The 2D/3D heterojunction perovskites have garnered increasing attention due to their exceptional moisture and thermal stability.However,few works have paid attention to the influence of the subsequent change process o...The 2D/3D heterojunction perovskites have garnered increasing attention due to their exceptional moisture and thermal stability.However,few works have paid attention to the influence of the subsequent change process of 2D/3D heterojunction PSC on the stability of PSCs.Moreover,the evolution of the interface and carrier dynamic behavior of the 2D/3D perovskite films with long-term operation has not been systematically developed befo re.In this work,the effects of 2D/3 D heterojunction evolution on the interface of perovskite films and different carrier dynamics during 2D/3D evolution are systematically analyzed for the first time.The decomposition of 2D/3D heterojunction in the perovskite film will have a certain impact on the surface and carrier dynamics behavior of perovskite.During the evolution of 2D/3D heterojunction,PbI_(2)crystals will appear,which will improve the interfacial energy level matching between the electron transport layer and perovskite film.With a long evolution time,some holes will appear on the surface of perovskite film.The open circuit voltage(V_(OC))of PSCs increased from 1.14 to1.18 V and the PCE increased to 23.21%after 300 h storage in the nitrogen atmosphere,and maintained 89%initial performance for with 3000 h stability test in N_(2)box.This discovery has a significant role in promoting the development of inverted heterojunction PSCs and constructing the revolution mechanism of charge carrier dynamic.展开更多
A logarithm representation of evolution operators is defined. Generators of invertible evolution families are characterized by the logarithm representation. In this article, using the logarithm representation, a conce...A logarithm representation of evolution operators is defined. Generators of invertible evolution families are characterized by the logarithm representation. In this article, using the logarithm representation, a concept of evolution operators without satisfying the semigroup property is introduced. In conclusion the existence of alternative infinitesimal generator is clarified.展开更多
With complex topographic and hydrological characteristics,the landslide-induced surge disaster chain readily develops in mountainous and gorge areas,posing a huge challenge for infrastructure construction.This landsli...With complex topographic and hydrological characteristics,the landslide-induced surge disaster chain readily develops in mountainous and gorge areas,posing a huge challenge for infrastructure construction.This landslide-induced surge disaster chain involves a complex fluid-solid coupling between the landslide mass and a water body and exhibits complex energy conversion and dissipation characteristics,which is challenging to deal with using traditional finite element analysis.In this study,the energy evolution characteristics in the whole process of the disaster chain were first investigated,and the momentum-conservation equations for different stages were established.Then,the two-phase doublepoint material point method(TPDP-MPM)was used to model the landslide-induced surge disaster chain,and an experiment involving block-induced surge was modeled and simulated to validate this method.Finally,three generalized models were established for the landslide-induced surge process in a U-shaped valley,including subaerial,partly submerged,and submarine scenarios.The interaction mechanism between the landslide mass and the water body in the disaster chain was revealed by defining the system energy conversion ratio and the mechanism of evolution of the disaster chain from the perspective of energy.The results help further evaluate the secondary disasters,given the submerged position of the landslide mass.展开更多
The literature suggests inconsistent evidence regarding the influence of danger on prosocial behavior.We explore this issue through a nationwide survey of 8567 households in China during the COVID-19 Omicron variant o...The literature suggests inconsistent evidence regarding the influence of danger on prosocial behavior.We explore this issue through a nationwide survey of 8567 households in China during the COVID-19 Omicron variant outbreak in 2022.In a zero-COVID policy,China chose to quarantine all neighborhoods with viral infections.The almost random presence of infected cases provides an opportunity to examine the relationship between the proximity of danger(i.e.potential Omicron infection)and the prosocial behavior of residents in quarantine zones.For the first time,we find an inverted U-shape relationship:residents exhibit a stronger prosocial behavior when living closer to infected cases in the neighborhood,but this positive effect diminishes when they are too close to each other.Furthermore,such non-linear relationship is salient in residents’interpersonal helping but not in their cooperative behavior.Policymakers should be mindful of the different prosocial responses and target their efforts to help communities navigate quarantine periods more effectively.展开更多
