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Topological chirality and achirality of the closed circular DNAs

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Chinese Science Bulletin 1997年第20期42卷 1705-1708页

作者： QIU Wenyuan and XIN Houwen1. department of Chemical physics, {2. of Science and Technology of{3., Hefei 2.3}02.,{3. 2. department of Chemistry, lanzhou university, lanzhou 73.000,{3. Depaitment of Chemical physics University of Science and Technology of China Hefei 230026 China

THE study of the relations between the topological structure and its function is one of the focus-es in modern chemistry and life science. In this note we set up a topological model to de-scribe the ccDNAs on the basis of Seifert construction in knot theory. Our model for theccDNAs helps to determine whether a structure is topologically chiral or achiral. This is one ofthe fundamental biological problems.

关键词： DNA topology knot theory topologiesl chirality topological achirality.

β-delayed proton decays near the proton drip line

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Science china(physics,Mechanics & Astronomy) 2005年第3期48卷 257-267页

作者： XU Shuwei 1 , LI Zhankui 1 , XIE Yuanxiang 1 , HUANG Wenxue 1 , SHU Nengchuan 2., CHEN Yongshou 2., XU Furong 3., WANG Kun 4 , PAN Qiangyan 1 , WANG Xudong 1 , YU Yong 1 & XING Yebing 1 1. Institute of modern {2., Chinese Academy of Sciences, {2. 73.000,{3. 2. Nuclear {2. department,{3. Institute of Atomic Energy, Beijing 102.13.{3. 3. department of Technical {2., Peking university, Beijing 100871,{3. 4. Shanghai Institute for Nuclear Research, Shanghai 2.1800,{3. 1. Institute of modern physics Chinese Academy of Sciences 730000 Lanzhou China 2. Nuclear physics department China Institute of Atomic Energy 102413 Beijing China 3. department of Technical {2. Peking University 100871 Beijing China 4. Shanghai Institute for Nuclear Research 201800 Shanghai China

We briefly reviewed the experimental study on a-delayed proton decays near the proton drip line published by our group during the period of 1996―2.04, namely the first observation of the a-delayed proton decays of 9 new nuclides in the rare-earth region and the new measurements of a-delayed proton decays of 5 nuclides in the mass ～90 region near the N = Z line with the aid of the “p-?” coincidence in combination with a He-jet tape transport system. In the meantime some important experimental technique details were supplemented. The experimental results, including the half -lives, spins, parities, deformations and production reaction cross sections for the 14 nuclei were summarized and compared with the current nuclear-model predictions, and then the following points were represented. (1) The experimental half-lives for 85Mo and 92.h as well as the predicted “waiting point” nuclei 89Ru and 93.d are 5―10 times longer than the theoretical predictions given by M?ller et al. using a macroscopic-microscopic model. It considerably influences the predictions of the abundances of the nuclides produced in the rp-process. (2. The current-model predictions are not consistent with the experimental assignments of the spins and parities for the proton drip-line nuclei 142.o and 12.Pm. However, the nuclear potential energy surface (PES) calculated by using a Woods- Saxon-Strutinsky method reproduced the experimental results. (3. The Alice code overestimated the production reaction cross sections of the studied 9 rare-earth nuclei by one order of magnitude or two, while HIVAP code overestimated them by one order of magnitude approximately.

关键词： proton drip line, β-delayed proton decay, He-jet tape transport system, "p-γ" coincidence, spin, parity, deformation, production reaction cross section.

A study of two-dimensional magnetic polaron

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Science china(physics,Mechanics & Astronomy) 2006年第4期49卷 421-429页

作者： LIU Tao1, ZHANG Huaihong1, FENG Mang1,2.& WANG Kelin1,3.1. School of Science, Southwest university of Science and Technology, Mianyang 62.010,{2. 2. Wuhan Institute of {2. and Mathematics, Chinese Academy of Sciences, Wuhan 43.070,{2. 3. department of modern physics, university of Science and Technology of{2., Hefei 2.0}02.,{2. School of Science Southwest University of Science Technology Mianyang 621010 China Wuhan Institute of physics Mathematics Chinese Academy of Sciences Wuhan 430070 China department of modern {2. University of Science Technology of china Hefei 230026 China

By using the variational method and anneal simulation, we study in this paper the self-trapped magnetic polaron (STMP) in two-dimensional anti-ferromagnetic material and the bound magnetic polaron (BMP) in ferromagnetic material. Schwinger angular momentum theory is applied to changing the problem into a coupling problem of carriers and two types of Bosons. Our calculation shows that there are single-peak and multi-peak structures in the two-dimensional STMP. For the ferromagnetic material, the properties of the two-dimensional BMP are almost the same as that in one-dimensional case; but for the anti-ferromagnetic material, the two-dimensional STMP structure is much richer than the one-dimensional case.

