A solid-phase sintering process for the low-cost fabrication of composite micro-channels was developed. Three kinds of composite micro-channels with metallic porous structures were designed. The sintering process was ...A solid-phase sintering process for the low-cost fabrication of composite micro-channels was developed. Three kinds of composite micro-channels with metallic porous structures were designed. The sintering process was studied and optimized to obtain porous-structured micro-channels with high porosity. The flow resistance and heat transfer performance in the composite micro-channels were investigated. The composite micro-channels show acceptable flow resistance, significant enhancement of heat transfer and dramatic improvement of flow boiling stability, which indicates a promising prospect for the application in forced convective heat transfer.展开更多
Flexible pressure sensors play an important role in the field of monitoring, owing to their inherent safety and the fact that they are embedded at the material level. Capacitive pressure sensors have been proven to be...Flexible pressure sensors play an important role in the field of monitoring, owing to their inherent safety and the fact that they are embedded at the material level. Capacitive pressure sensors have been proven to be quite versatile, with the ability to change the sensitivity and monitoring range by modifying the pore structure of the dielectric layer(elastic modulus). In this paper, capacitive pressure sensors are devised, comprising hierarchical porous polydimethylsiloxane. Due to the inherent hollow and hierarchical micropore structure, the capacitive pressure sensor allows operation at a wider pressure range(~1000 kPa) while maintaining sensitivity(6.33 MPa-1) in the range of 0–300 k Pa. Subsequently, the capacitance output model of the sensor is optimized, which provides an overall approximation of the experimental values for the sensor performance. Additionally, the signal response of the“break up the whole into parts”(by analysis of the whole sensor in parts) is simulated and outputted by the finite element analysis. The simplified analysis model provides a good understanding of the relationship between the local pressure and the signal response of the pressure sensor. For practical applications, seal monitoring and rubber wheel pressure array system are tested, and the proposed sensor shows sufficient potential for application in large deformation elastomer products.展开更多
Transition-metal nitrides exhibit wide potential windows and good electrochemical performance, but usually experience imbalanced practical applications in the energy storage field due to aggregation, poor circulation ...Transition-metal nitrides exhibit wide potential windows and good electrochemical performance, but usually experience imbalanced practical applications in the energy storage field due to aggregation, poor circulation stability, and complicated syntheses. In this study, a novel and simple multiphase polymeric strategy was developed to fabricate hybrid vanadium nitride/carbon(VN/C) membranes for supercapacitor negative electrodes, in which VN nanoparticles were uniformly distributed in the hierarchical porous carbon 3D networks. The supercapacitor negative electrode based on VN/C membranes exhibited a high specific capacitance of 392.0 F g^(-1) at 0.5 A g^(-1) and an excellent rate capability with capacitance retention of 50.5% at 30 A g^(-1). For the asymmetric device fabricated using Ni(OH)_2//VN/C membranes, a high energy density of 43.0 Wh kg^(-1) at a power density of800 W kg^(-1) was observed. Moreover, the device also showed good cycling stability of 82.9% at a current density of 1.0 A g^(-1) after 8000 cycles. This work may throw a light on simply the fabrication of other high-performance transition-metal nitridebased supercapacitor or other energy storage devices.展开更多
Hierarchically nanostructured porous carbonated hydroxyapatite coatings (HNPCs) on Ti6Al4V substrate were fabricated by a two-stage application route: fabrication of nacre coatings (NCs) on Ti6Al4V substrate by electr...Hierarchically nanostructured porous carbonated hydroxyapatite coatings (HNPCs) on Ti6Al4V substrate were fabricated by a two-stage application route: fabrication of nacre coatings (NCs) on Ti6Al4V substrate by electrophoretic technique, and conversion of NCs to HNPCs in a phosphate buffer solution (PBS) by microwave irradiation method. Their samples were characterized by using XRD, FT-IR, SEM, TEM, and N2 adsorption-desorption isotherms. The results show that the microwave irradiation technique improves obviously the conversion rate of NCs to HNPCs as compared with conventional method. After soaking the NCs in the PBS, calcium ions are released from the nacre particles and react with phosphate ions to form carbonated hydroxyapatite nanoparticles. These nanoparticles aggregate to form the plate-like carbonated apatite. The mesopores with a size of about 3.9 nm and macropores with the diameters of 1~4μm exist within and among the carbonated apatite plates, respectively. Simulated body fluid immersion tests reveal that the HNPCs have a good in vitro bioactivity.展开更多
