To predict the Elasto-Plastic Behaviors(EPBs)of aligned inclusions reinforced composites,this paper develops an interpolative Mori-Tanaka/Double-Inclusion(MT-DI)homogenization model with the secant formulation,and giv...To predict the Elasto-Plastic Behaviors(EPBs)of aligned inclusions reinforced composites,this paper develops an interpolative Mori-Tanaka/Double-Inclusion(MT-DI)homogenization model with the secant formulation,and gives the numerical implementation algorithms of the developed MT-DI model with the secant formulation.The Finite Element(FE)homogenization method is implemented to provide the "exact" EPBs of the composites and thus validate the MT-DI model with the secant formulation.The MT-DI model with the 2 nd-order secant formulation is validated to provide the more accurate predictions,while the MT-DI model with the 1 st-order secant formulation always gives the stiffer predictions.The results show that using the macro-stress and macrostrain as the inputs,the MT-DI model with the secant formulation gives the identical predictions.The predictions of the MT-DI model with the secant formulation vary between those of the MT and DI models with the secant formulation.Meanwhile,the MT-DI model with the secant formulation does not predict the accurate EPBs for the phases of the composites.展开更多
The SiC powders by AI or N doping have been synthesized by combustion synthesis, using AI powder and NH4Cl powder as the dopants and polytetrafluoroethylene as the chemical activator. Characterization by X-ray diffrac...The SiC powders by AI or N doping have been synthesized by combustion synthesis, using AI powder and NH4Cl powder as the dopants and polytetrafluoroethylene as the chemical activator. Characterization by X-ray diffraction, Raman spectrometer, scanning electron microscopy and energy dispersive spectrometer demonstrates the formation of Al doped SiC, N doped SiC and the AI and N co-doped SiC solid solution powders, respectively. The electric permittivities of prepared powders have been determined in the frequency range of 8.2-12.4 GHz. It indicates that the electric permittivities of the prepared SiC powders have been improved by the pure AI or N doping and decrease by the AI and N co-doping. The paper presents a method to adjust dielectric property of SiC powders in the GHz range.展开更多
This paper reports the effects of fiber breakage defects and waviness defects on the compressive fatigue behavior and the progressive damage evolution process of 3D Multiaxial Braided Composites (3DMBCs). Combined wit...This paper reports the effects of fiber breakage defects and waviness defects on the compressive fatigue behavior and the progressive damage evolution process of 3D Multiaxial Braided Composites (3DMBCs). Combined with finite element compression simulation and ultra-depth microscope, the internal defect content of composites with different braiding angles was determined. The results demonstrate that the weakening effect of waviness and fiber breakage defects is greater than the strengthening effect of the braiding angle. This causes the fatigue resistance of 3DMBCs with the 31° braiding angle being better in both directions of 0° and 90°. The increase of 4° waviness and 10% fiber breakage defect results in the average fatigue life of composites being shortened by 48% and the energy consumption rate increased by 10% at 85% stress level in 90° compression direction. The alteration in loading direction modifies the included angle corresponding to the stress component. The stress component parallel to the fiber direction under compressive fatigue load leads to interfacial debonding in the composites, whereas the stress component perpendicular to the fiber direction results in pronounced shear failure.展开更多
This paper presents an energy resolution study of the JUNO experiment,incorporating the latest knowledge acquired during the detector construction phase.The determination of neutrino mass ordering in JUNO requires an ...This paper presents an energy resolution study of the JUNO experiment,incorporating the latest knowledge acquired during the detector construction phase.The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV.To achieve this ambitious goal,significant efforts have been undertaken in the design and production of the key components of the JUNO detector.Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution,extending beyond the statistical fluctuations of the detected number of photons,such as the properties of the liquid scintillator,performance of photomultiplier tubes,and the energy reconstruction algorithm.To account for these effects,a full JUNO simulation and reconstruction approach is employed.This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution.The results of this study reveal an energy resolution of 2.95% at 1 Mev.Furthermore,this study assesses the contribution of major effects to the overall energy resolution budget.This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data collection.Moreover,it provides a guideline for comprehending the energy resolution characteristics of liquid scintillator-based detectors.展开更多
