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The anharmonic effect study of coupled Morse oscillators for the unimolecular reaction

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Science china Chemistry 2008年第12期51卷 1146-1152页

作者： YAO Li1,2.& LIN Sheng-Hsien2.31 Department of Physics, Dalian Maritime university, Dalian 11602., china 2.Institute of{2. and molecular Sciences, Academia Sinica, Taipei 10764, china 3 Department of Applied Chemistry and Institute of molecular Sciences, Chiao-Tung university, Hsinchu 3005., Taiwan, china 1. Department of Physics Dalian Maritime University Dalian 116026 China 2. Institute of atomic and molecular Sciences Academia Sinica Taipei 10764 China 3. Department of Applied Chemistry and Institute of molecular Sciences Chiao-Tung University Hsinchu 30051 Taiwan China

The importance of anharmonic effect in dissociation of molecular systems especially clusters has been noted. In this paper, we shall study the effect of coupled anharmonic oscillator of the standard bilinear form (SBF) Morse oscillator (MO) potential on unimolecular reaction. We shall use the systematic theoretical approach, YL method, proposed by Yao and Lin (YAO L, et. al. J Phys Chem A, 2.07, 111(2.): 672.-672.), which can evaluate anharmonic effects on the rate constants based on the transition state theory. In treating the anharmonic effect with the Morse oscillator potential on unimolecular reactions under collision-free conditions by using the RRKM (Rice-Ramsperger-Kassel-Marcus) theory, the in-verse Laplace transformation of the partition functions was used to obtain the total amount of state and density of state by using the first-order and the second-order approximations of the saddle-point method. To demonstrate the anharmonic effect of the SBF Morse model, we choose some model systems and a real reaction as examples.

关键词： anharmonic effect standard bilinear form Morse oscillator rate constant RRKM theory

Absence of State Collapse and Revival in a Superconducting Charge Qubit

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Communications in Theoretical Physics 2007年第12期48卷 1029-1032页

作者： HUO Wen-Yi~1 and LONG Gui-Lu~(1,2.3)~1 Department of Physics amd key laboratory for Quantum Information and Measurements,{2. {2.,Beijing100084,china~2.key laboratory for atomic and molecular nanosciences,{2. {2.,Beijing 100084,china~3 National laboratory for Information Science and Technology,Hsinghua {2.,Beijing 100084,china Department of Physics amd key laboratory for Quantum Information and Measurements Tsinghua University key laboratory for {2. and {2. nanosciences Tsinghua University National laboratory for Information Science and Technology Hsinghua Univers

The Hamiltonian of a superconducting charge qubit with a configuration of dc SQUID contains an interac-tion between the LC oscillator part and charge *** interaction may leads to quantum state collapse and revivalwhich degrades the charge qubits and leads to serious *** analysis shows that the existing charge qubitparameters do not lead to this phenomenon,which is very good for the superconducting charge

关键词： quantum computer superconducting charge qubit absence and revival

Consecutive reversible ionization-recombination reactions and ionic charge state distribution of Au plasma

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Science china(Physics,Mechanics & Astronomy) 2005年第5期48卷 575-584页

作者： ZHU Zhiyan1, ZHU Zhenghe1, TANG Changhuan1, TANG Yongjian2.& GAO Tao1 1. Institute of atomic and molecular Physics, Sichuan{2., Chengdu 610065. china 2. china Academy of Engineering Physics, Mianyang 62.900, china 1. Institute of atomic and molecular Physics Sichuan University 610065 Chengdu China 2. china Academy of Engineering Physics 621900 Mianyang China

The present work proposes kinetics of ionization-recombination to study the charge state distribution of Au plasma. The first step is to calculate the average lifetime, energy level structure, degeneracy and partition function of Au48+―Au5.+ by relativistic quantum mechanics, and next to compute the equilibrium constant and the second-order recombination rate constant by statistical thermodynamics. Based on these data, the differential equations of consecutive reversible ionization-recombination reactions are solved from which the charge state distribution and its average charge are derived. Finally, the influence of electron temperature and density on average charge is given in this paper. It is called the first-principle theory, for no experimental data are needed.

关键词： Au plasma, ionization-recombination dynamics, ionic charge state distribution, average charge.

