Improving cultivated land use eco-efficiency(CLUE)can effectively promote agricultural sustainability,particularly in developing countries where CLUE is generally low.This study used provincial-level data from China t...Improving cultivated land use eco-efficiency(CLUE)can effectively promote agricultural sustainability,particularly in developing countries where CLUE is generally low.This study used provincial-level data from China to evaluate the spatiotemporal evolution of CLUE from 2000 to 2020 and identified the influencing factors of CLUE by using a panel Tobit model.In addition,given the undesirable outputs of agricultural production,we incorporated carbon emissions and nonpoint source pollution into the global benchmark-undesirable output-super efficiency-slacks-based measure(GB-US-SBM)model,which combines global benchmark technology,undesirable output,super efficiency,and slacks-based measure.The results indicated that there was an upward trend in CLUE in China from 2000 to 2020,with an increase rate of 2.62%.The temporal evolution of CLUE in China could be classified into three distinct stages:a period of fluctuating decrease(2000-2007),a phase of gradual increase(2008-2014),and a period of rapid growth(2015-2020).The major grain-producing areas(MPAs)had a lower CLUE than their counterparts,namely,non-major grain-production areas(non-MPAs).The spatial agglomeration effect followed a northeast-southwest strip distribution;and the movement path of barycentre revealed a"P"shape,with Luoyang City,Henan Province,as the centre.In terms of influencing factors of CLUE,investment in science and technology played the most vital role in improving CLUE,while irrigation index had the most negative effect.It should be noted that these two influencing factors had different impacts on MPAs and non-MPAs.Therefore,relevant departments should formulate policies to enhance the level of science and technology,improve irrigation condition,and promote sustainable utilization of cultivated land.展开更多
In the era of stock development following the acceleration of urbanization,the revitalization of urban green space has assumed an increasingly significant role.Consequently,the management of urban trees has emerged as...In the era of stock development following the acceleration of urbanization,the revitalization of urban green space has assumed an increasingly significant role.Consequently,the management of urban trees has emerged as a critical focus of urban governance,contributing to the enhancement of livability in human settlements.This study offers a comprehensive analysis of the urban tree management system in Oxford,UK,identifying that its primary objective is to optimize and maintain a harmonious balance between human activities and the natural environment through the implementation of high-quality planting practices.The system emphasizes enhanced management practices and establishes a robust framework for the development of targeted policies and management regulations,utilizing i-Tree eco-efficiency assessment and real-time feedback mechanisms.China’s urban tree management is in its nascent stages,and there is an urgent need for the development of urban green space.By adopting the refined management assessment methodologies employed for urban trees in Oxford,UK,it is possible to enhance the ecological value of urban trees,which represent a significant green resource within cities,and contribute to the creation of more livable urban spaces.展开更多
Under the goal of "double carbon " strategy,the government and enterprises collaborate to form an efficient environmental governance symbiosis network to reduce pollution and carbon.Based on the panel data o...Under the goal of "double carbon " strategy,the government and enterprises collaborate to form an efficient environmental governance symbiosis network to reduce pollution and carbon.Based on the panel data of 30 provinces,the static and dynamic eco-efficiency of the symbiotic network of environmental governance PPP projects are measured by using the SBM model and Malmquist index considering the super-efficiency of non-expected output.The results show that:(1) 8 provinces,including Hebei,have efficiency values greater than 1;11 provinces,including Liaoning,have organizational technology and management levels conducive to efficiency improvement,and 12 provinces,including Zhejiang,are closest to optimal scale efficiency.(2) Redundancy of energy conservation and environmental protection expenditures,urban environmental infrastructure construction investment and new product development projects,insufficient waste gas treatment capacity,environmental emergencies and carbon emission redundancy are all significant factors affecting eco-efficiency.(3) The dynamic efficiency of 8 provinces,including Fujian,shows a decreasing trend,and the Malmquist index and its decomposition indicate that the utilization rate of environmental governance technology should be improved and environmental resources should be allocated rationally.展开更多
