检索结果-南通市图书馆

Journal of Thermal Science 2024年第2期33卷 501-508页

作者： LI weiwei MIAO Qi ZHANG Yelong DING Hongliang yang Sa LAI Yuan FENG Daili DING Yulong JIN Yi TAN Linghua School of Chemistry and Chemical Engineering Nanjing University of Science&TechnologyNanjing210094China National Special Superfine Powder Engineering Research Center Nanjing University of Science and TechnologyNanjing210094China Nanjing Jinhe Energy Material Co. LtdNanjing210047China School of Chemical Engineering University of BirminghamBirminghamB152TTUK School of Energy&Environmental Engineering University of Science and Technology BeijingBeijing100083China

In this paper,a novel ternary eutectic salt Na_(2)CO_(3)-Li_(2)CO_(3)-LiF was designed and investigated for concentrated solar power(CSP).The FactSage software was used to predict the composition and eutectic point of Na_(2)CO_(3)-Li_(2)CO_(3)-*** microstructure,thermophysical properties,and thermal stability of eutectic salts were experimentally measured using various analytical *** a mass ratio of 57%:32%:11%,the eutectic salt exhibited excellent thermal storage properties with a fusion enthalpy of 413 J/g and a melting point of 426.8℃.The excellent thermal stability of the eutectic salt was reflected by a weight loss of only 0.8% at 600℃.

关键词： phase change materials ternary eutectic salt latent heat thermal stability

First wetland mapping at 10-m spatial resolution in South America using multi-source and multi-feature remote sensing data

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第10期67卷 3252-3269页

作者： weiwei SUN Gang yang Yuling HUANG Dehua MAO Ke HUANG Lin ZHU Xiangchao MENG Tian FENG Chao CHEN Yong GE Department of Geography and Spatial Information Techniques Ningbo UniversityNingbo 315211China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences&Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Natural Resources and Planning Bureau Shanghai Pudong New DistrictShanghai 200100China Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China Faculty of Electrical Engineering and Computer Science Ningbo UniversityNingbo 315211China School of Geography Science and Geomatics Engineering Suzhou University of Science and TechnologySuzhou 215009China

Wetland degradation has been accelerating in recent years globally. Accurate information on the geographic distribution and categories of wetlands is essential for their conservation and management. Despite being the world′s fourth largest continent, South America has limited research on wetland mapping, and there is currently no available map that provides comprehensive information on wetland distribution and categories in the region. To address this issue, we used Sentinel-1, Sentinel-2 and SRTM data, developed a sample collection method and a wetland mapping method with a collection of multi-source features such as optical features, polarization features and shape features for South American wetlands. We produced a 10-m resolution wetland map based on the Google Earth Engine(GEE) platform. Our Level-1 wetland cover map accurately captured six wetland sub-categories with an overall accuracy of 96.24% and a kappa coefficient of 0.8649, while our Level-2 water cover map included five sub-categories with an overall accuracy of 97.23% and a kappa coefficient of0.9368. The results show that the total area of existing wetlands in South America is approximately 1,737,000 km~2, which is6.8% of the total land area. Among the ten wetland categories, shallow sea had the largest area(960,527.4 km~2), while aquaculture ponds had the smallest area 1513.6 km~2. Swamp had the second largest area(306,240.1 km~2). Brazil, Argentina,Venezuela, Bolivia, and Colombia were found to have the largest wetland areas, with Brazil and Colombia having the most diverse wetland categories. This product can serve as baseline data for subsequent monitoring, management, and conservation of South American wetlands.

关键词： Wetland mapping Google Earth Engine Sentinel imagery South America

A Server Placement Algorithm for Reducing Risk and Improving Power Utilization in Data Centers

在线全文

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2024年第1期29卷 158-173页

作者： Rui Chen Huikang Huang Xiaoxuan Luo weiwei Lin School of Computer Science and Engineering South China University of TechnologyGuangzhou 510006China Peng Cheng Laboratory Shenzhen 518066China

As the power demand in data centers is increasing,the power capacity of the power supply system has become an essential resource to be *** many data centers use power oversubscription to make full use of the power capacity,there are unavoidable power supply risks associated with ***,how to improve the data center power capacity utilization while ensuring power supply security has become an important *** solve this problem,we first define it and propose a risk evaluation metric called Weighted Power Supply Risk(WPSRisk).Then,a method,named Hybrid Genetic Algorithm with Ant Colony System(HGAACS),is proposed to improve power capacity utilization and reduce power supply risks by optimizing the server placement in the power supply *** uses historical power data of each server to find a better placement solution by population *** possesses not only the remarkable local search ability of Ant Colony System(ACS),but also enhances the global search capability by incorporating genetic operators from Genetic Algorithm(GA).To verify the performance of HGAACS,we experimentally compare it with five other placement *** experimental results show that HGAACS can perform better than other algorithms in both improving power utilization and reducing the riskof powersupply system.

