A functional interlayer based on two-dimensional(2D)porous modified vermiculite nanosheets(PVS)was obtained by acid-etching vermiculite nanosheets.The as-obtained 2D porous nanosheets exhibited a high specific surface...A functional interlayer based on two-dimensional(2D)porous modified vermiculite nanosheets(PVS)was obtained by acid-etching vermiculite nanosheets.The as-obtained 2D porous nanosheets exhibited a high specific surface area of 427 m^(2)·g^(-1)and rich surface active sites,which help restrain polysulfides(LiPSs)through good physi-cal and chemical adsorption,while simultaneously accelerating the nucleation and dissolution kinetics of Li_(2)S,effec-tively suppressing the shuttle effect.The assembled lithium-sulfur batteries(LSBs)employing the PVS-based inter-layer delivered a high initial discharge capacity of 1386 mAh·g^(-1)at 0.1C(167.5 mAh·g^(-1)),long-term cycling stabil-ity,and good rate property.展开更多
Zirconium alloy(Zr-4)is extensively utilized in nuclear fuel cladding materials due to its exceptional neutron economy,high ductility,and promising corrosion and irradiation resistance.Nevertheless,during the operatio...Zirconium alloy(Zr-4)is extensively utilized in nuclear fuel cladding materials due to its exceptional neutron economy,high ductility,and promising corrosion and irradiation resistance.Nevertheless,during the operational lifespan of the Zr-4 fuel tube,micro-oscillations induced by the high-speed flow of cooling water can cause wear between the cladding tube and grids.This leads to wear failure of the Zr-4 alloy tube,which seriously threatens the safe operation of nuclear stations.The application of protective coatings onto the surface of zirconium alloys serves to enhance their resistance against wear,while without changing of the existing reactor structure.In this study,FeCrAl/CrN and FeCrAl coatings were fabricated on the surface of Zr-4 alloy using dual-target co-sputtering technology.The effects of the CrN interlayer on the microstructure,mechanical properties,and tribological behavior of FeCrAl coating in air and B-Li water were investigated,and a comparative analysis with Zr-4 alloy was conducted.The results showed that the application of FeCrAl/CrN and FeCrAl coatings significantly enhanced the hardness and wear resistance of Zr-4 alloy.The introduction of the CrN interlayer increased the columnar grain size of the FeCrAl coating and caused a change in the preferred growth direction of the coating from(110)to(211).The CrN interlayer improved the hardness and wear resistance of the coating,it also led to a decrease in adhesion strength.The wear rates of FeCrAl/CrN coatings in air and B-Li water were the lowest,about 3.2×10^(-6) mm^(3)/(N·m)and 6.0×10^(-7) mm^(3)/(N·m),respectively.The lubricating effect of B-Li water effectively reduced the friction coefficient and wear rate of both FeCrAl/CrN and FeCrAl coatings.In air and B-Li water,the primary wear mechanisms for Zr-4 are adhesive wear and oxidative wear,while the main wear mechanisms for FeCrAl/CrN and FeCrAl coatings are abrasive wear and oxidative wear.These findings not only provided a theoretical basis for understanding the microstructure and wear performance of FeCrAl coatings but also offered important technical guidance for their practical application in the nuclear industry.展开更多
The basic principle of friction welding is intermetallic bonding at the stage of super plasticity attained with self-generating heat due to friction and finishing at upset pressure. Now the dissimilar metal joints are...The basic principle of friction welding is intermetallic bonding at the stage of super plasticity attained with self-generating heat due to friction and finishing at upset pressure. Now the dissimilar metal joints are especially popular in defense, aerospace, automobile, bio-medical,refinery and nuclear engineerings. In friction welding, some special alloys with dual phase are not joined successfully due to poor bonding strength. The alloy surfaces after bonding also have metallurgical changes in the line of interfacing. The reported research work in this area is scanty. Although the sound weld zone of direct bonding between Tie6Ale4 V and SS304 L was obtained though many trials, the joint was not successful. In this paper, the friction welding characteristics between Tie6Ale4 V and SS304 L into which pure oxygen free copper(OFC) was introduced as interlayer were investigated. Boxe Behnken design was used to minimize the number of experiments to be performed. The weld joint was analyzed for its mechanical strength. The highest tensile strength between Tie6Ale4 V and SS304 L between which pure copper was used as insert metal was acquired. Micro-structural analysis and elemental analysis were carried out by EDS, and the formation of intermetallic compound at the interface was identified by XRD analysis.展开更多
