Metal-organic frameworks(MOFs)have attracted significant interest as self-templates and precursors for the synthesis of carbon-based composites aimed at electromagnetic wave(EMW)absorption.However,the utilization of h...Metal-organic frameworks(MOFs)have attracted significant interest as self-templates and precursors for the synthesis of carbon-based composites aimed at electromagnetic wave(EMW)absorption.However,the utilization of high-temperature treatments has introduced uncertainties regarding the compositions and microstructures of resulting derivatives.Additionally,complete carbonization has led to diminished yields of the produced carbon composites,significantly limiting their practical applications.Consequently,the exploration of pristine MOF-based EMW absorbers presents an intriguing yet challenging endeavor,primarily due to inherently low electrical conductivity.In this study,we showcase the utilization of structurally robust Zr-MOFs as scaffolds to build highly conductive Zr-MOF/PPy composites via an inner-outer dual-modification approach,which involves the production of conducting polypyrrole(PPy)both within the confined nanoporous channels and the external surface of Zr-MOFs via post-synthetic modification.The interconnection of confined PPy and surface-lined PPy together leads to a consecutive and extensive conducting network to the maximum extent.This therefore entails outstanding conductivity up to~14.3 S cm^(-1) in Zr-MOF/PPy composites,which is approximately 1-2 orders of magnitude higher than that for conductive MOF nanocomposites constructed from either inner or outer modification.Benefiting from the strong and tunable conduction loss,as well as the induced dielectric polarization originated from the porous structures and MOF-polymer interfaces,Zr-MOF/PPy exhibits excellent microwave attenuation capabilities and a tunable absorption frequency range.Specifically,with only 15 wt.%loading,the minimum reflection loss(RLmin)can reach up to-67.4 dB,accompanied by an effective absorption bandwidth(EAB)extending to 6.74 GHz.Furthermore,the microwave absorption characteristics can be tailored from the C-band to the Ku-band by adjusting the loading of PPy.This work provides valuable insights into the fabrication of conductive MOF composites by presenting a straightforward pathway to enhance and reg-ulate electrical conduction in MOF-based nanocomposites,thus paving a way to facilely fabricate pristine MOF-based microwave absorbers.展开更多
Scientific research is a journey into an uncharted territory.Researchers need to have the big picture for navigation and at the same time be detail-oriented,as details make a difference.Here I offer a few tips for con...Scientific research is a journey into an uncharted territory.Researchers need to have the big picture for navigation and at the same time be detail-oriented,as details make a difference.Here I offer a few tips for conducting research that I summarized based on my 30+years of research experience.展开更多
This study addresses the challenge of high sintering temperatures in proton-conducting fuel cells(PCFCs)with BaCeO_(3)-doped electrolytes.We demonstrate that 1 mol%copper(Cu)doping at the B-site of BaCe_(0.7)Zr_(0.1)(...This study addresses the challenge of high sintering temperatures in proton-conducting fuel cells(PCFCs)with BaCeO_(3)-doped electrolytes.We demonstrate that 1 mol%copper(Cu)doping at the B-site of BaCe_(0.7)Zr_(0.1)(Dy_(0.1)|Yb_(0.1))_(0.2)O_(3-δ)(BCZDYb)improves sintering behavior,enabling densification at1400℃.However,Cu doping disrupts stoichiometry,creating barium vacancies and reducing protonaccepting cations,affecting overall conductivity.This mechanism is confirmed through density functional theory(DFT)calculations and various experimental techniques,including crystal structure analysis using X-ray diffraction(XRD)and morphology and elemental analysis via field emission scanning electron microscopy(FESEM)and energy-dispersive X-ray spectroscopy(EDS).Electrochemical measurements are performed using the electrochemical impedance spectroscopy(EIS).The ionic conductivity of1 mol%Cu-doped BCZDYb(BCZDYb-1)is 1.49×10^(-2)S cm^(-1)at 650℃,which is~3.58 times higher than that of BCZDYb sintered at 1200℃.The BCZDYb-1 exhibits~16 times higher grain boundary conductivity when sintered at 1400℃,compared to undoped BCZDYb.The single cell employing BCZDYb-1 as the electrolyte achieved a power density of~606 mW cm^(-2)at 550℃.These results indicate that a controlled amount of Cu doping can enhance densification while maintaining high ionic co nductivity,making it suitable for practical applications in PCFCs operating at lower temperatures.展开更多
“Three-in-one”cathode,achieved via B-site heavy-doping of transition elements(typically Co,Fe)into proton-conductive perovskite,holds promise for enhancing the performance of proton-conducting solid oxide fuel cell(...“Three-in-one”cathode,achieved via B-site heavy-doping of transition elements(typically Co,Fe)into proton-conductive perovskite,holds promise for enhancing the performance of proton-conducting solid oxide fuel cell(H-SOFC)operated below 650℃for electricity generation.However,its electrochemical behavior above 650℃,essential for improving the efficiency of H-SOFC for fuel conversion,remains insufficiently explored.It is still challenging to propose guidance for the design of“threein-one”cathode toward optimal H-SOFC performance below and above 650℃,with the prerequisite of gaining a comprehensive understanding of the roles of Co and Fe in determining the H-SOFC performance.This work is to address this challenge.Through theoretical/experimental studies,Co is identified to play a role in improving the oxygen reduction reaction(ORR)activity while Fe plays a role in facilitating the cathode/electrolyte interfacial proton conduction.Therefore,if the operating temperature is above 650℃,lowering the Co/Fe ratio in“three-in-one”cathode becomes crucial since the limiting factor shifts from ORR activity to proton conduction.Implementing this strategy,the SOFC using BaCo_(0.15)-Fe_(0.55)Zr_(0.1)Y_(0.1)Yb_(0.1)O_(3−δ)cathode achieves peak power densities of 1.67Wcm^(−2)under H-SOFC mode at 700℃and 2.32Wcm^(−2)under dual ion-conducting SOFC mode at 750℃,which are the highest reported values so far.展开更多
