Porous materials can be found in a variety of geophysical and engineering applications.The existence of thermal contact resistance at the interface between bilayered saturated porous strata would result in a significa...Porous materials can be found in a variety of geophysical and engineering applications.The existence of thermal contact resistance at the interface between bilayered saturated porous strata would result in a significant temperature difference at the interface.An attempt is made to study the thermo-hydro-mechanical coupling dynamic response of bilayered saturated porous strata with thermal contact resistance and elastic wave impedance.The corresponding analytical solutions for the dynamic response of bilayered saturated porous strata under a harmonic thermal load are derived by the operator decomposition method,and their rationality is verified by comparing them with existing solutions.The influences of thermal contact resistance,thermal conductivity ratio,and porosity ratio on the dynamic response of bilayered saturated porous strata are systematically investigated.Outcomes disclose that with the increase of thermal contact resistance,the displacement,pore water pressure and stress decrease gradually,and the temperature jump at the interface between two saturated porous strata increases.展开更多
Considering the thermal contact resistance and elastic wave impedance at the interface,in this paper we theoretically investigate the thermo-hydro-mechanical(THM)coupling dynamic response of bilayered saturated porous...Considering the thermal contact resistance and elastic wave impedance at the interface,in this paper we theoretically investigate the thermo-hydro-mechanical(THM)coupling dynamic response of bilayered saturated porous media.Fractional thermoelastic theory is applied to porous media with imperfect thermal and mechanical contact.The analytical solutions of the dynamic response of the bilayered saturated porous media are obtained in frequency domain.Furthermore,the effects of fractional derivative parameters and thermal contact resistance on the dynamic response of such media are systematically discussed.Results show that the effects of fractional derivative parameters on the dynamic response of bilayered saturated porous media are related to the thermal contact resistance at the interface.With increasing thermal contact resistance,the displacement,pore water pressure,and stress decrease gradually.展开更多
The fabrication of osteochondral tissue engineering scaffolds comprised of different layers is a big challenge. Herein, bilayers comprised of double network hydrogels with or without nano hydroxyapatite （HAp） were d...The fabrication of osteochondral tissue engineering scaffolds comprised of different layers is a big challenge. Herein, bilayers comprised of double network hydrogels with or without nano hydroxyapatite （HAp） were developed by exploiting the radical reaction of poly（ethylene glycol） diacrylate （PEGDA） and the Schiff-base reaction of N-carboxyethyl chitosan （CEC） and oxidized hyaluronic acid sodium （OHA） for osteochondral tissue engineering. The bilayered osteochondral scaffold was successfully fabricated based on the superior self-healing property of both hydrogels and evaluated by scanning electron microscopy, macroscopic observation and mechanical measurements. In addition, the hydrogels exhibited good biocompatibility as demonstrated by the in vitro cytotoxicity and in vivo implantation tests. The results indicated that the bilayered hydrogel had great potential for application in osteochondral tissue engineering.展开更多
Current--voltage measurements obtained from lead zirconate titanate/nickel bilayered hollow cylindrical magnetoelectric composite showed that a sinusoidal current applied to the copper coil wrapped around the hollow c...Current--voltage measurements obtained from lead zirconate titanate/nickel bilayered hollow cylindrical magnetoelectric composite showed that a sinusoidal current applied to the copper coil wrapped around the hollow cylinder circumference induces voltage across the lead zirconate titanate layer thickness. The current--voltage coefficient and the maximum induced voltage in lead zirconate titanate at 1~kHz and resonance （60.1~kHz） frequencies increased linearly with the number of the coil turns and the applied current. The resonance frequency corresponds to the electromechanical resonance frequency. The current--voltage coefficient can be significantly improved by optimizing the magnetoelectric structure geometry and/or increasing the number of coil turns. Hollow cylindrical lead zirconate titanate/nickel structures can be potentially used as current sensors.展开更多
Glass-ceramics are often used as sealants in solid oxide fuel cells (SOFC). But interfacing components, such as ferritic stainless steel and YSZ electrolyte, may vary in their requirements regarding sealing properties...Glass-ceramics are often used as sealants in solid oxide fuel cells (SOFC). But interfacing components, such as ferritic stainless steel and YSZ electrolyte, may vary in their requirements regarding sealing properties, especially in terms of thermal expansion. A bilayered glass-ceramic system was developed to overcome the mismatch in coefficients of thermal expansion (CTE) between ferritic steel and YSZ. Therefore, two different glass-ceramics with slightly different CTEs were developed, one with good bonding characteristics to the ferritic steel and the other to the YSZ electrolyte. Steel and electrolyte components were coated with a layer of their corresponding glass sealant paste and heated up to form a sandwich sample. During the heat treatment of the sealing process, the glasses are crystallized into glass-ceramics. The resulting interface between the two glass-ceramics is of special interest. Cross-sections of the sandwich samples were cut, polished and investigated using SEM. The glass-ceramics show continuous, gap-free layers and excellent bonding to both steel and YSZ. Energy release rates are measured for single and bilayered glass sealants by mechanical testing. The designed bilayered glass-ceramics fulfill the special requirements of ferritic steel and YSZ. They show excellent potential to become a new outstanding sealant for SOFCs.展开更多
