离子通道电子束回旋脉塞的等离子体波效应

 研究了离子通道回旋电子束脉塞（ICECM）中的等离子体波非线性效应。利用流体理论与自洽非线性理论方法对ICECM中等离子体波效应的微观机理进行了分析。研究发现，等离子体波加强了电子束的纵向群聚，束-波互作用的能量交换效率及系统增益得到明显提高。数值模拟计算表明，对于中等等离子体密度、1.5kA电流和1MV加速电压的电子束，系统能够获得的脉冲功率和频率分别为200MW和280GHz的毫米波束。     

光促进温和条件非贵金属催化下卤代烃与二氧化碳的羰基化反应及ESR谱研究

研究了卤代烃在光促进温和条件（常温常压）非贵金属[Co(acac)₂,Co(OAc)₂或CoCl₂]催化下与二氧化碳的羰基化反应；同时对反应过程中的ESR谱进行了研究. ESR谱研究表明，在光促进下二氧化碳参与的羰基化反应中有二氧化碳游离基负离子（CO^·-₂）[用DMPO（5,5-二甲基-1-吡咯啉-N-氧化物）捕获］生成.     

多环化合物中共轭双键13C NMR化学位移计算

介绍多环化合物中共轭双键¹³C NMR化学位移计算.     

侧链型聚合物DANS-PMMA脊形条波导的制备

有机聚合物的紫外漂白,经过一系列复杂的光化学反应,会使聚合物薄膜的折射率和厚度降低。在此基础上,利用金属掩模对聚合物薄膜进行选择性紫外漂白,制备出了聚合物脊形条波导。紫外漂白不需要对聚合物薄膜进行光刻和腐蚀便可获得边缘和表面比较整齐和光滑的脊形条波导,对减少波导的散射损耗十分有利。本文介绍了利用紫外漂白和金属掩模方法制备侧链型聚合物DANS（4－dimethylamino-4’nitro-stlibene)-PMMA(polymethyl methacrylate)脊形条波导的工艺过程,并对关键工艺进行了讨论。     

Acoustic radiation from a fluid-filled, subsurface vascular tube with internal turbulent flow due to a constriction

The vibration of a thin-walled cylindrical, compliant viscoelastic tube with internal turbulent flow due to an axisymmetric constriction is studied theoretically and experimentally. Vibration of the tube is considered with internal fluid coupling only, and with coupling to internal-flowing fluid and external stagnant fluid or external tissue-like viscoelastic material. The theoretical analysis includes the adaptation of a model for turbulence in the internal fluid and its vibratory excitation of and interaction with the tube wall and surrounding viscoelastic medium. Analytical predictions are compared with experimental measurements conducted on a flow model system using laser Doppler vibrometry to measure tube vibration and the vibration of the surrounding viscoelastic medium. Fluid pressure within the tube was measured with miniature hydrophones. Discrepancies between theory and experiment, as well as the coupled nature of the fluid-structure interaction, are described. This study is relevant to and may lead to further insight into the patency and mechanisms of vascular failure, as well as diagnostic techniques utilizing noninvasive acoustic measurements.     

Synthesis, structural and magnetic properties of the nanocomposite Fe63B23Nd7Y3Nb3Cr1 magnets

The Fe₆₃B₂₃Nd₇Y₃Nb₃Cr₁ nanocomposite magnets in the form of sheets have been prepared by copper mold casting technique. The phase evolution, crystal structure, microstructural and magnetic properties have been investigated in the as-cast and annealed states. The as-cast sheets show magnetically soft behaviors which become magnetically hard by thermal annealing. The optimal annealed microstructure was composed of nanosize soft magnetic α-Fe (19-29 nm) and hard magnetic Nd₂Fe₁₄B (45-55 nm) grains. The best hard magnetic properties such as intrinsic coercivity, _jH_c of 1119 kA/m, remanence, B_r of 0.44 T, magnetic induction to saturation magnetization ratio, M_r/M_s=0.61 and maximum energy product, (BH)_max of 55 kJ/m³ was obtained after annealing at 680 °C for 15 min. The annealing treatment above 680 °C results in non-ideal phase grains growth, which degrade the magnetic properties.     

Analytical and semi-analytical solutions to flows of two immiscible Maxwell fluids between moving plates

Unsteady flows of two immiscible Maxwell fluids in a rectangular channel bounded by two moving parallel plates are studied. The fluid motion is generated by a time-dependent pressure gradient and by the translational motions of the channel walls in their planes. Analytical solutions for velocity and shear stress fields have been obtained by using the Laplace transform coupled with the finite sine-Fourier transform. These analytical solutions are new in the literature and the method developed in this paper can be generalized to unsteady flows of n-layers of immiscible fluids. By using the Laplace transform and classical method for ordinary differential equations, the second form of the Laplace transforms of velocity and shear stress are determined. For the numerical Laplace inversion, two accuracy numerical algorithms, namely the Talbot algorithm and the improved Talbot algorithm are used.     

Brownian motion and thermophoresis effects on unsteady stagnation point flow of Eyring-Powell nanofluid: a Galerkin approach

This article concerns the analysis of an unsteady stagnation point flow of Eyring-Powell nanofluid over a stretching sheet. The influence of thermophoresis and Brownian motion is also considered in transport equations. The nonlinear ODE set is obtained from the governing nonlinear equations via suitable transformations. The numerical experiments are performed using the Galerkin scheme. A tabular form comparison analysis of outcomes attained via the Galerkin approach and numerical scheme (RK-4) is available to show the credibility of the Galerkin method. The numerical exploration is carried out for various governing parameters, namely, Brownian motion, steadiness, thermophoresis, stretching ratio, velocity slip, concentration slip, thermal slip, and fluid parameters, and Hartmann, Prandtl and Schmidt numbers. The velocity of fluid enhances with an increase in fluid and magnetic parameters for the case of opposing, but the behavior is reversed for assisting cases. The Brownian motion and thermophoresis parameters cause an increase in temperature for both cases (assisting and opposing). The Brownian motion parameter provides a drop-in concentration while an increase is noticed for the thermophoresis parameter. All the outcomes and the behavior of emerging parameters are illustrated graphically. The comparison analysis and graphical plots endorse the appropriateness of the Galerkin method. It is concluded that said method could be extended to other problems of a complex nature.     

微波烧结Al_2O_3陶瓷的研究

简要介绍了微波烧结的特点,对 Ａｌ２ Ｏ３ 陶瓷的微波烧结过程进行了介绍和分析,并同常规烧结进行了对比实验,在此基础上得出了一些结论,为陶瓷微波烧结提供了实验依据