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Solvothermal synthesis and ferromagnetic property of bamboo-shoot-like oriented carbon micromaterials

Chinese science Bulletin 2010年第33期55卷 3838-3841页

作者： YANG YongZhen1,2,LIU XuGuang1,3,REN WenFang1,3,QIU Li1,3 & XU BingShe1,2 1Key Laboratory of Interface science and engineering in Advanced materials(Taiyuan university of technology),Ministry of Education,Taiyuan 030024,china 2college of materials science and engineering,Taiyuan university of technology,Taiyuan 030024,china 3college of Chemistry and chemical engineering,Taiyuan university of technology,Taiyuan 030024,china Key Laboratory of Interface science and engineering in Advanced materials (Taiyuan university of technology) Ministry of Education Taiyuan 030024 China college of materials science and engineering Taiyuan University of Technology Taiyuan 030024 China college of Chemistry and chemical engineering Taiyuan University of Technology Taiyuan 030024 China

Bamboo-shoot-like oriented carbon micromaterials(BOCMs)were synthesized by a solvothermal method at 450°C for 4 h using deoiled asphalt(DOA)as carbon source,toluene as solvent,ferrocene as catalyst precursor and amphiphilic triblock copolymer P123 as *** morphology and structure of the products were characterized by X-ray diffraction,field emission scanning electron microscopy,high resolution transmission electron microscopy and Fourier transform infrared *** results reveal that the obtained products have good distribution with uniform diameters of about 0.5 ?m and the lengths of 1-1.5 μm,and hydrogen-carbon bonds are observed on the surface of *** growth mechanism of BOCMs is discussed,in which that the catalysis of ferrocene and the dispersion and assembly of the aromatic molecules of DOA directed by P123 are critical to the formation of the *** coercivity value(231.91 Oe)from the measurement of a vibrating sample magnetometer shows that the BOCMs have an obvious ferromagnetic behavior.

关键词：溶剂热合成铁磁性碳源场发射扫描电子显微镜高分辨透射电子显微镜傅里叶变换红外光谱两亲嵌段共聚物振动样品磁强计

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Effect of yttrium on the microstructure of a semi-solid A356 Al alloy

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Rare Metals 2008年第5期27卷 536-540页

作者： LIUZheng HU Yongmei Faculty of material and chemical engineering Jiangxi University of Science and Technology Ganzhou 341000 China

The semi-solid slurry of an A356 Al alloy, which was grain-fined by yttrium, was manufactured by low temperature pouring, The effects of grain-refining on the morphology and the grain size of the primary α phase in the semi-solid A356 Al alloy were researched. The results indicate that the semi-solid A356 AI alloy with particle-like and rosette-like primary α-Al can be prepared by low temperature pouring from a liquid grain-refined A356 alloy. The grain size and particle morphology of primary α-Al in the A356 Al alloy are markedly improved by the addition of 0.5 wt,% Y. The fining mechanism of Y on the morphology and grain size of the primary α-Al in the semi-solid A356 Al alloy was delved.

关键词： A356 Al alloy semi-solid yttrium low temperature pouring

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Predicting neutron star spins from twin kHz QPOs

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science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 247-248页

作者： SHI ChangSheng Department of Astronomy,Nanjing university,Nanjing 210093,china college of material science and chemical engineering,Hainan university,Hainan 570228,china 1. Department of Astronomy Nanjing University Nanjing 210093 China

We briefly review the proposed relations between the frequencies of twin kilohertz quasi-periodic oscillations(kHz QPOs) and the spin frequencies in neutron star low-mass X-ray binaries(NSLMXBs).To test the validity of the proposed models,we estimate the spin frequencies under these theoretical relations and compare them with the measured *** seems that magnetohydrodynamic(MHD) oscillations are more promising to account for the kHz QPOs.

关键词： win kHz QPOs spin neutron stars LMXBs

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Resolution of α-cyclohexyl-mandelic acid enantiomers by two-phase (O/W) recognition chiral extraction

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science china Chemistry 2007年第6期50卷 764-769页

作者： TANG KeWen1,2, ZHANG GuoLi2, HUANG KeLong2, LI Yuanjian3 & YI JianMin1,2 1 Department of Chemistry and chemical engineering, Hunan Institute of science and technology, Yueyang 414000, china 2 college of Chemistry and chemical engineering, Central South university, Changsha 410083, china 3 college of Pharmaceutical science, Central South university, Changsha 410078, china Department of Chemistry and chemical engineering Hunan Institute of Science and TechnologyYueyang 414000China college of Chemistry and chemical engineering Central South UniversityChangsha 410083China

