Silicone rubber(SR)is a versatile material widely used across various advanced functional applications,such as soft actuators and robots,flexible electronics,and medical devices.However,most SR molding methods rely on...Silicone rubber(SR)is a versatile material widely used across various advanced functional applications,such as soft actuators and robots,flexible electronics,and medical devices.However,most SR molding methods rely on traditional thermal processing or direct ink writing three-dimensional(3D)printing.These methods are not conducive to manufacturing complex structures and present challenges such as time inefficiency,poor accuracy,and the necessity of multiple steps,significantly limiting SR applications.In this study,we developed an SR-based ink suitable for vat photopolymerization 3D printing using a multi-thiol monomer.This ink enables the one-step fabrication of complex architectures with high printing resolution at the micrometer scale,providing excellent mechanical strength and superior chemical stability.Specifically,the optimized 3D printing SR-20 exhibits a tensile stress of 1.96 MPa,an elongation at break of 487.9%,and an elastic modulus of 225.4 kPa.Additionally,the 3D-printed SR samples can withstand various solvents(acetone,toluene,and tetrahydrofuran)and endure temperatures ranging from-50℃ to 180℃,demonstrating superior stability.As a emonstration of the application,we successfully fabricated a series of SR-based soft pneumatic actuators and grippers in a single step with this technology,allowing for free assembly for the first time.This ultraviolet-curable SR,with high printing resolution and exceptional stability performance,has significant potential to enhance the capabilities of 3D printing for applications in soft actuators,robotics,flexible electronics,and medical devices.展开更多
Silicon(Si)is considered one of the most promising anode materials for next-generation lithium-ion batteries due to its ultrahigh theoretical capacity.However,its application is significantly limited by severe volume ...Silicon(Si)is considered one of the most promising anode materials for next-generation lithium-ion batteries due to its ultrahigh theoretical capacity.However,its application is significantly limited by severe volume expansion,leading to structural degradation and poor cycling stability.Polymer binders play a critical role in addressing these issues by providing mechanical stabilization.Inspired by the mechanically adaptive architecture of spider webs,where stiff radial threads and extensible spiral threads act in synergy,a dual-thread architecture polymer binder(PALT)with energy dissipation ability enabled by integrating rigid and flexible domains is designed.The rigid poly(acrylic acid lithium)(PAALi)segments offer structural reinforcement,while the soft segments(poly(lipoic acid-tannic acid),LT)introduce dynamic covalent bonds and multiple hydrogen bonds that function as reversible sacrificial bonds,enhancing energy dissipation during cycling.Comprehensive experimental and computational analyses demonstrate effectively reduced stress concentration,improved structural integrity,and stable electrochemical performance over prolonged cycling.The silicon anode incorporating the PALT binder exhibits a satisfying capacity loss per cycle of 0.042% during 350 charge/discharge cycles at 3580 m A g^(-1).This work highlights a bioinspired binder design strategy that combines intrinsic rigidity with dynamic stress adaptability to advance the mechanical and electrochemical stability of silicon anodes.展开更多
Polyacrylic acid(PAA)-based binders have been demonstrated to significantly enhance the cycling stability of pure silicon(Si)anodes compared to other binder types.However,there is a notable lack of systematic and in-d...Polyacrylic acid(PAA)-based binders have been demonstrated to significantly enhance the cycling stability of pure silicon(Si)anodes compared to other binder types.However,there is a notable lack of systematic and in-depth investigation into the relationship between the molecular weight(MW)of PAA and its performance in pure Si anodes,leading to an absence of reliable theoretical guidance for designing and optimizing of PAA-based binders for these anodes.Herein,we select a series of PAA with varying MWs as binders for Si nanoparticle(SiNP)anodes to systematically identify the optimal MW of PAA for enhancing the electrochemical performance of SiNP anodes.The actual MWs of the various PAA were confirmed by gel permeation chromatography to accurately establish the relationship between MW and binder performance.Within an ultrawide weight average molecular weight(M_(w))range of 35.9-4850 kDa,we identify that the PAA binder with a M_(w)of 1250 kDa(PAA125)exhibits the strongest mechanical strength and the highest adhesion strength,attributed to its favorable molecular chain orientation and robust interchain interactions.These characteristics enable the SiNP anodes utilizing PAA125 to maintain the best interfacial chemistry and bulk mechanical structure stability,leading to optimal electrochemical performance.Notably,the enhancement in cycling stability of SiNP anode by PAA125 under practical application conditions is further validated by the 1.1 Ah LLNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/SiNP@PAA125 pouch cell.展开更多
Severe structural fractures and persistent side reactions at the interface with liquid electrolytes have hindered the commercialization of silicon(Si)anodes.Solid-state electrolytes present a promising solution to add...Severe structural fractures and persistent side reactions at the interface with liquid electrolytes have hindered the commercialization of silicon(Si)anodes.Solid-state electrolytes present a promising solution to address these issues.However,the high interfacial resistance of rigid ceramic electrolytes and the limited ionic conductivity of polymer electrolytes remain significant challenges,further complicated by the substantial volume expansion of Si.In this work,we chemically grafted a flame-retardant,self-healing polyurethane-thiourea polymer onto Li_(7)P_(3)S_(11)(SHPUSB-40%LPS)via nucleophilic addition,creating an electrolyte with exceptional ionic conductivity,high elasticity,and strong compatibility with Si anodes.We observed that FSI^(-)was strongly adsorbed onto the LPS surface through electrostatic interactions with sulfur vacancies,enhancing Li^(+)transport.Furthermore,SHPUSB-40%LPS exhibits dynamic covalent disulfide bonds and hydrogen bonds,enabling self-assembly of the electrolyte at the interface.This dynamic bonding provides a self-healing mechanism that mitigates structural changes during Si expansion and contraction cycles.As a result,the Si anode with SHPUSB-40%LPS presents excellent cycling stability,retaining nearly 53.5%of its capacity after 300 cycles.The practical applicability of this design was validated in a 2 Ah all-solid-state Si‖LiNi_(0.6)Mn_(0.2)Co_(0.2)O_(2)pouch cell,which maintained a stable Li-ion storage capacity retention of 76.3%after 350cycles at 0.5C.This novel solid-state electrolyte with selfhealing properties offers a promising strategy to address fundamental interfacial and performance challenges associated with Si anodes.展开更多
