Volatile organic compound(VOC) emission control and source apportionment in small-scale industrial areas have become key topics of air pollution control in China. This study proposed a novel characteristic factor and ...Volatile organic compound(VOC) emission control and source apportionment in small-scale industrial areas have become key topics of air pollution control in China. This study proposed a novel characteristic factor and pattern recognition(CF-PR) model for VOC source apportionment based on the similarity of characteristic factors between sources and receptors.A simulation was carried out in a typical industrial area with the CF-PR model involving simulated receptor samples. Refined and accurate source profiles were constructed through in situ sampling and analysis, covering rubber, chemicals, coating, electronics, plastics, printing, incubation and medical treatment industries. Characteristic factors of n-undecane,styrene, o-xylene and propane were identified. The source apportionment simulation results indicated that the predicted contribution rate was basically consistent with the real contribution rate. Compared to traditional receptor models, this method achieves notable advantages in terms of refinement and timeliness at similar accuracy, which is more suitable for VOC source identification and apportionment in small-scale industrial areas.展开更多
The epidemiologic characteristics of 631 infant pertussis cases 〈 12 months, which accounted for 57.42% of the total cases, were analyzed by descriptive epidemiology in Tianjin, between 2010 and 2015. The incidence o...The epidemiologic characteristics of 631 infant pertussis cases 〈 12 months, which accounted for 57.42% of the total cases, were analyzed by descriptive epidemiology in Tianjin, between 2010 and 2015. The incidence of infants was 104.66/100,000, which was 118 times higher than in other age groups （P 〈 0.001）. The primary type of pertussis simultaneously presented in households was adult-to-infant （70.51%）. The parents were identified as the source of infection in 80.18% of cases for infants. The positive rate of placental antibody transfer was 31.06% and 3.13% for 3-month-old infants. Infants presented the highest age-specific pertussis incidence. The most important reason was parents were the important sources of infection, and secondly the lower level of antibodies in neonates and the rapid waning of maternal antibody titer.展开更多
Based on data from through-hole and logging,we studied the failure characteristics of surface drainage wells for relieved coal gas in Huainan mining area and its influencing factors.The results show that the damaged p...Based on data from through-hole and logging,we studied the failure characteristics of surface drainage wells for relieved coal gas in Huainan mining area and its influencing factors.The results show that the damaged positions of drainage wells are mainly located at the thick clay layer in the low alluvium and the lithological interface in the upper section of bedrock in west mining area.The failure depth of casing is 244-670 m and concentrates at about 270-460 m deep.These damaged positions are mainly located in the bending zone according to three zones of rock layers in the vertical section above the roof divided. Generally,the casing begins to deform or damage before the face line about 30-150 m.Special formation structure and rock mass properties are the direct causes of the casing failure,high mining height and fast advancing speed are fundamental reasons for rock mass damage.However,the borehole configuration and spacing to the casing failure are not very clear.展开更多
Based on annual mean maximum and minimum temperatures,diurnal temperature range,precipitation,sunshine,total cloud cover and water barometric pressure data in Benxi County from 1958 to 2010,using statistical analysis,...Based on annual mean maximum and minimum temperatures,diurnal temperature range,precipitation,sunshine,total cloud cover and water barometric pressure data in Benxi County from 1958 to 2010,using statistical analysis,the results show that the annual and seasonal diurnal temperature ranges present significant decreasing tendencies,and the reducing tendency is the most remarkable in winter. Autumn reducing tendency is stronger than that in spring,and it is the weakest in summer. Annual and seasonal average temperatures,average maximum and minimum temperatures all present the remarkable rising trends. Rising trend of the minimum temperature is more significant than that of the maximum temperature. The monthly mean diurnal temperature range also presents reducing tendency,and the most reducing scope appear in January and February. Annual and season diurnal temperature range changes are related to sunshine,mean minimum temperature,mean maximum temperature,precipitation,total cloud cover and water barometric pressure,but various essential factors are different in each season. Annual mean temperature,annual mean minimum temperature,annual mean maximum temperature and annual diurnal temperature range all have sudden changes,but the age is inconsistent.展开更多