This paper presents a new chiral separation technology:two-phase(O/W)recognition chiral *** behavior of alpha-cyclohexyl-mandelic acid enantiomers was studied in the extraction system with D(L)-isobutyl tartrate in 1,2-dichloroethane organic phase and beta-CD derivatives in aqueous phase,and the influence of the kind and concentration of extractant and pH on extraction performance was *** experimental results indicate that two-phase(O/W)recognition chiral extraction is of strong chiral separation ***-^-CD,HE-beta-CD and Me-beta-CD have higher recognition ability for S-CHMA than that for R-CHMA,among which HP-beta-CD has the strongest ability;whereas,D-isobutyl tartrate has reversed recognition ability for *** the extraction system containing HP-beta-CD and D-isobutyl tartrate,e.e.% of S-CHMA in aqueous phase reached 27.6% by one stage extraction,and the distribution ratio for R-CHMA(k_R)and for S-CHMA(k_S)and separation factor(alpha)are 2.44,0.89 and 2.49,***,pH and concentration of extractant have great effects on chiral separation ***-phase(O/W)recognition chiral extraction has great significance for preparative separation of racemic compounds.

关键词： two-phase(W/0)recognition chiral extraction alpha-cyclohexyl-mandelic acid enantiomers

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New fossil elaterid (Coleoptera: Polyphaga: Elateridae) from Yixian Formation of western Liaoning, china

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Progress in Natural science:materials International 2007年第10期17卷 1244-1249页

作者： Chang Huali, Ren Dong and Shih Chungkun(college of Life science, Capital Normal university, beijing 100037, china) college of Life science Capital Normal University Beijing 100037 China

A new species of the elaterid genus Cryptocoelus Dolin and Nel, 2002 from the Late Jurassic to Early Cretaceous Yixian Formation in the western Liaoning, china is described. Diagnosis of the genus is revised, and the systematic position of the genus is briefly discussed. Because the elaterids originated in the Early to Mid-Jurassic, this new material from the Late Jurassic-Early Cretaceous will enhance our understanding of the transition between ancient elaterids and extant ones, bridge the gap of cryptic relationships between the Mesozoic cupedids and elaterids, and expand our knowledge of their evolutionary history.

关键词： Elateridae new species Yixian Formation china.

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Synthesis of a novel centipede-like copolymer of styrene and methyl methacrylate

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science china Chemistry 2007年第2期50卷 253-257页

作者： LI AiXiang1 & LU ZaiJun2 1 School of material science and engineering,Shandong university of technology,Zibo 255049,china 2 School of Chemistry and chemical engineering,Shandong university,Jinan 250100,china 1. School of material science and engineering Shandong University of Technology Zibo 255049 China 2. School of Chemistry and chemical engineering Shandong University Jinan 250100 China

A well-defined,A2B-type,centipede-like copolymer of styrene and methyl methacrylate(PS-PS-PMMA) was synthesized by the combination of living anionic polymerization and atom transfer radical polym-erization(ATRP) . The synthetic approach involves the coupling reaction of polystyrene(PS) backbone bearing 1,1-diphenylethene(DPE) pendant groups,produced by ATRP and Wittig reaction,with living polystyryllithium(PSLi) ,and subsequent polymerization of the resulting 1,1-diphenylmethyl anions with methy methacrylate. The centipede-like copolymer was characterized by 1H NMR,IR,SEC,SLS,and DSC measurements.

关键词： architecture atom transfer radical polymerization centipede-like copolymer coupling reaction living anionic polymerization

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Oxygen pressure dependent electro-resistance in La_(0.9)Sr_(0.1)MnO_3 thin films grown by laser molecular beam epitaxy

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science china(Physics,Mechanics & Astronomy) 2008年第3期51卷 232-236页

作者： OUYANG SiHua1,2,WANG ChunChang2,LIU GuoZhen2,HE Meng2, JIN KuiJuan2,DANG ZhiMin1 & L HuiBin21 college of materials science and engineering,beijing university of chemical technology,beijing 100029,china 2 beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of sciences,beijing 100080,china college of materials science engineering Beijing University of Chemical Technology Beijing 100029 China beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China

We report here studies on the influence of oxygen pressure on the electroresis-tance behavior of La0.9Sr0.1MnO3 thin films fabricated by laser molecular beam epi-taxy. It was found that the film deposited at lower oxygen pressure shows larger c-axis parameter,higher resistance,and more distinct electroresistance. These results reveal that the electroresistance of manganite thin films can be tuned by the conditions of film fabrication.

