Traditional Pt/C electrode materials are prone to corrosion and detachment during H_(2)S detection,leading to a decrease in fuel cell-type sensor performance.Here,a high-performance H_(2)S sensor based on Pt loaded Ti...Traditional Pt/C electrode materials are prone to corrosion and detachment during H_(2)S detection,leading to a decrease in fuel cell-type sensor performance.Here,a high-performance H_(2)S sensor based on Pt loaded Ti_(3)C_(2)electrode material with-O/-OH terminal groups was designed and prepared.Experimental tests showed that the Pt/Ti_(3)C_(2)sensor has good sensitivity(0.162μA/ppm)and a very low detection limit to H_(2)S(10 ppb).After 90 days of stability testing,the response of the Pt/Ti_(3)C_(2)sensor shows a smaller decrease of 2%compared to that of the Pt/C sensor(22.9%).Meanwhile,the sensor also has high selectivity and repeatability.The density functional theory(DFT)calculation combined with the experiment results revealed that the improved H_(2)S sensing mechanism is attributed to the fact that the strong interaction between Pt and Ti_(3)C_(2)via the Pt-O-Ti bonding can reduce the formation energy of Pt and Ti_(3)C_(2),ultimately prolonging the sensor’s service life.Furthermore,the catalytic property of Pt can decrease the adsorption energy and dissociation barrier of H_(2)S on Pt/Ti_(3)C_(2)surface,greatly enhance the ability to generate protons and effectively transfer charges,realizing good sensitivity and high selectivity of the sensor.The sensor works at room temperature,making it very promising in the field of H_(2)S detection in future.展开更多
Flexible deep brain neural interfaces,as an important research direction in the field of neural engineering,have broad application prospects in areas such as neural signal detection,treatment of neurological diseases,...Flexible deep brain neural interfaces,as an important research direction in the field of neural engineering,have broad application prospects in areas such as neural signal detection,treatment of neurological diseases,and intelligent control systems.However,chronic inflammatory responses caused by longterm implantation and the resulting electrode failure seriously hinder the clinical development of this technology.This review systematically explores the long-term stability issues of flexible deep brain neural interfaces,with a focus on analyzing the synergistic optimization of electrode geometric morphology and implantation strategies in regulating inflammatory responses.Additionally,this paper delves into innovative strategies,such as passive enhancement of biocompatibility through electrode surface functionalization and active inhibition of inflammation through drug-controlled release systems,offering new technical paths to extend electrode lifespan.By integrating and reviewing existing innovative methods for deep brain flexible electrodes,this study provides an important theoretical foundation and technical guidance for the development of high-stability neural interface devices.展开更多
Long-term stability of large span caverns is earnest but poorly understood in preservation of cultural relics.The life span of huge caverns is difficult to extrapolate from short period of monitoring or laboratory tes...Long-term stability of large span caverns is earnest but poorly understood in preservation of cultural relics.The life span of huge caverns is difficult to extrapolate from short period of monitoring or laboratory testing.A huge ancient quarry with 21 caverns whose original status is well kept over 1400 years was found in Tiantai County of South China.One of the caverns has an 81 m span which is far beyond the 50 m expectation on current knowledge.The tension at the core of long stability is the excavation speed versus deliberation.Here we show a unique technique of Digging Holes for Quarrying Vertical Flagstone(DQF)invented by ancestors to ensure the safety,which is much smarter compared to blasting and casting technique that commonly used after the Industrial Revolution.展开更多
Seawater electrolysis is promising for green hydrogen production, while its application is inhibited by sluggish anodic oxygen evolution reaction (OER) and rapid chloride corrosion‐induced electrode deactivation. Her...Seawater electrolysis is promising for green hydrogen production, while its application is inhibited by sluggish anodic oxygen evolution reaction (OER) and rapid chloride corrosion‐induced electrode deactivation. Herein, we report a conductive and ion‐ selective OER electrocatalyst with a CoFe alloy core and microporous metal‐doped carbon shell. Co/Fe‐N_(4)‐C active sites in the shell optimize the adsorption strength of intermediates and synergize with the metal core to endow the catalyst with high OER activity and selectivity, while the rich ultra‐micropores in the shell demonstrate a significant sieving effect to hinder Cl− transfer, thus protecting the inner Co/Fe‐N_(4)‐C active sites and metal core from Cl− corrosion. The catalyst is assembled in an alkaline seawater electrolyzer with an electrode geometric area of 254 cm^(2) and delivers a current density of 3000 A m^(-2) at 1.85 V for 330 h. Such catalysts can be synthesized in a large batch (100 g), providing sound opportunities for industrial seawater splitting.展开更多
