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Theoretical study on S_1(~1B_(3.)) state electronic structure and absorption spectrum of pyrazine

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science China chemistry 2008年第12期51卷 1166-1173页

作者： HE RongXing1, ZHU ChaoYuan 2, CHIN Chih-Hao3.& LIN Sheng-Hsien2,3.1 college of chemistry and Chemical Engineering, Southwest university, Chongqing 400715, China 2 {3. of Applied chemistry, Institute of Molecular science and Center for Interdisciplinary Molecular science, National Chiao-Tung university, Hsinchu 3.0, China 3.Institute of Atomic and Molecular sciences, Academia Sinica, Taipei 106, China 1. college of chemistry and Chemical Engineering Southwest University Chongqing 400715 China 2. department of Applied chemistry Institute of Molecular Science and Center for Interdisciplinary Molecular Science National Chiao-Tung University Hsinchu 300 China 3. Institute of Atomic and Molecular sciences Academia Sinica Taipei 106 China

Making use of a set of quantum chemistry methods, the harmonic potential surfaces of the ground state (S0(1Ag)) and the first (S1(1B3.)) excited state of pyrazine are investigated, and the electronic structures of the two states are characterized. In the present study, the conventional quantum mechanical method, taking account of the Born-Oppenheimer adiabatic approximation, is adopted to simulate the absorp-tion spectrum of S1(1B3.) state of pyrazine. The assignment of main vibronic transitions is made for S1(1B3.) state. It is found that the spectral profile is mainly described by the Franck-Condon progression of totally symmetric mode ν6a. For the five totally symmetric modes, the present calculations show that the frequency differences between the ground and the S1(1B3.) state are small. Therefore the displaced harmonic oscillator approximation along with Franck-Condon transition is used to simulate S1(1B3.) absorption spectra. The distortion effect due to the so-called quadratic coupling is demonstrated to be unimportant for the absorption spectrum, except the coupling mode ν10a. The calculated S1(1B3.) ab-sorption spectrum is in reasonable agreement with the experimental spectra.

关键词： pyrazine absorption spectrum quantum mechanical method electronic structure

The Cobordism Classification of Involution on DOLD Manifold P(1,2l)

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Acta Mathematica Sinica,English Series 1997年第1期13卷 9-20页

作者： Wu Zhende Liu Zongze (department of Mathematics,hebei Normal university,Shijazhuang 050016,China)Bai Ruipu (department of Mathematics,hebei university,baoding 071002,China) department of Mathematics Hebei Normal University department of Mathematics Hebei University

Supposing the smooth involution of the DOLD manifold P(2,2l)satisfies the following condition:the fiberation π:P(1,2l)×T_×(-1)S~∞→RP(∞)is totally nonhomologous to zero(cf.[1, p3.3.),this paper determines the cla... 详细信息

关键词： Stiefel-Whitney class Involution on smooth manifold Bordism class Wu formulas

Study on the Application of Gibberellin for the Spectrophotometric Determination of Arsenic,Phosphorus,Silicon and Germanium

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Chinese Chemical Letters 1997年第7期8卷 627-628页

作者： Yu Biao WANG(department of chemistry,Anhui Instructive college,Hefei 23.061)Qian Rong LI(Structure Research Lab, university of {3. and Technology ofChina,Hefei 23.026) ANHUI INSTRUCT COLL DEPT CHEMHEFEI 230061PEOPLES R CHINA UNIV SCI & TECHNOL CHINA STRUCT RES LABHEFEI 230026PEOPLES R CHINA

In the media of 0.66,0.96, 2. 16 and 0.54 mol/L ofH2SO4,the heteropoly acids of As,*** and Ge are separately reduced to corresponding heteropoly blues by gibberellin, which exhibit maxirnum absorptions at 83., 820, 810 and 805 nm with molar absorptivities of 2.64x104, 2.54x104 3.51x104 and 2.25x104 ***-1'cm-1 and linear ranges of 0-3.,0-15,0-10 and 0-3. μg/25mL, The method was applied to the determinations of As, P and Si in alloyed steel.

