检索结果-南通市图书馆

OBSERVATION AND ANALYSIS ON CHARACTERISTIC OF NATURAL riverS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2005年第5期17卷 615-620页

作者： LU Jin-you XU Hai-tao YAO Shi-ming yangtze river Scientific research institute Wuhan 430010 China

Based on the previous study on turbulent structure, field experiments on fluctuation velocity were carried out in section Huanglingmiao of main stream of yangtze river with a 3-D Doppler velocimeter. And a number of data such as velocity of different discharge and different vertical line were obtained. According to the field experiment data, period, frequency, period function and probability density function of large-scale coherent structure in natural river were prescribed by means of quantitative analysis. And the problem about distribution of time average velocity, turbulent intensity and Reynolds stress along depth were further analyzed and calculated. The results in this paper will deepen the understand of large-scale turbulent structure in natural river and so make the base for applying“turbulence theory” to water conservancy, hydroelectric, environment engineering and so on.

关键词： natural river large scale turbulence turbulent mechanism

Conservation genomics provides insights into genetic resilience and adaptation of the endangered Chinese hazelnut, Corylus chinensis

在线全文

学校读者我要写书评

暂无评论

Plant Diversity 2024年第3期46卷 294-308页

作者： Zhen Yang Lisong Liang Weibo Xiang Lujun Wang Qinghua Ma Zhaoshan Wang Key Laboratory of Tree Breeding and Cultivation National Forestry and Grassland AdministrationResearch Institute of ForestryChinese Academy of ForestryBeijing 100091China National Engineering research Center of Eco-Environment Protection for yangtze river Economic Belt China Three Gorges CorporationBeijing 100083China rare plants research institute of yangtze river China Three Gorges CorporationYichang 443133China research institute of Economic Forest Cultivation and Processing Anhui Academy of ForestryHefei 230031China

Global climate change has increased concerns regarding biodiversity ***,many key conservation issues still required further research,including demographic history,deleterious mutation load,adaptive evolution,and putative *** we generated the first chromosome-level genome of the endangered Chinese hazelnut,Corylus chinensis,and compared the genomic signatures with its sympatric widespread ***-C yunnanensis *** found large genome rearrangements across all Corylus species and identified species-specific expanded gene families that may be involved in *** genomics revealed that both *** and the *** complex had diverged into two genetic lineages,forming a consistent pattern of southwestern-northern *** size of the narrow southwestern lineages of both species have decreased continuously since the late Miocene,whereas the widespread northern lineages have remained stable(***) or have even recovered from population bottlenecks(*** complex) during the *** with ***-C. yunnanensis complex,*** showed significantly lower genomic diversity and higher inbreeding ***,*** carried significantly fewer deleterious mutations than ***-C. yunnanensis complex,as more effective purging selection reduced the accumulation of homozygous *** also detected signals of positive selection and adaptive introgression in different lineages,which facilitated the accumulation of favorable variants and formation of local ***,both types of selection and exogenous introgression could have mitigated inbreeding and facilitated survival and persistence of ***,our study provides critical insights into lineage differentiation,local adaptation,and the potential for future recovery of endangered trees.

关键词： Conservation genomics Demographic history Inbreeding Genetic load Runs of homozygosity Local adaptation

2－D　SIMULATION　OF　OPEN　CHANNEL　TURBULENT　FLOW　WITH　HIGH　REYNOLDS　NUMBER　BY　EMPLOYING　N－S　EQUATIONS　AND　IEM

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 1996年第1期8卷 44-51页

作者： Wang Ding-yang Liu He-dong(yangtze river Scientific research institute, Wuhan 430010, P. R. China) yangtze river Scientific research Inst Wuhan China

Since 1986, we have been studying the topic of simulating open channel turbulent flow, especially the back flow in extended section, by directly employing N-S equations. Now a breakthrough may be obtained. The simulat... 详细信息

关键词： turbulent flow open channel flow N-S equation.

EXPERIMENTAL STUDIES ON FREQUENCY CHARACTERISTICS OF THE FLUCTUATING PRESSURE ACTING ON THE APRON OF STILLING BASINS WITH LOW FROUDE NUMBER

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 1992年第4期4卷 21-26页

作者： Ding Zhuo-yi yangtze river Scientific research institute,Wuhan Hubei 430010,P.R.China yangtze river Scientific research Inst Wuhan China

Using four types of stilling basin models,this paper studies frequency characteris- tics of the fluctuating pressure acting on the stilling basin apron when Froude number is not greater than *** testing results show that the frequency of fluctuating pressure,f_s in the ranges of 0. 4Hz≤f_s≤1.1Hz.0.2Hz≤f_s≤2.5Hz and 0.4Hz≤f_s≤*** be used as the design frequency corresponding to three patterns of hydraulic *** reliability of f_s for three jump patterns is all nearly equal to 90%.