We have investigated the structural and electronic characteristics of hydrogenated boron-nitride bilayer（H–BNBN–H） using first-principles calculations. The results show that hydrogenation can significantly reduce ...We have investigated the structural and electronic characteristics of hydrogenated boron-nitride bilayer（H–BNBN–H） using first-principles calculations. The results show that hydrogenation can significantly reduce the energy gap of the BN–BN into the visible-light region. Interestingly, the electric field induced by the interface dipoles helps to promote the formation of well-separated electron–hole pairs, as demonstrated by the charge distribution of the VBM and CBM.Moreover, the applied bias voltage on the vertical direction of the bilayer could modulate the band gap, resulting in transition from semiconductor to metal. We conclude that H–BNBN–H could improve the solar energy conversion efficiency, which may provide a new way for tuning the electronic devices to meet different environments and demands.展开更多
X-ray detectors which convert X-ray irradiation into electrical signals play an important role in diverse applications including medical diagnosis,security examination,nondestructive inspection,personal X-ray dosimete...X-ray detectors which convert X-ray irradiation into electrical signals play an important role in diverse applications including medical diagnosis,security examination,nondestructive inspection,personal X-ray dosimeters and fundamental research[1–5].Recently,metal halide perovskites(MHP)have been developed as a promising family for X-ray detection contributing to their intrinsic advantages,e.g.,simple synthesis,efficient X-ray absorption and excellent semiconducting properties[5–10].展开更多
Poly(lactide-co-glycolide)-bilayered scaffolds with the same porosity or different ones on the two layers were fabricated,and the porosity effect on in vivo repairing of the osteochondral defect was examined in a comp...Poly(lactide-co-glycolide)-bilayered scaffolds with the same porosity or different ones on the two layers were fabricated,and the porosity effect on in vivo repairing of the osteochondral defect was examined in a comparative way for the first time.The constructs of scaffolds and bone marrow-derived mesenchymal stem cells were implanted into pre-created osteochondral defects in the femoral condyle of New Zealand white rabbits.After 12 weeks,all experimental groups exhibited good cartilage repairing according to macroscopic appearance,cross-section view,haematoxylin and eosin staining,toluidine blue staining,immunohistochemical staining and real-time polymerase chain reaction of characteristic genes.The group of 92%porosity in the cartilage layer and 77%porosity in the bone layer resulted in the best efficacy,which was understood by more biomechanical mimicking of the natural cartilage and subchondral bone.This study illustrates unambiguously that cartilage tissue engineering allows for a wide range of scaffold porosity,yet some porosity group is optimal.It is also revealed that the biomechanical matching with the natural composite tissue should be taken into consideration in the design of practical biomaterials,which is especially important for porosities of a multi-compartment scaffold concerning connected tissues.展开更多
Sr2Bi4Ti5O18(SBTi) single layered and Sr2Bi4Ti5O18 /Pb(Zr0.53Ti0.47)O3(SBTi/PZT) bilayered thin films have been prepared on Pt/TiO2/SiO2/Si substrates by pulsed-laser deposition(PLD).The related structural characteriz...Sr2Bi4Ti5O18(SBTi) single layered and Sr2Bi4Ti5O18 /Pb(Zr0.53Ti0.47)O3(SBTi/PZT) bilayered thin films have been prepared on Pt/TiO2/SiO2/Si substrates by pulsed-laser deposition(PLD).The related structural characterizations and electrical properties have been comparatively investigated.X-ray diffraction reveals that both films have crystallized into perovskite phases and scanning electron microscopy shows the sharp interfaces.Both films show well-saturated ferroelectric hysteresis loops,however,compared with the single layered SBTi films,the SBTi/PZT bilayered films have significantly increased remnant polarization(Pr) and decreased coercive field(Ec),with the applied field of 260 kV/cm.The measured Pr and Ec of SBTi and SBTi/PZT films were 7.9 C/cm 2,88.1 kV/cm and 13.0 C/cm 2,51.2 kV/cm,respectively.In addition,both films showed good fatigue-free characteristics,the switchable polarization decreased by 9% and 11% of the initial values after 2.2 10 9 switching cycles for the SBTi single layered films and the SBTi/PZT bilayered films,respectively.Our results may provide some guidelines for further optimization of multilayered ferroelectric thin films.展开更多
Based on the Smit-Suhl formula,we propose a universal approach for solving the magnon-magnon coupling problem in bilayer coupled systems(e.g.,antiferromagnets).This method requires only the energy expression,enabling ...Based on the Smit-Suhl formula,we propose a universal approach for solving the magnon-magnon coupling problem in bilayer coupled systems(e.g.,antiferromagnets).This method requires only the energy expression,enabling the automatic derivation of analytical expressions for the eigenmatrix elements via symbolic computation,eliminating the need for tedious manual calculations.Using this approach,we investigate the impact of magnetic hysteresis on magnon-magnon coupling in a system with interlayer Dzyaloshinskii-Moriya interaction(DMI).The magnetic hysteresis leads to an asymmetric magnetic field dependence of the resonance frequency and alters the number of degeneracy points between the pure optical and acoustic modes.Moreover,it can result in the coupling strength at the gap of the f–H phase diagram being nearly vanishing,contrary to the conventionally expected maximum.These results deepen the understanding of the effect of interlayer DMI on magnon–magnon coupling and the proposed universal method significantly streamlines the solving process of magnon–magnon coupling problems.展开更多
This research demonstrates a novel one-step electrochemical method to fabricate thick bilayer coatings on magnesium alloy in acid phosphate electrolyte containing aniline monomer and styrene-acrylic emulsion （SAE） w...This research demonstrates a novel one-step electrochemical method to fabricate thick bilayer coatings on magnesium alloy in acid phosphate electrolyte containing aniline monomer and styrene-acrylic emulsion （SAE） with pulsed DC voltage, The morphologies, XRD and FTIR results show that the bilayer coating consists of an inner oxide layer and an outer polyaniline （PANI）/SAE composite layer, It is believed that the bilayered structure achieved results from a hybrid process combining electropoly-merization （EPM） of aniiine, electrophoretic deposition （EPD） of SAE and plasma electrolyte oxidation （PEO） of magnesium alloy substrate. Electrochemical corrosion tests indicate that the bilayer coating can provide superior corrosion protection to the magnesium alloy substrate in 3.5 wt.% NaCl solution.展开更多
