Profile function properties with different variables are discussed, the formulae of stimulated absorption, spontaneous and stimulated emission, absorption and emission coefficients, and cross sections are deduced, and...Profile function properties with different variables are discussed, the formulae of stimulated absorption, spontaneous and stimulated emission, absorption and emission coefficients, and cross sections are deduced, and some confusing issues are clarified.展开更多
The static polarizabilities and the second-order hyperpolarizabilities of a series of tri-nuclear metal cluster models MS4(MPPh3)2(MPPh3) (M=Mo,W; M=Cu, Ag, Au) have been calculated within the first-principle theoreti...The static polarizabilities and the second-order hyperpolarizabilities of a series of tri-nuclear metal cluster models MS4(MPPh3)2(MPPh3) (M=Mo,W; M=Cu, Ag, Au) have been calculated within the first-principle theoretical framework. The model clusters have two fragments of rhombic units and it is the charge transfer from one of these moieties to the other that is responsible for nonlinear optical property. This kind of electronic delocalization, differentiated from that of planar p-system, is very interesting and is worthy for further investigation.展开更多
Obtaining the vertical distribution profile of trace gas is of great significance for studying the diffusion procedure of air pollution.In this article,a look-up table method based on multi-axis differential optical a...Obtaining the vertical distribution profile of trace gas is of great significance for studying the diffusion procedure of air pollution.In this article,a look-up table method based on multi-axis differential optical absorption spectroscopy(MAX-DOAS)technology is established for retrieving the tropospheric NO_(2) vertical distribution profiles.This method retrieves the aerosol extinction profiles with minimum cost function.Then,the aerosol extinction profiles and the atmospheric radiation transfer model(RTM)are employed to establish the look-up table for retrieving the NO_(2) vertical column densities(VCDs)and profiles.The measured NO_(2) differential slant column densities(DSCDs)are compared with the NO_(2) DSCDs simulated by the atmospheric RTM,and the NO_(2) VCDs,the weight factor of NO_(2) in the boundary layer,and the boundary layer height are obtained by the minimization process.The look-up table is established to retrieve NO_(2) VCDs based on MAX-DOAS measurements in Huaibei area,and the results are compared with the data from Copernicus Atmospheric Monitoring Service(CAMS)model.It is found that there are nearly consistent and the correlation coefficient R2 is more than 0.86.The results show that this technology provides a more convenient and accurate retrieval method for the stereoscopic monitoring of atmospheric environment.展开更多
In order to investigate the quantum phase transitions and the time-of-flight absorption pictures analyt- ically in a systematic way for ultracold Bose gases in bipartite optical lattices, we present a generalized Gree...In order to investigate the quantum phase transitions and the time-of-flight absorption pictures analyt- ically in a systematic way for ultracold Bose gases in bipartite optical lattices, we present a generalized Green＇s function method. Utilizing this method, we study the quantum phase transitions of ultracold Bose gases in two types of bipartite optical lattices, i.e., a hexagonal lattice with normal Bose-Hubbard interaction and a d-dimensional hypercubic optical lattice with extended Bose-Hubbard interaction. Furthermore, the time-of-flight absorption pictures of ultracold Bose gases in these two types of lat- tices are also calculated analytically. In hexagonal lattice, the time-of-flight interference patterns of ultracold Bose gases obtained by our analytical method are in good qualitative agreement with the exDerimental results of Soltan-Panahi, et al. [Nat. Phys. 7, 434 （2011）]. In square optical lattice, the emergence of peaks at（±π/a,±π/a） in the time-of-flight absorption pictures, which is believed to bea sort of evidence of the existence of a supersolid phase, is clearly seen when the system enters the compressible phase from charge-density-wave phase.展开更多
采用密度泛函理论的B3LYP方法和微扰论的MP2方法,研究了天冬氨酸分子旋光异构过程中,单体天冬氨酸分子手性碳上的氢向氨基氮转移、羧基内的氢转移和以2个水分子作H迁移媒介在羧基内氢转移反应的水溶剂效应.分析表明:水溶剂效应使手性碳1...采用密度泛函理论的B3LYP方法和微扰论的MP2方法,研究了天冬氨酸分子旋光异构过程中,单体天冬氨酸分子手性碳上的氢向氨基氮转移、羧基内的氢转移和以2个水分子作H迁移媒介在羧基内氢转移反应的水溶剂效应.分析表明:水溶剂效应使手性碳1C与它上面的氢12H的距离略缩短,12H与氨基氮5N的距离略伸长;使羧基的11H和9O的距离变长,羧基内氢转移反应的过渡态键角10O-11H-9O略变小;使2个水分子作H迁移桥梁情况下,羧基内氢转移反应的过渡态四元环结构的键角10O-11H-17O和20O-19H-9O减小.势能面计算表明:水溶剂效应使手性碳上的氢向氨基氮转移反应与羧基内的氢转移反应的能垒分别升高4.2和3.5(k J·mol-1);使2个水分子作H迁移媒介,羧基内氢转移反应的能垒升高11.9 k J·mol-1.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51172236,51272254,51102239,61205173,and 61405206)
文摘Profile function properties with different variables are discussed, the formulae of stimulated absorption, spontaneous and stimulated emission, absorption and emission coefficients, and cross sections are deduced, and some confusing issues are clarified.
