检索结果-南通市图书馆

Spatial and temporal variation of fish assemblages in a subtropical small stream of the Huangshan Mountain

Current Zoology 2010年第6期56卷 670-677页

作者： Yunzhi YAN Shan HE ling CHU Xiuying XIANG Yanju jia Juan TAO College of Life Sciences Anhui Normal University Provincial Key Laboratory of Biotic Environment and Ecological Safety in Anhui Wuhu 241000 Anhui China College of Biological Science and Engineering Hebei University of Economics and Business Shijiazhuang 050061 China Institute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China

Spatial and temporal variation of fish assemblages were investigated seasonally from May 2007 to February 2008 across 11 study sites in a subtropical small stream, the Puxi Stream, of the Huangshan Mountain. Along the longitudinal gradient from headwater to downstream, fish species richness and abundance increased gradually, but then decreased significantly at the lower reaches. The highest species richness and abundance were observed in August and the lowest in February. Based on analysis of similarities （ANOSIM）, fish assemblages were significantly different in spatial variation but not in temporal variation. Although differences were observed both among sites and among stream orders, the lower R value in order-variation suggested stream order was not the optimal factor explaining the spatial variation of fish assemblages. In addition, dam construction did not significantly alter fish assemblages in the sites adjacent to and immediately downstream to dams. Using cluster analysis and non-metric Multi Dimensional Scaling analysis （NMS）, assemblages were separated into three groups at a Bray-Curtis similarity value of 42%： the upper, middle and lower groups. Following analysis of similarity percentages of species contributions （SIM- PER）, shifts in occurrence or abundance of S. curriculus, Z. platypus, R. bitterling and A. fasciatus contributed most to the differences amongst the three groups. Standard Deviation Redundancy Analysis （RDA） suggested that habitat structure （such as elevation, substrate, and flow velocity） contributed to the spatial and temporal pattem of fish assemblages in the Puxi Stream. In conclusion, the fish assemblages in Puxi Stream presented significant spatial but not temporal variation. Human disturbance has perhaps induced the decrease in species diversity in the lower reaches. However, no significant change was observed for fish assemblages in sites far from and immediately downstream from low-head dams [Current Zoology 56 （6）： 670-677, 201

关键词： Assemblage structure Low-head dam Stream fish Spatial-temporal pattem

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Simulative technology for auxiliary fuel tank separation in a wind tunnel

引用

Chinese Journal of Aeronautics 2016年第3期29卷 608-616页

作者： Ma Xin Liu Wei Chen ling Li Xiao jia Zhenyuan Shang Zhiliang Key Laboratory for Precision and Non-traditional Machining Technology of the Ministry of Education Dalian University of Technology

In this paper, we propose a simulative experimental system in wind tunnel conditions lbr the separation of auxiliary fuel tanks from an aircraft. The experimental system consists of a simulative release mechanism, a scaled model and a pose measuring system. A new release mechanism was designed to ensure stability of the separation. Scaled models of the auxiliary fuel tank were designed and their moment of inertia was adjusted by installing counterweights inside the model. Pose param- eters of the scaled model were measured and calculated by a binocular vision system. Additionally, in order to achieve high brightness and high signal-to-noise ratio of the images in the dark enclosed wind tunnel, a new high-speed image acquisition method based on miniature self-emitting units was pre- sented. Accuracy of the pose measurement system and repeatability of the separation mechanism were verified in the laboratory. Results show that the position precision of the pose measurement system can reach 0.1 mm, the precision of the pitch and yaw angles is less than 0.1° and that of the roll angle can be up to 0.3°. Besides, repeatability errors of models＂ velocity and angular velocity controlled by the release mechanism remain small, satisfying the measurement requirements. Finally, experiments for the separation of auxiliary fuel tanks were conducted in the laboratory.

关键词： Aircraft auxiliary equipmentBinocular vision Position and attitude mea-surement Release mechanism Simulation experiment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Role of surface warming in the northward shift of tropical cyclone tracks over the South China Sea in November

引用

Acta Oceanologica Sinica 2017年第5期36卷 67-72页

作者： SUN jia WANG Guihua ZUO Juncheng ling Zheng LIU Dahai The First Institute of Oceanography State Oceanic AdministrationQingdao 266061China Laboratory for Regional Oceanography and Numerical Modeling Qingdao National Laboratory for Marine Science and TechnologyQingdao 266061China Institute of Atmospheric Sciences Department of Environmental Science and EngineeringFudan UniversityShanghai 200433China Key Laboratory of Coastal Disaster and Defense of Ministry of Education Hohai UniversityNanjing 210098China Guangdong Key Laboratory of Coastal Ocean Variability and Disater Prediction Guangdong Ocean UniversityZhanjiang 524088China

Tropical cyclones （TCs） formed in the Northwest Pacific Ocean （NWP） can cross the South China Sea （SCS） sometimes. It is found that the TC tracks in the SCS in November are shifted to the north after 1980 compared with those before 1980. Both data analyses and numerical simulations show that the surface warming in the SCS may contribute to this more northward shift. The warming produces a cyclonic atmosphere circulation anomaly in the northwestern SCS and an associated southerly in the central SCS steering the TCs to the north.

