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Lead (Ⅱ) Binding to Thionein

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Chinese Chemical Letters 1999年第1期10卷 87-90页

作者： Wei Guo HE De Ying CHU Jing Yue YANG Dan Feng.YAO Mei Cheng.SHAO(coll.ge of Chemistry and Molecular eng.neering Peking University. Beijing 100871) coll. of Chem. and Molec. eng. Peking University Beijing 100871 China

Lead (Ⅱ)-binding properties of rabbit liver thionein 2 (apo-MT2) have been *** kinds of complexes. Pb7-MT and Ph7-MT', are observed upon the binding of Ph2+ to apo-MTat different PH. From their characteristic peaks in UV and CD spectra. it is deduced that Ph2+ inPh7-MT is coordinated by four sulfhydryl groups in Td microsymmetry, while multiplecoordination types including two-coordination maybe present in Ph7-MT'

关键词： Thionein lead (Ⅱ) UV spectra circular dichroism multiple coordination

Study on Bicoordination Chiral Inducement Catalysis of (R)-4-Thiazolidinecarboxylic Acid

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Chinese Chemical Letters 2004年第12期15卷 1419-1422页

作者： Hui WANG Wei Wei PEI Guo Bin SUN Wei Ping YE coll.ge of Chemistry and Molecular eng.neering, Peking University, Beijing 100871 coll. of Chem. and Molec. eng. Peking University Beijing 100871 China

The bicoordination chiral inducement catalysis of (R)-4-thiazolidinecarboxylic acid inthe enantioselective borane reduction of prochiral ketones has been studied. The fact that theabsolute configuration of the main product can be changed by simply using different operationmethods was firstly verified. And the reason of bicoordination chiral inducement was discussed.

关键词： Bicoordination chiral inducement (R)-4-thiazolidinecarboxylic acid.

PA6 Obtained by Polymerization with Trifunctional Regulators and Its DSC Results

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Journal of China Textile University(eng.ish Edition) 2000年第4期17卷 16-19页

作者：戴礼兴王朝生李力锋黄南薰唐志廉 Klaus-Dieter Hungenberg BASF coll. of Materials eng. Soochow Univ. Suzhou 215021 China

Hydrolytic polymerization of 8 - caprolactam is carried out by the use of trimesinic acid as molecular weight controlling agent, and polyamide 6 with three branched chains is obtained. The initial concentrations of regulators almost have no effect on the conversion of caprolactam , while relative viscosity of the polymer is affected by the concentrations. DSC investigation shows that DSC curve changes from single peak for regular polyamide 6 to one peak with one shoulder or one small peak for polyamide 6 with three branched chains and the melting point decreases with the increase of the amount of trimesinic acid. In addition, the concentration of trimesinic acid being the same, DSC curves change from almost sharp single peak to double peak with increasing reaction time.

关键词： polymerization polyamide 6 trifunctional regulator

AN ORDINARY DIFFERENTIAL EQUATION FOR THE 2D TRANSIENT FREE-SURFACE GREEN FUNCTIONS

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Journal of Hydrodynamics 2002年第2期14卷 24-28页

作者： Duan Wen-yang coll.ge of Shipbuilding eng.neering, Harbin eng.neering University, Harbin 150001, ChinaPrice W.G. School of eng.neering Sciences, Ship Science, University of Southampton, UK coll. of Shipbuilding eng. Harbin Eng. Univ. Harbin 150001 China Sch. of eng. Sci. Ship Sci. Univ. of Southampton Southampton United Kingdom

Based on the Laplace transform an ordinary differential equation for the two-dimensional time-domain free-surface Green function in ship hydrodynamics is presented. The results for 2D Green function and its horizontal derivative are fifth-order ODEs and the vertical derivative satisfies a fourth-order ODE. All of these results may be used to accelerate the numerical computations for the time-domain BEM in marine hydrodynamics.

关键词： ship hydrodynamics time-domain Green function Laplace transform

Effect of Rare Earth on Thermal Shock Resistance of Steel 9Cr2Mo

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Journal of Rare Earths 2001年第2期19卷 153-156页

作者：李慧郭铁波 coll. of Mat. Sci. and Chem. eng. Yanshan Univ. Qinhuangdao 066004 China

The effect of rare earth elements on thermal shock resistance of cold roller steel 9Cr2Mo was investigated by means of X-ray diffractometry and optical microscopy. Experimental results show that the process of carbide precipitation of heat effect zone is restrained by adding RE elements in steel 9Cr2Mo. Therefore, thermal shock resistance of this steel can be improved.

