Fiber-shaped batteries that feature outstanding flexibility,light weight,and wovenability are extremely attractive for powering smart wearable electronic textiles,which further stimulates their demand in extreme envir...Fiber-shaped batteries that feature outstanding flexibility,light weight,and wovenability are extremely attractive for powering smart wearable electronic textiles,which further stimulates their demand in extreme environments.However,there are rare reports on ultralow-temperature fiber batteries to date.This is mainly attributed to the poor conductivity of electrodes and freezing of electrolytes that restrain their satisfactory flexible operation in cold environments.Herein,we propose a fiber cooper metal battery consisting of a conductive polyaniline cathode,an anti-freezing Cu(BF4)2+H3PO4electrolyte and an acidresistant copper wire anode,which can withstand various deformations at ultralow temperatures.Impressively,enhanced capacity and cyclic stability can be achieved by cryoactivated abundant reactive sites in the polyaniline,while benefiting from redox reactions with rapid kinetics involving protons rather than copper ions.Consequently,this well-designed polyaniline/Cu fiber battery delivers excellent flexibility without obvious capacity decay after being bent at-30℃,as well as a remarkable discharge capacity of 120.1 mA h g-1and a capacity retention of 96.8%after 2000 cycles at-50℃.The fiber batteries integrated into wearable textiles can power various electronic devices.These performances greatly outperform those of most reported works.Overall,this work provides a promising strategy toward applications of cryogenic wearable energy storage devices.展开更多
The quasi-metallic fibers were selected from 1 to 40 pieces and connected in parallel in this study.The giant magneto impedance(GMI)effect of Co-based melt extract fibers in the bundle mode was investigated,and the di...The quasi-metallic fibers were selected from 1 to 40 pieces and connected in parallel in this study.The giant magneto impedance(GMI)effect of Co-based melt extract fibers in the bundle mode was investigated,and the distribution of the surface circumferential magnetic field on the fibers was also analyzed.Such distribution was induced by the driving current,which gave rise to the circular magnetization process and the GMI effect.The improved GMI effect with much higher field sensitivity was observed in these fiber bundles.Results show that the field sensitivities of the four-fiber and six-fiber bundles reach 19.5 V·m·kA−1(at 1 MHz)and 30.8 V·m·kA−1(at 5 MHz).The circumferential magnetic field distributed throughout the fiber’s circumferential surface is rearranged and becomes uneven due to the magnetic interaction among fibers.There are both strengthened and weakened magnetic field parts around these fibers’surfaces.The strengthened magnetic field improves the circumferential domain magnetization of the surface,resulting in larger GMI effects.However,the weakened parts inhibit the circumferential magnetization process and,therefore,the GMI effect.This also induces greater magnetization damp because of the increased domain interactions under the strong skin effect.The co-effect between the magnetic domains and the circumferential magnetization induces the optimization of the GMI effect in the four-fiber bundles.The observed GMI effect proves that fibers in bundle form can modify the sensitivity of the GMI effect.Moreover,different fiber bundles could be tuned according to the working conditions in order to manipulate the GMI response.展开更多
Abstract: To enable the use of metallic components in direct methanol fuel cells (DMFCs), issues related to corrosion resistance must be considered because of an acid environment induced by the solid electrolyte. I...Abstract: To enable the use of metallic components in direct methanol fuel cells (DMFCs), issues related to corrosion resistance must be considered because of an acid environment induced by the solid electrolyte. In this study, we report the electrochemical behaviors of metal-fiber-based porous sintered components in a simulated corrosive environment of DMFCs. Three materials were evaluated: pure copper, AISI304, and AISI316L. The environmental factors and related mechanisms affecting the corrosion behaviors were analyzed. The results demonstrated that AISI316L exhibits the best performance. A higher SO4^2- concentration increases the risk of material corrosion, whereas an increase in methanol concentration inhibits corrosion. The morphological features of the corroded samples were also characterized in this study.展开更多
In order to avoid forming an electrical conductive network due to surface connections, the magnetic metal fibers were coated with SiO2, for surface modification by the sol-gel process. The microstructure, composition ...In order to avoid forming an electrical conductive network due to surface connections, the magnetic metal fibers were coated with SiO2, for surface modification by the sol-gel process. The microstructure, composition and electromagnetic characteristics of SiO2-coated and uncoated metal fibers were studied using SEM, EDAX, and a voter network analyzer. The reflectivity was simulated using the RAMCAD software. The electromagnetic parameters and absorption properties of SiO2-coated metal fibers were improved greatly due to optimal impendence matching and the electric conductivity decreased, compared to those of uncoated materials.展开更多
