三原子分子受迫振动模式研究

文章在分析刚性三原子分子动力学系统受迫振动模式的基础上,提出了三原子分子动力学系统在外力作用下的受迫振动模式.     

A2B模型的受迫振动模式研究

求解了三原子分子构架系统,即A2B动力学模型的受迫振动方程组,运用Maple程序分析了它的算例的振动图像,提出了A2B模型的受迫振动模式.     

受迫振动系统的构建与测量

利用计算机实测设备构建受迫振动系统,并实时测量了受迫振动系统的幅频和相频曲线,测量简单,结果准确.     

受迫振动非线性特性的教学拓展

受迫振动在大学物理和大学物理实验中均是重点教学内容,为了使学生更加深入理解受迫振动的非线性特性,本文基于波耳共振仪所涉及的非线性因素和实验数据,对受迫振动方程进行非线性修正,利用数值分析探讨其非线性特性.通过引入硬弹簧型杜芬方程,探讨系统由周期性运动进入混沌状态的演化,将受迫振动中相对稳定的平衡点与奇异吸引子进行类比,...     

简易共振实验演示仪

分析了教材中受迫振动和共振2个演示实验的缺点，自制了简易共振演示装置．使用该实验装置可测量固有频率，演示受迫振动及共振频率和固有频率的关系．     

音叉的共振频率与双臂质量的关系研究及其应用

通过对音叉振动系统的研究,分析了受迫振动系统振动振幅与驱动力频率的关系及音叉共振频率与双臂质量的关系,并用共振原理设计了振动式液体密度传感器.     

受迫阻尼振动系统动力学性质的研究

对受迫阻尼振动系统3种情况的动力学行为以及它们的能量状况作了较深入的定量研究,该研究对分析我们遇到的实际受迫振动系统有一定的指导意义。     

绝热气缸-导热活塞系统的振动特性

用计算机模拟的方法研究了绝热气缸中导热活塞的振动特性。在自由振动或受迫振动的情况下，系统在总体上都是和一个普通的阻尼振子相似的。与此同时，本也指明并分析了该热力学系统的一些独特而有趣的性质。     

受迫振动实验中几个问题的探讨

就受迫振动实验中振动系统半宽带、品质因素及稳定受迫振动强迫力与阻力做功进行研究和探讨。     

充液圆柱壳受迫振动的能量流输入及传播

以一无限长弹性充液圆柱壳的受迫振动能量流为研究对象,分别用Ｆｌｕｇｇｅ方程和Ｈｅｌｍｈｏｌｔｚ方程分析了壳体及声场的波运动,利用圆柱亮－流体的耦合条件,获得系统的振动特性方程．分析了此系统在周向线分布余弦简谐外载作用下的响应;用傅里叶变换和反交换得到能量流的输入,以及当受迫振动波沿着壳体轴向传播时,壳体各内力和壳内流体所携带能量流的变化规律．     

基于能量流动双PWM协调控制

基于双PWM结构,根据系统能量流动分析系统在能量平衡状态和能量不平衡状态下系统各部分间的能量关系,并建立双PWM结构能量数学模型。针对系统输出能量与消耗能量不平衡时造成的直流母线电压波动以及输出功率不匹配的问题,建立关于直流母线电压以及网侧电流d轴分量的约束条件,保证系统能量能够平滑变化。采用约束条件对整流器电压外环以及功率内环进行修正,用以实现整流侧输出能量与逆变侧消耗能量的快速平衡,达到双PWM结构间协调控制的目的。根据仿真结果表明,系统在电机功率突变时,能够实现能量的快速平衡,并且能够减少直流母线电压波动,减少网侧谐波分量和直流侧电容。     

基于太阳能甲醇分解的冷热电联产系统

本文从太阳能与化石能源综合互补利用的思路出发,将中低温太阳能利用与冷热电联产系统有机结合,研究提出了一种太阳能甲醇分解冷热电联产系统.该联产系统能够提高现有太阳能系统在中低温范围内的能源利用效率,并能部分替代化石能源.(火用)分析表明,系统节能关键在于太阳能供热甲醇分解过程有效减少了燃烧过程能量损失.本文的研究可为太阳能系统的发展及化石能源的替代提供新的思路.     

分布式能源系统与微型燃气轮机的发展与应用

集中式与分布式有机结合是21世纪能源工业重要发展方向,新的能源系统将可能影响到人类的生活方式和社会发展的进程。先进燃气轮机技术是21世纪能源与动力系统的核心关键技术,对于我国相关领域中的高新技术发展和移植有着极其重大的作用。我国发展先进燃气轮机技术具有重大战略意义和广阔的产业化前景。本文论述了分布式能源系统和新一代微型燃气轮机的重要性,介绍了国外分布式能源系统和微型燃气轮机的研究和生产情况,提出了分布式能源系统的主要发展方向。     

太阳能甲醇重整制氢-发电联产系统

基于不同用能系统整合和能的综合梯级利用思路,研究提出一种新颖的太阳能甲醇重整制氢-发电联产系统.将太阳能甲醇重整制氢与发电有机整合,不仅合理地利用中低温太阳能,同时实现甲醇重整制氢弛放气的综合利用.新的联产系统具有优良的热力性能,化石能源的相对节能率达到29%,制氢单位能耗降低为0.85 GJ/GJ-H2.研究表明,减小能量转化传递过程的品位差和合理利用太阳能热是系统节能的关键所在.研究成果将为太阳能多功能能源系统发展提供新方案与新思路.     

