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Problems on the application of geographic information systems to urban environmental management
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作者 何强 LONG +1 位作者 Tengrui 《Journal of Chongqing University》 CAS 2002年第2期50-53,共4页
Geographic information systems (GIS) are a widely used tool in urban planning and management. More and more cities and decision-makers require its attributes of promptness, precision and visualization. But the applica... Geographic information systems (GIS) are a widely used tool in urban planning and management. More and more cities and decision-makers require its attributes of promptness, precision and visualization. But the application of GIS in urban environmental management is still a new field and relevant researches are getting on tardily. As a subsystem of GIS, an urban environmental management geographic information system (UEMGIS) should be a complex multi-discipline and multi-objective tool to perform quantitative multi-dimension analysis and to transfer the results into an expression legible to an ordinary user. It should be a dynamic system of prompt functions based on upgradable databases, and be composed of many subsystems respectively specialized in items about water, air, waste and noise as well as relative standards and regulations. However, existing UEMGISs mostly rely on the basic GIS too much to design the actual requirements of applications and managements in themselves, and the unavailability of sufficient fundamental data has retarded their improvement. In the design of a UEMGIS, the standardization of data classification should be taken into consideration to make the data exchangeable and shareable among its subsystems and within every subsystem, and the applicable error limits for input data should be defined in accordance with the user抯 required precision of data out. Data acquisition can be easy and quick if remote sensing, global positioning system (GPS) and other technologies are combined with GIS. Rapidly progressing information technologies have been giving a bright prospect for the melioration of UEMGIS that will have great potential and wide application in environmental conservation. 展开更多
关键词 geographic information system urban environmental management global positioning system
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Analysis of Existing Problems and Treatment Methods of Urban Environmental Monitoring
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作者 Zhang Qiandong Song Xin 《Journal of Environmental Science and Engineering(A)》 2022年第2期49-54,共6页
With the rapid development of the city,the concept of ecological environment has been integrated into everyone’s heart.In the new era,people also have higher requirements for the quality of living environment.However... With the rapid development of the city,the concept of ecological environment has been integrated into everyone’s heart.In the new era,people also have higher requirements for the quality of living environment.However,at this stage,with the development of urbanization and industrialization,the problem of environmental pollution has become more and more serious.Therefore,we must do a good job in urban environmental monitoring,pay attention to the protection of urban environment,design and implement effective governance methods,so as to improve the quality of environmental governance.This article analyzes the problems in urban environmental monitoring,and formulates reasonable treatment methods and suggestions. 展开更多
关键词 urban environmental monitoring PROBLEMS governance methods ANALYSIS
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Coping with Multi-scale Climate Change:Study on the Application of Urban Environmental Climate Maps of Stuttgart,Germany
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作者 ZHANG Qi YANG Xin 《Journal of Landscape Research》 2021年第5期41-46,50,共7页
The development of modern cities has brought about tremendous changes in the climate environment.Faced with complex climate conditions,research on multi-scale climate change in cities is of great significance.The urba... The development of modern cities has brought about tremendous changes in the climate environment.Faced with complex climate conditions,research on multi-scale climate change in cities is of great significance.The urban environmental climate maps and the application of climate atlas tool in Stuttgart,Germany were studied,and the multi-scale application of urban environmental climate maps in Stuttgart,Germany was summarized through the analysis of the pre-planning,current construction situation,and landscape reconstruction of the German"Stuttgart 21"plan case.Besides,other important measures to cope with climate change in German were proposed,and finally multi-scale practical strategies to cope with urban climate and environment were summarized to provide ideas and methods for improving China’s future urban climate environment. 展开更多
