The z-axis-inclined 3D printing process using short carbon fiber-reinforced thermoplastic composites offers the potential for the support-free fabrication of complex structures and theoretically unlimited extension of...The z-axis-inclined 3D printing process using short carbon fiber-reinforced thermoplastic composites offers the potential for the support-free fabrication of complex structures and theoretically unlimited extension of printed components.It has emerged as a promising approach for in-orbit manufacturing of high-performance thermoplastic composite truss structures.However,extreme conditions of the space environment,such as high vacuum and fluctuating high-low temperatures,significantly alter the heat-transfer behavior during the printing process,often resulting in dimensional inaccuracies and degraded mechanical performance.Existing process optimization strategies fail to account for the coupled effects of vacuum and thermal extremes,limiting their applicability in guiding process design under varying vacuum temperature conditions.To address this gap,this study establishes a truss3D printing experimental platform with in situ temperature-monitoring capability under ground-simulated space conditions.It systematically investigates the effects of printing speed and structural geometry on the pre-bonding surface temperature and forming quality of truss structures in high-low temperature vacuum environments.This study reveals the mechanism by which processing and structural parameters affect the component performance through their influence on the pre-bonding surface temperature and dimensional accuracy.The experimental results show that under high-temperature vacuum conditions,the pre-bonding surface temperature is relatively high,resulting in good interfacial bonding.However,increasing the printing speed reduces the forming accuracy and leads to a decline in mechanical performance.In contrast,under low-temperature vacuum conditions,where the pre-bonding surface temperatures are lower,increasing the printing speed within a specific range effectively increases the surface temperature and bonding quality,thereby improving mechanical properties.Additionally,owing to frequent path transitions,the diagonal-strut truss exhibits a lower forming accuracy and pre-bonding surface temperature than the infilling truss,resulting in inferior mechanical performance in high-low temperature vacuum environments.展开更多
The reasons of the static strength dispersion and the fatigue life dispersion of composite laminates are analyzed in this article. It is concluded that the inner original defects, which derived from the manufacturing ...The reasons of the static strength dispersion and the fatigue life dispersion of composite laminates are analyzed in this article. It is concluded that the inner original defects, which derived from the manufacturing process of composite laminates, are the common and major reason of causing the random distributions of the static strength and the fatigue life. And there is a correlative relation between the two distributions. With the study of statistical relationship between the fatigue loading and the fatigue life in the uniform confidence level and the same survival rate S-N curves of material, the relationship between the static strength distribution and the fatigue life distribution through a material S-N curve model has been obtained. And then the model which is used to describe the distributions of fatigue life of composites, based on their distributions of static strength, is set up. This model reasonably reflects the effects of the inner original defects on the static strength dispersion and on the fatigue life dispersion of composite laminates. The experimental data of three kinds of composite laminates are employed to verify this model, and the results show that this model can predict the random distributions of fatigue life for composites under any fatigue loads fairly well.展开更多
In recent years,environmental pollution and energy crisis have become increasingly serious issues owing to the burning of fossil fuels.Among the many technologies,decomposition of water to produce hydrogen has attract...In recent years,environmental pollution and energy crisis have become increasingly serious issues owing to the burning of fossil fuels.Among the many technologies,decomposition of water to produce hydrogen has attracted much attention because of its sustainability and non-polluting characteristic.However,highly efficient decomposition of water that is driven by visible light is still a challenge.Herein,we report the large-scale preparation of step-scheme porous graphite carbon nitride/Zn0.2Cd0.8S-diethylenetriamine(Pg-C3N4/Zn0.2Cd0.8S-DETA)composite by a facile solvothermal method.It was found by UV-vis spectroscopy that 15%Pg-C3N4/Zn0.2Cd0.8S-DETA exhibited suitable visible absorption edge and band gap for water decomposition.The hydrogen production rate of 15%Pg-C3N4/Zn0.2Cd0.8S-DETA composite was 6.69 mmol g^-1 h^-1,which was 16.73,1.61,and 1.44 times greater than those of Pg-C3N4,CdS-DETA,and Zn0.2Cd0.8S-DETA,respectively.In addition,15%Pg-C3N4/Zn0.2Cd0.8S-DETA composite displayed excellent photocatalytic stability,which was maintained for seven cycles of photocatalytic water splitting test.We believe that 15%Pg-C3N4/Zn0.2Cd0.8S-DETA composite can be a valuable guide for the development of solar hydrogen production applications in the near future.展开更多
Graphite as a promising anode candidate of K-ion batteries(KIBs)has been increasingly studied currently,but corresponding rate performance and cycling stability are usually inferior to amorphous carbon materials.To pr...Graphite as a promising anode candidate of K-ion batteries(KIBs)has been increasingly studied currently,but corresponding rate performance and cycling stability are usually inferior to amorphous carbon materials.To protect the layer structure and further boost performance,tempura-like carbon/carbon nanocomposite of graphite@pitch-derived S-doped carbon(G@PSC)is designed and prepared by a facile and low-temperature modified molten salt method.This robust encapsulation structure makes their respective advantages complementary to each other,showing mutual promotion of electrochemical performances caused by synergy effect.As a result,the G@PSC electrode is applied in KIBs,delivering impressive rate capabilities(465,408,370,332,290,and 227 m A h g^(-1)at 0.05,0.2,0.5,1,2,and 5 A g^(-1))and ultralong cyclic stability(163 m A g^(-1)remaining even after 8000 cycles at 2 A g^(-1)).On basis of ex-situ studies,the sectionalized K-storage mechanism with adsorption(pseudocapacitance caused by S doping)-intercalation(pitch-derived carbon and graphite)pattern is revealed.Moreover,the exact insights into remarkable rate performances are taken by electrochemical kinetics tests and density functional theory calculation.In a word,this study adopts a facile method to synthesize high-performance carbon/carbon nanocomposite and is of practical significance for development of carbonaceous anode in KIBs.展开更多