Proton-conducting materials have attracted considerable interest because of their extensive application in energy storage and conversion devices.Among them,metal-organic frameworks(MOFs)present tremendous development ...Proton-conducting materials have attracted considerable interest because of their extensive application in energy storage and conversion devices.Among them,metal-organic frameworks(MOFs)present tremendous development potential and possibilities for constructing novel advanced proton conductors due to their special advantages in crystallinity,designability,and porosity.In particular,several special design strategies for the structure of MOFs have opened new doors for the advancement of MOF proton conductors,such as charged network construction,ligand functionalization,metal-center manipulation,defective engineering,vip molecule incorporation,and pore-space manipulation.With the implementation of these strategies,proton-conducting MOFs have developed significantly and profoundly within the last decade.Therefore,in this review,we critically discuss and analyze the fundamental principles,design strategies,and implementation methods targeted at improving the proton conductivity of MOFs through representative examples.Besides,the structural features,the proton conduction mechanism and the behavior of MOFs are discussed thoroughly and meticulously.Future endeavors are also proposed to address the challenges of proton-conducting MOFs in practical research.We sincerely expect that this review will bring guidance and inspiration for the design of proton-conducting MOFs and further motivate the research enthusiasm for novel proton-conducting materials.展开更多
A physical model of series of the conductivity on chain and the interchain conductivitybetween chains is proposed to explain enhanced conductivity of stretched conducting polymers.This model suggests that the enhanced...A physical model of series of the conductivity on chain and the interchain conductivitybetween chains is proposed to explain enhanced conductivity of stretched conducting polymers.This model suggests that the enhanced conductivity for stretched conducting polymers might bedue to increasing of the interchain conductivity between chains along the elongation direction afterdrawing processes if the conductivity on chain is assumed much larger than that of the interchainconductivity between chains. According to this model, it is expected that the temperaturedependence of conductivity measured by four-probe method for stretched conducting polymers iscontrolled by a variation of the interchain conductivity between chains with temperature, whichcan be used to explain that a metallic temperature dependence of conductivity for stretchedconducting polymers is not observed although the conductivity along the elongation direction isenhanced by two or three orders of magnitude.展开更多
The preparation of La0.4Sr0.6TiO3 （LSTO） buffer layer and YBa2Cu3O7-δ（YBCO） superconducting thick film by a low cost technology was studied. The crystal orientation of LSTO and YBCO films was detected by X-ray di...The preparation of La0.4Sr0.6TiO3 （LSTO） buffer layer and YBa2Cu3O7-δ（YBCO） superconducting thick film by a low cost technology was studied. The crystal orientation of LSTO and YBCO films was detected by X-ray diffraction, the conductivity of LSTO film and superconductivity of YBCO coating were investigated by standard four-probe method. Excellent in-plane alignment, smooth and dense LSTO buffer layer was successfully prepared on textured Ni-W taps by metal organic deposition （MOD）. YBCO thick film was fabricated by electrophoretic deposition （EPD）. The effects of applied voltage and deposition time on the YBCO coatings properties were studied. The results show that the critical current density of the YBCO coating deposited under 138 V for 35 min was about 600 A/cm2 （0 T, 77 K）.展开更多
The conducting tissue structure of transverse and longitudinal sections was observed on leaves of Podocarpus and Nageia.Results showed:in Podocarpus leaves,there is only one midrib,the xylem tracheid of midrib vascula...The conducting tissue structure of transverse and longitudinal sections was observed on leaves of Podocarpus and Nageia.Results showed:in Podocarpus leaves,there is only one midrib,the xylem tracheid of midrib vascular bundle is multi-form,transfusion tissue belongs to Cycas-type and transfusion tracheids are isodiametric,the accessory transfusion tracheids between palisade tissue and sponge tissue are developed;in Nageia leaves,there are plenty of parallel leaves,the xylem tracheids of each vein are relatively simple,transfusion tissue belongs to Taxus-type and transfusion tracheids are longer in longitudinal section than that in transverse section,the accessory transfusion tissue between palisade tissue and sponge tissue is absent.Considering other differences that in leaves of Podocarpus there are three resin ducts under vascular bundle of midrib,mesophyll cells are differentiated into palisade tissue and sponge tissue;in leaves of Nageia,there is only one resin duct under vascular bundle in each vein and no obvious differentiation in mesophyll cells,palisade tissue can be found on both sides,and sclereids can also be found in mesophyll tissue.The anatomical differences of leaf veins and mesophylls between Nageia and Podocarpus mentioned above support the viewpoint that Nageia and Podocarpus are two independent genera.展开更多
Disordered superconducting materials like NbTiN possess a high kinetic inductance fraction and an adjustable critical temperature, making them a good choice for low-temperature detectors. Their energy gap(D), critical...Disordered superconducting materials like NbTiN possess a high kinetic inductance fraction and an adjustable critical temperature, making them a good choice for low-temperature detectors. Their energy gap(D), critical temperature(T_(c)),and quasiparticle density of states(QDOS) distribution, however, deviate from the classical BCS theory due to the disorder effects. The Usadel equation, which takes account of elastic scattering, non-elastic scattering, and electro–phonon coupling,can be applied to explain and describe these deviations. This paper presents numerical simulations of the disorder effects based on the Usadel equation to investigate their effects on the △, Tc, QDOS distribution, and complex conductivity of the NbTiN film. Furthermore, NbTiN superconducting resonators with coplanar waveguide(CPW) structures are fabricated and characterized at different temperatures to validate our numerical simulations. The pair-breaking parameter α and the critical temperature in the pure state T_(c)^(P) of our NbTiN film are determined from the experimental results and numerical simulations. This study has significant implications for the development of low-temperature detectors made of disordered superconducting materials.展开更多