There is an urgent need to develop optimal solutions for deformation control of deep high‐stress roadways,one of the critical problems in underground engineering.The previously proposed four‐dimensional support(here...There is an urgent need to develop optimal solutions for deformation control of deep high‐stress roadways,one of the critical problems in underground engineering.The previously proposed four‐dimensional support(hereinafter 4D support),as a new support technology,can set the roadway surrounding rock under three‐dimensional pressure in the new balanced structure,and prevent instability of surrounding rock in underground engineering.However,the influence of roadway depth and creep deformation on the surrounding rock supported by 4D support is still unknown.This study investigated the influence of roadway depth and creep deformation time on the instability of surrounding rock by analyzing the energy development.The elastic strain energy was analyzed using the program redeveloped in FLAC3D.The numerical simulation results indicate that the combined support mode of 4D roof supports and conventional side supports is highly applicable to the stability control of surrounding rock with a roadway depth exceeding 520 m.With the increase of roadway depth,4D support can effectively restrain the area and depth of plastic deformation in the surrounding rock.Further,4D support limits the accumulation range and rate of elastic strain energy as the creep deformation time increases.4D support can effectively reduce the plastic deformation of roadway surrounding rock and maintain the stability for a long deformation period of 6 months.As confirmed by in situ monitoring results,4D support is more effective for the long‐term stability control of surrounding rock than conventional support.展开更多
The Xi-Modi meeting in August marked a pragmatic step toward normalizing bilateral relations,though analysts caution that long-term stability will require a more sustained strategic approach.
Photon-counting dual-comb spectroscopy(DCS)opens new possibilities for deploying DCS in scenarios previously constrained by limited detection sensitivity.However,inevitable optical path fluctuations hinder its practic...Photon-counting dual-comb spectroscopy(DCS)opens new possibilities for deploying DCS in scenarios previously constrained by limited detection sensitivity.However,inevitable optical path fluctuations hinder its practical implementation.Here,we propose a method to ensure the long-term stability of photon-counting DCS,overcoming turbulent optical paths,achieving attowatt-level detection sensitivity and quick acquisition times.Using a compact allfiber dual-comb system,we achieve 20 nm broadband DCS of H^(13)C^(14)N across the C-band with an average detected power of only 4 attowatts per-comb line.Despite significant vibrations throughout measurements,the spectra maintain comb-line resolution and shot-noise-limited signal-to-noise ratios.Additionally,the system demonstrates successful deployment in open-path measurements,overcoming 93 dB attenuation.Our approach enables remote sensing of CO_(2),H_(2)O,and HDO over a continuous 20-h observation period.This method highlights the potential for applications in fields such as metrology,quantum physics,and atmospheric sensing,especially in turbulent environments like open air or water,within a field-deployable system.展开更多
All-inorganic cesium lead halide based perovskite nanocrystals(PNCs)exhibit promising optoelectronic properties,but their poor stability and anion exchange reaction limit their broad commercial applications.Herein,we ...All-inorganic cesium lead halide based perovskite nanocrystals(PNCs)exhibit promising optoelectronic properties,but their poor stability and anion exchange reaction limit their broad commercial applications.Herein,we demonstrated the successful synthesis of blue-green-red emitting CsPbX_(3)(X=Cl/Br,Br,and Br/I)PNCs via hot injection method,followed by silica-coating and embedding in poly(methylmethacrylate)(PMMA)matrix.The photoluminescence(PL)spectra of SiO_(2)/PMMA-coated PNCs can be tuned continuously by regulating precursor composition ratio,from blue(CsPb(Cl_(0.5)/Br_(0.5))_(3);460 nm)to red(CsPb(Br_(0.4)/I_(0.6))_(3)via green(CsPbBr_(3);519 nm).The PNCs composite films exhibit improved stability(thermal-,moisture-,and photo-stability)because of the barrier formed by Si0_(2)/PMMA coating and also displayed exceptional photoluminescent quantum yield(PLQY of blue,green,and red-emitting Si0_(2)/PMMA coated PNCs are 37%,86%,and 71%,respectively)with longer lifetimes inhibiting anion exchange.Eventually,the PNCs-encapsulated Si0_(2)/PMMA composite films were integrated into the UV LED chip as down-converting materials to construct a prototype white-peLED unit.The designed white-peLED unit demonstrated bright white light generating CIE coordinates(0.349,0.350),a luminous efficiency(LE)of 39.2%and a color rendering index(CRI)of 84.7.The wide color gamut of 121.47%of NTSC and 98.56%of Rec.2020 is also achieved with the built w-LED system.Therefore,the results demonstrated that CsPbX_(3)(X=Cl/Br,Br,and Br/I)PNCs@SiO_(2)/PMMA composite films can be employed as efficient UV to visible color conversion materials for white-LEDs and backlighting.展开更多
