检索结果-南通市图书馆

Water quality and habitat drive phytoplankton taxonomic and functional group patterns in the Yangtze River

Ecological Processes 2024年第1期13卷 144-158页

作者： Wenqi Gao Fangyuan Xiong Ying Lu Wei Xin Haihua Wang Gangpeng Feng Chiping Kong Lei Fang Xiaoping Gao Yushun Chen State Key Laboratory of Freshwater Ecology and Biotechnology Institute of Hydrobiology Chinese Academy of Sciences University of Chinese Academy of Sciences Jiangxi institute for Fisheries Sciences Poyang Lake Fisheries Research Centre of Jiangxi Province East China sea Fisheries Research institute Chinese Academy of Fishery Sciences Jiujiang institute of Agricultural Sciences

Background Although phytoplankton are important primary producers in food webs, they are relatively less studied in large rivers compared to other types of systems. To fill this research gap, we studied phytoplankton taxonomic and functional composition and their relationships with water quality, habitat, climate, and land use across 30 river sections in the middle and lower reaches of the Yangtze River during 2017–*** Major observed phytoplankton groups were cyanobacteria, bacillariophyta, and chlorophyta. Phytoplankton total abundance, total biomass, and species richness significantly decreased in the dry season compared to the wet season, with the species and functional composition differing significantly between seasons. Phytoplankton species differences between seasons were mainly contributed by Oscillatoria sp., Pseudanabaena sp., and Melosira granulata. The dfferences in phytoplankton functional groups between seasons were mainly contributed by P（including Closterium sp., Melosira sp.）, Lo（including Merismopedia sp., Peridinium sp., Ceratium sp., and Gymnodinium sp.）, and J（including Pediastrum sp., Tetraedron sp., Crucigenia sp., Scenedesmus sp., and Coelastrum sp.）. The variance partitioning showed that water quality（NO3-N, total suspended solids, turbidity） and habitat（water flow, river bank and river channel conditions） were critical factors in shaping phytoplankton patterns, followed by climate and land *** Results indicated that there was significant seasonal variation of phytoplankton in the Yangtze River, with water quality and habitat primarily driving phytoplankton patterns. Our study contributes to the understanding of natural and anthropogenic factors that drive seasonal successional processes of phytoplankton in the Yangtze River. These findings have important implications for environmental management as well as towards the ecological restoration of large rivers.

关键词： Yangtze River Phytoplankton Functional group Water quality Physical habitat

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

Deep learning-based fault diagnostic network of high-speed train secondary suspension systems for immunity to track irregularities and wheel wear

引用

Railway Engineering Science 2022年第1期30卷 96-116页

作者： Yunguang Ye Ping Huang Yongxiang Zhang institute of land and sea transport systems Technical University of BerlinBerlin 10587Germany National United Engineering Laboratory of Integrated and Intelligent transportation Southwest Jiaotong UniversityChengdu 610031China institute for transport Planning and systems ETH Zurich8093 ZurichSwitzerland

Fault detection and isolation of high-speed train suspension systems is of critical importance to guarantee train running safety. Firstly, the existing methods concerning fault detection or isolation of train suspension systems are briefly reviewed and divided into two categories, i.e., model-based and data-driven approaches. The advantages and disadvantages of these two categories of approaches are briefly summarized. Secondly, a 1D convolution network-based fault diagnostic method for highspeed train suspension systems is designed. To improve the robustness of the method, a Gaussian white noise strategy(GWN-strategy) for immunity to track irregularities and an edge sample training strategy(EST-strategy) for immunity to wheel wear are proposed. The whole network is called GWN-EST-1 DCNN method. Thirdly, to show the performance of this method, a multibody dynamics simulation model of a high-speed train is built to generate the lateral acceleration of a bogie frame corresponding to different track irregularities, wheel profiles, and secondary suspension faults. The simulated signals are then inputted into the diagnostic network, and the results show the correctness and superiority of the GWN-EST-1DCNN method. Finally,the 1DCNN method is further validated using tracking data of a CRH3 train running on a high-speed railway line.