Diamond films were deposited on high-speed steel substrates by hot filament chemical vapor deposition （HFCVD） method. To minimize the early formation of graphite and to enhance the diamond film adhesion, a WC-Co coa...Diamond films were deposited on high-speed steel substrates by hot filament chemical vapor deposition （HFCVD） method. To minimize the early formation of graphite and to enhance the diamond film adhesion, a WC-Co coating was used as an interlayer on the steel substrates by high velocity oxy-fuel spraying. The effects of methane content on nucleation, quality, residual stress and adhesion of diamond films were investigated. The results indicate that the increasing methane content leads to the increase in nucleation density, residual stress, the degradation of quality and adhesion of diamond films. Diamond films deposited on high-speed steel （HSS） substrate with a WC-Co interlayer exhibit high nucleation density and good adhesion under the condition of the methane content initially set to be a higher value （4%, volume fraction） for 30 min, and then reduced to 2% for subsequent growth at pressure of 3 kPa and substrate temperature of 800 ℃.展开更多
The landslide disaster caused by the argillaceous interlayer not only destroys buildings,cultivated land,and roads but also seriously endangers human life and safety.This study concerns the mineral composition of sele...The landslide disaster caused by the argillaceous interlayer not only destroys buildings,cultivated land,and roads but also seriously endangers human life and safety.This study concerns the mineral composition of selected argillaceous interlayer and their strength characteristics.To study the mineral composition of argillaceous interlayers,8 kinds of samples in the southern Jiangsu region of China were analyzed utilizing X-ray diffraction(XRD).The repeated direct shear strength tests(RDST)were carried out on the undisturbed specimens of the argillaceous interlayer.The results show that the argillaceous interlayer with high content of kaolinite shows ductile failure mode,which means that there is no obvious residual strength in the shear process.The arrangement of mineral particles on the shear surface of the specimens after different shear displacements was observed under the scanning electron microscope(SEM).It was observed that mineral particles on the shear surface showed a more directional arrangement with the increase of shear displacement.Furthermore,the influence of shear direction on the argillaceous interlayer with completely oriented mineral particles was studied through numerical experiments with four shear strength mechanisms proposition proposed.The influence of the mineral arrangement on the action occasion and magnitude of dilatancy component of shear strength is clarified in the shear mechanism.展开更多
Multiple surface cracks and interfacial delamination are the major failure mechanisms in film/substrate systems.The effect of interlayer upon the failure mechanisms of interfacial delamination concomitant to surface c...Multiple surface cracks and interfacial delamination are the major failure mechanisms in film/substrate systems.The effect of interlayer upon the failure mechanisms of interfacial delamination concomitant to surface crack was explored.Finite element model was developed to obtain the stress and energy release rate(ERR),which governs the propagation of interface cracks.The dependences of delamination upon the geometry and constitutive properties of interlayer were examined.The results indicate that the effect of elastic modulus of interlayer on the steady state ERR is insignificant.In cases of different geometrical parameters,however,the steady ERR decreases with the increase of the interlayer thickness.These findings lead to the conclusion that the interlayer constraint has significant effect on the ERR and thus coating life,which can be adopted to modify the ceramic top coat.展开更多
The interlayer clay-organic complex is an important clay-organic association in sedimentary environments. The interlayer region of clay minerals not only provides storage space for organic matter, but also possesses s...The interlayer clay-organic complex is an important clay-organic association in sedimentary environments. The interlayer region of clay minerals not only provides storage space for organic matter, but also possesses solid acid sites; and these acid sites were proposed to be involved with the transformation of organic matter into liquid and gaseous hydrocarbons. However, the effect of the organic matter storage in the interlayer space of clay minerals on the hydrocarbons generation has not been made clear. In this study, the interlayer complex of 12-aminolauric acid (ALA) and Na+-montmorillonite (Na+-Mt), labeled as ALAinter-Mt (Na), was synthesized to investigate the role of the interlayer space of montmorillonite in hydrocarbon generation. Simply mixed ALA-Mt complex [ALA-Mt (Na)] was also prepared for comparison. The pyrolysis of ALA and ALA-Mt complexes was studied using thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR) and a high temperature-pressure system (a confined gold capsule-autoclave system).展开更多