关键词 urban environmental climate maps MULTI-SCALE Stuttgart 21 plan Climate coping strategy
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Urban environmental geological problems and its controlling countermeasures in Shandong province,China
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《Global Geology》 1998年第1期15-15,共1页
关键词 urban environmental geological problems and its controlling countermeasures in Shandong province China
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Planning and Orientation Analysis of Urban Environmental Landscape Aesthetic Value
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作者 Wei Wei 《Frontiers Research of Architecture and Engineering》 2019年第3期15-18,共4页
Landscape is people’s evaluation of the environment which is better and more meaningful to visit.Therefore,a landscape must have a good environment.Landscape exists in nature as well as in cities.Every corner of a ci... Landscape is people’s evaluation of the environment which is better and more meaningful to visit.Therefore,a landscape must have a good environment.Landscape exists in nature as well as in cities.Every corner of a city can be a landscape.Its connection with the city and the citizens is inseparable.However,due to the acceleration of urbanization,there are still many problems in the urban environment.To solve these problems perfectly,we should work from the aesthetic value and planning orientation of the landscape.Therefore,this paper discusses and analyzes the problems of urban environment and how to use the aesthetic value and orientation to construct urban environmental landscape. 展开更多
关键词 urban environment AESTHETICS VALUE Orientation analysis
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Landscape of global urban environmental resistome and its association with local socioeconomic and medical status
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作者 Jun Wu Yige Hu +21 位作者 Michael H Perlin David Danko Jun Lu Manuela Oliveira Johannes Werner Maria M Zambrano Maria A Sierra Olayinka O Osuolale Paweł Łabaj Nicolás Rascovan Nur Hazlin Hazrin-Chong Soojin Jang Haruo Suzuki Marina Nieto-Caballero Bharath Prithiviraj Patrick K H Lee Agnieszka Chmielarczyk Anna Różańska Yongxiang Zhao Lan Wang Christopher E Mason Tieliu Shi 《Science China(Life Sciences)》 SCIE CAS CSCD 2024年第6期1292-1301,共10页
Antimicrobial resistance(AMR)poses a critical threat to global health and development,with environmental factors—particularly in urban areas—contributing significantly to the spread of antibiotic resistance genes(AR... Antimicrobial resistance(AMR)poses a critical threat to global health and development,with environmental factors—particularly in urban areas—contributing significantly to the spread of antibiotic resistance genes(ARGs).However,most research to date has been conducted at a local level,leaving significant gaps in our understanding of the global status of antibiotic resistance in urban environments.To address this issue,we thoroughly analyzed a total of 86,213 ARGs detected within 4,728 metagenome samples,which were collected by the Meta SUB International Consortium involving diverse urban environments in 60 cities of 27 countries,utilizing a deep-learning based methodology.Our findings demonstrated the strong geographical specificity of urban environmental resistome,and their correlation with various local socioeconomic and medical conditions.We also identified distinctive evolutionary patterns of ARG-related biosynthetic gene clusters(BGCs)across different countries,and discovered that the urban environment represents a rich source of novel antibiotics.Our study provides a comprehensive overview of the global urban environmental resistome,and fills a significant gap in our knowledge of large-scale urban antibiotic resistome analysis. 展开更多
关键词 urban environment METAGENOME antibiotic resistance resistance diversity biosynthetic gene clusters
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Research Characteristics of Thermal Comfort of Urban Block Landscape Based on Knowledge Graph Analysis
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作者 FENG Shutong PENG Li +2 位作者 MA Minghao WANG Zhihao CONG Jing 《Journal of Landscape Research》 2024年第2期42-46,50,共6页
The landscape environment of urban blocks plays a significant role in improving the comfort of urban thermal environment and promoting green and high-quality development.The 342 papers related to the research on the i... The landscape environment of urban blocks plays a significant role in improving the comfort of urban thermal environment and promoting green and high-quality development.The 342 papers related to the research on the impact of urban block landscape environment on thermal comfort in China,collected by CNKI(China National Knowledge Infrastructure)from 2002 to 2022,are used as the research object.Through bibliometric statistical analysis,LLR algorithm,and cluster analysis,the current research status of the impact of urban block landscape environment on thermal comfort in China is analyzed and processed,and its external characteristics are identified.Using the information visualization software CiteSpace,the research topics in the field of the impact of urban block landscape environment on thermal comfort are presented in the form of knowledge graphs.Through co-occurrence analysis of keywords and trend of word frequency changes,the development trends of research hotspots and cutting-edge fields of the impact of urban block landscape environment on thermal comfort are determined,hoping to provide reference for future research in this field. 展开更多
