In this study,we developed a novel bilayered scaffold consisting of a bottom layer composed of the Decellularized Bovine Pericardium(DP)coated with Polyaniline Nanoparticles(PANINPs)and a top layer made of an electros...In this study,we developed a novel bilayered scaffold consisting of a bottom layer composed of the Decellularized Bovine Pericardium(DP)coated with Polyaniline Nanoparticles(PANINPs)and a top layer made of an electrospun Poly(lactic-co-glycolic acid)/Gelatin(PLGA/Gel)membrane incorporated with Vascular Endothelial Growth Fac-tor(VEGF)and hawthorn extract.Functionally,the DP supplies native Extracellular Matrix(ECM)components and mechanical support,while PANINPs provide conductivity.The electrospun PLGA/Gel layer mimics fibrous ECM.It incorporates bioactives,with VEGF promoting pro-angiogenic stimulation and hawthorn extract enhanc-ing anticoagulant activity,as well as increasing surface hydrophilicity.The tissue adhesive ensures the interfacial integrity between the two layers.Decellularization efficiency was confirmed histologically using 4',6-diamidino-2-phenylindole(DAPI)and Hematoxylin-Eosin(H&E)staining.The DP exhibited a DNA content of 115.9±47.8 ng/mg DNA,compared to 982.88±395.42 ng/mg in Native Pericardium(NP).The PANINPs had an average par-ticle size of 104.94±13.7 nm.The conductivity of PANINPs-coated decellularized pericardium was measured to be 9.093±8.6×10-4 S/cm using the four-point probe method.PLGA/Gel membranes containing hawthorn extract(1%,5%,10%,and 15%w/v)and VEGF(0.1μg/mL,0.5μg/mL,and 1μg/mL)were fabricated by electrospinning,result-ing in fiber diameters between 850 and 1200 nm and pore sizes between 14 and 20μm.The anticoagulant efficiency of the membranes containing hawthorn extract reached 430 s in the Activated Partial Thromboplastin Time Assay(aPTT).Mechanical testing revealed a tensile strength of 22.70±6.33 MPa,an elongation of 53.58±10.63%,and Young's modulus of 0.67±0.10 MPa.The scaffold also exhibited over 91%cell viability and excellent cardiomyo-cyte adhesion.The hemolysis ratio was determined to be 0.421±0.191%,which confirms its blood compatibility.Our results indicate that the proposed bilayered scaffold can be a promising candidate for cardiac patch applications.展开更多
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
A novel 2D bilayered Dion–Jacobson(DJ)type hybrid perovskite,(2-methyl-1,5-diaminopentane)(methylammonium)Pb2I7(1),with a narrow band gap of 1.96 eV has been reported,and such a DJ-type hybrid has been for the first ...A novel 2D bilayered Dion–Jacobson(DJ)type hybrid perovskite,(2-methyl-1,5-diaminopentane)(methylammonium)Pb2I7(1),with a narrow band gap of 1.96 eV has been reported,and such a DJ-type hybrid has been for the first time demonstrated to exhibit broadband photoresponsive properties with high photoresponsivity(13 A W^(−1)under a 10 V bias)and considerable switching ratios(>10^(3)).展开更多
Two-dimensional(2D)multilayered hybrid perovskites adopting intrinsic quantum-well structures have shown great application potential in the field of optoelectronics.Despite extensive studies,candidate perovskites comp...Two-dimensional(2D)multilayered hybrid perovskites adopting intrinsic quantum-well structures have shown great application potential in the field of optoelectronics.Despite extensive studies,candidate perovskites composed of cage-templated secondary ammonium cations are quite scarce,hindering their application in high efficiency devices.Here,a new 2D hybrid perovskite(IA)2(DMA)Pb_(2)Br_(7)(1,IA^(+)=isoamylammonium and DMA^(+)=dimethylammonium)was synthesised,in which the inorganic bilayered frameworks are templated by secondary organic DMA^(+)cations in the perovskite cavities.This structural characteristic is distinct from the homologues containing monovalent cations.An alternative array of organic spacing bilayers and inorganic perovskite sheets forms its quantum-well motif,which leads to intriguing physical properties.Consequently,the fabricated crystal-based array detector exhibits highly efficient photodetection behaviors,including a low dark current(∼20 pA),large responsivity(∼110 mA W-1)and high detectivity(∼2.8×10^(11) Jones).These merits are related to the in-plane photoactivity of the perovskite sheets and low dark current of the insulated organic spacing bilayers.Besides,our photodetector also enables a response to polarized light with a dichromatic ratio of∼1.15.These findings pave the way to design new photoactive hybrid perovskites and reveal their potential for application in high-performance optoelectronic devices.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
