The genetic relationships among oakleaf loquat （Eriobotrya prinoides）, Daduhe loquat （Eriobotrya prinoides var. dadunensis） and common loquat （Eriobotrya japonica） were studied by RAPD and ISSR markers. The resu...The genetic relationships among oakleaf loquat （Eriobotrya prinoides）, Daduhe loquat （Eriobotrya prinoides var. dadunensis） and common loquat （Eriobotrya japonica） were studied by RAPD and ISSR markers. The results showed that the similarity coefficient between oakleaf loquat and common loquat was minimal （0.6996 and 0.7219, respectively） and the similarity coefficient between oakleaf loquat and Daduhe loquat was maximal （0.8403 and 0.8211, respectively）, while the similarity coefficient between Daduhe loquat and common loquat was always intermediate （0.7195 and 0.7219, respectively）. The highest additivity was obtained when Daduhe loquat was regarded as the undetermined hybrid （44.9% and 45.8%, respectively）. The specific bands of oakleaf loquat and common loquat were present in Daduhe loquat. Thus, it could be concluded that Daduhe loquat was a hybrid of oakleaf loquat and common loquat.展开更多
Accurate description of the adsorption process of reactants on metal surfaces from theory is crucial for mechanistic understanding of activity and selectivity of metal catalysts, but it remains challengeable for the n...Accurate description of the adsorption process of reactants on metal surfaces from theory is crucial for mechanistic understanding of activity and selectivity of metal catalysts, but it remains challengeable for the nowadays first-principles theory due to the lack of proper exchange-correlation functional describing the distinct interactions involved. We studied here the potential energy surfaces of ethylene adsorption on Ag(111), Rh(111) and Ir(111) using density functional theory calculations and (meta)-GGA functional including PBE, BEEF-vdW, SCAN, and SCAN+rVV10. For ethylene adsorption on noble metal Ag(111), it is found that BEEF-vdW, SCAN and SCAN+rVV10 predict the presence of the physisorption states only. For Rh(111), both SCAN and SCAN+rVV10 find that there is a precursor physisorption state before the chemisorption state. In contrast, there is no precursor state found based on potential energy surfaces from BEEF-vdW and PBE. Whereas for Ir(111), BEEF-vdW predicts the existence of a rather shallow precursor physisorption state, in addition to the chemisorption state. Irrespective to the transition metals considered, we find that SCAN+rVV10 gives the strongest binding strength, followed by SCAN, and PBE/BEEF-vdW, accordingly. The present work highlights great dependence of potential energy surface of ethylene adsorption on transition metal surfaces and exchange-correlation functionals.展开更多
High temperature treatment of tungsten alloy of W-5wt.% TM （transition metals, TM = Ni, Fe, Cu, Co） nanopowder was run under different temperatures to cover the oxidation rate at different temperatures. The correlat...High temperature treatment of tungsten alloy of W-5wt.% TM （transition metals, TM = Ni, Fe, Cu, Co） nanopowder was run under different temperatures to cover the oxidation rate at different temperatures. The correlation was developed for certain temperatures to find an equation for the relation between time and weight. The thermal treatment was done for different quantities at certain times. The proposed equation studies the correlation between temperature, time, and weight. For each temperature, a number of points were recorded from the measured oxidation curve. The shape of the curves is well-represented in this paper. The final results will present the highest temperature, the maximum weight, and the maximum time for full oxidation at high and low temperatures.展开更多
意式庭院中的折纸世界阿根廷籍艺术家丹尼尔·冈萨雷斯（Daniel González）创作的大型户外装置作品。位于意大利米兰的Marselleria展览空间中,名为Pop-up Building Milan,冈萨雷斯从儿童立体图书里吸取灵感,运用轻松活泼的方式...意式庭院中的折纸世界阿根廷籍艺术家丹尼尔·冈萨雷斯（Daniel González）创作的大型户外装置作品。位于意大利米兰的Marselleria展览空间中,名为Pop-up Building Milan,冈萨雷斯从儿童立体图书里吸取灵感,运用轻松活泼的方式,通过对一件件纸板的灵活布置做出了一个展览：纸板被剪成特殊的图形,掏空或者翻折,让它们从二维世界里走出来。展开更多
This study used density functional theory and the quantum transport method to investigate the interfacial coupling and spin transport of transition metals(TMs)with a Fe,Co,and Ni/2H-VSe_(2)hybrid nanostructure.Because...This study used density functional theory and the quantum transport method to investigate the interfacial coupling and spin transport of transition metals(TMs)with a Fe,Co,and Ni/2H-VSe_(2)hybrid nanostructure.Because the indirect coupling of TM-Se-V led to an obvious reduction of the magnetic moment and the disappearance of the half-metal characteristics of 2H-VSe_(2),the expected spin-filtering effect of individual TMs and 2H-VSe_(2)deteriorated at the contact region.Nevertheless,all the TM/2H-VSe_(2)-based dual-probe devices exhibited an interesting bias-dependent spin-injection efficiency with a maximum output spin-polarized current of 666 mA mm-1 in Co/2H-VSe_(2).The proposed TM/2H-VSe_(2)-based spin-field-effect transistor demonstrated outstanding performance.The Ni/2H-VSe_(2)-based transistor achieved a maximum output spin-polarized current of 3117 m A mm-1 and demonstrated a good switching characteristic of 106 mV dec-1.Importantly,all transistors achieved a widely tunable scale of spin-extraction efficiency ranging consistently between 96%and-92%with gate bias.These results indicate a promising candidate for use in high-performance spintronic devices.展开更多
文摘The genetic relationships among oakleaf loquat （Eriobotrya prinoides）, Daduhe loquat （Eriobotrya prinoides var. dadunensis） and common loquat （Eriobotrya japonica） were studied by RAPD and ISSR markers. The results showed that the similarity coefficient between oakleaf loquat and common loquat was minimal （0.6996 and 0.7219, respectively） and the similarity coefficient between oakleaf loquat and Daduhe loquat was maximal （0.8403 and 0.8211, respectively）, while the similarity coefficient between Daduhe loquat and common loquat was always intermediate （0.7195 and 0.7219, respectively）. The highest additivity was obtained when Daduhe loquat was regarded as the undetermined hybrid （44.9% and 45.8%, respectively）. The specific bands of oakleaf loquat and common loquat were present in Daduhe loquat. Thus, it could be concluded that Daduhe loquat was a hybrid of oakleaf loquat and common loquat.
