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41.
利用现代材料生长技术纳米厚的半导体可以沿着良好的方向有序生长,形成层状半导体纳米结构.在这种半导体纳米结构中由于结构反演对称性破缺出现较强的自旋-轨道耦合,能有效消除半导体中电子的自旋简并,导致电子自旋极化效应,在自旋电子学领域中具有重要的应用.本文从理论上研究了单层半导体纳米结构中由Rashba型自旋-轨道耦合引起的电子自旋极化效应.由于Rashba型自旋-轨道耦合,相当强的电子自旋极化效应出现在该单层半导体纳米结构中.自旋极化率与电子的能量和平面内波矢有关,尤其是其可通过外加电场或半导体层厚度进行调控.因此,该单层半导体纳米结构可作为半导体自旋电子器件应用中的可控电子自旋过滤器. 相似文献
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基于多联机系统性能试验平台,作了多联机内机过滤器堵塞实验,测试了过滤器的堵塞对内机过滤器温差、蒸发过热度及制冷量的影响。实验得出,过滤器发生堵塞将导致过滤器前后出现温差且蒸发过热度异常偏大两个典型特征并严重影响制冷效果。该结论能为自动化监测和判断系统的控制策略和控制算法提供有效依据。 相似文献
43.
A 1550-nm linearly tunable continuous wave single-mode external cavity diode laser based on a single-cavity all-dielectric thin-film Fabry Pérot filter 下载免费PDF全文
A 1550-nm linearly tunable continuous wave (CW) single-mode external cavity diode laser (ECDL) based on a singlecavity all-dielectric thin-film Fabry-Pérot filter (s-AFPF) is proposed and realized in this paper. Its internal optical components as well as their operation mechanisms are introduced first, and then its longitudinal mode output characteristic is theoretically analyzed. Afterwards, we set up the experimental platform for the output characteristic measurement of this tunable ECDL; under different experimental conditions, we execute accurate and real-time measurements for the output central wavelength, output optical power, output longitudinal mode distribution, and the line-width of the tunable ECDL in its tuning process. By summing up the optimal experimental condition from the measured data, we obtain the optimal tunable ECDL relevant parameters: the tunable ECDL has a linear mode-hop-free wavelength tuning region of 1547.203 nm-1552.426 nm, a stable output optical power in the range of 40 μW-50 μW, and a stable output longitudinal mode distribution of a single longitudinal mode with a line-width in the range of 100 MHz-150 MHz. This tunable ECDL can be used in environmental gas monitoring, atomic and molecular laser spectroscopy research, precise measurements, and so on. 相似文献
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Suppose M and N are two r × r and s × s dilation matrices,respectively.Let ΓM and ΓN represent the complete sets of representatives of distinct cosets of the quotient groups M-TZr/Zr and N-TZs/Zs,respe... 相似文献
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A multilayer fiber bundle is used to couple the image in a remote sensing imaging system.The object image passes through all layers of the fiber bundle in micro-scanning mode.The malposition of adjacent layers arranged in a hexagonal pattern is at sub-pixel scale.Therefore,sub-pixel processing can be applied to improve the spatial resolution.The images coupled by the adjacent layer fibers are separated,and subsequently,the intermediate image is obtained by histogram matching based on one of the separated image called base image.Finally,the intermediate and base images are processed in the frequency domain.The malposition of the adjacent layer fiber is converted to the phase difference in Fourier transform.Considering the limited sensitivity of the experimental instruments and human sight,the image is set as a band-limited signal and the interpolation function of image fusion is found.The results indicate that a super-resolution image with ultra-high spatial resolution is obtained. 相似文献
46.
We prove some versions of modular convergence theorems for nonlinear Urysohn-type integral operators with respect to filter convergence. We consider pointwise filter convergence of functions giving also some applications to linear and nonlinear Mellin operators. We show that our results are strict extensions of the classical ones. 相似文献
47.
The laser spectroscopy of alkali-metal vapor is widely used in a number of applications, such as the Faraday anomalous dispersion optical fil- ter (FADOF), the active optical clock, and wavelength references.Is' The Cs electrodeless dis- charge vapor lamp has rich spectra, including 455 nm, 459 nm, 728 nm, 852 nm, 1359 nm, and 1470 nm. The 852 nm laser pumping atoms from 6S1/2 to 6P3/2 have been used in FADOF.The 1359nm wave- length transited from 7S1/2 to 6P1/2 of Cs atoms can be used in the field of active optical clocks. The concept of active optical clocks has been proposed since 2005. Due to its good performance in sta- bility, the active optical clock has been extensively in- vestigated theoretically and experimentally in recent years, such as the two-level active optical clock, and three-level active optical clock. When considering the performance of the active optical clock, we hope to reduce the second-order Doppler shift in thermal atomic beam and the light shift induced by the pump- ing laser. To solve this issue, our group has recently proposed a four-level active optical clock, such as K 1252.2nm, Cs 1469nm, Rb 1366.9nm and Rb 728 nm. Moreover, the Rb 728 nm four-level quantum system has potentially a better performance than three long wavelength ones of Rb. 相似文献
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张登兵 《数学的实践与认识》2010,40(18)
期望均衡是博弈局中人或局外人对于博弈均衡点的一致期望,强调互利共赢,它要求博弈群体的每个成员对期望均衡点有一个共同的预期.显然,基于纳什均衡的帕累托优化组合策略是一个比纳什均衡更有效的期望均衡.要实现期望均衡,可采用局中人参与的训练与学习使得群体的预期一致,也可采用第三方过滤器来达到期望目标.在期望均衡的概率分布下,个体行为的偏离不能比均衡态取得更多收益.否则,训练就是无效的,第三方过滤器就是不公平的. 相似文献