基金supported by the National Natural Science Foundation of China(NSFC.69978021 and 20173064)FPNSFC(E9910030).
文摘The static polarizabilities and the second-order hyperpolarizabilities of a series of tri-nuclear metal cluster models MS4(MPPh3)2(MPPh3) (M=Mo,W; M=Cu, Ag, Au) have been calculated within the first-principle theoretical framework. The model clusters have two fragments of rhombic units and it is the charge transfer from one of these moieties to the other that is responsible for nonlinear optical property. This kind of electronic delocalization, differentiated from that of planar p-system, is very interesting and is worthy for further investigation.
基金the National Natural Science Foundation of China(Grant No.41875040)the Top-notch Talents Program in Universities of Anhui Province,China(Grant No.gxbjZD2020067)the Natural Science Research Projects of Universities in Anhui Province,China(Grant No.KJ2020A0029).
文摘Obtaining the vertical distribution profile of trace gas is of great significance for studying the diffusion procedure of air pollution.In this article,a look-up table method based on multi-axis differential optical absorption spectroscopy(MAX-DOAS)technology is established for retrieving the tropospheric NO_(2) vertical distribution profiles.This method retrieves the aerosol extinction profiles with minimum cost function.Then,the aerosol extinction profiles and the atmospheric radiation transfer model(RTM)are employed to establish the look-up table for retrieving the NO_(2) vertical column densities(VCDs)and profiles.The measured NO_(2) differential slant column densities(DSCDs)are compared with the NO_(2) DSCDs simulated by the atmospheric RTM,and the NO_(2) VCDs,the weight factor of NO_(2) in the boundary layer,and the boundary layer height are obtained by the minimization process.The look-up table is established to retrieve NO_(2) VCDs based on MAX-DOAS measurements in Huaibei area,and the results are compared with the data from Copernicus Atmospheric Monitoring Service(CAMS)model.It is found that there are nearly consistent and the correlation coefficient R2 is more than 0.86.The results show that this technology provides a more convenient and accurate retrieval method for the stereoscopic monitoring of atmospheric environment.
基金Y.J. acknowledges Axel Pelster for his stimulating and fruitful discussions. Z.L. acknowledges inspir- ing discussions with Van Chen. This work was supported by the National Natural Science Foundation of China [Grant Nos. 11074043 （Z.L.）, 11274069 （Z.L.） and 11275119 （Y.J.）] and by the State Key Programs of China （Grant Nos. 2012CB921604 and 2009CB929204） （Z.L.）. This work was also supported by Ph.D. Programs Foundation of Ministry of Education of China under Grant No. 20123108110004 （Y.J.）.
文摘In order to investigate the quantum phase transitions and the time-of-flight absorption pictures analyt- ically in a systematic way for ultracold Bose gases in bipartite optical lattices, we present a generalized Green＇s function method. Utilizing this method, we study the quantum phase transitions of ultracold Bose gases in two types of bipartite optical lattices, i.e., a hexagonal lattice with normal Bose-Hubbard interaction and a d-dimensional hypercubic optical lattice with extended Bose-Hubbard interaction. Furthermore, the time-of-flight absorption pictures of ultracold Bose gases in these two types of lat- tices are also calculated analytically. In hexagonal lattice, the time-of-flight interference patterns of ultracold Bose gases obtained by our analytical method are in good qualitative agreement with the exDerimental results of Soltan-Panahi, et al. [Nat. Phys. 7, 434 （2011）]. In square optical lattice, the emergence of peaks at（±π/a,±π/a） in the time-of-flight absorption pictures, which is believed to bea sort of evidence of the existence of a supersolid phase, is clearly seen when the system enters the compressible phase from charge-density-wave phase.
文摘采用密度泛函理论的B3LYP方法和微扰论的MP2方法,研究了天冬氨酸分子旋光异构过程中,单体天冬氨酸分子手性碳上的氢向氨基氮转移、羧基内的氢转移和以2个水分子作H迁移媒介在羧基内氢转移反应的水溶剂效应.分析表明:水溶剂效应使手性碳1C与它上面的氢12H的距离略缩短,12H与氨基氮5N的距离略伸长;使羧基的11H和9O的距离变长,羧基内氢转移反应的过渡态键角10O-11H-9O略变小;使2个水分子作H迁移桥梁情况下,羧基内氢转移反应的过渡态四元环结构的键角10O-11H-17O和20O-19H-9O减小.势能面计算表明:水溶剂效应使手性碳上的氢向氨基氮转移反应与羧基内的氢转移反应的能垒分别升高4.2和3.5(k J·mol-1);使2个水分子作H迁移媒介,羧基内氢转移反应的能垒升高11.9 k J·mol-1.