关键词： High-speed train suspension system Fault diagnosis Track irregularities Wheel wear Deep learning Literature review

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

Autonomous aeroamphibious invisibility cloak with stochastic-evolution learning

引用

Advanced Photonics 2024年第1期6卷 64-72页

作者： Chao Qian Yuetian Jia Zhedong Wang Jieting Chen Pujing Lin Xiaoyue Zhu Erping Li Hongsheng Chen Zhejiang University ZJU-UIUC InstituteInterdisciplinary Center for Quantum InformationState Key Laboratory of Extreme Photonics and InstrumentationHangzhouChina Zhejiang University ZJU-Hangzhou Global Science and Technology Innovation CenterKey Laboratory of Advanced Micro/Nano Electronic Devices and Smart Systems of ZhejiangHangzhouChina Zhejiang University Jinhua Institute of Zhejiang UniversityJinhuaChina

Being invisible ad libitum has long captivated the popular imagination,particularly in terms of safeguarding modern high-end instruments from potential *** ago,the advent of metamaterials and transformation optics sparked considerable interest in invisibility cloaks,which have been mainly demonstrated in ground and waveguide ***,an omnidirectional flying cloak has not been achieved,primarily due to the challenges associated with dynamic synthesis of metasurface *** demonstrate an autonomous aeroamphibious invisibility cloak that incorporates a suite of perception,decision,and execution modules,capable of maintaining invisibility amidst kaleidoscopic backgrounds and neutralizing external *** physical breakthrough lies in the spatiotemporal modulation imparted on tunable metasurfaces to sculpt the scattering field in both space and frequency *** intelligently control the spatiotemporal metasurfaces,we introduce a stochastic-evolution learning that automatically aligns with the optimal solution through maximum probabilistic *** a fully self-driving experiment,we implement this concept on an unmanned drone and showcase adaptive invisibility in three canonical landscapes-sea,land,and air-with a similarity rate of up to 95%.Our work extends the family of invisibility cloaks to flying modality and inspires other research on material discoveries and homeostatic meta-devices.

关键词： intelligent metasurfaces optical materials and structures deep learning

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

Railway wheel profile fine-tuning system for profile recommendation

引用

Railway Engineering Science 2021年第1期29卷 74-93页

作者： Yunguang Ye Jonas Vuitton Yu Sun Markus Hecht institute of land and sea transport systems Technical University of Berlin10587 BerlinGermany College of transportation Science and Engineering Nanjing Tech UniversityNanjing 210009China

This paper develops a wheel profile fine-tuning system(WPFTS)that comprehensively considers the influence of wheel profile on wheel damage,vehicle stability,vehicle safety,and passenger *** can recommend one or more optimized wheel profiles according to train operators’needs,e.g.,reducing wheel wear,mitigating the development of wheel out-of-roundness(OOR),improving the shape stability of the wheel ***,WPFTS includes four modules:(I)a wheel profile generation module based on the rotary-scaling finetuning(RSFT)method;(II)a multi-objective generation module consisting of a rigid multi-body dynamics simulation(MBS)model,an analytical model,and a rigid–flexible MBS model,for generating 11 objectives related to wheel damage,vehicle stability,vehicle safety,and passenger comfort;(III)a weight assignment module consisting of an adaptive weight assignment strategy and a manual weight assignment strategy;and(IV)an optimization module based on radial basis function(RBF)and particle swarm optimization(PSO).Finally,three cases are introduced to show how WPTFS recommends a wheel profile according to train operators’*** them,a wheel profile with high shape stability,a wheel profile for mitigating the development of wheel OOR,and a wheel profile considering hunting stability and derailment safety are developed,respectively.

