What factors fundamentally determine the value of superconducting transition temperature Tc in high temperature superconductors has been the subject of intense debate.Following the establishment of an empirical law kn...What factors fundamentally determine the value of superconducting transition temperature Tc in high temperature superconductors has been the subject of intense debate.Following the establishment of an empirical law known as Homes'law,there is a growing consensus in the community that the Tc value of the cuprate superconductors is closely linked to the superfluid density(ρ_(s))of its ground state and the conductivity(σ)of its normal state.However,all the data supporting this empirical law(ρ_(s)=AσT_(c))have been obtained from the ambientpressure superconductors.In this study,we present the first high-pressure results about the connection of the quantities of ρ_(s) and σ with T_(c),through the studies on the Bi_(1.74)Pb_(0.38)Sr_(1.88)CuO_(6+δ)and Bi_(2)Sr_(2)CaCu_(2)O_(8+δ),in which the value of their high-pressure resistivity(ρ=1/σ)is achieved by adopting our newly established method,while the quantity ofρs is extracted using Homes'law.We highlight that the Tc values are strongly linked to the joint response factors of magnetic field and electric field,i.e.,ρ_(s) and σ,respectively,implying that the physics determining T_(c) is governed by the intrinsic electromagnetic fields of the system.展开更多
The practical application of rechargeable lithium metal batteries(LMBs) encounters significant challenges due to the notorious dendrite growth triggered by uneven Li deposition behaviors. In this work,a mechanically r...The practical application of rechargeable lithium metal batteries(LMBs) encounters significant challenges due to the notorious dendrite growth triggered by uneven Li deposition behaviors. In this work,a mechanically robust and single-ion-conducting interfacial layer, fulfilled by the strategic integration of flexible cellulose acetate(CA) matrix with rigid graphene oxide(GO) and Li F fillers(termed the CGL layer), is rationally devised to serve as a stabilizer for dendrite-free lithium(Li) metal batteries. The GCL film exhibits favorable mechanical properties with high modulus and flexibility that help to relieve interface fluctuations. More crucially, the electron-donating carbonyl groups(C=O) enriched in GCL foster a strengthened correlation with Li^(+), which availably aids the Li^(+)desolvation process and expedites facile Li^(+)mobility, yielding exceptional Li^(+) transference number of 0.87. Such single-ion conductive properties regulate rapid and uniform interfacial transport kinetics, mitigating the growth of Li dendrites and the decomposition of electrolytes. Consequently, stable Li anode with prolonged cycle stabilities and flat deposition morphologies are realized. The Li||LiFePO_(4) full cells with CGL protective layer render an outstanding cycling capability of 500 cycles at 3 C, and an ultrahigh capacity retention of 99.99% for over 220 cycles even under harsh conditions. This work affords valuable insights into the interfacial regulation for achieving high-performance LMBs.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
Electrocatalysis enables the industrial transition to sustainable production of chemicals using abundant precursors and electricity from renewable sources.De-centralized production of hydrogen peroxide(H_(2)O_(2))from...Electrocatalysis enables the industrial transition to sustainable production of chemicals using abundant precursors and electricity from renewable sources.De-centralized production of hydrogen peroxide(H_(2)O_(2))from water and oxygen of air is highly desirable for daily life and industry.We report an effective electrochemical refinery(e-refinery)for H_(2)O_(2)by means of electrocatalysis-controlled comproportionation reaction(2_(H)O+o→2HO),feeding pure water and oxygen only.Mesoporous nickel(Ⅱ)oxide(NiO)was used as electrocatalyst for oxygen evolution reaction(OER),producing oxygen at the anode.Conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)drove the oxygen reduction reaction(ORR),forming H_(2)O_(2)on the cathode.The reactions were evaluated in both half-cell and device configurations.The performance of the H_(2)O_(2)e-refinery,assembled on anion-exchange solid electrolyte and fed with pure water,was limited by the unbalanced ionic transport.Optimization of the operation conditions allowed a conversion efficiency of 80%.展开更多
The growing demand for substitutes of lithium chemistries in battery leads to a surge in budding novel anion-based electrochemical energy storage,where the chloride ion batteries(CIBs)take over the role.The applicatio...The growing demand for substitutes of lithium chemistries in battery leads to a surge in budding novel anion-based electrochemical energy storage,where the chloride ion batteries(CIBs)take over the role.The application of CIBs is limited by the dissolution and side reaction of chloride-based electrode materials in a liquid electrolyte.On the flipside,its solid-state electrolytes are scarcely reported due to the challenge in realizing fast Cl^(-)conductivity.The present study reports[Al(DMSO)_(6)]Cl_(3),a solid-state metal-organic material,allows chloride ion transfer.The strong Al-Cl bonds in AlCl_(3)are broken down after coordinating of Al^(3+)by ligand DMSO,and Cl^(-)in the resulting compound is weakly bound to complexions[Al(DMSO)_(6)]^(3+),which may facilitate Cl^(-)migration.By partial replacement of Cl^(-)with PF_(6)^(-),the room-temperature ionic conductivity of as-prepared electrolyte is increased by one order of magnitude from 2.172×10^(-5)S cm^(-1)to 2.012×10^(-4)S cm^(-1).When they are assembled with Ag(anode)/Ag-AgCl(cathode)electrode system,reversible electrochemical redox reactions occur on both sides,demonstrating its potential for solid-state chloride ion batteries.The strategy by weakening the bonding interaction using organic ligands between Cl^(-)and central metallic ions may provide new ideas for developing solid chloride-ion conductors.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
Solid-state electrolytes have attracted considerable attention in new energyrelated devices due to their high safety and broad application platform.Polyoxometalates(POMs)are a kind of molecular-level cluster compounds...Solid-state electrolytes have attracted considerable attention in new energyrelated devices due to their high safety and broad application platform.Polyoxometalates(POMs)are a kind of molecular-level cluster compounds with unique structures.In recent years,owing to their abundant physicochemical properties(including high ionic conductivity and reversible redox activity),POMs have shown great potential in becoming a new generation of solid-state electrolytes.In this review,an overview is investigated about how POMs have evolved as ion-conducting materials from basic research to novel solid-state electrolytes in energy devices.First,some expressive POM-based ion-conducting materials in recent years are introduced and classified,mainly inspecting their structural and functional relationship.After that,it is further focused on the application of these ionconducting electrolytes in the fields of proton exchange membranes,supercapacitors,and ion batteries.In addition,some properties of POMs(such as inherent dimension,capable of forming stable hydrogen bonds,and reversible bonding to water molecules)enable these functional POM-based electrolytes to be employed in innovative applications such as ion selection,humidity sensing,and smart materials.Finally,some fundamental recommendations are given on the current opportunities and challenges of POM-based ion-conducting electrolytes.展开更多