Nowadays,a stack of heavily doped polysilicon(poly-Si)and tunnel oxide(SiO_(x))is widely employed to improve the passivation performance in n-type tunnel oxide passivated contact(TOPCon)silicon solar cells.In this cas...Nowadays,a stack of heavily doped polysilicon(poly-Si)and tunnel oxide(SiO_(x))is widely employed to improve the passivation performance in n-type tunnel oxide passivated contact(TOPCon)silicon solar cells.In this case,it is critical to develop an in-line advanced fabrication process capable of producing high-quality tunnel SiO_(x).Herein,an in-line ozone-gas oxidation(OGO)process to prepare the tunnel SiO_(x) is proposed to be applied in n-type TOPCon solar cell fabrication,which has obtained better performance compared with previously reported in-line plasma-assisted N2O oxidation(PANO)process.In order to explore the underlying mechanism,the electrical properties of the OGO and PANO tunnel SiO_(x) are analyzed by deep-level transient spectroscopy technology.Notably,continuous interface states in the band gap are detected for OGO tunnel SiO_(x),with the interface state densities(D_(it))of 1.2×10^(12)–3.6×10^(12) cm^(-2) eV^(-1) distributed in Ev+(0.15–0.40)eV,which is significantly lower than PANO tunnel SiO_(x).Furthermore,X-ray photoelectron spectroscopy analysis indicate that the percentage of SiO_(2)(Si^(4+))in OGO tunnel SiO_(x) is higher than which in PANO tunnel SiO_(x).Therefore,we ascribe the lower D_(it) to the good inhibitory effects on the formation of low-valent silicon oxides during the OGO process.In a nutshell,OGO tunnel SiO_(x) has a great potential to be applied in n-type TOPCon silicon solar cell,which may be available for global photovoltaics industry.展开更多
Poly(p-phenylene-2,6-benzobisoxazole)(PBO)fiber and polytetrafluoroethylene(PTFE)resin have been widely acknowledged as excellent wave-transparent materials for future high-frequency applications due to their exceptio...Poly(p-phenylene-2,6-benzobisoxazole)(PBO)fiber and polytetrafluoroethylene(PTFE)resin have been widely acknowledged as excellent wave-transparent materials for future high-frequency applications due to their exceptional dielectric properties.However,the weak interfacial bonding between these two materials hampers their full potential.In this study,we successfully addressed this limitation by enhancing the surface roughness of PBO fibers and introducing active sites through the insitu grafting of silica nanowires.The added silica acted as an interfacial anchor on the PBO fiber surface,significantly improving the bonding force between PBO and PTFE.PBO/PTFE wave-transparent laminated composites were fabricated using hot compression molding.The results demonstrate that the PBO(treated with insitu grown silica)/PTFE laminated composites exhibit superior interlaminar shear strength(ILSS),flexural strength,flexural modulus,and tensile modulus compared to the pristine PBO/PTFE laminated composites.Specifically,these properties are found to be 58.6%,32.9%,138.1%,and 25.35%higher,respectively.Additionally,these composites demonstrate low dielectric constant and dielectric loss.Most notably,they achieve a wave transmittance of 91.45%at 10 GHz,indicating significant potential for wide-range applications in next-generation advanced military weapons,such as“lightweight/high-strength/wavetransparent”electromagnetic window materials,as well as civilian communication base stations.展开更多
The extreme volume expansion of the silicon(Si) anodes during repeated cycles seriously induces undesirable interfacial side reactions,forming an unstable solid electrolyte interphase(SEI) that degrades the electrode ...The extreme volume expansion of the silicon(Si) anodes during repeated cycles seriously induces undesirable interfacial side reactions,forming an unstable solid electrolyte interphase(SEI) that degrades the electrode integrity and cycle stability in lithium-ion batteries,limiting their practical applications.Despite considerable efforts to stabilize the SEI through surface modification,challenges persist in the development of high-performance Si anodes that effectively regulate intrinsic SEI properties and simultaneously facilitate electron/ion transport.Here,a highly conductive and organic electrolyte-compatible lamellar p-toluenesulfonic acid-doped polyaniline(pTAP) layer is proposed for constructing a robust artificial SEI on Si nanoparticles to achieve fast charging,lo ng-term cycle lifespan and high areal capacity.The spatially uniform pTAP layer,formed through a facile direct-encapsulation approach assisted by enriched hydrogen bonding,contributes to the effective formation of in situ SEI with an even distribution of the LiF-rich phase in its interlamination spaces.Furthermore,the integrated artificial SEI facilitates isotropic ion/electron transport,increased robustness,and effectively dissipates stress from volume changes.Consequently,a notably high rate performance of 570 mA h g^(-1),even at a substantially high current density of 10 A g^(-1),is achieved with excellent cyclic stability by showing a superior capacity over 1430 mA h g^(-1) at 1 A g^(-1) after 250 cycles and a high areal capacity of ca.2 mA h cm^(-2) at 0.5 C in a full cell system.This study demonstrates that the rational design of conductive polymers with SEI modulation for surface protection has great potential for use in high-energy-density Si anodes.展开更多
Silicon stands as a key anode material in lithium-ion battery ascribing to its high energy density.Nevertheless,the poor rate performance and limited cycling life remain unresolved through conventional approaches that...Silicon stands as a key anode material in lithium-ion battery ascribing to its high energy density.Nevertheless,the poor rate performance and limited cycling life remain unresolved through conventional approaches that involve carbon composites or nanostructures,primarily due to the un-controllable effects arising from the substantial formation of a solid electrolyte interphase(SEI)during the cycling.Here,an ultra-thin and homogeneous Ti doping alumina oxide catalytic interface is meticulously applied on the porous Si through a synergistic etching and hydrolysis process.This defect-rich oxide interface promotes a selective adsorption of fluoroethylene carbonate,leading to a catalytic reaction that can be aptly described as“molecular concentration-in situ conversion”.The resultant inorganic-rich SEI layer is electrochemical stable and favors ion-transport,particularly at high-rate cycling and high temperature.The robustly shielded porous Si,with a large surface area,achieves a high initial Coulombic efficiency of 84.7%and delivers exceptional high-rate performance at 25 A g^(−1)(692 mAh g^(−1))and a high Coulombic efficiency of 99.7%over 1000 cycles.The robust SEI constructed through a precious catalytic layer promises significant advantages for the fast development of silicon-based anode in fast-charging batteries.展开更多
By solving the magneto-transport equation for excess minority charge carriers in the base of the series vertical-junction silicon cell, the phenomenological parameters of the cell can be determined from the boundary c...By solving the magneto-transport equation for excess minority charge carriers in the base of the series vertical-junction silicon cell, the phenomenological parameters of the cell can be determined from the boundary conditions. Photocurrent density and photovoltage are determined for each value of applied magnetic field and corresponding optimum thickness, to establish the current-voltage characteristic (Jph(Sf, Sb, z, B, Hop)-Vph(Sf, Sb, z, B, Hop) of the silicon cell under polychromatic illumination. This study will make it possible to reduce the material used (by reducing the optimum thickness), which will help to lower prices. It will also enable us to reduce betting effects (lower series resistance), thereby boosting solar cell efficiency.展开更多