The organic gel-thermal reduction process was successfully used for the preparation of magnetic metal Ni, Fe, Fe-Ni fine fibers from raw materials of citric acid or lactic acid and metal salts. Ni, Fe and Fe-Ni fine f...The organic gel-thermal reduction process was successfully used for the preparation of magnetic metal Ni, Fe, Fe-Ni fine fibers from raw materials of citric acid or lactic acid and metal salts. Ni, Fe and Fe-Ni fine fibers synthesized were featured with diameters of around 1 μm and lengths of as long as 2 m for Ni fibers, 0.5 m for iron fibers, 1 m for Fe-Ni fibers. The structure, thermal decomposition process and morphologies of the gel precursors and fibers derived from thermal reduction of these gel precursors were characterized by FTIR, XRD,TG/DSC and SEM, respectively. The gel spinnability largely depends on molecular structures of metal-carboxylate complexes formed in the gel. It is reasoned that these gels consist of linear-type structural molecules [(C6H6O7)Ni]n or [(C6H5O7)2Ni3] for the nickel citrate gel, [(C3H5O3)3Fe] for the ferric lactate gel, [(C6H5O7)5(NiFe)3] for the iron-nickel citrate gel respectively and the gels obtain showed a good spinning performance.展开更多
Inspired by the curved branches of fractal trees, hooked Ni–Fe fibers were grown in situ in Ni–Fe composite coatings on a spheroidal graphite cast iron substrate. These hooked Ni–Fe fibers exhibited inclination ang...Inspired by the curved branches of fractal trees, hooked Ni–Fe fibers were grown in situ in Ni–Fe composite coatings on a spheroidal graphite cast iron substrate. These hooked Ni–Fe fibers exhibited inclination angles of about 39°, which was in accordance with the theoretical prediction of 37°. Ni–Fe nanostructures self-assembled to form dendrites and evolved into hooked fibers by an oriented attachment reaction. The orientation rotation of Ni–Fe nanostructures played an important role in the growth of curved hooked Ni–Fe fibers. During sliding wear tests, the volume loss of the spheroidal graphite cast iron substrate was 2.2 times as large as that of the Ni–Fe coating reinforced by hooked fibers. The good load-transferring ability of hooked Ni–Fe fibers led to an improvement in their wear properties during wear tests.展开更多
In this study, the laminated porous metal fiber sintered felt(PMFSF) functioning as catalyst support was used in a cylindrical methanol steam reforming(MSR) microreactor for hydrogen production. The PMFSF was fabricat...In this study, the laminated porous metal fiber sintered felt(PMFSF) functioning as catalyst support was used in a cylindrical methanol steam reforming(MSR) microreactor for hydrogen production. The PMFSF was fabricated by the low temperature solid-phase sintering method using metal fibers such as copper fibers and aluminum fibers which are obtained by the multi-tooth cutting method. The two-layer impregnation method was employed to coat Cu/Zn/Al/Zr catalyst on the PMFSF. The effect of fiber material, uniform porosity and gradient porosity on the performance of methano steam reforming microreactor was studied by varying the gas hourly space velocity(GHSV) and reaction temperature. Our results showed that the loading strength of porous copper fiber sintered felt(PCFSF) was better than porous aluminum fiber sintered felt(PAFSF). Under the same reaction conditions, the PCFSF showed higher methanol conversion and more H_2 output than PAFSF. Moreover, the gradient porosity(Type 5: 90%×80%×70%) of PMFSF used as the catalyst support in microreactor demonstrated a best reaction performance for hydrogen production.展开更多
The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and ...The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and the yield strengths under tensile and compressive loadings were derived which take account of thermal residual stresses. The asymmetries in the elastic modulus and the yield strength were interpreted using the derived expressions and the obtained results of the stress calculations. The model predictions have exhibited good agreements with the experimental results and also with the other theoretical predictions展开更多
Through theoretical analysis and finite element simulation,the low-velocity impact of rectangular foam-filled fiber metal laminate(FML)tubes is studied in this paper.According to the rigid-plastic material approximati...Through theoretical analysis and finite element simulation,the low-velocity impact of rectangular foam-filled fiber metal laminate(FML)tubes is studied in this paper.According to the rigid-plastic material approximation with modifications,simple analytical solutions are obtained for the dynamic response of rectangular foam-filled FML tubes.The numerical calculations for low-velocity impact of rectangular foam-filled FML tubes are conducted.The accuracy of analytical solutions and numerical results is verified by each other.Finally,the effects of the metal volume fraction of FMLs,the number of the metal layers in FMLs,and the foam strength on the dynamic response of foam-filled tubes are discussed through the analytical model in details.It is shown that the force increases with the increase in the metal volume fraction in FMLs,the number of the metal layers in FML,and the foam strength for the given deflection.展开更多
A new modification for the shear lag model is given and the expressions for the stiffness and yield Strength of short fiber metal matri×composite are derived. These expressions are then compared with our experime...A new modification for the shear lag model is given and the expressions for the stiffness and yield Strength of short fiber metal matri×composite are derived. These expressions are then compared with our experimental data in a SiCw/Al-Li T6 composite and the published experimental data on different SiCw/Al T6 composites and also compared with the previous shear lag models and the other theoretical models.展开更多
