On the web

One problem with the kudos and allure attached to the term ‘nano’ is that, inevitably, it’s included in the abstracts and titles of so many papers. The same is true for news stories, policy reports, and funding agency announcements. As a result, searching for information often brings up thousands of hits, and it is a far from simple task to narrow them down.     

On the influence of vacuum on the design and characterization of MEMS

The article will be focused on the influence of vacuum on resonant micro electromechanical sensor and actuator systems (MEMS). The system’s encapsulation with a pressure below atmospheric pressure plays a key role in the sensor performance especially in the field of vibration sensors. These sensors are becoming increasingly important for structural health or wear state monitoring in many engineering applications. Structural health, wear states and damage levels can be recognized by means of the vibration spectrum generated by propagating sound waves in solid materials known as ‘acoustic emission’. Commonly the vibration spectrum is measured by wide band accelerometers and subsequent Fourier transformation. Alternatively mechanical vibrations can be detected by resonant sensor systems. In particular these can be arrays of tiny cantilevers with multiple fixed Eigenfrequencies or single resonators with tunable Eigenfrequencies. Advantages of resonant pick-up compared to wide band sensors are the inherent spectral filtering and signal amplification in the mechanical domain due to the high quality factor at resonance. Therefore, an important design parameter is viscous damping of moving silicon cantilevers in the surrounding gas (e.g. air). The theoretical background of fluid-structural interactions and methods for experimental characterization of damping properties at atmospheric pressure and in evacuated environment will be presented. Measurements using a vacuum wafer prober for electrostatic actuation and optical motion sensing were conducted.     

钢液炉外精炼设备真空系统的设计分析

本文综合一些国内外有关资料，讨论了钢液炉外精炼设备真空系统设计中的一些技术问题，对放气量的确定、真空系统的气体负荷的等效换算以及真空泵容量的选择和能源消耗等进行了分析。给出蒸汽喷射泵的抽气能力与真空度的关系，可作为钢液炉外精炼设备的真空系统设计时参考。（注：1 Torr=133Pa）     

真空玻璃

通过理论计算及测试数据,说明真空玻璃具有良好的保温(隔热)性能,良好的隔声性能及防结露性能,节能效果明显;介绍真空玻璃"一步法"生产工艺流程及主要技术装备;论述目前制约真空玻璃推广应用的三大瓶颈(安全、价格、自动化)以及突破瓶颈的途径;指出:借鉴中空玻璃的发展经验,积极开发满足不同需求的真空玻璃新品种,将推动真空玻璃产业发展得更好,更快.     

真空技术在真空排污系统中的应用

真空排污系统是利用负压管道中的负压梯度将用户处排放的污水逐步输送、收集至真空站后集中处理及排放的污水收集系统。综述了真空排污系统的分类及适用范围,真空的获得及真空检漏测试的标准。介绍了真空排污系统中用户终端的形式和关键阀件。简述了真空排水管网的输送机理。比较了不同的真空罐排放方式及其技术关键。     

真空油炸技术

真空油炸是一种越来越受欢迎的食品加工技术，凭借自身的优点表现出广阔的发展前景。本文集中介绍了真空油炸的原理、工艺特点和生产流程，尤其针对真空油炸设备的加热、油炸、脱油、搅拌方式等进行了综合的分析和比较。     

真空绝热板导热系数与板内真空度关系研究

以理论模型计算和实验样品测试相对比的方法,研究了两种不同芯材真空绝热板导热系数与板内真空度之间的关系,利用逆真空法对真空绝热板板内压力进行了测试.探讨了真空绝热板制作工艺参数,保持板内真空度及延长使用寿命的方法.     

真空开关电弧形态的实验研究

真空电弧形态的研究对真空开关能否有效控制和保护电路有着重要的影响.本文设计了真空开关电弧实验系统,建立了基于高速摄像设备CMOS的真空开关电弧采集系统.通过该采集系统可以每秒200,000帧采集速度得到了真空开关电弧图像.实验结果表明,真空开关电弧起始处于扩散形态,随着电流的增大,电弧月逐渐集聚,并产生阳极斑点,峰值电流过后再次转变成扩散形态,最终在阴极表面形成很多阴极斑点,做高速运动并数量不断减少至电弧完全熄灭.     

On the theory of viscosity vacuum gauges

Developments in the theory of viscosity gauges of the moving ribbon or fibre type for operation at low pressure (in the region of large mean free paths) are critically reviewed. It is shown that a relatively recent refinement has been to take more realistic interactions between the gas molecules and the moving surface into account, though the effect on the gauge constant does not differ greatly from some of the earliest calculations in the literature.     