关键词： Wheel profile fine-tuning system Optimization Recommendation Wear Contact concentration index Multi-body dynamics simulation(MBS) Railway wheel

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

Solute transport and geochemical modeling of the coastal quaternary aquifer, Delta Dahab Basin, South Sinai, Egypt

引用

Acta Geochimica 2024年第1期43卷 16-39页

作者： Amira Samy Mustafa Eissa Seham Shahen Moustafa M.Said Rabab M.Abou-shahaba Division of Water Resources and Arid land Department of HydrogeochemistryDesert Research CenterCairoEgypt Egypt Desalination Research Center of Excellence Desert Research CenterCairoEgypt Center for Water Supply Studies S&E-Physical&Environmental SciencesTexas A&M University Corpus ChristiCorpus ChristiUSA Department of Chemistry Faculty of Science(Girls)Al-Azhar UniversityYousef Abbas StrNasr CityP.O.Box:11754CairoEgypt

The wadi dahab delta is in a dry, arid coastal zone within Egypt’s south Sinai Peninsula’s eastern portion. The primary water source is the Quaternary coastal alluvial aquifer. The groundwater salinity varies from 890to 8213 mg/L, with a mean value of 3417 mg/L. The dissolved major ions have been used to calculate the seawater mixing index(SWMI) using a linear equation that discriminates the groundwater mostly affected by water–rock interaction(SWMI 1>) and other samples mixed with seawater(SWMI seawater represented by a Red sea water sample(δ^(18)O + 1.64‰-δ^(2)H + 9.80‰) and reject brine water are considerably enriched the isotopic groundwater values. The geochemical NETPATH model constrained by the dissolved significant ions, isotopes, and the rock aquifer forming minerals as phases indicate the mixing percent with the seawater ranges from 9% to 97% of seawater from 91% to 3% of original recharge water. According to the seaWAT 3-D flow models, seawater has penetrated the Northeastern Dahab delta aquifer, with the intrusion zone extending1500 m inland. The salt dissolution, upwelling of saline water, recharge from the upstream mountain block, and seawater encroachment are the primary aspects contributing to the deterioration of groundwater quality. These findings may have significance for effective groundwater withdrawal management in arid locations worldwide with similar hydrogeological systems.

关键词： Groundwater geochemistry seawater intrusion Solute transport seaWAT

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

量化铁路车辆机械故障对轨道退化的影响

引用

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2020年第10期21卷 783-798页

作者： Yun-guang YE Da-chuan SHI Sara POVEDA-REYES Markus HECHT institute of land and sea transport systems Technical University of BerlinBerlin 10587Germany AITEC Parque TecnoldgicoValencia 46980Spain

目的:了解和量化铁路车辆机械故障对铁路基础设施退化的影响有利于提高列车安全性,合理制定维护策略,以及优化轨道收费模型。本研究为欧洲Shift2Rail-Assets4rail项目的一部分(报告以非公开的形式被递交),旨在量化铁路车辆机械故障对轨... 详细信息

目的:了解和量化铁路车辆机械故障对铁路基础设施退化的影响有利于提高列车安全性,合理制定维护策略,以及优化轨道收费模型。本研究为欧洲Shift2Rail-Assets4rail项目的一部分(报告以非公开的形式被递交),旨在量化铁路车辆机械故障对轨道退化的影响,为调整现有的轨道收费模型提供合理的建议。创新点:1.分析一个常见的铁路车辆机械故障(擦伤)对四个用于轨道收费模型的量化指标的影响;2.引入金代理模型方法以减少仿真次数。方法:1.建立一个带有擦伤的机车多体动力学模型,并考虑车轮和轨道的柔性;2.引入金代理模型以量化车辆速度和擦伤尺寸对四种损坏机制(轨道沉降、轨道构件疲劳、钢轨磨耗和钢轨滚动接触疲劳)的影响。结论:1.轨道沉降、轨道构件疲劳和钢轨磨耗随着擦伤尺寸和车速的增加而急剧增加,并且这种增加趋势随着擦伤尺寸和车速的增加而变得更加尖锐。2.在低速时,滚动接触疲劳随着擦伤尺寸的增加而逐渐增加;在高速时,它首先急剧增加,然后逐渐减小。3.擦伤对轨道构件疲劳和钢轨磨耗的影响最为显著,其次是轨道沉降和滚动接触疲劳。

关键词：铁路车辆故障轨道退化量化轨道收费擦伤

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

Rotary-scaling fine-tuning (RSFT) method for optimizing railway wheel profiles and its application to a locomotive

引用

Railway Engineering Science 2020年第2期28卷 160-183页

作者： Yunguang Ye Yayun Qi Dachuan Shi Yu Sun Yichang Zhou Markus Hecht institute of land and sea transport systems Technical University of Berlin10587 BerlinGermany State Key Laboratory of Traction Power Southwest Jiaotong UniversityChengdu 610331China College of transportation Science and Engineering Nanjing Tech UniversityNanjing 210009China