关键词： Study on the Application of Gibberellin for the Spectrophotometric Determination of Arsenic Phosphorus Silicon and Germanium

Molecular dynamics simulations on the structures and properties of ε-CL-20-based PBXs ——Primary theoretical studies on HEDM formulation design

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science China chemistry 2007年第6期50卷 737-745页

作者： XU XiaoJuan1,2, XIAO JiJun1, HUANG Hui3. LI JinShan3.& XIAO HeMing1 1 department of chemistry, Nanjing university of science and Technology, Nanjing 210094, China 2 department of chemistry, Yancheng Teacher’s college, Yancheng 224002, China 3.Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China department of chemistry Nanjing University of Science and TechnologyNanjing 210094China department of chemistry Yancheng Teacher''s CollegeYancheng 224002China Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900

Five polymer bonded explosives(PBXs)with the base explosive epsilon-CL-20(hexanitrohexaazaisowurtzi-tane),the most important high energy density compound(HEDC),and five polymer binders(Estane 5703.GAP,HTPB,PEG,and F_(23.4))were *** dynamics(MD)method was employed to investigate their binding energies(E_(bind))3.≈ epsilon-CL-20/GAP 3.4).By pair correlation function g(r)analyses,hydrogen bonds and vdw are found to be the main interactions between the two *** elasticity and isotropy of PBXs based epsilon-CL-20 can be obviously improved more than pure epsilon-CL-20 *** is not by changing the molecular structures of epsilon-CL-20 for each binder to affect the *** safety and energetic properties of these PBXs are mainly influenced by the thermal capability(C_p^(deg))and density(p)of binders,respectively.

关键词： high energy density material (HEDM), hexanitrohexaazaisowurtzitane (CL-20), polymer bonded explosives (PBXs), molecular dynamics (MD), compatibility, safety properties, mechanical properties, energetic properties

Minimal symmetric submanifolds in compact Riemannian symmetric spaces

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Chinese science Bulletin 1998年第21期43卷 1786-1789页

作者： LIANG Ke 1 and JIN Quanqin 1,2 1. department of Mathematics, Nankai university, Tianjin 3.0071, China 2. department of Mathematics,{3., baoding 071002, China department of Mathematics Nankai University Tianjin China department of Mathematics Hebei University Baoding China

A necessary and sufficient condition for a symmetric submanifold to be minimal in its ambient compact Riemannian symmetric space is given. By this condition a complete classification of non- minimal symmetric submanif... 详细信息

关键词： symmetric space symmetric submanifold mean curvature vector.

Adsorption and corrosion inhibition behavior of imidazole on cobalt electrodes studied by SERS and electrochemical methods

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science China chemistry 2005年第6期48卷 497-503页

作者： GU Wei1, LIU Guokun2, REN Bin2, WU Deyin2, GU Renao1 & TIAN Zhongqun2 1. department of chemistry, college of chemistry and Chemical Engineering, Suzhou {3., Suzhou 215006, China 2. State Key Laboratory for Physical chemistry of Solid Surfaces and department of chemistry, college of chemistry and Chemical Engineering, Xiamen {3., Xiamen 3.1005, China 1. department of chemistry College of Chemistry and Chemical Engineering Suzhou University 215006 Suzhou China 2. State Key Laboratory for Physical chemistry of Solid Surfaces and department of chemistry College of Chemistry and Chemical Engineering Xiamen University 361005 Xiamen China

The interaction of imidazole with Co electrodes in an electrochemical system was studied by surface-enhanced Raman scattering (SERS) and electrochemical methods. The SER spectra of Co in an imidazole solution as a function of the applied potential were analyzed and the assignment of the Raman bands was made. It was found that there were three kinds of sur-face species on the Co surface in different potential regions and they were interchangeable de-pending on the potential. In a relatively negative potential region (?1.2 to ?0.9 V), imidazole was adsorbed on the surface and its orientation might change from a vertical configuration via the N-end of the pyridine ring to a tilted configuration via the C2=N3.double bond. In a more positive potential region (?0.8 to ?0.7 V), the SERS signal from the adsorbed imidazole weakened and finally disappeared, meanwhile the signal from the Co and imidazole complex strengthened gradually. At the open circuit potential (?0.6 V), we detected very strong bands from the Co ox-ides. By comparing the Tafel curves of the Co electrode in the solution without and with imidazole, we found that imidazole has a marked effect on the corrosion inhibition of the Co electrode. This result demonstrates that we may be able to reveal the complicated interaction of surface species with metal surface at the molecular level by combining the SERS and electrochemical methods.