Polymer electrolytes(PEs)have been long recognized as the key materials to enable energy-dense batteries and render flexible energy devices practically viable,owing to their chemical and mechanical reliability.However...Polymer electrolytes(PEs)have been long recognized as the key materials to enable energy-dense batteries and render flexible energy devices practically viable,owing to their chemical and mechanical reliability.However,much of their promise is yet to be realized.The roomtemperature ion conductivity of existing PEs still falls short of the implementation criterion of 10^(-4) S cm^(-1) on the promise of acceptable mechanical properties,thereby precluding their practical application.The twin but inversely related duties of polymers,that is,functioning as both an ion-conducting medium and a structural backbone,underlie this issue but are less elucidated systematically.The polyacrylate(PA)family is among promising polymer matrices on account of ester polarity,electrode compatibility,chemical tunability,and mechanical durability.The extensive applicability of PA in plasticized gels,dry solids,and emerging composites makes PA-based PEs representative to illustrate the trade-off between ion conduction and mechanical strength.We herein seek to outline the stated long-standing conflict exemplified by PA-based PEs,focusing on crucial strategies toward balancing and reconciling the two mutually exclusive properties,with the intention of offering designing guidelines for next-generation PEs.展开更多
A novel normally-off double channel reverse conducting(DCRC)HEMT with an integrated MOS-channel diode(MCD)is proposed and investigated by TCAD simulation.The proposed structure has two features:one is double heterojun...A novel normally-off double channel reverse conducting(DCRC)HEMT with an integrated MOS-channel diode(MCD)is proposed and investigated by TCAD simulation.The proposed structure has two features:one is double heterojunctions to form dual 2DEG channels named the 1^(st)path and the 2^(nd)path for reverse conduction,and the other is the MCD forming by the trench source metal,source dielectric,and Ga N.At the initial reverse conduction stage,the MCD acts as a switch to control the 1^(st)path which would be turned on prior to the 2^(nd)path.Because of the introduction of the 1^(st)path,the DCRC-HEMT has an additional reverse conducting channel to help enhance the reverse conduction performance.Compared with the conventional HEMT(Conv.HEMT),the DCRC-HEMT can obtain a low reverse turn-on voltage(VRT)and its VRTis independent of the gate-source bias(VGS)at the same time.The DCRC-HEMT achieves the VRTof 0.62 V,which is 59.7%and 75.9%lower than that of the Conv.HEMT at VGS=0 V and-1 V,respectively.In addition,the forward conduction capability and blocking characteristics almost remain unchanged.In the end,the key fabrication flows of DCRC-HEMT are presented.展开更多
Graphene-based thermally conductive composites have been proposed as effective thermal management materials for cooling high-power electronic devices.However,when flexible graphene nanosheets are assembled into macros...Graphene-based thermally conductive composites have been proposed as effective thermal management materials for cooling high-power electronic devices.However,when flexible graphene nanosheets are assembled into macroscopic thermally conductive composites,capillary forces induce shrinkage of graphene nanosheets to form wrinkles during solution-based spontaneous drying,which greatly reduces the thermal conductivity of the composites.Herein,graphene nanosheets/aramid nanofiber(GNS/ANF)composite films with high thermal conductivity were prepared by in-plane stretching of GNS/ANF composite hydrogel networks with hydrogen bonds andπ-πinteractions.The in-plane mechanical stretching eliminates graphene nanosheets wrinkles by suppressing inward shrinkage due to capillary forces during drying and achieves a high in-plane orientation of graphene nanosheets,thereby creating a fast in-plane heat transfer channel.The composite films(GNS/ANF-60 wt%)with eliminated graphene nanosheets wrinkles showed a significant increase in thermal conductivity(146 W m^(−1)K^(−1))and tensile strength(207 MPa).The combination of these excellent properties enables the GNS/ANF composite films to be effectively used for cooling flexible LED chips and smartphones,showing promising applications in the thermal management of high-power electronic devices.展开更多
Mg-Al alloys have excellent strength and ductility but relatively low thermal conductivity due to Al addition.The accurate prediction of thermal conductivity is a prerequisite for designing Mg-Al alloys with high ther...Mg-Al alloys have excellent strength and ductility but relatively low thermal conductivity due to Al addition.The accurate prediction of thermal conductivity is a prerequisite for designing Mg-Al alloys with high thermal conductivity.Thus,databases for predicting temperature-and composition-dependent thermal conductivities must be established.In this study,Mg-Al-La alloys with different contents of Al2La,Al3La,and Al11La3phases and solid solubility of Al in the α-Mg phase were designed.The influence of the second phase(s) and Al solid solubility on thermal conductivity was investigated.Experimental results revealed a second phase transformation from Al_(2)La to Al_(3)La and further to Al_(11)La_(3)with the increasing Al content at a constant La amount.The degree of the negative effect of the second phase(s) on thermal diffusivity followed the sequence of Al2La>Al3La>Al_(11)La_(3).Compared with the second phase,an increase in the solid solubility of Al in α-Mg remarkably reduced the thermal conductivity.On the basis of the experimental data,a database of the reciprocal thermal diffusivity of the Mg-Al-La system was established by calculation of the phase diagram (CALPHAD)method.With a standard error of±1.2 W/(m·K),the predicted results were in good agreement with the experimental data.The established database can be used to design Mg-Al alloys with high thermal conductivity and provide valuable guidance for expanding their application prospects.展开更多
Despite the growing demand for transparent conductive films in smart and wearable electronics for electromagnetic interference(EMI)shielding,achieving a flexible EMI shielding film,while maintaining a high transmittan...Despite the growing demand for transparent conductive films in smart and wearable electronics for electromagnetic interference(EMI)shielding,achieving a flexible EMI shielding film,while maintaining a high transmittance remains a significant challenge.Herein,a flexible,transparent,and conductive copper(Cu)metal mesh film for EMI shielding is fabricated by self-forming crackle template method and electroplating technique.The Cu mesh film shows an ultra-low sheet resistance(0.18Ω□^(-1)),high transmittance(85.8%@550 nm),and ultra-high figure of merit(>13,000).It also has satisfactory stretchability and mechanical stability,with a resistance increases of only 1.3%after 1,000 bending cycles.As a stretchable heater(ε>30%),the saturation temperature of the film can reach over 110°C within 60 s at 1.00 V applied voltage.Moreover,the metal mesh film exhibits outstanding average EMI shielding effectiveness of 40.4 dB in the X-band at the thickness of 2.5μm.As a demonstration,it is used as a transparent window for shielding the wireless communication electromagnetic waves.Therefore,the flexible and transparent conductive Cu mesh film proposed in this work provides a promising candidate for the next-generation EMI shielding applications.展开更多