The increasing deployment of electronics in everyday life has generated great concerns regarding the effective disposal of waste from these components.Here,we focused on a facile sustainable and economical strategy to...The increasing deployment of electronics in everyday life has generated great concerns regarding the effective disposal of waste from these components.Here,we focused on a facile sustainable and economical strategy to provide ideas for this issue.This strategy relied on using appropriate mechanical treatment and sodium lignosulfonate coating to improve the dispersion and interfacial compatibility of bamboo fibers in poly(lactic acid).By optimising the particle size and concentration of sodium lignosulphonate,high value-added and green composites were prepared using sectional pressurization with a venting procedure.The treated composite displayed an ultra-smooth surface(roughness of 0.592 nm),impressive transient properties(disintegration and degradation behaviour after 30 d),and outstanding ultraviolet(UV)shielding properties(100%).These properties hold the promise of being an excellent substrate for electronic devices,especially for high-precision processing,transient electronics,and UV damage prevention.The satisfactory interfacial compatibility of the composites was confirmed by detailed characterisation regarding the related physicochemical properties.This investigation offers a sustainable approach for producing high value-added green composites from biomass and biomass-derived materials.展开更多
Silicon nanowires(SiNWs)have been used in a wide variety of applications over the past few decades due to their excellent material properties.The only drawback is the high production cost of SiNWs.The preparation of S...Silicon nanowires(SiNWs)have been used in a wide variety of applications over the past few decades due to their excellent material properties.The only drawback is the high production cost of SiNWs.The preparation of SiNWs from photovoltaic waste silicon(WSi)powders,which are high-volume industrial wastes,not only avoids the secondary energy consumption and environmental pollution caused by complicated recycling methods,but also realizes its high-value utilization.Herein,we present a method to rapidly convert photovoltaic WSi powders into SiNWs products.The flash heating and quenching provided by carbothermal shock induce the production of free silicon atoms from the WSi powders,which are rapidly reorganized and assembled into SiNWs during the vapor-phase process.This method allows for the one-step composite of SiNWs and carbon cloth(CC)and the formation of SiC at the interface of the silicon(Si)and carbon(C)contact to create a stable chemical connection.The obtained SiNWs-CC(SiNWs@CC)composites can be directly used as lithium anodes,exhibiting high initial coulombic efficiency(86.4%)and stable cycling specific capacity(2437.4 mA h g^(-1)at 0.5 A g^(-1)after 165 cycles).In addition,various SiNWs@C composite electrodes are easily prepared using this method.展开更多
Consisting of natural histidine residues,polyhistidine(PHis)simulates functional proteins.Traditional approaches towards PHis require the protection of imidazole groups before monomer synthesis and polymerization to p...Consisting of natural histidine residues,polyhistidine(PHis)simulates functional proteins.Traditional approaches towards PHis require the protection of imidazole groups before monomer synthesis and polymerization to prevent degradation and side reactions.In the contribution,histidine N-thiocarboxyanhydride(His-NTA)is directly synthesized in aqueous solution without protection.With the self-catalysis of the imidazole side group,the ring-closing reaction to form His-NTA does not require any activating reagent(e.g.,phosphorus tribromide),which is elucidated by density functional theory(DFT)calculations.His-NTA directly polymerizes into PHis bearing unprotected imidazole groups with designable molecular weights(4.2-7.7 kg/mol)and low dispersities(1.10-1.19).Kinetic experiments and Monte Carlo simulations reveal the elementary reactions and the relationship between the conversion of His-NTA and time during polymerization.Block copolymerization of His-NTA with sarcosine N-thiocarboxyanhydride(Sar-NTA)demonstrate versatile construction of functional polypept(o)ides.The triblock copoly(amino acid)PHis-b-PSar-b-PHis is capable to reversibly coordinate with transition metal ions(Fe^(2+),Co^(2+),Ni^(2+),Cu^(2+)and Zn^(2+))to form pH-sensitive hydrogels.展开更多
The rising prevalence of drug-resistant Gram-positive pathogens,particularly methicillin-resistant Staphy-lococcus aureus(MRSA)and vancomycin-resistant Enterococci(VRE),poses a substantial clinical challenge.Biofilm-a...The rising prevalence of drug-resistant Gram-positive pathogens,particularly methicillin-resistant Staphy-lococcus aureus(MRSA)and vancomycin-resistant Enterococci(VRE),poses a substantial clinical challenge.Biofilm-associated infections exacerbate this problem due to their inherent antibiotic resistance and complex structure.Current antibiotic treatments struggle to penetrate biofilms and eradicate persister cells,leading to prolonged antibiotic use and increased resistance.Host defense peptides(HDPs)have shown promise,but their clinical application is limited by factors such as enzymatic degradation and difficulty in largescale preparation.Synthetic HDP mimics,such as poly(2-oxazoline),have emerged as effective alter-natives.Herein,we found that the poly(2-oxazoline),Gly-POX_(20),demonstrated rapid and potent activity against clinically isolated multidrug-resistant Gram-positive strains.Gly-POX_(20) showed greater stability under physiological conditions compared to natural peptides,including resistance to protease degradation.Importantly,Gly-POX_(20) inhibited biofilm formation and eradicated mature biofilm and demonstrated superior in vivo therapeutic efficacy to vancomycin in a MRSA biofilm-associated mouse keratitis model,suggesting its potential as a novel antimicrobial agent against drug-resistant Gram-positive bacteria,especially biofilm-associated infections.展开更多
To address the increasing demand for massive data storage and processing,brain-inspired neuromorphic comput-ing systems based on artificial synaptic devices have been actively developed in recent years.Among the vario...To address the increasing demand for massive data storage and processing,brain-inspired neuromorphic comput-ing systems based on artificial synaptic devices have been actively developed in recent years.Among the various materials inves-tigated for the fabrication of synaptic devices,silicon carbide(SiC)has emerged as a preferred choices due to its high electron mobility,superior thermal conductivity,and excellent thermal stability,which exhibits promising potential for neuromorphic applications in harsh environments.In this review,the recent progress in SiC-based synaptic devices is summarized.Firstly,an in-depth discussion is conducted regarding the categories,working mechanisms,and structural designs of these devices.Subse-quently,several application scenarios for SiC-based synaptic devices are presented.Finally,a few perspectives and directions for their future development are outlined.展开更多
[4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid(Me-4PACz)self-assembled monolayer(SAM)as the hole transport materials have been demonstrated remarkable potential in perovskite solar cells(PSCs).However,the hyd...[4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid(Me-4PACz)self-assembled monolayer(SAM)as the hole transport materials have been demonstrated remarkable potential in perovskite solar cells(PSCs).However,the hydrophobicity of Me-4PACz presents a critical challenge for the fabrication of high-quality perovskite films due to its poor wettability.Here,a doped Al_(2)O_(3)with Me-4PACz to modify the Me-4PACz surface was proposed.On one hand,this approach improved the wettability of the Me-4PACz film,enhancing the coverage,uniformity,and buried interface properties of the perovskite film.On the other hand,compared to Al_(2)O_(3)modification alone,doping Al_(2)O_(3)with Me-4PACz allowed direct contact between the perovskite and Me-4PACz,resulting in better buried interface passivation.As a result,we achieved an efficiency of 22.71%for single-junction wide-bandgap perovskite solar cells(1.68 eV).Additionally,the efficiency of perovskite/silicon tandem solar cells was improved from 28.68%to 30.92%,with a significant reduction in hysteresis.Furthermore,the tandem cells demonstrated no degradation after 4200 s of operation at the maximum power point.展开更多
