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science China Chemistry 2004年第6期47卷 466-479页

作者： SONG Huajie1,2, XIAO Heming1 & DONG Haishan2 1. Department of Chemistry, Nanjing University of science and Technology, Nanjing 210094, China 2. institute of Chemical materials, China Academy of Engineering Physics, Mianyang 621900, China Department of Chemistry Nanjing University of Science and Technology Nanjing China institute of Chemical materials China Academy of Engineering Physics Mianyang China

The symmetry-adapted perturbation theory (SAPT) that has the ability in decompo- sition of the total interaction energy into physically meaningful components is used to provide a more fundamental understanding of intermolecular forces. This work was motivated by the diffi- culty of standard SAPT in computing the intermolecular interactions for large energetic dimer systems. SAPT based on Kohn-Sham orbitals (SAPT(DFT)) proves computationally efficient for these large systems, but has been shown to perform poorly for interaction energy components. The deficiencies of SAPT(DFT) result from wrong asymptotical behaviors of commonly used exchange-correlation potentials. To remove the deficiencies, two asymptotic corrections by means of van Leeuwen and Baerends (LB) model potential and Fermi-Amaldi (FA) type potential were applied into three small test systems comprising He2, HF2 and (N2)2 and a set of larger ni- tramide dimers at several separations. The results showed that when utilizing newly developed frequency-dependent density susceptibilities (FDDS) technique for computing dispersion energy, the FA asymptotic correction is very effective to circumvent these deficiencies in SAPT(DFT) and yields a good accuracy over the LB correction. The FA corrected SAPT(DFT) approach is capa- ble of correctly predicting all the quantitative trends in binding energies for all test cases and substantially reduces computational cost as compared with the standard SAPT calculations. The successful application of the approach to nitramide dimer demonstrates that it potentially pro- vides a good means to calculate accurately intermolecular forces in larger system such as en- ergetic systems.

关键词： intermolecular interaction, density functional theory (DFT), symmetry adapted perturbation theory (SAPT), asymptotic correction, frequency-dependent density susceptibilities (FDDS).

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Stability of a linear oscillator with damping force of the fractional-order derivative

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science China(Physics,Mechanics & Astronomy) 2010年第2期53卷 345-352页

作者： WANG ZaiHua1,2 & HU HaiYan1 1 institute of Vibration Engineering Research,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China 2 institute of science,PLA University of science and Technology,Nanjing 211101,China institute of Vibration Engineering Research Nanjing University of Aeronautics and Astronautics Nanjing China institute of science PLA University of Science and Technology Nanjing China

It begins with the study of damping representation of a linear vibration system of single degree of freedom (SDOF),from the view point of fractional calculus. By using the idea of stability switch,it shows that the linear term involving the fractional-order derivative of an order between 0 and 2 always acts as a damping force,so that the unique equilibrium is asymp-totically stable. Further,based on the idea of stability switch again,the paper proposes a scheme for determining the stable gain region of a linear vibration system under a fractional-order control. It shows that unlike the classical velocity feedback which can adjust the damping force only,a fractional-order feedback can adjust not only the damping force,but also the elastic re-storing force,and in addition,a fractional-order PDα control can either enlarge the stable gain region or narrow the stable gain region. For the dynamic systems described by integer-order derivatives,the asymptotical stability of an equilibrium is guaranteed if all characteristic roots stay in the open left half-plane,while for the systems with fractional-order derivatives,the asymptotical stability of an equilibrium is guaranteed if all characteristic roots stay within a sector in the complex plane. Analysis shows that the proposed method,based on the idea of stability switch,works effectively in the stability analysis of dynamical systems with fractional-order derivatives.

