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Improving the Quality of Public Space in Old Residential Areas Based on Superposition and Intervention:A Case Study of Baihuazhou District of Nanchang City
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作者 LI Shengnan 《Journal of Landscape Research》 2024年第4期13-16,20,共5页
With the development of cities,China has entered an era of stock planning.The functions of old residential areas in urban development can no longer meet the needs of residents in the new era for a better life,and new ... With the development of cities,China has entered an era of stock planning.The functions of old residential areas in urban development can no longer meet the needs of residents in the new era for a better life,and new standards have been put forward for the quality of public spaces for living.This paper analyzes and sorts out the characteristics and problems of the public space in the old residential areas of Baihuazhou district.Combining superposition and intervention techniques,the spatial,historical,cultural and other characteristic elements of the residential areas are preserved to the greatest extent.The public space in the old residential areas of Baihuazhou District is updated and reconstructed in order to achieve the goal of improving the quality of its public space. 展开更多
关键词 Superposition and intervention old residential area Public space Quality improvement Baihuazhou District
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Research on the Index System of Old Neighborhood Renovation Based on Green Building Evaluation Standard
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作者 Yufei Que 《Journal of Architectural Research and Development》 2024年第3期140-146,共7页
With the advancement of the transformation,the contradiction between the residents’demand for a better living environment and the convenience of living in the settlements comes to the fore.Effective identification,or... With the advancement of the transformation,the contradiction between the residents’demand for a better living environment and the convenience of living in the settlements comes to the fore.Effective identification,organic integration,timely adoption,and correct decision-making for the transformation of old neighborhoods are pressing issues in the transformation of old neighborhoods.Therefore,this paper takes the green building evaluation standards of various countries as the research basis and support for the construction of the transformation strategy of old neighborhoods.Through the collection and comparative analysis of the indicators of green building evaluation standards,the index system of transformation is formed,and it also provides a certain foundation for the subsequent related research. 展开更多
关键词 old neighborhoods Green building evaluation standards RENOVATION CRITERIA
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Analysis of Safety Assessment and Testing of Heavy Traffic Vehicles on Old Bridges Without Data
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作者 Qing Yang Jiang Feng 《Journal of World Architecture》 2024年第1期35-39,共5页
This article presents a real-life project that aimed to evaluate the safety of traffic vehicles on old bridges without any prior data.The project involved various safety inspections,including conventional,static,and d... This article presents a real-life project that aimed to evaluate the safety of traffic vehicles on old bridges without any prior data.The project involved various safety inspections,including conventional,static,and dynamic load inspections and safety assessments.After conducting these tests,it was concluded that the structure of the old bridge is relatively safe,with only a few bumps.The bridge could function normally following appropriate treatment.The analysis provides valuable insights into the assessment of the quality and safety of such bridges to ensure the safe driving of heavy vehicles. 展开更多
关键词 old bridge Absence of data Heavy vehicles Safety inspection Safety assessment
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THRESHOLD RESULT FOR SEMILINEAR PARABOLIC EQUATIONS WITH INDEFINITE NON-HOMOGENEOUS TERM
