Abstract:Tuberculosis(TB)remains a significant global health challenge,ranking second only to COVID-19 as the leading cause of death from a single infectious agent,with 1.3 million TB-related deaths reported in 2022.T...Abstract:Tuberculosis(TB)remains a significant global health challenge,ranking second only to COVID-19 as the leading cause of death from a single infectious agent,with 1.3 million TB-related deaths reported in 2022.Treatment efficacy has been compromised by the emergence of drug-resistant strains,including rifampin-resistant TB(RR-TB),multidrug-resistant TB(MDR-TB),and extensively drug-resistant TB(XDR-TB).Although first-line drugs like isoniazid,rifampicin,pyrazinamide,and ethambutol form the cornerstone of TB therapy,the rise of resistant strains necessitates the use of second-line drugs,which often come with increased toxicity and limited accessibility.Recent advances have focused on repurposing existing compounds and developing new drugs with novel mechanisms of action.Promising agents such as second-generation bedaquiline analogs(TBAJ-587,TBAJ-876),sudapyridine(WX-081),delamanid,pretomanid,and TBI-166(pyrifazimine)have shown efficacy against resistant Mtb strains.Innovative treatment regimens like the BPaLM protocol-combining bedaquiline,pretomanid,linezolid,and moxifloxacin-offer shorter,all-oral therapies with higher cure rates.展开更多
Desert rhizoliths are generally found as weathered,broken and scattered samples on dune field surface,but rarely insitu in their initial states buried under the soil of desert in the Badain Jaran Desert,northwest Chin...Desert rhizoliths are generally found as weathered,broken and scattered samples on dune field surface,but rarely insitu in their initial states buried under the soil of desert in the Badain Jaran Desert,northwest China.This study off ers an assessment of the morphological,mineralogical,and chemical properties of intact and in-situ rhizoliths found in soils of swales and depressions among dune chains.The characteristics of these rare and precious objects were assessed using optical polarizing microscopy,cathodoluminescence,scanning electronic microscopy,radiocarbon dating,and stable isotopic analyses,providing the opportunity for discussion of the rhizolith formation mechanisms and associated environmental conditions.Field and laboratory investigations showed that the in-situ intact rhizoliths were formed only in the places where Artemisia shrubs are living,and the remaining root relicts within rhizoliths belong to this species.The spatial distribution of rhizoliths also suggested that low topographic positions on a landscape provided soil moisture,and redox environments favored rhizolith formation.A semi-closed redox environment in the subsoil at swales and depressions,where water is always present,along with the sandy soil texture,facilitated fast water percolation to deeper depths and condensation.Such a soil environment not only provides water for Artemisia growth,but also for the weathering of minerals such as felspars and calcite from primary carbonates,and for the decomposition of root relicts.Furthermore,harsh climatic conditions,such as strong winds and solar radiation,led to water evaporation through dead root channels and triggered the calcification along the root relicts.The entrapped lithogenic carbonates and to a lesser extent the decomposition of Artemisia roots provided the carbon sources for the rhizoliths formation,while the weathering of soil minerals,particularly feldspars and carbonates,was the main source of Ca.Rhizoliths in the Badain Jaran desert formed relatively quickly,probably over a few soil drying episodes.This led to the entrapment of a large quantity of lithogenic carbonates(more than 90%of carbon)within rhizolith cement.The re-dissolution of the entrapped lithogenic carbonates in rhizolith tubes should be taken into account in the paleoenvironmental interpretation ofC ages,the latter suggesting that rhizoliths formed during the Holocene(~2053 years cal BP,based on root organic relicts).展开更多
The oriented actuation of biological muscles that relies on the contraction and relaxation of sarcomeres in myofibrils is the foundation of animal movement.Dielectric elastomers(DEs),which are deemed as a kind of prom...The oriented actuation of biological muscles that relies on the contraction and relaxation of sarcomeres in myofibrils is the foundation of animal movement.Dielectric elastomers(DEs),which are deemed as a kind of promising artificial muscles,can effectively transfer electric energy to mechanical energy within milliseconds under a stimulation of external electric field.Herein,the state-of-art in bioinspired oriented electroactuation of dielectric elastomer actuators(DEAs)is reviewed.The ori-ented electroactuation of DEAs shows directional movement with larger