For regional ecological management,it is important to evaluate the quality of ecosystems and analyze the underlying causes of ecological changes.Using the Google Earth Engine(GEE)platform,the remote sensing ecological...For regional ecological management,it is important to evaluate the quality of ecosystems and analyze the underlying causes of ecological changes.Using the Google Earth Engine(GEE)platform,the remote sensing ecological index(RSEI)was calculated for the Lijiang River Basin in Guangxi Zhuang Autonomous Region for 1991,2001,2011,and 2021.Spatial autocorrelation analysis was employed to investigate spatiotemporal variations in the ecological environmental quality of the Lijiang River Basin.Furthermore,geographic detectors were used to quantitatively analyze influencing factors and their interaction effects on ecological environmental quality.The results verified that:1)From 1991 to 2021,the ecological environmental quality of the Lijiang River Basin demonstrated significant improvement.The area with good and excellent ecological environmental quality in proportion increased by 19.69%(3406.57 km^(2)),while the area with fair and poor ecological environmental quality in proportion decreased by 10.76%(1860.36 km^(2)).2)Spatially,the ecological environmental quality of the Lijiang River Basin exhibited a pattern of low quality in the central region and high quality in the periphery.Specifically,poor ecological environmental quality characterized the Guilin urban area,Pingle County,and Lingchuan County.3)From 1991 to 2021,a significant positive spatial correlation was observed in ecological environmental quality of the Lijiang River Basin.Areas with high-high agglomeration were predominantly forests and grasslands,indicating good ecological environmental quality,whereas areas with low-low agglomeration were dominated by cultivated land and construction land,indicating poor ecological environmental quality.4)Annual average precipitation and temperature exerted the most significant influence on the ecological environmental quality of the basin,and their interactions with other factors had the great influence.This study aimed to enhance understanding of the evolution of the ecological environment in the Lijiang River Basin of Guangxi Zhuang Autonomous Region and provide scientific guidance for decision-making and management related to ecology in the region.展开更多
Nuclear single-proton resonances are sensitive to the Coulomb field,while the exchange term of Coulomb field is usually neglected due to its nonlocality.By combining the complex scaling method with the relativistic me...Nuclear single-proton resonances are sensitive to the Coulomb field,while the exchange term of Coulomb field is usually neglected due to its nonlocality.By combining the complex scaling method with the relativistic mean-field model,the influence of the Coulomb exchange term on the single-proton resonances is investigated by taking Sn isotopes and N=82 isotones as examples.It is found that the Coulomb exchange term reduces the singleproton resonance energy within the range of 0.4-0.6 MeV and leads to similar isotopic and isotonic trends of the resonance energy as those without the Coulomb exchange term.Moreover,the single-proton resonance width is also reduced by the Coulomb exchange term,whose influence generally decreases with the increasing neutron number and increases with the increasing proton number.However,the influence of the Coulomb exchange term cannot change the trend of the resonance width with respect to the neutron number and proton number.Furthermore,the influence of the Coulomb exchange term on the resonance width is investigated for the doubly magic nuclei ^(40)Ca,^(56,78)Ni,^(100,132)Sn,and ^(208)Pb.It is found that the Coulomb exchange term reduces the proton resonance width within 0.2 MeV,whose magnitude depends on the specific nucleus and the quantum numbers of resonant states.展开更多
In this paper,by considering the electrons in different external environments,including neutral atoms,a metal,and an extremely strong magnetic-field environment,the screened a-decay half-lives of the a emitters with p...In this paper,by considering the electrons in different external environments,including neutral atoms,a metal,and an extremely strong magnetic-field environment,the screened a-decay half-lives of the a emitters with proton number Z = 52–105 are systematically calculated.In the external environment,the decay energy and the interaction potential between a particle and daughter nucleus are both changed due to the electron screening effect and their variations are both very important for the electron screening effect.Besides,the electron screening effect is found to be closely related to the decay energy and its proton number.展开更多