关键词 urban block landscape environment Thermal comfort CiteSpace visualization analysis Research hotspots Research frontiers
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Implications of Dynamic Interactions between Meteorological Patterns and Surface Water Quality on Environmental Health—A Case Study of the Nairobi River
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作者 Haron Safari Hongbin Chen +1 位作者 Edwin Kipkirui Duncan Mbuge 《Journal of Geoscience and Environment Protection》 2024年第5期113-146,共34页
Urban areas face significant challenges in maintaining water quality amidst increasing urbanization and changing climatic patterns. This study investigates the complex interplay between meteorological variables and wa... Urban areas face significant challenges in maintaining water quality amidst increasing urbanization and changing climatic patterns. This study investigates the complex interplay between meteorological variables and water quality parameters in Nairobi City, focusing on the impacts of rainfall and temperature on surface water quality. Data from multiple sources, including the Water Resources Authority, Nairobi Water and Sewerage Company, and the World Bank’s Climate Change Knowledge Portal, were analyzed to assess the relationships between meteorological variables (rainfall and temperature) and water quality parameters (such as electroconductivity, biochemical oxygen demand, chloride, and pH). The analysis reveals varying impacts of rainfall and temperature on different water quality parameters. While parameters like iron and pH show strong relationships with both rainfall and temperature, others such as ammonia and nitrate exhibit moderate relationships. Additionally, the study highlights the influence of runoff, urbanization, and industrial activities on water quality, emphasizing the need for holistic management approaches. Recommendations encompass the establishment of annual publications on Nairobi River water quality, online accessibility of water quality data, development of hydrological models, spatial analysis, and fostering cross-disciplinary research collaborations. Implementing these recommendations can enhance water quality management practices, mitigate risks, and safeguard environmental integrity in Nairobi City. 展开更多
关键词 Water Quality Meteorological Conditions urban Environment environmental Health NAIROBI Water Quality Parameters
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Open-Air Quarries in the Urban Commune of Zinder (South-East Niger): An Opportunity with Strong Externalities
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作者 Karimou Dia Hantchi Abdoulkader Moussa Issaka +4 位作者 Bouba Hassane Mahamadou Bahari Ibrahim Charifatou Salissou Ousmane Sitou Lawali Moussa Konaté 《Geomaterials》 2024年第4期59-81,共23页
The framing of this theme would contribute to a better analysis of the benefits of open-air quarrying in Zinder, and should make it possible to understand and measure the socio-environmental externalities of this type... The framing of this theme would contribute to a better analysis of the benefits of open-air quarrying in Zinder, and should make it possible to understand and measure the socio-environmental externalities of this type of activity in an urban environment. The approach method consisted of carrying out surveys combined with field observations and interviews with the various stakeholders as well as the local population. The results obtained made it possible to identify both positive and negative impacts. The positive impacts are above all the advantages derived from these aggregate quarries, in particular, the creation of direct and permanent jobs and the increase in community income. The price of piling up a truck costs around 28,000 CFA ($56 CAN) and that of loading is around 10,000 F CFA ($20 CAN). This has the effect of removing young people (20 - 39 years old) from the circuit of migration outside the region and even the country. The possibility of using the extraction sites by the local population was identified, in terms of profits relating to fish farming, off-season crops, animal drinking and reclaimed plots. The study also noted negative externalities, such as the temptation of young boys to become involved in extractive activities for immediate gains at the expense of school attendance. Added to this is the upheaval in the topography of the urban landscape, pollution and nuisances (noise, visual and olfactory), while the disappearance or clogging of quarry ponds is the cause of frequent flooding in the neighborhoods. In short, corrective measures (e.g. the revegetation of sites) certainly make it possible to minimize the harmful impacts on the urban environment. But, to improve the performance and organizational capacity of the quarrying industry in Niger, even stronger regulation, training and awareness of stakeholders prove to be the necessary measures. 展开更多
