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The diophantine equation xy+yz+zx=m

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Chinese Science Bulletin 1999年第12期44卷 1093-1095页

作者： CAI Tianxin and JIAO Rongzhen department of mathematics , zhejiang university, hangzhou 310037, china Institute of mathematics , Tongji university, Shanghai 200092, china department of mathematics Zhejiang University Hangzhou China Institute of mathematics Tongji University Shanghai China

Under the generalized Riemann hypothesis, it is proved that the Diophantine equation xy + yz + zx = m always has a solution except for 18 positive integers m.

关键词： diophantine equation form class group ideal class group generalized Riemann hypothesis.

An extension of Bernstein-Bezier surface over the triangular domain

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Progress in Natural Science:Materials International 2007年第3期17卷 352-357页

作者： CAO Juan and WANG Guozhao (Institute of Image Processing and Computer Graphic, department of mathematics, zhejiang university, hangzhou 310027, china) Institute of Image Processing and Computer Graphic Department of Mathematics Zhejiang University Hangzhou 310027 China

In this paper, a set of quasi-Bernstein polynomials of degree n with one parameter is presented, which is an extension of the Bernstein polynomials over the triangular domain. Using the presented polynomials as basis functions, we construct a class of shape adjusting surfaces defined over the triangular domain with a shape parameter, namely, quasi-B-B parametric surfaces. These surfaces share many properties with the B-B parametric surfaces. In particular, when shape parameters equal 1, they degenerate to be the B-B parametric surfaces. By changing the value of the shape parameter, we can get different surfaces under the fixed control net.

关键词： triangular domain shape parameter Bezier surfaces.

Interaction mechanisms of organic contaminants with burned straw ash charcoal

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Journal of Environmental Sciences 2010年第10期22卷 1586-1594页

作者： Wenhai Huang,Baoliang Chen department of Environmental Science,zhejiang university,hangzhou 3.0028,china [a] department of Environmental Science Zhejiang University Hangzhou 310028 China

Black carbons （e.g., charcoal） have a great impact on the transport of organic contaminants in soil and water because of its strong affinity and ubiquity in the environment. To further elucidate their interaction mechanism, sorption of polar （p-nitrotoluene, m-dinitrobenzene and nitrobenzene） and nonpolar （naphthalene） aromatic contaminants to burned straw ash charcoal under different de-ashed treatments were investigated. The sorption isotherms fitted well with Freundlich equation, and the Freundlich N values were all around 0.31-0.38, being independent of the sorbate properties and sorbent types. After sequential removal of ashes by acid treatments （HCl and HCl-HF）, both adsorption and partition were enhanced due to the enrichment of charcoal component. The separated contribution of adsorption and partition to total sorption were quantified. The effective carbon content in ash charcoal functioned as adsorption sites, partition phases, and hybrid regions with adsorption and partition were conceptualized and calculated. The hybrid regions increased obviously after de-ashed treatment. The linear relationships of Freundlich N values with the charring-temperature of charcoal or biochar （the charred byproduct in biomass pyrolysis） were observed based on the current study and the cited publications which included 15 different temperatures （100-850℃）, 10 kinds of precursors of charcoal/biochar, and 10 organic sorbates.

关键词： ash charcoal organic pollutant adsorption partition effective carbon

Treatment of turtle-breeding wastewater and domestic fecal sewage with soil cultivating system

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Journal of Environmental Sciences 2001年第3期13卷 342-345页

作者： LAO Shan\|gen(department of Environmental Engineering, zhejiang university,hangzhou 310029, china) department of Environmental Engineering Zhejiang University Hangzhou 310029 China.

Turtle-breeding wastewater and domestic fecal sewage were treated by means of soil cultivating system. Results indicated that more than 50% CODCr and BOD5, of wastewaters were removed, removal rates of NH4+ -N could reach about 70%-80%, but PO43- could not be removed. The thesis analyzed functional mechanisms for pollutants and put forward main elements affecting treatment efficiencies, thus provided conditions for further research.