Kagome materials host intertwined phenomena,including nontrivial band topology,superconductivity,and complex charge-density-wave order,making them an important platform in condensed-matter physics and materials scienc...Kagome materials host intertwined phenomena,including nontrivial band topology,superconductivity,and complex charge-density-wave order,making them an important platform in condensed-matter physics and materials science.Motivated by extensive studies on the AV_(3)Sb_(5) family of materials,we perform high-throughput first-principles calculations to screen bilayer kagome AM_(6)X_(6) compounds with an MgFe_(6)Ge_(6)-prototype structure as potential weak-coupling superconductors.Thereafter,we systematically evaluate the thermodynamic,dynamic,and magnetic stabilities,followed by electron–phonon coupling(EPC)calculations and superconducting transition temperature estimates based on the Allen–Dynes-modified McMillan equation.From 168 candidates,we identify 31 weak-coupling superconductors that satisfy both the thermodynamic and dynamical stability criteria in our screening workflow.Focusing on compounds without partially filled f shells,we obtain superconducting transition temperatures(T_(c))of 0.65–3.97 K with EPC constants λ=0.37–0.62,indicating conventional weak-coupling superconductivity.The EPC is typically driven by vibrations within the kagome layers,with Sn-containing materials exhibiting low-frequency soft modes that contribute significantly to λ.By providing a global mapping of stability and weak-coupling superconductivity in bilayer kagome AM_(6)X_(6) compounds,this study offers a practical theoretical database and design principles for future experimental exploration.展开更多
Bilayer MoS2 is a promising channel candidate for extending Moore’s law,owing to its optimal channel thickness and improved suppression of extrinsic scattering compared to monolayers.However,its intrinsic phonon-limi...Bilayer MoS2 is a promising channel candidate for extending Moore’s law,owing to its optimal channel thickness and improved suppression of extrinsic scattering compared to monolayers.However,its intrinsic phonon-limited electron mobility is severely limited by enhanced K–Q intervalley scattering arising from the multivalley conduction band feature inherent to the bilayer structure.To overcome this bottleneck,we propose a“valley separation engineering”strategy that combines a twist angle near 30°with applied stress.Our first-principles calculations demonstrate that although valley separation can be continuously increased using this strategy,the electron mobility saturates at∼200 cm^(2)⋅V^(−1)⋅s^(−1).The saturation is attributed to the competition between the reduced effective mass and enhanced intravalley scattering induced by phonon softening once the detrimental intervalley scattering is effectively suppressed by sufficient valley separation.This study establishes a theoretical upper limit for the intrinsic electron transport of bilayer MoS2 masked by severe intervalley scattering.展开更多
When two layers of graphene are stacked with a twist angle of approximately 1.1°,strong interlayer coupling gives rise to a pair of flat bands in twisted bilayer graphene(TBG),resulting in pronounced electron–el...When two layers of graphene are stacked with a twist angle of approximately 1.1°,strong interlayer coupling gives rise to a pair of flat bands in twisted bilayer graphene(TBG),resulting in pronounced electron–electron interactions.At half filling of the flat bands,TBG exhibits correlated insulating states.Here,we investigate the electrical transport properties of heterostructures composed of TBG and the antiferromagnetic insulator chromium oxychloride(CrOCl),and propose a strategy to modulate the correlated insulating states in TBG.During the transition from a conventional phase to a strong interfacial coupling phase,kink-like features are observed in the charge neutrality point(CNP),correlated insulating state,and band insulating state.Under a perpendicular magnetic field,the system exhibits broadened quantum Hall plateaus in the strong interfacial coupling regime.Electrons localized in the CrOCl layer screen the bottom gate,rendering the carrier density in TBG less sensitive to variations in the bottom gate voltage.These phenomena are well captured by a charge-transfer model between TBG and CrOCl.Our results provide insights into the control of electronic correlations and topological states in graphene moirésystems via interfacial charge coupling.展开更多
