For the p-harmonic function with strictly convex level sets,we find an auxiliary function which comes from the combination of the norm of gradient of the p-harmonic function and the Gaussian curvature of the level set...For the p-harmonic function with strictly convex level sets,we find an auxiliary function which comes from the combination of the norm of gradient of the p-harmonic function and the Gaussian curvature of the level sets of p-harmonic function.We prove that this curvature function is concave with respect to the height of the p-harmonic function.This auxiliary function is an affine function of the height when the p-harmonic function is the p-Green function on ball.展开更多
The symmetry-adapted-duster configuration-interaction method is used to investigate the spectroscopicproperties of ~7Li_2(A^1∑_u^+) over the internuclear distance ranging from 2.4ao to 37ao.The complete potential ene...The symmetry-adapted-duster configuration-interaction method is used to investigate the spectroscopicproperties of ~7Li_2(A^1∑_u^+) over the internuclear distance ranging from 2.4ao to 37ao.The complete potential energycurves are calculated at numbers of basis sets.All the ab initio calculated points are fitted to the analytic MurrellSorbie function and then employed to compute the spectroscopic constants.By comparison,the spectroscopic constantsreproduced by the potential attained at D95(3df,3pd) are found to be very close to the experiments,a^d the values (T_e,D_e,R_e,ω_e,ω_eχ_e,α_e and B_e) are of 1.732 93 eV,1.161 36 eV,0.313 27 nm,251.95 cm^(-1),1.623 cm^(-1),0.005 35 cm^(-1),and0.490 cm^(-1),respectively.With the potential obtained at D95(3df,3pd),the totally 75 vibrational states are found whenJ=0.The vibrational levels,the classical turning points and the inertial rotation constants of the first 68 vibrationalstates are calculated for the first time and compared with the available measurements.Good agreement is obtained.The centrifugal distortion constants of the first 32 vibrational states are also reported for the first time.The reasonabledissociation limit for ~7Li_2(A^1∑_u^+) is deduced using the calculated results at present.展开更多
文摘为了克服传统电流源型变换器(current source converter,CSC)交流侧需要加装大容量交流电容器作为缓冲装置的缺点,将直流电流分配电路与传统并联式12脉波CSC相结合,研究了一种可以省去交流电容器并能有效抑制谐波的并联式7电平电流注入式电流源型变换器拓扑。该拓扑具有以下特点:通过开闭直流电流分配电路中的开关元件,将直流电流变换成2路幅值相同、相位互差30°、6倍于基波频率、7电平阶梯形周期变化且具有零值区间的三角波注入电流,两主桥开关元件在注入电流的零值区间内进行切换,实现了零电流开关(zero current switching,ZCS);变换器交流侧不需要配置大容量交流电容器,降低了设计成本,提高了系统的可靠性;主桥开关频率为50Hz的前提下,利用7电平阶梯形三角波注入电流可增加交流输出电流的电平数,改善了电流波形的谐波特性,使交流输出电流近似正弦波。另外还详细分析了新拓扑的工作机理,在PSCAD/EMTDC平台进行了仿真研究,搭建了实验平台,通过实验验证了理论分析的正确性和可行性。结果表明,所提出的新拓扑性能优良,结构简单,具有实用价值。
基金Research of the first author was supported by NSFC and Wu Wen-Tsun Key Laboratory of Mathematics.We finished this paper in the winter of 2009 as a part of the thesis of the second author in University of Science and Technology of China.
文摘For the p-harmonic function with strictly convex level sets,we find an auxiliary function which comes from the combination of the norm of gradient of the p-harmonic function and the Gaussian curvature of the level sets of p-harmonic function.We prove that this curvature function is concave with respect to the height of the p-harmonic function.This auxiliary function is an affine function of the height when the p-harmonic function is the p-Green function on ball.
基金The project supported by National Natural Science Foundation of China under Grant Nos.10574039 and 10174019
文摘The symmetry-adapted-duster configuration-interaction method is used to investigate the spectroscopicproperties of ~7Li_2(A^1∑_u^+) over the internuclear distance ranging from 2.4ao to 37ao.The complete potential energycurves are calculated at numbers of basis sets.All the ab initio calculated points are fitted to the analytic MurrellSorbie function and then employed to compute the spectroscopic constants.By comparison,the spectroscopic constantsreproduced by the potential attained at D95(3df,3pd) are found to be very close to the experiments,a^d the values (T_e,D_e,R_e,ω_e,ω_eχ_e,α_e and B_e) are of 1.732 93 eV,1.161 36 eV,0.313 27 nm,251.95 cm^(-1),1.623 cm^(-1),0.005 35 cm^(-1),and0.490 cm^(-1),respectively.With the potential obtained at D95(3df,3pd),the totally 75 vibrational states are found whenJ=0.The vibrational levels,the classical turning points and the inertial rotation constants of the first 68 vibrationalstates are calculated for the first time and compared with the available measurements.Good agreement is obtained.The centrifugal distortion constants of the first 32 vibrational states are also reported for the first time.The reasonabledissociation limit for ~7Li_2(A^1∑_u^+) is deduced using the calculated results at present.
