检索结果-南通市图书馆

Differential effects of two dominant plant species on community structure and invasibility in an old-field ecosystem

引用

journal of Plant Ecology 2011年第3期4卷 123-131页

作者： Lara Souza jake F.Weltzin nathan j.sanders Department of Ecology and Evolutionary Biology University of Tennessee1416 Circle DriveKnoxvilleTN 37996USA USA National Phenology Network National Coordinating Office1955 East 6th StreetTucsonAZ 85719USA

Aims In this study,we examined the effects of Solidago altissima(hereafter Solidago)and two species in the genus Verbesina,Verbesina virginica and Verbesina occidentalis(hereafter Verbesina),on the structure of an old-field plant community and establishment by an invasive plant species,Lespedeza cuneata(hereafter Lespedeza).Methods We removed Solidago,Verbesina and both Solidago and Verbesina from 4m^(-2)plots in an intact old-field community during two growing *** then quantified the effects of these removals on richness,evenness,diversity and composition of the subdominant plant *** also measured the total aboveground biomass and the aboveground biomass of the subdominant *** assess how these removals affected establishment by Lespedeza,we planted 20 seeds in each plot and tracked seedling emergence and survival for one growing *** Findings Subdominant community evenness and Shannon diversity were higher in plots from which Solidago and Verbesina were removed relative to control ***,there were no effects of dominant species removal on species richness or composition of the subdominant *** aboveground biomass was not affected by dominant species removal,suggesting that the community of subdominant species exhibited *** fact,subdominant community biomass was greater when Solidago,but not Verbesina,was *** availability was also greater in plots where Solidago was removed relative to control plots throughout the growing *** addition,removal of dominant species,in particular Solidago,indirectly reduced the emergence,but not survival,of Lespedeza seedlings by directly promoting subdominant community *** together,our results suggest that dominant old-field plant species affect subdominant community structure and indirectly promote establishment by Lespedeza.

关键词： compensation establishment invasive Lespedeza cuneata Solidago Verbesina

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

Aboveground resilience to species loss but belowground resistance to nitrogen addition in a montane plant community

引用

journal of Plant Ecology 2018年第3期11卷 351-363页

作者： Quentin D.Read jeremiah A.Henning Aimée T.Classen nathan j.sanders Department of Ecology and Evolutionary Biology University of Tennessee569 Dabney HallKnoxvilleTN 37996USA Rocky Mountain Biological Laboratory PO Box 615Crested ButteCO 81224USA Center for Macroecology Evolutionand ClimateNatural History Museum of DenmarkUniversity of CopenhagenUniversitetsparken 152100 CopenhagenDenmark Rubenstein School of Environment and Natural Resources University of VermontBurlingtonVT 05405USA

Aims Decades of empirical work have demonstrated how dominant plant species and nitrogen fertilization can influence the structure and function of plant *** recent studies have examined the interplay between these factors,but few such studies use an explicit trait-based *** this study,we use an explicit trait-based approach to identify potential mechanisms for community-level responses and to test ecological niche *** We experimentally manipulated plant communities(control,−dom-inant species,−random biomass)and nitrogen(N)inputs(control,+organic N,+inorganic N)in a fully factorial *** predicted that traits related to plants’ability to take up different forms of soil N would differ between dominant and subordinate species,resulting in interactive effects of dominant species loss and N fertilization on plant community structure and *** study took place in a montane meadow in the Rocky Mountains,Colorado,*** Findings After four years,the plant community in removal plots converged toward a species composition whose leaf and root functional traits resembled those of the previously removed dominant *** productivity generally increased with N addition:soil carbon efflux was~50%greater when either form of N was added,while inorganic N addition increased aboveground biomass pro-duction by~60%relative to *** increase in production was mediated by increased average height,leaf mass:area ratio and leaf dry matter content in plant communities to which we added inorganic *** to our predictions,there were no interactive effects of N fertilization and dominant species loss on plant com-munity structure or ecosystem *** plant community com-position in this study exhibited resistance to soil N addition and,given the functional convergence we observed,was resilient to spe-cies ***,our results indicate that the ability of species to compensate functionally for species loss confers

关键词： dominant species fertilization functional trait removal experiment resilience

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

Variation in the methods leads to variation in the interpretation of biodiversity-ecosystem multifunctionality relationships

