Crystallinity‐Controlled Germanium Nanowire Arrays: Potential Field Emitters

We report a simple method, oblique angle deposition, to directly synthesize aligned Ge nanowire arrays on a Si substrate. This process is accomplished by tilting the Si substrate and adjusting the incident angle of the evaporated Ge vapor flux with respect to the substrate normal to 87°. The resultant crystallinity of the Ge nanostructures can be tuned to either amorphous or poly‐ and single‐crystalline, depending on the substrate temperature and evaporation rate. The effects of thermal treatment on the morphology and structure of the Ge nanowires are discussed in detail. The field‐emission measurements show that increasing the annealing temperatures to about 550 °C results in a gradual increase in the maximum current density and a decrease in the turn‐on voltage, because of the decreased wire density originating from melting of the Ge nanowires. The field‐enhancement factor analysis shows there is an optimum range for Ge wire density and aspect ratio to obtain good emission performance. Ge nanowire arrays might find potential application in the field emitters of the future.     

基于改进扰动观察法的光伏阵列最大功率跟踪器的研究

光伏阵列由于输出特性具有非线性,为了提高发电效率,需要对其进行最大功率点跟踪（MPPT）。提出了一种基于改进扰动观察法的最大功率点跟踪器的设计方案,该方案在实现最大功率跟踪的基础上,解决了传统扰动观察法在响应速度与跟踪精度之间的矛盾。通过实验对比引入MPPT前后光伏阵列的输出,验证了方案的可行性与有效性。     

金属腔体孔阵电磁耦合的数值分析

本文针对正弦调制高斯脉冲激励下金属腔体的孔阵电磁耦合问题，使用Zeland公司的FIDELITY软件进行FDTD仿真，发现面积相同（即通风，散热量相等）时腔体电场耦合能力随着孔阵中孔的数目增多而下降，同时对不同形状孔阵及不同间距孔阵情况进行比较。     

行为NA的随机变量阵列加权和的完全收敛性(Ⅱ)

本文研究了行为NA的随机变量阵列加权和的完全收敛性,推广了行独立随机变量阵列相应的结果.且得到了任意随机变量阵列加权和完全收敛的一个定理.     

Children’s conceptions on the structure of an array: Using quick images as a gateway to multiplicative ideas

In this paper we report the conceptions about arrays that came to the fore as one class of second-grade students participated in whole classroom discussions and activities focused on the structure of arrays presented as a Quick Images routine. Before the intervention, students were not introduced to formal multiplication but had completed a unit on arrays. A constant comparative method was used to identify numeric and spatial structuring strategies that allowed for students’ conceptions about the structure of the array to emerge. Results indicated that not all students automatically use arrays as a composite of rows. We found that the use of Quick Images with larger arrays and non-arrays within the whole classroom discussion was successful at eliciting and directing students’ attention towards the spatial features of an array, including seeing an array as made of a composite of rows (or columns).     

Fabrication of High‐Density,Large‐Area Conducting‐Polymer Nanostructures

The low‐cost, large‐scale fabrication of high‐density conducting‐polymer nanostructures is desirable for a variety of applications. We report the realization of high‐density conducting‐polymer nanostructures through a combination of nanoimprint lithography, a copolymer strategy, and a lift‐off process. Atomic force microscopy and optical measurements reveal that the quality of the prepared structures is rather good, and a resolution of 100 nm is achieved. Electrical measurements show that the conducting‐polymer nanowires are conductive and indicate great anisotropy in the parallel and perpendicular directions. Moreover, by further connecting them with larger electrodes, these nanowire arrays function as nanosensors.     

准最佳二进阵列

本文首次对一般的m-准最佳二进阵列进行了系统性的统一研究。在m-准最佳二进阵列的频谱、体积和平衡性方面得出了一些新结果。特别地还发现了若干种构造最佳和准最佳二进阵列的新方法。利用这些新方法和前人已找出的低维低阶阵列就可以构造出无穷多类高维高阶的最佳(或准最佳)二进阵列。此外文中还提出了若干未解决的难题。     

DNA‐Assisted Monolayer Immobilization of 2D Opaline Arrays

DNA supramolecular recognition is employed for the immobilization of 2D photonic crystals of monodisperse colloidal microspheres. Amine‐terminated DNA oligomers are covalently attached to carboxy‐decorated microspheres and substrates while preserving their colloidal stability and organization properties. Following a capillary‐force‐assisted organization of DNA‐decorated microspheres into close‐packed 2D opaline arrays, the first monolayer is immobilized by DNA hybridization. Various parameters affecting the long‐range order of such opaline arrays are investigated, including surface hydrophobicity and the relative strengths of the specific versus nonspecific interactions. The type and concentration of salt and the process temperature are also optimized for the hybridization between microspheres and substrate. The selective removal of non‐specifically bound multilayers is accomplished by carefully passing an air/liquid interface over these arrays. DNA hybridization was found to play an important role in immobilizing the first monolayer of 2D opaline arrays while preserving its long‐range order, with an approximate binding strength three times higher than that of non‐specific interactions.