Benefiting from the high capacity of Zn metal anodes and intrinsic safety of aqueous electrolytes,rechargeable Zn ion batteries(ZIBs)show promising application in the post‐lithium‐ion period,exhibiting good safety,l...Benefiting from the high capacity of Zn metal anodes and intrinsic safety of aqueous electrolytes,rechargeable Zn ion batteries(ZIBs)show promising application in the post‐lithium‐ion period,exhibiting good safety,low cost,and high energy density.However,its commercialization still faces problems with low Coulombic efficiency and unsatisfied cycling performance due to the poor Zn/Zn2+reversibility that occurred on the Zn anode.To improve the stability of the Zn anode,optimizing the Zn deposition behavior is an efficient way,which can enhance the subsequent striping efficiency and limit the dendrite growth.The Zn deposition is a controlled kinetics‐diffusion joint process that is affected by various factors,such as the interaction between Zn2+ions and Zn anodes,ion concentration gradient,and current distribution.In this review,from an electrochemical perspective,we first overview the factors affecting the Zn deposition behavior and summarize the modification principles.Subsequently,strategies proposed for interfacial modification and 3D structural design as well as the corresponding mechanisms are summarized.Finally,the existing challenges,perspectives on further development direction,and outlook for practical applications of ZIBs are proposed.展开更多
基金the National Key R&D Program of China(No.2023YFB3210102).
文摘Traditional Pt/C electrode materials are prone to corrosion and detachment during H_(2)S detection,leading to a decrease in fuel cell-type sensor performance.Here,a high-performance H_(2)S sensor based on Pt loaded Ti_(3)C_(2)electrode material with-O/-OH terminal groups was designed and prepared.Experimental tests showed that the Pt/Ti_(3)C_(2)sensor has good sensitivity(0.162μA/ppm)and a very low detection limit to H_(2)S(10 ppb).After 90 days of stability testing,the response of the Pt/Ti_(3)C_(2)sensor shows a smaller decrease of 2%compared to that of the Pt/C sensor(22.9%).Meanwhile,the sensor also has high selectivity and repeatability.The density functional theory(DFT)calculation combined with the experiment results revealed that the improved H_(2)S sensing mechanism is attributed to the fact that the strong interaction between Pt and Ti_(3)C_(2)via the Pt-O-Ti bonding can reduce the formation energy of Pt and Ti_(3)C_(2),ultimately prolonging the sensor’s service life.Furthermore,the catalytic property of Pt can decrease the adsorption energy and dissociation barrier of H_(2)S on Pt/Ti_(3)C_(2)surface,greatly enhance the ability to generate protons and effectively transfer charges,realizing good sensitivity and high selectivity of the sensor.The sensor works at room temperature,making it very promising in the field of H_(2)S detection in future.
基金supported by the National Key Research and Development Program of China(2022YFC2402501,2022YFB3205602)the National Natural Science Foundation of China(Nos.62121003,T2293730,T2293731,62333020,62171434,and 62471291)+3 种基金the Major Program of Scientific and Technical Innovation 2030(2021ZD02016030)the Joint Foundation Program of the Chinese Academy of Sciences(No.8091A170201)the Scientific Instrument Developing Project of the Chinese Academy of Sciences(No.PTYQ2024BJ0009)the National Natural Science Foundation of Beijing(F252069)。
文摘Flexible deep brain neural interfaces,as an important research direction in the field of neural engineering,have broad application prospects in areas such as neural signal detection,treatment of neurological diseases,and intelligent control systems.However,chronic inflammatory responses caused by longterm implantation and the resulting electrode failure seriously hinder the clinical development of this technology.This review systematically explores the long-term stability issues of flexible deep brain neural interfaces,with a focus on analyzing the synergistic optimization of electrode geometric morphology and implantation strategies in regulating inflammatory responses.Additionally,this paper delves into innovative strategies,such as passive enhancement of biocompatibility through electrode surface functionalization and active inhibition of inflammation through drug-controlled release systems,offering new technical paths to extend electrode lifespan.By integrating and reviewing existing innovative methods for deep brain flexible electrodes,this study provides an important theoretical foundation and technical guidance for the development of high-stability neural interface devices.