The combination of classical Hodgkin’s lymphoma(cHL)and non-Hodgkin lymphoma coexisting in the same patient is not common,especially in one extranodal location.Here we present a rare case of composite diffuse large B...The combination of classical Hodgkin’s lymphoma(cHL)and non-Hodgkin lymphoma coexisting in the same patient is not common,especially in one extranodal location.Here we present a rare case of composite diffuse large B-cell lymphoma(DLBCL)and cHL occurring simultaneously in the stomach of a 53-year-old female who presented with upper abdominal discomfort and gas pain.Surgery was performed and the disease was diagnosed pathologically as composite lymphoma of DLBCL and cHL using hematoxylin-eosin and immunohistochemical staining.Epstein-Barr virus(EBV)infection was not detected by in situ hybridization for EBV-encoded RNA or immunohistochemistry for EBV latent membrane protein-1.Polymerase chain reaction analysis from the two distinct components of the tumor demonstrated clonal immunoglobulinκlight chain gene rearrangements.The patient died approximately 11 mo after diagnosis in spite of receiving eight courses of the CHOP and two courses of the rituximab-CHOP(RCHOP) chemotherapy regimen.This case report showed that the two distinct components,DLBCL and cHL,appeared to originate from the same clonal progenitor cell,and that EBV infection was not essential for transformation during the course of tumorigenesis.展开更多
The popularity of lithium–sulfur batteries has been increasing gradually due to their ultrahigh theoretical specific capacity and energy density. Nevertheless, they also have lots of drawbacks to be overcome, such as...The popularity of lithium–sulfur batteries has been increasing gradually due to their ultrahigh theoretical specific capacity and energy density. Nevertheless, they also have lots of drawbacks to be overcome, such as poor conductivity, severe volume expansion, and serious“shuttle effect”. In this work, reduced graphene oxide/molybdenum dioxide(rGO/MoO_(2)) composite is synthesized and applied to modify polypropylene separator. The modified polypropylene separator introduces synergistic tri-functions of physical adsorption, chemical interaction and catalytic effects, which can inhibit the“shuttle effect” and enhance the electrochemical performances of lithium-sulfur batteries. In the prepared r GO/MoO_(2) composite, the polar MoO_(2) chemically adsorbs the intermediate lithium polysulfide, while the rGO with good electrical conductivity not only acts as a physical barrier to prevent diffusion of polysulfide ions, but also improves the conversion efficiency of active material intercepted on the separator. As a consequence, the battery assembled with rGO/MoO_(2) modified polypropylene separator exhibits a reversible capacity of 757.5 mAh·g^(-1) after 200 cycles at0.2 C with a negligible capacity decay of 0.207% per cycle,which indicates a good long-period cycling stability. Furthermore, the rate performance and self-discharge suppression are also improved by introducing modified polypropylene separator. It shows that rGO/MoO_(2) composite is a promising material for separator modification in lithium-sulfur batteries.展开更多
Constructing a Z-scheme is a significant approach to improve the separation of photogene rated carriers for effective organic pollutant degradation.Herein,a BiVO4/ZnIn2S4(BZ) Z-scheme composite was successfully synthe...Constructing a Z-scheme is a significant approach to improve the separation of photogene rated carriers for effective organic pollutant degradation.Herein,a BiVO4/ZnIn2S4(BZ) Z-scheme composite was successfully synthesized,and applied to photodegrade methyl orange(MO) irradiated by a LED lamp.Anchoring the BiVO4 on the ZnIn2S4 nanoparticles promoted the separation of photogenerated electronholes and broadened the light response range.The detailed characterizations,including surface morphology,elements valence state,and photocurrent performance,demonstrated that the enhanced separation of photogenerated carriers was the pivotal reason for the enhanced photocatalysis reaction.Benefiting from the excellent photocatalytic characteristics,the 5% mass ratio of BZ composite presented the highest MO degradation rate of 0.00997 min^-1,which was 1.9 and 10.3 times greater than the virgin ZnIn2S4 and BiVO4,respectively.Furthermore,the BZ hybrid materials indicated a well photo-stability in the four recycling tests.展开更多
Lithium-sulfur(Li-S)battery is labeled as a promising high-energy-density battery system,but some inherent drawbacks of sulfur cathode materials using relatively complicated techniques impair the practical application...Lithium-sulfur(Li-S)battery is labeled as a promising high-energy-density battery system,but some inherent drawbacks of sulfur cathode materials using relatively complicated techniques impair the practical applications.Herein,an integrated approach is proposed to fabricate the high-performance rGO/VS_(4)/S cathode composites through a simple one-step solvothermal method,where nano sulfur and VS_(4) particles are uniformly distributed on the conductive rGO matrix.rGO and sulfiphilic VS_(4)provide electron transfer skeleton and physical/chemical anchor for soluble lithium polysulfides(LiPS).Meanwhile,VS_(4) could also act as an electrochemical mediator to efficiently enhance the utilization and reversible conversion of LiPS.Correspondingly,the rGO/VS_(4)/S composites maintain a high reversible capacity of 969 mAh/g at 0.2 C after 100 cycles,with a capacity retention rate of 82.3%.The capacity fade rate could lower to 0.0374%per cycle at 1 C.Moreover,capacity still sustains 795 m Ah/g after 100 cycles in the relatively high-sulfurloading battery(6.5 mg/cm^(2)).Thus,the suggested method in configuring the sulfur-based composites is demonstrated a simple and efficient strategy to construct the high-performance Li-S batteries.展开更多
The growing global demands of safe, low-cost and high working voltage energy storage devices trigger strong interests in novel battery concepts beyond state-of-art lithium-ion battery. Herein, a dualion battery based ...The growing global demands of safe, low-cost and high working voltage energy storage devices trigger strong interests in novel battery concepts beyond state-of-art lithium-ion battery. Herein, a dualion battery based on nanostructured Ni_3S_2/Ni foam@RGO(NSNR) composite anode is developed, utilizing graphite as cathode material and LiPF6-VC-based solvent as electrolyte. The battery operates at high working voltage of 4.2–4.5 V, with superior discharge capacity of ～90 m A h g^(-1) at 100 mA g^(-1), outstanding rate performance, and long-term cycling stability over 500 cycles with discharge capacity retention of ～85.6%. Moreover, the composite simultaneously acts as the anode material and the current collector, and the corrosion phenomenon can be greatly reduced compared to metallic Al anode. Thus, this work represents a significant step forward for practical safe, low-cost and high working voltage dual-ion batteries,showing attractive potential for future energy storage application.展开更多