Progress in the fast charging of high-capacity silicon monoxide(SiO)-based anode is currently hindered by insufficient conductivity and notable volume expansion.The construction of an interface conductive network effe...Progress in the fast charging of high-capacity silicon monoxide(SiO)-based anode is currently hindered by insufficient conductivity and notable volume expansion.The construction of an interface conductive network effectively addresses the aforementioned problems;however,the impact of its quality on lithium-ion transfer and structure durability is yet to be explored.Herein,the influence of an interface conductive network on ionic transport and mechanical stability under fast charging is explored for the first time.2D modeling simulation and Cryo-transmission electron microscopy precisely reveal the mitigation of interface polarization owing to a higher fraction of conductive inorganic species formation in bilayer solid electrolyte interphase is mainly responsible for a linear decrease in ionic diffusion energy barrier.Furthermore,atomic force microscopy and Raman shift exhibit substantial stress dissipation generated by a complete conductive network,which is critical to the linear reduction of electrode residual stress.This study provides insights into the rational design of optimized interface SiO-based anodes with reinforced fast-charging performance.展开更多
Understanding the thermal conductivity of granite is critical for many geological and deep engineering applications.The heated granite was subjected to air-,water-,and liquid nitrogen(LN2-)coolings in this context.The...Understanding the thermal conductivity of granite is critical for many geological and deep engineering applications.The heated granite was subjected to air-,water-,and liquid nitrogen(LN2-)coolings in this context.The transient hot-wire technique was used to determine the equivalent thermal conductivity(ETC)of the granite before and after treatment.The deterioration mechanism of ETC is analyzed from the meso-perspective.Finally,the numerical model is used to quantitatively study the impact of cooling rate on the microcrack propagation and heat conduction characteristics of granite.The results show that the ETC of granite is not only related to the heating temperature,but also affected by the cooling rate.The ETC of granite decreases nonlinearly with increasing heating temperature.A faster cooling rate causes a greater decrease in ETC at the same heating temperature.The higher the heating temperature,the stronger the influence of cooling rate on ETC.The main explanation for the decrease in ETC of granite is the increase in porosity and microcrack density produced by the formation and propagation of pore structure and microcracks during heating and cooling.Further analysis displays that the damage of granite at the heating stage is induced by the difference in thermal expansion and elastic properties of mineral particles.At the cooling stage,the faster cooling rate causes a higher temperature gradient,which in turn produces greater thermal stress.As a result,it not only causes new cracks in the granite,but also aggravates the damage at the heating stage,which induces a further decrease in the heat conduction performance of granite,and this scenario is more obvious at higher temperatures.展开更多
With an extension of the geological entropy concept in porous media,the approach called directional entrogram is applied to link hydraulic behavior to the anisotropy of the 3D fracture networks.A metric called directi...With an extension of the geological entropy concept in porous media,the approach called directional entrogram is applied to link hydraulic behavior to the anisotropy of the 3D fracture networks.A metric called directional entropic scale is used to measure the anisotropy of spatial order in different directions.Compared with the traditional connectivity indexes based on the statistics of fracture geometry,the directional entropic scale is capable to quantify the anisotropy of connectivity and hydraulic conductivity in heterogeneous 3D fracture networks.According to the numerical analysis of directional entrogram and fluid flow in a number of the 3D fracture networks,the hydraulic conductivities and entropic scales in different directions both increase with spatial order(i.e.,trace length decreasing and spacing increasing)and are independent of the dip angle.As a result,the nonlinear correlation between the hydraulic conductivities and entropic scales from different directions can be unified as quadratic polynomial function,which can shed light on the anisotropic effect of spatial order and global entropy on the heterogeneous hydraulic behaviors.展开更多
The application of solid polymer electrolytes(SPEs)is severely impeded by the insufficient ionic conductivity and low Li^(+)transference numbers(t_(Li)^(+)).Here,we report an iodine-driven strategy to address both the...The application of solid polymer electrolytes(SPEs)is severely impeded by the insufficient ionic conductivity and low Li^(+)transference numbers(t_(Li)^(+)).Here,we report an iodine-driven strategy to address both the two longstanding issues of SPEs simultaneously.Electronegative lodine-containing groups introduced on polymer chains effectively attract Li^(+)ions,facilitate Li^(+)transport,and promote the dissociation of Li salts.Meanwhile,iodine is also favorable to alleviate the strong O-Li^(+)coordination through a Lewis acidbase interaction,further improving the ionic conductivity and t_(Li)^(+).As a proof of concept,an iodinated single-ion conducting polymer electrolyte(IPE)demonstrates a high ionic conductivity of 0.93 mS cm^(-1)and a high t_(Li)^(+)of 0.86 at 25℃,which is among the best results ever reported for SPEs.Moreover,symmetric Li/Li cells with IPE achieve a long-term stability over 2600 h through the in-situ formed LiF-rich interphase.As a result,Li-S battery with IPE maintains a high capacity of 623.7 mAh g^(-1)over 300 cycles with an average Coulombic efficiency of 99%.When matched with intercalation cathode chemistries,Li/IPE/LiFePO_(4)and Li/IPE/LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)solid-state batteries also deliver high-capacity retentions of 95%and 97%at 0.2 C after 120 cycles,respectively.展开更多
With the rapid development of 5G information technology,thermal conductivity/dissipation problems of highly integrated electronic devices and electrical equipment are becoming prominent.In this work,“high-temperature...With the rapid development of 5G information technology,thermal conductivity/dissipation problems of highly integrated electronic devices and electrical equipment are becoming prominent.In this work,“high-temperature solid-phase&diazonium salt decomposition”method is carried out to prepare benzidine-functionalized boron nitride(m-BN).Subsequently,m-BN/poly(pphenylene benzobisoxazole)nanofiber(PNF)nanocomposite paper with nacremimetic layered structures is prepared via sol–gel film transformation approach.The obtained m-BN/PNF nanocomposite paper with 50 wt%m-BN presents excellent thermal conductivity,incredible electrical insulation,outstanding mechanical properties and thermal stability,due to the construction of extensive hydrogen bonds andπ–πinteractions between m-BN and PNF,and stable nacre-mimetic layered structures.Itsλ∥andλ_(⊥)are 9.68 and 0.84 W m^(-1)K^(-1),and the volume resistivity and breakdown strength are as high as 2.3×10^(15)Ωcm and 324.2 kV mm^(-1),respectively.Besides,it also presents extremely high tensile strength of 193.6 MPa and thermal decomposition temperature of 640°C,showing a broad application prospect in high-end thermal management fields such as electronic devices and electrical equipment.展开更多
