We investigate the electronic structure ofβ-uranium,which has five nonequivalent atomic sites in its unit cell,by means of the density functional theory plus Hubbard-U correction with U from linear response calculati...We investigate the electronic structure ofβ-uranium,which has five nonequivalent atomic sites in its unit cell,by means of the density functional theory plus Hubbard-U correction with U from linear response calculation.It is found that the 5f electronic correlations inβ-uranium are moderate.More interestingly,their strengths are site selective,depending on the local atomic environment of the present uranium atom.As a consequence,the occupation matrices and partial 5f density of states ofβ-uranium manifest site dependence.In addition,the complicate experimental structure ofβ-uranium could be well reproduced within this theoretical framework.展开更多
Chloroplasts were isolated from spinach treated with taCl3, CeCl3, and NdCl3. Because of owning 4f electron characteristics and alternation valence, Ce treatment presented the highest enhancement in light absorption, ...Chloroplasts were isolated from spinach treated with taCl3, CeCl3, and NdCl3. Because of owning 4f electron characteristics and alternation valence, Ce treatment presented the highest enhancement in light absorption, energy transfer from LHC Ⅱ to PS Ⅱ, excitation energy distribution from PS Ⅰ to PS Ⅱ, and fluorescence quantum yield around 680 nm. Compared with Ce treatment, Nd treatment resulted in relatively lower enhancement in these physiological indices, as Nd did not have alternation valence. La treatment presented the lowest enhancement, as La did not have either 4f electron or alternation valence. The increase in activities of whole chain electron transport, PS ⅡDCPIP photoreduction, and oxygen evolution of chloroplasts was of the following order： Ce〉Nd 〉La〉 control. However, the photoreduction activities of spinach PS I almost did not change with La, Ce, or Nd treatments. The results suggested that 4f electron characteristics and alternation valence of rare earths had a close relationship with photosynthesis improvement.展开更多
In this paper the absorption spectra of Nd-SXO-CPC complex by 4f electron transitions have been studied by zero-order and fourth-order derivative spectrophotome-try. The molar absorptivity is 2.6×10~3 1.mol^(-1)....In this paper the absorption spectra of Nd-SXO-CPC complex by 4f electron transitions have been studied by zero-order and fourth-order derivative spectrophotome-try. The molar absorptivity is 2.6×10~3 1.mol^(-1).cm^(-1) at 585 nm, the fourth-order derivative molar absorptivity is 1.4×10~4 1.mol^(-1).cm^(-1) at 584.5(-) and 587(+) nm. They are 300 times and 1600 times greater than those of the chloride, respectively.展开更多
In this paper the absorption spectra of 4f electron transitions of the neodymlum complex with 8-hydroxyquinoline and octylphenol poly(ethyleneglycol)ether have been studied. The marked intensification of the band at l...In this paper the absorption spectra of 4f electron transitions of the neodymlum complex with 8-hydroxyquinoline and octylphenol poly(ethyleneglycol)ether have been studied. The marked intensification of the band at low octylphenol poly(ethyleneglycol)ether concentration is found normally at 575 nm, and its resolution into three sharp bands centering at 572, 580 and 584 nm. The absorbances of the absorption maxima are 3.5 (at 572 nm), 7.2 (at 580 nm) and 10.2 (at 584 nm) times greater than that of the chloride.展开更多
The electronic structures of BaMgF4 crystals containing an F colour centre are studied within the framework of the fully relativistic self-consistent Direc-Slater theory, using a numerically discrete variational （DV...The electronic structures of BaMgF4 crystals containing an F colour centre are studied within the framework of the fully relativistic self-consistent Direc-Slater theory, using a numerically discrete variational （DV-Xa） method. It is concluded from the calculated results that the energy levels of the F colour centre are located in the forbidden band. The optical transition energy from the ground state to the excited state for the F colour centre is about 5.12 eV, which corresponds to the 242-nm absorption band. These calculated results can explain the origin of the absorption bands.展开更多
This paper presents CMOS circuit designs of a ternary adder and a ternary multiplier,formulated using transmission function theory.Binary carry signals appearing in these designs allow conventional look-ahead carry te...This paper presents CMOS circuit designs of a ternary adder and a ternary multiplier,formulated using transmission function theory.Binary carry signals appearing in these designs allow conventional look-ahead carry techniques to be used.Compared with previous similar designs,the circuits proposed in this paper have advantages such as low dissipation,low output impedance,and simplicity of construction.展开更多
