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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 2.0094, China 2. Institute of chemical materials, China {2. of engineering physics, mianyang 62.900, 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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Studies on the analytical potential energy function of diatomic molecular ion XY^+ using variational method

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Science China(physics,Mechanics & Astronomy) 2004年第2期47卷 154-164页

作者： LIU Guoyue1,3. SUN Weiguo1,2.& FENG Hao1 1. Institute of physics, Sichuan University, Chengdu 610065, China 2. College of {3. {2., Sichuan University, Chengdu 610065, China 3. mianyang Teacher抯 College, mianyang 62.000, China Correspondence should be addressed to Sun Weiguo (e-mail: weiguosun@*** or guoyueliu@ ***) Institute of physics Sichuan University Chengdu China mianyang Teacher's College Mianyang China College of chemical engineering Sichuan University Chengdu China

A new analytical potential energy function for diatomic molecular ion XY+ is proposed based on the energy consistent method (ECM). The Coulomb potential included in the new ionic potential contains multipole corrections, converges quickly and is variationally, changeable. The new potential and the ECM are applied to variationally studying the potential energies of eight electronic states of several diatomic molecular ions: the A2. state of CO+, the X2. g + state of Li 2.+ , the X2. g + state of He 2.+ , the 12.u state of Na 2.+ , the A2.u state of N 2.+ , the X1∑+ state of KrH+, the X2.+ state of SiO+ and the A2. state of SO+ ion. The present results agree excellently with the experiment-based Rydberg-Klein-Rees (RKR) potentials, and are superior to the commonly used Huxley-Murrell-Sorbie (HMS) analytical potentials, and are better in some cases than some quantum mechanicalab initio potentials in the ionic asymptotic and dissociation regions.

关键词： potential energy, diatomic ion, electronic state, variational method.

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Pressure effects on the absorption spectra of Na doped in solid Ar

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Science China(physics,Mechanics & Astronomy) 2004年第5期47卷 550-560页

作者： CUI Tian1, HE Wenjiong1, YIN Hongwei1, MA Yanming1, CHEN Changbo1, ZOU Guangtian1, WEI Mengfu2.& CHEN Changan2.1. National Laboratory of Superhard materials, Jilin University, Changchun 13.012. China 2. China academy of {2. physics, Box 919-71, mianyang 62.900, China National Laboratory of Superhard materials Jilin University Changchun China China academy of engineering {2. Mianyang China

In this work, the pressure influence on the absorption spectra of Na in solid Ar for various trapping sites is extensively investigated at T = 10 K and in the pressure range from 0 to 2.4 GPa by using Monte Carlo method with a constant pressure ensemble (NPT). For the trapping sites of nv = 1, 2. the absorption spectral widths increase progressively, the absorption peaks and the centroid spectral shift (CSS) tend to have a red shift with pressure increasing, even though there is no local structural symmetry change around Na atom caused by pressure. Highly symmetrical trapping site structure (nv = 1) determines a highly symmetrical triplet absorption feature at a low pressure. With the increase in pressure, the action from the Ar crystal field on the three energy levels of the 3. excited state of Na atom increases, resulting in the overlap of the three peaks. Low symmetrical trapping site structure (nv = 2. yields a low symmetrical triplet absorption pattern in which a large separation between the single?and the double?peaks exists at a low pressure. With the increase in pressure, the splitting between the singlet and the doublet increases, and the doublet merges as the pressure is larger than 2.4 GPa.

关键词： Monte Carlo, simulation, absorption spectra, doped system, pressure effect.

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Ab initio Calculation of Intermolecular Dispersion Energy and Induction Energy of Nitramide Dimer

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Chinese Journal of Chemistry 2004年第11期22卷 1377-1381页

作者：宋华杰肖鹤鸣董海山Institute of chemical materials China {2. of {3. physics mianyang Sichuan 62.900 China 黄奕刚Institute of chemical materials China {2. of {3. physics mianyang Sichuan 62.900 China 龙新平Institute of chemical materials China {2. of {3. physics mianyang Sichuan 62.900 China 汤业鹏Institute of chemical materials China {2. of {3. physics mianyang Sichuan 62.900 China Department of Chemistry Nanjing University of Science and Technology Nanjing Jiangsu 210094 China Institute of chemical materials China Academy of Engineering Physics Mianyang Sichuan 621900 China