Proton conducting ceramic cells(PCCs)are an attractive emerging technology operating in the intermediate temperature range of 500 to 700℃.In this work,we evaluate the production of hydrogen at intermediate temperatur...Proton conducting ceramic cells(PCCs)are an attractive emerging technology operating in the intermediate temperature range of 500 to 700℃.In this work,we evaluate the production of hydrogen at intermediate temperatures by proton conducting ceramic cell electrolysis(PCCEL).We demonstrate a highperformance steam electrolysis owing to a composite positrode based on BaGd_(0.8)La_(0.2)Co_(2)O_(6-δ)(BGLC1082)and BaZr0.5Ce0.4Y0.1O3-δ(BZCY541).The high reliability of PCCEL is demonstrated for 1680 h at a current density as high as-0.8 A cm^(-2)close to the thermoneutral cell voltage at 600℃.The electrolysis cell showed a specific energy consumption ranging from 54 to 66 kW h kg^(-1)that is comparable to state-of-the-art low temperature electrolysis technologies,while showing hydrogen production rates systematically higher than commercial solid oxide ceramic cells(SOCs).Compared to SOCs,the results verified the higher performances of PCCs at the relevant operating temperatures,due to the lower activation energy for proton transfer comparing with oxygen ion conduction.However,because of the p-type electronic conduction in protonic ceramics,the energy conversion rate of PCCs is relatively lower in steam electrolysis.The faradaic efficiency of the PCC in electrolysis mode can be increased at lower operating temperatures and in endothermic conditions,making PCCEL a technology of choice to valorize high temperature waste heat from industrial processes into hydrogen.To increase the faradaic efficiency by optimizing the materials,the cell design,or the operating strategy is a key challenge to address for future developments of PCCEL in order to achieve even more superior techno-economic merits.展开更多
Tissue engineering(TE)continues to be widely explored as a potential solution to meet critical clinical needs for diseased tissue replacement and tissue regeneration.In this study,we developed a poly(2-hydroxyethyl me...Tissue engineering(TE)continues to be widely explored as a potential solution to meet critical clinical needs for diseased tissue replacement and tissue regeneration.In this study,we developed a poly(2-hydroxyethyl methacrylate-co-methacrylic acid)(pHEMA-co-MAA)based hydrogel loaded with newly synthesized conductive poly(3,4-ethylene-dioxythiophene)(PEDOT)and polypyrrole(PPy)nanoparticles(NPs),and subsequently processed these hydrogels into tissue engineered constructs via three-dimensional(3D)printing.The presence of the NPs was critical as they altered the rheological properties during printing.However,all samples exhibited suitable shear thinning properties,allowing for the development of an optimized processing window for 3D printing.Samples were 3D printed into pre-determined disk-shaped configurations of 2 and 10 mm in height and diameter,respectively.We observed that the NPs disrupted the gel crosslinking efficiencies,leading to shorter degradation times and compressive mechanical properties ranging between 450 and 550 kPa.The conductivity of the printed hydrogels increased along with the NP concentration to(5.10±0.37)×10^(−7)S/cm.In vitro studies with cortical astrocyte cell cultures demonstrated that exposure to the pHEMA-co-MAA NP hydrogels yielded high cellular viability and proliferation rates.Finally,hydrogel antimicrobial studies with staphylococcus epidermidis bacteria revealed that the developed hydrogels affected bacterial growth.Taken together,these materials show promise for various TE strategies.展开更多
Clays have considerable influence on the electrical properties of hydrate-bearing sediments.It is desirable to understand the electrical properties of hydrate-bearing clayey sediments and to build hydrate saturation(S...Clays have considerable influence on the electrical properties of hydrate-bearing sediments.It is desirable to understand the electrical properties of hydrate-bearing clayey sediments and to build hydrate saturation(S_(h))models for reservoir evaluation and monitoring.The electrical properties of tetrahydrofuran-hydrate-bearing sediments with montmorillonite are characterized by complex conductivity at frequencies from 0.01 Hz to 1 kHz.The effects of clay and Sh on the complex conductivity were analyzed.A decrease and increase in electrical conductance result from the clay-swelling-induced blockage and ion migration in the electrical double layer(EDL),respectively.The quadrature conductivity increases with the clay content up to 10%because of the increased surface site density of counterions in EDL.Both the in-phase conductivity and quadrature conductivity decrease consistently with increasing Sh from 0.50 to 0.90.Three sets of models for Sh evaluation were developed.The model based on the Simandoux equation outperforms Archie’s formula,with a root-mean-square error(E_(RMS))of 1.8%and 3.9%,respectively,highlighting the clay effects on the in-phase conductivity.The fre-quency effect correlations based on in-phase and quadrature conductivities exhibit inferior performance(E_(RMS)=11.6%and 13.2%,re-spectively)due to the challenge of choosing an appropriate pair of frequencies and intrinsic uncertainties from two measurements.The second-order Cole-Cole formula can be used to fit the complex-conductivity spectra.One pair of inverted Cole-Cole parameters,i.e.,characteristic time and chargeability,is employed to predict S_(h) with an E_(RMS) of 5.05%and 9.05%,respectively.展开更多
基金supported by the National Key Research and Development Program of China(Grant Nos.2021YFA1401800 and 2022YFA1403900)the National Natural Science Foundation of China(Grant Nos.U2032214,12122414,12104487,and 12004419)+1 种基金the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB25000000)supported by the US Department of Energy,Office of Basic Energy Sciences(Grant No.DOE-sc0012704)。
文摘What factors fundamentally determine the value of superconducting transition temperature Tc in high temperature superconductors has been the subject of intense debate.Following the establishment of an empirical law known as Homes'law,there is a growing consensus in the community that the Tc value of the cuprate superconductors is closely linked to the superfluid density(ρ_(s))of its ground state and the conductivity(σ)of its normal state.However,all the data supporting this empirical law(ρ_(s)=AσT_(c))have been obtained from the ambientpressure superconductors.In this study,we present the first high-pressure results about the connection of the quantities of ρ_(s) and σ with T_(c),through the studies on the Bi_(1.74)Pb_(0.38)Sr_(1.88)CuO_(6+δ)and Bi_(2)Sr_(2)CaCu_(2)O_(8+δ),in which the value of their high-pressure resistivity(ρ=1/σ)is achieved by adopting our newly established method,while the quantity ofρs is extracted using Homes'law.We highlight that the Tc values are strongly linked to the joint response factors of magnetic field and electric field,i.e.,ρ_(s) and σ,respectively,implying that the physics determining T_(c) is governed by the intrinsic electromagnetic fields of the system.
