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Occurrence and potential risks of organophosphate esters in agricultural soils:A case study of Fuzhou City,Southeast China 被引量:1
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作者 Tao Wang Hong Zhang +6 位作者 Chong Huang Yujie Ben Hanlin Zhou Hangting Guo Yonghe Han Yong Zhang Ping Tong 《Journal of Environmental Sciences》 2025年第4期571-581,共11页
Fifty agricultural soil samples collected from Fuzhou,southeast China,were first investigated for the occurrence,distribution,and potential risks of twelve organophosphate esters(OPEs).The total concentration of OPEs(... Fifty agricultural soil samples collected from Fuzhou,southeast China,were first investigated for the occurrence,distribution,and potential risks of twelve organophosphate esters(OPEs).The total concentration of OPEs(ΣOPEs)in soil ranged from 1.33 to 96.5 ng/g dry weight(dw),with an average value of 17.1 ng/g dw.Especially,halogenated-OPEs were the predominant group with amean level of 9.75 ng/g dw,and tris(1-chloro-2-propyl)phosphate(TCIPP)was the most abundant OPEs,accounting for 51.1%ofΣOPEs.The concentrations of TCIPP andΣOPEs were found to be significantly higher(P<0.05)in soils of urban areas than those in suburban areas.In addition,the use of agricultural plastic films and total organic carbon had a positive effect on the occurrence of OPE in this study.The positive matrix factorization model suggested complex sources of OPEs in agricultural soils from Fuzhou.The ecological risk assessment demonstrated that tricresyl phosphate presented a medium risk to land-based organisms(0.1≤risk quotient<1.0).Nevertheless,the carcinogenic and noncarcinogenic risks for human exposure to OPEs through soil ingestion and dermal absorption were negligible.These findings would facilitate further investigations into the pollution management and risk control of OPEs. 展开更多
关键词 Organophosphate esters(OPEs) Agricultural soils Spatial distribution Source identification Risk assessment
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Spatio-temporal Evolution Characteristics and Driving Forces of Winter Urban Heat Island:A Case Study of Rapid Urbanization Area of Fuzhou City,China 被引量:3
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作者 WANG Zili LU Chunyan +4 位作者 SU Yanlin SU Yue YU Qianru LI Wenzhe YANG Nuocheng 《Chinese Geographical Science》 SCIE CSCD 2024年第1期135-148,共14页
Under the influence of anthropogenic and climate change,the problems caused by urban heat island(UHI)has become increasingly prominent.In order to promote urban sustainable development and improve the quality of human... Under the influence of anthropogenic and climate change,the problems caused by urban heat island(UHI)has become increasingly prominent.In order to promote urban sustainable development and improve the quality of human settlements,it is significant for exploring the evolution characteristics of urban thermal environment and analyzing its driving forces.Taking the Landsat series images as the basic data sources,the winter land surface temperature(LST)of the rapid urbanization area of Fuzhou City in China was quantitatively retrieved from 2001 to 2021.Combing comprehensively the standard deviation ellipse model,profile analysis and GeoDetector model,the spatio-temporal evolution characteristics and influencing factors of the winter urban thermal environment were systematically analyzed.The results showed that the winter LST presented an increasing trend in the study area during 2001–2021,and the winter LST of the central urban regions was significantly higher than the suburbs.There was a strong UHI effect from 2001 to 2021with an expansion trend from the central urban regions to the suburbs and coastal areas in space scale.The LST of green lands and wetlands are significantly lower than croplands,artificial surface and unvegetated lands.Vegetation and water bodies had a significant mitigation effect on UHI,especially in the micro-scale.The winter UHI had been jointly driven by the underlying surface and socio-economic factors in a nonlinear or two-factor interactive enhancement mode,and socio-economic factors had played a leading role.This research could provide data support and decision-making references for rationally planning urban layout and promoting sustainable urban development. 展开更多
关键词 winter urban heat island(UHI) rapid urbanization area land surface temperature(LST)retrieval profile analysis GeoDetector model Fuzhou City China
