Fluoride and nitrate enriched groundwater are potential threats to the safety of the groundwater supply that may cause significant effects on human health and public safety,especially in aggregated population areas an...Fluoride and nitrate enriched groundwater are potential threats to the safety of the groundwater supply that may cause significant effects on human health and public safety,especially in aggregated population areas and economic hubs.This study focuses on the high F^(−)and NO_(3)^(−)concentration groundwater in Tongzhou District,Beijing,North China.A total of 36 groundwater samples were collected to analyze the hydrochemical characteristics,elucidate genetic mechanisms and evaluate the potential human health risks.The results of the analysis indicate:Firstly,most of the groundwater samples are characterized by Mg-HCO_(3) and Na-HCO_(3) with the pH ranging from 7.19 to 8.28 and TDS with a large variation across the range 471-2337 mg/L.The NO_(3)^(−)concentration in 38.89%groundwater samples and the F^(−)concentration in 66.67%groundwater samples exceed the permissible limited value.Secondly,F^(−)in groundwater originates predominantly from water-rock interactions and the fluorite dissolution,which is also regulated by cation exchange,competitive adsorption of HCO_(3)−and an alkaline environment.Thirdly,the effect of sewage disposal and agricultural activities have a significant effect on high NO3-concentration,while the high F^(−)concentration is less influenced by anthropogenic activity.The alkaline environment favors nitrification,thus being conducive to the production of NO_(3)^(−).Finally,the health risk assessment is evaluated for different population groups.The results indicate that high NO_(3)^(−)and F^(−)concentration in groundwater would have the largest threat to children’s health.The findings of this study could contribute to the provision of a scientific basis for groundwater supply policy formulation relating to public health in Tongzhou District.展开更多
In the economic development of Beijing,although the share of the total amount of agricultural industry in the overall economy is relatively low,it has an important impact on the daily life of residents,social stabilit...In the economic development of Beijing,although the share of the total amount of agricultural industry in the overall economy is relatively low,it has an important impact on the daily life of residents,social stability and the development of other industries.Changping District,as an important agricultural production base of Beijing,its agricultural development has an indispensable strategic significance for the stability and growth of the entire regional economy.Therefore,it is very important to study the structure of agricultural industry in Changping District.Based on the detailed analysis of the agricultural industrial structure of Changping District,this paper uses the grey relation theory to analyze the different industries in the agricultural industrial structure of Changping District,including planting,forestry,animal husbandry,fishery and agricultural,forestry,service industries,in order to reveal the impact of these industries on the agricultural industrial structure of Changping District.Through this study,it comes up with specific and feasible suggestions for the optimization of agricultural industrial structure in Changping District,and provides valuable reference for the agricultural development of other areas in Beijing.展开更多
Drip irrigation and flood irrigation are major irrigation methods for maize crops in the Hetao Irrigation District,Inner Mongolia Autonomous Region,China.This research delves into the effects of these irrigation metho...Drip irrigation and flood irrigation are major irrigation methods for maize crops in the Hetao Irrigation District,Inner Mongolia Autonomous Region,China.This research delves into the effects of these irrigation methods on carbon dioxide(CO_(2))exchange and crop growth in this region.The experimental site was divided into drip and flood irrigation zones.The irrigation schedules of this study aligned with the local commonly used irrigation schedule.We employed a developed chamber system to measure the diurnal CO_(2)exchange of maize plants during various growth stages under both drip and flood irrigation methods.From May to September in 2020 and 2021,two sets of repeated experiments were conducted.In each experiment,a total of nine measurements of CO_(2)exchange were performed to obtain carbon exchange data at different growth stages of maize crop.During each CO_(2)exchange measurement event,CO_(2)flux data were collected every two hours over a day-long period to capture the diurnal variations in CO_(2)exchange.During each CO_(2)exchange measurement event,the biological parameters(aboveground biomass and crop growth rate)of maize and environmental parameters(including air humidity,air temperature,precipitation,soil water content,and photosynthetically active radiation)were measured.The results indicated a V-shaped trend in net ecosystem CO_(2)exchange in daytime,reducing slowly at night,while the net assimilation rate(net primary productivity)exhibited a contrasting trend.Notably,compared with flood irrigation,drip irrigation demonstrated significantly higher average daily soil CO_(2)emission and greater average daily CO_(2)absorption by maize plants.Consequently,within the maize ecosystem,drip irrigation appeared more conducive to absorbing atmospheric CO_(2).Furthermore,drip irrigation demonstrated a faster crop growth rate and increased aboveground biomass compared with flood irrigation.A strong linear relationship existed between leaf area index and light utilization efficiency,irrespective of the irrigation method.Notably,drip irrigation displayed superior light use efficiency compared with flood irrigation.The final yield results corroborated these findings,indicating that drip irrigation yielded higher harvest index and overall yield than flood irrigation.The results of this study provide a basis for the selection of optimal irrigation methods commonly used in the Hetao Irrigation District.This research also serves as a reference for future irrigation studies that consider measurements of both carbon emissions and yield simultaneously.展开更多
The slow traffic system is an important component of urban transportation,and the prerequisite and necessary condition for Beijing to continue promoting“green priority”are establishing a good urban slow traffic syst...The slow traffic system is an important component of urban transportation,and the prerequisite and necessary condition for Beijing to continue promoting“green priority”are establishing a good urban slow traffic system.Shijingshan District of Beijing City is taken as a research object.By analyzing and processing population distribution data,POI data,and shared bicycle data,the shortcomings and deficiencies of the current slow traffic system in Shijingshan District are explored,and corresponding solutions are proposed,in order to provide new ideas and methods for future urban planning from the perspective of data.展开更多