Silicon is believed to be a critical anode material for approaching the roadmap of lithium-ion batteries due to its high specific capacity. But this aim has been hindered by the quick capacity fading of its electrodes...Silicon is believed to be a critical anode material for approaching the roadmap of lithium-ion batteries due to its high specific capacity. But this aim has been hindered by the quick capacity fading of its electrodes during repeated charge–discharge cycles. In this work, a “soft-hard”double-layer coating has been proposed and carried out on ball-milled silicon particles. It is composed of inside conductive pathway and outside elastic coating, which is achieved by decomposing a conductive graphite layer on the silicon surface and further coating it with a polymer layer.The incorporation of the second elastic coating on the inside carbon coating enables silicon particles strongly interacted with binders, thereby making the electrodes displaying an obviously improved cycling stability. As-obtained double-coated silicon anodes deliver a reversible capacity of 2280 m Ah g^(-1)at the voltage of 0.05–2 V, and maintains over 1763 mAh g^(-1)after 50 cycles. The double-layer coating does not crack after the repeated cycling, critical for the robust performance of the electrodes. In addition, as-obtained silicon particles are mixed with commercial graphite to make actual anodes for lithium-ion batteries. A capacity of 714 mAh g^(-1)has been achieved based on the total mass of the electrodes containing 10 wt.% double-coated silicon particles. Compared with traditional carbon coating or polymeric coating, the double-coating electrodes display a much better performance. Therefore, the double-coating strategy can give inspiration for better design and synthesis of silicon anodes, as well as other battery materials.展开更多
Purpose–The brake pipe system was an essential braking component of the railway freight trains,but the existing E-type sealing rings had problems such as insufficient low-temperature resistance,poor heat stability an...Purpose–The brake pipe system was an essential braking component of the railway freight trains,but the existing E-type sealing rings had problems such as insufficient low-temperature resistance,poor heat stability and short service life.To address these issues,low-phenyl silicone rubber was prepared and tested,and the finite element analysis and experimental studies on the sealing performance of its sealing rings were carried out.Design/methodology/approach–The low-temperature resistance and thermal stability of the prepared lowphenyl silicone rubber were studied using low-temperature tensile testing,differential scanning calorimetry,dynamic thermomechanical analysis and thermogravimetric analysis.The sealing performance of the lowphenyl silicone rubber sealing ring was studied by using finite element analysis software abaqus and experiments.Findings–The prepared low-phenyl silicone rubber sealing ring possessed excellent low-temperature resistance and thermal stability.According to the finite element analysis results,the finish of the flange sealing surface and groove outer edge should be ensured,and extrusion damage should be avoided.The sealing rings were more susceptible to damage in high compression ratio and/or low-temperature environments.When the sealing effect was ensured,a small compression ratio should be selected,and rubbers with hardness and elasticity less affected by temperature should be selected.The prepared low-phenyl silicone rubber sealing ring had zero leakage at both room temperature(RT)and�508C.Originality/value–The innovation of this study is that it provides valuable data and experience for the future development of the sealing rings used in the brake pipe flange joints of the railway freight cars in China.展开更多
Grain-oriented silicon steels were prepared at different heating rates during high temperature annealing,in which the evolution of magnetic properties,grain orientations and precipitates were studied.To illustrate the...Grain-oriented silicon steels were prepared at different heating rates during high temperature annealing,in which the evolution of magnetic properties,grain orientations and precipitates were studied.To illustrate the Zener factor,the diameter and number density of precipitates of interrupted testing samples were statistically calculated.The effect of precipitate ripening on the Goss texture and magnetic property was investigated.Data indicated that the trend of Zener factor was similar under different heating rates,first increasing and then decreasing,and that the precipitate maturing was greatly inhibited as the heating rate increased.Secondary recrystallization was developed at the temperature of 1010℃when a heating rate of 5℃/h was used,resulting in Goss,Brass and{110}<227>oriented grains growing abnormally and a magnetic induction intensity of 1.90T.Furthermore,increasing the heating rate to 20℃/h would inhibit the development of undesirable oriented grains and obtain a sharp Goss texture.However,when the heating rate was extremely fast,such as 40℃/h,poor secondary recrystallization was developed with many island grains,corresponding to a decrease in magnetic induction intensity to 1.87 T.At a suitable heating rate of 20℃/h,the sharpest Goss texture and the highest magnetic induction of 1.94 T with an onset secondary recrystallization temperature of 1020℃were found among the experimental variables in this study.The heating rate affected the initial temperature of secondary recrystallization by controlling the maturation of precipitates,leading to the deviation and dispersion of Goss texture,thereby reducing the magnetic properties.展开更多
基金supported by the Strategic Priority Program of the Chinese Academy of Sciences(XDB0470303)the National Key R&D Program of China(2022YFB4600102and 2023YFE0209900)+4 种基金the National Natural Science Foundation of China(52175201 and 51935012)the science and technology projects of Gansu province(22JR5RA093,24JRRA044,24YFFA014 and 24ZDGA014)the Innovation and Entrepreneurship Team Project of YEDA(2021TD007)the special supporting project for provincial leading talents of Yantaithe Taishan Scholars Program。
文摘Silicone rubber(SR)is a versatile material widely used across various advanced functional applications,such as soft actuators and robots,flexible electronics,and medical devices.However,most SR molding methods rely on traditional thermal processing or direct ink writing three-dimensional(3D)printing.These methods are not conducive to manufacturing complex structures and present challenges such as time inefficiency,poor accuracy,and the necessity of multiple steps,significantly limiting SR applications.In this study,we developed an SR-based ink suitable for vat photopolymerization 3D printing using a multi-thiol monomer.This ink enables the one-step fabrication of complex architectures with high printing resolution at the micrometer scale,providing excellent mechanical strength and superior chemical stability.Specifically,the optimized 3D printing SR-20 exhibits a tensile stress of 1.96 MPa,an elongation at break of 487.9%,and an elastic modulus of 225.4 kPa.Additionally,the 3D-printed SR samples can withstand various solvents(acetone,toluene,and tetrahydrofuran)and endure temperatures ranging from-50℃ to 180℃,demonstrating superior stability.As a emonstration of the application,we successfully fabricated a series of SR-based soft pneumatic actuators and grippers in a single step with this technology,allowing for free assembly for the first time.This ultraviolet-curable SR,with high printing resolution and exceptional stability performance,has significant potential to enhance the capabilities of 3D printing for applications in soft actuators,robotics,flexible electronics,and medical devices.