As a key part of the pyrotechnic gas generator,the filter not only removes the particulate matter but also cools the hot gas to a safe level.This paper aims to improve the understanding of the basic heat and flow phen...As a key part of the pyrotechnic gas generator,the filter not only removes the particulate matter but also cools the hot gas to a safe level.This paper aims to improve the understanding of the basic heat and flow phenomenon in the gas generator.The pyrotechnic gas generator is modelling by a simplified filter structure with fiber arrays.A finite-volume model of the heat and fluid flow is proposed to simulate the detailed multi-dimensional flow and energy conversion behaviors.Several verification results are in good agreement with data in different references.Simulation results demonstrate that the filter can not only absorb heat from the gas but also cause the high intensity enhancement of the heat transfer.The performance difference between inline and staggered arrays is also discussed.The findings of the study put a further prediction tool for the understanding and design of the filter system with fibers.展开更多
Carbon fiber reinforced thermoplastic composites(CFRTP)and metals hybrid structures have been widely used in aircraft lightweight manufacturing.However,due to the significant difference in physical and chemical proper...Carbon fiber reinforced thermoplastic composites(CFRTP)and metals hybrid structures have been widely used in aircraft lightweight manufacturing.However,due to the significant difference in physical and chemical properties between CFRTP and metals,there are lots of challenges to connect them with high quality.Laser welding has a good application prospect in CFRTP and metals connection,and a significant research progress has been made in the exploration of CFRTP-metal laser joining mechanism,joining process optimization,joining strength improvement and joining defects controlling.However,there are still some problems need to be solved for this technology application.In this paper,the research progress of CFRTP-metal laser joining was summarized in three major aspects:theoretical modeling and simulation analysis,process exploration and parameter optimization,joint performance improvement and process innovation.And,problems and challenges of this technology were discussed,and the outlook of this research was provided.展开更多
The elasto-plastic buckling and postbuckling of fiber metal laminates (FML) are studied in this research. Considering the geometric nonlinearity of the structure and the elasto- plastic deformation of the metal laye...The elasto-plastic buckling and postbuckling of fiber metal laminates (FML) are studied in this research. Considering the geometric nonlinearity of the structure and the elasto- plastic deformation of the metal layers, the incremental Von Karman geometric relation of the FML with initial deflection is established. Moreover, an incremental elasto-plastic constitutive relation adopting the mixed hardening rule is introduced to depict the stress-strain relationship of the metal layers. Subsequently, the incremental nonlinear governing equations of the FML subjected to in-plane compressive loads are derived, and the whole problem is solved by the iterative method according to the finite difference method. In numerical examples, the effects of the initial deflection, the loading state, and the geometric parameters on the elasto-plastic buckling and postbuckling of FML are investigated, respectively.展开更多
The graft copolymerization of acrylic acid(AA) onto polyethylene glycol terephthalate(PET) fiber initialed by benzoy peroxide (BPO) was carried out in heterogeneous media.Moreover,modification of the grafted PET...The graft copolymerization of acrylic acid(AA) onto polyethylene glycol terephthalate(PET) fiber initialed by benzoy peroxide (BPO) was carried out in heterogeneous media.Moreover,modification of the grafted PET fiber(PET-AA) was done by changing the carboxyl group into acylamino group through the reaction with dimethylamine.The modified chelating fiber(NDWJN1) was characterized using elementary analysis,SEM and FT-IR spectroscopy.Adsorption kinetic curves indicated that NDWJNl could fast remove heavy metal ions and phytic acids from water effectively.Furthermore,batch kinetic studies indicated that heavy metal ions adsorbed to NDWJNl could be filted well by both pseudo-first-order and pseudo-second-order adsorption equations,but the intra-particle diffusion played a dominant role in the adsorption of phytic acids.展开更多
The formation of sintering necks between two metal fibers was investigated using the oval-oval model with respect to the fiber angle range of 0°-90°. Surface diffusion was assumed to be the predominant mecha...The formation of sintering necks between two metal fibers was investigated using the oval-oval model with respect to the fiber angle range of 0°-90°. Surface diffusion was assumed to be the predominant mechanism in every section of the junction of two metal fibers in this model, which was addressed numerically using the level- set method. The growth rates of the sintering necks in the direction of the bisector of obtuse angle, the bisector of acute angle and the fiber axis were discussed in detail. It is found that the growth rate of the sintering necks decreases with fiber angle increasing in the direction of the fiber axis and the bisector of acute angle. However, an opposite variation in growth rate of sintering necks can be found in the direction of the bisector of obtuse angle. The numerical simulation results show that the growth rate of the sintering necks is significantly affected by the initial local geomet- rical structure which is determined by the fiber angle.展开更多
