We theoretically investigate the excited state intramolecular proton transfer(ESIPT) behavior of the novel fluorophore bis-imine derivative molecule HNP which was designed based on the intersection of 1-(hydrazonometh...We theoretically investigate the excited state intramolecular proton transfer(ESIPT) behavior of the novel fluorophore bis-imine derivative molecule HNP which was designed based on the intersection of 1-(hydrazonomethyl)-naphthalene-2-ol and 1-pyrenecarboxaldehyde. Especially, the density functional theory(DFT) and time-dependent density functional theory(TDDFT) methods for HNP monomer are introduced. Moreover, the "our own n-layered integrated molecular orbital and molecular mechanics"(ONIOM) method(TDDFT:universal force field(UFF)) is used to reveal the aggregation-induced emission(AIE) effect on the ESIPT process for HNP in crystal. Our results confirm that the ESIPT process happens upon the photoexcitation for the HNP monomer and HNP in crystal, which is distinctly monitored by the optimized geometric structures and the potential energy curves. In addition, the results of potential energy curves reveal that the ESIPT process in HNP will be promoted by the AIE effect. Furthermore, the highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO) for the HNP monomer and HNP in crystal have been calculated. The calculation demonstrates that the electron density decrease of proton donor caused by excitation promotes the ESIPT process. In addition, we find that the variation of atomic dipole moment corrected Hirshfeld population(ADCH) charge for proton acceptor induced by the AIE effect facilitates the ESIPT process. The results will be expected to deepen the understanding of ESIPT dynamics for luminophore under the AIE effect and provide insight into future design of high-efficient AIE compounds.展开更多
This paper studies the random internal wave equations describing the density interface displacements and the velocity potentials of N-layer stratified fluid contained between two rigid walls at the top and bottom. The...This paper studies the random internal wave equations describing the density interface displacements and the velocity potentials of N-layer stratified fluid contained between two rigid walls at the top and bottom. The density interface displacements and the velocity potentials were solved to the second-order by an expansion approach used by Longuet-Higgins （1963） and Dean （1979） in the study of random surface waves and by Song （2004） in the study of second- order random wave solutions for internal waves in a two-layer fluid. The obtained results indicate that the first-order solutions are a linear superposition of many wave components with different amplitudes, wave numbers and frequencies, and that the amplitudes of first-order wave components with the same wave numbers and frequencies between the adjacent density interfaces are modulated by each other. They also show that the second-order solutions consist of two parts： the first one is the first-order solutions, and the second one is the solutions of the second-order asymptotic equations, which describe the second-order nonlinear modification and the second-order wave-wave interactions not only among the wave components on same density interfaces but also among the wave components between the adjacent density interfaces. Both the first-order and second-order solutions depend on the density and depth of each layer. It is also deduced that the results of the present work include those derived by Song （2004） for second-order random wave solutions for internal waves in a two-layer fluid as a particular case.展开更多
In the present paper, the random interfacial waves in N-layer density-stratified fluids moving at different steady uniform speeds are researched by using an expansion technique, and the second-order asymptotic solutio...In the present paper, the random interfacial waves in N-layer density-stratified fluids moving at different steady uniform speeds are researched by using an expansion technique, and the second-order asymptotic solutions of the random displacements of the density interfaces and the associated velocity potentials in N-layer fluid are presented based on the small amplitude wave theory. The obtained results indicate that the wave-wave second-order nonlinear interactions of the wave components and the second-order nonlinear interactions between the waves and currents are described. As expected, the solutions include those derived by Chen （2006） as a special case where the steady uniform currents of the N-layer fluids are taken as zero, and the solutions also reduce to those obtained by Song （2005） for second-order solutions for random interfacial waves with steady uniform currents if N = 2.展开更多