Oxygen evolution reaction(OER)is a bottleneck half-reaction in many important energy conversion processes(e.g.,water splitting),and one of the key issues lies to develop high-efficiency,cost-effective OER electrocatal...Oxygen evolution reaction(OER)is a bottleneck half-reaction in many important energy conversion processes(e.g.,water splitting),and one of the key issues lies to develop high-efficiency,cost-effective OER electrocatalysts.Rather than those popular extrinsic modulations of any catalysts with gradually degraded performance,we aim at the utilization of the intermediates offered from the undergoing OER as long-standing electrocatalysts.Herein,by inverted design,we extracted the bimetallic borides(FeCoB_(2))-derived intermediates metal borates in the OER,unlocking their potential as a selffunctionalized highly active catalytic phase in-situ formed on the metal boride surface for continuing OER operation.Mechanistically,the surface metal atoms are oxidized to oxyhydroxides,and the surface metalloids(B)are further transformed to the corresponding oxoanions to form metal borates.Such OER self-produced electrocatalyst exhibits a small overpotential of 295 mV at 10 mA/cm2 and its high catalytic activity lasts even after 200 h.Compared with FeCoB_(2),the catalytic activity of this electrochemically activated FeCoB_(2) is~7 times higher.The in-situ formed metal borate is dominatingly responsible for the obtained high catalytic activity.Such unique OER-produced self-functionalization surfaces of metal borates afford to greatly reduce the energy barrier of the continuing OER,thereby accelerating the reaction process.展开更多
Through inverted-design rather than modifying the generally-assumed S active sites in popular MoS_(2),we unlock the potential of Mo sites and successfully prepared novel MoS_(2)@Ni_(3)S_(2)/NF core-shell nanospheres a...Through inverted-design rather than modifying the generally-assumed S active sites in popular MoS_(2),we unlock the potential of Mo sites and successfully prepared novel MoS_(2)@Ni_(3)S_(2)/NF core-shell nanospheres as a catalyst for the high-performance hydrogen evolution reaction(HER).TheΔGH at the Mo site is optimized via Ni_(3)S_(2)to achieve excellent HER activity.At low current densities,it has similar activity to the Pt/C.However,its performance is better than Pt/C at high density.Moreover,our catalyst shows a considerable stability at a variety of current densities for 50 h,promising to substitute noble metal catalysts in application of commercial alkaline electrocatalysts.展开更多
基金financial support provided by the Sichuan Science and Technology Program(No.2022NSFSC0226)Sichuan Science and Technology Program(No.2023ZYD0163)+6 种基金the Production-Education Integration Demonstration Project of Sichuan Provincethe Photovoltaic Industry Production-Education Integration Comprehensive Demonstration Base of Sichuan Province(Sichuan Financial Education[2022]No.106)China Tianfu Yongxing Laboratory Science and Technology Key Project(2023KJGG15)National Key Research and Development Program of China(2022YFB3803300)Beijing Natural Science Foundation(IS23037)the Department for Energy Security and Net Zero(project ID:NEXTCCUS)the ACT program(Accelerating CCS Technologies,Horizon2020 project NO.691712)。
文摘The 2D/3D heterojunction perovskites have garnered increasing attention due to their exceptional moisture and thermal stability.However,few works have paid attention to the influence of the subsequent change process of 2D/3D heterojunction PSC on the stability of PSCs.Moreover,the evolution of the interface and carrier dynamic behavior of the 2D/3D perovskite films with long-term operation has not been systematically developed befo re.In this work,the effects of 2D/3 D heterojunction evolution on the interface of perovskite films and different carrier dynamics during 2D/3D evolution are systematically analyzed for the first time.The decomposition of 2D/3D heterojunction in the perovskite film will have a certain impact on the surface and carrier dynamics behavior of perovskite.During the evolution of 2D/3D heterojunction,PbI_(2)crystals will appear,which will improve the interfacial energy level matching between the electron transport layer and perovskite film.With a long evolution time,some holes will appear on the surface of perovskite film.The open circuit voltage(V_(OC))of PSCs increased from 1.14 to1.18 V and the PCE increased to 23.21%after 300 h storage in the nitrogen atmosphere,and maintained 89%initial performance for with 3000 h stability test in N_(2)box.This discovery has a significant role in promoting the development of inverted heterojunction PSCs and constructing the revolution mechanism of charge carrier dynamic.
文摘A logarithm representation of evolution operators is defined. Generators of invertible evolution families are characterized by the logarithm representation. In this article, using the logarithm representation, a concept of evolution operators without satisfying the semigroup property is introduced. In conclusion the existence of alternative infinitesimal generator is clarified.
基金supported by the National Natural Science Foundation of China(Grant Nos.52179117 and U21A20159)the Youth Innovation Promotion Association of Chinese Academy of Sciences(CAS)(Grant No.2021325).