引用

journal of Plant Ecology 2020年第4期13卷 431-441页

作者： Xin jing Case M.Prager Aimée T.Classen Fernando T.Maestre jin-Sheng He nathan j.sanders Rubenstein School of Environment and Natural Resources University of VermontBurlingtonVT 05405USA Gund Institute for Environment University of VermontBurlingtonVT 05405USA Center for Macroecology Evolutionand ClimateNatural History Museum of DenmarkCopenhagenDenmark Departamento de Biología GeologíaFísica y Química InorgánicaEscuela Superior de Ciencias Experimentales y TecnologíaUniversidad Rey Juan CarlosMóstoles 28933Spain Departamento de Ecología and Instituto Multidisciplinar para el Estudio del Medio“Ramon Margalef” Universidad de AlicanteAlicanteSpain Department of Ecology College of Urban and Environmental SciencesPeking UniversityBeijingChina Environmental Program Rubenstein School of Environment and Natural ResourcesUniversity of VermontBurlingtonVT 05405USA Present address:Department of Earth and Environmental Sciences KU LeuvenCelestijnenlaan 200E3001 LeuvenBelgium

Aims Biodiversity is often positively related to the capacity of an ecosystem to provide multiple functions simultaneously(***).However,there is some controversy over whether biodiversity–multifunctionality relationships depend on the number of functions ***,investigators have documented contrasting findings that the effects of biodiversity on ecosystem multifunctionality do not change or increase with the number of ecosystem ***,we provide some clarity on this issue by examining the statistical underpinnings of different multifunctionality *** We used simulations and data from a variety of empirical studies conducted across spatial scales(from local to global)and biomes(temperate and alpine grasslands,forests and drylands).We revisited three methods to quantify multifunctionality including the averaging approach,summing approach and threshold-based *** Findings Biodiversity–multifunctionality relationships either did not change or increased as more functions were *** results were best explained by the statistical underpinnings of the averaging and summing multifunctionality ***,by averaging the individual ecosystem functions,the biodiversity–multifunctionality relationships equal the population mean of biodiversity-single function relationships,and thus will not change with the number of ***,by summing the individual ecosystem functions,the strength of biodiversity–multifunctionality relationships increases as the number of functions *** proposed a scaling standardization method by converting the averaging or summing metrics into a scaling metric,which would make comparisons among different biodiversity *** addition,we showed that the range-relevant standardization can be applied to the threshold-based approach by solving for the mathematical artefact of the approach(*** effects of biodiversity may artificially increase with

关键词： averaging approach biodiversity ecosystem multifunctionality multiple threshold approach plant species richness spatial scale

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 parallel-plate resonator:An RF probe for MR and MRI studies over a wide frequency range

引用

Magnetic Resonance Letters 2023年第4期3卷 306-318页

作者： Andres Ramírez Aguilera Kevin j.sanders Gillian R.Goward Bruce *** UNB MRI Centre Department of PhysicsUniversity of New BrunswickFrederictonNew BrunswickE3B 5A3Canada Department of Chemistry McMaster UniversityHamiltonOntarioL8S 4L8Canada

We explore the use of the parallel-plate resonator for the study of thin cuboid samples over a wide range of magnetic resonance *** parallel-plate resonator functions at frequencies from tens to hundreds of *** parallel-plate resonators are presented and discussed in a frequency range from 8 to 500 *** resonance experiments were performed on both horizontal and vertical bore magnet systems with lithium and hydrogen ***-plate radiofrequency(RF)probes are easy to build and easy to *** and simulations showed good sensitivity of the parallel-plate RF probe geometry with a small decrease in sensitivity at higher frequencies.

关键词： Parallel-plate resonator Optimization Magnetic resonance/magnetic resonance imaging(MR/MRI) Batteries

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

Multinuclear MR and MRI study of lithium-ion cells using a variable field magnet and a fixed frequency RF probe

引用

Magnetic Resonance Letters 2024年第1期4卷 10-20页

作者： Andrés Ramírez Aguilera Florin Marica Kevin j.sanders Md Al Raihan C.Adam Dyker Gillian R.Goward Bruce *** UNB MRI Centre Department of PhysicsUniversity of New BrunswickFrederictonNew BrunswickE3B 5A3Canada Department of Chemistry McMaster UniversityHamiltonOntarioL8S 4L8Canada Department of Chemistry University of New BrunswickFrederictonNew BrunswickE3B 5A3Canada

An exploratory multinuclear magnetic resonance(MR)and magnetic resonance imaging(MRI)study was performed on lithium-ion battery cells with ^(7)Li,^(19)F,and ^(1)H measurements.A variable field superconducting magnet with a fixed frequency parallel-plate radiofrequency(RF)probe was employed in the *** magnetic field was changed to set the resonance frequency of each nucleus to the fixed RF probe frequency of 33.7 *** cartridge-like lithium-ion cells,with graphite anodes and LiNi_(0.5)Mn_(0.3)Co_(0.2)O_(2)(NMC)cathodes,were *** cell was pristine,and one was charged to a cell voltage of 4.2 *** results presented demonstrate the great potential of the variable field magnet approach in multinuclear measurement of lithium-ion *** methods open the door for developing faster and simpler methods for detecting,quantifying,and interpreting MR and MRI data from lithium-ion and other batteries.