网页界面优化设计的分析与研究

网络是现代化的、最能影响人们生活方式的信息传媒系统.以感性工学理论为指导,针对网页界面优化设计的相关文献进行整合探讨,并在此基础之上进一步分析论述了网页界面优化设计的内容、方法,为设计学理论与计算机技术相结合的网页界面优化设计构建了科学的设计方法体系.     

立式往复真空泵的结构设计

本文介绍了立式往复真空泵的结构设计.采用了阀门轴向布置结构,合理设计了泵的气阀、弹簧力、密封、平衡通道结构,选择了易磨损部件的材料.实践表明,所设计的真空泵在提高真空度、降低功耗和提高零部件寿命方面取得了令人满意的效果.     

真空下皮革鞣制工艺的研究

介绍了皮革真空转鼓的结构、鞣制机理及其应用;通过正交试验分析了真空条件下皮革鞣制工艺,分别以收缩温度、皮内的Cr2O3含量、C2O3的吸收率为考察指标,讨论了各因素对不同指标的影响;将收缩温度(95℃)及Cr2O3的吸收率结合作为考察指标,得到了真空条件下鞣制的优化工艺.结果表明:鞣制时间越长,铬粉用量越大,皮革的收缩温度越高.综合考虑收缩温度及Cr2O3的吸收率,鞣制时间越长综合得分越高.     

On the thermal contact resistance under vacuum

The author analyzes the heat exchange under vacuum between two bodies whose adjoining surfaces are in contact at discrete spots uniformly spaced along parallel and equidistant zones. The theoretical values of the thermal contact resistance are compared with experimental data.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 17, No. 5, pp. 951–957, November, 1969.     

石英真空计的设计

本文提出一种用特性曲线设计石英真空计的方法.实验发现,在一定的条件下,与石英晶振串接的电阻尺上的电压UBC与气体压强P有一定的函数关系.这个电压UBC经过放大、检波与调节后的读数V与气体压强P的关系V-P曲线称特性曲线.实验证明该曲线具有很好的稳定性和重复性.用该曲线可以测量气体压强.     

真空厕所终端控制系统的研究

真空厕所在国内属于新型的环保厕所,具有节水、臭气少、冲刷效果好等优点。针对真空厕所终端设备的控制进行研究,对其工作原理、总体结构、关键技术、面临的问题及其解决方法等作了详细的分析和阐述。     

真空绝热板热工性能的研究

介绍真空绝热板的构造及加工工艺，对其高效绝热热工性能进行理论分析及实验数据测试，运用数理统计及计算机数值模拟的方法分析其热工性能随自身参数及制造工艺的变化规律，提出产品生产、施工及使用中应注意的问题和改进的意见。     

往复真空泵的参数化设计系统开发

介绍了基于SolidWorks的往复真空泵参数化设计方法。以VB为二次开发工具,开发了往复真空泵的参数化设计系统。该系统分为三大功能模块,能很好地实现参数化和自动化。举例介绍了系统完成参数化设计的方法与步骤。系统对完成总图装配起到事半功倍的效果,提高了产品的设计效率。     

A vacuum arc plasma source with extended design

A vacuum‐arc plasma source having an extended design, operating in pulse regime and generating directed conveyer‐type flow was created and investigated. The identified regularity of development of arc discharge allowed controlling generation modes of the plasma source, providing the secure fixation of the cathode spots on the working surface and accelerated conversion of the cathode in the working mode. In this case each stage of development of arc discharge is determined by the conditions of existence of the cathode spots on the working surface of the cathode.     

罗茨真空泵运行可靠性指标考核探讨

目前罗茨真空泵验收规范中采用零流量压缩比和最大允许压差来考核罗茨真空泵的性能。本文作者根据实际应用及可操作性,建议采用零流量压缩比和罗茨真空泵的排气口气体温度考核罗茨真空泵的性能。由于零流量压缩比的测量与现在的测量方法没有多大区别,因此本文没有详细讨论。     

凝水器对真空冷却效果的影响分析

以水为对象作了多组实验，对真窀冷却机理进行探讨并对盘管热负荷进行了分析，文章指出真空预冷过程中凝水器盘管温度可能升高。研究表明，当凝水器盘管温度很低时可以关闭制冷机以节约能源。