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The results of studying the magnetomechanical effects in classical superconductors are analyzed. The energy losses are determined,
and a number of macroscopic parameters are calculated using a developed model. The studies of superconductors by the method
of rotation of a body suspended without contact are described. The results obtained are analyzed, and the values of some parameters
are determined. 相似文献
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亲水性材料固相萃取-紫外导数光谱法检测血中茚满二酮灯抗凝 … 总被引:6,自引:1,他引:5
本文报导了血中茚满二酮类抗凝血杀鼠剂敌鼠、氯敌鼠、杀鼠酮的亲水性材料固相萃取-紫外导数光谱检测法。血样用pH5缓冲液等体积稀释后加于西雷脱硅藻土柱上,柱用乙酸乙 酯洗脱,将洗脱液挥发干净,剩余物用pH10缓冲液溶解,测定所得溶液的二阶导数光谱进行定性和定量分析。三种杀鼠剂以10mg/L的量加于空白血中测得萃取率为85%以上,血中三种杀鼠剂的检出限低于2mg/L。萃取中亲水性硅藻土可用硅胶和氧化铝代替, 相似文献
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超光谱成像仪红外系统热控技术研究 总被引:2,自引:1,他引:1
介绍了超光谱成像仪红外系统的应用价值,总结了红外系统在光学元件、焦平面器件、光机结构等不同部分的热控需求。通过主动热控与被动热控的比较,阐述了超光谱成像仪红外系统热控策略,并且归纳了适合其要求的热控技术。其中针对红外系统焦平面热控,对辐射制冷和机械制冷进行了比较,并简要介绍了斯特林制冷机。最后总结了目前超光谱成像仪红外系统热控的关键问题。 相似文献
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用于高速数据通信的梯度塑料光纤 总被引:1,自引:0,他引:1
概述了梯度塑料光纤的开发历史和现状。从应用于高速数据通信的角度 ,介绍了聚甲基丙烯酸甲酯(PMMA)、全氘化和全氟化梯度塑料光纤的损耗、带宽、稳定性和寿命。详细介绍了梯度塑料光纤的损耗光谱和损耗机制 ,介绍了制作梯度塑料光纤的界面凝胶聚合技术和两种扩散法 ,分析了梯度塑料光纤的制作方法同折射率剖面和带宽的关系 ,讨论了梯度塑料光纤的稳定性同掺杂物质的关系。同时介绍了高稳定性梯度塑料光纤的研究进展及今后的发展动向 相似文献
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The dynamic characteristics of one blade, two discs and one shrouded, bladed disc, having 87 blades, are predicted by the application of the finite element method of analysis. The discs are modelled by using both annular and sector elements. The blades are modelled by means of shell elements. The shrouds are represented by both lumped masses and straight beam elements. The predicted frequencies are compared with experimental results. 相似文献
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单轴晶光轴干涉图成因的理论分析 总被引:1,自引:0,他引:1
借助于数学工具和一种简单的实验装置,用直观的方法,使理论分析和图形相结合,从理论上解释了单轴晶光轴干涉图的成因,并给出了在白光照射下的干涉花样。搭建了实验光路,结果表明:若用单色光照射,干涉图为明暗相间圆环;若用白光照射,则为一个套一个的环状等色曲线。愈向视域边缘,干涉色级数愈高,等色曲线的数目愈多,密度愈大,表示晶体的双折射率愈大。实验结果与理论分析相吻合。 相似文献
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《中国光学快报(英文版)》2015,(8)
The inclusions in conventionally grown KD2PO4(DKDP) crystals are investigated. The inclusions are captured by a light-scattering technique. The sizes are determined by an optical microscope and a transmission electron microscope(TEM), and the compositions are analyzed by time of flight secondary ion mass spectrometry(TOF-SIMS) and an energy dispersive spectrometer(EDS). Two kinds of inclusions are observed in the DKDP crystals: a submicron-scale inclusion and a micron-scale inclusion. The typical submicron-scale inclusions contain growth solution, and their sizes range from tens to hundreds of nanometers, whereas the micron-scale inclusions contain growth solution and the metal element Na, and the sizes are tens of microns. The possible formation mechanisms of the inclusions are discussed, and the influence of the inclusions on laser-induced damage behaviors are analyzed and discussed. 相似文献
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利用基于密度泛函理论的第一性原理方法,研究了掺杂铁、钴和镍原子的锯齿型磷烯纳米带(ZPNR)的磁电子学特性.研究表明,掺杂和未掺杂ZPNR的结构都是稳定的.当处于非磁态时,未掺杂和掺杂钴原子的ZPNR为半导体,而掺杂铁或者镍原子的ZPNR为金属.自旋极化计算表明,未掺杂和掺杂钴原子的ZPNR无磁性,而掺杂铁或者镍原子的ZPNR有磁性,但只能表现出铁磁性.处于铁磁态时,掺杂铁原子的ZPNR为磁性半导体,而掺杂镍原子的ZPNR为磁性半金属.掺杂铁或者镍原子的ZPNR的磁性主要由杂质原子贡献,产生磁性的原因则是在ZPNR中存在未配对电子.掺杂位置对ZPNR的磁电子学特性有一定的影响.该研究对于发展基于磷烯纳米带的纳米电子器件具有重要意义. 相似文献