For better performance of dye sensitized solar cells （DSSCs）, a bilayer structured electrode was constructed by employing a mesoporous anatase TiO2 overlayer above a commercial P25 TiO2 nanoparticles underlayer. The...For better performance of dye sensitized solar cells （DSSCs）, a bilayer structured electrode was constructed by employing a mesoporous anatase TiO2 overlayer above a commercial P25 TiO2 nanoparticles underlayer. The mesoporous anatase TiO2, prepared through a facile surfactant-assisted sol-gel process, possessed large pore size and well inter-connected network structure, both beneficial for dye adsorption and electron transfer. The dye adsorption capability of the mesoporous TiO2 was nearly twice that of the P25 counterpart. In the electrode, the mesoporous TiO2 film enhanced both dye adsorption and lightharvest, to increase photocurrent （Jsc） from 12.32 to 14.78 mA/cm^2. Compared to the single P25 TiO2 film, the synergy of the mesoporous TiO2 and the P25 TiO2 nanoparticle films in the electrode resulted in a 24% improvement in light-to-electricity conversion efficiency （η）. This bilayered electrode provides an alternative approach for further developing a photovoltaic device with better cell performance.展开更多
This article examines the influence of annealing temperature on fracture toughness and forming limit curves of dissimilar aluminum/silver sheets.In the cold roll bonding process,after brushing and acid washing,the pre...This article examines the influence of annealing temperature on fracture toughness and forming limit curves of dissimilar aluminum/silver sheets.In the cold roll bonding process,after brushing and acid washing,the prepared surfaces are placed on top of each other and by rolling with reduction more than 50%,the bonding between layers is established.In this research,the roll bonding process was done at room temperature,without the use of lubricants and with a 70%thickness reduction.Then,the final thickness of the Ag/Al bilayer sheet reached 350μm by several stages of cold rolling.Before cold rolling,it should be noted that to decrease the hardness created due to plastic deformation,the roll-bonded samples were subjected to annealing heat treatment at 400℃for 90 min.Thus,the final samples were annealed at 200,300 and 400℃for 90 min and cooled in a furnace to examine the annealing temperature effects.The uniaxial tensile and microhardness tests measured mechanical properties.Also,to investigate the fracture mechanism,the fractography of the cross-section was examined by scanning electron microscope(SEM).To evaluate the formability of Ag/Al bilayer sheets,forming limit curves were obtained experimentally through the Nakazima test.The resistance of composites to failure due to cracking was also investigated by fracture toughness.The results showed that annealing increases the elongation and formability of the Ag/Al bilayer sheet while reduces the ultimate tensile strength and fracture toughness.However,the changing trend is not the same at different temperatures,and according to the results,the most significant effect is obtained at 300℃and aluminum layers.It was also determined that by increasing annealing temperature,the fracture mechanism from shear ductile with small and shallow dimples becomes ductile with deep cavities.展开更多
Sugars are widely recognized for their ability to stabilize cell membranes during dehydration.However,the precise mechanisms by which sugars interact with lipid bilayers remain unclear.This mini-review synthesizes fou...Sugars are widely recognized for their ability to stabilize cell membranes during dehydration.However,the precise mechanisms by which sugars interact with lipid bilayers remain unclear.This mini-review synthesizes four key hypotheses explaining sugar-mediated protection of dehydrated bilayers:the Water Replacement Hypothesis(WRH),Hydration Force Hypothesis(HFH),Headgroup Bridging Hypothesis(HBH),and Vitrification Hypothesis(VH).We argue that these mechanisms are not mutually exclusive but instead operate synergistically under different cellular contexts.We propose that these hypotheses are not mutually exclusive but likely operate under different cellular contexts.Future studies should prioritize the development of biologically realistic membrane models-incorporating diverse lipids,proteins,and asymmetric leaflets-to elucidate the exact roles and mechanisms of sugars in membrane stabilization.Such advancements will enhance our understanding of anhydrobiosis and inform cryopreservation strategies for mammalian cells.展开更多
Osteochondral defects pose an enormous challenge,and no satisfactory therapy is available to date due to the hierarchy of the native tissue consisting of articular cartilage and subchondral bone.Constructing a scaffol...Osteochondral defects pose an enormous challenge,and no satisfactory therapy is available to date due to the hierarchy of the native tissue consisting of articular cartilage and subchondral bone.Constructing a scaffold with biological function and biomimetic structure is the key to achieving a high-quality repair effect.Herein,a natural polymer-based bilayer scaffold with a porous architecture similar to that of osteochondral tissue is designed,involving the transforming growth factor-beta3-liposome-loaded upper layer for superficial cartilage regeneration and the nanohydroxyapatite-coated lower layer for subchondral bone rehabilitation.This research is conducted to evaluate the effects of nanoparticle-modified bilayer scaffold to mimic the hierarchical pro-chondrogenic and proosteogenic microenvironment for the recruited endogenous bone marrow mesenchymal stem cells.The fabricated composites were evaluated for mechanical,physicochemical,biological properties,in vitro and in vivo tissue regeneration potential.Overall,the current bilayer scaffold could regenerate a cartilage-bone integrated tissue with a seamless interfacial integration and exhibited superior tissue repair outcomes compared to other single layer scaffolds based on morphological,radiological and histological evaluation,verifying that this novel graft could be an effective approach to tissue-engineered analogs of cartilage-subchondral bone and offer new therapeutic opportunities for osteochondral defect-associated diseases.展开更多
