Magnetic properties of mixed Ising system with random field

A spin-1/2 and spin-3/2 mixed Ising system in a random field is studied by the use of effective-field theory with correlations. The phase diagrams and thermal behaviours of magnetizations are investigated numerically for the honeycomb lattice (z=3) and square lattice (z=4) respectively. The tricritical behaviours for both honeycomb and square lattices, as well as the reentrant behaviour for the square lattice are found.     

时域差分方法在软接触结晶器电磁场计算中的修正

通过对简化模型的理论推导,修正了Gandhi提出的低频电磁场的高频近似方法,使其适用于软接触结晶器电磁场计算.并利用三维程序对简化模型进行了验算,在此基础上,计算了软接触结晶器内的磁场、涡流和电磁力的分布.     

同伦算法在并联机器人运动学中的应用

讨论同伦算法求解并联机器人运动学正问题.通过参系数同伦法大大减少了跟踪路径的数目,从而提高了同伦算法的效率使之对求解一般非线性代数方程组更为可行.采用这一算法,求出了中科院沈阳自动化研究所机器人开放研究实验室的新型并联机器人模型的全部正解.为新模型的机构分析和实时控制提供了理论依据.     

The Bounds of the General M and J Sets and the Estimations for the Hausdorff's Dimension of the General J Set

The bounds of the general M and J sets were analytically offered. Some of the bounds were optimal in certain meaning. It not only solved the primary problem of the construction of fractal sets by escape time algorithm, and followed from the conclusion, but also offered two estimations of some special Julia set’s Hausdorff’s dimension by approximate linearization method. Foundation item: the National Natural Science Foundation of China (69974008). Biography: LIX Xiang-dong (1967-), Associate Professor, Doctor     

Self-Similar Solutions of Fracture Dynamics Problems on Axially Symmetry

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准各向同性高电流密度导体弯曲特性研究

提出了一种准各向同性高工程电流密度高温超导导体的有限元模型,利用该有限元模型计算了导体在不同弯曲半径下的应变分布以及临界电流衰减程度,并对导体样品进行了弯曲实验.实验结果和仿真结果基本一致,基于该有限元模型进一步计算了导体的不同参数对弯曲半径的影响.该研究为准各向同性高工程电流密度高温超导导体在聚变磁体领域的应用提供了...     

THE STABILITY AND APPROXIMATION PROPERTIES OF RITZ-VOLTERRA PROJECTION AND APPLICATION,I

The purpose of this paper is to study the stability and approximation properties of Ritz-Volterra projection. Through constructing a new type of Green functions and making use of various properties and estimates related with the functions, we prove that the Ritz-Volterra projection defined on the finite-dimensional subspace S_h of H_o~1 possesses the W_p~1-stability and the optimal approxi mation properties in W_p~1 and L_p for 2≤p≤∞. Our results, in this paper, can be applied to the finite element approximations for many evolution equations such as parabolic and hyperbolic integrodifferential equations,Sobolevequations and visco-elasticity, etc.     

几个小分子静电势的密度泛函理论计算

运用多种密度泛函理论(DFT)方法和从头算(ab initio)方法,研究了具有代表性的一系列分子的静电势,选择QCISD计算出的分子静电势为标准静电势,通过比较多种DFT法和QCISD从头算,以及它们之间的均方根偏差和静电势差值曲线图,结果表明B3LYP-DFT法与QCISD-ab initio法计算结果较吻合,暗示了B3LYP-DFT法在得到分子静电势时是一个有用的工具,尤其对于从头计算难以进行研究的大分子体系.     

离子浮选法对Co(Ⅱ)-P2O74--月桂胺三元配合物的研究

用一种新的分离方法-离子浮选法对Co(Ⅱ)-P₂O₇^4--月桂胺(C₁₂H₂₅NH₂)三元配合物进行了研究.利用摩尔比法和斜率比法测得在实验浓度范围内,生成两种颜色很浅的配合物,其组成为[Co(P₂O₇)]·[RNH₃]₂和[Co(P₂O₇)₂]·[RNH₃]₆.在25±0.5℃,μ=0.1(NaNO₃)条件下,利用Bjerrum-Rossotti作图法求得Co(Ⅱ)-P₂O₇^4-lgβ₁=6.19,该值与文献值十分吻合.并获得lgβ₂=10.69.采用微机统计分析,得到与作图法一致的结果.本文给出两种三元配合物结构,指出月桂胺中N未参加配位,红外光谱,核磁共振波谱及电子光谱支持上述结论.