With the successful holding of Beijing Winter Olympic Games in 2022,the planning and cultural services of Shijingshan District have been reviewed,but the systematic planning theory has not been fully applied.Through t...With the successful holding of Beijing Winter Olympic Games in 2022,the planning and cultural services of Shijingshan District have been reviewed,but the systematic planning theory has not been fully applied.Through the big data research method,the location advantages and disadvantages of Shijingshan District were analyzed,and the distribution of its cultural facilities was defined.Feasible optimization schemes were proposed according to its advantages and disadvantages as well as the experience and conditions of the Winter Olympics.展开更多
Huang Di Nei Jing(《黄帝内经》The Yellow Emperor’s Inner Classic) has been the source text of Chinese medicine knowledge and innovation for over two thousand years. Despite this key relevance, many of its ideas and p...Huang Di Nei Jing(《黄帝内经》The Yellow Emperor’s Inner Classic) has been the source text of Chinese medicine knowledge and innovation for over two thousand years. Despite this key relevance, many of its ideas and practices have proven difficult to understand and implement fully into clinical practice. Cultural and language differences can be compounded with these challenges but may also present new opportunities for advancement and insight when studied by researchers outside of the originating culture. This article introduces the method of Classical-Text Archaeology and delves into the author’s two-decade journey of researching this text, with a discussion on cultural differences and issues of medical scholarship.展开更多
This work was devoted to the study of the physico-chemical properties of two clay minerals from the Mountain District (West Côte d'Ivoire) referenced ME1 and ME2. These samples were characterized by the exper...This work was devoted to the study of the physico-chemical properties of two clay minerals from the Mountain District (West Côte d'Ivoire) referenced ME1 and ME2. These samples were characterized by the experimental techniques, such as X-ray diffraction (XRD), Infrared spectroscopy (IR), Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), Differential Thermal Analysis and Thermogravimetry (DTA-TG), Brunauer, Emett and Teller method (BET), laser particle size analysis and Scanning Electron Microscope (SEM). The main results of these analyses reveal that the two clay samples mainly contain quartz (52.91% for ME1 and 51.72% for ME2), kaolinite (36.60% for ME1 and 41.6% for ME2) and associated phases, namely goethite and hematite (13.47% for ME1 and 11.00% for ME2). The specific surface values obtained for samples ME1 and ME2 are 34.78 m2/g and 29.18 m2/g respectively. The results obtained show that the samples studied belong to the kaolinite family. After calcination, they could have good pozzolanic activity and therefore be used in the manufacture of low-carbon cements.展开更多
The 2024 National Science and Technology Week and Beijing Science and Technology Week opened in Shougang Park in Shijingshan District from May 25 to June 1.Under the theme of“Carrying forward the spirit of scientists...The 2024 National Science and Technology Week and Beijing Science and Technology Week opened in Shougang Park in Shijingshan District from May 25 to June 1.Under the theme of“Carrying forward the spirit of scientists and inspiring societal innovation,”this event focused on the new-generation IT technology,medical health,energy and technology,modern agriculture and intelligent manufacturing industries.展开更多
“Jing Ye Si”is a classical poem with international influence by the Chinese poet Li Bai in the Tang Dynasty,which expresses the poet’s deep nostalgia.This paper compares and analyzes its two English versions transl...“Jing Ye Si”is a classical poem with international influence by the Chinese poet Li Bai in the Tang Dynasty,which expresses the poet’s deep nostalgia.This paper compares and analyzes its two English versions translated by the Chinese translator Xu Yuanchong and the British translator W.J.B.Fletcher based on the“three beauties”principle(beauty in sense,beauty in sound,and beauty in form),and discovers that the English version of Xu basically achieves the unity of the“three beauties”,while the English version of Fletcher realizes the“beauty in sound and form”,but deviates from the“beauty in sense”mainly owing to the inaccurate comprehension of the moon as an image and other factors.This analysis may afford us with certain reference in poetry translation.展开更多
With the development of cities,China has entered an era of stock planning.The functions of old residential areas in urban development can no longer meet the needs of residents in the new era for a better life,and new ...With the development of cities,China has entered an era of stock planning.The functions of old residential areas in urban development can no longer meet the needs of residents in the new era for a better life,and new standards have been put forward for the quality of public spaces for living.This paper analyzes and sorts out the characteristics and problems of the public space in the old residential areas of Baihuazhou district.Combining superposition and intervention techniques,the spatial,historical,cultural and other characteristic elements of the residential areas are preserved to the greatest extent.The public space in the old residential areas of Baihuazhou District is updated and reconstructed in order to achieve the goal of improving the quality of its public space.展开更多
Based on the monitoring data of ambient air quality and meteorological observation data,the characteristics and meteorological influencing factors of air pollution in Luojiang District of Deyang City from 2018 to 2022...Based on the monitoring data of ambient air quality and meteorological observation data,the characteristics and meteorological influencing factors of air pollution in Luojiang District of Deyang City from 2018 to 2022 were analyzed.The results show that from 2018 to 2022,the main air pollutants affecting the air quality of Luojiang District of Deyang City were PM_(2.5) and PM_(10),and the primary pollutant on heavy pollution days was basically PM_(2.5).PM_(2.5) and PM_(10) pollution showed obvious seasonal differences,and PM_(2.5) concentration exceeded the limit mainly in spring and winter,among which it was the most serious in early spring,especially in January and February,followed by December.PM_(10) exceeding the standard had a high seasonal correlation with PM_(2.5) exceeding the standard,mainly in spring and winter,among which it was the most serious in winter,especially in December,followed by January.PM_(2.5) and PM_(10) pollution showed an overall weakening trend.PM_(2.5) and PM_(10) concentration were closely related to meteorological factors such as temperature,relative humidity,wind speed,precipitation and air pressure,and were mainly affected by rainfall.展开更多