基金National Natural Science Foundation of China (No. 22209014)5.5 Engineering Research & Innovation Team Project of Beijing Forestry University (No.BLRC 2023B05)。
文摘The practical application of rechargeable lithium metal batteries(LMBs) encounters significant challenges due to the notorious dendrite growth triggered by uneven Li deposition behaviors. In this work,a mechanically robust and single-ion-conducting interfacial layer, fulfilled by the strategic integration of flexible cellulose acetate(CA) matrix with rigid graphene oxide(GO) and Li F fillers(termed the CGL layer), is rationally devised to serve as a stabilizer for dendrite-free lithium(Li) metal batteries. The GCL film exhibits favorable mechanical properties with high modulus and flexibility that help to relieve interface fluctuations. More crucially, the electron-donating carbonyl groups(C=O) enriched in GCL foster a strengthened correlation with Li^(+), which availably aids the Li^(+)desolvation process and expedites facile Li^(+)mobility, yielding exceptional Li^(+) transference number of 0.87. Such single-ion conductive properties regulate rapid and uniform interfacial transport kinetics, mitigating the growth of Li dendrites and the decomposition of electrolytes. Consequently, stable Li anode with prolonged cycle stabilities and flat deposition morphologies are realized. The Li||LiFePO_(4) full cells with CGL protective layer render an outstanding cycling capability of 500 cycles at 3 C, and an ultrahigh capacity retention of 99.99% for over 220 cycles even under harsh conditions. This work affords valuable insights into the interfacial regulation for achieving high-performance LMBs.
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the competence centre Fun Mat-II funded by the Swedish Agency for Innovation Systems(Vinnova,grant no 2016-05156)Swedish Energy Agency(project no 42022-1)+3 种基金Swedish Research Council(VR 2021-04427,VR 2019-05577,VR 2016–05990)the Centre in Nanoscience and Technology(CeNano,Linkoping Institute of Technology(LiTH),Linkoping University,2020,2021)the Swedish Government Strategic Research Area in Materials Science on Advanced Functional Materials at Linkoping University(Faculty Grant SFO-Mat-Li U No.2009-00971)the Knut and Alice Wal enberg Foundation(H2O2,KAW 2018.0058),for support
文摘Electrocatalysis enables the industrial transition to sustainable production of chemicals using abundant precursors and electricity from renewable sources.De-centralized production of hydrogen peroxide(H_(2)O_(2))from water and oxygen of air is highly desirable for daily life and industry.We report an effective electrochemical refinery(e-refinery)for H_(2)O_(2)by means of electrocatalysis-controlled comproportionation reaction(2_(H)O+o→2HO),feeding pure water and oxygen only.Mesoporous nickel(Ⅱ)oxide(NiO)was used as electrocatalyst for oxygen evolution reaction(OER),producing oxygen at the anode.Conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)drove the oxygen reduction reaction(ORR),forming H_(2)O_(2)on the cathode.The reactions were evaluated in both half-cell and device configurations.The performance of the H_(2)O_(2)e-refinery,assembled on anion-exchange solid electrolyte and fed with pure water,was limited by the unbalanced ionic transport.Optimization of the operation conditions allowed a conversion efficiency of 80%.
基金supported by the Czech Science Foundation(GACR No.2016124J)supported by the grant of Specific university researchgrant No.A2_FCHT_2022_056
文摘The growing demand for substitutes of lithium chemistries in battery leads to a surge in budding novel anion-based electrochemical energy storage,where the chloride ion batteries(CIBs)take over the role.The application of CIBs is limited by the dissolution and side reaction of chloride-based electrode materials in a liquid electrolyte.On the flipside,its solid-state electrolytes are scarcely reported due to the challenge in realizing fast Cl^(-)conductivity.The present study reports[Al(DMSO)_(6)]Cl_(3),a solid-state metal-organic material,allows chloride ion transfer.The strong Al-Cl bonds in AlCl_(3)are broken down after coordinating of Al^(3+)by ligand DMSO,and Cl^(-)in the resulting compound is weakly bound to complexions[Al(DMSO)_(6)]^(3+),which may facilitate Cl^(-)migration.By partial replacement of Cl^(-)with PF_(6)^(-),the room-temperature ionic conductivity of as-prepared electrolyte is increased by one order of magnitude from 2.172×10^(-5)S cm^(-1)to 2.012×10^(-4)S cm^(-1).When they are assembled with Ag(anode)/Ag-AgCl(cathode)electrode system,reversible electrochemical redox reactions occur on both sides,demonstrating its potential for solid-state chloride ion batteries.The strategy by weakening the bonding interaction using organic ligands between Cl^(-)and central metallic ions may provide new ideas for developing solid chloride-ion conductors.
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financial support from the National Natural Science Foundation of China(No.21871042,21471028,No.21671036,No.21673098,No.21975211)support from the Innovative Research Group Project of NSFC(22021001)+5 种基金the National Key Research and Development Program(2021YFA1502300)Changbai Mountain Scholarship,Natural Science Foundation of Jilin Province(No.20200201083JC)Natural Science Foundation of Department of Education of Jilin Province(No.JJKH20201169KJ)the Fundamental Research Funds for the Central Universities(20720190035)Nanqiang Young Top-notch Talent Fellowship in Xiamen Universitysupported by Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences.
文摘Solid-state electrolytes have attracted considerable attention in new energyrelated devices due to their high safety and broad application platform.Polyoxometalates(POMs)are a kind of molecular-level cluster compounds with unique structures.In recent years,owing to their abundant physicochemical properties(including high ionic conductivity and reversible redox activity),POMs have shown great potential in becoming a new generation of solid-state electrolytes.In this review,an overview is investigated about how POMs have evolved as ion-conducting materials from basic research to novel solid-state electrolytes in energy devices.First,some expressive POM-based ion-conducting materials in recent years are introduced and classified,mainly inspecting their structural and functional relationship.After that,it is further focused on the application of these ionconducting electrolytes in the fields of proton exchange membranes,supercapacitors,and ion batteries.In addition,some properties of POMs(such as inherent dimension,capable of forming stable hydrogen bonds,and reversible bonding to water molecules)enable these functional POM-based electrolytes to be employed in innovative applications such as ion selection,humidity sensing,and smart materials.Finally,some fundamental recommendations are given on the current opportunities and challenges of POM-based ion-conducting electrolytes.
