检索结果-南通市图书馆

High-resolution short-term prediction of the COVID-19 epidemic based on spatial-temporal model modified by historical meteorological data

引用

Fundamental Research 2024年第3期4卷 527-539页

作者： Bin chen ruming chen Lin Zhao Yuxiang Ren Li Zhang Yingjie Zhao Xinbo Lian Wei Yan Shuoyuan Gao College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China Collaborative Innovation Center of Western Ecological Security Lanzhou UniversityLanzhou 730000China

In the global challenge of Coronavirus disease 2019(COVID-19)pandemic,accurate prediction of daily new cases is crucial for epidemic prevention and socioeconomic *** contrast to traditional local,one-dimensional time-series data-based infection models,the study introduces an innovative approach by formulating the short-term prediction problem of new cases in a region as multidimensional,gridded time series for both input and prediction targets.A spatial-temporal depth prediction model for COVID-19(ConvLSTM)is presented,and further ConvLSTM by integrating historical meteorological factors(Meteor-ConvLSTM)is refined,considering the influence of meteorological factors on the propagation of *** correlation between 10 meteorological factors and the dynamic progression of COVID-19 was evaluated,employing spatial analysis techniques(spatial autocorrelation analysis,trend surface analysis,etc.)to describe the spatial and temporal characteristics of the *** the original ConvLSTM,an artificial neural network layer is introduced to learn how meteorological factors impact the infection spread,providing a 5-day forecast at a 0.01°×0.01°pixel *** results using real dataset from the 3.15 outbreak in Shanghai demonstrate the efficacy of Meteor-ConvLSTM,with reduced RMSE of 0.110 and increased R^(2) of 0.125(original ConvLSTM:RMSE=0.702,R^(2)=0.567;Meteor-ConvLSTM:RMSE=0.592,R^(2)=0.692),showcasing its utility for investigating the epidemiological characteristics,transmission dynamics,and epidemic development.

关键词： COVID-19 Prediction ConvLSTM Refined prediction Meteorological factors Spatial-temporal analysis

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

Zn和Cu对纯镁的微观组织与导电性能的影响研究

引用

四川冶金 2024年第3期46卷 67-74页

作者：陈汝明廖启宇胡文鑫王一凡乐启炽东北大学材料电磁过程研究教育部重点实验室辽宁沈阳110819 东北大学材料科学与工程学院辽宁沈阳110819 东北大学辽宁省轻量化用关键金属结构材料重点实验室辽宁沈阳110819 包头稀土研究院内蒙古包头014000

本文研究了Zn和Cu元素的添加对纯Mg微观组织和导电性能的影响。结果表明,Zn和Cu能明显细化纯Mg的铸态组织,且元素添加量越多,晶粒尺寸越细小。铸态Mg-Zn和Mg-Cu合金的导电率均随着元素添加量的增加而不断降低。Mg-Zn合金中,固溶在基体... 详细信息

本文研究了Zn和Cu元素的添加对纯Mg微观组织和导电性能的影响。结果表明,Zn和Cu能明显细化纯Mg的铸态组织,且元素添加量越多,晶粒尺寸越细小。铸态Mg-Zn和Mg-Cu合金的导电率均随着元素添加量的增加而不断降低。Mg-Zn合金中,固溶在基体中的溶质原子是影响导电率的主要因素;Mg-Cu合金中,第二相是影响导电率的主要因素。当元素添加量相同时,Zn对导电率的降低作用比Cu要更加显著。分别选取Mg-2.5%Zn合金和Mg-4%Cu合金在不同挤压温度下(200℃、300℃、400℃)进行挤压变形。Mg-2.5%Zn合金随着挤压温度提高,晶粒尺寸增大,第二相数量减少,导电率先降低再升高,但均低于其铸态合金的导电率。Mg-4%Cu合金随着挤压温度提高,晶粒尺寸增大,第二相数量无明显变化,导电率不断升高,均高于其铸态合金的导电率。

关键词：二元镁合金显微组织挤压变形导电率固溶原子

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

Message from the Guest Editor for the Special Issue

引用

China Communications 2008年第4期5卷 89-89页

作者： Prof.chen ruming

"Emergency Communica-tions" systems, especially the "Social Integrated Emergency Response Communications " Systems, are the professional communications systems with great social value and realistic significance, built... 详细信息

