Temporal and spatial response characteristics of vegetation NDVI to the variation of temperature and precipitation in the whole year, spring, summer and autumn was analyzed from April 1998 to March 2008 based on the S...Temporal and spatial response characteristics of vegetation NDVI to the variation of temperature and precipitation in the whole year, spring, summer and autumn was analyzed from April 1998 to March 2008 based on the SPOT VGT-NDVI data and daily temperature and precipitation data from 205 meteorological stations in eastern China. The results indicate that as a whole, the response of vegetation NDVI to the variation of temperature is more pronounced than that of precipitation in eastern China. Vegetation NDVI maximally responds to the variation of temperature with a lag of about 10 days, and it maximally responds to the variation of precipitation with a lag of about 30 days. The response of vegetation NDVI to temperature and precipitation is most pronounced in autumn, and has the longest lag in summer. Spatially, the maximum response of vegetation NDVI to the variation of temperature is more pronounced in the northern and middle parts than in the southern part of eastern China. The maximum response of vegetation NDVI to the variation of precipitation is more pronounced in the northern part than in the middle and southern parts of eastern China. The response of vegetation NDVI to the variation of temperature has longer lag in the northern and southern parts than in the middle part of eastern China. The response of vegetation NDVl to the variation of precipitation has the longest lag in the southern part, and the shortest lag in the northern part of eastern China. The response of vegetation NDVI to the variation of temperature and precipitation in eastern China is mainly consistent with other results, but the lag time of vegetation NDVI to the variation of temperature and precipitation has some differences with those results of the monsoon region of eastern China.展开更多
Considering three longitudinal displacement functions and uniform axial displacement functions for shear lag effect and uniform axial deformation of thin-walled box girder with varying depths,a simple and efficient me...Considering three longitudinal displacement functions and uniform axial displacement functions for shear lag effect and uniform axial deformation of thin-walled box girder with varying depths,a simple and efficient method with high precision to analyze the shear lag effect of thin-walled box girders was proposed.The governing differential equations and boundary conditions of the box girder under lateral loading were derived based on the energy-variational method,and closed-form solutions to stress and deflection corresponding to lateral loading were obtained.Analysis and calculations were carried out with respect to a trapezoidal box girder under concentrated loading or uniform loading and a rectangular box girder under concentrated loading.The analytical results were compared with numerical solutions derived according to the high order finite strip element method and the experimental results.The investigation shows that the closed-form solution is in good agreement with the numerical solutions derived according to the high order finite strip method and the experimental results,and has good stability.Because of the shear lag effect,the stress in cross-section centroid is no longer zero,thus it is not reasonable enough to assume that the strain in cross-section centroid is zero without considering uniform axial deformation.展开更多
Background:Hand,foot,and mouth disease(HFMD)has become an emerging infectious disease in China in the last decade.There has been evidence that meteorological factors can influence the HFMD incidence,and understanding ...Background:Hand,foot,and mouth disease(HFMD)has become an emerging infectious disease in China in the last decade.There has been evidence that meteorological factors can influence the HFMD incidence,and understanding the mechanisms can help prevent and control HFMD.Methods:HFMD incidence data and meteorological data in Minhang District,Shanghai were obtained for the period between 2009 and 2015.Distributed lag non-linear models(DLNMs)were utilized to investigate the impact of meteorological factors on HFMD incidence after adjusting for potential confounders of long time trend,weekdays and holidays.Results:There was a non-linear relationship between temperature and HFMD incidence,the RR of 5th percentile compared to the median is 0.836(95%CI:0.671-1.042)and the RR of 95th percentile is 2.225(95%CI:1.774-2.792),and the effect of temperature varied across age groups.HFMD incidence increased with increasing average relative humidity(%)(RR=1.009,95%CI:1.005-1.015)and wind speed(m/s)(RR=1.197,95%CI:1.118-1.282),and with decreasing daily rainfall(mm)(RR=0.992,95%CI:0.987-0.997)and sunshine hours(h)(RR=0.966,95%CI:0.951-0.980).Conclusions:There were significant relationships between meteorological factors and childhood HFMD incidence in Minhang District,Shanghai.This information can help local health agencies develop strategies for the control and prevention of HFMD under specific climatic conditions.展开更多