To satisfy the interfacial shear force continuity conditions, a new model is proposed for the two-layer composite beam with partial interaction by modifying Reddy＇s higher order beam theory. The governing differentia...To satisfy the interfacial shear force continuity conditions, a new model is proposed for the two-layer composite beam with partial interaction by modifying Reddy＇s higher order beam theory. The governing differential equations for free vibration and buckling are formulated using the Hamilton＇s principle, the natural frequencies and axial forces are thus analytically obtained by Laplace transform technique. The analytical results are verified through the comparison with those of several other models common in use; and the presented model is found to be a finer one than the Reddy＇s. A parametric study is also performed to investigate the effects of geometry and material parameters.展开更多
The novel quaternary ammonium bromide (QAB)-containing oligomers were synthesized and applied for developing an antibacterial resin composite. Compressive strength (CS) and S. mutans (an oral bacteria strain) viabilit...The novel quaternary ammonium bromide (QAB)-containing oligomers were synthesized and applied for developing an antibacterial resin composite. Compressive strength (CS) and S. mutans (an oral bacteria strain) viability were used to evaluate the mechanical strength and antibacterial activity of the formed composites. All the QAB-modified resin composites showed significant antibacterial activity and mechanical strength reduction. Increasing chain length and loading significantly enhanced the antibacterial activity but dramatically reduced the CS as well. The 30-day aging study showed that the incorporation of the QAB accelerated the degradation of the composite, suggesting that the QAB may not be well suitable for development of antibacterial dental resin composites or at least the QAB loading should be well controlled, unlike its use in dental glass-ionomer cements. The work in this study is beneficial and valuable to those who are interested in studying antibacterial dental resin composites.展开更多
To enhance the Young’s modulus(E)and strength of titanium alloys,we designed titanium matrix composites with intercon-nected microstructure based on the Hashin-Shtrikman theory.According to the results,the in-situ re...To enhance the Young’s modulus(E)and strength of titanium alloys,we designed titanium matrix composites with intercon-nected microstructure based on the Hashin-Shtrikman theory.According to the results,the in-situ reaction yielded an interconnected microstructure composed of Ti_(2)C particles when the Ti_(2)C content reached 50vol%.With widths of 10 and 230 nm,the intraparticle Ti lamellae in the prepared composite exhibited a bimodal size distribution due to precipitation and the unreacted Ti phase within the grown Ti_(2)C particles.The composites with interconnected microstructure attained superior properties,including E of 174.3 GPa and ultimate flexural strength of 1014 GPa.Compared with that of pure Ti,the E of the composite was increased by 55% due to the high Ti_(2)C content and interconnected microstructure.The outstanding strength resulted from the strong interfacial bonding,load-bearing capacity of interconnected Ti_(2)C particles,and bimodal intraparticle Ti lamellae,which minimized the average crack driving force.Interrupted flexural tests revealed preferential crack initiation along the{001}cleavage plane and grain boundary of Ti_(2)C in the region with the highest tensile stress.In addition,the propagation can be efficiently inhibited by interparticle Ti grains,which prevented the brittle fracture of the composites.展开更多
This contribution deals with the development of a three-node triangular plane finite element to analyze the transient hygroscopic behavior of 2/2 twill flax fabric-reinforced epoxy composite.Several plates of this mat...This contribution deals with the development of a three-node triangular plane finite element to analyze the transient hygroscopic behavior of 2/2 twill flax fabric-reinforced epoxy composite.Several plates of this material were fabricated using the vacuum infusion process and composite specimens were then cut and aged in tap water at room temperature until saturation.To simplify,a plane modelling of water diffusion in the aged specimens is adopted and Fick’s model is used to describe the water diffusion kinetics.To highlight the heterogeneity of the flax-epoxy samples,the twill flax fabrics waviness is modelled with a sinusoidal undulation.In particular,we show that the proposed finite element formulation allows estimating the flax fiber radial diffusion coefficient by an inverse approach.展开更多
Tribological behaviour of aluminium alloy (Al-Si10Mg) reinforced with alumina (9%) and graphite (3%) fabricated by stir casting process was investigated. The wear and frictional properties of the hybrid metal matrix c...Tribological behaviour of aluminium alloy (Al-Si10Mg) reinforced with alumina (9%) and graphite (3%) fabricated by stir casting process was investigated. The wear and frictional properties of the hybrid metal matrix composites was studied by performing dry sliding wear test using a pin-on-disc wear tester. Experiments were conducted based on the plan of experiments generated through Taguchi’s technique. A L27 Orthogonal array was selected for analysis of the data. Investigation to find the influence of applied load, sliding speed and sliding distance on wear rate, as well as the coefficient of friction during wearing process was carried out using ANOVA and regression equations for each response were developed. Objective of the model was chosen as ‘smaller the better’ characteristics to analyse the dry sliding wear resistance. Results show that sliding distance has the highest influence followed by load and sliding speed. Finally, confirmation tests were carried out to verify the experimental results and Scanning Electron Microscopic studies were done on the wear surfaces.展开更多
In the work,rGO nanosheet is synthesized using the typical Hummer’s method,then Cu12Sb4 S13 quantum dots@rGO composites are prepared by solvent thermal method,and Cu12Sb4 S13 quantum dots with the average size of 5 n...In the work,rGO nanosheet is synthesized using the typical Hummer’s method,then Cu12Sb4 S13 quantum dots@rGO composites are prepared by solvent thermal method,and Cu12Sb4 S13 quantum dots with the average size of 5 nm are densely distributed on the surface of rGO sheet.NH3 gas response of Cu12Sb4 S13quantum dots@rGO nanosheet composites at room te mperature of 25℃is enhanced compared with the pure Cu12Sb4 S13 quantum dots and rGO nanosheet,and the composites possess an excellent stability during the humidity range of 45%-80%with a low detection limit of 1 ppm,which is related with the intrinsic hydrophobicity characteristic of Cu12Sb4 S13 quantum dots.It also proves that Cu12Sb4 S13quantum dots@rGO nanosheet composites have a quite high selectivity towards ammonia compared with ethanol,methanol,acetone,toluene,hydrogen sulfide and nitrogen dioxide at room temperature.The gas sensing mechanism of the composites is discussed primarily.展开更多