关键词： tropical cyclone track South China Sea sea surface temperature

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Electron-Electron Interaction Effect on the Conformational Soliton of Deoxyribonucleic Acid

引用

Chinese Physics Letters 1999年第8期16卷 613-615页

作者： ZHANG ling-yun SUN Hong LIN jia-ti Institute of Theoretical Physics Chinese Academy of SciencesBeijing 100080 Department of Modern Applied Physics Center of Atomic and Molecular SciencesTsinghua UniversityBeijing 100084 Department of Applied Physics Tianjin UniversityTianjin 300072

The local conformational behavior of deoxyribonucleic acid(DNA)has been discussed by considering the electron-electron *** set up the coupled nonlinear equations to describe the interaction between the longitudinal displacement of DNA backbone and the electronic wave *** the case of approximated condition,we obtain the analytic solution of the electronic wave function and longitudinal *** influence of electron-electron interaction upon the parameters of conformational soliton such as the amplitude and width have been *** the increasing of electron-electron interaction,the amplitude and half-width will increase.

关键词： interaction. function. Electron

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Holocene high lake-levels and pan-lake period on Badain Jaran Desert

引用

Science China Earth Sciences 2016年第8期59卷 1633-1641页

作者： WANG NaiAng NING Kai LI ZhuoLun WANG YiXin jia Peng MA ling College of Earth and Environmental Sciences Lanzhou University Lanzhou 730000 China History & Culture School of Lanzhou University Lanzhou 730000 China

Many lakes exist in southeastern Badain Jaran Desert and its hinterland, including 110 perennial lakes and some seasonal or extinct lakes. Geomorphological, sedimentological, and bioglyph evidence obtained from field investigations on Badain Jaran Desert lake group, alongside measurements and dating performed on lake relic, prove that these lakes expanded while the climate was relatively wet during early and middle Holocene. The dating results suggest that the pan-lake period of the Badain Jaran Desert began at 10 cal kyr BP, before which the limnic peat period occurred(11–10 cal kyr BP). Many lakes reached their maximal water-level during 8.6–6.3 cal kyr BP and retreated or dried up in the late Holocene(about 3.5–0 cal kyr BP). During that period, the precipitation at Badain Jaran Desert may have reached 200 mm yr^(-1) for 7.7–5.3 cal kyr BP, inferred from both the age and precipitation rate of calcareous root tubes. The water balance calculation shows that wetter and warmer climate and the increase of underground water recharge were key factors in maintaining and developing the lake group at both centennial and millennial time scales. Furthermore, lake surface expansion and the increasing fresh water availability set the background for the prosperous prehistoric culture.

关键词： Badain Jaran Desert Holocene High lake-level Pan-lake period Peat period Water balance Prehistoric culture

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

UBA domain protein SUF1 interacts with NatA-complex subunit NAA15 to regulate thermotolerance in Arabidopsis

引用

Journal of Integrative Plant Biology 2022年第7期64卷 1297-1302页

作者： Ze-Ting Song Xiao-Jie Chen ling Luo Feifei Yu jian-Xiang Liu jia-jia Han State Key Laboratory of Plant Physiology and Biochemistry College of Life SciencesZhejiang UniversityHangzhou 310027China Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology Institute of BiodiversitySchool of Ecology and Environmental ScienceYunnan UniversityKunming 650500China Laboratory of Ecology and Evolutionary Biology State Key Laboratory for Conservation and Utilization of Bio-Resources in YunnanYunnan UniversityKunming 650500China College of Grassland Science and Technology China Agricultural UniversityBeijing 100083China

During recovery from heat stress,plants clear away the heat-stress-induced misfolded proteins through the ubiquitin-proteasome system(UPS).In the UPS,the recognition of substrate proteins by E3 ligase can be regulated by the N-terminal acetyltransferase A(NatA)***,we determined that Arabidopsis STRESS-RELATED UBIQUITIN-ASSOCIATED-DOMAIN PROTEIN FACTOR 1(SUF1)interacts with the NatA complex core subunit NAA15 and positively regulates *** suf1 and naa15 mutants are sensitive to heat stress;the NatA substrate NSNC1 is stabilized in suf1 mutant plants during heat stress ***,SUF1 and its interactor NAA15 play important roles in basal thermotolerance in Arabidopsis.

关键词： basal thermotolerance heat stress NAA15 NatA complex SUF1 UBA-domain protein

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Factor-GARCH Model for High Dimensional Volatilities

引用

Acta Mathematicae Applicatae Sinica 2022年第3期38卷 635-663页

作者： Xiao-ling LI Yuan LI jia-zhu PAN Xing-fa ZHANG School of Economics and Statistics Guangzhou UnversityGuangzhou 510006China College of Mathematics and Informatics South China Agricultural UniversityGuangzhou 510642China Department of Mathematics&Statistics University of StrathclydeGlasgow G11XHUK

This paper proposes a method for modelling volatilities(conditional covariance matrices)of high dimensional dynamic *** combine the ideas of approximate factor models for dimension reduction and multivariate GARCH models to establish a model to describe the dynamics of high dimensional *** condition and thresholding technique are applied to the estimation of the error covariance matrices,and quasi maximum likelihood estimation(QMLE)method is used to estimate the parameters of the common factor conditional covariance *** theories are developed for the proposed *** Carlo simulation studies and real data examples are presented to support the methodology.