基金National Natural Science Foundation of China,Grant/Award Numbers:21975271,22139001Shandong Energy Institute,Grant/Award Number:SEI I202127+3 种基金Youth Innovation Promotion Association of CAS,Grant/Award Number:2019214Key Scientific and Technological Innovation Project of Shandong,Grant/Award Number:2020CXGC010401Major basic research projects of Shandong Natural Science Foundation,Grant/Award Number:ZR2020ZD07Strategic Priority Research Program of Chinese Academy of Sciences,Grant/Award Number:XDA22010600。
文摘Polymer electrolytes(PEs)have been long recognized as the key materials to enable energy-dense batteries and render flexible energy devices practically viable,owing to their chemical and mechanical reliability.However,much of their promise is yet to be realized.The roomtemperature ion conductivity of existing PEs still falls short of the implementation criterion of 10^(-4) S cm^(-1) on the promise of acceptable mechanical properties,thereby precluding their practical application.The twin but inversely related duties of polymers,that is,functioning as both an ion-conducting medium and a structural backbone,underlie this issue but are less elucidated systematically.The polyacrylate(PA)family is among promising polymer matrices on account of ester polarity,electrode compatibility,chemical tunability,and mechanical durability.The extensive applicability of PA in plasticized gels,dry solids,and emerging composites makes PA-based PEs representative to illustrate the trade-off between ion conduction and mechanical strength.We herein seek to outline the stated long-standing conflict exemplified by PA-based PEs,focusing on crucial strategies toward balancing and reconciling the two mutually exclusive properties,with the intention of offering designing guidelines for next-generation PEs.
基金the National Natural Science Foundations of China(Grant Nos.61874149 and U20A20208)the Outstanding Youth Science and Technology Foundation of China(Grant No.2018-JCJQ-ZQ-060)。
文摘A novel normally-off double channel reverse conducting(DCRC)HEMT with an integrated MOS-channel diode(MCD)is proposed and investigated by TCAD simulation.The proposed structure has two features:one is double heterojunctions to form dual 2DEG channels named the 1^(st)path and the 2^(nd)path for reverse conduction,and the other is the MCD forming by the trench source metal,source dielectric,and Ga N.At the initial reverse conduction stage,the MCD acts as a switch to control the 1^(st)path which would be turned on prior to the 2^(nd)path.Because of the introduction of the 1^(st)path,the DCRC-HEMT has an additional reverse conducting channel to help enhance the reverse conduction performance.Compared with the conventional HEMT(Conv.HEMT),the DCRC-HEMT can obtain a low reverse turn-on voltage(VRT)and its VRTis independent of the gate-source bias(VGS)at the same time.The DCRC-HEMT achieves the VRTof 0.62 V,which is 59.7%and 75.9%lower than that of the Conv.HEMT at VGS=0 V and-1 V,respectively.In addition,the forward conduction capability and blocking characteristics almost remain unchanged.In the end,the key fabrication flows of DCRC-HEMT are presented.
基金the National Natural Science Foundation of China(No.51972162).
文摘Graphene-based thermally conductive composites have been proposed as effective thermal management materials for cooling high-power electronic devices.However,when flexible graphene nanosheets are assembled into macroscopic thermally conductive composites,capillary forces induce shrinkage of graphene nanosheets to form wrinkles during solution-based spontaneous drying,which greatly reduces the thermal conductivity of the composites.Herein,graphene nanosheets/aramid nanofiber(GNS/ANF)composite films with high thermal conductivity were prepared by in-plane stretching of GNS/ANF composite hydrogel networks with hydrogen bonds andπ-πinteractions.The in-plane mechanical stretching eliminates graphene nanosheets wrinkles by suppressing inward shrinkage due to capillary forces during drying and achieves a high in-plane orientation of graphene nanosheets,thereby creating a fast in-plane heat transfer channel.The composite films(GNS/ANF-60 wt%)with eliminated graphene nanosheets wrinkles showed a significant increase in thermal conductivity(146 W m^(−1)K^(−1))and tensile strength(207 MPa).The combination of these excellent properties enables the GNS/ANF composite films to be effectively used for cooling flexible LED chips and smartphones,showing promising applications in the thermal management of high-power electronic devices.
基金financially supported by the National Key Research and Development Program of China (No.2021YFB3701001)the National Natural Science Foundation of China (No.U2102212)+1 种基金the Shanghai Rising-Star Program (No.21QA1403200)the Shanghai Engineering Research Center for Metal Parts Green Remanufacture (No.19DZ2252900) from Shanghai Engineering Research Center Construction Project。
文摘Mg-Al alloys have excellent strength and ductility but relatively low thermal conductivity due to Al addition.The accurate prediction of thermal conductivity is a prerequisite for designing Mg-Al alloys with high thermal conductivity.Thus,databases for predicting temperature-and composition-dependent thermal conductivities must be established.In this study,Mg-Al-La alloys with different contents of Al2La,Al3La,and Al11La3phases and solid solubility of Al in the α-Mg phase were designed.The influence of the second phase(s) and Al solid solubility on thermal conductivity was investigated.Experimental results revealed a second phase transformation from Al_(2)La to Al_(3)La and further to Al_(11)La_(3)with the increasing Al content at a constant La amount.The degree of the negative effect of the second phase(s) on thermal diffusivity followed the sequence of Al2La>Al3La>Al_(11)La_(3).Compared with the second phase,an increase in the solid solubility of Al in α-Mg remarkably reduced the thermal conductivity.On the basis of the experimental data,a database of the reciprocal thermal diffusivity of the Mg-Al-La system was established by calculation of the phase diagram (CALPHAD)method.With a standard error of±1.2 W/(m·K),the predicted results were in good agreement with the experimental data.The established database can be used to design Mg-Al alloys with high thermal conductivity and provide valuable guidance for expanding their application prospects.
基金This work was financially supported by the National Natural Science Foundation of China(Grant No.523712475,2072415 and 62101352)Shenzhen Science and Technology Program(RCBS20210706092343016).
