Using the finite element method (FEM) in two dimensions and the CST MICROWAVE STUDIO? (CST MWS) Transient Solver, the electromagnetic (EM) analysis and the design of a novel compact ultra wideband (UWB) bandpass filte...Using the finite element method (FEM) in two dimensions and the CST MICROWAVE STUDIO? (CST MWS) Transient Solver, the electromagnetic (EM) analysis and the design of a novel compact ultra wideband (UWB) bandpass filter using rectangular coaxial cables with square inner conductors, convenient for high power applications, are presented. The design of the UWB BP filter is based on the use of impedance steps and coupled-line sections. The center frequency around 6.85 GHz was selected, the bandwidth is between 3-10 GHz, the insertion-loss amounts to around 0.35 dB and the return loss is found higher than 10 dB in a large frequency range (4-9.5) GHz. The simulated results of stopband performances are better than 15 dB for a frequency range up to 11 GHz. For the selected center frequency and on a substrate with a dielectric constant of 2.03, the rectangular coaxial cables BPF with square inner conductors is only 6.7 × 8.9 × 33.4 mm in size.展开更多
Lithium halide solid-state electrolytes,with the general formula of Li_(3±m)M_(n)X_(6),are regarded as the promising families of electrolyte material for all solid-state lithium-ion batteries because of the relat...Lithium halide solid-state electrolytes,with the general formula of Li_(3±m)M_(n)X_(6),are regarded as the promising families of electrolyte material for all solid-state lithium-ion batteries because of the relatively good ionic conductivity,high oxidative stability against high-voltage oxide cathodes,and broad electrochemical stability window[1].Here,M stands for one or multiple metal elements and X for one or multiple halogen elements.展开更多
The mechanical,thermodynamic properties and electrical conductivities of L1_(2)-Al_(3)X(X=Zr,Sc,Er,Yb,Hf)structural phases in aluminum conductors were investigated through a first-principles study.The results demonstr...The mechanical,thermodynamic properties and electrical conductivities of L1_(2)-Al_(3)X(X=Zr,Sc,Er,Yb,Hf)structural phases in aluminum conductors were investigated through a first-principles study.The results demonstrate that all structural phases have good alloy-forming ability and structural stability,where Al_(3)Zr is the most superior.Al_(3)Zr,Al_(3)Hf and Al_(3)Sc have enhanced shear and deformation resistance in comparison to other phases.Within the temperature range of 200−600 K,Al_(3)Er and Al_(3)Yb possess the greatest thermodynamic stability,followed by Al_(3)Hf,Al_(3)Zr and Al_(3)Sc.Al_(3)Er and Al_(3)Yb have higher thermodynamic stability than Al_(3)Hf,Al_(3)Zr and Al_(3)Sc.All structural phases exhibit substantial metallic properties,indicating their good electrical conductivity.The electrical conductivities of Al_(3)Hf and Al_(3)Zr are higher than those of Al_(3)Er,Al_(3)Yb and Al_(3)Sc.The covalent bond properties in Al_(3)Sc,Al_(3)Er and Al_(3)Yb enhance the hardness,brittleness and thermodynamic stability of the structural phase.The thermodynamic stability of Al_(3)Sc is significantly reduced by ionic bonds.展开更多
Machine learning is an emerging method to discover new materials with specific characteristics.An unsupervised machine learning research is highlighted to discover new potential lithium ionic conductors by screening a...Machine learning is an emerging method to discover new materials with specific characteristics.An unsupervised machine learning research is highlighted to discover new potential lithium ionic conductors by screening and clustering lithium compounds,providing inspirations for the development of solid-state electrolytes and practical batteries.展开更多
Copper is widely used as conductive components in transmission lines,facing severe corrosion risks.The current passing through copper conductors will significantly affect its corrosion process,yet there is a lack of d...Copper is widely used as conductive components in transmission lines,facing severe corrosion risks.The current passing through copper conductors will significantly affect its corrosion process,yet there is a lack of detailed study on the corrosion mechanism under this specific condition.Thus,this study inves-tigated the effect of direct current current-carrying(DC C-C)conditions on the atmospheric corrosion behavior of copper conductors under thin electrolyte layer(TEL)through electrochemical measurements and corrosion exposure experiments.Results revealed that the presence of DC C-C significantly hastened the corrosion process of copper conductors in the TEL,leading to distinct corrosion patterns at the input and output ends.Furthermore,both the extent of corrosion acceleration and the unevenness of corrosion were positively correlation with the DC C-C level.The above phenomenon was attributed to the special motion of charged particles and paramagnetic substances in TEL under the self-generated magnetic field.展开更多
With increasing water depth,marine drilling conductors exhibit higher slenderness ratios,significantly reducing their resistance to environmental loads in Arctic waters.These conductors,when subjected to combined wind...With increasing water depth,marine drilling conductors exhibit higher slenderness ratios,significantly reducing their resistance to environmental loads in Arctic waters.These conductors,when subjected to combined wind,current,and ice loads,may experience substantial horizontal displacements and bending moments,potentially compromising off-shore operational safety and wellhead stability.Additionally,soil disturbance near the mudline diminishes the conductor’s bearing capacity,potentially rendering it inadequate for wellhead support and increasing operational risks.This study introduces a static analysis model based on plastic hinge theory to evaluate conductor survivability.The conductor analysis divides the structure into three segments:above waterline,submerged,and embedded below mudline.An idealized elastic-plastic p-y curve model characterizes soil behavior beneath the mudline,while the finite difference method(FDM)analyzes the conductor’s mechanical response under complex pile-head boundary conditions.Numerical simulations using ABAQUS validate the plastic hinge approach against conventional methods,confirming its accuracy in predicting structural performance.These results provide valuable insights for optimizing installation depths and bearing capacity designs of marine drilling conductors in ice-prone regions.展开更多