The existing multi-objective wheel profile optimization methods mainly consist of three sub-modules:(1)wheel profile generation,(2)multi-body dynamics simulation,and(3)an optimization *** the first module,a comparably conservative rotary-scaling finetuning(RSFT)method,which introduces two design variables and an empirical formula,is proposed to fine-tune the traditional wheel profiles for improving their engineering *** the second module,for the TRAXX locomotives serving on the Blankenburg–Rubeland line,an optimization function representing the relationship between the wheel profile and the wheel–rail wear number is established based on Kriging surrogate model(KSM).For the third module,a method combining the regression capability of KSM with the iterative computing power of particle swarm optimization(PSO)is proposed to quickly and reliably implement the task of optimizing wheel ***,with the RSFT–KSM–PSO method,we propose two wear-resistant wheel profiles for the TRAXX locomotives serving on the Blankenburg–Rubeland line,namely S1002-S and *** S1002-S profile minimizes the total wear number by 30%,while the S1002-M profile makes the wear distribution more uniform through a proper sacrifice of the tread wear number,and the total wear number is reduced by 21%.The quasi-static and hunting stability tests further demonstrate that the profile designed by the RSFT–KSM–PSO method is promising for practical engineering applications.

关键词： Wheel profile optimization Wear reduction Rotary-scaling fine-tuning Particle swarm optimization Kriging surrogate model

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

Responses of Nutrients to the Precipitation Variation and land Use in Subtropical Monsoonal Small Mountainous Rivers:A Case Study of Baixi Watershed

引用

Journal of Ocean University of China 2024年第2期23卷 383-391页

作者： TIAN Yuan GAO Fei CAO Ke LV Shenghua DUAN Xiaoyong YIN Ping Qingdao institute of Marine Geology China Geological SurveyMinistry of Natural ResourcesQingdao 266237China Laboratory for Marine Geology Laoshan LaboratoryQingdao 266237China

Small mountainous rivers are characterized by large instantaneous fluxes and susceptible to extreme weather events,which can rapidly transport materials into the sea and have a significant impact on the ecological environment of estuaries and *** order to investigate the seasonal characteristics of nutrients in small mountainous rivers in the subtropical monsoon region and the output pattern to the sea during heavy precipitation,surveys on the mountainous rivers were carried out in Baixi watershed in August 2020(wet season),March 2021(dry season)and June 2021(Meiyu period).The results showed that the dissolved inorganic nitrogen(DIN)of the rivers has an average concentration of 752μg L^(−1)in the wet season and 1472μg L^(−1)in the dry *** concentrations of dissolved inorganic phosphorus(DIP)in wet season and dry season were 63μg L^(−1)and 51μg L^(−1),*** by the changes of land use in sub-watersheds,DIN concentrations in the mainstream increased from 701μg L^(−1)in the upper reaches to 1284μg L^(−1)in the middle *** rainstorms during the Meiyu period in the watershed caused the pulse runoff in the *** maximum daily runoff reached 70 times that before *** maximum daily fluxes of DIN and DIP were 109 and 247 times that before rains,*** view that the watershed experienced several rainstorms in the wet season,the river,with pulse runoff,carries a large amount of nutrients into the sea in a short time,which will have a significant impact on the environment of Sanmen bay and its adjacent sea.

关键词： small mountainous river uneven precipitation rainstorm pulse runoff nitrogen and phosphorus

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

Relative Impacts of sea Ice Loss and Atmospheric Internal Variability on the Winter Arctic to East Asian Surface Air Temperature Based on Large-Ensemble Simulations with NorESM2

引用

Advances in Atmospheric Sciences 2024年第8期41卷 1511-1526页

作者： Shengping HE Helge DRANGE Tore FUREVIK Huijun WANG Ke FAN Lise Seland GRAFF Yvan J.ORSOLINI Geophysical institute University of Bergen and Bjerknes Centre for Climate ResearchBergen 5020Norway Nansen Environmental and Remote Sensing Center Bergen 5007Norway Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science&TechnologyNanjing 211544China Nansen-Zhu International Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 511458China School of Atmospheric Science Sun Yat-Sen Universityand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Norwegian Meteorological institute Oslo 0313Norway Norwegian institute for Air Research Kjeller 2007Norway

