利用线阵CCD实现宽波段、大视场短脉冲激光波长的远场测量

介绍了一种利用线阵ＣＣＤ实现宽波段、大视场脉冲激光波长及方向远场测量的原理和实验装置；对强烈背景下激光信号的提取与处理方法进行了理论分析和实验研究，给出了系统信噪比与探测器件工作频率的理论公式；最后简要介绍了远场实验和测试结果     

试制STM-R80钻探用无缝钢管

采用42MnMo7、41MnV5钢锻坯,经热轧穿孔、冷拔加工,试制出STM-R80地质钻探管。该地质管经检验和使用,质量符合要求。介绍了钢的化学成分、试制的主要工艺过程及其参数。     

Three-temperature modeling of carrier-phonon interactions in thin GaAs film structures irradiated by picosecond pulse lasers

This article investigates numerically the carrier-phonon interactions in thin gallium arsenide (GaAs) film structures irradiated by subpicosecond laser pulses to figure out the role of several recombination processes on the energy transport during laser pulses and to examine the effects of laser fluences and pulses on non-equilibrium energy transfer characteristics in thin film structures. The self-consistent hydrodynamic equations derived from the Boltzmann transport equations are established for carriers and two different types of phonons, i.e., acoustic phonons and longitudinal optical (LO) phonons. From the results, it is found that the two-peak structure of carrier temperatures depends mainly on the pulse durations, laser fluences, and nonradiative recombination processes, two different phonons are in nonequilibrium state within such lagging times, and this lagging effect can be neglected for longer pulses. Finally, at the initial stage of laser irradiation, SRH recombination rates increases sufficiently because the abrupt increase in carrier number density no longer permits Auger recombination to be activated. For thin GaAs film structures, it is thus seen that Auger recombination is negligible even at high temperature during laser irradiation.     

Effects of Working Fluid,Tubeside Enhancement and Bundle Depth on the Optimized Fin Geometry of a Horizontal Condenser Tube

A theoretical study has been made to optimize the fin geometry of a horizontal finned tube which is to be usedfor condensers that handle the vapor load of a liquid phase change cooling module.Systematic numerical calcu-lations of the vapor to coolant heat transfer have been performed for parametric values of fin height,fin spacing,vertical bundle depth and tubeside heat transfer coefficient.Three dielectric fluids (R-113,FC-72,and FC-87)at atmospheric pressure were selected as the working fluids.For a single tube with optimized fin geometry,theaverage heat flux increased in the order of FC-87,R-113 and FC-72.Both the optimum fin height and optimumfin spacing increased with increasing vertical bundle depth.     

锅炉未焊透椭圆接管结构应力数值分析

应用有限元法对未焊透的椭圆接管结构进行了应力数值分析,并应用压力容器分析设计法,对该结构进行了疲劳分析,得出结构因未焊透缺陷导致疲劳破坏。     

石油套管的壁厚公差对承载能力的影响

石油套管的强度计算是按API标准进行的，它未能反映高强度套管和尺寸公差对抗压溃能力的影响。利用弹塑性力学理论建立理想的石油套管的抗压溃能力计算公式，并考虑套管的壁厚公差对计算公式进行修正。用该方法对受均匀载荷及非均匀载荷作用的套管进行分析，并同有限元计算结果相比，两者十分吻合，说明该方法的有效性。     

乙烯裂解炉对流段局部结构设计改进

介绍了乙烯裂解炉对流段的结构功能,各部件局部结构的改善设计。     

Metallurgical Investigation of a Prematurely Failed Concentric Reducer Tube Used in a Hot-Rolling Mill

A concentric reducer tube, which was a part of the top exit roughing hydraulic descaler in a hot strip mill failed prematurely under working pressure. A detailed metallurgical investigation comprising physical examination, optical microscopy, scanning electron microscopy, and electron probe microanalysis was carried out to find out the genesis of the failure. Physical examination revealed cracks located symmetrically around the circumference of the tube that ran along its full length, up to the weld beads at both ends. Optical microscopy of etched samples revealed a banded ferrite-pearlite structure and the existence of forging folds near the change-in-section(160° fillets). Cracks were found to initiate from these forging folds. No structural abnormalities were found in the weld beads and heat-affected zones.     

城市供水管网漏损探讨

就漏损控制这一项复杂的系统工程，详细地介绍了我国城市供水管网的漏损现状，分析了进行漏损控制产生的效益，造成漏损的主要原因及防治措施，提出漏损量的大小是衡量供水管网技术技术和运行的重要指标。