Cochlear hair cell(HC)damage is a primary cause of sensorineural hearing loss.In this study,we performed metabolomic profiling of cochlear sensory epithelium following neomycin-induced HC injury and identified elevate...Cochlear hair cell(HC)damage is a primary cause of sensorineural hearing loss.In this study,we performed metabolomic profiling of cochlear sensory epithelium following neomycin-induced HC injury and identified elevated arginine metabolism as a key metabolic characteristic of damaged HCs.Using a highly sensitive and specific biosensor,we confirmed that injury induced an increase in arginine levels within cochlear HCs.By manipulating the levels of arginine and its downstream metabolites,we discovered that unmetabolized arginine exerts a strong protective effect on cochlear HCs,independent of its downstream metabolites,such as nitric oxide.Furthermore,integrated metabolomic and transcriptomic analyses revealed that arginine plays a critical role in reprogramming phospholipid metabolism.Arginine supplementation enhanced membrane phospholipid saturation through the Lands cycle and de novo lipogenesis,and protected HCs from phospholipid peroxidation-induced membrane damage and subsequent cell death.Notably,arginine supplementation protected hearing from both noise-and aminoglycoside-induced injury in mice.These findings underscore the role of unmetabolized arginine in modulating phospholipid metabolism and preventing membrane damage in cochlear HCs,highlighting that targeting phospholipid metabolism is an effective hearing protection strategy.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
文摘In this study,we developed a novel bilayered scaffold consisting of a bottom layer composed of the Decellularized Bovine Pericardium(DP)coated with Polyaniline Nanoparticles(PANINPs)and a top layer made of an electrospun Poly(lactic-co-glycolic acid)/Gelatin(PLGA/Gel)membrane incorporated with Vascular Endothelial Growth Fac-tor(VEGF)and hawthorn extract.Functionally,the DP supplies native Extracellular Matrix(ECM)components and mechanical support,while PANINPs provide conductivity.The electrospun PLGA/Gel layer mimics fibrous ECM.It incorporates bioactives,with VEGF promoting pro-angiogenic stimulation and hawthorn extract enhanc-ing anticoagulant activity,as well as increasing surface hydrophilicity.The tissue adhesive ensures the interfacial integrity between the two layers.Decellularization efficiency was confirmed histologically using 4',6-diamidino-2-phenylindole(DAPI)and Hematoxylin-Eosin(H&E)staining.The DP exhibited a DNA content of 115.9±47.8 ng/mg DNA,compared to 982.88±395.42 ng/mg in Native Pericardium(NP).The PANINPs had an average par-ticle size of 104.94±13.7 nm.The conductivity of PANINPs-coated decellularized pericardium was measured to be 9.093±8.6×10-4 S/cm using the four-point probe method.PLGA/Gel membranes containing hawthorn extract(1%,5%,10%,and 15%w/v)and VEGF(0.1μg/mL,0.5μg/mL,and 1μg/mL)were fabricated by electrospinning,result-ing in fiber diameters between 850 and 1200 nm and pore sizes between 14 and 20μm.The anticoagulant efficiency of the membranes containing hawthorn extract reached 430 s in the Activated Partial Thromboplastin Time Assay(aPTT).Mechanical testing revealed a tensile strength of 22.70±6.33 MPa,an elongation of 53.58±10.63%,and Young's modulus of 0.67±0.10 MPa.The scaffold also exhibited over 91%cell viability and excellent cardiomyo-cyte adhesion.The hemolysis ratio was determined to be 0.421±0.191%,which confirms its blood compatibility.Our results indicate that the proposed bilayered scaffold can be a promising candidate for cardiac patch applications.
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(21871167)National Natural Science Foundation of Shanxi Province(No.201801D221098)1331 Project of Shanxi and Horizontal Project of School Enterprise Cooperation(No.231023901001).
