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Progress in Natural Science:Materials International 2009年第8期19卷 1003-1009页

作者： Haiming Qi , Weidong Yu institute of Electronics, Chinese Academy of Sciences, Beijing 1.01.0, {1. [a]institute of Electronics Chinese Academy of Sciences Beijing 100190 China

In order to improve the performance of block adaptive quantization (BAQ) when the output of the analog to digital converter (ADC) is saturated, this paper proposes an anti-saturation BAQ algorithm. First, the concept of the standard deviation of the output signal (SDOS) of the ADC is proposed. Also, unlike traditional normalization processing, SDOS is used and the mapping between SDOS and the average signal magnitude is deduced. Second, the saturation term is introduced to the Lloyd–Max quantizer and an optimal non-uniform scalar quantizer for saturated SAR raw data quantization is proposed. After this, the implementation scheme for the proposed algorithm using an FPGA is analyzed in detail. Third, the relationships among the saturation degree of the signal, the peak-topeak value of the ADC, standard deviation of the input and output signal of the ADC and the average signal magnitude are deduced. Based on these relationships, a power compensation decoder is designed for encoding. Numerical experiment results based on ERS-1.and the simulated data show that the performance of the proposed algorithm is better than that of BAQ.

关键词： Synthetic aperture radar (SAR) Raw data compression Block adaptive quantization (BAQ) Anti-saturation

Mitigation of lake eutrophication:Loosen nitrogen control and focus on phosphorus abatement

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Progress in Natural Science:Materials International 2009年第10期19卷 1445-1451页

作者： Haijun Wang,Hongzhu Wang institute of Hydrobiology,The Chinese Academy of Sciences,Wuhan {1.0072,china [a]institute of Hydrobiology The Chinese Academy of Sciences Wuhan 430072 China

Traditionally,nitrogen control is generally considered an important component of reducing lake eutrophication and cyanobacteria ***,this viewpoint is refuted recently by researchers in china and North *** the present paper,the traditional viewpoint of nitrogen control is pointed out to lack a scientific basis:the N/P hypothesis is just a subjective assumption;bottle bioassay experiments fail to simulate the natural process of nitrogen *** multi-year comparative research in more than {1. Yangtze lakes indicates that phosphorus is the key factor determining phytoplankton growth regardless of nitrogen concentrations and that total phytoplankton biomass is determined by total phosphorus and not by total nitrogen *** results imply that,in the field,nitrogen control will not decrease phytoplankton *** finding is supported by a long-term whole-lake experiment from North *** outcomes can be generalized in terms that a reduction in nitrogen loading may not decrease the biomass of total phy-toplankton as it can stimulate blooms of nitrogen-fixing *** mitigate eutrophication,it is not nitrogen but phosphorus that should be reduced,unless nitrogen concentrations are too high to induce direct toxic impacts on human beings or other ***,details are provided on how to reduce controls on nitrogen and how to mitigate eutrophication.

关键词： Lake eutrophication Cyanobacteria blooms Lake restoration

Singular analysis of two-dimensional bifurcation system

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Science china(Technological Sciences) 2010年第3期53卷 608-611页

作者： CHEN YuShu& QIN ZhaoHong School of Astronautics,Harbin institute of Technology,Harbin 1.0001.{1. 1. School of Astronautics Harbin Institute of Technology Harbin 150001 China

Bifurcation properties of two-dimensional bifurcation system are studied in this *** unfolding and transition sets of the bifurcation equations are *** whole parametric plane is divided into several different persistent regions according to the type of motion,and the different qualitative bifurcation diagrams in different persistent regions are *** bifurcation properties of the two-dimensional bifurcation system are compared with its reduced one-dimensional *** is found that the system which is reduced to one dimension has lost many bifurcation properties.