基金supported by the National Key R&D Program of China (No.2017YFB0602205 and No.2018YFA0208603)the National Natural Science Foundation of China (No.91645202)the Chinese Academy of Sciences (No.QYZDJ-SSW-SLH054)
文摘Accurate description of the adsorption process of reactants on metal surfaces from theory is crucial for mechanistic understanding of activity and selectivity of metal catalysts, but it remains challengeable for the nowadays first-principles theory due to the lack of proper exchange-correlation functional describing the distinct interactions involved. We studied here the potential energy surfaces of ethylene adsorption on Ag(111), Rh(111) and Ir(111) using density functional theory calculations and (meta)-GGA functional including PBE, BEEF-vdW, SCAN, and SCAN+rVV10. For ethylene adsorption on noble metal Ag(111), it is found that BEEF-vdW, SCAN and SCAN+rVV10 predict the presence of the physisorption states only. For Rh(111), both SCAN and SCAN+rVV10 find that there is a precursor physisorption state before the chemisorption state. In contrast, there is no precursor state found based on potential energy surfaces from BEEF-vdW and PBE. Whereas for Ir(111), BEEF-vdW predicts the existence of a rather shallow precursor physisorption state, in addition to the chemisorption state. Irrespective to the transition metals considered, we find that SCAN+rVV10 gives the strongest binding strength, followed by SCAN, and PBE/BEEF-vdW, accordingly. The present work highlights great dependence of potential energy surface of ethylene adsorption on transition metal surfaces and exchange-correlation functionals.
文摘High temperature treatment of tungsten alloy of W-5wt.% TM （transition metals, TM = Ni, Fe, Cu, Co） nanopowder was run under different temperatures to cover the oxidation rate at different temperatures. The correlation was developed for certain temperatures to find an equation for the relation between time and weight. The thermal treatment was done for different quantities at certain times. The proposed equation studies the correlation between temperature, time, and weight. For each temperature, a number of points were recorded from the measured oxidation curve. The shape of the curves is well-represented in this paper. The final results will present the highest temperature, the maximum weight, and the maximum time for full oxidation at high and low temperatures.
文摘意式庭院中的折纸世界阿根廷籍艺术家丹尼尔·冈萨雷斯（Daniel González）创作的大型户外装置作品。位于意大利米兰的Marselleria展览空间中,名为Pop-up Building Milan,冈萨雷斯从儿童立体图书里吸取灵感,运用轻松活泼的方式,通过对一件件纸板的灵活布置做出了一个展览：纸板被剪成特殊的图形,掏空或者翻折,让它们从二维世界里走出来。
基金the 111 project(B12026)the National Natural Science Foundation of China(61904142)the Natural Science Basic Research Plan in Shaanxi Province of China(2019ZDLGY16-03)。
文摘This study used density functional theory and the quantum transport method to investigate the interfacial coupling and spin transport of transition metals(TMs)with a Fe,Co,and Ni/2H-VSe_(2)hybrid nanostructure.Because the indirect coupling of TM-Se-V led to an obvious reduction of the magnetic moment and the disappearance of the half-metal characteristics of 2H-VSe_(2),the expected spin-filtering effect of individual TMs and 2H-VSe_(2)deteriorated at the contact region.Nevertheless,all the TM/2H-VSe_(2)-based dual-probe devices exhibited an interesting bias-dependent spin-injection efficiency with a maximum output spin-polarized current of 666 mA mm-1 in Co/2H-VSe_(2).The proposed TM/2H-VSe_(2)-based spin-field-effect transistor demonstrated outstanding performance.The Ni/2H-VSe_(2)-based transistor achieved a maximum output spin-polarized current of 3117 m A mm-1 and demonstrated a good switching characteristic of 106 mV dec-1.Importantly,all transistors achieved a widely tunable scale of spin-extraction efficiency ranging consistently between 96%and-92%with gate bias.These results indicate a promising candidate for use in high-performance spintronic devices.