stroke,directional output,and higher energy trans-formation efficiency.In general,most of the DEs are mechanically isotropic with uniform expansion deformation,yet in practical applications they usually utilize deformation in limited direction,leading to energy waste in other directions.Thus,we have principally reviewed the efforts from physical engineering mainly based upon mechanically isotropic DEs to material preparation for mechanically anisotropic DEs,aimed at achieving oriented electroactuation of DEAs.Meanwhile,the typical bionic applications of DEAs with oriented electroactuation are introduced,the main challenges are summarized,and some perspectives for promoting this area are also proposed.We firmly believe that the development of DEAs with oriented elec-troactuation can significantly impact the fields of artificial muscles for flexible actuators and soft robotics.展开更多
Combination of flexible multifunctional stealth technology properties such as electromagnetic(EM)and infrared(IR)stealth is crucial to the development of aerospace,military,and electronic fields,but the synthesis tech...Combination of flexible multifunctional stealth technology properties such as electromagnetic(EM)and infrared(IR)stealth is crucial to the development of aerospace,military,and electronic fields,but the synthesis technology still has a significant challenge.Herein,we have successfully designed and synthesized highly flexible MXene@cellulose lamellae/borate ion(MXCB)sheets with strong high‐temperature EM‐IR bi‐stealth through sequential bridging of hydrogen and covalent bonds.The resultant MXCB sheets display high conductivity and good mechanical features such as flexibility,stretchability,fatigue resistance,and ultrasonic damage.MXCB sheets have a high tensile strength of 795 MPa.Furthermore,MXCB sheets with different thicknesses indicate exceptional high‐temperature thermal‐camouflage characteristics.This reduces the radiation temperature of the target object(>300°C)to 100°C.The conductivity of MXCB sheet with 3μm thickness is 6108 S/cm and the EM interference(EMI)shielding value is 39.74 dB.The normalized surface‐specific EMI SE absolute shielding effectiveness(SSE/t)is as high as 39312.78 dB·cm2/g,which remained 99.39%even after 10,000 times repeated folding.These multifunctional ultrathin MXCB sheets can be arranged by vacuum‐assisted induction to develop EM‐IR bi‐stealth sheet.展开更多
Nickel cobalt sulfides （Ni-Co-S） have attracted extensive attention for application in electronic devices owing to their excellent conductivity and high electrochemical capacitance. To facilitate the large-scale pra...Nickel cobalt sulfides （Ni-Co-S） have attracted extensive attention for application in electronic devices owing to their excellent conductivity and high electrochemical capacitance. To facilitate the large-scale practical application of Ni-Co-S, the excellent rate capability and cyclic stability of these compounds must be fully exploited. Thus, hierarchical Ni-Co-S@Ni-W-O （Ni-Co-S-W） core/shell hybrid nanosheet arrays on nickel foam were designed and synthesized herein via a facile three-step hydrothermal method, followed by annealing in a tubular furnace under argon atmosphere. The hybrid structure was directly assembled as a free-standing electrode, which exhibited a high specific capacitance of 1,988 F·g^-1 at 2 A·g^-1 and retained an excellent capacitance of approximately 1,500 F·g^-1 at 30 A·g^-1, which is superior to the performance of the pristine Ni-Co-S nanosheet electrode. The assembled asymmetric supercapacitors achieved high specific capacitance （155 F·g^-1 at 1 A·g^-1）, electrochemical stability, and a high energy density of 55.1 W·h·kg^-1 at a power density of 799.8 W·kg^-1 with the optimized Ni-Co-S-W core/shell nanosheets as the positive electrode, activated carbon as the negative electrode, and 6 M KOH as the electrolyte.展开更多
The safety issues of lithium-ion batteries have received attention because flammable organic electrolytes are used.Also,the commercial polyolefin separator will undergo severe thermal shrinkage when the internal tempe...The safety issues of lithium-ion batteries have received attention because flammable organic electrolytes are used.Also,the commercial polyolefin separator will undergo severe thermal shrinkage when the internal temperature of the battery increases to 130-160°C,which increases the risk.Therefore,the development of a high thermal stability and high-safety separator is an effective strategy to improve battery safety.Herein,we design a green,cellulose-based separator(Cel@DBDPE)with a unique encapsulation structure for lithium-ion batteries,in which functional flame retardants(DBDPE)are wrapped in microscrolls formed by the self-rolling of 2D cellulose nanosheets upon freeze-drying.This structure can firmly anchor DBDPE particles in