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Effects of combined substitution of Dy and Mo or Si on the crystal structures and magnetic properties of Nd_(1-y)Dy_yFe_(11-x)TiM_x(M=Mo,Si) compounds

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Science china chemistry 2009年第8期52卷 1097-1103页

作者： LI XiangJun,ZHENG Na,HU ZhongBo & YUAN ZhuoBin college of chemistry and chemical engineering,Graduate university of Chinese Academy of Sciences,Beijing 100049,{2. college of chemistry and chemical engineering Graduate University of Chinese Academy of Sciences Beijing China

A series of Nd1-yDyyFe11-xTiMx(M=Mo,Si) alloys have been prepared by arc melting and studied by X-ray diffraction and neutron *** samples are found to crystallize in the ThMn12.type *** lattice parameters a and c and unit cell volume V of Nd0.5Dy0.5Fe11-xTiMox alloys increase linearly with increasing content of Mo(x),while the lattice parameters a and c and unit cell volume V of Nd0.5Dy0.5Fe11-xTiSix alloys decrease linearly with increasing content of Si(x).In NdyDy1-yFe11-xTiMx(M=Mo,Si) compounds,Ti and Mo atoms preferentially occupy the 8i sites and Si atoms preferentially occupy the 8j and 8f *** measurements show that the substitution of Fe by either Mo or Si leads to a decrease in the Curie temperature.

关键词： rare earth-transition metal compounds crystal structure X-ray diffraction neutron diffraction

AlkB recognition of a bulky DNA base adduct stabilized by chemical cross-linking

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Science china chemistry 2010年第1期53卷 86-90页

作者： YI ChengQi1 & HE Chuan1,2.1Department of chemistry,university of Chicago,Chicago,Illinois 60637,USA 2.epartment of {2. Biology,college of chemistry and Molecular engineering,Peking university,Beijing 100871,china Department of chemistry University of Chicago Chicago USA Department of chemical Biology College of Chemistry and Molecular Engineering Peking University Beijing China

*** AlkB is a direct DNA/RNA repair protein that oxidatively reverses N1 alkylated purines and N3 alkylated pyrimidines to regular *** crystal structures have revealed N1-methyl adenine(1-meA) recognition by AlkB and a unique base flipping mechanism,but how the AlkB active site can accommodate bulky base adducts is largely *** a previously developed chemical cross-linking technique,we crystallized AlkB with a duplex DNA containing a caged thymine base(cagedT).The structure revealed a flexible hairpin lid and a reorganized substrate recognition loop used by AlkB to accommodate *** observations demonstrate,at the molecular level,how bulky DNA adducts may be recognized and processed by AlkB.

关键词： DNA/RNA repair AlkB caged thymine disulfide cross-linking bulky base adduct

Controlled synthesis and magnetic properties of Fe_3O_4 walnut spherical particles and octahedral microcrystals

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Science china(Technological Sciences) 2008年第11期51卷 1911-1920页

作者： JIAO Hua1,2.& YANG HeQing1 1 Key Laboratory of Macromolecular Science of Shaanxi Province, School of chemistry and Materials Science, Shaanxi Normal university, Xi’an 710062. {2. 2.Department of chemistry and chemical engineering, Weinan Teachers university, Wei nan 714000, {2. Key Laboratory of Macromolecular Science of Shaanxi Province School of Chemistry and Materials Department of chemistry and chemical {2. Weinan Teachers University

Magnetite Fe3O4 walnut spherical particles and octahedral microcrystals were suc- cessfully synthesized from K4 [Fe (CN) 6], K3 [Fe (CN) 6] and NaOH reagents via a simple hydrothermal process. And the uniform morphology of octahedral micro- crystals was obtained in the presence of ethylene glycol. The morphology and structure of products were characterized by powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results showed that the Fe3O4 walnut spherical particles and octahedral microcrystals were single crystals with the face-center cubic structure and with size distributions from 2.2.to 8.6 μm and 1.6 to 12.5 μm, respectively. Their magnetic properties were detected by a vibrating sample magnetometer at room temperature. The walnut spherical parti- cles exhibited a ferromagnetic behavior with the coercive force (Hc), saturation magnetization (Ms) and remanent magnetization (Mr) being 150.57 Oe, 97.634 and 12.05 emu/g, respectively. For the octahedral microcrystals they were 75.2. Oe, 101.90 and 6.69 emu/g, respectively. Different sizes of walnut spherical particles were controlled synthesized through adjusting the NaOH concentration. It was found that ethylene glycol molecules have a significant effect on the formation of Fe3O4 octahedra. A possible mechanism was also proposed to account for the growth of these Fe3O4 products

