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排序方式: 共有309条查询结果,搜索用时 15 毫秒
91.
92.
研究了一种基于InGaAs/InP多量子阱的全光偏振开关,讨论了相空间填充(PSF)效应引起的激子饱和以及光学非线性,计算了在抽运光下的阱中载流子布居数随时间的变化,推导出了探测光偏振态的主轴瞬态旋转角.计算结果表明,在100 pJ飞秒脉冲抽运下该全光开关理论旋转角最大可达60°. 相似文献
93.
研究了Ce填充分数对富Co组成的填充式skutterudite化合物:CeyFe1.5 sub>Co2.5Sb12(y=0—0.46)的热电传输特性的影响.CeyFe1.5Co2.5Sb12有现为p型传导.霍尔系数RH sub>随Ce填充分数的增加而增加,空穴浓度p和电导率σ随Ce填充分数的增加而减少.泽贝克 系数α随Ce填
关键词:
填充分数
载流子浓度
电导率
泽贝克系数
晶格热导率 相似文献
94.
95.
A novel, fully-analytical design sensitivity formulation for transient, turbulent, free surface flows is derived and implemented in the context of finite element analysis. The time-averaged, turbulent form of the Navier–Stokes equations are solved using a mixing length model, in conjunction with the volume of fluid (VOF) method to model the free surface movement. The design derivatives of these governing equations are computed and solved to find the analytical sensitivities of the fluid position, velocity and pressure fields with respect to shape design variables. The computational efficiency produced by evaluating the sensitivities analytically is demonstrated. The design of the runner and gating system of a simple block casting is presented as an example application for using sensitivity information in design. The analytical sensitivity routine is coupled to a numerical optimizer to yield an automated method for optimal design of the casting rigging system. The results produce runner shapes which eliminate mold-gas aspiration. © 1998 John Wiley & Sons, Ltd. 相似文献
96.
Summary Separation of the enantiomers of a variety of basic drugs by affinity capillary electrophoresis has been investigated using
α1-acid glycoprotein (α1-AGP) as chiral selector. In order to use a high concentration of α1-AGP without causing low detection sensitivity, the partial filling technique was employed. Enantiomer separations were performed
under conditions (a running buffer at pH 5.0 or 6.0) causing the protein to migrate toward the injection end. Twenty nine
basic racemates were successfully separated by optimizing the protein concentration, buffer pH and organic modifier. α1-AGP obtained from three different suppliers was used to investigate differences among the proteins from different sources.
Although most of the racemates were similarly separated with any of the three types of α1-AGP, some racemates, e.g. acebutolol behaved differently with the three types. The reasons for the different enantioselectivities
of the three types of α1-AGP has not yet been clarified. The method was used to test the optical purity of commercial sulpiride enantiomers and it
was found that the method was suitable and applicable for the purpose. 相似文献
97.
A. K. Ghosh W. B. Sampson S. W. Kim D. Leroy L. R. Oberli M. N. Wilson 《Physica C: Superconductivity and its Applications》1998,310(1-4):335-339
The relative stability of LHC type cables has been measured by the direct heating of one of the individual strands with a short duration current pulse. The minimum energy required to initiate a quench has been determined for a number of cables which have a central core to increase the effective inter-strand cross-over resistance. Experiments were performed in both normal helium at 4.4 K and superfluid at 1.9 K. Conductors in general are less stable at the lower temperature when measured at the same fraction of critical current. Results show that the cored-cables, even when partially filled with solder or with a ‘porous-metal' filler exhibit a relatively low stability at currents close to the critical current. It is speculated that the high inter-strand electrical and thermal resistance inherent in these cables may affect the stability at high currents. 相似文献
98.
波纹圆孔光栏的衍射及其设计 总被引:2,自引:1,他引:1
详细研究了波纹光珠菲涅耳衍射特征,提出并论证了调幅正弦波纹光栏级在较大的菲涅耳数范围内有效地抑制光束中央部分的衍射调制,并给出这类波纹光栏用于高功率光系统的设计程序。 相似文献
99.
Analytical solution of the fundamental space filling mode of photonic crystal fibers 总被引:1,自引:0,他引:1
Yan-feng Li Ching-yue Wang Zi-han Wang Ming-lie Hu Lu Chai 《Optics & Laser Technology》2007,39(2):322-326
Analytical solution of the fundamental space filling mode of photonic crystal fibers is revisited based on previous results by Midrio et al. [J Lightwave Technol 2000;18(7):1031–7]. The fundamental space filling mode is designated HE11 mode following the conventional mode classification. A comparison is made between the vectorial method and the scalar method when identical parameters are used in the analytical solution. A more accurate radius of the equivalent circular unit cell is determined. 相似文献
100.
V. P. Korkhov Ye. A. Faitelson T. I. Glaskova Yu. O. Jansons 《Mechanics of Composite Materials》2005,41(4):365-370
Properties of a model composite based on an ED-22 epoxy binder, cured with polyprophylene polyamine, and disperse LiF crystals as a filler were investigated by the methods of dilatometry and X-ray diffractometry. It was established that the density of cross-links of the epoxy binder in the interphase layer was lower than in a block specimen. Therefore, the thermal expansion of the composite on heating to 120°C, in terms of that of the binder, grew significantly with the degree of filling ϕ, and the water uptake also increased at the initial stage. The presence of absorbed water led to considerable changes in the structure and properties of the composite interphase: the binder became more cross-linked, its structural ordering decreased, the thermal expansion at heating diminished by a factor of 3. 7 (at ϕ = 50%), and the glass-transition temperature increased. As a result of long-term action of moisture, changes in the internal stresses had an extreme character.__________Translated from Mekhanika Kompozitnykh Materialov, Vol. 41, No. 4, pp. 535–544, July–August, 2005. 相似文献