the separator to prevent them from undergoing exfoliation and does not affect the properties of the separator,such as the thickness and the pore structure.Compared with commercial polypropylene,Cel@DBDPE has excellent thermal stability and flame retardancy.The former makes it less prone to thermal shrinkage and the latter can effectively prevent the combustion of the electrolyte,showing an efficient self-extinguishing ability.Moreover,the Cel@DBDPE is only 15μm in size and has competitive properties comparable to polypropylene.Thus,there is no sacrifice in the electrochemical performance of battery when the Cel@DBDPE is used as separator.This study provides a new structural design for the construction of a high-safety separator.展开更多
We study the exponential sums involving l：burmr coeffcients ot Maass forms and exponential functions of the form e（anZ）, where 0 ≠ α∈R and 0 〈 β 〈 1. An asymptotic formula is proved for the nonlinear exponent...We study the exponential sums involving l：burmr coeffcients ot Maass forms and exponential functions of the form e（anZ）, where 0 ≠ α∈R and 0 〈 β 〈 1. An asymptotic formula is proved for the nonlinear exponential sum ∑x〈n≤2x λg（n）e（αnβ）, when β = 1/2 and ｜α｜ is close to 2√ q C Z＋, where Ag（n） is the normalized n-th Fourier coefficient of a Maass cusp form for SL2 （Z）. The similar natures of the divisor function 7（n） and the representation function r（n） in the circle problem in nonlinear exponential sums of the above type are also studied.展开更多
Power sources with strong mechanical properties and high-energy density are highly desirable for the next-generation flexible electronics.However,the challenge arises from the current electrode structure design,which ...Power sources with strong mechanical properties and high-energy density are highly desirable for the next-generation flexible electronics.However,the challenge arises from the current electrode structure design,which is unable to bring both satisfactory mechanical and electrochemical properties with high active materials content and mass.Herein,we reported novel flexible,highstrength,and mechanically stable TiO_(2)-based film electrodes for advanced sodium-ion batteries,achieving an ultrahigh strength(up to≈60 MPa)and commercial-level areal capacity(4.5 mAh cm^(-2)).Highly-dispersed TiO_(2) and interlaced carbon nanotube(CNT)networks are embedded in the sheet-liked cellulose to form porous,high-conductive,and high-active TiO_(2)-C nanosheets that is basic building subunits of TiO_(2)-C films,allowing the films with structural robustness and origami-level flexibility.This strategy reconciles the contradiction between mechanical properties and active material content in flexible electrodes,and the fabricated electrode with a high TiO_(2) content of>65%can be bent more than 11000 times without breaking.Meanwhile,good capacity and excellent cycle stability(0.02‰capacity-decay rate over 9000 cycles)of TiO_(2)-C film under a higher active content(75%)has well satisfied the demands of flexible energy storage devices for electrochemical performances.This TiO_(2)-C subunit assembly methodology demonstrates enormous potential in high-strength/toughness flexible electrode construction for flexible electronics.展开更多
Piezoresistive sensors,as an indispensable part of electronic and intelligent wearable devices,are often hindered by nonrenewable resources(graphene,conventional metal,or silicon).Biomass-derived carbonaceous material...Piezoresistive sensors,as an indispensable part of electronic and intelligent wearable devices,are often hindered by nonrenewable resources(graphene,conventional metal,or silicon).Biomass-derived carbonaceous materials boast many advantages such as their light weight,renewability,and excellent chemical stabilization.However,a major challenge is that the strength and resilience of carbon-based piezoresistive materials still falls short of requirements due to their random microarchitectures which cannot provide sufficiently good stress distribution.Encouraged by the excellent compressible properties and extraordinary strength of the Thalia dealbata stem,we propose a wood biomassderived carbon piezoresistive sensor with an artificial interconnected lamellar structure like the stem itself.By introducing a freezing-induced assembly process,a wood-based,completely delignified,nano-lignocellulose material can be built into a“bridges supported lamellar”type architecture,where subsequent freeze-drying and pyrolysis results in carbon aerogel monoliths.The resultant bioinspired carbon sponge has high compressibility and strength,of the order of two to five times higher than that of conventional metal,carbon,and organic materials.Combined with excellent biocompatible properties and chemical durability,these are useful properties for intelligent wearable devices and human-motion detection.展开更多