关键词： a hydrothermal route Fe3O4 walnut spherical particles octahedral microcrystals magnetic property

Corrosion of titanium in supercritical water oxidation environments

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中国有色金属学会会刊：英文版 2002年第6期12卷 1054-1057页

作者：卢建树毛志远张九渊college of chemical {2. Zhejiang university of Technology 马淳安college of chemical {2. Zhejiang university of Technology 毛信表college of chemical {2. Zhejiang university of Technology 李肖华college of chemical {2. Zhejiang university of Technology college of chemical {2. Zhejiang University of Technology college of Materials and chemical {2. Zhejiang University

Supercritical water oxidation (SCWO) can effectively destroy many kinds of civilian and military wastes. The high temperature and high pressure SCWO operation conditions generate very corrosive environment that many engineering materials fail to withstand. Preliminary test shows that titanium may be a promising material in most of SCWO conditions. Commercially pure titanium is tested in four kinds of SCWO environments. Phenol, sodium dodecyl benzosulfonate, n amine phenol, and chlorpyrifos were chosen as typical target pollutants. The results show that titanium is only superficially attacked in the first three SCWO environments while in chlorpyrifos SCWO medium titanium is corroded. The corrosion is temperature dependent, with heavier corrosion occurring at near critical temperature. X ray diffraction analysis shows that the corrosion products consist of titanium oxy phosphates and titanium oxide, in which Ti 5O 4(PO 4) 4 is the main phase.

关键词：钛腐蚀超临界水氧化

MCM-41 Prepared with Ionic Liquid and Cethytrimethylammonium Bromide as Co-templates

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Journal of Wuhan university of Technology(Materials Science) 2009年第1期24卷 25-29页

作者：张光旭 School of chemical engineering Wuhan University of Technology college of chemistry and Molecular sciences Wuhan University

The mesoporous molecular sieves MCM-41 were prepared using room tempera-ture ionic liquid （RTIL） synthesized in laboratory and cethytrimethylammonium bromide （CTAB） as compound templates for the first time. They were prepared under low aging temperature and short aging time. Via characterizing by XRD and nitrogen adsorption instrument, MCM-41 synthesized by this new method exhibited good crystal structure and narrow pore distribution. The following pre-paratory conditions was optimal： the molar ratio of RTIL to CTAB was 1.0∶1.0, aging at 80 ℃, for 40 h and calcined at 540 ℃. It is found that the acidified MCM-41 improves its activity as catalyst over the unmodified ones.

关键词： mesoporous molecular sieve hydrothermal crystallization co-templates ionicliquid MCM-41

An efficient chiral synthesis of (R)-N-[3-acetyl-4-(2.hydroxy-3-isopropylamino-propoxy)phenyl]-butanamide with high enantioselectivity

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Science china chemistry 2009年第8期52卷 1216-1219页

作者： WANG NaiXing1,2.& TANG XinLiang1,3 1 Technical Institute of Physics and chemistry,Chinese Academy of Sciences,Beijing 100080,china 2.{2.,Graduate university of Chinese Academy of Sciences,Beijing 100049,china 3 School of chemical engineering and Environment,Beijing Institute of Technology,Beijing 100081,china Technical Institute of Physics and chemistry Chinese Academy of Sciences Beijing China college of chemistry and chemical engineering Graduate University of Chinese Academy of Sciences Beijing China School of chemical engineering and Environment Beijing Institute of Technology Beijing China

R-Enantiomer of the β-receptor antagonist N-[3-acetyl-4-(2.hydroxy-3-isopropylamino-propoxy)phenyl] butanamide with high enantioselectivity was synthesized from cheap starting materials and enantiopure chiral reagent through an efficient,convenient and practical synthetic *** product was detected by 1H NMR,13C NMR,and MS,and the enatiomeric excess was determined by chiral HPLC analysis using a chiracel AD-H column.