关键词： frequency characteristics fluctuating pressure stilling basin apron

在线全文

学校读者我要写书评

暂无评论

Contact theory

Science China(Technological Sciences) 2015年第9期58卷 1450-1496页

作者： SHI GenHua College of Engineering & Information Technology University of Chinese Academy of Sciences China Renewable Energy Engineering institute yangtze river Scientific research institute

Contacts between two general blocks are the fundamental problem for discontinuous analysis. There are different contact points in different block positions, and there may have infinite contact point pairs in the same block position. In this paper, a new concept of an entrance block for solving the contacts between two general blocks is introduced. The boundary of an entrance block is a contact cover system. Contact covers may consist of contact vectors, edges, angles or polygons. Each contact cover defines a contact point and all closed-contact points define the movements, rotations and deformations of all blocks as in real cases. Given a reference point, the concept of entrance block simplifies the contact computation in the following ways.(1) The shortest distance between two blocks can be computed by the shortest distance between the reference point and the surface of the entrance block.(2) As the reference point outside the entrance block moves onto the surface of entrance block, the first entrance takes place. This first entrance point on the entrance block surface defines the contact points and related contact locations.(3) If the reference point is already inside the entrance block, it will exit the entrance block along the shortest path. The corresponding shortest exit point on the entrance block surface defines the contact points and related contact locations. All blocks and angles here are defined by inequality equations. Algebraic operations on blocks and angles are described here. Since the blocks and angles are point sets with infinite points, the geometric computations are difficult, and therefore the geometric computations are performed by related algebraic operations.

关键词： contact finite cover system point set discontinuous computation block

EXPERIMENTAL STUDY OF SCOUR RATE IN CONSOLIDATED COHESIVE SEDIMENT

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2010年第1期22卷 51-57页

作者： TAN Guang-ming JIANG Lei SHU Cai-wen LV Ping WANG Jun State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China Anhui Bureau of yangtze river Management Wuhu 241000 China yangtze river Scientific research institute Wuhan 430010 China

The erosion process of a cohesive sediment after consolidation was studied experimentally in a closed conduit system. The test samples investigated in this study are mixtures of sand and clay with variable compositions and different consolidation times. The main concern of this study is the effects of the dry density of the consolidated sediment on scour rate. A scour rate formula is derived and further interpreted based on the experimental results.

关键词： cohesive sediment consolidation dry density scour rate scour rate formula

Single-cell omics: experimental workflow, data analyses and applications

在线全文

学校读者我要写书评

暂无评论

Science China Life Sciences 2025年第1期68卷 5-102页

作者： Fengying Sun Haoyan Li Dongqing Sun Shaliu Fu Lei Gu Xin Shao Qinqin Wang Xin Dong Bin Duan Feiyang Xing Jun Wu Minmin Xiao Fangqing Zhao Jing-Dong J.Han Qi Liu Xiaohui Fan Chen Li Chenfei Wang Tieliu Shi Department of Clinical Laboratory the Affiliated Wuhu Hospital of East China Normal University (The Second People's Hospital of Wuhu City) Pharmaceutical Informatics institute College of Pharmaceutical SciencesZhejiang University Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration (Tongji University) Ministry of EducationOrthopaedic DepartmentTongji HospitalBioinformatics DepartmentSchool of Life Sciences and TechnologyTongji University Frontier Science Center for Stem Cells School of Life Sciences and TechnologyTongji University Translational Medical Center for Stem Cell Therapy and institute for Regenerative Medicine Shanghai East HospitalBioinformatics DepartmentSchool of Life Sciences and TechnologyTongji University research institute of Intelligent Computing Zhejiang Lab Shanghai research institute for Intelligent Autonomous Systems Center for Single-cell Omics School of Public HealthShanghai Jiao Tong University School of Medicine National Key Laboratory of Chinese Medicine Modernization Innovation Center of Yangtze River DeltaZhejiang University Center for Bioinformatics and Computational Biology Shanghai Key Laboratory of Regulatory Biologythe Institute of Biomedical Sciences and School of Life SciencesEast China Normal University Beijing institutes of Life Science Chinese Academy of Sciences Peking-Tsinghua Center for Life Sciences Academy for Advanced Interdisciplinary StudiesCenter for Quantitative Biology (CQB)Peking University Zhejiang Key Laboratory of Precision Diagnosis and Therapy for Major Gynecological Diseases Women's HospitalZhejiang University School of Medicine Key Laboratory of Advanced Theory and Application in Statistics and Data Science-MOE School of StatisticsEast China Normal University