关键词： cobalt, imidazole, inhibition, surface-enhanced Raman spectroscopy, Tafel plot.

SYNTHESIS AND PROPERTIES OF LIQUID CRYSTAL POLYSILOXANES WITH MESOGENIC STILBENE SIDE GROUPS

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Chinese Journal of Polymer science 2000年第2期18卷 95-99页

作者： Dong Zhang Yan-tao Zhu Da-hui Zhao Xin-hua Wan Qi-feng Zhou department of Polymer science & Engineering, college of {3., Peking university, Beijing 100871, China Peking Univ Coll Chem Dept Polymer Sci & Engn Beijing 100871 Peoples R China

A variety of mesomorphic side-chain polysiloxanes were synthesized by using hydrosilylation reaction with dicyclopentadienylplatinum(II) (DPPC) as the catalyst. The mesogenic groups are derivatives of stilbene with cyano or nitro tail groups. The products were characterized by DSC, X-ray diffraction and polarizing optical microscopy (POM). All the polymers were found to have relatively low T-g and can form a smectic liquid crystal phase.

关键词： liquid crystal polymer polysiloxane

Critical Range of Soil Boron for Prognosis of Boron Deficiency in Oilseed Rape

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Pedosphere 2001年第3期11卷 283-288页

作者： WEI YOUZHANG department of Soil science and Agricultural chemistry, Zhejiang {3., Hangzhou 3.0029 (China) 浙江大学浙江杭州 310029

Relationships between seed yields of oilseed rape (Brassica napus L.) and extractable boron concentrations in three soil layers (A, P and W) were investigated through ten experiments on three types of soils (Alluvic Entisols, Udic Ferrisols and Stagnic Anthrosols) in northern, western and middle Zhejiang Province. Among several mathematical models used to described the relationships, the polynomial equation, y = a + bx + cx2 + dx3. where y is the yield of oilseed rape seed and x the extractable boron concentration in P layer of soil, was the best one. The critical range of the concentrations corresponding to 90% of the maximum oilseed rape yield was 0.40-0.52 mg kg-1. The extractable boron concentration of the P layers of the soils was the most stable. The critical range determined was verified through the production practices of oilseed rape in Zhejiang and Anhui provinces.

关键词： boron deficiency critical range oilseed rape soil layer

Discrepancy of the magnetic behaviors and crystalline structure on the Co/FeMn and FeMn/Co interfaces with ultrathin Pt spacer

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Rare Metals 2010年第5期29卷 473-479页

作者： LIU Yang,FU Yanqiang,JIN Chuan,and FENG Chun department of Materials Physics and chemistry,university of {3. and Technology Beijing,Beijing 100083.China department of Materials Physics and chemistry University of Science and Technology Beijing Beijing China

The exchange coupling at the ferromagnetic/antiferromagnetic （FM/AFM） interface is influenced by both the magnetic structure and the crystalline micro-structure. Co/FeMn/Co thin films with 0.4 nm Pt spacer layer inserted into the Co/FeMn and FeMn/Co interface respectively were deposited by means of magnetron sputtering. The two interfaces upon and beneath the FeMn layer show distinct behaviors before and after the Pt spacer inserted. There is a remarkable shrink of the interracial uncompensated spins within the FeMn bottom interracial monolayers, whereas a relaxation of the pinning strength of the FeMn interfacial spins along the out-of-plane direction occurs at the top in- terface. XRD analysis indicates the Pt layer upon the FeMn layer forms an fcc （002） texture, implying the magnetic discrepancy between the top and bottom FeMn interfaces has crystalline structural origins.

关键词： interfaces exchange coupling exchange bias spacer stress anisotropy lattice match