Seldom could metals and alloys maintain excellent properties in cryogenic condition, such as the ductility, owing to the restrained dislocation motion.However, a face-centered-cubic(FCC) CoCrFeNi highentropy alloy(HEA...Seldom could metals and alloys maintain excellent properties in cryogenic condition, such as the ductility, owing to the restrained dislocation motion.However, a face-centered-cubic(FCC) CoCrFeNi highentropy alloy(HEA) with great ductility is investigated under the cryogenic environment. The tensile strength of this alloy can reach a maximum at 1,251±10 MPa, and the strain to failure can stay at as large as 62% at the liquid helium temperature. We ascribe the high strength and ductility to the low stacking fault energy at extremely low temperatures,which facilitates the activation of deformation twinning.Moreover, the FCC→HCP(hexagonal close-packed) transition and serration lead to the sudden decline of ductility below 77 K. The dynamical modeling and analysis of serrations at 4.2 and 20 K verify the unstable state due to the FCC→HCP transition. The deformation twinning together with phase transformation at liquid helium temperature produces an adequate strain-hardening rate that sustains the stable plastic flow at high stresses, resulting in the serration feature.展开更多
Based on a five-variable theoretical ecosystem model, the stability of equilibrium state and the nonlinear feature of the transition between a grassland state and a desert state are investigated. The approach of the c...Based on a five-variable theoretical ecosystem model, the stability of equilibrium state and the nonlinear feature of the transition between a grassland state and a desert state are investigated. The approach of the conditional nonlinear optimal perturbations （CNOPs）, which are the nonlinear generalization of the linear singular vectors （LSVs）, is adopted. The numerical results indicate that the linearly stable grassland and desert states are nonlinearly unstable to large enough initial perturbations on the condition that the moisture index # satisfies 0.3126 〈 μ 〈 0.3504. The perturbations represent some kind of anthropogenic influence and natural factors. The results obtained by CNOPs, LSVs and Lyapunov vectors （LVs） are compared to analyze the nonlinear feature of the transition between the grassland state and the desert state. Besides this, it is shown that the five-variable model is superior to the three-variable model in providing more visible signals when the transitions occur.展开更多
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
It is well known that amorphous metals prepared by rapid cooling from liquid statehave many excellent macroscopic properties, and this is mainly determined by their specialmicrostructures. Accordingly, to understand t...It is well known that amorphous metals prepared by rapid cooling from liquid statehave many excellent macroscopic properties, and this is mainly determined by their specialmicrostructures. Accordingly, to understand the relationship between the structures andproperties, it will have important theoretical and practical significance to find out the tran-sition feature of the microstructural configurations by tracking the forming process展开更多
In this study,we devised a computational framework called Supervised Feature Learning and Scoring(SuperFeat)which enables the training of a machine learning model and evaluates the canonical cellular statuses/features...In this study,we devised a computational framework called Supervised Feature Learning and Scoring(SuperFeat)which enables the training of a machine learning model and evaluates the canonical cellular statuses/features in pathological tissues that underlie the progression of disease.This framework also enables the identification of potential drugs that target the presumed detrimental cellular features.This framework was constructed on the basis of an artificial neural network with the gene expression profiles serving as input nodes.The training data comprised single-cell RNA sequencing datasets that encompassed the specific cell lineage during the developmental progression of cell features.A few models of the canonical cancer-involved cellular statuses/features were tested by such framework.Finally,we illustrated the drug repurposing pipeline,utilizing the training parameters derived from the adverse cellular statuses/features,which yielded successful validation results both in vitro and in vivo.SuperFeat is accessible at https://github.com/weilin-genomics/rSuperFeat.展开更多
基金supported in part by the Nationa Natural Science Foundation of China (51471025, 51671020, 51471024 and 11771407)the Department of Energy (DOE), Office of Fossil Energy, National Energy Technology Laboratory (DE-FE-0011194)+1 种基金the support from the US Army Research Office project (W911NF-13-1-0438)the support from the National Science Foundation (DMR-1611180 and 1809640)
文摘Seldom could metals and alloys maintain excellent properties in cryogenic condition, such as the ductility, owing to the restrained dislocation motion.However, a face-centered-cubic(FCC) CoCrFeNi highentropy alloy(HEA) with great ductility is investigated under the cryogenic environment. The tensile strength of this alloy can reach a maximum at 1,251±10 MPa, and the strain to failure can stay at as large as 62% at the liquid helium temperature. We ascribe the high strength and ductility to the low stacking fault energy at extremely low temperatures,which facilitates the activation of deformation twinning.Moreover, the FCC→HCP(hexagonal close-packed) transition and serration lead to the sudden decline of ductility below 77 K. The dynamical modeling and analysis of serrations at 4.2 and 20 K verify the unstable state due to the FCC→HCP transition. The deformation twinning together with phase transformation at liquid helium temperature produces an adequate strain-hardening rate that sustains the stable plastic flow at high stresses, resulting in the serration feature.
基金Funding was provided by grants from the state Key Development Program for Basic Research(Grant No.2006CB400503)the KZCX3-SW-230 of the Chinese Academy of Sciences(CAS)and National Natural Science Foundation of China(Grant No.40675030).
文摘Based on a five-variable theoretical ecosystem model, the stability of equilibrium state and the nonlinear feature of the transition between a grassland state and a desert state are investigated. The approach of the conditional nonlinear optimal perturbations （CNOPs）, which are the nonlinear generalization of the linear singular vectors （LSVs）, is adopted. The numerical results indicate that the linearly stable grassland and desert states are nonlinearly unstable to large enough initial perturbations on the condition that the moisture index # satisfies 0.3126 〈 μ 〈 0.3504. The perturbations represent some kind of anthropogenic influence and natural factors. The results obtained by CNOPs, LSVs and Lyapunov vectors （LVs） are compared to analyze the nonlinear feature of the transition between the grassland state and the desert state. Besides this, it is shown that the five-variable model is superior to the three-variable model in providing more visible signals when the transitions occur.
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.
基金Project supported by the National Natural Science Foundation of China.
文摘It is well known that amorphous metals prepared by rapid cooling from liquid statehave many excellent macroscopic properties, and this is mainly determined by their specialmicrostructures. Accordingly, to understand the relationship between the structures andproperties, it will have important theoretical and practical significance to find out the tran-sition feature of the microstructural configurations by tracking the forming process
基金supported by grants from the Shanghai Jiao Tong University,the Renji Hospital Start-up funding for New PI,the Natural Science Foundation of Shanghai Science and Technology Innovation Action Plan(Grant No.21ZR1441500)the Young Talent of Hunan(Grant No.2020RC3066)+1 种基金the Hunan Natural Science Fund for Excellent Young Scholars(Grant No.2021JJ20003)the China Postdoctoral Science Foundation(Grant No.2021T140197).
文摘In this study,we devised a computational framework called Supervised Feature Learning and Scoring(SuperFeat)which enables the training of a machine learning model and evaluates the canonical cellular statuses/features in pathological tissues that underlie the progression of disease.This framework also enables the identification of potential drugs that target the presumed detrimental cellular features.This framework was constructed on the basis of an artificial neural network with the gene expression profiles serving as input nodes.The training data comprised single-cell RNA sequencing datasets that encompassed the specific cell lineage during the developmental progression of cell features.A few models of the canonical cancer-involved cellular statuses/features were tested by such framework.Finally,we illustrated the drug repurposing pipeline,utilizing the training parameters derived from the adverse cellular statuses/features,which yielded successful validation results both in vitro and in vivo.SuperFeat is accessible at https://github.com/weilin-genomics/rSuperFeat.