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作者 谢君辉 戴求亿 刘芳 《Acta Mathematica Scientia》 SCIE CSCD 2012年第6期2302-2314,共13页
In this paper, we study the threshold result for the initial boundary value problem of non-homogeneous semilinear parabolic equations {μt-△μ=g(μ)+λf(x),(x,t)∈Ω×(0,T),μ=0,(x,t)∈ Ω×[0,T)... In this paper, we study the threshold result for the initial boundary value problem of non-homogeneous semilinear parabolic equations {μt-△μ=g(μ)+λf(x),(x,t)∈Ω×(0,T),μ=0,(x,t)∈ Ω×[0,T),μ(x,0)=μ0(x)≥0,x∈Ω.By combining a priori estimate of global solution with property of stationary solution set of problem (P), we prove that the minimal stationary solution Uλ(x) of problem (P) is stable, whereas, any other stationary solution is an initial datum threshold for the existence and nonexistence of global solution to problem (P). 展开更多
关键词 parabolic equations initial boundary value problem global solution thresh-old result non-homogenous tern:
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Research on the feasibility of storage and estimation model of storage capacity of CO_(2)in fissures of coal mine old goaf 被引量:4
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作者 Yang Ding Shugang Li +4 位作者 Bing Zhu Haifei Lin Jingfei Zhang Junhong Tan Wenbin Chen 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第6期675-686,共12页
The concept of the carbon cycle in the old goaf of a coal mine based on CO_(2)utilization and storage was put forward adhering to the principle of low-carbon development,utilization of space resources in old goafs,and... The concept of the carbon cycle in the old goaf of a coal mine based on CO_(2)utilization and storage was put forward adhering to the principle of low-carbon development,utilization of space resources in old goafs,and associated gas resources development.Firstly,the evolution characteristics of overburden fissures in the goaf of the case was studied using a two-dimensional physical similarity simulation test,the sealing performance of the caprocks after stabilization was analyzed,and the fissures were counted and classi-fied.Then,the process of gaseous CO_(2)injection in the connected fissure was simulated by Ansys Fluent software,and the migration law and distribution characteristics of CO_(2)under the condition of gaseous CO_(2)injection were analyzed.Finally,the estimation models of free CO_(2)storage capacity in the old goaf were constructed considering the proportion of connected fissure and the effectiveness of CO_(2)injection.The CO_(2)storage capacity in the old goaf of the case coal mine was estimated.The results showed that a caprock group of“hard-thickness low-permeability hard-thickness”was formed after the caprock-fissures system in the goaf of the case tended to be stable vertically.The connected fissure,occlude cracks,and micro-fractures in the goaf accounted for 85.5%,8.5%,and 6%of the total fissures,respectively.Gaseous CO_(2)first migrated to the bottom of the connected fissure after CO_(2)was injected into the goaf,then spread horizontally along the bottom of the connected fissure after reaching the bottom,and finally spread longitudinally after filling the bottom of the entire connected fissure.The theoretical and effective storage capacities of free CO_(2)at normal temperature and pressure in the old goaf of the case were 9757 and 7477 t,respectively.The effective storage capacity of free CO_(2)at normal temperature and pressure in the old goaf after all minefield mined was 193404 t.The research can provide some reference for the coal mining industry to help the goal of“carbon peaking and carbon neutrality”. 展开更多
关键词 Carbon cycle old goaf FISSURE CO_(2)storage FEASIBILITY Storage capacity
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Structural Damage Identification System Suitable for Old Arch Bridge in Rural Regions: Random Forest Approach 被引量:1
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作者 Yu Zhang Zhihua Xiong +2 位作者 Zhuoxi Liang Jiachen She Chicheng Ma 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第7期447-469,共23页
