共查询到16条相似文献,搜索用时 390 毫秒
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利用微型制冷技术的最新成果,设计和制作了一台适用于高温超导微波子系统的脉冲管制冷机.制冷机冷头微振动精密测量表明,这台脉冲管制冷机冷头的最大振动比商品化的传统制冷机要小1~2个数量级左右.首次成功地将特殊设计的高温超导谐振腔与上述制冷机组成实用电子学子系统.实验表明,在同样条件下器件在传统制冷机(斯特林机)内出现的噪声,在脉冲管制冷机中完全消失,充分表明了脉冲管制冷的优越性,显示了由脉冲管制冷机与高温超导器件组成的实用电子学子系统的潜在应用前景. 相似文献
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窄线宽稳频激光器在工业生产控制中具有广泛的应用,但自由运转的半导体激光器的频率漂移限制了激光器的使用。为稳定半导体激光器的频率,提出了一种基于二次谐波吸收特性来实现窄线宽二极管激光器的稳频新方法,利用1.396 μm的DFB二极管激光器测量水汽的二次谐波信号来实现激光的稳频,实验结果表明在100 h内激光器输出波长漂移有效的抑制在±0.16 pm范围内,激光稳频后,其吸收峰的位置不随环境温度的变化而漂移。该方法具有简单、可靠等优点,对二极管激光频率的稳定具有广阔的应用前景。 相似文献
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Jin-Ping Xu 《International Journal of Infrared and Millimeter Waves》1994,15(12):2061-2068
Harmonic injection locking behavior of millimeter wave second harmonic Gunn oscillators is studied based on an equivalent circuit model. A large signal model of Gunn device in harmonic mode operation is employed. Injection locking curves of voltage amplitude and phase difference between injected current and harmonic voltage are calculated by means of describing function technique. Stability of the locked harmonic oscillators is also investigated. It is revealed that the harmonic locking bandwidth is much smaller than that of fundamental wave oscillators and is closely related to the susceptance slope parameter of fundamental wave circuit. It is also found that the stable region is smaller than that of fundamental wave oscillators. Some conclusions have been made for the application of harmonic injection locking technique. 相似文献
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基于小型低温制冷机的高温超导材料超导转变温度测量装置 总被引:1,自引:0,他引:1
高温超导材料的超导转变温度是判断超导材料性能优劣的一个重要指标,而超导材料转变温度的测量一般采用输运方法进行电阻随温度变化来确定.本文介绍一种新近研制的基于低温制冷机的高温超导材料超导转变温度测量装置,能有效的将样品温度从室温连续均匀的降至35K,通过Lab VIEW编写的数据采集系统人机界面,采用电流换向技术消除热电势,可以准确测量出超导材料的超导转变温度.经实验验证,该测量装置测量精确和重复性良好,可作为有效判定高温超导材料性能优劣的一种手段. 相似文献
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K. V. Kalashnikov A. A. Artanov L. V. Filippenko V. P. Koshelets 《Physics of the Solid State》2016,58(11):2191-2195
The regimes of operation of a superconductor–insulator–superconductor tunnel junction based on three-layer structures Nb/AlOx/Nb and Nb/AlN/NbN as a harmonic mixer (for frequencies of the order of 600 and 20 GHz, respectively) and a frequency up-converter (in the frequency range from 0.1 to 5.0 GHz) have been investigated experimentally. The quasiparticle and Josephson mixing regimes have been compared. It has been shown that, in some practical applications, such as the use of the superconductor–insulator–superconductor junction as a cryogenic harmonic phase detector, the Josephson mixing regime is more preferable, because it can provide a higher signal and a greater signal-to-noise ratio as compared to the quasiparticle mixing regime. It has also been demonstrated that the Josephson mixing regime is promising for the use in signal multiplexing systems for superconducting detectors. 相似文献
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Daming Wang 《International Journal of Infrared and Millimeter Waves》1995,16(12):2097-2101
This is a brief account of a design of the digital frequency meter applied to mm wave techniques. In measurement of frequency by the method of oscillatory absorption, it has two harmonic mixing systems instead of the usual single harmonic mixing system. 相似文献
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最近发现的水合钴氧化物超导体在某些方面具有与高温超导体十分相似的性质.本文报道含有高浓度的水合氢离子的钴氧化物超导体的超导电性磁测量结果.通过对样品的M(H,T)的测量,得到了大致的H~T相图.最后还讨论了系统中可能存在的2D-3D转变. 相似文献