Bond dissociation energies for removal of nitrogen dioxide groups in 10 aliphatic nitro compounds, including nitromethane, nitroethylene, nitroethane, dinitromethane, 1-nitropropane, 2-nitropropane, 1-nitrobutane, 2-m...Bond dissociation energies for removal of nitrogen dioxide groups in 10 aliphatic nitro compounds, including nitromethane, nitroethylene, nitroethane, dinitromethane, 1-nitropropane, 2-nitropropane, 1-nitrobutane, 2-methyl-2-nitropropane, nitropentane, and nitrohexane, are calculated using the highly accurate complete basis set （CBS-Q） and the three hybrid density functional theory （DFT） methods B3LYP, B3PW91 and B3P86 with 6-31G^＊＊ basis set. By comparing the computed bond dissociation energies and experimental results, we find that the B3LYP/6-31G^＊＊ and B3PW91/6-31G^＊＊ methods are incapable of predicting the satisfactory bond dissociation energy （BDE）. However, B3P86/6-31G^＊＊ and CBS-Q computations are capable of giving the calculated BDEs, which are in extraordinary agreement with the experimental data. Nevertheless, since CBS-Q computational demands increase rapidly with the number of containing atoms in molecules, larger molecules soon become prohibitively expensive. Therefore, we suggest to take the B3P86/6-31G^＊＊ method as a reliable method of computing the BDEs for removal of the NO2 groups in the aliphatic nitro compounds.展开更多
With a two-channel model, we study the influence of temperature, external voltage and magnetic flux on the line shape of the Fano resonance, and show that in the Luttinger liquid case, the background transmittance and...With a two-channel model, we study the influence of temperature, external voltage and magnetic flux on the line shape of the Fano resonance, and show that in the Luttinger liquid case, the background transmittance and the asymmetric parameter depend strongly on the temperature and external voltage, while for the Landau Fermi liquid case they are nearly independent of these parameters in the low energy region. Moreover, we demonstrate that the asymmetric parameter changes periodically with an external magnetic flux, which is consistent with the recent experimental data.展开更多
Spin-orbit coupling in a gate-controlled In0.53 Ga0.47 As/InP quantum well is investigated in the presence of a large Zeeman effect. We develop a fourier-transform fitting procedure to extract the zero-field spin-spli...Spin-orbit coupling in a gate-controlled In0.53 Ga0.47 As/InP quantum well is investigated in the presence of a large Zeeman effect. We develop a fourier-transform fitting procedure to extract the zero-field spin-splitting Rashba parameter α. The bare 9 factor value is found to be of the order of 3 from magnetotransport measurements in tilted magnetic fields. It is found that both Zeeman splitting and Rashba splitting play important roles in determining the total spin splitting in In0.53Ga0.47 As.展开更多
We present a simple demonstration of the nonfeasibility of metal-insulator transition in an exactly two-dimensional （2D） system. The Hartree-Fock potential in the 3D system is suitably modified and presented for the...We present a simple demonstration of the nonfeasibility of metal-insulator transition in an exactly two-dimensional （2D） system. The Hartree-Fock potential in the 3D system is suitably modified and presented for the 2D case. The many body effects are included in the screening function, and binding energies of a donor are obtained as a function of impurity concentration so as to find out the possible way leading metal-insulator transition in the 2D system. While solving for the binding energy for a shallow donor in an isolated well of a GaAs/Ga1-x Als As superlattice system within the effective mass approximation, it leads to unphysical results for higher concentrations. It shows that the phase transition, the bound electron entering into the conduction band whereby （H）min=0, is not possible beyond this concentration. The results suggest thai a phase transition is impossible in 213 systems, supporting the scaling theory of localization. The results are compared with the existing data available and discussed in the light of existing literature.展开更多
A negative differential mobility (NDM) of the two-dimensional carrier-gas against some proper external regulator allowing for gradual controlled modification of the nanointerfacial environment tends to occur as interw...A negative differential mobility (NDM) of the two-dimensional carrier-gas against some proper external regulator allowing for gradual controlled modification of the nanointerfacial environment tends to occur as interwoven with nanophotonic device functionality. In this work, several instances, in our two-decade principal research, of both experimental observation and conceptual prediction concerning nanophotonics NDM are reconsidered towards outlining a global potential for the appearance of the effect.展开更多
基金Supported by the National Natural Science Foundation of China under grant Nos 10376021, 10274055, the Chinese Academy of Engineering Physics, and the Research Fund for the Doctoral Programme of High Education of China under grant No 20020610001.
