We report comprehensive angle-resolved photoemission investigations on the electronic structures and nematicity of the parent compounds of the iron-based superconductors including CeFeAsO, BaFe2As2, NaFeAs, FeSe and u...We report comprehensive angle-resolved photoemission investigations on the electronic structures and nematicity of the parent compounds of the iron-based superconductors including CeFeAsO, BaFe2As2, NaFeAs, FeSe and undoped FeSe/SrTiO3 films with 1, 2 and 20 layers. While the electronic structure near tile Brillouin zone center F varies dramatically among different materials, the electronic structure near the Brillouin zone corners （M points）, as well as their temperature dependence, are rather similar. The electronic structure near the zone corners is dominated by the electronic nematicity that gives rise to a band splitting of the dxz and dyz bands below the nematie transition temperature. A clear relation is observed between the band splitting magnitude arid the onset temperature of nematicity. Our results may shed light on the origin of nematicity, its effect on the electronic structures, and its relation with superconductivity in the iron-based superconductors.展开更多
The general frame for the system of intelligence science was proposed, the common features of the researching objects of the intelligence science were summarized. The intelligence science consists of three portions: s...The general frame for the system of intelligence science was proposed, the common features of the researching objects of the intelligence science were summarized. The intelligence science consists of three portions: scientific foundation, technical methodology and application fields. The common features of intelligence science include complexity, intersection, nonlinearity, anthropomorphic property, uncertainty, incompleteness and distribution etc. The new proposed scientific branch would reflect the new height, new thought and new way for developing the control science and intelligent systems from one angle, and present a strong wish for establishing a new branch of intelligence science.展开更多
Prolyl oligopeptidase (POP) is a cytosolic enzyme involved in the metabolism of many peptide hormones and neuropeptides (1). It was recently reported that POP is responsible
China has proposed to achieve carbon neutrality by 2060.Although previous studies have assessed net-zero emissions pathways in China,the diversity observed in these studies in terms of model construction and parameter...China has proposed to achieve carbon neutrality by 2060.Although previous studies have assessed net-zero emissions pathways in China,the diversity observed in these studies in terms of model construction and parameter setting has led to inconsistent conclusions on some key issues,such as energy transition.This study employs a multi-model comparison method to examine the significance of China's carbon neutrality target on its energy systems by assessing 67 carbon neutrality scenarios in China that are collected from the ADVANCE database,and identifying the differences between energy transition pathways under BEF60 scenarios(i.e.scenarios realising carbon neutrality by 2060)and AFT60 scenarios(i.e.scenarios realising carbon neutrality after 2060).Results show that China needs a larger deployment of low-carbon electricity,a higher electrification rate and more carbon sequestration amount under BEF60 scenarios than those under AFT60 scenarios.Meanwhile,the magnitude of the difference between the two categories of scenarios varies significantly in terms of different outcome indicators.Those that present significant disparities include the deployment scale of solar power(increasing by 160%),the electrification rate of the building sector(increasing by 27%)and the carbon sequestration amount of biomass power with carbon capture and storage(increasing by 380%).In addition,this study selects six indicators to present the technological and economic characteristics of various energy systems of China at the point of net-zero emissions.Exploring the relationships between characteristics,this research identifies the common features among various net-zero energy systems.A great share of non-biomass renewable power generation is always associated with a relatively high per capita energy use,implying that high renewables penetration may relax restrictions on energy consumption,which should be addressed for China when making efforts to promote energy transition.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11190022,11334010 and 11534007the National Basic Research Program of China under Grant No 2015CB921000the Strategic Priority Research Program(B)of Chinese Academy of Sciences under Grant No XDB07020300
文摘We report comprehensive angle-resolved photoemission investigations on the electronic structures and nematicity of the parent compounds of the iron-based superconductors including CeFeAsO, BaFe2As2, NaFeAs, FeSe and undoped FeSe/SrTiO3 films with 1, 2 and 20 layers. While the electronic structure near tile Brillouin zone center F varies dramatically among different materials, the electronic structure near the Brillouin zone corners （M points）, as well as their temperature dependence, are rather similar. The electronic structure near the zone corners is dominated by the electronic nematicity that gives rise to a band splitting of the dxz and dyz bands below the nematie transition temperature. A clear relation is observed between the band splitting magnitude arid the onset temperature of nematicity. Our results may shed light on the origin of nematicity, its effect on the electronic structures, and its relation with superconductivity in the iron-based superconductors.
基金Projects (60234030 60404021) supported by the National Natural Science Foundation of China
文摘The general frame for the system of intelligence science was proposed, the common features of the researching objects of the intelligence science were summarized. The intelligence science consists of three portions: scientific foundation, technical methodology and application fields. The common features of intelligence science include complexity, intersection, nonlinearity, anthropomorphic property, uncertainty, incompleteness and distribution etc. The new proposed scientific branch would reflect the new height, new thought and new way for developing the control science and intelligent systems from one angle, and present a strong wish for establishing a new branch of intelligence science.
文摘Prolyl oligopeptidase (POP) is a cytosolic enzyme involved in the metabolism of many peptide hormones and neuropeptides (1). It was recently reported that POP is responsible
基金Financial support was obtained from the Key Project of the National Natural Science Foundation of China(72140007)the National Key Research and Development Program of China(2018YFA0606504)Energy Foundation(G-2009-32445).
文摘China has proposed to achieve carbon neutrality by 2060.Although previous studies have assessed net-zero emissions pathways in China,the diversity observed in these studies in terms of model construction and parameter setting has led to inconsistent conclusions on some key issues,such as energy transition.This study employs a multi-model comparison method to examine the significance of China's carbon neutrality target on its energy systems by assessing 67 carbon neutrality scenarios in China that are collected from the ADVANCE database,and identifying the differences between energy transition pathways under BEF60 scenarios(i.e.scenarios realising carbon neutrality by 2060)and AFT60 scenarios(i.e.scenarios realising carbon neutrality after 2060).Results show that China needs a larger deployment of low-carbon electricity,a higher electrification rate and more carbon sequestration amount under BEF60 scenarios than those under AFT60 scenarios.Meanwhile,the magnitude of the difference between the two categories of scenarios varies significantly in terms of different outcome indicators.Those that present significant disparities include the deployment scale of solar power(increasing by 160%),the electrification rate of the building sector(increasing by 27%)and the carbon sequestration amount of biomass power with carbon capture and storage(increasing by 380%).In addition,this study selects six indicators to present the technological and economic characteristics of various energy systems of China at the point of net-zero emissions.Exploring the relationships between characteristics,this research identifies the common features among various net-zero energy systems.A great share of non-biomass renewable power generation is always associated with a relatively high per capita energy use,implying that high renewables penetration may relax restrictions on energy consumption,which should be addressed for China when making efforts to promote energy transition.