The rate constants of the nucleophilic reactions between amines and benzhydrylium ions were calculated using first-principles theoretical methods. Solvation models including PCM, CPCM, and COSMORS, as well as differen...The rate constants of the nucleophilic reactions between amines and benzhydrylium ions were calculated using first-principles theoretical methods. Solvation models including PCM, CPCM, and COSMORS, as well as different types of atomic radii including UA0, UAKS, UAHF, Bondi, and UFF, and several single-point energy calculation methods （B3LYP, B3P86, B3PW91, BHANDH, PBEPBE, BMK, M06, MP2, and ONIOM method） were examined. By comparing the correlation between experimental rate constants and the calculated values, the ONIOM（CCSD（T）/6-311＋＋G（2df,2p）：B3LYP/6-311＋＋G（2df,2p））//B3LYP/6- 31G（d）/PCM/UFF） method was found to perform the best. This method was then employed to calculate the rate constants of the reactions between diverse amines and diarylcarbenium ions. The calculated rate constants for 65 reactions of amines with diarylcarbenium ions are in agreement with the experimental values, indicating that it is feasible to predict the rate constant of a reaction between an amine and a diarylcarbenium ion through ab initio calculation.展开更多
A generalized spectral Green’s function formulation of N-layer substrate structure is given with three dimension sources, which is a set of closed form formulas. A full-wave analysis model for rectangular microstrip ...A generalized spectral Green’s function formulation of N-layer substrate structure is given with three dimension sources, which is a set of closed form formulas. A full-wave analysis model for rectangular microstrip antennas covered with N-dielectric layers has been established by using the above spectral Green’s function. The unknown surface current density on the niicrostrip patch for such structure is found as a solution of an integral equation. The input VSWR and radiation patterns of the antenna are also obtained. The numerical results have been verified by the experimental results.展开更多
Graphene, a new two-dimensional carbon material, is a rising star of physics, chemistry and materials science. In this work, we report the recent experimental researches on the Raman spectra and the temperature-depend...Graphene, a new two-dimensional carbon material, is a rising star of physics, chemistry and materials science. In this work, we report the recent experimental researches on the Raman spectra and the temperature-dependent features of graphenes and car- bon nanoscrolls, which are evolved from graphene and have an open tubular structure. The layer-dependent Raman enhancing characteristics of n-layer graphenes for crystal violet, and the thickness-dependent morphologies of gold on n-layer graphenes are also systematically investigated. Meanwhile, the aggregations of ferromagnetic and paramagnetic atoms at edges of gra- phenes and graphite are observed and the mechanisms are discussed.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11574115 and 11704146)
文摘We theoretically investigate the excited state intramolecular proton transfer(ESIPT) behavior of the novel fluorophore bis-imine derivative molecule HNP which was designed based on the intersection of 1-(hydrazonomethyl)-naphthalene-2-ol and 1-pyrenecarboxaldehyde. Especially, the density functional theory(DFT) and time-dependent density functional theory(TDDFT) methods for HNP monomer are introduced. Moreover, the "our own n-layered integrated molecular orbital and molecular mechanics"(ONIOM) method(TDDFT:universal force field(UFF)) is used to reveal the aggregation-induced emission(AIE) effect on the ESIPT process for HNP in crystal. Our results confirm that the ESIPT process happens upon the photoexcitation for the HNP monomer and HNP in crystal, which is distinctly monitored by the optimized geometric structures and the potential energy curves. In addition, the results of potential energy curves reveal that the ESIPT process in HNP will be promoted by the AIE effect. Furthermore, the highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO) for the HNP monomer and HNP in crystal have been calculated. The calculation demonstrates that the electron density decrease of proton donor caused by excitation promotes the ESIPT process. In addition, we find that the variation of atomic dipole moment corrected Hirshfeld population(ADCH) charge for proton acceptor induced by the AIE effect facilitates the ESIPT process. The results will be expected to deepen the understanding of ESIPT dynamics for luminophore under the AIE effect and provide insight into future design of high-efficient AIE compounds.
基金Project supported by the National Science Fund for Distinguished Young Scholars （Grant No 40425015）, the Cooperative Project of Chinese Academy Sciences and the China National 0ffshore oil Corporation （＂Behaviours of internal waves and their roles on the marine structures＂） and the National Natural Science Foundation of China （Grant No10461005）.