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Spatiotemporal Evolution of Urban Heat Islands and Optimization of Spatial Network Construction in the Central Urban Area of Fuzhou City, China
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作者 ZHAO Qiuyue YU Kunyong +3 位作者 GENG Jianwei LIN Jiqing AI Jingwen LIU Jian 《Chinese Geographical Science》 SCIE CSCD 2024年第5期917-930,共14页
Although accelerated urbanization has led to economic prosperity,it has also resulted in urban heat island effects.Therefore,identifying methods of using limited urban spaces to alleviate heat islands has become an ur... Although accelerated urbanization has led to economic prosperity,it has also resulted in urban heat island effects.Therefore,identifying methods of using limited urban spaces to alleviate heat islands has become an urgent issue.In this study,we assessed the spatiotemporal evolution of urban heat islands within the central urban area of Fuzhou City,China from 2010 to 2019.This assessment was based on a morphological spatial pattern analysis(MSPA)model and an urban thermal environment spatial network constructed us-ing the minimum cumulative resistance(MCR)model.Optimization measures for the spatial network were proposed to provide a theor-etical basis for alleviating urban heat islands.The results show that the heat island area within the study area gradually increased while that of urban cold island area gradually decreased.The core area was the largest of the urban heat island patch landscape elements with a significant impact on other landscape elements,and represented an important factor underlying urban heat island network stability.The thermal environment network revealed a total of 197 thermal environment corridors and 93 heat island sources.These locations were then optimized according to the current land use,which maximized the potential of 1599.83 ha.Optimization based on current land use led to an increase in climate resilience,with effective measures showing reduction in thermal environment spatial network structure and function,contributing to the mitigation of urban heat island.These findings support the use of current land use patterns during urban heat island mitigation measure planning,thus providing an important reference basis for alleviating urban heat island effects. 展开更多
关键词 urban heat island spatiotemporal analysis circuit theory post optimization evaluation climate mitigation Fuzhou City China
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A Distinguishing Method and Distribution Characteristics of Fog and Haze Days in Fuzhou 被引量:1
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作者 Wang Hong Zheng Qiuping +1 位作者 Sui Ping Yu Hua 《Meteorological and Environmental Research》 CAS 2014年第4期1-4,共4页
For data of atmospheric composition missing, fog and haze days were distinguished based on the standard of meteorological industry Observation and Forecasting Levels of Haze (QX/T113-2010) and four user-defined stan... For data of atmospheric composition missing, fog and haze days were distinguished based on the standard of meteorological industry Observation and Forecasting Levels of Haze (QX/T113-2010) and four user-defined standards, and using data of surface meteorological factors in Fuzhou City, China from 2005 to 2011, temporal distributions of fog and haze days were analyzed respectively to provide methods for fog and haze forecast. The results showed that there were 28.9 fog days and 89.7 haze days per year in Fuzhou. Both fog and haze days were variable, and there might be a day difference of twice to thrice among the years. They were the most in 2007, and then decreased in recent years. Both fog and haze days were more in winter and spring, accounted for 94.1% and 70.1% respectively, while in summer and autumn, they only accounted for 5.9% and 29.9% respectively. In a day, fog mainly occurred from night to early morning, while haze occurred mainly at about noon, which demonstrated that fog and haze are different synoptic phenomena. The mass concentration of PM2.5 in fog days was 34 μg/m^3, while it was 61 μg/m^3 in haze days, and in 22% of haze days it was larger than 75 μg/m3, which was above the national second-grade ambient air quality standard. 展开更多
关键词 Fog day Haze day Distinguishing method Temporal distribution Fuzhou China
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Evaluation and Analysis of Nutrients in Tobacco-Planting Soil in Fuzhou City 被引量:2
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作者 Yanyan LI Xiaohu FENG +4 位作者 Youwu ZHANG Fei QI Libing WANG Rui ZHANG Zhigao ZHANG 《Agricultural Biotechnology》 CAS 2018年第5期194-200,共7页