The potential energy surface and reaction mechanism corresponding to the reaction of ytterbium monocation with fluoromethane, which represents a prototype of the activation of C-F bond in fluorohydrocarbons by bare la...The potential energy surface and reaction mechanism corresponding to the reaction of ytterbium monocation with fluoromethane, which represents a prototype of the activation of C-F bond in fluorohydrocarbons by bare lanthanide cations, have been investigated for the first time by using density functional theory. A direct fluorine abstraction mechanism was revealed, and the related thermochemistry data were determined. The electron-transfer reactivity of the reaction was analyzed using the two-state model, and a strongly avoided crossing behavior on the transition state region was shown. The present results support the reaction mechanism inferred from early experimental data and the related thermochemistry data can provide a guide for further experimental researches.展开更多
The above-threshold detachment of F- ions induced by a linearly polarized few-cycle laser pulse is investigated theoretically using the strong-field approximation model without considering the rescattering mechanism. ...The above-threshold detachment of F- ions induced by a linearly polarized few-cycle laser pulse is investigated theoretically using the strong-field approximation model without considering the rescattering mechanism. We first derive an analytical form of transition amplitude for describing the strong-field photodetachment of F- ions. The integration over time in transition amplitude can be performed using the numerical integration method or the saddle-point （SP） method of Shearer et al. [Phys. Rev. A 88 （2013） 033415]. The validity of the SP method is carefully examined by comparing the energy spectra and photoelectron angular distributions （PADs） with those obtained from the numerical integration method. By considering the volume effect of a focused laser beam, both the energy spectra and the low-energy PADs calculated by the numerical integration method agree very well with the experimental results.展开更多
Ab initio electronic structure calculations are reported for low-lying electronic states,X ~1Σ^+and A ~1Π of the N_2F^+ molecule.Geometric parameters for the ground state X ~1Σ^+ are predicted by means of mul- tire...Ab initio electronic structure calculations are reported for low-lying electronic states,X ~1Σ^+and A ~1Π of the N_2F^+ molecule.Geometric parameters for the ground state X ~1Σ^+ are predicted by means of mul- tireference single and double excitation configuration interaction(MRSDCI)calculations with a double zeta plus polarization(DZ+P)basis set.Vertical excitation energy for these two electronic states is determined using MRSDCI/DZ+P calculations at the ground state equilibrium geometry.The oscillator strength for the X^1Σ+→ A ~1Π transition and the radiative lifetime for the A^1Π state are calculated based on the MRSDCI wavefunc- tions.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.22176181,11874329,11934020,and U1930121)the Foundation of the President of China Academy of Engineering Physics (Grant No.YZJJZQ2022011)the Foundation of Science and Technology on Surface Physics and Chemistry Laboratory (Grant No.WDZC202101)。
文摘We investigate the electronic structure ofβ-uranium,which has five nonequivalent atomic sites in its unit cell,by means of the density functional theory plus Hubbard-U correction with U from linear response calculation.It is found that the 5f electronic correlations inβ-uranium are moderate.More interestingly,their strengths are site selective,depending on the local atomic environment of the present uranium atom.As a consequence,the occupation matrices and partial 5f density of states ofβ-uranium manifest site dependence.In addition,the complicate experimental structure ofβ-uranium could be well reproduced within this theoretical framework.
基金Project supported by the National Natural Science Foundation of China (20671067, 30470150)
文摘Chloroplasts were isolated from spinach treated with taCl3, CeCl3, and NdCl3. Because of owning 4f electron characteristics and alternation valence, Ce treatment presented the highest enhancement in light absorption, energy transfer from LHC Ⅱ to PS Ⅱ, excitation energy distribution from PS Ⅰ to PS Ⅱ, and fluorescence quantum yield around 680 nm. Compared with Ce treatment, Nd treatment resulted in relatively lower enhancement in these physiological indices, as Nd did not have alternation valence. La treatment presented the lowest enhancement, as La did not have either 4f electron or alternation valence. The increase in activities of whole chain electron transport, PS ⅡDCPIP photoreduction, and oxygen evolution of chloroplasts was of the following order： Ce〉Nd 〉La〉 control. However, the photoreduction activities of spinach PS I almost did not change with La, Ce, or Nd treatments. The results suggested that 4f electron characteristics and alternation valence of rare earths had a close relationship with photosynthesis improvement.