基金supported by the Guangxi Natural Science Foundation(2020GXNSFAA297266)Doctoral Research Foundation of Guilin University of Technology(GUTQDJJ2007059)Guangxi Hidden Metallic Mineral Exploration Key Laboratory。
文摘For regional ecological management,it is important to evaluate the quality of ecosystems and analyze the underlying causes of ecological changes.Using the Google Earth Engine(GEE)platform,the remote sensing ecological index(RSEI)was calculated for the Lijiang River Basin in Guangxi Zhuang Autonomous Region for 1991,2001,2011,and 2021.Spatial autocorrelation analysis was employed to investigate spatiotemporal variations in the ecological environmental quality of the Lijiang River Basin.Furthermore,geographic detectors were used to quantitatively analyze influencing factors and their interaction effects on ecological environmental quality.The results verified that:1)From 1991 to 2021,the ecological environmental quality of the Lijiang River Basin demonstrated significant improvement.The area with good and excellent ecological environmental quality in proportion increased by 19.69%(3406.57 km^(2)),while the area with fair and poor ecological environmental quality in proportion decreased by 10.76%(1860.36 km^(2)).2)Spatially,the ecological environmental quality of the Lijiang River Basin exhibited a pattern of low quality in the central region and high quality in the periphery.Specifically,poor ecological environmental quality characterized the Guilin urban area,Pingle County,and Lingchuan County.3)From 1991 to 2021,a significant positive spatial correlation was observed in ecological environmental quality of the Lijiang River Basin.Areas with high-high agglomeration were predominantly forests and grasslands,indicating good ecological environmental quality,whereas areas with low-low agglomeration were dominated by cultivated land and construction land,indicating poor ecological environmental quality.4)Annual average precipitation and temperature exerted the most significant influence on the ecological environmental quality of the basin,and their interactions with other factors had the great influence.This study aimed to enhance understanding of the evolution of the ecological environment in the Lijiang River Basin of Guangxi Zhuang Autonomous Region and provide scientific guidance for decision-making and management related to ecology in the region.
基金partly supported by the National Natural Science Foundation of China(No.11205004)the Key Research Foundation of Education Ministry of Anhui Province of China(No.KJ2016A026)
文摘Nuclear single-proton resonances are sensitive to the Coulomb field,while the exchange term of Coulomb field is usually neglected due to its nonlocality.By combining the complex scaling method with the relativistic mean-field model,the influence of the Coulomb exchange term on the single-proton resonances is investigated by taking Sn isotopes and N=82 isotones as examples.It is found that the Coulomb exchange term reduces the singleproton resonance energy within the range of 0.4-0.6 MeV and leads to similar isotopic and isotonic trends of the resonance energy as those without the Coulomb exchange term.Moreover,the single-proton resonance width is also reduced by the Coulomb exchange term,whose influence generally decreases with the increasing neutron number and increases with the increasing proton number.However,the influence of the Coulomb exchange term cannot change the trend of the resonance width with respect to the neutron number and proton number.Furthermore,the influence of the Coulomb exchange term on the resonance width is investigated for the doubly magic nuclei ^(40)Ca,^(56,78)Ni,^(100,132)Sn,and ^(208)Pb.It is found that the Coulomb exchange term reduces the proton resonance width within 0.2 MeV,whose magnitude depends on the specific nucleus and the quantum numbers of resonant states.
基金supported by the National Natural Science Foundation of China(Nos.11175085,11235001,11375086,and 11120101005)by the 973 Program of China(No.2013CB834400)+1 种基金by the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)by the Open Project Program of the State Key Laboratory of Theoretical Physics,Institute of Theoretical Physics,Chinese Academy of Sciences,China(No.Y5KF141CJ1)
文摘In this paper,by considering the electrons in different external environments,including neutral atoms,a metal,and an extremely strong magnetic-field environment,the screened a-decay half-lives of the a emitters with proton number Z = 52–105 are systematically calculated.In the external environment,the decay energy and the interaction potential between a particle and daughter nucleus are both changed due to the electron screening effect and their variations are both very important for the electron screening effect.Besides,the electron screening effect is found to be closely related to the decay energy and its proton number.