[Objective] The aim was to explore the nutrient status of tobacco-planting soil, and find out the fertilization strategy for flue-cured tobacco. [Method] The nutrient contents in 142 soil samples from 7 tobacco planti... [Objective] The aim was to explore the nutrient status of tobacco-planting soil, and find out the fertilization strategy for flue-cured tobacco. [Method] The nutrient contents in 142 soil samples from 7 tobacco planting counties in Fu Zhou city were determined and evaluated. [Result] The organic matter content was on the high side, and most soil was acid soil. The soil had abundant total nitrogen, total phosphorus and total potassium, moderate available nitrogen and available phosphorus, low available potassium, high water soluble chlorine, low soil cation exchange capacity and rich effective zinc, but effective boron was famine. [Conclusion] The meta-acid soil should be conducted with pH adjustment, and rational nitrogen, phosphorus and potassium application. 展开更多
关键词 Tobacco soil PH Water soluble chlorine Fuzhou
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Active Fault Exploration and Seismic Hazard Assessment in Fuzhou City 被引量:8
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作者 Zhu Jinfang Huang Zonglin +7 位作者 Xu Xiwei Zheng Rongzhang Fang Shengmin Bai Denghai Wang Guangcai Min Wei Wen Xueze Han Zhujun 《Earthquake Research in China》 2005年第3期224-239,共16页
It has been proven by a number of earthquake case studies that an active fault-induced earthquake beneath a city can be devastating. It is an urgent issue for seismic hazard reduction to explore the distribution of ac... It has been proven by a number of earthquake case studies that an active fault-induced earthquake beneath a city can be devastating. It is an urgent issue for seismic hazard reduction to explore the distribution of active faults beneath the urban area and identify the seismic source and the risks underneath. As a pilot project of active fault exploration in China, the project, entitled “Active fault exploration and seismic hazard assessment in Fuzhou City”, started in early 2001 and passed the check before acceptance of China Earthquake Administration in August 2004. The project was aimed to solve a series of scientific issues such as fault location, dating, movement nature, deep settings, seismic risk and hazard, preparedness of earthquake prevention and disaster reduction, and etc. by means of exploration and assessment of active faults by stages, i.e., the preliminary survey and identification of active faults in target area, the exploration of deep seismotectonic settings, the risk evaluation of active seismogenic faults, the construction of geographic information system of active faults, and so on. A lot of exploration methods were employed in the project such as the detection of absorbed mercury, free mercury and radon in soil, the geological radar, multi-channel DC electrical method, tsansient electromagnetic method, shallow seismic refraction and reflection, effect contrast of explored sources, and various sounding experiments, to establish the buried Quaternary standard section of the Fuzhou basin. By summing up, the above explorations and experiments have achieved the following results and conclusions : 展开更多
关键词 fuzhou city active fault exploration seismic hazard assessment SEISMOTECTONICS
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Images Difference of ASAR Data for Rice Crop Mapping in Fuzhou, China
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作者 WANG Xiaoqin SHI Xiaoming LING Feilong 《Geo-Spatial Information Science》 2010年第2期123-129,共7页
This paper introduces ENVISAT ASAR data application on rice field mapping in the Fuzhou area, using multi-temporal ASAR dual polarization data acquired in 2005. The procedure for ASAR data processing here includes dat... This paper introduces ENVISAT ASAR data application on rice field mapping in the Fuzhou area, using multi-temporal ASAR dual polarization data acquired in 2005. The procedure for ASAR data processing here includes data calibration, image registration, speckle reduction and conversion of data format from amplitude to dB for backscatter. The backscatter of rice increases with the rice growing stages, which was much different from other land covers. Based on image difference techniques, 6 schemes were designed with ASAR different temporal and polarization data for rice field mapping. Difference images between images in the early period of rice crop and growing or ripening period, are more suitable for rice extraction than those difference images between different polarizations in the same date. The most accurate result of late rice extraction was achieved based on the difference of HH polarization data acquired in October and August. Therefore, for rice field mapping, the temporal information is more important than polarization information. The data during the early growing season of rice is very important for high accuracy rice mapping. 展开更多