关键词 Open-Air Quarries urban Environment Community Income Externalities Zinder
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Characteristics and Trends of Urban Waterfront Human Settlements Based on CiteSpace
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作者 Binbin Zhang Jinghao Li +1 位作者 Ying Ma Nanwei Wu 《Journal of World Architecture》 2024年第2期146-153,共8页
Urban waterfront human settlements have gradually become a hot topic for research in recent years.Using CiteSpace,597 publications from 2017 to 2023 that were retrieved from the Web of Science were analyzed and sorted... Urban waterfront human settlements have gradually become a hot topic for research in recent years.Using CiteSpace,597 publications from 2017 to 2023 that were retrieved from the Web of Science were analyzed and sorted out,and the following characteristics were found:(1)The research hotspots transitioned from thermal comfort evaluation to the functional mechanism of water bodies,and then to the impact on the environment and residents’behavior.(2)The integration of disciplines has promoted the diversification of perspectives on urban waterfront human settlements,and the content has become more concentrated in interdisciplinary fields.Research on corresponding technology and methods of urban waterfront human settlement has improved,and so has the extensiveness of the experiments.(3)The research on urban waterfront human settlement from the perspective of ecology has been improving.The research focuses more on the harmonious coexistence of ecological and cultural values and human beings. 展开更多
关键词 urban waterfront living environment Bibliometric analysis urban thermal environment Ecological civilization construction Online publication:May 20 2024
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Leaf developmental stability of Platanus acerifolia under urban environmental stress and its implication as an environmental indicator
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作者 ZHANG Hao WANG Xiangrong 《Frontiers in Biology》 CSCD 2006年第4期411-417,共7页
The developmental stability indices,leaf width based fluctuating asymmetry(FA1),and lateral vein length based directional asymmetry(RDA1)of Platanus acerifolia were studied.All the leaves were sampled from 14 sites th... The developmental stability indices,leaf width based fluctuating asymmetry(FA1),and lateral vein length based directional asymmetry(RDA1)of Platanus acerifolia were studied.All the leaves were sampled from 14 sites that were categorized based on different urban environmental stress levels(UESL)in Shanghai metropolitan,China.Besides,foliar stomatal density and stomatal length were also studied as the subsidiary indices to test the availability of developmental stability indices as the indicator under a stressful environment.Results showed seasonal variation of FA1 and RDA1 existed among the 14 sites,but the data showed significant negative correlation between FA1 and UESL(FA1=0.029−0.0009UESL+0.0003UESL2,r=0.7665,P=0.0014).However,a similar trend was not found between RDA1 and UESL.Furthermore,the significant correlation among FA1 and leaf stomatal length and stomatal density implied they could be used as indicators of urban stress levels on a small scale.It seemed that RDA1 was possibly a normal parameter during leaf development but it was unavailable for use as an indicator of urban stresses. 展开更多
关键词 SHANGHAI Platanus acerifolia developmental stability urban environmental stresses
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Urban Waterfront Space Design under the Concept of Ecological Conservation:A Case Study of Hefei Swan Lake
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作者 LI Quanjun GE Juan +1 位作者 WANG Mengqing HU Yueyue 《Journal of Landscape Research》 2023年第4期45-49,共5页