关键词： chiral synthesis enantioselectivity enatiomeric excess chiral HPLC analysis

Synthesis and Crystal Structure of 4,6Di-tert-butyl-2.hydroxy-3-(N-1-phenylethyliminomethyl) phenyl bis(triphenylphosphine)palladium bromide

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Chinese Journal of Structural chemistry 1999年第4期18卷 54-59页

作者： XU JiaXi\ ZHANG ZeYing\= (college of chemistry and Molecular {2., Peking university, Beijing 100871, china) Coll. of Chem. and Molec. Eng. Peking University Beijing 100871 China

１ＩＮＴＲＯＤＵＣＴＩＯＮＰａｌａｄｉｕｍｃｏｍｐｌｅｘｅｓｓｕｃｈａｓｔｅｔｒａｋｉｓ（ｔｒｉｐｈｅｎｙｌｐｈｏｓｐｈｉｎｅ）ｐａｌａｄｉｕｍａｒｅａｋｉｎｄｏｆｉｍｐｏｒｔａｎｔｃａｔａｌｙｓｔｓｉｎｔｈｅｒｅａ... 详细信息

１ＩＮＴＲＯＤＵＣＴＩＯＮＰａｌａｄｉｕｍｃｏｍｐｌｅｘｅｓｓｕｃｈａｓｔｅｔｒａｋｉｓ（ｔｒｉｐｈｅｎｙｌｐｈｏｓｐｈｉｎｅ）ｐａｌａｄｉｕｍａｒｅａｋｉｎｄｏｆｉｍｐｏｒｔａｎｔｃａｔａｌｙｓｔｓｉｎｔｈｅｒｅａｃｔｉｏｎｏｆｃａｒｂｏｎｃａｒ...

关键词： palladium complex synthesis molecular structure crystal structure

Thermal oxide synthesis and characterization of Fe_3O_4 nanorods and Fe_2._3 nanowires

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Science china chemistry 2009年第5期52卷 599-604页

作者： JIAO Hua1,2.& YANG HeQing1 1 Key Laboratory of Macromolecular Science of Shaanxi Province, School of chemistry and Materials Science, Shaanxi Normal university, Xi’an 710062. {2. 2.Department of chemistry and chemical engineering, Weinan Teacher’s university, Weinan 714000, {2. Key Laboratory of Macromolecular Science of Shaanxi Province School of Chemistry and Materials Science Shaanxi Normal University Xi’an China Department of chemistry and chemical {2. Weinan Teacher’s University Weinan China

Fe3O4 nanorods and Fe2.3 nanowires have been synthesized through a simple thermal oxide reaction of Fe with C2.2.4 solution at 2.0-600℃ for 1 h in the air. The morphology and structure of Fe3O4 nanorods and Fe2.3 nanowires were detected with powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The influence of temperature on the morphology development was experimentally investigated. The results show that the polycrystals Fe3O4 nanorods with cubic structure and the average diameter of 0.5-0.8 μm grow after reaction at 2.0-500℃ for 1 h in the air. When the temperature was 600℃, the samples completely became Fe2.3 nanowires with hexagonal structure. It was found that C2.2.4 molecules had a significant effect on the formation of Fe3O4 nanorods. A possible mechanism was also proposed to account for the growth of these Fe3O4 nanorods.

关键词： thermal oxide process nanorods nanowires C2.2.4 iron sheet

Study on the Separation of Co^(2.) from Zn^(2.) , Cd^(2.) by Anion-exchange Chromatography

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Journal of Central South university 2000年第2期12卷 88-91页

作者： WANG Xin yan,ZHOU Chun shan,WANG Yan (college of chemistry and chemical engineering, Central South university of Technology, Changsha 410083, {2.) college of chemistry and chemical engineering Central South University of Technology Changsha China

The separation of Co 2. from Zn 2. , Cd 2. by anion exchange chromatography was discussed. The chromatographic column containing anion resin 2.1×7 which was saturated with a solution of ammonium chloride. The effects of the eluant acidity and eluant composition on the separation were investigated. The results indicate that this anion exchange chromatography is suitable to the separation of Co 2. from Zn 2. , Cd 2. , and the condition of separation is simple and convenient. When the column is saturated with NH 4Cl solution (2.0 mol/L, pH=4.0), the separation can be completed effectively. Zn 2. and Cd 2. can also be separa ted when different eluants are used and the pure solution with high concentration of Zn 2. , Cd 2. respectively can be obtained ea sily.

关键词： anion exchange chromatography Zn 2. Cd 2. Co 2. separation