The monthly variation,temporal-spatial distribution,transportation characteristics of vapour field at middle and lower atmosphere and their effects on drought in Beijing,Tianjin and Hebei districts were studied,which ...The monthly variation,temporal-spatial distribution,transportation characteristics of vapour field at middle and lower atmosphere and their effects on drought in Beijing,Tianjin and Hebei districts were studied,which have a guiding significance on predicting climate and arranging agricultural production in the district.展开更多
In China,the urban industrial district is usually an organic concentrated district including many factories that are in big,middle or small size,and are coordinated in the process of production,or use infrastructure i...In China,the urban industrial district is usually an organic concentrated district including many factories that are in big,middle or small size,and are coordinated in the process of production,or use infrastructure in common.The formation and development of the urban industrial district in China are affected by not only general factors such as natural factor,transportation factor,labour factor,ecologic factor,but also special factors such as agglomeration factor,technologic factor and social factor.To the district’s formation, both the social factors and natural factors are important,especially the attitude the government have towards the district and the regional natural condition.But the agglomeration, market and transportation costs here are not as important as those in the traditional Industrial Location Theory.Now we must pay great attention to these three factors owing to the new economic conditions in China.In the development of the district,the main factors are technology and agglomeration.This indicates that the technologic factor is gradually the essential condition in the development of the district.Besides,we must also know the affection of the eclologic factor in the development of the district.According to the reality of Caohejing district,this paper gives every factor mark in the Analytic Hierarchy Process(AHP).With the result of the AHP,some suggestions have been put forward to Caohejing Hi-Tech Park and other urban industrial districts as well.展开更多
Objective To describe epidemiologic features of an outbreak of severe acute respiratory syndrome (SARS) in Dongcheng District, Beijing occurred in a period between March and May 2003. Methods Data of SARS cases notifi...Objective To describe epidemiologic features of an outbreak of severe acute respiratory syndrome (SARS) in Dongcheng District, Beijing occurred in a period between March and May 2003. Methods Data of SARS cases notified from Dongcheng District Center for Disease Control and Prevention (CDC )and supplemented by other channels were collected. Clinicians and officials of local hospitals were interviewed in groups and medical records of fatal cases of SARS were reviewed to verify the diagnosis. Stored serum specimens of the patients were detected for IgG antibody against SARS Co-V by enzyme-linked immunosorbent assay (ELISA). All the data were input into dataset files by Microsoft Excel-2000 software and analyzed with SPSS version 10.0 software. Results Outbreak of SARS in Dongcheng District started on March 14, 2003 with a peak in mid- and late April, and dropped in early May. A total of 572 reported cases were collected during this period in Dongcheng District, Beijing, and 99 of them were excluded from SARS, because of diagnosis of common cold, regular pneumonia, measles and rubella, etc. Actually, 473 SARS cases, which included 390 (82.5%) probable cases and 83 (17.5%) suspect cases, were analyzed. About 90% of the probable cases were positive for IgG antibody. Attack rate of SARS in permanent residents of Dongcheng District was 28.3 per 100 000. Forty-one of them died, with a case-fatality rate of 8.7%. Persons were all susceptible to infection of SARS Co-V, with the highest proportion at ages of 20-50 years, which accounted for 68.7% of the total cases. Average age of the patients at their onset was 40.7 years. No gender difference in SARS cases was found. Number of SARS cases in health-care workers (HCWs) accounted for 18.0% and that in retired workers accounted for 15.4% of the total cases. Cases occurred in all 10 sub-districts of Dongcheng, with the highest in Beixinqiao and Andingmen Sub-districts. Totally, 230 of the 572 notified cases (40.2%) were hospitalized at local hospitals under the jurisdiction of Dongcheng District. Eighteen of 85 cases of SARS occurred in HCWs of local hospitals, accounting for 4.5% of the total number of HCWs working at wards caring for SARS patients or fever clinics. There were 34.7% of SARS cases without any histories of contact before the onset of the disease. Familial aggregation phenomena were observed in 41.8% of the cases and 18.1% of households. And 7.4% (attack rate ) of those exposed to SARS cases suffered from the illness during the periods of quarantine. Conclusions SARS appeared to be infectious in origin and caused outbreak in Dongcheng District, Beijing introduced by an imported case traveling from Hong Kong in a period between March and May 2003. People are all susceptible to infection of SARS Co-V, which mainly threatens the young adults and the middle-aged, as well as HCWs and the retired workers. The main mode of transmission is direct exposure to SARS patients in a near distance at hospitals or families via droplets spread. Prevention and control of SARS should be focused on early isolation of patients and quarantine for close contacts. Current available measures to prevent and control SARS are proved to be effective.展开更多
Groundwater environment evolution can comprehensively reflect groundwater dynamics. Based on the relationship between the groundwater system and the external environment in Jinghuiqu irrigation district, adopting the ...Groundwater environment evolution can comprehensively reflect groundwater dynamics. Based on the relationship between the groundwater system and the external environment in Jinghuiqu irrigation district, adopting the Principal Component Analysis method, variation characteristics of environmental factors including climate and human activity and their impact on groundwater were systematically analyzed. The results show that groundwater level in Jinghuiqu irrigation district has been significantly dropped in nearly 34 years;the reduction of surface water irrigation use, which reduced the amounts of groundwater recharge and destroyed the water balance, is considered as the most direct cause for falling of regional groundwater level. Besides, reduction in precipitation, increase of evaporation also accelerated the declining of the groundwater level at some extent. Finally, a predicting method of groundwater depth based on BP neural network is developed. The experimental results show that the predicting model can reasonablely predict the groundwater level in Jinghuiqu irrigation district with a high precision.展开更多