An effectively mild solvent solution containing NaOH/PEG was employed to dissolve the cellulose extracted from the wheat straw.With further combined regeneration process and freeze-drying,the cellulose aerogel was suc...An effectively mild solvent solution containing NaOH/PEG was employed to dissolve the cellulose extracted from the wheat straw.With further combined regeneration process and freeze-drying,the cellulose aerogel was successfully obtained.Scanning electron microscope,X-ray diffraction technique,Fourier transform infrared spectroscopy,and Brunauer-Emmett-Teller were used to characterize this cellulose aerogel of low density(about 40 mg·cm^(–3))and three-dimensional network with large specific surface area(about 101 m2·g^(–1)).Additionally,with a hydrophobic modification by trimethylchlorosilane,the cellulose aerogel showed a strong absorptive capacity for oil and dye solutions.展开更多
We observed a novel voltage peak in the proximity-induced superconducting gold(Au) nanowire while cooling the sample through the superconducting transition temperature. The voltage peak turned dip during warming. The ...We observed a novel voltage peak in the proximity-induced superconducting gold(Au) nanowire while cooling the sample through the superconducting transition temperature. The voltage peak turned dip during warming. The voltage peak or dip was found to originate respectively from the emergence or vanishing of the proximity-induced superconductivity in the Au nanowire.The amplitude of the voltage signal depends on the temperature scanning rate, and it cannot be detected when the temperature is changed slower than 0.03 K/min. This transient feature suggests the non-equilibrium property of the effect. Ginzburg-Landau model clarified the voltage peak by considering the emergence of Cooper pairs of relatively lower free energy in superconducting W contact and the non-equilibrium diffusion of Cooper pairs and quasiparticles.展开更多
Electrocatalysis plays a central role in electrochemical energy storage and conversion systems,providing a number of sustainable processes for future technologies.As a green,renewable,and abundant natural polymer mate...Electrocatalysis plays a central role in electrochemical energy storage and conversion systems,providing a number of sustainable processes for future technologies.As a green,renewable,and abundant natural polymer material,the unique structure and physicochemical properties of wood and its derivatives provide a unique application advantage in the field of electrocatalysis,which has aroused intense attention from researchers.At present,researchers have developed many wood-based catalytic electrodes by taking advantage of the anisotropic hierarchical porous structure of wood and abundant active functional groups on the cell wall surface of wood.Here,a comprehensive review of recent progress in the design and synthesis of woodinspired electrodes for electrocatalytic reactions is summarized.Starting from the role and importance of the electrocatalytic process in the whole energy conversion system,this review highlights the composition and structure of wood,analyzes the mechanisms of electrocatalytic hydrogen evolution reaction(HER),oxygen evolution reaction(OER),urea oxidation reaction(UOR),and oxygen reduction reaction(ORR),and discusses the structure-activity relationship between the structural properties and electrochemical activity of wood-inspired electrodes.Finally,the opportunities,challenges,and future directions in the application of wood and its derivatives in the field of electrocatalysis are prospected.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2022YFC2302903).
文摘Abstract:Tuberculosis(TB)remains a significant global health challenge,ranking second only to COVID-19 as the leading cause of death from a single infectious agent,with 1.3 million TB-related deaths reported in 2022.Treatment efficacy has been compromised by the emergence of drug-resistant strains,including rifampin-resistant TB(RR-TB),multidrug-resistant TB(MDR-TB),and extensively drug-resistant TB(XDR-TB).Although first-line drugs like isoniazid,rifampicin,pyrazinamide,and ethambutol form the cornerstone of TB therapy,the rise of resistant strains necessitates the use of second-line drugs,which often come with increased toxicity and limited accessibility.Recent advances have focused on repurposing existing compounds and developing new drugs with novel mechanisms of action.Promising agents such as second-generation bedaquiline analogs(TBAJ-587,TBAJ-876),sudapyridine(WX-081),delamanid,pretomanid,and TBI-166(pyrifazimine)have shown efficacy against resistant Mtb strains.Innovative treatment regimens like the BPaLM protocol-combining bedaquiline,pretomanid,linezolid,and moxifloxacin-offer shorter,all-oral therapies with higher cure rates.
