Quantitative studies on the national-scale effects of extreme climatic events on soil organic carbon(SOC)remain scarce,thus limiting our understanding of SOC dynamics.This study utilized 4515 publicly available soil s...Quantitative studies on the national-scale effects of extreme climatic events on soil organic carbon(SOC)remain scarce,thus limiting our understanding of SOC dynamics.This study utilized 4515 publicly available soil samples to quantify the impacts of 19 extreme climatic indices(ECIs)onΔSOC reservoirs in China through a hybrid space-for-time and meta-analysis approach.Overall,16/19 ECIs were negatively correlated withΔSOC,with the minimum temperature of the coldest night(TNn)showing the strongest negative correlation.Notably,topographic factors played a pivotal role in the modeling process,contributing an average of 25%,followed by ECIs.Under the influence of the ECIs,SOC exhibited spatial variation.Extreme heat resulted in the greatest SOC losses in cold regions,such as North China,with average reductions of>5%,whereas its impact was weaker in South China,with SOC losses of∼3%.Extreme cold and wet indices promoted SOC accumulation in the Northeast China,with increases of∼3%,but showed a weaker response in the humid region,where the SOC increased by only 1%.At the national scale,the impacts of extreme climatic events on SOC in the0–20 cm ranged from-2.36 Pg to 2.34 Pg.Different ecosystems responded variably,with forest and grassland ecosystems being more sensitive to ECIs,potentially due to higher organic matter inputs and greater ecosystem complexity.In contrast,bare land exhibited weaker responses due to limited vegetation cover and organic inputs.These findings provide valuable insights into SOC dynamics at national scale during extreme climatic events.展开更多
Single-pixel imaging(SPI)is a prominent scattering media imaging technique that allows image transmission via one-dimensional detection under structured illumination,with applications spanning from long-range imaging ...Single-pixel imaging(SPI)is a prominent scattering media imaging technique that allows image transmission via one-dimensional detection under structured illumination,with applications spanning from long-range imaging to microscopy.Recent advancements leveraging deep learning(DL)have significantly improved SPI performance,especially at low compression ratios.However,most DL-based SPI methods proposed so far rely heavily on extensive labeled datasets for supervised training,which are often impractical in real-world scenarios.Here,we propose an unsupervised learningenabled label-free SPI method for resilient information transmission through unknown dynamic scattering media.Additionally,we introduce a physics-informed autoencoder framework to optimize encoding schemes,further enhancing image quality at low compression ratios.Simulation and experimental results demonstrate that high-efficiency data transmission with structural similarity exceeding 0.9 is achieved through challenging turbulent channels.Moreover,experiments demonstrate that in a 5 m underwater dynamic turbulent channel,USAF target imaging quality surpasses traditional methods by over 13 dB.The compressive encoded transmission of 720×720 resolution video exceeding 30 seconds with great fidelity is also successfully demonstrated.These preliminary results suggest that our proposed method opens up a new paradigm for resilient information transmission through unknown dynamic scattering media and holds potential for broader applications within many other scattering media imaging technologies.展开更多
Aprotic lithium-oxygen batteries possess ultrahigh energy density but suffer from the sluggish decomposition of discharge product,quick depletion of Li anode and cleavage of electrolyte,in close association with oxyge...Aprotic lithium-oxygen batteries possess ultrahigh energy density but suffer from the sluggish decomposition of discharge product,quick depletion of Li anode and cleavage of electrolyte,in close association with oxygen reduction reaction at the cathode.Herein,highly dispersed silver nanoparticles are used to enhance the lithium-oxygen battery with 1.0 M lithium perchlorate in dimethyl sulfoxide.It is observed that film-like amorphous lithium peroxide is formed through surface pathway instead of bulk crystals,due to the incorporation of silver nanoparticles dispersed in the electrolyte,which subsequently accelerates the decomposition of the discharge product by offering more active sites and improved conductivity.The released silver nanoparticles after battery charging can be re-used in the following cycles.Experiments and theoretical calculation further indicate that the suspended silver nanoparticles can adsorb the soluble oxygen reduction intermediates,which are responsible for the alleviation of oxidative cleavage of electrolyte and corrosion of lithium anode.The lifespan of lithium oxygen batteries is therefore significantly extended from 55 to 390 cycles,and the rate performance and full-discharge capacity are also largely enhanced.The battery failure is attributed to the coalescence and growth of silver nanoparticles in the electrolyte,and further improvement on colloid stability is underway.展开更多
