非晶硅太阳能电池的光学分析

我们采用一种新方法——光学导纳分析,把非晶硅太阳能电池看作由吸收膜和透明膜组成的多层膜系,计算了该膜系的光学导纳,分析了电池的光学性质。 电池吸收谱中存在干涉峰。通过考察各层膜光学参数对光吸收的影响,发现(ⅰ)高反射背接触的电池结构可增加0.6—0.7μm的吸收,(ⅱ)非晶硅膜厚能改变干涉峰在光谱中的位置;(ⅲ)减反膜(AR)与短波区的反射率密切相关,选择最佳AR膜厚能够减少反射损失;并且AR最佳膜厚几乎与非晶硅膜厚无关。     

Wilson lines in Chern-Simons theory and link invariants

The vacuum expectation values of Wilson line operators W(L) in the Chern-Simons theory are computed to second order to perturbation theory. The meaning of the framing procedure for knots is analyzed in the context of the Chern-simons field theory. The relation between W(L) and the link invariant polynomials is discussed. We derive an explicit analytic expression for the second coefficient of the Alexander-Conway polynomial, which is related to the Arf- and Casson-invariant. We present also some new relations between the HOMFLY coefficients.     

CoMnNiO非晶薄膜的热激电导

本文主要讨论CoMnNiO非晶薄膜的热激电导机制。     

用于半导体器件瞬态特性研究的大幅度矩形纳秒脉冲发生器

本文提出了一个用于半导体激光器和其他高速器件瞬态特性研究的大幅度矩形纳秒脉冲发生器的设计.为了产生一对极性相反的高速同步脉冲,在设计中采用了我国发明的新功能器件──双向负阻晶体管(BNRT).为了获得高速大电流主脉冲输出,采用了同时触发的双雪崩晶体管串联组合电路.所研制的发生器的主脉冲输出,其电压幅度高达200V(在50Ω负载)、峰值电流为4A、上升时间约2ns、宽度5-100ns、晃动小于50ps.而且输出脉冲波形呈良好的矩形,其过冲和顶部不平坦度均小于±3％.     

Synthesis of silatranyl- and 3,7,10-trimethylsilatranyl-cyclopropanes

Treatment of silatranyl- and 3,7,10-trimethylsilatranyl-ethylenes with diazomethane/Pd(OAc)₂ gives the corresponding silatranylcyclopropanes in high yields.     

ESAS—功能强大的大区联网集群系统

本文分析了ＥＳＡＳ集群系统的信令格式，硬件结构和软件特点，并介绍了该系统灵活的组网特性，丰富的移动台功能和广域调度功能等。     

Hg_(1-x)Cd_xTe反型层子能带结构的实验研究

本文在4.2K下测定了液相外延HgCdTe MIS结构样品的电容谱,磁阻振荡以及迴旋共振效应,并从实验测量结果,采用物理参数拟合法,确定了该样品在电量子限条件下反型层电子子能带结构,包括基态子能带能量E_o、费密能级E_F,子能带电子有效质量m~*(E_F)、m~*(E_o)、反型层平均厚度Z_i、耗尽层厚度Z_d,以及它们随子能带电子浓度N_s的变化。     

Al_xGa_(1-x)As_ySb_(1-y)/GaSb的LPE生长与性质研究

在GaSb衬底上用LPE法生长了晶格匹配的AlGaAsSb外延层。用室温光致发光和X射线双晶衍射分别测量了材料的禁带宽度和晶格常数,并与用内插法计算的结果进行了比较。用C-V和van der Pauw法测量了样品的电学参数。用激光喇曼散射和低温光致发光研究了材料的光学性质,观察到了类GaSb的LO模和类AlSb的LO模以及LO声子与等离子激元的耦合模L_-;对x=0.2,y=0.025的样品,由低温到室温的变温光致发光测量确定的禁带宽度的温度系数为-3.2×10~(-4)eV/K。此外对于晶格失配,P型的原因以及PL谱峰的展宽等问题进行了讨论。     

The Prandtl number effect near the onset of Bénard convection in a porous medium

This note focuses on Kladias and Prasad's claim that the critical Rayleigh number for the onset of Bénard convection in an infinite horizontal porous layer increases as the Prandtl number decreases, and argues that the critical Rayleigh number (Ra_c) depends only on the Darcy number (Da), as linear stability analysis indicates. The two-dimensional steady-convection problem is then solved numerically to document the convection heat transfer effect of the Rayleigh number, Darcy number, Prandtl number, and porosity. The note concludes with an empirical correlation for the overall Nusselt number, which shows the effect of Prandtl number at above-critical Rayleigh numbers. The correlation is consistent with the corresponding correlation known for Bénard convection in a pure fluid.     

Effects of oxidation and surface roughness on contact angle

Contact angle is known to be a parameter that effects boiling. This study was undertaken to measure contact angle of high and low surface tension fluids on copper and aluminum surfaces.Data were taken for polished, oxidized, and rough surfaces. A simple, yet fairly accurate method of measuring the static equilibrium contact angle of a solid/liquid interface is presented. The principles of a line light source and tilting plate were modified and then combined in the design of this apparatus. The angles obtained and their variation with the solid surface properties were in good agreement with previously published data. The contact angle of distilled water o of the organic fluids and refrigerants tested were in the range of 2–5°. Roughness and oxidation reduce the contact angle. If the depth of the roughness is less than 0.5 μm contact angle. The apparatus is fairly simple in construction, is inexpensive, and has good reproductibity. The measured angles were then compared to those measured with the sessile drop method.