关键词： server placement power utilization power supply risk swarm intelligence algorithm

Predicting changes in the suitable habitats of six halophytic plant species in the arid areas of Northwest China

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

Journal of Arid Land 2024年第10期16卷 1380-1408页

作者： yang Ao TU Wenqin YIN Benfeng ZHANG Shujun ZHANG Xinyu ZHANG Qing HUANG Yunjie HAN Zhili yang Ziyue ZHOU Xiaobing ZHUANG weiwei ZHANG Yuanming College of Life Sciences Xinjiang Normal University/Xinjiang Key Laboratory of Special Species Conservation andRegulatory Biology/Key Laboratory of Special Environment Biodiversity Application and Regulation in Xinjiang/KeyLaboratory of Plant Stress Biology in Arid LandUrumqi 830054China State Key Laboratory of Desert and Oasis Ecology Key Laboratory of Ecological Safety and Sustainable Development in AridLandsXinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Xinjiang Key Laboratory of Biodiversity Conservation and Application in Arid Lands Xinjiang Institute of Ecology andGeographyChinese Academy of SciencesUrumqi 830011China Xinjiang Field Scientific Observation Research Station of Tianshan Wild Fruit Forest Ecosystem Yili Botanical GardenXinjiang Institute of Ecology and GeographyChinese Academy of SciencesXinyuan 835800China State Key Laboratory of Earth Surface Processes and Resource Ecology College of Life SciencesBeijing Normal UniversityBeijing 100875China University of Chinese Academy of Sciences Beijing 100049China College of Biological Sciences University of California DavisDavisCA 95616USA College of Ecology and Environment Xinjiang UniversityUrumqi 830017China College of Resources and Environment/Xinjiang Key Laboratory of Soil and Plant Ecological Processes Xinjiang AgriculturalUniversityUrumqi 830052China College of Grassland Science Xinjiang Agricultural UniversityUrumqi 830052China

In the context of changes in global climate and land uses,biodiversity patterns and plant species distributions have been significantly *** salinization is a growing problem,particularly in the arid areas of Northwest *** are ideal for restoring soil salinization because of their adaptability to salt *** this study,we collected the current and future bioclimatic data released by the WorldClim database,along with soil data from the Harmonized World Soil Database(v1.2)and A Big Earth Data Platform for Three *** the maximum entropy(MaxEnt)model,the potential suitable habitats of six halophytic plant species(Halostachys caspica(Bieb.)***.,Halogeton glomeratus(Bieb.)***.,Kalidium foliatum(Pall.)Moq.,Halocnemum strobilaceum(Pall.)Bieb.,Salicornia europaea L.,and Suaeda salsa(L.)Pall.)were assessed under the current climate conditions(average for 1970-2000)and future(2050s,2070s,and 2090s)climate scenarios(SSP245 and SSP585,where SSP is the Shared Socio-economic Pathway).The results revealed that all six halophytic plant species exhibited the area under the receiver operating characteristic curve values higher than 0.80 based on the MaxEnt model,indicating the excellent performance of the MaxEnt *** suitability of the six halophytic plant species significantly varied across regions in the arid areas of Northwest *** different future climate change scenarios,the suitable habitat areas for the six halophytic plant species are expected to increase or decrease to varying *** global warming progresses,the suitable habitat areas of ***,***,and *** exhibited an increasing *** contrast,the suitable habitat areas of ***,***,and *** showed an opposite ***,considering the ongoing global warming trend,the centroids of the suitable habitat areas for various halophytic plant species would migrate to different degrees,and four halophytic plant species,namely,S.

