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Chinese Journal of Polymer Science 2000年第1期18卷 25-31页

作者： Yan-feng Li Jun-rong Li Lian-di Fu Yao-zeng Li Department of Chemistry, lanzhou University, lanzhou 730000, China gansu Natural Energy Research Institute, lanzhou 730000, China gansu Provincial Institute of Drug Control, lanzhou 730000, China 兰州大学甘肃兰州甘肃自然能源所甘肃兰州 730000 甘肃省药检所甘肃兰州 730000

A kind of macroporous bead carrier of copolymer containing monomer units of N-aminoethyl acrylamide and vinylalcohol was synthesized, i.e. the MR-AA carrier. Papain was immobilized on the carrier using glutaraldehyde as the couplingagent. The enzymatic activity of the immobilized papain was compared with free papain using casein as a substrate, and theeffects of glutaraldehyde concentration, pH, temperature, time and papain amount added on the activity recovery were alsoinvestigated. The results show that the MR-AA carrier contains reactive primary amine groups, hydrophilic amido links andhydroxyl groups, as well as macroporous structures based on its matrix (MR-AV matrix), furthermore, the activity recoveryof papain in the immobilization could reach 48%/～58%. In comparison with free papain, the resulting immobilized papainexhibits a remarkable thermostability and better reusability.

关键词： Immobilization Papain Proteolytic enzyme Macroporous bead carrier

Synthesis and Characterization of New Schiff Base and Polyoxa-azaCryptands and Their Rare Earth Cryptates with [1+1] Condensation and Reduction Methods

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Chinese Chemical Letters 1999年第12期10卷 995-998页

作者： Zhen MA Ru Dong YANG Lan YAN(Department of Chemistry, lanzhou University, lanzhou, gansu 730000) Department of Chemistry Lanzhou University Lanzhou Gansu 730000 China

The Schiff base cryptand and its cryptates were synthesized with the methods of [1+1] condensation of trialdehyde and tris(2-aminoethyl)amine and obtained in 60-65%, 5-25% and 70-80% yields respectively with or without some rare earth elements as templates. The polyoxa-aza cryptand was produced in 72% and 60-70% yields with reduction of Schiff base and its cryptates respectively.

关键词： Schiff base polyoxa-aza cryptand rare earth condensation

Spectrofluorimetric determination of terbium with terephthalic acid

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Rare Metals 2002年第4期21卷 255-259页

作者： ZHAO Guohu and ZHAO JunBasic Science Department, gansu Agricultural University, lanzhou 730070, China Basic Science Department Gansu Agricultural University Lanzhou 730070

A Spectrofluorimetric method has been developed for the determination ofterbium(Ⅲ) based on the formation of a complex with terephthalic acid [benzene-1, 4-dicarboxylicacid (TPA)] in slightly acidic aqueous solution in the presence of gelatin. Terbium ion can form astable complex with TPA with the stoichiometry of 1:2. The best excitation and maximum emissionwavelengths are observed at 260 nm and 545 nm, respectively. The fluorescence intensity of terbiumcomplex gets the strongest within 20 min and remains stable up to 10 h, and it is proportional toterbium(Ⅲ) concentration in the range of 4.0x10^(-5)-1.6x10^(-7) mol·L^(-1) under the optimumconditions. The fluorescence system has good selectivity, sensitivity and stability. The relativestandard deviation is still within +-4% in the presence of 1200-fold amounts of the other lanthanideions when the concentration of terbium(Ⅲ) is 1.0x10^(-6) mol·L^(-1) and common co-existing ionshardly interfere the determination. It has been applied to the direct fluorimetric determination oftrace terbium (Ⅲ) in rare earth ores and oxides.