关键词： two-dimensional bifurcation system bifurcation singular analysis

Oil and gas potential assessment for coal measure source rocks on absolute concentration of n-alkanes and aromatic hydrocarbons

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Science china Earth Sciences 2009年第S1期52卷 51-58页

作者： ZHAO HongJing1.2,3,ZHANG Min2,3 & WANG ZhiYong4.1.{1. University of Geosciences,Wuhan 4.0074.{1. 2 Geochemical Department of Yangtze University,Jingzhou 4.4.23,{1. 3 The Key Laboratory of Exploration Technologies for Oil and Gas Resources,Ministry of Education,Yangtze University,Jingzhou 4.4.23,{1. 4.Research {4. of Petroleum Exploration and Development,TuHa Oilfield,Hami 839009,{1. 1. china University of Geosciences Wuhan 430074 China 2. Geochemical Department of Yangtze University Jingzhou 434023 China 3. The Key Laboratory of Exploration Technologies for Oil and Gas Resources Ministry of Education Yangtze University Jingzhou 434023 China 4. Research {1. of Petroleum Exploration and Development TuHa Oilfield Hami 839009 China

Absolute concentration of normal alkanes(n-alkanes) and aromatic hydrocarbons in bitumen extracted from source rocks in the period of thermodegradation from Turpan-Hami Basin suggests that aromatic hydrocarbons are dominant in coal and carbargilite while n-alkanes are dominant in mudstones. Bulkrock analysis and gas chromatograph/mass spectrum(GC-MS) of source rocks shows aromatic hydrocarbons are dominant in total ion chromatograms(TIC) of samples with poor perhydrous macerals while n-alkanes are dominant in TICs of samples with abundant perhydrous macerals. The identification of oil-prone and gas prone property based on GC-MS of bitumen "A" together with bulkrock analysis indicates that source rocks from Shengbei area are more oil-prone while source rocks from Qiudong and Xiaocaohu areas are more gas-prone,coinciding with the distribution of oil and gas reservoirs in Taibei Sag. Ratios used to identify oil-prone and gas-prone property for source rocks from Turpan Basin are proposed:n-alkanes >1.0 μg·mg-1.aromatics 1. μg·mg-1.and n-alkanes/aromatics >8 for oil-prone source rock bitumen while n-alkanes2 μg·mg-1.aromatics >4. μg·mg-1.and n-alkanes/aromatics 1.5 for gas-prone source rock bitumen.

关键词： oil-prone gas-prone assessment ratio normal alkanes aromatic hydrocarbons absolute concentration Turpan Basin

FINITE VOLUME METHOD FOR SIMULATION OF VISCOELASTIC FLOW THROUGH A EXPANSION CHANNEL

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Journal of Hydrodynamics 2009年第3期21卷 360-365页

作者： FU Chun-quan JIANG Hai-mei YIN Hong-jun SU Yu-chi ZENG Ye-ming Key Laboratory of Enhanced Oil and Gas Recovery of Ministry of Education Daqing Petroleum Institute Daqing 163318 China china National Offshore Oil Company Research Center Beijing 100027 China china National Offshore Oil Corporation Limited Beijing 100010 China Oil Recovery Plant No.1 Daqing Oilfield Corp. Ltd. Daqing 163001 China

A finite volume method for the numerical solution of viscoelastic flows is given. The flow of a differential Upper-Convected Maxwell （UCM） fluid through an abrupt expansion has been chosen as a prototype example. The conservation and constitutive equations are solved using the Finite Volume Method （FVM） in a staggered grid with an upwind scheme for the viscoelastic stresses and a hybrid scheme for the velocities. An enhanced-in-speed pressure-correction algorithm is used and a method for handling the source term in the momentum equations is employed. Improved accuracy is achieved by a special discretization of the boundary conditions. Stable solutions are obtained for higher Weissenberg number （We）, further extending the range of simulations with the FVM. Numerical results show the viscoelasticity of polymer solutions is the main factor influencing the sweeo efficiency.

关键词： Upper-Convected Maxwell (UCM) model finite volume method viscoelasticity sweep efficiency

FORMATION AND INFLUENCING FACTORS OF FREE SURFACE VORTEX IN A BARREL WITH A CENTRAL ORIFICE AT BOTTOM

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Journal of Hydrodynamics 2009年第2期21卷 238-244页

作者： LI Hai-feng CHEN Hong-xun MA Zheng ZHOU Yi Shanghai institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China china Ship Scientific Research Center Wuxi 214082 China

Based on the Navier-Stokes equations with considering the effect of the Coriolis force, the finite volume method was employed to discretize the governing equations, the SIMPLE method was adopted to solve the discretized equations, and the flow field in a barrel with an outlet at the center of the bottom was simulated. The numerical results agree well with the experimental data. From the Lagrangian, the relations among the acceleration, the Coriolis force and the viscosity force were analyzed. The results show that the Coriolis force is the major factor that causes the formation of the vortex. The flow fields in the flume under different incoming flow conditions were numerically simulated using the software Fluent. The numerical simulations show good agreement with the experiments for the shape and position of the vortex.

