Vacancy ordering and lithium insertion in III2VI3 nanowires

Superlattice structures resulting from vacancy ordering have been observed in many materials. Here we report vacancy ordering behavior in III₂VI₃ nanowires. The formation of layer-like structural vacancies has been achieved during the synthesis of In₂Se₃ nanowires through a vapor-transport route. Doping In₂Se₃ nanowires with small amounts of Ga during synthesis can completely change the structural vacancy ordering from a layer-like to a screw-like pattern for (In _x Ga_1−x )₂Se₃ nanowires. Lithium atoms can fill in the layer-like structural vacancies of In₂Se₃ nanowires and generate new types of vacancy and lithium atom ordering superlattices. The screw-patterned vacancies of (In _x Ga_1−x )₂Se₃ nanowires show reversible lithium insertion. Our results contribute to the understanding of structure property correlations of III₂VI₃ materials used in lithium ion storage, photovoltaics, and phase change memory.     

传导性电磁干扰噪声分离网络识别特性的实验与仿真研究

介绍了传导性电磁干扰噪声分离的目的及意义,并对传导性电磁干扰噪声的分离技术作了讨论,论述了EMI测试中所用的线性阻抗稳定网络（LISN）以及4种分离网络.以实验和仿真的方式重点对其中的两种分离网络的性能进行了研究.通过对比和分析,得出实验和仿真的结果具有良好的一致性,在某些情况下,仿真可以代替实验进行一些研究.通过仿真,进一步探讨了分布电容和元件精度对分离网络性能的影响,结果表明,分布电容对网络的性能有一定影响,Guo网络的分离特性受分布参数的影响较小;而元件精度对分离网络的性能几乎不造成影响.     

简单排序算法的改进

本文对三种简单排序方法———冒泡排序、选择排序、插入排序分别进行了改进 ,进行了相应的算法复杂度分析 ,并编出程序上机实验 ,对改进的算法与原算法所运行的时间进行了比较     

A fast general slew constrained minimum cost buffering algorithm

As VLSI technology moves to the nanoscale regime, ultra-fast slew buffering techniques considering buffer cost minimization are highly desirable. The existing technique proposed in [S. Hu, C. Alpert, J. Hu, S. Karandikar, Z. Li, W. Shi, C.-N. Sze, Fast algorithms for slew constrained minimum cost buffering, IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems 26 (11) (2007) 2009-2022] is able to efficiently perform buffer insertion with a simplified assumption on buffer input slew. However, when handling more general cases without input slew assumptions, it becomes slow despite the significant buffer savings. In this paper, a fast buffering technique is proposed to handle the general slew buffering problem. Instead of building solutions from scratch, the new technique efficiently optimizes buffering solutions obtained with the fixed input slew assumption. Experiments on industrial nets demonstrate that our algorithm is highly efficient. Compared to the commonly used van Ginneken style buffering, up to 49× speed up is obtained and often 10% buffer area is saved. Compared to the algorithm without input slew assumption proposed in [S. Hu, C. Alpert, J. Hu, S. Karandikar, Z. Li, W. Shi, C.-N. Sze, Fast algorithms for slew constrained minimum cost buffering, IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems 26 (11) (2007) 2009-2022], up to 37× speedup can be obtained with slight sacrifice in solution quality.     

1550nm低推挽电压聚合物定向耦合电光开关的设计

应用保角变换法、镜像法、耦合模理论和电光调制理论设计了一种推挽电极聚合物脊形波导定向耦合电光开关,阐述了基本结构和工作原理,给出了器件的设计和优化过程,主要分析了耦合长度、开关电压、输出光功率、插入损耗、串扰等特性. 为了实现正常的开关功能,讨论了制作公差、波谱漂移以及单模光纤耦合损耗对器件性能的影响. 模拟结果表明,所设计的开关的耦合长度为3082μm,开关电压为2.14V;插入损耗小于1.14dB,串扰小于-30dB. 与BPM仿真结果以及实验结果的对比表明,文中提出的波导和电极的理论分析与计算方法具有较高的精度和可行性.     