基金the Natural Science Foundation of China(41561046)Chinese-German Centre(Sino-German Mobility M-0069)the German Research Foundation(DFG)(ZA 1068/4-1)。
文摘Desert rhizoliths are generally found as weathered,broken and scattered samples on dune field surface,but rarely insitu in their initial states buried under the soil of desert in the Badain Jaran Desert,northwest China.This study off ers an assessment of the morphological,mineralogical,and chemical properties of intact and in-situ rhizoliths found in soils of swales and depressions among dune chains.The characteristics of these rare and precious objects were assessed using optical polarizing microscopy,cathodoluminescence,scanning electronic microscopy,radiocarbon dating,and stable isotopic analyses,providing the opportunity for discussion of the rhizolith formation mechanisms and associated environmental conditions.Field and laboratory investigations showed that the in-situ intact rhizoliths were formed only in the places where Artemisia shrubs are living,and the remaining root relicts within rhizoliths belong to this species.The spatial distribution of rhizoliths also suggested that low topographic positions on a landscape provided soil moisture,and redox environments favored rhizolith formation.A semi-closed redox environment in the subsoil at swales and depressions,where water is always present,along with the sandy soil texture,facilitated fast water percolation to deeper depths and condensation.Such a soil environment not only provides water for Artemisia growth,but also for the weathering of minerals such as felspars and calcite from primary carbonates,and for the decomposition of root relicts.Furthermore,harsh climatic conditions,such as strong winds and solar radiation,led to water evaporation through dead root channels and triggered the calcification along the root relicts.The entrapped lithogenic carbonates and to a lesser extent the decomposition of Artemisia roots provided the carbon sources for the rhizoliths formation,while the weathering of soil minerals,particularly feldspars and carbonates,was the main source of Ca.Rhizoliths in the Badain Jaran desert formed relatively quickly,probably over a few soil drying episodes.This led to the entrapment of a large quantity of lithogenic carbonates(more than 90%of carbon)within rhizolith cement.The re-dissolution of the entrapped lithogenic carbonates in rhizolith tubes should be taken into account in the paleoenvironmental interpretation ofC ages,the latter suggesting that rhizoliths formed during the Holocene(~2053 years cal BP,based on root organic relicts).
基金Zhejiang Provincial Natural Science Foundation of China(Grant No.LQ24E030001)National Natural Science Foundation of China(Grant No.22305221)+2 种基金China Postdoctoral Science Foundation(Grant No.2022M712299)the Research Foundation of Talented Scholars of Zhejiang A&F University(Grant No.2020FR067)Natural Science Foundation of Zhejiang Province.
文摘The oriented actuation of biological muscles that relies on the contraction and relaxation of sarcomeres in myofibrils is the foundation of animal movement.Dielectric elastomers(DEs),which are deemed as a kind of promising artificial muscles,can effectively transfer electric energy to mechanical energy within milliseconds under a stimulation of external electric field.Herein,the state-of-art in bioinspired oriented electroactuation of dielectric elastomer actuators(DEAs)is reviewed.The ori-ented electroactuation of DEAs shows directional movement with larger stroke,directional output,and higher energy trans-formation efficiency.In general,most of the DEs are mechanically isotropic with uniform expansion deformation,yet in practical applications they usually utilize deformation in limited direction,leading to energy waste in other directions.Thus,we have principally reviewed the efforts from physical engineering mainly based upon mechanically isotropic DEs to material preparation for mechanically anisotropic DEs,aimed at achieving oriented electroactuation of DEAs.Meanwhile,the typical bionic applications of DEAs with oriented electroactuation are introduced,the main challenges are summarized,and some perspectives for promoting this area are also proposed.We firmly believe that the development of DEAs with oriented elec-troactuation can significantly impact the fields of artificial muscles for flexible actuators and soft robotics.