Palm fiber (PF) reinforced acrylonitrile butadiene styrene (ABS) composite matrix was prepared by employing Injection Moulding Machine (IMM). Palm fiber was collected from ten different trees of different age group fr...Palm fiber (PF) reinforced acrylonitrile butadiene styrene (ABS) composite matrix was prepared by employing Injection Moulding Machine (IMM). Palm fiber was collected from ten different trees of different age group from Comilla region in Bangladesh. Three sets of samples were prepared for three different wt% (5%, 10% and 20%) of fiber contents. The mechanical (tensile strength, flexural stress, micro hardness, Leeb’s rebound hardness) and physical (bulk density and water absorption) properties were measured. The observed result reveals that the tensile strength (TS) and flexural stress (FS) were decreased with increasing fiber contents in the PF-ABS composites except 10% fiber content.展开更多
Investigated by this study is an MFC actuator attached to the surface of a Carbon Fiber Reinforced Polymer(CFRP)composite beam to form a beam actuator system.Analytically capturing the characteristics of such system i...Investigated by this study is an MFC actuator attached to the surface of a Carbon Fiber Reinforced Polymer(CFRP)composite beam to form a beam actuator system.Analytically capturing the characteristics of such system is essential.A novel analytical methodology considering the transverse shear strain and active stiffening effect is proposed,which was newly applied to analyze the static and dynamic behaviors of the beam actuator system.The governing equations of the beam actuator system were obtained via generalized Hamilton’s principle.A distributed transfer function formulation was developed.Then,the closed form solution was derived by using the Green’s function.Frequency response,natural frequencies,and modal shapes of the beam actuator system were obtained.The solution is analytical without using any truncated series or admissible functions at any arbitrary boundary conditions.Finite Element Method(FEM)results were also obtained to compare with that of the proposed method.The predictions of the analyses were verified experimentally,which shows the correctness and effectiveness of the proposed method.展开更多
In this study, S-doped NbSea （NbSo.aSel.8） powders were fabricated, and the corresponding Cu-based composites （Cu/NbSo.eSe1.8） were obtained by powder metallurgy technique. The phase compositions, physical, and tr...In this study, S-doped NbSea （NbSo.aSel.8） powders were fabricated, and the corresponding Cu-based composites （Cu/NbSo.eSe1.8） were obtained by powder metallurgy technique. The phase compositions, physical, and tribological properties of Cu-based composites were investigated systematically. The results show that Cu matrix reacts with NbSo.2Sel.8 to produce Cu2Se and Cu0.38NbSo.2Se1.8 during sintering process, which influences the physical and tribological properties of Cu-based composites significantly. Specially, with NbS0.2Se1.8 content increasing, the density of Cu/ NbSo.2Se1.8 composites decreases, and the hardness increases firstly and then decreases, while the electric resistivity in- creases slightly. In addition, the incorporation of NbSo.2Se1.8 enhances the tribological properties of Cu greatly, which is attributed to the lubricating effect of Cuo,38NbSo.2Se1.8 and the reinforcement effect of Cu2Se. In particular, when the content of NbSo.2Sel.8 is 6 wt%, the Cu-based composite has the best tribological properties.展开更多
The main challenges in development of traditional liquid lithium-sulfur batteries are the shuttle effect at the cathode caused by the polysulfide and the safety concern at the Li metal anode arose from the dendrite fo...The main challenges in development of traditional liquid lithium-sulfur batteries are the shuttle effect at the cathode caused by the polysulfide and the safety concern at the Li metal anode arose from the dendrite formation.All-solid-state lithium-sulfur batteries have been proposed to solve the shuttle effect and prevent short circuits.However,solid-solid contacts between the electrodes and the electrolyte increase the interface resistance and stress/strain,which could result in the limited electrochemical performances.In this work,the cathode of all-solid-state lithium-sulfur batteries is prepared by depositing sulfur on the surface of the carbon nanotubes(CNTs@S)and further mixing with Li10GeP2S12 electrolyte and acetylene black agents.At 60℃,CNTs@S electrode exhibits superior electrochemical performance,delivering the reversible discharge capacities of 1193.3,959.5,813.1,569.6 and 395.5 mAhg^-1 at the rate of 0.1,0.5,1,2 and 5 C,respectively.Moreover,the CNTs@S is able to demonstrate superior high-rate capability of 660.3 mAhg^-1 and cycling stability of 400 cycles at a high rate of 1.0 C.Such uniform distribution of the CNTs,S and Li10GeP2S12 electrolyte increase the electronic and ionic conductivity between the cathode and the electrolyte hence improves the rate performance and capacity retention.展开更多
基金supported by National Key Research and Development Program of China(Grant No.2023YFB4605301)the National Natural Science Foundation of China(Grant No.52130506)。
文摘The z-axis-inclined 3D printing process using short carbon fiber-reinforced thermoplastic composites offers the potential for the support-free fabrication of complex structures and theoretically unlimited extension of printed components.It has emerged as a promising approach for in-orbit manufacturing of high-performance thermoplastic composite truss structures.However,extreme conditions of the space environment,such as high vacuum and fluctuating high-low temperatures,significantly alter the heat-transfer behavior during the printing process,often resulting in dimensional inaccuracies and degraded mechanical performance.Existing process optimization strategies fail to account for the coupled effects of vacuum and thermal extremes,limiting their applicability in guiding process design under varying vacuum temperature conditions.To address this gap,this study establishes a truss3D printing experimental platform with in situ temperature-monitoring capability under ground-simulated space conditions.It systematically investigates the effects of printing speed and structural geometry on the pre-bonding surface temperature and forming quality of truss structures in high-low temperature vacuum environments.This study reveals the mechanism by which processing and structural parameters affect the component performance through their influence on the pre-bonding surface temperature and dimensional accuracy.The experimental results show that under high-temperature vacuum conditions,the pre-bonding surface temperature is relatively high,resulting in good interfacial bonding.However,increasing the printing speed reduces the forming accuracy and leads to a decline in mechanical performance.In contrast,under low-temperature vacuum conditions,where the pre-bonding surface temperatures are lower,increasing the printing speed within a specific range effectively increases the surface temperature and bonding quality,thereby improving mechanical properties.Additionally,owing to frequent path transitions,the diagonal-strut truss exhibits a lower forming accuracy and pre-bonding surface temperature than the infilling truss,resulting in inferior mechanical performance in high-low temperature vacuum environments.