In the process of new urbanization,the population of megacities is increasing rapidly,the scale of cities is expanding,and the supply of service facilities has been unable to meet the demand.As an important carrier of...In the process of new urbanization,the population of megacities is increasing rapidly,the scale of cities is expanding,and the supply of service facilities has been unable to meet the demand.As an important carrier of urban governance and urban management,the police station should properly deal with the existing problems in the urban police stations,and improve the quality of life of residents by optimizing urban service facilities,which is of great significance for the implementation of people-oriented new urbanization.Taking Changping District of Beijing as an example,this study pointed out that there were many problems in police stations in Changping District.For example,the area of land is not up to the standard,the service capacity is not up to the demand,and the facilities are not up to the demand.Then,three planning strategies:adjusting the planning standards of facilities,optimizing the spatial layout of facilities,and strengthening the later guarantee of facilities were put forward,so as to improve people’s satisfaction with life,promote the high-quality development of new urbanization,and provide reference for the supplement of service facilities in megacities.展开更多
China is in the process of rapid urbanization,and wise land use is critical to the long-term sustainability of Chinese cities.Promotion of a compact city is typically believed to be helpful for sustainable land use ma...China is in the process of rapid urbanization,and wise land use is critical to the long-term sustainability of Chinese cities.Promotion of a compact city is typically believed to be helpful for sustainable land use management.However,given the fact that Chinese cities are characterized by high population densities,the applicability of a more compact solution to expand cities in China remains questionable;there is little evidence to support the many claims in its favor.In seeking to provide empirical data to explore the application of compact city theory in China,one of the key problems researchers face is the task of measuring the urban compactness,in order to objectively investigate the current characteristics of urban compactness.To meet this need,indices were developed for measuring the urban land use compactness,by which the spatial distribution characteristics of urban land use compactness were identified and applied to the Chaoyang District of Beijing.The conclusions can be made as follows:(1) comprehensive land use compactness in Chaoyang District has increased during the period of 2001-2007,especially the population density;(2) the spatial distribution of land use compactness has the characteristics of a ring structure,which shows a decreasing trend with its distance to the city center;(3) there is a strong positive correlation between urban land use compactness and location.The better the location is,the higher the land use compactness is.展开更多
Group A streptococcus (GAS) causes a wide range of diseases in the human population. GAS diseases are more common in children than in adults, with clinical manifestations ranging from pharyngitis and impetigo to inv...Group A streptococcus (GAS) causes a wide range of diseases in the human population. GAS diseases are more common in children than in adults, with clinical manifestations ranging from pharyngitis and impetigo to invasive infections and post streptococcal sequelae, such as acute rheumatic fever and acute post-streptococcal glomerulonephritis[1]. GAS harbors a host of virulence factors that contribute to its complex pathogenicity and differences in the disease severity and frequency. M protein, one of the major virulence factors, is encoded by the emm gene induces a type of specific host immune response and confers antiphagocytic properties.展开更多
Due to the rapid urban construction, commercial districts in Beijing are constructed near subway stations. Good landscape greening plays a crucial role in improving the environmental quality of the area around subway ...Due to the rapid urban construction, commercial districts in Beijing are constructed near subway stations. Good landscape greening plays a crucial role in improving the environmental quality of the area around subway stations. At present, there are few studies on the landscape greening around subway stations adjacent to commercial districts. In this paper, field research on landscapes in the commercial district around seven typical subway stations was conducted to monitor real-time noise and crowd activities and analyze the utilization status of street parks, in order to provide a reference for the construction and renovation of the landscape greening around subway stations near commercial districts.展开更多
Ecological conservation area,as the main water source and ecological barrier of a city,provides ecosystem service for urban sustainable development.Land use simulation and forecast could be beneficial to improve futur...Ecological conservation area,as the main water source and ecological barrier of a city,provides ecosystem service for urban sustainable development.Land use simulation and forecast could be beneficial to improve future land use efficiency and environmental protection.In this paper,we took the Miyun district as the study area and applied the CLUE-S model for land use simulation,based on land use data in 2001 and 2010.Eight key driving factors were selected,including elevation,slope,distance,population density and others.Based on the adjusted model parameters,the land use patterns of 2020 in Miyun district were simulated respectively for rapid growth scenario,land use planning scenario and ecological protection scenario and then identify the area needed extraordinary supervision in land planning implementation.The results showed that the simulation accuracy for 2010 reached 85%considerably,implying that the CLUE-S model is well fitted for modeling the land use pattern in Miyun district.Construction land increases and cultivated land decreases dramatically by 2020 in rapid growth and land use planning scenarios.The potential land use change tends to occur near Miyun reservoir,while the sensitive area for ecological protection and land planning implementation are distributed around urban area,Fengjiayu and Jugezhuang town.Some opencast mine areas,which would be converted to forest land in planning,will be hard to execute in the actual situation,so these areas should be paid more attention in land management.The conclusions made in this study will provide data reference and basic information for the future ecological protection and land use planning implementation in Miyun district,which could also be useful for other similar cities.展开更多
基金supported by the project of China Geological Survey(Grant No.DD20221677-2)the fundamental research funds of Chinese Academy of Geological Sciences Basal Research Fund(Grant No.JKYQN202307).