文摘In this paper the absorption spectra of Nd-SXO-CPC complex by 4f electron transitions have been studied by zero-order and fourth-order derivative spectrophotome-try. The molar absorptivity is 2.6×10~3 1.mol^(-1).cm^(-1) at 585 nm, the fourth-order derivative molar absorptivity is 1.4×10~4 1.mol^(-1).cm^(-1) at 584.5(-) and 587(+) nm. They are 300 times and 1600 times greater than those of the chloride, respectively.
文摘In this paper the absorption spectra of 4f electron transitions of the neodymlum complex with 8-hydroxyquinoline and octylphenol poly(ethyleneglycol)ether have been studied. The marked intensification of the band at low octylphenol poly(ethyleneglycol)ether concentration is found normally at 575 nm, and its resolution into three sharp bands centering at 572, 580 and 584 nm. The absorbances of the absorption maxima are 3.5 (at 572 nm), 7.2 (at 580 nm) and 10.2 (at 584 nm) times greater than that of the chloride.
基金supported by the Foundation of Shanghai Municipal Education Committee,China (Grant No. 09YZ210)the Shanghai Leading Academic Discipline Project (Grant No. S30502)
文摘The electronic structures of BaMgF4 crystals containing an F colour centre are studied within the framework of the fully relativistic self-consistent Direc-Slater theory, using a numerically discrete variational （DV-Xa） method. It is concluded from the calculated results that the energy levels of the F colour centre are located in the forbidden band. The optical transition energy from the ground state to the excited state for the F colour centre is about 5.12 eV, which corresponds to the 242-nm absorption band. These calculated results can explain the origin of the absorption bands.
基金Project supported by the National Natural Science Foundation of China.
文摘This paper presents CMOS circuit designs of a ternary adder and a ternary multiplier,formulated using transmission function theory.Binary carry signals appearing in these designs allow conventional look-ahead carry techniques to be used.Compared with previous similar designs,the circuits proposed in this paper have advantages such as low dissipation,low output impedance,and simplicity of construction.
基金supported by the National Science Foundation of Shandong Province(No.Z2000B02).
文摘The potential energy surface and reaction mechanism corresponding to the reaction of ytterbium monocation with fluoromethane, which represents a prototype of the activation of C-F bond in fluorohydrocarbons by bare lanthanide cations, have been investigated for the first time by using density functional theory. A direct fluorine abstraction mechanism was revealed, and the related thermochemistry data were determined. The electron-transfer reactivity of the reaction was analyzed using the two-state model, and a strongly avoided crossing behavior on the transition state region was shown. The present results support the reaction mechanism inferred from early experimental data and the related thermochemistry data can provide a guide for further experimental researches.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11647150,11464026,11664035 and 11364038the Young Talents Program of Gansu Province in 2016+1 种基金the Scientific Research Program of the Higher Education Institutions of Gansu Province under Grant No 2016A-068the Doctoral Scientific Research Foundation of Lanzhou City University under Grant No LZCU-BS2015-04
文摘The above-threshold detachment of F- ions induced by a linearly polarized few-cycle laser pulse is investigated theoretically using the strong-field approximation model without considering the rescattering mechanism. We first derive an analytical form of transition amplitude for describing the strong-field photodetachment of F- ions. The integration over time in transition amplitude can be performed using the numerical integration method or the saddle-point （SP） method of Shearer et al. [Phys. Rev. A 88 （2013） 033415]. The validity of the SP method is carefully examined by comparing the energy spectra and photoelectron angular distributions （PADs） with those obtained from the numerical integration method. By considering the volume effect of a focused laser beam, both the energy spectra and the low-energy PADs calculated by the numerical integration method agree very well with the experimental results.
文摘Ab initio electronic structure calculations are reported for low-lying electronic states,X ~1Σ^+and A ~1Π of the N_2F^+ molecule.Geometric parameters for the ground state X ~1Σ^+ are predicted by means of mul- tireference single and double excitation configuration interaction(MRSDCI)calculations with a double zeta plus polarization(DZ+P)basis set.Vertical excitation energy for these two electronic states is determined using MRSDCI/DZ+P calculations at the ground state equilibrium geometry.The oscillator strength for the X^1Σ+→ A ~1Π transition and the radiative lifetime for the A^1Π state are calculated based on the MRSDCI wavefunc- tions.
