动脑筋挖潜力生动形象地上好历史课

要生动形象地上好历史课,必须动脑筋、想办法,文章提出了巧用数学增兴趣,咏史绝句增韵味、运用多媒体增效果等三种方法.     

Moessbauer Investigation of the Ferromagnetic Coupling in Copper-Iron Polycyanides

One of the Prussian blue analogs, molecular magnet Cu3^Ⅲ [Fe^Ⅲ (CN)6]2.11.6H2 O, was investigated by Moessbauer spectroscopy. It was found that transition temperature was around Tc = 18.5 K from paramagnetic phase to ferromagnetic phase. The β value of the critical exponent is around 0.338 at magnetic ordering temperature.Therefore, the ferromagnetic coupling interaction of Cu-Fe cyanide could be clearly explained by spin wave theory.     

A Mossbauer study of the magnetic coupling in iron phosphorous trisulfides

The polycrystalline sample of layered compound FePS_3 has been investigated by using M?ssbauer spectroscopy (12K to 300K), magnetic susceptibility measurements, x-ray diffraction and FTIR spectroscopy. The antiferromagnetic order exists below T_N=120.5±1K. The M?ssbauer spectra below T_N indicate that the magnetization axis is perpendicular to the layer of FePS_3, and the divalent iron cations are in their high spin configurations. By fitting the hyperfine field parameters near the Néel temperature, we obtain information on the nature of magnetic interactions in the material. The results show that the magnetic coupling can be treated by the two-dimensional Ising model, and it can be interpreted on the basis of a crystal-field effect.     

一维DCA交通流模型分析

利用ＤＣＡ交通流模型模拟了单线路单速的效能情况，利用演化规则表达式推导出速度及流量的解析表达式，并分析了二粒子最近邻关联随密度的变化情况。     

大樱桃早果高产栽培技术

大樱桃具有果大、肉硬、耐贮藏和成熟较晚的特性。为解决成熟期较晚和提高产量，提出了大樱桃建园、选用优良品种、树形修剪、阶段管理、病虫害防治和促进早果的栽培技术措施。     

余代数上余倾斜余模的结构

研究了余代数上余倾斜余模的结构特征,证明了每个余倾斜余模都可以写成不可分解的两两非同构的余模的直和形式,每个余倾斜余模包含所有的内射不可分解模作为直和项.最后构造了余倾斜余模的两个例子.     

研究热流体的13速格子Bhatnagar-Gross-Krook模型

采用13速六方格子BhatnagarGrossKrook模型研究热流体力学.在根据Fourier热导定律确定局域平衡分布函数的系数时,可引入参数k,使热导系数λ=(2ρ+9k)(τ-12),切粘滞系数与热导系数之比的Prandtl数不再局限于常数1/2,从而扩大了模型的应用范围该模型可用于高雷诺数的热流体的模拟. 关键词：     

基于九速四方格子模型的二维对流扩散方程格子Boltzmann方法模拟

用九速正方格子模型给出了二维对流扩散方程的格子Boltzmann方法。由对流扩散方程的对流系数和扩散系数确定了局域平衡分布函数的系数。计算机模拟结果与理论结果吻合很好。     

基于九速四方格子模型的二维对流扩散方程格子Boltzmann方法模拟

用九带正方格子模型给出了二维对流扩散方程的格子Ｂｏｌｔｚｎａｎｎ方法,由对流扩散方程的对流系数的扩散系数确定了局域平衡分布函数的系数。计算机模拟结果与理论结果吻合很好。     

[Co(en)_3][Fe(CN)_6]·H_2O的磁性研究

合成了氰根桥联配合物[Co(en)3][Fe(CN)6]·H2O,使用元素分析、红外光谱等对配合物进行了表征。首次通过对该配合物的磁化率测定表明金属离子通过氰根传递弱反铁磁作用,计算求得分子磁体有效磁距μeff的实验值与理论值。并根据Curie-Weiss定律拟合获得居里常数C=0.45968emu·K/mol,顺磁居里温度θ=-8.23117K。