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31.
M.M. Glazov 《Solid State Communications》2007,142(9):531-535
Spin dynamics of two-dimensional electron gas confined in an asymmetrical quantum well is studied theoretically in the regime where the scattering frequency is comparable with the spin precession frequency due to the conduction band spin splitting. The spin polarization is shown to demonstrate quantum beats. If the spin splitting is determined by both bulk and structural asymmetry mechanisms the beats are damped at zero temperature even in the absence of a scattering. We calculate the decay of spin beats due to the thermal broadening of the electron distribution function and electron scattering. The magnetic field applied along the structure growth axis is shown to increase the frequency of the beats and shift system towards the collision dominated regime. 相似文献
32.
L. G. Glazov 《JETP Letters》2007,86(2):98-101
Simple but very general formulas determining the parameters of the statistical distribution of inelastic energy losses (in particular, their most probable values) by relativistic ions as functions of the velocity and path length in a substance have been derived on the basis of the generalization of the classical Landau approach and steepest descent method. These expressions are more accurate than the well-known formulas and significantly expand the domains of applicability of the latter. Comparison with the numerical results confirms the high accuracy of the resulting analytical representations in wide intervals of the parameters and reveals their limitation. 相似文献
33.
针对航空胶片冲洗机控制困难表现其电机负载不均匀,低速运行情况下电机震动剧烈.研制了专用的反馈控制系统.以双89C51单片机为核心组成控制电路,编写了系统操作程序和数字PID控制程序.对PID参量对控制系统稳定性的影响进行了分析,得出适应于本系统的PID控制规律,并经过大量的试验,获得了能使各档速度稳定运行下的PID控制参量.实践表明,该控制系统运行稳定可靠,低速控制准确度在3%以内,中高速准确度达到1%. 相似文献
34.
35.
Y. Jongen M. Abs W. Kleeven S. Zaremba A. A. Glazov S. V. Gurskiy O. V. Karamyshev G. A. Karamysheva N. A. Morozov 《Physics of Particles and Nuclei Letters》2011,8(4):386-390
Compact superconducting isochronous cyclotron C400 [1] has been designed at IBA (Belgium) in collaboration with the JINR (Dubna). This cyclotron will be the first cyclotron in
the world capable of delivering protons, carbon and helium ions for therapeutic use. 12C6+ and 4He2+ ions will be accelerated to 400 MeV/u energy and extracted by electrostatic deflector, H2+ ions will be accelerated to the energy of 265 MeV/u and extracted by stripping. It is planned to use two normal conducting
RF cavities for ion beam acceleration in the cyclotron C400. Computer model of the double gap delta RF cavity with 4 stems
was developed in the general-purpose simulation software CST STUDIO SUITE. Necessary resonant frequency and increase of the
voltage along the gaps were achieved. Optimization of the RF cavity parameters leads us to the cavity with quality factor
about 14000, RF power dissipation is equal to about 50 kW per cavity. 相似文献
36.
Sparse asymptotic minimum variance based bearing estimation algorithm for a single vector hydrophone
For underwater target detection using a single vector hydrophone, sparse asymptotic minimum variance(SAMV) method is used to estimate the target bearing. The SAMV discretizes the entire scanning space and the target bearing is located at the position of the discrete direction. The SAMV algorithm utilizes the sparsity of the spatial signal to improve the estimation performance of the target bearing. Background noise level(BNL) of the bearing estimation of SAMV algorithm is lower than those of the conventional beam forming(CBF)method and minimum variance distortionless response(MVDR) method for different signal noise ratios(SNRs). When the SNR is higher than 0 d B, the direction-finding error of this algorithm is less than 2°. Moreover, the SAMV algorithm has a better dimensional orientation resolution capability. The experimental results show that the SAMV algorithm gives a bearing and time recording map with a lower BNL, which effectively verifies the effectiveness of SAMV algorithm in terms of underwater target detection. 相似文献
37.
分别采用全多孔型硅胶基键合强阴离子交换柱与氨丙基键合硅胶柱,在低波长 200 nm 处检测,分离测定了磷霉素 探讨了流动相条件,如p H 值、离子强度等对磷霉素保留及分离选择性的影响,优化分离条件,建立了一种测定磷霉素的高效液相色谱新方法方法简便、快速 相似文献
38.
G. B. Manelis S. V. Glazov D. B. Lempert E. A. Salgansky 《Russian Chemical Bulletin》2011,60(7):1301-1317
The works studying filtration combustion of solid fuels in the countercurrent mode are reviewed. The phenomenon of superadiabatic
overheating is described. The data of experimental and theoretical studies and some results of the development of technological
processes of production of thermal or electric energy from substandard raw materials and extraction of valuable components
(for example, rare metals) from unconventional sources (industrial wastes, poor ores, burrows, etc.) are presented. The processes of safe treatment of problematic wastes are considered. 相似文献
39.
利用提升小波从蛋白质序列中提取出它们相互作用的频谱特征,经支持向量机训练学习后,用于预测蛋白质间的相互作用.模拟计算结果表明,在阳性数据和阴性数据平衡的前提下,利用提升小波获取的低维蛋白质相互作用特征向量可以得到较高预测精度.进一步阐述了不同物种的蛋白质相互作用网络有着不同特征,为了得到更准确的预测结果,需要利用不同的方法提取蛋白质相互作用的特征. 相似文献
40.
一种新的自动调焦方法—离轴探测法 总被引:2,自引:0,他引:2
本文提出了的种新的自动调焦方法——离轴探测法,此法没用任何附加元件,结构简单、装调容易、线性度好、灵敏度高、调焦范围大、实用性强;介绍了此法的原理、理论计算结果及实验结果;给出了应用实例. 相似文献