关键词： free surface vortex Coriolis force numerical simulation

Discussion about mechanism of harmful algal blooms breakout

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Acta Oceanologica Sinica 2005年第1期24卷 101-106页

作者： BUXianwei XUWeiyi ZHUDedi CHENGengxin KeyLaboratoryofOceanDynamicProcessesandSatelliteOceanographyofStateOceanicadministration Hangzhou310012China／／SecondInstituteofOceanographyStateOceanicAdministrationHangzhou310012China

HAB (harmful algal bloom) is a serious marine ecological disaster. Up to now there is no definite conclusion about its mechanism of *** observation results show that the HAB breakout in the Xiangshan Bay was mainly caused by physical convergence ca-pacity,and the breakout process had no direct relation to *** a new idea it is thought that the process of the HAB breakout is mainly a physical convergence or accumulation process in some areas. A hypothesis about dynamic mechanism of the HAB appearing in the area off the Changjiang Estuary is put forward according to hydrology and topography and the past work, and a breakthrough is expected to be made for doing further research.

关键词： HABs plume iront upwelling convergence eutrophication

ON SOME CONSTANTS OF QUASICONFORMAL DEFORMATION AND ZYGMUND CLASS

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Chinese Annals of Mathematics,Series B 1995年第3期16卷 325-330页

作者： CHEN JIXIU WEI HANBAI(institute of Mathematics, Fudan University, Shanghai 200{1.3, china.) FUDAN UNIV INST MATHSHANGHAI 200433PEOPLES R CHINA

A real-valued function f(x)on belongs to Zygmund class if its Zygmund norm It is proved that when f ∈, there exists an extension F(z)of f to H = {Imz > 0} such that It is also proved that if f(0)=f(1.= 0,then

关键词： Quasiconformal deformation Zygmund class Beurling-Ahlfors extension.

Vocational Teaching Cube System of Engineering Graphics

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CADDM 2003年第Z1期 61-65页

作者： Yang Daofu 1.Liu Shenli2 1.ellow River Conservancy Technical institute, Kaifeng {1.5001. china 2Zhengzhou institute of Light Industry, Zhengzhou {1.0002, china

Based on long-time research on vocational teaching cube theory in graphics education and analyzing on the intellectual structure in the process of reading engineering drawing, the graphics intellectual three-dimensional model, which is made up of 1.0 cubes, is founded and tested in higher vocational graphics education. This system serves as a good guidance to the graphics teaching.

关键词： vocational education graphics intelligence 1.0 cubes theoretical model teaching system

Experimental Study of the Differentiation of Mesenchymal stem Cells ( MSCs) after Indirect Co-culture with Ligament Fibroblasts

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生物医学工程学杂志 2005年第S1期22卷 143-144页

作者： Lei ZHANG~(1.2) Xiong WANG~(2△) Huai-Qing CHEN~1.(institute of Biomedical Engineering, West {1. Medical Center, Sichuan University, Chengdu 61.04.,{1.)2(Equipe Mécanique et Ingénierie Cellulaire et Tissulaire, Institut National Polytechnique de Lorraine, 54.00 Vandoeuvre-lès-Nancy, France) institute of Biomedical Engineering West China Medical Center Sichuan University Chengdu 610041 China Equipe Mecanique et Ingénierie Cellulaire et Tissulaire Institut National Polytechnique de Lorraine 54500 Vandoeuvre-lès-Nancy France Equipe Mecanique et Ingénierie Cellulaire et Tissulaire Institut National Polytechnique de Lorraine 54500 Vandoeuvre-lès-Nancy France institute of Biomedical Engineering West China Medical Center Sichuan University Chengdu 610041 China

1.IntroductionToday tissue engineering is known to be a new technique which, based on biological and physical manipulations on cells, aims at the regeneration and reconstruction of tissues or organs in vitro. To construct active ligament tissue by this technique, the following three key points should be considered: choice of cells, scaffold, and the mechanical conditions in vitro. But the studies on ligament cell biology are still in an early stage[1..

关键词： MSCs In after Indirect Co-culture with Ligament Fibroblasts Experimental Study of the Differentiation of Mesenchymal stem Cells stem