自控温电伴热材料在仪表测量管线上的应用

文章就化工自动化仪表测量管线的伴热问题,介绍了自控温电伴热材料的特点、伴热设计、施工方案以及运行中的注意事项。     

稠油井注汽系统的热效率分析

建立了热采注汽系统热效率的计算模型。根据XX油田数据计算了2个注汽系统的热效率。提出了提高注汽系统热效率的三项措施：（1）降低锅炉的过剩空气系数；（2）按最大允许热损失设计地面输汽管线的保温层厚度；（3）使用视导热系数小的隔热油管，按箍增加隔热结构，防止热封隔器的泄漏等。     

Silicon power MOSFET at low temperatures: A two-dimensional computer simulation study

Understanding how the structure of the unit-cell affects the cryogenic performance of a Si power Metal Oxide Semiconductor Field Effect Transistor (MOSFET) is an important step toward optimizing of the device for cryogenic operations. In this paper, numerical simulations of the Si power Double Diffused MOSFET’ (DMOS) are performed at room temperature and cryogenic temperatures. Physically based models for temperature dependent silicon properties are employed in the simulations. The performances of power DMOS’ with various unit-cell structures are compared at both room temperature and low temperatures. The effect of the cell structure on the on-resistance and breakdown voltage of the device are analyzed. The simulation results suggest that the device optimized for room temperature operation can be further optimized at cryogenic temperatures.     

Spectral Feature Analysis of Semiconductor Thin Disk Laser

The semiconductor thin disk laser is a new type of semiconductor laser. This work gives the basic operation function of the semiconductor disk laser, and analyses the heat effect by the experimentally measured photoluminescence spectrum of the laser chip at different pump power and different temperatures. We can see that: with increasing pump power, the thermal effect of the gain material becomes seriously and causes the saturation of carrier lifetime, so the electron-hole pair created in the absorbtion lay...     

西安地铁区间隧道通过地裂缝带的施工方案

通过对西安地铁区间隧道通过地裂缝的特点分析,提出了几种地铁区间隧道通过地裂缝的方法,指出地铁结构采用这些方法能够适应地裂缝的变形发展,并在地裂缝活动的情况下维持地面交通和地铁的正常运营。     

Direct evaluation of singular integrals in elastoplastic analysis by the boundary element method

This paper presents a new method for the direct and accurate evaluation of strongly singular integrals in the sense of Cauchy principal values and weakly singular integrals over quadratic boundary elements in three-dimensional stress analysis and quadratic internal cells in two-dimensional elastoplastic analysis by the boundary element method. A quadratic triangle polar co-ordinate transformation technique is applied to reduce the order of singularity of the singular integrals. Next, a form of Stokes' theorem is introduced in order to remove the singularity in the Cauchy principal value integrals; therefore, the evaluation of these integrals can be carried out by standard Gaussian quadrature. Numerical examples of 2-D elastoplastic problems and a 3-D elastic problem show the effectiveness and efficiency of the method.     

隧道式中药材干燥机

通过对我国中药材干燥现状及主要问题的分析，阐述了一种能应用于广大农村地区的隧道式中药材干燥机。着重讨论了电加热器、隧道和物料小车的设计问题，确定了合理的结构参数。性能试验表明，该机适用于各类中药材的干燥作业。     

泰钢950四辊平整机液压APC及弯辊控制系统的特点

结合工作实践，介绍了泰钢950四辊平整机液压APC及弯辊控制系统的控制模式、控制原理、系统组成、系统特点等。     

绿色环保型水-乙二醇抗燃液

介绍了环保型水一乙二醇液压液的发展状况及性能特点，对比了环保型水－乙二醇液压液与其它润滑材料的生物降解性，表明这类水－乙二醇液压液是极具发展的环境友好型的抗燃液介质。     

Ni|MH二次电池负极用贮氢合金的研究发展

本文详细综述了近年Ni MH二次电池负极用贮氢合金的研究发展概况。依次阐述了AB5、AB2与Ni Ni基、V Ti基固溶体合金以及Mg Ni合金的电化学性能。讨论了改善电化学性能的一些方法 ,同时给出目前一些研究成果