关键词 ENVISAT ASAR rice crop mapping images difference Fuzhou
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A Study on the Translation of Public Signs in Fuzhou
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作者 张妮 《海外英语》 2016年第18期143-145,共3页
Public signs, as a city's "name card", have attracted wide attention. However,inappropriate translation of public signs are ubiquitous with some even cause misunderstandings for international visitors. I... Public signs, as a city's "name card", have attracted wide attention. However,inappropriate translation of public signs are ubiquitous with some even cause misunderstandings for international visitors. In this paper, we first introduce the function of public signs, then through case analysis many problems are exposed and those errors bring a lot of inconvenience for foreigners who live and work in China.What's worse, to some extent, China's image and reputation will also be undermined.Finally, an appeal is made for a standardized translation of public signs and more research should be done and effective measures should be taken to improve the quality of the language environment and public signs translation. 展开更多
关键词 Fuzhou public signs TRANSLATION ANALYSIS
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Division of Buried Late Quaternary Strata of the Fuzhou Basin
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作者 Zheng Rongzhang Chen Guihua +3 位作者 Xu Xiwei Zhu Jinfang Huang Zonglin Li Jianping 《Earthquake Research in China》 2006年第3期316-325,共10页
Based on detailed logging of fourteen drill holes, combined with the results of other researchers, the preliminary summarization on sedimentary characteristics of the late Pleistocene of the Fuzhou basin is done. The ... Based on detailed logging of fourteen drill holes, combined with the results of other researchers, the preliminary summarization on sedimentary characteristics of the late Pleistocene of the Fuzhou basin is done. The deposition of Fuzhou basin began from about 56.5ka BP and the sediments are composed of gravel, sand, clay and silt, which show a depositional sequence with granularity becoming smaller from the lower to the upper and a big lateral variation of lithology. There are three silt layers in late Quaternary strata of Fuzhou basin. The first and second layers were developed during the middle and late Holocene, the deposition time is about 7.86ka BP to 1.44 ka BP and they are the results of "Changle Transgression". The third was developed during the late of late Pleistocene and the deposition time is from 44ka BP to 20ka BP and it is the result of "Fuzhou Transgression". The buried late Quaternary sediments in Fuzhou basin can be divided into upper Pleistocene series and Holocene series, which include four formations from old to new. They are the Longhai formation ( Q3p 1), Dongshan formation (Qhd), Changle formation (Qhc) and Jiangtian formation (Qhj), respectively. The Longhai formation can be divided into three members and belongs to the Pleistocene series, other three formations belong to the Holocene series. 展开更多
关键词 Strata division Late Quaternary Fuzhou basin
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Urban Expansion and Its Influencing Factors in Natural Wetland Distribution Area in Fuzhou City,China 被引量:8
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作者 CAI Yuanbin ZHANG Hao +2 位作者 PAN Wenbin CHEN Yanhong WANG Xiangrong 《Chinese Geographical Science》 SCIE CSCD 2012年第5期568-577,共10页