关键词： turtle-breeding wastewater fecal sewage soil CODCr BOD5 N P

TENSOR PRODUCTS OF JACOBSON RADICALS IN NEST ALGEBRAS

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Chinese Annals of mathematics,Series B 2003年第3期24卷 323-330页

作者： DONG ZHE Departinent of mathematics, zhejiang university, hangzhou 310027, china. Institute of mathematics, Fudan university, Shanghai 200433, china. zhejiang Univ Dept Math Hangzhou 310027 Peoples R China Fudan Univ Inst Math Shanghai 200433 Peoples R China

This paper studies the tensor product RN RM of Jacobson radicals in nest algebras, and obtains that RN RM = {T∈B(H1 H2) : T(N M)(?)N_ M_, N∈N,M∈M}; and based on the characterization of rank-one operators in RN RM,i... 详细信息

关键词： Jacobson radical Tensor product Nest algebra

Nitric oxide:A potential key point of the signaling network leading to plant secondary metabolite biosynthesis

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Progress in Natural Science:Materials International 2007年第12期17卷 1397-1404页

作者： Xu Maojun(department of Biotechnology, zhejiang Gongshang university, hangzhou 310035, china) department of Biotechnology Zhejiang Gongshang University Hangzhou 310035 China

The endogenous signaling network of plants plays important roles in mediating the exogenous factor-induced biosynthesis of secondary metabolites. Nitric oxide (NO) has emerged as a key signaling molecule in plants recently. Numerous studies demonstrated that the main signaling molecules such as salicylic acid (SA), jasmonic acid (JA), reactive oxygen species (ROS), and NO were not only involved in regulating plant secondary metabolite biosynthesis but also interacted to form a complex signaling network by mutual inhibition and/or synergy. The recent progress in the signal network of plant secondary metabolite biosynthesis has been discussed in this paper. Furthermore, we propose a hypothetical model to show that NO might act as a potential molecular switch in the signaling network leading to plant secondary metabolite biosynthesis.

关键词： plant secondary metabolites biosynthesis signaling network nitric oxide salicylic acid jasmonic acid reactive oxygen species.

A new method for designing a developable surface utilizing the surface pencil through a given curve

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Progress in Natural Science:Materials International 2008年第1期18卷 105-110页

作者： Hongyan Zhao,Guojin Wang* department of mathematics and State Key Laboratory of CAD&CG,zhejiang university,hangzhou 310027,china department of mathematics and State Key Laboratory of CAD&CG Zhejiang University Hangzhou 310027 China

This paper proposes a new method for designing a developable surface by constructing a surface pencil passing through a given curve, which is quite in accord with the practice in industry design and *** utilizing the Frenet trihedron frame,we derive the necessary and suffcient conditions to construct a developable surface through a given *** the requirements in shoemak- ing and garment-manufacture industries,we also study the special case of specifying the given curve as a *** given geodesic can be classified into three types corresponding to each type of developable *** also present the polynomial representation of the developable *** algorithm is convenient and effcient for applications in engineering.

关键词： CAD/CAM Developable surface Geodesic Frenet frame

Mechanisms of granular activated carbon anaerobic fluidized-bed process for treating phenols wastewater

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Journal of Environmental Sciences 2002年第1期14卷 132-135页

作者： LAO Shan gen (department of Environmental Engineering, zhejiang university, hangzhou 310029, china) department of Environmental Engineering Zhejiang University Hangzhou 310029

Granular activated carbon (GAC) anaerobic fluidized bed reactor was applied to treating phenols wastewater. When influent phenol concentration was 1000 mg/L, volume loadings of phenol and COD Cr were 0 39 kg/(m 3·d) and 0 98 kg/(m 3·d), their removal rates were 99 9% and 96 4% respectively. From analyzing above results, the main mechanisms of the process are that through fluidizing GAC, its adsorption is combined with biodegradation, both activities are brought into full play, and phenol in wastewater is effectively decomposed. Meanwhile problems concerning gas liquid separation and medium plugging are well solved.

关键词： granular activated carbon (GAC) anaerobic fluidized bed phenol removal rate

MULTIPLICITY OF POSITIVE SOLUTIONS FOR AN ELLIPTIC SYSTEM

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Analysis in Theory and Applications 2003年第2期19卷 145-152页

作者： Han Zhaoxiu (zhejiang university, china)department of mathematics zhejiang university hangzhou,zhejiang,3.0028 P.R.china 1. department of mathematics Zhejiang University 310028 Hangzhou Zhejiang P. R. China

By considering the properties of , we show the multiplicity of at least two positivesolutions of the elliptic system.

关键词： multiplicity elliptic system