This paper studies the method for measuring the loop resistance of GIS conductor pole based on the super capacitor producing impulse current up to several thousand amperes. This method overcomes the limitations of con...This paper studies the method for measuring the loop resistance of GIS conductor pole based on the super capacitor producing impulse current up to several thousand amperes. This method overcomes the limitations of conventional diagnostic method. Typical GIS conductor poles are chosen. Based on FEA and lab tests, the effect of different forms of current and contact condition, relationship between the temperature of contact and the loop resistance is researched. In full- scale testing under realistic operating conditions on the new 220 kV GIS using prototype instrumentation a very good sensitivity in an early stage was obtained.展开更多
For large-scale energy storage devices,all-solid-state sodium-ion batteries(SIBs)have been revered for the abundant resources,low cost,safety performance and a wide operating temperature range.Na-ion solid-state elect...For large-scale energy storage devices,all-solid-state sodium-ion batteries(SIBs)have been revered for the abundant resources,low cost,safety performance and a wide operating temperature range.Na-ion solid-state electrolytes(Na-ion SSEs)are the critical parts and mostly determine the electrochemical performance of SIBs.Among the studied ones,inorganic Na-ion SSEs stand out for their good safety performance and high ionic conductivity.In this review,we outline the research progress of inorganic SSEs in SIBs based on the perspectives of crystal structure,performance optimization,synthesis methods,allsolid-state SIBs,interface modification and related characterization techniques.We hope to provide some ideas for the design of future high-performance Na-ion SSEs.展开更多
Black phosphorus(BP)is recognized as a promising anode for sodium-ion batteries(SIBs)due to its high safety and theoretical capacity.However,traditional ball milling methodologies for fabricating BP composite anodes h...Black phosphorus(BP)is recognized as a promising anode for sodium-ion batteries(SIBs)due to its high safety and theoretical capacity.However,traditional ball milling methodologies for fabricating BP composite anodes have not satisfactorily addressed the challenges of poor rate performance and short cycle life.To fill this scientific gap,we herein pioneer incorporating the sodium fast ionic conductorβ"-Al_(2)O_(3)into ball-milled BP with carbon,which facilitates the formation of three-dimensional mass transfer channels in the resulting composite.To stabilize these channels,we develop a novel and environmentally friendly functional binder that outperforms traditional binders in thermal stability,wettability,and mechanical properties.The newly established binder is capable of remarkably mitigating volume expansion and interfacial side reactions in the BP/β"-Al_(2)O_(3)/C composite anode.Additionally,we identify synergistic effects of the binder interacting with the BP/β"-Al_(2)O_(3)/C composite during cycling,characterized by the in-situ formation of P-O-C bonds,which is the first instance of a strong,durable chemical bond between the binder and the active material to the best of our knowledge.These advancements allow the composite electrode to exhibit exceptional sodium storage,including high initial Coulombic efficiency and long-term cycling stability,which surpasses most previous phosphorus-based anodes fabricated via traditional approaches.Notably,when paired with a Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_7(NFPP)cathode,the full cell exhibits unexpectedly high energy and power densities,highlighting the BP potential in SIBs.The findings presented in the present work contribute to the promotion of economical and efficient applications of phosphorus-based anode materials.展开更多
Increasing the charging cut-off voltage can significantly enhance the energy density of LiCoO_(2).However,the continuous deterioration of interface structure and transport kinetics under high voltage poses challenges ...Increasing the charging cut-off voltage can significantly enhance the energy density of LiCoO_(2).However,the continuous deterioration of interface structure and transport kinetics under high voltage poses challenges to electrochemical stability.This work proposes to in-situ construct a uniform element gradient modification structure on the surface and subsurface of LiCoO_(2).The modification structure contains an Sb_(2)O_(3)&SbF_(x)composite coating layer and an Sb-F doped spinel-like transition layer,simultaneously.The modified sample maintains an initial discharge specific capacity of 221.2 mA h g^(-1)and a capacity retention of 86%after 200 cycles at 3–4.6 V and 0.5 C.Moreover,it has a discharge specific capacity of163.3 mA h g^(-1)at a high rate of 5 C.Meanwhile,combining highly electronegative Sb^(3+)&F^(-)that widen the Li^(+)transport channel with the amorphous coating of F^(-)doped Sb_(2)O_(3)with higher conductivity improves the interface transport kinetics.This breaks the stereotypical view in traditional concepts that fluorinated coatings or inert metal oxide coatings inhibit Li^(+)transport.Moreover,the inert composite coating combined with Sb–O–F with high bond energy stabilizes the surface structure.A series of characterizations confirm that the joint improvement of interface structure stability and transport kinetics significantly enhances the electrochemical performance of LiCoO_(2).展开更多