关键词： Multinuclear MR/MRI Variable field magnet Lithium-ion battery Parallel-plate rf probe

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

Global blue carbon accumulation in tidal wetlands increases with climate change

引用

National Science Review 2021年第9期8卷 145-155页

作者： Faming Wang Christian j.sanders Isaac R.Santos jianwu Tang Mark Schuerch Matthew L.Kirwan Robert E.Kopp Kai Zhu Xiuzhen Li jiacan Yuan Wenzhi Liu Zhian Li Xiaoliang Research Station for Tropical Coastal Ecosystems Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems and the CAS Engineering Laboratory for Ecological Restoration of Island and Coastal Ecosystems South China Botanical Garden Chinese Academy of Sciences Center of Plant Ecology Core Botanical Gardens Chinese Academy of Sciences Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) State Key Laboratory of Estuarine and Coastal Research and Institute of Eco-Chongming East China Normal University National Marine Science Centre School of Environment Science and Engineering Southern Cross University Department of Marine Sciences University of Gothenburg Lincoln Centre for Water and Planetary Health School of Geography University of Lincoln Virginia Institute of Marine Science College of William and Mary Department of Earth and Planetary Sciences and Rutgers Institute of Earth Ocean and Atmospheric Sciences Rutgers University Department of Environmental Studies University of California Department of Atmospheric and Oceanic Sciences Fudan University CAS Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of Sciences

Coastal tidal wetlands produce and accumulate significant amounts of organic carbon(C) that help to mitigate climate change. However, previous data limitations have prevented a robust evaluation of the global rates and mechanisms driving C accumulation. Here, we go beyond recent soil C stock estimates to reveal global tidal wetland C accumulation and predict changes under relative sea level rise, temperature and precipitation. We use data from literature study sites and our new observations spanning wide latitudinal gradients and 20 countries. Globally, tidal wetlands accumulate 53.65(95%CI: 48.52–59.01)Tg C yr-1, which is ～30% of the organic C buried on the ocean floor. Modeling based on current climatic drivers and under projected emissions scenarios revealed a net increase in the global C accumulation by2100. This rapid increase is driven by sea level rise in tidal marshes, and higher temperature and precipitation in mangroves. Countries with large areas of coastal wetlands, like Indonesia and Mexico, are more susceptible to tidal wetland C losses under climate change, while regions such as Australia, Brazil, the USA and China will experience a significant C accumulation increase under all projected scenarios.

关键词： coastal wetlands blue C C burial rate global change

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Appendectomy and Clostridium difficile colitis:Relationships revealed by clinical observations and immunology

引用

World journal of Gastroenterology 2013年第34期19卷 5607-5614页

作者： nathan L sanders R Randal Bollinger Ryan Lee Steven Thomas William Parker Department of Surgery Duke University Medical Center

Advances in understanding the interaction between the human immune system and the microbiome have led to an improved understanding of the function of the vermiform appendix as a safe-house for beneficial bacteria in the *** advances have been made despite long standing clinical observations that the appendectomy is a safe and effective ***,more recent clinical data show that an appendectomy puts patients at increased risk for recurrent Clostridium difficile(***)-associated colitis,and probably other diseases associated with an altered *** the same time,appendectomy does not apparently put patients at risk for an initial onset of ***-associated *** clinical observations point toward the idea that the vermiform appendix might not effectively protect the microbiome in the face of broad spectrum antibiotics,the use of which precedes the initial onset of ***-associated ***,these observations point to the idea that historically important threats to the microbiome such as infectious gastrointestinal pathogens have been supplanted by other threats,particularly the use of broad spectrum antibiotics.