Discovery showed that some of the rivers in Lee＇s Ferry area run on bedrocks while some are on the alluvium,based on geomorphology,the different kinds of channel characteristics can influence whether these rivers run...Discovery showed that some of the rivers in Lee＇s Ferry area run on bedrocks while some are on the alluvium,based on geomorphology,the different kinds of channel characteristics can influence whether these rivers run on bed rock or alluvium. By analyzing the velocity,discharge,width and depth,hydraulic radius and comparing the different channel characteristics of rivers in other areas with Lee＇s Ferry,it is observed that the channel discharge,velocity and the hydraulic radius play an important role in controlling the transport-limited river and these factors can be inferred to be correct even for all the river channels in Arizona.展开更多
Objective To study the differences in blood pressure (BP) levels and the main factors raising BP among the population in Guangdong Province. Methods The data analyzed stem from the sampling survey of hypertension in G...Objective To study the differences in blood pressure (BP) levels and the main factors raising BP among the population in Guangdong Province. Methods The data analyzed stem from the sampling survey of hypertension in Guangdong Province in 1991, covering 42, 894 subjects over 15 years old. Individual characteristics included age, sex, occupation, education, smoking, alcohol drinking and body mass index (BMI) . Results Systolic and diastolic BP increased with age. The hypertension prevalence rate in male is higher than in female. The age - adjusted prevalence rate in office personnel is the highest (12.9 % ) among all occupations. It was increased with education level and BMI (in people educated at university and over is 13. 1 % ), and higher in smokers and alcohol-drinkers than non-smokers and non -alcohol-drinkers. Conclusions Age, occupation, education, smoking, alcohol drinking and BMI all effect BP. These risk factors should be reduced in the Guangdong population.展开更多
Purple Soil distributes extensively and mainly in China. Because of abundant easily weatherable parent rocks/ materials and unstable soil structure, and also influenced by parent materials, usage systems, and slope gr...Purple Soil distributes extensively and mainly in China. Because of abundant easily weatherable parent rocks/ materials and unstable soil structure, and also influenced by parent materials, usage systems, and slope gradients, erosion and sediment production of purple soils are very severe with main fashions of water erosion and gravitational erosion. Basing on observed data in small watersheds, rainfall erosivity, vegetation coverage, previous soil water content, flow and relating factors such as climate, topograph of small watershed, land usage, and soil kinds are all the influence factors of erosion and erodibility of purple soil as well as sediment production and transport in small watershed of purple hilly areas. The effective technological countermeasures of ecosystem restoration, agricultural tillage for water conservation and erosion prevention, agriculture project, and soil changing for fertility and anti-erosion were provided.展开更多
Objective To investigate the clinical features and prognostic factors of nosocomially acquired candidemia.Methods A retrospective analysis was conducted for hospitalized patients with nosocomial candidemia between Jan...Objective To investigate the clinical features and prognostic factors of nosocomially acquired candidemia.Methods A retrospective analysis was conducted for hospitalized patients with nosocomial candidemia between January 2012 and December 2014 at the First Affiliated Hospital of Anhui Medical University.The univariate展开更多
To understand the pollution characteristics of atmospheric particles and heavy metals in winter in Chang-Zhu-Tan city clusters, China, total suspended particulate （TSP） and PMI0 samples were collected in cities of C...To understand the pollution characteristics of atmospheric particles and heavy metals in winter in Chang-Zhu-Tan city clusters, China, total suspended particulate （TSP） and PMI0 samples were collected in cities of Changsha, Zhuzhou and Xiangtan from December 2011 to January 2012, and heavy metals of Cd, Pb, Cr, and As were analyzed. It shows that the average TSP concentration in Changsha, Zhuzhou and Xiangtan were （183 ± 73）, （201± 84） and （190 ±66） μg/m3 respectively, and the average PM10 were （171 ± 82）, （178 ± 65） and （179 ± 55） μg/m3 respectively. The lowest TSP and PM10 concentrations occurred at the background Shaping site of Changsha. The average ratio of p（PM10）/p（TSP） was 91.9%, ranging from 81.3% to 98.9%. Concerning heavy metals, in TSP samples, the concentration of Cr, As, Cd and Pb were 28.8-56.5, 18.1-76.3, 3.9-26.1 and 148.0-460.9 ng/m3, respectively, while in PMI0 samples, were 16.4--42.1, 15.5-67.9, 3.3-22.2 and 127.9-389.3 ng/m3, respectively. The enrichment factor of Cd was the highest, followed by Pb and As, while that of Cr was the lowest.展开更多