The elasto-plastic postbuckling of fiber metal laminated beams with delamination and the energy release rate along the delamination front are discussed in this paper. Considering geometrical nonlinearity, thermal envi...The elasto-plastic postbuckling of fiber metal laminated beams with delamination and the energy release rate along the delamination front are discussed in this paper. Considering geometrical nonlinearity, thermal environment and geometrical initial imperfection, the incremental nonlinear equilibrium equations of delaminated fiber metal laminated beams are established, which are solved using the differential quadrature method and iterative method. Based on these, according to the J-integral theory, the elasto-plastic energy release rate is studied. The effects of some important parameters on the elasto-plastic postbuckling behavior and energy release rate of the aramid reinforced aluminum laminated beams are discussed in details.展开更多
In this work, a simple, low cost and sensitive voltammetric sensor was developed for the simultaneous detection of lead (Pb2+), cadmium (Cd2+), and zinc (Zn2+) ions based on a disposable carbon fiber rod (CF...In this work, a simple, low cost and sensitive voltammetric sensor was developed for the simultaneous detection of lead (Pb2+), cadmium (Cd2+), and zinc (Zn2+) ions based on a disposable carbon fiber rod (CFR). The important factors to enhance the sensing property were creation of a clean surface by dealing with CFR at a high potential and electrochemical deposition of bismuth (Bi) film to improve the accumulation of heavy metal ions. The morphology and conductivity of such activated CFR was characterized by scanning electron microscopy and electrochemical impedance spectroscopy, respectively. In terms of application, differential pulse anodic stripping voltammetry (DPASV) was employed for the simultaneous detection of Pb2+, Cd2+, and Zn2+ on Bi film-coated activated CFR. Experimental parameters, such as the pH value of buffer solution, stirring speed and enrichment factors were optimized. Under optimal conditions, the DPASV peak currents showed good linear relationships with Pb2+, Cd2+ and Zn2+ concentrations in the range of 0.5-2.25 μg/L, 0.5-4.0 μg/L and 1.0- 4.0 μg/L with detection limits of 0.1, 0.3 and 1.0 μg/L (SIN = 3), respectively. Finally, the proposed analysis system was successfully utilized for the simultaneous detection of Pb2+, Cd2+, and Zn2+ contents in rice samples. This study indicated that Bi film-coated activated CFR based DPASV sensor can be a promising and reliable tool for rapid analysis of emergency Dollution affairs of heavv metal ions in food.展开更多
It is known that fiber metal laminates (FML) as one of hybrid materials with thin metal sheets and fiber/epoxy layers have the characteristics of the excellent damage tolerance, fatigue and impact properties with a ...It is known that fiber metal laminates (FML) as one of hybrid materials with thin metal sheets and fiber/epoxy layers have the characteristics of the excellent damage tolerance, fatigue and impact properties with a relatively low density. Therefore, the mechanical components using FML can contribute the enhanced safety level of the sound construction toward the whole body. In this study, the impact performance of carbon reinforced aluminum laminates (CARAL) is investigated by experiments and numerical simulations. Drop weight tests are carried out with the weight of 4.7 kg at the speed of 1 and 2 m/s, respectively. Dynamic non-linear transient analyses are also accomplished using a finite element analysis software, ABAQUS. The experiment results and numerical results are compared with impact load-time histories. Also, energy-time histories are applied to investigate the impact performance of CARAL.展开更多
基金the financial support from the National Natural Science Foundation of China(52273171 and 21875055)the Shenzhen Research Foundation Project(GXWD20201230155427003)。
文摘Fiber-shaped batteries that feature outstanding flexibility,light weight,and wovenability are extremely attractive for powering smart wearable electronic textiles,which further stimulates their demand in extreme environments.However,there are rare reports on ultralow-temperature fiber batteries to date.This is mainly attributed to the poor conductivity of electrodes and freezing of electrolytes that restrain their satisfactory flexible operation in cold environments.Herein,we propose a fiber cooper metal battery consisting of a conductive polyaniline cathode,an anti-freezing Cu(BF4)2+H3PO4electrolyte and an acidresistant copper wire anode,which can withstand various deformations at ultralow temperatures.Impressively,enhanced capacity and cyclic stability can be achieved by cryoactivated abundant reactive sites in the polyaniline,while benefiting from redox reactions with rapid kinetics involving protons rather than copper ions.Consequently,this well-designed polyaniline/Cu fiber battery delivers excellent flexibility without obvious capacity decay after being bent at-30℃,as well as a remarkable discharge capacity of 120.1 mA h g-1and a capacity retention of 96.8%after 2000 cycles at-50℃.The fiber batteries integrated into wearable textiles can power various electronic devices.These performances greatly outperform those of most reported works.Overall,this work provides a promising strategy toward applications of cryogenic wearable energy storage devices.
