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A 2-D HYDRODYNAMIC MODEL FOR THE RIVER,LAKE AND NETWORK SYSTEM IN THE JINGJIANG REACH ON THE UNSTRUCTURED QUADRANGLES

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Journal of Hydrodynamics 2010年第3期22卷 419-429页

作者： ZHANG Xi-bing HU De-chao WANG Min State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan430072 China yangtze River Scientific Research institute Wuhan 430010 China State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China

The main river, the Dongting Lake and river networks in the Jingjiang reach of the yangtze River constitute a complex water system, for which a full 2-D hydrodynamic model is established instead of the traditional 1-D or compound models for simulation of such complex systems, based on the latest developments of computer technologies and numerical methods. To better handle irregular boundaries and keep the computation cost well in a reasonable limit, unstructured grids of moderate scale are used. In addition, a dynamic boundary tracking method is proposed to simulate variable flow domains at different floods, especially, when the moderate scale gird can not describe flows in narrow river-network channels at low water levels. The t9 semi-implicit method and the Eulerian-Lagrangian Method （ELM） are adopted, which make the model unconditionally stable with respect to the gravity wave speed and Courant number restrictions. Properties and efficiency of the model are discussed, and it is concluded that the new model is robust and efficient enough for the simulation of a big, complex water system. Validation tests show that the simulation results agree well with field data. It takes about 0.96 h to complete the computation of a 76 d flood, which indicates that the model is efficient enough for engineering applications.

关键词： 2-D numerical model river network unstructured grid semi-implicit Eulerian-Lagrangian Method (ELM) boundarytracking

Detect early stage lung cancer by a LAMP microfluidic chip system with a real-time fluorescent filter processor

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Science china Chemistry 2012年第4期55卷 508-514页

作者： WANG TongZhou1, ZHANG Ye1, HUANG GuoLiang1,2,3, WANG Can2, XIE Lan1, MA Li2, LI ZhiYong2, LUO XianBo2, TIAN Hao2, LI Qiang1, LI Xin1, LV ZhouYan1 & BAO XiaoFan11Department of Biomedical Engineering, School of Medicine, tsinghua university, Beijing 100084, china 2National Engineering Research Center for Beijing Biochip Technology, Beijing 102206, china 3yangtze delta region institute of tsinghua university, Hangzhou 330401, china Department of Biomedical Engineering School of Medicine Tsinghua University Beijing China National Engineering Research Center for Beijing Biochip Technology Beijing China yangtze delta region institute of tsinghua university Hangzhou China

This work presents a promising clinical molecular diagnostics for early stage lung cancer. This novel diagnostic method utilized the loopmediated isothermal amplification （LAMP）, micro fluidic chips and a confocal optical detector with a nonlinear fluorescent filter processor. An isothermal amplification based microfluidic chip for the early diagnostics of lung cancer was developed and a confocal optical detector was improved by a novel real-time fluorescent filter to sensitively monitor the DNA amplification procedure with high signal to noise ratio and fluorescence collecting ability. Experiment showed that a rapid diagnostic of lung cancer by detecting the existence of the CEA mRNA could be performed in only 5 laL of reaction assay in less than 45 min. While the traditional intube RTPCR set consumed more than 25 -μL of the assay and took more than 90 rain.

关键词： microfluidic chip – isothermal amplification – lung cancer – confocal detection – non linear filter

Study on the two and three-parameter working stability regions of 3Y-TZP suspension

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Science china(Technological Sciences) 2006年第5期49卷 547-568页

作者： CHEN Youqiang1, 2, ZHANG Xinni3, CHEN Sha’ou3 & QI Ping3 1. Department of Chemistry, Qingdao university, Qingdao 266071, china 2. Department of Chemistry, tsinghua university, Beijing 100084, china 3. Department of Physics, Qingdao university, Qingdao 266071, china Department of Physics Qingdao University