Agricultural eco-efficiency is an important indicator to measure the sustainable development and high-quality development of agriculture.Based on the agricultural input-output data of 37 districts(counties)in Chongqin...Agricultural eco-efficiency is an important indicator to measure the sustainable development and high-quality development of agriculture.Based on the agricultural input-output data of 37 districts(counties)in Chongqing from 2004 to 2019,this paper uses the static SBM model and the DDF-BML index method to calculate the agricultural eco-efficiency of each district and county in Chongqing and conduct a comparative analysis.The comprehensive analysis of static and dynamic calculation results shows that the agricultural eco-efficiency of Chongqing is low,the agricultural input-output efficiency of various districts and counties is insufficient,and slack variables are common,so the ability of agricultural sustainable development still needs to be improved.The main sources of agricultural eco-efficiency are the progress of agricultural green technology and the efficiency of agricultural green technology.However,as far as the actual situation of Chongqing is concerned,the efficiency of agricultural green technology shows a downward trend,which has an inhibitory effect on the improvement of agricultural eco-efficiency.Therefore,in the process of agricultural ecological development in the future,Chongqing will focus on improving the efficiency of agricultural green technology as a starting point,implement agricultural technology innovation and promotion,improve the level of farmers’science and technology and culture,and achieve"technology to the countryside,demonstration to households,and application to the country."At the same time,it is necessary to further improve the construction of agricultural and rural infrastructure,and promote the"outward migration"of frontier technologies in agricultural production to radiate agricultural development in surrounding districts and counties.展开更多
使用Visual Basic编程,采用正则表达式批量提取由Web of Science导出的Bib Tex题录中所有Keywords字段关键词,按需合并所得关键词的同义词、近义词及词形变化词,然后将出现频度的统计数据写入Excel表,并编制Excel宏自动生成折线图,实现...使用Visual Basic编程,采用正则表达式批量提取由Web of Science导出的Bib Tex题录中所有Keywords字段关键词,按需合并所得关键词的同义词、近义词及词形变化词,然后将出现频度的统计数据写入Excel表,并编制Excel宏自动生成折线图,实现关键词分布的简单可视化。情报工作者后续可借助Excel功能对该程序生成的Excel表执行复杂的数据组合分析,以提高工作效率。展开更多
This paper uses the ecological footprint model to make comparison of the eco-efficiency of arable land ecological footprint in different years in Hubei Province, and makes comparison of that in Hubei and some countrie...This paper uses the ecological footprint model to make comparison of the eco-efficiency of arable land ecological footprint in different years in Hubei Province, and makes comparison of that in Hubei and some countries. The results indicate that, since 1965, the eco-efficiency of arable land ecological footprint in Hubei has been improved year by year. However, the efficiency of arable land ecological footprint, compared with some other areas in the world, is much lower. In 1965, average eco-efficiency of world arable land ecological footprint is 3 421 US dollar/hm^2 while that of Hubei Province is 134 US dollar/hm^2, about 1/26 of the world's average level. The eco-efficiency of arable land ecological footprint for 2003 in Hubei Province, however, has become about 1/9 of the world's average level for the same year. Finally the author puts forward the ways to raise the eco-efficiency of arable land ecological footprint.展开更多
Eco-efficiency is a valuable tool for managing and solving issues involving resource consumption and pollution emission in current production processes.Despite the popularity of the term"eco-efficiency"in bu...Eco-efficiency is a valuable tool for managing and solving issues involving resource consumption and pollution emission in current production processes.Despite the popularity of the term"eco-efficiency"in business,limited attention has been paid to measuring and reporting regional eco-efficiency for local government policy makers.Based on the concept and method of eco-efficiency,an indicator system of regional eco-efficiency is established in this study.The indicator system comprises 22 indicators,which are divided in to three categories including socio-economic development,resources consumption, environmental pressure.As a promising statistical technique, principle component analysis is used to set the weight of indicators which attempts to calculate the eco-efficiency indices of Qingdao's Chengyang District.The results show that the eco-efficiency of Chengyang District has clearly improved 35.1% with small fluctuation from 1995 to 2003.Socio-economic development index and resources consumption index also represent obvious increasing trends.The correlation coefficient between soci-economic development index and resources consumption index is 0.979,which means the social progress and economic growth of Chengyang District depend on an extravagant consumption of resources.The environmental pressure index increased slowly before 1997 and declined gradually after 1997,due to more attention being paid to environmental protection by local government in recent years.Chengyang District still keeps the traditional economic development mode with a high consumption and high production,so the emphases of future development should put on improving the improving the efficient use of natural resources and promoting environmental management sustainability.The results show that the indicators system of regional eco-efficiency is a promising method to quantitatively evaluate resources and environmental efficiency and provide an effective decision-making support for local governments.展开更多
