The effect of delay time on photoelectron spectra and state populations of a four-level ladder K2 molecule is investigated by a pump1–pump2–probe pulse via the time-dependent wave packet approach. The periodical mot...The effect of delay time on photoelectron spectra and state populations of a four-level ladder K2 molecule is investigated by a pump1–pump2–probe pulse via the time-dependent wave packet approach. The periodical motion of the wave packet leads to the periodical change of the photoelectron spectra. The Autler–Townes triple splitting appears at zero delay time, double splitting appears at nonzero delay time between pump1 and pump2 pulses, and no splitting appears at nonzero delay time between pump2 and probe pulses. The periodical change of the state populations with the delay time may be due to the coupling effect between the two pulses. It is found that the selectivity of the state populations may be attained by regulating the delay time. The results can provide an important basis for realizing the optical control of molecules experimentally.展开更多
Functional traits play a vital role in mediating the responses of ecosystem services to environmental changes and in predicting the functioning of the ecosystem.However,the connection between functional traits and eco...Functional traits play a vital role in mediating the responses of ecosystem services to environmental changes and in predicting the functioning of the ecosystem.However,the connection between functional traits and ecosystem services has become increasingly intricate due to climate change and human activities for degraded ecosystems.To investigate this relationship,we selected 27 sampling sites in the Yanhe River Basin of the Chinese Loess Plateau,each containing two types of vegetation ecosystems:natural vegetation and artificial vegetation ecosystems.At each sampling site,we measured ecosystem services and calculated the composition index of community traits.We established a response–effect trait framework that included environmental factors such as climate,elevation and human activities.Our results showed that leaf tissue density(LTD)was the overlapping response and effect trait when responding to climate change.LTD is positively correlated with mean annual temperature and negatively correlated with supporting services.Under the influence of human activities,leaf nitrogen content and leaf dry matter content were carriers of environmental change.Comparing the two vegetation ecosystems,the relationship between functional traits and ecosystem services showed divergent patterns,indicating that human activities increased the uncertainty of the relationship between functional traits and ecosystem services.Trait-based ecology holds promise for enhancing predictions of ecosystem services responses to environmental changes.However,the predictive ability is influenced by the complexity of environmental changes.In conclusion,our study highlights the importance of understanding the complex connection between functional traits and ecosystem services in response to climate changes and human activities.展开更多
Metal halide perovskites are attractive for light-emitting diodes due to their superior optoelectronic properties such as tunable bandgaps,high photoluminescence quantum yields(PLQYs),high color purities and solution ...Metal halide perovskites are attractive for light-emitting diodes due to their superior optoelectronic properties such as tunable bandgaps,high photoluminescence quantum yields(PLQYs),high color purities and solution processability[1–6].In the past several years,impressive progress has been made in perovskite light-emitting diodes(PeLEDs)via microstructure engineering[7],charge balancing[8],surface defect passivation[9,10],metal ion doping[11,12]and dimensional engineering[13].As such,the green,red and near-infrared PeLEDs have achieved impressive external quantum efficiencies(EQEs)exceeding 20%[7,8,14,15].However,the performances of pure-blue PeLEDs,i.e.,brightness and EQEs,still lag largely behind those of the green and red counterparts,which severely impedes the PeLED application in full-color display and solid-state lighting.展开更多
Li Mn_(2)O_(4)(LMO)is the substance of choice for small and medium-sized energy storage materials in daily life.In this work,Li3InCl6(LIC)is prepared on the surface of LiMn_(2)O_(4)by hydrothermal method using InCl_(3...Li Mn_(2)O_(4)(LMO)is the substance of choice for small and medium-sized energy storage materials in daily life.In this work,Li3InCl6(LIC)is prepared on the surface of LiMn_(2)O_(4)by hydrothermal method using InCl_(3)and LiCl as raw materials.This method stabilizes the LMO crystal structure by uniformly coating the LIC on the LMO surface and effectively maintains the morphology of LMO crystals during the cycling process.SEM and EDS analysis confirm the morphology and homogeneity of the synthesized material LIC on the LMO surface.The prepared material is put into a battery,and the charge-discharge test is carried out at 0.5 C and 1 C.The results show that the LIC surface-modified samples exhibit more than 6%higher cycling performance than the unmodified samples after long cycling.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11704178 and 11764041)the Scientific Research Fund of Hunan Provincial Education Department,China(Grant No.15B204)
文摘The effect of delay time on photoelectron spectra and state populations of a four-level ladder K2 molecule is investigated by a pump1–pump2–probe pulse via the time-dependent wave packet approach. The periodical motion of the wave packet leads to the periodical change of the photoelectron spectra. The Autler–Townes triple splitting appears at zero delay time, double splitting appears at nonzero delay time between pump1 and pump2 pulses, and no splitting appears at nonzero delay time between pump2 and probe pulses. The periodical change of the state populations with the delay time may be due to the coupling effect between the two pulses. It is found that the selectivity of the state populations may be attained by regulating the delay time. The results can provide an important basis for realizing the optical control of molecules experimentally.
