Effect of transverse static magnetic field on stimulated brillouin scattering of electromagnetic wave

Stimulated Brillouin scattering of a plane polarised electromagnetic wave propagating perpendicular to a static magnetic field has been investigated analytically in ann-type piezoelectric semiconductor-plasma. Using coupled mode theory the dispersion relation is obtained and the threshold value of the amplitude of electromagnetic wave for the onset of instability is studied for both the forward and back-scattered modes. The role of the magnetostatic field on the threshold conditions for the unstable mode has been discussed.     

测量单模光纤模场直径的一种新方法

本文根据单模光纤模场直径的横向位移定义,提出了一种测量模场直径的新方法——远场高斯掩模匹配法.讨论了几种测量及数据处理方法.最后给出了初步的实验结果.     

计入横向剪切变形时层合板位移差分解法

在考虑横向剪切变形对层合板弹性解的影响时，本文提出一种数值计算方法。由边界条件给出边界结点位移的表达式，根据薄板的经典理论和一阶横向剪切变形理论导出位移增量所满足的平衡微分方程，引用经典理论计算的横向剪力修正了荷载列阵。致使在较粗的网格划分时、宽广的层合板长厚比范围内，仍能得到与解析解颇为一致的数值解。     

A Comparative Study on Electrochemical Oxidation of Phenol in Two Types of Cells

Electrochemical oxidation of phenol was studied using Ti/IrO₂/RuO₂ anode and a carbon/polytetrafluoroethylene (C/PTFE) O₂-fed cathode which generated hydrogen peroxide (H₂O₂) by the reduction of oxygen in the undivided cell and the divided cell with a cotton diaphragm. For degradation mechanism of phenol on the cathode and anode, two kinds of cells are similar. However, the basic condition of the cathodic compartment in the divided cell was prone to H₂O₂ changed to and HO ₂ ⁻ and HO^·. So, the mineralization of phenol in the divided cell was better than that in the undivided cell.__________From Elektrokhimiya, Vol. 41, No. 7, 2005, pp. 810–816.Original English Text Copyright © 2005 by Wang Hui, Yu Xiujuan, Wu Lan, Wang Qiang, Sun Dezhi.The text was submitted by the authors in English.     

相对论重离子碰撞中逐事件横动量起伏的蒙特卡洛研究

用蒙特卡罗模型研究了相对论重离子碰撞中逐事件横动量起伏与多重数的关联, 发现蒙特卡罗产生器,HIJING,不能描述实验现象. 提出了一个简单的蒙特卡罗模型, 可以与实验一致, 有助于理解逐事件横动量起伏与多重数关联的动力学起源.     

Interaction of Plane Stress Waves in a Three-Layer Structure. 1. Degenerate Solutions in Terms of Characteristics for a Homogeneous Structure

Exact expressions in terms of characteristics for calculating the normal-stress waves propagating across the layers of different materials are deduced. A one-dimensional boundary-value problem is considered for a three-layer structure of sandwich type. The faces of the layered structure are free from loads or one of them is rigidly fixed (variant 1), or one face is rigidly fixed and the other is subjected to an impact of a mass M with a speedV₀ (variant 2). For the boundary conditions of variant 1, relationships are obtained which allow one to reduce the analytical continuation of a solution in time to a periodic procedure if solely the initial disturbances of the strain field in the layers are given. It is shown that, in this case, the Cauchy problem with the initial strain field is reduced to graphoanalytically constructing the superposition patterns of the forward and backward waves. The fundamental features of the construction are demonstrated for a uniform bar with a piecewise constant distribution of strains along its length. To solve the problem of impact loading in variant 2, analytical results for a uniform plate are used, which allows us to account for the direction of mass forces in collision. In the latter case, the possibility of mass recoil is revealed in the first and second time cycles. The analytical constructions presented are focused on an exact calculation of stresses upon response of a layered plate to initial disturbances within its layers, as well as to an external dynamic action. __________ Translated from Mekhanika Kompozitnykh Materialov, Vol. 41, No. 5, pp. 585–606, September–October, 2005.     

Grüneisen parameter and elastic constants of crystals and vitreous bodies

The squared ratio of the root-mean-square sound velocity to the velocity of transverse acoustic waves has a meaning of the average dimension of localization regions of energy accumulated by a deformable body. The Grüneisen parameter of solid bodies with identical values of this dimension depends linearly on the parameter γ3 being an unambiguous function of the Poisson coefficient. Solid bodies are grouped according to values of the average dimension of energy localization regions. The Belomestnykh–Tesleva formula relating the Grüneisen parameter to the Poisson coefficient follows from the suggested approach. The nature of the interrelation between these quantities is discussed. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 3–11, March, 2009.     

Non-collinearity in high energy processes

We discuss the treatment of intrinsic transverse momenta in high energy scattering processes. Within the field theoretical framework of QCD, the process is described in terms of correlators containing quark and gluon fields. The correlators, parametrized in terms of distribution and fragmentation functions, contain matrix elements of nonlocal field configurations requiring a careful treatment to assure colour gauge invariance. It leads to nontrivial gauge links connecting the parton fields. For the transverse momentum-dependent correlators the gauge links give rise to time reversal odd phenomena, showing up as single spin and azimuthal asymmetries. The gauge links, arising from multi-gluon initial and final state interactions, depend on the colour flow in the process, challenging universality.      

Rhodotron型加速器粒子动力学研究

Rhodotron是一种新型的CW电子加速器,已经广泛应用于辐照加工的很多领域.本文利用Parmela程序研究其动力学特性,深入分析了束团的同步条件、相聚过程以及在CW工作状态下束团相遇碰撞等一系列纵向动力学问题;并详细探讨了空间电荷效应、横向聚焦过程的实现、初始参量对横向束流特性的影响等横向动力学问题.在上述研究基础上,计算出束流损失功率的分布,并比较了模拟计算结果与Rhodotron原型机的实际参数,两者的结果基本一致,由此证明了这种研究方法的可行性.     

分流技术强化超声速混合及燃烧的数值模拟

本文提出一个利用分流技术强化超声速横侧射流混合及燃烧的新方法,即通过一个细小通道连通燃料喷口上下游,上游高压流体部分分流到下游,从底部抬高燃料穿透深度.应用修正可压缩性的 k-ε湍流模型,对不同喷射压力下冷态及燃烧流场进行数值模拟.有无采用分流技术的结果对比表明,分流技术能有效增大混合效率和燃烧效率,分流孔位置是一重要影响因素.观察到两类强化混合及燃烧的机制,合理布置分流孔位置可使燃烧效率相对提高 25% 以上.