检索结果-南通市图书馆

science china chemistry 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 mater.als science, heilongjiang university, har.in 150080, china State Key Laboratory of Theoretical and Computational chemistry Institute of Theoretical Chemistry Jilin University Changchun China school of chemistry and mater.als science Heilongjiang University Harbin China

We have studied the ground and excited states of the three dendriticpolynuclear Pt(ll) complexes 1-[Cl(PH3)2PtC ident to C]-3,5-[HC ident to C]C6H3 (1),1,3-[CI(PH3)2PtCident to C]2-5-[HC ident to C]C6H3 (2),and 1,3,5-[CI(PH3)2-PtC ident to C]3C6H3 (3),by using theB3LYP and UB3LYP methods,*** approach with the PCM model was performed to predict theemission spectra properties of 1-3 in CH2Cl2 *** first predicted the excited-stategeometries for the three *** the change of the number of Pt(ll) atom,1-3 show thedifferent geometry structures in both the ground and excited states;furthermore,the increase of themetal density from 1 to 3 results in the red shift of the lowest-energy emissions along *** luminescent properties of 1 are somewhat different from those of 2 and *** emissionproperties of 2 and 3 are richer than *** conclusion can give a good support for designing thehigh efficient luminescent mater.als.

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

Ln_2MO_4 cathode mater.als for solid oxide fuel cells

在线全文

学校读者我要写书评

暂无评论

science china chemistry 2011年第6期54卷 898-910页

作者： ZHAO Hui, LI Qiang & SUN LiPing Key Laboratory of Functional Inorganic material chemistry, Ministry of Education school of chemistry and mater.als science, heilongjiang university, har.in 150080, china Key Laboratory of Functional Inorganic material chemistry Ministry of Education school of chemistry and mater.als science Heilongjiang University Harbin China

One of the major challenges to develop "intermediate temperature" solid oxide fuel cells is finding a novel cathode material, which can meet the following requirements: (1) high electronic conductivity; (2) chemical compatibility with the electrolyte; (3) a matched thermal expansion coefficient (TEC); (4) stability in a wide range of oxygen partial pressure; and (5) high catalytic activity for the oxygen reduction reaction (ORR). In this short review, a survey of these requirements for K2NiF4-type material with the formula Ln2MO4, Ln = La, Pr, Nd, Sm; M = Ni, Cu, Fe, Co, Mn, is presented. The composition-dependent TEC, electrical conductivity and oxygen transport property are considered. The Ln2MO4 mater.als exhibit improved chemical stability and compatibility with most of the traditional electrolytes. The complete fuel cells integrated with Ln2MO4 mater.als as cathodes show promising results. Furthermore, these mater.als are considered as cathodes of protonic ceramic fuel cell (PCFC), and/or anodes of high temperature steam electrolysis (HTSE). First results show excellent performances. The versatility of these Ln2MO4 mater.als is explained on the basis of structural features and the ability to accommodate oxygen non-stoichiometry.

关键词： intermediate temperature solid oxide fuel cells (ITSOFCs) cathode K2NiF4-type structure oxygen non-stoichiometry

Theoretical studies on Ru(fppz)_2(CO)L (L=N-heterocyclic ligand):Electronic structure,absorption,phosphorescence,and solvatochromism

在线全文

学校读者我要写书评

暂无评论

science china chemistry 2008年第12期51卷 1211-1220页

作者： LIU Tao1, ZHOU Xin1, BAI FuQuan1, ZHANG JianPo1, XIA BaoHui1,2, PAN QingJiang3 & ZHANG HongXing1 1 State Key Laboratory of Theoretical and Computational chemistry, Institute of Theoretical chemistry, Jilin university, Changchun 130023, china 2 College of chemistry, Jilin university, Changchun 130023, china 3 Laboratory of Physical chemistry, school of chemistry and mater.als science, heilongjiang university, har.in 150080, china State Key Laboratory of Theoretical and Computational chemistry Institute of Theoretical Chemistry Jilin University Changchun China College of chemistry Jilin University Changchun China Laboratory of Physical chemistry School of Chemistry and Materials Science Heilongjiang University Harbin China