The current artificial bone is unable to accurately replicate the inhomogeneity and anisotropy of human cancellous bone.To address this issue,we proposed a personalized approach based on clinical CT images to design m...The current artificial bone is unable to accurately replicate the inhomogeneity and anisotropy of human cancellous bone.To address this issue,we proposed a personalized approach based on clinical CT images to design mechanical equivalent porous structures for artificial femoral heads.Firstly,supported by Micro and clinical CT scans of 21 bone specimens,the anisotropic mechanical parameters of human cancellous bone in the femoral head were characterized using clinical CT values(Hounsfield unit).After that,the equivalent porous structure of cancellous bone was designed based on the gyroid surface,the influence of its degree of anisotropy and volume fraction on the macroscopic mechanical parameters was investigated by finite element analysis.Furthermore,a mapping relationship between CT values and the porous structure was established by jointly solving the mechanical parameters of the porous structure and human cancellous bone,allowing the design of personalized gradient porous structures based on clinical CT images.Finally,to verify the mechanical equivalence,implant press-in tests were conducted on 3D-printed artificial femoral heads and human femoral heads,the influence of the porous structure’s cell size in bone-implant interaction problems was also explored.Results showed that the minimum deviations of press-in stiffness(<15%)and peak load(<5%)both occurred when the cell size was 20%to 30%of the implant diameter.In conclusion,the designed porous structure can replicate the human cancellous bone-implant interaction at a high level,indicating its effectiveness in optimizing the mechanical performance of 3D-printed artificial femoral head.展开更多
The research on high-performance electromagnetic wave absorption materials with high-temperature and oxidative stability in extreme environments is gaining popularity.Herein,the lightweight silicon carbide nanowires(S...The research on high-performance electromagnetic wave absorption materials with high-temperature and oxidative stability in extreme environments is gaining popularity.Herein,the lightweight silicon carbide nanowires(SiC_(nws))/SiC composites are fabricated with in-situ SiC interface on one-dimensional oriented SiC_(nws)skeleton,which collaborative configuration by 3D printing and freeze casting assembly.The con-structed porous structure optimizes the impedance matching degree and scattering intensity,the maximum effective absorption bandwidth(EAB_(max))of 5.9 GHz and the minimum reflection loss(RL_(min))of−41.4 dB can be realized.Considering the inherent oxidation resistance of SiC,the composites present well-maintained absorption performance at 600℃.Even at 1100℃,the EAB_(max)of 4.9 GHz and RLmin of−30.4 dB also demonstrate the high-temperature absorption stability of the composites,indicating exceptional wave absorption properties and thermal stability.The slight attenuation can be attributed to the decrease in impedance matching capability accompanying the elevated dielectric constant.This work clarifies the impact of structure and component synergy on wave absorption behavior,and offers a novel approach to producing high-performance and high-temperature resistance ceramic-based electromagnetic wave absorption materials suitable for extreme environments.展开更多
Porous spherical MnCo_(2)S_(4) was synthesized by a simple solvothermal method.Thanks to the well-designedbimetallic composition and the unique porous spherical structure,the MnCo_(2)S_(4) electrode exhibited an excep...Porous spherical MnCo_(2)S_(4) was synthesized by a simple solvothermal method.Thanks to the well-designedbimetallic composition and the unique porous spherical structure,the MnCo_(2)S_(4) electrode exhibited an exceptionalspecific capacitance of 190.8 mAh·g^(-1)at 1 A·g^(-1),greatly higher than the corresponding monometallic sulfides MnS(31.7 mAh·g^(-1))and Co_(3)S_(4)(86.7 mAh·g^(-1)).Impressively,the as-assembled MnCo_(2)S_(4)||porous carbon(PC)hybridsupercapacitor(HSC),showed an outstanding energy density of 76.88 Wh·kg^(-1)at a power density of 374.5 W·kg^(-1),remarkable cyclic performance with a capacity retention of 86.8% after 10000 charge-discharge cycles at 5 A·g^(-1),and excellent Coulombic efficiency of 99.7%.展开更多