关键词： terbium spectrofluorimetry terephthalic acid gelatin

Synthesis of 6-aryl substituted 3-(5'-phenyl-2H-tetrazole-2'-methylene)-S-triazolo[3,4-b]-1,3,4-thiadiazoles

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Chinese Journal of Chemistry 1995年第5期13卷 448-453页

作者： ZHANG, Zi-Yi ZOU, NingNational Laboratory of Applied Organic Chemistry, Department of Chemistry, lanzhou University, lanzhou, gansu 730000, China National Laboratory of Applied Organic Chemistry Department of Chemistry Lanzhou University Lanzhou Gansu 7S0000 China

In this paper , 10 novel 6-aryl-3-(5'-phenyl-2H-tetrazole-2'-methylene)-S-triazolo[3, 4-b]-1,3,4-thiadiazoles have been synthesized by the condensation of 3-(5'-phenyl-2H-tetrazole-2'-methylene)-4-amino-5-mercapto-1,2,4-triazole with various aromatic carboxylic acids in the presence of phosphorus oxychloride. The structure of these compounds was determined by elemental analysis , UV, IR, 1H NMR and MS. Their spectral properties were also discussed.

关键词： S-triazolo[3,4-b]-1,3,4-thiadiazole synthesis spectral analysis

Dusty cloud radiative forcing derived from satellite data for middle latitude regions of East Asia

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Progress in Natural Science:Materials International 2006年第10期16卷 1084-1089页

作者： HUANG Jianping , WANG Yujie, WANG Tianhe and YI Yuhong ( College of Atmospheric Sciences, lanzhou University, lanzhou 730000, China gansu Provincial Meteorological Bureau, lanzhou 730020, China) College of Atmospheric Sciences Lanzhou University Lanzhou 730000 China gansu Provincial Meteorological Bureau Lanzhou 730020 China

The dusty cloud radiative forcing over the middle latitude regions of East Asia was estimated by using the 2-year (July 2002-June 2004) data of collocated clouds and the Earth's radiant energy system (CERES) scanner and moderate resolution imaging spectroradiometer (MODIS) from Aqua Edition IB SSF (single scanner footprint). The dusty cloud is defined as the cloud in dust storm environment or dust contaminated clouds. For clouds growing in the presence of dust, the instantaneous short-wave (SW) forcing at the top of the atmosphere (TOA) is about - 275. 7 W/m for cloud over dust (COD) region. The clouds developing in no-dust cloud (CLD) regions yield the most negative short-wave (SW) forcing ( - 311.0 W/m2), which is about 12.8% stronger than those in COD regions. For long-wave (LW) radiative forcing, the no-dust cloud (CLD) is around 102.8 W/m2 , which is 20% less than the LW forcing from COD regions. The instantaneous TOA net radiative forcing for the CLD region is about - 208.2 W/m2, which is 42.1 % larger than the values of COD regions. The existence of dust aerosols under clouds significantly reduces the cooling effect of clouds.

关键词： dust storm cloud radiative forcing global warming dust aerosol-cloud-climate interaction.

CLASSIFICATION AND EXISTENCE OF POSITIVE SOLUTIONS OF SECOND ORDER NONLINEAR DIFFERENTIAL EQUATIONS WITH DELAY DEPENDING ON THE UNKNOWN FUNCTION

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Acta Mathematica Scientia 2004年第3期24卷 403-411页

作者： LiWantong DongZhongqi DepartmentofMathematics LanzhouUniversityLanzhouGansu730000China

A class of second order nonlinear differential equations with delay depenging on the unknown function of the fromin the case where ∫0∞ ds/r(s) < ∞ is studied. Various classifications of their eventually positive solutions are given in terms of their asymptotic magnitudes, and necessary as well as sufficient conditions for the existence of these solutions are also obtained.

关键词： Nonlinear differential equation with delay eventually positive solution asymptotic behavior fixed point theorem

Study on the Reaction of Proteins with 5-Nitrosalicylfluorone-molybdenum(Ⅵ) Complex by Spectrophotometry in PVA 124 Microemulsion

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Chinese Journal of Chemistry 2004年第7期22卷 714-718,615页

作者：魏琴吴丹杜斌张慧欧庆瑜lanzhou Institute of Chemical Physics Chinese Academy of Sciences lanzhou gansu 730000 China School of Chemistry & Chemical Engineering Jinan University Jinan Shandong 250022 China Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou Gansu 730000 China School of Chemistry & Chemical Engineering Jinan University Jinan Shandong 250022 China