关键词： rare earths steel 9Cr2Mo thermal shock resistance

Spectra and Upconversion of Neodymium Tungstate Crystals

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Journal of Rare Earths 2001年第4期19卷 246-249页

作者：臧竞存刘燕行方方 coll. of Mat. Sci. and eng. Beijing Polytech. Univ. Beijing 100022 China

The neodymium tungstate single crystals Nd-2(WO4)(3) were grown using the Czochralski method. The energy level scheme of Nd3+, was obtained through the spectral measurement. The upconversion luminescence of the crystals at 457 and 657 nm, corresponding to the (D5/2-->I11/2)-D-4-I-4 and (2)G(7/2)-->I-4(9/2) transitions, respectively, excited by 808 nm of a laser diode, was observed at room temperature. The fluorescence intensity and the excitation light power have a linear relationship at 457 nm and a quadratic relationship at 657 nm.

关键词： rare earths Nd-2(WO4)(3) single crystals upconversion spectra

Effect of Impurities and Cerium on Stress Concentration Sensitivity of Al-Li Based Alloys

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Journal of Rare Earths 2002年第1期20卷 51-55页

作者：孟亮田丽 coll. of Mat. Sci. and Chem. eng. Zhejiang Univ. Hangzhou 310027 China

A notch sensitivity factor was derived in order to evaluate the stress concentration sensitivity of Al Li based alloys. The factor values for the Al Li alloy sheets containing various contents of impurities and cerium addition were evaluated by determining the mech.nical properties. It is found that the impurities Fe, Si, Na and K significantly enhance the stress concentration sensitivity of the alloys 2090 and 8090, whereas cerium addition reduces the stress concentration sensitivity to a certain degree for the high streng.h alloys. However, an excess amount of cerium addition in the high ductility alloy 1420 can significantly increase the stress concentration sensitivity. As compared with conventional aluminum alloys, the Al Li based alloys generally show high stress concentration sensitivity. Therefore, a special attention must be paid to this problem in the practical application of Al Li based alloys.

关键词： rare earths cerium impurity Al Li based alloy stress concentration

HOMOGENIZATION TREATMENT OF Mg-Al-Zn(MM)MAGNESIUM ALLOY INGOTS

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Acta Metallurgica Sinica(eng.ish Letters) 2002年第6期15卷 545-550页

作者： K. Yu and W.X. Licoll.ge of Materials Science and eng.neering, Central South University, Changsha 410083, China coll. of Mat. Sci. and eng. Central South Univ. Changsha 410083 China

The Mg-Al-Zn series AZ31 and AZ31+MM alloys are homogenized at 673, 723 and 753K respectively. The hardness of alloy ingots at different heat-treated states is measured and the micro structures are observed. The optim... 详细信息

关键词： magnesium alloy homogenization diffusion

Base－Catalyzed　Rearrangement　of　11－Isopropylidene－anti－4，5－Epoxyendo－Tricyclo［6．2．1．0^（2，7）］　Undeca－4，9－Diene－3，6－Dione

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Chinese Chemical Letters 1996年第10期7卷 902-904页

作者： Xiao Pei GUAN Jian Guang SUN and Yong Zhong YU(coll.ge of Chemical eng.neering and Materials Science, Beijing Institute of Technology, 100081 Beijing) coll. of Chem. eng. and Mat. Science Beijing Institute of Technology 100081 Beijing

Treatment of 11-isopropylidene-anti-4, 5-epoxy-endo-tricyclo[6. 2. 1. 02.7] undeca-4, 9-diene-3,6-dione(6) with methanolic sodium hydroxide results in Favorskii-type ring contraction with concomitant Cope rearrangement and Haller-Bauer cleavage, thereby affording dimethyl9-isopropxlidene-cis-bicyclo[4. 3. 0 ] nonane-(2S)-2, 3-dicarboxylate(7) as the ultimate product. The structure of 7 was confirmed by single crystal X-ray analysis

关键词： Rearrangement Isopropylidene Base Catalyzed