基金the National Natural Science Foundation of China(32201497)for the financial support of this research。
文摘Silicon(Si)is considered one of the most promising anode materials for next-generation lithium-ion batteries due to its ultrahigh theoretical capacity.However,its application is significantly limited by severe volume expansion,leading to structural degradation and poor cycling stability.Polymer binders play a critical role in addressing these issues by providing mechanical stabilization.Inspired by the mechanically adaptive architecture of spider webs,where stiff radial threads and extensible spiral threads act in synergy,a dual-thread architecture polymer binder(PALT)with energy dissipation ability enabled by integrating rigid and flexible domains is designed.The rigid poly(acrylic acid lithium)(PAALi)segments offer structural reinforcement,while the soft segments(poly(lipoic acid-tannic acid),LT)introduce dynamic covalent bonds and multiple hydrogen bonds that function as reversible sacrificial bonds,enhancing energy dissipation during cycling.Comprehensive experimental and computational analyses demonstrate effectively reduced stress concentration,improved structural integrity,and stable electrochemical performance over prolonged cycling.The silicon anode incorporating the PALT binder exhibits a satisfying capacity loss per cycle of 0.042% during 350 charge/discharge cycles at 3580 m A g^(-1).This work highlights a bioinspired binder design strategy that combines intrinsic rigidity with dynamic stress adaptability to advance the mechanical and electrochemical stability of silicon anodes.
基金funding supports of the National Natural Science Foundation of China(52402315,52172244,51874104,and 52172190)the"Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang"(2023R01007)the Zhejiang Provincial"Jianbing"and"Lingyan"R&D Programs(Grant No.2024C01262)。
文摘Polyacrylic acid(PAA)-based binders have been demonstrated to significantly enhance the cycling stability of pure silicon(Si)anodes compared to other binder types.However,there is a notable lack of systematic and in-depth investigation into the relationship between the molecular weight(MW)of PAA and its performance in pure Si anodes,leading to an absence of reliable theoretical guidance for designing and optimizing of PAA-based binders for these anodes.Herein,we select a series of PAA with varying MWs as binders for Si nanoparticle(SiNP)anodes to systematically identify the optimal MW of PAA for enhancing the electrochemical performance of SiNP anodes.The actual MWs of the various PAA were confirmed by gel permeation chromatography to accurately establish the relationship between MW and binder performance.Within an ultrawide weight average molecular weight(M_(w))range of 35.9-4850 kDa,we identify that the PAA binder with a M_(w)of 1250 kDa(PAA125)exhibits the strongest mechanical strength and the highest adhesion strength,attributed to its favorable molecular chain orientation and robust interchain interactions.These characteristics enable the SiNP anodes utilizing PAA125 to maintain the best interfacial chemistry and bulk mechanical structure stability,leading to optimal electrochemical performance.Notably,the enhancement in cycling stability of SiNP anode by PAA125 under practical application conditions is further validated by the 1.1 Ah LLNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/SiNP@PAA125 pouch cell.
基金supported financially by the National Natural Science Foundation of China(No.52172202)Science and Technology Program of Guangzhou,China(No.SL2024A03J00326)+1 种基金Key Research and Development project of High-Level Scientific and Technological Talent Introduction for Luliang City(No.2023RC27)the Basic Research Program(Free Exploration Category)Project for Shanxi Province(No.202303021222251)
文摘Severe structural fractures and persistent side reactions at the interface with liquid electrolytes have hindered the commercialization of silicon(Si)anodes.Solid-state electrolytes present a promising solution to address these issues.However,the high interfacial resistance of rigid ceramic electrolytes and the limited ionic conductivity of polymer electrolytes remain significant challenges,further complicated by the substantial volume expansion of Si.In this work,we chemically grafted a flame-retardant,self-healing polyurethane-thiourea polymer onto Li_(7)P_(3)S_(11)(SHPUSB-40%LPS)via nucleophilic addition,creating an electrolyte with exceptional ionic conductivity,high elasticity,and strong compatibility with Si anodes.We observed that FSI^(-)was strongly adsorbed onto the LPS surface through electrostatic interactions with sulfur vacancies,enhancing Li^(+)transport.Furthermore,SHPUSB-40%LPS exhibits dynamic covalent disulfide bonds and hydrogen bonds,enabling self-assembly of the electrolyte at the interface.This dynamic bonding provides a self-healing mechanism that mitigates structural changes during Si expansion and contraction cycles.As a result,the Si anode with SHPUSB-40%LPS presents excellent cycling stability,retaining nearly 53.5%of its capacity after 300 cycles.The practical applicability of this design was validated in a 2 Ah all-solid-state Si‖LiNi_(0.6)Mn_(0.2)Co_(0.2)O_(2)pouch cell,which maintained a stable Li-ion storage capacity retention of 76.3%after 350cycles at 0.5C.This novel solid-state electrolyte with selfhealing properties offers a promising strategy to address fundamental interfacial and performance challenges associated with Si anodes.
基金supported by the National Natural Science Foundation of China(Nos.62025403 and U23A20354)the Natural Science Foundation of Zhejiang Province(LD22E020001)+1 种基金“Pioneer”and“Leading Goose”R&D Program of Zhejiang(2022C01215,2024C01055)the Fundamental Research Funds for the Central Universities(226-2022-00200).