The application of 5'-nitrosalicylfluorone (5'-NSF)-molybdenum(VI) complex as a spectroscopic probe was studied. In the buffer medium of HOAc-NaOAc at 3.45 and in the presence of PVA 124 microemulsion, 5'-NSF-Mo(VI) complex combines protein rapidly to form a stable compound, leading to an absorbance decrease at 525 nm of 5'-NSF-Mo(VI) complex. According to this change, microdetermination of protein has been described. Bovine serum albumin (BSA) could be determined in the linear range of 0—16 g昺L-1 with the detection limit of 11 ngmL-1. Many amino acid and metal ions studied do not interfere with the assay. The method possesses high sensitivity as well as high selectivity. It can be used to determine protein in human urine and milk powder successfully. The relative standard deviations are in all instances less than 4.7%, and the recoveries are between 97.6% and 106.0%. Moreover, the binding number of BSA with the complex, which is determined by using molar ratio, Rosenthanl graphic and slope ratio methods, is in good agreement with each other.

关键词： protein spectrophotometry 5'-NSF-Mo(VI) complex microemulsion

Phytoestrogen genistein decreases contractile response of aortic artery in vitro and arterial blood pressure in vivo

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Acta Pharmacologica Sinica 2004年第3期25卷 59-64页

作者： Hong-fang LI1,Long-de WANG2,Song-yi QU Department of Physiology,lanzhou Medical College,lanzhou 730000 2Affiliated Hospital,gansu Chinese Medical College,lanzhou 730020,China Department of Physiology Lanzhou Medical College Lanzhou 730000 Affiliated Hospital Gansu Chinese Medical College Lanzhou 730020

AIM: To determine the mechanisms of effects of phytoestrogen genistein on the contracted rabbit aortic arteries in vitro, and observe the effect of genistein and 17-β estradiol on mean arterial pressure (MAP) in ovariectomized (OVX) rats. METHODS: (1) Strips of rabbit aortic smooth muscle were suspended in organ baths containing Kreb’s solution, and then isometric tension was measured. (2) Female mature Wistar rats underwent a bilateral ovariectomy (OVX). Sham-operated rats (SHAM) were used as controls. After administration of genistein (0.4 mg·kg-1·d-1, sc), 17-β estradiol (1 mg·kg-1·d-1, sc) or theirvehicle sesame oil for 21 d,MAP was measured. RESULTS: (1) Similar to 17-β estradiol, genistein could dose-dependently relax 40 mmol/L KCl-precontracted arterial strips. Incubation with Nω-L-nitro-arginine (L-NNA), methylene blue (MB), indomethacin, propranolol or endothelium removal did not affect relaxation induced by genistein. In calcium-free solution containing 0.01mmol/L egtazic acid (EGTA), genistein inhibited not only the first phase contraction induced by noradrenaline (NA), but also the second contraction induced by CaCl2. In addition, genistein could reduce the contractile responses of NA, KCl and CaCl2, and shift their cumulative concentration-response curves rightward. (2) MAP in OVX rats was significantlyhigher compared with that of SHAM rats. However,after chronically treatment with genistein or 17-β estradiol for 21 d the baseline MAP in OVX rats was reduced significantly. CONCLUSIONS: (1) The vasodilator effect of genistein in vitro is endothelium independent and not related to the nitric oxide, its mechanisms being probably due to inhibition of Ca2+ influx through calcium channels in a noncompetitive manner and Ca2+ release from intracellular store induced by NA. (2) Administration of genistein or 17-β estradiol can chronically decrease MAP in OVX rats.

关键词： genistein aorta smooth muscle muscle relaxation calciumchannel vascular endothelium blood pressure

A Facile Synthesis of (-)-5_αH,7β,10_α-Eudesmane-3,1 1-diene

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Chinese Chemical Letters 1996年第12期7卷 1081-1082页

作者： Ning ZOU Dong Liang CHENG Xin Fu PAN Yao Zu CHEN(Department of Chemistry, lanzhou University, lanzhou, gansu 730000) Department of Chemistry Lanzhou University Lanzhou Gansu 730000

s: The convenient synthesis of (-)-5αH.7β 10α-eudesmane-3. 11-dielle 1 has been achieved in four steps starting from R-(-)-carvone. The key step is the reductive deoxygenation of α,β-unsaturated tosylhydrazone to... 详细信息

关键词： A Facile Synthesis of Eudesmane-3,1 1-diene H,7