This data article describes the dataset from a national cross-sectional questionnaire survey on Chinese internal migrants in 2017.The survey was part of the Chinese Migrants Dynamic Survey,which is an annually conduct...This data article describes the dataset from a national cross-sectional questionnaire survey on Chinese internal migrants in 2017.The survey was part of the Chinese Migrants Dynamic Survey,which is an annually conducted large-scale national questionnaire survey on internal migrants.The respondents in the described dataset were migrants and registered local residents aged over 15 years old.A multistage stratified probability-proportionalto-size(PPS) sampling method based on the 2016 annual report data of China Migrant Population was adopted.The questionnaire was designed to collect demographic information of respondents and their family members,intention of migration or settlement,health status,health services accessibility,social integration,and epidemic influencing factors of common diseases,including hypertension,type 2 diabetes,diarrhea,fever,rash,icterus,conjunctival redness,cold,and other illnesses or injuries.The sample population in this survey include 13,998 internal migrants and 14,000 registered local residents from eight domestic cities/prefecture/districts across China.It is the most widely covering and highly representative dataset on common diseases and influencing factors of internal migrants in China.The dataset can be used to study common diseases and influencing factors among floating Chinese population.It provides data support for government to improve healthcare accessibility and the equity of public health services for internal migrants in China.展开更多
The automatic all-sky imager developed by the Institute of Atmospheric Physics,Chinese Academy of Sciences,provides all-sky visible images in the red,green,and blue channels.This paper presents three major cali-bratio...The automatic all-sky imager developed by the Institute of Atmospheric Physics,Chinese Academy of Sciences,provides all-sky visible images in the red,green,and blue channels.This paper presents three major cali-bration experiments of the all-sky imager,geometric an-gular calibration,optical calibration,and radiometric calibration,and then infers an algorithm to retrieve rela-tive radiance from the all-sky images.Field experiments show that the related coefficient between retrieved radi-ance and measured radiance is about 0.91.It is feasible to use the algorithm to retrieve radiance from images.The paper sets up a relationship between radiance and the im-age,which is useful for using the all-sky image in nu-merical-simulations that predict more meteorological pa-rameters.展开更多
An unusual fog and haze event lasted for one week took place during 1–7 December,2011 over North China.To investigate the characteristics and mechanism of formation,evolution,and transition of the fog and haze event,...An unusual fog and haze event lasted for one week took place during 1–7 December,2011 over North China.To investigate the characteristics and mechanism of formation,evolution,and transition of the fog and haze event,we studied the microphysical properties such as aerosol,cloud condensation nuclei(CCN),fog droplet spectrum and liquid water content(LWC),as well as horizontal visibility and boundary layer properties,using the data collected in the Project of Low-Visibility Weather Monitoring and Forecasting in the Beijing-Tianjin region.The results indicate that the long-lasting fog and haze event occurred in a high pressure weather system and calm wind condition.The stable boundary-layer structure resulted from temperature inversions that were built by warm advection and radiation cooling provided a favorable condition for the accumulation of polluted aerosols and the formation and development of the fog and haze event.In particular,the continuous southerly wet flow advection made the process a persistent and long-lasting event.The horizontal visibility was almost below 2 km in the whole process,and the lowest visibility was only 56 m.The average LWC was about 10-3 g m-3,and the maximum LWC reached 0.16 g m-3.The aerosol number concentration was more than 10000 cm-3,and its mass concentration ranged from 50 to 160 -g m-3.The further study shows that the fog and haze event experienced three main processes in different intensities during the whole period,each process could be divided into three main stages:aerosol accumulation,transition and mixture of aerosol and fog,and dissipation.Each stage had different physical features:the aerosol accumulation stage was characterized by the increase of aerosol number concentration in Aitken nuclei and accumulation mode sequentially.In the transition and mixing stage of fog and haze,the latent heating produced by fog droplet condensation process and high aerosol number concentration condition intensified the Brownian coagulation process,which induced the small size of aerosols to become larger ones and enhanced the CCN activation process,thereby promoting the explosive development of the fog event.The ratio of aerosol activated to CCN reached 17%,and the ratio of CCN converted to fog droplet exceeded 100%,showing an explosively broadening of fog droplet spectrum.The decrease and dissipation of the fog was caused by an increased solar radiation heating or the passage of cold frontal system.展开更多
文摘This data article describes the dataset from a national cross-sectional questionnaire survey on Chinese internal migrants in 2017.The survey was part of the Chinese Migrants Dynamic Survey,which is an annually conducted large-scale national questionnaire survey on internal migrants.The respondents in the described dataset were migrants and registered local residents aged over 15 years old.A multistage stratified probability-proportionalto-size(PPS) sampling method based on the 2016 annual report data of China Migrant Population was adopted.The questionnaire was designed to collect demographic information of respondents and their family members,intention of migration or settlement,health status,health services accessibility,social integration,and epidemic influencing factors of common diseases,including hypertension,type 2 diabetes,diarrhea,fever,rash,icterus,conjunctival redness,cold,and other illnesses or injuries.The sample population in this survey include 13,998 internal migrants and 14,000 registered local residents from eight domestic cities/prefecture/districts across China.It is the most widely covering and highly representative dataset on common diseases and influencing factors of internal migrants in China.The dataset can be used to study common diseases and influencing factors among floating Chinese population.It provides data support for government to improve healthcare accessibility and the equity of public health services for internal migrants in China.