关键词： halophytes climate change global warming maximum entropy(MaxEnt)model soil salinization suitable habitats Northwest China

Microearthquake reveals the lithospheric structure at midocean ridges and oceanic transform faults

在线全文

学校读者我要写书评

暂无评论

Journal of Oceanology and Limnology 2024年第3期42卷 697-700页

作者： Zhiteng YU Jiabiao LI weiwei DING Key Laboratory of Submarine Geosciences&Second Institute of Oceanography Ministry of Natural ResourcesHangzhou 310012China

Mid-ocean ridge and oceanic transforms are among the most prominent features on the seafloor surface and are crucial for understanding seafloor spreading and plate tectonic dynamics,but the deep structure of the oceanic lithosphere remains poorly *** large number of microearthquakes occurring along ridges and transforms provide valuable information for gaining an indepth view of the underlying detailed seismic structures,contributing to understanding geodynamic processes within the oceanic *** studies have indicated that the maximum depth of microseismicity is controlled by the 600-℃***,this perspective is being challenged due to increasing observations of deep earthquakes that far exceed this suggested isotherm along mid-ocean ridges and oceanic transform *** mechanisms have been proposed to explain these deep events,and we suggest that local geodynamic processes(e.g.,magma supply,mylonite shear zone,longlived faults,hydrothermal vents,etc.)likely play a more important role than previously thought.

关键词： microearthquake mid-ocean ridge oceanic transform fault oceanic lithosphere thermal structure earthquake location

Jamming Assisted Covert Wireless Communication in Multi-Channel Systems

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第9期21卷 211-224页

作者： Che Bohan Sha Nan yang.weiwei Lu Xingbo Gao Chang Army Engineering University of PLA Nanjing 210007China Beijing University of Posts and Telecommunications Beijing 100876China

This paper investigates the jammerassisted multi-channel covert wireless communication(CWC)by exploiting the randomness of sub-channel selection to confuse the *** particular,we propose two sub-channel selection transmission schemes,named random sub-channel selection(RSS)scheme and maximum sub-channel selection(MSS)scheme,to enhance communication *** each proposed scheme,we first derive closed-form expressions of the transmission outage probability(TOP),the average effective rate,and the minimum average detection error probability(DEP).Then,the average effective covert rate(ECR)is maximized by jointly optimizing the transmit power at the transmitter and the number of *** results show that there is an optimal value of the number of sub-channels that maximizes the average *** also find that to achieve the maximum average ECR,a larger number of subchannels are needed facing a stricter covertness constraint.

关键词： covert wireless communication jamming multi-channel system

Facile interfacial synthesis of gold micronails with adjustable length and roughness and their superior SERS properties for the detection of p-aminothiophenol Author links open overlay panel

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第8期91卷 333-340页

作者： Hang Li Kaisheng Yao Tianhang Liu weiwei Lu School of Chemistry and Chemical Engineering Henan University of Science and TechnozlogyLuoyang471023China School of Physics and Engineering Henan University of Science and TechnologyLuoyang471023China

Au hierarchical architectures with special morphology and structures are strongly desired in varied ***,a simple synthesis method was developed for the one-step preparation of Au micronails(MNs)at the planar liquid-liquid interface under mild *** well-defined Au MNs were grown and constructed at CHCl_(3)-H_(2)O interface at room temperature using aniline in CHCl_(3)as reducing agent and HAuCl_(4)in H_(2)O as precursor and no surfactant or seed is *** intriguing Au MNs with rough surface consist of big heads and thin rods,just like iron nails in ***,through simple changing the reagent concentrations,the length and surface roughness of Au MNs can be adjusted *** effects of a series of factors on the morphology and structure of the products are studied in *** p-aminothiophenol as a molecular probe,the as-obtained Au MNs all exhibit dramatically improved surface enhanced Raman scattering sensitivity and high reproducibility,the enhancement factor and limit of detection of Au MNs are 5.4×10^(5)and 1.0×10^(-10),respectively.

关键词： Au micronails Liquid-liquid interface synthesis Surface enhanced Raman scattering P-aminothiophenol

MCR-YOLO model for underwater target detection based on multi-color spatial features

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

Optoelectronics Letters 2024年第5期20卷 313-320页

作者： LIU Peiyu XING weiwei MA Yixuan School of Software Engineering Beijing Jiaotong UniversityBeijing 100044China