文摘A novel 2D bilayered Dion–Jacobson(DJ)type hybrid perovskite,(2-methyl-1,5-diaminopentane)(methylammonium)Pb2I7(1),with a narrow band gap of 1.96 eV has been reported,and such a DJ-type hybrid has been for the first time demonstrated to exhibit broadband photoresponsive properties with high photoresponsivity(13 A W^(−1)under a 10 V bias)and considerable switching ratios(>10^(3)).
基金supported by the NSFC(22125110,21875251,21833010,22075285,and 21921001)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(ZDBS-LY-SLH024)+4 种基金the Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZR126)the Strategic Priority Research Program of the CAS(XDB20010200)the National Postdoctoral Program for Innovative Talents(BX2021315)the Youth Innovation Promotion of CAS(Y201851)the National Postdoctoral Program for Innovative Talents(BX2021315).
文摘Two-dimensional(2D)multilayered hybrid perovskites adopting intrinsic quantum-well structures have shown great application potential in the field of optoelectronics.Despite extensive studies,candidate perovskites composed of cage-templated secondary ammonium cations are quite scarce,hindering their application in high efficiency devices.Here,a new 2D hybrid perovskite(IA)2(DMA)Pb_(2)Br_(7)(1,IA^(+)=isoamylammonium and DMA^(+)=dimethylammonium)was synthesised,in which the inorganic bilayered frameworks are templated by secondary organic DMA^(+)cations in the perovskite cavities.This structural characteristic is distinct from the homologues containing monovalent cations.An alternative array of organic spacing bilayers and inorganic perovskite sheets forms its quantum-well motif,which leads to intriguing physical properties.Consequently,the fabricated crystal-based array detector exhibits highly efficient photodetection behaviors,including a low dark current(∼20 pA),large responsivity(∼110 mA W-1)and high detectivity(∼2.8×10^(11) Jones).These merits are related to the in-plane photoactivity of the perovskite sheets and low dark current of the insulated organic spacing bilayers.Besides,our photodetector also enables a response to polarized light with a dichromatic ratio of∼1.15.These findings pave the way to design new photoactive hybrid perovskites and reveal their potential for application in high-performance optoelectronic devices.
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financial support from the Guangdong Provincial Quantum Science Strategic Initiative (Grant No.GDZX2501011)the Guangdong Basic and Applied Basic Research Foundation (Grant No.2024A1515010484)+7 种基金the financial support from the Guangdong Basic and Applied Basic Research Foundation (Grant No.2022A1515110404)the Guangdong Basic and Applied Basic Research Foundation (Grant No.2023A1515140188)the Guangdong Basic and Applied Basic Research Foundation (Grant No.2022A1515110322)the National Natural Science Foundation of China (Grant Nos.U2330104 and 12574028)financial support from the National Natural Science Foundation of China (Grant No.12304095)support from the National Natural Science Foundation of China (Grant No.12404190)the financial support from the National Key R&D Program of China (Grant No.2022YFA1403103)the China Postdoctoral Science Foundation (Grant No.2024M762275)。
文摘Kagome materials host intertwined phenomena,including nontrivial band topology,superconductivity,and complex charge-density-wave order,making them an important platform in condensed-matter physics and materials science.Motivated by extensive studies on the AV_(3)Sb_(5) family of materials,we perform high-throughput first-principles calculations to screen bilayer kagome AM_(6)X_(6) compounds with an MgFe_(6)Ge_(6)-prototype structure as potential weak-coupling superconductors.Thereafter,we systematically evaluate the thermodynamic,dynamic,and magnetic stabilities,followed by electron–phonon coupling(EPC)calculations and superconducting transition temperature estimates based on the Allen–Dynes-modified McMillan equation.From 168 candidates,we identify 31 weak-coupling superconductors that satisfy both the thermodynamic and dynamical stability criteria in our screening workflow.Focusing on compounds without partially filled f shells,we obtain superconducting transition temperatures(T_(c))of 0.65–3.97 K with EPC constants λ=0.37–0.62,indicating conventional weak-coupling superconductivity.The EPC is typically driven by vibrations within the kagome layers,with Sn-containing materials exhibiting low-frequency soft modes that contribute significantly to λ.By providing a global mapping of stability and weak-coupling superconductivity in bilayer kagome AM_(6)X_(6) compounds,this study offers a practical theoretical database and design principles for future experimental exploration.