Layered sodium trititanate(Na_(2)Ti_(3)O_(7),NTO)is a promising anode material for sodium-ion batteries(NIBs)for large-scale energy storage applications because of its relatively low charge potential and low cost.Howe...Layered sodium trititanate(Na_(2)Ti_(3)O_(7),NTO)is a promising anode material for sodium-ion batteries(NIBs)for large-scale energy storage applications because of its relatively low charge potential and low cost.However,NTO suffers from unsatisfactory structural stability against cycling and poor electron conductivity.Herein,an isovalent doping strategy using Sn^(4+)to partially replace Ti^(4+)is demonstrated for improving the cycling stability and rate capability of NTO.The isovalent doping of Sn^(4+)does not alter the valence state of Ti^(4+),thus maintaining the lattice integrality and structural stability.Moreover,the Sn^(4+)dopant creates more Na^(+)-preferable travel channels and expands the interlayer spacing,thus increasing Na^(+)diffusivity.As a result,a Sn^(4+)-doped Na_(2)Ti_(3)O_7(NSTO)electrode exhibits a reversible Na^(+)storage specific capacity of 176 mA h g^(-1)at 0.1C and an ultra-long cycling life with 80.2%capacity retention after5000 cycles at 1C,far outperforming the undoped and aliovalent-doping NTO electrodes reported in the literature.In addition,the NSTO electrode delivers a rate capability of 102 mA h g^(-1)at 5C,higher than that of the NTO electrode(62 mA h g^(-1)).In situ X-ray diffraction characterization results reveal that Na^(+)storage in NSTO undergoes a partial solid-solution reaction mechanism,which is completely different from the two-phase transition mechanism of NTO.Density functional theory calculation results demonstrate that Sn^(4+)doping strengthens the Ti-O bond,contributing to structural stability.This work provides a robust approach to significantly improving the electrochemical performance of NTO-based anode materials for developing long-life NIBs.展开更多
The next generation of mobile communication is committed to establishing an integrated three-dimensional network that encompasses air,land,and sea.The visible light spectrum is situated within the transmission window ...The next generation of mobile communication is committed to establishing an integrated three-dimensional network that encompasses air,land,and sea.The visible light spectrum is situated within the transmission window for underwater communication,making visible light laser communication a focus of intense research.展开更多
Anatase titanium dioxide(TiO_(2))is a potential anode material for sodium-ion batteries(NIBs).However,the low electronic conductivity and sluggish ion diffusion kinetics at high rate hamper its practical applications....Anatase titanium dioxide(TiO_(2))is a potential anode material for sodium-ion batteries(NIBs).However,the low electronic conductivity and sluggish ion diffusion kinetics at high rate hamper its practical applications.Herein,we demonstrate a sol-gel approach to the synthesis of thermally stable anatase nanoparticles with a carbon shell as anode materials for NIBs.A sample calcined at 750℃(designated as H-750TiO_(2)@C)exhibits high-rate capability and excellent stability against cycling with no capacity loss after 2000 cycles at 1 A g^(-1).In situ X-ray diffraction and Raman spectroscopy characterization results reveal a nearly zero-strain characteristic of the anatase phase during charge/discharge processes.In situ transmission electron microscopy,ex situ X-ray photoelectron spectroscopy,and scanning electron microscope characterization results of samples collected at different charged and discharged states suggest that the anatase phase undergoes an irreversible sodiationactivation during the initial discharge process to form a sodiated-TiO_(2)phase.A full cell assembled with H-750TiO_(2)@C as the anode and Na_(3)V_(2)(PO_(4))_(3)as the cathode delivers an energy density of 220Whkg^(-1),demonstrating H-750TiO_(2)@C is a potential anode material for NIBs.展开更多
基金supported by the Open Project of Technology Innovation Center for Natural Ecosystem Carbon Sink(Grant No.CS2023D02)the Open Research Fund of Key Laboratory of Digital Earth Science,Aerospace Information Research Institute Chinese Academy of Sciences,Chinese Academy of Sciences(Grant No.2022LDE007)+5 种基金the Talent Program“Tianchi Talent(Young Doctor)”in Xinjiang Uygur Autonomous Region,National Natural Science Foundation of China(Grant No.42401065)Guangdong Basic and Applied Basic Research Foundation(Grant No.2023A1515011273)Shenzhen Polytechnic University Research Fund(Grant No.6025310064K)the Innovation Training Program for Undergraduates at the Autonomous Region Level in 2024(Grant No.S202410755009)the Innovation Training Program for Undergraduates at the University Level in 2024(Grant No.XJUSRT-24008)the National Innovation Training Program for College Students in 2024(Grant No.202410755009)。