In this paper, an improved algorithm, web-based keyword weight algorithm (WKWA), is presented to weight keywords in web documents. WKWA takes into account representation features of web documents and advantages of t...In this paper, an improved algorithm, web-based keyword weight algorithm (WKWA), is presented to weight keywords in web documents. WKWA takes into account representation features of web documents and advantages of the TF*IDF, TFC and ITC algorithms in order to make it more appropriate for web documents. Meanwhile, the presented algorithm is applied to improved vector space model (IVSM). A real system has been implemented for calculating semantic similarities of web documents. Four experiments have been carried out. They are keyword weight calculation, feature item selection, semantic similarity calculation, and WKWA time performance. The results demonstrate accuracy of keyword weight, and semantic similarity is improved.展开更多
To save the local storage,users store the data on the cloud server who offers convenient internet services.To guarantee the data privacy,users encrypt the data before uploading them into the cloud server.Since encrypt...To save the local storage,users store the data on the cloud server who offers convenient internet services.To guarantee the data privacy,users encrypt the data before uploading them into the cloud server.Since encryption can reduce the data availability,public-key encryption with keyword search(PEKS)is developed to achieve the retrieval of the encrypted data without decrypting them.However,most PEKS schemes cannot resist quantum computing attack,because the corresponding hardness assumptions are some number theory problems that can be solved efficiently under quantum computers.Besides,the traditional PEKS schemes have an inherent security issue that they cannot resist inside keywords guessing attack(KGA).In this attack,a malicious server can guess the keywords encapsulated in the search token by computing the ciphertext of keywords exhaustively and performing the test between the token and the ciphertext of keywords.In the paper,we propose a lattice-based PEKS scheme that can resist quantum computing attacks.To resist inside KGA,this scheme adopts a lattice-based signature technique into the encryption of keywords to prevent the malicious server from forging a valid ciphertext.Finally,some simulation experiments are conducted to demonstrate the performance of the proposed scheme and some comparison results are further shown with respect to other searchable schemes.展开更多
According to the eco-efficiency theory, combined with agricultural production characteristics, I point out the environmental impact and substance energy consumption characteristics of agricultural production. Based on...According to the eco-efficiency theory, combined with agricultural production characteristics, I point out the environmental impact and substance energy consumption characteristics of agricultural production. Based on this, I establish the eco-efficiency evaluation indicator system for agricultural production, and conduct a comprehensive analysis on the agricultural eco-efficiency of 17 prefecture-level cities in Anhui Province, using data envelopment analysis method.展开更多
A search strategy over encrypted cloud data based on keywords has been improved and has presented a method using different strategies on the client and the server to improve the search efficiency in this paper. The cl...A search strategy over encrypted cloud data based on keywords has been improved and has presented a method using different strategies on the client and the server to improve the search efficiency in this paper. The client uses the Chinese and English to achieve the synonym construction of the keywords, the establishment of the fuzzy-syllable words and synonyms set of keywords and the implementation of fuzzy search strategy over the encryption of cloud data based on keywords. The server side through the analysis of the user’s query request provides keywords for users to choose and topic words and secondary words are picked out. System will match topic words with historical inquiry in time order, and then the new query result of the request is directly gained. The analysis of the simulation experiment shows that the fuzzy search strategy can make better use of historical results on the basis of privacy protection for the realization of efficient data search, saving the search time and improving the efficiency of search.展开更多
Keywords with the retrieval value clearly show the main contents, enhance the influence of academic periodicals, highlight specific information, and generalize information, but because of the ignorance of the value of...Keywords with the retrieval value clearly show the main contents, enhance the influence of academic periodicals, highlight specific information, and generalize information, but because of the ignorance of the value of keywords from some authors and editors, the lack of canonical guidance, and limitations of the editorial knowledge structure, there are some problems concerning keywords in academic papers, such as papers containing too many or too few keywords, or keywords being used in a way that is too general or colloquial. According to academic principle, accurate principle, logical principle, comprehensive principle, it is imperative to discuss how to choose keywords properly.展开更多
基金supported by the National Natural Science Foundation of China(72373117)the Chinese Universities Scientific Fund(Z1010422003)+1 种基金the Major Project of the Key Research Base of Humanities and Social Sciences of the Ministry of Education(22JJD790052)the Qinchuangyuan Project of Shaanxi Province(QCYRCXM-2022-145).