文摘Nowadays,a stack of heavily doped polysilicon(poly-Si)and tunnel oxide(SiO_(x))is widely employed to improve the passivation performance in n-type tunnel oxide passivated contact(TOPCon)silicon solar cells.In this case,it is critical to develop an in-line advanced fabrication process capable of producing high-quality tunnel SiO_(x).Herein,an in-line ozone-gas oxidation(OGO)process to prepare the tunnel SiO_(x) is proposed to be applied in n-type TOPCon solar cell fabrication,which has obtained better performance compared with previously reported in-line plasma-assisted N2O oxidation(PANO)process.In order to explore the underlying mechanism,the electrical properties of the OGO and PANO tunnel SiO_(x) are analyzed by deep-level transient spectroscopy technology.Notably,continuous interface states in the band gap are detected for OGO tunnel SiO_(x),with the interface state densities(D_(it))of 1.2×10^(12)–3.6×10^(12) cm^(-2) eV^(-1) distributed in Ev+(0.15–0.40)eV,which is significantly lower than PANO tunnel SiO_(x).Furthermore,X-ray photoelectron spectroscopy analysis indicate that the percentage of SiO_(2)(Si^(4+))in OGO tunnel SiO_(x) is higher than which in PANO tunnel SiO_(x).Therefore,we ascribe the lower D_(it) to the good inhibitory effects on the formation of low-valent silicon oxides during the OGO process.In a nutshell,OGO tunnel SiO_(x) has a great potential to be applied in n-type TOPCon silicon solar cell,which may be available for global photovoltaics industry.
基金supported by the National Natural Science Foundation of China(No.U21A2094)CASHIPS Director’s Fund(Nos.YZJJZX202015,YZJJ202304-CX,YZJJ2023QN36)+1 种基金Anhui Province Postdoctoral Researcher Research Project(No.E24F0D27)Central Government Guiding Local Government Science and Technology Development Special Fund Project(No.2022ZB09002).
文摘Poly(p-phenylene-2,6-benzobisoxazole)(PBO)fiber and polytetrafluoroethylene(PTFE)resin have been widely acknowledged as excellent wave-transparent materials for future high-frequency applications due to their exceptional dielectric properties.However,the weak interfacial bonding between these two materials hampers their full potential.In this study,we successfully addressed this limitation by enhancing the surface roughness of PBO fibers and introducing active sites through the insitu grafting of silica nanowires.The added silica acted as an interfacial anchor on the PBO fiber surface,significantly improving the bonding force between PBO and PTFE.PBO/PTFE wave-transparent laminated composites were fabricated using hot compression molding.The results demonstrate that the PBO(treated with insitu grown silica)/PTFE laminated composites exhibit superior interlaminar shear strength(ILSS),flexural strength,flexural modulus,and tensile modulus compared to the pristine PBO/PTFE laminated composites.Specifically,these properties are found to be 58.6%,32.9%,138.1%,and 25.35%higher,respectively.Additionally,these composites demonstrate low dielectric constant and dielectric loss.Most notably,they achieve a wave transmittance of 91.45%at 10 GHz,indicating significant potential for wide-range applications in next-generation advanced military weapons,such as“lightweight/high-strength/wavetransparent”electromagnetic window materials,as well as civilian communication base stations.
基金National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) [NRF-2021R1A5A1084921]the “Human Resources Program in Energy Technology” of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea [No. 20204010600100]the Materials and Components Technology Development Program of the Ministry of Trade, Industry and Energy (MOTIE, Korea) and Korea Electronics Technology Institute (KETI) [20012224]。
文摘The extreme volume expansion of the silicon(Si) anodes during repeated cycles seriously induces undesirable interfacial side reactions,forming an unstable solid electrolyte interphase(SEI) that degrades the electrode integrity and cycle stability in lithium-ion batteries,limiting their practical applications.Despite considerable efforts to stabilize the SEI through surface modification,challenges persist in the development of high-performance Si anodes that effectively regulate intrinsic SEI properties and simultaneously facilitate electron/ion transport.Here,a highly conductive and organic electrolyte-compatible lamellar p-toluenesulfonic acid-doped polyaniline(pTAP) layer is proposed for constructing a robust artificial SEI on Si nanoparticles to achieve fast charging,lo ng-term cycle lifespan and high areal capacity.The spatially uniform pTAP layer,formed through a facile direct-encapsulation approach assisted by enriched hydrogen bonding,contributes to the effective formation of in situ SEI with an even distribution of the LiF-rich phase in its interlamination spaces.Furthermore,the integrated artificial SEI facilitates isotropic ion/electron transport,increased robustness,and effectively dissipates stress from volume changes.Consequently,a notably high rate performance of 570 mA h g^(-1),even at a substantially high current density of 10 A g^(-1),is achieved with excellent cyclic stability by showing a superior capacity over 1430 mA h g^(-1) at 1 A g^(-1) after 250 cycles and a high areal capacity of ca.2 mA h cm^(-2) at 0.5 C in a full cell system.This study demonstrates that the rational design of conductive polymers with SEI modulation for surface protection has great potential for use in high-energy-density Si anodes.
基金the National Key R&D Plan of the Ministry of Science and Technology of China(2022YFE0122400)National Natural Science Foundation of China(52002238,22102207)+1 种基金Science and Technology Commission of Shanghai Municipality(22ZR1423800,21ZR1465200,23ZR1423600)Shanghai Municipal Education Commission and the NSRF via the Program Management Unit for Human Resources&Institutional Development,Research and Innovation(B49G680115).
文摘Silicon stands as a key anode material in lithium-ion battery ascribing to its high energy density.Nevertheless,the poor rate performance and limited cycling life remain unresolved through conventional approaches that involve carbon composites or nanostructures,primarily due to the un-controllable effects arising from the substantial formation of a solid electrolyte interphase(SEI)during the cycling.Here,an ultra-thin and homogeneous Ti doping alumina oxide catalytic interface is meticulously applied on the porous Si through a synergistic etching and hydrolysis process.This defect-rich oxide interface promotes a selective adsorption of fluoroethylene carbonate,leading to a catalytic reaction that can be aptly described as“molecular concentration-in situ conversion”.The resultant inorganic-rich SEI layer is electrochemical stable and favors ion-transport,particularly at high-rate cycling and high temperature.The robustly shielded porous Si,with a large surface area,achieves a high initial Coulombic efficiency of 84.7%and delivers exceptional high-rate performance at 25 A g^(−1)(692 mAh g^(−1))and a high Coulombic efficiency of 99.7%over 1000 cycles.The robust SEI constructed through a precious catalytic layer promises significant advantages for the fast development of silicon-based anode in fast-charging batteries.