Rotational energy and limits to fusion reactions between two nuclei

The energy balance of the fusion process between two nuclei is discussed with respect to the rotational energy. Two energy regimes are obtained. In the first regime the increase of rotational energy of the compound system as function of incident energy is governed by the moment of inertia of the two-fragment system at the barrier configuration. The faster increase of rotational energy of the compound system is furnished by theQ-value. In a sliding collision only part of theQ-value can be converted into rotational energy. Therefore, the Yrast limit in the population of the compound nucleus cannot be reached. When this source of energy is exhausted at a certain angular momentum, a second regime is obtained; then the increase of angular momentum and rotational energy as function of incident energy must be determined by the moment of inertia of the compound system.     

A stochastic averaging method for analyzing vibro-impact systems under Gaussian white noise excitations

A new stochastic averaging method for predicting the response of vibro-impact (VI) systems to random perturbations is proposed. First, the free VI system (without damping and random perturbation) is analyzed. The impact condition for the displacement is transformed to that for the system energy. Thus, the motion of the free VI systems is divided into periodic motion without impact and quasi-periodic motion with impact according to the level of system energy. The energy loss during each impact is found to be related to the restitution factor and the energy level before impact. Under the assumption of lightly damping and weakly random perturbation, the system energy is a slowly varying process and an averaged Itô stochastic differential equation for system energy can be derived. The drift and diffusion coefficients of the averaged Itô equation for system energy without impact are the functions of the damping and the random excitations, and those for system energy with impact are the functions of the damping, the random excitations and the impact energy loss. Finally, the averaged Fokker–Plank–Kolmogorov (FPK) equation associated with the averaged Itô equation is derived and solved to yield the stationary probability density of system energy. Numerical results for a nonlinear VI oscillator are obtained to illustrate the proposed stochastic averaging method. Monte-Carlo simulation (MCS) is also conducted to show that the proposed stochastic averaging method is quite effective.     

Self-powered active vibration control using a single electric actuator

The authors have proposed self-powered active vibration control systems that achieve active vibration control using regenerated vibration energy. Such systems do not require external energy to produce a control force. This paper presents a self-powered system in which a single actuator realizes active control and energy regeneration.The system proposed needs to regenerate more energy than it consumes. To discuss the feasibility of this system, the authors proposed a method to calculate the balance between regenerated and consumed energies, using the dynamical property of the system, the feedback gain of the active controller, the specifications of the actuator, and the power spectral density of disturbance. A trade-off was found between the performance of the active controller and the energy balance. The feedback gain of the active controller is designed to have good suppression performance under conditions where regenerated energy exceeds consumed energy.A practical system to achieve self-powered active vibration control is proposed. In the system, the actuator is connected to the condenser through relay switches, which decide the direction of the electric current, and a variable resistor, which controls the amount of the electric current. Performance of the self-powered active vibration was examined in experiments; the results showed that the proposed system can produce the desired control force with regenerated energy, and that it had a suppression performance similar to that of an active control system using external energy. It was found that self-powered active control is attainable under conditions obtained through energy balance analysis.     

基于甲醇化学链燃烧的新型燃气轮机间冷循环

本文提出一种新颖的甲醇化学链燃烧动力循环系统.该系统利用空气压缩的间冷热提供甲醇和Fe2O3反应热,将间冷的低温热转换为高品位化学能;同时得到预冷的空气吸收燃烧产物Fe2O3的显热,降低了还原反应的温度.与常规化学链循环相比,该循环利用间冷的热量代替高温Fe2O3的显热提供还原反应的反应热,系统内能量品位匹配更加合理.根据图像(火用)分析方法,阐明了甲醇化学链燃烧过程(火用)损失减少和间冷热品位提升的机理.本文对新循环进行了分析,并以常规化学链循环为参照,研究了其性能.新循环的效率较高,同时可以实现CO2无能耗的分离.     

Optimizing a refinery using the pinch technology and the mind method

The Pinch Technology and the MIND method are combined in the analysis of a Swedish refinery. The heat exchanger network of the crude distillation system is analysed using the Pinch Technology. The results show that the steam demand from the boiler units in the energy supply part of the system can be reduced by 20% in the optimized heat exchanger network and by 21% when a heat pump is added to the system. A multi-period cost optimization of the operating strategy is performed using the MIND method. The results from the Pinch analysis are then input to the MIND optimization. The system cost of the total energy system of the refinery is optimized with regard to flexibility in the process system as well as changes of energy costs and the operating conditions of the cogeneration unit. The combination of methods shows that significant capital savings can be achieved when the energy saving potential of the process system is integrated in the overall operating strategy of the energy system. It is, in this case, possible to compare investments in energy saving measures to investments in increased steam production capacity.     

磁性物质中冷无序能的作用

在研究物质的磁性时,考虑了电子之间的正交换能(A1>0,导致电子自旋平行排列)和负交换能(A2<0,导致电子自旋反平行排列)两项各自的物理作用,不是简单地只以它们的代数和为判据.提出冷无序能的概念:当A1>|A2|(A=A1-|A2|>0)时,A1为有序能,A2为冷无序能;当A1<|A2|(A<0)时,A2为有序能,A1为冷无序能.物质的磁性决定于热运动能、有序能以及冷无序能之间的竞争.考虑了冷无序能导致“冷无序”的物理功能,将冷无序能变换为等效温度,在统计物理的框架内处理了铁磁性、反铁磁性转变和自旋玻璃冻结问题.A2=0的体系具有Weiss铁磁性,|A2|A1=1的体系表现自旋玻璃磁性,1>|A2|A1>0的体系同时具有铁磁性和自旋玻璃磁性,1>A1|A2|>0的体系同时具有反铁磁性和自旋玻璃磁性. 关键词： 交换能 冷无序能 铁磁性 反铁磁性 自旋玻璃