We study the determinants of China ＇s bilateral local currency swap lines that were established following the recent global finance crisis. It is found that economic factors, political considerations and institutiona...We study the determinants of China ＇s bilateral local currency swap lines that were established following the recent global finance crisis. It is found that economic factors, political considerations and institutional characteristics, including trade intensity, economic size, strategic partnership, free trade agreements, corruption and stability, affect the decision to sign a swap line agreement. Once a swap line agreement decision is made, the size of the swap line is then mainly affected by trade intensity, economic size and the presence of a free trade agreement. The results are quite robust with respect to the choices of the Heckman two-stage framework or the proportional hazard model. The gravity effect captured by distances between China and its counterparts, if present, is mainly observed during the early part of the sample period under consideration.展开更多
基金supported by Key Research and Development Program of Zhejiang Province (2021C03178, 2021C03165)。
文摘Volatile organic compound(VOC) emission control and source apportionment in small-scale industrial areas have become key topics of air pollution control in China. This study proposed a novel characteristic factor and pattern recognition(CF-PR) model for VOC source apportionment based on the similarity of characteristic factors between sources and receptors.A simulation was carried out in a typical industrial area with the CF-PR model involving simulated receptor samples. Refined and accurate source profiles were constructed through in situ sampling and analysis, covering rubber, chemicals, coating, electronics, plastics, printing, incubation and medical treatment industries. Characteristic factors of n-undecane,styrene, o-xylene and propane were identified. The source apportionment simulation results indicated that the predicted contribution rate was basically consistent with the real contribution rate. Compared to traditional receptor models, this method achieves notable advantages in terms of refinement and timeliness at similar accuracy, which is more suitable for VOC source identification and apportionment in small-scale industrial areas.
基金supported by the Research Fund of Tianjin Health and Family Planning Commission 2015KY18Science and Technology Major Project of Chinese Preventive Medicine Association Q2017A1225
文摘The epidemiologic characteristics of 631 infant pertussis cases 〈 12 months, which accounted for 57.42% of the total cases, were analyzed by descriptive epidemiology in Tianjin, between 2010 and 2015. The incidence of infants was 104.66/100,000, which was 118 times higher than in other age groups （P 〈 0.001）. The primary type of pertussis simultaneously presented in households was adult-to-infant （70.51%）. The parents were identified as the source of infection in 80.18% of cases for infants. The positive rate of placental antibody transfer was 31.06% and 3.13% for 3-month-old infants. Infants presented the highest age-specific pertussis incidence. The most important reason was parents were the important sources of infection, and secondly the lower level of antibodies in neonates and the rapid waning of maternal antibody titer.
基金sponsored by the National High-Tech Research and Development Program of China(No.2007AA06Z220)the Key Science and Technology Program of Ministry of Education(No. 307014)the Research Program of Huainan Mining Group.
文摘Based on data from through-hole and logging,we studied the failure characteristics of surface drainage wells for relieved coal gas in Huainan mining area and its influencing factors.The results show that the damaged positions of drainage wells are mainly located at the thick clay layer in the low alluvium and the lithological interface in the upper section of bedrock in west mining area.The failure depth of casing is 244-670 m and concentrates at about 270-460 m deep.These damaged positions are mainly located in the bending zone according to three zones of rock layers in the vertical section above the roof divided. Generally,the casing begins to deform or damage before the face line about 30-150 m.Special formation structure and rock mass properties are the direct causes of the casing failure,high mining height and fast advancing speed are fundamental reasons for rock mass damage.However,the borehole configuration and spacing to the casing failure are not very clear.
文摘Based on annual mean maximum and minimum temperatures,diurnal temperature range,precipitation,sunshine,total cloud cover and water barometric pressure data in Benxi County from 1958 to 2010,using statistical analysis,the results show that the annual and seasonal diurnal temperature ranges present significant decreasing tendencies,and the reducing tendency is the most remarkable in winter. Autumn reducing tendency is stronger than that in spring,and it is the weakest in summer. Annual and seasonal average temperatures,average maximum and minimum temperatures all present the remarkable rising trends. Rising trend of the minimum temperature is more significant than that of the maximum temperature. The monthly mean diurnal temperature range also presents reducing tendency,and the most reducing scope appear in January and February. Annual and season diurnal temperature range changes are related to sunshine,mean minimum temperature,mean maximum temperature,precipitation,total cloud cover and water barometric pressure,but various essential factors are different in each season. Annual mean temperature,annual mean minimum temperature,annual mean maximum temperature and annual diurnal temperature range all have sudden changes,but the age is inconsistent.