We determined the variation tendency of viscosity (η) at various solids load- ing (α) for 3Y-TZP suspension as a function of dispersant concentration (Cw) using vis- cosity measurement, measured the diameter of particles as a function of Cw in very dilute suspension using light scattering method, and obtained the surface features of the sedi- ment of suspension with different Cw using SEM. We also discussed the influence of the microstructure of adsorbed polymer layers on particles and their interactions in the dis- persing medium on the stability of suspension. Then two different stable states and two different unstable states for 3Y-TZP suspension were given. Accordingly, the (Cw, η), (Cw, α), and (α, η) two-parameter, and (Cw, α, η) three-parameter stability maps were con- structed. Based on the DLVO theory calculations, the dispersant concentration, particle distance (r), and interparticle potential energy (VT) maps with various solids loading for 3Y-TZP aqueous suspension were also constructed. In (Cw, r) two-parameter coordinate system, the stable motion region map for particles was established. The Cw, α, and VT,max (the highest potential energy) surface of the potential barrier map was obtained through calculation and simulation on the basis of the surfaces of Cw, r, VT maps introduced above. The (Cw, α) two-parameter stability map was then obtained from the Cw, α, VT,max map. The results showed that this theoretical map can qualitatively prove the experimentally obtained results—the existence of different dispersed states of particles in suspension system and the variation tendency of suspension stability with changing each parame- ter—were reasonable.

关键词： 3Y-TZP, suspension, stability, DLVO theory, interparticle potential energy.

A SEMI-IMPLICIT 3-D NUMERICAL MODEL USING SIGAM-COORDINATE FOR NON-HYDROSTATIC PRESSURE FREE-SURFACE FLOWS

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Journal of Hydrodynamics 2011年第2期23卷 212-223页

作者： HU De-chao FAN Bei-lin WANG Guang-qian ZHANG Hong-wu State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China yangtze River Scientific Research institute Wuhan 430010 China

A 3-D numerical formulation is proposed on the horizontal Cartesian, vertical sigma-coordinate grid for modeling non-hydrostatic pressure flee-surface flows. The pressure decomposition technique and 0 semi-implicit method are used, with the solution procedure being split into two steps. First, with the implicit parts of non-hydrostatic pressures excluded, the provisional velocity field and free surface are obtained by solving a 2-D Poisson equation. Second, the theory of the differential operator is employed to derive the 3-D Poisson equation for non-hydrostatic pressures, which is solved to obtain the non-hydrostatic pressures and to update the provisional velocity field. When the non-orthogonal sigma-coordinate transformation is introduced, additional terms come into being, resulting in a 15-diagonal, diagonally dominant but unsymmetric linear system in the 3-D Poisson equation for non-hydrostatic pressures. The Biconjugate Gradient Stabilized （BiCGstab） method is used to solve the resulting 3-D unsymmetric linear system instead of the conjugate gradient method, which can only be used for symmetric, positive-definite linear systems. Three test cases are used for validations. The successful simulations of the small-amplitude wave, a supercritical flow over a ramp and a turbulent flow in the open channel indicate that the new model can simulate well non-hydrostatic flows, supercritical flows and turbulent flows.

关键词： 3-D numerical model non-hydrostatic sigma-coordinate semi-implicit pressure-splitting

人乳头瘤病毒疫苗应用真实世界研究长三角地区专家建议

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中华预防医学杂志 2024年第5期58卷 577-587页

作者：长三角宫颈癌及女性下生殖道感染防控联盟长三角免疫规划一体化项目组王新宇陈直平不详浙江大学医学院附属第一医院杭州310003 浙江省疾病预防控制中心杭州310051

子宫颈癌已成为严重威胁女性健康的全球公共卫生问题,接种人乳头瘤病毒(HPV)疫苗是预防子宫颈癌的重要一级预防措施。随着中国HPV疫苗应用的加快,开展HPV疫苗应用的真实世界研究(RWS)能够指导疫苗的合理应用,对于中国加速消除子宫颈癌... 详细信息