文摘Fluoride and nitrate enriched groundwater are potential threats to the safety of the groundwater supply that may cause significant effects on human health and public safety,especially in aggregated population areas and economic hubs.This study focuses on the high F^(−)and NO_(3)^(−)concentration groundwater in Tongzhou District,Beijing,North China.A total of 36 groundwater samples were collected to analyze the hydrochemical characteristics,elucidate genetic mechanisms and evaluate the potential human health risks.The results of the analysis indicate:Firstly,most of the groundwater samples are characterized by Mg-HCO_(3) and Na-HCO_(3) with the pH ranging from 7.19 to 8.28 and TDS with a large variation across the range 471-2337 mg/L.The NO_(3)^(−)concentration in 38.89%groundwater samples and the F^(−)concentration in 66.67%groundwater samples exceed the permissible limited value.Secondly,F^(−)in groundwater originates predominantly from water-rock interactions and the fluorite dissolution,which is also regulated by cation exchange,competitive adsorption of HCO_(3)−and an alkaline environment.Thirdly,the effect of sewage disposal and agricultural activities have a significant effect on high NO3-concentration,while the high F^(−)concentration is less influenced by anthropogenic activity.The alkaline environment favors nitrification,thus being conducive to the production of NO_(3)^(−).Finally,the health risk assessment is evaluated for different population groups.The results indicate that high NO_(3)^(−)and F^(−)concentration in groundwater would have the largest threat to children’s health.The findings of this study could contribute to the provision of a scientific basis for groundwater supply policy formulation relating to public health in Tongzhou District.
文摘In the economic development of Beijing,although the share of the total amount of agricultural industry in the overall economy is relatively low,it has an important impact on the daily life of residents,social stability and the development of other industries.Changping District,as an important agricultural production base of Beijing,its agricultural development has an indispensable strategic significance for the stability and growth of the entire regional economy.Therefore,it is very important to study the structure of agricultural industry in Changping District.Based on the detailed analysis of the agricultural industrial structure of Changping District,this paper uses the grey relation theory to analyze the different industries in the agricultural industrial structure of Changping District,including planting,forestry,animal husbandry,fishery and agricultural,forestry,service industries,in order to reveal the impact of these industries on the agricultural industrial structure of Changping District.Through this study,it comes up with specific and feasible suggestions for the optimization of agricultural industrial structure in Changping District,and provides valuable reference for the agricultural development of other areas in Beijing.
基金supported by the Shandong Province Natural Science Foundation Youth Branch(ZR2023QC157)the National Natural Science Foundation of China(51979233)+1 种基金the Key Research and Development Project of Shaanxi Province(2022KW-47,2022NY-220)the Heze University Doctoral Research Fund(XY21BS24,XY22BS17).
文摘Drip irrigation and flood irrigation are major irrigation methods for maize crops in the Hetao Irrigation District,Inner Mongolia Autonomous Region,China.This research delves into the effects of these irrigation methods on carbon dioxide(CO_(2))exchange and crop growth in this region.The experimental site was divided into drip and flood irrigation zones.The irrigation schedules of this study aligned with the local commonly used irrigation schedule.We employed a developed chamber system to measure the diurnal CO_(2)exchange of maize plants during various growth stages under both drip and flood irrigation methods.From May to September in 2020 and 2021,two sets of repeated experiments were conducted.In each experiment,a total of nine measurements of CO_(2)exchange were performed to obtain carbon exchange data at different growth stages of maize crop.During each CO_(2)exchange measurement event,CO_(2)flux data were collected every two hours over a day-long period to capture the diurnal variations in CO_(2)exchange.During each CO_(2)exchange measurement event,the biological parameters(aboveground biomass and crop growth rate)of maize and environmental parameters(including air humidity,air temperature,precipitation,soil water content,and photosynthetically active radiation)were measured.The results indicated a V-shaped trend in net ecosystem CO_(2)exchange in daytime,reducing slowly at night,while the net assimilation rate(net primary productivity)exhibited a contrasting trend.Notably,compared with flood irrigation,drip irrigation demonstrated significantly higher average daily soil CO_(2)emission and greater average daily CO_(2)absorption by maize plants.Consequently,within the maize ecosystem,drip irrigation appeared more conducive to absorbing atmospheric CO_(2).Furthermore,drip irrigation demonstrated a faster crop growth rate and increased aboveground biomass compared with flood irrigation.A strong linear relationship existed between leaf area index and light utilization efficiency,irrespective of the irrigation method.Notably,drip irrigation displayed superior light use efficiency compared with flood irrigation.The final yield results corroborated these findings,indicating that drip irrigation yielded higher harvest index and overall yield than flood irrigation.The results of this study provide a basis for the selection of optimal irrigation methods commonly used in the Hetao Irrigation District.This research also serves as a reference for future irrigation studies that consider measurements of both carbon emissions and yield simultaneously.
