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价值链视角下中国新能源汽车产业网络及其机制

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Journal of Geographical Sciences 2024年第4期34卷 779-803页

作者：何瑶杨永春王绍博 College of Earth and Environmental Sciences Lanzhou UniversityLanzhou 730000China Key Laboratory of Western China's Environmental Systems Ministry of Education of the People's Republic of ChinaLanzhou UniversityLanzhou 730000China Institute of County Economic Development Lanzhou UniversityLanzhou 730000China

Based on the data of listed companies in the core industry chain of China's new energy vehicles in 2015 and 2021,this paper constructs their industrial network from the perspective of the value chain,and uses methods such as social network and negative binomial regression model to study the characteristics,evolution,differences,and formation mechanisms of different value chain *** results show that:(1)R&D-oriented,production-oriented,and service-oriented networks share several common features:These networks are simultaneously expanding in scale and transitioning towards more efficient“small world”network;The degree distribution in these networks follows a power-law distribution,indicating a scale-free network structure;There is a decrease in the power-law exponent of network's degree distribution,indicating an increase in network ***,there is a significant positive correlation between the degrees of nodes in networks with diverse value chains,suggesting that the same node holds a similar level of significance across different networks.(2)The number of power-prestige,power and prestige nodes increases in the networks of all value chain segments,except in the service-oriented network,where there are no power *** each value chain network,these nodes have different agglomeration directions:In R&D-oriented network,the nodes tend to cluster around headquarters and high-level *** contrast,service-oriented network shows a concentration of nodes in municipalities,sub-provincial and provincial ***,production-oriented network demonstrates a clustering of nodes in traditional production bases.(3)Different value-added segments of industry form different types of agglomeration in pursuit of different factor endowments and agglomeration effect,and form the spatial structure of the strongest connection industrial network with different *** R&D-oriented networks have always been an integrated and closely connec

关键词： value chain new energy vehicle industry listed company industrial network core-periphery structure

基于改进PFCM算法的多重耦合电能质量扰动识别分析

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电力科学与工程 2024年第8期40卷 1-9页

作者：杨用春杨林新能源电力系统国家重点实验室(华北电力大学) 河北保定071003

非线性负荷、电力电子设备以及网络因素的复杂交互导致了电能质量问题的多样化及相互耦合。电力用户生产的多种运行方式,进一步增加了电能质量的不确定性,使其呈现出概率性分布。鉴于传统统计学方法在处理分析大规模电能质量数据时的局... 详细信息

非线性负荷、电力电子设备以及网络因素的复杂交互导致了电能质量问题的多样化及相互耦合。电力用户生产的多种运行方式,进一步增加了电能质量的不确定性,使其呈现出概率性分布。鉴于传统统计学方法在处理分析大规模电能质量数据时的局限性,提出了一种改进的可能模糊C均值(PossiblefuzzyC-means,PFCM)聚类算法,并通过引入协方差矩阵和熵权法对原始数据进行预处理,有效提高了聚类分析的准确性和鲁棒性。首先针对改进的IEEE33节点系统进行仿真建模,并基于场景的方式生成得到电能质量特征数据;随后通过3种不同的算法挖掘出网络电能质量分布特征信息;最后通过对比3种算法的识别结果,验证了改进PFCM算法在电能质量扰动识别方面的有效性和优越性。

关键词：电能质量聚类分析电压暂降三相不平衡谐波

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实施项目式学习培养初中生英语高阶思维

英语教师 2024年第20期24卷 151-154,164页

作者：杨泳春广东省中山火炬高技术产业开发区第二中学广东中山528400

指出英语学科中培养高阶思维是提升英语学科核心素养的重要内容和途径。分析目前人教版(Go For It!)初中英语教材Section A最后一个板块在教学中存在利用率比较低的问题,以及项目式学习在此部分教学中实施的可行性。阐述布鲁姆认知分类... 详细信息