With the proposal of the concept that lucid waters and lush mountains are invaluable assets,ecological issues have become increasingly important issues of concern to people.The process of urbanization is accelerating,... With the proposal of the concept that lucid waters and lush mountains are invaluable assets,ecological issues have become increasingly important issues of concern to people.The process of urbanization is accelerating,and the importance of urban waterfront space in improving the environmental quality of the city and people’s quality of life,enhancing the vitality of the city,the overall appearance of the city,and the competitiveness of the city,is receiving increasing attention.And how to properly handle the construction and development of urban waterfront space has become increasingly prominent in urban planning.Under the the concept of“ecological conservation”,it is thought that the construction of urban waterfront space should follow the principle of harmony between nature and man,and strengthen the multifaceted connection of the city.Through field research on Swan Lake,a comprehensive evaluation of the problems in the plank road and land ecology is conducted.It is proposed to improve the current situation of Swan Lake by grasping the two keywords of“waterfront”and“city”,and starting from the improvement of water body and the enhancement of urban cultural construction in the lake area. 展开更多
关键词 Ecological conservation urban environmental improvement Waterfront space
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ENVIRONMENTAL SUSTAINABILITY AND SCENARIOS OF URBANIZATION IN ARID AREA——A Case Study in Wuwei City of Gansu Province 被引量:4
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作者 YOUFei LIYu DONGSuo-cheng 《Chinese Geographical Science》 SCIE CSCD 2005年第2期120-130,共11页
Based on data of questionnaire and field survey and two developing models of Business As Usual (BAU) and the Intensive Urbanization (IU), this article, taking Wuwei City, a medium size city and typical oasis arid area... Based on data of questionnaire and field survey and two developing models of Business As Usual (BAU) and the Intensive Urbanization (IU), this article, taking Wuwei City, a medium size city and typical oasis arid area in Gansu Province with very vulnerable and sensitive natural environment but long history of oasis economy, as an example, evaluated the sustainability of its environment and analyzed the scenarios of Wuwei’s household energy consumption, waste discharge in transportation industry, primary industry, secondary industry, tertiary industry, by the integration of the systematical dynamics model Stella and Polestar language to simulate the future development of the research area. The results showed that, first, the developing model of IU was propitious to Wuwei City named for oasis economy and vulnerable natural environment. The strategy of "Intensive Urbanization" can change the structure of energy utilization, and improve the efficiency of energy utilization. Second, the proportion of domestic energy consumption will decrease with industrialization and economic development, while that of tertiary industry, secondary industry and transportation will gradually grow up according to strategy of "Intensive Urbanization". Third, the Wuwei City is facing a severe eco-environmental crisis under the conventional patterns of development and a better future under a sustainable urbanization scenario, in the next 10 to 20 years. The different developing trends were clarified and the relative countermeasures were put forward for the policy makers according to the driving forces. 展开更多
关键词 impact of urbanization on environment sustainability of eco-environment scenario analysis Wuwei City arid area
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ANALYSIS ON THE SPATIAL DISTRIBUTION VARIATION CHARACTERISTIC OF URBAN HEAT ENVIRONMENTAL QUALITY AND ITS MECHANISM——A Case Study of Hangzhou City 被引量:3
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作者 WANGWei-wu ZHULi-zhong +1 位作者 WANGRen-chao SHIYong-jung 《Chinese Geographical Science》 SCIE CSCD 2003年第1期39-47,共9页
Urban heat environmental quality (UHEQ) is affected by the interacting of weather condition and underlying surface framework of urban area. In the last two decades, many researchers from domestic and overseas have stu... Urban heat environmental quality (UHEQ) is affected by the interacting of weather condition and underlying surface framework of urban area. In the last two decades, many researchers from domestic and overseas have studied many problems at the aspect of urban heat environment such as urban heat islands, urban air temperature and their relation with urban land cover, city population, air pollution etc. In the recent years, Hangzhou, acting as a center city of Zhejiang Province in China, its urbanization quantum and quantity have both changed greatly, in particular, representing as business affairs building, resident real property and all kinds of specialty market having arisen in built-up zone. Based on Landsat TM images data in 1991 and 1999, urban underlying surface temperature value and Normalized Difference Vegetation Index (NDVI) were calculated using image interpreting and supervised classification technique by remote sensing software ERDAS image 8.4. The relation model between urban underlying surface temperature (UUST) and urban air temperature was setup according to the certain correlation pattern. Reference to the relational standard of assessing human comfort and other meteorology data of Hangzhou City in summer, the spatial distribution characteristic and the spatial variation degree of human comfort of heat environmental quality are estimated and mapped on a middle scale, that is, in six districts of Hangzhou City . Then the paper reveals the main characteristic of spatial variation from 1991 to 1999. Lastly, the change mechanism is analyzed and discussed from the viewpoint of city planning, construction and environmental protection. 展开更多
