检索结果-南通市图书馆

A Survey on Event Tracking in Social Media Data Streams

Big Data Mining and Analytics 2024年第1期7卷 217-243页

作者： Zixuan Han Leilei Shi Lu Liu Liang Jiang jiawei fang Fanyuan Lin Jinjuan Zhang John Panneerselvam Nick Antonopoulos School of Computer Science and Communication Engineering and Jiangsu Key Laboratory of Security Technology for Industrial Cyberspace Jiangsu UniversityZhenjiang 212013China School of Computing and Mathematical Sciences University of LeicesterLeicesterLE17RHUK Ocean College Jiangsu University of Science and TechnologyZhenjiang 212100China University Executive Office Edinburgh Napier UniversityEdinburghEH114BNUK

Social networks are inevitable parts of our daily life,where an unprecedented amount of complex data corresponding to a diverse range of applications are *** such,it is imperative to conduct research on social events and patterns from the perspectives of conventional sociology to optimize services that originate from social *** tracking in social networks finds various applications,such as network security and societal governance,which involves analyzing data generated by user groups on social networks in real ***,as deep learning techniques continue to advance and make important breakthroughs in various fields,researchers are using this technology to progressively optimize the effectiveness of Event Detection(ED)and tracking *** this regard,this paper presents an in-depth comprehensive review of the concept and methods involved in ED and tracking in social *** introduce mainstream event tracking methods,which involve three primary technical steps:ED,event propagation,and event ***,we introduce benchmark datasets and evaluation metrics for ED and tracking,which allow comparative analysis on the performance of mainstream ***,we present a comprehensive analysis of the main research findings and existing limitations in this field,as well as future research prospects and challenges.

关键词： Event Detection(ED) event propagation event evolution social networks

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

基于多时相Sentinel-2A影像的狼毒分布识别

引用

草业科学 2024年第2期41卷 322-331页

作者：房家玮胡念钊王怀玉刘咏梅西北大学城市与环境学院陕西西安710127 陕西省地表系统与环境承载力重点实验室陕西西安710127

狼毒(Stellera chamaejasme)是近年来青藏高原高寒草地的主要入侵毒杂草之一,及时高效的调查与监测可为狼毒综合防控与退化草地恢复提供重要的技术支持。本研究选取花期前与盛花期的Sentinel-2A多光谱影像,将Google Earth Engine平台去... 详细信息

狼毒(Stellera chamaejasme)是近年来青藏高原高寒草地的主要入侵毒杂草之一,及时高效的调查与监测可为狼毒综合防控与退化草地恢复提供重要的技术支持。本研究选取花期前与盛花期的Sentinel-2A多光谱影像,将Google Earth Engine平台去云、环境要素掩膜、特征优选和随机森林分类相结合,探讨区域尺度的狼毒遥感识别方法。结果表明,通过狼毒敏感指数计算,以及Spearman秩相关性分析与随机森林重要性排序相结合的二次降维,提取了7项狼毒分类特征并构建了4个特征组合方案。与单时相特征组合相比,多时相特征组合有效提高了狼毒识别精度,其中,基于随机森林模型的6个特征组合方案的分类总精度为84.62%,狼毒分类精度均大于80%,识别效果最佳。本研究显示,影像去云及掩膜预处理能够有效减少分类干扰信息,花期前与盛花期提取的多时相特征组合增强了狼毒群落与其他群落的影像光谱差异,在区域尺度狼毒遥感识别中具有较好的应用潜力。

关键词：去云特征优选分层掩膜多时相分析随机森林敏感指数狼毒

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

Nanomechanics: emerging opportunities for future computing

引用

Science China(Information Sciences) 2021年第10期64卷 245-247页

作者： Zenghui WANG jiawei fang Pengcheng ZHANG Rui YANG Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China University of Michigan-Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong University

The exploration for greater computing power has existed for a long time. Since the 1960 s, transistors in modern electronic computers have kept advancing following Moore’s ***, as silicon transistors continue to scale down, they face challenges such as increases in OFF-state leakage power due to the limited subthreshold swing, incompatibility with high-temperature operation, and lack of ***, new types of computing devices are being explored to address these problems.