A huge number of old arch bridges located in rural regions are at the peak of maintenance.The health monitoring technology of the long-span bridge is hardly applicable to the small-span bridge,owing to the absence of ... A huge number of old arch bridges located in rural regions are at the peak of maintenance.The health monitoring technology of the long-span bridge is hardly applicable to the small-span bridge,owing to the absence of technical resources and sufficient funds in rural regions.There is an urgent need for an economical,fast,and accurate damage identification solution.The authors proposed a damage identification system of an old arch bridge implemented with amachine learning algorithm,which took the vehicle-induced response as the excitation.A damage index was defined based on wavelet packet theory,and a machine learning sample database collecting the denoised response was constructed.Through comparing three machine learning algorithms:Back-Propagation Neural Network(BPNN),Support Vector Machine(SVM),and Random Forest(R.F.),the R.F.damage identification model were found to have a better recognition ability.Finally,the Particle Swarm Optimization(PSO)algorithm was used to optimize the number of subtrees and split features of the R.F.model.The PSO optimized R.F.model was capable of the identification of different damage levels of old arch bridges with sensitive damage index.The proposed framework is practical and promising for the old bridge’s structural damage identification in rural regions. 展开更多
关键词 old arch bridge damage identification machine learning random forest particle swarm optimization
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An Extended Fuzzy-DEMATEL System for Factor Analyses on Social Capital Selection in the Renovation of Old Residential Communities
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作者 Guoshuai Sun Xiuru Tang +1 位作者 Shuping Wan Jiao Feng 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第2期1041-1067,共27页
China has been promoting the renovation of old residential communities vigorously.Due to the financial pressure of the government and the sustainability of the renovation of old residential communities,public-private ... China has been promoting the renovation of old residential communities vigorously.Due to the financial pressure of the government and the sustainability of the renovation of old residential communities,public-private partnerships(PPP)have already gained attention.The selection of social capital is key to improving the efficiency of the PPP model in renovating old residential communities.In order to determine the influencing factors of social capital selection in the renovation of old residential communities,this paper aims to find an effective approach and analyze these factors.In this paper,a fuzzy decision-making and trial evaluation laboratory(fuzzy-DEMATEL)technique is extended and amore suitable systemis developed for the selection of social capital using the existing group decisionmaking theory.In the first stage,grounded theory is used to extract the unabridged key influencing factors for social capital selection in the renovation of old residential communities.Secondly,by considering the impact of expert weights,the key influencing factors are identified.The interactions within these influencing factors are discussed and the credibility of the results is verified by sensitivity analysis.Finally,these key influencing factors are sorted by importance.Based on the results,the government should focus on a technical level,organizationalmanagement abilities,corporate reputation,credit status,etc.This study provides the government with a theoretical basis and a methodology for evaluating social capital selection. 展开更多
关键词 Social capital selection fuzzy-DEMATEL influencing factors renovation of old residential communities grounded theory
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Chemical and physical studies of metallic alloy-based old Indian coins with LIBS coupled with multivariate analysis
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作者 Vikas GUPTA Abhishekh Kumar RAI +3 位作者 Tejmani KUMAR Rajendhar JUNJURI G Manoj KUMAR A K RAI 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第9期91-103,共13页