文摘With complex topographic and hydrological characteristics,the landslide-induced surge disaster chain readily develops in mountainous and gorge areas,posing a huge challenge for infrastructure construction.This landslide-induced surge disaster chain involves a complex fluid-solid coupling between the landslide mass and a water body and exhibits complex energy conversion and dissipation characteristics,which is challenging to deal with using traditional finite element analysis.In this study,the energy evolution characteristics in the whole process of the disaster chain were first investigated,and the momentum-conservation equations for different stages were established.Then,the two-phase doublepoint material point method(TPDP-MPM)was used to model the landslide-induced surge disaster chain,and an experiment involving block-induced surge was modeled and simulated to validate this method.Finally,three generalized models were established for the landslide-induced surge process in a U-shaped valley,including subaerial,partly submerged,and submarine scenarios.The interaction mechanism between the landslide mass and the water body in the disaster chain was revealed by defining the system energy conversion ratio and the mechanism of evolution of the disaster chain from the perspective of energy.The results help further evaluate the secondary disasters,given the submerged position of the landslide mass.
基金supported in part by the National Natural Science Foundation of China(72033003,12071088,91846302 and 71973107).
文摘The literature suggests inconsistent evidence regarding the influence of danger on prosocial behavior.We explore this issue through a nationwide survey of 8567 households in China during the COVID-19 Omicron variant outbreak in 2022.In a zero-COVID policy,China chose to quarantine all neighborhoods with viral infections.The almost random presence of infected cases provides an opportunity to examine the relationship between the proximity of danger(i.e.potential Omicron infection)and the prosocial behavior of residents in quarantine zones.For the first time,we find an inverted U-shape relationship:residents exhibit a stronger prosocial behavior when living closer to infected cases in the neighborhood,but this positive effect diminishes when they are too close to each other.Furthermore,such non-linear relationship is salient in residents’interpersonal helping but not in their cooperative behavior.Policymakers should be mindful of the different prosocial responses and target their efforts to help communities navigate quarantine periods more effectively.
基金Financially supported by the National Natural Science Foundation of China(51872115,52101256,51932003)China Postdoctoral Science Foundation Project(2020M680043)+1 种基金Science and Technology Research Project of the Department of Education of Jilin Province(JJKH20211083KJ)2020 International Cooperation Project of the Department of Science and Technology of Jilin Province(20200801001GH)。
文摘Oxygen evolution reaction(OER)is a bottleneck half-reaction in many important energy conversion processes(e.g.,water splitting),and one of the key issues lies to develop high-efficiency,cost-effective OER electrocatalysts.Rather than those popular extrinsic modulations of any catalysts with gradually degraded performance,we aim at the utilization of the intermediates offered from the undergoing OER as long-standing electrocatalysts.Herein,by inverted design,we extracted the bimetallic borides(FeCoB_(2))-derived intermediates metal borates in the OER,unlocking their potential as a selffunctionalized highly active catalytic phase in-situ formed on the metal boride surface for continuing OER operation.Mechanistically,the surface metal atoms are oxidized to oxyhydroxides,and the surface metalloids(B)are further transformed to the corresponding oxoanions to form metal borates.Such OER self-produced electrocatalyst exhibits a small overpotential of 295 mV at 10 mA/cm2 and its high catalytic activity lasts even after 200 h.Compared with FeCoB_(2),the catalytic activity of this electrochemically activated FeCoB_(2) is~7 times higher.The in-situ formed metal borate is dominatingly responsible for the obtained high catalytic activity.Such unique OER-produced self-functionalization surfaces of metal borates afford to greatly reduce the energy barrier of the continuing OER,thereby accelerating the reaction process.
基金supported by the National Natural Science Foundation of China(grant Nos.51872115,52101256)the Project funded by China Postdoctoral Science Foundation(grant No.2020M680043)+1 种基金Science and Technology Research Project of the Department of Educationof JilinProvince(grant No.JKH20211083KJ)2020 INTERNATIONAL COOPERATION Project of the Department of Science and Technology of Jjilin Province(grant No.20200801001GH).
文摘Through inverted-design rather than modifying the generally-assumed S active sites in popular MoS_(2),we unlock the potential of Mo sites and successfully prepared novel MoS_(2)@Ni_(3)S_(2)/NF core-shell nanospheres as a catalyst for the high-performance hydrogen evolution reaction(HER).TheΔGH at the Mo site is optimized via Ni_(3)S_(2)to achieve excellent HER activity.At low current densities,it has similar activity to the Pt/C.However,its performance is better than Pt/C at high density.Moreover,our catalyst shows a considerable stability at a variety of current densities for 50 h,promising to substitute noble metal catalysts in application of commercial alkaline electrocatalysts.