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effect of static magnetic field on activity of immobilized α-amylase

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Chinese Science Bulletin 1997年第2期42卷 127-130页

作者： YAN Liushui, ZHU Yuanbao, he-shuang’e and CAO Zhixiang1 department of chemical engineering, Nanchang Institute of Aeronautical Technology, Nanchang 330034, China 2. department of chemistry and chemical engineering, hunan university, changsha 410082. China department of chemical engineering Nanchang Institute of Aenwututical Techndogy Nanchang China department of chemistry and chemical engineering Hunan University Changsha China

BIOLOGICAL effect of magnetic field is one of the three major subjects of contemporary biomagnetism, and is also the basis of applied biomagnetism. In order to explore magnetic biological effects, the influence of various sorts of magnetic field on many living systems as well as their different constructural levels has been extensively studied. However, only a few studies with in vitro enzyme have been reported, and few researches concerning the influence of magnetic field on immobilized enzyme reactions have been published. This note describes

关键词： static magnetic field immobilized α-amylase enzyme activity oscillatory behaviour.

Piezoelectric transmission spectroelectrochemistry with a normal piezoelectric quartz crystal as an optically-transparent electrode

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Chinese Journal of chemistry 1994年第5期12卷 425-431页

作者： XIe, Qing-Ji PANG, Xiao-Yong NIe, Li-Hua YAO, Shou-Zhuo department of chemistry and chemical engineering, hunan university, changsha, hunan 410082. China department of chemistry and chemical engineering Hunan University Changsha Hunan 410082 China

Piezoelectric transmission spectroelectrochemistry (PTSeC), i.e., the combination of electrochemistry and spectroelectrochemistry (SeC) with electrochemical quartz crystal microbalance (eQCM) technique is reported by using a normal piezoelectric quartz crystal (PQC) as an optically-transparent electrode (OTe). A theoretical relationship between the PQC response and the spectroelectrochemical response is derived and used to estimate the apparent molar absorptivity of the absorbing species deposited on the OTe on the PQC surface. The complex of copper with aspartic acid is used to test this new PQC-SeC technique. Results show that the combination of three such diverse techniques provides a very useful methodology for studying electrode processes and electrode surface characteristics in situ.

关键词： Piezoelectronic transimission spectroelectrochemistry optically-transparent electrode electrochemical quartz crystal microbalance copper aspartic acid.

A Series Piezoelectric Quartz Crystal Response Kinetics for *** Growth in the Presence of Cu(Ⅱ)

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Journal of Central South university 2000年第1期12卷 15-19页

作者： CHAI Li yuan 1,2 ,WeI Wan zhi 2,YAO Shou zhuo 2(1. department of Metallurgical Science and engineering, Central South university of Technology, changsha 410083, China 2. College of chemistry and chemical engineering, hunan university, changsha department of Metallurgical Science and engineering Central South University of Technology Changsha China College of chemistry and chemical engineering Hunan University Changsha China

The kinetics on the growth of *** in the presence of Cu(Ⅱ) was studied using of series piezoelectric quartz crystal (SPQC). Arsenic ion inhibits the growth of *** , which is consistent with the previous results by other measuring methods. This further demonstrates that the SPQC can monitor the chemical activity of *** growth. Cupric ion accelerates the growth of *** . The mechanism was discussed, i. e., copper promotes the protein enzyme of *** , rusticyanin, to form over the range of cupric ion concentration studied. The reaction order of cupric ion in accelerating the bacterial growth is 0.067. The growth of *** is dependent on temperature, the apparent reaction activation energy decreases from 25.56 kJ/mol to 18.32 kJ/mol because of the addition of 10 mg/L Cu(Ⅱ) to the bacterial growth solution of pH 2.0 at initial inoculum of 10%.

关键词： series piezoelectric quartz crystal T.ferrooxidans growth kinetics sigmoid curve cupric ion

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 Technology Yueyang China College of chemistry and chemical engineering Central South University Changsha China College of Pharmaceutical Science Central South University Changsha China

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

Crystal structure of a novel two-dimensional supramolecular network based on polyoxoanion and yttrium~Ⅲcoordination cation

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Science China chemistry 2005年第Z1期48卷 9-13页

