改进型钢轨钻孔机的研制及应用

阐述了钢轨钻孔机的现状与改进方案,论述了钢轨钻孔机的研制过程及现场应用,分析了钢轨钻孔机的测试结论,并介绍了改进型钢轨钻孔机。     

资源有限的加权总完工时间单机排序问题

本讨论资源有限的加权总工时间单机排序问题，对现在仍为OPEN问题1｜pj=bj-ajuj，∑uj≤U｜∑wjCj给出了一个有关最优解中最优资源分配的重要性质，并利用该性质分别给出了三种情况bj=b,wj=w,aj=a；bj=b,wj=w,uj=u；aj=a,wj=w,uj=u的最优算法。     

半导体带电粒子探测器的研制及其在空间物理中的应用

阐述了空间辐射环境监测的意义,描述了半导体带电粒子探测器的研制及由其组成的望远镜系统在空间物理中的应用,并给出了用此探测器在卫星上进行地球辐射环境监测、太阳质子事件和地磁暴探测的部分结果.     

用示波器检测电磁学黑盒子实验I——物理奥林匹克选拔赛考题之一

介绍了可以用作物理奥林匹克实验培训的电学黑盒子实验的设计思想、实验内容和相应的参考答案 ,并对用该试题在中国物理奥林匹克集训队考试的结果进行了分析 .     

Least‐squares meshfree method for incompressible Navier–Stokes problems

A least‐squares meshfree method based on the first‐order velocity–pressure–vorticity formulation for two‐dimensional incompressible Navier–Stokes problem is presented. The convective term is linearized by successive substitution or Newton's method. The discretization of all governing equations is implemented by the least‐squares method. Equal‐order moving least‐squares approximation is employed with Gauss quadrature in the background cells. The boundary conditions are enforced by the penalty method. The matrix‐free element‐by‐element Jacobi preconditioned conjugate method is applied to solve the discretized linear systems. Cavity flow for steady Navier–Stokes problem and the flow over a square obstacle for time‐dependent Navier–Stokes problem are investigated for the presented least‐squares meshfree method. The effects of inaccurate integration on the accuracy of the solution are investigated. Copyright © 2004 John Wiley & Sons, Ltd.     

Behavior and surface energies of polybenzoxazines formed by polymerization with argon,oxygen, and hydrogen plasmas

Polybenzoxazine (PBZZ) thin films can be fabricated by the plasma‐polymerization technique with, as the energy source, plasmas of argon, oxygen, or hydrogen atoms and ions. When benzoxazine (BZZ) films are polymerized through the use of high‐energy argon atoms, electronegative oxygen atoms, or excited hydrogen atoms, the PBZZ films that form possess different properties and morphologies in their surfaces. High‐energy argon atoms provide a thermodynamic factor to initiate the ring‐opening polymerization of BZZ and result in the polymer surface having a grid‐like structure. The ring‐opening polymerization of the BZZ film that is initiated by cationic species such as oxygen atoms in plasma, is propagated around nodule structures to form the PBZZ. The excited hydrogen atom plasma initiates both polymerization and decomposition reactions simultaneously in the BZZ film and results in the formation of a porous structure on the PBZZ surface. We evaluated the surface energies of the PBZZ films polymerized by the action of these three plasmas by measuring the contact angles of diiodomethane and water droplets. The surface roughness of the films range from 0.5 to 26 nm, depending on the type of carrier gas and the plasma‐polymerization time. By estimating changes in thickness, we found that the PBZZ film synthesized by the oxygen plasma‐polymerization process undergoes the slowest rate of etching in CF₄ plasma. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 4063–4074, 2004     

ns脉冲激光对K9玻璃的破坏实验

 采用高速PIN光电探测器和高带宽的数字存储示波器，实时检测透射光脉冲和散射光脉冲的变化特征，并将之用作材料破坏的光学判据，测量得到K9玻璃在1.06μm纳秒脉冲激光作用下的能量损伤阈值约18mJ，相应的能量密度阈值为1.0kJ/cm²。通过分析透射光脉冲和散射光脉冲的特征，给出了材料的破坏时刻，并推断出K9玻璃所能承受的极限光强为10¹⁵W/m²。研究了能量透过率与泵浦能量的关系，并初步探讨了透明材料的破坏机理。结果表明：在多纵模激光的作用下，透明光学材料破坏是电离击穿与自聚焦效应综合作用的结果。     

连续照明时成像对比度与气象条件的关系

 通过同轴激光连续照明成像模型分析了大气后向散射对成像对比度的影响，得出了考虑散射因素时成像对比度的计算公式。基于不同气象条件下大气粒子散射特点，讨论了霾和雾两种不同天气时成像对比度随照明距离的变化规律，并与实验结果进行了对比，计算结果与实验吻合较好。     

利用普通视频CCD作为紫外激光和软X射线探测器的研究

 介绍了利用价格便宜的普通视频CCD来获取紫外激光和软X射线图像的方法和应用结果，以代替价格昂贵的紫外CCD、使用不方便的X光胶片或者昂贵的X光CCD，其关键点是：（1）去除CCD相机的自动增益校正；（2）将相机的校正系数γ值设置为1；（3）去除CCD相机前面的保护窗。作为一种简易的装置，可以用于紫外激光测量及激光与等离子体相互作用研究。结果表明，采用改造后的普通视频CCD测量紫外激光光斑，准确可靠，其灵敏度比科学级紫外CCD的低一个量级，它还可以测量软X射线的二维分布，作为X光针孔相机使用非常方便。     

Isolation of 2-Chloro-5-methylpyridine from its Isomer 2-Chloro-3-methylpyridine by Formation of its Copper(II) Complex

2-Chloro-5-methylpyridine is an important intermediate for the preparation of biological active compounds, especially insecticides1, e.g. imidacloprid2, and is usually manufac- tured from 3-methylpyridine N-oxide. However, the manufacturing process also forms the by-products: 3-methylpyridine and its isomer 2-chloro-3-methylpyridine3. The pro- perties of the isomers are similar, it is difficult to separate by ordinary methods, such as distillation. Scheme 1 79.4%13.6%5.2%NClCH3NCH3ClNC…