关键词 urban heat environmental quality (UHEQ) remote sensing geographicinformation system ( GIS) spatial distribution variation mechanism
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Exploration on Environmental Education Though Construction of Global Parks in Zibo City
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作者 Xue Wei 《Journal of World Architecture》 2023年第3期1-5,共5页
In this paper,the development status of environmental education in representative urban parks in Zibo City is investigated,studied,analyzed,and summarized.Besides,the role of natural resource commentary systems,waste ... In this paper,the development status of environmental education in representative urban parks in Zibo City is investigated,studied,analyzed,and summarized.Besides,the role of natural resource commentary systems,waste sorting center visitations,and specialty gardens are expounded.In order to provide a reference for the integration of environmental education in the construction and renovation of parks in Zibo City,the problems in several practices like specialty gardens and WeChat public account is discussed. 展开更多
关键词 urban environmental education
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A Scheme for a Sustainable Urban Water Environmental System During the Urbanization Process in China 被引量:6
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作者 Huibin Yu Yonghui Song +2 位作者 Xin Chang Hongjie Gao Jianfeng Peng 《Engineering》 2018年第2期26-29,共4页
Urbanization is a potential factor in economic development, which is a main route to social development. As the scale of urbanization expands, the quality of the urban water environment may deteriorate, which can have... Urbanization is a potential factor in economic development, which is a main route to social development. As the scale of urbanization expands, the quality of the urban water environment may deteriorate, which can have a negative impact on sustainable urbanization. Therefore, a comprehensive understanding of the functions of the urban water environment is landscape, culture, and economy. Furthermore, a the urban water environment, which is associated necessary, including its security, resources, ecology, deep analysis is required of the theoretical basis of with geographical location, landscape ecology, and a low-carbon economy. In this paper, we expound the main principles for constructing a system for the urban water environment (including sustainable development, ecological priority, and regional differ- ences), and suggest the content of an urban water environmental system. Such a system contains a nat- ural water environment, an economic water environment, and a social water environment. The natural water environment is the base, an effective economic water environment is the focus, and a healthy social water environment is the essence of such a system. The construction of an urban water environment should rely on a comprehensive security system, complete scientific theory, and advanced technology. 展开更多
关键词 urbanIZATION urban water environment Water function Security system
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Novel algorithm for detection and identification of radioactive materials in an urban environment 被引量:1
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作者 Hao-Lin Liu Hai-Bo Ji +3 位作者 Jiang-Mei Zhang Jing Lu Cao-Lin Zhang Xing-Hua Feng 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第10期103-116,共14页
This study introduces a novel algorithm to detect and identify radioactive materials in urban settings using time-series detector response data. To address the challenges posed by varying backgrounds and to enhance th... This study introduces a novel algorithm to detect and identify radioactive materials in urban settings using time-series detector response data. To address the challenges posed by varying backgrounds and to enhance the quality and reliability of the energy spectrum data, we devised a temporal energy window. This partitioned the time-series detector response data, resulting in energy spectra that emphasize the vital information pertaining to radioactive materials. We then extracted characteristic features of these energy spectra, relying on the formation mechanism and measurement principles of the gammaray instrument spectrum. These features encompassed aggregated counts, peak-to-flat ratios, and peak-to-peak ratios. This methodology not only simplified the interpretation of the energy spectra's physical significance but also eliminated the necessity for peak searching and individual peak analyses. Given