检索结果-南通市图书馆

近日，中国农业科学院蜜蜂研究所联合曲靖师范学院等单位科研人员发现甘肃省熊蜂呈现四大生物地理区系，净初级生产力是影响熊蜂多样性分布的最主要因素。该研究成果在线发表在《昆虫(Insects)》上。熊蜂是众多植物的传粉者，在陆地生态系统中发挥着十分重要的作用。明确影响熊蜂分布的因素对于熊蜂多样性保护至关重要。

关键词： Gansu biodiversity biogeographic regionalization bumblebees canonical correspondence analysis

来源：

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Personal finance / 8th ed.

引用

2007年

作者： j.ck r. Kapoor Les r. Dlabay r.ber. j. hughes.

来源：畅想之星图书光盘版（南... 评论

在线全文

畅想之星图书光盘版（南通市图书馆镜像）

学校读者我要写书评

暂无评论

Isogeometric Collocation:A Mixed Displacement-Pressure Method for Nearly Incompressible Elasticity Dedicated to Professor Karl Stark Pister for his 95th birthday

引用

Computer Modeling in Engineering & Sciences 2021年第12期129卷 1125-1150页

作者： S.Morganti F.Fahrendorf L.De Lorenzis j.A.Evans T.j.r.hughes.A.reali Department of Electrical Computer and Biomedical EngineeringUniversita degli Studi di PaviaPavia27100Italy Institute of Applied Mechanics Technische Universitat BraunschweigBraunschweig38106Germany Department of Mechanical and Process Engineering Zurich8092Switzerland Department of Aerospace Engineering Sciences University of Colorado BoulderColorado80309USA Institute for Computational Engineering and Sciences The University of Texas at AustinTexas78712USA Department of Civil Engineering and Architecture Universita degli Studi di PaviaPavia27100Italy

We investigate primal and mixed u−p isogeometric collocation methods for application to nearly-incompressible isotropic *** primal method employs Navier’s equations in terms of the displacement unknowns,and the mixed method employs both displacement and pressure *** benchmarks for what might be considered acceptable accuracy,we employ constant-pressure Abaqus finite elements that are widely used in engineering *** a basis of comparisons,we present results for compressible *** the methods were completely satisfactory for the compressible ***,results for low-degree primal methods exhibited displacement locking and in general deteriorated in the nearly-incompressible *** results for the mixed methods behaved very well for two of the problems we studied,achieving levels of accuracy very similar to those for the compressible *** third problem,which we consider a“torture test”presented a more complex story for the mixed methods in the nearly-incompressible case.

关键词： Isogeometric analysis isogeometric collocation nearly-incompressible elasticity

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

Modification of tenascin-r expression following unilateral labyrinthectomy in rats indicates its possible role in neural plasticity of the vestibular neural circuit

引用

Neural regeneration research 2015年第9期10卷 1463-1470页

作者： Botond Gaal Einar ?rn j.hannesson Amit Dattani Agnes Magyar Ildikó Wéber Clara Matesz Department of Anatomy Histology and Embryology Faculty of Medicine and Faculty of Dentistry University of Debrecen Department of Pediatric Surgery Faculty of Medicine Clinical Center University of Debrecen MTA-DE Neuroscience research Group University of Debrecen

We have previously found that unilateral labyrinthectomy is accompanied by modification of hyaluronan and chondroitin sulfate proteoglycan staining in the lateral vestibular nucleus of rats and the time course of subsequent reorganization of extracellular matrix assembly correlates to the restoration of impaired vestibular function. The tenascin-r has repelling effect on pathfinding during axonal growth/regrowth, and thus inhibits neural circuit repair. By using immunohistochemical method, we studied the modification of tenascin-r expression in the superior, medial, lateral, and descending vestibular nuclei of the rat following unilateral labyrin- thectomy. On postoperative day 1, tenascin-r reaction in the perineuronal nets disappeared on the side of labyrinthectomy in the superior, lateral, medial, and rostral part of the descending vestibular nuclei. On survival day 3, the staining intensity of tenascin-r reaction in perineuronal nets recovered on the operated side of the medial vestibular nucleus, whereas it was restored by the time of postoperative day 7 in the superior, lateral and rostral part of the descending vestib- ular nuclei. The staining intensity of tenascin-r reaction remained unchanged in the caudal part of the descending vestibular nucleus bilaterally. regional differences in the modification of tena- scin-r expression presented here may be associated with different roles of individual vestibular nuclei in the compensatory processes. The decreased expression of the tenascin-r may suggest the extracellular facilitation of plastic modifications in the vestibular neural circuit after lesion of the labyrinthine receptors.