The present work aims to demonstrate the capabilities of Laser-induced Breakdown Spectroscopy(LIBS)coupled with a multivariate technique for rapid quantification and classification of old Indian coins made of various ... The present work aims to demonstrate the capabilities of Laser-induced Breakdown Spectroscopy(LIBS)coupled with a multivariate technique for rapid quantification and classification of old Indian coins made of various alloys.Thirteen old Indian coins in different years of circulation,(1922–1986)were selected for the study.The concentrations were determined by Calibration free LIBS(CF-LIBS)method.The concentration of cuprum(Cu)is negligible,and aluminum(Al)is maximum in the first five coins,and vice-versa in the remaining eight coins.Two different multivariate methods,Principal Component Analysis(PCA)and Soft Independent Modelling of Class Analogy(SIMCA)have been used to classify and identify the coins.PCA classified all thirteen samples into four main alloy categories.The discernment of unknown samples to their probable class membership of alloy was performed using SIMCA.The surface hardness(Brinell hardness number)is linearly correlated with the plasma temperature and LIBS intensity ratios.The sample surface of the first and fifth coin belongs to Al-alloy,having the least surface hardness,and it became harder for Cu–Ni alloy,Ni-brass alloy,and bronze alloy.The hardness of the surface is more for bronze sample twelve.It is also observed that the plasma temperature increases monotonically with the Brinell hardness number.This analysis provides valuable information on fabrication methodology and explains large diversification in the elementary composition of old coins. 展开更多
关键词 LIBS metallic alloy stoichiometric ablation PCA SIMCA old indian coins surface hardness
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Improving the Use of Insecticide-Treated Nets among Children under Five Years Old in Benin, West Africa
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作者 Emmanuel Houessou Tatchémè Filémon Tokponnon 《Advances in Infectious Diseases》 2023年第2期137-158,共22页
Background: In Benin, malaria represents the first cause of consultation and hospitalization (48% for children under 5 years old) in health units. It also accounts for 23.1% of deaths recorded in health facilities (Mo... Background: In Benin, malaria represents the first cause of consultation and hospitalization (48% for children under 5 years old) in health units. It also accounts for 23.1% of deaths recorded in health facilities (MoH, 2019). Between the two main components of vector control adopted by Benin government, the mass distribution campaigns of Insecticide-Treated Nets (ITNs) remained the only proven cost-effective way to rapidly achieve high and equitable coverage (WHO, 2017). After the fourth mass distribution campaign conducted in 2017, the Demographic and Health Survey (DHS) data indicated that the percentage of children who slept under an ITN has increased from 20% in 2006 to 70% in 2011-2012 and to 76% in 2017-2018 while the incidence of malaria (tested positive) is increasing rapidly among children under 5 years old, growing from 36.5% in 2009 to 28.8% in 2012 and then to 51.4% in 2019. This study aims to understand this contrast by identifying the origin of the increase in ITN use over time among children under five years old and the factors which determine this use. Methods: Data from the Demographic and Health Survey (DHS) conducted in Benin respectively in 2006 and in 20018 were used during the analysis, which covered 13,445 children under five years old from 2006 DHS and 12,255 children from 2017-2018 DHS. Firstly, the data were analyzed using decomposition method to highlight the origin of the increase of ITN use over time among children under five years old. Secondly, the chi-square test analysis estimated the association between ITN use and some characteristics (wealth index, maternal or caregiver education level and child age). Finally, the logistic regression model was used to identify the main factors, which influence the net use over the study period. Results: This study shows that the improvement of basic conditions is the main origin of behavior change in the use of ITNs among children under five years old. This improvement of the basic conditions consists of making ITNs available in households