This paper principally focuses on land use dynamics,urban expansion and underlying driving forces in the Natural Wetland Distribution Area(NWDA)of Fuzhou City in the southeastern China.Based on time series Landsat TM/... This paper principally focuses on land use dynamics,urban expansion and underlying driving forces in the Natural Wetland Distribution Area(NWDA)of Fuzhou City in the southeastern China.Based on time series Landsat TM/ETM+imageries and historical data,relationships between urban land expansion and its influencing factors from 1989 to 2009 were analyzed by using an integrated approach of remote sensing(RS)and geographic information system(GIS)techniques.The results showed that built-up land increased from 151.16 km2in 1989 to 383.76 km 2in 2009. Approximately 64.25%of the newly emerging built-up land was converted from cropland(29.47%),forest and shrub (25.78%),water(3.73%),wetland(4.61%),and bare land(0.66%)during 1989 and 2009.With a remarkable decrease in cropland,the proportion of non-agricultural population increased by 23.6%.Moreover,rapid development of infrastructures,facilities,industrial parks,and urban and rural settlements along the Minjiang River resulted in the eastward and southward expansion of built-up land.Additionally,the growth pattern of built-up land in the NWDA is highly correlated with socio-economic factors,including the gross domestic product(GDP),GDP per capita,and structure of industry.As a result,the observed environmental degradation such as loss of cropland and wetland due to heavy pressure of rapid urbanization have greatly impaired the carrying capacity of city.Thus,in addition to scientific and rational policies towards minimizing the adverse effects of urbanization,coordination between the administrative agencies should be urgently strengthened to balance the conflicts between urban development and ecological conservation to make sure the sustainable land use. 展开更多
关键词 land use urban expansion natural wetland socio-economic factors remote sensing (RS) geographic in-formation system (GIS)
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A Case Study of Typical Regional Pollution Transport in Fuzhou City 被引量:1
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作者 Wang Hong Xie Zuxin +2 位作者 Zheng Qiuping Li Yan 《Meteorological and Environmental Research》 CAS 2016年第3期15-18,26,共5页
Based on data of PM2.5 hourly concentration and HYSPLIT model backward trajectory in coastal cities of Fujian Province during January 25 -26, 2014, a typical regional pollution process affecting Fujian from the north ... Based on data of PM2.5 hourly concentration and HYSPLIT model backward trajectory in coastal cities of Fujian Province during January 25 -26, 2014, a typical regional pollution process affecting Fujian from the north to the south and the east to the west on January 26 was investiga- ted. Taking Fuzhou as an example, based on weather situation on the ground and at high altitudes as well as corresponding meteorological data such as wind direction, wind velocity, and visibility, the changes of meteorological elements before, during and after the pollution were compared. Based on the V-3θ atmospheric vertical structure diagrams, the weather reasons for the generation, maintaining and dissipation of the pollution were discussed. The results indicated that the regional pollution was transported from the northeast to the southwest. The northeasterly air flow in front of the cold ridge strengthened and moved toward the east, so that the pollutant from the north affected Fujian form the north to the south and from the east to the west. As a result, there was a dramatic increase of pollutant concentration, rapid drop of visibility, and deterioration of air quality in the affected areas. The heavy pollution process featured high-speed transport and short-time generation. The air quality changed from good state to heavy pollution in just 3 -4 hours. The maximum of IAQIpM2.5 reached 280. The whole pollution process lasted for 14 hours. Solar radiation had been deeply affected by aerosol clouds, so that atmospheric stratification was extremely stable. Along with the eastward movement of cold high pressure into the sea, the dominant wind direction near the ground changed from the northeast to the east, so that the source of the pollutant was cut off , and air quality quickly turned well. The changes of atmospheric vertical structure indicated that the high inversion layer and clouds near 700 hPa kept lower air clean and blocked upper pollution transport. The later sudden increase of wind speed and strengthening of atmospheric mechanical turbu- lent destroyed inversion layer, so that the upper pollutants invaded air near the ground rapidly. During the period of high pollution, the isothermal layer (aerosol clouds) leaded to decrease of wind speed, and the atmosphere became more stable. The pollution ended until the wind field changed. 展开更多
关键词 Regional pollution transport Meteorological factors Atmospheric vertical structure HYSPLIT model backward trajectory China