Transparent and conducting zirconium-doped zinc oxide films with high transparency and relatively low resistivity have been successfully prepared by radio frequency （RF） msgnetron sputtering at room temperature, The...Transparent and conducting zirconium-doped zinc oxide films with high transparency and relatively low resistivity have been successfully prepared by radio frequency （RF） msgnetron sputtering at room temperature, The RF power is varied from 75 to 150 W. At first the crystallinity and conductivity of the film are improved and then both of them show deterioration with the increase of the RF power, The lowest resistivity achieved is 2.07 × 10^-3Ωcm at an RF power of 100W with a Hall mobility of 16cm^2V^-1s^-1 and a carrier concentration of 1.95 × 10^20 cm^-3. The films obtained are polycryetalline with a hexagonal structure and a preferred orientation along the c-axis, All the films have a high transmittance of approximately 92% in the visible range. The optical band gap is about 3.33 eV for the films deposited at different RF powers.展开更多
Corrosion protection of the hull steel by the conventional epoxy paint containing a small amount of commercial poly（3,4-ethylenedioxythiophene）/poly（styrene sulfonate） （PEDOT/PSS）, which is one of the most popul...Corrosion protection of the hull steel by the conventional epoxy paint containing a small amount of commercial poly（3,4-ethylenedioxythiophene）/poly（styrene sulfonate） （PEDOT/PSS）, which is one of the most popular and successful inherently conducting polymers as the corrosion inhibitor was studied. The corrosion behavior of the samples was investigated in seawater by electrochemical impedance spectroscopy and open circuit potential. Scanning electron microscopy was used to observe the surface morphology of the samples after corrosion. It was found that adding a small amount of PEDOT/PSS to the epoxy resin can significantly improve its corrosion protection.展开更多
In recent years,as a new class of two-dimensional polymer,covalent organic frameworks（COFs） have attracted intensive attention and developed rapidly.This review provides an overview of a type of COFs which can be ut...In recent years,as a new class of two-dimensional polymer,covalent organic frameworks（COFs） have attracted intensive attention and developed rapidly.This review provides an overview of a type of COFs which can be utilized as organic semiconductors.Carefully choosing monomers as the building blocks will bestow different types of semiconducting character on COFs.We summarize the p-type,n-type and ambipolar semiconducting COFs and highlight the effects of π-functional building blocks on the photoconductive behaviors of the semiconducting COFs.展开更多
Three-dimensional graphene/conducting polymer（3DGCP） composites have received significant attention in recent years due to their unique structures and promising applications in energy storage.With the structural div...Three-dimensional graphene/conducting polymer（3DGCP） composites have received significant attention in recent years due to their unique structures and promising applications in energy storage.With the structural diversity of graphene and π-functional conducting polymers via rich chemical routes,a number of 3DGCP composites with novel structures and attractive performance have been developed.Particularly,the hierarchical porosity,the interactions between graphene and conducting polymers as well as the their synergetic effects within 3DGCP composites can be well combined and elaborated by various synthetic methods,which made 3DGCP composites show unique electrochemical properties and significantly improved performance in energy storage fields compared to other graphenebased composites.In this short review,we present recent advances in 3DGCP composites in developing effective strategies to prepare 3DGCP composites and exploring them as a unique platform for supercapacitors with unprecedented performance.The challenges and future opportunities are also discussed for promotion of further study.展开更多
Excellent antibacterial performance of polyaniline （PAni） against Escherichia coli and Gram-positive Staphylococcus aureus microorganisms has been demonstrated under both dark and visible light conditions. The elect...Excellent antibacterial performance of polyaniline （PAni） against Escherichia coli and Gram-positive Staphylococcus aureus microorganisms has been demonstrated under both dark and visible light conditions. The electrostatic adherence between the PAni molecules and the bacteria may play a very important role for the antibacterial reaction of the PAni. As a result of our investigation, conducting PAni and its composites/blends are believed to be useful as a new type of antibacterial agent, self-clean as well as multifunctional material for improving the human health and living environment.展开更多
Lithium-sulfur(Li-S) batteries and lithium-selenium(Li-Se) batteries,as environmental protection energy storage systems with outstanding theoretical specific capacities and high energy densities,have become the hotspo...Lithium-sulfur(Li-S) batteries and lithium-selenium(Li-Se) batteries,as environmental protection energy storage systems with outstanding theoretical specific capacities and high energy densities,have become the hotspots of current researches.Besides,elemental S(Se) raw materials are widely sourced and their production costs are both low,which make them considered one of the new generations of high energy density electrochemical energy storage systems with the most potential for development.However,poor conductivity of elemental S/Se and the notorious "shuttle effect" of lithium polysulfides(polyselenides) severely hinder the commercialization of Li-S/Se batteries.Thanks to the excellent electrical conductivity and strong absorption of lithium polysulfide(polyselenide) about electronically conducting polymer,some of the above thorny problems have been effectively alleviated.The review presents the fundamental studies and current development trends of common electronically conducting polymers in various components of Li-S/Se batteries,which involves polyaniline(PANI) polypyrrole(PPy),and polythiophene(PTh) with its derivatives,e.g.polyethoxythiophene(PEDOT) and poly(3,4-ethylene dioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS).Finally,the review not only summarizes the research directions and challenges facing the application of electronically conducting polymers,but also looks forward to the development prospects of them,which will provide a way for the practical use of electronically conducting polymers in Li-S/Se batteries with outstanding electrochemical properties in the short run.展开更多