Micro-mechanical analysis of dynamic processes of nanomanipulation

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Science china(Physics,Mechanics & Astronomy) 2004年第z1期47卷 88-92页

作者： HU Jie, ZHANG Yujun, LI Peng, WANG Hui, HUANG Lan & HU YuanzhongState key laboratory of Tribology,{2., Beijing 100084, {2. Department of Physics,{2., Beijing 100084, {2. College of Chemistry and molecular Engineering, Peking university, Beijing 100871, {2. 1. State key laboratory of Tribology Tsinghua University 100084 Beijing China 2. Department of Physics Tsinghua University 100084 Beijing China 3. College of Chemistry and molecular Engineering Peking University 100871 Beijing China

In this study, atomic force microscope (AFM) tips are used as tools to cut and manipulate carbon nanotubes on various surfaces. The lateral forces acting on AFM tips during manipulation are also recorded and analyzed from the perspective of micro-mechanics. It is found that differences in surface conditions can lead to obvious increase in micro-friction between nanotube and substrate. And also due to rehybridization, carbon nanotubes present excellent resilience when undergoing different degrees of strain. Finally, carbon nanotubes can complexly deform from elastic stage to plastic stage before complete rupture.

关键词： nanomanipulation, carbon nanotubes, AFM tips, micro-mechanics.

Antisense Tiam1 Down-Regulates the Invasiveness of 95. Cells in Vitro

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Acta Biochimica et Biophysica Sinica 2004年第8期36卷 537-540页

作者： Min HOU, Li TAN, Xia WANG, and Yun-Song ZHU Department of molecular Genetics, Shanghai Medical College, Fudan university & {2. {2. of molecular Medicine, Ministry of National Education, Shanghai 2.0032. {5. Department of molecular Genetics Shanghai Medical College Fudan University & Key Laboratory of Molecular Medicine Ministry of National Education

As a specific guanine nucleotide exchange factor of Rac1, Tiam1 (T-lymphoma invasion and metastasis inducing protein 1) is involved in a number of cellular events, such as cytoskeleton reorganization, cell adhesion, and cell migration. Since Tiam1 was implicated in the invasion and metastasis of T-lymphoma cells and breast tumor cells, we compared the expression level of Tiam1 in two human giant-cell lung carcinoma cell strains with high or low metastasis potential, and found that Tiam1 expression level in high-metastatic 95. cells was higher than that in low-metastatic 95. cells. To further confirm the role of Tiam1 in invasion and metastasis, we constructed the antisense Tiam1 expression plasmid (pcDNA3-anti- Tiam1), which was transfected into 95. cells. A stable transfected clone with decreased Tiam1 expression was screened and selected for further research. Transwell assay showed that down-regulation of endogenous Tiam1 by anti-Tiam1 can reduce the in vitro invasiveness of 95. cells. Our results suggested that Tiam1 signaling contributed to the invasion and metastasis of the human giant-cell lung carcinoma cells.

关键词： T-lymphoma invasion and metastasis inducing protein 1 (Tiam1) invasion and metastasis

Parametric instabilities in quantum plasmas with electron exchange-correlation effects

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Chinese Physics B 2013年第2期22卷 341-346页

作者：何彩霞薛具奎 key laboratory of {2. & {2. Physics and Functional Materials of Gansu Province College of Physics and Electronics EngineeringNorthwest Normal University

Parametric instabilities induced by the nonlinear interaction between high frequency quantum Langmuir waves and low frequency quantum ion-acoustic waves in quantum plasmas with the electron exchange-correlation effects are *** using the quantum hydrodynamic equations with the electron exchange-correlation correction,we obtain an effective quantum Zaharov model,which is then used to derive the modified dispersion relations and the growth rates of the decay and four-wave *** influences of the electron exchange-correlation effects and the quantum effects on the existence of quantum Langmuir waves and the parametric instabilities are discussed in *** is shown that the electron exchange-correlation effects and quantum effects are strongly *** quantum Langmuir wave can propagate in quantum plasmas only when the electron exchange-correlation effects and the quantum effects satisfy a certain *** electron exchange-correlation effects tend to enhance the parametric instabilities,while quantum effects suppress the instabilities.

