Cusped Solitons and Loop-Solitons of Reduced Ostrovsky Equation

The qualitative theory of differential equations is applied to the Ostrovsky equation. The cusped soliton and loop-soliton solutions of the Ostrovsky equation are obtained. Asymptotic behavior of cusped soliton solutions is given. Numerical simulations are provided for cusped solitons and so-calledloop-solitons of the Ostrovsky equation.     

α-螺旋蛋白质分子链上的孤立子寿命

以连续近似条件下的孤立子为初始条件,对α-螺旋蛋白质分子链上动力学方程的数值解进行了讨论,发现在不考虑热振动影响的情况下,α-螺旋蛋白质分子链上孤立子的寿命仍是有限的.     

Travelling wave solutions for a second order wave equation of KdV type

The theory of planar dynamical systems is used to study the dynamical behaviours of travelling wave solutions of a nonlinear wave equations of KdV type.In different regions of the parametric space,sufficient conditions to guarantee the existence of solitary wave solutions,periodic wave solutions,kink and anti-kink wave solutions are given.All possible exact explicit parametric representations are obtained for these waves.     

Bifurcations of travelling wave solutions for Jaulent-Miodek equations

By using the theory of bifurcations of planar dynamic systems to the coupled Jaulent-Miodek equations,the existence of smooth solitary travelling wave solutions and uncountably infinite many smooth periodic travelling wave solutions is studied and the bifurcation parametric sets are shown.Under the given parametric conditions,all possible representations of explicit exact solitary wave solutions and periodic wave solutions are obtained.     

高压气体淬火过程中的温度场与相变耦合问题的计算

高压气体淬火技术是一种现代的、有效的材料加工技术．在Cheng所得到的高压气体淬火过程中非线性表面换热系数的基础上,用有限单元法对钢淬火过程的温度场与相变耦合问题进行了模拟计算．在数值计算中,材料的热物性系数被处理为温度和相变体积百分比的函数．为避免数值解的震荡,采用了Norsette有理近似法．     

Al(OH)3和Sr(OH)2复合粉末的制备及性能研究

本文采用活化Al-Sr合金粉末水解反应制备Al(OH)3和Sr(OH)2复合粉末,利用XRD,SEM,EDS,BET及激光粒度仪对复合粉末进行结构和性能研究.研究结果表明,Al(OH)3和Sr(OH)2的复合粉末中Sr/Al比例与配比相比有所偏移,但在复合粉末中两者均匀混合,具有化学组成的微观均匀性.复合粉末微观形貌为1～3μm片状小颗粒叠加的团聚颗粒,BET比表面积较大,达到45.2m2/g,水解产物粒度分布均匀,D50为27.58μm,D25/D75为0.76.     

Prediction of spectral interference in inductively coupled plasma-atomic emission spectrometry by primary computer expert system

Spectra and spectral interferences in inductively coupled plasma-atomic emission spectrometry, ICP-AES, have been simulated and predicted by a primary expert system under contrasting conditions of local temperature equilibrium (LTE) and non-LTE. In this expert system a comprehensive computer model has been applied to provide expert knowledge on an non-LTE ICP discharge, analyte ionization and excitation, and spectral line shape. The system also includes several databases to supply the calculation with spectral and elemental parameters. Some typical examples are illustrated, with satisfactory outcomes. It is found that predictions under non-LTE conditions are much closer to the reality than those under LTE conditions.     

Lead time and response time in a pull production control system

In the late 80s, most manufacturers have shifted their manufacturing strategies from cost and quality to speed. This paper focuses on two performance measures of speed: manufacturing lead time and response time. Manufacturing lead time is the sum of the processing time to convert raw material to finished goods and the waiting time at the buffers. Response time is the time between the customer places an order and the customer receives the order. In this paper we develop a queueing model of a pull-based production control system for a single-stage facility. The intent of the model is two-fold. First, we highlight the trade-off between manufacturing lead time and response time. Second, we develop an optimization model to determine an optimal control system that guarantees certain delivery performance (in terms of response time).     

具投放的中立型时滞竞争扩散系统正周期解的存在性

利用Nussbaum 度理论建立了具投放的中立型时滞竞争扩散系统 x′₁(t)=x₁(t)[a₁(t)-b₁(t)x₁(t)-c₁(t)y(t) ]+D₁(t)[x₂(t)-x₁(t)]+S₁(t), x′₂(t)=x₂(t)[a₂(t)-b₂(t)x₂(t)]+D₂(t)[x₁(t)-x₂(t) ]+S₂(t), y′(t)=y(t)[a₃(t)-b₃(t)y(t)-α(t)y(t-τ₁(t))-β(t) ∫⁰_τ k(s)y(t+s)ds -γ(t)y’(t-τ₂(t))-c₃(t)x₁(t)]. 存在正周期解的一个充分条件.     

锂-二氧化碳电池关键材料的研究进展

可充式锂-二氧化碳电池为捕获CO2和能量存储提供了一种新方法.尽管该技术从发展之初至今取得了很大进步,但它们在实际应用中还面临着许多限制和挑战.其中,在充放电机理方面的研究,虽然取得了显著的成就,但仍存在一些争议.目前,大部分的锂-二氧化碳电池研究在提高电池性能方面,主要针对的是阴极催化剂的制备,例如,碳基催化剂、贵金...