关键词： MEMS NEMS mechanical computing logic devices switches resonators

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

乡村产业振兴带头人联农带农效应及其影响因素研究——基于福建“头雁”项目的实证分析

引用

福建农林大学学报（哲学社会科学版） 2024年第2期27卷 18-26,51页

作者：刘飞翔方佳薇林之棋福建农林大学乡村振兴学院福建福州350002

从就业效应、增收效应、技术效应、组织效应等4个维度构建乡村产业振兴带头人联农带农效应指标体系,采用熵权TOPSIS模型测算各指标的权重,对福建“头雁”项目进行实证分析,并通过OLS回归模型分析影响联农带农效应的因素。在此基础上,提... 详细信息

从就业效应、增收效应、技术效应、组织效应等4个维度构建乡村产业振兴带头人联农带农效应指标体系,采用熵权TOPSIS模型测算各指标的权重,对福建“头雁”项目进行实证分析,并通过OLS回归模型分析影响联农带农效应的因素。在此基础上,提出通过“头雁”项目培育更多、更优质的乡村产业带头人;完善利益联结机制,促进农民致富增收;激活乡村经济引擎,拓宽农民就业渠道;优化相关政策,打造良好的联农带农环境;完善社会化服务体系,推动科技成果应用转化等建议,为乡村产业振兴提供现实参考和借鉴路径。

关键词：乡村产业振兴带头人联农带农效应分析影响因素

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

毕节烟区不同产地烟叶的感官质量特征及关键香气成分

引用

烟草科技 2024年第8期57卷 21-31页

作者：方嘉炜严锦申钟帅蓝军黄嘉杰杨天旭姜俊红王维华南农业大学农学院广州市天河区510642 广东中烟工业有限责任公司广州市天河区510000

为研究毕节烟区不同产地烟叶感官质量的差异,并明确有关键影响的香气成分,以毕节烟区8个县(区、市)的42份C3F烤烟作为材料,采用感官质量评价和HS-SPME-GC-MS技术对毕节烟叶的感官质量和香气成分进行分析。结果表明:①毕节不同产地烟叶... 详细信息

为研究毕节烟区不同产地烟叶感官质量的差异,并明确有关键影响的香气成分,以毕节烟区8个县(区、市)的42份C3F烤烟作为材料,采用感官质量评价和HS-SPME-GC-MS技术对毕节烟叶的感官质量和香气成分进行分析。结果表明:①毕节不同产地烟叶在感官品质方面存在较明显的差异,中、西部产地烟叶质量整体优于东部产地。②共定性到318种挥发性成分,结合OPLS-DA模型分析和rOAV分析,筛选出13种VIP>1且rOAV>1的香气成分,进一步通过与感官质量指标的相关性分析,确认β-大马酮、香叶基丙酮、戊酸叶醇酯、2,5-二甲基-4-羟基-3(2H)-呋喃酮、2-苯乙醇和苯乙醛是使毕节不同产地烟叶风格差异的关键香气成分。③毕节各产地烟叶的2-苯乙醇和2,5-二甲基-4-羟基-3(2H)-呋喃酮的相对含量均较高,这可能是毕节烟区烟叶的蜂蜜味和甜味较为突出的主要原因。

关键词：烟叶毕节烟区顶空固相微萃取-气相色谱-质谱联用法(HS-SPME-GC-MS) 感官质量评价香气成分相对香气活度值

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

Experimental Investigation and X-Ray Computed Microtomography Simulation on Thermal Physical Properties of Foundation Materials after Molten Salt Leakage in the Storage Tank

引用

Journal of Thermal Science 2024年第2期33卷 591-601页

作者： WANG Zhaowen ZHOU Hao LUO jiawei LI Yawei fang Hao LIU Tianxiao State Key Laboratory of Clean Energy Utilization Institute for Thermal Power EngineeringZhejiang UniversityHangzhou310027China

This paper studied the thermal physical properties of foundation materials in the molten salt tank of thermal energy storage system after molten salt leakage by Transient plane source experiment and X-ray computed microtomography simulation *** microstructure,thermal properties and pressure resistance with different particle diameters were *** measured heat conductivities from Transient plane source experiment for three cases are 0.49 W/(m·K),0.48 W/(m·K),and 0.51 W/(m·K),and the porosity is 30.1%,30.7%,and 31.2% *** heat conductivity simulating results of three cases are 0.471 W/(m·K),0.482W/(m·K),and 0.513 W/(m·K).The ratio of difference between the results of simulation and Transient plane source measurement is as low as 1.2%,verifying the reliability of experimental and simulation results to a certain *** with the heat conductivity of 0.097-0.129 W/(m·K) and porosity of 71.6%-78.9% without leaking salt,the porosity is reduced by more than 50% while the heat conductivity increased by 4 to 5 times after molten salt *** significant increase in heat conductivity has a great impact on security operation,structure design,and modeling of the tank foundation for solar power plants.