基金supported by the National Key R&D Program of China (Grant No.2022YFA1402503)the High Performance Computing Center of Jilin University,China。
文摘Bilayer MoS2 is a promising channel candidate for extending Moore’s law,owing to its optimal channel thickness and improved suppression of extrinsic scattering compared to monolayers.However,its intrinsic phonon-limited electron mobility is severely limited by enhanced K–Q intervalley scattering arising from the multivalley conduction band feature inherent to the bilayer structure.To overcome this bottleneck,we propose a“valley separation engineering”strategy that combines a twist angle near 30°with applied stress.Our first-principles calculations demonstrate that although valley separation can be continuously increased using this strategy,the electron mobility saturates at∼200 cm^(2)⋅V^(−1)⋅s^(−1).The saturation is attributed to the competition between the reduced effective mass and enhanced intravalley scattering induced by phonon softening once the detrimental intervalley scattering is effectively suppressed by sufficient valley separation.This study establishes a theoretical upper limit for the intrinsic electron transport of bilayer MoS2 masked by severe intervalley scattering.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.52225207 and 52350001)the Shanghai Pilot Program for Basic Research–Fudan University 21TQ1400100(Grant No.21TQ006)the Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)。
文摘When two layers of graphene are stacked with a twist angle of approximately 1.1°,strong interlayer coupling gives rise to a pair of flat bands in twisted bilayer graphene(TBG),resulting in pronounced electron–electron interactions.At half filling of the flat bands,TBG exhibits correlated insulating states.Here,we investigate the electrical transport properties of heterostructures composed of TBG and the antiferromagnetic insulator chromium oxychloride(CrOCl),and propose a strategy to modulate the correlated insulating states in TBG.During the transition from a conventional phase to a strong interfacial coupling phase,kink-like features are observed in the charge neutrality point(CNP),correlated insulating state,and band insulating state.Under a perpendicular magnetic field,the system exhibits broadened quantum Hall plateaus in the strong interfacial coupling regime.Electrons localized in the CrOCl layer screen the bottom gate,rendering the carrier density in TBG less sensitive to variations in the bottom gate voltage.These phenomena are well captured by a charge-transfer model between TBG and CrOCl.Our results provide insights into the control of electronic correlations and topological states in graphene moirésystems via interfacial charge coupling.
基金supported by the National Natural Science Foundation of China(82271159,82425018,82071049,81830029,82192860,81922018,82201283,82101219,and 82192861)Shanghai Clinical Medical Research Center for Otolaryngology Diseases(20MC1920200)the STI2030-Major Projects(2022ZD0205400).
文摘Cochlear hair cell(HC)damage is a primary cause of sensorineural hearing loss.In this study,we performed metabolomic profiling of cochlear sensory epithelium following neomycin-induced HC injury and identified elevated arginine metabolism as a key metabolic characteristic of damaged HCs.Using a highly sensitive and specific biosensor,we confirmed that injury induced an increase in arginine levels within cochlear HCs.By manipulating the levels of arginine and its downstream metabolites,we discovered that unmetabolized arginine exerts a strong protective effect on cochlear HCs,independent of its downstream metabolites,such as nitric oxide.Furthermore,integrated metabolomic and transcriptomic analyses revealed that arginine plays a critical role in reprogramming phospholipid metabolism.Arginine supplementation enhanced membrane phospholipid saturation through the Lands cycle and de novo lipogenesis,and protected HCs from phospholipid peroxidation-induced membrane damage and subsequent cell death.Notably,arginine supplementation protected hearing from both noise-and aminoglycoside-induced injury in mice.These findings underscore the role of unmetabolized arginine in modulating phospholipid metabolism and preventing membrane damage in cochlear HCs,highlighting that targeting phospholipid metabolism is an effective hearing protection strategy.
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).
