在相对旋转坐标系下采用Harten,Lax and van Leer contact(HLLC)格式离散对流项,自行开发了基于多块结构化网格的有限体积程序,实现了对叶轮机械内部流场的数值求解.分别对半开式径向叶轮、闭式后弯叶轮展开数值模拟,程序和商业软件计...在相对旋转坐标系下采用Harten,Lax and van Leer contact(HLLC)格式离散对流项,自行开发了基于多块结构化网格的有限体积程序,实现了对叶轮机械内部流场的数值求解.分别对半开式径向叶轮、闭式后弯叶轮展开数值模拟,程序和商业软件计算得到的不同叶高处表面压力数据,其相对差异不超过1%,验证了算法的正确性.针对湍流方程的扩散项,分别使用完全离散和略去交叉导数项离散,通过对湍流黏度等值线、气动轴向力和力矩的比较表明:在网格正交性较好的情况下,略去交叉导数项的离散对计算结果的影响小于1%,显著地减小湍流方程离散的计算量.展开更多
Different types of stilbene derivatives (D-p-D, A-p-A, D-p-A) were investigated with AM1, and specially, equilibrium geometries of symmetrical stilbene derivatives (D-p-D) were studied using of PM3. With the same meth...Different types of stilbene derivatives (D-p-D, A-p-A, D-p-A) were investigated with AM1, and specially, equilibrium geometries of symmetrical stilbene derivatives (D-p-D) were studied using of PM3. With the same method INDO/CI, the UV-vis spectra were explored and the position and strength of the two-photon absorption were predicated by Sum-Over-States expression. The relationships of the structures, spectra and nonlinear optical properties have been examined. The influence of various substituents on two photon absorption cross-sections was discussed micromechanically.展开更多
Using two different Lie groups, two different Schwarzian derivatives of holomorphic mappings on domains in C n are defined and discussed. The necessary and sufficient conditions for annihilation of these two different...Using two different Lie groups, two different Schwarzian derivatives of holomorphic mappings on domains in C n are defined and discussed. The necessary and sufficient conditions for annihilation of these two different Schwarzian derivatives are given.展开更多
In the point view of Lie group, the cross ratio and Schwarzian derivative in C n are defined and discussed, especially the Schwarzian derivative of holomorphic mappings on the domains in matrix space C m×n is def...In the point view of Lie group, the cross ratio and Schwarzian derivative in C n are defined and discussed, especially the Schwarzian derivative of holomorphic mappings on the domains in matrix space C m×n is defined and discussed. It is proved that it is invariant up to similarity under the group of holomorphic automorphism of the Grassmann manifold C G(m,n) . And it is also proved that the Schwarzian derivative equals zero if and only if the mapping is linearly fractional.展开更多
文摘在相对旋转坐标系下采用Harten,Lax and van Leer contact(HLLC)格式离散对流项,自行开发了基于多块结构化网格的有限体积程序,实现了对叶轮机械内部流场的数值求解.分别对半开式径向叶轮、闭式后弯叶轮展开数值模拟,程序和商业软件计算得到的不同叶高处表面压力数据,其相对差异不超过1%,验证了算法的正确性.针对湍流方程的扩散项,分别使用完全离散和略去交叉导数项离散,通过对湍流黏度等值线、气动轴向力和力矩的比较表明:在网格正交性较好的情况下,略去交叉导数项的离散对计算结果的影响小于1%,显著地减小湍流方程离散的计算量.
基金Project supported by the National Natural Science Foundation of China (Nos. 20273023 90101026) and the Key Laboratory for Supramolecular Structure and Material of Jilin University.
文摘Different types of stilbene derivatives (D-p-D, A-p-A, D-p-A) were investigated with AM1, and specially, equilibrium geometries of symmetrical stilbene derivatives (D-p-D) were studied using of PM3. With the same method INDO/CI, the UV-vis spectra were explored and the position and strength of the two-photon absorption were predicated by Sum-Over-States expression. The relationships of the structures, spectra and nonlinear optical properties have been examined. The influence of various substituents on two photon absorption cross-sections was discussed micromechanically.
文摘Using two different Lie groups, two different Schwarzian derivatives of holomorphic mappings on domains in C n are defined and discussed. The necessary and sufficient conditions for annihilation of these two different Schwarzian derivatives are given.
文摘In the point view of Lie group, the cross ratio and Schwarzian derivative in C n are defined and discussed, especially the Schwarzian derivative of holomorphic mappings on the domains in matrix space C m×n is defined and discussed. It is proved that it is invariant up to similarity under the group of holomorphic automorphism of the Grassmann manifold C G(m,n) . And it is also proved that the Schwarzian derivative equals zero if and only if the mapping is linearly fractional.
