Soliton formation in electron-temperature-gradient-driven magnetoplasma

Electron-temperature-gradient(ETG)-driven solitons are studied in a plasma.We derive the linear dispersion relation and an admitted solitary wave solution Korteweg–de Vries-typeequation(Kd V)for the ETG mode in the nonlinear regime by using the Braginskii model and a transformation.It is found that the ETG mode supports only rarefactive solitons.It is also observed that the ratio of electron-to-ion temperature t=T T,_e _ithe ratio of gradient scale lengths h=L L,_(en) _Tand the magnetic field B affect both the amplitude and width of a soliton.It is found that the soliton profile changes with variation in these parameters.We apply the homotopy perturbation method to the derived Kd V equation.It is found this method is computationally attractive and the results are very impressive.This work may be useful to study the low electrostatic modes in inhomogeneous electron–ion plasma with density and ETGgradients.For illustration,the model has been applied to tokamak plasma.     

建筑采暖设计软件HPM的应用

HPM是PKPM系列建筑、结构、水暖电集成化CAD系统中采暖设计软件。该软件具有自动化程序高,制图、计算一体化的特点,实际工作中,软件本身有些局了性。通过对HPM的使用,提出了HPM软件在采暖设计工作中存在的问题,以及相应的解决方法,为设计工作的顺利进行提供了帮助。     

智能大楼布线系统的电磁防护问题

智能大楼已成为信息社会的重要支撑设施,必须考虑防护强微波ＨＰＭ辐射的破坏作用,在大楼建设阶段就要进行智能大楼布线系统电磁加固设计。分析了外界电磁波对智能大楼信息系统的有害影响,研究了垂直和水平布线上的感应电流并且推导了理论的和简化和设计公式,提出了智能大楼布线系统电磁加固的设计方法。     

高功率微波的发展与现状

简要介绍了高功率微波产生的原前正迅速发展的高功率微波的应用前景及其发展趋势.     

大功率微波电子注器件及其发展

本文综述了大功率微波管最新进展,指出以电子注和场互作用为基础的大功率微波管,相对论高功率微波源,真空微电子器件是国防和信息系统的核心器件,其技术进展将为２１世纪军事电子装备的发展提供强有力的支持,也将对信息社会产生深远影响。     

海藻硫酸多糖对HPM辐射致GC-2细胞损伤保护作用研究

探讨了海藻硫酸多糖(SP)对高功率微波(HPM)致小鼠精母细胞系GC-2细胞的损伤防治作用及其机制,为新型抗电磁辐射药物开发提供基础.将GC-2细胞分为药物组、药物对照组、辐射组和正常对照组,采用平均功率密度为30 mW/cm2的S波段HPM辐照15 min,药物组和药物对照组于照射前24h加入SP(终浓度25 μg/...     

Heat transfer analysis of CNTs-water nanofluid flow between nonparallel plates: Approximate solutions

Approximate solutions are given to investigate the problem of heat transfer and flow of a nanofluid between two nonparallel plates. Two different types of carbon nanotube (CNT) nanoparticles, namely functionalized single-walled carbon nanotubes and functionalized multi-walled carbon nanotubes are considered with water as the base fluid. The chemical functionalization is attributed to the attachment of the covalent bond of functional groups onto carbon nanotubes. Using the appropriate similarity variables, the model partial differential equations are transformed into ordinary differential equations and tackled analytically via the homotopy perturbation method. Comparison of the obtained results is carried out with those obtained by the previously published in the literature as well as the Runge–Kutta–Fehlberg method and an excellent agreement is achieved. The effects of various emerging parameters on nanofluid velocity, temperature, skin friction coefficient, and Nusselt number are illustrated graphically and comprehensively discussed.     

Peristaltic flow of a Phan‐Thien‐Tanner nanofluid in a diverging tube

The present study examines the peristaltic flow of a PTT nanofluid in a diverging tube. This is the first article on the PTT peristaltic flow in nanofluid. The governing equations for PTT nanofluid are modelled in a cylindrical coordinates system. The flow is investigated in a wave frame of reference moving with velocity of the wave c₁. Temperature and nanoparticle equations are coupled so the homotopy perturbation method is used to calculate the solutions of temperature and nanoparticle equations, while exact solutions have been evaluated for the velocity profile and pressure gradient. The solutions analyze the Brownian motion number N_b, thermophoresis number N_t, local temperature Grashof number B_r, and local nanoparticle Grashof number G_r. The effects of various physical parameters of the model are investigated and discussed. It is observed that the pressure rise decreases with the increase in thermophoresis number N_t. Increases are noted in the Brownian motion parameter N_b and the thermophoresis parameter N_t as the temperature profile increases. Streamlines have been plotted at the end of the article. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.20386     

超硬磨具用耐高温酚醛树脂结合剂的合成与表征

采用硼酸和N-(4-羟基苯基)马来酰亚胺(N-HPM)联合改性酚醛树脂(PF),制得具有良好耐热性和机械性能的PF。热分析实验结果表明:改性PF的耐热性能明显优于纯PF,改性PF失重10%的温度为490℃,比纯PF提高了130℃。实验结果表明:改性PF制得磨具样条的抗折和抗冲击强度比纯PF制得的样条均提高40%以上。     

高功率微波大气传播数值计算的加速方法

用时域有限差分法(FDTD)对高功率微波(HPM)大气传播进行数值仿真时,所要关心的仅是传播目标点HPM波形的分布,而传播过程中每一空间点不需要考虑,所以可将传播空间分段计算,在分段点处需要增加一个吸收边界,并将传播到该点的HPM保存下来,作为后继计算空间的源加入到其后一空间步,完成数据传递。通过这样循环处理可以达到节约计算时间和存储内存的目的,从而达到加速计算的目的。