Combining the single-grain low-temperature apatite fission track with high-temperature zircon U-Pb dating of sandstone can better reveal the temporal association between the source and depositional site, and identify ...Combining the single-grain low-temperature apatite fission track with high-temperature zircon U-Pb dating of sandstone can better reveal the temporal association between the source and depositional site, and identify both the age component of the source terrain and subsequent thermo-tectonic events after deposition. This paper introduces the single- grain zircon U-Pb dating and fission track (FT) dating of sediments from the Beipiao basin in Northeast China. The U-Pb ages of 18 single zircon grains collected from the early Jurassic Beipiao Formation range from 194.3±2.9 to 233.8±4.2 Ma and most of apatite FT ages are about 30-40 Ma, indicating that the eastern part of the Yan-Liao orogenic belt experienced an obvious tectonic seesawing during Meso-Cenozoic time. The eastern part of Liaoning Province (the Liaodong block) uplifted in the early Mesozoic (230-190 Ma) and formed a geological landscape of high mountains, while the western part of the province (the Liaoxi area) subsided relatively and thousand-meter-scale sediments were deposited. During the Cenozoic (30-40 Ma), the Liaoxi area uplifted as a whole, and the Xialiaohe Basin sank intensively. The topographic landscape had a great change: high mountains in the west and east of Liaoning Province and low plains in the central area.展开更多
To avoid the direct contact with mouse cells and possible heterogeneous pathogen in future application, we need to replace mouse embryonic fibroblasts with human fibroblasts as the feeder layer to maintain human embry...To avoid the direct contact with mouse cells and possible heterogeneous pathogen in future application, we need to replace mouse embryonic fibroblasts with human fibroblasts as the feeder layer to maintain human embryonic stem cells growth in the undifferentiated state. We success-fully use human fibroblasts derived from aborted fetus and adult prepuce as feeder layer to maintain human embryonic stem cells growth. During the passage and growth on this feeder layer, the human embryonic stem cells can keep their undifferentiated state.展开更多
基金the National Natural Science Foundation of China(No.40306010)Chinese Academy of Sciences(No.KZCX2-SW-117).
文摘Combining the single-grain low-temperature apatite fission track with high-temperature zircon U-Pb dating of sandstone can better reveal the temporal association between the source and depositional site, and identify both the age component of the source terrain and subsequent thermo-tectonic events after deposition. This paper introduces the single- grain zircon U-Pb dating and fission track (FT) dating of sediments from the Beipiao basin in Northeast China. The U-Pb ages of 18 single zircon grains collected from the early Jurassic Beipiao Formation range from 194.3±2.9 to 233.8±4.2 Ma and most of apatite FT ages are about 30-40 Ma, indicating that the eastern part of the Yan-Liao orogenic belt experienced an obvious tectonic seesawing during Meso-Cenozoic time. The eastern part of Liaoning Province (the Liaodong block) uplifted in the early Mesozoic (230-190 Ma) and formed a geological landscape of high mountains, while the western part of the province (the Liaoxi area) subsided relatively and thousand-meter-scale sediments were deposited. During the Cenozoic (30-40 Ma), the Liaoxi area uplifted as a whole, and the Xialiaohe Basin sank intensively. The topographic landscape had a great change: high mountains in the west and east of Liaoning Province and low plains in the central area.
基金supported by the National Natural Science Foundation of China(Grant Nos.30030070 and 3010403048)the National Major Basic Research Project(Grant No.001CB51010)+1 种基金the Natural Science Fund of Hunan Province(Grant No.00JJY2036)the Science and Technology Conquest of Hunan Province(Grant No.01SSY1001).
文摘To avoid the direct contact with mouse cells and possible heterogeneous pathogen in future application, we need to replace mouse embryonic fibroblasts with human fibroblasts as the feeder layer to maintain human embryonic stem cells growth in the undifferentiated state. We success-fully use human fibroblasts derived from aborted fetus and adult prepuce as feeder layer to maintain human embryonic stem cells growth. During the passage and growth on this feeder layer, the human embryonic stem cells can keep their undifferentiated state.
