The experiments show that ultrasonic motors can operate under vacuum condition , but the performance is different from that under general condition , its unloaded speed decreases significantly , while the stall - torque increases a bit 试验结果表明，超声电机可以在真空环境下工作，但性能较常态环境下有所变化，其空载转速明显下降，堵转力矩有所增大。
Aimed at the working characteristics of axial parts under high temperature and vacuum environment , this paper put forward a temperature controlling method for changing the partial thermal resistance of axial under the stable uneven temperature field 摘要针对高温真空环境下轴类零件的工作特点，提出了在稳定非均匀温度场下改变轴局部热阻的控温方法。
Testing research specifies that mpt can reliably start up for ar , he , n2 , h2 , and air under the vacuum condition , and that ignition is easiest with ar , than with n2 , and most difficult with he 实验研究表明，在真空环境下，对于推进剂工质ar 、 he 、 n _ 2 、 h _ 2和空气启动可靠。 ar最容易启动， n _ 2次之， he最难；微波功率越大，越容易启动；并且在一定真空度范围内最容易启动。
5 . experimental study on start - up , steady work and performance of mpt were completed first time in china . the performance curves of mpt were obtained and the influence of parameters such as microwave power , gas flux , etc . on performance was studied 在国内首次进行了mpt真空环境启动、稳定工作特性和性能实验，测取了mpt的性能参数曲线，研究了微波功率、工质气体流量等参数对mpt性能的影响。
The working principle of liquid helium cryocondensation pump is strong absorptive force between 4 . 2k cryogenic surface and gas molecules . the pump has great advantage in large instant pumping speed under high gas load , large working pressure range , high & neat ultimate vacuum 利用4 . 2k低温面对气体的物理吸附机制实现高气载下瞬时大抽速的液氦低温冷凝泵，具有工作压强范围宽、能获得清洁真空环境的特点。
In this thesis , the mechanism analysis and numerical simulation on the coupling flow field of microwave plasma within resonant cavity of mpt was discussed and the subsystem of small thrust measurement as well as the vacuum experimental study of mpt were completed 在航天飞行器上有广阔的应用前景。本论文对mpt微波等离子体耦合流场进行了机理分析和数值模拟，建立了mpt的小推力测量系统，协同进行了mpt真空环境实验研究。
A ppt test set has been made , and a measurement system of ppt ' s electric properties ( voltage and discharge current ) , isp and thrust has been established . measurement of electric properties of the ppt and its isp , thrust has been carried out 通过大量的研究工作，制造了脉冲等离子体推力器样机，设计并建立了地面真空环境下对于样机的放电参数（电压、电流变化）以及推力、比冲的测量环境，并对所研制的样机进行了电参数和比冲及推力的测量。
The ground tests of inflatable structures can hardly reflect real work environment in space because of the effect of gravity and atmospheric pressure . and tiny gravity and vacuum can hardly be satisfied at the same time . moreover , the cost of space testing is prohibitive expensive 空间充气展开结构的空间实验花费往往极为昂贵,而由于重力和大气压力的影响,充气结构的地面实验又很难模拟实际空间工作环境,微重力和真空环境也很难在较大空间内同时实现。
When an engine works under the vacuum condition . so existing experimental products can be proof - tested by it and all test results obtained will be used for reference for the aero craft . accordingly , the technology studied in the thesis is quite significative to improve the efficiency of the engines of space propulsion system , economize limited resources on the spacecrafts , and prolong their lives 其目的是建立一个能满足小推力液体火箭发动机动态推力测试的系统,以便能够根据空间推进系统对发动机越来越高的工作性能要求,真实有效地反映发动机在真空环境下的工作状态等,对已经设计和生产出的发动机在高空模拟条件下进行实际测试,从而提供发动机的动态性能指标,为发动机的定型提供试验数据和依据。
Our business scope includes research , development , design and production of following products : vacuum and high pressure equipment for environmental cleaning , parking and revenue control systems , vehicle emergency lights and sirens , audible and visual signaling , lighting , cable connectors , plugs and receptacles used for mining ; sale of the self - produced products ; and provision of technical service and technical consulting 经营范围为高压及真空环境清洁设备，停车场电子收费系统设备，车用警灯和警报器，可视和可听的信号灯和报警设备，矿用灯具、连接器、插头和插座的研究、开发、设计、生产；销售自产产品以及提供配套服务；技术服务和技术咨询。