文摘The reasons of the static strength dispersion and the fatigue life dispersion of composite laminates are analyzed in this article. It is concluded that the inner original defects, which derived from the manufacturing process of composite laminates, are the common and major reason of causing the random distributions of the static strength and the fatigue life. And there is a correlative relation between the two distributions. With the study of statistical relationship between the fatigue loading and the fatigue life in the uniform confidence level and the same survival rate S-N curves of material, the relationship between the static strength distribution and the fatigue life distribution through a material S-N curve model has been obtained. And then the model which is used to describe the distributions of fatigue life of composites, based on their distributions of static strength, is set up. This model reasonably reflects the effects of the inner original defects on the static strength dispersion and on the fatigue life dispersion of composite laminates. The experimental data of three kinds of composite laminates are employed to verify this model, and the results show that this model can predict the random distributions of fatigue life for composites under any fatigue loads fairly well.
基金supported by the National Natural Science Foundation of China(51572103,51502106)the Distinguished Young Scholar of Anhui Province(1808085J14)+2 种基金the Foundation for Young Talents in College of Anhui Province(gxyqZD2017051)the Key Foundation of Educational Commission of Anhui Province(KJ2016SD53)Innovation Team of Design and Application of Advanced Energetic Materials(KJ2015TD003)~~
文摘In recent years,environmental pollution and energy crisis have become increasingly serious issues owing to the burning of fossil fuels.Among the many technologies,decomposition of water to produce hydrogen has attracted much attention because of its sustainability and non-polluting characteristic.However,highly efficient decomposition of water that is driven by visible light is still a challenge.Herein,we report the large-scale preparation of step-scheme porous graphite carbon nitride/Zn0.2Cd0.8S-diethylenetriamine(Pg-C3N4/Zn0.2Cd0.8S-DETA)composite by a facile solvothermal method.It was found by UV-vis spectroscopy that 15%Pg-C3N4/Zn0.2Cd0.8S-DETA exhibited suitable visible absorption edge and band gap for water decomposition.The hydrogen production rate of 15%Pg-C3N4/Zn0.2Cd0.8S-DETA composite was 6.69 mmol g^-1 h^-1,which was 16.73,1.61,and 1.44 times greater than those of Pg-C3N4,CdS-DETA,and Zn0.2Cd0.8S-DETA,respectively.In addition,15%Pg-C3N4/Zn0.2Cd0.8S-DETA composite displayed excellent photocatalytic stability,which was maintained for seven cycles of photocatalytic water splitting test.We believe that 15%Pg-C3N4/Zn0.2Cd0.8S-DETA composite can be a valuable guide for the development of solar hydrogen production applications in the near future.
基金the financial support from the National Natural Science Foundation of China(No.91963118)the 111 Project(No.B13013)supported by the Open Project Program of Key Laboratory of Preparation and Application of Environmental Friendly Materials(Jilin Normal University),Ministry of Education,China(No.2020004)。
文摘Graphite as a promising anode candidate of K-ion batteries(KIBs)has been increasingly studied currently,but corresponding rate performance and cycling stability are usually inferior to amorphous carbon materials.To protect the layer structure and further boost performance,tempura-like carbon/carbon nanocomposite of graphite@pitch-derived S-doped carbon(G@PSC)is designed and prepared by a facile and low-temperature modified molten salt method.This robust encapsulation structure makes their respective advantages complementary to each other,showing mutual promotion of electrochemical performances caused by synergy effect.As a result,the G@PSC electrode is applied in KIBs,delivering impressive rate capabilities(465,408,370,332,290,and 227 m A h g^(-1)at 0.05,0.2,0.5,1,2,and 5 A g^(-1))and ultralong cyclic stability(163 m A g^(-1)remaining even after 8000 cycles at 2 A g^(-1)).On basis of ex-situ studies,the sectionalized K-storage mechanism with adsorption(pseudocapacitance caused by S doping)-intercalation(pitch-derived carbon and graphite)pattern is revealed.Moreover,the exact insights into remarkable rate performances are taken by electrochemical kinetics tests and density functional theory calculation.In a word,this study adopts a facile method to synthesize high-performance carbon/carbon nanocomposite and is of practical significance for development of carbonaceous anode in KIBs.