子宫颈癌已成为严重威胁女性健康的全球公共卫生问题,接种人乳头瘤病毒(HPV)疫苗是预防子宫颈癌的重要一级预防措施。随着中国HPV疫苗应用的加快,开展HPV疫苗应用的真实世界研究(RWS)能够指导疫苗的合理应用,对于中国加速消除子宫颈癌的策略和实践具有重要的意义。长三角宫颈癌及女性下生殖道感染防控联盟和长三角免疫规划一体化项目组组织专家制定了《人乳头瘤病毒疫苗应用真实世界研究长三角地区专家建议》。本文基于中国医疗信息化和HPV疫苗接种现况,结合国内外研究的文献和案例,阐述了HPV疫苗接种和评价的数据链,介绍了RWS的研究设计、研究方向、数据库建设、数据治理和统计分析,对开展HPV疫苗RWS实践中的问题提出了专家建议,旨在指导HPV疫苗应用的RWS,促进中国真实世界证据的产生。

关键词：人乳头瘤病毒疫苗真实世界研究专家建议长三角地区

Coacervate Structures of CdI_2 Thin Film Grown during Phase Transformation

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Journal of Materials Science & Technology 1997年第4期13卷 296-298页

作者： Xiaoyan YE and Lili CAO(Dept. of Chemistry, tsinghua university, Beijing 100084, china)Jizhong ZHANG and Hengde LI(Dept. of Materials Scieuce & Engineering, tsinghua university, Beijing 100084, china) Dept. of Chemistry Tsinghua University Beijing 100084 China Dept. of Materials Science and Engineering Tsinghua University Beijing 100084 China

The microstructure of CdI2 thin film grown during vapor-phase deposition was investigated by scanning electron microscopy (SEM). The thin film deposited on Si crystal consists of numerous sunflower-like aggregates. These aggregates display well self-assembly characteristics. The size of Sunflower-like aggregates is between 12 and 44 μm. Each sunflower-like aggregate is surrounded with many adjacent wings-'petals'. The structure of central region of the 'sunflower' is obviously difFerent from that of the 'petal'. Electron spectroscopy for chemical analysis (ESCA) was employed in determining the chemical valence of the thin film. Self-organization efFect is used to explain the coring growth process of CdI2 thin film

关键词： Thin Coacervate Structures of CdI2 Thin Film Grown during Phase Transformation

Soil erosion and sediment transport in the gullied Loess Plateau:Scale effects and their mechanisms

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Science china(Technological Sciences) 2009年第5期52卷 1283-1292页

作者： LI TieJian1,WANG GuangQian1,XUE Hai2,3 & WANG Kai4 1 State Key Laboratory of Hydroscience and Engineering,tsinghua university,Beijing 100084,china 2 Yellow River Engineering Consulting Co.,Ltd.,Zhengzhou 450003,china 3 North china institute of Water Conservancy and Hydropower,Zhengzhou 450008,china 4 china institute of Water Resources and Hydropower Research,Beijing 100038,china State Key Laboratory of Hydroscience and Engineering Tsinghua University china institute of Water Resources and Hydropower Research

Scale effects exist in the whole process of rainfall-3-runoff-3-soil erosion-3-sediment transport in river basins. The differences of hydrographs and sediment graphs in different positions in a river basin are treated as basic scale effects, which are more complex in the gullied Loess Plateau, a region notorious for high intensity soil erosion and hyper-concentrated sediment-laden flow. The up-scaling method of direct extrapolation that maintains dynamical mechanism effective in large scale application was chosen as the methodology of this paper. Firstly, scale effects of hydrographs and sediment graphs were analyzed by using field data, and key sub-processes and their mechanisms contributing to scale effects were clearly defined. Then, the Digital Yellow River Model that integrates sub-models for the subprocesses was used with high resolution to simulate rainfall-3-runoff-3-soil erosion-3-sediment transport response in Chabagou watershed, and the distributed results representing scale effects were obtained. Finally, analysis on the simulation results was carried out. It was shown that gravitational erosion and hyper-concentrated flow contribute most to the spatial variation of hydrographs and sediment graphs in the spatial scale. Different spatial scale distributions and superposition of different sub-processes are the mechanisms of scale effects.

