数字化电子手册开发平台的研究

本文主要讨论数字化电子手册开发平台的设计实现,分析了该开发平台的系统结构需求、功能和组成,并给出了该开发平台的使用实例。     

弹簧CAD技术研究

通过对弹簧设计与绘图在工程设计中地位和作用的分析,提出了一个基于弹簧设计与绘图一体化的总体方案,从而建立了弹簧ＣＡＤ系统 。     

Interface structure at the large misfit, still common epitaxy β-FeSi2(101) or (110)//Si(111)

In this paper we compare the elastic energies obtained by tight-binding molecular dynamics simulations for several strained structures of β-FeSi₂, corresponding to the most frequent epitaxial relationships ‘on’ and ‘in’ silicon. Our results confirm that, for coherent interfaces, the very common β-FeSi₂(101) or (110)//Si(111) orientation generates a very large contribution to the elastic energy, due to the large misfit. Therefore, we suggest that the frequent nucleation of such epitaxial relationships in precipitates is provided by the correspondence of the two-dimensional crystal structure for the Si sites between Si(111) and β-FeSi₂(101) or (110). We show it to be maintained even after misfit relaxation in the silicon matrix, as simulated by a large-scale molecular dynamics run.     

Interface crack interacting with a microvoid in the near-tip process zone

This paper deals with the elastic problem of an interface macrocrack interacting with a near-tip microvoid in the process zone. The `pseudo-traction-edge-dislocation method' (abbreviated PTEDM) proposed by Zhao and Chen (1996) is extended to treat the macrocrack-microvoid interaction problem in bimaterial solids. A system of singular integral equations with Hilbert kernel is reduced and solved numerically, which provides a fundamental understanding of the interaction effect. Numerical results are given for six kinds of bimaterial combinations (Hutchinson, Meer and Rice, 1987). The J-integral analysis is also applied to the interaction problem, and some useful conclusions are presented in detail.     

认知Mesh网络的动态分层图路由模型及路由策略

该文提出了在认知无线电Mesh网络环境下的动态分层图路由模型,该模型将节点感知范围内的信道可用性用两状态离散时间马尔可夫链建模,建立认知无线电Mesh网络拓扑和连通性的动态模型。基于该模型提出了一种跨层设计的动态接口分配方案。仿真结果表明,动态分层图模型在适应接入频谱的动态变化和描述认知无线电Mesh网络的拓扑结构方面,表现出比静态分层图模型更加优异的性能。     

A three-dimensional finite element analysis of interface delamination in a ductile film/hard substrate system induced by wedge indentation

Interface delamination and arching of a ductile thin film on a hard substrate subject to microwedge indentation were investigated systematically using a three-dimensional finite element method. A traction-separation law was introduced to simulate the cohesion and failure behavior of the interface between the film and the substrate. The effects of the interface strength and the length of the microwedge indenter on the onset and growth of interface delamination and film arching were analyzed. It was shown that a two-dimensional to three-dimensional transition of stress state occurs during indentation, depending on the indenter length and indentation depth. Conditions for using two-dimensional and three-dimensional models were suggested.     

Improvement of stability for organic solar cells by using molybdenum trioxide buffer layer

We demonstrated that the stability of organic solar cells (OSCs) under light irradiation is markedly enhanced by inserting a molybdenum trioxide (MoO₃) buffer layer between an anode layer of indium tin oxide (ITO) and a p-type layer of 5,10,15,20-tetraphenylporphyrin (H₂TPP) or N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (α-NPD). The use of the MoO₃ layer also enhanced open-circuit voltages and power conversion efficiencies of the OSCs due to an increase in built-in potential. From results of stability test of hole-only α-NPD devices, we concluded that the OSC degradation occurs near the ITO/p-type layer interface and that the use of the MoO₃ layer can prevent the degradation at this interface.     

Surface functionalisation of bacterial cellulose as the route to produce green polylactide nanocomposites with improved properties

The effect of surface functionalisation of bacterial cellulose nanofibrils (BC) and their use as reinforcement for polylactide (PLLA) nanocomposites was investigated. BC was functionalised with various organic acids via an esterification reaction. This rendered the otherwise hydrophilic BC hydrophobic and resulted in better compatibility (interfacial adhesion) between PLLA and BC. A direct wetting method, allowing the determination of the contact angle of polymer droplets on a single BC nanofibre, was developed to quantify the interfacial adhesion between PLLA and functionalised BC. It was found that the contact angle between PLLA droplets and functionalised BC decreased with increasing chain lengths of the organic acids used to hydrophobise BC. A novel method to compound BC with PLLA based on thermally induced phase separation (TIPS) to yield a dry form of pre-extrusion composite was also developed. The mechanical properties of the surface functionalised BC reinforced PLLA nanocomposites showed significant improvements when compared to neat PLLA and BC reinforced PLLA. The thermal degradation and viscoelastic behaviour of the nanocomposites were also improved over neat PLLA.     

Energy absorption capability of nanocomposites: A review

Experimental evidence shows that some nanocomposites with special matrices and filler materials may achieve significant and simultaneous improvements in stiffness, fracture toughness, impact energy absorption and vibration damping, and these characteristics could be of particular importance in automobile or airplane structures. This paper reviews relevant literature which deals with various manifestations of energy absorption of composites from the nano to the macro-scale, with emphasis on the nano-scale. Energy absorption mechanisms in nanocomposites will be examined, along with important influence factors, such as shape, dimension and stiffness of particles, type of matrix, particle volume fraction, distribution of particles and the particle–matrix interfacial properties by both experiments and simulation methods. Relevant potential applications will be discussed, and the key related issues that need to be resolved in the future will be addressed.     

Novel plating solution for electroless deposition of gold film onto glass surface

In this paper, a simple and environmentally friendly electroless plating solution of chloroauric acid (HAuCl₄) and hydrogen peroxide (H₂O₂) for depositing gold film onto (3-aminopropyl)-trimethoxysilane (APTMS) -coated glass surface has been developed. APTMS as an adhesive reagent was used to attach the gold nanoparticles (AuNPs) onto the glass substrate. These AuNPs could be regarded as the preferential nucleation or catalytic sites for gold electroless reduction, which accelerated the reduction of Au³⁺ on the glass surface and effectively prevented the formation of gold metal in the bulk solution. During the gold plating process, H₂O₂ as the reducing agent was thermodynamically capable of reducing Au³⁺ ions from the HAuCl₄ precursor to gold atoms, which deposited onto the glass surface and finally formed the continuous gold film. The resulting gold film was characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and atomic force microscope (AFM), respectively.