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Theoretical study of bifurcated bent blue-shifted hydrogen bonds CH_2.Y

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Science china chemistry 2008年第7期51卷 623-631页

作者： LI AnYong School of chemistry and chemical {2., Southwest university, Chongqing 400715, china School of chemistry and chemical {2. Southwest UniversityChongqing 400715China

Ab initio quantum chemistry methods were applied to study the bifurcated bent hydrogen bonds Y… H2.Z (Z = O, S, Se) and Y…H2.Z2.(Z = F, Cl, Br) (Y = Cl-, Br-) at the MP2.6-311++G(d,p) and MP2.6-311++G(2.f,2.) levels. The results show that in each complex there are two equivalent blue-shifted H-bonds Y…H—C, and that the interaction energies and blue shifts are large, the energy of each Y…H—C H-bond is 15-2. kJ/mol, and Δr(CH) = -0.1 - -0.5 pm and Δv(CH) = 30 - 80 cm-1. The natural bond orbital analysis shows that these blue-shifted H-bonds are caused by three factors: large rehybridization; small direct intermolecular hyperconjugation and larger indirect intermolecular hy- perconjugation; large decrease of intramolecular hyperconjugation. The topological analysis of elec- tron density shows that in each complex there are three intermolecular critical points: there is one bond critical point between the acceptor atom Y and each hydrogen, and there is a ring critical point inside the tetragon YHCH, so these interactions are exactly H-bonding.

关键词： bifurcated bent H-bonds blue-shifted H-bonds topological property of electron density intramolecular hyperconjugation

Fabrication,property characterization and toughening mechanism of HA-ZrO_2.CaO)/316L fibre composite biomaterials

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Science china(Technological Sciences) 2008年第7期51卷 957-967页

作者： ZOU JianPeng1, HE ZeQiang2. ZHOU ZhongCheng1, HUANG BaiYun1, CHEN QiYuan3 & RUAN JianMing1 1 State Key Laboratory for Powder Metallurgy, Central South university, changsha 410083, {2. 2.Institute of chemistry and chemical engineering, Jishou university, Jishou 416000, {2. 3 Institute of chemistry and chemical engineering, Central South university, changsha 410083, {2. State Key Laboratory for Powder Metallurgy Central South University Changsha 410083 China Institute of chemistry and chemical {2. Jishou University Jishou 416000 China Institute of chemistry and chemical {2. Central South University Changsha 410083 China

HA-ZrO2.CaO)/316L fibre composites were successfully fabricated with vacuum sintering method and their properties and toughening mechanism were studied. The results showed that HA-ZrO2.CaO)/316L fibre biocomposite having 2. vol% fibres had optimal comprehensive properties with bending strength, Young's modulus, fracture toughness and relative density equal to 140.1 MPa, 117.8 GPa, 5.81 MPa·m1/2.and 87.1%, respectively. The research also addressed that different volume ratios of the composites led to different metallographic microstructures, and that metallographic morphologies change regularly with volume ratios of the composites. 316L fibres were distributed randomly and evenly in the composites and the integration circumstance of the two phases was very well since there were no obvious flaws or pores in the composites. Two toughening mechanisms including ZrO2.phase transformation toughening mechanism and fibre pulling-out toughening mechanism existed in the compsites with the latter being the main toughening mechanism.

关键词： vacuum sintering fabrication property characterization toughening mechanism biomaterials

APPLICATION OF SIMPLEX-DEVIATION-PATTERN RECOGNITION TO THE CONFIRMATION OF THE ELECTRODE REACTION MECHANISM

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Chinese chemical Letters 1991年第3期2卷 237-238页

作者： Zheng Qi ZHANG Zhao Peng CHENG and Yu Cong ZHANG Department of chemistry and chemical {2.,hunan university,changsha,410082

Three hypotheses of the electrochemical reaction mechanism of the Dy(III)-ALC complex were put forward,based on the experimental *** it has been confirmed by simplex-deviation-pattern reoognition that the pola- rograp... 详细信息

关键词：工工 ALC exp APPLICATION OF SIMPLEX-DEVIATION-PATTERN RECOGNITION TO THE CONFIRMATION OF THE ELECTRODE REACTION MECHANISM Dy