关键词： nerve regeneration extracellular matrix brainstem vestibular system vestibular lesion vestibular compensation perineuronal net neural plasticity neural regeneration

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 machine learning approach for regional geochemical data:Platinum-group element geochemistry vs geodynamic settings of the North Atlantic Igneous Province

引用

Geoscience Frontiers 2021年第3期12卷 42-59页

作者： j.rdan j.Lindsay Hannah S.r.hughes.Christopher M.Yeomans j.ns C.Ø.Andersen Iain McDonald Camborne School of Mines University of ExeterPenryn CampusPenrynCornwall TR109FEUnited Kingdom School of Earth and Ocean Sciences Main CollegeCardiff UniversityPark PlaceCardiff CF103ATUnited Kingdom

Whilst traditional approaches to geochemistry provide valuable insights into magmatic processes such as melting and element fractionation,by considering entire regional data sets on an obj.ctive basis using machine learning algorithms(MLAs),we can highlight new facets within the broader data structure and significantly enhance previous geochemical *** platinum-group element(PGE)budget of lavas in the North Atlantic Igneous Province(NAIP)has been shown to vary systematically according to age,geographic location and geodynamic *** the large multi-element geochemical data set available for the region,MLAs were employed to explore the magmatic controls on these shifting *** key advantage of using machine learning in analysis is its ability to cluster samples across multi-dimensional(i.e.,multi-element)*** NAIP data set is manipulated using Principal Component Analysis(PCA)and t-Distributed Stochastic Neighbour Embedding(t-SNE)techniques to increase separability in the data alongside clustering using the k-means *** new multi-element classification is compared to the original geographic classification to assess the performance of both *** workflow provides a means for creating an obj.ctive high-dimensional investigation on a geochemical data set and particularly enhances the identification of metallogenic anomalies across the *** techniques used highlight three distinct multi-element end-members which successfully capture the variability of the maj.rity of elements included as input *** end-members are seen to fluctuate in prominence throughout the NAIP,which we propose reflects the changing geodynamic environment and melting ***,the variability of Pt and Pd are not reflected in MLA-based clustering trends,suggesting that they vary independently through controls not readily demonstrated by the NAIP maj.r or trace element data structure(i.e.,other proxies for magmatic differe

关键词： Platinum-group elements Machine learning Plume Geochemistry Metallogenesis Mantle

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

Thermal convection in ice sheets: New data, new tests

引用

Natural Science 2012年第7期4卷 409-418页

作者： Terence j. hughes Emeritus of Earth Sciences and Climate Change University of Maine 404 North Sixth Street Fort Pierre South Dakota 57532 USA

Thermal convection in the Antarctic Ice Sheet was proposed in 1970. Demonstrating its existence proved to be elusive. In 2009, tributaries to ice streams were postulated as the surface expression of underlying thermal convection rolls aligned in directions of advective ice flow. Two definitive tests of this hypothesis are now possible, using highly accurate ice elevations and velocities provided by the European, j.panese, and Canadian Space Agencies that allow icestream tributaries and their velocities to be mapped. These tests are 1) measuring lowering of tributary surfaces to see if lowering is due only to advective ice thinning, or also requires lowering en masse in the broad descending part of convective flow, and 2) measuring transverse surface ice velocities to see if ice entering tributaries from the sides increases while crossing lateral shear zones, as would be required if this flow is augmented by convective flow ascending in the narrow side shear zones and diverted into tributaries by advective ice flow. If (1) and (2) are applied to tributaries converging on Byrd Glacier, the same measurements can be conducted when tributaries pack together to become “flow stripes” down Byrd Glacier and onto the ross Ice Shelf to see if (2) is reduced when lateral advection stops. This could determine if thermal convection remains active or shuts down as ice thins. Thermal convection in the Antarctic Ice Sheet would raise three questions. Can it cause the ice sheet to self-destruct as convective flow turns on and off? Does it render invalid climate records extracted at depth from ice cores? Can the ice sheet be studied as a miniature mantle analogous in some respects to Earth’s mantle?

关键词： Thermal Convection Antarctic Ice Sheet Climate Change rising Sea Level

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

The effect of temperature on ionic liquid modified Fe-N-C catalysts for alkaline oxygen reduction reaction

引用

j.urnal of Energy Chemistry 2022年第5期31卷 324-329页

作者： Thomas Wolker Kai Brunnengr.ber.Ioanna Martinaiou Nick Lorenz Gui-rong Zhang Ulrike I.Kramm Bastian j.M.Etzold Department of Chemistry Ernst-Berl-Institut für Technische und Makromolekulare ChemieTechnical University of Darmstadt64287 DarmstadtGermany Department of Chemistry Catalysts and Electrocatalysts GroupTechnical University of Darmstadt64287 DarmstadtGermany Graduate School of Excellence Energy Science and Engineering Technical University of Darmstadt64287 DarmstadtGermany Department of Materials and Earth Sciences Technical University of Darmstadt64287 DarmstadtGermany School of Chemical Engineering and Technology Tiangong UniversityTianjin 300387China

Modifying solid catalysts with an ionic liquid layer is an effective approach for boosting the performance of both Pt-based and non-precious metal catalysts toward the oxygen reduction reaction. While most studies operated at room temperature it remains unclear whether the IL-associated boosting effect can be maintained at elevated temperature, which is of high relevance for practical applications in low temperature fuel cells. Herein, Fe-N-C catalysts were modified by introducing small amounts of hydrophobic ionic liquid, resulting in boosted electrocatalytic activity towards the alkaline oxygen reduction reaction at room temperature. It is demonstrated that the boosting effect can be maintained and even strengthened when increasing the electrolyte temperature up to 70℃. These findings show for the first time that the incorporation of ionic liquid is a suited method to obtain advanced noble metal-free electrocatalysts that can be applied at operating temperature condition.

关键词： Oxygen reduction reaction Non-precious metal catalyst Ionic liquid Fe-N-C catalyst Temperature effect

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：