关键词： approximate factor models conditional variance-covariance matrix multivariate GARCH sparse estimation thresholding

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Periodontal Ligament Stem Cells Reverse the High Glucose Level-Induced Inflammatory State of Macrophages

引用

Biomedical and Environmental Sciences 2022年第7期35卷 674-679页

作者： LIU Yun Xia DING Xiao ling TANG Shuai CUI Shu Yue LIU jia jia DING Gang School of Stomatology Weifang Medical UniversityWeifang 261053ShandongChina Clinical Competency Training Center Weifang Medical UniversityWeifang 261053ShandongChina

Periodontitis is a chronic infectious disease characterized by plaque biofilm as its main pathogenic factor;its clinical manifestations include gingival inflammation,alveolar bone resorption,attachment loss,and periodontal pocket formation,all of which eventually lead to tooth loss and seriously affect the quality of life of patients[1].This illness has a close relationship with blood sugar levels in patients with diabetes and is one of the most important complications of diabetes[2].Macrophages are an important part of host immune responses and exhibit powerful functions of identifying,phagocytizing,and removing bacteria;macrophage polarization is involved in the pathogenesis of periodontitis[3].

关键词： inflammation removing eventually

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Self-assembly Induced by Complexation of Diblock Copolyelectrolytes and Oppositely Charged Homopolymers

引用

Chinese Journal of Polymer Science 2024年第9期42卷 1321-1332,I0006页

作者： ling Zhao Zhi-Yuan Yin jia-Di jiang Er-Qiang Chen Shuang Yang Beijing National Laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCenter for Soft Mater Science and EngineeringCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China

We investigate the solution self-assembly of a mixture of positively charged homopolymers and AB diblock copolymers,in which the A blocks are negatively charged,and the B blocks are *** electrostatic complexation between oppositely charged polymers drives the formation of many ordered *** microstructures and phase diagrams are calculated using self-consistent field theory(SCFT)based on an ion-pair model with an equilibrium constant K to characterize the strength of binding between positively and negatively charged *** effects of the charge ratio,representing the ratio of charges from the homopolymer over all charges from polymers in the system,on the ordered structure are systematically studied,both for hydrophobic and hydrophilic A *** charge ratio plays an important role in determining the phase boundaries in the phase diagram of salt concentration versus polymer *** also provide information about the varying tendency of the domain spacing and core size of the spherical phase when the charge ratio is changed,and the results are in good agreement with *** studies provide a deep understanding of the self-assembled microstructures of oppositely charged diblock copolymer-homopolymer systems.

关键词： Self-assembly Polyelectrolyte complexation Self-consistent field theory Ion-pair

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Intracellular redox potential-driven live-cell synthesis of CdSe quantum dots in Staphylococcus aureus

引用

Science China Chemistry 2024年第3期67卷 990-999页

作者： Cai-Qin Wu An-An Liu Xu Li jia-Wei Tu Juan Kong ling-ling Yang jian-Hong jia Chuan Wang Bin Hu Zhi-Xiong Xie Dai-Wen Pang The Institute for Advanced Studies College of Chemistry and Molecular SciencesCollege of Life SciencesHubei Key Laboratory of Cell HomeostasisWuhan UniversityWuhan 430072China Research Center for Analytical Sciences College of ChemistryState Key Laboratory of Medicinal Chemical BiologyTianjin Key Laboratory of Biosensing and Molecular RecognitionFrontiers Science Center for New Organic MatterFrontiers Science Center for Cell Responsesand Haihe Laboratory of Sustainable Chemical TransformationsNankai UniversityTianjin 300071China

Biosynthesized semiconductor quantum dots(QDs) have bright fluorescence,adjustable particle sizes,and environmental friendliness,endowing them with convenience and potential for biological *** to the unclear mechanism of the cellular environment on the live-cell synthesis of QDs,it is still difficult to regulate their optical ***,the critical role of the intracellular redox environment in regulating the fluorescence properties of biosynthesized CdSe QDs in Staphylococcus aureus(***) has been *** glutathione peroxidase(GPx) activity directly affects the intracellular H_(2)O_(2) produced in the SeO_(3)^(2-) reduction,which further manipulates the glutathione redox cycle to determine the content of low-valence *** a result,the fluorescence intensity of the synthesized CdSe QDs increases by 60% in the GPx overexpressed *** cellular redox potential that is controlled by the GSH redox cycle provides the driving force for the reduction of SeO_(3)^(2-),facilitating the synthesis of CdSe QDs in *** *** proposed mechanism of the cellular redox state provides a new perspective for regulating the synthesis of semiconductor nanomaterials in live cells.

关键词： redox H_(2)O_(2) peroxidase quantum dot Staphylococcus aureus

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：