检索结果-南通市图书馆

Geographical features and development models of estuarine cities

Journal of Geographical Sciences 2024年第1期34卷 25-40页

作者： chen mingxing XIAN Yue HUANG Yaohuan SUN Zhigang WU chengbin Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China College of Resource and Environment University of Chinese Academy of SciencesBejing 100049China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China Zhongke Shandong Dongying Institute of Geography Dongying 257509ShandongChina CAs Engineering Laboratory for Yellow River Delta Modern Agriculture Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China

Cities are the key areas for human beings to achieve sustainable development goals in the future.Estuarine cities are a special type of coastal city in urgent need of a clear definition.This paper proposed that estuarine cities are cities developed on the coast where rivers and oceans meet and defined four connotations,including the intersection of rivers and marine water systems,the coordinated development of land and oceans,the location advantages of connecting rivers and seas,and the important fragility of the ecological environment.We used Hydro SHEDS,OSM,GPW,and urban socioeconomic statistics and selected 50 estuarine cities with large rivers as representatives to summarize the main geographical basis and socioeconomic characteristics.Cities are primarily found in low-altitude,flat regions with average annual temperatures that mainly vary from 10℃to 25℃,relatively abundant precipitation,and extensive biological resources.There are substantial variations in the socioeconomic features of estuarine cities.We proposed eight development patterns,including open and inclusive city spirit,high-quality livable cities,high-quality development driven by innovation,integration of internal and external communication with ports and cities,construction of an international financial center,ecological environment protection and restoration,active promotion of cultural tourism,and positive international exchanges.

关键词： estuarine cities great rivers development models sustainability physical geography socioeconomy

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

Population evolution at the prefecture-level city scale in China:Change patterns and spatial correlations

引用

Journal of Geographical Sciences 2022年第7期32卷 1281-1296页

作者： XIAN Yue chen mingxing Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China College of Resource and Environment University of Chinese Academy of SciencesBeijing 100049China

China has entered a new stage of high-quality urbanization.Therefore,it is critical to grasp the latest population distribution and dynamics.Using mean-variance grading,Moran’s index,and the Theil index,this study compared the differences in population changes between 2010–2020 and 2000–2010 at the prefecture-level city scale based on census data to analyze the new trends in population evolution.We found that:(1)New growth poles of the population are inland provincial capitals,forming rapid-growing zones together with coastal urban agglomerations.Population growth in over 60%of the cities in the northern coastal urban agglomeration has slowed.(2)The scope of population loss in inland areas is constantly expanding.In the northeastern part of China,92.7%of the cities have lost population,making this a typical population loss area.(3)Population shrinkage in the northeastern region and growth in the Pearl River Delta urban agglomeration show diffusion characteristics,while population patterns around the provincial capital are in a polarized stage.(4)The Theil index of population distribution increased,with 83.91%of differences coming from between groups,indicating that the gap between cities of different sizes has further expanded.This study provides scientific support for the coordinated promotion of nearby and remote urbanization.

关键词： population distribution agglomeration and decentralization pattern change nearby urbanization prefecture-level city

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

Urbanization of county in China:Spatial patterns and influencing factors

引用

Journal of Geographical Sciences 2022年第7期32卷 1241-1260页

作者： ZHANG Hua chen mingxing LIANG chen Beijing Key Laboratory of Environmental Remote Sensing and Digital Cities Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

This paper uses the fifth and sixth census data and 2018 demographic statistics to analyze the spatiotemporal evolution of the urbanization of county in China and the factors that influence the evolution.The paper reveals that the urbanization level of counties is a weak area in China’s overall urbanization.During the period from 2000 to 2010,the spatial patterns of the urbanization level of counties remained stable.Counties with high-level urbanization were concentrated in the coastal areas of the eastern region,while counties that experienced rapid urbanization were mainly located in the central and western regions.Regression analyses indicate that harsh natural endowments that constrain economic development are the most important factors that hinder the urbanization of county;these factors include marginalized locations far away from center cities,high altitudes,and a population with a low education level.This paper also compares two theoretical modes of new-type urbanization,nearby urbanization and remote urbanization,and argues that the new-type urbanization of county is the main form of nearby urbanization and provides an example of urbanization for developing countries worldwide.