The separator with excellent mechanical and thermal properties are highly required for lithium ion batteries(LIBs).Therefore,it is crucial to develop novel nanofbrous membranes with enhanced mechanical strength and th...The separator with excellent mechanical and thermal properties are highly required for lithium ion batteries(LIBs).Therefore,it is crucial to develop novel nanofbrous membranes with enhanced mechanical strength and thermal stability.In this work,the fuorinated polyimide(FPI)was synthesized and blended with polyvinylidene fuoride(PVDF)to fabricate composite nanofbrous membranes(CNMs)via electrospinning method.Benefting from the introduction of aromatic FPI,the prepared PVDF/FPI nanofbrous membranes were endowed with enhanced mechanical strength and thermal stability.When the FPI content increased from 0 to 30 wt%,the tensile strength of composite nanofbrous membranes enhanced from 1.57 to 2.30 MPa.Moreover,there are almost no dimensional shrinkage for the CNM-30 containing 30 wt%FPI after heat treatment at 160℃ for 1 h.Furthermore,the prepared CNMs show improved electrochemical performances in comparison with neat PVDF and commercial Celgard membranes.The electrolyte uptake and ionic conductivity of the CNMs could reach to 522.4% and 1.14 ms·cm^(−1),respectively.The prepared CNMs could provide an innovative and promising approach for the development and design of high-performance separators.展开更多
Plasmonic surface of flexible multilayered nanofibers possesses special superiority for the surface-enhanced Raman scattering(SERS)sensing of molecules and microbial cells.However,the fabrication of flexible plasmonic...Plasmonic surface of flexible multilayered nanofibers possesses special superiority for the surface-enhanced Raman scattering(SERS)sensing of molecules and microbial cells.However,the fabrication of flexible plasmonic nanofibers with high sensitivity and reproducibility is difficult.Herein,we report a smart strategy for fabricating flexible plasmonic fibers,in which compact and homogeneous gold nanoparticles(Au NPs)are in-situ grown on the high-curvature surface of multilayered fibers of electrospun polyvinylidene fluoride(PVDF).Firstly,the surface of PVDF fibers is changed electrically,and Au seeds are deposited on the surface of PVDF fibers using electrostatic driving force.Secondly,a stable AuI_(4)−complex is formed employing coordination between I−and AuCl4−ions,which could decrease the reduction potential of AuCl4−and restrain the self-nucleation,and then the reduction reaction of AuI4−is initiated by introducing PVDF@Au seeds to pull down the barrier of potential energy.Finally,in-situ growth of AuNPs is generated on the high-curvature surface of PVDF nanofibers,and large-scale hotspots are generated by adjacent AuNPs coupling in the three-dimensional(3D)space of multilayered fibers.Membrane of PVDF@Au nanofibers also realizes the sensitive detection of thiram molecules(low limit of detection of 0.1 nM)and good reproducibility(relative standard deviation of 10.6%).Meanwhile,due to the multilayered construction of PVDF@Au nanofibers,a valid SERS signal on 3D surface of bacteria could be generated.3D distribution of hotspots on multilayered PVDF@Au nanofibers gives a clear advantage for SERS sensing of organic molecules and microbial cells.展开更多
基金the financial support from the Natural Science Basic Research Program of Shaanxi(No.2019JQ857)the Doctoral Scientific Research Foundation of Xi’an Polytechnic University(No.BS201863)+1 种基金the China Textile Industry Federation Science and Technology Guidance Project(No.2019002)the Tianyuan Open Fund Project(No.tywl2019-14)。
文摘To predict the Elasto-Plastic Behaviors(EPBs)of aligned inclusions reinforced composites,this paper develops an interpolative Mori-Tanaka/Double-Inclusion(MT-DI)homogenization model with the secant formulation,and gives the numerical implementation algorithms of the developed MT-DI model with the secant formulation.The Finite Element(FE)homogenization method is implemented to provide the "exact" EPBs of the composites and thus validate the MT-DI model with the secant formulation.The MT-DI model with the 2 nd-order secant formulation is validated to provide the more accurate predictions,while the MT-DI model with the 1 st-order secant formulation always gives the stiffer predictions.The results show that using the macro-stress and macrostrain as the inputs,the MT-DI model with the secant formulation gives the identical predictions.The predictions of the MT-DI model with the secant formulation vary between those of the MT and DI models with the secant formulation.Meanwhile,the MT-DI model with the secant formulation does not predict the accurate EPBs for the phases of the composites.