关键词： vibration system fractional-order derivative asymptotical stability stability switch

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Delayed Hopf bifurcation in time-delayed slow-fast systems

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science China(Technological sciences) 2010年第3期53卷 656-663页

作者： ZHENG YuanGuang1 & WANG ZaiHua1,2 1 institute of Vibration Engineering Research,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China 2 institute of science,PLA University of science and Technology,Nanjing 211101,China institute of Vibration Engineering Research Nanjing University of Aeronautics and Astronautics Nanjing China institute of science PLA University of Science and Technology Nanjing China

This paper presents an investigation on the phenomenon of delayed bifurcation in time-delayed slow-fast differential *** the two delayed's have different *** delayed bifurcation means that the bifurcation does not happen immediately at the bifurcation point as the bifurcation parameter passes through some bifurcation point,but at some other point which is above the bifurcation point by an obvious *** a time-delayed system,the evolution of the system depends not only on the present state but also on past *** this paper,the time-delayed slow-fast system is firstly simplified to a slow-fast system without time delay by means of the center manifold reduction,and then the so-called entry-exit function is defined to characterize the delayed bifurcation on the basis of Neishtadt's *** shows that delayed Hopf bifurcation exists in time-delayed slow-fast systems,and the theoretical prediction on the exit-point is in good agreement with the numerical calculation,as illustrated in the two illustrative examples.

关键词： time delay delayed bifurcation Hopf bifurcation slow-fast systems exit-point entry-exit function

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DFT and TDDFT investigations on the ground and excited states for polynuclear platinum(II) complexes containing the rigid phenylacetylide ligand

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中国科学：化学英文版 2007年第5期50卷 599-606页

作者： ZHOU Xin1, PAN QingJiang2, LI MingXia1,2, ZHANG HongXing1 & Tang AuChin1 1 State Key Laboratory of Theoretical and Computational Chemistry, institute of Theoretical Chemistry, Jilin University, Changchun 130023, China 2 School of Chemistry and materials science, Heilongjiang University, Harbin 150080, China State Key Laboratory of Theoretical and Computational Chemistry Institute of Theoretical Chemistry Jilin University Changchun China School of Chemistry and materials science Heilongjiang University Harbin China

We have studied the ground and excited states of the three dendritic polynuclear Pt(II) complexes 1-[Cl(PH3)2PtC≡≡ C]-3,5-[HC≡≡ C]C6H3 (1), 1,3-[Cl(PH3)2PtC≡≡ C]2-5-[HC≡≡ C]C6H3 (2), and 1,3,5-[Cl(PH3)2- PtC≡≡ C]3C6H3 (3), by using the B3LYP and UB3LYP methods, respectively. TDDFT approach with the PCM model was performed to predict the emission spectra properties of 1―3 in CH2Cl2 solution. We first predicted the excited-state geometries for the three complexes. With the change of the number of Pt(II) atom, 1―3 show the different geometry structures in both the ground and excited states; fur- thermore, the increase of the metal density from 1 to 3 results in the red shift of the lowest-energy emissions along the series. The luminescent properties of 1 are somewhat different from those of 2 and 3. The emission properties of 2 and 3 are richer than 1. Our conclusion can give a good support for designing the high efficient luminescent materials.

关键词： excited state, luminescence, dendritic platinum(Ⅱ) complexes, DFT, TDDFT

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A simple method of synthesizing multi-wall carbon nanotubes/SnO core/shell nanostructure

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Rare Metals 2007年第S1期26卷 191-194页

作者： SUN Xue1),CHU Yi2),WANG Dawei3),DU Jinhong3),ZHANG Baoyou2),and WANG Fuping1)1) School of science,Harbin institute of Technology,Harbin 150001,China 2) School of materials science and Engineering,Harbin institute of Technology,Harbin 150001,China 3) Shenyang national Laboratory for materials science,institute of Metal Research,Chinese Academy of sciences,Shenyang 110016,China Harbin Inst Technol Sch Sci Harbin 150001 Peoples R China Harbin Inst Technol Sch Mat Sci & Engn Harbin 150001 Peoples R China Chinese Acad Sci Inst Met Res Shenyang Natl Lab Mat Sci Shenyang 110016 Peoples R China