In order to analyze mechanism of casing damage,the uniaxial compression experiment and creep experiment of interbedded mudstone samples from Sanan development area of Daqing Oilfield under different water contents wer...In order to analyze mechanism of casing damage,the uniaxial compression experiment and creep experiment of interbedded mudstone samples from Sanan development area of Daqing Oilfield under different water contents were carried out.The changes of the mudstone's mechanical parameters and creep characteristics with the increment of water saturation were studied.The results indicate that the rock strength and elastic modulus decrease rapidly with the increment of water content,at the same time,the creep strain and creep strain rate of steady state increase with the increment of water content,and also the steady state creep strain rate is enhanced with the increment of deviatoric stress.Through the creep characteristic curves,a non-linear creep constitutive equation of mudstone considering the change of water contents is established,which will be used in future numerical analysis.展开更多
A Ti interlayer with thickness about 300 nm was sputtered on Cu microchannels, followed by an ultrasonic seeding with nanodiamond powders. Adherent diamond film with crystalline grains close to thermal equilibrium sha...A Ti interlayer with thickness about 300 nm was sputtered on Cu microchannels, followed by an ultrasonic seeding with nanodiamond powders. Adherent diamond film with crystalline grains close to thermal equilibrium shape was tightly deposited by hot-filament chemical vapor deposition(HF-CVD). The nucleation and growth of diamond were investigated with micro-Raman spectroscope and field emission scanning electron microscope(FE-SEM) with energy dispersive X-ray detector(EDX). Results show that the nucleation density is found to be up to 1010 cm-2. The enhancement of the nucleation kinetics can be attributed to the nanometer rough Ti interlayer surface. An improved absorption of nanodiamond particles is found, which act as starting points for the diamond nucleation during HF-CVD process. Furthermore, finite element simulation was conducted to understand the thermal management properties of prepared diamond/Cu microchannel heat sink.展开更多
Shale gas, which is derived from organic matters in shale and stored in shale deposits, is an important unconventional gas resource and attracts attention due to its significant requirement in the hydrocarbon producti...Shale gas, which is derived from organic matters in shale and stored in shale deposits, is an important unconventional gas resource and attracts attention due to its significant requirement in the hydrocarbon production. Methane (CH4) is the dominant component of shale gas, and adsorbed gas is an important reservoir form. Many studies have investigated the adsorption capacities and adsorption mechanisms of CH4 in shale. Organic matters and clay minerals have been proposed to be the two major components for CH4 adsorption. Adsorption of CH4 in organic matters, such as the adsorption capacity and effects of characteristics of the organic matters, has been well investigated. However, studies on CH4 adsorption on clay minerals have mainly focused on evaluating the adsorption capacity, and very little information about the adsorption mechanism has been provided. For example, the adsorption sites and factors influencing CH4 adsorption on clay minerals remain unclear. Three main reasons account for this: (1) the co-existence of organic matters in samples affects the evaluation of CH4 adsorption on clay minerals; (2) the pressures used during adsorption are not representative of actual reservoir pressures; and (3) the clay minerals selected have low swelling capacity and a smaller interlayer distances than a CH4 size, resulting in the misunderstanding of the CH4 adsorption sites.展开更多
Flexural and eigen-buckling analyses for rectangular steel-concrete partially composite plates(PCPs)with interlayer slip under simply supported and clamped boundary conditions are conducted using the weak form quadrat...Flexural and eigen-buckling analyses for rectangular steel-concrete partially composite plates(PCPs)with interlayer slip under simply supported and clamped boundary conditions are conducted using the weak form quadrature element method(QEM).Both of the derivatives and integrals in the variational description of a problem to be solved are directly evaluated by the aid of identical numerical interpolation points in the weak form QEM.The effectiveness of the presented numerical model is validated by comparing numerical results of the weak form QEM with those from FEM or analytic solution.It can be observed that only one quadrature element is fully competent for flexural and eigen-buckling analysis of a rectangular partially composite plate with shear connection stiffness commonly used.The numerical integration order of quadrature element can be adjusted neatly to meet the convergence requirement.The quadrature element model presented here is an effective and promising tool for further analysis of steel-concrete PCPs under more general circumstances.Parametric studies on the shear connection stiffness and length-width ratio of the plate are also presented.It is shown that the flexural deflections and the critical buckling loads of PCPs are significantly affected by the shear connection stiffness when its value is within a certain range.展开更多