The current work addresses the challenge of elucidating the performance of fluoroelastomers within the HMX(octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine)based polymer-bonded explosives(PBXs).To simulate the confine...The current work addresses the challenge of elucidating the performance of fluoroelastomers within the HMX(octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine)based polymer-bonded explosives(PBXs).To simulate the confined interface in PBXs,bilayer films of F2314/HMX and F2311/HMX were designed.Neutron reflectivity(NR),nanoindentation,and X-ray reflectivity(XRR)were employed to examine the layer thickness,interface characteristics,diffusion behavior,and surface morphology of the bilayers.NR measurements revealed interface thicknesses of 45Å and 98Å for F2314/HMX and F2311/HMX,respectively,indicating deeper penetration of F2311 into the HMX matrix.NR also suggested a denser polymer network with a higher scattering length density(SLD)near the HMX interface for both fluoroelastomers,while the bound layer of F2311 was notably thicker.Nanoindentation cross-checks and confirms the presence of a bound layer,highlighting the differences in stiffness and diffusion ability between the two polymers.The consistency between the NR and nanoindentation results suggests that F2311 demonstrates better flexibility and elasticity,whereas F2314 is stiffer and more plastic.Accordingly,the structures and performances of different fluoroelastomers at the HMX interface are discussed,which can provide valuable insights into the selection of binders for PBX formulations tailored to specific applications.展开更多
This study demonstrates the successful fabrication of solid-state bilayers using LiFePO_(4)(LFP)cathodes and Li_(1.3)Al_(0.3)Ti_(1.7)(PO_(4))_(3)(LATP)-based Composite Solid Electrolytes(CSEs)via Cold Sintering Proces...This study demonstrates the successful fabrication of solid-state bilayers using LiFePO_(4)(LFP)cathodes and Li_(1.3)Al_(0.3)Ti_(1.7)(PO_(4))_(3)(LATP)-based Composite Solid Electrolytes(CSEs)via Cold Sintering Process(CSP).By optimizing the sintering pressure,it is achieved an intimate contact between the cathode and the solid electrolyte,leading to an enhanced electrochemical performance.Bilayers cold sintered at 300 MPa and a low-sintering temperature of 150℃exhibit high ionic conductivities(0.5 mS cm^(-1))and stable specific capacities at room temperature(160.1 mAh g^(-1)LFP at C/10 and 75.8 mAh g^(-1)_(LFP)at 1 C).Moreover,an operando electrochemical impedance spectroscopy(EIS)technique is employed to identify limiting factors of the bilayer kinetics and to anticipate the overall electrochemical behavior.Results suggest that capacity fading can occur in samples prepared with high sintering pressures due to a volume reduction in the LFP crystalline cell.This work demonstrates the potential of CSP to produce straightforward high-performance bilayers and introduces a valuable non-destructive instrument for understanding and avoiding degradation in solid-state lithium-based batteries.展开更多
The semiconductor gas sensors used for xylene gas detection in real time has been restricted by the inadequate sensitivity and selectivity.Constructing a bilayer cascade sensor with the catalysis-gas sensitivity syner...The semiconductor gas sensors used for xylene gas detection in real time has been restricted by the inadequate sensitivity and selectivity.Constructing a bilayer cascade sensor with the catalysis-gas sensitivity synergistic is considered as an effective solution.Herein,the Ag@CeO_(2)nanosheets are synthesized by heat treating the Ag@Ce-MOF,which synthesized via solvothermal method.The morphological evolution of cerium metalorganic framework(Ce-MOF),regulated by Ag ions,is investigated,and the transformation mechanism is proposed.The bilayer sensors were constructed by using WO_(3)nanofibers,prepared via the electrospinning method,as the sensitive layer and the Ag@CeO_(2)nanosheets as the catalytic layer,respectively.The bilayer sensors exhibit remarkable performance in response to xylene.The response value(R_(a)/R_(g))of WO_(3)/Ag@CeO_(2)sensor to10 ppm xylene gas reaches 32.13 at the operating temperature of 160℃.Additionally,the sensor displays an exceptional response to even trace amounts of xylene,as low as parts per billion(ppb).The catalysis-gas sensitivity synergistic mechanism was elucidated by capturing catalytic intermediates using online mass spectrometry.These findings provide a novel strategy for benzene series(BTEX)sensor and offer a novel approach to prepare twodimensional Ce-MOF and its derived materials with tailored properties.展开更多
We investigate the energy bands,magnetism,and superconductivity of bilayer octagraphene with A-A stackingunder a perpendicular electric field.A tight-binding model is used to analyze the band structure of the system.T...We investigate the energy bands,magnetism,and superconductivity of bilayer octagraphene with A-A stackingunder a perpendicular electric field.A tight-binding model is used to analyze the band structure of the system.The doubling of the unit cell results in each band of the single layer splitting into two.We find that applyinga perpendicular electric field increases the band splitting.As the electric field strength increases,the nestingof the Fermi surface(FS)weakens,eventually disrupting the antiferromagnetic order,and bilayer octagrapheneexhibits superconductivity.Spin fluctuations can induce unconventional superconductivity with s±-wave pairing.Applying a perpendicular electric field to bilayer octagraphene parent weakens the nesting of the FS,ultimatelykilling the spin-density-wave(SDW)ordered state and transitioning it into the superconducting state,whichworks as a doping effect.We use the random-phase approximation approach to obtain the pairing eigenvaluesand pairing symmetries of the perpendicular electric field-tuned bilayer octagraphene in the weak coupling limit.By tuning the strength of the perpendicular electric field,the critical interaction strength for SDW order can bemodified,which in turn may promote the emergence of unconventional superconductivity.展开更多
基金Projects(52108347,52178371)supported by the National Natural Science Foundation of ChinaProject(LQ22E080010)supported by the Exploring Youth Project of Zhejiang Natural Science Foundation,China。
文摘Porous materials can be found in a variety of geophysical and engineering applications.The existence of thermal contact resistance at the interface between bilayered saturated porous strata would result in a significant temperature difference at the interface.An attempt is made to study the thermo-hydro-mechanical coupling dynamic response of bilayered saturated porous strata with thermal contact resistance and elastic wave impedance.The corresponding analytical solutions for the dynamic response of bilayered saturated porous strata under a harmonic thermal load are derived by the operator decomposition method,and their rationality is verified by comparing them with existing solutions.The influences of thermal contact resistance,thermal conductivity ratio,and porosity ratio on the dynamic response of bilayered saturated porous strata are systematically investigated.Outcomes disclose that with the increase of thermal contact resistance,the displacement,pore water pressure and stress decrease gradually,and the temperature jump at the interface between two saturated porous strata increases.