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Detection and Analysis of Number of Ralstonia solanacearum in Soil before Winter Tillage in Fuzhou Tobacco-growing Area, Jiangxi Province 被引量:1
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作者 Zhang Zhigao Hu Liwei +3 位作者 Feng Xiaohu Mou Wenjun Wang Libing Zhang Rui 《Plant Diseases and Pests》 CAS 2019年第5期1-3,10,共4页
[Objective]The paper was to optimize the tobacco planting area in Fuzhou City and to prevent the outbreak of tobacco bacterial wilt in large area.[Method]At the end of 2017,soil samples were collected from plots plann... [Objective]The paper was to optimize the tobacco planting area in Fuzhou City and to prevent the outbreak of tobacco bacterial wilt in large area.[Method]At the end of 2017,soil samples were collected from plots planned to be planted with tobacco in the following year in Yihuang,Guangchang,Lichuan and Le’an counties.[Result]Among 352 plots,116 plots were infected by Ralstonia solanacearum,while 236 plots were free of the pathogen,and the infected plots accounted for 32.95% of total plots.Among them,75 plots exceeded the order of magnitudes of 103,accounting for 21.31% of total plots and 64.66% of infected plots.It is suggested that the plots with an order of magnitude above 103 should be pretreated with quicklime or purple soil,or conducted crop rotation,or seeds must be directly abandoned;the dosage of biocontrol agents should be increased in planting.The plots with an order of magnitude below 103 should be pretreated with quicklime or purple soil,and the dosage of biocontrol agents should be increased in planting.[Conclusion]The results provide reliable theoretical basis and data support for soil improvement and bacterial wilt control. 展开更多
关键词 TOBACCO Ralstonia SOLANACEARUM Winter TILLAGE BIOCONTROL
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Exploring the spatiotemporal relationship between green infrastructure and urban heat island under multi‐source remote sensing imagery:A case study of Fuzhou City 被引量:1
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作者 Tingting Hong Xiaohui Huang +2 位作者 Guangjian Chen Yiwei Yang Lijia Chen 《CAAI Transactions on Intelligence Technology》 SCIE EI 2023年第4期1337-1349,共13页
Green Infrastructure(GI)has garnered increasing attention from various regions due to its potential to mitigate urban heat island(UHI),which has been exacerbated by global climate change.This study focuses on the cent... Green Infrastructure(GI)has garnered increasing attention from various regions due to its potential to mitigate urban heat island(UHI),which has been exacerbated by global climate change.This study focuses on the central area of Fuzhou city,one of the“furnace”cities,and aims to explore the correlation between the GI pattern and land surface temperature(LST)in the spring and autumn seasons.The research adopts a multiscale approach,starting from the urban scale and using urban geographic spatial characteristics,multispectral remote sensing data,and morphological spatial pattern analysis(MSPA).Significant MSPA elements were tested and combined with LST to conduct a geographic weighted regression(GWR)experiment.The findings reveal that the UHI in the central area of Fuzhou city has a spatial characteristic of“high temperature in the middle and low temperature around,”which is coupled with a“central scattered and peripheral concentrated”distribution of GI.This suggests that remote sensing data can effectively be utilised for UHI inversion.Additionally,the study finds that the complexity of GI,whether from the perspective of the overall GI pattern or the classification study based on the proportion of the core area,has an impact on the alleviation of UHI in both seasons.In conclusion,this study underscores the importance of a reasonable layout of urban green infrastructure for mitigating UHI. 展开更多
关键词 geographic weighted regression green infrastructure image analysis morphological spatial pattern analysis statistical analysis urban heat island
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Compilation of Control Guidelines for the Skyline along the Minjiang River(Fuzhou Section)
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作者 LI Chengqing 《Journal of Landscape Research》 2021年第1期96-99,共4页
