磁场对水系统内能影响的MC计算机模拟方法研究

用Monte-Carlo计算机模拟方法,通过对一个含有64个水分子的三维体系在磁场作用时内能变化的计算,定量评估了磁场强度及温度对磁处理效应的影响。研究发现:水的内能与外加磁场强度的关系曲线是一条多极值曲线;水-水径向分布函数伴峰的高度与磁感应强度也具有多极值特征;计算机模拟结果与实验结果基本一致,计算机模拟确实是从分子水平研究磁处理机理的有效方法。     

二维傅里叶变换引起的谱失真

用计算机模拟方法讨论了在谱线重叠的条件下，谱线强度因二维傅里叶变换而引起严重失真的问题，并结合例子详细研究了未被人们注意的一些情况。     

ALICE实验中光子谱仪的触发选判机制的模拟研究

对ALICE实验光子谱仪的触发选判机制进行了模拟研究, 内容包括: 1) 对光子谱仪的能量重建性能进行了研究, 通过计算机模拟检验光子谱仪探测器对大横动量范围的入射粒子的能量重建性能; 2) 对光子谱仪探测器的事件触发效率进行了研究, 通过计算机模拟分析触发阈值的选取并计算触发效率; 3) 对光子谱仪探测器的事件触发频率进行了研究, 通过计算机模拟对p-p和Pb-Pb两种碰撞模式下的触发频率分别进行了估算和讨论.     

DNA超分子水凝胶的粗粒化建模与模拟

DNA超分子水凝胶在生物、医学领域具有广阔的应用前景,基于计算模拟技术研究其分子结构与其宏观性能关系具有重要意义.归因于其复杂的结构和较大的相关时间空间尺度,目前针对DNA水凝胶的分子建模与模拟研究比较缺乏.本文建立了一种DNA水凝胶的粗粒化模型,采用分子动力学模拟的方法针对一种模块化纯DNA水凝胶进行了研究.模拟结果表明其凝胶态介观结构为多孔海绵状,其交联度与水凝胶的浓度成正相关,并得出了其转变温度的范围等.模拟结果与相关实验定性或半定量符合,表明该模型可能用于该模块化DNA水凝胶等类似系统的结构功能关系研究.     

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。     

刚体绕瞬心的转动方程的计算机模拟

在《大学物理》上曾对刚体绕瞬心的转动方程进行过广泛深入的讨论，这些讨论都是建立在解析分析的基础上，本则用计算机模拟的方法研究这个方程．计算机模拟的结果不仅形象直观地表现了公式的丰富内涵，也证明计算机模拟是教学研究的一种优秀工具．     

光学实验的计算机仿真

基于计算机仿真技术,以光学干涉实验和滤波实验为研究对象,应用Matlab软件数值模拟了杨氏双缝干涉实验和多光束干涉实验干涉图形和光强分布图,数值模拟了光学滤波实验字母滤波后的频谱图和字母成像图,结果表明,计算机仿真结果能够清晰的表达出实验和理论的效果。研究结果为光学实验的课堂教学提供了参考。     

旋转活塞发动机传热过程的分析和计算机模拟

考虑了旋转活塞发动机扫流、泄漏和点火燃烧的特点以及水侧壁面的沸腾换热,对这种新型发动机传热过程进行了分析,并根据本文提出的传热模型对传热过程进行了计算机模拟。所得的结果同实验值做了比较,其结果是相符的。     

高斯光束夫琅禾费单缝衍射的数值模拟

采用计算机对高斯光束的夫琅禾费单缝衍射作数值模拟,并与标准夫琅禾费单缝衍射进行对比分析,讨论了衍射场的一些基本特征     

多晶材料晶粒生长的计算机模拟研究

多晶固体材料显微结构的演化与诸多因素密切相关 ,是一复杂的过程。运用适当的计算机模拟方法进行模拟 ,实现对晶粒生长的预测 ,可为材料研究提供新的方法和重要依据。此文以晶粒生长动力学为基础 ,建立晶粒生长模型 ;分析了晶粒生长过程的计算机模拟理论和方法 ;以MonteCarlo方法为基础 ,提出快速Q statepotts算法 ,简化计算量 ,在PC机上编程实现了正常晶粒生长过程的计算机模拟。得到的显微结构图逼真度较好。通过对结果进行分析处理 ,得到的生长因子为 0 .4 7。     

Numerical simulation of high-gradient magnetic filtration

We have reported on the results of a numerical simulation of high-gradient magnetic filtration of ultradisperse corrosion products from water coolants. These results have made it possible to establish optimal technical characteristics of high-gradient magnetic filters. The results have been used to develop test samples of high-gradient magnetic filters (HGMFs) with different magnetic systems to purify technological water media of atomic power plants from activated corrosion products.     