关键词： self-trapped magnetic polaron, bound magnetic polaron, impurity potential, anti-ferromagnet.

The formation and stability of Si_(1-x)C_x alloys in Si implanted with carbon ions

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Chinese Science Bulletin 2001年第3期46卷 200-204页

作者： WANG Yinshu, LI Jinmin, JIN Yunfan, WANG Yutian, SUN Guosheng & LIN Lanying1. department of physics, Beijing Normal {2., Beijing 100875,{3. 2. Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083.{3. 3. Institute of modern physics, Chinese Academy of Sciences, lanzhou 73.000,{3. department of physics Beijing Normal University Beijing China Institute of Semiconductors Chinese Academy of Sciences Beijing China Institute of modern physics Chinese Academy of Sciences Lanzhou China

Si1-xCx alloys of carbon (C) concentration between 0.6%-1.0% were grown in Si by ion implantation and high temperature annealing. The formation of Si1-xCx alloys under different ion doses and their stability during annealing were studied. If the implanted dose was less than that for amorphizing Si crystals, the implanted C atoms would like to combine with defects produced during implantation and it was difficult to form Si1-xCx alloys after being annealed at 850℃. With the increment of implanted C ion doses, the lattice damage increased and it was easier to form Si1-xCx alloys. But the lattice strain would become saturate and only part of implanted carbon atoms would occupy the substitutional positions to form Si1-xCx alloys as the implanted carbon dose increased to a certain degree. Once Si1-xCx alloys were formed, they were stable at 950℃, but part of their strain would release as the annealing temperature increased to 1 000℃. Stability of the alloys became worse with the increment of carbon

关键词： ion implantation Si1-xCx alloys stability of Si1-xCx alloys.

Density-functional formula for strongly correlated systems

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Progress in Natural Science:Materials International 2005年第5期15卷 395-401页

作者： WANG Huaiyu1*, HAN Rushan2.and CHEN Nanxian1(1. department of physics, Tsinghua {2., Beijing 100084,{3. 2. department of physics, Peking {2., Beijing 100871,{3.) department of physics Tsinghua University Beijing 100084 China department of physics Peking University Beijing 100871 China

Density functional method is applied for strongly correlated systems. Based on the assumption that the systems are composed of electrons in singly-occupied orbitals and those in doubly-occupied orbitals, a set of self-consistent equations are obtained by standard variation procedure. The equations consist of two parts. One part is to solve the wave functions of the electrons in singly-occupied orbitals and the other is to solve the wave functions of the electrons in doubly-occupied orbitals. The physical meanings of the terms appearing in the equations are discussed.

关键词： density-functional theory strongly correlated systems doubly-occupied orbital two-particle wave function self-consistent equations.

Radiobiological response of human hepatoma and normal liver cells exposed to carbon ions generated by Heavy Ion Research Facility in lanzhou

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Science china(physics,Mechanics & Astronomy) 2006年第1期49卷 72-76页

作者： YANG Jianshe1,2. LI Wenjian1, JIN Xiaodong1, JING Xigang1, GUO Chuanling1, WEI Wei1 & GAO Qingxiang3.1. Institute of modern {2., Chinese Academy of Sciences, {2. 73.000,{3. 2. Life Science School of North West Normal university, {2. 73.070,{3. 3. Life Science School of lanzhou university, {2. 73.000,{3. 1. Institute of modern physics Chinese Academy of Sciences Lanzhou 730000 China 2. Life Science School of North West Normal university Lanzhou 730070 China 3. Life Science School of lanzhou university Lanzhou 730000 China

Human hepatoma and normal liver cells were irradiated with 12.6+ ion beams (LET = 96.05 keV/μm) and γ-rays at Heavy Ion Research Facility in lanzhou (HIRFL). The chromatid breaks and break types were detected using the premature chromosome con- densation technique. Our experimental results showed that chromatid breaks seem to have a good relation with 12.6+ absorbed dose and 12.6+ are more effective to induce chromatid breaks as compared to the γ-rays. For 12.6+ ion irradiation the major break was isochromatid break, while chromatid breaks were dominant for γ-ray irradiation. We also observed that the Relative Biology Effectiveness (RBE) of 12.6+ ion is about 2.5 times higher than that of γ-rays.