Synthesis and magnetic properties of CdS/α-Fe_2._3 hierarchical nanostructures

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Science china(Physics,Mechanics & Astronomy) 2009年第7期52卷 997-1002页

作者： CHEN YuJin1,2.3, SHI XiaoLing1, CAO MaoSheng1 & ZHU ChunLing4 1 School of Materials Science and engineering, Beijing Institute of Technology, Beijing 100081, china 2.Micro-Nano Technologies Research Center,{2., changsha 410082. china 3 College of Science, Harbin engineering university, Harbin 150001, china 4 College of Material Science and chemical engineering, Harbin engineering university, Harbin 150001, china 1. School of Materials Science and engineering Beijing Institute of Technology Beijing 100081 China 2. Micro-Nano Technologies Research Center Hunan University Changsha 410082 China 3. College of Science Harbin Engineering University Harbin 150001 China 4. College of Material Science and chemical engineering Harbin Engineering University Harbin 150001 China

CdS/α-Fe2.3 hierarchical nanostructures, where the CdS nanorods grow irregularly on the side surface of α-Fe2.3 nanorods, were synthesized via a three-step process. The diameters and lengths of CdS nanorods can be tuned by changing the ethylenediamine (EDA) and Cd ion concentrations. The magnetic investigations by superconducting quantum interference device indicate that the hierarchical nanostructures have an Morin transition at lower temperature (2.0 K) than that of the single bulk α-Fe2.3 materials (2.3 K). Importantly, the hierarchical nanostructures exhibit weakly ferromagnetic characteristics at 300 K. A sharp peak assigned to the surface trap induced emission are observed in room temperature PL spectra. Combining with the optoelectronic properties of CdS, the CdS/ α-Fe2.3 hierarchical nanostructures may be used as multi-functional materials for optoelectronic and magnetic devices.

关键词： α-Fe2.3 CdS hierarchical nanostructures magnetic properties

One-pot synthesis of crystalline SnO_2.nanoparticles and their low-temperature ethanol sensing characteristics

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Science china(Physics,Mechanics & Astronomy) 2009年第10期52卷 1601-1605页

作者： CHEN YuJin1,2.3,ZHU ChunLing4,WANG LiJiao3 & WANG TaiHong2.1 School of Materials Science and engineering,Beijing Institute of Technology,Beijing 100081,china 2.Micro-Nano Technologies Research Center,{2. university,changsha 410082.china 3 College of Science,Harbin engineering university,Harbin 150001,china 4 College of Material Science and chemical engineering,Harbin engineering university,Harbin 150001,china School of Materials Science and engineering Beijing Institute of Technology Beijing 100081 China Micro-Nano Technologies Research Center Hunan University Changsha 410082 China College of Science Harbin Engineering University Harbin 150001 China College of Material Science and chemical engineering Harbin Engineering University Harbin 150001 China

Crystalline SnO2.nanoparticles(NPs) with a diameter less than 6 nm are synthesized using potassium stannate trihydrate as the precursor in a basic *** synthesized NPs can detect ethanol at a ppm level even at 100℃.Furthermore,the NPs have good selectivity to *** excellent ethanol sensing performances are attributed to the small size effect according to the space-charge model.

关键词： SnO2 nanoparticles sensing characteristics

Preparation and electrochemical performance of spherical Fe_3O_4 as anode materials for Li-ion batteries

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Science china(Technological Sciences) 2009年第11期52卷 3219-3223页

作者： WANG FangBin, CHEN Jie, HUANG KeLong & LIU SuQin College of chemistry & chemical {2., Central South university, changsha 410083, china 1. College of chemistry & chemical {2. Central South University Changsha 410083 China

Fe3O4 nano-powder was prepared by the hydrothermal method. The structure and morphology of the product were characterized by X-ray diffraction (XRD) and scanning electronic microscopy (SEM). The as-prepared powder has regularly spherical morphology, and the average size of product is about 2. nm. The possible application use of this material as the active mass of anode for rechargeable Li batteries was examined by cyclic voltammeter (CV), galvanostatic charge/*** experimental results showed that this material exhibited large specific capacity at the first cycle, and the discharge and charge capacity retention of this electrode are 37.04% and 48.76%, respectively. Furthermore, the impedance change of Fe3O4 electrode under different cycle number and potential was examined.