基金Sponsored by Beijing Natural Science Foundation General Project(8212009)Construction of Philosophy and Social Sciences Base in Beijing-Research on Beijing Urban Renewal and Comprehensive Management of Old Community En-vironment2023 Education Reform Project of North China University of Technology(108051360023XN264-25).
文摘The slow traffic system is an important component of urban transportation,and the prerequisite and necessary condition for Beijing to continue promoting“green priority”are establishing a good urban slow traffic system.Shijingshan District of Beijing City is taken as a research object.By analyzing and processing population distribution data,POI data,and shared bicycle data,the shortcomings and deficiencies of the current slow traffic system in Shijingshan District are explored,and corresponding solutions are proposed,in order to provide new ideas and methods for future urban planning from the perspective of data.
基金Sponsored by the General Project of Beijing Higher Education Association in 2022(MS2022414)Innovation and Entrepreneurship Training Planning Project for University Students in 2023。
文摘With the successful holding of Beijing Winter Olympic Games in 2022,the planning and cultural services of Shijingshan District have been reviewed,but the systematic planning theory has not been fully applied.Through the big data research method,the location advantages and disadvantages of Shijingshan District were analyzed,and the distribution of its cultural facilities was defined.Feasible optimization schemes were proposed according to its advantages and disadvantages as well as the experience and conditions of the Winter Olympics.
文摘Huang Di Nei Jing(《黄帝内经》The Yellow Emperor’s Inner Classic) has been the source text of Chinese medicine knowledge and innovation for over two thousand years. Despite this key relevance, many of its ideas and practices have proven difficult to understand and implement fully into clinical practice. Cultural and language differences can be compounded with these challenges but may also present new opportunities for advancement and insight when studied by researchers outside of the originating culture. This article introduces the method of Classical-Text Archaeology and delves into the author’s two-decade journey of researching this text, with a discussion on cultural differences and issues of medical scholarship.
文摘This work was devoted to the study of the physico-chemical properties of two clay minerals from the Mountain District (West Côte d'Ivoire) referenced ME1 and ME2. These samples were characterized by the experimental techniques, such as X-ray diffraction (XRD), Infrared spectroscopy (IR), Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), Differential Thermal Analysis and Thermogravimetry (DTA-TG), Brunauer, Emett and Teller method (BET), laser particle size analysis and Scanning Electron Microscope (SEM). The main results of these analyses reveal that the two clay samples mainly contain quartz (52.91% for ME1 and 51.72% for ME2), kaolinite (36.60% for ME1 and 41.6% for ME2) and associated phases, namely goethite and hematite (13.47% for ME1 and 11.00% for ME2). The specific surface values obtained for samples ME1 and ME2 are 34.78 m2/g and 29.18 m2/g respectively. The results obtained show that the samples studied belong to the kaolinite family. After calcination, they could have good pozzolanic activity and therefore be used in the manufacture of low-carbon cements.
文摘The 2024 National Science and Technology Week and Beijing Science and Technology Week opened in Shougang Park in Shijingshan District from May 25 to June 1.Under the theme of“Carrying forward the spirit of scientists and inspiring societal innovation,”this event focused on the new-generation IT technology,medical health,energy and technology,modern agriculture and intelligent manufacturing industries.
文摘“Jing Ye Si”is a classical poem with international influence by the Chinese poet Li Bai in the Tang Dynasty,which expresses the poet’s deep nostalgia.This paper compares and analyzes its two English versions translated by the Chinese translator Xu Yuanchong and the British translator W.J.B.Fletcher based on the“three beauties”principle(beauty in sense,beauty in sound,and beauty in form),and discovers that the English version of Xu basically achieves the unity of the“three beauties”,while the English version of Fletcher realizes the“beauty in sound and form”,but deviates from the“beauty in sense”mainly owing to the inaccurate comprehension of the moon as an image and other factors.This analysis may afford us with certain reference in poetry translation.
文摘With the development of cities,China has entered an era of stock planning.The functions of old residential areas in urban development can no longer meet the needs of residents in the new era for a better life,and new standards have been put forward for the quality of public spaces for living.This paper analyzes and sorts out the characteristics and problems of the public space in the old residential areas of Baihuazhou district.Combining superposition and intervention techniques,the spatial,historical,cultural and other characteristic elements of the residential areas are preserved to the greatest extent.The public space in the old residential areas of Baihuazhou District is updated and reconstructed in order to achieve the goal of improving the quality of its public space.
文摘Based on the monitoring data of ambient air quality and meteorological observation data,the characteristics and meteorological influencing factors of air pollution in Luojiang District of Deyang City from 2018 to 2022 were analyzed.The results show that from 2018 to 2022,the main air pollutants affecting the air quality of Luojiang District of Deyang City were PM_(2.5) and PM_(10),and the primary pollutant on heavy pollution days was basically PM_(2.5).PM_(2.5) and PM_(10) pollution showed obvious seasonal differences,and PM_(2.5) concentration exceeded the limit mainly in spring and winter,among which it was the most serious in early spring,especially in January and February,followed by December.PM_(10) exceeding the standard had a high seasonal correlation with PM_(2.5) exceeding the standard,mainly in spring and winter,among which it was the most serious in winter,especially in December,followed by January.PM_(2.5) and PM_(10) pollution showed an overall weakening trend.PM_(2.5) and PM_(10) concentration were closely related to meteorological factors such as temperature,relative humidity,wind speed,precipitation and air pressure,and were mainly affected by rainfall.
