Two kinds of glassy sulfurs are synthesized by thrapid compression method from liquid sulfur at temperatures below and above the X-transition point. The glassy sulfur has different colors and transparencies, depending...Two kinds of glassy sulfurs are synthesized by thrapid compression method from liquid sulfur at temperatures below and above the X-transition point. The glassy sulfur has different colors and transparencies, depending on temperature, which may inherit some structural information from the transition. Raman spectrum studies of these samples show that a large fraction of polymeric chains exist in the glassy sulfur, even in the one solidified from T 〈 Tλ. We find that a higher compression rate instead of a higher temperature of the parent liquid captures more polymeric chains. Pressure-induced glassy sulfur presents high thermal stability compared with temperature quenched glassy sulfur and could transform into liquid sulfur directly without crystallization through an abnormal exothermic melting course. High energy x-ray diffraction is utilized to study the local order of the pressure-induced glassy sulfur.展开更多
The eclogites from the Altyn Tagh, northwestern China have been subjected to medium-temperature and high-pressure metamorphism, and then overprinted by the amphibolite to granulite facies retrograde metamorphism, A co...The eclogites from the Altyn Tagh, northwestern China have been subjected to medium-temperature and high-pressure metamorphism, and then overprinted by the amphibolite to granulite facies retrograde metamorphism, A complex compositionai zoning was well preserved in the garnet porphyroblast formed during the metamorphism of eclogite facies. This zoning recorded P-T path of multistage metamorphism, and an early retrogressive process with features of decreasing pressure and increasing temperature. This evidences a short residence time for the eclogite at peak metamorphism and early retrogression, and thus rapid tectonic uplift history.展开更多
Ethyl (Z)-α-formylamino-β-arylacrylates were obtained in good yields by the condensation of ethyl N, N-diformylamino acetate and aromatic aldehydes in the presence of sodium ethoxide in ethanol. The structure of eth...Ethyl (Z)-α-formylamino-β-arylacrylates were obtained in good yields by the condensation of ethyl N, N-diformylamino acetate and aromatic aldehydes in the presence of sodium ethoxide in ethanol. The structure of ethyl α-formylaminocinnamate was characterized by single crystal X-ray diffraction measurement.展开更多
基金supported by the Joint Funds of the National Natural Science Foundation of China(Grant No.U1530402)the National Natural Science Foundation of China(Grant No.11004163)+2 种基金the Fundamental Research Funds for the Central Universities,China(Grant No.2682014ZT31)the Department of Energy National Nuclear Security Administration(Grant No.DE-NA0001974)the Department of Energy Basic Energy Sciences(Grant Nos.DE-FG02-99ER45775and DE-AC02-06CH11357)
文摘Two kinds of glassy sulfurs are synthesized by thrapid compression method from liquid sulfur at temperatures below and above the X-transition point. The glassy sulfur has different colors and transparencies, depending on temperature, which may inherit some structural information from the transition. Raman spectrum studies of these samples show that a large fraction of polymeric chains exist in the glassy sulfur, even in the one solidified from T 〈 Tλ. We find that a higher compression rate instead of a higher temperature of the parent liquid captures more polymeric chains. Pressure-induced glassy sulfur presents high thermal stability compared with temperature quenched glassy sulfur and could transform into liquid sulfur directly without crystallization through an abnormal exothermic melting course. High energy x-ray diffraction is utilized to study the local order of the pressure-induced glassy sulfur.
文摘The eclogites from the Altyn Tagh, northwestern China have been subjected to medium-temperature and high-pressure metamorphism, and then overprinted by the amphibolite to granulite facies retrograde metamorphism, A complex compositionai zoning was well preserved in the garnet porphyroblast formed during the metamorphism of eclogite facies. This zoning recorded P-T path of multistage metamorphism, and an early retrogressive process with features of decreasing pressure and increasing temperature. This evidences a short residence time for the eclogite at peak metamorphism and early retrogression, and thus rapid tectonic uplift history.
文摘Ethyl (Z)-α-formylamino-β-arylacrylates were obtained in good yields by the condensation of ethyl N, N-diformylamino acetate and aromatic aldehydes in the presence of sodium ethoxide in ethanol. The structure of ethyl α-formylaminocinnamate was characterized by single crystal X-ray diffraction measurement.
