Molecular structure, vibrational frequency and infrared intensity of UF6 are investigated by using the revised Perdew Burke-Enzerhof function with the triple-zeta polarized basis set. The calculation results are in go...Molecular structure, vibrational frequency and infrared intensity of UF6 are investigated by using the revised Perdew Burke-Enzerhof function with the triple-zeta polarized basis set. The calculation results are in good agreement with the experimental values and indicate the existence of a stable U2F6 molecule with a multiple bonded U2 unit. The calculation results also predict that the D3d symmetry of U2F6 is more stable than D3h. The optimized geometries, vibrational frequencies, and infrared intensities are also reported for U2F6 molecules in D3d symmetry. In addition, the isotopic shift of vibrational frequencies of the two molecules under isotopic substitution of uranium atom are also investigated with the same method. The U2F6 molecule is predicted to be better than UF6 for laser uranic isotope separation.展开更多
Geometrical optimization and theoretical calculation of the vibrational frequencies have been performed for C2B10H12, NB11H12 and C2B10Cl by using Gaussian 92 program at 6-31G basis set. The results obtained in this w...Geometrical optimization and theoretical calculation of the vibrational frequencies have been performed for C2B10H12, NB11H12 and C2B10Cl by using Gaussian 92 program at 6-31G basis set. The results obtained in this work are in agreement with experimental ones. The optimized geometry and vibrational spectra show that the icosahedral configuration remains unchanged upon converting from B12H122- to the title compounds. The vibrational spectrum of C2B10H11Cl features the absence of C-Cl stretching vibration. But the (C2B10H11)-Cl vibration mode in the low frequency region is as the case for two-atom molecules if the group (C2B10H11) is considered as a pseudoatom展开更多
The modal vibration of the rotor is the main cause of excessive vibration of the aeroengine overall structure.To attenuate the vibration of the rotor under different modal shapes from the perspective of energy control...The modal vibration of the rotor is the main cause of excessive vibration of the aeroengine overall structure.To attenuate the vibration of the rotor under different modal shapes from the perspective of energy control,the intrinsic physical relationships between rotor modal shapes and instantaneous vibrational energy flow transmission characteristics is derived from the general equation of motion base on the structural intensity method.A dual-rotor-support-casing coupling model subjected to the rotor unbalanced forces is established by the finite element method in this paper.The transmission,conversion and balance relationships of the vibrational energy flow for the rotors in the first-order bending modal shape,the conical whirling modal shape and the translational modal shape are analyzed,respectively.The results show that the vibrational energy flow transmitted to the structure can be converted into the strain energy,the kinetic energy and the energy dissipated by the damping of the structure.The vibrational energy flow transmission characteristics of rotors with different modal shapes are quite different.Especially for the first-order bending modal shape,the vibrational energy flow and the strain energy are transmitted and converted to each other in the middle part of the rotor shaft,resulting in large deformation at this part.To attenuate this harmful vibration,the influences of grooving on the shaft on the first-order bending vibration are studied from the perspective of transmission control of vibrational energy flow.This study can provide theoretical references and guidance for the vibration attenuation of the rotors in different modal shapes from a more essential perspective.展开更多
The (4000), (3100) and (5000) local mode vibrational bands of germane were recorded with high resolution spectroscopy. The anomalous relative intensities of these bands were found and explained with a bond bond coupli...The (4000), (3100) and (5000) local mode vibrational bands of germane were recorded with high resolution spectroscopy. The anomalous relative intensities of these bands were found and explained with a bond bond coupling dipole moment model. The calculated results, which were also compared with those from the former theoretical model, agree well with the experimental data.展开更多
THE Ar-N<sub>2</sub> complex plays an important role in atmosphere chemistry. Recently, the potential energy functions （PEF） CPV, BTT, MMSV, M3SV, MMSV’ have been determined by comparing the relevant ex...THE Ar-N<sub>2</sub> complex plays an important role in atmosphere chemistry. Recently, the potential energy functions （PEF） CPV, BTT, MMSV, M3SV, MMSV’ have been determined by comparing the relevant experimental information, such as the molecular beam scattering measurements, virial coefficient data, bulk transport and relaxation phenomena, pressure-broadening and shift of spectroscopic infrared and Raman lines. The pure rotational spectrum of the Ar-<sup>14</sup>N<sub>2</sub>, Ar-<sup>15</sup>N<sub>2</sub>, and Ar-<sup>14</sup>N <sup>15</sup>N isotopomers have been measured by Jager展开更多
The Ar-N<sub>2</sub> complex plays an important role in atmosphere chemistry.Recently,thepotential energy functions（PEF）CPV,BTT,MMSV,M3SV,MMSV’ have beendetermined by comparing the relevant experimental...The Ar-N<sub>2</sub> complex plays an important role in atmosphere chemistry.Recently,thepotential energy functions（PEF）CPV,BTT,MMSV,M3SV,MMSV’ have beendetermined by comparing the relevant experimental information,such as the molecular beamscattering measurements,virial coefficient data,bulk transport and relaxation phenomena,pressure-broadening and shift of spectroscopic infrared and Raman lines.The展开更多
基金Project supported by the Natural Science Foundation of Shaanxi Province, China (Grant No. 2009JM1007)
文摘Molecular structure, vibrational frequency and infrared intensity of UF6 are investigated by using the revised Perdew Burke-Enzerhof function with the triple-zeta polarized basis set. The calculation results are in good agreement with the experimental values and indicate the existence of a stable U2F6 molecule with a multiple bonded U2 unit. The calculation results also predict that the D3d symmetry of U2F6 is more stable than D3h. The optimized geometries, vibrational frequencies, and infrared intensities are also reported for U2F6 molecules in D3d symmetry. In addition, the isotopic shift of vibrational frequencies of the two molecules under isotopic substitution of uranium atom are also investigated with the same method. The U2F6 molecule is predicted to be better than UF6 for laser uranic isotope separation.