基金Supported by National Natural Sciences Foundations of China(40875032 and 40875002)Talents Culture Foundations of Beijing City (20051D0200802)~~
文摘The monthly variation,temporal-spatial distribution,transportation characteristics of vapour field at middle and lower atmosphere and their effects on drought in Beijing,Tianjin and Hebei districts were studied,which have a guiding significance on predicting climate and arranging agricultural production in the district.
文摘In China,the urban industrial district is usually an organic concentrated district including many factories that are in big,middle or small size,and are coordinated in the process of production,or use infrastructure in common.The formation and development of the urban industrial district in China are affected by not only general factors such as natural factor,transportation factor,labour factor,ecologic factor,but also special factors such as agglomeration factor,technologic factor and social factor.To the district’s formation, both the social factors and natural factors are important,especially the attitude the government have towards the district and the regional natural condition.But the agglomeration, market and transportation costs here are not as important as those in the traditional Industrial Location Theory.Now we must pay great attention to these three factors owing to the new economic conditions in China.In the development of the district,the main factors are technology and agglomeration.This indicates that the technologic factor is gradually the essential condition in the development of the district.Besides,we must also know the affection of the eclologic factor in the development of the district.According to the reality of Caohejing district,this paper gives every factor mark in the Analytic Hierarchy Process(AHP).With the result of the AHP,some suggestions have been put forward to Caohejing Hi-Tech Park and other urban industrial districts as well.
文摘Objective To describe epidemiologic features of an outbreak of severe acute respiratory syndrome (SARS) in Dongcheng District, Beijing occurred in a period between March and May 2003. Methods Data of SARS cases notified from Dongcheng District Center for Disease Control and Prevention (CDC )and supplemented by other channels were collected. Clinicians and officials of local hospitals were interviewed in groups and medical records of fatal cases of SARS were reviewed to verify the diagnosis. Stored serum specimens of the patients were detected for IgG antibody against SARS Co-V by enzyme-linked immunosorbent assay (ELISA). All the data were input into dataset files by Microsoft Excel-2000 software and analyzed with SPSS version 10.0 software. Results Outbreak of SARS in Dongcheng District started on March 14, 2003 with a peak in mid- and late April, and dropped in early May. A total of 572 reported cases were collected during this period in Dongcheng District, Beijing, and 99 of them were excluded from SARS, because of diagnosis of common cold, regular pneumonia, measles and rubella, etc. Actually, 473 SARS cases, which included 390 (82.5%) probable cases and 83 (17.5%) suspect cases, were analyzed. About 90% of the probable cases were positive for IgG antibody. Attack rate of SARS in permanent residents of Dongcheng District was 28.3 per 100 000. Forty-one of them died, with a case-fatality rate of 8.7%. Persons were all susceptible to infection of SARS Co-V, with the highest proportion at ages of 20-50 years, which accounted for 68.7% of the total cases. Average age of the patients at their onset was 40.7 years. No gender difference in SARS cases was found. Number of SARS cases in health-care workers (HCWs) accounted for 18.0% and that in retired workers accounted for 15.4% of the total cases. Cases occurred in all 10 sub-districts of Dongcheng, with the highest in Beixinqiao and Andingmen Sub-districts. Totally, 230 of the 572 notified cases (40.2%) were hospitalized at local hospitals under the jurisdiction of Dongcheng District. Eighteen of 85 cases of SARS occurred in HCWs of local hospitals, accounting for 4.5% of the total number of HCWs working at wards caring for SARS patients or fever clinics. There were 34.7% of SARS cases without any histories of contact before the onset of the disease. Familial aggregation phenomena were observed in 41.8% of the cases and 18.1% of households. And 7.4% (attack rate ) of those exposed to SARS cases suffered from the illness during the periods of quarantine. Conclusions SARS appeared to be infectious in origin and caused outbreak in Dongcheng District, Beijing introduced by an imported case traveling from Hong Kong in a period between March and May 2003. People are all susceptible to infection of SARS Co-V, which mainly threatens the young adults and the middle-aged, as well as HCWs and the retired workers. The main mode of transmission is direct exposure to SARS patients in a near distance at hospitals or families via droplets spread. Prevention and control of SARS should be focused on early isolation of patients and quarantine for close contacts. Current available measures to prevent and control SARS are proved to be effective.
文摘Groundwater environment evolution can comprehensively reflect groundwater dynamics. Based on the relationship between the groundwater system and the external environment in Jinghuiqu irrigation district, adopting the Principal Component Analysis method, variation characteristics of environmental factors including climate and human activity and their impact on groundwater were systematically analyzed. The results show that groundwater level in Jinghuiqu irrigation district has been significantly dropped in nearly 34 years;the reduction of surface water irrigation use, which reduced the amounts of groundwater recharge and destroyed the water balance, is considered as the most direct cause for falling of regional groundwater level. Besides, reduction in precipitation, increase of evaporation also accelerated the declining of the groundwater level at some extent. Finally, a predicting method of groundwater depth based on BP neural network is developed. The experimental results show that the predicting model can reasonablely predict the groundwater level in Jinghuiqu irrigation district with a high precision.