the requirements of imbalanced multi-classification, we created a detection and identification model using a weighted k-nearest neighbors(KNN) framework. This model recognized that energy spectra of identical radioactive materials exhibit minimal inter-class similarity. Consequently, it considerably boosted the classification accuracy of minority classes, enhancing the classifier's overall efficacy. We also executed a series of comparative experiments. Established methods for radionuclide identification classification, such as standard KNN, support vector machine, Bayesian network, and random tree, were used for comparison purposes. Our proposed algorithm realized an F1 measure of 0.9868 on the time-series detector response data, reflecting a minimum enhancement of 0.3% in comparison with other techniques. The results conclusively show that our algorithm outperforms others when applied to time-series detector response data in urban contexts. 展开更多
关键词 Gamma-ray spectral analysis Nuclide identification urban environment Temporal energy window Peakratio spectrum analysis Weighted KNN
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Study on urban water environmental support capacity
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作者 Guo Huaicheng Ye Wenhu(Center of Environmental Sciences , Peking University , Beijing 100871 , China) 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1995年第4期430-434,共5页
StudyonurbanwaterenvironmentalsupportcapacityGuoHuaicheng;YeWenhu(CenterofEnvironmentalSciences,PekingUniver... StudyonurbanwaterenvironmentalsupportcapacityGuoHuaicheng;YeWenhu(CenterofEnvironmentalSciences,PekingUniversity,Beijing10087... 展开更多
关键词 water environmental support capacity urban water environment development variablesi supportvariables.
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Changes in the growth of Scots pine(Pinus sylvestris L.)stands in an urban environment in European Russia since 1862
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作者 Aleksandr V.Lebedev 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第5期1279-1287,共9页
A century and a half ago,in the European part of Russia(Moscow),forest scientists established the first long-term observations of forests,many of which are under observation to the present day.In the twentieth century... A century and a half ago,in the European part of Russia(Moscow),forest scientists established the first long-term observations of forests,many of which are under observation to the present day.In the twentieth century,climate changes and,due to industrial development,forest areas were under air pollution.Based on observations from 157 sites,this study shows that the growth and density of Scots pine(Pinus sylvestris L.)have decreased by the end of the twentieth century.The environment has changed,and the growth and development of plantations has slowed.Pine yields(-34%stand volume)and their life expectancy(on average 50 years)have decreased.These changes are critical for forestry and for the management of forests in urban centers.Due to the decline in growth,ecosystem functions by urban forests has decreased.In order to increase the sustainability of urban forests and the provision of ecosystem services,it is preferable to create multi-species stands with a complex structure. 展开更多
关键词 Forest stand Scots pine Stand growth urbanized environment Human footprint
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Retrieval and Regional Distribution Analysis of Ammonia,Sulfur Dioxide and Nitrogen Dioxide in the Urban Environment Using Ultraviolet DOAS Algorithm
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作者 Hao Chen Jie Xu +5 位作者 YiboHu Fuzhou Niu Zhiyan Li Dan Wang Guizhong Fu Chuanxin Li 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第2期1251-1262,共12页
Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorptio... Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorption Spectroscopy(DOAS)and multiple-pass cell technique.Typical trace gas pollutants,NH3,SO2,and NO2,were explored using their optical spectral characteristics in deep ultraviolet wavelength range from 210 to 215 nm.The gas concentration was retrieved by Lambert-Beer’s law and nonlinear least square method.With an optimized optical alignment,the detection limits of NH3,SO2,NO2 were estimated to be 2.2,2.3,and 36.2 ppb,respectively.The system was used in carrying out some cruise observations in Chengdu,China.During the entire period,the polluted gases showed varied distribution and typical daily average concentrations ofNH3,SO2,NO2 were 23.2,3.5,and 106.0 ppb,respectively.The contributions from different sources were analyzed combined with the HYSPLIT model.Results show that the portable DOAS system is a convenient and effective tool for regional distribution measurement and pollution source monitoring. 展开更多
关键词 Ultraviolet DOAS algorithm retrieve method white cell urban environment regional distribution
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