往复轴密封间隙内磁性液体流动状态的研究

为了解决往复轴磁性液体密封中存在的问题,研究了往复轴以不同速度和行程运动时,密封间隙内磁性液体的流动状态,重点研究了往复轴密封间隙内磁性液体流动机理、往复轴运动所带走磁性液体的量、往复轴磁性液体密封的失效原因及往复轴磁性液体密封新结构的设计.实践表明所设计的新结构在某些应用场合是非常有效的.     

9胆固醇类离子液体作为空间油润滑轴承抗磨添加剂的性能研究#br#

本文合成了一种新型胆固醇类磷酸酯离子液体(记作［Col］［DBP］)，通过一系列结构及理化性能表征，发现该离子液体具有良好热稳定性，在合成烃类油(MAC)中具有优良的油溶性.然后利用真空球 盘摩擦试验机对比考察了［Col］［DBP］与另外两种油溶性离子液体(［P88816］［DOSS］与［P8888］［DEHP］)作为MAC添加剂对钢/PI、钢/PA两种摩擦副的润滑抗磨性能，结果表明：对于钢/PI摩擦副，三种油溶性离子液体均表现出显著的抗磨性能，其中［Col］［DBP］离子液体的抗磨性能最优，［P8888］［DEHP］离子液体的减摩效果最好；对于钢/PA摩擦副，三种油溶性离子液体作为MAC添加剂，均未起到显著的润滑抗磨作用.利用OM和SEM对磨损表面进行分析表征，发现三种离子液体均能明显改善MAC润滑条件下摩擦副的犁沟效应，获得较为光滑平整的磨损表面.     

一种推进系统故障诊断反问题模型与算法

针对大型液体火箭推进系统故障诊断工作的需要, 建立了一种推进系统故障诊断反问题模型,并提出了基于遗传算法的反问题求解算法.在对故障诊断反问题的特点与困难及其求解方法研究的基础上,重点论述了基于遗传算法的反问题求解算法和基本过程.最后,给出了液体火箭推进系统故障诊断反问题求解的具体例子,表明所建立的推进系统故障诊断反问题模型及所提出的算法是合理有效的.      

苏／俄的潜地弹道导弹

固、液导弹齐上阵 前苏联先后发展了六代潜地导弹共8种型号,有6种是液体导弹,2种是固体导弹。在发展潜地导弹的同时,也相应建造了五种级别弹道导弹潜艇及其改进型。 第一代导弹“SS—N—4”从50年代末期开始装备,采用可贮液体推进剂,射程近,精度低,只能从潜艇水面发射。第二代导弹“SS—N—5”发射方式改用潜艇水下发射。第     

CCPL液体冷却罩(LCS)结构设计与分析

液体冷却罩是CCPL与CPL的主要区别之一 ,文章概述了液体冷却罩的主要作用和设计过程 ,讨论了液体冷却罩的不同结构设计方案 ,分析了它们的特性 ,通过比较认为 ,当工作环境与CCPL传输距离不同时 ,可选择不同结构的液体冷却罩 ,其中 ,由冷凝管道提供冷负荷的液体冷却罩设计方案是一种最具有前途的设计方案。     

不同驱动电压波形对电润湿液体透镜驱动效率的影响

研制了测试电润湿液体透镜在驱动电压作用下变焦过程的装置，详细分析了测试机理，用该装置实验研究了交流电压、交直流混合电压及直流电压三种不同波形驱动电润湿液体透镜的变焦过程，结果表明交流电压的驱动效率最高，交直流混合电压驱动效率次之，直流电压驱动效率最低；并对这一结果作出了合理的解释。     

苦尽甘来中国地地导弹事业的起步（上）

地地战略导弹是从陆地发射，用来打击敌方政治经济中心、军事和工业基地、核武器库、交通枢纽等重要战略目标的导弹。这类导弹，按动力装置区分为液体导弹和固体导弹两大类，通常携带核弹头，射程远，速度快，命中精度高，杀伤破坏威力大，是一种强大的威慑力量，在现代军事装备中占有特殊的地位。中国于20世纪50年代中期决定研制地地战略导弹，从仿制液体近程地地导弹起步，相继研制成功液体中近程、中程、中远程、洲际地地导弹和固体地地导弹，并陆续装备部队。[编者按]     

