利用空间多普勒调谐技术冷却原子及其速度单一化

本文理论计算了用圆锥管内多次全反射激光而产生的多普勒频移来冷却原子束的机制。给出了最佳冷却原子束的圆锥管的夹角、长度、反射次数及激光入、出射角等参数。理论计算了原子束经过圆锥管冷却的速度分布情况。数值计算结果表明：采用两个长１３０ｃｍ的锥形管来冷却原子束，选用合适的失谐量可使极大部分速度小于１２００ｍ／ｓ的原子冷却到８ｌｍ／ｓ，并且可得到单一速度的高亮度的原子束。     

高炉煤气喷水降温控制方法

用ＫＭＭ调节器根据温控偏差和喷水量计算两个调节参数，对水量调节阀进行开度调节来控制最终喷水量，从而达到准确有效控制布袋除尘器入口煤气温度的目的。     

PVC四通管注射模设计

介绍了PVC四通管注射模设计 ,阐述了弯型芯的旋转抽芯过程以及模具顶出、回程及冷却系统设计。实践证明 ,该模具结构合理 ,生产的塑件可以满足设计要求     

高瓦斯矿井复合顶板炮采工作面瓦斯治理

结合该矿采煤工作面实际情况,阐述了高瓦斯矿井复合顶板炮采工作面的关键技术处理措施,保证了煤炭的安全生产。解决了高瓦斯矿井复合顶板炮采工作面瓦斯治理难的问题。     

电传动装甲车辆冷却系统水路性能试验研究

根据电传动装甲车辆冷却系统高低温双泵双循环设计要求,通过台架联机试验全面测试了冷却系统双循环水路及各循环支路温度变化和水流量分配特性、发电机绕阻温度变化规律及低温循环水路工作性能,测试结果表明:发电机冷却水路与发动机循环水路串联可行,双循环水路及各循环支路水流量和进出口温度变化满足动力系统不同工作状态散热要求,所选部件匹配合理,达到设计要求.     

蒸发式冷凝在制冷工艺上的应用

分析对比制冷工艺中几种冷凝方式，指出发展蒸发式冷凝技术对制冷系统节能的重要意义；通过分析蒸发式冷凝的换热机理，在试验和实践的基础上讨论了影响蒸发式冷凝器性能的几个重要因素。     

Z900MCM综述

介绍了Z900 MCM设计和布局,可控塌陷芯片连接(C4)工艺在Z900 MCM组装中的应用。从设计上通过加入垂直电感器及去耦电容器减小其噪声。通过基板测试和功能测试,剔除有缺陷的基板和芯片。Z900 MCM采用先进的MCM—D技术和MCM返工及冷却技术。Z900 MCM平均无故障时间高达40年。     

灯泡贯流式机组发电机冷却装置技术改造方式的探讨

灯泡贯流式发电机组直径小,转速低,发电机的通风冷却是一个难点。通过对京南、马骝滩、石面坦及南津渡等水电站的发电机运行过程中出现的温升过高,定子线棒绝缘受损等问题的分析,提出了解决的措施与改进方案,并对灯泡贯流式机组冷却系统的设计提出了建议,可供参考和借鉴。     

煤矿污染防治技术群及其评价

通过对枣庄矿区污染防治工作的调查研究，分析了煤矿开采对环境的影响，总结出当前煤矿污染防治的适用技术群，井对其相关问题进行评价。     

Effects of the cryogenic cooling on the fatigue strength of the AISI 304 stainless steel ground components

For environmental considerations, the substitution of the conventionally used oil-based grinding fluids has nowadays become strongly recommended. Although several alternatives have been proposed, cryogenic cooling by liquid nitrogen is the non-polluting coolant that has been given relatively more attention because of its very low temperature. In this investigation, in order to contribute to developing this promising cooling mode, its beneficial effects on the ground surface integrity of the AISI 304 stainless steel and their consequences on the fatigue lifetime are explored. Results of this investigation show that grinding under cryogenic cooling mode generates surfaces with lower roughness, less defects, higher work hardening and less tensile residual stresses than those obtained on surfaces ground under oil-based grinding fluid. These surface enhancements result into substantial improvements in the fatigue behaviour of components ground under this cooling mode. An increasing rate of almost 15% of the endurance limit at 2 × 10⁶ cycles could be realized. SEM analyses of the fatigue fracture surfaces have shown that the fatigue cracks observed on the specimens ground under cryogenic cooling are shorter (i.e., 30-50 μm) than those generated under oil-based cooling mode (i.e., 150-200 μm). The realized improvements in the surface integrity and in the fatigue behaviour are thought to be related to the reduction of the grinding zone temperature observed under cryogenic cooling, as no significant differences between the grinding force components for both cooling modes have been observed.