关键词： new-type urbanization urbanization of county nearby urbanization spatial patterns influencing factors

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

Revisiting the Relationship Between Urbanization and Economic Development in China Since the Reform and Opening-up

引用

Chinese Geographical Science 2022年第1期32卷 1-15页

作者： LIANG Longwu chen mingxing LU Dadao Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China Key Laboratory of Regional Sustainable Development Modeling Chinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

The relationship between urbanization and economic development has become a hot topic in the scientific community due to its great practical significance,and economic and social value.However,this relationship continues to change dynamically.In the new stage of urbanization,it is urgent to reveal the causal relationship quantitatively and diagnose the future direction systematically.Based on this,this paper calculates the contribution rate of China’s urbanization to economic development from 1978 to 2019 and uses the panel data cointegration test method to explore the causal relationship between urbanization and economic development in China.The study has three principal results.First,the contribution rate of urbanization to economic growth has maintained the overall growth trend from1978 to 2019,but the growth rate of urbanization’s contribution to economic growth has been relatively low since 2012.It is an important reason that the real estate sector has moved into a new stage of transformation.Second,the cointegration test shows that economic development is a significant factor in advancing urbanization and the urbanization is the product of economic development.Urbanization has a positive feedback effect on economic development,but this effect does not pass the 5%significance level test.The impulse response function shows that the impact of urbanization on economic development is relatively small and stable,indicating that it is limited that the boost of economic development by land-centered urbanization.Third,China’s urbanization and economic development have both shown rapid growth for some time,but their relationship is still the low level of coordination,which has also led to a downward trend in the contribution of new-type,people-oriented urbanization to economic growth in recent years.In the future,China’s urbanization and economy need to maintain relatively medium-low speed growth in the medium-long term,and we should boost the coordinated development of urbanization and economy from low level to high

关键词： urbanization economic development causal relationship people-oriented medium-low growth speed

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

Enhancing the Trustworthiness of 6G Based on Trusted Multi-Cloud Infrastructure:A Practice of Cryptography Approach

引用

工程与科学中的计算机建模(英文) 2024年第1期138卷 957-979页

作者： mingxing Zhou Peng Xiao Qixu Wang Shuhua Ruan Xingshu chen Menglong Yang School of Cyber Science and Engineering Sichuan UniversityChengdu610207China Cyber Science Research Institute Sichuan UniversityChengdu610207China Information Center China Southern Power Grid Yunnan Power Grid Co.Ltd.Kunming650000China School of Aeronautics and Astronautics Sichuan UniversityChengdu610065China*Corresponding Author:QixuWang.Email:qixuwang@***

Due to the need for massive device connectivity,low communication latency,and various customizations in 6G architecture,a distributed cloud deployment approach will be more relevant to the space-air-ground-sea integrated network scenario.However,the openness and heterogeneity of the 6G network cause the problems of network security.To improve the trustworthiness of 6G networks,we propose a trusted computing-based approach for establishing trust relationships inmulti-cloud scenarios.The proposed method shows the relationship of trust based on dual-level verification.It separates the trustworthy states of multiple complex cloud units in 6G architecture into the state within and between cloud units.Firstly,SM3 algorithm establishes the chain of trust for the system’s trusted boot phase.Then,the remote attestation server(RAS)of distributed cloud units verifies the physical servers.Meanwhile,the physical servers use a ring approach to verify the cloud servers.Eventually,the centralized RAS takes one-time authentication to the critical evidence information of distributed cloud unit servers.Simultaneously,the centralized RAS also verifies the evidence of distributed RAS.We establish our proposed approach in a natural OpenStack-based cloud environment.The simulation results show that the proposed method achieves higher security with less than a 1%system performance loss.

