黏聚力模型的微观机理研究

目前,力学界广泛采用黏聚力模型表征界面的力学响应,模拟界面的开裂与裂纹扩展。黏聚力模型是一个宏观唯象的模型,是对不同空间尺度界面现象的简化,具体表示为界面相对位移与粘结力的解析关系式。模型的不足之处是缺乏物理基础

界面能的尺度依赖性及其对界面断裂强度的影响

金属/陶瓷界面由于在催化转换、场效应晶体管、防腐蚀涂层和热势垒涂层等领域应用广泛而受到越来越多的关注。材料的失效和破坏往往首先发生在界面,因此界面能的研究具有重要意义。尤其随着电子器件的微型化,界面能的尺度效应不能忽略。本文通过同时考虑界面能的化学和结构贡献建立了金属/陶瓷界面能尺度效应的解

基因编辑的技术分析与思考

基因编辑技术已成为当今非常重要的生物工程技术，在生物医药、生物环保以及农业生产领域有着极 其广泛的应用。本研究通过对基因编辑相关专利和期刊文献的分析，揭示了基因编辑技术的发展现状与趋 势，并基于对CRISPR技术的专利分析以及重要研发机构的专利布局分析，对我国基因编辑技术的发展提出了 对策与建议，为相关领域的研究人员及决策者提供参考。</p

曲面综合法复杂齿面啮合仿真分析方法研究

根据空间曲面啮合原理，构建共轭曲面的数理综合模型；基于该模型坐标变换，求得弧齿锥齿轮大、小轮齿面的数理解；基于曲面综合，给出齿面修形梯度曲面（简称Ease-off曲面）的构建方法；以齿面的旋转投影平面为坐标平面划分网格，计算了小轮修形齿面与共轭齿面的法向修形量，得到弧齿锥齿轮Ease-off曲面；通过解析Ease-off曲面，获得了完整的齿面接触形态：差曲线、接触路径、传动误差等，与齿面实际接触斑点形态高度一致。为复杂齿面的拓扑设计、啮合形态仿真提供了一种准确可行的手段

Interface energy and its influence on interface fracture between metal and ceramic thin films in nanoscale

A theoretical model about the size-dependent interface energy between two thin films with different materials is developed by considering the chemical bonding contribution based on the thermodynamic expressions and the structure strain contribution based on the mechanical characteristics. The interface energy decreases with reducing thickness of thin films, and is determined by such available thermodynamic and mechanical parameters as the melting entropy, the melting enthalpy, the shear modulus of two materials, etc. The predicted interface energies of some metal/MgO and metal/Al2O3 interfaces based on the model are consistent with the results based on the molecular mechanics calculation. Furthermore, the interface fracture properties of Ag/MgO and Ni/Al2O3 based on the atomistic simulation are further compared with each other. The fracture strength and the toughness of the interface with the smaller structure interface energy are both found to be lower. The intrinsic relations among the interface energy, the interface strength, and the fracture toughness are discussed by introducing the related interface potential and the interface stress. The microscopic interface fracture toughness is found to equal the structure interface energy in nanoscale, and the microscopic fracture strength is proportional to the fracture toughness. (C) 2010 American Institute of Physics. [doi:10.1063/1.3501090

Nano-size Effect of Interface Energy and Its Effect on Interface Fracture

An analytical model about size-dependent interface energy of metal/ceramic interfaces in nanoscale is developed by introducing both the chemical energy and the structure stain energy contributions. The dependence of interface energy on the interface thickness is determined by the melting enthalpy, the molar volume, and the shear modulus of two materials composing the interfaces, etc. The analytic prediction of the interface energy and the atomic scale simulation of the interface fracture strength are compared with each other for Ag/MgO and Ni/Al2O3 interfaces, the fracture strength of the interface with the lower chemical interface energy is found to be larger. The potential of Ag/MgO interface related to the interface energy is calculated, and the interface stress and the interface fracture strength are estimated further. The effect of the interface energy on the interface strength and the behind mechanism are discussed

Cockayne syndrome

Review on Cockayne syndrome, with data on clinics, and the genes involved

The atomistic simulation study of Ag/MgO interface tension fracture

Metal/ceramic interfaces have wide applications and the interface fracture plays an important role in determining mechanical behaviors of related structures. The cohesive zone model is widely used to modelling the crack opening and extension, especially used to modelling the interface crack. Although this model is widely used, it is a macroscopic phenomenological model, and its atomistic scale mechanism attracts great attention. In this paper an interface atomistic model of Ag/MgO is used to study the microscopic interface opening mode and some interesting results are discovered. By considering all atomic interaction potentials related to the interfacial structure in the molecular mechanics calculation, the interface tension stress-displacement curves for several interface structures with different sizes are simulated, and fracture properties upon displacing Ag and MgO adjacent to the interface are revealed based on the simulation results and by developing a series model on interface fracture properties. The results indicate that the interface fracture strength is independent of the size of interface structures for ideal interfaces, the total tension displacement of interface structures increases and the fracture appears catastrophic characteristic with increasing unit thickness, which is explained well by the series model. Furthermore, the interface separation behaviors of interfaces with the atomic vacancy and dislocations are simulated, the study indicates that the interface strength decreases for the interfaces with defects, and the defects decrease the catastrophic tendency. (C) 2017 Elsevier B. V. All rights reserved.</p

基因编辑的技术分析与思考

基因编辑技术已成为当今非常重要的生物工程技术，在生物医药、生物环保以及农业生产领域有着极 其广泛的应用。本研究通过对基因编辑相关专利和期刊文献的分析，揭示了基因编辑技术的发展现状与趋 势，并基于对CRISPR技术的专利分析以及重要研发机构的专利布局分析，对我国基因编辑技术的发展提出了 对策与建议，为相关领域的研究人员及决策者提供参考。</p