环路热管蒸发器毛细芯传热流动特性的一维分析

文章通过对液体在环路热管蒸发器毛细芯中的两种蒸发状态——表面蒸发状态、汽膜蒸发状态的分析，对液体在环路热管蒸发器毛细芯中的传热流动特性进行了一维数值计算，理论计算表明：在毛细芯正常工作状态下，液体在毛细芯中的蒸发属于表面蒸发，只有在进口液体存在过冷度时，汽膜蒸发才有可能存在。另外，文章还对毛细芯的壁厚、毛细芯的导热系数、进口液体的过冷度等因素对毛细芯传热流动特性的影响进行了讨论。     

动静压轴承列入重点推广

最近,从中航设备改造研制厂了解到,该厂研制的WMB液体动静压混合轴承,已为国防科工委、航空航天部列入“八五”期间重点推广高技术项目。 动静压混合轴承是一种兼备液体动压轴承和静压轴承二者优点,而又克服了二者缺点的新型液体滑动轴承。它利用液体静压作用将主轴浮起悬在油膜中间,克服了动压轴承启动时     

捍卫国家尊严中国洲际地地导弹研制回顾

1965年3月，中央专委决定研制洲际导弹，并下达了主要战术技术指标。同年8月，由一院副院长屠守锷主持进行了洲际地地导弹方案论证。洲际地地导弹用的液体火箭发动机是中国液体地地战略导弹中推力最大的发动机。任新民主持进行了发动机方案论证，     

Solutions of the hydromagnetic equation with magnetic null points

Numerical simulations of magnetic reconnection with uniform resistivity show that the length of the current sheet increases for increasing magnetic Reynolds number. In order to prevent the current sheet from growing in general the resistivity is assumed to be localized. For uniform resistivity the reconnection proceeds much slower than for localized resistivity. In this paper analytical solutions of the hydromagnetic equation are presented for localized and uniform resistivity. It is shown that there exists an essential singularity in the behaviour of a solution of magnetic reconnection in the limit of large magnetic Reynolds number: For prescribed boundary conditions the solution for localized resistivity does not approach the solution for uniform resistivity in the limit of large magnetic Reynolds number.     

平面磁流体波穿透圆柱面分层赤道电离层和大气层的理论

给出了平面磁流体快波穿透圆柱面分层模型的赤道电离层和大气层的理论．平面磁流体快波被分解成柱面波,柱面波在圆柱分层介质中的传播被化为一个两点边值问题,给出了所需统治方程和边界条件．     

Numerical simulation of reconnection in an emerging magnetic flux region

The resistive MHD equations are numerically solved in two dimensions for an initial-boundary-value problem which simulates reconnection between an emerging magnetic flux region and an overlying coronal magnetic field. The solution involves both ideal-MHD and resistive-MHD processes, and the solution shows an evolution which is remarkably suggestive of the preflare, impulsive, and main phases of the flare-cycle.     

流动对太阳黑子精细结构的影响

考虑磁扩散率为温度的函数以及绝热条件,线性扰动磁流力学方程组的色散方程是频率的三次方程。由于沿磁场流动的速度u₀小于声速u_s,即ε=u₀2/u_s2是一个小量,在零级近似下解色散方程,得到了磁扩散不稳定性。本文进一步讨论在一级近似下小流动对磁扩散不稳定性的影响。结果表明,小流动不破坏磁扩散不稳定性的存在,并且,它对波数空间中的不稳定区也影响不大。      

Strong magnetic field effect on the dissolution process of tetragonal lysozyme crystals.