指出英语学科中培养高阶思维是提升英语学科核心素养的重要内容和途径。分析目前人教版(Go For It!)初中英语教材Section A最后一个板块在教学中存在利用率比较低的问题,以及项目式学习在此部分教学中实施的可行性。阐述布鲁姆认知分类学、支架理论、项目式学习POEM流程。以人教版初中《英语》七年级(下)Unit 4 Don’t eat in class为例,对基于项目式学习的高阶思维培养实施步骤进行系统阐述。

关键词：项目式学习高阶思维初中英语英语学科核心素养

基于LSTM神经网络的风力发电量短期预测研究

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电力系统装备 2024年第2期 13-15页

作者：杨永春山西省安装集团股份有限公司山西太原030032

基于LSTM神经网络的风力发电短期预测方法和传统的风力发电短期预测方法相比,其更贴近风力发电的实测值。文章首先采集需要的风力发电量数据,再对采集的风力发电量数据进行预处理,提高数据的可用性,在得到更高质量的风力发电量数据后,... 详细信息

基于LSTM神经网络的风力发电短期预测方法和传统的风力发电短期预测方法相比,其更贴近风力发电的实测值。文章首先采集需要的风力发电量数据,再对采集的风力发电量数据进行预处理,提高数据的可用性,在得到更高质量的风力发电量数据后,构建对风力发电量进行短期预测的LSTM短期预测模型。最后根据LSTM短期预测模型,生成相关的预测结果,完成基于LSTM神经网络的风力发电量短期预测研究,再进行基于LSTM神经网络的风力发电量短期预测试验。试验结果表明,基于LSTM神经网络的风力发电量短期预测精确度高。

关键词： LSTM神经网络发电预测风力发电量短期预测

Urban Redevelopment, Gentrification and Gentrifiers in Post-reform Inland China: A Case Study of Chengdu, China

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Chinese Geographical Science 2017年第1期27卷 151-164页

作者： HUANG Xing yang yongchun School of Architecture State Key Laboratory of Subtropical Building Science South China University of Technology Department of Geography Kyushu University Key Laboratory of Western China's Environmental Systems School of Resource and Environmental Science Lanzhou University College of Urban and Environmental Science Northwest University

Since its process evolved in recent years, the definition of gentrification has expanded to cover different forms of social upgrading, new spaces and new actors around the world. Studies on gentrification in Chinese cities began to take off in the 2000 s. However, they all mainly focused on the newly emerging global cities and there has been a lack of investigation on provincial cities. Furthermore, discussions on gentrifiers′ profiles and their motivations for housing choice are absent from literature on Chinese gentrification. Therefore, this paper aims to assess the relevance of the broad definition of gentrification in provincial Chinese cities through empirical research on urban redevelopment projects in Chengdu, and to examine the characteristics of gentrifiers(as new incoming residents) in it. The results show the rationality of gentrification processes as urban redevelopment in Chengdu, and reveal original outcomes on the corresponding gentrifiers′ profiles and the motivations behind their housing choice, which are different from the general features of gentrifiers in standard Western gentrification research.

关键词： gentrification new-build gentrification urban redevelopment projects gentrifiers motivations for housing choice Chengdu China

Spatial evolution and growth mechanism of urban networks in western China:A multi-scale perspective

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Journal of Geographical Sciences 2022年第3期32卷 517-536页

作者： yang Liangjie WANG Jing yang yongchun School of Geography and Environmental Sciences Northwest Normal UniversityLanzhou 730070China School of Resources and Environmental Lanzhou UniversityLanzhou 730070China