基金Project supported by the National Natural Science Foundation of China(Nos.52108347 and 51779217)the Primary Research and Development Plan of Zhejiang Province(Nos.2019C03120 and 2020C01147),China。
文摘Considering the thermal contact resistance and elastic wave impedance at the interface,in this paper we theoretically investigate the thermo-hydro-mechanical(THM)coupling dynamic response of bilayered saturated porous media.Fractional thermoelastic theory is applied to porous media with imperfect thermal and mechanical contact.The analytical solutions of the dynamic response of the bilayered saturated porous media are obtained in frequency domain.Furthermore,the effects of fractional derivative parameters and thermal contact resistance on the dynamic response of such media are systematically discussed.Results show that the effects of fractional derivative parameters on the dynamic response of bilayered saturated porous media are related to the thermal contact resistance at the interface.With increasing thermal contact resistance,the displacement,pore water pressure,and stress decrease gradually.
基金financially supported by the National Natural Science Foundation of China(Grant No.21574045,51372085)the Guangzhou Science and Technology Program(Grant No.201508010060)the Fundamental Research Funds for the Central Universities
文摘The fabrication of osteochondral tissue engineering scaffolds comprised of different layers is a big challenge. Herein, bilayers comprised of double network hydrogels with or without nano hydroxyapatite （HAp） were developed by exploiting the radical reaction of poly（ethylene glycol） diacrylate （PEGDA） and the Schiff-base reaction of N-carboxyethyl chitosan （CEC） and oxidized hyaluronic acid sodium （OHA） for osteochondral tissue engineering. The bilayered osteochondral scaffold was successfully fabricated based on the superior self-healing property of both hydrogels and evaluated by scanning electron microscopy, macroscopic observation and mechanical measurements. In addition, the hydrogels exhibited good biocompatibility as demonstrated by the in vitro cytotoxicity and in vivo implantation tests. The results indicated that the bilayered hydrogel had great potential for application in osteochondral tissue engineering.
基金supported by the National Natural Science Foundation of China (Grant Nos. 50572006, 50802008 and 50874010)the Natural Science Foundation of Beijing, China (Grant No. 2073026)+2 种基金the Program for New Century Excellent Talents in University(Grant No. 20060420152)Scholars and Innovative Research Team in University (Grant No. 0509)Alex A. Volinsky wouldlike to acknowledge support from NSF (Grant No. CMMI-0600266)
文摘Current--voltage measurements obtained from lead zirconate titanate/nickel bilayered hollow cylindrical magnetoelectric composite showed that a sinusoidal current applied to the copper coil wrapped around the hollow cylinder circumference induces voltage across the lead zirconate titanate layer thickness. The current--voltage coefficient and the maximum induced voltage in lead zirconate titanate at 1~kHz and resonance （60.1~kHz） frequencies increased linearly with the number of the coil turns and the applied current. The resonance frequency corresponds to the electromechanical resonance frequency. The current--voltage coefficient can be significantly improved by optimizing the magnetoelectric structure geometry and/or increasing the number of coil turns. Hollow cylindrical lead zirconate titanate/nickel structures can be potentially used as current sensors.
文摘Glass-ceramics are often used as sealants in solid oxide fuel cells (SOFC). But interfacing components, such as ferritic stainless steel and YSZ electrolyte, may vary in their requirements regarding sealing properties, especially in terms of thermal expansion. A bilayered glass-ceramic system was developed to overcome the mismatch in coefficients of thermal expansion (CTE) between ferritic steel and YSZ. Therefore, two different glass-ceramics with slightly different CTEs were developed, one with good bonding characteristics to the ferritic steel and the other to the YSZ electrolyte. Steel and electrolyte components were coated with a layer of their corresponding glass sealant paste and heated up to form a sandwich sample. During the heat treatment of the sealing process, the glasses are crystallized into glass-ceramics. The resulting interface between the two glass-ceramics is of special interest. Cross-sections of the sandwich samples were cut, polished and investigated using SEM. The glass-ceramics show continuous, gap-free layers and excellent bonding to both steel and YSZ. Energy release rates are measured for single and bilayered glass sealants by mechanical testing. The designed bilayered glass-ceramics fulfill the special requirements of ferritic steel and YSZ. They show excellent potential to become a new outstanding sealant for SOFCs.
基金Project supported by the National Natural Science Foundation of China(Grant No.11574167)
文摘We have investigated the structural and electronic characteristics of hydrogenated boron-nitride bilayer（H–BNBN–H） using first-principles calculations. The results show that hydrogenation can significantly reduce the energy gap of the BN–BN into the visible-light region. Interestingly, the electric field induced by the interface dipoles helps to promote the formation of well-separated electron–hole pairs, as demonstrated by the charge distribution of the VBM and CBM.Moreover, the applied bias voltage on the vertical direction of the bilayer could modulate the band gap, resulting in transition from semiconductor to metal. We conclude that H–BNBN–H could improve the solar energy conversion efficiency, which may provide a new way for tuning the electronic devices to meet different environments and demands.
基金supported by the National Natural Science Foundation of China(22435005,22193042,21921001,22125110,22122507,22201284,22305105,U21A2069)the Natural Science Foundation of Jiangxi Province(20224BAB213003,2024BAB25129)the Jiangxi Provincial Education Department Science and Technology Research Foundation(GJJ2200384).
文摘X-ray detectors which convert X-ray irradiation into electrical signals play an important role in diverse applications including medical diagnosis,security examination,nondestructive inspection,personal X-ray dosimeters and fundamental research[1–5].Recently,metal halide perovskites(MHP)have been developed as a promising family for X-ray detection contributing to their intrinsic advantages,e.g.,simple synthesis,efficient X-ray absorption and excellent semiconducting properties[5–10].
基金This work was supported by Chinese Ministry of Science and Technology(973 Programs No.2009CB930000 and No.2011CB606203)National Science Foundation of China(Grant No.21034002,31170925,and 51273046)+1 种基金Science and Technology Developing Foundation of Shanghai(Grant No.13XD1401000)Shanghai International Science and Technology Partnership Program(No.11540702700).
