In the experiment, by taking Quercus engleriana Seem., Betula albo- sinensis Burk., Abies faxoniana Rehd. and Fargesia rufa Yi, in the vegetation restoration pattern area of Beichuan Nature Reserve as the research obj...In the experiment, by taking Quercus engleriana Seem., Betula albo- sinensis Burk., Abies faxoniana Rehd. and Fargesia rufa Yi, in the vegetation restoration pattern area of Beichuan Nature Reserve as the research objects, the study on the biomass models, the biomass distribution law of single plant and the growth rule of every organ of the four tree species was made. The results indicated that in the compositions of all of the species, the proportion of trunk biomass was the highest, while that of trunk biomass was the lowest, the proportions of branch and root biomasses varied depending on species; in the comparison of correlativity between the proportions of biomasses of all nutrition organs and biomass of single plant, the relations were generally significant, the tree trunks were positively related while the roots were negatively related; the proportion of trunk biomass of all species was significantly and negatively related to the proportions of leaf and branch biomasses, while the biomass of leaves was significantly and positively related to the biomass of branches.展开更多
AIM:To examine the association between parity and gastric cancer (the cases are almost all premenopausal women) risk in a cohort of young parous women.METHODS:The study cohort consisted of all women with a record of a...AIM:To examine the association between parity and gastric cancer (the cases are almost all premenopausal women) risk in a cohort of young parous women.METHODS:The study cohort consisted of all women with a record of a first and singleton childbirth in the Birth Register between 1978 and 1987.We tracked each woman from the time of her first childbirth to December 31,2008.Their vital status was ascertained by linking records to the computerized mortality database.Cox proportional hazard regression models were used to estimate hazard ratios of death from gastric cancer associated with parity.RESULTS:There were 1090 gastric cancer deaths (85.87% of them were premenopausal) during 33686828 person-years of follow-up.The mortality rate of gastric cancer was 3.24 cases per 100000 person-years.A trend of increasing risk of gastric cancer was seen with increasing parity.The adjusted hazard ratio was 1.24 [confidence interval (95% CI):1.02-1.50] for women who had borne two to three children,and 1.32 (95% CI:1.01-1.72) for women with four or more births,when compared with women who had given birth to only one child.CONCLUSION:These results suggest that higher parity may increase the risk of death from gastric cancer among premenopausal women.展开更多
In this study, the relationship between the QBO （quasi-biennial oscillation）, which is seen at the equatorial stratosphere, and critical frequency of layer （Es） sporadically observed at the ionospheric E region wa...In this study, the relationship between the QBO （quasi-biennial oscillation）, which is seen at the equatorial stratosphere, and critical frequency of layer （Es） sporadically observed at the ionospheric E region was analyzed by using multiple regression model. For this analysis, Es layer critical frequency （foEs） obtained from four different stations at equatorial region and QBO measured at 10 hPa altitude values were used. The positive relationship between foEs and QBO was observed at all stations. An increase of 1 m/s at QBO leads to an increase of 0.01 Mhz, 0.02 Mhz, 0.02 Mhz and 0.01 Mhz （Jicamarca, Ascension, Manila and Kwajalein） on foEs, respectively. Expect for Manila station, westerly phase of QBO has greater effect on foEs compared to easterly phase of QBO at all other stations. It is seen that the changes occurred on foEs can be explained by the QBO at rates 47%, 46%, 32% and 44% for Jicamarca, Ascension, Manila and Kwajalein stations, respectively.展开更多
基金Supported by the Restoring&Reconstruction Project of Giant Panda Habitat after the Wenchuan Earthquake in Beichuan Qiang Minority Autonomous County~~
文摘In the experiment, by taking Quercus engleriana Seem., Betula albo- sinensis Burk., Abies faxoniana Rehd. and Fargesia rufa Yi, in the vegetation restoration pattern area of Beichuan Nature Reserve as the research objects, the study on the biomass models, the biomass distribution law of single plant and the growth rule of every organ of the four tree species was made. The results indicated that in the compositions of all of the species, the proportion of trunk biomass was the highest, while that of trunk biomass was the lowest, the proportions of branch and root biomasses varied depending on species; in the comparison of correlativity between the proportions of biomasses of all nutrition organs and biomass of single plant, the relations were generally significant, the tree trunks were positively related while the roots were negatively related; the proportion of trunk biomass of all species was significantly and negatively related to the proportions of leaf and branch biomasses, while the biomass of leaves was significantly and positively related to the biomass of branches.
基金Supported by A grant from the National Science Council,Executive Yuan,Taiwan,No.NSC-94-2314-B-037-056
文摘AIM:To examine the association between parity and gastric cancer (the cases are almost all premenopausal women) risk in a cohort of young parous women.METHODS:The study cohort consisted of all women with a record of a first and singleton childbirth in the Birth Register between 1978 and 1987.We tracked each woman from the time of her first childbirth to December 31,2008.Their vital status was ascertained by linking records to the computerized mortality database.Cox proportional hazard regression models were used to estimate hazard ratios of death from gastric cancer associated with parity.RESULTS:There were 1090 gastric cancer deaths (85.87% of them were premenopausal) during 33686828 person-years of follow-up.The mortality rate of gastric cancer was 3.24 cases per 100000 person-years.A trend of increasing risk of gastric cancer was seen with increasing parity.The adjusted hazard ratio was 1.24 [confidence interval (95% CI):1.02-1.50] for women who had borne two to three children,and 1.32 (95% CI:1.01-1.72) for women with four or more births,when compared with women who had given birth to only one child.CONCLUSION:These results suggest that higher parity may increase the risk of death from gastric cancer among premenopausal women.
文摘In this study, the relationship between the QBO （quasi-biennial oscillation）, which is seen at the equatorial stratosphere, and critical frequency of layer （Es） sporadically observed at the ionospheric E region was analyzed by using multiple regression model. For this analysis, Es layer critical frequency （foEs） obtained from four different stations at equatorial region and QBO measured at 10 hPa altitude values were used. The positive relationship between foEs and QBO was observed at all stations. An increase of 1 m/s at QBO leads to an increase of 0.01 Mhz, 0.02 Mhz, 0.02 Mhz and 0.01 Mhz （Jicamarca, Ascension, Manila and Kwajalein） on foEs, respectively. Expect for Manila station, westerly phase of QBO has greater effect on foEs compared to easterly phase of QBO at all other stations. It is seen that the changes occurred on foEs can be explained by the QBO at rates 47%, 46%, 32% and 44% for Jicamarca, Ascension, Manila and Kwajalein stations, respectively.