关键词： La0.9Sr0.1MnO3 thin film electroresistance effect laser molecular beam epitaxy

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Preparation of nanocrystalline BaTiO_3 ceramics

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science china(Technological sciences) 2009年第6期52卷 1730-1734页

作者： DENG XiangYun1,2,LI DeJun1,LI JianBao2,WANG XiaoHui3 & LI LongTu3 1 college of Physics and Electronic Information,Tianjin Normal university,Tianjin 300387,china 2 materials and chemical engineering Institute,Key Laboratory for Hainan Advantage Resources and Applied technology in chemical engineering material of Ministry of Education,Hainan Provincial Key Laboratory of Research on Utilization of Si-Zr-Ti,Hainan university,Haikou 570228,china 3 Department of materials science and engineering,Tsinghua university,beijing 100084,china college of Physics and Electronic Information Tianjin Normal University Tianjin 300387 China materials and chemical engineering Institute Key Laboratory for Hainan Advantage Resources and Applied Technology in Chemical Engineering Material of Ministry of Education Hainan Provincial Key Laboratory of Research on Utilization of Si-Zr-Ti Hainan University Haikou 570228 China Department of materials science and engineering Tsinghua University Beijing 100084 China

The high-dense nanocrystalline BaTiO3(BT)ceramics with grain size smaller than 100nm have been successfully prepared by the two step sintering and the spark plasma sintering(SPS)*** successive transitions in nanograin BT ceramics from rhombohedral to orthorhombic,tetragonal and cubic transitions,similar to those in coarse BT ceramics,were revealed by in-situ temperature dependent Raman *** multiphase coexistence and the diffused phase transition character were demonstrated in the 8nm nanocrystalline BT ceramics.

关键词： nanocrystalline BaTiO3 ceramics preparation microstructure size effect

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Preparation, characterization and salt-resistance of a coal based super absorbent composite

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Mining science and technology 2010年第6期20卷 864-871页

作者： CHU Mo, HUANG Zhanbin, XU Bang, FANG Tao, DUAN Hui School of chemical and Environmental engineering, china university of Mining & technology, beijing 100083, china [a] School of chemical Environmental engineering China University of Mining & Technology Beijing 100083 China

Potassium humate was extracted from brown coal. A novel super absorbent composite, poly （acrylic acid-co-acryla- mide）/potassium humate （PAA-AM/KHA）, was prepared by graft polymerization of acrylic acid, acrylamide and coal based potassium humate using N, N＇-methylenebisacrylamide as a crosslinker and potassium peroxydisulfate as an initiator. The effects of reaction temperature, degree of neutralization of the poly （acrylic acid） and the amounts of crosslinker, initiator and potassium humate were investigated. Salt resistance tests were also carded out. The composite prepared under optimal conditions had a potassium bumate content of 10% and exhibited a water absorption of 770 g/g in distilled water, and 349, 286 and 41 gig in 0.5 mol/L KC1, MgC12 and A1CI3 solutions respectively. The results indicate that the salt resistance of PAA-AM/KHA was superior to that of poly （acrylic acid-co-acrylamide） because of the collaborative effect of functional groups of the coal based potassium humate. The PAA-AM/KHA micro powder was characterized by IR spectroscopy and the micrographic surface was characterized by scanning electron microscopy. Introduction of potassium humate into the poly （acrylic acid-co-acrylamide） structure creates a composite more suitable for use as a water-managing material in the renewal of arid and desert environments. The salt resisting property of the composite is improved, production costs are reduced and the growth stimulant effect is still present.

关键词： brown coal coal based potassium humate superabsorbent salt-resistant property

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Synthesis of nano onion-like fullerenes by using Fe/Al_2O_3 as catalyst by chemical vapor deposition

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Chinese science Bulletin 2009年第1期54卷 137-141页

作者： LIU XuGuang1,2,WANG CunJing1,2,YANG YongZhen1,3,GUO XingMei1,2,WEN HaiRong1,2 & XU BingShe1,3 1 Key Laboratory of Interface science and engineering in Advanced materials,Ministry of Education,Taiyuan university of Tech-nology,Taiyuan 030024,china 2 college of Chemistry and chemical engineering,Taiyuan university of technology,Taiyuan 030024,china 3 college of materials science and engineering,Taiyuan university of technology,Taiyuan 030024,china Key Laboratory of Interface science and engineering in Advanced materials Ministry of Education Taiyuan University of Technology Taiyuan 030024 China college of Chemistry and chemical engineering Taiyuan University of Technology Taiyuan 030024 China college of materials science and engineering Taiyuan University of Technology Taiyuan 030024 China

Nano-carbon materials were synthesized by the catalytic decomposition of acetylene at 400℃ by using Fe/Al2O3 as catalyst. The product was refluxed in 36% concentrated HCl at 60℃ for 48 h in order to re-move the catalyst support. The samples were examined by scanning and high resolution transmission electron microscopy,energy dispersive spectroscopy and X-ray diffraction. The results show that nano onion-like fullerenes encapsulating a Fe3C core were obtained. These had a structure of stacked graphitic fragments,with diameters ranging from 15―50 nm. When the product was further heat-treated at 1100℃ for 2 h,nano onion-like fullerenes with a clear concentric graphitic layer structure were obtained. The growth mechanism of nano onion-like fullerenes encapsulating metal cores is suggested to follow a vapor-solid growth model.

关键词：纳米碳材料化学蒸发沉积作用合成增长机制

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