旅行商问题的一种选择性集成求解方法

针对大型TSP(traveling salesman problem)实例很难找到最优解的问题,提出了一种选择性集成求解方法。首先通过扩大路径法来选择集成多个较好解,构造出若干个极大路径;然后采用顶点插入法将剩余顶点和这些极大路径连接成一个哈密顿回路;最后使用2-opt方法对该回路进行提升。试验结果表明,算法在5个TSP实例上得出的最好解的最大偏差为1.69%,说明本算法可以有效求解TSP。     

卡扣设计参数对连接性能的影响分析

针对某SUV进行路试时前车门出现内饰板抖动异响、卡扣弹出等问题,首先对用作连接的卡扣插拔过程进行有限元仿真和实验分析,仿真和实验结果表明,卡扣存在连接性能不达企业要求、角度设计不合理等问题。其次探讨了卡扣设计参数中的材料、瓣厚和角度对连接性能的作用规律,得出卡扣最佳选材为POM、瓣厚为1.4 mm、角度为150°,此设计参数使原卡扣保持力提高了49.1%。最终通过车门振动实验验证了优化后卡扣成功解决了内饰板抖动异响等问题。本文为卡扣设计和选用提供参考依据。     

MEMS制造中反应离子刻蚀工艺的模型及仿真

反应离子刻蚀（RIE）的二维物理模型,包括各向同性和各向异性两部分。该速率公式的参数由实验提取,随RIE工艺参数而变化。采用线算法和C＋＋编写用于模拟RIE刻蚀的计算机模拟软件,该软件可以对各种不同的起始条件进行模拟。对公式中的角度计算过程中可能出现的各种情况分别进行了讨论。为了确保软件的精度和稳定性,算法采用了添加点和减少点的方法,最后给出模拟软件的模拟结果,与实验结果比较吻合。     

Synthesis and crystal structure of（C5Me4SiMe3）[（^iPrN）2CCH2SiMe3]2Y

Reaction of (C5Me4SiMe3)Y(CH2SiMe)2(THF) with two equivalents of iPrN=C=NiPr in hexane at room temperature afforded a mixed-ligand yttrium complex (C5Me4SiMe3)[(iPrN)2CCH2SiMe3]2Y. X-ray diffraction revealed that the center metal was nine-coordinated by one cyclopentadienyl ring and two amidinate ligands, and adopted a four-legged piano stool geometry.     

The Oro‐Ileal Transit of Cellulose

ABSTRACT: The effects of cellulose and the interindividual variations on the transit time in the small intestine remain unclear, but no previous study has to date taken these factors into sufficient consideration. We assessed the oro‐ileal transit time and the recovery percentage of cellulose in the terminal ileum looking at interindividual variations. Seven healthy males received 100 mL of a dietary fiber‐free basal diet with 5 g cellulose and 5 g of polyethylene glycol 4000. The ileal contents were aspirated every 30 min via an experimental tube placed in the terminal ileum to assess the oro‐ileal transit time and the recovery percentage of cellulose. The mean percentage (with standard deviation) of the amounts of cellulose collected in the terminal ileum was 98.4%± 16.5% (ranging from 67.4% to 114.5%) with a coefficient variation of 16.8%. The average times (in hours) taken for 20%, 40%, 60%, and 80% of cellulose to reach the terminal ileum were 5.5 ± 1.1, 6.7 ± 0.7, 8.5 ± 1.3, and 8.8 ± 1.2, respectively, with large interindividual variations. In conclusion, the averaged recovery percentage of cellulose in the terminal ileum was approximately 100%, in accordance with the present generally accepted definition of dietary fiber. However, there were large interindividual variations in the oro‐ileal transit time and the percentage of cellulose recovered.