Single ion gel polymer electrolyte has the advantages of high Li^(+)conductivity and dendrite mitigation.However,the addition of organic solvent makes the electrolyte flammable,posing serious safety hazards.Herein,we ...Single ion gel polymer electrolyte has the advantages of high Li^(+)conductivity and dendrite mitigation.However,the addition of organic solvent makes the electrolyte flammable,posing serious safety hazards.Herein,we report a flame-retard ant cross-linked sp^(3)boron-based single-ion gel polymer electrolyte(BSIPE).BSIPE was prepared by a simple one-step photoinitiated in situ thiol-ene click reaction.Due to the boron-based anions being immobilized in the cross-linking network,the developed BSIPE/PFN exhibits a high t_(Li^(+))(0.87),which can mitigate concentration polarization phenomenon and suppress the growth of lithium dendrites.BSIPE/PFN plasticized with triethyl phosphate(TEP),fluoroethylene carbonate(FEC)and LiNO_(3)exhibits enhanced ionic conductivity of 4.25×10^(-4)S cm^(-1)at 30℃ and flame retardancy.FEC and LiNO_(3) are conducive to form a stable solid electrolyte interphase(SEI)rich in Li_(3)N and LiF to improve interface stability.As expected,the dendrite-free Li‖BSIPE/PFN‖Li symmetric cell exhibits considerable cycling life over 1500 h.BSIPE/PFN significantly boosts the performance of LFP‖Li cell,which displays a capacity retention of 84.6%after 500 cycles.The BSIPE/PFN has promising applications in highsafety and high-performance lithium metal batteries.展开更多
Despite great advancements in organic mixed ionic-electronic conductors(OMIECs),their applications remain predominantly restricted to three-electrode organic electro-chemical transistors(OECTs),which rely on an additi...Despite great advancements in organic mixed ionic-electronic conductors(OMIECs),their applications remain predominantly restricted to three-electrode organic electro-chemical transistors(OECTs),which rely on an additional electrolyte layer to balance ionic and electronic transport,resulting in indirect coupling of charge carriers.While direct coupling has the potential to greatly simplify device architectures,it remains underexplored in OMIECs due to the inherent imbalance between electronic and ionic conductivities.In this study,we introduce a straightforward approach to achieve balanced OMIECs and employ them as channel materials in two-electrode organic electrochemical memristors.These devices provide clear evidence of direct coupling between electronic and ionic carriers and exhibit exceptional performance in synaptic device applications.Our findings offer new insights into charge carrier transport mechanisms in OMIECs and establish organic electrochemical memristors as a promising new class of organic electronic devices for next-generation neuromorphic applications.展开更多
The proximity effect is very significant to investigate transient peak voltages and EMC related problems of a conductor system. In this paper, effect of energized single conductor in close proximity of an Al plate whe...The proximity effect is very significant to investigate transient peak voltages and EMC related problems of a conductor system. In this paper, effect of energized single conductor in close proximity of an Al plate when an Al plate is used as return path is investigated to find out proximity effect. The analysis involves simulation by the Finite Time Domain Method (FDTD) in comparison with field measurements. It is observed that the current distribution is uneven in pipe conductor due to the proximity effect of varying heights from ground.展开更多
Single-ion conductors based on covalent organic frameworks(COFs)have garnered attention as a potential alternative to currently prevalent inorganic ion conductors owing to their structural uniqueness and chemical vers...Single-ion conductors based on covalent organic frameworks(COFs)have garnered attention as a potential alternative to currently prevalent inorganic ion conductors owing to their structural uniqueness and chemical versatility.However,the sluggish Li+conduction has hindered their practical applications.Here,we present a class of solvent-free COF single-ion conductors(Li-COF@P)based on weak ion-dipole interaction as opposed to traditional strong ion-ion interaction.The ion(Li+from the COF)-dipole(oxygen from poly(ethylene glycol)diacrylate embedded in the COF pores)interaction in the Li-COF@P promotes ion dissociation and Li+migration via directional ionic channels.Driven by this single-ion transport behavior,the Li-COF@P enables reversible Li plating/stripping on Li-metal electrodes and stable cycling performance(88.3%after 2000 cycles)in organic batteries(Li metal anode||5,5’-dimethyl-2,2’-bis-p-benzoquinone(Me2BBQ)cathode)under ambient operating conditions,highlighting the electrochemical viability of the Li-COF@P for all-solid-state organic batteries.展开更多
On the basis of expounding the corrosion mechanism of the stator hollow copper conductor in the water-cooling generator, methods of preventing corrosion of the stator hollow copper conductor in the wa-ter-cooling gene...On the basis of expounding the corrosion mechanism of the stator hollow copper conductor in the water-cooling generator, methods of preventing corrosion of the stator hollow copper conductor in the wa-ter-cooling generator through adjusting water quality of its cooling water have been proposed. For internal water cooling systems which are airtight, the corrosion of the hollow copper conductor can be prevented through keeping foreign oxygen and carbon dioxide from entering the system, and the amount of oxygen in the internal water can be lowered by blowing high purity nitrogen. For systems not airtight, the corrosion of the hollow copper conductor can be inhibited through lowering the amount of oxygen to some extent by sealing and increasing pH value by processing part of cooling water with bypass small flow sodium-type mix-bed.展开更多
High-temperature superconducting(HTS)rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have significant potential in high-current and high-field applications.However,owing to the weak interface strength of th...High-temperature superconducting(HTS)rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have significant potential in high-current and high-field applications.However,owing to the weak interface strength of the laminated composite REBCO CCs,the damage induced by the thermal mismatch stress under a combination of epoxy impregnation,cooling,and quenching can cause premature degradation of the critical current.In this study,a three-dimensional(3D)electromagnetic-thermal-mechanical model based on the H-formulation and cohesive zone model(CZM)is developed to study the critical current degradation characteristics in an epoxy-impregnated REBCO CC caused by the damage during a quench.The temperature variation,critical current degradation of the REBCO CC,and its degradation onset temperature calculated by the numerical model are in agreement with the experimental data taken from the literature.The delamination of the REBCO CC predicted by the numerical model is consistent with the experimental result.The numerical results also indicate that the shear stress is the main contributor to the damage propagation inside the REBCO CC.The premature degradation of the critical current during a quench is closely related to the interface shear strength inside the REBCO CC.Finally,the effects of the coefficient of thermal expansion(CTE)of the epoxy resin,thickness of the substrate,and substrate material on the critical current degradation characteristics of the epoxy-impregnated REBCO CC during a quench are also discussed.These results help us understand the relationship between the current-carrying degradation and damage in the HTS applications.展开更多
