Long-chain alkenones were detected in samples of sea surface sediments from the Chukchi Sea and the Bering Sea areas, the Arctic Pole. The analysis result indicates that C37:3 methylketone is predominate in the long-c...Long-chain alkenones were detected in samples of sea surface sediments from the Chukchi Sea and the Bering Sea areas, the Arctic Pole. The analysis result indicates that C37:3 methylketone is predominate in the long-chain alkenones from the Chukchi and Bering Sea sediments. The abundance of C37 to C39 unsaturated alkenones changes in an order of C37 > C38 > C39. Based on C37 /C38 ratio, the detected organism precursors of the long-chain alkenones are mainly coccolithophrid (Emiliania huxleyi). By the calibration relationship between U37k and U37k indices, the sea surface paleotemperature in these seas is estimated. The estimated values of U37k vary from 4.147℃ to 5.706℃ , with a mean value of 5.092℃.展开更多
The existence of the Cretaceous-Tertiary （K/T） boundary in the non-marine succession is expected at Jiayin in the Heilongjiang River area, China. Zircons from a tuff sample from the Baishantou Member of Wuyun Format...The existence of the Cretaceous-Tertiary （K/T） boundary in the non-marine succession is expected at Jiayin in the Heilongjiang River area, China. Zircons from a tuff sample from the Baishantou Member of Wuyun Formation in Jiayin were analyzed by the laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS） U-Pb dating and fission-track dating methods. Ages of 64.1±0.7 Ma （U-Pb） and 61.7±1.8 Ma （fission-track dating） were obtained, which allow reevaluation of a previously reported late Maastrichian age for the tuff layer that was in conflict with the paleontological evidence. These results confirm the Danian age of the section in agreement with the paleontological evidence.展开更多
AT the 13th Confucius Institute Conference held in Chengdu,capital of southwest China’s Sichuan Province,Professor Sir Keith Burnett,former president and vice chancellor of the University of Sheffield and a member of...AT the 13th Confucius Institute Conference held in Chengdu,capital of southwest China’s Sichuan Province,Professor Sir Keith Burnett,former president and vice chancellor of the University of Sheffield and a member of the Council of Confucius Institute Headquarters,told China Today his experience with China and Chinese people.展开更多
This experiment was conducted in order to verify the role of Vitamin K1 as a cell growth inhibitor on the U937 cell line. This experiment was performed in two parts—one with a lesser concentration of Vitamin K1, and ...This experiment was conducted in order to verify the role of Vitamin K1 as a cell growth inhibitor on the U937 cell line. This experiment was performed in two parts—one with a lesser concentration of Vitamin K1, and the other with a range of concentrations from low-to-high. Through the remaining number of U937 cells, as well as cell areas, it was concluded that the presence of Vitamin K1 reduces the number of cancer cells. It was also concluded that as Vitamin K1 concentration increases, so does the frequency and effects of apoptosis.展开更多
基金This study was supported by the First Chinese National Scientific Observation for the Arctic the Development Program of NKBR
文摘Long-chain alkenones were detected in samples of sea surface sediments from the Chukchi Sea and the Bering Sea areas, the Arctic Pole. The analysis result indicates that C37:3 methylketone is predominate in the long-chain alkenones from the Chukchi and Bering Sea sediments. The abundance of C37 to C39 unsaturated alkenones changes in an order of C37 > C38 > C39. Based on C37 /C38 ratio, the detected organism precursors of the long-chain alkenones are mainly coccolithophrid (Emiliania huxleyi). By the calibration relationship between U37k and U37k indices, the sea surface paleotemperature in these seas is estimated. The estimated values of U37k vary from 4.147℃ to 5.706℃ , with a mean value of 5.092℃.
基金the Project NSFC No30220130698the Project "111" of China for their support the National Science Council,Taiwan(grant 97-2811-M- 002-040)
文摘The existence of the Cretaceous-Tertiary （K/T） boundary in the non-marine succession is expected at Jiayin in the Heilongjiang River area, China. Zircons from a tuff sample from the Baishantou Member of Wuyun Formation in Jiayin were analyzed by the laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS） U-Pb dating and fission-track dating methods. Ages of 64.1±0.7 Ma （U-Pb） and 61.7±1.8 Ma （fission-track dating） were obtained, which allow reevaluation of a previously reported late Maastrichian age for the tuff layer that was in conflict with the paleontological evidence. These results confirm the Danian age of the section in agreement with the paleontological evidence.
文摘AT the 13th Confucius Institute Conference held in Chengdu,capital of southwest China’s Sichuan Province,Professor Sir Keith Burnett,former president and vice chancellor of the University of Sheffield and a member of the Council of Confucius Institute Headquarters,told China Today his experience with China and Chinese people.
文摘This experiment was conducted in order to verify the role of Vitamin K1 as a cell growth inhibitor on the U937 cell line. This experiment was performed in two parts—one with a lesser concentration of Vitamin K1, and the other with a range of concentrations from low-to-high. Through the remaining number of U937 cells, as well as cell areas, it was concluded that the presence of Vitamin K1 reduces the number of cancer cells. It was also concluded that as Vitamin K1 concentration increases, so does the frequency and effects of apoptosis.
