PIC16C57单片机构成的温度测量控制网络

文章介绍的温度测量控制网络由多台现场测控仪表、一台指令收发器和一台管理微机构成，可实现远程通讯     

电场和温度对铁电薄膜开关特性的影响

本文运用KA模型研究了铁电薄膜的电畴反转特性与外电场强度以及温度的关系，结果表明，开关电流随电场强度增大而增大，在居里点附近随温度上升而下降，远低于居里点时随温度上升而增大。开关时间随电场强度和温度提高而缩短。     

改善ZnO压敏元件温度特性的研究

从实验上探索了降低ＺｎＯ压敏陶瓷元件泄漏电流温度系数的途径和方法，研制了特殊添加物，在通常的ＺｎＯ压敏瓷料中添加适量特殊添加物，可以改变ＺｎＯ压敏陶瓷泄漏电流的温度特性，达到降低泄漏电流温度系数的目的。泄漏电流随温度变化在３１～３４°Ｃ出现极大值可能是杂质离子对电子的散射作用所致。     

怎样选用元器件讲座（十三）：MZ2型PTC限流元件

PTC限流元件是一种具有恢复特性的正温度系数热敏电阻。PTC限流元件的主体材料是钛酸钡(BaTiO3),掺以能改善居里点温度的物质和极微量的导电杂质(如稀土元素镧),经研磨、挤压成型、高温烧结而成的复合钛酸盐的N型半导体陶瓷。图1为PTC限流元件的外型图。限流元件PTC在达到一个特定的温度前,电阻值随温度变化非常缓慢。当超过这个温度时,PTC的阻值急剧增大,发     

多路温度自动检测系统

本文介绍了采用计算机对粮仓的多路温度进行自动测试的系统，详细分析了多路温度自动检测系统硬件电路及其软件设计。     

热电效应和热电偶

 热电效应是热电温度测量的基础。该效应是德国医生塞贝克于1821年发现的,因此也称塞贝克效应。本文首先介绍塞贝克效应是如何发现的,然后在说明热电温度计的基本原理的基础上,简单介绍热电偶的基本结构、种类、用途以及今后的发展。     

Electromagnetic Instabilities Excited by Electron Temperature Anisotropy

One-dimensional particle-in-cell simulations are performed to investigate the nonlinear evolution of electromagnetic instabilities excited by the electron temperature anisotropy in homogeneous plasmas with different parameters. The results show that the electron temperature anisotropy can excite the two right-hand electromagnetic instabilities, one has the frequency higher than Ωe, the other is the whistler instability with larger amplitude, and its frequency is below Ωe. Their dispersion relations are consistent with the prediction from the cold plasma theory. In the initial growth stage (prediction from linear theory), the frequency of the dominant mode (the mode whose amplitude is large enough) of the whistler wave almost does not change, but in the saturation stage the situation is different. In the case that the ratio of electron plasma frequency to cyclotron frequency is larger than 1, the frequency of the dominant mode of the whistler wave driRs from high to low continuously. However, for the case of the ratio smaller than 1, besides the original dominant mode of the whistler wave whose frequency is about 2.6ωe, another dominant mode whose frequency is about 1.55ωe also begins to be excited at definite time, and its amplitude increases with time until it exceeds the original dominant mode.     

基于ACPI的高精度微处理器系统温度监视芯片ADM1023

ADM1023是由美国ANALOG DEVICES公司生产的温度监视芯片，该芯片具有高精度，双通道工作等特点，文中详细讨论了ADM1023的主要参数，结构性能，工作原理及应用设计等问题。     

In-Plane Thermal Diffusivity Measurement of Thin Films Based on the Alternating-Current Calorimetric Method Using an Optical Reflectivity Technique

An advanced ac calorimetric method to measure thermal diffusivity of a thin sample is developed by using an optical reflectivity technique. A modulated infrared laser is used to heat the front surface of a foil specimen. The reflectivity of a continuous-wave He-Ne laser at the rear surface of the specimen is detected by a photoreceiver.