It is proposed that the Gaussian type distribution constantb qi in the Gaussian model depends on the coordination numberq i of sitei, and that the relation ${{b_{q_i } } \mathord{\left/ {\vphantom {{b_{q_i } } {b_{q_j...It is proposed that the Gaussian type distribution constantb qi in the Gaussian model depends on the coordination numberq i of sitei, and that the relation ${{b_{q_i } } \mathord{\left/ {\vphantom {{b_{q_i } } {b_{q_j } }}} \right. \kern-0em} {b_{q_j } }} = {{q_q } \mathord{\left/ {\vphantom {{q_q } {q_q }}} \right. \kern-0em} {q_q }}$ holds amongb qi ’s. The Gaussian model is then studied on a family of the diamond-type hierarchical (or DH) lattices, by the decimation real-space renormalization group following spin-rescaling method. It is found that the magnetic property of the Gaussian model belongs to the same universal class, and that the critical pointK* and the critical exponentv are given by ${{K^ * = b_{q_i } } \mathord{\left/ {\vphantom {{K^ * = b_{q_i } } {q_i }}} \right. \kern-0em} {q_i }}$ and $\nu = {1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-0em} 2}$ , respectively.展开更多
基于高温高压合成金刚石过程中铁基触媒及其金属包膜中存在大量Fe3C型碳化物的实验结果,利用余氏理论(empirical electron theory of solid and molecule,EET)分析了Fe3C型碳化物内C-C键组成晶面和与之对应的金刚石晶面的共价电子密度,...基于高温高压合成金刚石过程中铁基触媒及其金属包膜中存在大量Fe3C型碳化物的实验结果,利用余氏理论(empirical electron theory of solid and molecule,EET)分析了Fe3C型碳化物内C-C键组成晶面和与之对应的金刚石晶面的共价电子密度,发现它们在一级近似下存在连续性,满足程氏理论(improved Thomas-Fermi-Dirac theory advanced by Cheng,TFDC)提出的原子界面边界条件。分析结果表明:高温高压下的金刚石单晶生长与 Fe3C型碳化物的分解有关。在4种Fe3C型碳化物中,(Fe,Ni)3C内的C-C键组成晶面和与之对应的金刚石晶面的共价电子密度连续的组数最多。因而认为:合成金刚石过程中使用含镍的铁基触媒,在高温高压下形成的(Fe,Ni)3C作为碳源,最容易转变为金刚石。展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 19775008)the National Basic Research Project "Nonlinear Science"+1 种基金the National Education Committee Foundation for Training PhD students the Natural Science Found
文摘It is proposed that the Gaussian type distribution constantb qi in the Gaussian model depends on the coordination numberq i of sitei, and that the relation ${{b_{q_i } } \mathord{\left/ {\vphantom {{b_{q_i } } {b_{q_j } }}} \right. \kern-0em} {b_{q_j } }} = {{q_q } \mathord{\left/ {\vphantom {{q_q } {q_q }}} \right. \kern-0em} {q_q }}$ holds amongb qi ’s. The Gaussian model is then studied on a family of the diamond-type hierarchical (or DH) lattices, by the decimation real-space renormalization group following spin-rescaling method. It is found that the magnetic property of the Gaussian model belongs to the same universal class, and that the critical pointK* and the critical exponentv are given by ${{K^ * = b_{q_i } } \mathord{\left/ {\vphantom {{K^ * = b_{q_i } } {q_i }}} \right. \kern-0em} {q_i }}$ and $\nu = {1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-0em} 2}$ , respectively.
文摘基于高温高压合成金刚石过程中铁基触媒及其金属包膜中存在大量Fe3C型碳化物的实验结果,利用余氏理论(empirical electron theory of solid and molecule,EET)分析了Fe3C型碳化物内C-C键组成晶面和与之对应的金刚石晶面的共价电子密度,发现它们在一级近似下存在连续性,满足程氏理论(improved Thomas-Fermi-Dirac theory advanced by Cheng,TFDC)提出的原子界面边界条件。分析结果表明:高温高压下的金刚石单晶生长与 Fe3C型碳化物的分解有关。在4种Fe3C型碳化物中,(Fe,Ni)3C内的C-C键组成晶面和与之对应的金刚石晶面的共价电子密度连续的组数最多。因而认为:合成金刚石过程中使用含镍的铁基触媒,在高温高压下形成的(Fe,Ni)3C作为碳源,最容易转变为金刚石。