关键词： heat conductivity X-ray computed microtomography foundation materials three-phase threshold algorithm molten salt leakage

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

Effects of Biochar Inoculation with Bacillus megaterium on Rice Soil Phosphorus Fraction Transformation and Bacterial Community Dynamics

引用

Rice science 2024年第4期31卷 361-365,I0001-I0003页

作者： YU Keru XUE Zhaokun fang Xianzhi MA jiawei WANG Yongjun LIU Dan YE Zhengqian State Key Laboratory of Subtropical Silviculture Zhejiang A&F UniversityHangzhou 311300China Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province Zhejiang A&F UniversityHangzhou 311300China Department of Forest Protection College of Forestry and BiotechnologyZhejiang A&F UniversityHangzhou 311300China

Rice husk biochar inoculated with Bacillus megaterium(BM)(referred to as BM-inoculated biochar, BMB) and uninoculated rice husk biochar(RHB) were added to soil at two rates(0.5%, as BMB1 and RHB1, respectively, and 1.0%, as BMB2 and RHB2, respectively) in an incubation experiment to comprehensively evaluate their effects on basic soil properties, phosphorus(P) fractions, bacterial community composition, and P-cycling genes.

关键词： soil comprehensive Transformation

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

Nickel-iron in the second coordination shell boost single-atomicsite iridium catalysts for high-performance urea electrooxidation

引用

Nano Research 2024年第5期17卷 3919-3926页

作者： Xiaoyu Chen jiawei Wan Jing Chai Liang Zhang fang Zhang Qinghua Zhang Lin Gu Lirong Zheng Ranbo Yu Department of Physical Chemistry School of Metallurgical and Ecological EngineeringUniversity of Science and Technology BeijingBeijing 100083China State Key Laboratory of Biochemical Engineering Key Laboratory of Biopharmaceutical Preparation and DeliveryChinese Academy of SciencesInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China Center for Combustion Energy School of Vehicle and MobilityState Key Laboratory of Intelligent Green Vehicle and MobilityTsinghua UniversityBeijing 100084China Analysis and Testing Center Beijing Institute of TechnologyBeijing 100081China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Beijing National Center for Electron Microscopy and Laboratory of Advanced Materials Department of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China

Single-atom catalysts(SACs)with high catalytic activity as well as great stability are demonstrating great promotion in electrocatalytic energy conversion,which is also a big challenge to ***,we proposed a facile synthetic strategy to construct nickel-iron bimetallic hydroxide nanoribbon stabilized single-atom iridium catalysts(Ir-NiFe-OH),where the nickel-iron hydroxide nanoribbon not only can serve as good electronic conductor,but also can well stabilize and fully expose single-atom *** as catalyst for urea oxidation reaction(UOR),it exhibited excellent UOR performance that it only needed a low operated potential of 1.38 V to achieve the current density of 100 mA·cm^(-2).In-situ Fourier transform infrared spectroscopy,X-ray absorption spectrum,and density functional theory calculations proved that Ir species are active centers and the existence of both Ni and Fe in the local structure of Ir atom can optimize the d-band center of Ir species,promoting the adsorption of intermediates and desorption of products for *** hydrogen evolution reaction(HER)/UOR electrocatalytic cell demanded voltages of 1.46 and 1.50 V to achieve 50 and 100 mA·cm^(-2),respectively,which demonstrated a higher activity and better stability than those of conventional *** work opens a new avenue to develop catalysts for UORs with boosted activity and stability.