基金Supported by the(2012)Sino-American 121 Program,Sino-American Cooperation on Higher Education and Professional Development,CCIEE
文摘Discovery showed that some of the rivers in Lee＇s Ferry area run on bedrocks while some are on the alluvium,based on geomorphology,the different kinds of channel characteristics can influence whether these rivers run on bed rock or alluvium. By analyzing the velocity,discharge,width and depth,hydraulic radius and comparing the different channel characteristics of rivers in other areas with Lee＇s Ferry,it is observed that the channel discharge,velocity and the hydraulic radius play an important role in controlling the transport-limited river and these factors can be inferred to be correct even for all the river channels in Arizona.
文摘Objective To study the differences in blood pressure (BP) levels and the main factors raising BP among the population in Guangdong Province. Methods The data analyzed stem from the sampling survey of hypertension in Guangdong Province in 1991, covering 42, 894 subjects over 15 years old. Individual characteristics included age, sex, occupation, education, smoking, alcohol drinking and body mass index (BMI) . Results Systolic and diastolic BP increased with age. The hypertension prevalence rate in male is higher than in female. The age - adjusted prevalence rate in office personnel is the highest (12.9 % ) among all occupations. It was increased with education level and BMI (in people educated at university and over is 13. 1 % ), and higher in smokers and alcohol-drinkers than non-smokers and non -alcohol-drinkers. Conclusions Age, occupation, education, smoking, alcohol drinking and BMI all effect BP. These risk factors should be reduced in the Guangdong population.
基金Supported by Knowledge Innovation Program of Chinese Academy of Sciences(KZCX3-SW-330, KZCX2-SW-319).
文摘Purple Soil distributes extensively and mainly in China. Because of abundant easily weatherable parent rocks/ materials and unstable soil structure, and also influenced by parent materials, usage systems, and slope gradients, erosion and sediment production of purple soils are very severe with main fashions of water erosion and gravitational erosion. Basing on observed data in small watersheds, rainfall erosivity, vegetation coverage, previous soil water content, flow and relating factors such as climate, topograph of small watershed, land usage, and soil kinds are all the influence factors of erosion and erodibility of purple soil as well as sediment production and transport in small watershed of purple hilly areas. The effective technological countermeasures of ecosystem restoration, agricultural tillage for water conservation and erosion prevention, agriculture project, and soil changing for fertility and anti-erosion were provided.
文摘Objective To investigate the clinical features and prognostic factors of nosocomially acquired candidemia.Methods A retrospective analysis was conducted for hospitalized patients with nosocomial candidemia between January 2012 and December 2014 at the First Affiliated Hospital of Anhui Medical University.The univariate
基金supported by the National Department Public Benefit Research Foundation(No.201109005)the National Natural Science Foundation of China(No.41205093)
文摘To understand the pollution characteristics of atmospheric particles and heavy metals in winter in Chang-Zhu-Tan city clusters, China, total suspended particulate （TSP） and PMI0 samples were collected in cities of Changsha, Zhuzhou and Xiangtan from December 2011 to January 2012, and heavy metals of Cd, Pb, Cr, and As were analyzed. It shows that the average TSP concentration in Changsha, Zhuzhou and Xiangtan were （183 ± 73）, （201± 84） and （190 ±66） μg/m3 respectively, and the average PM10 were （171 ± 82）, （178 ± 65） and （179 ± 55） μg/m3 respectively. The lowest TSP and PM10 concentrations occurred at the background Shaping site of Changsha. The average ratio of p（PM10）/p（TSP） was 91.9%, ranging from 81.3% to 98.9%. Concerning heavy metals, in TSP samples, the concentration of Cr, As, Cd and Pb were 28.8-56.5, 18.1-76.3, 3.9-26.1 and 148.0-460.9 ng/m3, respectively, while in PMI0 samples, were 16.4--42.1, 15.5-67.9, 3.3-22.2 and 127.9-389.3 ng/m3, respectively. The enrichment factor of Cd was the highest, followed by Pb and As, while that of Cr was the lowest.
文摘We study the determinants of China ＇s bilateral local currency swap lines that were established following the recent global finance crisis. It is found that economic factors, political considerations and institutional characteristics, including trade intensity, economic size, strategic partnership, free trade agreements, corruption and stability, affect the decision to sign a swap line agreement. Once a swap line agreement decision is made, the size of the swap line is then mainly affected by trade intensity, economic size and the presence of a free trade agreement. The results are quite robust with respect to the choices of the Heckman two-stage framework or the proportional hazard model. The gravity effect captured by distances between China and its counterparts, if present, is mainly observed during the early part of the sample period under consideration.