Conductor externalization and insulation failure are frequent complications with the recalled St. Jude Medical Riata implantable cardioverter-defibrillator(ICD) leads. Conductor externalization is a "unique"...Conductor externalization and insulation failure are frequent complications with the recalled St. Jude Medical Riata implantable cardioverter-defibrillator(ICD) leads. Conductor externalization is a "unique" failure mechanism: Cables externalize through the insulation("inside-out" abrasion) and appear outside the lead body. Recently, single reports described a similar failure also for Biotronik leads. Moreover, some studies reported a high rate of electrical dysfunction(not only insulation failure) with Biotronik Linox leads and a reduced survival rate in comparison with the competitors. In this paper we describe the case of a patient with a Biotronik Kentrox ICD lead presenting with signs of insulation failure and conductor externalization at fluoroscopy. Due to the high risk of extraction we decided to implant a new lead, abandoning the damaged one; lead reimplant was uneventful. Subsequently, we review currently available literature about Biotronik Kentrox and Linox ICD lead failure and in particular externalized conductors. Some single-center studies and a nonprospective registry reported a survival rate between 88% and 91% at 5 years for Linox leads, significantly worse than that of other manufacturers. However, the preliminary results of two ongoing multicenter, prospective registries(GALAXY and CELESTIAL) showed 96% survival rate at 5 years after implant, well within industry standards. Ongoing data collection is needed to confirm longer-term performance of this family of ICD leads.展开更多
(NH4)3PW12O40 and(NH4)3PW12O40-H3PO4 composites have been synthesized by precipitation method.Their phase compositions,thermal stability and morphologies have been investigated.The synthesized composites maintain the ...(NH4)3PW12O40 and(NH4)3PW12O40-H3PO4 composites have been synthesized by precipitation method.Their phase compositions,thermal stability and morphologies have been investigated.The synthesized composites maintain the same structures as pure(NH4)3PW12O40 where phosphoric acid is preserved in residual space of the"spongy crystals"of(NH4)3PW12O40.FT-IR spectra confirm the strong interactions between phosphoric acid and Keggin ions.Pristine(NH4)3PW12O40 shows poor conductivity in air at high temperatures and strongly depends on water molecules for proton transport.The composites exhibit a much higher conductivity compared with pure(NH4)3PW12O40.The highest conductivity achieved is 0.14 S/cm at 170℃where continuous channels based on phosphoric acid for proton transportation are probably established.Such high conductivity of(NH4)3PW12O40-H3PO4 composites implies promising applications in fuel cells and other electrochemical devices.展开更多
A novel planar leaky-wave antenna of conductor modulating periodic structure formillimeter wave application is proposed.Using the theory of two-dimensional periodic admittancesurface,theoretical analysis,numerical cal...A novel planar leaky-wave antenna of conductor modulating periodic structure formillimeter wave application is proposed.Using the theory of two-dimensional periodic admittancesurface,theoretical analysis,numerical calculation and experimental study are carried out for thiskind of antenna.A planar antenna of conductor modulating periodic structure is realized in 8mmwave band.It has an aperture area of 90×90mm^2.The measured performances of the antennaare good.展开更多
LaMnO_(3)(LMO) cap layers with different surface roughness were prepared on epi-MgO/ion-beam-assisted deposition (IBAD) MgO/solution deposition planarized (SDP) Y<sub>2</sub>O<sub>3</sub>/Haste...LaMnO_(3)(LMO) cap layers with different surface roughness were prepared on epi-MgO/ion-beam-assisted deposition (IBAD) MgO/solution deposition planarized (SDP) Y<sub>2</sub>O<sub>3</sub>/Hastelloy tape. The effects of the surface roughness of LMO on the crystallization, texture and superconducting properties of Yba<sub>2</sub>Cu<sub>3</sub>O<sub>7?δ </sub> (YBCO) films were systematically investigated. The crystallization and epitaxial texture of resulting YBCO film are significantly improved with the surface roughness of LMO decreasing from 7.0 to 1.3nm. High-performance YBCO-coated conductors could be achieved if surface roughness of LMO cap layer is well controlled.展开更多
文摘Using the finite element method (FEM) in two dimensions and the CST MICROWAVE STUDIO? (CST MWS) Transient Solver, the electromagnetic (EM) analysis and the design of a novel compact ultra wideband (UWB) bandpass filter using rectangular coaxial cables with square inner conductors, convenient for high power applications, are presented. The design of the UWB BP filter is based on the use of impedance steps and coupled-line sections. The center frequency around 6.85 GHz was selected, the bandwidth is between 3-10 GHz, the insertion-loss amounts to around 0.35 dB and the return loss is found higher than 10 dB in a large frequency range (4-9.5) GHz. The simulated results of stopband performances are better than 15 dB for a frequency range up to 11 GHz. For the selected center frequency and on a substrate with a dielectric constant of 2.03, the rectangular coaxial cables BPF with square inner conductors is only 6.7 × 8.9 × 33.4 mm in size.