The finite element formulation for analyzing static damage near a conducting crack in a thin piezoelectric plate is established from the virtual work principle of piezoelectricity.The damage fields under various mecha...The finite element formulation for analyzing static damage near a conducting crack in a thin piezoelectric plate is established from the virtual work principle of piezoelectricity.The damage fields under various mechanical and electrical loads are calculated carefully by using an effective iterative procedure.The numerical results show that all the damage fields around a crack tip are fan-shaped and the electric field applied has great influence on the mechanical damage, which is related to the piezoelectric properties.展开更多
Nonfullerene organic solar cells(OSCs)have achieved breakthrough with pushing the efficiency exceeding 17%.While this shed light on OSC commercialization,high-performance flexible OSCs should be pursued through soluti...Nonfullerene organic solar cells(OSCs)have achieved breakthrough with pushing the efficiency exceeding 17%.While this shed light on OSC commercialization,high-performance flexible OSCs should be pursued through solution manufacturing.Herein,we report a solution-processed flexible OSC based on a transparent conducting PEDOT:PSS anode doped with trifluoromethanesulfonic acid(CF3SO3H).Through a low-concentration and low-temperature CF3SO3H doping,the conducting polymer anodes exhibited a main sheet resistance of 35Ωsq−1(minimum value:32Ωsq−1),a raised work function(≈5.0 eV),a superior wettability,and a high electrical stability.The high work function minimized the energy level mismatch among the anodes,hole-transporting layers and electron-donors of the active layers,thereby leading to an enhanced carrier extraction.The solution-processed flexible OSCs yielded a record-high efficiency of 16.41%(maximum value:16.61%).Besides,the flexible OSCs afforded the 1000 cyclic bending tests at the radius of 1.5 mm and the long-time thermal treatments at 85°C,demonstrating a high flexibility and a good thermal stability.展开更多
Lithium-sulfur(Li-S)batteries have attracted increased interest because of the high theoretical energy density,low cost,and environmental friendliness.Conducting polymers(CPs),as one of the most promising materials us...Lithium-sulfur(Li-S)batteries have attracted increased interest because of the high theoretical energy density,low cost,and environmental friendliness.Conducting polymers(CPs),as one of the most promising materials used in Li-S batteries,can not only facilitate electron transfer and buffer the large volumetric change of sulfur benefiting from their porous structure and excellent flexibility,but also enable stronger physical/chemical adsorption capacity toward polysulfides(LiPSs)when doped with abundant heteroatoms to promote the sulfur redox kinetics and achieve the high sulfur loading.This review firstly introduces the properties of various CPs including structural CPs(polypyrrole(PPy),polyaniline(PANi),polyethylene dioxothiophene[PEDOT])and compound CPs(polyethylene oxide(PEO),polyvinyl alcohol(PVA)and poly(acrylic acid)[PAA]),and their application potential in Li-S batteries.Furthermore,the research progress of various CPs in different components(cathode,separator,and interlayer)of Li-S batteries is systematically summarized.Finally,the application perspective of the CPs in Li-S batteries as a potential guidance is comprehensively discussed.展开更多
Insulating parts are easily subjected to pollution which may cause damage to the electric system. A typical disc insulator is chosen as the target to test its flashover voltage by using an artificial pollution system....Insulating parts are easily subjected to pollution which may cause damage to the electric system. A typical disc insulator is chosen as the target to test its flashover voltage by using an artificial pollution system. This test system aims at obtaining characteristic parameters of damage for chosen conducting sola to the selected insulator. Experimental results show that thickness and electric conductivity of pollutant layer over insulators are the main parameters in damage evaluation. The flashover voltage decreases with increase of thickness and/or conductivity. These results provide a better basis on further revealing the damaging nature of conducting sol materials.展开更多
The contact problem for thermoelectric materials with functionally graded properties is considered.The material properties,such as the electric conductivity,the thermal conductivity,the shear modulus,and the thermal e...The contact problem for thermoelectric materials with functionally graded properties is considered.The material properties,such as the electric conductivity,the thermal conductivity,the shear modulus,and the thermal expansion coefficient,vary in an exponential function.Using the Fourier transform technique,the electro-thermoelastic problems are transformed into three sets of singular integral equations which are solved numerically in terms of the unknown normal electric current density,the normal energy flux,and the contact pressure.Meanwhile,the complex homogeneous solutions of the displacement fields caused by the gradient parameters are simplified with the help of Euler’s formula.After addressing the non-linearity excited by thermoelectric effects,the particular solutions of the displacement fields can be assessed.The effects of various combinations of material gradient parameters and thermoelectric loads on the contact behaviors of thermoelectric materials are presented.The results give a deep insight into the contact damage mechanism of functionally graded thermoelectric materials(FGTEMs).展开更多
基金supported by the Fundamental Research Funds for the Central Universities(Nos.2232023D-01 and 2232023D-07)the Shanghai Science&Technology Committee(No.22ZR1403300)the National Natural Science Foundation of China(No.52372040).
