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随着二代高温超导带材从实验室走出,二代高温超导带材进入商业化大规模生产和应用阶段.针对不同的应用场景对热学、电学和力学性能的特殊要求,需要对二代高温超导带材匹配不同的后处理工艺,例如分切、镀铜以及封装等.为了解决现有常用封装材料(紫铜和不锈钢)各自的短板,本文采用铜合金材料封装,详细对比了铜银合金与黄铜与现有常用封装材料在超导带材稳态过电流能力和轴向拉伸性能的差异.发现铜银合金封装的二代高温超导带材的综合性能优于紫铜封装和不锈钢封装的二代高温超导带材.本文的研究也为实际应用中二代高温超导带材的选型提供参考. 相似文献
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超导滤波器、超导卫星接收机和超导气象雷达的研究进展 总被引:7,自引:0,他引:7
近年来,国际上高温超导微波器件的应用取得了重大突破,国内的高温超导微波应用也取得了重要进展.文章回顾了中国科学院物理研究所在探索具有高性能的高温超导滤波器以及同一芯片上不同类型超导滤波器的集成等方面的一些进展,其中部分滤波器分别在相对带宽(优于0.25%)、返回损耗(优于-22.5dB)、带边陡度(例如大于140dB/MHz)、指定频段的抑制(超过110dB)等方面显示了优异的性能.对于在国内进行的首次高温超导滤波器空间环境模拟试验、首次使用高温超导滤波器子系统的卫星接收机前端地面试验和首次使用高温超导微波子系统的气象雷达的现场试验,文章也做了介绍. 相似文献
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本文在双面YBCO高温超导薄膜上设计并制备了两节大功率超导滤波器,根据滤波器功率承载能力与最大电流密度之间的关系,减小电流密度和分散电流密度的分布是提高功率承载能力的关键.本文采用增加超导谐振器尺寸、优化几何结构及改进馈线耦合方式的方法,设计了两节2 GHz频段梭型谐振器结构的滤波器.设计及测量结果显示了馈线结构及谐振器几何尺寸优化程度对超导滤波器功率承载能力有不同程度的影响,说明了在大功率超导滤波器设计中应选用无结点间隙耦合式馈线以抑制电流密度的聚集.采用优化后的谐振器结构制备的梭型两节超导滤波器经测试功率承载能力为2 W.超导滤波器的尺寸为25×12 mm LaAlO3基片,中心频率2.022 GHz,相对带宽为2.4%.同时给出了超导滤波器功率测试的结构和方法. 相似文献
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研制了一种适用于超导子系统接收机前端的免调谐窄带高温超导滤波器.其中心频率为2287 MHz,带宽为8 MHz.该高温超导滤波器采用了10阶准椭圆(quasi-elliptic)函数型结构,并引入了2对改善带边陡度的传输零点.滤波器的计算机仿真是用Sonnet软件完成的.为了达到免调谐的目的,选用了一种结构简单的双折线型谐振器.此滤波器是在直径为2英寸、厚度约为0.5mm MgO衬底的双面超导薄膜上制作的.测量结果表明,该滤波器在未经调谐的情况下具有很好的性能:相对带宽0.35%,带外抑制>80 dB,插入损耗<0.2 dB,反射损耗<-15.5dB(通带7MHz范围之内). 相似文献
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简要描述了微通道板的工作原理,介绍了微通道板的主要特征性能及其工作参数,包括厚度、开口面积比、增益及增益均匀性、动态范围、噪声、工作寿命和空间分辨率等,阐述了这些特征性能和参数彼此间的相互关联和相互制约的特殊关系。在此基础上,对影响和制约微通道板名个特征性能和参数的特殊关系及因素作了详细分析。这项工作对进一步认识和协调处理微通道板的各种特征性能和参数有着非常积极的作用。 相似文献
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双波段激光防护多层反射膜的设计 总被引:1,自引:0,他引:1
利用TFCalc膜系设计软件,从理论上对激光防护多层反射膜的光学性能进行了分析。计算了各个膜系的理论投射率曲线。分析了各个因素(如膜系结构、膜层奇偶性、起膜材料)对膜层光学性质的影响。并设计了以ZrO2和SiO2为膜层材料,聚碳酸酯(PC)为基体材料,可以同时防护532nm和1064nm波长激光的1∶2型多层反射薄膜。在532nm和1064nm处的理论透过率都达到了0.01%(光学密度D=4)。并在PC镜片表面镀上23层1∶5型激光反射膜,对理论设计进行验证。对其在400nm~1200nm波长范围内的光学性能进行了测试,测试结果与理论计算值基本吻合。 相似文献
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Significant effect of electron transfer between current collector and active material on high rate performance of Li4Ti5O12 下载免费PDF全文
The rate and cycling performances of the electrode materials are affected by many factors in a practical complicated electrode process. Learning about the limiting step in a practical electrochemical reaction is very important to effectively improve the electrochemical performances of the electrode materials. Li4Ti5O12, as a zero-strain material, has been considered as a promising anode material for long life Li-ion batteries. In this study, our results show that the Li4Ti5O12 pasted on Cu or graphite felt current collector exhibits unexpectedly higher rate performance than on Al current collector. For Li4Ti5O12, the electron transfer between current collector and active material is the critical factor that affects its rate and cycling performances. 相似文献
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《Revue Generale de Thermique》1996,35(414):408-416