文摘Lithium halide solid-state electrolytes,with the general formula of Li_(3±m)M_(n)X_(6),are regarded as the promising families of electrolyte material for all solid-state lithium-ion batteries because of the relatively good ionic conductivity,high oxidative stability against high-voltage oxide cathodes,and broad electrochemical stability window[1].Here,M stands for one or multiple metal elements and X for one or multiple halogen elements.
基金National Natural Science Foundation of China (No. 52274403)。
文摘The mechanical,thermodynamic properties and electrical conductivities of L1_(2)-Al_(3)X(X=Zr,Sc,Er,Yb,Hf)structural phases in aluminum conductors were investigated through a first-principles study.The results demonstrate that all structural phases have good alloy-forming ability and structural stability,where Al_(3)Zr is the most superior.Al_(3)Zr,Al_(3)Hf and Al_(3)Sc have enhanced shear and deformation resistance in comparison to other phases.Within the temperature range of 200−600 K,Al_(3)Er and Al_(3)Yb possess the greatest thermodynamic stability,followed by Al_(3)Hf,Al_(3)Zr and Al_(3)Sc.Al_(3)Er and Al_(3)Yb have higher thermodynamic stability than Al_(3)Hf,Al_(3)Zr and Al_(3)Sc.All structural phases exhibit substantial metallic properties,indicating their good electrical conductivity.The electrical conductivities of Al_(3)Hf and Al_(3)Zr are higher than those of Al_(3)Er,Al_(3)Yb and Al_(3)Sc.The covalent bond properties in Al_(3)Sc,Al_(3)Er and Al_(3)Yb enhance the hardness,brittleness and thermodynamic stability of the structural phase.The thermodynamic stability of Al_(3)Sc is significantly reduced by ionic bonds.
基金Supported by the National Key Research and Development Program(2016YFA0202500)National Natural Science Foundation of China(21825501)。
文摘Machine learning is an emerging method to discover new materials with specific characteristics.An unsupervised machine learning research is highlighted to discover new potential lithium ionic conductors by screening and clustering lithium compounds,providing inspirations for the development of solid-state electrolytes and practical batteries.
基金supported by the National Natu-ral Science Foundation of China(Nos.52171074 and 52471084)the Young Elite Scientists Sponsorship Program by CAST(No.YESS20220137)the Science and Technology Commission of Shanghai Municipality(No.19DZ2271100).
文摘Copper is widely used as conductive components in transmission lines,facing severe corrosion risks.The current passing through copper conductors will significantly affect its corrosion process,yet there is a lack of detailed study on the corrosion mechanism under this specific condition.Thus,this study inves-tigated the effect of direct current current-carrying(DC C-C)conditions on the atmospheric corrosion behavior of copper conductors under thin electrolyte layer(TEL)through electrochemical measurements and corrosion exposure experiments.Results revealed that the presence of DC C-C significantly hastened the corrosion process of copper conductors in the TEL,leading to distinct corrosion patterns at the input and output ends.Furthermore,both the extent of corrosion acceleration and the unevenness of corrosion were positively correlation with the DC C-C level.The above phenomenon was attributed to the special motion of charged particles and paramagnetic substances in TEL under the self-generated magnetic field.
基金financially supported by the National Natural Science Foundation of China(Grant No.U22B20126)the National Key Research and Development Program of China(Grant No.2022YFC2806100).
文摘With increasing water depth,marine drilling conductors exhibit higher slenderness ratios,significantly reducing their resistance to environmental loads in Arctic waters.These conductors,when subjected to combined wind,current,and ice loads,may experience substantial horizontal displacements and bending moments,potentially compromising off-shore operational safety and wellhead stability.Additionally,soil disturbance near the mudline diminishes the conductor’s bearing capacity,potentially rendering it inadequate for wellhead support and increasing operational risks.This study introduces a static analysis model based on plastic hinge theory to evaluate conductor survivability.The conductor analysis divides the structure into three segments:above waterline,submerged,and embedded below mudline.An idealized elastic-plastic p-y curve model characterizes soil behavior beneath the mudline,while the finite difference method(FDM)analyzes the conductor’s mechanical response under complex pile-head boundary conditions.Numerical simulations using ABAQUS validate the plastic hinge approach against conventional methods,confirming its accuracy in predicting structural performance.These results provide valuable insights for optimizing installation depths and bearing capacity designs of marine drilling conductors in ice-prone regions.