Globalization and informatization promote the evolution of urban spatial organization from a hierarchical structure mode to a network structure mode,forming a complex network *** study considers the coupling of“space of flows”and“spaces of places”as the core and“embeddedness”as the link and a relevant theoretical basis;then we construct a conceptual model of urban networks and explore the internal logic of enterprise networks and city *** the interlocking-affiliate network model and data from China’s top 500 listed companies,this study constructs a directed multi-valued relational matrix between cities in western China from 2005 to *** social network analysis and the multiple regression of quadratic assignment program model(MRQAP),this study adopts a“top-down”research perspective to analyze the spatio-temporal evolution and growth mechanism of the city network in western China from three nested spatial scales:large regions,intercity agglomerations,and intracity *** results show the following:(1)Under the large regional scale,the city network has good symmetry,obvious characteristics of hierarchical diffusion,neighborhood diffusion,and cross-administrative regional connection,presenting the“core-periphery”structural pattern.(2)The network of intercity agglomerations has the characteristics of centralization,stratification,and geographical proximity.(3)The internal network of each urban agglomeration presents a variety of network structure modes,such as dual-core,single-core,and multicore modes.(4)Administrative subordination and economic system proximity have a significant positive impact on the city network in western *** differences in internet convenience,investment in science and technology,average time distance,and economic development have negative effects on the growth and development of city networks.(5)The preferential attachment is the internal driving force of the city network development.

关键词： interlocking-affiliate network model urban agglomerations western China centrality multiple regression of quadratic assignment program(MRQAP)

Cross-border Urban Networks Based on Manufacturing Global Value Chain:A Study of Listed Companies in Western China

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Chinese Geographical Science 2023年第6期33卷 1033-1052页

作者： MAN Shan yang yongchun ZENG Tonggang WANG Meimei College of Earth and Environmental Sciences Lanzhou UniversityLanzhou730000China Key Laboratory of Western China’s Environmental Systems Ministry of Education of the People’s Republic of ChinaLanzhou UniversityLanzhou730000China

Cross-border investment is essential for western China’s *** value chain(GVC)forms cross-border investment networks between industries in western China and overseas *** on GVC,this study uses the social network analysis method,entropy method,multi-index comprehensive evaluation method,and quadratic assignment procedure analysis method to examine the characteristics and influencing factors of the urban networks of research and development(R&D),production,and sales formed as a result of the overseas investments of listed manufacturing companies in western *** showed that the three types of investment networks involved multiple industry types and multiple central cities with differentiated diversity and *** R&D urban network’s leading sub-industries were the mechanical equipment and instruments,medicine and biological products,and metal and nonmetal *** destination cities were mostly those home to educational and scientific research *** production urban network’s leading sub-industries were the mechanical equipment,instrument,and food and beverage *** destination cities were mostly regional central cities in developing *** sales urban network’s leading sub-industries were the mechanical equipment and instrument,metal and nonmetal,and petrochemical and plastics *** destination cities were numerous and *** addition,the R&D urban network easily formed specialized clusters,core nodes easily controlled the production urban network,and individual nodes did not easily control the sales urban *** and economic system advantages greatly impacted the three network *** the different influencing factors,this study suggests optimizing the institutional investment environment to narrow the institutional gap,adjusting and optimizing the investment layout to expand overseas markets,and increasing R&D funds to stimulate technological progress

关键词： manufacturing industry Global value chain(GVC) overseas investment cross-border networks western China

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牛结节性皮肤病免疫抗体监测的Meta分析

畜牧兽医学报 2024年第8期55卷 3649-3658页

作者：沈鹏王艺任炜杰杨永春宋厚辉王志亮浙江农林大学动物科技学院·动物医学院杭州311300 中国动物卫生与流行病学中心青岛266000 南京农业大学动物医学院教育部动物健康与食品安全国际合作联合实验室江苏省外国专家工作室南京210095

疫苗接种是预防牛结节性皮肤病(lumpy skin disease, LSD)的重要措施,但是疫苗接种后诱导的体液免疫应答水平参差不齐,目前尚缺乏评价疫苗免疫效果的有效手段。本文使用R软件利用Meta分析对已发表的LSD免疫抗体监测结果进行统计,并进行... 详细信息

