Dear Editor,Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),theseventh coronavirus known to jump from intermediate hosts to humans,has resulted in a worldwide pandemic and caused immense economicdamage(Tan...Dear Editor,Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),theseventh coronavirus known to jump from intermediate hosts to humans,has resulted in a worldwide pandemic and caused immense economicdamage(Tan et al.,2020;Zhu et al.,2020).It is believed that coronavirus spillover may occur again in the future.Human exposure to a bat coro-navirus has been serologically confimed in a rural area of China,indi-cating that the coronavirus spillover occurred,although the origin andfrequency of spillovers are unclear(Wang et al.,2018).展开更多
Although a variety of precursors have been proposed for the formation of high molecular weight hydro-carbons (HMWHCs) in crude oil, their precise origin re-mains elusive. Quantitative studies of macrocrystalline wax a...Although a variety of precursors have been proposed for the formation of high molecular weight hydro-carbons (HMWHCs) in crude oil, their precise origin re-mains elusive. Quantitative studies of macrocrystalline wax and microcrystalline wax content of source rock extracts from the Damintun depression, Liaohe Basin, a typical high wax producing area, coupled with microscopical maceral composition studies and pyrolysis-GC analysis indicate that oil shale enriched in lacustrine biomass makes a primary contribution to wax in oil. The main precursors of high wax oil are lacustrine alginites and their amorphous matrix, which are highly aliphatic in nature and have high genera-tive potential for HMWHCs. Wax generation efficiency could be affected by organic material abundance and matur-ity. The high abundance and low maturity of organic mate-rial are favorite for the formation of high quantity of wax, which declines with decreasing organic abundance and in-creasing thermal maturity. This suggests that wax is derived from organic-rich lacustrine biomass at early stages of maturation (RO = 0.4%—0.7%). Although the contribution of high plant cuticular wax and sporopollen cannot be ruled out, lacustrine biomass is more important in the formation of high wax oil.展开更多
Fabrication of YBCO superconducting thick films by electrophoresis has been widely reported. However, the value of critical current density (J c) is far from what the practical application requires. The superconductin...Fabrication of YBCO superconducting thick films by electrophoresis has been widely reported. However, the value of critical current density (J c) is far from what the practical application requires. The superconducting thick films are obtained using top-seeded melt growth method with different proportional Y2BaCuO5 (Y211) addition. High-pressure oxygen has been used in the annealing process to improve the uniformity of the oxygen content in the superconducting thick films. When 40mol% Y211 powder is added to the YBa2Cu3O7–5 (Y123) powder,J c for the superconducting thick film by approaches described above reaches 7.008×103 A/cm2 (77 K, 0 T), which is greater than the value ever reported.展开更多
基金supported by the National Natural Science Foundation of China(82102365,92269115,32270996,82061138020)the Science and Technology Innovation Program of the Hunan Province of China(2022RC3079)+7 种基金the SC1-PHE-CORONAVIRUS-2020:Advancing Knowledge for the Clinical and Public Health Response to the 2019-nCoV Epidemic’from the European Commission(CORONADX,no.101003562,to Y-PL)Natural Science Foundation of the Hunan Province of China(2021JJ40006,2022JJ30095)Educational Commission of the Hunan Province of China(21A0529)the Clinical Medical Innovation Technology Guide Project of the Hunan Province(2021SK50304,2021SK50306 and 2021SK50312)the Scientific Research Innovation Project of Graduate of Hunan Province(CX20221024)the Scientific Research Innovation Project of Graduate of University of South China(213YXC019)approved by the Institutional Ethical Review Board of The Central Hospital of Shaoyang,Hunan Province,China(V.1.0,20200301)The First People's Hospital of Chenzhou,Hunan Province,China(V.3.0,2021001)。
文摘Dear Editor,Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),theseventh coronavirus known to jump from intermediate hosts to humans,has resulted in a worldwide pandemic and caused immense economicdamage(Tan et al.,2020;Zhu et al.,2020).It is believed that coronavirus spillover may occur again in the future.Human exposure to a bat coro-navirus has been serologically confimed in a rural area of China,indi-cating that the coronavirus spillover occurred,although the origin andfrequency of spillovers are unclear(Wang et al.,2018).
文摘Although a variety of precursors have been proposed for the formation of high molecular weight hydro-carbons (HMWHCs) in crude oil, their precise origin re-mains elusive. Quantitative studies of macrocrystalline wax and microcrystalline wax content of source rock extracts from the Damintun depression, Liaohe Basin, a typical high wax producing area, coupled with microscopical maceral composition studies and pyrolysis-GC analysis indicate that oil shale enriched in lacustrine biomass makes a primary contribution to wax in oil. The main precursors of high wax oil are lacustrine alginites and their amorphous matrix, which are highly aliphatic in nature and have high genera-tive potential for HMWHCs. Wax generation efficiency could be affected by organic material abundance and matur-ity. The high abundance and low maturity of organic mate-rial are favorite for the formation of high quantity of wax, which declines with decreasing organic abundance and in-creasing thermal maturity. This suggests that wax is derived from organic-rich lacustrine biomass at early stages of maturation (RO = 0.4%—0.7%). Although the contribution of high plant cuticular wax and sporopollen cannot be ruled out, lacustrine biomass is more important in the formation of high wax oil.
基金supported the State Key Program of China,the National Natural Science Foundation of China(Grant No.G1999064604)Paper's Foundation Beijing Jiaotong University(Grant No.PD244).
文摘Fabrication of YBCO superconducting thick films by electrophoresis has been widely reported. However, the value of critical current density (J c) is far from what the practical application requires. The superconducting thick films are obtained using top-seeded melt growth method with different proportional Y2BaCuO5 (Y211) addition. High-pressure oxygen has been used in the annealing process to improve the uniformity of the oxygen content in the superconducting thick films. When 40mol% Y211 powder is added to the YBa2Cu3O7–5 (Y123) powder,J c for the superconducting thick film by approaches described above reaches 7.008×103 A/cm2 (77 K, 0 T), which is greater than the value ever reported.