文摘A functional interlayer based on two-dimensional(2D)porous modified vermiculite nanosheets(PVS)was obtained by acid-etching vermiculite nanosheets.The as-obtained 2D porous nanosheets exhibited a high specific surface area of 427 m^(2)·g^(-1)and rich surface active sites,which help restrain polysulfides(LiPSs)through good physi-cal and chemical adsorption,while simultaneously accelerating the nucleation and dissolution kinetics of Li_(2)S,effec-tively suppressing the shuttle effect.The assembled lithium-sulfur batteries(LSBs)employing the PVS-based inter-layer delivered a high initial discharge capacity of 1386 mAh·g^(-1)at 0.1C(167.5 mAh·g^(-1)),long-term cycling stabil-ity,and good rate property.
文摘Zirconium alloy(Zr-4)is extensively utilized in nuclear fuel cladding materials due to its exceptional neutron economy,high ductility,and promising corrosion and irradiation resistance.Nevertheless,during the operational lifespan of the Zr-4 fuel tube,micro-oscillations induced by the high-speed flow of cooling water can cause wear between the cladding tube and grids.This leads to wear failure of the Zr-4 alloy tube,which seriously threatens the safe operation of nuclear stations.The application of protective coatings onto the surface of zirconium alloys serves to enhance their resistance against wear,while without changing of the existing reactor structure.In this study,FeCrAl/CrN and FeCrAl coatings were fabricated on the surface of Zr-4 alloy using dual-target co-sputtering technology.The effects of the CrN interlayer on the microstructure,mechanical properties,and tribological behavior of FeCrAl coating in air and B-Li water were investigated,and a comparative analysis with Zr-4 alloy was conducted.The results showed that the application of FeCrAl/CrN and FeCrAl coatings significantly enhanced the hardness and wear resistance of Zr-4 alloy.The introduction of the CrN interlayer increased the columnar grain size of the FeCrAl coating and caused a change in the preferred growth direction of the coating from(110)to(211).The CrN interlayer improved the hardness and wear resistance of the coating,it also led to a decrease in adhesion strength.The wear rates of FeCrAl/CrN coatings in air and B-Li water were the lowest,about 3.2×10^(-6) mm^(3)/(N·m)and 6.0×10^(-7) mm^(3)/(N·m),respectively.The lubricating effect of B-Li water effectively reduced the friction coefficient and wear rate of both FeCrAl/CrN and FeCrAl coatings.In air and B-Li water,the primary wear mechanisms for Zr-4 are adhesive wear and oxidative wear,while the main wear mechanisms for FeCrAl/CrN and FeCrAl coatings are abrasive wear and oxidative wear.These findings not only provided a theoretical basis for understanding the microstructure and wear performance of FeCrAl coatings but also offered important technical guidance for their practical application in the nuclear industry.
文摘The basic principle of friction welding is intermetallic bonding at the stage of super plasticity attained with self-generating heat due to friction and finishing at upset pressure. Now the dissimilar metal joints are especially popular in defense, aerospace, automobile, bio-medical,refinery and nuclear engineerings. In friction welding, some special alloys with dual phase are not joined successfully due to poor bonding strength. The alloy surfaces after bonding also have metallurgical changes in the line of interfacing. The reported research work in this area is scanty. Although the sound weld zone of direct bonding between Tie6Ale4 V and SS304 L was obtained though many trials, the joint was not successful. In this paper, the friction welding characteristics between Tie6Ale4 V and SS304 L into which pure oxygen free copper(OFC) was introduced as interlayer were investigated. Boxe Behnken design was used to minimize the number of experiments to be performed. The weld joint was analyzed for its mechanical strength. The highest tensile strength between Tie6Ale4 V and SS304 L between which pure copper was used as insert metal was acquired. Micro-structural analysis and elemental analysis were carried out by EDS, and the formation of intermetallic compound at the interface was identified by XRD analysis.
