介质极化的瞬时相位与振幅

求解电子运动的二阶微分方程，在旋转波近似下，介质在外场突然变化时产生的瞬态感应极化与外场同频，但相位总是落后，最大落后为π/2；振幅大小与初态有关，随时间按指数规律衰减，衰减快慢由介质的阻尼系数决定。     

化学与化工——化学与化工学科研究进展

在气体泄漏监测工作中选择合适的示踪剂是非常重要的。近年来，围绕示踪剂的研究开展了大量的工作，为了寻求现有示踪剂的改进，开展了全氟二甲基环丁烷示踪剂在carboxen-569分子筛上的吸附行为研究，考察了温度和采样速度对示踪剂穿透体积和安全采样体积的影响，确定了大气示踪剂样品的采集工艺参数和热解吸条件，为该示踪剂的应用奠定基础。     

Bistable Behaviour of N Two-Level Atoms Interacting with the Field inside a High-Q Cavity Containing a Nonlinear Kerr-Like Medium

Taking the intensity-dependent coupling between atoms and cavity mode into account, we investigate a system consisting of N homogeneously broadened two-level atoms interacting with the field inside a single-mode Fabry- Perot cavity containing a nonlinear Kerr-like medium. We derive the steady-state bistable behaviour of the system, and further analyse in details the influence of several critical parameters on the bistable behaviour.     

一类非经典扩散方程整体解的存在唯一性及长时间行为

本文讨论非经典扩散方程第一初边值问题整体解的存在唯一性及长时间行为，建立了一系列新的结果，较好地改进许多已有的结论．     

Double-Humped Transverse Density Profile in Two-Dimensional Chute Flow with Rough Sidewalls

We study a two-dimensional granular rapid flow with rough sidewalls stuck with the same size discs by molecular dynamics simulation. A transient state of the double-humped density profile in the flowing process has been found, which appears and moves as travelling wave and is the same as the phenomena in the recent experiments [Acta Phys. Sin. 53 （2004） 3389 （in Chinese）]. Our simulation shows that the rough sidewalls play an important role in the converting momentum of boundary discs from the vertical direction to the horizontal one through particle collisions to form this profile and the good elasticity of discs ensures this effect. The appearance of the double-humped profile may be a precursor, which determines if the whole flow will be far repulsed from the boundary and become dilute eventually.     

无界区域R1上推广的B-BBM方程的整体吸引子

本文研究了无界区域R^1上推广的B—BBM方程的长时间动力学行为，证明了该方程整体吸引子的存在性．     

THE LARGE TIME BEHAVIOR OF SPECTRAL APPROXIMATION FOR A CLASS OF PSEUDOPARABOLIC VISCOUS DIFFUSION EQUATION

The asymptotic behavior of the solutions to a class of pseudoparabolic viscous diffusion equation with periodic initial condition is studied by using the spectral method. The semidiscrete Fourier approximate solution of the problem is constructed and the error estiation between spectral approximate solution and exact solution on large time is also obtained. The existence of the approximate attractor AN and the upper semicontinuity d(AN,A)→0 are proved.     

SYNTHESIS OF POLYMER—SUPPORTED PALLADIUM CATALYSTS AND THEIR CATALYTIC BEHAVIOR FOR THE SELECTIVE HYDROGENATION OF MESITYL OXIDE

Copolymer of styrene-divinylbenzene in bead from was made by suspension polymerization.After chloromethylation and amination,five kinds of polymeric amines were thus obtained.These polymers were reacted with palladium chloride,and were then reduced.The polymer-supported catalysts synthesized above were used to catalyze the selective hydrogenation of mesityl oxide under reaction conditions of 80℃ and 10kg/cm^2,using methanol as a solvent.The catalytic activity and MIBK(methyl isobutyl ketone) formation selectivity of the catalysts were examined.     

L-半胱氨酸自组装膜电极上锌离子的电化学行为及分析应用

锌是人体必需的微量元素 ,也是金属酶的组成部分和酶的激活剂 ,目前已知有 80多种酶的活性与锌的存在有关 ,因此研究锌在生物分子 (如Ｌ 半胱胺酸 )自组装膜结构中的电化学行为 ,对于研究和了解生物体内生命物质的电子转移及生命现象的本质具有重要意义。本文研究Ｚｎ2 +在Ｌ 半胱氨酸自组装修饰金电极[1～3] ,Ｃｙｓ/ＳＡＭ/Ａｕ上的电化学行为 ,建立了测定Ｚｎ2 +浓度的新方法 ,用于人体发样中痕量Ｚｎ2 +的测定 ,与目前所报道的锌的测定方法[4] 相比 ,具有快速、准确、灵敏度高等特点。1　实验部分1 1　仪器与试剂ＣＨＩ660型电化学工作…