To quantify the relative contributions of Arctic sea ice and unforced atmospheric internal variability to the “warm Arctic, cold East Asia”(WACE) teleconnection, this study analyses three sets of large-ensemble simulations carried out by the Norwegian Earth System Model with a coupled atmosphere–land surface model, forced by seasonal sea ice conditions from preindustrial, present-day, and future periods. Each ensemble member within the same set uses the same forcing but with small perturbations to the atmospheric initial state. Hence, the difference between the present-day(or future) ensemble mean and the preindustrial ensemble mean provides the ice-loss-induced response, while the difference of the individual members within the present-day(or future) set is the effect of atmospheric internal variability. Results indicate that both present-day and future sea ice loss can force a negative phase of the Arctic Oscillation with a WACE pattern in winter. The magnitude of ice-induced Arctic warming is over four(ten) times larger than the ice-induced East Asian cooling in the present-day(future) experiment;the latter having a magnitude that is about 30% of the observed cooling. sea ice loss contributes about 60%(80%) to the Arctic winter warming in the present-day(future) experiment. Atmospheric internal variability can also induce a WACE pattern with comparable magnitudes between the Arctic and East Asia. Ice-lossinduced East Asian cooling can easily be masked by atmospheric internal variability effects because random atmospheric internal variability may induce a larger magnitude warming. The observed WACE pattern occurs as a result of both Arctic sea ice loss and atmospheric internal variability, with the former dominating Arctic warming and the latter dominating East Asian cooling.

关键词： Arctic sea ice loss warm Arctic–cold East Asia atmospheric internal variability large-ensemble simulation NorESM2 PAMIP

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

Causes of 2022 summer marine heatwave in the East China seas

引用

Advances in Climate Change Research 2023年第5期14卷 633-641页

作者： Hong-Jian TAN Rong-Shuo CAI Dong-Ping BAI Karim HILMI Kareem TONBOL Third institute of Oceanography Ministry of Natural ResourcesXiamen 361005China National de Recherche Halieutique Casablanca 20100Morocco College of Maritime transport and Technology Arab Academy for ScienceTechnology&Maritime TransportAlexandria 1209Egypt

Recent occurrences of marine heatwaves(MHWs)in coastal China seas have caused serious impacts on marine ecosystem services and ***,the underlying physical process,including local drivers and remote associations,remains poorly understood,thereby hindering accurate *** this study,we reported an extreme MHW event in the East China seas(ECSs,including the Bohai,Yellow,and East China sea),lasting for 75 d with a maximum intensity of 1.96℃relative to 1982-2011 during the summer *** ECSs MHW event was triggered by a combination of anomalous atmospheric and oceanic conditions,including enhanced insolation,weakened surface wind speed,suppressed latent heat loss from ocean,a shallower mixed layer,and upper ocean current ***-layer temperature budget diagnosis suggested that changes in the ECSs temperature were dominated by the surface net heat flux,largely due to strong shortwave radiation flux,during the development and decay of the MHW *** advection also created favorable conditions for the maintenance of the *** physical drivers were further regulated by the westward expanded and intensified western Pacific subtropical high(WPSH),potentially linked to the negative phase of Indian Ocean Dipole(IOD).Despite the three years(2020-2022)consecutive La Niña events,the ECSs summer MHWs appeared to be more closely linked to negative IOD events,with a lagging period of 1-3 *** seasonal precursor signals of the negative IOD have the potential to affect local physical drivers of ECSs MHWs through regulating the strength and position of WPSH,thus serving as a promising predictor for the ECSs *** future likelihood and intensity of the ECSs MHWs are projected to increase substantially in the coming decades,largely due to broad-scale warming attributed to anthropogenic climate ***,there is an urgent need to develop MHW forecasting and early warning systems,and robust approaches to address climat

关键词： Marine heatwaves East China seas Indian ocean dipole Western Pacific subtropical high

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

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：