基金supported by the CAS‘light of West China’program(XAB2020YN04)and the Natural Science Foundation of China(41977077 and 41671289).
文摘Functional traits play a vital role in mediating the responses of ecosystem services to environmental changes and in predicting the functioning of the ecosystem.However,the connection between functional traits and ecosystem services has become increasingly intricate due to climate change and human activities for degraded ecosystems.To investigate this relationship,we selected 27 sampling sites in the Yanhe River Basin of the Chinese Loess Plateau,each containing two types of vegetation ecosystems:natural vegetation and artificial vegetation ecosystems.At each sampling site,we measured ecosystem services and calculated the composition index of community traits.We established a response–effect trait framework that included environmental factors such as climate,elevation and human activities.Our results showed that leaf tissue density(LTD)was the overlapping response and effect trait when responding to climate change.LTD is positively correlated with mean annual temperature and negatively correlated with supporting services.Under the influence of human activities,leaf nitrogen content and leaf dry matter content were carriers of environmental change.Comparing the two vegetation ecosystems,the relationship between functional traits and ecosystem services showed divergent patterns,indicating that human activities increased the uncertainty of the relationship between functional traits and ecosystem services.Trait-based ecology holds promise for enhancing predictions of ecosystem services responses to environmental changes.However,the predictive ability is influenced by the complexity of environmental changes.In conclusion,our study highlights the importance of understanding the complex connection between functional traits and ecosystem services in response to climate changes and human activities.
基金We acknowledge the financial support from the National Natural Science Foundation of China(51571184,21501165,21875236,21573211,21633007)the National Key R&D Program on Nano Science and Technology(2016YFA0200602,2018YFA0208702)+3 种基金the Fundamental Research Funds for the Central Universities(WK2060190085)the Joint Funds from Hefei National Synchrotron Radiation Laboratory(KY2060000111)the Anhui Initiative in Quantum Information Technologies(AHY090200)We also thank the support from the USTC Center for Micro and Nanoscale Research and Fabrication.
文摘Metal halide perovskites are attractive for light-emitting diodes due to their superior optoelectronic properties such as tunable bandgaps,high photoluminescence quantum yields(PLQYs),high color purities and solution processability[1–6].In the past several years,impressive progress has been made in perovskite light-emitting diodes(PeLEDs)via microstructure engineering[7],charge balancing[8],surface defect passivation[9,10],metal ion doping[11,12]and dimensional engineering[13].As such,the green,red and near-infrared PeLEDs have achieved impressive external quantum efficiencies(EQEs)exceeding 20%[7,8,14,15].However,the performances of pure-blue PeLEDs,i.e.,brightness and EQEs,still lag largely behind those of the green and red counterparts,which severely impedes the PeLED application in full-color display and solid-state lighting.
基金supported by Guangxi Higher Education Key Laboratory of Advanced MaterialsCenter of Ecological Collaborative Innovation for Aluminum Industry in Guangxi+4 种基金CITIC Dameng Mining Industries Limited-Guangxi University Joint Research Institute of Manganese Resources Utilization and Advanced Materials TechnologyGuangxi University-CITIC Dameng Mining Industries Limited Joint Base of Postgraduate CultivationNational Natural Science Foundation of China(No.11364003)Guangxi Innovation Driven Development Project(Nos.AA17204100,AA18118052)the Natural Science Foundation of Guangxi Province(No.2018GXNSFAA138186)。
文摘Li Mn_(2)O_(4)(LMO)is the substance of choice for small and medium-sized energy storage materials in daily life.In this work,Li3InCl6(LIC)is prepared on the surface of LiMn_(2)O_(4)by hydrothermal method using InCl_(3)and LiCl as raw materials.This method stabilizes the LMO crystal structure by uniformly coating the LIC on the LMO surface and effectively maintains the morphology of LMO crystals during the cycling process.SEM and EDS analysis confirm the morphology and homogeneity of the synthesized material LIC on the LMO surface.The prepared material is put into a battery,and the charge-discharge test is carried out at 0.5 C and 1 C.The results show that the LIC surface-modified samples exhibit more than 6%higher cycling performance than the unmodified samples after long cycling.
