大功率倒装结构LED芯片热模拟及热分析

对功率型倒装结构发光二极管（LED）温度场分布进行了有限元模拟，与实测结果进行了比较，并结合传热学基本原理对模拟结果进行了分析。结果表明，凸点的形状及分布与芯片内部温差有着密切的关系，蓝宝石的厚度对芯片内部温差也有一定的影响。同时，对倒装结构与正装结构的热阻进行了比较。

Layout Design and Optimization of RF Spiral Inductors on Silicon Substrate

The effects of key geometrical parameters on the performance of integrated spiral inductors are investigated with the 3D electromagnetic simulator HFSS. While varying geometrical parameters such as the number of turns （N）,the width of the metal traces （W）,the spacing between the traces （S）,and the inner diameter （ID）, changes in the performance of the inductors are analyzed in detail. The reasons for these changes in performance are presented. Simulation results indicate that the performance of an integrated spiral inductor can be improved by optimizing its layout. Some design rules are summarized.

N×N集成光开关阵列模型

报道了由2N个1×N多模干涉马赫-曾德尔光开关组成的N×N光开关阵列结构，分析了这种结构的开关阵列优势和局限性。用场传输矩阵方法建立了1×N多模干涉光开关的光场传输方程。给出了光开关阵列从任一输入端输入、从任一输出端正输出时阵列开关的工作条件。在上述原理及理论基础上分析了4×4光开关阵列的结构和工作条件。

固态量子计算

量子计算机拥有比经典计算机更为强大的计算能力。人们普遍认为，量子计算机最终将会在固态系统中实现。文章介绍了三种固态量子计算机的方案，它们分别基于固态核磁共振、超导结和量子点。

非均匀传输线型谐振腔的研究

分析了周期性电容盘片加载的同轴线的传输特性 ,并将其应用于四分之一波长线谐振腔 ,利用传输线理论和数值模拟两种方法分析了这种腔体的谐振特性 ,得到了谐振频率、Q值与盘片半径、盘片个数间的关系 ,并论证了这种方法在减小腔体尺寸方面的可行性及在一台质子回旋加速器腔体中的应用

Study on nanohardness of helium-implanted 4H-SiC

The hardness of 4H-SiC, which was high-temperature (500 K) helium-Implanted to fluences of 3 x 10(16) Ions cm(-2) and subsequently thermally annealed at the temperature ranging from 773 to 1273 K, was studied by nanoindentation It is found that the hardness of the implanted 4H-SiC increases at the first, then decreases, and then increases again with increasing annealing tempeature in the temperature range of 500-1273 K, and significant increase in hardness is observed at 773 K. The behavior is ascribed to the changes of the density, length, and tangling of the covalent Si-C bond through the recombination of point defects, clustering of He-vacancy, and growth of helium bubbles during the thermal annealing

封育对科尔沁沙地小叶锦鸡儿群落植被特征及空间异质性的影响

以科尔沁沙地小叶锦鸡儿群落为对象,分析了放牧和不同封育年限下小叶锦鸡儿群落的植被特征及植被分布的小尺度空间异质性。结果表明:放牧和封育样地内植被均以1年生草本植物为主,物种数没有明显差异;封育6年、封育12年样地的植株密度分别为(124.46±5.22)株.m-2和(203.05±10.38)株.m-2,显著高于放牧样地(P<0.05);封育样地的Shannon-Wiener多样性指数、Simpson多样性指数、Pielou均匀度指数均低于放牧样地,并随着封育年限的增加而减小;封育样地植被分布的小尺度空间异质性小于放牧样地,并且封育年限越长,空间异质性越小。