关键词： ZTE Message from the Guest Editor for the Special Issue

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

Breeding and application of Jiafuzhan,a new elite early indica rice cultivar in China

引用

Frontiers in Biology 2007年第2期2卷 144-150页

作者： WANG Houcong HUANG Huakang QIU Simi ZHANG Shi FANG Yashun CAI Jinlei ZHENG Xuan HUANG Yumin chen ruming SUN Chuanzhi chen Shuanglong CHI Xiaowen LIAO Xinying ZHANG Weiqing ZHONG Xinbin School of Life Sciences Xiamen UniversityXiamen 361005China Fujian Seed Station Fuzhou 350001China Xiamen Seed Management Station Xiamen 361012China Xiamen Agriculture Technology Extension Center Xiamen 361003China

After 20 years of dedicated research,Jiafuzhan has been successfully developed under the new technologies in breeding high-quality early indica rice *** rice quality has almost reached the A-level Editable Rice of Agriculture Department of China,and its average production reaches 400-500 kg/(666.7 m^(2)).This new cultivar also has other characteristics such as enhanced resistance of blast and fallen,steady productivity,and strong *** has been put into production of over 11.4×10^(4)hm^(2)in Fujian Province and has been introduced and extended in other Provinces like Jiangxi,Guangdong,and Guangxi,*** successes of breeding Jiafuzhan is a solution to the existing perennial problems in the rice industry,such as poor grain quality of big-grain rice and early indica rice,low productivity,and poor blast resistance of elite rice.

关键词： Jiafuzhan early indica rice high quality

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

Strategic Considerations on Development of WiMAX and Its Relationship with 3G and 4G

引用

ZTE Communications 2005年第1期3卷 48-50,53页

作者： chen ruming (Communications Science and Technology Commission, Ministry of Information Industry, Beijing 100037, China)

The paper states the characteristics and basic market positioning of WiMAX. It should be noted that WiMax is a new generation WMAN (Wideband MAN) broadband wireless access standard with good forward extensibility. It is emphasized that the basic market positioning of WiMAX should be nothing but WMAN applications. It is predicted that the applications of WiMax would face severe challenges mainly due to its high cost, at least at the initial stage. Finally the paper gives all-around analysis on the relationship between Wi-Fi, WiMAX, WBMA, 3G, 3G+ and 4G.

关键词： WiMAX rate Strategic Considerations on Development of WiMAX and Its Relationship with 3G and 4G

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

对IP技术发展中一些问题的思考

引用

电信科学 2005年第8期21卷 6-9页

作者：陈如明信息产业部无线电管理局北京100037

本文首先介绍了IP技术发展中存在的主要问题,针对IP安全问题和QoS问题提出了发展战略,尤其针对IPv6发展中的一些关键问题进行了深入探讨。

关键词：下一代网络服务质量 IPv6 IP技术安全问题 S问题

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

2000年世界无线电通信大会(WRC-2000)新进展及相应对策考虑(续)

引用

电信科学 2000年第10期16卷 1-5页

作者：陈如明信息产业部无线电管理局北京100804

世界无线电通信大会(WRC)是国际电联涉及无线电频率、卫星轨道资源的划分、分配、指配、规划及管理的全球盛会。本文介绍了WRC 2000大会概况及重要新进展(确定IMT 2000附加频谱 ,重新规划1、3区卫星广播业务 ,扩展卫星无线电导航业务新... 详细信息

世界无线电通信大会(WRC)是国际电联涉及无线电频率、卫星轨道资源的划分、分配、指配、规划及管理的全球盛会。本文介绍了WRC 2000大会概况及重要新进展(确定IMT 2000附加频谱 ,重新规划1、3区卫星广播业务 ,扩展卫星无线电导航业务新频段 ,以及包括HAPS在内的HDFS的新工作频段及其共用问题) ,论述了其可能的战略影响及相应对策考虑。

关键词： WRC-2000 IMT-2000 无线电通信国际会议

来源：

维普期刊数据库

同方期刊数据库评论