文摘This paper studies the method for measuring the loop resistance of GIS conductor pole based on the super capacitor producing impulse current up to several thousand amperes. This method overcomes the limitations of conventional diagnostic method. Typical GIS conductor poles are chosen. Based on FEA and lab tests, the effect of different forms of current and contact condition, relationship between the temperature of contact and the loop resistance is researched. In full- scale testing under realistic operating conditions on the new 220 kV GIS using prototype instrumentation a very good sensitivity in an early stage was obtained.
基金supported by the National Natural Science Foundation of China(Nos.22175070,22293041)supported by the National Key Research and Development Program(Nos.2021YFB2500200,2021YFB2400300)+1 种基金the National Natural Science Foundation of China(No.52177214)China Fujian Energy Devices Science and Technology Innovation Laboratory Open Fund(No.21C-OP202211)。
文摘For large-scale energy storage devices,all-solid-state sodium-ion batteries(SIBs)have been revered for the abundant resources,low cost,safety performance and a wide operating temperature range.Na-ion solid-state electrolytes(Na-ion SSEs)are the critical parts and mostly determine the electrochemical performance of SIBs.Among the studied ones,inorganic Na-ion SSEs stand out for their good safety performance and high ionic conductivity.In this review,we outline the research progress of inorganic SSEs in SIBs based on the perspectives of crystal structure,performance optimization,synthesis methods,allsolid-state SIBs,interface modification and related characterization techniques.We hope to provide some ideas for the design of future high-performance Na-ion SSEs.
基金supported by the National Key R&D Program of China(2022YFB3807700)the National Natural Science Foundation of China(52072217,22179071,51772169,and 52104313)+3 种基金the Hubei Provincial Natural Science Foundation of China(2023AFB618 and 2024AFB993)the Hubei Natural Science Foundation Innovation Group Project(2022CFA020)the Joint Funds of the Hubei Natural Science Foundation Innovation and Development(2022CFD034)the Major Technological Innovation Project of Hubei Science and Technology Department(2019AAA164)。
文摘Black phosphorus(BP)is recognized as a promising anode for sodium-ion batteries(SIBs)due to its high safety and theoretical capacity.However,traditional ball milling methodologies for fabricating BP composite anodes have not satisfactorily addressed the challenges of poor rate performance and short cycle life.To fill this scientific gap,we herein pioneer incorporating the sodium fast ionic conductorβ"-Al_(2)O_(3)into ball-milled BP with carbon,which facilitates the formation of three-dimensional mass transfer channels in the resulting composite.To stabilize these channels,we develop a novel and environmentally friendly functional binder that outperforms traditional binders in thermal stability,wettability,and mechanical properties.The newly established binder is capable of remarkably mitigating volume expansion and interfacial side reactions in the BP/β"-Al_(2)O_(3)/C composite anode.Additionally,we identify synergistic effects of the binder interacting with the BP/β"-Al_(2)O_(3)/C composite during cycling,characterized by the in-situ formation of P-O-C bonds,which is the first instance of a strong,durable chemical bond between the binder and the active material to the best of our knowledge.These advancements allow the composite electrode to exhibit exceptional sodium storage,including high initial Coulombic efficiency and long-term cycling stability,which surpasses most previous phosphorus-based anodes fabricated via traditional approaches.Notably,when paired with a Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_7(NFPP)cathode,the full cell exhibits unexpectedly high energy and power densities,highlighting the BP potential in SIBs.The findings presented in the present work contribute to the promotion of economical and efficient applications of phosphorus-based anode materials.
基金supported by the National Natural Science Foundation of China(22075170)employed resources from the BL11B station of the Shanghai Synchrotron Radiation Facility(SSRF,under contract number:2023-SSRF-PT-502681)。
文摘Increasing the charging cut-off voltage can significantly enhance the energy density of LiCoO_(2).However,the continuous deterioration of interface structure and transport kinetics under high voltage poses challenges to electrochemical stability.This work proposes to in-situ construct a uniform element gradient modification structure on the surface and subsurface of LiCoO_(2).The modification structure contains an Sb_(2)O_(3)&SbF_(x)composite coating layer and an Sb-F doped spinel-like transition layer,simultaneously.The modified sample maintains an initial discharge specific capacity of 221.2 mA h g^(-1)and a capacity retention of 86%after 200 cycles at 3–4.6 V and 0.5 C.Moreover,it has a discharge specific capacity of163.3 mA h g^(-1)at a high rate of 5 C.Meanwhile,combining highly electronegative Sb^(3+)&F^(-)that widen the Li^(+)transport channel with the amorphous coating of F^(-)doped Sb_(2)O_(3)with higher conductivity improves the interface transport kinetics.This breaks the stereotypical view in traditional concepts that fluorinated coatings or inert metal oxide coatings inhibit Li^(+)transport.Moreover,the inert composite coating combined with Sb–O–F with high bond energy stabilizes the surface structure.A series of characterizations confirm that the joint improvement of interface structure stability and transport kinetics significantly enhances the electrochemical performance of LiCoO_(2).