文摘Despite the growing demand for transparent conductive films in smart and wearable electronics for electromagnetic interference(EMI)shielding,achieving a flexible EMI shielding film,while maintaining a high transmittance remains a significant challenge.Herein,a flexible,transparent,and conductive copper(Cu)metal mesh film for EMI shielding is fabricated by self-forming crackle template method and electroplating technique.The Cu mesh film shows an ultra-low sheet resistance(0.18Ω□^(-1)),high transmittance(85.8%@550 nm),and ultra-high figure of merit(>13,000).It also has satisfactory stretchability and mechanical stability,with a resistance increases of only 1.3%after 1,000 bending cycles.As a stretchable heater(ε>30%),the saturation temperature of the film can reach over 110°C within 60 s at 1.00 V applied voltage.Moreover,the metal mesh film exhibits outstanding average EMI shielding effectiveness of 40.4 dB in the X-band at the thickness of 2.5μm.As a demonstration,it is used as a transparent window for shielding the wireless communication electromagnetic waves.Therefore,the flexible and transparent conductive Cu mesh film proposed in this work provides a promising candidate for the next-generation EMI shielding applications.
基金the National Natural Science Foundation of China(Nos.22209095 and 22238004).
文摘Progress in the fast charging of high-capacity silicon monoxide(SiO)-based anode is currently hindered by insufficient conductivity and notable volume expansion.The construction of an interface conductive network effectively addresses the aforementioned problems;however,the impact of its quality on lithium-ion transfer and structure durability is yet to be explored.Herein,the influence of an interface conductive network on ionic transport and mechanical stability under fast charging is explored for the first time.2D modeling simulation and Cryo-transmission electron microscopy precisely reveal the mitigation of interface polarization owing to a higher fraction of conductive inorganic species formation in bilayer solid electrolyte interphase is mainly responsible for a linear decrease in ionic diffusion energy barrier.Furthermore,atomic force microscopy and Raman shift exhibit substantial stress dissipation generated by a complete conductive network,which is critical to the linear reduction of electrode residual stress.This study provides insights into the rational design of optimized interface SiO-based anodes with reinforced fast-charging performance.
基金the Natural Science Foundation of China(Grant No.42241145)supported by the Natural Science Foundation of China(Grant No.41941018)General Projects for Scientific and Technological Innovation of China Coal Science and Industry Group(Grant No.2022-MS001).
文摘Understanding the thermal conductivity of granite is critical for many geological and deep engineering applications.The heated granite was subjected to air-,water-,and liquid nitrogen(LN2-)coolings in this context.The transient hot-wire technique was used to determine the equivalent thermal conductivity(ETC)of the granite before and after treatment.The deterioration mechanism of ETC is analyzed from the meso-perspective.Finally,the numerical model is used to quantitatively study the impact of cooling rate on the microcrack propagation and heat conduction characteristics of granite.The results show that the ETC of granite is not only related to the heating temperature,but also affected by the cooling rate.The ETC of granite decreases nonlinearly with increasing heating temperature.A faster cooling rate causes a greater decrease in ETC at the same heating temperature.The higher the heating temperature,the stronger the influence of cooling rate on ETC.The main explanation for the decrease in ETC of granite is the increase in porosity and microcrack density produced by the formation and propagation of pore structure and microcracks during heating and cooling.Further analysis displays that the damage of granite at the heating stage is induced by the difference in thermal expansion and elastic properties of mineral particles.At the cooling stage,the faster cooling rate causes a higher temperature gradient,which in turn produces greater thermal stress.As a result,it not only causes new cracks in the granite,but also aggravates the damage at the heating stage,which induces a further decrease in the heat conduction performance of granite,and this scenario is more obvious at higher temperatures.
基金supported by the National Natural Science Foundation of China(Nos.42077243,52209148,and 52079062).
文摘With an extension of the geological entropy concept in porous media,the approach called directional entrogram is applied to link hydraulic behavior to the anisotropy of the 3D fracture networks.A metric called directional entropic scale is used to measure the anisotropy of spatial order in different directions.Compared with the traditional connectivity indexes based on the statistics of fracture geometry,the directional entropic scale is capable to quantify the anisotropy of connectivity and hydraulic conductivity in heterogeneous 3D fracture networks.According to the numerical analysis of directional entrogram and fluid flow in a number of the 3D fracture networks,the hydraulic conductivities and entropic scales in different directions both increase with spatial order(i.e.,trace length decreasing and spacing increasing)and are independent of the dip angle.As a result,the nonlinear correlation between the hydraulic conductivities and entropic scales from different directions can be unified as quadratic polynomial function,which can shed light on the anisotropic effect of spatial order and global entropy on the heterogeneous hydraulic behaviors.
基金supported by the National Science Foundation of China(Grant No.5202780089)the Fundamental Research Funds for the Central Universities(HUST:2172020kfy XJJS089)the Open Research Fund of CNMGE Platform&NSCC-TJ(Grant No.CNMGE202101006)
文摘The application of solid polymer electrolytes(SPEs)is severely impeded by the insufficient ionic conductivity and low Li^(+)transference numbers(t_(Li)^(+)).Here,we report an iodine-driven strategy to address both the two longstanding issues of SPEs simultaneously.Electronegative lodine-containing groups introduced on polymer chains effectively attract Li^(+)ions,facilitate Li^(+)transport,and promote the dissociation of Li salts.Meanwhile,iodine is also favorable to alleviate the strong O-Li^(+)coordination through a Lewis acidbase interaction,further improving the ionic conductivity and t_(Li)^(+).As a proof of concept,an iodinated single-ion conducting polymer electrolyte(IPE)demonstrates a high ionic conductivity of 0.93 mS cm^(-1)and a high t_(Li)^(+)of 0.86 at 25℃,which is among the best results ever reported for SPEs.Moreover,symmetric Li/Li cells with IPE achieve a long-term stability over 2600 h through the in-situ formed LiF-rich interphase.As a result,Li-S battery with IPE maintains a high capacity of 623.7 mAh g^(-1)over 300 cycles with an average Coulombic efficiency of 99%.When matched with intercalation cathode chemistries,Li/IPE/LiFePO_(4)and Li/IPE/LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)solid-state batteries also deliver high-capacity retentions of 95%and 97%at 0.2 C after 120 cycles,respectively.
