基于原子轨道理论的社区用户排序

对虚拟社区中的用户进行排序并识别其中存在的特殊用户(如网络水军)是件有意义的工作。在原子轨道理论的启发下,该文将用户在虚拟社区中的活动"想象"为一种"特殊粒子"的运动,设计了计算用户"能量"的方法,进而根据用户能量等级对用户排序、识别特殊用户。通过分析仿真系统在不同条件下生成的数据,该文验证了用户能量计算方法的可行性、基于用户能量的用户排序方法的有效性。实验结果表明:该文方法的平均召回率大于82%。

Atomic orbitals modulated dual functional bimetallic phosphides derived from MOF on MOF structure for boosting high efficient overall water splitting

The electronic modulation characteristics of efficient metal phosphide electrocatalysts can be utilized to tune the performance of oxygen evolution reaction(OER).However,improving the overall water splitting performance remains a challenging task.By building metal organic framework(MOF)on MOF heterostructures,an efficient strategy for controlling the electrical structure of MOFs was presented in this study.ZIF-67 was in-situ synthesized on MIL-88(Fe)using a two-step self-assembly method,followed by low-temperature phosphorization to ultimately synthesize FeP-CoP_(3)bimetallic phosphides.By combining atomic orbital theory and theoretical calculations(density functional theory),the results reveal the successful modulation of electronic orbitals in FeP-CoP_(3)bimetallic phosphides,which are synthesized from MOF on MOF structure.The synergistic impact of the metal center Co species and the phase conjugation of both kinds of MOFs are responsible for this regulatory phenomenon.Therefore,the catalyst demonstrates excellent properties,demonstrating HER 81 mV(η10)in a 1.0 mol L^(−1)KOH solution and OER 239 mV(η50)low overpotentials.The FeP-CoP_(3)linked dual electrode alkaline batteries,which are bifunctional electrocatalysts,have a good electrocatalytic ability and may last for 50 h.They require just 1.49 V(η50)for total water breakdown.Through this technique,the electrical structure of electrocatalysts may be altered to increase catalytic activity.

Non-additivity of Methyl Group in the Single-electron Lithium Bond of H3C… Li-H Complex

The non-additivity of the methyl groups in the single-electron lithium bond was investigated using ab initio calculations at the B3LYP/6-311＋＋G＊＊ and UMP2/6-311＋＋G＊＊ levels. The strength of the interaction in the H3C… LiH, H3CH2C… LiH, （H3C）2HC… LiH, and u v （H3C）3C… LiH complexes was analyzed in term of the geometries, energies, frequency shifts, stabilization energies, charges, and topological parameters. It is shown that （H3C）3C radical with LiH forms the strongest single-electron lithium bond, followed by （H3C）2HC radical, then H3CH2C radical, and H3C radical forms the weakest single-electron lithium bond. A positive non-additivity is present among methyl groups. Natural bond orbital and atoms in molecules analyses were used to estimate such conclusions. Furthermore, there are few linear/nonlinear relationships in the system and the interaction mode of single-electron Li- bond is different from the single-electron H-bond and single-electron halogen bond.

Double—Pulse Spectra and Closed—Orbits：Photodetachment of H^— in parallel Electric and Magnetic Fields

We derive a formula for double-pulse spectra from closed-orbit theory. We then calculate the double-pulse photodetachment spectra of H? in the presence of parallel electric and magnetic fields. We analyze the spectra in terms of closed-orbits of the system. We suggest a method for the measurement of a phase associated with each closed-orbit.

Semiclassical Calculation of Recurrence Spectra of Rydberg Hydrogen Atom Near a Metal Surface

Using closed orbit theory, we give a clear physical picture description of the Rydberg hydrogen atom near a metal surface and calculate the Fourier transformed recurrence spectra of this system at different scaled energies below ionization threshold. The results show that with the increase of the scaled energy, the number of the closed orbit increases greatly. Some of the orbits are created by the bifurcation of the perpendicular orbit. This case is quite similar to the Rydberg atom in an electric field. When the scaled energy increases furthermore, chaotic orbits appear. This study provides a different perspective on the dynamical behavior of the Rydberg atom near a metal surface.

Oscillations in Total Photodetachment Cross Sections of a Triatomic Anion

The total photodetachment cross section of a linear triatomic anion is derived for arbitrary laser polarization direction. The cross section is ,shown to be strongly oscillatory when the laser polarization direction is parallel to the axis of the system; the oscillation amplitude decreases and vanishes as the angle between the laser polarization and the anion axis increases and becomes perpendicular to the axis. The average cross section over the orientations of the triatomie system is also obtained. The cross section of the triatomic anion is compared with the cross section of a two-center system. We find there are two oscillation frequencies in the triatomie anion in contrast to only one oscillation frequency in the two-center case. Closed-orbit theory is used to explain the oscillations.

On the Bonding Nature of Noble Gas Compounds MRg^(+) and MRgF(M=Co,Rh,Ir;Rg=Ar,Kr,Xe)

The structure and stability of the compounds MRg^(+)and MRg F(Rg=Ar,Kr,and Xe;M=Co,Rh,and Ir)were investigated using the B3 LYP,MP2,MP4(SDQ)and CCSD(T)methods.We reported the geometry,vibrational frequencies and thermodynamics properties of these compounds.A series of theoretical methods on the basis of wavefunction analysis,including natural bond orbitals,atoms in molecules,electron localization function,and energy decomposition analysis,were performed to explore bonding nature of the M-Rg and Rg-F bonds.These bonds are mainly noncovalent,the metal weakly interacts with Rg in MRg^(+),but their interaction is much stronger in MRg F.The neutral molecule MRg F can be well described by the Lewis structure[MRg]^(+)F^(-).