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上海光源二期工程建设计划研制一台多极超导扭摆器用于生物医学的X射线成像及治疗。该多极超导扭摆器由21对NbTi超导线圈组成,磁极气隙为22mm,在储存环束流电子能量为3.5GeV时其特征能量为33keV,覆盖的能量范围为20keV到120keV,可用于K边吸收成像、衍射增强成像、相衬成像、CT和微束放射治疗。文中的主要内容为一个具有21个磁极,周期长度为140mm,气隙中心磁感应强度为4.2T的多极超导扭摆器的磁场设计,包括磁极和线圈的参数设计、端部结构和周期磁场的积分场设计,以及简要的超导线圈应力应变分析。 相似文献
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廖于翔唐跃进任丽王壮 《低温与超导》2017,(5):29-33
目前的失超检测的方法多针对超导线圈的直流工作状态。在交流损耗等实验研究及部分电力应用中,超导线圈将工作在交流通流状态。为了保障这种情况下超导线圈的安全,需要进行交流失超检测方法的研究。设计了用于高温超导线圈交流通流的失超检测方法,将桥路交流电压信号转换为直流信号后,对工作在交流通流情况下的超导线圈的失超状态进行判断。通过搭建实验平台进行了相关的实验。实验结果显示,采用这种方法能够有效地对工作在交流情况下的超导线圈进行失超检测。 相似文献
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EAST装置做为全超导托卡马克装置,其纵场和极向场线圈全部由超导磁体组成,所以进行安全,准确,有效的超导线圈的失超保护是装置安全运行的首要环节.由于等离子体电流的建立必须由极向场线圈系统提供极快速的磁通变化,随之产生较高的交流损耗使得极向场线圈很容易发生失超.如何对快速交变脉冲磁场下的超导线圈进行有效的失超检测,这在世界上也无先例可循.EAST装置的失超检测系统经过几十轮单饼超导线圈实验及多轮装置正式放电实验后逐步建立和完善起来,并已通过工程验收满足了装置实验运行要求.本文主要介绍了EAST装置失超检测系统的基本结构和检测原理,重点阐述了极向场超导磁体失超检测的设计方法及实验结果。 相似文献
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提出了第三代同步辐射光源中的低温超导电流扭摆器和室温水冷电流扭摆器的物理设计方案。文中还讨论了电流扭摆器内腔中的磁场的分布特性,测量方法和电流扭摆器的制造技术的可行性。 相似文献
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合肥扭摆器光源的特性和利用 总被引:2,自引:0,他引:2
国家同步辐射实验室正在设计和制造一台6T单周期超导扭摆器,把合肥同步辐射光源的可用范围延伸到X射线,满足部分X射线用户的要求,利用扭摆器光源装备四条光束线,分别用于X射线吸收精细结构,生物大分子晶体多波长反常衍射,X射线深度光刻和高分辩X射线衍射的研究。 相似文献
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针对地面最小操纵速度试飞的光电测试需求,提出一种基于机载摄影测量与地面光电跟踪测量相结合的光电测试方法。简要介绍了地面最小操纵速度试飞光电测试系统设计;详细论述了系统标定、地面跟踪目标自动检测、基于机载摄影的飞机偏心距测量、基于光电跟踪测量的飞机航迹与速度测量等方法原理;总结了飞行试验测试实施流程;最后开展了飞行试验验证。试验结果表明,该方法有效可靠,可提供直观的飞机侧偏过程画面,实现飞机偏离跑道方向优于2 mm、高程方向优于2 cm和航向优于5 cm的定位测量精度,完全满足地面最小操纵速度试飞对光电测试数据的完整性、直观性和准确可靠性等要求。 相似文献
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Stanley Gudder 《International Journal of Theoretical Physics》1997,36(12):2681-2705
An effect test space, or E-test space, for short, is a generalization of a test space that is able to describe unsharp measurements.
Effects in an E-test space correspond to yes-no measurements, and observables correspond to general measurements that may
have more than two values. Sharpness, compatibility, and orthogonality of effects are considered. It is shown that every observable
is determined by its eigenvalues and eigeneffects. The spectrum of an observable is studied and special types of observables
are investigated. Orthocomplements and a natural local sum on an E-test space are introduced. Relationships between the resulting
structures and previously studied frameworks are presented. 相似文献
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Bashurin V. P. Budnikov I. N. Klevtsov V. A. Ktitorov L. V. Lazareva A. S. Meshkov E. E. Novikova I. A. Pletenev F. A. Fedorenko Ya. V. Yanbaev G. M. 《Technical Physics》2015,60(7):1093-1095
Technical Physics - Methods of laboratory modeling of 2D water flows in a rectangular channel are developed. The flow is produced in a vertical tube of a rectangular cross section when water flows... 相似文献
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Some of the factors which affect the noise attenuating properties of ear defenders have been investigated by using a commercial artificial ear embedded in a wooden head. The head can be adjusted in shape, hair length and contour in the area around the ear, where earmuff cushions seal to the head, to simulate variations in the wearers' heads. Measurements of earmuff attenuation have been made with a sequence of 20 different configurations of the adjustable head, and these have been compared with similar measurements using 20 human heads. To carry out these comparisons, a second microphone was sealed into four different designs of earmuff, to measure the noise inside these earmuffs when they were fitted to human heads and the adjustable head. For all four instrumented earmuffs, the mean and the standard deviation 0f the attenuation in each 1 /3-octave band between 40 Hz and 10 kHz measured On the adjustable head compared favourably with results from the same earmuffs tested On the 20 human heads. 相似文献
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《Physica A》2005,355(1):176-182
Copulas are often used in finance to characterize the dependence between assets. However, a choice of the functional form for the copula is an open question in the literature. This paper develops a goodness-of-fit test for copulas based on positive definite bilinear forms. The suggested test avoids the use of plug-in estimators that is the common practice in the literature. The test statistics can be consistently computed on the basis of V-estimators even in the case of large dimensions. The test is applied to a dataset of US large cap stocks to assess the performance of the Gaussian copula for the portfolios of assets of various dimension. The Gaussian copula appears to be inadequate to characterize the dependence between assets. 相似文献
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For a given pure state of a composite quantum system we analyze the product of its projections onto a set of locally orthogonal separable pure states. We derive a bound for this product analogous to the entropic uncertainty relations. For bipartite systems the bound is saturated for maximally entangled states and it allows us to construct a family of entanglement measures, we shall call collectibility. As these quantities are experimentally accessible, the approach advocated contributes to the task of experimental quantification of quantum entanglement, while for a three-qubit system it is capable to identify the genuine three-party entanglement. 相似文献
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现役运载火箭一体化测发系统的单任务测试模式,已无法满足运载火箭的高密度、快速测发的需求。通过控制软件多线程设计实现多任务控制的并行处理;使用分布式执行终端,同步完成并行测试功能。设计具有包含多任务信息的通讯协议,实现并行测试信息的网络传输。利用软件的共享缓存技术实现多任务之间的信息交互。在信息传输中通过字节流模式进行先进先出的实时通信,保证了运载火箭测发的实时性。通过对一体化测发系统的并行测试研究,可实现一套测发控系统对箭上多个子系统同时进行测试。
并行测试技术的研究利用了计算机系统并行处理能力,通过测发软件的并行设计,实现可由用户控制的多任务并行测试系统,提高了运载火箭的测试效率和节省测试费用,是解决运载火箭高密度、低成本发射的一种技术途径。 相似文献