文摘Poly(lactide-co-glycolide)-bilayered scaffolds with the same porosity or different ones on the two layers were fabricated,and the porosity effect on in vivo repairing of the osteochondral defect was examined in a comparative way for the first time.The constructs of scaffolds and bone marrow-derived mesenchymal stem cells were implanted into pre-created osteochondral defects in the femoral condyle of New Zealand white rabbits.After 12 weeks,all experimental groups exhibited good cartilage repairing according to macroscopic appearance,cross-section view,haematoxylin and eosin staining,toluidine blue staining,immunohistochemical staining and real-time polymerase chain reaction of characteristic genes.The group of 92%porosity in the cartilage layer and 77%porosity in the bone layer resulted in the best efficacy,which was understood by more biomechanical mimicking of the natural cartilage and subchondral bone.This study illustrates unambiguously that cartilage tissue engineering allows for a wide range of scaffold porosity,yet some porosity group is optimal.It is also revealed that the biomechanical matching with the natural composite tissue should be taken into consideration in the design of practical biomaterials,which is especially important for porosities of a multi-compartment scaffold concerning connected tissues.
基金supported by the National Natural Science Foundation(Grant Nos. 50805076 and 51275237)the National Natural Science Key Corporation Foundations (Grant No. 61161120323)Science Research Foundation at NUAA (Grant No. NS2012014)
文摘Sr2Bi4Ti5O18(SBTi) single layered and Sr2Bi4Ti5O18 /Pb(Zr0.53Ti0.47)O3(SBTi/PZT) bilayered thin films have been prepared on Pt/TiO2/SiO2/Si substrates by pulsed-laser deposition(PLD).The related structural characterizations and electrical properties have been comparatively investigated.X-ray diffraction reveals that both films have crystallized into perovskite phases and scanning electron microscopy shows the sharp interfaces.Both films show well-saturated ferroelectric hysteresis loops,however,compared with the single layered SBTi films,the SBTi/PZT bilayered films have significantly increased remnant polarization(Pr) and decreased coercive field(Ec),with the applied field of 260 kV/cm.The measured Pr and Ec of SBTi and SBTi/PZT films were 7.9 C/cm 2,88.1 kV/cm and 13.0 C/cm 2,51.2 kV/cm,respectively.In addition,both films showed good fatigue-free characteristics,the switchable polarization decreased by 9% and 11% of the initial values after 2.2 10 9 switching cycles for the SBTi single layered films and the SBTi/PZT bilayered films,respectively.Our results may provide some guidelines for further optimization of multilayered ferroelectric thin films.
基金supported by the National Key Research and Development Program of China (MOST)(Grant No.2022YFA1402800)the Chinese Academy of Sciences (CAS) Presidents International Fellowship Initiative (PIFI)(Grant No.2025PG0006)+3 种基金the National Natural Science Foundation of China (NSFC)(Grant Nos.51831012,12274437,and 52161160334)the CAS Project for Young Scientists in Basic Research (Grant No.YSBR-084)the CAS Youth Interdisciplinary Teamthe China Postdoctoral Science Foundation (Grant No.2025M773402)。
文摘Based on the Smit-Suhl formula,we propose a universal approach for solving the magnon-magnon coupling problem in bilayer coupled systems(e.g.,antiferromagnets).This method requires only the energy expression,enabling the automatic derivation of analytical expressions for the eigenmatrix elements via symbolic computation,eliminating the need for tedious manual calculations.Using this approach,we investigate the impact of magnetic hysteresis on magnon-magnon coupling in a system with interlayer Dzyaloshinskii-Moriya interaction(DMI).The magnetic hysteresis leads to an asymmetric magnetic field dependence of the resonance frequency and alters the number of degeneracy points between the pure optical and acoustic modes.Moreover,it can result in the coupling strength at the gap of the f–H phase diagram being nearly vanishing,contrary to the conventionally expected maximum.These results deepen the understanding of the effect of interlayer DMI on magnon–magnon coupling and the proposed universal method significantly streamlines the solving process of magnon–magnon coupling problems.
文摘This research demonstrates a novel one-step electrochemical method to fabricate thick bilayer coatings on magnesium alloy in acid phosphate electrolyte containing aniline monomer and styrene-acrylic emulsion （SAE） with pulsed DC voltage, The morphologies, XRD and FTIR results show that the bilayer coating consists of an inner oxide layer and an outer polyaniline （PANI）/SAE composite layer, It is believed that the bilayered structure achieved results from a hybrid process combining electropoly-merization （EPM） of aniiine, electrophoretic deposition （EPD） of SAE and plasma electrolyte oxidation （PEO） of magnesium alloy substrate. Electrochemical corrosion tests indicate that the bilayer coating can provide superior corrosion protection to the magnesium alloy substrate in 3.5 wt.% NaCl solution.
基金supported by the National Natural Science Foundation of China (20925621)Shanghai Rising-Star Program (09QH1400700,09QA1401500)+4 种基金Special Projects for Key Laboratories in Shanghai (09DZ2202000,10DZ2211100)Special Projects for Nanotechnology of Shanghai (0952nm02100)Shanghai Pujiang Program (09PJ1403200)Basic Research Program of Shanghai (10JC1403300)Fundamental Research Funds for the Central Universities
文摘For better performance of dye sensitized solar cells （DSSCs）, a bilayer structured electrode was constructed by employing a mesoporous anatase TiO2 overlayer above a commercial P25 TiO2 nanoparticles underlayer. The mesoporous anatase TiO2, prepared through a facile surfactant-assisted sol-gel process, possessed large pore size and well inter-connected network structure, both beneficial for dye adsorption and electron transfer. The dye adsorption capability of the mesoporous TiO2 was nearly twice that of the P25 counterpart. In the electrode, the mesoporous TiO2 film enhanced both dye adsorption and lightharvest, to increase photocurrent （Jsc） from 12.32 to 14.78 mA/cm^2. Compared to the single P25 TiO2 film, the synergy of the mesoporous TiO2 and the P25 TiO2 nanoparticle films in the electrode resulted in a 24% improvement in light-to-electricity conversion efficiency （η）. This bilayered electrode provides an alternative approach for further developing a photovoltaic device with better cell performance.