基金Project supported by the National Natural Science Foundation of ChinaDoctoral Foundation of the State Education Commision of China
文摘Geometrical optimization and theoretical calculation of the vibrational frequencies have been performed for C2B10H12, NB11H12 and C2B10Cl by using Gaussian 92 program at 6-31G basis set. The results obtained in this work are in agreement with experimental ones. The optimized geometry and vibrational spectra show that the icosahedral configuration remains unchanged upon converting from B12H122- to the title compounds. The vibrational spectrum of C2B10H11Cl features the absence of C-Cl stretching vibration. But the (C2B10H11)-Cl vibration mode in the low frequency region is as the case for two-atom molecules if the group (C2B10H11) is considered as a pseudoatom
基金supported by the National Key Technology Research and Development Program of China(No.2016YFB0901402)the Major Program of National Natural Science Foundation of China(No.51790513)。
文摘The modal vibration of the rotor is the main cause of excessive vibration of the aeroengine overall structure.To attenuate the vibration of the rotor under different modal shapes from the perspective of energy control,the intrinsic physical relationships between rotor modal shapes and instantaneous vibrational energy flow transmission characteristics is derived from the general equation of motion base on the structural intensity method.A dual-rotor-support-casing coupling model subjected to the rotor unbalanced forces is established by the finite element method in this paper.The transmission,conversion and balance relationships of the vibrational energy flow for the rotors in the first-order bending modal shape,the conical whirling modal shape and the translational modal shape are analyzed,respectively.The results show that the vibrational energy flow transmitted to the structure can be converted into the strain energy,the kinetic energy and the energy dissipated by the damping of the structure.The vibrational energy flow transmission characteristics of rotors with different modal shapes are quite different.Especially for the first-order bending modal shape,the vibrational energy flow and the strain energy are transmitted and converted to each other in the middle part of the rotor shaft,resulting in large deformation at this part.To attenuate this harmful vibration,the influences of grooving on the shaft on the first-order bending vibration are studied from the perspective of transmission control of vibrational energy flow.This study can provide theoretical references and guidance for the vibration attenuation of the rotors in different modal shapes from a more essential perspective.
文摘The (4000), (3100) and (5000) local mode vibrational bands of germane were recorded with high resolution spectroscopy. The anomalous relative intensities of these bands were found and explained with a bond bond coupling dipole moment model. The calculated results, which were also compared with those from the former theoretical model, agree well with the experimental data.
文摘THE Ar-N<sub>2</sub> complex plays an important role in atmosphere chemistry. Recently, the potential energy functions （PEF） CPV, BTT, MMSV, M3SV, MMSV’ have been determined by comparing the relevant experimental information, such as the molecular beam scattering measurements, virial coefficient data, bulk transport and relaxation phenomena, pressure-broadening and shift of spectroscopic infrared and Raman lines. The pure rotational spectrum of the Ar-<sup>14</sup>N<sub>2</sub>, Ar-<sup>15</sup>N<sub>2</sub>, and Ar-<sup>14</sup>N <sup>15</sup>N isotopomers have been measured by Jager
基金supported by the National Natural Science Foundation of China.
文摘The Ar-N<sub>2</sub> complex plays an important role in atmosphere chemistry.Recently,thepotential energy functions（PEF）CPV,BTT,MMSV,M3SV,MMSV’ have beendetermined by comparing the relevant experimental information,such as the molecular beamscattering measurements,virial coefficient data,bulk transport and relaxation phenomena,pressure-broadening and shift of spectroscopic infrared and Raman lines.The