The dispersion energies, induction energies and their exchange counterparts (exchange-dispersion and ex-change-induction energies) between two interacting nitramide molecules at several separations are derived based upon symmetry-adapted perturbation theory (SAPT). The results show that (1) the effect of intramonomer electron correlation on dispersion energies and induction energies for nitramide dimer system is remarkable especially in the region near the van der Waals minimum distance (0.42.nm). (2. At smaller separations the dispersion energies and the induction energies are largely quenched by their exchange counterparts, and this case in induction interaction is much more remarkable than in dispersion interaction. (3. Since at shorter distances there exists the strong short-range interaction due to electron transfer which quickly decays and even disappears at larger separations, the two different R-dependency formulae of induction energies were found: one is ca. R-12.7 at short distances, and the other ca. R-7.0 at large separations. The latter R-dependency is similar to that (ca. R-7.2. of dispersion. (4) In the case of strong polar interaction existing in nitramide dimer, the true induction correlation terms of higher order than t(2.)indE may be important.

关键词： dispersion energy induction energy nitramide dimer symmetry-adapted perturbation theory

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Point-piezomagnetic Properties of the FeCuNbSiB Alloy Strips

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Journal of Wuhan University of Technology(materials Science) 2009年第1期24卷 114-118页

作者：朱正吼 School of materials Sciences and engineering Nanchang University

The piezomagnetic properties of rapidly quenched Fe73.5Cu1Nb3.i13.5B9 alloy strips were investigated in as-quenched state and after annealing for 2.h in vacuum in the temperature range of 100-3.0 ℃. The impedance of amorphous strips increases with frequency, and sensitively de-creases with stress increasing, especially in the frequency range of 10-100 MHz. The impedance in-creases approximately linearly with frequency below the critical frequency, but begins to decrease non-linearly with frequency above the critical frequency. The higher the point compressive stress is, the smaller the critical frequency will be. The stability of piezomagnetic properties is very excellent. The impedance of amorphous strips after annealing, especially at 3.0 ℃, decreases very strongly. The impedance and the absolute values of the sensitive degree of couple layers＇ amorphous strips are lower than those of single layer strips.

关键词： piezomagnetic properties amorphous strips impedance

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chemical Extraction Preparation of Delithiated Cathode materials of Li-ion Battery

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Journal of Wuhan University of Technology(materials Science) 2009年第6期24卷 863-866页

作者：闫时建 School of materials Science and engineering Taiyuan University of Science and Technology

A method of conventional chemical reaction to prepare delithiated cathode materials of Li-ion battery was introduced. The cathode material of Li-ion battery was mixed with oxidizing agent Na2.2.8 in water solution, and the solution was stirred continuously to make the chemical reaction proceed sufficiently, then the reaction product was filtered and finally the insoluble delithiated cathode material was obtained. A series of tests were conducted to verify the composition, crystal structure and electrochemical property of the delithiated cathode materials were all desirable. This method overcomes the shortcomings of battery charging preparation and chemical extraction preparation employing other oxidizing agents.

关键词： chemical extraction delithiated cathode material Li-ion battery

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The Influence of Temperature on the Afterglow Feature of SrAl_2._4∶Eu,Dy Phosphors

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Journal of Wuhan University of Technology(materials Science) 2006年第3期21卷 120-122页

作者：王兵 materials School Southwest University of Science and TechnologyMianyang 621010China

Using a self-designed temperature testing box in which Xenon-lamp irradiation can be applied, the afterglow feature of SrAl2.4： Eu, Dy as a function of temperature has been researched. Two sorts of SrAl2.4 ： Eu, Dy phosphors, namely highest quality commercial one and the self-synthesized one by solid-state reaction process were employed. Results reveal a common phenomenon behaving as phosphorescent sudden extinguishments at a certain low temperature although their threshold temperature value （ about 2.3.K） has a slight difference . The general charueteristic for the influence of temperature on the afterglow feature presents, compared to the luminescent decay at room temperature （RT）, a bigger and faster decrease of phosphorescent brightness with the reduction of temperature, while decay curves still maitain the same pattern composed of a quick decline part and a platform falling part during which the phosphorescent brightness at 2.3.K is only aboat 1/2.as big as that at RT, and at 2.3.K the figure has changed to about 1/3. Finally , the reason of previous observed results has been analyzed briefly in theory.