基金The authors are grateful for the support and funding from the Foundation of National Natural Science Foundation of China(52373089 and 51973173)Startup Foundation of Chongqing Normal University(23XLB011),Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN202300561)Fundamental Research Funds for the Central Universities。
文摘With the rapid development of 5G information technology,thermal conductivity/dissipation problems of highly integrated electronic devices and electrical equipment are becoming prominent.In this work,“high-temperature solid-phase&diazonium salt decomposition”method is carried out to prepare benzidine-functionalized boron nitride(m-BN).Subsequently,m-BN/poly(pphenylene benzobisoxazole)nanofiber(PNF)nanocomposite paper with nacremimetic layered structures is prepared via sol–gel film transformation approach.The obtained m-BN/PNF nanocomposite paper with 50 wt%m-BN presents excellent thermal conductivity,incredible electrical insulation,outstanding mechanical properties and thermal stability,due to the construction of extensive hydrogen bonds andπ–πinteractions between m-BN and PNF,and stable nacre-mimetic layered structures.Itsλ∥andλ_(⊥)are 9.68 and 0.84 W m^(-1)K^(-1),and the volume resistivity and breakdown strength are as high as 2.3×10^(15)Ωcm and 324.2 kV mm^(-1),respectively.Besides,it also presents extremely high tensile strength of 193.6 MPa and thermal decomposition temperature of 640°C,showing a broad application prospect in high-end thermal management fields such as electronic devices and electrical equipment.
基金The China Scholarship Council is acknowledged for the doctoral scholarship of Haoyu Zheng(201806160173)The German Federal Ministry for Education and Research is acknowledged for funding via the Project ARCADE(03SF0580A)。
文摘Proton conducting ceramic cells(PCCs)are an attractive emerging technology operating in the intermediate temperature range of 500 to 700℃.In this work,we evaluate the production of hydrogen at intermediate temperatures by proton conducting ceramic cell electrolysis(PCCEL).We demonstrate a highperformance steam electrolysis owing to a composite positrode based on BaGd_(0.8)La_(0.2)Co_(2)O_(6-δ)(BGLC1082)and BaZr0.5Ce0.4Y0.1O3-δ(BZCY541).The high reliability of PCCEL is demonstrated for 1680 h at a current density as high as-0.8 A cm^(-2)close to the thermoneutral cell voltage at 600℃.The electrolysis cell showed a specific energy consumption ranging from 54 to 66 kW h kg^(-1)that is comparable to state-of-the-art low temperature electrolysis technologies,while showing hydrogen production rates systematically higher than commercial solid oxide ceramic cells(SOCs).Compared to SOCs,the results verified the higher performances of PCCs at the relevant operating temperatures,due to the lower activation energy for proton transfer comparing with oxygen ion conduction.However,because of the p-type electronic conduction in protonic ceramics,the energy conversion rate of PCCs is relatively lower in steam electrolysis.The faradaic efficiency of the PCC in electrolysis mode can be increased at lower operating temperatures and in endothermic conditions,making PCCEL a technology of choice to valorize high temperature waste heat from industrial processes into hydrogen.To increase the faradaic efficiency by optimizing the materials,the cell design,or the operating strategy is a key challenge to address for future developments of PCCEL in order to achieve even more superior techno-economic merits.
基金research conducted with the financial support of Science Foundation Ireland under the SFI Research Infrastructure Programme (21/RI/9831)the funding provided by the Irish Research Council through the Irish Research Council Enterprise Partnership Scheme with Johnson and Johnson (EPSPG/2020/78)
文摘Tissue engineering(TE)continues to be widely explored as a potential solution to meet critical clinical needs for diseased tissue replacement and tissue regeneration.In this study,we developed a poly(2-hydroxyethyl methacrylate-co-methacrylic acid)(pHEMA-co-MAA)based hydrogel loaded with newly synthesized conductive poly(3,4-ethylene-dioxythiophene)(PEDOT)and polypyrrole(PPy)nanoparticles(NPs),and subsequently processed these hydrogels into tissue engineered constructs via three-dimensional(3D)printing.The presence of the NPs was critical as they altered the rheological properties during printing.However,all samples exhibited suitable shear thinning properties,allowing for the development of an optimized processing window for 3D printing.Samples were 3D printed into pre-determined disk-shaped configurations of 2 and 10 mm in height and diameter,respectively.We observed that the NPs disrupted the gel crosslinking efficiencies,leading to shorter degradation times and compressive mechanical properties ranging between 450 and 550 kPa.The conductivity of the printed hydrogels increased along with the NP concentration to(5.10±0.37)×10^(−7)S/cm.In vitro studies with cortical astrocyte cell cultures demonstrated that exposure to the pHEMA-co-MAA NP hydrogels yielded high cellular viability and proliferation rates.Finally,hydrogel antimicrobial studies with staphylococcus epidermidis bacteria revealed that the developed hydrogels affected bacterial growth.Taken together,these materials show promise for various TE strategies.
基金supported by the Fundamental Research Funds for the Central Universities(No.20CX05005A)the Major Scientific and Technological Projects of CNPC(No.ZD2019-184-001)+2 种基金the PetroChina Innovation Foundation(No.2018D-5007-0214)the Shandong Provincial Natural Science Foundation(No.ZR2019MEE095)the National Natural Science Foundation of China(No.42174141).
文摘Clays have considerable influence on the electrical properties of hydrate-bearing sediments.It is desirable to understand the electrical properties of hydrate-bearing clayey sediments and to build hydrate saturation(S_(h))models for reservoir evaluation and monitoring.The electrical properties of tetrahydrofuran-hydrate-bearing sediments with montmorillonite are characterized by complex conductivity at frequencies from 0.01 Hz to 1 kHz.The effects of clay and Sh on the complex conductivity were analyzed.A decrease and increase in electrical conductance result from the clay-swelling-induced blockage and ion migration in the electrical double layer(EDL),respectively.The quadrature conductivity increases with the clay content up to 10%because of the increased surface site density of counterions in EDL.Both the in-phase conductivity and quadrature conductivity decrease consistently with increasing Sh from 0.50 to 0.90.Three sets of models for Sh evaluation were developed.The model based on the Simandoux equation outperforms Archie’s formula,with a root-mean-square error(E_(RMS))of 1.8%and 3.9%,respectively,highlighting the clay effects on the in-phase conductivity.The fre-quency effect correlations based on in-phase and quadrature conductivities exhibit inferior performance(E_(RMS)=11.6%and 13.2%,re-spectively)due to the challenge of choosing an appropriate pair of frequencies and intrinsic uncertainties from two measurements.The second-order Cole-Cole formula can be used to fit the complex-conductivity spectra.One pair of inverted Cole-Cole parameters,i.e.,characteristic time and chargeability,is employed to predict S_(h) with an E_(RMS) of 5.05%and 9.05%,respectively.