高电荷态离子与表面相互作用

论述了高电荷态离子与表面相互作用的过程 ,说明了发射电子、发射光子、负离子、中性粒子、正离子的散射和发射的物理机理以及应用前景 .介绍了在兰州重离子国家实验室ECR源建立高电荷态离子与表面相互作用的原子物理平台的重要意义和将要开展的工作.The interaction between highly charged ions and surface is investigated, the mechanisms for emissions of electrons, photons and scattered neutral particles, negative and positive ions are reviewed. We report a new atomic physics station in ECR and our work plan.     

Calculation of Interaction Potentials between Spherical and Deformed Nuclei

The interaction potential for spherical-deformed reaction partners is calculated. The shape, separation and orientation dependence of the interaction potential and fusion cross section of the system ^32S＋^154Sm are investigated within the double-folding model of the deformed nuclei. The effective nucleon-nucleon interaction is taken to be the M3Y-Reid potential. The density is considered for three terms of the expansion using the truncated multipole expansion method, which is a deformed Fermi shape With quadrupole and hexadecapole for the density distribution of ^154Sm. It is found for the interaction potential that the height and the position of barrier strongly depend on the deformations, the orientation angle of the deformed nucleus, and hence produce great effects on fusion cross section. The integrated fusion cross section is in good agreement with the experimental data.     

硫酸钠溶液中方解石表面油膜脱附机理研究

摘要：本文重点研究油湿型方解石表面形成的过程和方解石表面油膜在SO42-作用下脱附的过程,从分子尺度探究油膜形成机理和SO42-作用机理。首先,为模拟碳酸盐岩储层实际而建立油湿型碳酸盐岩表面。范德华力和静电作用下油分子运动到方解石表面形成双层结构的油膜,方解石由水湿变为油湿。结果表明,与第二层相比,第一层排列更有序,结构更稳定,对储层润湿性影响更大。而后,研究方解石表面油膜在SO42-作用下脱附的过程和作用机理。方解石表面油膜的脱附可以分为两步：静电作用下水通道的形成;氢键作用下水膜的形成。最终,方解石表面由油湿变为水湿。研究表明：SO42-参与了方解石表面油膜脱附过程中重要的静电力作用和氢键作用,加速了水通道和水膜的形成,加速了方解石表面油膜的脱附,对储层润湿性影响较大。     

Molecular-Dynamics Simulation of the Interaction of Argon Cluster Ions with Titanium Surface

The molecular-dynamics simulation of impacts of accelerated argon cluster ions with titanium surface is carried out. The dependences of the dimensions of the produced defects and of the number of sputtered titanium atoms on the cluster-ion dimensions, energies, and incidence angles are studied.     

The Effect of Interaction Range in Relativistic Microscopic Optical Potentials

Starting from the Walecka model about relativistic nucleon-meson field theory,the effect of interaction range in the relativistic microscopic optical potentials for nucleon-nucleus is included by folding the optical potentials in Local Density Approximity with nucleon-nucleon interaction potentials from the Walecka model.The present potentials are used to analyze the proton elastic scattering from nuclei.The agreement of the present calculation with experiment data is better than that of LDA.     

荧光光谱法研究蒜头果蛋白与金属离子的相互作用

蒜头果蛋白(malanin)是从云南、广西特有植物蒜头果中分离纯化出的一种新的、具有抗肿瘤活性的糖蛋白。用荧光光谱法研究了Cu2+,Ag+和Ca2+对malanin和apo-malanin溶液(经EDTA透析脱去金属离子后的脱金属蛋白)荧光强度的影响。结果表明,Cu2+对malanin和apo-malanin荧光均有明显的静态猝灭现象,其离解常数K_d分别为2.37×10-4和2.66×10-4 mol·L-1;Ag+对malanin的荧光强度变化不大,但对apo-malanin荧光强度却有明显的静态猝灭现象,其离解常数K_d为2.37×10-4 mol·L-1;而Ca2+对malanin和apo-malanin荧光强度均无明显变化,说明Ca2+对维持malanin分子天然构象具有重要作用。     

胡椒酸乙酯与牛血清白蛋白的相互作用及金属离子的影响

采用荧光光谱研究了胡椒酸乙酯与牛血清白蛋白(BSA)的相互作用。实验结果表明:胡椒酸乙酯与BSA形成基态复合物从而猝灭BSA的内源性荧光,猝灭原因主要为静态猝灭和非辐射能量转移作用。胡椒酸乙酯对BSA的猝灭速率常数Kq为1.451×1013L.mol-1.s-1(25℃)和1.136×1013L.mol-1.s-1(37℃),胡椒酸乙酯与BSA的结合常数KA为9.484×105L.mol-1(25℃)和1.355×106L.mol-1(37℃),结合位点数n为1.18(25℃)和1.24(37℃)。根据Frster偶极-偶极非辐射能量转移理论得到结合距离r为2.68 nm(25℃)和2.81 nm(37℃)。通过热力学参数的计算,确定胡椒酸乙酯与牛血清白蛋白的相互作用是熵增加和吉布斯自由能降低的自发过程,主要作用力为疏水作用力。讨论了共存金属离子对胡椒酸乙酯与BSA的相互作用的影响。     

Interaction between Pazufloxacin and DNA Mediated by Copper(II) Ions

The influence of copper(II) ions on the binding of Pazufloxacin (PFLX), which is a forth generation quinolone antimicrobial agent, to calf thymus DNA (CTDNA) has been investigated by fluorescence, absorption spectroscopy and viscosity measurement. The results show that PFLX and Cu(2+) can form binary complex with mole ratio 2:1, PFLX and CTDNA can form complex mediated by Cu(2+). A ternary system of PFLX-Cu(2+)-DNA were proposed. The experimental results show that the PFLX binds to CTDNA by two kinds of binding modes, intercalative mode and groove binding mode.     