关键词： biological response, tumor cell, normal cell, heavy ion HIRFL.

Accurate studies on the full vibrational energy spectra and molecular dissociation energies for some electronic states of N_(2.molecule

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Science china(physics,Mechanics & Astronomy) 2005年第4期48卷 385-398页

作者： REN Weiyi1,2. SUN Weiguo1, HOU Shilin3.& FENG Hao4 1. Institute of physics, College of Chemical Engineering, Sichuan {2., Chengdu 610065,{2. 2. Institute of Theoretical physics, Xihua Normal {2., Nanchong 63.002.{2. 3. department of physics,{2. Oceanography {2., Qingdao 2.6003.{2. 4. College of physics, Sichuan {2., Chengdu 610065,{2. 1. Institute of physics College of Chemical Engineering Sichuan University 610065 Chengdu China 2. Institute of Theoretical physics Xihua Normal University 637002 Nanchong China 3. department of {2. China Oceanography University 266003 Qingdao China 4. College of physics Sichuan University 610065 Chengdu China

It is usually very difficult to directly obtain molecular dissociation energy De and all accurate high-lying vibrational energies for most diatomic electronic states using modern experimental techniques or quantum theories, and it is also very difficult to give accurate analytical expression for diatomic molecular dissociation energy. This study proposes a new analytical formula for obtaining accurate molecular dissociation energy based on the LeRoy and Bernstein’s energy expression in dissociation limit. A set of full vibrational energy spectra for some electronic states of N2.molecule are studied using the algebraic method (AM) suggested recently, and the corresponding accurate molecular dissociation energies are evaluated using the proposed new formula and high-lying AM vibrational energies. The results show that the AM spectra and the new theoretical dissociation energies agree excellently with experimental data, and thereby providing a new physical approach to generating accurate dissociation energies for electronic states of diatomic molecules.

关键词： vibrational energy, dissociation energy, nitrogen molecule, algebraic method.

Structure analysis of ^(159)Sm and properties of odd-mass neutron-rich nuclei in mass-160 region

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Science china(physics,Mechanics & Astronomy) 2011年第S1期54卷 81-87页

作者： YANG YingChun1 & SUN Yang1,2.3.1 department of {2., Shanghai Jiao Tong {2., Shanghai 2.02.0,{3. 2.nstitute of modern {2., Chinese Academy of Sciences, lanzhou 73.000,{3. 3.0} of {2. and Astronomy, {2. of Tennessee, Knoxville, Tennessee 3.996, USA 1. department of physics Shanghai Jiao Tong University Shanghai 200240 China2. Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China3. Department of Physics and Astronomy University of Tennessee Knoxville Tennessee 37996 USA

Recent fission experiment data provide interesting structure information for neutron-rich nuclei in the mass A ～ 160 region. We apply the projected shell model to study the strongly-deformed, neutron-rich Sm isotopes. We perform calculations for rotational bands up to spin I = 2. (2./2. for even-even (odd-neutron) Sm isotopes, and analyze the band structure of low-lying states with quasiparticle excitations. Emphasis is given to rotational bands based on one-quasiparticle (1-qp) configurations in the odd-mass 159Sm. The 159 Sm result is discussed together with those of the even-even isotopes 158,160Sm. New bands in 159Sm based on neutron 1-qp 1/2.and 5/2. configurations are predicted. Electromagnetic transition probabilities are discussed.

关键词： projected shell model neutron-rich nuclei low-lying excitations isomeric states

Potential energy surfaces for low-lying electronic states of SO_2

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Science china Chemistry 2006年第4期49卷 289-295页

作者： LI Anyang1, SUO Bing2. WEN Zhenyi2.& WANG Yubin2.1. Shanxi Key Laboratory of Physico-inorganic Chemistry, department of Chemistry, Northwest university, Xi’an 710069,{2. 2. Institute of {3. physics, Northwest university, Xi’an 710069,{2. 1. Shanxi Key Laboratory of Physico-inorganic Chemistry Department of Chemistry Northwest University Xi’an 710069 China 2. Institute of modern physics Northwest University Xi’an 710069 China

The potential energy surfaces for the nine low-lying electronic states of SO2.have been constructed by using the multi-reference second order perturbation theory (MRPT2. with the basis set cc-pVTZ. The optimized geometries and the adiabatic excitation energies of these states are in good agreement with experiments and previous calculations. The crossings and avoided crossings dis- played in the potential energy surfaces are expounded.

关键词： cross of PES, MRPT2. SO2 (sulfur dioxide).