关键词： Appendectomy Clostridium difficile Colitis Diarrheal illness Vermiform appendix

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

Coastal blue carbon in China as a nature-based solution toward carbon neutrality

引用

The Innovation 2023年第5期4卷 109-123页

作者： Faming Wang jihua Liu Guoming Qin jingfan Zhang jinge Zhou jingtao Wu Lulu Zhang Poonam Thapa Christian j.sanders Isaac R.Santos Xiuzhen Li Guanghui Lin Qihao Weng jianwu Tang Nianzhi jiao Hai Ren Xiaoliang Research Station of Tropical Coastal Ecosystems Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystemsand the CAS Engineering Laboratory for Ecological Restoration of lsland and Coastal EcosystemsSouth China Botanical GardenChinese Academy of SciencesGuangzhou 510650China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 510650China Marine Research Institute Shandong UniversityQingdao 266237China University of Chinese Academy of Sciences Beijing 100049China National Marine Science Centre Faculty of Science and EngineeringSouther Cross UniversityCoffs HarbourNSW 2450Australia Department of Marine Sciences University of Gothenburg41319 GothenburgSweden State Key Laboratory of Estuarine and Coastal Research and Instiute of Eco-Chongming East China Normal UniversityShanghai 201100China Key Laboratory for Earth System Modeling Ministry of EducationDepartment of Earth System ScienceTsinghua UniversityBejing 100084China Laboratory of Stable Isotope and Gulf Ecology Institute of Ocean EngineeringTsinghua's Shenzhen International Graduate SchoolShenzhen 518055China Department of Land Surveying and Geo-nformatics The Hong Kong Polytechnic UniversiyHongkong 99077China Innovative Research Center for Carbon Neutralization Global ONCE ProgramXiamen 361005China

To achieve the Paris Agreement,China pledged to become“Carbon Neutral”by the *** addition to massive decarbonization,this would require significant changes in ecosystems toward negative CO_(2)*** ability of coastal blue carbon ecosystems(BCEs),including mangrove,salt marsh,and seagrass meadows,to sequester large amounts of CO_(2)makes their conservation and restoration an important“nature-based solution(NbS)”for climate adaptation and *** this review,we examine how BCEs in China can contribute to climate *** the national scale,the BCEs in China store up to 118 Tg C across a total area of 1,440,377 ha,including over 75%as unvegetated tidal *** annual sedimental C burial of these BCEs reaches up to 2.06 Tg C year^(−1),of which most occurs in salt marshes and tidal *** lateral C flux of mangroves and salt marshes contributes to 1.17 Tg C year^(−1)along the Chinese *** and restoration of BCEs benefit climate change mitigation and provide other ecological services with a value of$32,000 ha^(−1)year^(−1).The potential practices and technologies that can be implemented in China to improve BCE C sequestration,including their constraints and feasibility,are also *** directions are suggested to improve blue carbon estimates on aerial extent,carbon stocks,sequestration,and mitigation *** and preserving BCEs would be a cost-effective step to achieve Carbon Neutral by 2060 in China despite various barriers that should be removed.

关键词： tidal coastal carbon

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

Validating neural networks for spectroscopic classification on a universal synthetic dataset

引用

npj Computational Materials 2023年第1期9卷 1325-1336页

作者： jan Schuetzke nathan j.Szymanski Markus Reischl Institute for Automation and Applied Informatics Karlsruhe Institute of TechnologyKarlsruhe 76131Germany Department of Materials Science&Engineering Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA Department of Materials Science&Engineering UC BerkeleyBerkeleyCA 94720USA

To aid the development of machine learning models for automated spectroscopic data classification,we created a universal synthetic dataset for the validation of their *** dataset mimics the characteristic appearance of experimental measurements from techniques such as X-ray diffraction,nuclear magnetic resonance,and Raman spectroscopy among *** applied eight neural network architectures to classify artificial spectra,evaluating their ability to handle common experimental *** all models achieved over 98%accuracy on the synthetic dataset,misclassifications occurred when spectra had overlapping peaks or *** found that non-linear activation functions,specifically ReLU in the fully-connected layers,were crucial for distinguishing between these classes,while adding more sophisticated components,such as residual blocks or normalization layers,provided no performance *** on these findings,we summarize key design principles for neural networks in spectroscopic data classification and publicly share all scripts used in this study.

关键词： spectroscopic adding classify

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

雷达元器件的新发展

引用

现代雷达 1990年第3期12卷 60-67页

作者： Robert j.sanders 陈能秋 ITT Gilfillan

正确选择结构形式,改进功率分配/合成网络,提高晶体管的功率电平和工作频率,指明了设计先进雷达发射机的方法。

关键词：雷达元器件接收机

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：