Multi-wall carbon nanotubes(MWNTs)/SnO core/shell nanosturcture was synthesized by a simple solution-based method,in which SnCl2 was solved in distilled water containing dispersed MWNTs,then stired,filtered and washed in ambient atmosphere,finally dryed in air at 90 ℃ for 6 *** MWNTs/SnO core/shell nanostructure was characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM).It is found that surface defects of MWNTs are necessary for the deposition of *** mechanism of the SnO nanocoating formation through the hydrolysis of SnCl2 in water(4SnCl_2+2H_2O-Sn_4(OH)2Cl_6+2HCl) was presented.

关键词： precipitate isothermal aging thermodynamic calculation phase diagram high nitrogen austenitic stainless steel

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Electronic structure and magnetic properties of metastable SmCo_(7) compound

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science China(Physics,Mechanics & Astronomy) 2005年第3期48卷 325-335页

作者： ZHANG Changwen 1 , LI Hua 1 , DONG Jianmin 1 , WANG Yongjuan 1 , PAN Fengchun 1 , ZHANG Jian 1 , GUO Yongquan 2 & LI Wei 2 1. School of Physics and Microelectronics, Shandong University, Jinan 250100, China 2. institute of Functional materials, Central Iron and Steel Research institute, Beijing 100081, China School of Physics and Microelectronics Shandong University Jinan China institute of Functional materials Central Iron and Steel Research Institutes Beijing China

The electronic density of states, spin-splittings and atomic magnetic moments of SmCo 7 compound have been studied using spin-polarized MS-Xα method. The results show that a few of electrons are transferred to Sm(5d 0 ) orbital because of orbital hybridization between Sm and Co atoms in the compound. The exchange interactions between 3d and 5d electrons lead to the magnetic coupling between Sm and Co, and therefore, result in the long-range ferromagnetic order inside the SmCo 7 compound. There are negative exchange couplings occurring at some levels, which weakens the strength of average coupling around Co lattice. So, the Curie temperature and Co-moment of SmCo 7 decrease distinctly compared with pure Co. Compared with SmCo 5 compound, the disordered substitution of Co-Co “dumbbell-atom” pairs for Sm changes the local environment of Co lattice, which makes the 2e site bear negative magnetic moment. The strength of hybridization near Fermi level weakens and the free energy of the compound increases obviously. Thus, SmCo 7 is a metastable compound at room temperature. Considering the localization of 4f electrons and a few of 5d electrons arising from the orbital hybridization, the magnetic moment of Sm atom will be 1.61μ B in SmCo 7 compound, which is in agreement with the experimental values of Sm 3+ ion- moment and Sm atom-moment in metals.

关键词： electronic structure, spin polarization, atomic magnetic moment, exchange coupling, Curie temperature.

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Characteristics of shape memory and superelasticity for TiNi thin films

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中国有色金属学会会刊：英文版 2000年第3期10卷 375-377页

作者： HE Zhi rong(贺志荣) 1, S.Miyazaki 2 1. Department of Mechanical Engineering, Shaanxi institute of Technology, Hanzhong 723003, P.R.China 2. University of tsukuba, japan 陕西工学院陕西汉中 University of tsukuba 日本

TiNi shape memory alloy thin films were deposited by using a RF magnetron sputtering apparatus. The transformation and shape memory characteristics of the thin films have been investigated by using DSC and tensile tes... 详细信息

关键词： TiNi alloy shape memory effect superelasticity thin film

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Modeling the fate of paddy field pesticide in surface water and environmental risk assessment

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Journal of Environmental sciences 2000年第3期12卷 337-343页

作者： LI Shi\|yu 1, Tohru Morioka 2 (1. institute of Environmental science, Zhongshan University, Guangzhou 510275, China. E-mail: eeslsy@*** 2.Department of Environmental Engineering, Osaka University, Yamada oka 2 1, Suita, Osaka 565, japan. E- 中山大学广东广州 51 0 2 75 Osaka University 日本 Osaka 56 5