基金supported by the National Natural Science Foundation of China(U22A20140,52072138)Shenzhen Science and Technology Program(JCYJ20220818100418040 and JCYJ20220530160816038)。
基金supported by the Nanning Innovation and Entrepreneurship Leading Talents“Yongjiang Plan”Project of Guangxi Province,China(No.2021016)Zhejiang Provincial Natural Science Foundation for Distinguished Young Scholars of China(No.LR19C160001)the Scientific Research Foundation of Zhejiang A&F University(No.2019FR009).
文摘Combination of flexible multifunctional stealth technology properties such as electromagnetic(EM)and infrared(IR)stealth is crucial to the development of aerospace,military,and electronic fields,but the synthesis technology still has a significant challenge.Herein,we have successfully designed and synthesized highly flexible MXene@cellulose lamellae/borate ion(MXCB)sheets with strong high‐temperature EM‐IR bi‐stealth through sequential bridging of hydrogen and covalent bonds.The resultant MXCB sheets display high conductivity and good mechanical features such as flexibility,stretchability,fatigue resistance,and ultrasonic damage.MXCB sheets have a high tensile strength of 795 MPa.Furthermore,MXCB sheets with different thicknesses indicate exceptional high‐temperature thermal‐camouflage characteristics.This reduces the radiation temperature of the target object(>300°C)to 100°C.The conductivity of MXCB sheet with 3μm thickness is 6108 S/cm and the EM interference(EMI)shielding value is 39.74 dB.The normalized surface‐specific EMI SE absolute shielding effectiveness(SSE/t)is as high as 39312.78 dB·cm2/g,which remained 99.39%even after 10,000 times repeated folding.These multifunctional ultrathin MXCB sheets can be arranged by vacuum‐assisted induction to develop EM‐IR bi‐stealth sheet.
基金This work was supported by the National Natural Science Foundation of China （No. 51672109）, National Basic Research Program of China （No. 2015CB932600）, Program for HUST Interdisciplinary Innovation Team （No. 2015ZDTD038） and the Fundamental Research Funds for the Central University （No. 2017KFKJXX007）, Natural Science Foundation of Shandong Province for Excellent Young Scholars （No. ZR2016JL015）, Scientific Research Foundation of Zhejiang A＆F University （No. 2014FR077）.
文摘Nickel cobalt sulfides （Ni-Co-S） have attracted extensive attention for application in electronic devices owing to their excellent conductivity and high electrochemical capacitance. To facilitate the large-scale practical application of Ni-Co-S, the excellent rate capability and cyclic stability of these compounds must be fully exploited. Thus, hierarchical Ni-Co-S@Ni-W-O （Ni-Co-S-W） core/shell hybrid nanosheet arrays on nickel foam were designed and synthesized herein via a facile three-step hydrothermal method, followed by annealing in a tubular furnace under argon atmosphere. The hybrid structure was directly assembled as a free-standing electrode, which exhibited a high specific capacitance of 1,988 F·g^-1 at 2 A·g^-1 and retained an excellent capacitance of approximately 1,500 F·g^-1 at 30 A·g^-1, which is superior to the performance of the pristine Ni-Co-S nanosheet electrode. The assembled asymmetric supercapacitors achieved high specific capacitance （155 F·g^-1 at 1 A·g^-1）, electrochemical stability, and a high energy density of 55.1 W·h·kg^-1 at a power density of 799.8 W·kg^-1 with the optimized Ni-Co-S-W core/shell nanosheets as the positive electrode, activated carbon as the negative electrode, and 6 M KOH as the electrolyte.
基金supported by the National Natural Science Foundation of China(Nos.U22A20140,52072138)the National Key Research and Development Program of China(No.2018YFE0206900).