and informing household members about the benefits of ITN use. So, the free ITN distribution campaigns, routine distribution, awareness campaigns about the benefits of ITN use are the strategies, which increase the household capacities and knowledge, allowing household members to make their children sleep under net. The analysis also shows that region of residence, wealth index of household, household size, religion, and child age continue to determine the ITN use among children under age 5 years old and MNCP will integrate the factors in malaria prevention strategies in order to achieve universal use of ITNs. Conclusions: Although, sleeping under ITN behavior has indeed spread among children under 5 years old, policymakers and other stakeholders should design strategies to maintain and improve the current level of ITN use to reach the collective protection threshold (80% according to WHO). Therefore, to address the challenges of universal use of ITN, the study recommends expanding the routine distribution system to private sector health centers;discussing issues related to health service utilization (particularly ITN use) within a consultation framework at the communal level. In addition, collecting qualitative and quantitative data in the Oueme region will allow better understanding of all aspects of the ITN use gap among children under 5 years. 展开更多
关键词 MALARIA Long-Lasting Insecticidal Net (LLIN) Child under 5 Years old Health Policy BENIN
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Transformation Design of Old Parks Based on Behavior Psychology: A Case Study of Hefei Xiaoyaojin Park
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作者 GE Juan CAO Menghan +3 位作者 CHEN Jiaxin HU Yueyue LI Quanjun LI Yinan 《Journal of Landscape Research》 2023年第5期35-40,共6页
City park undertakes the function of urban core green island. Hefei Xiaoyaojin Park providesa leisure and entertainment place for Hefei citizens. Although it has been continuously transformed andupgraded, there are st... City park undertakes the function of urban core green island. Hefei Xiaoyaojin Park providesa leisure and entertainment place for Hefei citizens. Although it has been continuously transformed andupgraded, there are still many places to be improved. Through behavior observation and questionnaire,the usage and satisfaction evaluation of tourists in Xiaoyaojin Park were obtained, and the transformationdesign of Xiaoyaojin Park was analyzed from the perspective of behavior psychology by analyzing thebehavior of tourists in different zones of Xiaoyaojin. Based on the premise of exploring the behaviorof tourists in different spaces, a city park environment that meets the needs of tourists can be created bypromoting the cultural context of the Three Kingdoms, improving the plant landscape and infrastructureof the site, optimizing the spatial function, and exploring the park design and transformation strategy that ismore in line with the needs of people, in order to provide new ideas for the future landscape transformationof Xiaoyaojin park, and offer reference suggestions for the future transformation design of old city parks. 展开更多
关键词 Behavior psychology old park City park Environmental optimization
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Landscape Upgrading and Transformation of Old Urban Parks from the Perspective of Place Attachment:A Case Study of Nanchang Bayi Park
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作者 Baoyong LI Yuanqing WEN +1 位作者 Bo PENG Huimin TAN 《Meteorological and Environmental Research》 CAS 2023年第2期28-34,41,共8页
On the basis of combing the relevant theories of place attachment, the planning framework of upgrading and reconstruction of old parks based on place attachment was put forward. Taking Nanchang Bayi Park as an example... On the basis of combing the relevant theories of place attachment, the planning framework of upgrading and reconstruction of old parks based on place attachment was put forward. Taking Nanchang Bayi Park as an example, the methods and key points of landscape improvement and transformation of old urban parks based on place attachment were explained to provide new ways and references for the renewal of old urban parks. 展开更多