文摘The combination of classical Hodgkin’s lymphoma(cHL)and non-Hodgkin lymphoma coexisting in the same patient is not common,especially in one extranodal location.Here we present a rare case of composite diffuse large B-cell lymphoma(DLBCL)and cHL occurring simultaneously in the stomach of a 53-year-old female who presented with upper abdominal discomfort and gas pain.Surgery was performed and the disease was diagnosed pathologically as composite lymphoma of DLBCL and cHL using hematoxylin-eosin and immunohistochemical staining.Epstein-Barr virus(EBV)infection was not detected by in situ hybridization for EBV-encoded RNA or immunohistochemistry for EBV latent membrane protein-1.Polymerase chain reaction analysis from the two distinct components of the tumor demonstrated clonal immunoglobulinκlight chain gene rearrangements.The patient died approximately 11 mo after diagnosis in spite of receiving eight courses of the CHOP and two courses of the rituximab-CHOP(RCHOP) chemotherapy regimen.This case report showed that the two distinct components,DLBCL and cHL,appeared to originate from the same clonal progenitor cell,and that EBV infection was not essential for transformation during the course of tumorigenesis.
基金financially supported by the National Natural Science Foundation of China (Nos.21606065 and 21676067)Anhui Provincial Natural Science Foundation (Nos.1708085QE98 and 1908085QE178)+1 种基金the Fundamental Research Funds for the Central Universities (Nos.JZ2017YYPY0253,JZ2017HGTB0198,JZ2018HGBZ0138 and PA2020GDGP0054)the Opening Project of CAS Key Laboratory of Materials for Energy Conversion (No.KF2018003)。
文摘The popularity of lithium–sulfur batteries has been increasing gradually due to their ultrahigh theoretical specific capacity and energy density. Nevertheless, they also have lots of drawbacks to be overcome, such as poor conductivity, severe volume expansion, and serious“shuttle effect”. In this work, reduced graphene oxide/molybdenum dioxide(rGO/MoO_(2)) composite is synthesized and applied to modify polypropylene separator. The modified polypropylene separator introduces synergistic tri-functions of physical adsorption, chemical interaction and catalytic effects, which can inhibit the“shuttle effect” and enhance the electrochemical performances of lithium-sulfur batteries. In the prepared r GO/MoO_(2) composite, the polar MoO_(2) chemically adsorbs the intermediate lithium polysulfide, while the rGO with good electrical conductivity not only acts as a physical barrier to prevent diffusion of polysulfide ions, but also improves the conversion efficiency of active material intercepted on the separator. As a consequence, the battery assembled with rGO/MoO_(2) modified polypropylene separator exhibits a reversible capacity of 757.5 mAh·g^(-1) after 200 cycles at0.2 C with a negligible capacity decay of 0.207% per cycle,which indicates a good long-period cycling stability. Furthermore, the rate performance and self-discharge suppression are also improved by introducing modified polypropylene separator. It shows that rGO/MoO_(2) composite is a promising material for separator modification in lithium-sulfur batteries.
基金financial supports from the National Natural Science Foundation of China(Nos.51908485 and 51608468)the China Postdoctoral Science Foundation(No.2019T120194)the University Science and Technology Program Project of Hebei Provincial Department of Education(No.QN2018258)。
文摘Constructing a Z-scheme is a significant approach to improve the separation of photogene rated carriers for effective organic pollutant degradation.Herein,a BiVO4/ZnIn2S4(BZ) Z-scheme composite was successfully synthesized,and applied to photodegrade methyl orange(MO) irradiated by a LED lamp.Anchoring the BiVO4 on the ZnIn2S4 nanoparticles promoted the separation of photogenerated electronholes and broadened the light response range.The detailed characterizations,including surface morphology,elements valence state,and photocurrent performance,demonstrated that the enhanced separation of photogenerated carriers was the pivotal reason for the enhanced photocatalysis reaction.Benefiting from the excellent photocatalytic characteristics,the 5% mass ratio of BZ composite presented the highest MO degradation rate of 0.00997 min^-1,which was 1.9 and 10.3 times greater than the virgin ZnIn2S4 and BiVO4,respectively.Furthermore,the BZ hybrid materials indicated a well photo-stability in the four recycling tests.
基金supported by the National Natural Science Foundation of China(No.21905289)the Independent Cultivation Program of Innovation Team of Ji’nan City(No.2019GXRC011)+1 种基金the Natural Science Foundation of Shandong Province(No.ZR2020QE062)China Postdoctoral Science Foundation(No.2021T140268)。
文摘Lithium-sulfur(Li-S)battery is labeled as a promising high-energy-density battery system,but some inherent drawbacks of sulfur cathode materials using relatively complicated techniques impair the practical applications.Herein,an integrated approach is proposed to fabricate the high-performance rGO/VS_(4)/S cathode composites through a simple one-step solvothermal method,where nano sulfur and VS_(4) particles are uniformly distributed on the conductive rGO matrix.rGO and sulfiphilic VS_(4)provide electron transfer skeleton and physical/chemical anchor for soluble lithium polysulfides(LiPS).Meanwhile,VS_(4) could also act as an electrochemical mediator to efficiently enhance the utilization and reversible conversion of LiPS.Correspondingly,the rGO/VS_(4)/S composites maintain a high reversible capacity of 969 mAh/g at 0.2 C after 100 cycles,with a capacity retention rate of 82.3%.The capacity fade rate could lower to 0.0374%per cycle at 1 C.Moreover,capacity still sustains 795 m Ah/g after 100 cycles in the relatively high-sulfurloading battery(6.5 mg/cm^(2)).Thus,the suggested method in configuring the sulfur-based composites is demonstrated a simple and efficient strategy to construct the high-performance Li-S batteries.