Influence of different technical, energetic and economic scenarios on the decision of installing a new heat exchanger. This article proposes to examine the decision of installing a new heat exchanger in a working industrial unit in order to improve its energy performances. This examination is based on a new graphical method permitting us to approach the decision while taking into consideration the operating, technological and conjunctural variables.The analysis of the results shows that improvement in energy performances of an industrial unit does not always contribute to improving its economic performances. Factors that govern this contribution are in increasing importance: the choice of heat exchanger's configuration, the energy scenarios, the energy to be saved and the choice of the construction material of the heat exchanger. 相似文献
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Abrasive is one of key influencing factors on the surface quality during the chemical mechanic polishing (CMP). α-Alumina particles, as a kind of widely used abrasive in CMP slurries, often cause to surface defects because of its high hardness. In the present paper, a series of novel alumina/silica core-shell abrasives in slurries were described. The CMP performances of the alumina/silica core-shell abrasives on hard disk substrate were investigated by using a SPEEDFAM-16B-4M CMP equipment. Experimental results indicate that the CMP performances are strong dependent on the coated SiO2 content of the alumina/silica composite abrasives. Slurries containing the alumina/silica composite abrasives exhibited lower surface roughness and waviness as well as lower topographical variations and less scratch than that containing pure alumina abrasive under the same testing conditions. 相似文献
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B H Repp 《The Journal of the Acoustical Society of America》1990,88(2):622-641
The timing patterns of 19 complete performances of the third movement of Beethoven's Piano Sonata op. 31, No. 3, were measured from oscillograms and analyzed statistically. One purpose of the study was to search for a timing pattern resembling the "Beethoven pulse" [Clynes, in Studies of Music Performance (Royal Academy of Music, Stockholm, 1983), pp. 76-181]. No constant pulse was found at the surface in any of the performances. Local patterns could be interpreted as evidence for an "underlying" pulse of the kind described by Clynes, but they could also derive from structural musical factors. On the whole, the artists' timing patterns served to underline the structure of the piece; lengthening at phrase boundaries and at moments of melodic/harmonic tension were the most salient features. A principal components analysis suggested that these timing variations in the Minuet could be described in terms of two orthogonal factors, one capturing mainly phrase-final lengthening, and the other reflecting phrase-internal variation as well as tempo changes. A group of musically experienced listeners evaluated the performances on a number of rating scales. Their judgments showed some significant relations to the measured timing patterns. Principal components analysis of the rating scales yielded four dimensions interpreted as force, individuality, depth, and speed. These preliminary results are encouraging for the development of more precise methods of music performance evaluation. 相似文献
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极紫外、软X-射线变线距平面光栅单色仪的研究 总被引:3,自引:2,他引:1
高性能极紫外、软X射线单色仪的研制对高亮度同步辐射光源的应用具有十分重要的意义。对Itou的变线距平面光栅单色仪作了详细的分析研究,发现它的光栅工作曲线几乎与单色仪的入、出射臂长度等参量无关,仅取决于单色仪设计的边界条件。其曲线方程和SX-700单色仪的完全类似。该单色仪不仅具有很好的光栅效率和高级次谐波抑制性能,而且有利于几条光束线共享一个电子储存环窗口的光路优化设计。 相似文献
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