关键词： parametric instabilities quantum Langmuir waves electron exchange-correlation

Biocompatibility evaluation in vitro. Part III: Cytotoxicity expression of human and animal osteoblasts on the biomaterials

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Journal of Central South university 2001年第3期13卷 147-155页

作者： RUAN Jian-ming 1,M.H. Grant 2.(1. State key laboratory for Powder Metallurgy, Central South {2., Changs ha 410083, {2. 2. Bioengineering Unit, Strathclyde {2., Glasgow, G4 0NW, UK) 1. State key laboratory for Powder Metallurgy Central South University 410083 Changsha China 2. Bioengineering Unit Strathclyde University G4 0NW Glasgow UK

Exclusion and inflammation in the clinic are observe d for various reas ons including material che- mical composition, physical properties as well a s macr o- and micro-structure of the implants, surface condition of the implants, and also patient dependent factors. Cytotoxicity expression of cells is a central issue i n current biocompatibility to screen the potential implant materials and drugs. This study was aimed at investigation reaction between the potential implant mat erials and surround tissue. Cytotoxicity of human and rat osteoblast in the mate rial extracts was determinated by testing standards such as GHS assay, MTT assay , alkaline phosphatase activity assay, LDH assay, and Lowry assay. Research resu lts demonstrated that compared with the control condition polystyrene culture pl a te both human and rat osteoblast cells have normal phenotypic expression in hydr oxyapatite extract, and this expression was statistically restricted in hydroxya patite-spinel extract. How- ever, this restrict, e.g. cytotoxicity could be partially eliminated by immersion treatment of the materials in culture medium.

关键词： biomaterial cytotoxicity biological molecular technique

Zinc up-regulated the expression of the rice metallonthionein gene family and enhanced the zinc tolerance of yeast cells

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Progress in Natural Science:Materials International 2007年第10期17卷 1166-1171页

作者： Xu Yufeng, Zhou Gongke, Li Yiqin and Liu Jinyuan(laboratory of molecular Biology and Protein Science laboratory of the Ministry of Education, Department of Biological Sciences and Biotechnology, tsinghua university, Beijing 100084, china) laboratory of molecular Biology and Protein Science laboratory of the Ministry of Education Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China

Northern blot and functional complementation assay were employed to analyze the effects of zinc on expression of ten rice metallothionein genes (OsMT-Is) in rice seedlings and the growth of yeast cells transformed with OsMT-Is. Northern blot revealed that in shoots of the rice seedlings treated with different Zn2.concentrations, expression of most members of OsMT-I family was increased, except the type 4 OsMT-Is (OsMT-I-4a, 4b and 4c). In roots, Zn2.significantly increased the transcription of OsMT-I-1b and OsMT-I-2., but reduced the trascription of OsMT-I-1a and OsMT-I-3a. When these ten cDNAs were heterologously expressed in zinc sensitive yeast mutant, all transgenic yeasts showed increased tolerance to Zn2., and zinc accumulation in these yeast cells also increased. These indicated that OsMT-I family members might respond to extra Zn2., and they could enhance Zn2. tolerance of cells by direct binding Zn2..

关键词： rice metallothionein induced expression Zn2. tolerance.

molecular dynamics simulations of non-Fourier heat conduction

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Progress in Natural Science:Materials International 2008年第8期18卷 999-1007页

作者： Qixin Liu, Peixue Jiang *, Heng Xiang key laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering,{2., Beijing 100084, {2. key laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Thermal Engineering Tsinghua University Beijing 100084 China

Unsteady heat conduction is known to deviate significantly from Fourier’s law when the system time and length scales are within certain temporal and spatial windows of relaxation. Classical molecular dynamics simulations were used to investigate unsteady heat conduction in argon thin films with a sudden temperature increase or heat flux at one surface to study the non-Fourier heat conduction effects in argon thin films. The studies were conducted with both pure argon films and films with vacancy defects. The temperature profiles in the argon films showed the existence of mechanical waves when the thin film was suddenly heated and the wave nature of the heat propagation. The flux phase relaxation time, sq, and the temperature phase relaxation time, st, were calculated from the temporal variations of the energy flux and temperature distribution in the film. Comparisons of the MD temperature profiles with temperature profiles predicted by Fourier’s law show that Fourier’s law is not able to predict the temperature variations with time. Different film thicknesses were also studied to illustrate the variation of the time needed for the films to reach steady-state temperature profiles after a sudden temperature rise at one surface and to illustrate the finite speed of the energy waves.

关键词： molecular dynamics simulation Non-Fourier heat conduction Argon thin film