一种自支撑金纳米薄膜的制备、结构和氮吸附特性

以一种新的硅微米/纳米结构复合体系——硅纳米孔柱阵列作为还原性衬底，采用浸渍技术制备出一种自支撑的金纳米薄膜，并对其表面形貌和结构进行了表征.实验表明，金纳米薄膜的制备过程是一个自终止过程.当硅纳米孔柱阵列被耗尽后，浸渍溶液中Au³⁺的还原反应将自行终止；同时，所形成的金纳米薄膜自动与衬底脱离并成为一种自支撑薄膜.薄膜的形成机理被归因于硅纳米孔柱阵列所具有的高的表面活性和还原性.用能量弥散x射线谱对薄膜表面化学成分分析的结果表明，如此制备的金纳米薄膜具有很强的氮吸附和氮储存能力.这一特性有可能在气体传感器、空气分离和氮纯化以及氮化合物的膜合成器等技术领域得到应用. 关键词： 自支撑金纳米薄膜 硅纳米孔柱阵列 浸渍技术     

Al-Cu阻抗匹配状态方程实验系统误差讨论

通过阻抗匹配实验可以获得物质高压状态方程参数。测量不确定度和是否存在系统误差是评价参数质量的两个重要方面。形象地说不确定度表示参数的误差棒大小，系统误差表示参数值本身的取向趋势。     

基于支持向量机对种群特征回归分析的自适应遗传算法

在分析标准遗传算法易发生早熟收敛的基础上,提出了遗传算法种群特征代间海明距离的概念,代间海明距离可以较好的反映算法运行的总体与动态性能.应用支持向量机对遗传算法的代间海明距离进行了回归分析,遗传算法依据回归分析结果调整其整体优化策略,同时依据算法当前运行情况自适应调整种群的多样性,有效地避免了遗传算法的早熟收敛.数值实验结果表明,该改进算法搜索整体性较强,搜索效率优于标准遗传算法,提高全局优化能力.     

Structure of Multi-Species Charged-Particles with Competing Interactions in a Quadratic Trap

Multi-species charged-particles interacting with each other by a competing short-range attraction and long-range repulsion potential confined in a quadratic trap are studied with molecular dynamics simulations. It is found that particles with similar mass-to-charge ratio tend to populate a common shell, whose location depends on the particle mass-to-charge ratio, and that the greater the latter is, the closer the particles to the centre of the trap are. This rule for the ground-state configuration is independent of the total particle and species numbers in the system.     

从一道高考题谈导数中的切线问题

2004年重庆市高考文科数学第15题:已知曲线y=1/3x3 4/3,则过点P(2,4)的切线方程是____.     

Magnetic Properties of Diluted Magnetic Semiconductor Zn1-xMnxO Nanowires

Zn1-xMnxO nanowires (x = 0.035 and 0.13) have been synthesized by the vapour phase growth at 500℃. The compositional lines scanned in the energy dispersive x-ray spectroscopy (EDX) modes exhibit the homogeneous distribution of manganese in ZnO nanowires, The magnetic property measurement results show that the magnetization changes linearly with the field at high temperature, while it changes nonlinearly at low temperature,and all of the data can be well fitted by the modified Brillouin function. The magnetization of the Zn1-xMnxO nanowires show paramagnetic the behaviour for x -- 0.035 while it exhibits the ferromagnetic behaviour for x=0.13 at 5 K, which indicate that the ferromagnetism might be related to the manganese content.     

利用光学渡越辐射进行强流束诊断

当匀速运动的带电粒子通过介质交界面时，在库仑场重建的过程中，会产生渡越辐射，位于可见光波段的渡越辐射被称为光学渡越辐射（OTR）。它作为一种束流诊断工具，具有空间分辨率高、时间响应快、多参数同时测量、对束流影响小、装置简单等特点，能够测量束剖面、发散角、发射度、能量、束流的宏脉冲长度和微脉冲长度等多个参数，因此在国外加速器领域得到了比较广泛的应用。     

弱碱HYY树脂对链霉素分离纯化的研究

作者用ＨＹＹ弱碱树脂对链霉素的分离纯化进行了实验，详细地研究了树脂的吸附和脱附性能，吸附量达２８万／ｍｌ树脂，脱附率达９６％，获得了较满意的结果。     

Influence of Inert Gas Pressure on Growing Rate of Nanocrystalline Silicon Film Prepared by Pulsed Laser Deposition

Nanocrystalline silicon film (nc-Si) was prepared by pulsed laser deposition in different inert gas atmospheres such as He, Ne and Ar. The influence of inert gas pressure on growing rate of the film was investigated. The results show that with increasing gas pressure, growing rate first increases and reaches its maximum and then decreases; the gas pressure at the maximum of growing rate is proportional to the reciprocal of atomic mass of gas. The rate maximum is 0.315 A/pulse when He gas pressure is 8.3 Pa. The dynamic process is analysed theoretically by means of resputtering from the film surface and scattering of ablated particles. Ehrthermore, our results are compared with those in the case of Ag target.     

在浅海环境中潜艇隐蔽占位航路研究

本文运用平滑平均场理论和动态规划方法，研究潜艇如何利用水声环境蔽占位，重点分析了在水声环境比较好和比较差的两种典型情况下，潜艇用定速和每航段用最低速度占位问题，结果表明在不同的水声环境和相互态势下，潜艇须采用不同的隐蔽航路占位。