碱土金属原子与Ne原子间相互作用势的理论计算

本文基于无任何可调参数的势模型计算了碱土金属原子(Be、Mg、Ca、Sr、Ba)与Ne原子间相互作用势,得到的势能曲线及势阱位置和深度与现有的从头计算结果符合较好.本文的计算结果进一步验证了碱土金属原子与稀有气体原子间交换能主要来自碱土金属原子最外层s电子与稀有气体原子最外层p电子之间的交换作用.     

Spectral Dependencies of the Surface Photo-Charge Effect at Conducting Surfaces

Investigations show that the surface photo-charge effect has been observed for all solids. In this paper, experimentally obtained spectral dependencies of this effect at surfaces of several conductors (viz., Cu, Pb, Ag, brass,) are shown and discussed.     

分子和金表面相互作用的第一性原理研究

从第一性原理出发利用密度泛函理论研究了 4 ,4′ 二巯基联苯分子和金表面的相互作用 ,并利用了前线轨道理论和微扰理论定量地确定了该相互作用能常数. By using density functional theory, we have investigated the interaction between a thiol-phenyl molecule (4-4′-dimercaptodibenzene) and a gold surface. The frontier orbit theory and the perturbation theory are also employed to determine quantitatively the constant of interaction energy. The results show that the bonding between the sulfur atom and the gold atoms corresponds mainly to the covalent bond and some molecular orbits are extended over the molecule and gold cluster which certainly give channels...     

On the Relation between Effective Potentials and Realistic Potentials

A velocity dependent effective potential of s- and p-wave interaction denoted by VG2 has been applied to calculate the parameters of nuclear matter. Using this potential, the binding energy of a group of double closed shell nuclei is calculated according to the shell model. Also, the binding energy of ¹²C and ¹⁶O is calculated assuming Brink's model and using the VG2 interaction together with the potential deduced by Arickx et al. Reasonable agreement with experimental data is obtained.     

两种药物与金属离子的作用

研究了磺胺间甲氧嘧啶、诺氟沙星与Ce3+,La3+,Tb3+,Co2+,Fe3+作用体系的荧光和紫外特性。结果表明,La3+和Tb3+对磺胺间甲氧嘧啶的荧光起增敏作用,而Fe3+,Co2+,Ce3+使磺胺间甲氧嘧啶的荧光猝灭;Ce3+,La3+,Tb3+,Co2+,Fe3+对诺氟沙星的荧光均起猝灭作用。紫外的测定结果与荧光基本相同。     

Dynamic Potential of Interaction between Nitrogen Atoms and Aluminum Crystal Surface

Specific features of the angular distributions of accelerated neutral nitrogen atoms at the grazing angles of incidence on the Al(001) crystal surface have been investigated by the computer simulation method. The N–Al pair interaction potential is approximated by the three-parameter Morse potential with the energydependent coefficients. The angular distributions of scattered atoms have been simulated taking into account the interaction between atoms and several atomic layers in the lattice and the atomic displacement during thermal oscillations. The parameters of the pair potential of accelerated neutral nitrogen atoms in the energy range from 10 to 70 keV have been determined according to the best agreement between the calculated dependence of the rainbow scattering angle on the energy of particles incident on the crystal surface and the available experimental data.

     

Patterns of the Ionization Potentials of Multicharged Ions of Heavy Elements

JETP Letters - Available calculated data on the ionization potentials of ions in the ground state with the number of electrons Ne ≤ 46 are analyzed for elements with atomic numbers 55 ≤...     

荧光光谱法研究肌红蛋白活性中心铁卟啉与铜离子的相互作用

首次应用荧光光谱法研究了肌红蛋白 (FePP Mb)的活性中心铁卟啉与铜离子的相互作用 ,结果表明在水溶液中肌红蛋白中的铁可被铜离子取代 ,形成铜卟啉化合物 (CuPP Mb) ,并且随着体系中铜离子量的增加 ,其相互作用增强。本课题从蛋白质的角度研究了金属离子同生物大分子相互作用的现象并探讨了作用机理 ,可以为进一步研究有害重金属在人体内作用及毒害机理提供一定的理论依据。同时 ,本文采用的荧光光谱法与常规的UV和CD法相比有较高的灵敏度。     

西那沙星与牛血清白蛋白的相互作用及共存金属离子影响的研究

应用荧光光谱法、紫外分光光度法研究了在不同酸度、温度条件下,西那沙星(Sinafloxacin)与牛血清白蛋白(bovine serum albumins,BSA)的相互作用,研究表明：西那沙星对BSA内源荧光的猝灭机制属于形成复合物所引起的静态猝灭,利用荧光猝灭双倒数图计算了西那沙星与牛血清白蛋白之间的结合常数K_D,根据Fōrster非辐射能量转移理论计算出西那沙星与牛血清白蛋白结合时授体-受体间的结合距离r=3.64 nm、能量转移效率E=0.163,表明两者之间有较强的作用,并根据热力学参数确定了西那沙星与牛血清白蛋白之间的主要作用力类型为静电作用力,同时采用同步荧光、三维荧光技术考察了西那沙星对BSA构象的影响。此外,讨论了共存Cu2+,Fe3+,Zn2+,Mg2+对西那沙星与BSA结合作用的影响。为探讨西那沙星在生物体内与蛋白质的作用机理和生物学效应提供了理论依据。