Minjiang River is the mother river of Fuzhou.The skyline views on both sides of the Minjiang River directly refl ect the characteristics of Fuzhou’s urban style.Compiling guidelines for the control of the skyline alo... Minjiang River is the mother river of Fuzhou.The skyline views on both sides of the Minjiang River directly refl ect the characteristics of Fuzhou’s urban style.Compiling guidelines for the control of the skyline along the Minjiang River will provide guidance measures for optimizing and enhancing the skyline landscape along the Minjiang River.From the fi ve elements of rhythm,permeability,visual centrality,sense of mountain display and layering,evaluation criteria are established for the skyline along the Minjiang River,and targeted guidance and optimization measures are constructed. 展开更多
关键词 Sense of rhythm Permeability Visual centrality Sense of mountain display Sense of layering
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Revitalization Strategy in Conservation and Renewal of Historical and Cultural Districts:A Case Study of Shangxiahang in Fuzhou City
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作者 CHEN Bicheng 《Journal of Landscape Research》 2021年第3期57-62,共6页
Taking the revitalization strategy in conservation and renewal of Shangxiahang historical and cultural district as an example,the paper analyzes the main problems at the present stage and the main contradictions with ... Taking the revitalization strategy in conservation and renewal of Shangxiahang historical and cultural district as an example,the paper analyzes the main problems at the present stage and the main contradictions with urban development,and puts forward the revitalization practice for conservation and renewal of Shangxiahang historical district by using related revitalization theory and planning principles.Furthermore,the contemporary practicality of Shangxiahang district is increased on the basis of protection,giving play to its contemporary charm. 展开更多
关键词 Shangxiahang historical and cultural district Conservation and renewal REVITALIZATION
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Research on the Application and Public Experience of Green Landscape Color Art in Fuzhou
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作者 Ying Ouyang 《Frontiers Research of Architecture and Engineering》 2019年第2期25-28,共4页
In the landscape design, the green landscape is an indispensable landscape element, and the plant color is an important factor affecting the green landscape. The color matching and layout are inseparable from the rese... In the landscape design, the green landscape is an indispensable landscape element, and the plant color is an important factor affecting the green landscape. The color matching and layout are inseparable from the research on color art. Color art not only affects our vision, but also influences people's psychology and behavior through vision. In the following, Fuzhou will be used as an example to analyze the application of color art in the green landscape and the public experience. 展开更多
关键词 COLOR ART Green LANDSCAPE PUBLIC EXPERIENCE
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An SEIHR model with age group and social contact for analysis of Fuzhou COVID-19 large wave
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作者 Xiaomin Lan Guangmin Chen +5 位作者 Ruiyang Zhou Kuicheng Zheng Shaojian Cai Fengying Wei Zhen Jin Xuerong Mao 《Infectious Disease Modelling》 CSCD 2024年第3期728-743,共16页
The main epidemiological features such as basic reproduction number,effective reproduction number and sensitivity analysis were extensively discussed for multi-age groups SEIHR model in this study.Firstly,by using of ... The main epidemiological features such as basic reproduction number,effective reproduction number and sensitivity analysis were extensively discussed for multi-age groups SEIHR model in this study.Firstly,by using of the next generation matrix method,basic reproduction number R0 of the total population was estimated as 1.57 using parameter values of four age groups of Fuzhou COVID-19 large wave.Given age group k,the values of R_(0k)(age group k to age group k),the values of R_(o)^(k)(an infected of age group k to the total population)and the values of R_(o)^(k)>R_(0k)>R_(o)^(k)(an infected of the total population to age group k)were also estimated,in which the explorations of the impacts of age groups revealed that the relationship was valid.Then,the fluctuating tendencies of effective reproduction number Rt were demonstrated by using two approaches(the surveillance data and the SEIHR model)for Fuzhou COVID-19 large wave,during which high-risk group(G4 group)mainly contributed the infection scale due to high susceptibility to infection