基金the support of the National Natural Scientific Foundation of China (Grant No. 51002113)the foundation of Xi an Polytechnic University (Grant No. BS0911)the Natural Science Basic Research Plan in Shaanxi Province of China (Grant No.2009JQ6009)
文摘The SiC powders by AI or N doping have been synthesized by combustion synthesis, using AI powder and NH4Cl powder as the dopants and polytetrafluoroethylene as the chemical activator. Characterization by X-ray diffraction, Raman spectrometer, scanning electron microscopy and energy dispersive spectrometer demonstrates the formation of Al doped SiC, N doped SiC and the AI and N co-doped SiC solid solution powders, respectively. The electric permittivities of prepared powders have been determined in the frequency range of 8.2-12.4 GHz. It indicates that the electric permittivities of the prepared SiC powders have been improved by the pure AI or N doping and decrease by the AI and N co-doping. The paper presents a method to adjust dielectric property of SiC powders in the GHz range.
基金supported by the National Natural Science Foundation,China(Nos.52073224,12472141 and 12002248)the Natural Science Foundation of Shaanxi Province,China(Nos.2023KXJ-034 and 2023KXJ-005)+3 种基金Xi’an Science and Technology Plan Project,China(No.2022JH-ZCZC-0004)the Young Talent Fund of University Association for Science and Technology in Shaanxi,China(No.20210509)the Scientific Research Project of Shaanxi Provincial Education Department,China(No.22JC035)Shaanxi Outstanding Youth Science Fund Project,China(No.2024JC-JCQN-03).
文摘This paper reports the effects of fiber breakage defects and waviness defects on the compressive fatigue behavior and the progressive damage evolution process of 3D Multiaxial Braided Composites (3DMBCs). Combined with finite element compression simulation and ultra-depth microscope, the internal defect content of composites with different braiding angles was determined. The results demonstrate that the weakening effect of waviness and fiber breakage defects is greater than the strengthening effect of the braiding angle. This causes the fatigue resistance of 3DMBCs with the 31° braiding angle being better in both directions of 0° and 90°. The increase of 4° waviness and 10% fiber breakage defect results in the average fatigue life of composites being shortened by 48% and the energy consumption rate increased by 10% at 85% stress level in 90° compression direction. The alteration in loading direction modifies the included angle corresponding to the stress component. The stress component parallel to the fiber direction under compressive fatigue load leads to interfacial debonding in the composites, whereas the stress component perpendicular to the fiber direction results in pronounced shear failure.
基金Supported by the Chinese Academy of Sciencesthe National Key R&D Program of China+20 种基金the CAS Center for Excellence in Particle Physics,Wuyi Universitythe Tsung-Dao Lee Institute of Shanghai Jiao Tong University in Chinathe Institut National de Physique Nucléaire et de Physique de Particules(IN2P3)in Francethe Istituto Nazionale di Fisica Nucleare(INFN)in Italythe Italian-Chinese collaborative research program MAECI-NSFCthe Fond de la Recherche Scientifique(F.R.S-FNRS)FWO under the"Excellence of Science-EOS"in Belgiumthe Conselho Nacional de Desenvolvimento Científico e Tecnològico in Brazilthe Agencia Nacional de Investigacion y Desarrollo and ANID Millennium Science Initiative Program—ICN2019_044 in Chilethe Charles University Research Centre and the Ministry of Education,Youth,and Sports in Czech Republicthe Deutsche Forschungsgemeinschaft(DFG)the Helmholtz Associationthe Cluster of Excellence PRISMA+in Germanythe Joint Institute of Nuclear Research(JINR)Lomonosov Moscow State University in Russiathe joint Russian Science Foundation(RSF)National Natural Science Foundation of China(NSFC)research programthe MOST and MOE in Taiwan,Chinathe Chulalongkorn University and Suranaree University of Technology in Thailandthe University of California at Irvinethe National Science Foundation in USA。
文摘This paper presents an energy resolution study of the JUNO experiment,incorporating the latest knowledge acquired during the detector construction phase.The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV.To achieve this ambitious goal,significant efforts have been undertaken in the design and production of the key components of the JUNO detector.Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution,extending beyond the statistical fluctuations of the detected number of photons,such as the properties of the liquid scintillator,performance of photomultiplier tubes,and the energy reconstruction algorithm.To account for these effects,a full JUNO simulation and reconstruction approach is employed.This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution.The results of this study reveal an energy resolution of 2.95% at 1 Mev.Furthermore,this study assesses the contribution of major effects to the overall energy resolution budget.This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data collection.Moreover,it provides a guideline for comprehending the energy resolution characteristics of liquid scintillator-based detectors.