Within the fields of underwater robotics and ocean information processing, computer vision-based underwater target detection is an important area of research. Underwater target detection is made more difficult by a number of problems with underwater imagery, such as low contrast, color distortion, fuzzy texture features, and noise interference, which are caused by the limitations of the unique underwater imaging environment. In order to solve the above challenges, this paper proposes a multi-color space residual you only look once(MCR-YOLO) model for underwater target detection. First, the RGB image is converted into YCb Cr space, and the brightness channel Y is used to extract the non-color features of color-biased images based on improved Res Net50. Then, the output features of three scales are combined between adjacent scales to exchange information. At the same time, the image features integrated with low-frequency information are obtained via the low-frequency feature extraction branch and the three-channel RGB image, and the features from the three scales of the two branches are fused at the corresponding scales. Finally, multi-scale fusion and target detection are accomplished utilizing the path aggregation network(PANet) framework. Experiments on relevant datasets demonstrate that the method can improve feature extraction of critical targets in underwater environments and achieve good detection accuracy.

关键词： underwater image utilizing

Green batch prepared a novel C/P co-doping urchin-like TiO_(2)for enhanced photocatalytic degradation and mineralization of trimethoprim

在线全文

学校读者我要写书评

暂无评论

Emerging Contaminants 2024年第3期10卷 181-192页

作者： weiwei yang Qingwei Bu Ruiqing Zhao Haitao Huang Weijia Xu Nan Jia Qianhui Shi Lei yang Jianfeng Tang Gang Yu School of Chemical&Environmental Engineering China University of Mining&Technology-BeijingBeijing100083PR China State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing100085PR China Key Laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen361021PR China Advanced Interdisciplinary Institute of Environment and Ecology Beijing Normal UniversityBeijing102299PR China

In advancing the practical application of photocatalytic degradation for pollutant removal,batch preparation of environmentally friendly photocatalysts plays a crucial ***,we prepared C/P co-doped urchin-like TiO_(2)(C/PeTiO_(2))through a straightforward room temperature impregnation and atmospheric annealing *** acid served as the dopant precursor for introducing C and P onto the TiO_(2)*** doping process was verified through energy dispersive X-ray spectroscopy(EDX),electron spin resonance(ESR),and X-ray photoelectron spectroscopy(XPS)*** C/PeTiO_(2)photocatalyst exhibited exceptional efficiency in degrading the target compound trimethoprim(TMP),achieving a degradation of 98%TMP within 60 min and a mineralization of 40%TMP within 120 min,which were respectively 2.4 and 1.6 times higher than that of pristine TiO_(2).The intermediate products of TMP were detected,and a plausible degradation pathway was *** characterization results also confirmed that C/P co-doping could effectively enhance the carrier separation efficiency of C/PeTiO_(2).The catalysts prepared using the scaled-up impregnation system and reusing the phytic acid solution consistently demonstrated stable catalytic performance,which confirmed the viability of the method for green and batch preparation of C/P co-doped TiO_(2).Notably,the obtained catalyst consistently exhibited high degradation efficacy in various real water bodies,highlighting its substantial potential for practical *** green and batch preparation method of C/PeTiO_(2)introduces a novel approach to the practical application of photocatalysis technology in treatment of water contaminants.

关键词： C/PeTiO_(2) Co-doping Phytic acid Trimethoprim Photocatalytic degradation

Cooperative Covert Communication in Multi-Antenna Broadcast Channels

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

China Communications 2024年第6期21卷 246-260页

作者： Qiao Sen Liu Guangjie Ji Xiaopeng Liu weiwei School of Electrical and Information Engineering Nanjing University of Information Science and TechnologyNanjing 210044China School of Automation Nanjing University of Science and TechnologyNanjing 210094China

With the gradual popularization of 5G communications,the application of multi-antenna broadcasting technology has become ***,this study aims to investigate the wireless covert communication in the two-user cooperative multi-antenna broadcast *** focus on the issue that the deteriorated reliability and undetectability are mainly affected by the transmission *** tackle this issue,we design a scheme based on beamforming to increase the reliability and undetectability of wireless covert communication in the multi-antenna broadcast *** first modeled and analyzed the cooperative multi-antenna broadcasting system,and put forward the target *** we use the SCA(successive convex approximation)algorithm to transform the target problem into a series of convex *** the convex problems are solved and the covert channel capacity is *** order to verify the effectiveness of the scheme,we conducted simulation *** simulation results show that the proposed beamforming scheme can effectively improve the reliability and undetectability of covert communication in multi-antenna broadcast channels.

关键词： beamforming covert communication multi-antenna broadcast channels OFDM