文摘Quantitative studies on the national-scale effects of extreme climatic events on soil organic carbon(SOC)remain scarce,thus limiting our understanding of SOC dynamics.This study utilized 4515 publicly available soil samples to quantify the impacts of 19 extreme climatic indices(ECIs)onΔSOC reservoirs in China through a hybrid space-for-time and meta-analysis approach.Overall,16/19 ECIs were negatively correlated withΔSOC,with the minimum temperature of the coldest night(TNn)showing the strongest negative correlation.Notably,topographic factors played a pivotal role in the modeling process,contributing an average of 25%,followed by ECIs.Under the influence of the ECIs,SOC exhibited spatial variation.Extreme heat resulted in the greatest SOC losses in cold regions,such as North China,with average reductions of>5%,whereas its impact was weaker in South China,with SOC losses of∼3%.Extreme cold and wet indices promoted SOC accumulation in the Northeast China,with increases of∼3%,but showed a weaker response in the humid region,where the SOC increased by only 1%.At the national scale,the impacts of extreme climatic events on SOC in the0–20 cm ranged from-2.36 Pg to 2.34 Pg.Different ecosystems responded variably,with forest and grassland ecosystems being more sensitive to ECIs,potentially due to higher organic matter inputs and greater ecosystem complexity.In contrast,bare land exhibited weaker responses due to limited vegetation cover and organic inputs.These findings provide valuable insights into SOC dynamics at national scale during extreme climatic events.
基金supported by the Natural Science Foundation of China Project(No.62525102).
文摘Single-pixel imaging(SPI)is a prominent scattering media imaging technique that allows image transmission via one-dimensional detection under structured illumination,with applications spanning from long-range imaging to microscopy.Recent advancements leveraging deep learning(DL)have significantly improved SPI performance,especially at low compression ratios.However,most DL-based SPI methods proposed so far rely heavily on extensive labeled datasets for supervised training,which are often impractical in real-world scenarios.Here,we propose an unsupervised learningenabled label-free SPI method for resilient information transmission through unknown dynamic scattering media.Additionally,we introduce a physics-informed autoencoder framework to optimize encoding schemes,further enhancing image quality at low compression ratios.Simulation and experimental results demonstrate that high-efficiency data transmission with structural similarity exceeding 0.9 is achieved through challenging turbulent channels.Moreover,experiments demonstrate that in a 5 m underwater dynamic turbulent channel,USAF target imaging quality surpasses traditional methods by over 13 dB.The compressive encoded transmission of 720×720 resolution video exceeding 30 seconds with great fidelity is also successfully demonstrated.These preliminary results suggest that our proposed method opens up a new paradigm for resilient information transmission through unknown dynamic scattering media and holds potential for broader applications within many other scattering media imaging technologies.
基金financially supported by the National Natural Science Foundation of China(Nos.51874051 and 21163004)the Natural Science Foundation of Guangxi(No.2018GXNSFAA281184 and 2019GXNSFAA245046)the Bagui Scholar Program of Guangxi Province。
文摘Aprotic lithium-oxygen batteries possess ultrahigh energy density but suffer from the sluggish decomposition of discharge product,quick depletion of Li anode and cleavage of electrolyte,in close association with oxygen reduction reaction at the cathode.Herein,highly dispersed silver nanoparticles are used to enhance the lithium-oxygen battery with 1.0 M lithium perchlorate in dimethyl sulfoxide.It is observed that film-like amorphous lithium peroxide is formed through surface pathway instead of bulk crystals,due to the incorporation of silver nanoparticles dispersed in the electrolyte,which subsequently accelerates the decomposition of the discharge product by offering more active sites and improved conductivity.The released silver nanoparticles after battery charging can be re-used in the following cycles.Experiments and theoretical calculation further indicate that the suspended silver nanoparticles can adsorb the soluble oxygen reduction intermediates,which are responsible for the alleviation of oxidative cleavage of electrolyte and corrosion of lithium anode.The lifespan of lithium oxygen batteries is therefore significantly extended from 55 to 390 cycles,and the rate performance and full-discharge capacity are also largely enhanced.The battery failure is attributed to the coalescence and growth of silver nanoparticles in the electrolyte,and further improvement on colloid stability is underway.