基金the National Natural Science Foundation of China(Nos.51861031 and 51604159)the Natural Science Foundation of Ningxia,China(No.2018AAC03056).
文摘The quasi-metallic fibers were selected from 1 to 40 pieces and connected in parallel in this study.The giant magneto impedance(GMI)effect of Co-based melt extract fibers in the bundle mode was investigated,and the distribution of the surface circumferential magnetic field on the fibers was also analyzed.Such distribution was induced by the driving current,which gave rise to the circular magnetization process and the GMI effect.The improved GMI effect with much higher field sensitivity was observed in these fiber bundles.Results show that the field sensitivities of the four-fiber and six-fiber bundles reach 19.5 V·m·kA−1(at 1 MHz)and 30.8 V·m·kA−1(at 5 MHz).The circumferential magnetic field distributed throughout the fiber’s circumferential surface is rearranged and becomes uneven due to the magnetic interaction among fibers.There are both strengthened and weakened magnetic field parts around these fibers’surfaces.The strengthened magnetic field improves the circumferential domain magnetization of the surface,resulting in larger GMI effects.However,the weakened parts inhibit the circumferential magnetization process and,therefore,the GMI effect.This also induces greater magnetization damp because of the increased domain interactions under the strong skin effect.The co-effect between the magnetic domains and the circumferential magnetization induces the optimization of the GMI effect in the four-fiber bundles.The observed GMI effect proves that fibers in bundle form can modify the sensitivity of the GMI effect.Moreover,different fiber bundles could be tuned according to the working conditions in order to manipulate the GMI response.
基金financially supported by the Natural Science Foundation of Guangdong Province, China (No. S2013040016899)the Fundamental Research Funds for Central Universities of China (No. 2013ZM0003)+1 种基金the National Natural Science Foundation of China (No. 51275180)the Open Fund of Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures (No. 2013001)
文摘Abstract: To enable the use of metallic components in direct methanol fuel cells (DMFCs), issues related to corrosion resistance must be considered because of an acid environment induced by the solid electrolyte. In this study, we report the electrochemical behaviors of metal-fiber-based porous sintered components in a simulated corrosive environment of DMFCs. Three materials were evaluated: pure copper, AISI304, and AISI316L. The environmental factors and related mechanisms affecting the corrosion behaviors were analyzed. The results demonstrated that AISI316L exhibits the best performance. A higher SO4^2- concentration increases the risk of material corrosion, whereas an increase in methanol concentration inhibits corrosion. The morphological features of the corroded samples were also characterized in this study.
文摘In order to avoid forming an electrical conductive network due to surface connections, the magnetic metal fibers were coated with SiO2, for surface modification by the sol-gel process. The microstructure, composition and electromagnetic characteristics of SiO2-coated and uncoated metal fibers were studied using SEM, EDAX, and a voter network analyzer. The reflectivity was simulated using the RAMCAD software. The electromagnetic parameters and absorption properties of SiO2-coated metal fibers were improved greatly due to optimal impendence matching and the electric conductivity decreased, compared to those of uncoated materials.