文摘Metal-organic frameworks(MOFs)have attracted significant interest as self-templates and precursors for the synthesis of carbon-based composites aimed at electromagnetic wave(EMW)absorption.However,the utilization of high-temperature treatments has introduced uncertainties regarding the compositions and microstructures of resulting derivatives.Additionally,complete carbonization has led to diminished yields of the produced carbon composites,significantly limiting their practical applications.Consequently,the exploration of pristine MOF-based EMW absorbers presents an intriguing yet challenging endeavor,primarily due to inherently low electrical conductivity.In this study,we showcase the utilization of structurally robust Zr-MOFs as scaffolds to build highly conductive Zr-MOF/PPy composites via an inner-outer dual-modification approach,which involves the production of conducting polypyrrole(PPy)both within the confined nanoporous channels and the external surface of Zr-MOFs via post-synthetic modification.The interconnection of confined PPy and surface-lined PPy together leads to a consecutive and extensive conducting network to the maximum extent.This therefore entails outstanding conductivity up to~14.3 S cm^(-1) in Zr-MOF/PPy composites,which is approximately 1-2 orders of magnitude higher than that for conductive MOF nanocomposites constructed from either inner or outer modification.Benefiting from the strong and tunable conduction loss,as well as the induced dielectric polarization originated from the porous structures and MOF-polymer interfaces,Zr-MOF/PPy exhibits excellent microwave attenuation capabilities and a tunable absorption frequency range.Specifically,with only 15 wt.%loading,the minimum reflection loss(RLmin)can reach up to-67.4 dB,accompanied by an effective absorption bandwidth(EAB)extending to 6.74 GHz.Furthermore,the microwave absorption characteristics can be tailored from the C-band to the Ku-band by adjusting the loading of PPy.This work provides valuable insights into the fabrication of conductive MOF composites by presenting a straightforward pathway to enhance and reg-ulate electrical conduction in MOF-based nanocomposites,thus paving a way to facilely fabricate pristine MOF-based microwave absorbers.
文摘Scientific research is a journey into an uncharted territory.Researchers need to have the big picture for navigation and at the same time be detail-oriented,as details make a difference.Here I offer a few tips for conducting research that I summarized based on my 30+years of research experience.
基金supported by the National Key Research and Development Program of China(2021YFB4001400)the Cooperation Project of Shan-dong Energy Group Co.,Ltd.(20200871)supported by 111 Project 2.0(BP0618008).
文摘This study addresses the challenge of high sintering temperatures in proton-conducting fuel cells(PCFCs)with BaCeO_(3)-doped electrolytes.We demonstrate that 1 mol%copper(Cu)doping at the B-site of BaCe_(0.7)Zr_(0.1)(Dy_(0.1)|Yb_(0.1))_(0.2)O_(3-δ)(BCZDYb)improves sintering behavior,enabling densification at1400℃.However,Cu doping disrupts stoichiometry,creating barium vacancies and reducing protonaccepting cations,affecting overall conductivity.This mechanism is confirmed through density functional theory(DFT)calculations and various experimental techniques,including crystal structure analysis using X-ray diffraction(XRD)and morphology and elemental analysis via field emission scanning electron microscopy(FESEM)and energy-dispersive X-ray spectroscopy(EDS).Electrochemical measurements are performed using the electrochemical impedance spectroscopy(EIS).The ionic conductivity of1 mol%Cu-doped BCZDYb(BCZDYb-1)is 1.49×10^(-2)S cm^(-1)at 650℃,which is~3.58 times higher than that of BCZDYb sintered at 1200℃.The BCZDYb-1 exhibits~16 times higher grain boundary conductivity when sintered at 1400℃,compared to undoped BCZDYb.The single cell employing BCZDYb-1 as the electrolyte achieved a power density of~606 mW cm^(-2)at 550℃.These results indicate that a controlled amount of Cu doping can enhance densification while maintaining high ionic co nductivity,making it suitable for practical applications in PCFCs operating at lower temperatures.
基金supported by the Natural Sciences and Engineering Research Council(NSERC)of Canada,Discovery Grant(GRPIN-2016-05494)Strategic Research Projects of Alberta Innovates Technology Futures(#G2016000655)funding from the Canada First Research Excellence Fund(CFREF-2015-00001).
文摘“Three-in-one”cathode,achieved via B-site heavy-doping of transition elements(typically Co,Fe)into proton-conductive perovskite,holds promise for enhancing the performance of proton-conducting solid oxide fuel cell(H-SOFC)operated below 650℃for electricity generation.However,its electrochemical behavior above 650℃,essential for improving the efficiency of H-SOFC for fuel conversion,remains insufficiently explored.It is still challenging to propose guidance for the design of“threein-one”cathode toward optimal H-SOFC performance below and above 650℃,with the prerequisite of gaining a comprehensive understanding of the roles of Co and Fe in determining the H-SOFC performance.This work is to address this challenge.Through theoretical/experimental studies,Co is identified to play a role in improving the oxygen reduction reaction(ORR)activity while Fe plays a role in facilitating the cathode/electrolyte interfacial proton conduction.Therefore,if the operating temperature is above 650℃,lowering the Co/Fe ratio in“three-in-one”cathode becomes crucial since the limiting factor shifts from ORR activity to proton conduction.Implementing this strategy,the SOFC using BaCo_(0.15)-Fe_(0.55)Zr_(0.1)Y_(0.1)Yb_(0.1)O_(3−δ)cathode achieves peak power densities of 1.67Wcm^(−2)under H-SOFC mode at 700℃and 2.32Wcm^(−2)under dual ion-conducting SOFC mode at 750℃,which are the highest reported values so far.
