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Synthesis and proton conductibility of ternary germanic heteropoly acids

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Rare Metals 2004年第4期23卷 296-299页

作者： SANGXiaoguang wuQingyin Departmentofchemistry ZhejiangUniversityHangzhou310027China

The ternary germanic heteropoly acids H_5GeW_(11)O_(40) centre dot 22H_2O andH_5GeMo_(11)VO_(40) centre dot 24H_2O were synthesized for the first time by the stepwiseacidification and the stepwise addition of solution of the component elements. The products werecharacterized by ICP, IR, UV, XRD and TG-DTA. The proton conductibility and the activation energy ofproton conduction of the heteropoly acids were investigated.

关键词： inorganic solid chemistry heteropoly acid synthesis Keggin structure germanium tungsten molybdenum vanadium conductivity activation energy

Preparation and Conductivity of Triheteropoly Tungstozincoaluminic Acid

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Rare Metals 2001年第4期20卷 221-223页

作者： Qingyin wu Department of chemistry, zhejiang university, hangzhou 310027, china 浙江大学浙江杭州 310027

The ternary undecatungstozincoaluminic heteropoly acid H-7[Al(H2O)ZnW11O39](.)12H(2)O was prepared by the ion exchanging-cooling method. The optimal proportion of solutions of the component elements and the pH of the synthesis reaction were given. The product was characterized by chemical analysis, potentiometric titration, IR, UV, XRD and TG-DTA. AC impedance measurement results show that its proton conductivity is 1.37x10(-4) S/cm at 18 degreesC.

关键词： heteropoly acid tungstozincoaluminic acid protonic conductivity

CHEMOENZYMATIC SYNTHESIS OF BIODEGRADABLE POLY(1’-O-VINYLADIPOYL-SUCROSE)

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Chinese Journal of Polymer Science 2002年第6期20卷 579-584页

作者： De-shui Lu Qi wu Xian-fu Lin Department of chemistry zhejiang university hangzhou 310027, china Department of chemistry Zhejiang University Hangzhou 310027

A novel polymer containing the sucrose group was synthesized by radical polymerization from an enzymatically prepared monomer, 1'-O-vinyladipoyl-sucrose (VAS). Transesterification reaction of sucrose with divinyl adipate in anhydrous pyridine catalyzed by an alkaline protease from Bacillus subtilis at 60degreesC for 7 days gave VAS (yield 55%) without any blocking/deblocking steps. The vinyl sucrose ester could be polymerized with potassium persulfate and H2O2 as initiator to give poly(1'-O-vinyladipoyl-sucrose) with M-n = 33,000 and M-w = 53,200, M-w/M-n = 1.61. The polymer was biodegradable. After 6 days in aqueous buffer (pH 7), this alkaline protease could degrade poly(1'-O-vinyladipoyl-sucrose) to M. of ca. 1080, M-w/M-n = 3.30 (37degreesC), and M-n of ca. 5200, M-w/M-n = 2.44 (4degreesC). The polymer containing the sucrose branch would be a functional material in various application fields.

关键词： divinyladipate sucrose alkaline protease polymerization biodegradation

POLYMERIZATION OF γ-STEARYL-α,l-GLUTAMATE N-CARBOXYANHYDRIDE USING RARE EARTH COORDINATION CATALYSTS

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Chinese Journal of Polymer Science 2000年第4期18卷 369-372页

作者： Xiao-ping Hu Jian wu Zhi-kang Xu Lin-xian Feng Institute of Polymer Science, zhejiang university, hangzhou 310027, china Department of chemistry, zhejiang university, hangzhou 310027, china 浙江大学浙江杭州

A rare earth coordination system was first investigated as a new type of catalyst for the ring-openingpolymerization of α-amino acid N-carboxyanhydrides (NCAs). The results for the polymerization of γ-stearyl-α,L-glutamate(SLG) NCA using neodymium acetylacetonate (Nd(acac)_3)- or neodymium tris(2-ethylhexylphosphonate) (Nd(P_(204))_3)-triethylaluminum-water as catalysts were compared with those using conventional catalysts. It was found that the helicalpoly(γ-stearyl-L-glutamate) with high molecular weight as well as narrow molecular weight distribution can be obtained inthe presence of Nd(acac)_3/AlEt_3-1/2H_2O. The polymer obtained was characterized by IR and NMR spectroscopy.