基金The authors gratefully acknowledge the supports from the Emergency Support and Public Safety Scientifc Research Projects of National Advanced Functional Fiber Innovation Center(2020-fx020009)The Postgraduate Innovation Foundation of Xi’an Polytechnic University(CHX2020037)Natural Science Foundation of Education Department of Shaanxi Province(21JK0657).
文摘The separator with excellent mechanical and thermal properties are highly required for lithium ion batteries(LIBs).Therefore,it is crucial to develop novel nanofbrous membranes with enhanced mechanical strength and thermal stability.In this work,the fuorinated polyimide(FPI)was synthesized and blended with polyvinylidene fuoride(PVDF)to fabricate composite nanofbrous membranes(CNMs)via electrospinning method.Benefting from the introduction of aromatic FPI,the prepared PVDF/FPI nanofbrous membranes were endowed with enhanced mechanical strength and thermal stability.When the FPI content increased from 0 to 30 wt%,the tensile strength of composite nanofbrous membranes enhanced from 1.57 to 2.30 MPa.Moreover,there are almost no dimensional shrinkage for the CNM-30 containing 30 wt%FPI after heat treatment at 160℃ for 1 h.Furthermore,the prepared CNMs show improved electrochemical performances in comparison with neat PVDF and commercial Celgard membranes.The electrolyte uptake and ionic conductivity of the CNMs could reach to 522.4% and 1.14 ms·cm^(−1),respectively.The prepared CNMs could provide an innovative and promising approach for the development and design of high-performance separators.
基金This work is supported by the National Natural Science Foundation of China(No.81801122)Natural Science Basic Research Program of Shaanxi(No.2020JQ-529)+4 种基金Scientific Research Program Funded by Shaanxi Provincial Education Department(No.20JK0658)The industry-University-Research collaborative innovation project of Keqiao Textile Industry Innovation Institute of Xi’an Polytechnic University(No.19KQZD01)Xi’an Science and Technology Project(GXYD7.3)Key R&D projects of Shaanxi(No.2020GY-273)Project of China National Textile Industry Association(No.2020047)。
文摘Plasmonic surface of flexible multilayered nanofibers possesses special superiority for the surface-enhanced Raman scattering(SERS)sensing of molecules and microbial cells.However,the fabrication of flexible plasmonic nanofibers with high sensitivity and reproducibility is difficult.Herein,we report a smart strategy for fabricating flexible plasmonic fibers,in which compact and homogeneous gold nanoparticles(Au NPs)are in-situ grown on the high-curvature surface of multilayered fibers of electrospun polyvinylidene fluoride(PVDF).Firstly,the surface of PVDF fibers is changed electrically,and Au seeds are deposited on the surface of PVDF fibers using electrostatic driving force.Secondly,a stable AuI_(4)−complex is formed employing coordination between I−and AuCl4−ions,which could decrease the reduction potential of AuCl4−and restrain the self-nucleation,and then the reduction reaction of AuI4−is initiated by introducing PVDF@Au seeds to pull down the barrier of potential energy.Finally,in-situ growth of AuNPs is generated on the high-curvature surface of PVDF nanofibers,and large-scale hotspots are generated by adjacent AuNPs coupling in the three-dimensional(3D)space of multilayered fibers.Membrane of PVDF@Au nanofibers also realizes the sensitive detection of thiram molecules(low limit of detection of 0.1 nM)and good reproducibility(relative standard deviation of 10.6%).Meanwhile,due to the multilayered construction of PVDF@Au nanofibers,a valid SERS signal on 3D surface of bacteria could be generated.3D distribution of hotspots on multilayered PVDF@Au nanofibers gives a clear advantage for SERS sensing of organic molecules and microbial cells.