基金Project(1343-74236000005) supported by the Innovation Foundation for Postgraduates of Hunan Province, ChinaProject(ZKJ2008001) supported by the Open Fund for Valuable Instruments of Central South University, ChinaProject(2008112048) supported by the Open Fund of State Key Laboratory of Metallurgy, China
文摘Diamond films were deposited on high-speed steel substrates by hot filament chemical vapor deposition （HFCVD） method. To minimize the early formation of graphite and to enhance the diamond film adhesion, a WC-Co coating was used as an interlayer on the steel substrates by high velocity oxy-fuel spraying. The effects of methane content on nucleation, quality, residual stress and adhesion of diamond films were investigated. The results indicate that the increasing methane content leads to the increase in nucleation density, residual stress, the degradation of quality and adhesion of diamond films. Diamond films deposited on high-speed steel （HSS） substrate with a WC-Co interlayer exhibit high nucleation density and good adhesion under the condition of the methane content initially set to be a higher value （4%, volume fraction） for 30 min, and then reduced to 2% for subsequent growth at pressure of 3 kPa and substrate temperature of 800 ℃.
基金Project(41672258) supported by the National Natural Science Foundation of ChinaProject(2018045) supported by the Land and Resources Science&Technology Project of Jiangsu Province,China。
文摘The landslide disaster caused by the argillaceous interlayer not only destroys buildings,cultivated land,and roads but also seriously endangers human life and safety.This study concerns the mineral composition of selected argillaceous interlayer and their strength characteristics.To study the mineral composition of argillaceous interlayers,8 kinds of samples in the southern Jiangsu region of China were analyzed utilizing X-ray diffraction(XRD).The repeated direct shear strength tests(RDST)were carried out on the undisturbed specimens of the argillaceous interlayer.The results show that the argillaceous interlayer with high content of kaolinite shows ductile failure mode,which means that there is no obvious residual strength in the shear process.The arrangement of mineral particles on the shear surface of the specimens after different shear displacements was observed under the scanning electron microscope(SEM).It was observed that mineral particles on the shear surface showed a more directional arrangement with the increase of shear displacement.Furthermore,the influence of shear direction on the argillaceous interlayer with completely oriented mineral particles was studied through numerical experiments with four shear strength mechanisms proposition proposed.The influence of the mineral arrangement on the action occasion and magnitude of dilatancy component of shear strength is clarified in the shear mechanism.
基金Project(2013CB035700) supported by the National Basic Research Program of ChinaProjects(11272259,11321062,11002104) supported by the National Natural Science Foundation of China
文摘Multiple surface cracks and interfacial delamination are the major failure mechanisms in film/substrate systems.The effect of interlayer upon the failure mechanisms of interfacial delamination concomitant to surface crack was explored.Finite element model was developed to obtain the stress and energy release rate(ERR),which governs the propagation of interface cracks.The dependences of delamination upon the geometry and constitutive properties of interlayer were examined.The results indicate that the effect of elastic modulus of interlayer on the steady state ERR is insignificant.In cases of different geometrical parameters,however,the steady ERR decreases with the increase of the interlayer thickness.These findings lead to the conclusion that the interlayer constraint has significant effect on the ERR and thus coating life,which can be adopted to modify the ceramic top coat.
文摘The interlayer clay-organic complex is an important clay-organic association in sedimentary environments. The interlayer region of clay minerals not only provides storage space for organic matter, but also possesses solid acid sites; and these acid sites were proposed to be involved with the transformation of organic matter into liquid and gaseous hydrocarbons. However, the effect of the organic matter storage in the interlayer space of clay minerals on the hydrocarbons generation has not been made clear. In this study, the interlayer complex of 12-aminolauric acid (ALA) and Na+-montmorillonite (Na+-Mt), labeled as ALAinter-Mt (Na), was synthesized to investigate the role of the interlayer space of montmorillonite in hydrocarbon generation. Simply mixed ALA-Mt complex [ALA-Mt (Na)] was also prepared for comparison. The pyrolysis of ALA and ALA-Mt complexes was studied using thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR) and a high temperature-pressure system (a confined gold capsule-autoclave system).
