超高压光纤压力传感器理论和实验研究

本文提出了一种新型超高压光纤压力传感器.并用一种几何光学计算方法,用来计算该传感器的耦合系数曲线.在此基础上,设计并加工出一种具有新特点的超高压光纤压力传感器.这种传感器的实验研究结果与理论分析一致.     

SAW滤波器通带倾斜的预畸补偿设计

本文给出一种用等周期间隔的变迹换能器以补偿SAW滤波器通带倾斜的预畸设计方法.介绍了在两种基片上设计制作的三种滤波器,在补偿前后的实验结果.结果表明,这是一种简便而有效的补偿设计法.     

用于稀土永磁测量的强脉冲磁场装置

本文介绍了一种高性能强脉冲磁场装置的研究结果.提出了一种提高脉冲幅度和脉冲宽度的简单而有效的方法.     

计算顺磁-铁磁相变临界磁场的一种方法

利用线性自旋波方法并结合Hellmann-Feynman定理引入一种计算量子磁性系统临界磁场的方法.计算两种特殊模型的临界磁场,并将理论结果与数值结果进行比较,理论值与数值结果高度吻合,验证了理论方法的准确性.     

光切成型石墨电极三维模面测量技术的研究

基于光切法三角测量原理,提出一种实现成型石墨电极三维模面的扫描测量方案.文中讨论了光切法三维测量原理及系统组成,并提出了一种基于均匀点阵的虚拟网格标定技术,最后给出了奥迪车门模型石墨电极模面的实际测量结果.通过对测量结果的分析表明此方案简易可行.     

强流直流束在螺线管透镜中传输的Lie映射

用Lie代数方法分析了强流直流柬在螺线管透镜中的传输,考虑了两种情况:一种情况是外磁场力大于空间电荷力,另一种情况是外磁场力小于空间电荷力.得到两种情况下的传输矩阵.分析结果编制成了程序,并计算了ECR离子源之后的束流传输系统.     

强流直流束在螺线管透镜中传输的Lie映射

用Lie代数方法分析了强流直流束在螺线管透镜中的传输, 考虑了两种情况：一种情况是外磁场力大于空间电荷力, 另一种情况是外磁场力小于空间电荷力. 得到两种情况下的传输矩阵. 分析结果编制成了程序, 并计算了ECR离子源之后的束流传输系统.     

类比推理教学法在非线性物理中的应用

在物理学的方法论中,类比法是一种逻辑思维方法,也是一种重要的创新思维方式.文中以刚性摆的运动为例,应用类比推理法,对约瑟夫森结、滑移电荷密度波等非线性物理中的现象进行了研究,所得结果与实验和数值计算结果相符合.     

关于准热力学理论的几点看法

关于围绕平均值的涨落存在着两种理论,一种是用系综分布函数计算涨落,称为系综理论,一种是认为热力学基本方程在偏离平均值时也成立,用它和玻尔兹曼关系来计算涨落的准热力学理论.这两种理论有无关系?国内几本教科书的讲法,大体有以下几种情况:1.完全没触及;2.仅仅指出一些量的涨落值,两种理论得到的结果相同,未作进一步的结论; 3.认为两种几率表达式只是不同的表现形式,即认为两种理论应有完全相同的结果;4.认为只有对于某些量(能量和粒子数)的涨落计算,才能得到相同的结果.我们觉得对于处理同一问题的几种理论作出评价,搞清它们之间的关系…     

Appell方程Mei对称性导致的一种新型守恒量

研究完整系统Appell方程Mei对称性导致的一种新型守恒量.首先,给出完整系统Appell方程Mei对称性的定义和判据.其次,得到用Appell函数表示的完整系统Appell方程Mei对称性导致的一种新型守恒量.最后,举例说明由所得结果可找到新的守恒量.     