Either a homogeneous or inhomogeneous magnetic field has been known to dampen the protein crystal growth. To date the mechanism is not clear. However, it was generally proposed that the magnetic field may dampen the convection in the solution, resulting in a reduced crystal growth rate and possibly a good crystal quality, similar to the case of protein crystal growth in space. To understand the mechanism of the magnetic field effect on protein crystal growth, further explorations on the magnetic field effect on protein solution, on the processes of crystal growth and dissolution, and on different crystallization (solution) systems, should be valuable. In this paper we present our recent efforts to study magnetic field effects on the dissolution processes of tetragonal lysozyme crystals under a strong magnetic field. A layer of oriented tetragonal lysozyme crystals was prepared under a temperature gradient and magnetic field, after that the crystals were dissolved by increasing the temperature of the solution. The lysozyme molecules will diffuse upwards due to the steep concentration gradient at the lower side of the cell caused by the dissolution. The evolution of the concentration in the solution was measured in-situ using a Mach-Zehnder interferometer. The results confirmed that the dissolution process of the crystals was slowed by the magnetic field. Judging from the concentration evolution versus time at different positions in the solution, we concluded that the apparent diffusion coefficient of lysozyme molecules was decreased by the magnetic field. The results were discussed using a suspended crystal model in the initial dissolution stage.     

Interstellar magnetic fields

For three decades, magnetic fields have been known to permeate interstellar space. Each decade focussed attention on a different problem concerning the role of magnetic fields in star formation, and developed distinct techniques for the solution of the respective problem. A historical perspective of this period is given first. Then theoretical studies of the role of magnetic fields in star formation are reviewed critically, with emphasis on the dynamical processes occuring in collapsing interstellar clouds and on the interplay between theory and observation. A synthesis in the form of a scenario, albeit incomplete, for star formation in magnetic clouds is given. Prospects for the solution, during the 1980's, for remaining fundamental problems are discussed, and the need for certain kinds of observations is emphasized.     

Alfvén波在任意流场、磁场位形中的传播

本文研究具有任意偏振和非单色的Alfvén波, 在任意流场、磁场位形且有粘、热各向异性等离子体流介质中的传播.采用WKB近似可以获得它的波幅矢量的张量表达式, 它是介质密度、速度、磁场、Alfvén波速、热各向异性和粘性的函数.文中对简单情形进行了讨论, 结果表明:本文结果是对普遍情形的一种简明的综合和概括, 便于研究三维传播问题.      

嵌套闭磁场结构内CME产生和传播的数值模拟

给出了特殊类型的日冕物质抛射(CME)数值模拟定性结果,这种CME核心闭磁场结构前半部分磁力线的方向与太阳整体偶极场磁力线的方向相反．计算结果表明,这种CME核心闭磁场结构磁力线与太阳整体偶极场反向磁力线之间存在过渡磁场结构,在向外传播时过渡磁场结构所占的面积逐渐增大．这一结果可以用来解释飞船为什么能够观测到一类双极磁云,这类磁云前半部分磁场方向与太阳整体偶极场方向相反．为了模拟这一数值结果,强调需要采用包含嵌套闭磁场的冕流背景结构,并在合适的位置触发CME．     

圆柱坐标中的非轴对称磁静平衡及其对太阳黑子的应用

本文采用圆柱坐标并假定总压力(气压和磁压之和)只与高度有关, 求得了三维两分量磁静平衡方程的通解.通过调节这一通解中出现的两个任意函数可得到各种特解.在应用这种特解去解释有关太阳物理现象时将不受小扰动条件的限制.同时, 我们找到一组特解, 可定性解释黑子内部的纤维结构和黑子外形的非轴对称性.      

Model of a fluxtube with a twisted magnetic field in the stratified solar atmosphere

We build a single vertical straight magnetic fluxtube spanning the solar photosphere and the transition region which does not expand with height. We assume that the fluxtube containing twisted magnetic fields is in magnetohydrostatic equilibrium within a realistic stratified atmosphere subject to solar gravity. Incorporating specific forms of current density and gas pressure in the Grad–Shafranov equation, we solve the magnetic flux function, and find it to be separable with a Coulomb wave function in radial direction while the vertical part of the solution decreases exponentially. We employ improved fluxtube boundary conditions and take a realistic ambient external pressure for the photosphere to transition region, to derive a family of solutions for reasonable values of the fluxtube radius and magnetic field strength at the base of the axis that are the free parameters in our model. We find that our model estimates are consistent with the magnetic field strength and the radii of Magnetic bright points (MBPs) as estimated from observations. We also derive thermodynamic quantities inside the fluxtube.