A full-dimensional analytical potential energy surface for the F+CH_4→HF+CH_3 reaction

A full-dimensional analytical potential energy surface(APES) for the F + CH4 →HF + CH3 reaction is developed based on 7127 ab initio energy points at the unrestricted coupled-cluster with single,double,and perturbative triple excitations.The correlation-consistent polarized triple-split valence basis set is used.The APES is represented with a many-body expansion containing 239 parameters determined by the least square fitting method.The two-body terms of the APES are fitted by potential energy curves with multi-reference configuration interaction,which can describe the diatomic molecules(CH,H2,HF,and CF) accurately.It is found that the APES can reproduce the geometry and vibrational frequencies of the saddle point better than those available in the literature.The rate constants based on the present APES support the experimental results of Moore et al.[Int.J.Chem.Kin.26,813(1994)].The analytical first-order derivation of energy is also provided,making the present APES convenient and efficient for investigating the title reaction with quasiclassical trajectory calculations.     

Potential energy curve study on the ^3Π electronic states of GaX （X=F,Cl, and Br） molecules

The potential energy curves （PECs） of the 3Π states of GaX （X=F, Cl, and Br） molecules are calculated using the multireference configuration interaction method with a large contracted basis set aug-cc-pV5Z. The PECs are accurately fitted to analytical potential energy functions （APEFs） using the Murrell–Sorbie potential function. The spectroscopic parameters for the states are determined using the obtained APEFs, and compared with the theoretical and experimental data available presently in the literature.     

Dynamic mechanism for encapsulating two HIV replication inhibitor peptides with carbon nanotubes

Encapsulation of biomolecules inside a carbon nanotube(CNT) has attracted great interest because it could enable the delivery of nanoscale pharmaceutical drugs with CNT-based devices.Using a molecular dynamics simulation,we investigate the dynamic process by which human immunodeficiency virus(HIV) replication inhibitor peptides(HRIPs) are encapsulated in a water solution contained inside a CNT.The van der Waals attraction between the HRIPs and the CNT and the root-mean-square deviation are used to analyse the evolution of the encapsulation.It is found that the interaction between the HRIPs and the CNT is the main driving force for the encapsulation process,which does not cause an obvious conformational change to the HRIPs.     

改性聚酯异形中空微孔纤维性能研究

利用不同的异形喷丝板,将聚对苯二甲酸乙二酯(PET)与不同间苯二甲酸- 5- 磺酸基团摩尔含量的共聚酯(HCDP)共混纺丝,制得一系列改性聚酯纤维.改性纤维的断裂强度随共混HCDP中磺酸基团摩尔含量的增加呈现下降趋势,但该趋势在磺酸基团含量达到一定数量后出现回升.纤维对阳离子染料的吸收率随磺酸基团摩尔含量的增加而增加,但对分散染料而言此差异较小,并且不论何种染料,纤维横截面的变化对上染率的影响均不明显.碱处理对纤维上染率影响巨大.纤维保水率与纤维碱处理后形成的具有毛细效应的微孔结构以及异型纤维本身形成的毛细结构有密切关系,而且纤维对水分的传输性能在很大程度上取决于纤维的横截面形状,纤维碱处理后形成的微孔特别是透孔结构有助于输水性能的改善.     

Si6X(X=Cu,Ag,和Au)团簇多激子产生的从头算研究

利用对称性组态相互作用理论（SAC-CI）和LANL2DZ基组研究Si₆X（X=Cu、Ag和Au）团簇的多激子产生（MEG）.在团簇的MEG计算之前,基于密度泛函理论和全电子基组DZP-DKH,对团簇的几何结构进行优化并且经过频率分析确认团簇的能量稳定性.结果表明：多激子的主导成分是双激子,这些团簇的MEG都出现在可见光范围内,团簇的MEG强的部分在紫外线范围内,为利用MEG制备光俘获材料提供信息.     

Theoretical Study of the Influence of Femtosecond Laser Wavelength on the Evolution of a Double-Minimum Electronic Excited State Wave Packet for NaRb

Employing the two-state model and the time-dependent wave packet method, the influence of femtosecond laser wavelength on the evolution of the double-minimum electronic excited state wave packet is numerically investigated. For different laser wavelengths, evolutions of the double-minimum electronic excited state wave packet with time and internuclear distance are different. One can control the evolution of the wave packet by varying the laser wavelength appropriately, which will benefit the light manipulation of atomic and molecular processes. Furthermore, study of the dynamics of the NaRb molecule may yield clues to creating an ultracold molecule.     

激光场强度对NO电子态粒子数布居影响的理论研究

用含时波包方法研究了激光场强度对NO各电子态上粒子数布居的影响.在计算中,采用了四态模型.利用分裂算符傅里叶变换方法求解Schrdinger方程,得到各个电子态的波函数,从而求得各个电子态上粒子数的布居.计算结果表明,不同强度的抽运光对各个电子态上粒子数布居会产生不同的影响.通过改变激光强度可以实现对电离产率的控制,这种思想对实现原子分子过程的激光操控具有重要意义.     

精确研究光电离散射截面的新方法

利用单个原子精确的光电离散射截面和物质的复介电常数,并考虑一定的分子力学模型,可以对凝聚态物质中的原子光电离截面进行定量研究.孙卫国等最近提出了一套研究真实体系中原子光电离截面的新方法.本文首次应用它们来研究碱土金属钠在不同密度状态下的光电离截面,结果表明新的光电离截面公式比著名的孤立原子光电离截面公式更具有优越性.     

An alternative view of condensed-phase photoionization

This paper proposes an accurate valuable interpretation scheme to study the evolvement of the photoionization processes from the isolated to the condensed atoms by a unique ab initio method. The variations of the photoionization cross sections of the atomic sodium with the photoelectron energy and the boundary radius of the atomic configuration space are studied in this new scheme by the R-matrix method. The discrepancy in the photoionization spectra of the isolated and the condensed sodium has been explained quantitatively and understood successfully by this alternative view in detail for the first time.     

Ultra-High Sensitivity Viscometer Based on a Torsion Pendulum

Based on a conventional torsion pendulum,we develop a forced oscillation viscometer with ultra-high viscosity sensitivity of 2×10~(-7)Pa·s working at frequencies near the resonance.The viscosity is achieved by exploiting the phase lag for the angle displacement behind the torque,instead of the resonant curve,i.e.,the variation of angle displacement amplitude versus frequency.The general formula for the measurement of the visco-elasticit.y of complex fluids is also presented.With such precision it is easy to measure tiny change in viscosity result from circumstantial influences.Deionized water and two kinds of NaCl aqueous solutions are chosen to demonstrate the performance of our home-made torsion pendulum-based viscometer.