文摘The safety issues of lithium-ion batteries have received attention because flammable organic electrolytes are used.Also,the commercial polyolefin separator will undergo severe thermal shrinkage when the internal temperature of the battery increases to 130-160°C,which increases the risk.Therefore,the development of a high thermal stability and high-safety separator is an effective strategy to improve battery safety.Herein,we design a green,cellulose-based separator(Cel@DBDPE)with a unique encapsulation structure for lithium-ion batteries,in which functional flame retardants(DBDPE)are wrapped in microscrolls formed by the self-rolling of 2D cellulose nanosheets upon freeze-drying.This structure can firmly anchor DBDPE particles in the separator to prevent them from undergoing exfoliation and does not affect the properties of the separator,such as the thickness and the pore structure.Compared with commercial polypropylene,Cel@DBDPE has excellent thermal stability and flame retardancy.The former makes it less prone to thermal shrinkage and the latter can effectively prevent the combustion of the electrolyte,showing an efficient self-extinguishing ability.Moreover,the Cel@DBDPE is only 15μm in size and has competitive properties comparable to polypropylene.Thus,there is no sacrifice in the electrochemical performance of battery when the Cel@DBDPE is used as separator.This study provides a new structural design for the construction of a high-safety separator.
基金Acknowledgements This work was partially supported by the National Natural Science Foundation of China （Grant Nos. 11101239, 10971119）, the Program for Changjiang Scholars and Innovative Research Team in University （IRT1264）, and the Independent Innovation Foundation of Shandong University （Grant No. 2012ZRYQ005）.
文摘We study the exponential sums involving l：burmr coeffcients ot Maass forms and exponential functions of the form e（anZ）, where 0 ≠ α∈R and 0 〈 β 〈 1. An asymptotic formula is proved for the nonlinear exponential sum ∑x〈n≤2x λg（n）e（αnβ）, when β = 1/2 and ｜α｜ is close to 2√ q C Z＋, where Ag（n） is the normalized n-th Fourier coefficient of a Maass cusp form for SL2 （Z）. The similar natures of the divisor function 7（n） and the representation function r（n） in the circle problem in nonlinear exponential sums of the above type are also studied.
基金Cultivating Excellent Doctoral Dissertation of Forestry Engineering,Grant/Award Number:LYGCYB20202014National Key Research and Development Program of China,Grant/Award Number:2018YFE0206900National Natural Science Foundation of China,Grant/Award Number:51772115。
文摘Power sources with strong mechanical properties and high-energy density are highly desirable for the next-generation flexible electronics.However,the challenge arises from the current electrode structure design,which is unable to bring both satisfactory mechanical and electrochemical properties with high active materials content and mass.Herein,we reported novel flexible,highstrength,and mechanically stable TiO_(2)-based film electrodes for advanced sodium-ion batteries,achieving an ultrahigh strength(up to≈60 MPa)and commercial-level areal capacity(4.5 mAh cm^(-2)).Highly-dispersed TiO_(2) and interlaced carbon nanotube(CNT)networks are embedded in the sheet-liked cellulose to form porous,high-conductive,and high-active TiO_(2)-C nanosheets that is basic building subunits of TiO_(2)-C films,allowing the films with structural robustness and origami-level flexibility.This strategy reconciles the contradiction between mechanical properties and active material content in flexible electrodes,and the fabricated electrode with a high TiO_(2) content of>65%can be bent more than 11000 times without breaking.Meanwhile,good capacity and excellent cycle stability(0.02‰capacity-decay rate over 9000 cycles)of TiO_(2)-C film under a higher active content(75%)has well satisfied the demands of flexible energy storage devices for electrochemical performances.This TiO_(2)-C subunit assembly methodology demonstrates enormous potential in high-strength/toughness flexible electrode construction for flexible electronics.
基金Hubei Provincial Natural Science Foundation of China,Grant/Award Number:2019CFA002National Basic Research Program of China,Grant/Award Number:2015CB932600+1 种基金the Fundamental Research Funds for the Central University,Grant/Award Number:2019kfyXMBZ018Zhejiang Provincial Natural Science Foundation for Distinguished Young Scholars of China,Grant/Award Number:LR19C160001。
文摘Piezoresistive sensors,as an indispensable part of electronic and intelligent wearable devices,are often hindered by nonrenewable resources(graphene,conventional metal,or silicon).Biomass-derived carbonaceous materials boast many advantages such as their light weight,renewability,and excellent chemical stabilization.However,a major challenge is that the strength and resilience of carbon-based piezoresistive materials still falls short of requirements due to their random microarchitectures which cannot provide sufficiently good stress distribution.Encouraged by the excellent compressible properties and extraordinary strength of the Thalia dealbata stem,we propose a wood biomassderived carbon piezoresistive sensor with an artificial interconnected lamellar structure like the stem itself.By introducing a freezing-induced assembly process,a wood-based,completely delignified,nano-lignocellulose material can be built into a“bridges supported lamellar”type architecture,where subsequent freeze-drying and pyrolysis results in carbon aerogel monoliths.The resultant bioinspired carbon sponge has high compressibility and strength,of the order of two to five times higher than that of conventional metal,carbon,and organic materials.Combined with excellent biocompatible properties and chemical durability,these are useful properties for intelligent wearable devices and human-motion detection.