关键词： single-atom iridium coordinate structure nanoribbon urea electrooxidation

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

毕节烟区烤烟的质量及其空间分布特征

引用

贵州农业科学 2024年第5期52卷 30-40页

作者：严锦申黄瑞寅钟帅蓝军杨天旭方嘉炜姜俊红王维广东中烟有限责任公司广东广州510000 华南农业大学广东广州510000

【目的】探明贵州毕节烟区不同植烟地烤烟的质量及其空间分布特征,为毕节烟区烤烟的总体生产布局规划与工业企业合理利用产区不同质量特征烟叶原料提供参考。【方法】选择毕节烟区各县域42个烟叶点126份烤烟样品,运用隶属函数法和聚类... 详细信息

【目的】探明贵州毕节烟区不同植烟地烤烟的质量及其空间分布特征,为毕节烟区烤烟的总体生产布局规划与工业企业合理利用产区不同质量特征烟叶原料提供参考。【方法】选择毕节烟区各县域42个烟叶点126份烤烟样品,运用隶属函数法和聚类分析法分析不同质量烟叶的空间分布特征。【结果】毕节烟区不同产地烤烟的烟碱、总糖、还原糖、淀粉、总氮和钾含量分别为2.40%~3.76%、30.90%~36.33%、23.80%~27.48%、3.49%~5.75%、1.78%~2.50%和2.00%~3.07%。化学成分指标、外观质量指标与感官评价指标间存在相关或极显著相关性。感官质量、外观质量、化学成分和综合得分分别为64.26~77.01分、74.08~84.75分、55.33~86.66分和0.748~1.213分。在平方欧氏距离为5处可将毕节烟区分为4类,综合得分依次为Ⅰ类>Ⅱ类>Ⅲ类>Ⅳ类,其中,Ⅰ类烤烟的感官和外观质量总体表现最好,Ⅱ类烤烟次之,Ⅲ类烤烟差,Ⅳ类烤烟整体较差。Ⅰ类烟区基本分布在毕节中部,大部分集中在大方县和纳雍县域内;Ⅱ类烟区分布在毕节中部和西北;Ⅲ类烟区在毕节占比最大,涵盖毕节的大部分地区;Ⅳ类烟区零散分布在毕节偏北部和偏南部的边缘地区。【结论】毕节烟区在平方欧氏距离为5处分为4类,综合得分依次为Ⅰ类>Ⅱ类>Ⅲ类>Ⅳ类;海拔1300~1800 m区域烟叶综合质量最优,海拔1800~2200 m区域烟叶较优;海拔800~1300 m区域烟叶最差。

关键词：烤烟质量评价聚类分析空间分布毕节烟区

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

Improving iconic memory through contrast detection training with HOA-corrected vision

引用

Fundamental Research 2024年第1期4卷 95-102页

作者： Ling Gong Junlei Zhao Yun Dai Zili Wang fang Hou Yudong Zhang Zhong-Lin Lu jiawei Zhou State Key Laboratory of Ophthalmology Optometry and Vision ScienceEye HospitalSchool of Ophthalmology and OptometryWenzhou Medical UniversityWenzhou 325027China Institute of Optics and Electronics Chinese Academy of SciencesChengdu 610209China The Key Laboratory of Adaptive Optics Chinese Academy of SciencesChengdu 610209China Chengdu University of Traditional Chinese Medicine Chengdu 610075China Division of Arts and Sciences New York University ShanghaiShanghai 200126China Center for Neural Science Department of PsychologyNew York UniversityNew York 10003United States NYU-ECNU Institute of Brain and Cognitive Science at NYU Shanghai Shanghai 200062China

Iconic memory and short-term memory are not only crucial for perception and cognition,but also of great importance to mental ***,we first showed that both types of memory could be improved by improving limiting processes in visual processing through perceptual *** adults were trained in a contrast detection task for ten days,with their higher-order aberrations(HOA)corrected in *** found that the training improved not only their contrast sensitivity function(CSF),but also their iconic memory and baseline information maintenance for short-term memory,and the relationship between memory and CSF improvements could be well-predicted by an observer *** results suggest that training the limiting component of a cognitive task with visual perceptual learning could improve visual *** may also provide an empirical foundation for new therapies to treat people with poor sensory memory.

关键词： Perceptual learning Iconic memory Higher-order aberrations Contrast sensitivity Short-term memory

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：