关键词： 6G multi-cloud trusted Infrastructure remote attestation commercial cipher

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

Matrix-Mediated Color-Tunable Ultralong Organic Room Temperature Phosphorescence of 7H-Benzo[c]carbazole Derivatives

引用

CCS Chemistry 2024年第3期6卷 798-811页

作者： chen Qian Xue Zhang Zhimin Ma Xiaohua Fu Zewei Li Huiwen Jin mingxing chen Hong Jiang Zhiyong Ma Beijing Advanced Innovation Center for Soft Matter Science and Engineering State Key Laboratory of Organic–Inorganic CompositesCollege of Chemical EngineeringBeijing University of Chemical TechnologyBeijing 100029 Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871

Building on the recent systematic research on 1Hbenzo[f]indole(Bd),an important advancement in constructing ultralong organic room temperature(UORTP)materials with a universal strategy via a readily obtained unit(7H-Benzo[c]carbazole,BCz)is proposed in this work.Pure powders of BCz and its derivatives merely exhibit blue fluorescence at ambient condition.However,when BCz and its derivatives are dispersed into polymer or powder matrixes,strong photo-activated green UORTP can be observed from their doped systems at room temperature.Moreover,the UORTP color can be tuned between green and yellow depending on the matrix.The ultralong phosphorescence originates from the generation of charge-separated states via radicals.The matrixes play a key role in both stabilizing charge-separated states and controlling UORTP color.More interestingly,when using polymethyl methacrylate as matrix,the doped films achieve stronger photo-activated ultralong phosphorescence underwater than in air at room temperature.Comparedwith Bd,BCz achieves better performance not only in ultralong phosphorescence properties but also in practical applications.This work gains a deeper insight into the mechanism of UORTP and paves a new approach to applying organic phosphorescent materials to underwater coating and imaging.

关键词： 7H-Benzo[c]carbazole ultralong organic room temperature phosphorescence ion radical matrix-mediated color tunning underwater application

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

Rural-urban governance toward Sustainable Development Goals

引用

Journal of Geographical Sciences 2022年第7期32卷 1405-1408页

作者： YE Chao chen mingxing chen Ruishan LIAO Chuan Key Laboratory of Geographic Information Science(Ministry of Education) School of Geographic SciencesResearch Center for China Administrative DivisionEast China Normal UniversityShanghai 200241China Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China Department of Landscape Architecture School of DesignShanghai Jiao Tong UniversityShanghai 200240China School of Sustainability Arizona State UniversityTempeAZ 85281USA

With the rapid development of globalization and information&communication technology(ICT),the unprecedented urban development has brought humankind into an era of“planetary urbanization”,and the parallel situation of mobility and instability is increasingly prominent(Lewis and Maslin,2015;Dryzek,2016;Steffen et al.,2018;Elmqvist et al.

关键词： Sustainable Rural urban

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

Flexible interdigitated layered framework with multiple accessible active sites for high-performance CH_(3)I capture

引用

Science China Chemistry 2024年第5期67卷 1569-1577页

作者： Bo Tai Baoyu Li Linwei He Zhonglin Ma Shujing Lin mingxing Zhang Junchang chen Fuqi Wu Long chen Xing Dai Fuyin Ma Zhifang Chai Shuao Wang State Key Laboratory of Radiation Medicine and Protection School for Radiological and interdisciplinary Sciences(RAD-X)and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education InstitutionsSoochow UniversitySuzhou 215123China

The development of adsorbent materials for effective capture of radioactive iodomethane(CH_(3)I) from the off-gas of used nuclear fuel reprocessing, remains a significant and challenging line of research because currently state-of-art adsorbents still suffer from low binding affinity with CH_(3)I. Here, we proposed a brand-new adsorption topological structure by developing a 2D interdigitated layered framework, named SCU-20, featuring slide-like channel with multiple active sites for CH_(3)I capture. The responsive rotating-adaptive aperture of SCU-20 enables the optimal utilization of all active sites within the pore for highly selective recognition and capture of CH_(3)I. A record-breaking CH_(3)I uptake capacity of 1.84 g/g was achieved under static sorption conditions with saturated CH_(3)I vapor. Both experimental and theoretical findings demonstrated that the exceptional uptake of SCU-20 towards CH_(3)I can be attributed to the confined physical electrostatic adsorption of F sites, coupled with the chemical nitrogen methylation reaction with uncoordinated N atoms of pyrazine. Moreover, dynamic CH_(3)I uptake capacity potentially allows for the capture of CH_(3)I in simulated real-world off gas reprocessing conditions. This study highlights the potential of SCU-20 as a promising candidate for efficient capture of iodine species and contributes to the development of effective solutions for radioactive iodine remediation.