作者： he Shuiyang,PeNG Ke,NING Wei,WANG Daqi & SHI Qizhen department of chemistry,Northwest university and Shaanxi Key Laboratory of Physico-Inorganic chemistry,Xi’an 710069,China College of chemistry and chemical engineering,Liaocheng university,Liaocheng 252059,China department of chemistry Northwest University and Shaanxi Key Laboratory of Physico-Inorganic Chemistry Xi’an China College of chemistry and chemical engineering Liaocheng University Liaocheng China

A novel compound (NH4)2Y(H2O)8[PMo10V2O40]·10H2O has been prepared in an aqueous solution and characterized by elemental analysis, IR, and TG-DTG analysis. X-ray diffraction analysis was carried out on (NH4)2Y(H2O)8 [PMo10V2O40]·10H2O single crystal, which crystallizes in the monoclinic system of a space group P21/C with a=0.9871(3) nm,b=1.5424(5) nm,c=2.7924(9) nm,β=94.183(5)°and Z=2. In the compound, a two-dimensional network is constructed by the PMo10V2O405- anion and the Y(H2O)83+ cation building blocks via hydrogen bonding exhibiting the porous structure.

关键词： crystal structure, polyoxoanion, yttrium, supramolecular network.

Intrachain and Interchain Interactions in Polystyrene: Dilute andSemidilutc Solutions

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Chinese chemical Letters 1999年第11期10卷 961-964页

作者： Xin Song LI Guo Chang WANG Bing Lin he(department of chemical engineering, Southeast university, Naming 210096)(Institute of Polymer chemistry, Nankai university, Tianjin 300071) department of chemical engineering Southeast University Nanjing 210096 China Institute of Polymer chemistry Nankai University Tianjin 300071 China

excimer formation in pyrenyl labeled polystyrene has been investigated in dilutesolution region. The change of the intensity ratio of excimer to monomer (Ie/Im) with increasingconcentration (C), is interpreted by intrachain and interchain interactions. The double logarithmicPlot of Ie/Im vs C displays two critical points, Cs at about 2.5×10-3g/ml and C+ at about 3.2×10-2g/ml. In dilute region Cexcimer formation may be controlled by intrachain interaction.

关键词： excimer fluorescence dilute solution chain interaction critical concentration.

Sol-gel preparation and characterization of Li_(1.3)Al_(0.3)Ti_(1.7)(PO_4)_3 sintered with flux of LiBO_2

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Rare Metals 2010年第5期29卷 515-518页

作者： WU Xianming,LI Runxiu,CheN Shang,he Zeqiang,and MA Mingyou College of chemistry and chemical engineering,Jishou university,Jishou 416000,China College of chemistry and chemical engineering Jishou University Jishou China

Li1.3Al0.3Ti1.7（PO4）3 pellets sintered with different mole fractions of LiBO2 were prepared by sol-gel method. The structural identification, surface morphology, ionic conductivity, and activation energy of the pellets were studied by X-ray diffraction, scanning electron microscopy, and electrochemical impedance spectroscopy. The results show that all the Li1.3Al0.3Ti1.7（PO4）3 pellets sintered with different mole fractions of LiBO2 have similar X-ray diffraction patterns. The sintered pellet becomes denser and the boundary and comer of the particles become illegible with the increase of LiBO2. Among the Lil.3Al0.3Ti1.7（PO3）4 pellets sintered with different mole fractions of LiBO2, the one sintered with 1 mol% LiBO2 shows the highest ionic conductivity of 3.95×10^-4 ***^-1 and the lowest activation energy of 0.2469 eV.

关键词： phosphates sol-gel process sintering ionic conductivity electrochemical impedance spectroscopy

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 2department of chemical 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

entanglement of Polymer Chains in Concentrated Region by Fluorescence Probe Technique

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Chinese chemical Letters 1999年第9期10卷 795-798页

作者： Xin Song LI Guo Chang WANG Bing Lin he(1 department of chemical engineering, Southeast university. Nanjing 2100962 Institute of polymer chemistry, Nankai university. Tianjin 300071) department of chemical engineering Southeast University Nanjing 210096 China Institute of Polymer chemistry Nankai University Tianjin 300071 China

The fluorescence of polystyrene labeled with pyrenyl groups has been investigated in concentrated solutions. The ratio of excimer to monomer intensities (I-c/I-m) of pyrenyl labels is found to vary with increasing polymer concentration (C) and display fractional dependence on the C. A critical concentration, C-m at about 0.32g/ml, is first manifested. The results are interpreted by interchain interaction and entanglement of polymer chains.

关键词： fluorescence spectroscopy entanglement critical concentration