Dynamical properties of magnetized two-dimensional one-component plasma

Molecular dynamics simulation are used to examine the effect of a uniform perpendicular magnetic field on a two-dimensional interacting electron system. In this simulation we include the effect of the magnetic field classically through the Lorentz force. Both the Coulomb and the magnetic forces are included directly in the electron dynamics to study their combined effect on the dynamical properties of the 2D system. Results are presented for the velocity autocorrelation function and the diffusion constants in the presence and absence of an external magnetic field. Our simulation results clearly show that the external magnetic field has an effect on the dynamical properties of the system.     

Monte Carlo simulation and optical transmission studies of lattice-tunable column arrays composed of ferrofluids

The aggregation and rearrangement of nanoparticles embedded in a thin cell of ferrofluid at various applied magnetic fields was studied by Monte Carlo simulation. Regular microcolumns with the axis parallel to the magnetic field were observed with column size and spacing depending on the ramp speed of the applied field. Our model successfully simulated the reported experimental results that the column size decreases as the ramp speed increases, which is attributed to the diminishing time to achieve the final assembled state at a given final magnetic field. Column arrays of tunable lattice constants characterizing various spectroscopic dispersions are elucidated. The hexagonal structure of the aggregation of magnetic nanoparticles and optical dispersion were observed through an optical microscope. The transmission diffraction spectra depending on column spacings and sizes of the column array are simulated to yield results comparable to the experiment.     

Dynamics of charged particles in the field of a spherical magnetic dipole

The results of numerical simulation of the dynamics of charged particles in the field of a spherical magnetic dipole are reported. Interesting features revealed in this dynamics can be used in analysis of near-Earth space with the help of charged particle beams.     

Simulation of the External Magnetic Field Effect on Fusion Plasma

Issues of numerical simulation of an experiment on compression and heating of a target in a magnetic field are discussed. It is found that the applied magnetic field predominantly increases the plasma lifetime and plasma jet characteristics (velocity, Mach number, density, etc.). An analysis of the effects of the application of an external magnetic field on the behavior of plasma-driven guns (plasma jets) and laser-driven systems (laser beams) is carried out. Thermodynamic questions in simulation of experiments on magnetic inertial synthesis are touched upon.     

The Influence of Magnetic Field on Electrokinetic Potential of Colloidal Particles

Russian Physics Journal - The influence of a magnetic field on the electrokinetic potential of colloidal particles in a water flow oversaturated with deposited salts is reported. For the first...     

磁约束磁控溅射源的磁场设计

磁控溅射镀膜机中的磁场分布对靶材利用率有着重要影响。为了提高磁控溅射源的靶材利用率,设计组抛弃了传统的"跑道环"形式的磁场设计理念,而是将永磁体或电磁体分置溅射靶的两侧,使其在溅射靶表面上方产生磁约束(磁镜)磁场。本设计使用有限元分析方法对磁场进行仿真计算,通过模拟磁场计算结果和实测结果的比较,验证有限元方法的可靠性。Ansys有限元分析软件对磁场分布进行仿真模拟,大大简化了计算并缩短了设计周期。通过实验验证,磁约束磁场大大提高了靶材的利用率。     

Effect of weak magnetic fields on the properties of water and ice

We establish that a number of physical properties of water and ice are significantly changed by an alternating magnetic field of a certain frequency. The changes in the physical parameters of ice are several times stronger than the changes in the corresponding parameters of water. Heating water to 50°C destroys the magnetic effects. When the field is much weaker than the geomagnetic field, a change in water purity (bidistilled instead of distilled water) only broadens the extrema observed in the state dependences of water and ice on the frequency of the alternating magnetic field of constant amplitude. The magnitude and intensity of these extrema are unaffected by water purity. The effects of the geomagnetic field on the properties of ice and water are also discussed.Translated form Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 13–17, May, 1988.     

A one-dimensional fluid simulation of a magnetized DC discharge including the non-uniform effects of the magnetic field

A one-dimensional simulation of a magnetized DC discharge is conducted based on the fluid equations that consider the non-uniform effects of the magnetic field. We apply a dielectric relaxation scheme (DRS) as an efficient numerical algorithm that was recently developed for simulation of low-temperature process plasmas. The simulation results, such as the spatial profiles of ion densities, electron densities, electron fluxes, and electric fields, are compared with the simulation results for which the non-uniform effects of the magnetic field are neglected.