基金This work was supported by the National Basic Research Program of China (No.2013CBA01603),the National Natural Science Foundation of China (No.61335006),and Chinese Academy of Sciences (Nos.1731300500015 and XDB07030100).
基金Project(4013311)supported by the National Science Foundation of Iran(INSF)。
文摘This article examines the influence of annealing temperature on fracture toughness and forming limit curves of dissimilar aluminum/silver sheets.In the cold roll bonding process,after brushing and acid washing,the prepared surfaces are placed on top of each other and by rolling with reduction more than 50%,the bonding between layers is established.In this research,the roll bonding process was done at room temperature,without the use of lubricants and with a 70%thickness reduction.Then,the final thickness of the Ag/Al bilayer sheet reached 350μm by several stages of cold rolling.Before cold rolling,it should be noted that to decrease the hardness created due to plastic deformation,the roll-bonded samples were subjected to annealing heat treatment at 400℃for 90 min.Thus,the final samples were annealed at 200,300 and 400℃for 90 min and cooled in a furnace to examine the annealing temperature effects.The uniaxial tensile and microhardness tests measured mechanical properties.Also,to investigate the fracture mechanism,the fractography of the cross-section was examined by scanning electron microscope(SEM).To evaluate the formability of Ag/Al bilayer sheets,forming limit curves were obtained experimentally through the Nakazima test.The resistance of composites to failure due to cracking was also investigated by fracture toughness.The results showed that annealing increases the elongation and formability of the Ag/Al bilayer sheet while reduces the ultimate tensile strength and fracture toughness.However,the changing trend is not the same at different temperatures,and according to the results,the most significant effect is obtained at 300℃and aluminum layers.It was also determined that by increasing annealing temperature,the fracture mechanism from shear ductile with small and shallow dimples becomes ductile with deep cavities.
基金supported by the National Natural Science Foundation of China,China(Grant No.52376052)the Anhui Provincial Natural Science Foundation,China(Grant No.2308085ME174).
文摘Sugars are widely recognized for their ability to stabilize cell membranes during dehydration.However,the precise mechanisms by which sugars interact with lipid bilayers remain unclear.This mini-review synthesizes four key hypotheses explaining sugar-mediated protection of dehydrated bilayers:the Water Replacement Hypothesis(WRH),Hydration Force Hypothesis(HFH),Headgroup Bridging Hypothesis(HBH),and Vitrification Hypothesis(VH).We argue that these mechanisms are not mutually exclusive but instead operate synergistically under different cellular contexts.We propose that these hypotheses are not mutually exclusive but likely operate under different cellular contexts.Future studies should prioritize the development of biologically realistic membrane models-incorporating diverse lipids,proteins,and asymmetric leaflets-to elucidate the exact roles and mechanisms of sugars in membrane stabilization.Such advancements will enhance our understanding of anhydrobiosis and inform cryopreservation strategies for mammalian cells.
基金supported by grants from the China Postdoctoral Science Foundation(Nos.2022TQ0397,2022MD723744,2022M710564,2022M720603)Natural Science Foundation of China(Nos.82272553,82102571,81974346,8210257,82472404)+8 种基金Chongqing Municipal Medical Youth Talent Support Program,Chongqing,China(No.YXQN202408)Natural Science Foundation of Chongqing,China(Nos.CSTB2022NSCQ-MSX0089,CSTB2022NSCQ-MSX0104,CSTB2024NSCQMSX0532)Joint Medical Research Project of Health Commission&Science and Technology Bureau of Chongqing,China(No.2024QNXM032)Special Project for the Central Government to Guide the Development of Local Science and Technology in Sichuan Province(No.2023ZYD0071)National Natural Science Foundation of Sichuan(No.24NSFSC1274)Project of Innovative Science Research for Postgraduate of Chongqing Municipal Education Committee,Chongqing,China(Nos.CYS22389,CYB240224)National Natural Science Foundation of Sichuan(No.2024NSFSC0678)Research Project of the Affiliated Hospital of North Sichuan Medical College(Nos.2023ZD002,2023-2ZD001,2024JB001)Disciplines Construction Program of The Third Affiliated Hospital of Chongqing Medical University(Nos.KY23035,KY23041).
文摘Osteochondral defects pose an enormous challenge,and no satisfactory therapy is available to date due to the hierarchy of the native tissue consisting of articular cartilage and subchondral bone.Constructing a scaffold with biological function and biomimetic structure is the key to achieving a high-quality repair effect.Herein,a natural polymer-based bilayer scaffold with a porous architecture similar to that of osteochondral tissue is designed,involving the transforming growth factor-beta3-liposome-loaded upper layer for superficial cartilage regeneration and the nanohydroxyapatite-coated lower layer for subchondral bone rehabilitation.This research is conducted to evaluate the effects of nanoparticle-modified bilayer scaffold to mimic the hierarchical pro-chondrogenic and proosteogenic microenvironment for the recruited endogenous bone marrow mesenchymal stem cells.The fabricated composites were evaluated for mechanical,physicochemical,biological properties,in vitro and in vivo tissue regeneration potential.Overall,the current bilayer scaffold could regenerate a cartilage-bone integrated tissue with a seamless interfacial integration and exhibited superior tissue repair outcomes compared to other single layer scaffolds based on morphological,radiological and histological evaluation,verifying that this novel graft could be an effective approach to tissue-engineered analogs of cartilage-subchondral bone and offer new therapeutic opportunities for osteochondral defect-associated diseases.
基金supported in part by the National Natural Science Foundation of China(Nos.12335018,12105264,and 12275248)NSAF Joint Fund Project(Nos.U2230107,U1730244,U2130207)+1 种基金Innovation and Development Fund of China Academy of Engineering Physics(No.CXKS20240052)Central Guidance for Local Science and Technology Development Fund Project(No.2023ZYDF075).