基金the National Natural Science Foundation of China(No.50474038,50674048)
文摘The organic gel-thermal reduction process was successfully used for the preparation of magnetic metal Ni, Fe, Fe-Ni fine fibers from raw materials of citric acid or lactic acid and metal salts. Ni, Fe and Fe-Ni fine fibers synthesized were featured with diameters of around 1 μm and lengths of as long as 2 m for Ni fibers, 0.5 m for iron fibers, 1 m for Fe-Ni fibers. The structure, thermal decomposition process and morphologies of the gel precursors and fibers derived from thermal reduction of these gel precursors were characterized by FTIR, XRD,TG/DSC and SEM, respectively. The gel spinnability largely depends on molecular structures of metal-carboxylate complexes formed in the gel. It is reasoned that these gels consist of linear-type structural molecules [(C6H6O7)Ni]n or [(C6H5O7)2Ni3] for the nickel citrate gel, [(C3H5O3)3Fe] for the ferric lactate gel, [(C6H5O7)5(NiFe)3] for the iron-nickel citrate gel respectively and the gels obtain showed a good spinning performance.
基金financially supported by the Project of Education Department of Liaoning Province,China(No.990790)the National Natural Science Foundation of China(No.51402035)
文摘Inspired by the curved branches of fractal trees, hooked Ni–Fe fibers were grown in situ in Ni–Fe composite coatings on a spheroidal graphite cast iron substrate. These hooked Ni–Fe fibers exhibited inclination angles of about 39°, which was in accordance with the theoretical prediction of 37°. Ni–Fe nanostructures self-assembled to form dendrites and evolved into hooked fibers by an oriented attachment reaction. The orientation rotation of Ni–Fe nanostructures played an important role in the growth of curved hooked Ni–Fe fibers. During sliding wear tests, the volume loss of the spheroidal graphite cast iron substrate was 2.2 times as large as that of the Ni–Fe coating reinforced by hooked fibers. The good load-transferring ability of hooked Ni–Fe fibers led to an improvement in their wear properties during wear tests.
基金supported by the Natural Science Fundation of Fujian Province of China (No. 2017J06015)the Foundation of Public Welfare Research and Capacity Building in Guangdong Province (No. 2014A010106002)+2 种基金the State Key Laboratory of Catalytic Materials and Reaction Engineering (RIPP, SINOPEC) under Project No. 33600000-15-ZC06070004the supports from the Fundamental Research Funds for Central Universities, the Xiamen University (No. 20720160079)the Collaborative Innovation Center of HighEnd Equipment Manufacturing in Fujian are also acknowledged
文摘In this study, the laminated porous metal fiber sintered felt(PMFSF) functioning as catalyst support was used in a cylindrical methanol steam reforming(MSR) microreactor for hydrogen production. The PMFSF was fabricated by the low temperature solid-phase sintering method using metal fibers such as copper fibers and aluminum fibers which are obtained by the multi-tooth cutting method. The two-layer impregnation method was employed to coat Cu/Zn/Al/Zr catalyst on the PMFSF. The effect of fiber material, uniform porosity and gradient porosity on the performance of methano steam reforming microreactor was studied by varying the gas hourly space velocity(GHSV) and reaction temperature. Our results showed that the loading strength of porous copper fiber sintered felt(PCFSF) was better than porous aluminum fiber sintered felt(PAFSF). Under the same reaction conditions, the PCFSF showed higher methanol conversion and more H_2 output than PAFSF. Moreover, the gradient porosity(Type 5: 90%×80%×70%) of PMFSF used as the catalyst support in microreactor demonstrated a best reaction performance for hydrogen production.
文摘The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and the yield strengths under tensile and compressive loadings were derived which take account of thermal residual stresses. The asymmetries in the elastic modulus and the yield strength were interpreted using the derived expressions and the obtained results of the stress calculations. The model predictions have exhibited good agreements with the experimental results and also with the other theoretical predictions
基金the National Natural Science Foundation of China(Nos.11872291 and11972281)the Jiangsu Key Laboratory of Engineering Mechanics,Southeast University+2 种基金the Fundamental Research Funds for the Central Universities(No.LEM21B01)the Key Laboratory of Impact and Safety Engineering(Ningbo University),Ministry of Education(No.cj202002)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2020JM-034)。
文摘Through theoretical analysis and finite element simulation,the low-velocity impact of rectangular foam-filled fiber metal laminate(FML)tubes is studied in this paper.According to the rigid-plastic material approximation with modifications,simple analytical solutions are obtained for the dynamic response of rectangular foam-filled FML tubes.The numerical calculations for low-velocity impact of rectangular foam-filled FML tubes are conducted.The accuracy of analytical solutions and numerical results is verified by each other.Finally,the effects of the metal volume fraction of FMLs,the number of the metal layers in FMLs,and the foam strength on the dynamic response of foam-filled tubes are discussed through the analytical model in details.It is shown that the force increases with the increase in the metal volume fraction in FMLs,the number of the metal layers in FML,and the foam strength for the given deflection.