文摘By solving the magneto-transport equation for excess minority charge carriers in the base of the series vertical-junction silicon cell, the phenomenological parameters of the cell can be determined from the boundary conditions. Photocurrent density and photovoltage are determined for each value of applied magnetic field and corresponding optimum thickness, to establish the current-voltage characteristic (Jph(Sf, Sb, z, B, Hop)-Vph(Sf, Sb, z, B, Hop) of the silicon cell under polychromatic illumination. This study will make it possible to reduce the material used (by reducing the optimum thickness), which will help to lower prices. It will also enable us to reduce betting effects (lower series resistance), thereby boosting solar cell efficiency.
基金supported by the National Natural Science Foundation of China(Nos.31971741 and 31760195)the Yunnan Fundamental Research Projects(Nos.2018FB066 and 202001AT070141)the Yunnan Agricultural Basic Research Special Projects(No.202101BD070001-086).
文摘The increasing deployment of electronics in everyday life has generated great concerns regarding the effective disposal of waste from these components.Here,we focused on a facile sustainable and economical strategy to provide ideas for this issue.This strategy relied on using appropriate mechanical treatment and sodium lignosulfonate coating to improve the dispersion and interfacial compatibility of bamboo fibers in poly(lactic acid).By optimising the particle size and concentration of sodium lignosulphonate,high value-added and green composites were prepared using sectional pressurization with a venting procedure.The treated composite displayed an ultra-smooth surface(roughness of 0.592 nm),impressive transient properties(disintegration and degradation behaviour after 30 d),and outstanding ultraviolet(UV)shielding properties(100%).These properties hold the promise of being an excellent substrate for electronic devices,especially for high-precision processing,transient electronics,and UV damage prevention.The satisfactory interfacial compatibility of the composites was confirmed by detailed characterisation regarding the related physicochemical properties.This investigation offers a sustainable approach for producing high value-added green composites from biomass and biomass-derived materials.
基金partially funded by the National Natural Science Foundation of China(52074255,52274412)。
文摘Silicon nanowires(SiNWs)have been used in a wide variety of applications over the past few decades due to their excellent material properties.The only drawback is the high production cost of SiNWs.The preparation of SiNWs from photovoltaic waste silicon(WSi)powders,which are high-volume industrial wastes,not only avoids the secondary energy consumption and environmental pollution caused by complicated recycling methods,but also realizes its high-value utilization.Herein,we present a method to rapidly convert photovoltaic WSi powders into SiNWs products.The flash heating and quenching provided by carbothermal shock induce the production of free silicon atoms from the WSi powders,which are rapidly reorganized and assembled into SiNWs during the vapor-phase process.This method allows for the one-step composite of SiNWs and carbon cloth(CC)and the formation of SiC at the interface of the silicon(Si)and carbon(C)contact to create a stable chemical connection.The obtained SiNWs-CC(SiNWs@CC)composites can be directly used as lithium anodes,exhibiting high initial coulombic efficiency(86.4%)and stable cycling specific capacity(2437.4 mA h g^(-1)at 0.5 A g^(-1)after 165 cycles).In addition,various SiNWs@C composite electrodes are easily prepared using this method.
基金financially supported by the National Natural Science Foundation of China(Nos.22271252 and 22201105)。
文摘Consisting of natural histidine residues,polyhistidine(PHis)simulates functional proteins.Traditional approaches towards PHis require the protection of imidazole groups before monomer synthesis and polymerization to prevent degradation and side reactions.In the contribution,histidine N-thiocarboxyanhydride(His-NTA)is directly synthesized in aqueous solution without protection.With the self-catalysis of the imidazole side group,the ring-closing reaction to form His-NTA does not require any activating reagent(e.g.,phosphorus tribromide),which is elucidated by density functional theory(DFT)calculations.His-NTA directly polymerizes into PHis bearing unprotected imidazole groups with designable molecular weights(4.2-7.7 kg/mol)and low dispersities(1.10-1.19).Kinetic experiments and Monte Carlo simulations reveal the elementary reactions and the relationship between the conversion of His-NTA and time during polymerization.Block copolymerization of His-NTA with sarcosine N-thiocarboxyanhydride(Sar-NTA)demonstrate versatile construction of functional polypept(o)ides.The triblock copoly(amino acid)PHis-b-PSar-b-PHis is capable to reversibly coordinate with transition metal ions(Fe^(2+),Co^(2+),Ni^(2+),Cu^(2+)and Zn^(2+))to form pH-sensitive hydrogels.
基金financially supported by the National Key Research and Development Program of China(no.2022YFC2303100)National Natural Science Foundation of China(nos.T2325010,22305082,52203162,and 22075078)+1 种基金Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism(Shanghai Municipal Education Commission),the Fundamental Research Funds for the Central Universities(nos.JKVD1241029 and JKD01241701)Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry(Changchun Institute of Applied Chemistry,Chinese Academy of Sciences),the Open Project of Engineering Research Center of Dairy Quality and Safety Control Technology(Ministry of Education,no.R202201).
文摘The rising prevalence of drug-resistant Gram-positive pathogens,particularly methicillin-resistant Staphy-lococcus aureus(MRSA)and vancomycin-resistant Enterococci(VRE),poses a substantial clinical challenge.Biofilm-associated infections exacerbate this problem due to their inherent antibiotic resistance and complex structure.Current antibiotic treatments struggle to penetrate biofilms and eradicate persister cells,leading to prolonged antibiotic use and increased resistance.Host defense peptides(HDPs)have shown promise,but their clinical application is limited by factors such as enzymatic degradation and difficulty in largescale preparation.Synthetic HDP mimics,such as poly(2-oxazoline),have emerged as effective alter-natives.Herein,we found that the poly(2-oxazoline),Gly-POX_(20),demonstrated rapid and potent activity against clinically isolated multidrug-resistant Gram-positive strains.Gly-POX_(20) showed greater stability under physiological conditions compared to natural peptides,including resistance to protease degradation.Importantly,Gly-POX_(20) inhibited biofilm formation and eradicated mature biofilm and demonstrated superior in vivo therapeutic efficacy to vancomycin in a MRSA biofilm-associated mouse keratitis model,suggesting its potential as a novel antimicrobial agent against drug-resistant Gram-positive bacteria,especially biofilm-associated infections.
基金supported by the Natural Science Foundation of Zhejiang Province(Grant No.LQ24F040007)the National Natural Science Foundation of China(Grant No.U22A2075)the Opening Project of State Key Laboratory of Polymer Materials Engineering(Sichuan University)(Grant No.sklpme2024-1-21).