疫苗接种是预防牛结节性皮肤病(lumpy skin disease, LSD)的重要措施,但是疫苗接种后诱导的体液免疫应答水平参差不齐,目前尚缺乏评价疫苗免疫效果的有效手段。本文使用R软件利用Meta分析对已发表的LSD免疫抗体监测结果进行统计,并进行亚组分析,综合评价免疫抗体监测的意义。通过计算机分别检索中国知网、万方数据知识服务平台、维普中文科技期刊数据库、PubMed、Web of science等中英文数据库,检索时限截止至2023年7月,收集LSD免疫抗体监测的相关文献,根据制定的文献纳入与排除标准,共纳入符合筛选条件的文献24篇,涉及羊痘疫苗的文献共有13篇,涉及LSD疫苗的文献共有13篇,其中2篇文献同时涉及羊痘疫苗和LSD疫苗,包含8 638例样本,其中阳性样本2 782份,结局指标为免疫抗体阳性率。Meta分析结果显示,羊痘疫苗的免疫抗体水平为41%(95%CI:27%~55%),LSD疫苗的免疫抗体水平为73%(95%CI:64%~86%),各文献间的同质性较低,两种疫苗之间无显著性差异(P=0.59),与羊痘疫苗接种(P=0.12)和LSD疫苗接种(P=0.077)相关的文献均提示未存在明显发表偏移;按养殖环境和检测方法分类进行亚组分析,不同养殖环境(P=0.84)和检测方法(P=0.40)均无显著性差异,两亚组均非异质性的主要来源。本文结果提示,使用免疫抗体监测方法评价免疫效果存在较大的不确定性,在实际工作中需要综合分析研判。

关键词：牛结节性皮肤病羊痘疫苗免疫抗体监测 Meta分析

Assessment of Human Impacts on Vegetation in Built-up Areas in China Based on AVHRR,MODIS and DMSP_OLS Nighttime Light Data,1992–2010

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Chinese Geographical Science 2014年第2期24卷 231-244页

作者： LIU Qinping yang yongchun TIAN Hongzhen ZHANG Bo GU Lei College of Earth and Environmental Sciences Lanzhou University School of Management Tianjin Polytechnic University Key Laboratory of Western China's Environment Systems of the Ministry of Education Lanzhou University Department of Cultural Geography Faculty of Spatial ScienceUniversity of Groningen

Since the reform and opening-up program started in 1978,the level of urbanization has increased rapidly in *** urban expansion and restructuring have had significant impacts on the ecological environment especially within built-up *** this study,ArcGIS 10,ENVI 4.5,and Visual FoxPro 6.0 were used to analyze the human impacts on vegetation in the built-up areas of 656Chinese cities from 1992 to ***,an existing algorithm was refined to extract the boundaries of the built-up areas based on the Defense Meteorological Satellite Program Operational Linescan System(DMSP_OLS)nighttime light *** improved algorithm has the advantages of high accuracy and ***,a mathematical model(Human impacts(HI))was constructed to measure the impacts of human factors on vegetation during rapid urbanization based on Advanced Very High Resolution Radiometer(AVHRR)Normalized Difference Vegetation Index(NDVI)and Moderate Resolution Imaging Spectroradiometer(MODIS)*** values greater than zero indicate relatively beneficial effects while values less than zero indicate proportionally adverse *** results were analyzed from four aspects:the size of cities(metropolises,large cities,medium-sized cities,and small cities),large regions(the eastern,central,western,and northeastern China),administrative divisions of China(provinces,autonomous regions,and municipalities)and vegetation zones(humid and semi-humid forest zone,semi-arid steppe zone,and arid desert zone).Finally,we discussed how human factors impacted on vegetation changes in the built-up *** found that urban planning policies and developmental stages impacted on vegetation changes in the built-up *** negative human impacts followed an inverted′U′shape,first rising and then falling with increase of urban ***′s national policies,social and economic development affected vegetation changes in the built-up *** findings can provide a scientific basis for municipal planning de

关键词： vegetation change human impact urbanization built-up areas nighttime light data Normalized Difference Vegetation Index(NDVI)