A series of ruthenium(II) complexes Ru(fppz)2(CO)L [fppz = 3-trifluoromethyl-5(2-pyridyl)pyrazole; L = pyridine (1), 4-dimethylaminopyridine (2), 4-cyanopyridine (3)] were designed and investigated theo-retically to explore their electronic structures, absorption, and emissions as well as the solvatochrom-ism. The singlet ground state and triplet excited state geometries were fully optimized at the B3LYP/LANL2DZ and CIS/LANL2DZ level, respectively. The HOMO of 1-3 is composed of dyz(Ru) atom and π(fppz). The LUMO of 1 and 2 is dominantly contributed by π*(fppz) orbital, but that of 3 is con-tributed by π*(L). Absorption and phosphorescence in vacuo, C6H12, and CH3CN media were calculated using the TD-DFT level of theory with the PCM model based on the optimized ground and excited state geometries, respectively. The lowest-lying absorption of 1 and 2 at 387 and 391 nm is attributed to {[dyz(Ru) + π(fppz)] → [π*(fppz)]} transition, but that of 3 at 479 nm is assigned to {[dyz(Ru) + π(fppz)] → [π*(L)]} transition. The phosphorescence of 1 and 2 at 436 and 438 nm originates from 3{[dyz(Ru) + π(fppz)] [π*(fppz)]} excited state, while that of 3 at 606 nm is from 3{[dyz(Ru) + π(fppz)] [π*(L)]} excited state. The calculation results showed that the absorption and emission transition character can be changed from MLCT/ILCT to MLCT/LLCT transition by altering the substituent on the L ligand. The phosphorescence of 1 and 2 does not have solvatochromism, but that of 3 at 606 nm (vacuo), 584 nm (C6H12), and 541 nm (CH3CN) is strongly dependent on the solvent polarity, so introducing elec-tron-withdrawing group on ligand L will induce remarkable solvatochromism.

关键词： ruthenium complex DFT phosphorescence solvatochromism

Electrochemical deposition of nano-structured ZnO on the nanocrystalline TiO_2 film and its characterization

在线全文

学校读者我要写书评

暂无评论

science china chemistry 2010年第8期53卷 1732-1736页

作者： LIN JingSheng,FU Wei,JING LiQiang,QU YiChun & LI ZhiJun Key Laboratory of Functional Inorganic material chemistry (Ministry of Education) school of chemistry and material science,heilongjiang university,har.in 150080,china Key Laboratory of Functional Inorganic material chemistry (Ministry of Education) school of chemistry and material science Heilongjiang University Harbin China

One-dimensional structure of ZnO nanorod arrays on nanocrystalline TiO2/ITO conductive glass substrates has been fabricated by cathodic reduction electrochemical deposition methods in the three-electrode system,with zinc nitrate aqueous solution as the electrolyte,and were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM),energy-dispersive X-ray (EDX) and photoluminescence (PL) *** effects of film substrates,electrolyte concentration,deposition time,and methenamine (HMT) addition on ZnO deposition and its luminescent property were investigated in *** results show that,compared with on the ITO glass substrate,ZnO is much easily achieved by electrochemical deposition on the TiO2 nanoparticle thin *** is hexagonally structured wurtzite with the c-axis preferred growth,and further forms nanorod arrays vertically on the *** is favorable to the growth of ZnO to extend the deposition time,to increase the electrolyte concentration,and to add a certain amount of HMT in the system,consequently improving the crystallinity and orientation of ZnO *** is demonstrated that the obtained ZnO arrays with high crystallinity and good orientation display strong band-edge UV (375 nm) and weak surface-state-related green (520 nm) emission peaks.

关键词： zinc oxide nanorod array electrochemical deposition nanocrystalline titanium dioxide film photoluminescence

Meet Our New Editorial Board Members of Rising Stars

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of chemistry 2024年第16期42卷 1797-1805页

作者： Editorial Office of Chinese Journal of chemistry 不详

Editorial Board Memberof Rising Stars:Xiulin Fan,Professor,school of mater.als science and Engineering Zhejiang university,Hangzhou,***:2003-2007,*** university,china.2007-2012,*** university,china(Supervisor:*** Chen).

关键词： china. Editorial Hangzhou

Structures and stability of isomers of[C,N,N,P]system

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

science china chemistry 2005年第5期48卷 415-423页

作者： KAN Wei1,2, ZHONG Hua1, YU Haitao1, FU Honggang1,3 & SUN Jiazhong1,3 1. school of chemistry and mater.als science, heilongjiang university, har.in 150080, china 2. school of chemistry and Chemical Engineering, Qiqihar university, Qiqihar 161006, china 3. State Key Laboratory of Theoretical and Computational chemistry, Institute of Theoretical chemistry, Jilin university, Changchun 130023, china school of chemistry and mater.als science Heilongjiang University Harbin China school of chemistry and Chemical Engineering Qiqihar University Qiqihar China Jilin university Changchun China