文摘A new modification for the shear lag model is given and the expressions for the stiffness and yield Strength of short fiber metal matri×composite are derived. These expressions are then compared with our experimental data in a SiCw/Al-Li T6 composite and the published experimental data on different SiCw/Al T6 composites and also compared with the previous shear lag models and the other theoretical models.
基金This work is supported by the National Natural Science Foundation of China(Grant No.11972194)the Fundamental Research Funds for the Central Universities,No.30918011323China Postdoctoral Science Foundation funded project(Grant No.2015M581797).
文摘As a key part of the pyrotechnic gas generator,the filter not only removes the particulate matter but also cools the hot gas to a safe level.This paper aims to improve the understanding of the basic heat and flow phenomenon in the gas generator.The pyrotechnic gas generator is modelling by a simplified filter structure with fiber arrays.A finite-volume model of the heat and fluid flow is proposed to simulate the detailed multi-dimensional flow and energy conversion behaviors.Several verification results are in good agreement with data in different references.Simulation results demonstrate that the filter can not only absorb heat from the gas but also cause the high intensity enhancement of the heat transfer.The performance difference between inline and staggered arrays is also discussed.The findings of the study put a further prediction tool for the understanding and design of the filter system with fibers.
基金co-supported by the Shenzhen Basic Research projects(JCYJ20200109144604020,JCYJ20200109144608205 and JCYJ20210324120001003)Yangzhou Hanjiang Science and Technology project(HJZ2021003)+1 种基金Ningbo 2025 major projects(2022Z013)Zhejiang basic public welfare research program(LGG20E050009)。
文摘Carbon fiber reinforced thermoplastic composites(CFRTP)and metals hybrid structures have been widely used in aircraft lightweight manufacturing.However,due to the significant difference in physical and chemical properties between CFRTP and metals,there are lots of challenges to connect them with high quality.Laser welding has a good application prospect in CFRTP and metals connection,and a significant research progress has been made in the exploration of CFRTP-metal laser joining mechanism,joining process optimization,joining strength improvement and joining defects controlling.However,there are still some problems need to be solved for this technology application.In this paper,the research progress of CFRTP-metal laser joining was summarized in three major aspects:theoretical modeling and simulation analysis,process exploration and parameter optimization,joint performance improvement and process innovation.And,problems and challenges of this technology were discussed,and the outlook of this research was provided.
基金supported by the National Natural Science Foundation of China(No.11272117)
文摘The elasto-plastic buckling and postbuckling of fiber metal laminates (FML) are studied in this research. Considering the geometric nonlinearity of the structure and the elasto- plastic deformation of the metal layers, the incremental Von Karman geometric relation of the FML with initial deflection is established. Moreover, an incremental elasto-plastic constitutive relation adopting the mixed hardening rule is introduced to depict the stress-strain relationship of the metal layers. Subsequently, the incremental nonlinear governing equations of the FML subjected to in-plane compressive loads are derived, and the whole problem is solved by the iterative method according to the finite difference method. In numerical examples, the effects of the initial deflection, the loading state, and the geometric parameters on the elasto-plastic buckling and postbuckling of FML are investigated, respectively.
基金support provided by the Key National Nature Science Fund(No.50938004)the National Science Funds for Young Scientists(No.50102582)+1 种基金Nature Science Fund of Jiangsu Province(No. BK2010381)the Fundamental Research Funds for the Central Universities
文摘The graft copolymerization of acrylic acid(AA) onto polyethylene glycol terephthalate(PET) fiber initialed by benzoy peroxide (BPO) was carried out in heterogeneous media.Moreover,modification of the grafted PET fiber(PET-AA) was done by changing the carboxyl group into acylamino group through the reaction with dimethylamine.The modified chelating fiber(NDWJN1) was characterized using elementary analysis,SEM and FT-IR spectroscopy.Adsorption kinetic curves indicated that NDWJNl could fast remove heavy metal ions and phytic acids from water effectively.Furthermore,batch kinetic studies indicated that heavy metal ions adsorbed to NDWJNl could be filted well by both pseudo-first-order and pseudo-second-order adsorption equations,but the intra-particle diffusion played a dominant role in the adsorption of phytic acids.
