CO_2-N_2系统中光电流信号的产生机理

本文采用窄带滤波器测定了CO_2-N_2放电管在CO_2激光照射下的光电流信号,并用二阶微分网络法测量了相应的电子能量分布,认为:CO_2-N_2气体放电管中,光电流信号的产生是由于处在电子激发态上的CO_2分子和N_2分子受到10.6μm激光扰动,逐级电离的速率发生变化所致。

含气泡液态金属的磁流体力学和Hartmann流动

本文给出含气泡液态金属的磁流体力学基本方程,以及Hartmann流动的解。

地球极区的磁流体力学慢激波

<正> 离子在极区电离层被加热和加速以后,逃离地球引力场而形成极风。低能离子通过极风而传送到磁层中,成为磁层粒子的一个重要来源,越来越受到人们的重视。极风的主要成分是H~+、He~+和少量低能的O~+,其中氢离子流量为10~7—5×10~8/厘米~2•秒,氦离子的流量为10~5—10~7/厘米~2•秒。探险号31在极区距地球500—3000公里处测得平行于地磁场的H~+外流速

CSM玻璃钢层间剪切断裂

本文对CSM-GRP层间剪切断裂用实验与分析方法进行了研究。用英国标准BS4994规定的双槽试件拉剪法测量了层间剪切强度(ILSS)。用有限元法计算了应力分布、损伤扩展和复合型应力强度因子。并讨论了BS4994规定的这一试验方法的可靠性。

快速静电探针的研制与应用

<正> 1.引言静电探针作为等离子体诊断的一种基本手段,在许多高温气体动力学的地面模拟实验设备(诸如电弧加热器、等离子体风洞、火箭发动机、激波管、高速弹道靶等)以及再人飞行试验中均有广泛的应用。因此,它对于同遥测、通

An improvement on the theoretical model for the large-scale coherent structures in the outer region of a turbulent boundary layer

According to the experimental results, there exist large-scale coherent structures in the outer region of a turbulent boundary layer, which have been studied by many authors.As experimental results, Antonia (1990) showed the phase- aver aged streamlines and isovorticity lines of the large-scale coherent structures in a turbulent boundary layer for different Reynolds numbers. Based on the hydrodynamic stability theory, the 2-D theoretical model for the large-scale structures was proposed by Luo and Zhou, in which the eddy viscosity was defined as a complex function of the position in the normal direction. The theoretical results showed in ref. were in agreement with those in ref. However, there were two problems in the results. One is that in the experimental results, there were divergent focuses between two saddle points in the streamlines, but in the theoretical results, there were centers. The other is that the stretched parts of the isovorticity lines appear at the location of centers in the theoretical results, while in the experimental results they located somewhere between the focuses and saddle points. The reason is that the computations were based on a 2-D model.

Experimental-study of free-surface oscillations of a liquid bridge by optical diagnostics

A non-contact optical method, consisting of a projecting grating technique for the relative measurement of a surface, and a technique of absolute measurement at a fixed point on the surface, are applied to measure the free surface vibration in a liquid bridge of half floating zone with small typical scale of a few of mm for emphasizing the thermocapillary effect in comparison with the effect of buoyancy. The radii variations in both longitudinal and azimuthal directions are obtained, and, then, the feature of surface wave could be analyzed in detail. The results show that there are values of principal oscillatory frequencies at different positions of free surface. The amplitudes of surface waves in longitudinal and azimuthal directions are several mum and several tenths of mum in order of magnitude. The phase of two-dimensional surface waves is different at different height for fixed cross section or at different azimuthal angle for fixed height. The wave features are discussed for the cases of typical parameter ranges.

Note on the instability of capillary jet with thermocapillarity

In this paper, we examine a new basic state of long axisymmetric liquid zone, subjected to axial temperature gradients which induce steady viscous flow driven by thermocapillarity. Axial velocity 1/4S-1/2R(B) of liquid zone connects pulling velocity of single crystal. The stability of liquid zone with pulling velocity 1/4S-1/2R(B) to small axisymmetric disturbance is examined The eigenvalue problems on the stability are derived. A special case (eta = 0) is discussed.