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Preparation and characterization of bis(dimolybdo-nonatungstogermanate)lanthanates of potassium

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Rare Metals 2003年第1期22卷 6-9页

作者： WU QingyinDepartment of Chemistry, zhejiang university, hangzhou 3.0027, china Department of Chemistry Zhejiang University Hangzhou 310027 China

The heteropoly complexes K_(13.[Ln(GeW_9Mo_2O_(3.))_2] centre dot nH_2O (Ln =La, Ce, Pr, Nd, and Sm) were prepared for the first time and characterized by chemical analysis,infrared (IR) spectrum, ultraviolet (UV) spectrum, X-ray powder diffraction, and thermal ***, UV spectra, and X-ray powder diffraction studies show that the structure of the heteropolycomplexes is a square antiprism consisting of eight oxygen atoms of two GeW_9Mo_2O_(3.)^(8-)heteropolyanions and a lanthanide ion. The thermostability of heteropoly complexes is lower thanthat of saturated Keggin structure dodecatungstogermanate.

关键词： inorganic chemistry heteropoly complex chemical synthesis lanthanates germanium

Identification of a bi-directional promoter from Tomato yellow leaf curl china virus

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Progress in Natural Science:Materials International 2006年第3期16卷 281-286页

作者： GUAN Cuiping and ZHOU Xueping (institute of Biotechnology, zhejiang university, hangzhou 3.0029, {3.) [a]institute of Biotechnology Zhejiang University Hangzhou China

A bi-directional promoter of Tomato yellow leaf curl china virus (TYLCCNV) was obtained with the total DNA from TYLCCNV isolate Y10 infected tobacco leaves as a template. Plant expression vectors were constructed by fusing the amplified DNA fragment with the gus gene and nopaline terminator in different orientations. The vectors containing promoter fragments were transferred into leaf cells and plant stems of Nicotiana benthamiana by Agrobacterium-mediated method. Transient expression results showed that both the complementary and virion-sense promoters could drive the gus gene to express, and the GUS activity of the complementary-sense promoter was stronger than that of the virion-sense. Co-expression of the vector containing βC1 gene of TYLCCNV DNAβ with the vector containing a bi-directional promoter revealed that the βC1 protein has no impact on expression of either the virion- or the complementary-sense promoter.

关键词： Tomato yellow leaf curl china virus bi-directional promoter transient expression geminivirus.

Multiple products of B-splines used in CAD system

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Progress in Natural Science:Materials International 2006年第4期16卷 425-430页

作者： XU Huixia and WANG Guojin institute of Images and Graphics, zhejiang university, hangzhou 3.0027, {3. State Key Laboratory of CAD&CG, zhejiang university, hangzhou 3.0027, {3. [a]Institution of Images and Graphics Zhejiang University Hangzhou China [b]State key Laboratary of CAD CG Zhejiang University Hangzhou China

The function upgrade of computer aided design (CAD) system requested that the multiple product of B-spline functions should be represented as a linear combination of some suitable (usually higher-degree) B-splines. In this paper, we apply the theory of spline space and discrete B-splines to deduce the representation of the coefficients of all terms of the linear combination, which can be directly applied to software coding in system development.

关键词： computer aided design (CAD) NURBS Marsden’s identity.

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 3.0027, {3. Department of Chemistry, zhejiang university, hangzhou 3.0027, {3. zhejiang Univ Dept Chem Hangzhou 310027 Peoples R China zhejiang Univ Inst Polymer Sci Hangzhou 310027 Peoples R China

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)

Strong near-epoch dependence

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Science china Mathematics 2004年第4期47卷 497-507页

作者： LIN ZhengyanDepartment of Mathematics, zhejiang university, hangzhou 3.0028, china 1. Department of Mathematics Zhejiang University 310028 Hangzhou China

We introduce a new class of dependent sequences of random variables, which is a subclass of near-epoch dependent sequences, but can also be approximated by mixing sequences. For this kind of sequences of random variables, we call them strong nearepoch dependent sequences, a p-order, p ＞ 2, (maximum) moment inequality is established under weaker dependence sizes.

关键词： near-epoch dependence, mixingale, strong near-epoch dependence, moment inequality, convergence.

Allocation of power generating and shipping of Hanjiang upstream cascade

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Progress in Natural Science:Materials International 2005年第8期15卷 733-741页

作者： LIU Junping1* and CHANG Mingqi 2,3.1. School of Civil Engineering and Architecture, zhejiang university of Technology, hangzhou 3.0014, china 2. {3. of Water Resources & Hydroelectric Engineering, Xi'an university of Technology, Xi'an 710048, china 3. Shanxi {3. of Water Resources, Taiyuan 03.001, china) School of Civil Engineering and Architecture Zhejiang University of Technology Hangzhou 310014 China institute of Water Resources and Hydroelectric Engineering Xi'an University of Technology Xi'an 710048 China Shanxi institute of Water Resources Taiyuan 030001 China

The optimal model and simulating model of the Hanjiang cascade reservoirs operation with one day as its calculating period are established to coordinate the contradictions between power generating and shipping. The optimal model is solved by progressive optimality algorithm method adopting the theory of large system decomposing and coordinating. By analyzing the water allocation results obtained from six schemes, which are two cascades, four cascades and seven cascades joint operation considering shipping or not, the contradiction degree between power generating and shipping is investigated and some joint operation schemes are proposed.