关键词 Landscape upgrading and transformation old urban parks Place attachment
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Application of the Concept of“Endowing the Old with the New”in Urban Renewal
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作者 JI Yuan 《Journal of Landscape Research》 2023年第2期21-26,共6页
The renewal of ancient cities is an important part of the urban renewal work in China.However,there are few studies on the general historical ancient cities at the county level in China,and there is no guidance on the... The renewal of ancient cities is an important part of the urban renewal work in China.However,there are few studies on the general historical ancient cities at the county level in China,and there is no guidance on the renewal path.Through the practice of the renewal design project of Suining County,Xuzhou City,it makes an exploratory study on the renewal concept and mode.It first interprets the connotation and implementation path of the renewal concept of“endowing the old with the new”.Based on the texture analysis of the ancient city of Suining,it finally determines the design theme that tracing the historical context of the ancient city.Using the renewal techniques such as“extraction-transformationactivation”,through the renewal strategies such as“building new space,shaping new landscape,inheriting new culture and pregnant with new environment”,it realizes the regeneration of urban historical context and meets the needs of residents'modern life,so as to provide reference and guidance for the renovation of general historical ancient cities at the county level in China. 展开更多
关键词 Endowing the old with the new Ancient city renewal Update design Application research
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Construction of Industrialization Development Model for"1+4+X"Community-Based Elderly Care in Gannan Old Revolutionary Base Area in the Context of Population Aging
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作者 Chenxin YANG Jun XIAO +2 位作者 Liyuan WANG Jiaxin LIU Yangkai LU 《Asian Agricultural Research》 2023年第5期8-10,16,共4页
In the context of controlling population development in a planned way,China entered an aging society in the early 21 st century.In this context,how to meet the needs of the elderly care and form an effective elderly c... In the context of controlling population development in a planned way,China entered an aging society in the early 21 st century.In this context,how to meet the needs of the elderly care and form an effective elderly care model has become a key problem to be solved urgently by local government departments.With the continuous advancement of the elderly care policy,the community-based elderly care has gradually become the mainstream and is in the stage of vigorous promotion.Taking the Gannan old revolutionary base area in Jiangxi Province as an example,this study puts forward"1+4+X"community-based elderly care model based on the policy system of community-based elderly care,the physical and mental health of the elderly,the material space and the construction of evaluation system,and explores how to promote the application of this community model efficiently in the form of industrialization,so as to drive the economic growth of the Gannan old revolutionary base area,promote the employment development and improve the community-based elderly care service. 展开更多
关键词 Community-based elderly care New elderly care model Gannan old revolutionary base area
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三重价值链耦合协调发展对企业绿色全要素生产率的影响
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作者 陈姝兴 钟欣鹏 郑凌峰 《中国人口·资源与环境》 CSCD 北大核心 2024年第3期151-165,共15页
省内价值链、国内价值链和全球价值链(三重价值链)的融合发展,是畅通国内国际双循环,也是中国企业经济软着陆的关键抓手。在高质量发展有序推进的背景下,绿色全要素生产率成为衡量企业发展的重要指标,因此有必要探讨三重价值链耦合协调... 省内价值链、国内价值链和全球价值链(三重价值链)的融合发展,是畅通国内国际双循环,也是中国企业经济软着陆的关键抓手。在高质量发展有序推进的背景下,绿色全要素生产率成为衡量企业发展的重要指标,因此有必要探讨三重价值链耦合协调发展对企业绿色全要素生产率的影响。该研究利用世界投入产出表、中国多区域投入产出表、上市公司数据测算了三重价值链耦合协调度,基于SBM方法测算包含非期望产出的绿色全要素生产率,整合得到770家上市公司2012年、2015年和2017年的平衡面板数据,通过多维固定效应回归考察三重价值链耦合协调度对企业绿色全要素生产率的影响,研究结果表明:①存在三重价值链耦合协调度提升→GVC嵌入度深化→企业绿色全要素生产率增长的正向传播机制,但效果随着企业的要素密集度增加呈现递减趋势。②机制研究和异质性分析表明,前向耦合协调发展为企业绿色全要素生产率带来更有效和长期的动能,而后向耦合协调发展为劳动密集型企业带来短期显著的绿色生产率提升。基于此,该研究提出了布局本土产业、协调三链关系的相关政策建议:①地方政府应发挥主观能动性,评估本地企业优势,保证在政策制定上更加微观具体,劳动密集型的省份或行业有效利用三重价值链的协调发展为企业的转型升级奠定基础,为地方行业的协同发展打通阻碍。②在要素投入端,注重对地方高新技术企业的资源分配,同时区域间合作完成生产供应端的高度集成,增强前向耦合协调发展对于企业内涵式增长能力的促进效应,兼顾供应链流程的绿色环保标准。③加强省域间的政策协调性和交易通达性,提高各地区企业省域间的市场专业化分工,而非单独地嵌入GVC市场,利用集聚效应推动产业全面升级,打破国内市场循环的技术壁垒。 展开更多