文摘The current work addresses the challenge of elucidating the performance of fluoroelastomers within the HMX(octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine)based polymer-bonded explosives(PBXs).To simulate the confined interface in PBXs,bilayer films of F2314/HMX and F2311/HMX were designed.Neutron reflectivity(NR),nanoindentation,and X-ray reflectivity(XRR)were employed to examine the layer thickness,interface characteristics,diffusion behavior,and surface morphology of the bilayers.NR measurements revealed interface thicknesses of 45Å and 98Å for F2314/HMX and F2311/HMX,respectively,indicating deeper penetration of F2311 into the HMX matrix.NR also suggested a denser polymer network with a higher scattering length density(SLD)near the HMX interface for both fluoroelastomers,while the bound layer of F2311 was notably thicker.Nanoindentation cross-checks and confirms the presence of a bound layer,highlighting the differences in stiffness and diffusion ability between the two polymers.The consistency between the NR and nanoindentation results suggests that F2311 demonstrates better flexibility and elasticity,whereas F2314 is stiffer and more plastic.Accordingly,the structures and performances of different fluoroelastomers at the HMX interface are discussed,which can provide valuable insights into the selection of binders for PBX formulations tailored to specific applications.
基金support from Generalitat Valenciana under Pla Complementari“Programa de Materials Avanc¸ats”,2022(grant number MFA/2022/030)Ministerio de Ciencia,Innovaci´on y Universidades(Spain)(grant number MCIN/AEI/10.13039/501100011033)+1 种基金support from UJI(UJI-2023-16 and GACUJIMC/2023/08)Generalitat Valenciana through FPI Fellowship Program(grant numbers ACIF/2020/294 and CIACIF/2021/050).
文摘This study demonstrates the successful fabrication of solid-state bilayers using LiFePO_(4)(LFP)cathodes and Li_(1.3)Al_(0.3)Ti_(1.7)(PO_(4))_(3)(LATP)-based Composite Solid Electrolytes(CSEs)via Cold Sintering Process(CSP).By optimizing the sintering pressure,it is achieved an intimate contact between the cathode and the solid electrolyte,leading to an enhanced electrochemical performance.Bilayers cold sintered at 300 MPa and a low-sintering temperature of 150℃exhibit high ionic conductivities(0.5 mS cm^(-1))and stable specific capacities at room temperature(160.1 mAh g^(-1)LFP at C/10 and 75.8 mAh g^(-1)_(LFP)at 1 C).Moreover,an operando electrochemical impedance spectroscopy(EIS)technique is employed to identify limiting factors of the bilayer kinetics and to anticipate the overall electrochemical behavior.Results suggest that capacity fading can occur in samples prepared with high sintering pressures due to a volume reduction in the LFP crystalline cell.This work demonstrates the potential of CSP to produce straightforward high-performance bilayers and introduces a valuable non-destructive instrument for understanding and avoiding degradation in solid-state lithium-based batteries.
基金financially supported by the National Natural Science Foundation of China(Nos.62471303,62071300,22176127,22301181,22406130 and 22476131)Shanghai Sailing Program(Nos.23YF1429000 and 22YF1430400)
文摘The semiconductor gas sensors used for xylene gas detection in real time has been restricted by the inadequate sensitivity and selectivity.Constructing a bilayer cascade sensor with the catalysis-gas sensitivity synergistic is considered as an effective solution.Herein,the Ag@CeO_(2)nanosheets are synthesized by heat treating the Ag@Ce-MOF,which synthesized via solvothermal method.The morphological evolution of cerium metalorganic framework(Ce-MOF),regulated by Ag ions,is investigated,and the transformation mechanism is proposed.The bilayer sensors were constructed by using WO_(3)nanofibers,prepared via the electrospinning method,as the sensitive layer and the Ag@CeO_(2)nanosheets as the catalytic layer,respectively.The bilayer sensors exhibit remarkable performance in response to xylene.The response value(R_(a)/R_(g))of WO_(3)/Ag@CeO_(2)sensor to10 ppm xylene gas reaches 32.13 at the operating temperature of 160℃.Additionally,the sensor displays an exceptional response to even trace amounts of xylene,as low as parts per billion(ppb).The catalysis-gas sensitivity synergistic mechanism was elucidated by capturing catalytic intermediates using online mass spectrometry.These findings provide a novel strategy for benzene series(BTEX)sensor and offer a novel approach to prepare twodimensional Ce-MOF and its derived materials with tailored properties.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1402802)the National Natural Science Foundation of China(Grant Nos.12494591 and 92165204)+4 种基金the Leading Talent Program of Guangdong Special Projects(Grant No.201626003)the Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices(Grant No.2022B1212010008)the Research Center for Magnetoelectric Physics of Guangdong Province(Grant No.2024B0303390001)the Guangdong Provincial Quantum Science Strategic Initiative(Grant No.GDZX2401010)supported by the National Natural Science Foundation of China(Grant Nos.12234016 and 12074031)。
文摘We investigate the energy bands,magnetism,and superconductivity of bilayer octagraphene with A-A stackingunder a perpendicular electric field.A tight-binding model is used to analyze the band structure of the system.The doubling of the unit cell results in each band of the single layer splitting into two.We find that applyinga perpendicular electric field increases the band splitting.As the electric field strength increases,the nestingof the Fermi surface(FS)weakens,eventually disrupting the antiferromagnetic order,and bilayer octagrapheneexhibits superconductivity.Spin fluctuations can induce unconventional superconductivity with s±-wave pairing.Applying a perpendicular electric field to bilayer octagraphene parent weakens the nesting of the FS,ultimatelykilling the spin-density-wave(SDW)ordered state and transitioning it into the superconducting state,whichworks as a doping effect.We use the random-phase approximation approach to obtain the pairing eigenvaluesand pairing symmetries of the perpendicular electric field-tuned bilayer octagraphene in the weak coupling limit.By tuning the strength of the perpendicular electric field,the critical interaction strength for SDW order can bemodified,which in turn may promote the emergence of unconventional superconductivity.
