分子高激发振动态的动力学特性研究

运用经典哈密顿代数方法,结合单摆的运动特点表示两个化学键之间的振动耦合.对水分子高激发态下两个氧氢键(O—H)伸缩振动动力学的研究结果表明,靠近分界线的中间能级的相空间中较易出现混沌轨道,而较高或较低能级的相空间中则具有比较规则的周期运动 关键词： 高激发振动 共振 混沌     

振动系统的模态分析实验设计

利用模态分析原理和简单试验仪器，得到了直观的悬臂梁和圆盘前4阶模态振型，使学生熟悉了模态分析原理和测试方法，有利于学生对振动规律的理解．     

Grid‐free surface vorticity method applied to flow induced vibration of flexible cylinders

In order to study cross flow induced vibration of heat exchanger tube bundles, a new fluid–structure interaction model based on surface vorticity method is proposed. With this model, the vibration of a flexible cylinder is simulated at Re=2.67 × 10⁴, the computational results of the cylinder response, the fluid force, the vibration frequency, and the vorticity map are presented. The numerical results reproduce the amplitude‐limiting and non‐linear (lock‐in) characteristics of flow‐induced vibration. The maximum vibration amplitude as well as its corresponding lock‐in frequency is in good agreement with experimental results. The amplitude of vibration can be as high as 0.88D for the case investigated. As vibration amplitude increases, the amplitude of the lift force also increases. With enhancement of vibration amplitude, the vortex pattern in the near wake changes significantly. This fluid–structure interaction model is further applied to simulate flow‐induced vibration of two tandem cylinders and two side‐by‐side cylinders at similar Reynolds number. Promising and reasonable results and predictions are obtained. It is hopeful that with this relatively simple and computer time saving method, flow induced vibration of a large number of flexible tube bundles can be successfully simulated. Copyright © 2004 John Wiley & Sons, Ltd.     

电磁诱导透明和导致极慢光速的机制

根据有关文献 ,描述了电磁诱导透明和导致光速极慢的物理机制 ,并对实验结果也做了介绍     

Flow Search Approach and New Bounds for the m-Step Linear Conjugate Gradient Algorithm

A flow search approach is presented in this paper. In the approach, each iterative process involves a subproblem, whose variables are the stepsize parameters. Every feasible solution of the subproblem corresponds to some serial search stages, the stepsize parameters in different search stages may interact mutually, and their optimal values are determined by evaluating the total effect of the interaction. The main idea of the flow search approach is illustrated via the minimization of a convex quadratic function. Based on the flow search approach, some properties of the m-step linear conjugate gradient algorithm are analyzed and new bounds on its convergence rate are also presented. Theoretical and numerical results indicate that the new bounds are better than the well-known ones.     

双振动合成仪器的设计

指出了用示波器演示双振动合成的不足，设计了BS—Ⅱ型双频调相信号仪，并给出了应用该仪器获得的部分实验图象。     

Predicting vibration signals of automobile engine using chaos theory

Condition monitoring and life prediction of the vehicle engine is an important and urgent problem during the vehicle development process. The vibration signals that are closely associated with the engine running condition and its development trend are complex and nonlinear. The chaos theory is used to treat the nonlinear dynamical system recently. A novel chaos method in conjunction with SVD (singular value decomposition)denoising skill are used to predict the vibration time series. Two types of time series and their prediction errors are provided to illustrate the practical utility of the method.     

受迫振动演示实验装置

本文叙述用示波器显示来演示受迫振动的实验装置，可直观地向学生展示受迫振动的幅频特性和相频特性。     

多巴酚丁胺的流动注射化学发光法测定

在盐酸介质中 ,高锰酸钾可氧化多巴酚丁胺产生化学发光 ,甲醛对该反应有较强的增敏作用 ,据此 ,建立了流动注射化学发光法测定多巴酚丁胺的方法 ;方法的线性范围为0.1～100mg·L -1,检出限为0.07mg·L -1 ,相对标准偏差为1.2 %(n=11,ρ=1.0mg·L -1) ;该法用于药物中多巴酚丁胺含量的测定 ,结果令人满意。     

流动注射原子吸收光谱法测定富硒天麻、葡萄及大米中的硒

建立了流动注射氢化物发生-原子吸收光谱法测定富硒天麻、葡萄及大米中硒的方法。测定硒的线性范围为0．33μg/L-50μg/L，相对标准偏差小于3％，加标回收率为93％-106％。方法已广泛应用于实际样品中微量硒的测定。