文摘This paper studies the random internal wave equations describing the density interface displacements and the velocity potentials of N-layer stratified fluid contained between two rigid walls at the top and bottom. The density interface displacements and the velocity potentials were solved to the second-order by an expansion approach used by Longuet-Higgins （1963） and Dean （1979） in the study of random surface waves and by Song （2004） in the study of second- order random wave solutions for internal waves in a two-layer fluid. The obtained results indicate that the first-order solutions are a linear superposition of many wave components with different amplitudes, wave numbers and frequencies, and that the amplitudes of first-order wave components with the same wave numbers and frequencies between the adjacent density interfaces are modulated by each other. They also show that the second-order solutions consist of two parts： the first one is the first-order solutions, and the second one is the solutions of the second-order asymptotic equations, which describe the second-order nonlinear modification and the second-order wave-wave interactions not only among the wave components on same density interfaces but also among the wave components between the adjacent density interfaces. Both the first-order and second-order solutions depend on the density and depth of each layer. It is also deduced that the results of the present work include those derived by Song （2004） for second-order random wave solutions for internal waves in a two-layer fluid as a particular case.
基金supported by the Natural Science Foundation of Inner Mongolia,China (Grant No 200711020116)Open Fund of the Key Laboratory of Ocean Circulation and Waves,Chinese Academy of Sciences (Grant No KLOCAW0805)+1 种基金the Key Program of the Scientific Research Plan of Inner Mongolia University of Technology,China (Grant No ZD200608)the National Science Fund for Distinguished Young Scholars of China (Grant No 40425015)
文摘In the present paper, the random interfacial waves in N-layer density-stratified fluids moving at different steady uniform speeds are researched by using an expansion technique, and the second-order asymptotic solutions of the random displacements of the density interfaces and the associated velocity potentials in N-layer fluid are presented based on the small amplitude wave theory. The obtained results indicate that the wave-wave second-order nonlinear interactions of the wave components and the second-order nonlinear interactions between the waves and currents are described. As expected, the solutions include those derived by Chen （2006） as a special case where the steady uniform currents of the N-layer fluids are taken as zero, and the solutions also reduce to those obtained by Song （2005） for second-order solutions for random interfacial waves with steady uniform currents if N = 2.
文摘The rate constants of the nucleophilic reactions between amines and benzhydrylium ions were calculated using first-principles theoretical methods. Solvation models including PCM, CPCM, and COSMORS, as well as different types of atomic radii including UA0, UAKS, UAHF, Bondi, and UFF, and several single-point energy calculation methods （B3LYP, B3P86, B3PW91, BHANDH, PBEPBE, BMK, M06, MP2, and ONIOM method） were examined. By comparing the correlation between experimental rate constants and the calculated values, the ONIOM（CCSD（T）/6-311＋＋G（2df,2p）：B3LYP/6-311＋＋G（2df,2p））//B3LYP/6- 31G（d）/PCM/UFF） method was found to perform the best. This method was then employed to calculate the rate constants of the reactions between diverse amines and diarylcarbenium ions. The calculated rate constants for 65 reactions of amines with diarylcarbenium ions are in agreement with the experimental values, indicating that it is feasible to predict the rate constant of a reaction between an amine and a diarylcarbenium ion through ab initio calculation.
基金Partly supported by the Research Item B96(56) of the Ministry of Railways of China
文摘A generalized spectral Green’s function formulation of N-layer substrate structure is given with three dimension sources, which is a set of closed form formulas. A full-wave analysis model for rectangular microstrip antennas covered with N-dielectric layers has been established by using the above spectral Green’s function. The unknown surface current density on the niicrostrip patch for such structure is found as a solution of an integral equation. The input VSWR and radiation patterns of the antenna are also obtained. The numerical results have been verified by the experimental results.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10774032, 90921001, 50825206)
文摘Graphene, a new two-dimensional carbon material, is a rising star of physics, chemistry and materials science. In this work, we report the recent experimental researches on the Raman spectra and the temperature-dependent features of graphenes and car- bon nanoscrolls, which are evolved from graphene and have an open tubular structure. The layer-dependent Raman enhancing characteristics of n-layer graphenes for crystal violet, and the thickness-dependent morphologies of gold on n-layer graphenes are also systematically investigated. Meanwhile, the aggregations of ferromagnetic and paramagnetic atoms at edges of gra- phenes and graphite are observed and the mechanisms are discussed.