基金supported by the National Natural Science Foundation of China (No. 51725401)the Fundamental Research Funds for the Central Universities (FRF-TP-15-002C1 and FRF-TP17-002C2)
文摘The growing global demands of safe, low-cost and high working voltage energy storage devices trigger strong interests in novel battery concepts beyond state-of-art lithium-ion battery. Herein, a dualion battery based on nanostructured Ni_3S_2/Ni foam@RGO(NSNR) composite anode is developed, utilizing graphite as cathode material and LiPF6-VC-based solvent as electrolyte. The battery operates at high working voltage of 4.2–4.5 V, with superior discharge capacity of ～90 m A h g^(-1) at 100 mA g^(-1), outstanding rate performance, and long-term cycling stability over 500 cycles with discharge capacity retention of ～85.6%. Moreover, the composite simultaneously acts as the anode material and the current collector, and the corrosion phenomenon can be greatly reduced compared to metallic Al anode. Thus, this work represents a significant step forward for practical safe, low-cost and high working voltage dual-ion batteries,showing attractive potential for future energy storage application.
基金Project supported by the National High Technology Research and Development Program of China(No.2009AA032303-2)
文摘To satisfy the interfacial shear force continuity conditions, a new model is proposed for the two-layer composite beam with partial interaction by modifying Reddy＇s higher order beam theory. The governing differential equations for free vibration and buckling are formulated using the Hamilton＇s principle, the natural frequencies and axial forces are thus analytically obtained by Laplace transform technique. The analytical results are verified through the comparison with those of several other models common in use; and the presented model is found to be a finer one than the Reddy＇s. A parametric study is also performed to investigate the effects of geometry and material parameters.
文摘The novel quaternary ammonium bromide (QAB)-containing oligomers were synthesized and applied for developing an antibacterial resin composite. Compressive strength (CS) and S. mutans (an oral bacteria strain) viability were used to evaluate the mechanical strength and antibacterial activity of the formed composites. All the QAB-modified resin composites showed significant antibacterial activity and mechanical strength reduction. Increasing chain length and loading significantly enhanced the antibacterial activity but dramatically reduced the CS as well. The 30-day aging study showed that the incorporation of the QAB accelerated the degradation of the composite, suggesting that the QAB may not be well suitable for development of antibacterial dental resin composites or at least the QAB loading should be well controlled, unlike its use in dental glass-ionomer cements. The work in this study is beneficial and valuable to those who are interested in studying antibacterial dental resin composites.
基金financially supported by the National Key R&D Program of China(No.2021YFB3701203)the National Natural Science Foundation of China(Nos.U22A20113,52201116,52071116,and 52261135543)+1 种基金Heilongjiang Touyan Team ProgramChina Postdoctoral Science Foundation(No.2022M710939).
文摘To enhance the Young’s modulus(E)and strength of titanium alloys,we designed titanium matrix composites with intercon-nected microstructure based on the Hashin-Shtrikman theory.According to the results,the in-situ reaction yielded an interconnected microstructure composed of Ti_(2)C particles when the Ti_(2)C content reached 50vol%.With widths of 10 and 230 nm,the intraparticle Ti lamellae in the prepared composite exhibited a bimodal size distribution due to precipitation and the unreacted Ti phase within the grown Ti_(2)C particles.The composites with interconnected microstructure attained superior properties,including E of 174.3 GPa and ultimate flexural strength of 1014 GPa.Compared with that of pure Ti,the E of the composite was increased by 55% due to the high Ti_(2)C content and interconnected microstructure.The outstanding strength resulted from the strong interfacial bonding,load-bearing capacity of interconnected Ti_(2)C particles,and bimodal intraparticle Ti lamellae,which minimized the average crack driving force.Interrupted flexural tests revealed preferential crack initiation along the{001}cleavage plane and grain boundary of Ti_(2)C in the region with the highest tensile stress.In addition,the propagation can be efficiently inhibited by interparticle Ti grains,which prevented the brittle fracture of the composites.
文摘This contribution deals with the development of a three-node triangular plane finite element to analyze the transient hygroscopic behavior of 2/2 twill flax fabric-reinforced epoxy composite.Several plates of this material were fabricated using the vacuum infusion process and composite specimens were then cut and aged in tap water at room temperature until saturation.To simplify,a plane modelling of water diffusion in the aged specimens is adopted and Fick’s model is used to describe the water diffusion kinetics.To highlight the heterogeneity of the flax-epoxy samples,the twill flax fabrics waviness is modelled with a sinusoidal undulation.In particular,we show that the proposed finite element formulation allows estimating the flax fiber radial diffusion coefficient by an inverse approach.
文摘Tribological behaviour of aluminium alloy (Al-Si10Mg) reinforced with alumina (9%) and graphite (3%) fabricated by stir casting process was investigated. The wear and frictional properties of the hybrid metal matrix composites was studied by performing dry sliding wear test using a pin-on-disc wear tester. Experiments were conducted based on the plan of experiments generated through Taguchi’s technique. A L27 Orthogonal array was selected for analysis of the data. Investigation to find the influence of applied load, sliding speed and sliding distance on wear rate, as well as the coefficient of friction during wearing process was carried out using ANOVA and regression equations for each response were developed. Objective of the model was chosen as ‘smaller the better’ characteristics to analyse the dry sliding wear resistance. Results show that sliding distance has the highest influence followed by load and sliding speed. Finally, confirmation tests were carried out to verify the experimental results and Scanning Electron Microscopic studies were done on the wear surfaces.