关键词： Fe3O4 lithium battery anode electrochemical performance

Mathematic Expression of Kinetic Compensation Effect and Relationship between the Exothermic Decomposition Temperature and Critical Temperature of Thermal Explosion of Eighty-six Energetic Materials

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含能材料 2001年第1期9卷 8-9页

作者： HU Rong zu 1, YANG De suo 2. ZHANG Jiao qiang 3 (1. Department of chemistry,Northwest university, Xi′an 710065, {2. 2. Department of chemistry and chemical engineering, Baoji College of Arts and Science, Baoji 72.007, {2. 3. Department of 西北大学陕西西安 710065 宝鸡文理学院陕西 721007 西北工业大学陕西西安 710072

Two relationships are established using the least squares method,between the kinetic parameters (the apparent activation energy and pre exponential constant),and the exothermic decomposition temperature and ther... 详细信息

关键词： critical temperature of thermal explosion decomposition temperature DSC energetic materials.

Novel nanoporous binary Ag-Ni electrocatalysts for hydrazine oxidation

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Rare Metals 2010年第1期29卷 26-31页

作者： YI Qingfeng, LI Lei, YU Wenqiang, LIU Xiaoping, ZHOU Zhihua, and NIE Huidong School of chemistry and chemical {2., hunan university of Science and Technology, Xiangtan 4112.1, china School of chemistry and chemical {2. Hunan University of Science and Technology

From an aqueous mixture of Ag（I）-EDTA complex and Ni（II） nitrate, silver and nickel particles were co-deposited on the surface of titanium substrates by the hydrothermal method using hydrazine hydrate as a reduction agent. The prepared titanium-supported nano-scale Ag and Ag-Ni particles （nano Ag/Ti, nano Ag86Ni14/Ti, nano Ag77Ni2./Ti, and nano Ag74Ni2./Ti） exhibit nanoporous 3D network textures. Their electrocatalytic activity towards hydrazine oxidation in alkaline solutions was evaluated by cyclic voltammetry and chronoamperometry. The results show that the four samples present a low onset potential of ca. -0.60 V vs. SCE and considerably high and stable anodic current densities for hydrazine oxidation. Among them, the nano Ag86Ni14/Ti electrode exhibits the highest anodic current density towards hydrazine oxidation, showing an increment of electro-active sites on the nano Ag86Ni14/Ti due to the addition of Ni to Ag particles.

关键词： electrocatalyst silver hydrazine oxidation fuel cell

Studies on the Synthesis, Properties and Preparation Methods of Zeolite ZK-4

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chemical Research in Chinese Universities 2000年第4期16卷 306-312页

作者： ZHAO Zhen-hua and YIN Du-lin (Department of chemistry, hunan Normal {2., changsha 410081, P. R. china) hunan Normal Univ Dept Chem Changsha 410081 Peoples R China

A zeolite designated as ZK-4 was synthesized hydrothermally in the system (TMA)2.Na2.-Al2.3- SiO2. H2. at 80 - 100℃ with tetramethylammonium hydroxide as an organic templating agent. The pure zeolite ZK-4 could be prepared by using the mother liquor obtained after filtration as the source of templating agent. The effect of some synthetic conditions such as the amount of tetramethylammonium hydroxide used, n [ (TMA)2. + Na2.] /n (Al2.3) ratio, n (SiO2./n(Al2.3) ratio and crystallization time, etc. on the crystalline phase of the product was investigated. When the following molar ratios of the reaction mixture, n (SiO2./n (Al2.3) 4-10, n[(TMA)2.+Na2.]/ n (Al2.3 ) > 7, n (Na2.)/n (Al2.3)=0. 5-2. 0, n (H2.)/ n(A12.3)=80-450, were used, pure zeolite ZK-4 could be obtained. The synthetic products were characterized by X-ray powder diffraction, atomic absorption spectrophotometry (AAS), adsorption measurement, thermogravimetric analysis(TGA), and 2.Si magic angle spinning nuclear magnetic resonance technique. Zeolite ZK-4 has a higher thermal stability than sodium zeolite A due to higher n(Si)/n(Al) ratio of zeolite ZK-4.

关键词： Zeolite ZK-4 Molecular sieve Zeolite synthesis Property,Tetramethylammonium hydroxide template