应力导致的薄栅氧化层漏电流瞬态特性研究

分别研究了FN隧穿应力和热空穴(HH)应力导致的薄栅氧化层漏电流瞬态特性.在这两种应力条件下,应力导致的漏电流(SILC)与时间的关系均服从幂函数关系,但是二者的幂指数不同.热空穴应力导致的漏电流中,幂指数明显偏离-1,热空穴应力导致的漏电流具有更加显著的瞬态特性.研究结果表明:热空穴SILC机制是由于氧化层空穴的退陷阱效应和正电荷辅助遂穿中心的湮没.利用热电子注入技术,正电荷辅助隧穿电流可被大大地减弱.     

固体介质中光速减慢现象的研究

利用均匀加宽介质中的光谱烧孔效应在红宝石晶体中观测到了最慢为27.55±0.05m/s的极慢光速. 且介质中光传输的群速度与激光的调制频率、激光光功率以及晶体的晶格方向有关. 调制频率越低、相互作用越强,介质中的光速越慢.关键词：光速减慢光谱烧孔红宝石     

LBO晶体的布里渊散射与弹性和压电系数的测量

简述了应用布里渊散射测量晶体的弹性和压电系数的方法,推导了C_2v点群晶体(100),(010)和(001)晶面内任意波矢方向的布里渊散射张量及声速各向异性方程.根据上述方法及结果,用180°散射测量了LBO晶体不同波矢方向的布里渊散射谱,得到了LBO晶体在特超声频率下所有独立的弹性和压电系数,并依此计算了该晶体的声速各向异性曲线.关键词：     

DyP5O14晶体的新相

本文首次观察到具有单斜I(P2₁/c)的DyP₅O₁₄晶体,并用光学显微镜,X射线结构分析和红外光谱等方法予以证明。DyP₅O₁₄在室温下存在着mmmF₂/m类铁弹体的单斜I结构,其铁弹相变温度为159±3℃。单斜I的DyP₅O₁₄的晶胞参数,a=8.62?,b=8.84?,c=12.82?,β=90.28°。这一发现是L_关键词：     

Bending Loss Calculation of a Dielectric-Loaded Surface Plasmon Polariton Waveguide Structure

Based on full 3D finite element method simulations, the transmission of a dielectric-loaded surface plasmon polariton waveguide （DLSPPW） based 1/4 circle is calculated for a 90° bend model and a 270° bend model, respectively. It is found that the 270° bend model gives almost pure bending loss while the 90° bend model contains additional coupling loss. The models are applied to deduce the loss and unloaded quality factor of DLSPPW based waveguide ring resonators （WRRs） and the results of the 270° bend model agree well with direct simulating results of the WRRs. Thus the 270° bend model gives a fast and simple way to calculate bending loss and it is helpful for WRR design because no wavelength scan is needed.     

Efficient C2-Symmetric Chiral Schiff Bases for Lanthanide-catalyzed Asymmetric Hydrogenation of Acetophenone

The finding of new chiral metal catalysts for enantioselective reactions has been the subject of many investigations in recent years1,2. Metal-catalyzed, especially transition metal-catalyzed asymmetric hydrogenation of prochiral ketones was an efficient …     

A Two-coordinate Copper(Ⅰ) Complex Constructed from Cyanuric Acid and 4,4′-Bipyridyl:Synthesis,Structure and Photoluminescence

A two-coordinate copper(Ⅰ)complex,Cu_2(bipy)(H_2L)_2(1)(H_3L=cyanuric acid,bipy=4,4'-bipyridyl),whichexhibits strong photoluminescence,has been synthesized under hydrothermal conditions and structurally character-ized by single crystal X-ray diffraction.The compound crystallizes in the monoclinic space group P2_1/n,with cellparameters:M_r=539.42,a=13.4806(5),b=4.5234(2),c=15.4952(8),β=105.526(3)°,V=910.39(7)~3,Z=2 and μ=3.52 mm~(-1).In the structure the two Cu(Ⅰ)ions are bridged by bipy to form a two-coordinate copper(Ⅰ)dimer.The adjacent dimer units are connected by hydrogen bonding interactions,resulting in 1D zigzag chainsalong the c axis.1 emits intense yellow light when excited with UV light.     

碲氢化钠与苯并咪唑盐的反应和醛的合成新方法

自1975年Barton首次制备了碲氢化钠以来,由于它是一种温和的选择性还原剂和良好的亲核试剂,并具有试剂易得、后处理方便等优点,在有机合成中的应用得到了迅速发展[1-5].例如,Barton等[1]用碲氢化钠对吡啶盐和异喹啉盐的季铵化的碳氮双键在碱性乙醇溶液中还原脱卤能生成加氢衍生物.本文则首次报道碲氢化钠对苯并咪唑盐还原脱卤生成苯并咪唑烷的反应.其合成路线如图示1所示:     

重力场中竖壁上水滴界面形状热力学平衡的稳定性分析

１前言水蒸汽在冷壁面上的冷凝方式有两种：膜状冷凝和滴状冷凝。由于工业生产的需要,对现行工业用冷凝器中膜状冷凝的研究,从理论模式到实际设计计算都已经达到相当完善的程度。滴状冷凝较之膜状冷凝是一种高效的换热方式,从１９３０年Ｓｃｈｍｉｄｔｅｔａｌ发现这种高效的换热方式以来,半个多世纪中进行过大量的研究工作。但由于滴状冷凝过程的复杂性,从理论模式的建立到工业化应用都没有取得实质性进展。本文在文献［１］的基础上继续从热力学观点,分析在重力作用下,疏水性竖壁上生成的水滴界面形状的热力学平衡稳定性,建立了相…