基金support by the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(SKLGP2011K007)Chengdu University of Technology,the Key Research Program of the Chinese Academy of Sciences(KZZD-EW-05-02)+2 种基金by the National Natural Science Foundation of China(NSFC)(Nos.40972198,41172269)support is also from the Chinese Special Funds for Major State Basic Research Project under Grant No.2010CB732001Help provided by Master Chang Shen,Long Fu of Heidong CiEn Temple,and Mr.He Wantong during field investigations is thankfully acknowledged.
文摘Long-term stability of large span caverns is earnest but poorly understood in preservation of cultural relics.The life span of huge caverns is difficult to extrapolate from short period of monitoring or laboratory testing.A huge ancient quarry with 21 caverns whose original status is well kept over 1400 years was found in Tiantai County of South China.One of the caverns has an 81 m span which is far beyond the 50 m expectation on current knowledge.The tension at the core of long stability is the excavation speed versus deliberation.Here we show a unique technique of Digging Holes for Quarrying Vertical Flagstone(DQF)invented by ancestors to ensure the safety,which is much smarter compared to blasting and casting technique that commonly used after the Industrial Revolution.
基金Funding provided by the National Key R&D Program of China(Grant No.2021YFB3801301)National Natural Science Foundation of China(Grant Nos.22378119,22075076,and 22208092)the Key R&D Plan for Science and Technology in Huai'an City(Industrial Category,HAG202301).
文摘Seawater electrolysis is promising for green hydrogen production, while its application is inhibited by sluggish anodic oxygen evolution reaction (OER) and rapid chloride corrosion‐induced electrode deactivation. Herein, we report a conductive and ion‐ selective OER electrocatalyst with a CoFe alloy core and microporous metal‐doped carbon shell. Co/Fe‐N_(4)‐C active sites in the shell optimize the adsorption strength of intermediates and synergize with the metal core to endow the catalyst with high OER activity and selectivity, while the rich ultra‐micropores in the shell demonstrate a significant sieving effect to hinder Cl− transfer, thus protecting the inner Co/Fe‐N_(4)‐C active sites and metal core from Cl− corrosion. The catalyst is assembled in an alkaline seawater electrolyzer with an electrode geometric area of 254 cm^(2) and delivers a current density of 3000 A m^(-2) at 1.85 V for 330 h. Such catalysts can be synthesized in a large batch (100 g), providing sound opportunities for industrial seawater splitting.
基金support from the National Key Research and Development Program of China(Nos.2023YFC2907300 and 2019YFE0118500)the National Natural Science Foundation of China(Nos.U22A20598 and 52104107)the Natural Science Foundation of Jiangsu Province(No.BK20200634).
文摘There is an urgent need to develop optimal solutions for deformation control of deep high‐stress roadways,one of the critical problems in underground engineering.The previously proposed four‐dimensional support(hereinafter 4D support),as a new support technology,can set the roadway surrounding rock under three‐dimensional pressure in the new balanced structure,and prevent instability of surrounding rock in underground engineering.However,the influence of roadway depth and creep deformation on the surrounding rock supported by 4D support is still unknown.This study investigated the influence of roadway depth and creep deformation time on the instability of surrounding rock by analyzing the energy development.The elastic strain energy was analyzed using the program redeveloped in FLAC3D.The numerical simulation results indicate that the combined support mode of 4D roof supports and conventional side supports is highly applicable to the stability control of surrounding rock with a roadway depth exceeding 520 m.With the increase of roadway depth,4D support can effectively restrain the area and depth of plastic deformation in the surrounding rock.Further,4D support limits the accumulation range and rate of elastic strain energy as the creep deformation time increases.4D support can effectively reduce the plastic deformation of roadway surrounding rock and maintain the stability for a long deformation period of 6 months.As confirmed by in situ monitoring results,4D support is more effective for the long‐term stability control of surrounding rock than conventional support.
文摘The Xi-Modi meeting in August marked a pragmatic step toward normalizing bilateral relations,though analysts caution that long-term stability will require a more sustained strategic approach.
基金supported by the National Natural Science Foundation of China(42125402,42188101)the B-type Strategic Priority Program of CAS Grant No.XDB 0780000,the National Natural Science Foundation of China(42304165,52122003,42374185,92476112)+1 种基金Innovation Program for Quantum Science and Technology(2021ZD0300300)the New Cornerstone Science Foundation through the XPLORER PRIZE,the National Key R&D Program of China(2023YFC3081100).
