共查询到20条相似文献,搜索用时 109 毫秒
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A. V. Vizir E. M. Oks M. V. Shandrikov G. Yu. Yushkov 《Instruments and Experimental Techniques》2003,46(3):384-387
The design, operating features, and parameters of a bulk plasma generator based on a steady-state low-pressure discharge with the additional injection of electrons from an external emitter are described. An additional constricted-arc discharge plasma is used as an electron emitter. This type of a discharge system ensures the formation of a homogeneous and stable gas plasma with a concentration of up to 2 ×1010 cm–3 in a volume of 1 m3 at a pressure of up to 3 × 10–4 Torr in a vacuum chamber. At a discharge current of up to 10 A, its voltage is 100–150 V. The device is characterized by a high efficiency of the energy utilization and a long service life, can operate with chemically active gases, and is easy to adjust and maintain. 相似文献
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An analytical program was conducted to establish recommended types of gas-lubricated journal bearings for use in miniature cryogenic turbomachinery. Very high rotative speeds, and the limiting damping properties of gas, indicated that fractional frequency whirl is prevalent, and the most difficult problem to overcome. Of the many journal bearing types investigated, the tilting pad hydro-dynamic and porous hydrostatic journal bearings were suited to the application. A novel spring mounted, three shoe, porous hydrostatic bearing is discussed in terms of design and experimental results. A 1/2 inch diameter journal bearing is subjected to loading and speeds to 700 grams and 65,000 rpm, respectively. Excellent performance in terms of load capacity, power loss, and flow are indicated. Orbit motions of the floated bearing with respect to the supported shaft demonstrate desirable stability characteristics for the range of tests. 相似文献
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O. V. Karpov V. N. Krutikov V. D. Kutovoi S. V. Sherstobitov 《Instruments and Experimental Techniques》2003,46(6):776-779
A rectangular-pulse generator based on a Josephson chip is described. An array consisting of 512 nonhysteretic Josephson junctions connected in series and pumped by a 10-GHz-microwave oscillator is used. The sampling step and maximum amplitude depend on the used chip and pump frequency, and are 0.04 and 10 mV, respectively. The switching time is 600 ns with current control and 50 ns with the microwave power modulation. 相似文献
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多极触发起弧等离子体发生器实验装置分别对不同贮能水平、不同毛细管几何参数以及不同毛细管材料等情况进行放电实验研究及分析,可得出负载效率、最高温度、平均电阻等测量参数与贮能水平和毛细管几何参数之间的关系。 相似文献
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提出一种利用SOPC (System on a Programmable Chip)技术及DDS技术开发信号发生器的方法,只需用一片FPGA芯片加必要的外围电路就可以实现函数信号发生器的功能.所设计的信号发生器可以输出正弦波、三角波、矩形波3种波形,且矩形波的占空比可调.每种输出波形的频率最小值为1 Hz,最小步进值为1 Hz. 相似文献
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一种基于AD9850的超声波信号发生器 总被引:1,自引:0,他引:1
为满足海底沉积物声学特性的实验室测量,该文基于DDS专用芯片AD9850,设计了一种高精度可编程的超声波信号发生器。介绍了AD9850的基本原理和工作特点,给出了单片机与AD9850的硬件接口模块、功率放大电路模块。运用此信号发生器产生的超声波对海底沉积物柱状样品的声特性进行实验测量,并对实验结果进行分析。 相似文献
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《机械工程与自动化》2015,(6)
研究了基于AD9854的信号发生器的相关控制技术。以STC12LE5A56S2单片机为例,详细阐述了单片机对AD9854芯片的控制,以及PC机和单片机之间的串口通信技术。所设计的信号发生器可以利用上位机通过串口对下位机进行控制,实现数据的发送和接收,从而方便有效地控制AD9854的工作。该控制系统具有操作简单、实用性强、控制界面可视化等优点,具有一定的实用价值。 相似文献
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用AD7008构成可程控正弦波信号发生器 总被引:2,自引:0,他引:2
本文介绍一种以AD7008为核心的正弦波信号发生器.正弦信号的频率和幅度通过单片机来设定.AD7008的输出信号通过一个由MAX262构成的程控带通滤波器进行滤波处理,程控滤波器的中心频率f0和Q值由单片机根据正弦信号的频率来设定.DDS是近几年发展起来的新型频率合成技术,具有极为广阔的应用前景. 相似文献
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为避免因受到温度升高的影响而导致燃气发电机冷却风扇叶片发生断裂的故障,采用有限元仿真分析方法,并结合工程实际情况,对上述问题进行了调查和分析,同时对破裂表面进行研究得出破裂是高周期疲劳造成的结果.仿真技术应力的计算表明,该应力小于叶片材料的疲劳耐力极限,这些应力和力都不会导致断裂. 相似文献
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A. V. Balovnev I. G. Grygoryeva G. Kh. Salakhutdinov 《Instruments and Experimental Techniques》2018,61(1):91-93
A single-channel compact (ø5 × 10 mm) noise-immune spectrometer has been developed for measuring X-ray spectra of micropinch-discharge plasma in the energy range of 1?25 keV using the filter method. The spectrometer is based on an array of lithium fluoride LiF thermoluminescent detectors placed in series, which are also used as filters for X-ray spectrum selection. 相似文献
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Li Song Fan Peng Gao Jingming Yang Hanwu Chen Dongqun Qian Baoliang 《Instruments and Experimental Techniques》2022,65(5):759-765
Instruments and Experimental Techniques - A compact repetitive high-power pulse generator, which could be used for high voltage applications including high power microwave and low temperature... 相似文献