AIM: To evaluate the radicalness and safety of laparoscopic D2 dissection for gastric cancer. METHODS: Clinicopathological data from 209 patients with gastric cancer, who underwent radical gastrectomy with D2 dissecti...AIM: To evaluate the radicalness and safety of laparoscopic D2 dissection for gastric cancer. METHODS: Clinicopathological data from 209 patients with gastric cancer, who underwent radical gastrectomy with D2 dissection between January 2007 and February 2011, were analyzed retrospectively. Among these patients, 131 patients underwent laparoscopyassisted gastrectomy (LAG) and 78 underwent open gastrectomy (OG). The parameters analyzed included operative time, blood loss, blood transfusion, morbidity, mortality, the number of harvested lymph nodes (HLNs), and pathological stage.RESULTS: There were no significant differences in sex, age, types of radical resection [radical proximal gastrectomy (PG + D2), radical distal gastrectomy (DG + D2) and radical total gastrectomy (TG + D2)], and stages between the LAG and OG groups (P > 0.05). Among the two groups, 127 cases (96.9%) and 76 cases (97.4%) had 15 or more HLNs, respectively. The average number of HLNs was 26.1 ± 11.4 in the LAG group and 24.2 ± 9.3 in the OG group (P = 0.233). In the same type of radical resection, there were no signifi cant differences in the number of HLNs between the two groups (PG + D2: 21.7 ± 7.5 vs 22.4 ± 9.3; DG + D2: 25.7 ± 11.0 vs 22.3 ± 7.9; TG + D2: 30.9 ± 13.4 vs 29.3 ± 10.4; P > 0.05 for all comparisons). Tumor free margins were obtained in all cases. Compared with OG group, the LAG group had signifi cantly less blood loss, but a longer operation time (P < 0.001). The morbidity of the LAG group was 9.9%, which was not signifi cantly different from the OG group (7.7%) (P = 0.587). The mortality was zero in both groups. CONCLUSION: Laparoscopic D2 dissection is equivalent to OG in the number of HLNs, regardless of tumor location. Thus, this procedure can achieve the same radicalness as OG.展开更多
GIMMS （Global Inventory Modeling and Mapping Studies） NDVI （Normalised Difference Vegetation Index） from 1982 to 2006 and MODIS （Moderate Resolution Imaging Spectroradiometer） NDVI from 2001 to 2010 were blended...GIMMS （Global Inventory Modeling and Mapping Studies） NDVI （Normalised Difference Vegetation Index） from 1982 to 2006 and MODIS （Moderate Resolution Imaging Spectroradiometer） NDVI from 2001 to 2010 were blended to extract the, grass coverage and analyze its spatial pattern. The response of grass coverage to climatic variations at annual and monthly time scales was analyzed. Grass coverage distribution had increased from northwest to southeast across China. During 1982-2010, the mean nationwide grass coverage was 34% but exhibited apparent spatial heterogeneity, being the highest （61.4%） in slope grasslands and the lowest （17.1%） in desert grasslands. There was a slight increase of the grass coverage with a rate of 0.17% per year. Increase in slope grasslands coverage was as high as 0.27% per year, while in the plain grasslands and meadows the grass coverage in- crease was the lowest （being 0.11% per year and 0.1% per year, respectively）. Across China, the grass coverage with extremely significant increase （P〈0.01） and significant increase （P〈0.05） accounted for 46.03% and 11% of the total grassland area, respectively, while those with extremely significant and significant decrease accounted for only 4.1% and 3.24%, respectively. At the annual time scale, there are no significant correlations between grass coverage and annual mean temperature and precipitation. However, the grass coverage was somewhat affected by temperature in alpine and sub-alpine grassland, alpine and sub-alpine meadow, slope grassland and meadow, while grass coverage in desert grassland and plain grassland was more affected by precipitation. At the monthly time-scale, there are significant correlations between grass coverage with both temperature and precipitation, indicating that the grass coverage is more affected by seasonal fluctuations of hydrothermal conditions. Additionally, there is one-month time lag-effect between grass coverage and climate factors for each grassland types.展开更多
基金National Natural Science Foundation of China, No.40901031 Shanghai Natural Science Foundation, No.09ZR1428800+3 种基金 National Key Project of Scientific and Technical Supporting Programs, No.2007BAC29B05 Special Project of Research-style Operation in Shanghai Meteorological Bureau, No.YJ200803 No.YJ200805 National 863 Program, No.2006AA12Z104