水位骤变时的饱和-不饱和渗流数值计算

本文应用全隐式交替方向迭代法对水位骤变时的饱和-不饱和渗流问题求出了数值解。对于赤井模型,计算结果与实验结果十分接近,比有限元法的计算结果好。对于大尺度的驹田蓄水池模型,计算结果与有限元法的结果基本一致。     

冲击压缩下NaCl单晶光辐射特性的研究

 用光辐射技术研究了氯化钠单晶冲击压缩下的光辐射特性,得到了在45～70 GPa压力范围内NaCl单晶的光谱吸收系数随冲击压力的变化,把这一结果与Kormer等人的结果比较,发现在较低压力下与Kormer等人的结果相差较少,当压力较高时实验结果比Kormer等人的结果约大1个数量级。并用实验结果计算了电子迁移率随冲击温度的变化,得到的结果与Ziman理论基本一致,从而解决了一直来Kormer的实验结果与Ziman理论不一致的困难,进一步证明了Ziman理论的正确性。     

Melting of xenon monolayers - computer simulations

The results of Monte Carlo simulations of xenon monolayers deposited on graphite are presented. Systems of various surface densities and in a wide range of temperatures are investigated. The results are compared to the experimental data and to the previous results for nitrogen. The results of simulations are in good agreement with the experimental ones and confirm that melting in two dimensions is vacancy-driven. Typical real-space configurations of Xe atoms and calculated specific heat results are shown.     

Meson-Meson Scattering on Anisotropic Lattices

Using the tadpole improved Wilson quark action on small, coarse, and anisotropic lattices, meson-meson scattering lengths are calculated within quenched approximation. The study covers pion-pion scattering in the I=2 channel and kaon-pion scattering in the I=3/2 channel. The results are extrapolated towards the chiral limit. Finite volume and finite lattice spacing errors are also analyzed and results in the infinite volume and continuum limit are obtained. Our results are compared with the results obtained using Roy equations, chiral perturbation theory, dispersion relations, and the experimental data. We also compare our results with other lattice results on the scattering lengths.     

抗爆容器内爆炸流场数值模拟

 采用计算流体动力学中的二阶精度TVD差分格式和特殊算子分裂法,按轴对称问题,对半球顶圆柱筒密闭式抗爆容器内部爆炸流场进行了数值模拟。计算得到的容器壁面载荷分布与实验结果基本一致。不同时刻爆炸流场压力分布图像清晰地描述了容器壁面的冲击波加载过程。     

用质点源方法计算三维内电磁脉冲

本文给出用质点法求解三维长方腔体中的初级电流及其相应的内电磁脉冲的数值结果。井把这种方法得到的结果与三维欧拉方法的计算结果作了比较。在相同的计算条件下,两种方法得到的结果符合较好。     

Excited states of muonium in atomic hydrogen

Muonium formation in excited states in muon-hydrogen charge-exchange collision is investigated using a method developed in a previous paper. Differential cross-section results are found to resemble positronium formation cross-section results of positron—hydrogen charge-exchange problem. Forward differential and integrated cross-sections are computed for muon energy of 2 keV and higher. Total muonium formation cross-sections are computed using Jackson and Schiff scaling rules. Muonium formation cross-section results obtained from proton—hydrogen charge-exchange cross-section results, using velocity scaling are compared with the results of the present calculation     

Elastic scattering of electrons by hydrogen atoms in the (2p) state

Conclusion Since our results are the first set of results in this field, their accuracy can be judged when further results through other methods and through experiment are available.The author is grateful to Dr. J. N. Das for his constant help and encouragement in the preparation of this paper. The numerical results reported in this paper have been calculated on the IBM 1130 at Calcutta University.     

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The simulation results of the plasma reconstruction were obtained and compared with the accurate balance results. With the introduction of random errors in the simulation process, robustness of the inversion procedure had been verified. The reconstruction results using the experimental data from EAST device had been compared with the inversion results from EAST’s RTEFIT to verify the correctness of the results that a single time and the continuous-time inversion. The results show that, choosing the current distribution model and magnetic diagnostic data through the equilibrium reconstruction algorithm can correctly identify the plasma shape.     

Computation of triple differential cross-sections with the inclusion of exchange effects in atomic K-shell ionization by relativistic electrons for symmetric geometry

The triple differential cross-section for K-shell ionization of silver and copper atoms by relativistic electrons have been computed in the coplanar symmetric geometry with the inclusion of exchange effects following the multiple scattering theory of Das and Seal [1] multiplied by suitable spinors. Present computed results are marginally improved in some cases from the previous computed results [2]. Present results are compared with measured values [3] and with previous computation results [2]. Some other theoretical computational results are also presented here for comparison.