关键词： afterglow SrAl2.4:Eu,Dy low temperature

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Theoretical study of ZnO adsorption and bonding on Al_2._3.0001) surface

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Science China(physics,Mechanics & Astronomy) 2004年第6期47卷 664-675页

作者： LI Yanrong1,YANG Chun1,2.XUE Weidong1,LI Jinshan3.& LIU Yonghua3.1.Institute of Microelectronics and Solid State Electronics,University of Electronic Science and Technol- ogy of China,Chengdu 610054,China 2.Institute of Mathematics and Software Science,Sichuan Normal University,Chengdu 610068,China 3.Institute of chemical {3.,China {2. of engineering physics,mianyang 62.000,China Institute of Microelectronics and Solid State Electronics University of Electronic Science and Technology of China Chengdu 610054 China Institute of Mathematics and Software Science Sichuan Normal University Chengdu 610068 China Institute of chemical materials China Academy of Engineering Physics Mianyang 621000 China

ZnO adsorption on sapphire (0001) surface is theoretically calculated by using a plane wave ultrasoft pseudo-potential method based on ab initio molecular dynamics. The results reveal that the surface relaxation in the first layer Al-O is reduced, even eliminated after the surface adsorption of ZnO, and the chemical bonding energy is 43..3.±3..6) kJ·mol?1. The chemical bond of ZnO (0.185 ± 0.01 nm) has a 3.° angle away from the adjacent Al-O bond, and the stable chemical adsorption position of the Zn is deflected from the surface O-hexagonal symmetry with an angle of about 3.°. The analysis of the atomic populations, density of state and bonding electronic density before and after the adsorption indicates that the chemical bond formed by the O2.of the ZnO ? and the surface Al3. has a strong ionic bonding characteristic, while the chemical bond formed by the Zn2. and the surface O2.has an obvious covalent characteristic, which ? comes mainly from the hybridization of the Zn 4s and the O 2. and partially from that of the Zn 3. and the O 2..

关键词： α-Al2.3.(0001) ZnO ab initio molecular dynamics chemical adsorption density of states

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Effect of Lanthanum-praseodymium-cerium Mischmetal on Mechanical Properties and Microstructure of Mg-A1 Alloys

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Journal of Wuhan University of Technology(materials Science) 2011年第1期26卷 102-104页

作者：易勇 Research Center of Laser Fusion China Academy of Engineering Physics School of materials Science & engineering Southwest University of Science & Technology

The effects of lanthanum-praseodymium-cerium mischmetal （LPC） on the microstructure and mechanical properties of Mg-Al alloy were investigated. With the addition of LPC, an additional rod-like Al11La3.phase was deposited in the alloy. LPC greatly improves the tensile strength of cast Mg-Al alloys but negatively affects the elongation of cast alloys above 473.K. Cast alloys are strengthened by both precipitation strengthening and dispersion strengthening at ambient temperature. When the temperature exceeds 473.K, only the dispersion operates as a strengthening mechanism.

关键词： lanthanum-praseodymium-cerium mischmetal Mg-alloy microstructure mechanical properties

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Morphological Evolution of Nb_2._5 in a Solvothermal Reaction: From Nb_2._5 Grains to Nb_2._5 Nanorods and Hexagonal Nb_2._5 Nanoplatelets

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Journal of Wuhan University of Technology(materials Science) 2009年第2期24卷 245-248页

作者：胡卫兵 School of chemical and Environmental engineering Hubei Institute for Nationalities Department of physics Huazhong University of Science and Technology

Novel Nb2.5 nanorods and polygonal Nb2.5 platelets were generated by a simple solvothermal technique. The geometry evolution of the resultant Nb2.5 from amorphous nanoparticles to crystallized particles, from polygonal platelets to well-elongated nanorods was been studied in detail. The processing parameters, including the reaction temperature, reaction time, concentration of the precursors, and pH value of the solution, which affect the shape and size of the nanorods, were investigated. The Nb2.5 nanorods with different aspect ratios were examined by XRD, SEM and TEM. The experimental results show that Nb2.5 nanorod is the orthorhombic structure and well-crystallized. The growth of the nanorods follows their [001] direction. The successful generation of high quality Nb2.5 nanorods is not only important for transition metal oxide research, but also potentially important for further formation of new Nb-based 1-D nanostructures, such as NbS2.and NbN.

关键词： solvothermal morphological evolution Nb2.5 nanomateraials

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