用神经网络消除温度对传感器输出的影响

针对温度对半导体压力传感器输出影响的问题,提出一种新的消除方法———神经网络法,建立了2-6-1神经网络结构,并利用神经网络的学习记忆功能,消除了温度对传感器输出的影响,实际运行结果表明,该方法具有实用、高效等特点。     

压阻式流速传感器研究

介绍了一种流速传感器的工作原理、结构设计和关键工艺。该传感器基于毕托管的工作原理来测量流速,采用压阻式差压传感器测量流体中的总压与静压之差。整个装置体积小、重量轻,可实现便携式检测。对流速传感器的标定测试方法进行了探讨和试验验证,实际测量和使用表明:流速测量结果准确可靠,准确度达0.5%FS。     

一种简易的径向位移引伸计

介绍了一种简易径向位移引伸计的结构及设计方法,根据其一次敏感元件的力学模型,推导了一次敏感元件的灵敏度。利用电阻应变测量技术,对自行设计的一套以65Mn薄钢片为一次敏感元件的引伸计进行了标定,实验表明:引伸计具有较高的灵敏度和线性度。与计算值相比,灵敏度误差仅为0.8%。该引伸计可用于内压循环弯曲管道及类似构件的径向变形的测量。     

中医传感针及配套多通道测量仪的研制

研制的中医传感针及其配套多通道测量仪用于实时、在体、同时测量中医经络上多个穴位点的温度、氧分压及pH值。测量的数据可有选择性地显示或送到上位PC机处理、存储。给出了该传感针的设计原理、测量仪的硬件结构及典型的测量方法和结果。测试结果表明:留针后穴位的温度基本上不随时间变化,而氧分压和pH值则在一定时间内会随着时间的增加而改变,最后,趋于稳定。     

Anomalous wear behavior of MoS2 films in moderate vacuum and dry nitrogen

440C steel thrust ball bearing races lubricated with 1 m thick sputtered films of MoS₂ were tested in the unidirectional and oscillatory modes against bare steel balls in moderate (10^–4–10^–5 Pa 10^–6–10^–7 Torr) vacuum and in 1 atmosphere of 99.999% pure ( 1 ppm water) N₂ in the same unbaked environmental chamber. Over 90% of the residual gases in the chamber vacuum consisted of H₂O vapor. The bearings operated in N₂ showed substantially longer lives compared to the specimens tested in vacuum. Scanning electron microscope (SEM) tribometry was also performed on an MoS₂ film powder-burnished onto a 440C flat. This flat was repeatedly oscillated against bare, hemispherical-tipped 440C pins on fresh wear tracks in the same type of N₂ and column vacuum of ~10^–3 Pa 10^–5 Torr itself containing over 90% residual H₂O. The SEM-generated results on the burnished film confirmed the same, atmosphere-dependent difference in wear life observed with the sputtered layers. Varying the moisture content of the burnished flat and its immediate environment by cryosorption predictably manipulated the coefficient of friction and wear life of MoS₂. The various possible causes of this perplexing phenomenon are reviewed, and a plausible hypothesis is offered attributing the unexpected wear life reduction to the physico-chemical consequences of residual H₂O hydrogen-bonding to the oxidized and/or hydrated edge and basal plane sites of MoS₂ in moderate vacuum. The site-specific sorption of water is severely hindered in 1 atm N₂ by the gas molecules disrupting the H-bonding mechanism.     

扁平绕带容器轴向与环向强度试验研究

扁平绕带容器是我国首创的具有良好发展前景的一种高压容器。本文进行了扁平绕带容器轴向强度试验研究，根据钢带层间摩擦力，导出了与实测值相当吻合，计算简便，易于工程应用的轴向，环向爆破压力计算公式。并从理论上阐明了现有几种环向爆破压力公式之间的内在联系，为实现轴向，环向等强度设计提供了理论依据。     

Freeze substitution of high-pressure frozen samples: the visibility of biological membranes is improved when the substitution medium contains water

Biological membranes are often poorly visible with the electron microscope after high‐pressure freezing and freeze‐substitution. The water content of the sample and of the substitution medium is one factor among others that strongly influences membrane visibility. In order to investigate this effect, high‐pressure frozen yeast cells, rat‐pancreas tissue and arthropod tissue were freeze‐substituted with and without adding water to the substitution medium. The visibility of the biological membranes was generally improved if the substitution medium contained 1–5% water. The effect was especially pronounced in yeast cells, where membrane visibility was poor after freeze‐substitution with water‐free medium but good after addition of 5% water to the substitution medium.     

试论切削液的发展方向

回顾了金属切削的工艺过程。切削液的主要作用是冷却和润滑，其效果反映在刀具的使用寿命上。影响刀具寿命的主要因素，是切削刀具的表面温度。水基切削液以其导热系数大、成本低，得到长足发展。由于环保要求日益严格，水基切削液的使用费由原来占生产费1％上升到12％～17％，水基切削液的价格优势不复存在。根据国内外的实验研究，切削油中加入极压剂，切削表面的摩擦下降60％～80％；加氢基础油黏度低、闪点高、蒸发损失少，为油基切削液低粘化创造了必要条件。油基切削液的研究和发展有广阔前景。     

高压氢气罐的裂纹成因分析及强度校核

对洛阳分公司炼油厂重整装置的四台储氢罐在进行压力容器检验时发现的裂纹进行了分析，认为是制造过程中形成的裂纹，并对这些裂纹进行了处理和强度校核。     

水合抛光加工的运动学特性

建立了旋摆驱动方式下水合平面抛光过程中工件的运动学模型,揭示了抛光盘开孔方式对蓝宝石衬底的水合抛光均匀性影响规律。旋摆驱动条件下,杉木抛光盘的开孔方式对蓝宝石衬底水合抛光加工全局均匀性和局部均匀性具有重要的作用,局部均匀性的阶梯状分布为直线、圆环和螺旋线开孔方式的共性特征。与直线、圆环开孔方式相比,在一定的参数取值条件下,螺旋线开孔方式可更好地实现水合抛光加工的全局均匀性和局部均匀性要求。