文摘Improving cultivated land use eco-efficiency(CLUE)can effectively promote agricultural sustainability,particularly in developing countries where CLUE is generally low.This study used provincial-level data from China to evaluate the spatiotemporal evolution of CLUE from 2000 to 2020 and identified the influencing factors of CLUE by using a panel Tobit model.In addition,given the undesirable outputs of agricultural production,we incorporated carbon emissions and nonpoint source pollution into the global benchmark-undesirable output-super efficiency-slacks-based measure(GB-US-SBM)model,which combines global benchmark technology,undesirable output,super efficiency,and slacks-based measure.The results indicated that there was an upward trend in CLUE in China from 2000 to 2020,with an increase rate of 2.62%.The temporal evolution of CLUE in China could be classified into three distinct stages:a period of fluctuating decrease(2000-2007),a phase of gradual increase(2008-2014),and a period of rapid growth(2015-2020).The major grain-producing areas(MPAs)had a lower CLUE than their counterparts,namely,non-major grain-production areas(non-MPAs).The spatial agglomeration effect followed a northeast-southwest strip distribution;and the movement path of barycentre revealed a"P"shape,with Luoyang City,Henan Province,as the centre.In terms of influencing factors of CLUE,investment in science and technology played the most vital role in improving CLUE,while irrigation index had the most negative effect.It should be noted that these two influencing factors had different impacts on MPAs and non-MPAs.Therefore,relevant departments should formulate policies to enhance the level of science and technology,improve irrigation condition,and promote sustainable utilization of cultivated land.
基金Beijing Urban Governance Research Base of North China University of Technology(2024CSZL07).
文摘In the era of stock development following the acceleration of urbanization,the revitalization of urban green space has assumed an increasingly significant role.Consequently,the management of urban trees has emerged as a critical focus of urban governance,contributing to the enhancement of livability in human settlements.This study offers a comprehensive analysis of the urban tree management system in Oxford,UK,identifying that its primary objective is to optimize and maintain a harmonious balance between human activities and the natural environment through the implementation of high-quality planting practices.The system emphasizes enhanced management practices and establishes a robust framework for the development of targeted policies and management regulations,utilizing i-Tree eco-efficiency assessment and real-time feedback mechanisms.China’s urban tree management is in its nascent stages,and there is an urgent need for the development of urban green space.By adopting the refined management assessment methodologies employed for urban trees in Oxford,UK,it is possible to enhance the ecological value of urban trees,which represent a significant green resource within cities,and contribute to the creation of more livable urban spaces.
基金supported by Major Social Science Project of Tianjin Education Commission(Grant No. 2019JWZD36)。
文摘Under the goal of "double carbon " strategy,the government and enterprises collaborate to form an efficient environmental governance symbiosis network to reduce pollution and carbon.Based on the panel data of 30 provinces,the static and dynamic eco-efficiency of the symbiotic network of environmental governance PPP projects are measured by using the SBM model and Malmquist index considering the super-efficiency of non-expected output.The results show that:(1) 8 provinces,including Hebei,have efficiency values greater than 1;11 provinces,including Liaoning,have organizational technology and management levels conducive to efficiency improvement,and 12 provinces,including Zhejiang,are closest to optimal scale efficiency.(2) Redundancy of energy conservation and environmental protection expenditures,urban environmental infrastructure construction investment and new product development projects,insufficient waste gas treatment capacity,environmental emergencies and carbon emission redundancy are all significant factors affecting eco-efficiency.(3) The dynamic efficiency of 8 provinces,including Fujian,shows a decreasing trend,and the Malmquist index and its decomposition indicate that the utilization rate of environmental governance technology should be improved and environmental resources should be allocated rationally.