基金supported by the National Natural Science Foundation of China(No.11674258)the 111 Project(No.B18038)+4 种基金Key projects of Natural Science Foundation of Hubei Province(No.2019CFA044)Applied Basic Research Program of Wuhan(No.2018010401011278)Science and Technology Innovation Program of Hubei Province(No.2018B KJ005)Natural Science Foundation of Hunan Province,China(No.2018JJ3527)Students Innovation and Entrepreneurship Training Program(No.20181049721003)。
文摘In the work,rGO nanosheet is synthesized using the typical Hummer’s method,then Cu12Sb4 S13 quantum dots@rGO composites are prepared by solvent thermal method,and Cu12Sb4 S13 quantum dots with the average size of 5 nm are densely distributed on the surface of rGO sheet.NH3 gas response of Cu12Sb4 S13quantum dots@rGO nanosheet composites at room te mperature of 25℃is enhanced compared with the pure Cu12Sb4 S13 quantum dots and rGO nanosheet,and the composites possess an excellent stability during the humidity range of 45%-80%with a low detection limit of 1 ppm,which is related with the intrinsic hydrophobicity characteristic of Cu12Sb4 S13 quantum dots.It also proves that Cu12Sb4 S13quantum dots@rGO nanosheet composites have a quite high selectivity towards ammonia compared with ethanol,methanol,acetone,toluene,hydrogen sulfide and nitrogen dioxide at room temperature.The gas sensing mechanism of the composites is discussed primarily.
文摘Palm fiber (PF) reinforced acrylonitrile butadiene styrene (ABS) composite matrix was prepared by employing Injection Moulding Machine (IMM). Palm fiber was collected from ten different trees of different age group from Comilla region in Bangladesh. Three sets of samples were prepared for three different wt% (5%, 10% and 20%) of fiber contents. The mechanical (tensile strength, flexural stress, micro hardness, Leeb’s rebound hardness) and physical (bulk density and water absorption) properties were measured. The observed result reveals that the tensile strength (TS) and flexural stress (FS) were decreased with increasing fiber contents in the PF-ABS composites except 10% fiber content.
文摘Investigated by this study is an MFC actuator attached to the surface of a Carbon Fiber Reinforced Polymer(CFRP)composite beam to form a beam actuator system.Analytically capturing the characteristics of such system is essential.A novel analytical methodology considering the transverse shear strain and active stiffening effect is proposed,which was newly applied to analyze the static and dynamic behaviors of the beam actuator system.The governing equations of the beam actuator system were obtained via generalized Hamilton’s principle.A distributed transfer function formulation was developed.Then,the closed form solution was derived by using the Green’s function.Frequency response,natural frequencies,and modal shapes of the beam actuator system were obtained.The solution is analytical without using any truncated series or admissible functions at any arbitrary boundary conditions.Finite Element Method(FEM)results were also obtained to compare with that of the proposed method.The predictions of the analyses were verified experimentally,which shows the correctness and effectiveness of the proposed method.
基金financially supported by the National Nature Science Foundation of China(Nos.51405199 and21301075)the Natural Science Foundation of Jiangsu Province(Nos.BK20140551 and BK20140562)+4 种基金the Postdoctoral Science Foundation of China(No.2014M561579)the Postdoctoral Science Foundation of Jiangsu Province(No.1401106C)the Opening Foundation of Jiangsu Province Material Tribology Key Laboratory(No.Kjsmcx201304)the Senior Intellectuals Fund of Jiangsu University(No.13JDG099)the Industry-Academy-Research Union Foundation of Jiangsu Province(No.BY2013065-05)
文摘In this study, S-doped NbSea （NbSo.aSel.8） powders were fabricated, and the corresponding Cu-based composites （Cu/NbSo.eSe1.8） were obtained by powder metallurgy technique. The phase compositions, physical, and tribological properties of Cu-based composites were investigated systematically. The results show that Cu matrix reacts with NbSo.2Sel.8 to produce Cu2Se and Cu0.38NbSo.2Se1.8 during sintering process, which influences the physical and tribological properties of Cu-based composites significantly. Specially, with NbS0.2Se1.8 content increasing, the density of Cu/ NbSo.2Se1.8 composites decreases, and the hardness increases firstly and then decreases, while the electric resistivity in- creases slightly. In addition, the incorporation of NbSo.2Se1.8 enhances the tribological properties of Cu greatly, which is attributed to the lubricating effect of Cuo,38NbSo.2Se1.8 and the reinforcement effect of Cu2Se. In particular, when the content of NbSo.2Sel.8 is 6 wt%, the Cu-based composite has the best tribological properties.
基金supported by the National Key R&D Program of China (Grant no. 2016YFB0100105)the National Natural Science Foundation of China (Grant no. 51872303)+1 种基金Zhejiang Provincial Natural Science Foundation of China (Grant no. LD18E020004, LQ16E020003, LY18E020018, LY18E030011)Youth Innovation Promotion Association CAS (2017342)
文摘The main challenges in development of traditional liquid lithium-sulfur batteries are the shuttle effect at the cathode caused by the polysulfide and the safety concern at the Li metal anode arose from the dendrite formation.All-solid-state lithium-sulfur batteries have been proposed to solve the shuttle effect and prevent short circuits.However,solid-solid contacts between the electrodes and the electrolyte increase the interface resistance and stress/strain,which could result in the limited electrochemical performances.In this work,the cathode of all-solid-state lithium-sulfur batteries is prepared by depositing sulfur on the surface of the carbon nanotubes(CNTs@S)and further mixing with Li10GeP2S12 electrolyte and acetylene black agents.At 60℃,CNTs@S electrode exhibits superior electrochemical performance,delivering the reversible discharge capacities of 1193.3,959.5,813.1,569.6 and 395.5 mAhg^-1 at the rate of 0.1,0.5,1,2 and 5 C,respectively.Moreover,the CNTs@S is able to demonstrate superior high-rate capability of 660.3 mAhg^-1 and cycling stability of 400 cycles at a high rate of 1.0 C.Such uniform distribution of the CNTs,S and Li10GeP2S12 electrolyte increase the electronic and ionic conductivity between the cathode and the electrolyte hence improves the rate performance and capacity retention.
