According to the national standard(2006)on tropical cyclone(TC)intensity,TCs are categorized into six intensity types,namely,tropical depression(TD),tropical storm(TS),severe tropical storm(STS), typhoon(TY),severe ty...According to the national standard(2006)on tropical cyclone(TC)intensity,TCs are categorized into six intensity types,namely,tropical depression(TD),tropical storm(TS),severe tropical storm(STS), typhoon(TY),severe typhoon(STY),and super severe typhoon(SSTY).Fifty-eight years(1949–2006)of the datasets from the Yearbook of Typhoons and Yearbook of Tropical Cyclones were used to study the variation characteristics of TCs making landfalls in China's Mainland,Hainan and Taiwan islands.The main results are as follows.First,interannual or interdecadal variations in the number of landfalling TCs at different intensities exist.As far as long-term trends are concerned,the TD and TS frequencies show a significant linearly decreasing trend while those of STY show a significant linearly increasing trend.Second, a significant period of 6–8 years exist in the variations of annual landfalling TD,TS,and STS frequencies while quasi-16-year periods are found in the annual TY frequency.Third,TD and TS are generated mostly over the South China Sea,while TY,STY,and SSTY mostly over the waters southeast of the Bashi Channel and the ocean to the east of the Philippines.Fourth,as far as interdecadal trends are concerned,the frequencies of landfalling TD and TS generated over the South China Sea show significant linearly decreasing trends.However,TY and STY show significant linearly increasing trends.展开更多
Objective： The aim of the research was to study the clinical and epidemiological characteristics of incidence of colorectal cancer in North China. Methods： Analysis and summary were made for 704 colorectal cancer pa...Objective： The aim of the research was to study the clinical and epidemiological characteristics of incidence of colorectal cancer in North China. Methods： Analysis and summary were made for 704 colorectal cancer patients diagnosed from 2004 to 2008 in North China. Results： （1） Of 704 colorectal cancer patients, the median age was 56 years old, and the mean age was 58.2. There was no statistic difference in age between male and female cases, P 〉 0.05. （2） The male-female ratio was 1.62：1. （3） The proportion of rectal cancer was 62.92%, and incidence of the left colon cancer was higher than that of right colon cancer, P 〈 0.05. （4） Of 712 lesions, 658 cases were adenocarcinoma accounting for 92.4%, 34 were malignant adenoma accounting for 4.8%, and 20 carcinoid accounting for 2.8%. （5） The 48.9% of patients belonged to stages 0 to 11B. Conclusion： The cases of colorectal cancer in North China is mainly rectal cancers, and the incidence of left colon cancer is higher than that of right colon cancer. The histopathological classification is mainly adenocarcinoma, and the ratio of early stage is high.展开更多
A pair of northeast-southwest-tilted mid-tropospheric ridges and troughs on the continental scale was observed to be the key circulation feature common among wintertime extensive and persistent low tempera-ture events...A pair of northeast-southwest-tilted mid-tropospheric ridges and troughs on the continental scale was observed to be the key circulation feature common among wintertime extensive and persistent low tempera-ture events (EPLTE) in China.During the persistence of such anomalous circulations,the split flow over the inner Asian continent and the influent flow over the southeast-ern coast of China correspond well to the expanded and amplified Siberian high with tightened sea level pressure gradients and hence,a strong,cold advection over south-eastern China.The western Pacific subtropical high tends to expand northward during the early stages of most EPLTEs.展开更多
基金Natural Science Foundation of China(40765002)Public Interest Research Special Foundation(meteorology)of China(200906002)
文摘According to the national standard(2006)on tropical cyclone(TC)intensity,TCs are categorized into six intensity types,namely,tropical depression(TD),tropical storm(TS),severe tropical storm(STS), typhoon(TY),severe typhoon(STY),and super severe typhoon(SSTY).Fifty-eight years(1949–2006)of the datasets from the Yearbook of Typhoons and Yearbook of Tropical Cyclones were used to study the variation characteristics of TCs making landfalls in China's Mainland,Hainan and Taiwan islands.The main results are as follows.First,interannual or interdecadal variations in the number of landfalling TCs at different intensities exist.As far as long-term trends are concerned,the TD and TS frequencies show a significant linearly decreasing trend while those of STY show a significant linearly increasing trend.Second, a significant period of 6–8 years exist in the variations of annual landfalling TD,TS,and STS frequencies while quasi-16-year periods are found in the annual TY frequency.Third,TD and TS are generated mostly over the South China Sea,while TY,STY,and SSTY mostly over the waters southeast of the Bashi Channel and the ocean to the east of the Philippines.Fourth,as far as interdecadal trends are concerned,the frequencies of landfalling TD and TS generated over the South China Sea show significant linearly decreasing trends.However,TY and STY show significant linearly increasing trends.
文摘Objective： The aim of the research was to study the clinical and epidemiological characteristics of incidence of colorectal cancer in North China. Methods： Analysis and summary were made for 704 colorectal cancer patients diagnosed from 2004 to 2008 in North China. Results： （1） Of 704 colorectal cancer patients, the median age was 56 years old, and the mean age was 58.2. There was no statistic difference in age between male and female cases, P 〉 0.05. （2） The male-female ratio was 1.62：1. （3） The proportion of rectal cancer was 62.92%, and incidence of the left colon cancer was higher than that of right colon cancer, P 〈 0.05. （4） Of 712 lesions, 658 cases were adenocarcinoma accounting for 92.4%, 34 were malignant adenoma accounting for 4.8%, and 20 carcinoid accounting for 2.8%. （5） The 48.9% of patients belonged to stages 0 to 11B. Conclusion： The cases of colorectal cancer in North China is mainly rectal cancers, and the incidence of left colon cancer is higher than that of right colon cancer. The histopathological classification is mainly adenocarcinoma, and the ratio of early stage is high.
基金supported by the National Key Technologies R&D Program of China (Grant No.2009BAC51B02)
文摘A pair of northeast-southwest-tilted mid-tropospheric ridges and troughs on the continental scale was observed to be the key circulation feature common among wintertime extensive and persistent low tempera-ture events (EPLTE) in China.During the persistence of such anomalous circulations,the split flow over the inner Asian continent and the influent flow over the southeast-ern coast of China correspond well to the expanded and amplified Siberian high with tightened sea level pressure gradients and hence,a strong,cold advection over south-eastern China.The western Pacific subtropical high tends to expand northward during the early stages of most EPLTEs.