基金supported by the Natural Science Foundation of Fujian Province(Grant No.2022J01320)。
文摘Agricultural eco-efficiency is an important indicator to measure the sustainable development and high-quality development of agriculture.Based on the agricultural input-output data of 37 districts(counties)in Chongqing from 2004 to 2019,this paper uses the static SBM model and the DDF-BML index method to calculate the agricultural eco-efficiency of each district and county in Chongqing and conduct a comparative analysis.The comprehensive analysis of static and dynamic calculation results shows that the agricultural eco-efficiency of Chongqing is low,the agricultural input-output efficiency of various districts and counties is insufficient,and slack variables are common,so the ability of agricultural sustainable development still needs to be improved.The main sources of agricultural eco-efficiency are the progress of agricultural green technology and the efficiency of agricultural green technology.However,as far as the actual situation of Chongqing is concerned,the efficiency of agricultural green technology shows a downward trend,which has an inhibitory effect on the improvement of agricultural eco-efficiency.Therefore,in the process of agricultural ecological development in the future,Chongqing will focus on improving the efficiency of agricultural green technology as a starting point,implement agricultural technology innovation and promotion,improve the level of farmers’science and technology and culture,and achieve"technology to the countryside,demonstration to households,and application to the country."At the same time,it is necessary to further improve the construction of agricultural and rural infrastructure,and promote the"outward migration"of frontier technologies in agricultural production to radiate agricultural development in surrounding districts and counties.
文摘使用Visual Basic编程,采用正则表达式批量提取由Web of Science导出的Bib Tex题录中所有Keywords字段关键词,按需合并所得关键词的同义词、近义词及词形变化词,然后将出现频度的统计数据写入Excel表,并编制Excel宏自动生成折线图,实现关键词分布的简单可视化。情报工作者后续可借助Excel功能对该程序生成的Excel表执行复杂的数据组合分析,以提高工作效率。
文摘This paper uses the ecological footprint model to make comparison of the eco-efficiency of arable land ecological footprint in different years in Hubei Province, and makes comparison of that in Hubei and some countries. The results indicate that, since 1965, the eco-efficiency of arable land ecological footprint in Hubei has been improved year by year. However, the efficiency of arable land ecological footprint, compared with some other areas in the world, is much lower. In 1965, average eco-efficiency of world arable land ecological footprint is 3 421 US dollar/hm^2 while that of Hubei Province is 134 US dollar/hm^2, about 1/26 of the world's average level. The eco-efficiency of arable land ecological footprint for 2003 in Hubei Province, however, has become about 1/9 of the world's average level for the same year. Finally the author puts forward the ways to raise the eco-efficiency of arable land ecological footprint.
文摘Eco-efficiency is a valuable tool for managing and solving issues involving resource consumption and pollution emission in current production processes.Despite the popularity of the term"eco-efficiency"in business,limited attention has been paid to measuring and reporting regional eco-efficiency for local government policy makers.Based on the concept and method of eco-efficiency,an indicator system of regional eco-efficiency is established in this study.The indicator system comprises 22 indicators,which are divided in to three categories including socio-economic development,resources consumption, environmental pressure.As a promising statistical technique, principle component analysis is used to set the weight of indicators which attempts to calculate the eco-efficiency indices of Qingdao's Chengyang District.The results show that the eco-efficiency of Chengyang District has clearly improved 35.1% with small fluctuation from 1995 to 2003.Socio-economic development index and resources consumption index also represent obvious increasing trends.The correlation coefficient between soci-economic development index and resources consumption index is 0.979,which means the social progress and economic growth of Chengyang District depend on an extravagant consumption of resources.The environmental pressure index increased slowly before 1997 and declined gradually after 1997,due to more attention being paid to environmental protection by local government in recent years.Chengyang District still keeps the traditional economic development mode with a high consumption and high production,so the emphases of future development should put on improving the improving the efficient use of natural resources and promoting environmental management sustainability.The results show that the indicators system of regional eco-efficiency is a promising method to quantitatively evaluate resources and environmental efficiency and provide an effective decision-making support for local governments.