关键词： Rare earth coordination catalyst Ring-opening polymerization Polypeptide Poly(γ-stearyl-α,L-glutamate)

Immobilized chitosan as a selective absorbent for the nickel removal in water sample

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Journal of Environmental Sciences 2003年第5期15卷 633-638页

作者： wu Jian min, WANG Yong yao (Department of chemistry, College of Science, zhejiang university, hangzhou 310027, china. ) Department of chemistry College of Science Zhejiang University Hangzhou 310027 Chin

Method for preparation of chitosan immobilized on silica gel(CTS silica) was described. The CTS silica was used as absorbent for the absorption of nickel in water. The results showed that this absorbent had relatively high selectivity and strong affinity to nickel. The maximum absorption capacity for nickel can reach 667 mg/g of chitosan. Factors that affect the absorption capacity, such as pH, ion strength and the presence of calcium, EDTA and the mechanism of absorption were discussed in detail. The absorbent can be regenerated with acid and reused for several times. The recovery rate for nickel can reach 99 99%. This absorbent filled in a column can be used in nickel removal from wastewater and drinking water.

关键词： immobilized chitosan nickel wastewater treatment

ON MULTIPLE POSITIVE SOLUTIONS FOR A NONLINEAR ELLIPTIC PROBLEM IN R^N

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Chinese Annals of Mathematics,Series B 2000年第3期21卷 351-358页

作者： YANG HAITAO(Department of Mathematics, zhejiang university, hangzhou 310027, china.) wu SHAOPING(Department of Mathematics, zhejiang university, hangzhou 310027, china.) Department of Mathematics Zhejiang University Hangzhou 310027 China

By making use of Variational method, the authors obtain some results about existence of multiple positive solutions and their asymptotic behavior as the parameter →＋∞ for a semilinear elliptic problem in RN.

关键词： Critical point Asymptotic behavior Concentration

HOMOCLINIC ORBITS FOR LAGRANGIAN SYSTEMS

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Chinese Annals of Mathematics,Series B 1996年第2期17卷 245-256页

作者： wu SHAOPING Departmentof Mathematics, zhejiang university, hangzhou, 310027, china. 浙江大学数学系浙江杭州

The existence of at least two homoclinic orbits for Lagrangian system (LS) is proved, wherethe Lagrangian L(t,x,y) =1/2∑aij(x)yiyj-V(t, x), in which the potential V(t,x) is globallysurperquadratic in x and T-periodic... 详细信息

关键词： Lagrangian systerm Superquadratic growth Concentration-compactness Minimax argument

Extension of a quantized enveloping algebra by a Hopf algebra

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Science china Mathematics 2010年第5期53卷 300-307页

作者： wu ZhiXiang Department of Mathematics,zhejiang university,hangzhou 310027,china Department of Mathematics Zhejiang University Hangzhou China

Suppose that H is a Hopf algebra,and g is a generalized Kac-Moody algebra with Cartan matrix A =(aij)I×I,where I is an index set and is equal to either {1,2,...,n} or the natural number set *** f,g be two mappings from I to G(H),the set of group-like elements of H,such that the multiplication of elements in the set {f(i),g(i)|i ∈I} is *** we define a Hopf algebra Hgf Uq(g),where Uq(g) is the quantized enveloping algebra of g.

关键词： quantum enveloping algebra Hopf algebra Kac-Moody algebra

Rotationally symmetric translating soliton of H^k-flow

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Science china Mathematics 2010年第4期53卷 1011-1016页

作者： SHENG WeiMin & wu Chao Department of Mathematics,zhejiang university,hangzhou 310027,china Department of Mathematics Zhejiang University Hangzhou China

This paper mainly considers the translating soliton of H k-flow for k > *** give the asymptotic expression of the entire rotationally symmetric translating soliton,and obtain non-convex 'Wing-like' solution as well as... 详细信息

关键词： H k-flow translating soliton 'Wing-like' solution