文摘Temporal and spatial response characteristics of vegetation NDVI to the variation of temperature and precipitation in the whole year, spring, summer and autumn was analyzed from April 1998 to March 2008 based on the SPOT VGT-NDVI data and daily temperature and precipitation data from 205 meteorological stations in eastern China. The results indicate that as a whole, the response of vegetation NDVI to the variation of temperature is more pronounced than that of precipitation in eastern China. Vegetation NDVI maximally responds to the variation of temperature with a lag of about 10 days, and it maximally responds to the variation of precipitation with a lag of about 30 days. The response of vegetation NDVI to temperature and precipitation is most pronounced in autumn, and has the longest lag in summer. Spatially, the maximum response of vegetation NDVI to the variation of temperature is more pronounced in the northern and middle parts than in the southern part of eastern China. The maximum response of vegetation NDVI to the variation of precipitation is more pronounced in the northern part than in the middle and southern parts of eastern China. The response of vegetation NDVI to the variation of temperature has longer lag in the northern and southern parts than in the middle part of eastern China. The response of vegetation NDVl to the variation of precipitation has the longest lag in the southern part, and the shortest lag in the northern part of eastern China. The response of vegetation NDVI to the variation of temperature and precipitation in eastern China is mainly consistent with other results, but the lag time of vegetation NDVI to the variation of temperature and precipitation has some differences with those results of the monsoon region of eastern China.
基金Projects(51078355,50938008) supported by the National Natural Science Foundation of ChinaProject(CX2011B093) supported by the Doctoral Candidate Research Innovation Program of Hunan Province, ChinaProject(20117Q008) supported by the Basic Scientific Research Funds for Central Universities of China
文摘Considering three longitudinal displacement functions and uniform axial displacement functions for shear lag effect and uniform axial deformation of thin-walled box girder with varying depths,a simple and efficient method with high precision to analyze the shear lag effect of thin-walled box girders was proposed.The governing differential equations and boundary conditions of the box girder under lateral loading were derived based on the energy-variational method,and closed-form solutions to stress and deflection corresponding to lateral loading were obtained.Analysis and calculations were carried out with respect to a trapezoidal box girder under concentrated loading or uniform loading and a rectangular box girder under concentrated loading.The analytical results were compared with numerical solutions derived according to the high order finite strip element method and the experimental results.The investigation shows that the closed-form solution is in good agreement with the numerical solutions derived according to the high order finite strip method and the experimental results,and has good stability.Because of the shear lag effect,the stress in cross-section centroid is no longer zero,thus it is not reasonable enough to assume that the strain in cross-section centroid is zero without considering uniform axial deformation.
基金This research was supported by the National Natural Science Foundation of China(grant number 81673239)the National Science Fund for Distinguished Young Scholars(grant number 81325017)+1 种基金Chang Jiang Scholars Program(grant number T2014089)the Fourth Round of Three-Year Public Health Action Plan of Shanghai,China(grant numbers 15GWZK0202,15GWZK0101).
文摘Background:Hand,foot,and mouth disease(HFMD)has become an emerging infectious disease in China in the last decade.There has been evidence that meteorological factors can influence the HFMD incidence,and understanding the mechanisms can help prevent and control HFMD.Methods:HFMD incidence data and meteorological data in Minhang District,Shanghai were obtained for the period between 2009 and 2015.Distributed lag non-linear models(DLNMs)were utilized to investigate the impact of meteorological factors on HFMD incidence after adjusting for potential confounders of long time trend,weekdays and holidays.Results:There was a non-linear relationship between temperature and HFMD incidence,the RR of 5th percentile compared to the median is 0.836(95%CI:0.671-1.042)and the RR of 95th percentile is 2.225(95%CI:1.774-2.792),and the effect of temperature varied across age groups.HFMD incidence increased with increasing average relative humidity(%)(RR=1.009,95%CI:1.005-1.015)and wind speed(m/s)(RR=1.197,95%CI:1.118-1.282),and with decreasing daily rainfall(mm)(RR=0.992,95%CI:0.987-0.997)and sunshine hours(h)(RR=0.966,95%CI:0.951-0.980).Conclusions:There were significant relationships between meteorological factors and childhood HFMD incidence in Minhang District,Shanghai.This information can help local health agencies develop strategies for the control and prevention of HFMD under specific climatic conditions.