基金Project supported by the Science Foundation of Shanghai Municipal Commission of Science and Technology (Grant No.055115001)
文摘In this paper, an improved algorithm, web-based keyword weight algorithm (WKWA), is presented to weight keywords in web documents. WKWA takes into account representation features of web documents and advantages of the TF*IDF, TFC and ITC algorithms in order to make it more appropriate for web documents. Meanwhile, the presented algorithm is applied to improved vector space model (IVSM). A real system has been implemented for calculating semantic similarities of web documents. Four experiments have been carried out. They are keyword weight calculation, feature item selection, semantic similarity calculation, and WKWA time performance. The results demonstrate accuracy of keyword weight, and semantic similarity is improved.
基金The authors would like to thank the support from Fundamental Research Funds for the Central Universities(No.30918012204)The authors also gratefully acknowledge the helpful comments and suggestions of other researchers,which has improved the presentation.
文摘To save the local storage,users store the data on the cloud server who offers convenient internet services.To guarantee the data privacy,users encrypt the data before uploading them into the cloud server.Since encryption can reduce the data availability,public-key encryption with keyword search(PEKS)is developed to achieve the retrieval of the encrypted data without decrypting them.However,most PEKS schemes cannot resist quantum computing attack,because the corresponding hardness assumptions are some number theory problems that can be solved efficiently under quantum computers.Besides,the traditional PEKS schemes have an inherent security issue that they cannot resist inside keywords guessing attack(KGA).In this attack,a malicious server can guess the keywords encapsulated in the search token by computing the ciphertext of keywords exhaustively and performing the test between the token and the ciphertext of keywords.In the paper,we propose a lattice-based PEKS scheme that can resist quantum computing attacks.To resist inside KGA,this scheme adopts a lattice-based signature technique into the encryption of keywords to prevent the malicious server from forging a valid ciphertext.Finally,some simulation experiments are conducted to demonstrate the performance of the proposed scheme and some comparison results are further shown with respect to other searchable schemes.
基金Supported by Special Project for Youth Research in Anhui Institute of Architecture&Industry(20104012)
文摘According to the eco-efficiency theory, combined with agricultural production characteristics, I point out the environmental impact and substance energy consumption characteristics of agricultural production. Based on this, I establish the eco-efficiency evaluation indicator system for agricultural production, and conduct a comprehensive analysis on the agricultural eco-efficiency of 17 prefecture-level cities in Anhui Province, using data envelopment analysis method.
文摘A search strategy over encrypted cloud data based on keywords has been improved and has presented a method using different strategies on the client and the server to improve the search efficiency in this paper. The client uses the Chinese and English to achieve the synonym construction of the keywords, the establishment of the fuzzy-syllable words and synonyms set of keywords and the implementation of fuzzy search strategy over the encryption of cloud data based on keywords. The server side through the analysis of the user’s query request provides keywords for users to choose and topic words and secondary words are picked out. System will match topic words with historical inquiry in time order, and then the new query result of the request is directly gained. The analysis of the simulation experiment shows that the fuzzy search strategy can make better use of historical results on the basis of privacy protection for the realization of efficient data search, saving the search time and improving the efficiency of search.
文摘Keywords with the retrieval value clearly show the main contents, enhance the influence of academic periodicals, highlight specific information, and generalize information, but because of the ignorance of the value of keywords from some authors and editors, the lack of canonical guidance, and limitations of the editorial knowledge structure, there are some problems concerning keywords in academic papers, such as papers containing too many or too few keywords, or keywords being used in a way that is too general or colloquial. According to academic principle, accurate principle, logical principle, comprehensive principle, it is imperative to discuss how to choose keywords properly.