基金supported by the China Scholarship Council(No.202408120105)National Natural Science Foundation of China(32301530)+5 种基金Young Elite Scientist Sponsorship Program by CAST(No.YESS20230242)Tianjin Excellent Special Commissioner for Agricultural Science and Technology Project(23ZYCGSN00580)Natural Science Foundation of Tianjin(23JCZDJC00630)China Postdoctoral Science Foundation(2023M740563)State Key Laboratory of Pulp and Paper Engineering(202412,202413)the Central Publicinterest Scientific Institution Basa Research Fund(No.Y2022QC30).
文摘Proton-conducting materials have attracted considerable interest because of their extensive application in energy storage and conversion devices.Among them,metal-organic frameworks(MOFs)present tremendous development potential and possibilities for constructing novel advanced proton conductors due to their special advantages in crystallinity,designability,and porosity.In particular,several special design strategies for the structure of MOFs have opened new doors for the advancement of MOF proton conductors,such as charged network construction,ligand functionalization,metal-center manipulation,defective engineering,vip molecule incorporation,and pore-space manipulation.With the implementation of these strategies,proton-conducting MOFs have developed significantly and profoundly within the last decade.Therefore,in this review,we critically discuss and analyze the fundamental principles,design strategies,and implementation methods targeted at improving the proton conductivity of MOFs through representative examples.Besides,the structural features,the proton conduction mechanism and the behavior of MOFs are discussed thoroughly and meticulously.Future endeavors are also proposed to address the challenges of proton-conducting MOFs in practical research.We sincerely expect that this review will bring guidance and inspiration for the design of proton-conducting MOFs and further motivate the research enthusiasm for novel proton-conducting materials.
基金This work was supported by the National Natural Science Foundation of China and the Chinese Academy of Sciences.
文摘A physical model of series of the conductivity on chain and the interchain conductivitybetween chains is proposed to explain enhanced conductivity of stretched conducting polymers.This model suggests that the enhanced conductivity for stretched conducting polymers might bedue to increasing of the interchain conductivity between chains along the elongation direction afterdrawing processes if the conductivity on chain is assumed much larger than that of the interchainconductivity between chains. According to this model, it is expected that the temperaturedependence of conductivity measured by four-probe method for stretched conducting polymers iscontrolled by a variation of the interchain conductivity between chains with temperature, whichcan be used to explain that a metallic temperature dependence of conductivity for stretchedconducting polymers is not observed although the conductivity along the elongation direction isenhanced by two or three orders of magnitude.
基金Project(N100602010)supported by the Fundamental Research Funds for the Central Universities of China
文摘The preparation of La0.4Sr0.6TiO3 （LSTO） buffer layer and YBa2Cu3O7-δ（YBCO） superconducting thick film by a low cost technology was studied. The crystal orientation of LSTO and YBCO films was detected by X-ray diffraction, the conductivity of LSTO film and superconductivity of YBCO coating were investigated by standard four-probe method. Excellent in-plane alignment, smooth and dense LSTO buffer layer was successfully prepared on textured Ni-W taps by metal organic deposition （MOD）. YBCO thick film was fabricated by electrophoretic deposition （EPD）. The effects of applied voltage and deposition time on the YBCO coatings properties were studied. The results show that the critical current density of the YBCO coating deposited under 138 V for 35 min was about 600 A/cm2 （0 T, 77 K）.
基金Supported by the Basic Natural Science Research Fundation of the Jiangsu Higher Education Institutions of China(06KJD180201)~~
文摘The conducting tissue structure of transverse and longitudinal sections was observed on leaves of Podocarpus and Nageia.Results showed:in Podocarpus leaves,there is only one midrib,the xylem tracheid of midrib vascular bundle is multi-form,transfusion tissue belongs to Cycas-type and transfusion tracheids are isodiametric,the accessory transfusion tracheids between palisade tissue and sponge tissue are developed;in Nageia leaves,there are plenty of parallel leaves,the xylem tracheids of each vein are relatively simple,transfusion tissue belongs to Taxus-type and transfusion tracheids are longer in longitudinal section than that in transverse section,the accessory transfusion tissue between palisade tissue and sponge tissue is absent.Considering other differences that in leaves of Podocarpus there are three resin ducts under vascular bundle of midrib,mesophyll cells are differentiated into palisade tissue and sponge tissue;in leaves of Nageia,there is only one resin duct under vascular bundle in each vein and no obvious differentiation in mesophyll cells,palisade tissue can be found on both sides,and sclereids can also be found in mesophyll tissue.The anatomical differences of leaf veins and mesophylls between Nageia and Podocarpus mentioned above support the viewpoint that Nageia and Podocarpus are two independent genera.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11925304 and 12020101002)the Chinese Academy of Sciences Program(Grant No.GJJSTD20210002).
