最后,使用扫描电镜SEM观察到了炭黑颗粒在粘接剂树脂中的分布情况。     

Differential study of substituted and unsubstituted cobalt phthalocyanines for gas sensor applications

The conductivity of CoPc (cobalt phthalocyanine) and Co[(SO₃Na)_2,3Pc] was measured under a flow of two different gases (NH₃ and O₃), during exposure/recovery cycles. It appears that the relative responses are linearly related to the concentration, in the 20-200 ppb range for O₃ and in the 20-200 ppm range for NH₃. Observed during time, the sensing parameters allow a qualitative understanding of the kinetics. The comparative study of those products under both different gases gave interesting results for sensor applications. Whereas CoPc is sensitive to both gases, its sulfonated counterpart is only sensitive to NH₃.     

Discrete modelling of the electrochemical performance of SOFC electrodes

The composite anode and cathode of solid oxide fuel cells (SOFC) are modelled as sintered mixtures of electrolyte and electrocatalyst particles. A particle packing is first created numerically by the discrete element method (DEM) from a loose packing of 40 000 spherical, monosized, homogeneously mixed, and randomly positioned particles. Once the microstructure is sintered numerically, the effective electrode conductivity is determined by discretization of the particle packing into a resistance network. Each particle contact is characteristic of a bond resistance that depends on contact geometry and particle properties. The network, which typically consists of 120 000 bond resistances in total, is solved using Kirchhoff's current law. Distributions of local current densities and particle potentials are then performed. We investigate how electrode performance depends on parameters such as electrode composition, thickness, density and intrinsic material conductivities that are temperature dependent. The simulations show that the best electrode performance is obtained for compositions close to the percolation threshold of the electronic conductor. Depending on particle conductivities, the electrode performance is a function of its thickness. Additionally, DEM simulations generate useful microstructural information such as: coordination numbers, triple phase boundary length and percolation thresholds.     

电磁炉原理与常见故障分析

随着生活水平的提高,老百姓对安全卫生的炊事用具逐渐接受,电磁炉也进入了千家万户。所以电磁炉常见故障分析就显得很有必要。     

四通道12位带回读功能的高压DAC设计

基于0.8μm 40V BCD工艺,设计并实现了一款可工作于±15V电源电压的四通道12位DAC。电路由寄存器、R-2R电阻阵列和接成单位增益模式的运算放大器构成。实测结果显示,VDD= +15V,VSS= -15V,VLOGIC= +5V,VREFH= +10V,VREFL= -10V,负载RL=2kΩ,CL=100pF时,DAC的输出摆幅为-10V ~ +10V, DNL指标为±1.2LSB,INL指标为±1.5LSB。     

用于粉冶温压的分级电阻式加热系统及控制研制

介绍了分级电阻式粉末冶金温压加热系统总体方案，在结构上采用加热器和恒温器两级电阻式加热管加热。加热模块的控制选用TMA-7412Z型智能双数显调节仪，压机模块采用普通粉末压机的控制方式，送料模块及整个温压系统的控制采用PLC。给出了配有浮动阴模的温压系统PLC接线图及信号时序图。在此基础上，开发出HGWY—Ⅱ型粉末冶金温压精密成形系统。     

分级电阻式粉末冶金温压加热系统

介绍粉末冶金温压加热系统总体方案 ,给出本套设备的实验结果及有关加热设备的性能曲线。本加热设备结构简单 ,预热时间短 ,操作简单 ,在一般的粉末冶金压机上加上本套设备 ,可方便地组成温压系统 ,进行温压生产。     

T形铠装铂电阻传感器

本文叙述了在涤纶、锦纶等化纤生产中应用的Ｔ形铠装铂电阻传感器的结构、性能、加工及使用情况等。     

恒温晶振(OCXO)精密恒温箱温度控制电路分析

设计高稳定的晶体振荡器，必须有性能良好的恒温箱来保证其频率稳定，恒温箱中选择一个性能良好的温度控制电路对稳定频率有重要作用，高性能的控制电路能改善OCXO整体性能，进而选择合适的控制策略来优化控制电路。通过对恒温箱的多种温度控制电路分析及各种电路的工作原理的研究，说明各个参数之间的关系以及其对恒温箱整体性能的影响，提出了选择和改进温度控制电路的方法，对设计高稳定的OCXO提供了很好的依据。