Numerical Computation of Figure-eight Solution for 3-body Problems

The main goal of this paper is to compute the Figure-eight solutions for the planar Newtonian 3-body problem with equal masses by finding the critical points of the functional associated with the motion equations of 3-body in plane R2. The algorithm adopted here is the steepest descent method, which is simple but very valid for our problem.     

用参考圆法演示简谐振动

对受迫振动仪进行了改进，通过参考圆法，演示了作镁速圆周运动的质点在直径方向上的投影所作的运动为简谐振动。     

AFC^＊一代数上的映射

本文讨论AFC^＊一代数中的一些映射的线性性质和它们的局部性质之间的关系．研究AFC^＊一代数A上的保持乘法的局部自同构Ф在A中矩阵单位系上的作用。证明了Ф是A上的自同构。对于UHF代数上满等距的结构，还证明了UHF代数上的2-局部（满线性）等距是线性的．     

A model for a uniform steady-state vacuum arc with a hot anode

A model is formulated and evaluated for a Uniform electrical discharge sustained in vapor evaporated from an arc-heated anode. The plasma potential is positive with respect to both the cathode and anode. For a Cu anode, the anodic vapor dominates the plasma for current densities exceeding 8 kA/m². The anode heating potential is approximately 6.5 V, and the dominant cooling mechanism is evaporation for current densities exceeding 20 kA/m². Over the range 10 to 10000 kA/m², the electron density increases from 8×10¹⁷ to 5×10²³ m^-3, while the ionization fraction rises from 0.3% to 4%. At the lower end of this current range the electrical resistivity of 4 mΩ-m is determined primarily by electron-neutral collisions, while with increasing current the resistivity decreases to 0.7 mΩ-m, with electron-ion collisions contributing an equal share. This hot-anode vacuum arc may have potential for industrial application as a macroparticle-free high-deposition-rate coating source     

Quantum Phase Transition in Quasi-two-dimensional Heisenberg Antiferromagnet with Single-Ion Anisotropy

In the present paper, we investigate the quantum phase transition in a spatially anisotropic antiferrornagnetic Heisenberg model of S =1 with single-ion energy anisotropy. By using the Schwinger boson representation, we calculate the Gaussian correction to the critical value J⊥^c caused by quantum spin fluctuations. We find that, for the positive single-ion energy, a nonzero value of J⊥^c is always needed to stabilize the antiferromagnetic long-range order in this model. It resolves a difference among literature and shows clearly that the effect of quantum fluctuations may qualitatively change a result obtained by the mean-field theories on lower-dimensional systems.     

硅色敏器件对复色光色差辨识能力的数值分析

对复色光的光谱功率分布和色敏器件光谱响应的实验曲线进行了函数拟合，采用Mathematica 4．2计算了具有不同峰值波长和半高宽的高斯分布的复色光在色敏器件中产生的电流比．计算结果表明，待测复色光的峰值波长和半高宽变化对两种典型的色敏器件的输出信号影响的权重比分别为100：1和10：1。权重比说明色敏器件的输出电流比随峰值波长和半高宽的变化非常灵敏，但两者权重不同，其中峰值波长的变化影响更为显著，是影响复色光颜色变化的主要因素．数值分析的结果表明，硅双结色敏器件对复色光色差有良好的辨识能力．两种器件权重比的差异说明了器件制作工艺与其辨识能力的关系，为器件合理设计提供了理论依据．     

Richards模型在蔬菜生长预测中的应用

本文从 Richards模型的数学表达出发 ,阐述了模型中各参数初始值的确定以及优化过程 .并利用菜花和菠菜的试验数据建立其“最优”生长模型 .     

Perforation of steel and polycarbonate plates by tumbling projectiles

An experimental investigation to assess the effect of tumbling by hard-steel, blunt-faced cylindrical projectiles on the impact response of thin 4130 steel and polycarbonate target plates was performed. Deformation and failure phenomena were observed and discussed; comparisons of the results with analytical models and numerical stimulation, described in a previous paper, were also performed for the steel targets. The final velocity of the projectile and the crater length in the target were correlated with the striker impact angle (or yaw angle with a zero oblique angle); reasonable agreement was attained among the experimental, analytical and numerical results. It was found that an increase of the impact angle can increase the velocity drop and the crater length markedly. The increase tends to be stabilized after the impact angle exceeds 50° and the consequences in such a case are almost the same as in side-on impact.     

低通量慢中子对Bi系超导体的辐照效应

本文研究低通量慢中子对Bi系超导体的辐照效应。实验结果表明:(1)Bi系超导体在适量慢中子辐照后,临界电流密度J_c和零电阻温度T_c0都有不同程度提高;(2)低通量慢中子和高通量快中子对Bi系超导体具有相似的辐照效应。 关键词：