基金financially supported by the National Natural Science Foundation of China (Nos. 51174236 and 51134003)the National Basic Research Program of China (No. 2011CB606306)the Opening Project of State Key Laboratory of Porous Metal Materials (No. PMM-SKL-4-2012)
文摘The formation of sintering necks between two metal fibers was investigated using the oval-oval model with respect to the fiber angle range of 0°-90°. Surface diffusion was assumed to be the predominant mechanism in every section of the junction of two metal fibers in this model, which was addressed numerically using the level- set method. The growth rates of the sintering necks in the direction of the bisector of obtuse angle, the bisector of acute angle and the fiber axis were discussed in detail. It is found that the growth rate of the sintering necks decreases with fiber angle increasing in the direction of the fiber axis and the bisector of acute angle. However, an opposite variation in growth rate of sintering necks can be found in the direction of the bisector of obtuse angle. The numerical simulation results show that the growth rate of the sintering necks is significantly affected by the initial local geomet- rical structure which is determined by the fiber angle.
基金Project supported by the National Natural Science Foundation of China(No.11272117)
文摘The elasto-plastic postbuckling of fiber metal laminated beams with delamination and the energy release rate along the delamination front are discussed in this paper. Considering geometrical nonlinearity, thermal environment and geometrical initial imperfection, the incremental nonlinear equilibrium equations of delaminated fiber metal laminated beams are established, which are solved using the differential quadrature method and iterative method. Based on these, according to the J-integral theory, the elasto-plastic energy release rate is studied. The effects of some important parameters on the elasto-plastic postbuckling behavior and energy release rate of the aramid reinforced aluminum laminated beams are discussed in details.
基金financially supported by the National Natural Science Foundation of China(Nos. 21675062, 21305050)the Science and Technology Planning Project of Fujian Province, China (No. 2017J05024)+2 种基金Program for New Century Excellent Talents in Fujian Province University(NCETFJ)Program for the Cultivation of Outstanding Young Scientific Researches in Fujian Universities (COYSRFJ)the opening project of Fujian Provincial EngineeringTechnology Research Center of Marine Functional Food(No. C11172)
文摘In this work, a simple, low cost and sensitive voltammetric sensor was developed for the simultaneous detection of lead (Pb2+), cadmium (Cd2+), and zinc (Zn2+) ions based on a disposable carbon fiber rod (CFR). The important factors to enhance the sensing property were creation of a clean surface by dealing with CFR at a high potential and electrochemical deposition of bismuth (Bi) film to improve the accumulation of heavy metal ions. The morphology and conductivity of such activated CFR was characterized by scanning electron microscopy and electrochemical impedance spectroscopy, respectively. In terms of application, differential pulse anodic stripping voltammetry (DPASV) was employed for the simultaneous detection of Pb2+, Cd2+, and Zn2+ on Bi film-coated activated CFR. Experimental parameters, such as the pH value of buffer solution, stirring speed and enrichment factors were optimized. Under optimal conditions, the DPASV peak currents showed good linear relationships with Pb2+, Cd2+ and Zn2+ concentrations in the range of 0.5-2.25 μg/L, 0.5-4.0 μg/L and 1.0- 4.0 μg/L with detection limits of 0.1, 0.3 and 1.0 μg/L (SIN = 3), respectively. Finally, the proposed analysis system was successfully utilized for the simultaneous detection of Pb2+, Cd2+, and Zn2+ contents in rice samples. This study indicated that Bi film-coated activated CFR based DPASV sensor can be a promising and reliable tool for rapid analysis of emergency Dollution affairs of heavv metal ions in food.
基金supported by a grant-in-aid for the Na-tional Core Research Center Program from the Ministry of Education Science & Technology and the Korea Science & Engineering Foundation (No. R15-2006-022-01001-0)support by the Korea Science and Engineering Foundation (KOSEF) NRL Program grant funded by the Korea government (MEST) (No. R0A-2008-000-20017-0)
文摘It is known that fiber metal laminates (FML) as one of hybrid materials with thin metal sheets and fiber/epoxy layers have the characteristics of the excellent damage tolerance, fatigue and impact properties with a relatively low density. Therefore, the mechanical components using FML can contribute the enhanced safety level of the sound construction toward the whole body. In this study, the impact performance of carbon reinforced aluminum laminates (CARAL) is investigated by experiments and numerical simulations. Drop weight tests are carried out with the weight of 4.7 kg at the speed of 1 and 2 m/s, respectively. Dynamic non-linear transient analyses are also accomplished using a finite element analysis software, ABAQUS. The experiment results and numerical results are compared with impact load-time histories. Also, energy-time histories are applied to investigate the impact performance of CARAL.