Cells are the fundamental units of biological systems and exhibit unique development trajectories and molecular features. Our exploration of how the genomes orchestrate the formation and maintenance of each cell, and control the cellular phenotypes of various organismsis, is both captivating and intricate. Since the inception of the first single-cell RNA technology, technologies related to single-cell sequencing have experienced rapid advancements in recent years. These technologies have expanded horizontally to include single-cell genome, epigenome,proteome, and metabolome, while vertically, they have progressed to integrate multiple omics data and incorporate additional information such as spatial sc RNA-seq and CRISPR screening. Single-cell omics represent a groundbreaking advancement in the biomedical field,offering profound insights into the understanding of complex diseases, including cancers. Here, we comprehensively summarize recent advances in single-cell omics technologies, with a specific focus on the methodology section. This overview aims to guide researchers in selecting appropriate methods for single-cell sequencing and related data analysis.

关键词： single-cell sequencing genome epigenome proteomics metabolomics multimodal spatial transcriptomics CRISPR screening

The loss of genetic diversity during captive breeding of the endangered sculpin, Trachidermus fasciatus, based on ISSR markers: implications for its conservation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Oceanology and Limnology 2011年第5期29卷 958-966页

作者：毕潇潇杨巧莉高天翔李创举 Fisheries College Ocean University of China yangtze river Fisheries research institute Chinese Academy of Fishery Sciences

Abstract Inter-simple sequence repeat （ISSR） markers were used to determine the genetic variation and genetic differentiation of cultured and wild populations of Trachidermus fasciatus, an endangered catadromous fish species in China. Six selected primers were used to amplify DNA samples from 85 individuals, and 353 loci were detected. Relatively low genetic diversity was detected in the cultured population （the percentage of polymorphic loci PPL=73.80%, Nei＇s gene diversity h--0.178 2, Shannon information index I=0.276 9）. However, the genetic diversity at the species level was relatively high （PPL-91.78%; h = 0.258 3, I= 0.398 6）. The UPGMA tree grouped together the genotypes almost according to their cultured and wild origin, showing distinct differences in genetic structure between wild and cultured populations. The pairwise F^t values confirmed significant genetic differentiation between wild and cultured samples. The cultivated population seems to be low in genetic diversity as a result of detrimental genetic effects in the captive population. The results suggest that ISSR markers are effective for rapid assessment of the degree of diversity of a population, thus giving important topical information relevant to preserving endangered species.

关键词： inter-simple sequence repeat (ISSR) Trachidermusfasciatus conservation genetic diversity genetic differentiation

Longitudinal variations of hydraulic characteristics of overland flow with different roughness

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2014年第1期26卷 66-74页

作者：王协康闫旭峰周苏芬黄尔刘兴年 State Key Laboratory of Hydraulics and Mountain river Engineering Sichuan University yangtze river Scientific research institute Department of Civil and Structural Engineering The Hong Kong Polytechnic University

The evolution of the overland flow velocity along the distance downslope on smooth and granular beds in different cases is investigated by means of the electrolyte tracer via flume experiments. The results demonstrate that a non-uniform flow regime and a uniform flow regime exist in the development process of the overland flow. Owing to the different attributes of beds＇ roughness, the position of those zones with different flow regimes varies correspondingly：（1） the overland flow on granular beds enters into the uniform regime much sooner, additionally, the roll waves tend to appear because of the presence of the proper flow resistance impa-rted by the roughness （coarse sands）, and large slopes （20o and 25o） which makes the flow velocities and depths to undulate spatially. Furthermore, the flow resistance of the overland flows with different roughness elements, that is the non-sands, the fine sands and the coarse sands, is calculated. A quadratic interpolation method of the third order accuracy is employed in the calculation of the longitu-dinal flow resistance. The results show that it is rational to use the bed slope to approximate the hydraulic energy slope over a rela-tive small roughness （the present roughness）, however on the other hand, if the mean flow velocities and depths rather than the local parameters are used to calculate the flow resistance, a considerable error will be induced within the non-uniform regime of the over-land flows, including the acceleration zone and the roll-wave zone.

关键词： overland flow longitudinal hydraulic characteristics flow resistance quadratic interpolation