基金Supported by The Capital Medical Development Research Fund, No. 2009-2093
文摘AIM: To evaluate the radicalness and safety of laparoscopic D2 dissection for gastric cancer. METHODS: Clinicopathological data from 209 patients with gastric cancer, who underwent radical gastrectomy with D2 dissection between January 2007 and February 2011, were analyzed retrospectively. Among these patients, 131 patients underwent laparoscopyassisted gastrectomy (LAG) and 78 underwent open gastrectomy (OG). The parameters analyzed included operative time, blood loss, blood transfusion, morbidity, mortality, the number of harvested lymph nodes (HLNs), and pathological stage.RESULTS: There were no significant differences in sex, age, types of radical resection [radical proximal gastrectomy (PG + D2), radical distal gastrectomy (DG + D2) and radical total gastrectomy (TG + D2)], and stages between the LAG and OG groups (P > 0.05). Among the two groups, 127 cases (96.9%) and 76 cases (97.4%) had 15 or more HLNs, respectively. The average number of HLNs was 26.1 ± 11.4 in the LAG group and 24.2 ± 9.3 in the OG group (P = 0.233). In the same type of radical resection, there were no signifi cant differences in the number of HLNs between the two groups (PG + D2: 21.7 ± 7.5 vs 22.4 ± 9.3; DG + D2: 25.7 ± 11.0 vs 22.3 ± 7.9; TG + D2: 30.9 ± 13.4 vs 29.3 ± 10.4; P > 0.05 for all comparisons). Tumor free margins were obtained in all cases. Compared with OG group, the LAG group had signifi cantly less blood loss, but a longer operation time (P < 0.001). The morbidity of the LAG group was 9.9%, which was not signifi cantly different from the OG group (7.7%) (P = 0.587). The mortality was zero in both groups. CONCLUSION: Laparoscopic D2 dissection is equivalent to OG in the number of HLNs, regardless of tumor location. Thus, this procedure can achieve the same radicalness as OG.
基金The National Natural Science Foundation of China, No.41271361 National Basic Research Program of China, No.2010CB950702+2 种基金 The APN Projects, No.ARCP2013-16NMY-Li The Public Sector Linkages Program supported by AusAID, No.64828 China＇s High-tech Special Projects, No.2007AA 10Z231
文摘GIMMS （Global Inventory Modeling and Mapping Studies） NDVI （Normalised Difference Vegetation Index） from 1982 to 2006 and MODIS （Moderate Resolution Imaging Spectroradiometer） NDVI from 2001 to 2010 were blended to extract the, grass coverage and analyze its spatial pattern. The response of grass coverage to climatic variations at annual and monthly time scales was analyzed. Grass coverage distribution had increased from northwest to southeast across China. During 1982-2010, the mean nationwide grass coverage was 34% but exhibited apparent spatial heterogeneity, being the highest （61.4%） in slope grasslands and the lowest （17.1%） in desert grasslands. There was a slight increase of the grass coverage with a rate of 0.17% per year. Increase in slope grasslands coverage was as high as 0.27% per year, while in the plain grasslands and meadows the grass coverage in- crease was the lowest （being 0.11% per year and 0.1% per year, respectively）. Across China, the grass coverage with extremely significant increase （P〈0.01） and significant increase （P〈0.05） accounted for 46.03% and 11% of the total grassland area, respectively, while those with extremely significant and significant decrease accounted for only 4.1% and 3.24%, respectively. At the annual time scale, there are no significant correlations between grass coverage and annual mean temperature and precipitation. However, the grass coverage was somewhat affected by temperature in alpine and sub-alpine grassland, alpine and sub-alpine meadow, slope grassland and meadow, while grass coverage in desert grassland and plain grassland was more affected by precipitation. At the monthly time-scale, there are significant correlations between grass coverage with both temperature and precipitation, indicating that the grass coverage is more affected by seasonal fluctuations of hydrothermal conditions. Additionally, there is one-month time lag-effect between grass coverage and climate factors for each grassland types.
