钒基固溶体储氢材料弹性性质第一性原理研究

采用基于密度泛函理论的第一性原理赝势平面波方法,计算了（59Cr-41Ti）_100－xV_x（x=5,15,30,60,80,100）六种钒基储氢合金的晶格常数、弹性性质和电子态密度,计算结果与实验值符合较好.发现当x=60时的钒基合金具有较好弹性性质,杨氏模量为14930 GPa,切变模量为5442 GPa及体弹模量为19396 GPa.结合实验循环性能分析认为在吸放氢过程中合金已经发生塑性变形,弹性 关键词： 钒基固溶体 储氢合金材料 密度泛函理论 弹性性质     

ICF靶场中光束口径与列阵间隔的研究

从靶场反射镜架模块的机械结构设计布局所需几何空间的角度出发,根据大口径、列阵器件的特殊要求,给出符合“神光III”装置总体技术要求的ICF靶场光束口径与列阵间隔之间的关系,得出靶场Δ纵、Δ横应满足的公式.     

Ⅱ-Ⅵ型量子点制备及其在生物检测中应用研究进展

Ⅱ Ⅵ型量子点特殊而优良的可见光区荧光性质使得它们在生物识别及检测中具有潜在的应用前景 ,因而引起人们的广泛关注。本文概述了Ⅱ Ⅵ型量子点的制备及其在生物检测中应用的研究进展     

Stereoselective Mannich reactions catalyzed by Tröger’s base derivatives in aqueous media

A Tröger’s base derivative (5,12-dimethyl-3,10-diphenyl-1,3,4,8,10,11-hexaazatetracyclo [6.6.1.0^2,6.0^9,13]pentadeca-2(6),4,9(13),11-tetraenes) was used as an efficient catalyst for the three-component Mannich reactions of aromatic aldehydes and aromatic amines with ketones in water at room temperature. This rapid reaction afforded the corresponding β-amino ketones in good yields with excellent stereoselectivity.     

Theoretical study on reaction mechanism of isocyanate radical NCO with ethene

The NCO + C₂H₄ reaction is simple and prototype for reaction of the NCO radical with unsaturated hydrocarbons, and it is considered to be important in fuel‐rich combustion. In this article, we for the first time perform detailed theoretical investigations for its reaction mechanism based on Gaussian‐3//B3LYP scheme covering various entrance and decomposition channels. The most favorable channel is firstly the NCO and C₂H₄ approach each other, forming a weakly‐bound complex L1 OCN···C₂H₄, followed by the formation of isomer L2 OCNCH₂CH₂ via a small barrier of 1.3 kcal/mol. Transition states of any decomposable or isomeric channels for L2 in energy are much higher than reactants, which indicate that adduct L2 has stabilization effect in this NCO + C₂H₄ reaction. The direct H‐abstraction channel leading to P1 HNCO + C₂H₃, might have an important contribution to the eventual products in high temperature. These results can well explain available kinetic experiment. Moreover, reaction mechanism for the title reaction is significantly different from the NCO + C₂H₂ reaction which proceeds on most favorably to generate the products HCN + HCCO and OCCHCN + H via a four‐membered ring intermediate. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009     

“苏丹红风波”引起的思考

简单介绍苏丹红的物理化学性质、合成方法、毒性以及检测方法。     

孔雀石绿与水产品安全

对孔雀石绿的理化性质、致毒机理及检测方法等进行了简单的介绍。     

Analysis of a viral disease model with saturated contact rate

A viral disease model with saturated contact rate is introduced and investigated. The model consists a host species, which is divided into two classes the susceptible and infected, and a virus, which causes a viral disease in the host and as the host induces, the infected releases more virus into the environment. Taking the virus replication rate as the bifurcating parameter, we prove that there exists a threshold value beyond which the endemic equilibrium bifurcates from the free disease one. Further increasing the value, the endemic equilibrium loses its stability, Hopf bifurcation occurs and a periodic solution arises from it. The orbital stability of the periodic orbits is analyzed by applying Poore’s condition. In the last, numerical simulation of the model is employed to explain the mathematical results of this paper.     

Solution dependence on initial conditions in differential variational inequalities

In the first part of this paper, we establish several sensitivity results of the solution x(t, ξ) to the ordinary differential equation (ODE) initial-value problem (IVP) dx/dt = f(x), x(0) =  ξ as a function of the initial value ξ for a nondifferentiable f(x). Specifically, we show that for $\Xi_T \equiv \{\,x(t,\xi^0): 0 \leq t \leq T\,\}$ , (a) if f is “B-differentiable” on $\Xi_T$ , then so is the solution operator x(t;·) at ξ⁰; (b) if f is “semismooth” on $\Xi_T$ , then so is x(t;·) at ξ⁰; (c) if f has a “linear Newton approximation” on $\Xi_T$ , then so does x(t;·) at ξ⁰; moreover, the linear Newton approximation of the solution operator can be obtained from the solution of a “linear” differential inclusion. In the second part of the paper, we apply these ODE sensitivity results to a differential variational inequality (DVI) and discuss (a) the existence, uniqueness, and Lipschitz dependence of solutions to subclasses of the DVI subject to boundary conditions, via an implicit function theorem for semismooth equations, and (b) the convergence of a “nonsmooth shooting method” for numerically computing such boundary-value solutions.