基金supported by the National Natural Science Foundation of China(22179149,22075329,51573215,and 21978332)Research and Development Project of Henan Academy Sciences China(232018002)。
文摘Single ion gel polymer electrolyte has the advantages of high Li^(+)conductivity and dendrite mitigation.However,the addition of organic solvent makes the electrolyte flammable,posing serious safety hazards.Herein,we report a flame-retard ant cross-linked sp^(3)boron-based single-ion gel polymer electrolyte(BSIPE).BSIPE was prepared by a simple one-step photoinitiated in situ thiol-ene click reaction.Due to the boron-based anions being immobilized in the cross-linking network,the developed BSIPE/PFN exhibits a high t_(Li^(+))(0.87),which can mitigate concentration polarization phenomenon and suppress the growth of lithium dendrites.BSIPE/PFN plasticized with triethyl phosphate(TEP),fluoroethylene carbonate(FEC)and LiNO_(3)exhibits enhanced ionic conductivity of 4.25×10^(-4)S cm^(-1)at 30℃ and flame retardancy.FEC and LiNO_(3) are conducive to form a stable solid electrolyte interphase(SEI)rich in Li_(3)N and LiF to improve interface stability.As expected,the dendrite-free Li‖BSIPE/PFN‖Li symmetric cell exhibits considerable cycling life over 1500 h.BSIPE/PFN significantly boosts the performance of LFP‖Li cell,which displays a capacity retention of 84.6%after 500 cycles.The BSIPE/PFN has promising applications in highsafety and high-performance lithium metal batteries.
基金supported by the National Natural Science Foundation of China(4020969,62405044,and 52173156)Fund by Science Research Project of Hebei Education Department(HY2024050011)+1 种基金Natural Science Foundation of Sichuan Province(25NSFSC1287)Foundation of Yanshan University(1050030 and 8190299).
文摘Despite great advancements in organic mixed ionic-electronic conductors(OMIECs),their applications remain predominantly restricted to three-electrode organic electro-chemical transistors(OECTs),which rely on an additional electrolyte layer to balance ionic and electronic transport,resulting in indirect coupling of charge carriers.While direct coupling has the potential to greatly simplify device architectures,it remains underexplored in OMIECs due to the inherent imbalance between electronic and ionic conductivities.In this study,we introduce a straightforward approach to achieve balanced OMIECs and employ them as channel materials in two-electrode organic electrochemical memristors.These devices provide clear evidence of direct coupling between electronic and ionic carriers and exhibit exceptional performance in synaptic device applications.Our findings offer new insights into charge carrier transport mechanisms in OMIECs and establish organic electrochemical memristors as a promising new class of organic electronic devices for next-generation neuromorphic applications.
文摘The proximity effect is very significant to investigate transient peak voltages and EMC related problems of a conductor system. In this paper, effect of energized single conductor in close proximity of an Al plate when an Al plate is used as return path is investigated to find out proximity effect. The analysis involves simulation by the Finite Time Domain Method (FDTD) in comparison with field measurements. It is observed that the current distribution is uneven in pipe conductor due to the proximity effect of varying heights from ground.
基金supported by the Basic Science Research Program (No.RS-2024-00344021) through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and future Planningthe financial support from the National Natural Science Foundation of China (52103277)+2 种基金the Program for Science & Technology Innovation Talents in Universities of Henan Province (23HASTIT015)Natural Science Foundation of Henan Province (242300421073)supported by the Technology Innovation Program (20010960) funded by the Ministry of Trade, Industry & Energy (MOTIE, Korea)
文摘Single-ion conductors based on covalent organic frameworks(COFs)have garnered attention as a potential alternative to currently prevalent inorganic ion conductors owing to their structural uniqueness and chemical versatility.However,the sluggish Li+conduction has hindered their practical applications.Here,we present a class of solvent-free COF single-ion conductors(Li-COF@P)based on weak ion-dipole interaction as opposed to traditional strong ion-ion interaction.The ion(Li+from the COF)-dipole(oxygen from poly(ethylene glycol)diacrylate embedded in the COF pores)interaction in the Li-COF@P promotes ion dissociation and Li+migration via directional ionic channels.Driven by this single-ion transport behavior,the Li-COF@P enables reversible Li plating/stripping on Li-metal electrodes and stable cycling performance(88.3%after 2000 cycles)in organic batteries(Li metal anode||5,5’-dimethyl-2,2’-bis-p-benzoquinone(Me2BBQ)cathode)under ambient operating conditions,highlighting the electrochemical viability of the Li-COF@P for all-solid-state organic batteries.
文摘On the basis of expounding the corrosion mechanism of the stator hollow copper conductor in the water-cooling generator, methods of preventing corrosion of the stator hollow copper conductor in the wa-ter-cooling generator through adjusting water quality of its cooling water have been proposed. For internal water cooling systems which are airtight, the corrosion of the hollow copper conductor can be prevented through keeping foreign oxygen and carbon dioxide from entering the system, and the amount of oxygen in the internal water can be lowered by blowing high purity nitrogen. For systems not airtight, the corrosion of the hollow copper conductor can be inhibited through lowering the amount of oxygen to some extent by sealing and increasing pH value by processing part of cooling water with bypass small flow sodium-type mix-bed.