Nine isomers, twenty transition states, and some relative dissociation fragments of [C,N,N,P] system were located at the B3LYP/6-311G(d) and QCISD(t)/6-311+G(2df) (single-point) levels of theory, and the isomerization, structures, and stability of these obtained isomers were suggested. The results indicate that four nonlinear chainlike isomers NCNP, NCPN, CNPN, and CNNP with 2A′ electronic state are kinetically stable. Other isomers are kinetically unstable to-wards isomerization or dissociation because of the corresponding smaller reaction barriers. Furthermore, calculated vibrational frequencies, rotational constants, dipole moments, the first adiabatic ionization energies, and adiabatic electron affinities of the four isomers may provide some theoretical information that is helpful for identifying their existence in future laboratory and interstellar investigations. The results are also compared with [Si,N,N,P] system.

关键词： potential energy surface, [C,N,N,P] system, isomerization, kinetic stability.

Uniqueness and local stability for the inverse scattering problem of determining the cavity

在线全文

学校读者我要写书评

暂无评论

science china Mathematics 2005年第8期48卷 1113-1123页

作者： FENG Lixin & MA Fuming LMAM, school of Mathematical sciences, Peking university, Beijing 100871, china school of Mathematical sciences, heilongjiang university, har.in 150080, china school of Mathematical sciences, Jilin university, Changchun 130012, china LMAM School of Mathematical Sciences Peking University Beijing China school of Mathematical sciences Heilongjiang University Harbin China school of Mathematical sciences Jilin University Changchun China

Considering a time-harmonic electromagnetic plane wave incident on an arbitrarily shaped open cavity embedded in infinite ground plane, the physical process is modelled by Maxwell's equations. We investigate the inverse problem of determining the shape of the open cavity from the information of the measured scattered field. Results on the uniqueness and the local stability of the inverse problem in the 2-dimensional TM (transverse magnetic) polarization are proved in this paper.

关键词： uniqueness, stability, Maxwell's equations, inverse scattering problem.

Meet Our New Editorial Board Members of Spotlights

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of chemistry 2024年第16期42卷 1932-1936页

作者： Editorial Office of Chinese Journal of chemistry 不详

Editorial Board Member of *** ***,College of mater.als science and Engineering Beijing university of Chemical ***:2006-2010,B.S.,mater.als science and Engineering,Beijing university of Chemical Technology.2010-2015,Ph... 详细信息

关键词： Spotlight Editorial Board

Photodecomposition of H_2S to H_2 over Cd_xZn_(1-x)S composite photocatalysts

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2009年第2期28卷 137-141页

作者： Bai, Xuefeng Wu, Dan Wang, Peng school of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China heilongjiang Institute of Petrochemistry Harbin 150040 China school of chemistry and material science Heilongjiang University Harbin 150080 China

A series of CdxZn1-xS (x = 0.1-0.9) photocatalysts were prepared by coprecipitation. They could form solid solution semiconductors with hexagonal phase in agreement with pure CdS by characterization of XRD. The photophysical properties of CdxZn1-xS photocatalysts were measured by UV-Vis diffuse reflectance spectrum and surface photovoltage spectroscopy (SPS). The band gap energy gradually reduced with the increasing of x value in CdxZn1-xS,and when x = 0.7,the Cd0.7Zn0.3S photocatalyst had the strongest sur...

关键词： hydrogen production photodecomposition composite photocatalyst solid solution semiconductor

Structure and kinematic analysis of a novel 2-DOF translational parallel robot

在线全文

学校读者我要写书评

暂无评论

Progress in Natural science:mater.als International 2007年第10期17卷 1213-1219页

作者： Chen Tao1, Wu Chao2 and Liu Xinjun2(1. school of Application science and Technology, har.in university of science and Technology, har.in 150080, china 2. Department of Precision Instruments, Tsinghua university, Beijing 100084, china) school of Application science and Technology Harbin University of Science and Technology Harbin 150080 China Department of Precision Instruments Tsinghua University Beijing 100084 China

This paper addresses the analysis of a novel parallel robot with 2 translational degrees of freedom (DOFs). The robot can position a rigid body in a plane with constant orientation. The kinematic structure of the robot is first described in detail. Some kinematic problems, such as the inverse and forward kinematics, velocity, and singularity are then analyzed. The working and assembly modes are discussed. Since it is the most important index to design a robot, the workspace of the robot is studied systematically in this paper. Based on the analysis of reachable workspace and singularity, a kind of workspace concept characterizing the region that the end-effector of the robot can reach in practice is defined. The results of this paper will be very useful for the design and application of the robot.

关键词： parallel robot degree of freedom kinematics workspace.