文摘Disordered superconducting materials like NbTiN possess a high kinetic inductance fraction and an adjustable critical temperature, making them a good choice for low-temperature detectors. Their energy gap(D), critical temperature(T_(c)),and quasiparticle density of states(QDOS) distribution, however, deviate from the classical BCS theory due to the disorder effects. The Usadel equation, which takes account of elastic scattering, non-elastic scattering, and electro–phonon coupling,can be applied to explain and describe these deviations. This paper presents numerical simulations of the disorder effects based on the Usadel equation to investigate their effects on the △, Tc, QDOS distribution, and complex conductivity of the NbTiN film. Furthermore, NbTiN superconducting resonators with coplanar waveguide(CPW) structures are fabricated and characterized at different temperatures to validate our numerical simulations. The pair-breaking parameter α and the critical temperature in the pure state T_(c)^(P) of our NbTiN film are determined from the experimental results and numerical simulations. This study has significant implications for the development of low-temperature detectors made of disordered superconducting materials.
基金Project supported by the National Key Basic Research and Development Programme of China （Grant No 2001CB610504） and the National Natural Science Foundation of China （Grant Nos 60576039 and 10374060）.Acknowledgments We thank Dr Wang Zhuo and Dr Yang ChangHong for their assistance in the experiment.
文摘Transparent and conducting zirconium-doped zinc oxide films with high transparency and relatively low resistivity have been successfully prepared by radio frequency （RF） msgnetron sputtering at room temperature, The RF power is varied from 75 to 150 W. At first the crystallinity and conductivity of the film are improved and then both of them show deterioration with the increase of the RF power, The lowest resistivity achieved is 2.07 × 10^-3Ωcm at an RF power of 100W with a Hall mobility of 16cm^2V^-1s^-1 and a carrier concentration of 1.95 × 10^20 cm^-3. The films obtained are polycryetalline with a hexagonal structure and a preferred orientation along the c-axis, All the films have a high transmittance of approximately 92% in the visible range. The optical band gap is about 3.33 eV for the films deposited at different RF powers.
基金the financial support from the National Natural Science Foundation of China(Nos.50963002 and 51073074)
文摘Corrosion protection of the hull steel by the conventional epoxy paint containing a small amount of commercial poly（3,4-ethylenedioxythiophene）/poly（styrene sulfonate） （PEDOT/PSS）, which is one of the most popular and successful inherently conducting polymers as the corrosion inhibitor was studied. The corrosion behavior of the samples was investigated in seawater by electrochemical impedance spectroscopy and open circuit potential. Scanning electron microscopy was used to observe the surface morphology of the samples after corrosion. It was found that adding a small amount of PEDOT/PSS to the epoxy resin can significantly improve its corrosion protection.
基金the support from National Program for Thousand Young Talents of Chinathe National Natural Science Foundation of China(No.21544001)Fudan University
文摘In recent years,as a new class of two-dimensional polymer,covalent organic frameworks（COFs） have attracted intensive attention and developed rapidly.This review provides an overview of a type of COFs which can be utilized as organic semiconductors.Carefully choosing monomers as the building blocks will bestow different types of semiconducting character on COFs.We summarize the p-type,n-type and ambipolar semiconducting COFs and highlight the effects of π-functional building blocks on the photoconductive behaviors of the semiconducting COFs.
基金supported by The Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning(No.TP2015002)the National Natural Science Foundation of China(No.51403099)
文摘Three-dimensional graphene/conducting polymer（3DGCP） composites have received significant attention in recent years due to their unique structures and promising applications in energy storage.With the structural diversity of graphene and π-functional conducting polymers via rich chemical routes,a number of 3DGCP composites with novel structures and attractive performance have been developed.Particularly,the hierarchical porosity,the interactions between graphene and conducting polymers as well as the their synergetic effects within 3DGCP composites can be well combined and elaborated by various synthetic methods,which made 3DGCP composites show unique electrochemical properties and significantly improved performance in energy storage fields compared to other graphenebased composites.In this short review,we present recent advances in 3DGCP composites in developing effective strategies to prepare 3DGCP composites and exploring them as a unique platform for supercapacitors with unprecedented performance.The challenges and future opportunities are also discussed for promotion of further study.
文摘Excellent antibacterial performance of polyaniline （PAni） against Escherichia coli and Gram-positive Staphylococcus aureus microorganisms has been demonstrated under both dark and visible light conditions. The electrostatic adherence between the PAni molecules and the bacteria may play a very important role for the antibacterial reaction of the PAni. As a result of our investigation, conducting PAni and its composites/blends are believed to be useful as a new type of antibacterial agent, self-clean as well as multifunctional material for improving the human health and living environment.
基金the National Natural Science Foundation of China(51973157)the Special Grade of the Financial Support from the China Postdoctoral Science Foundation(2020T130469)+1 种基金the China Postdoctoral Science Foundation Grant(2019 M651047)the Science and Technology Plans of Tianjin(19PTSYJC00010)for their financial support。
文摘Lithium-sulfur(Li-S) batteries and lithium-selenium(Li-Se) batteries,as environmental protection energy storage systems with outstanding theoretical specific capacities and high energy densities,have become the hotspots of current researches.Besides,elemental S(Se) raw materials are widely sourced and their production costs are both low,which make them considered one of the new generations of high energy density electrochemical energy storage systems with the most potential for development.However,poor conductivity of elemental S/Se and the notorious "shuttle effect" of lithium polysulfides(polyselenides) severely hinder the commercialization of Li-S/Se batteries.Thanks to the excellent electrical conductivity and strong absorption of lithium polysulfide(polyselenide) about electronically conducting polymer,some of the above thorny problems have been effectively alleviated.The review presents the fundamental studies and current development trends of common electronically conducting polymers in various components of Li-S/Se batteries,which involves polyaniline(PANI) polypyrrole(PPy),and polythiophene(PTh) with its derivatives,e.g.polyethoxythiophene(PEDOT) and poly(3,4-ethylene dioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS).Finally,the review not only summarizes the research directions and challenges facing the application of electronically conducting polymers,but also looks forward to the development prospects of them,which will provide a way for the practical use of electronically conducting polymers in Li-S/Se batteries with outstanding electrochemical properties in the short run.