基金supported by the national natural science foundation of China (Grant Nos.40505006 and 40775026)
文摘The automatic all-sky imager developed by the Institute of Atmospheric Physics,Chinese Academy of Sciences,provides all-sky visible images in the red,green,and blue channels.This paper presents three major cali-bration experiments of the all-sky imager,geometric an-gular calibration,optical calibration,and radiometric calibration,and then infers an algorithm to retrieve rela-tive radiance from the all-sky images.Field experiments show that the related coefficient between retrieved radi-ance and measured radiance is about 0.91.It is feasible to use the algorithm to retrieve radiance from images.The paper sets up a relationship between radiance and the im-age,which is useful for using the all-sky image in nu-merical-simulations that predict more meteorological pa-rameters.
基金supported by the National Meteorology Public Welfare Industry Research Project(Grant No.GYHY200806001)the Program for Postgraduates Research Innovation of Jiangsu Higher Education Institutions(Grant No.CXZZ13-0511)the Special Foundation of Chinese Academy of Meteorological Sciences(Grant No.2011Z005)
文摘An unusual fog and haze event lasted for one week took place during 1–7 December,2011 over North China.To investigate the characteristics and mechanism of formation,evolution,and transition of the fog and haze event,we studied the microphysical properties such as aerosol,cloud condensation nuclei(CCN),fog droplet spectrum and liquid water content(LWC),as well as horizontal visibility and boundary layer properties,using the data collected in the Project of Low-Visibility Weather Monitoring and Forecasting in the Beijing-Tianjin region.The results indicate that the long-lasting fog and haze event occurred in a high pressure weather system and calm wind condition.The stable boundary-layer structure resulted from temperature inversions that were built by warm advection and radiation cooling provided a favorable condition for the accumulation of polluted aerosols and the formation and development of the fog and haze event.In particular,the continuous southerly wet flow advection made the process a persistent and long-lasting event.The horizontal visibility was almost below 2 km in the whole process,and the lowest visibility was only 56 m.The average LWC was about 10-3 g m-3,and the maximum LWC reached 0.16 g m-3.The aerosol number concentration was more than 10000 cm-3,and its mass concentration ranged from 50 to 160 -g m-3.The further study shows that the fog and haze event experienced three main processes in different intensities during the whole period,each process could be divided into three main stages:aerosol accumulation,transition and mixture of aerosol and fog,and dissipation.Each stage had different physical features:the aerosol accumulation stage was characterized by the increase of aerosol number concentration in Aitken nuclei and accumulation mode sequentially.In the transition and mixing stage of fog and haze,the latent heating produced by fog droplet condensation process and high aerosol number concentration condition intensified the Brownian coagulation process,which induced the small size of aerosols to become larger ones and enhanced the CCN activation process,thereby promoting the explosive development of the fog event.The ratio of aerosol activated to CCN reached 17%,and the ratio of CCN converted to fog droplet exceeded 100%,showing an explosively broadening of fog droplet spectrum.The decrease and dissipation of the fog was caused by an increased solar radiation heating or the passage of cold frontal system.
