一种基于模拟植物生长算法的输电网故障诊断方法

将模拟植物生长算法应用于输电网故障诊断,提出了将开关及设备电流转化成整形变量的方法,建立输电网故障诊断模型.仿真实验验证了模型的正确性、有效性及高容错性.     

基于改进模拟植物生长算法的输电网络扩展规划

输电网络规划是一个复杂的组合优化问题,若以选择线路回数为变量抽象出模型,则输电网扩展问题可以归结为一类整数规划问题.对模拟植物生长算法进行改进,形成了适于解整数规划问题的改进模拟植物生长算法,并将此算法应用到电力系统输电网络扩展规划中.为了加快算法收敛,采用了Kruskal算法来获取初始点,提出了一种快速判别网络连通的算法.最后,实例计算结果表明了该方法的可行性.     

2D Boron Sheets: Structure,Growth, and Electronic and Thermal Transport Properties

The structures of boron clusters, such as flat clusters and fullerenes, resemble those of carbon. Various two‐dimensional (2D) borophenes have been proposed since the production of graphene. The recent successful fabrication of borophene sheets has prompted extensive researches, and some unique properties are revealed. In this review, the recent theoretical and experimental progress on the structure, growth, and electronic and thermal transport properties of borophene sheets is summarized. The history of prediction of boron sheet structures is introduced. Existing with a mixture of triangle lattice and hexagonal lattice, the structures of boron sheets have peculiar characteristics of polymorphism and show significant dependence on the substrate. Due to the unique structure and complex B? B bonds, borophene sheets have many interesting electronic and thermal transport properties, such as strong nonlinear effect, strong thermal transport anisotropy, high thermal conductance in the ballistic transport and low thermal conductivity in the diffusive transport. The growth mechanism and synthesis of borophene sheets on different metal substrates are also presented. The successful prediction and synthesis will shed light on the exploration of new novel materials. Besides, the outstanding and peculiar properties of borophene make them tempting platform for exploring novel physical phenomena and extensive applications.     

PECVD法低温沉积多晶硅薄膜的研究

在玻璃衬底上采用常规的PKCVD法在低温(≤400℃)条件下制得大颗较(直径＞100nm)、择优取向(220)明显的多晶硅薄膜。选用的反应气体为SiF4和H2混合气体。加入少量的SiH4后，沉积速率提高了近10倍。分析认为，在低温时促使多晶硅结构形成的反应基元应是SiFmHn(m n≤3)，而不可能是SiHn(n≤3)基团。     

复杂微结构三维形貌测量方法的研究

微结构三维形貌测量是研究微加工工艺和微尺寸特性的重要测试内容。本文提出一种基于相移显微干涉术、利用干涉陶建立二维结构模板指导相位展开的新方法,它不仅适用于静态测量,而且能应用于在动态测量中,特别是微机电系统（MEMS）器件的运动测量。以微谐振器为测试器件,对其运动梳齿结构进行了静态三维形貌测量,实验的离面理论测量精度优于0．5nm,测试结构内部的面内理论测量精度优于0．5μm,而边缘尺寸因受到边缘提取方法的影响,其测量精度仅在μm量级。对该方法的缺点和发展方向做了探讨。     

电子产品研制阶段可靠性增长试验研究

结合工程实际经验,深入讨论了可靠性增长过程及实现途径,在保持试验条件和改进过程不变的条件下,实施了对具体型号电子产品的可靠性增长试验,达到了预期的可靠性增长目标,并且利用可靠性增长试验的数学模型(AMSAA模型)来评估产品的可靠性增长,对开展可靠性增长与可靠性增长试验工作具有重要的实际意义.     

Chemical natures and distributions of metal impurities in multicrystalline silicon materials

We present a comprehensive summary of our observations of metal‐rich particles in multicrystalline silicon (mc‐Si) solar cell materials from multiple vendors, including directionally‐solidified ingot‐grown, sheet, and ribbon, as well as multicrystalline float zone materials contaminated during growth. In each material, the elemental nature, chemical states, and distributions of metal‐rich particles are assessed by synchrotron‐based analytical x‐ray microprobe techniques. Certain universal physical principles appear to govern the behavior of metals in nearly all materials: (a) Two types of metal‐rich particles can be observed (metal silicide nanoprecipitates and metal‐rich inclusions up to tens of microns in size, frequently oxidized), (b) spatial distributions of individual elements strongly depend on their solubility and diffusivity, and (c) strong interactions exist between metals and certain types of structural defects. Differences in the distribution and elemental nature of metal contamination between different mc‐Si materials can largely be explained by variations in crystal growth parameters, structural defect types, and contamination sources. Copyright © 2006 John Wiley & Sons, Ltd.     

关联规则快速聚焦算法研究与实现

提出了一种实用的快速聚焦关联规则更新算法。在需要反复调整最小支持度的情况下,如何充分利用以往挖掘过程中的信息,避免多次扫描数据集;在如何有针对性的产生候选项集,从而减少候选集的规模;在如何提高候选项集的支持事务计数的效率等方面进行了研究,给出了算法的具体实现。通过分析,本算法是可行的。     

硼原子对Si(100)衬底上Ge量子点生长的影响

研究了硼原子对 Si( 1 0 0 )衬底上 Ge量子点自组织生长的影响 .硼原子的数量由 0单原子层变到 0 .3单原子层 .原子力显微镜的观察表明 ,硼原子不仅对量子点的大小 ,而且对其尺寸均匀性及密度都有很大影响 .当硼原子的数量为 0 .2单原子层时 ,获得了底部直径为 60± 5nm,面密度为 6× 1 0 9cm- 2 ,且均匀性很好的 Ge量子点 .另外 ,还简单讨论了硼原子对 Ge量子点自组织生长影响的机制 .     

Self‐Assembling,Bioinspired Wax Crystalline Surfaces with Time‐Dependent Wettability

One of the most fascinating properties of materials in nature is the superhydrophobic and self‐cleaning capabilities of different plant surfaces. This is usually achieved by the hydrophobic cuticles that are made of cutin and contain wax crystals both within them and on their surfaces. Here, bioinspired n‐hexatriacontane wax films are deposited via thermal evaporation and it is shown that the surface evolves in time via self‐assembly. This leads to a dramatic change in the wetting properties with a transition from hydrophobic to superhydrophobic characteristics, which takes place within several days at room temperature. This phenomenon is investigated and strain‐induced recrystallization is proposed to be the mechanism for it. This work could become the basis for the inspiration and production of tuned, time‐dependant, temperature‐sensitive, variable‐wettability surfaces.