文摘Bond dissociation energies for removal of nitrogen dioxide groups in 10 aliphatic nitro compounds, including nitromethane, nitroethylene, nitroethane, dinitromethane, 1-nitropropane, 2-nitropropane, 1-nitrobutane, 2-methyl-2-nitropropane, nitropentane, and nitrohexane, are calculated using the highly accurate complete basis set （CBS-Q） and the three hybrid density functional theory （DFT） methods B3LYP, B3PW91 and B3P86 with 6-31G^＊＊ basis set. By comparing the computed bond dissociation energies and experimental results, we find that the B3LYP/6-31G^＊＊ and B3PW91/6-31G^＊＊ methods are incapable of predicting the satisfactory bond dissociation energy （BDE）. However, B3P86/6-31G^＊＊ and CBS-Q computations are capable of giving the calculated BDEs, which are in extraordinary agreement with the experimental data. Nevertheless, since CBS-Q computational demands increase rapidly with the number of containing atoms in molecules, larger molecules soon become prohibitively expensive. Therefore, we suggest to take the B3P86/6-31G^＊＊ method as a reliable method of computing the BDEs for removal of the NO2 groups in the aliphatic nitro compounds.
基金Supported by the National Natural Science Foundation of China under Grant Nos 90403015 and10647005,the Science and Technology Foundation of Guizhou Province under Grant No 20043017, and the Natural Science Foundation of Education Department of Guizhou Province under Grant No 2006216.
文摘With a two-channel model, we study the influence of temperature, external voltage and magnetic flux on the line shape of the Fano resonance, and show that in the Luttinger liquid case, the background transmittance and the asymmetric parameter depend strongly on the temperature and external voltage, while for the Landau Fermi liquid case they are nearly independent of these parameters in the low energy region. Moreover, we demonstrate that the asymmetric parameter changes periodically with an external magnetic flux, which is consistent with the recent experimental data.
基金Supported by the Special Funds for Major State Basic Research Project under Grant No 2007CB924901, the National Natural Science Foundation of China under Grant No 60221502, the Knowledge Innovation Programme of Chinese Academy of Sciences under Grant No C2-12, and Science and Technology Commission of Shanghai under Grant No 07JC14059.
文摘Spin-orbit coupling in a gate-controlled In0.53 Ga0.47 As/InP quantum well is investigated in the presence of a large Zeeman effect. We develop a fourier-transform fitting procedure to extract the zero-field spin-splitting Rashba parameter α. The bare 9 factor value is found to be of the order of 3 from magnetotransport measurements in tilted magnetic fields. It is found that both Zeeman splitting and Rashba splitting play important roles in determining the total spin splitting in In0.53Ga0.47 As.
文摘We present a simple demonstration of the nonfeasibility of metal-insulator transition in an exactly two-dimensional （2D） system. The Hartree-Fock potential in the 3D system is suitably modified and presented for the 2D case. The many body effects are included in the screening function, and binding energies of a donor are obtained as a function of impurity concentration so as to find out the possible way leading metal-insulator transition in the 2D system. While solving for the binding energy for a shallow donor in an isolated well of a GaAs/Ga1-x Als As superlattice system within the effective mass approximation, it leads to unphysical results for higher concentrations. It shows that the phase transition, the bound electron entering into the conduction band whereby （H）min=0, is not possible beyond this concentration. The results suggest thai a phase transition is impossible in 213 systems, supporting the scaling theory of localization. The results are compared with the existing data available and discussed in the light of existing literature.
文摘A negative differential mobility (NDM) of the two-dimensional carrier-gas against some proper external regulator allowing for gradual controlled modification of the nanointerfacial environment tends to occur as interwoven with nanophotonic device functionality. In this work, several instances, in our two-decade principal research, of both experimental observation and conceptual prediction concerning nanophotonics NDM are reconsidered towards outlining a global potential for the appearance of the effect.