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The spin-wave excitations in anisotropic Kondo lattice model are studied using the spin Green's function. Both the ferromagnetic and antiferromagnetic cases are considered. The equations to determine the spectrum of low-energy excitations are given. The anisotropy gaps are obtained, and the long-wavelength and strong-coupling limits are analyzed. 相似文献
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介绍了EAST离子回旋共振加热系统调制型高压电源的总体设计方案,详细讨论了电源模块的构造、电路和工作原理,对电源控制保护系统的组成部分及其功能做了全面的论述,对电源的调制和短路保护能力进行了实际测试,给出了相应的实验数据和波形,证明了电源设计方案的正确性和可靠性。 相似文献
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The natural frequencies of liquid in a liquid-filled cylindrical rigid tank without and with baffles are evaluated. An annular plate is used as a baffle, which is fitted to the inner periphery of a cylindrical tank. Both rigid and flexible baffles are considered. Finite elements are used to discretize both the liquid and the structural domain. The slosh frequencies of liquid are computed for different dimensions, thicknesses and positions of baffles, both rigid and flexible considering the circumferential wave number as one. The axisymmetric and other asymmetric modes are not studied. The results obtained for rigid baffle case are comparable with the existing results. The coupled vibration frequencies of the tank-flexible-baffle system are computed considering the effect of sloshing of liquid. 相似文献
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Rodney Loudon 《物理学进展》2013,62(66):243-280
The contributions of magnons to the optical properties of antiferromagnets having the rutile structure are discussed. The properties considered are electric-dipole active two-magnon absorption in the infra-red, and magnon sidebands on sharp-line exciton transitions in the visible. The discussion is based on a thorough treatment of the properties of excitons and magnons in the antiferromagnetically ordered state. The site-group and space-group symmetries of the magnetic excitations are derived and the selection rules for electric and magnetic dipole transitions are determined. The occurrence of magnetic Davydov splittings of the excitons is investigated, and their symmetry properties throughout the Brillouin zone are derived. The functional dependences of exciton energy on wave vector are calculated. Applications of the theory are made to experimental results on excitons and magnons in MnF2, FeF2 and CoF2. The possible mechanisms for two-magnon and magnon-sideband absorption are discussed, and the influence of crystal symmetry on these mechanisms is described. The two-magnon state responsible for electric-dipole absorption is identified and selection rules for electric-dipole activity are presented. A spin Hamiltonian for the two-magnon process is set up and used to derive expressions for absorption coefficients for electric vector parallel and perpendicular to the crystal c-axis. Comparison with experiment for MnF2 yields numerical values for the parameters of the basic coupling mechanism. The exciton-magnon states which give rise to magnon-sideband absorption are explicitly constructed and electric-dipole selection rules are derived for all possible types of sideband. Spin Hamiltonians for the various magnonsideband absorption processes are presented and used to derive expressions for sideband shapes. The results are applied to the experimental spectra for MnF2 and FeF2 and the sideband shapes in MnF2 are calculated numerically. The sideband shapes observable in emission spectra are also briefly discussed. 相似文献