文摘Photon-counting dual-comb spectroscopy(DCS)opens new possibilities for deploying DCS in scenarios previously constrained by limited detection sensitivity.However,inevitable optical path fluctuations hinder its practical implementation.Here,we propose a method to ensure the long-term stability of photon-counting DCS,overcoming turbulent optical paths,achieving attowatt-level detection sensitivity and quick acquisition times.Using a compact allfiber dual-comb system,we achieve 20 nm broadband DCS of H^(13)C^(14)N across the C-band with an average detected power of only 4 attowatts per-comb line.Despite significant vibrations throughout measurements,the spectra maintain comb-line resolution and shot-noise-limited signal-to-noise ratios.Additionally,the system demonstrates successful deployment in open-path measurements,overcoming 93 dB attenuation.Our approach enables remote sensing of CO_(2),H_(2)O,and HDO over a continuous 20-h observation period.This method highlights the potential for applications in fields such as metrology,quantum physics,and atmospheric sensing,especially in turbulent environments like open air or water,within a field-deployable system.
基金the Space Core Technology Development Program(No.2017M1A3A3A02016782).
文摘All-inorganic cesium lead halide based perovskite nanocrystals(PNCs)exhibit promising optoelectronic properties,but their poor stability and anion exchange reaction limit their broad commercial applications.Herein,we demonstrated the successful synthesis of blue-green-red emitting CsPbX_(3)(X=Cl/Br,Br,and Br/I)PNCs via hot injection method,followed by silica-coating and embedding in poly(methylmethacrylate)(PMMA)matrix.The photoluminescence(PL)spectra of SiO_(2)/PMMA-coated PNCs can be tuned continuously by regulating precursor composition ratio,from blue(CsPb(Cl_(0.5)/Br_(0.5))_(3);460 nm)to red(CsPb(Br_(0.4)/I_(0.6))_(3)via green(CsPbBr_(3);519 nm).The PNCs composite films exhibit improved stability(thermal-,moisture-,and photo-stability)because of the barrier formed by Si0_(2)/PMMA coating and also displayed exceptional photoluminescent quantum yield(PLQY of blue,green,and red-emitting Si0_(2)/PMMA coated PNCs are 37%,86%,and 71%,respectively)with longer lifetimes inhibiting anion exchange.Eventually,the PNCs-encapsulated Si0_(2)/PMMA composite films were integrated into the UV LED chip as down-converting materials to construct a prototype white-peLED unit.The designed white-peLED unit demonstrated bright white light generating CIE coordinates(0.349,0.350),a luminous efficiency(LE)of 39.2%and a color rendering index(CRI)of 84.7.The wide color gamut of 121.47%of NTSC and 98.56%of Rec.2020 is also achieved with the built w-LED system.Therefore,the results demonstrated that CsPbX_(3)(X=Cl/Br,Br,and Br/I)PNCs@SiO_(2)/PMMA composite films can be employed as efficient UV to visible color conversion materials for white-LEDs and backlighting.
基金The authors acknowledge the National Key Research and Development Program(No.2022YFE0121000)Fundamental Research Funds for the Central Universitiesthe Project for Graduate Innovation Team of the Northwestern Polytechnical University,and the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(No.CX2021042).
文摘Benefiting from the high capacity of Zn metal anodes and intrinsic safety of aqueous electrolytes,rechargeable Zn ion batteries(ZIBs)show promising application in the post‐lithium‐ion period,exhibiting good safety,low cost,and high energy density.However,its commercialization still faces problems with low Coulombic efficiency and unsatisfied cycling performance due to the poor Zn/Zn2+reversibility that occurred on the Zn anode.To improve the stability of the Zn anode,optimizing the Zn deposition behavior is an efficient way,which can enhance the subsequent striping efficiency and limit the dendrite growth.The Zn deposition is a controlled kinetics‐diffusion joint process that is affected by various factors,such as the interaction between Zn2+ions and Zn anodes,ion concentration gradient,and current distribution.In this review,from an electrochemical perspective,we first overview the factors affecting the Zn deposition behavior and summarize the modification principles.Subsequently,strategies proposed for interfacial modification and 3D structural design as well as the corresponding mechanisms are summarized.Finally,the existing challenges,perspectives on further development direction,and outlook for practical applications of ZIBs are proposed.