文摘To address the increasing demand for massive data storage and processing,brain-inspired neuromorphic comput-ing systems based on artificial synaptic devices have been actively developed in recent years.Among the various materials inves-tigated for the fabrication of synaptic devices,silicon carbide(SiC)has emerged as a preferred choices due to its high electron mobility,superior thermal conductivity,and excellent thermal stability,which exhibits promising potential for neuromorphic applications in harsh environments.In this review,the recent progress in SiC-based synaptic devices is summarized.Firstly,an in-depth discussion is conducted regarding the categories,working mechanisms,and structural designs of these devices.Subse-quently,several application scenarios for SiC-based synaptic devices are presented.Finally,a few perspectives and directions for their future development are outlined.
基金supported by the National Key Research and Development Program of China(2023YFB4202503)the cooperation project between Three Gorges Corporation and Nankai University(202103571)+6 种基金the National Natural Science Foundation Joint Fund(U21A2072)the National Science Foundation(62274099,62104115)Tianjin Science and Technology Project(24ZXZSSS00160)Yunnan Provincial Science and Technology Project at Southwest United Graduate School(202302A0370009)the China Higher Education Discipline Innovation Overseas Expert Introduction Project(B16027)the Haihe Laboratory of Sustainable Chemical Transformationsthe Fundamental Research Funds for the Central Universities,Nankai University。
文摘[4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid(Me-4PACz)self-assembled monolayer(SAM)as the hole transport materials have been demonstrated remarkable potential in perovskite solar cells(PSCs).However,the hydrophobicity of Me-4PACz presents a critical challenge for the fabrication of high-quality perovskite films due to its poor wettability.Here,a doped Al_(2)O_(3)with Me-4PACz to modify the Me-4PACz surface was proposed.On one hand,this approach improved the wettability of the Me-4PACz film,enhancing the coverage,uniformity,and buried interface properties of the perovskite film.On the other hand,compared to Al_(2)O_(3)modification alone,doping Al_(2)O_(3)with Me-4PACz allowed direct contact between the perovskite and Me-4PACz,resulting in better buried interface passivation.As a result,we achieved an efficiency of 22.71%for single-junction wide-bandgap perovskite solar cells(1.68 eV).Additionally,the efficiency of perovskite/silicon tandem solar cells was improved from 28.68%to 30.92%,with a significant reduction in hysteresis.Furthermore,the tandem cells demonstrated no degradation after 4200 s of operation at the maximum power point.
基金supported by the National Natural Science Foundation of China (No. 22008256)。
文摘Silicon is believed to be a critical anode material for approaching the roadmap of lithium-ion batteries due to its high specific capacity. But this aim has been hindered by the quick capacity fading of its electrodes during repeated charge–discharge cycles. In this work, a “soft-hard”double-layer coating has been proposed and carried out on ball-milled silicon particles. It is composed of inside conductive pathway and outside elastic coating, which is achieved by decomposing a conductive graphite layer on the silicon surface and further coating it with a polymer layer.The incorporation of the second elastic coating on the inside carbon coating enables silicon particles strongly interacted with binders, thereby making the electrodes displaying an obviously improved cycling stability. As-obtained double-coated silicon anodes deliver a reversible capacity of 2280 m Ah g^(-1)at the voltage of 0.05–2 V, and maintains over 1763 mAh g^(-1)after 50 cycles. The double-layer coating does not crack after the repeated cycling, critical for the robust performance of the electrodes. In addition, as-obtained silicon particles are mixed with commercial graphite to make actual anodes for lithium-ion batteries. A capacity of 714 mAh g^(-1)has been achieved based on the total mass of the electrodes containing 10 wt.% double-coated silicon particles. Compared with traditional carbon coating or polymeric coating, the double-coating electrodes display a much better performance. Therefore, the double-coating strategy can give inspiration for better design and synthesis of silicon anodes, as well as other battery materials.
基金supported by the Science and Technology Research and Development Plan of the China State Railway Group Company Limited(No.Q2023J012).
文摘Purpose–The brake pipe system was an essential braking component of the railway freight trains,but the existing E-type sealing rings had problems such as insufficient low-temperature resistance,poor heat stability and short service life.To address these issues,low-phenyl silicone rubber was prepared and tested,and the finite element analysis and experimental studies on the sealing performance of its sealing rings were carried out.Design/methodology/approach–The low-temperature resistance and thermal stability of the prepared lowphenyl silicone rubber were studied using low-temperature tensile testing,differential scanning calorimetry,dynamic thermomechanical analysis and thermogravimetric analysis.The sealing performance of the lowphenyl silicone rubber sealing ring was studied by using finite element analysis software abaqus and experiments.Findings–The prepared low-phenyl silicone rubber sealing ring possessed excellent low-temperature resistance and thermal stability.According to the finite element analysis results,the finish of the flange sealing surface and groove outer edge should be ensured,and extrusion damage should be avoided.The sealing rings were more susceptible to damage in high compression ratio and/or low-temperature environments.When the sealing effect was ensured,a small compression ratio should be selected,and rubbers with hardness and elasticity less affected by temperature should be selected.The prepared low-phenyl silicone rubber sealing ring had zero leakage at both room temperature(RT)and�508C.Originality/value–The innovation of this study is that it provides valuable data and experience for the future development of the sealing rings used in the brake pipe flange joints of the railway freight cars in China.
文摘Grain-oriented silicon steels were prepared at different heating rates during high temperature annealing,in which the evolution of magnetic properties,grain orientations and precipitates were studied.To illustrate the Zener factor,the diameter and number density of precipitates of interrupted testing samples were statistically calculated.The effect of precipitate ripening on the Goss texture and magnetic property was investigated.Data indicated that the trend of Zener factor was similar under different heating rates,first increasing and then decreasing,and that the precipitate maturing was greatly inhibited as the heating rate increased.Secondary recrystallization was developed at the temperature of 1010℃when a heating rate of 5℃/h was used,resulting in Goss,Brass and{110}<227>oriented grains growing abnormally and a magnetic induction intensity of 1.90T.Furthermore,increasing the heating rate to 20℃/h would inhibit the development of undesirable oriented grains and obtain a sharp Goss texture.However,when the heating rate was extremely fast,such as 40℃/h,poor secondary recrystallization was developed with many island grains,corresponding to a decrease in magnetic induction intensity to 1.87 T.At a suitable heating rate of 20℃/h,the sharpest Goss texture and the highest magnetic induction of 1.94 T with an onset secondary recrystallization temperature of 1020℃were found among the experimental variables in this study.The heating rate affected the initial temperature of secondary recrystallization by controlling the maturation of precipitates,leading to the deviation and dispersion of Goss texture,thereby reducing the magnetic properties.