The risk of drinking water is greatly concerned because of the large amount of pesticide applied to paddy field and the contamination of drinking water sources due to the runoff. A mathematical model is developed, based on the mass balance, to predict the fate of paddy field pesticides from application, runoff and mixing in a river, taking account of the physical chemical properties and processes of volatilization, degradation, adsorption and desorption. The model is applied to a river basin in japan to estimate the contaminant level of several popularly used pesticides at the water intakes. The health risk in drinking water induced by each pesticide concerned is estimated and evaluated by comparing with the acceptable daily intake values(ADI) and with that induced by trihalomethanes. An index to evaluate the total risk of all pesticides appearing in water is proposed. The methods for risk management are also discussed.

关键词： modeling pesticide paddy field environmental risk assessment drinking water

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Greenhouse gas emissions from a constructed wetland for municipal sewage treatment

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Journal of Environmental sciences 2002年第1期14卷 27-33页

作者： TAI Pei dong 1, LI Pei jun 1 , SUN Tie heng 1, HE Yao wu 1, ZHOU Qi xing 1 GONG Zong qiang 1, Motoyuki Mizuochi 2, Yuhei Inamori 2 (1 institute of Applied Ecology, Chinese Academy of sciences, Shenyang 110015, China. 2.national Insti institute of Applied Ecology Chinese Academy of Sciences 110015 China. E-mail:[email protected] national institute for Environmental Studies 16-2 Onagawa Tsukuba Ibaraki 305 Japan

The fluxes of greenhouse gases (methane and nitrous oxide) emission from a constructed wetland in the Eastern China as municipal sewage treatment were measured from June 1999 to August 2000 by the closed chamber method. The constructed wetland for municipal sewage treatment is a significant source of methane, up to 976 6×10 6 g CH 4/a, which was emitted from the constructed wetland with the area of 495000 m 2 and wastewater loading rate of 12000 m 3/d. Its daily mean methane flux reached 5 22 g CH 4/(m 2·d), 250 times as much as that in natural wetland in the same latitude region. 227 8 mg CH 4 was produced from the treatment of 1 liter wastewater, up to 700—1000 times as much as that in the secondary treatment. The emission of nitrous oxide from the constructed wetland is not higher than that from secondary treatment of wastewater, only 0 07 mgN 2O/L.

关键词： greenhouse gas emission constructed wetland municipal sewage methane nitrous oxide

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Morphologies of Fe-66.7 at.%Si alloy solidified in a drop tube

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science China(Physics,Mechanics & Astronomy) 2005年第6期48卷 658-666页

作者： WANG Haiyan1,2, LIU Riping1, MA Mingzhen1, JING Qin1, LI Gong1, SUN Liling2 & WANG Wenkui1,2 1. Key Laboratory of Metastable materials science & Technology, Yanshan University, Qinhuangdao 066004, China 2. institute of Physics, Chinese Academy of sciences, Beijing 100080, China Key Laboratory of Metastable materials science & Technology Yanshan University Qinhuangdao China institute of Physics Chinese Academy of Sciences Beijing China

Solidification of 0.1―1.0 mm diameter droplets of Fe-66.7 at.%Si alloy was achieved in a 3 m drop tube. The XRD, EDS, and SEM measurements reveal that all the droplets are composed of the primary phase α and the α+ε eutectic. With decreasing droplet diameter, the growth mode of the primary phase α changes from faceted to nonfaceted growth and the eutectic changes from needle-like to anomalous eutectic. In addition, the width of the primary phase α decreases with decreasing droplet size. The different cooling rates and undercooling levels corresponding to the samples with different sizes are responsible for the morphology changes. The cooling rates of the samples with different diameters during free fall were calculated and their effects on the microstructure formation were discussed. This kind of transition is also found inside the same sample, which is due to the larger cooling rate on the surface than at the center.

关键词： Fe-Si alloy, solidification, drop tube, undercooling.

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