基金Project supported by the National Natural Science Foundation of China(Nos.12302278,U2241267,12172155,and 11932008)the Fundamental Research Funds for the Central Universities of China(No.lzujbky-2022-48)the Natural Science Foundation of Gansu Province of China(No.24JRRA473)。
文摘High-temperature superconducting(HTS)rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have significant potential in high-current and high-field applications.However,owing to the weak interface strength of the laminated composite REBCO CCs,the damage induced by the thermal mismatch stress under a combination of epoxy impregnation,cooling,and quenching can cause premature degradation of the critical current.In this study,a three-dimensional(3D)electromagnetic-thermal-mechanical model based on the H-formulation and cohesive zone model(CZM)is developed to study the critical current degradation characteristics in an epoxy-impregnated REBCO CC caused by the damage during a quench.The temperature variation,critical current degradation of the REBCO CC,and its degradation onset temperature calculated by the numerical model are in agreement with the experimental data taken from the literature.The delamination of the REBCO CC predicted by the numerical model is consistent with the experimental result.The numerical results also indicate that the shear stress is the main contributor to the damage propagation inside the REBCO CC.The premature degradation of the critical current during a quench is closely related to the interface shear strength inside the REBCO CC.Finally,the effects of the coefficient of thermal expansion(CTE)of the epoxy resin,thickness of the substrate,and substrate material on the critical current degradation characteristics of the epoxy-impregnated REBCO CC during a quench are also discussed.These results help us understand the relationship between the current-carrying degradation and damage in the HTS applications.
文摘Conductor externalization and insulation failure are frequent complications with the recalled St. Jude Medical Riata implantable cardioverter-defibrillator(ICD) leads. Conductor externalization is a "unique" failure mechanism: Cables externalize through the insulation("inside-out" abrasion) and appear outside the lead body. Recently, single reports described a similar failure also for Biotronik leads. Moreover, some studies reported a high rate of electrical dysfunction(not only insulation failure) with Biotronik Linox leads and a reduced survival rate in comparison with the competitors. In this paper we describe the case of a patient with a Biotronik Kentrox ICD lead presenting with signs of insulation failure and conductor externalization at fluoroscopy. Due to the high risk of extraction we decided to implant a new lead, abandoning the damaged one; lead reimplant was uneventful. Subsequently, we review currently available literature about Biotronik Kentrox and Linox ICD lead failure and in particular externalized conductors. Some single-center studies and a nonprospective registry reported a survival rate between 88% and 91% at 5 years for Linox leads, significantly worse than that of other manufacturers. However, the preliminary results of two ongoing multicenter, prospective registries(GALAXY and CELESTIAL) showed 96% survival rate at 5 years after implant, well within industry standards. Ongoing data collection is needed to confirm longer-term performance of this family of ICD leads.
基金supported financially by the National Natural Science Foundation of China(No.21401142,51972233)the Natural Science Foundation of Shanghai(No.19ZR1459200)+3 种基金the National 1000-Plan Programthe Shanghai Science and Technology Commission(No.14DZ2261100)the South Taihu Elite Projectthe Fundamental Research Funds for the Central Universities.
文摘(NH4)3PW12O40 and(NH4)3PW12O40-H3PO4 composites have been synthesized by precipitation method.Their phase compositions,thermal stability and morphologies have been investigated.The synthesized composites maintain the same structures as pure(NH4)3PW12O40 where phosphoric acid is preserved in residual space of the"spongy crystals"of(NH4)3PW12O40.FT-IR spectra confirm the strong interactions between phosphoric acid and Keggin ions.Pristine(NH4)3PW12O40 shows poor conductivity in air at high temperatures and strongly depends on water molecules for proton transport.The composites exhibit a much higher conductivity compared with pure(NH4)3PW12O40.The highest conductivity achieved is 0.14 S/cm at 170℃where continuous channels based on phosphoric acid for proton transportation are probably established.Such high conductivity of(NH4)3PW12O40-H3PO4 composites implies promising applications in fuel cells and other electrochemical devices.
文摘A novel planar leaky-wave antenna of conductor modulating periodic structure formillimeter wave application is proposed.Using the theory of two-dimensional periodic admittancesurface,theoretical analysis,numerical calculation and experimental study are carried out for thiskind of antenna.A planar antenna of conductor modulating periodic structure is realized in 8mmwave band.It has an aperture area of 90×90mm^2.The measured performances of the antennaare good.
基金financially supported by the National Science Foundation of China(No.91421110)the National High Technology Research and Development Program of China(No.2014AA032702)+2 种基金the National Basic Research Program of China(No.2015CB358600)Sichuan Youth Science and Technology Innovation Research Team Fund(No.2011JTD0006)Sichuan Provincial Fund for Distinguished Young Academic and Technology Leaders(No.2014JQ0011)
文摘LaMnO_(3)(LMO) cap layers with different surface roughness were prepared on epi-MgO/ion-beam-assisted deposition (IBAD) MgO/solution deposition planarized (SDP) Y<sub>2</sub>O<sub>3</sub>/Hastelloy tape. The effects of the surface roughness of LMO on the crystallization, texture and superconducting properties of Yba<sub>2</sub>Cu<sub>3</sub>O<sub>7?δ </sub> (YBCO) films were systematically investigated. The crystallization and epitaxial texture of resulting YBCO film are significantly improved with the surface roughness of LMO decreasing from 7.0 to 1.3nm. High-performance YBCO-coated conductors could be achieved if surface roughness of LMO cap layer is well controlled.