基金supported by the Natural Science Foundation of Shandong Province(ZR2022QB025 and ZR2021QF070)the Start-up Foundation of Qingdao University(DC2000005025)。
文摘Layered sodium trititanate(Na_(2)Ti_(3)O_(7),NTO)is a promising anode material for sodium-ion batteries(NIBs)for large-scale energy storage applications because of its relatively low charge potential and low cost.However,NTO suffers from unsatisfactory structural stability against cycling and poor electron conductivity.Herein,an isovalent doping strategy using Sn^(4+)to partially replace Ti^(4+)is demonstrated for improving the cycling stability and rate capability of NTO.The isovalent doping of Sn^(4+)does not alter the valence state of Ti^(4+),thus maintaining the lattice integrality and structural stability.Moreover,the Sn^(4+)dopant creates more Na^(+)-preferable travel channels and expands the interlayer spacing,thus increasing Na^(+)diffusivity.As a result,a Sn^(4+)-doped Na_(2)Ti_(3)O_7(NSTO)electrode exhibits a reversible Na^(+)storage specific capacity of 176 mA h g^(-1)at 0.1C and an ultra-long cycling life with 80.2%capacity retention after5000 cycles at 1C,far outperforming the undoped and aliovalent-doping NTO electrodes reported in the literature.In addition,the NSTO electrode delivers a rate capability of 102 mA h g^(-1)at 5C,higher than that of the NTO electrode(62 mA h g^(-1)).In situ X-ray diffraction characterization results reveal that Na^(+)storage in NSTO undergoes a partial solid-solution reaction mechanism,which is completely different from the two-phase transition mechanism of NTO.Density functional theory calculation results demonstrate that Sn^(4+)doping strengthens the Ti-O bond,contributing to structural stability.This work provides a robust approach to significantly improving the electrochemical performance of NTO-based anode materials for developing long-life NIBs.
基金National Natural Science Foundation of China(62031011,61925104)National Key Researchand Development Program of China(2022YFB2802803).
文摘The next generation of mobile communication is committed to establishing an integrated three-dimensional network that encompasses air,land,and sea.The visible light spectrum is situated within the transmission window for underwater communication,making visible light laser communication a focus of intense research.
基金This work was supported by the start-up funding of Qingdao University(No.DC2000005025).
文摘Anatase titanium dioxide(TiO_(2))is a potential anode material for sodium-ion batteries(NIBs).However,the low electronic conductivity and sluggish ion diffusion kinetics at high rate hamper its practical applications.Herein,we demonstrate a sol-gel approach to the synthesis of thermally stable anatase nanoparticles with a carbon shell as anode materials for NIBs.A sample calcined at 750℃(designated as H-750TiO_(2)@C)exhibits high-rate capability and excellent stability against cycling with no capacity loss after 2000 cycles at 1 A g^(-1).In situ X-ray diffraction and Raman spectroscopy characterization results reveal a nearly zero-strain characteristic of the anatase phase during charge/discharge processes.In situ transmission electron microscopy,ex situ X-ray photoelectron spectroscopy,and scanning electron microscope characterization results of samples collected at different charged and discharged states suggest that the anatase phase undergoes an irreversible sodiationactivation during the initial discharge process to form a sodiated-TiO_(2)phase.A full cell assembled with H-750TiO_(2)@C as the anode and Na_(3)V_(2)(PO_(4))_(3)as the cathode delivers an energy density of 220Whkg^(-1),demonstrating H-750TiO_(2)@C is a potential anode material for NIBs.
