He-Ne绿色激光最佳增益条件的研究

获得了He-Ne543nm激光线小信号增益系数随放电管中氦氖气体的配比、总气压及放电电流的变化关系。找出上述三参数的最佳值,并做了最佳激光输出验证。     

A comparison of the diffusion of iodine into CdTe,Hg0.8Cd0.2Te and Zn0.05Cd0.95Te

Studies on the diffusion of iodine into CdTe, mercury cadmium telluride (Hg_0.8Cd_0.2Te, referred to as MCT) and zinc cadmium telluride (Zn_0.5Cd_0.95Te, referred to as ZCT) in the temperature range of 20 to 600°C are compared and discussed. The concentration profiles were measured using a radiotracer sectioning technique. As with the diffusion studies using the halogens into CdTe, the profiles were composed of four parts to which a computer package consisting of the sum of four complementary error functions (erfc) gave satisfactory fits. The diffusivity for the diffusion of iodine into MCT was faster than for the diffusion into CdTe, which was faster than for the diffusion into ZCT. The high diffusivity for the fastest profile part at 20°C indicates that when iodine is diffused from the vapor into these materials, it is not a suitable long term stable dopant in devices where sharp junctions are required.     

程控电话交换机过电流保护元件用高性能PTC陶瓷的研制

阐述了高性能ＰＴＣ陶瓷材料制备的基本要点，并以基方固溶体化学组成、原材料选择、复合添加物改性以及特定烧结工艺等方面开展工作，制得了居里温度为９０℃左右、室温体积电阻率为３０Ω·ｃｍ，电阻率突变ρνｍａｘ／ρνｍｉｎ＞１０５、电阻率温度系数α≈１５％／℃、耐电压强度≥１５０Ｖ／ｍｍ的高性能ＰＴＣ陶瓷材料。此材料制得的元件能满足程控电话交换机过电流保护的要求。     

Study of the numerical simulation of tight sandstone gas molecular diffusion based on digital core technology

Diffusion is an important mass transfer mode of tight sandstone gas. Since nano-pores are extensively developed in the interior of tight sandstone, a considerable body of research indicates that the type of diffusion is mainly molecular diffusion based on Fick’s law. However, accurate modeling and understanding the physics of gas transport phenomena in nanoporous media is still a challenge for researchers and traditional investigation (analytical and experimental methods) have many limitations in studying the generic behavior. In this paper, we used Nano-CT to observe the pore structures of samples of the tight sandstone of western of Sichuan. Combined with advanced image processing technology, threedimensional distributions of the nanometer-sized pores were reconstructed and a tight sandstone digital core model was built, as well the pore structure parameters were analyzed quantitatively. Based on the digital core model, the diffusion process of methane molecules from a higher concentration area to a lower concentration area was simulated by a finite volume method. Finally, the reservoir’s concentration evolution was visualized and the intrinsic molecular diffusivity tensor which reflects the diffusion capabilities of this rock was calculated. Through comparisons, we found that our calculated result was in good agreement with other empirical results. This study provides a new research method for tight sandstone digital rock physics. It is a foundation for future tight sandstone gas percolation theory and numerical simulation research.     

USED CARS测量对撞式扩散火焰的温度分布

介绍了用USED CARS技术测量对撞式甲烷/空气扩散火焰前滞止区和尾流区的温度分布剖面。在滞止区富甲烷边观察到甲烷燃烧前的热解过程;尾流区温度高于滞止区温度,表明在滞止区有未完全燃烧的中间产物存在,在尾流区发现C2及CH的光谱也证明了这一点。     

Tensile, creep, and ABI tests on sn5%sb solder for mechanical property evaluation

Sn5%Sb is one of the materials considered for replacing lead containing alloys for soldering in electronic packaging. We evaluated the tensile properties of the bulk material at varied strain-rates and temperatures (to 473K) to determine the underlying deformation mechanisms. Stress exponents of about three and seven were observed at low and high stresses, respectively, and very low activation energies for creep (about 16.7 and 37.7 kJ/mole) were noted. A maximum ductility of about 350% was noted at ambient temperature. Creep tests performed in the same temperature regime also showed two distinct regions, albeit with slightly different exponents (three and five) and activation energy (about 54.4 kJ/mole). Ball indentation tests were performed on the shoulder portions of the creep samples (prior to creep tests) using a Stress-Strain Microprobe^@ (Advanced Technology Corporation) at varied indentation rates (strain-rates). The automated ball indentation (ABI) data were at relatively high strain-rates; however, they were in excellent agreement with creep data, while both these results deviated from the tensile test data. Work is planned to perform creep at high stresses at ambient and extend ABI tests to elevated temperatures.     

基于单片机加压控制的PCD复合片真空扩散焊接

文章针对普通钎焊的聚晶金刚石钻头剪切强度不高，提出了采用单片机加压控制的PCD复合片真空扩散焊接的设计思想，在对原真空扩散焊机液压改造的基础上给出如何由单片机控制加压的电路和程序流程设计。实际应用表明，该技术经济实用，有较好的经济效益。     

调压装置的位置对TDS智能流量计测量结果的影响

在介绍该新型的TDS智能旋进流量计的基础上,针对某天然气输气站上出现的输差不正常的情况,介绍了该输气站将调压装置与流量计位置进行试探性交换的举措,并取得了较理想的改造效果。     

油藏数值模拟求解中的IMPIMS方法

在油藏数值模拟中对数值模型进行求解,目前基本有两类方法一类是顺序求解法,如IMPES方法和IMPIMS方法;一类是联立求解法,如半隐式法和全隐式法。IMPIMS方法是一种顺序求解方法,是IMPES和半隐式方法的混合变种。它既具有半隐式求解饱和度的特点,又保留了IMPES方法省内存,省计算工作量的优势。     

共同沟天然气管道泄漏报警的模型实验

所谓共同沟,即通常所说的地下综合管沟或管廊,是专门用于集中敷设各种市政管线的地下隧道。与传统直接埋地的敷设方式相比,共同沟是一种先进的敷设方式。按相似原理和“最不利原则”设计模型实验,采用甲烷模拟共同沟（狭长空间）中天然气管道的微小泄漏,分析了甲烷的泄漏量和模型的断面宽度对纵向布置的探头报警时间的影响,提出了“单宽泄漏量”的概念,并得出了模型实验的相似条件。根据实验数据的走势,采用抛物线函数进行数据拟合,最终得出报警响应时间的经验公式。