基金supported by the National Natural Science Foundation of China(31270590)China Postdoctoral Science Foundation funded project(2013M540263)Doctoral Candidate Innovation Research Support Program of Science&Technology Review(kjdb2012006).
文摘An effectively mild solvent solution containing NaOH/PEG was employed to dissolve the cellulose extracted from the wheat straw.With further combined regeneration process and freeze-drying,the cellulose aerogel was successfully obtained.Scanning electron microscope,X-ray diffraction technique,Fourier transform infrared spectroscopy,and Brunauer-Emmett-Teller were used to characterize this cellulose aerogel of low density(about 40 mg·cm^(–3))and three-dimensional network with large specific surface area(about 101 m2·g^(–1)).Additionally,with a hydrophobic modification by trimethylchlorosilane,the cellulose aerogel showed a strong absorptive capacity for oil and dye solutions.
基金supported by the National Basic Research Program of China(Grant Nos.2017YFA0303300,and 2013CB934600)the National Natural Science Foundation of China(Grant No.11774008)+3 种基金the Open Research Fund Program of the State Key Laboratory of Low-Dimensional Quantum Physics(Grant No.KF201703)at Tsinghua University the Key Research Program of the Chinese Academy of Sciences(Grant No.XDPB08-1)the Peking University President’s Fund for Undergraduate Research(2013)Penn State was supported by NSF grants(MRSEC)(Grant Nos.DMR-0820404 and DMR-1420620)
文摘We observed a novel voltage peak in the proximity-induced superconducting gold(Au) nanowire while cooling the sample through the superconducting transition temperature. The voltage peak turned dip during warming. The voltage peak or dip was found to originate respectively from the emergence or vanishing of the proximity-induced superconductivity in the Au nanowire.The amplitude of the voltage signal depends on the temperature scanning rate, and it cannot be detected when the temperature is changed slower than 0.03 K/min. This transient feature suggests the non-equilibrium property of the effect. Ginzburg-Landau model clarified the voltage peak by considering the emergence of Cooper pairs of relatively lower free energy in superconducting W contact and the non-equilibrium diffusion of Cooper pairs and quasiparticles.
基金supported by the National Key R&D Program of China(2023YFD2201403)the National Natural Science Foundation of China(32371508,32401265)+1 种基金the Scientific Research Foundation of Zhejiang A&F University(2019FR009)the Science Research and Technology Development Plan of Nanning(20231033).
文摘Electrocatalysis plays a central role in electrochemical energy storage and conversion systems,providing a number of sustainable processes for future technologies.As a green,renewable,and abundant natural polymer material,the unique structure and physicochemical properties of wood and its derivatives provide a unique application advantage in the field of electrocatalysis,which has aroused intense attention from researchers.At present,researchers have developed many wood-based catalytic electrodes by taking advantage of the anisotropic hierarchical porous structure of wood and abundant active functional groups on the cell wall surface of wood.Here,a comprehensive review of recent progress in the design and synthesis of woodinspired electrodes for electrocatalytic reactions is summarized.Starting from the role and importance of the electrocatalytic process in the whole energy conversion system,this review highlights the composition and structure of wood,analyzes the mechanisms of electrocatalytic hydrogen evolution reaction(HER),oxygen evolution reaction(OER),urea oxidation reaction(UOR),and oxygen reduction reaction(ORR),and discusses the structure-activity relationship between the structural properties and electrochemical activity of wood-inspired electrodes.Finally,the opportunities,challenges,and future directions in the application of wood and its derivatives in the field of electrocatalysis are prospected.