关键词 三重价值链耦合协调度 绿色全要素生产率 多维固定效应 门限效应
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基本养老服务制度的政策逻辑与内涵特征 被引量:1
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作者 左菁 《重庆社会科学》 北大核心 2024年第2期82-100,共19页
现阶段建立基本养老服务制度是在新时期我国转变政府职能和提升政府民生治理能力的背景下,进一步划分政府、家庭、市场等养老主体在养老服务中的责任边界,强化政府“兜底线、保基本”的养老保障职责,增强老年人的普遍幸福感和获得感的... 现阶段建立基本养老服务制度是在新时期我国转变政府职能和提升政府民生治理能力的背景下,进一步划分政府、家庭、市场等养老主体在养老服务中的责任边界,强化政府“兜底线、保基本”的养老保障职责,增强老年人的普遍幸福感和获得感的制度探索。然而,当前基本养老服务政策内容较为薄弱,相关理论研究也较为匮乏,本文以系统梳理基本养老服务发展脉络为出发点,深入挖掘基本养老服务制度形成的政策逻辑,详细阐释基本养老服务制度的内涵与特征,为基本养老服务制度完善提供思路。 展开更多
关键词 养老服务 基本养老服务 公共服务 基本养老服务制度
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近10年国内老年血液透析研究热点的可视化分析 被引量:1
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作者 王晶 李琳 +3 位作者 郝德 汪梦洁 张帆 张枭霄 《全科护理》 2024年第6期1046-1050,共5页
目的:分析我国老年血液透析患者的研究现状、热点及趋势。方法:检索中国知网(CNKI)、万方数据库、维普数据库、中国生物医学文献数据库近10年发表的老年血液透析相关文献,应用CiteSpace 6.2.R7对相关研究的作者、研究机构、关键词进行... 目的:分析我国老年血液透析患者的研究现状、热点及趋势。方法:检索中国知网(CNKI)、万方数据库、维普数据库、中国生物医学文献数据库近10年发表的老年血液透析相关文献,应用CiteSpace 6.2.R7对相关研究的作者、研究机构、关键词进行可视化分析。结果:检索出符合要求的文献1545篇,文献发文量保持平稳增长,2018年为发文高峰;发文期刊多为医疗类期刊,发文量最多的作者为罗洋、陈文和郭一丹,各6篇;发文量较多的地区集中在北京、上海、南京和四川。老年血液透析研究热点集中在治疗、用药、预后和并发症的管理。结论:老年血液透析研究内容较广泛、热点不突出;研究领域内作者及机构合作不紧密,未形成稳定的核心作者群;目前的研究水平发展较不均衡,护理研究内容和质量有待加强。 展开更多
关键词 血液透析 老年 CITESPACE 可视化分析
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脱粒机构数字孪生系统构建与应用
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作者 刘大欣 周德义 +2 位作者 于亚军 胡伟 于春生 《农业工程》 2024年第8期34-38,共5页
农业脱粒机构结构复杂、工况恶劣,在进行实物研究时耗时费力。采用数字孪生系统可以实时监控脱粒机构的工作状态,预测故障,积累数据并提供解决方案。对脱粒机构数字孪生系统的研究表明,选取脱粒滚筒扭矩、滚筒转速、轴承温度、振动加速... 农业脱粒机构结构复杂、工况恶劣,在进行实物研究时耗时费力。采用数字孪生系统可以实时监控脱粒机构的工作状态,预测故障,积累数据并提供解决方案。对脱粒机构数字孪生系统的研究表明,选取脱粒滚筒扭矩、滚筒转速、轴承温度、振动加速度及消耗功率作为关键参数可对脱粒机构物理实体进行准确地状态判断,运用Unity软件和AMESim软件构建物理实体的数字孪生系统可用于虚拟仿真,使用ZigBee无线通信方式进行数据交互能够满足数字孪生系统数据交互的需求。 展开更多
关键词 数字孪生系统 脱粒机构 脱粒滚筒 数字建模 数据交互
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延迟退休对青年人就业的挤入效应研究 被引量:2
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作者 刘凤芹 王美甜 毕蕾 《财经问题研究》 北大核心 2024年第4期94-106,共13页
本文从理论上提出了延迟退休对青年人就业产生挤入效应的两条途径,并基于2005年1%人口抽样调查微观数据和2010年第六次全国人口普查微观数据,采用双向固定效应模型实证研究了延迟退休对青年人就业的影响及作用机制。研究结果显示:延迟... 本文从理论上提出了延迟退休对青年人就业产生挤入效应的两条途径,并基于2005年1%人口抽样调查微观数据和2010年第六次全国人口普查微观数据,采用双向固定效应模型实证研究了延迟退休对青年人就业的影响及作用机制。研究结果显示:延迟退休不仅不会挤出青年人就业,反而会对其产生挤入效应。异质性分析结果表明,相较于男性青年人,延迟退休对女性青年人就业的促进作用偏弱;高学历老年人延迟退休能够促进高学历青年人就业,低学历老年人延迟退休能够促进低学历青年人就业。机制分析结果表明,延迟退休通过降低实际老年抚养比促进青年人就业。调节效应分析结果表明,经济发展水平对延迟退休与青年人就业之间的关系存在正向调节效应。本文的研究结论支持政府为增加劳动力供给提出的延迟退休政策,建议推进渐进式、弹性式延迟退休政策。在实行延迟退休政策的同时,政府应适时调整其他相关政策。在三孩生育政策全面放开阶段,政府应重视年轻家庭对祖辈隔代照料的需求。此外,政府应鼓励老年劳动力提升自身人力资本水平。 展开更多
关键词 延迟退休 青年人就业 人口结构 实际老年抚养比
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牵引式油莎豆收获机设计与试验
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作者 董润坚 肖戟 +3 位作者 刘文亮 国文慧 王新阳 刘枫 《中国农机化学报》 北大核心 2024年第1期21-27,共7页
根据东北地区油莎豆收获的农艺要求以及土地情况,为切实解决油莎豆收获机械化程度低、收获成本高、油莎豆根、豆、土分离困难的问题,设计一种牵引式油莎豆收获机。通过升运网链系统、脱粒滚筒、双层4阶4箱式逐稿器分离装置、清选风机和... 根据东北地区油莎豆收获的农艺要求以及土地情况,为切实解决油莎豆收获机械化程度低、收获成本高、油莎豆根、豆、土分离困难的问题,设计一种牵引式油莎豆收获机。通过升运网链系统、脱粒滚筒、双层4阶4箱式逐稿器分离装置、清选风机和具有漏土功能的籽粒输送系统等工作部件,使油莎豆收获过程具有良好的分离性、流动性和多重清选功能,可有效防止根茎的缠绕、筛网堵塞和分离不净等问题。田间作业试验结果表明:该机具有动力消耗小、作业效率高等特点,样机的整体收获洁净率可达到90.86%。 展开更多
关键词 油莎豆收获机 升运网链 脱粒滚筒 逐稿器
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跨境电商对我国经济增长的影响——基于省级面板数据实证分析
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作者 李娜 《上海节能》 2024年第8期1277-1285,共9页
跨境电商作为贸易新业态,能够很好地改善传统贸易方式、激发国内市场活力、扩大国内市场需求,同时也为促进我国经济增长注入新活力。采用我国2012—2021年省级面板数据,通过构建跨境电商指标体系,研究跨境电商对于我国经济增长的影响效... 跨境电商作为贸易新业态,能够很好地改善传统贸易方式、激发国内市场活力、扩大国内市场需求,同时也为促进我国经济增长注入新活力。采用我国2012—2021年省级面板数据,通过构建跨境电商指标体系,研究跨境电商对于我国经济增长的影响效应,同时还采用门槛效应模型来研究跨境电商交易额对我国经济增长是否存在非线性关系。研究结果表明,在做基准回归时,跨境电商对我国经济增长具有显著的促进作用。考虑控制变量的情况下,促进作用仍然存在。将跨境电商划分行业发展、运输物流、政策管理三维度,分别研究对我国经济增长影响,结果表明都产生显著的正向影响。在进行面板门槛效应回归时发现,跨境电商交易额对我国经济增长存在单一门槛效应,超过门槛值影响系数变大,表明跨境电商交易额对我国经济增长存在边际效用递增的影响。从加大跨境电商综合试验区的设立、推进跨境电商基础设施建设、推进跨境电商技术人才培养以及提升互联网信息化水平这四个方面提出完善跨境电商发展的相关建议。 展开更多
关键词 跨境电商 经济增长 异质性 非线性关系 门槛效应
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