关键词： scale effect soil erosion hyper-concentrated sediment-laden flow the Loess Plateau

Effect of streambed sediment on benthic ecology

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International Journal of Sediment Research 2009年第3期24卷 325-338页

作者： Xuehua DUAN1, Zhao-Yin WANG2, Mengzhen XU3, and Kang ZHANG41 Ph.D., Jiangyin Environmental Monitoring Station, Jiangyin 214431, china, Dept. of Hydraulic Engineering, tsinghua university,2 Prof., State Key Laboratory of Hydroscience and Engineering, tsinghua university, Beijing 100084, china, 3 Doctoral candidate, State Key Laboratory of Hydroscience and Engineering, tsinghua university, Beijing 100084, china,4 Doctoral candidate, State Key Laboratory of Hydroscience and Engineering, tsinghua university, Beijing 100084, china Ph.D. Jiangyin Environmental Monitoring Station Jiangyin 214431 China Dept. of Hydraulic Engineering Tsinghua University Prof. State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China Tel: 86-10-62773448(O) Doctoral candidate State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China

Benthic macroinvertebrates have been commonly used as indicator species for assessment of aquatic ecology. Streambed sediment, or substrate, plays an important role in habitat conditions for macroinvertebrate communities. Field investigations were done to study the benthic diversity and macroinvertebrate compositions in various stream substrata. Sampling sites with different bed sediment, latitude, and climate were selected along the yangtze River, the Yellow River, the East River, and the Juma River, in china. The results show that benthic community structures found in different substrata clearly differ, while those found in substrata of similar composition and flow conditions but in different macroclimates are similar. The study, thus, demonstrates that the benthic macroinvertebrate community is mainly affected by substrate composition and flow conditions, but is generally unaffected by latitudinal position and macroclimate. Taxa richness of the macroinvertebrate community was found to be the highest on hydrophyte-covered cobbles, high on moss-covered bedrock, and low on clay beds and cobble beds devoid of plant biomass. Sandy beds are compact and unstable, thus, no benthic macroinvertebrates were found colonizing such substrata. Aquatic insects account for most of the macroinvertebrates collected in these rivers. Different insects dominate in different types of substrata: mainly EPT species (Ephemeroptera, Plecoptera, Trichoptera) in cobble, gravel, and moss-covered bedrock; and Chironomidae larvae in clay beds. The relation between the number of species in the samples and the size of the sampling area fits a power function of the species area. One square meter (1m2) is suggested as the minimum sampling area. A substrate suitability index is proposed by integrating the suitability of sediment, periphyton, and benthic organic materials for macroinvertebrates. The biodiversity of macroinvertebrates increases linearly with the substrate suitability index. Benthic ta

关键词： Streambed sediment Macroinvertebrates Benthic ecology Substrate suitability Biodiversity

Critical slope gradient for compulsory abandonment of farmland on the hilly Loess Plateau

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Chinese Science Bulletin 1998年第5期43卷 409-412页

作者： TANG Keli+1, ZHANG Keli 1,2 and LEI Aling 1,3 1. institute of Soil and Water Conservation, Chinese Academy of Sciences, Yangling 712100, china 2. Department of Hydraulic Engineering, tsinghua university, Beijing 100084, china 3. Water Resources C institute of Soil and Water Conservation Chinese Academy of Sciences Yangling China Department of Hydraulic Engineering Tsinghua University Beijing China Water Resources Conservation Bureau of yangtze River Ministry of Water Resources Wuhan China

Scientific evidence for the upper limit of farmland is proposed. Shallow gully erosion is one of erosion types distributed extensively on sloping farmland in the hilly regions of the Loess Plateau. Field observation and aerial photos interpretation, as well as laboratory experiments show that the shallow gully erosion occurring on the steeper farmland in the hilly regions of the Loess Plateau is an important factor leading to intensive erosion on slope, because of its extensive distribution and intensive runoff collection. The data on the formation, development and distribution of shallow gullies on sloping farmland indicate that critical slope gradient for shallow gully initiation ranges from 15 to 20 degrees with an average of 18.2 degrees. Therefore, it is suggested that critical slope gradient for compulsory abandonment of farmland on the hilly Loess Plateau should be kept within the critical slope gradient for shallow gully initiation to prevent shallow gully formation in order to control soil loss more effectively. But as the first step, the cultivation on the slopes with slope larger than 25 degrees where the maximum erosion occurs should be strictly forbidden.

关键词： hilly region of Loess Plateau upper limitation for farmland shallow gully erosion erosion dynamic.