热防护材料高温异型传感器校准技术研究

高温异型传感器广泛应用在热防护材料研究领域，因其测温部分比通用温度传感器尺寸短，现有的校准装置无法满足该类传感器的校准需求。针对高温异型传感器无法校准的问题，提出了一种应用专用高温恒温炉、基于比较法的校准方法，研制了高温异型传感器校准装置，实现了该类温度传感器的量值溯源，并进行了不确定度分析。     

Impact of rain on wave retrieval from Sentinel-1 synthetic aperture radar images in tropical cyclones

The main objective of our work was to investigate the impact of rain on wave observations from C-band (~5.3 GHz) synthetic aperture radar (SAR) in tropical cyclones. In this study, 10 Sentinel-1 SAR images were available from the Satellite Hurricane Observation Campaign, which were taken under cyclonic conditions during the 2016 hurricane season. The third-generation wave model, known as Simulating WAves Nearshore (SWAN) (version 41.31), was used to simulate the wave fields corresponding to these Sentinel-1 SAR images. In addition, rainfall data from the Tropical Rainfall Measuring Mission satellite passing over the spatial coverage of the Sentinel-1 SAR images were collected. The simulated results were validated against significant wave heights (SWHs) from the Jason-2 altimeter and European Centre for Medium-Range Weather Forecasts data, revealing a root mean square error (RMSE) of ~0.5 m with a 0.25 scatter index. Winds retrieved from the VH-polarized Sentinel-1 SAR images using the Sentinel-1 Extra Wide-swath Mode Wind Speed Retrieval Model after Noise Removal were taken as prior information for wave retrieval. It was discovered that rain did indeed affect the SAR wave retrieval, as evidenced by the 3.21-m RMSE of SWHs between the SAR images and the SWAN model, which was obtained for the ~1000 match-ups with raindrops. The raindrops dampened the wave retrieval when the rain rate was < ~5 mm/hr; however, they enhanced wave retrieval for higher rain rates. It was also found that the portion of the rain-induced ring wave with a wave number > 0.05 rad/m (~125 m wavelength) was clearly observed in the SAR-derived wave spectra.     

基于幅频响应特性的半球谐振子频率裂解与固有刚度轴方位角测定方法

半球谐振子频率裂解与固有刚度轴方位角是影响陀螺性能指标的核心因素。提出了一种基于幅频响应特性的半球谐振子频率裂解与固有刚度轴方位角测定方法，采用压电激振台扫频激振，多普勒激光测振仪检测谐振子的幅频响应特性，通过幅频响应特性曲线分析实现频率裂解与固有刚度轴方位角的测定。对该方法进行了理论分析，搭建了实验装置，并对半球谐振子进行了测试，结果表明：该方法频率裂解测量精度优于0.01Hz，固有频率主轴方位角确定精度优于±1.17°，具有良好的可行性，在半球谐振陀螺研制方面具有良好的参考意义。     

数字多用表自动检定校准系统

本文介绍了一种数字多用表的自动检定校准系统的构成及软件设计 ,并对系统软件的设计方法 ,主要功能及主要特色进行了讨论。     

基于Matlab语言的系统可靠性仿真

Matlab是一种高性能数值计算语言 ,本文用Matlab语言编制系统可靠性仿真程序 ,并给出了具体实例。此方法比其他方法简单有效 ,可适用于复杂系统。     

面向对象技术的防空导弹Simulink建模与仿真

为防空导弹系统性能改进研究和优化设计,提出了一种新的方法,首先给出了一般防空导弹制导控制系统的数学模型,并采用面向对象建模技术结合动态仿真软件Simulink建立了仿真模型并进行了仿真研究,该模型具有容易理解,可重复使用,易于扩展等优点,即通过部分模块更换或改变参数等就可对该系统在其他条件下进行仿真,仿真结果和实际遥测数据基本吻合,表明了该模型和方法的有效性和实用性。     

S7-300液位控制系统下位机的实现

利用以太网,结合西门子现场总线搭建了过程控制平台,完成了对温度、压力、流量和液位这些典型过程参数的采集、存储和分析,并利用PID算法通过对变频器、电控阀门的控制,实现恒压供水任务,进而完成对于水箱液位稳定的控制.     

一种新的六端口测量系统自校准方法

提出了一种新的六端口自校准方法.本方法从六端口相对功率理论出发,导出了六端口系统常数的自校准方程,给出了求解系统常数初值的方法,并利用梯度法对方程组求解,仿真结果表明用一个匹配负载、四个失配负载就可以解出系统常数.