基金Youth Fund Project of the National Natural Science Foundation of China(51608009)Youth Top Talent Training Project of Support Plan for the Construction of High-level Teachers of Beijing Municipal Colleges and Universities in 2019(CIT&TCD201904010).
文摘In the process of new urbanization,the population of megacities is increasing rapidly,the scale of cities is expanding,and the supply of service facilities has been unable to meet the demand.As an important carrier of urban governance and urban management,the police station should properly deal with the existing problems in the urban police stations,and improve the quality of life of residents by optimizing urban service facilities,which is of great significance for the implementation of people-oriented new urbanization.Taking Changping District of Beijing as an example,this study pointed out that there were many problems in police stations in Changping District.For example,the area of land is not up to the standard,the service capacity is not up to the demand,and the facilities are not up to the demand.Then,three planning strategies:adjusting the planning standards of facilities,optimizing the spatial layout of facilities,and strengthening the later guarantee of facilities were put forward,so as to improve people’s satisfaction with life,promote the high-quality development of new urbanization,and provide reference for the supplement of service facilities in megacities.
基金financed by the National Natural Science Foundation of China(Grant nos.40635026and40901068)Special Fund from the Science and Technology Department of Beijing Municipality(Grant no.zz0922)the Postdoctoral Science Foundation of China(Grant no.200902133)
文摘China is in the process of rapid urbanization,and wise land use is critical to the long-term sustainability of Chinese cities.Promotion of a compact city is typically believed to be helpful for sustainable land use management.However,given the fact that Chinese cities are characterized by high population densities,the applicability of a more compact solution to expand cities in China remains questionable;there is little evidence to support the many claims in its favor.In seeking to provide empirical data to explore the application of compact city theory in China,one of the key problems researchers face is the task of measuring the urban compactness,in order to objectively investigate the current characteristics of urban compactness.To meet this need,indices were developed for measuring the urban land use compactness,by which the spatial distribution characteristics of urban land use compactness were identified and applied to the Chaoyang District of Beijing.The conclusions can be made as follows:(1) comprehensive land use compactness in Chaoyang District has increased during the period of 2001-2007,especially the population density;(2) the spatial distribution of land use compactness has the characteristics of a ring structure,which shows a decreasing trend with its distance to the city center;(3) there is a strong positive correlation between urban land use compactness and location.The better the location is,the higher the land use compactness is.
文摘Group A streptococcus (GAS) causes a wide range of diseases in the human population. GAS diseases are more common in children than in adults, with clinical manifestations ranging from pharyngitis and impetigo to invasive infections and post streptococcal sequelae, such as acute rheumatic fever and acute post-streptococcal glomerulonephritis[1]. GAS harbors a host of virulence factors that contribute to its complex pathogenicity and differences in the disease severity and frequency. M protein, one of the major virulence factors, is encoded by the emm gene induces a type of specific host immune response and confers antiphagocytic properties.
基金Sponsored by National Natural Science Foundation of China(51508004)Science and Technology Plans of Ministry of Housing and Urban-Rural Development of the People’s Republic of China,Opening Projects of Beijing Advanced Innovation Center for Future Urban Design,Beijing University of Civil Engineering,Architecture(UDC2017030712)+1 种基金2018 Beijing Municipal University Academic Human Resources Development-Youth Talent Support Program(PXM2018_014212_000043)North China University of Technology "YuYOU" Talent Training Program
文摘Due to the rapid urban construction, commercial districts in Beijing are constructed near subway stations. Good landscape greening plays a crucial role in improving the environmental quality of the area around subway stations. At present, there are few studies on the landscape greening around subway stations adjacent to commercial districts. In this paper, field research on landscapes in the commercial district around seven typical subway stations was conducted to monitor real-time noise and crowd activities and analyze the utilization status of street parks, in order to provide a reference for the construction and renovation of the landscape greening around subway stations near commercial districts.
文摘Ecological conservation area,as the main water source and ecological barrier of a city,provides ecosystem service for urban sustainable development.Land use simulation and forecast could be beneficial to improve future land use efficiency and environmental protection.In this paper,we took the Miyun district as the study area and applied the CLUE-S model for land use simulation,based on land use data in 2001 and 2010.Eight key driving factors were selected,including elevation,slope,distance,population density and others.Based on the adjusted model parameters,the land use patterns of 2020 in Miyun district were simulated respectively for rapid growth scenario,land use planning scenario and ecological protection scenario and then identify the area needed extraordinary supervision in land planning implementation.The results showed that the simulation accuracy for 2010 reached 85%considerably,implying that the CLUE-S model is well fitted for modeling the land use pattern in Miyun district.Construction land increases and cultivated land decreases dramatically by 2020 in rapid growth and land use planning scenarios.The potential land use change tends to occur near Miyun reservoir,while the sensitive area for ecological protection and land planning implementation are distributed around urban area,Fengjiayu and Jugezhuang town.Some opencast mine areas,which would be converted to forest land in planning,will be hard to execute in the actual situation,so these areas should be paid more attention in land management.The conclusions made in this study will provide data reference and basic information for the future ecological protection and land use planning implementation in Miyun district,which could also be useful for other similar cities.