基金Project supported by the National Natural Science Foundation of China (No.10172036)the Education Ministry Scientific Research Foundation for Returned Overseas Chinese Scholars.
文摘The finite element formulation for analyzing static damage near a conducting crack in a thin piezoelectric plate is established from the virtual work principle of piezoelectricity.The damage fields under various mechanical and electrical loads are calculated carefully by using an effective iterative procedure.The numerical results show that all the damage fields around a crack tip are fan-shaped and the electric field applied has great influence on the mechanical damage, which is related to the piezoelectric properties.
基金The authors acknowledge funding from the National Natural Science Foundation of China(61974150 and 51773213)Key Research Program of Frontier Sciences,CAS(QYZDB-SSW-JSC047)+1 种基金the Fundamental Research Funds for the Central Universities,the CAS-EU S&T cooperation partner program(174433KYSB20150013)the Natural Science Foundation of Ningbo(2018A610135).
文摘Nonfullerene organic solar cells(OSCs)have achieved breakthrough with pushing the efficiency exceeding 17%.While this shed light on OSC commercialization,high-performance flexible OSCs should be pursued through solution manufacturing.Herein,we report a solution-processed flexible OSC based on a transparent conducting PEDOT:PSS anode doped with trifluoromethanesulfonic acid(CF3SO3H).Through a low-concentration and low-temperature CF3SO3H doping,the conducting polymer anodes exhibited a main sheet resistance of 35Ωsq−1(minimum value:32Ωsq−1),a raised work function(≈5.0 eV),a superior wettability,and a high electrical stability.The high work function minimized the energy level mismatch among the anodes,hole-transporting layers and electron-donors of the active layers,thereby leading to an enhanced carrier extraction.The solution-processed flexible OSCs yielded a record-high efficiency of 16.41%(maximum value:16.61%).Besides,the flexible OSCs afforded the 1000 cyclic bending tests at the radius of 1.5 mm and the long-time thermal treatments at 85°C,demonstrating a high flexibility and a good thermal stability.
基金supported by the National Natural Science Foundation of China(51978569 and 52172097)Key Research and Development Program of Shaanxi Province(2022GY-301)+4 种基金Basic and Public Projects of Zhejiang Province(LGF21E020001)China Postdoctoral Science Foundation(2020 M683467)Basic Research Operating Expenses of XJTU(xzy022022041)China Scholarship Council foundation(201906285020 and 202206280212)support from Faraday Institution LiSTAR Programme(EP/S003053/1,Grant FIRG014).
文摘Lithium-sulfur(Li-S)batteries have attracted increased interest because of the high theoretical energy density,low cost,and environmental friendliness.Conducting polymers(CPs),as one of the most promising materials used in Li-S batteries,can not only facilitate electron transfer and buffer the large volumetric change of sulfur benefiting from their porous structure and excellent flexibility,but also enable stronger physical/chemical adsorption capacity toward polysulfides(LiPSs)when doped with abundant heteroatoms to promote the sulfur redox kinetics and achieve the high sulfur loading.This review firstly introduces the properties of various CPs including structural CPs(polypyrrole(PPy),polyaniline(PANi),polyethylene dioxothiophene[PEDOT])and compound CPs(polyethylene oxide(PEO),polyvinyl alcohol(PVA)and poly(acrylic acid)[PAA]),and their application potential in Li-S batteries.Furthermore,the research progress of various CPs in different components(cathode,separator,and interlayer)of Li-S batteries is systematically summarized.Finally,the application perspective of the CPs in Li-S batteries as a potential guidance is comprehensively discussed.
基金Sponsored by State Key Laboratory of Explosion Science and Technology Research Foundation (ZDKT08-04)
文摘Insulating parts are easily subjected to pollution which may cause damage to the electric system. A typical disc insulator is chosen as the target to test its flashover voltage by using an artificial pollution system. This test system aims at obtaining characteristic parameters of damage for chosen conducting sola to the selected insulator. Experimental results show that thickness and electric conductivity of pollutant layer over insulators are the main parameters in damage evaluation. The flashover voltage decreases with increase of thickness and/or conductivity. These results provide a better basis on further revealing the damaging nature of conducting sol materials.
基金supported by the National Natural Science Foundation of China(Nos.11972257,11832014,11762016,11472193)the Fundamental Research Funds for the Central Universities(No.22120180223)。
文摘The contact problem for thermoelectric materials with functionally graded properties is considered.The material properties,such as the electric conductivity,the thermal conductivity,the shear modulus,and the thermal expansion coefficient,vary in an exponential function.Using the Fourier transform technique,the electro-thermoelastic problems are transformed into three sets of singular integral equations which are solved numerically in terms of the unknown normal electric current density,the normal energy flux,and the contact pressure.Meanwhile,the complex homogeneous solutions of the displacement fields caused by the gradient parameters are simplified with the help of Euler’s formula.After addressing the non-linearity excited by thermoelectric effects,the particular solutions of the displacement fields can be assessed.The effects of various combinations of material gradient parameters and thermoelectric loads on the contact behaviors of thermoelectric materials are presented.The results give a deep insight into the contact damage mechanism of functionally graded thermoelectric materials(FGTEMs).