基金Project(2002CB412704) supported by the Major State Basic Research Development Program of China
文摘In order to analyze mechanism of casing damage,the uniaxial compression experiment and creep experiment of interbedded mudstone samples from Sanan development area of Daqing Oilfield under different water contents were carried out.The changes of the mudstone's mechanical parameters and creep characteristics with the increment of water saturation were studied.The results indicate that the rock strength and elastic modulus decrease rapidly with the increment of water content,at the same time,the creep strain and creep strain rate of steady state increase with the increment of water content,and also the steady state creep strain rate is enhanced with the increment of deviatoric stress.Through the creep characteristic curves,a non-linear creep constitutive equation of mudstone considering the change of water contents is established,which will be used in future numerical analysis.
基金Project(21271188) supported by the National Natural Science Foundation of China
文摘A Ti interlayer with thickness about 300 nm was sputtered on Cu microchannels, followed by an ultrasonic seeding with nanodiamond powders. Adherent diamond film with crystalline grains close to thermal equilibrium shape was tightly deposited by hot-filament chemical vapor deposition(HF-CVD). The nucleation and growth of diamond were investigated with micro-Raman spectroscope and field emission scanning electron microscope(FE-SEM) with energy dispersive X-ray detector(EDX). Results show that the nucleation density is found to be up to 1010 cm-2. The enhancement of the nucleation kinetics can be attributed to the nanometer rough Ti interlayer surface. An improved absorption of nanodiamond particles is found, which act as starting points for the diamond nucleation during HF-CVD process. Furthermore, finite element simulation was conducted to understand the thermal management properties of prepared diamond/Cu microchannel heat sink.
文摘Shale gas, which is derived from organic matters in shale and stored in shale deposits, is an important unconventional gas resource and attracts attention due to its significant requirement in the hydrocarbon production. Methane (CH4) is the dominant component of shale gas, and adsorbed gas is an important reservoir form. Many studies have investigated the adsorption capacities and adsorption mechanisms of CH4 in shale. Organic matters and clay minerals have been proposed to be the two major components for CH4 adsorption. Adsorption of CH4 in organic matters, such as the adsorption capacity and effects of characteristics of the organic matters, has been well investigated. However, studies on CH4 adsorption on clay minerals have mainly focused on evaluating the adsorption capacity, and very little information about the adsorption mechanism has been provided. For example, the adsorption sites and factors influencing CH4 adsorption on clay minerals remain unclear. Three main reasons account for this: (1) the co-existence of organic matters in samples affects the evaluation of CH4 adsorption on clay minerals; (2) the pressures used during adsorption are not representative of actual reservoir pressures; and (3) the clay minerals selected have low swelling capacity and a smaller interlayer distances than a CH4 size, resulting in the misunderstanding of the CH4 adsorption sites.
基金Project(51508562)supported by the National Natural Science Foundation of ChinaProject(ZK18-03-49)supported by the Scientific Research Program of National University of Defense Technology,China
文摘Flexural and eigen-buckling analyses for rectangular steel-concrete partially composite plates(PCPs)with interlayer slip under simply supported and clamped boundary conditions are conducted using the weak form quadrature element method(QEM).Both of the derivatives and integrals in the variational description of a problem to be solved are directly evaluated by the aid of identical numerical interpolation points in the weak form QEM.The effectiveness of the presented numerical model is validated by comparing numerical results of the weak form QEM with those from FEM or analytic solution.It can be observed that only one quadrature element is fully competent for flexural and eigen-buckling analysis of a rectangular partially composite plate with shear connection stiffness commonly used.The numerical integration order of quadrature element can be adjusted neatly to meet the convergence requirement.The quadrature element model presented here is an effective and promising tool for further analysis of steel-concrete PCPs under more general circumstances.Parametric studies on the shear connection stiffness and length-width ratio of the plate are also presented.It is shown that the flexural deflections and the critical buckling loads of PCPs are significantly affected by the shear connection stiffness when its value is within a certain range.