关键词： cascade power generating contradiction shipping optimal operation.

In-situ FTIR studies of dimethyl ether adsorption on H-ZSM-5 zeolites

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Chinese Journal of Chemistry 1996年第6期14卷 497-505页

作者： JIANG, Xuan-ZhenDepartment of Chemistry, zhejiang university, hangzhou, zhejiang {3., china Department of Chemistry Zhejiang University Hangzhou Zhejiang 310027 China

In situ infrared spectra of dimethyl ether adsorbed on two H-ZSM-5 zeolites are reported which are different in both lattice and extraframework aluminium contents. A number of dissociatively adsorbed dimethyl ether species associated respectively with the Bronsted acid sites, the external silanol groups and extraframework aluminium species at different temperatures are identified. In particular, dimethyl ether reacts with non acidic hydroxyl species associated with extraframework aluminium to form the third methoxy species. The distributions of hydrocarbons desorbed from a single pulse of dimethyl ether (1.0 mL) onto these zeolite samples are presented. Propene is the major product, and the yield of hydrocarbons correlates with the concentration of Bronsted acid bound methoxy groups.

关键词： In situ FTIR dimethyl ether adsorption extraframework aluminium bound methoxy species hydrocarbon products

Quasi-static Analysis of Thrust-loaded Angular Contact Ball Bearings Part Ⅱ:Results and Discussion

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Chinese Journal of Mechanical Engineering 2012年第1期25卷 81-87页

作者： CHEN Wenhua1,2,MA Zikui1,GAO Liang1,LI Xinglin3.and PAN Jun2 1 institute of Mechanical Design,zhejiang university,hangzhou 3.0027,{3. 2 institute of Mechanical Design and Manufacturing,zhejiang Sci-Tech university,hangzhou 3.0018,{3. 3.State Testing Laboratory of hangzhou Bearing Test & Research Center,hangzhou 3.0022,{3. 1. institute of Mechanical Design Zhejiang University Hangzhou 310027 China 2. institute of Mechanical Design and Manufacturing Zhejiang Sci-Tech University Hangzhou 310018 China 3. State Testing Laboratory of hangzhou Bearing Test & Research Center Hangzhou 310022 China

Ball bearings are widely employed mechanical components characterized by high precision and quality,and usually play important roles in various rotary machines and *** advanced applications require a deep understanding of their various kinematic and tribological characteristics that are essential to predict the fatigue endurance,relieve the vibration and minimize the power dissipation of ball bearings in particular *** angular contact ball bearing under a specified operating condition is simulated with the quasi-static/creepage analytical model proposed in the preceding *** results demonstrate that the ball bearing is a statically determinate *** the balls spin on both inner and outer races means the ball is controlled by neither the inner nor the outer *** friction between the ball and raceway renders the inner and outer contact angles *** larger the coefficient of friction is,the larger the angle *** tangential traction perpendicular to the rolling direction due to the spin induces a gyro-like rotation of the ball with respect to the raceway even if no inertial effects are *** tangential elastic compliance of contacting surfaces gives rise to locked areas within the contact patch and transforms the sliding lines from circles into *** differential slip due to the close conformity of the ball and raceway makes the sliding and traction distributions asymmetric,which will influence the location of the spinning center of the ball with respect to the *** quasi-static/creepage model can be used to reveal the operating behaviors of ball bearings running under steady conditions and to optimize the design of ball bearings for specific applications.

关键词： ball bearing quasi-static creepage differential slip tangential elastic compliance

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A general communication performance evaluation model based on routing path decomposition

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Journal of zhejiang university-Science C(Computers and Electronics) 2011年第7期12卷 561-573页

作者： Ai-lian CHENG 1,Yun PAN 1,2,Xiao-lang YAN 2,Ruo-hong HUAN 3.(1 Department of Information Science and Electronic Engineering,zhejiang university,hangzhou 3.0027,china) (2 {3. of VLSI Design,zhejiang university,hangzhou 3.0027,china) (3.College of Computer Science and Technology,zhejiang university of Technology,hangzhou 3.0023.china) Department of Information Science and Electronic Engineering Zhejiang University institute of VLSI Design Zhejiang University

The network-on-chip (NoC) architecture is a main factor affecting the system performance of complicated multi-processor systems-on-chips (MPSoCs).To evaluate the effects of the NoC architectures on communication efficiency,several kinds of techniques have been developed,including various simulators and analytical *** simulators are accurate but time consuming,especially in large space explorations of diverse network configurations;in contrast,the analytical models are fast and flexible,providing alternative methods for performance *** this paper,we propose a general analytical model to esti-mate the communication performance for arbitrary NoCs with wormhole routing and virtual channel flow *** resolve the inherent dependency of successive links occupied by one packet in wormhole routing,we propose the routing path decomposition approach to generating a series of ordered link *** we use the traditional queuing system to derive the fine-grained transmission latency for each network *** to our experiments,the proposed analytical model provides a good approximation of the average packet latency to the simulation results,and estimates the network throughput precisely under various NoC configurations and ***,the analytical model runs about 10 5 times faster than the cycle-accurate NoC *** applications of the model including bottleneck detection and virtual channel allocation are also presented.

关键词： Analytical model Communication performance Network-on-chip (NoC) Queuing system Routing path decom-position Virtual channel