and high risks to basic diseases.Further,the sensitivity analysis using two approaches(the sensitivity index and the PRCC values)revealed that susceptibility to infection of age groups played the vital roles,while the numerical simulation showed that infection scale varied with the changes of social contacts of age groups.The results of this study claimed that the high-risk group out of the total population was concerned by the local government with the highest susceptibility to infection against COVID-19.Conclusions This study verified that the partition structure of age groups of the total population,the susceptibility to infection of age groups,the social contacts among age groups were the important contributors of infection scale.The less social contacts and adequate hospital beds for high-risk group were profitable to control the spread of COVID-19.To avoid the emergence of medical runs against new variant in the future,the policymakers from local government were suggested to decline social contacts when hospital beds were limited. 展开更多
关键词 COVID-19 model Age group Omicron BA.5.2 variant Contact matrixSocial contact
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钢管混凝土组合结构桥梁设计原理与技术发展综述 被引量:12
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作者 姜磊 刘永健 +4 位作者 周绪红 陈宝春 牟廷敏 刘君平 陈洪明 《中国公路学报》 北大核心 2025年第3期278-302,共25页
从国内外工程界对钢管混凝土桥梁应用中脱黏和脱空问题的长期质疑,以及钢和混凝土2种材料差异角度入手,综述了钢管混凝土结构界面黏结性能、界面传力性能和结构承载性能3个方面的研究进展,厘清界面脱黏机理,及其由此带来的界面传力和组... 从国内外工程界对钢管混凝土桥梁应用中脱黏和脱空问题的长期质疑,以及钢和混凝土2种材料差异角度入手,综述了钢管混凝土结构界面黏结性能、界面传力性能和结构承载性能3个方面的研究进展,厘清界面脱黏机理,及其由此带来的界面传力和组合作用失效机理。针对此问题,提出内栓钉和PBL加劲型钢管混凝土桥梁结构,并综述创新结构在界面工作性能、节点力学性能、壁板屈曲性能和构件承载性能4个方面的研究成果,论证了创新结构实现钢管和混凝土共同工作的可行性。结果表明:钢和混凝土2种材料在热传导、收缩徐变、泊松比、弹性模量、强度、截面尺度和成型方式等方面均存在较大差异,是产生钢管混凝土脱黏和脱空、界面传力和组合作用失效的根本原因;钢管混凝土界面黏结强度试验结果离散性大,切向和法向黏结强度均不高于1.5 MPa,混凝土水化热、日照温差、混凝土收缩徐变和轴压荷载、疲劳荷载等多种因素耦合作用下,服役期钢管混凝土桥梁界面不可避免地发生脱黏;不同体系的钢管混凝土桥梁界面传力可分为构件和节点界面传力,尚缺少完善的桥梁界面传力模型,仅能借鉴房建中柱顶构件界面传力和梁-柱节点界面传力模型;不同类型脱黏对钢管混凝土承载性能影响不同,球冠形脱黏影响最小,部分环形脱黏次之,环形脱黏影响最明显;钢管混凝土中内设的栓钉可以起到连接件作用,确保了界面工作性能和节点传力的可靠性;内设的PBL则兼具连接件和加劲肋作用,一方面,确保了钢管混凝土界面和节点传力的可靠性,另一方面,增强了壁板的局部稳定和构件承载机理。 展开更多
关键词 桥梁工程 钢管混凝土桥梁 综述 组合结构 脱黏 界面传力 承载机理 内栓钉钢管混凝土 PBL加劲型钢管混凝土
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基于区块链的可信分布式工业数据治理方案 被引量:5
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作者 黄荣 杨文琴 宋志刚 《浙江大学学报(工学版)》 北大核心 2025年第2期269-277,共9页
针对当前工业系统缺乏统一的产品数据共享服务,限制了用户获取可信的产品追溯信息的问题,基于区块链设计可信分布式工业数据治理方案,实现高效、安全的产品数据共享与治理.产品数据生成者将数据提交到区块链系统之前,在离链状态下对产... 针对当前工业系统缺乏统一的产品数据共享服务,限制了用户获取可信的产品追溯信息的问题,基于区块链设计可信分布式工业数据治理方案,实现高效、安全的产品数据共享与治理.产品数据生成者将数据提交到区块链系统之前,在离链状态下对产品数据进行压缩和加密.为了在离链过程中使产品数据可用,系统通过2种类型的区块链交易(生成者交易和数据交易)支持离链/链上数据访问.提供混合访问控制机制用于加密产品数据,将秘密密钥仅提供给经过授权的数据用户.该方案能够有效地保护产品数据的隐私性,提供细粒度的访问控制,能够对产品数据生成的全流程进行溯源.系统性能的测试结果表明,在secp256k1椭圆曲线上(提供128 bit安全性),密钥生成阶段的计算和通信开销不高于81.592 ms和2.83 kB,数据提交阶段不高于50.251 ms和3.59 kB,数据更新时间不超过251.596 ms,数据读取时间不高于311.104 ms.与同类方案的性能比较结果证实了该方案的高效性. 展开更多
关键词 区块链 数据可信治理 隐私保护 细粒度访问控制 全流程溯源
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复合植物精油和丁酸梭菌对断奶仔猪生长性能以及血浆生化、抗氧化和免疫指标的影响 被引量:2
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作者 方桂友 刘景 +3 位作者 俞清霞 陈鑫珠 缪伏荣 董志岩 《动物营养学报》 北大核心 2025年第1期204-216,共13页
本试验旨在探究饲粮添加复合植物精油和丁酸梭菌对断奶仔猪生长性能以及血浆生化、抗氧化和免疫指标的影响。选取250头初始体重为(6.48±0.42)kg的“杜长大”三元杂交断奶仔猪[断奶日龄为(25±3)日龄],随机分成5个组,每组5个重... 本试验旨在探究饲粮添加复合植物精油和丁酸梭菌对断奶仔猪生长性能以及血浆生化、抗氧化和免疫指标的影响。选取250头初始体重为(6.48±0.42)kg的“杜长大”三元杂交断奶仔猪[断奶日龄为(25±3)日龄],随机分成5个组,每组5个重复,每个重复10头猪(公母各5头)。负对照组(NC组)饲喂低蛋白质氨基酸平衡基础饲粮(不添加抗生素,饲粮粗蛋白质水平为17.72%),正对照组(抗生素组,PC组)饲喂基础饲粮+20 mg/kg硫酸黏杆菌素+50 mg/kg杆菌肽锌+75 mg/kg金霉素,试验1组(T1组)饲喂基础饲粮+500 mg/kg复合植物精油,试验2组(T2组)饲喂基础饲粮+500 mg/kg丁酸梭菌,试验3组(T3组)饲喂基础饲粮+500 mg/kg复合植物精油+500 mg/kg丁酸梭菌。预试期3 d,正试期16 d。结果表明:1)与NC组相比,PC组和T3组平均日增重(ADG)极显著提高(P<0.01),T1组和T2组ADG显著提高(P<0.05);PC组和T3组料重比(F/G)显著降低(P<0.05);PC组和T3组腹泻率极显著降低(P<0.01),T1组和T2组腹泻率显著降低(P<0.05)。各组间平均日采食量(ADFI)无显著差异(P>0.05)。2)与NC组相比,PC组、T1组、T2组和T3组血浆二胺氧化酶(DAO)活性和内毒素含量显著降低(P<0.05);PC组和T3组血浆胰岛素样生长因子-Ⅰ(IGF-Ⅰ)含量极显著提高(P<0.01),T1组和T2组血浆IGF-Ⅰ含量显著提高(P<0.05)。3)与NC组相比,PC组、T2组和T3组血浆超氧化物歧化酶(SOD)活性显著提高(P<0.05),PC组、T1组、T2组和T3组血浆谷胱甘肽过氧化物酶(GSH-Px)活性显著提高(P<0.05),PC组和T3组血浆总抗氧化能力(T-AOC)极显著提高(P<0.01),T1组和T2组血浆T-AOC显著提高(P<0.05)。4)与NC组相比,PC组和T3组血浆免疫球蛋白G(IgG)含量极显著提高(P<0.01),T1组和T2组血浆IgG含量显著提高(P<0.05);PC组和T3组血浆白细胞介素-1β(IL-1β)含量显著降低(P<0.05),PC组、T1组和T3组血浆白细胞介素-6(IL-6)含量显著降低(P<0.05),PC组、T1组和T3组血浆白细胞介素-10(IL-10)含量显著提高(P<0.05)。与PC组相比,T3组血浆IgG、IL-1β、IL-6和IL-10含量均无显著差异(P>0.05)。综上所述,在低蛋白质氨基酸平衡饲粮中添加复合植物精油和丁酸梭菌均可提高断奶仔猪ADG,降低腹泻率,改善肠道黏膜屏障功能,并增强机体抗氧化能力和免疫功能,且二者联合添加效果优于单一添加,与复合抗生素效果相近。 展开更多
关键词 复合植物精油 丁酸梭菌 断奶仔猪 生长性能 血浆生化指标 抗氧化 免疫
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