关键词： 2D interdigitated layered framework iodomethane dual-sites electrostatic interaction physisorption and chemisorption

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

Regional variation of urban air quality in China and its dominant factors

引用

Journal of Geographical Sciences 2022年第5期32卷 853-872页

作者： ZHAO Yanyan ZHANG Xiaoping chen mingxing GAO Shanshan LI Runkui College of Resources and Environment University of Chinese Academy of SciencesBeijing100049China Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing100101China

It is of great theoretical and practical importance to carry out research on the spatio-temporal evolution of urban air pollution and its driving forces,which helps to facilitate a deeper understanding of the mutual feedback mechanisms between the urban environment and socio-economic systems.Comprehension of these mechanisms will contribute to the design and implementation of efficient environmental policies that ultimately will improve the quality of urbanization development.This paper illustrates the spatio-temporal evolutionary characteristics of six urban ambient air pollutant concentrations,namely,CO,NO_(2),O_(3),PM_(10),PM_(2.5),SO_(2),in 286 sample cities above the prefecture level in China from 2014 to 2019.The interactions between the pollutant concentrations are analyzed based on panel regression models.A random forest model is then employed to explore the correlations between the concentrations of these six pollutants and 13 natural and socio-economic impact factors to isolate the most crucial ones.The results reveal three aspects.First,within the research period,the average annual concentration of O_(3)increased while that of other pollutants decreased year by year.Second,there were significant interactions between concentrations of the six pollutants,leading to obvious compound air pollution in urban areas.Third,the impact of natural and socio-economic factors on urban air quality varied greatly among different air pollutants,with air temperature,vegetation coverage,urbanization level and traffic factors ranking high and the different response thresholds to the dominant influencing factors.In light of the limited ability of humans to control the natural environment and meteorological conditions,it is recommended that urban air quality be further improved by optimizing urban density,controlling anthropogenic emission sources,and implementing strict air pollution prevention and control measures.

关键词： urban air quality spatio-temporal evolution random forest model impact factor

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

基于双缝干涉水导激光打孔的仿真研究

引用

光电子．激光 2024年第2期35卷 198-206页

作者：陈云邓明星武汉科技大学汽车与交通工程学院湖北武汉430070

水导激光加工技术具有热效应小、精度高、无刀具损坏等优点,被应用到高精度元件的加工中。为减小激光聚焦光斑直径以利于激光与水射流的精确耦合、提高激光孔的质量,提出了基于双缝干涉原理以减小激光聚焦光斑直径的方法。构建了传统水... 详细信息

水导激光加工技术具有热效应小、精度高、无刀具损坏等优点,被应用到高精度元件的加工中。为减小激光聚焦光斑直径以利于激光与水射流的精确耦合、提高激光孔的质量,提出了基于双缝干涉原理以减小激光聚焦光斑直径的方法。构建了传统水导激光和双缝干涉水导激光打孔的几何模型和数学模型;基于COMSOL分别进行仿真,对比和分析了在激光束参数、加工条件均相同的条件下,传统水导激光和双缝干涉水导激光打孔时对激光孔轮廓的演化、热影响区域分布和重铸层大小的影响。结果表明:与传统水导激光相比,采用双缝干涉水导激光加工技术能有效地减小激光孔直径、锥角、热影响区域宽度和重铸层大小,在现有条件下进一步减小激光聚焦光斑直径。

关键词：水导激光双缝干涉热影响区域重铸层

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

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：