The increasingly serious electromagnetic(EM)radiation and related pollution effects have gradually attracted people's attention in the information age.Hence,it's crucial to develop adaptive shielding materials...The increasingly serious electromagnetic(EM)radiation and related pollution effects have gradually attracted people's attention in the information age.Hence,it's crucial to develop adaptive shielding materials with minimum EM waves(EMW)reflection.In this paper,Ag nanoparticles loaded mesoporous carbon hollow spheres(MCHS@Ag)were synthesized by chemical reduction method,and cellulose nanofibers(CNF)/MXene/MCHS@Ag homogeneous composites were prepared.The total EM interference shielding efficiency(SET)of CNF/MXene/MCHS@Ag composite film was 32.83 dB(at 12.4 GHz),and the absorption effectiveness(SEA)was improved to 26.6 dB,which was 63.1%and 195.5%higher than that of CNF/MXene/MCHS composite film.The low dielectric property of MCHS effectively optimized the impedance matching between the composites and air.The hollow porous structure prolonged the transmission path of EMW and increased the absorption loss of the composites.At the same time,Ag nanoparticles located the MCHS were helpful to construct the internal conductive path overcoming the damage of the conductive property caused by the low dielectric of MCHS.This research adopts a straightforward method to construct a lightweight,pliable,and mesoporous composites for EMI shielding,which serves a crucial role in the current era of severe EM pollution.展开更多
To efficiently address the current high cost associated with preparing pseudo-boehmite from organic aluminum,a low-cost alternative,AlCl_(3),is employed as the raw material.The sol-gel method is utilized,and H_(2)O_(2...To efficiently address the current high cost associated with preparing pseudo-boehmite from organic aluminum,a low-cost alternative,AlCl_(3),is employed as the raw material.The sol-gel method is utilized,and H_(2)O_(2)is incorporated for the modification of pseudo-boehmite.The modification mechanism is thoroughly investigated through the use of X-ray powder diffractometer,scanning electron microscope,and BET data analysis,as well as molecular dynamics simulations.Under specific conditions(temperature at 80°C,pH=7,and H_(2)O_(2)volume ratios of 0.5:1,1:1,and 2:1),mesoporous pseudo-boehmite is synthesized with a specific surface area of 227 m^(2)/g,a pore volume of 0.281 cm^(3)/g,a pore size of 6.78 nm,and a peptizing index of 99.47%.A novel and innovative methodology for the cost-effective production of high-performance alumina is offered through the approach.展开更多
With the impact of energy crisis and environmental problems,it is urgent to develop green sustainable energy.Osmotic energy stored in the salinity difference between seawater and river water is one of the sustainable,...With the impact of energy crisis and environmental problems,it is urgent to develop green sustainable energy.Osmotic energy stored in the salinity difference between seawater and river water is one of the sustainable,abundant,and renewable energy.However,the membranes used to capture osmotic energy by reverse electrodialysis(RED)always suffer from low ion selectivity,low stability and low power.Hydrogels with three-dimensional(3D)networks have shown great potential for ion transportation and energy conversion.In this work,based on the homogeneity and porosity characteristics of acrylamide(AM)hydrogel,as well as the remarkable stability and abundant negative charge of 3-sulfopropyl acrylate potassium salt(SPAK),a high-performance AM/SPAK cation-selective hydrogel membrane was successfully developed for harvesting osmotic energy.Compared to AM hydrogels,utilizing AM/SPAK as a monomer mixture greatly facilitated the preparation of homogeneous polymers,exhibiting a porous structure,exceptional ion selectivity,and remarkable stability.A maximum output power density of 13.73 W/m^(2)was achieved at a 50-fold NaCl concentration gradient,exceeding the commercial requirement of 5 W/m^(2).This work broadens the idea for the construction and application of composite hydrogel in high efficiency osmotic energy conversion.展开更多
The skin wound is susceptible to bacterial invasion,which hinders the healing of the wound,especially when infected with multi-drug resistant strains.This demands novel bioactive materials to combat bacterial infectio...The skin wound is susceptible to bacterial invasion,which hinders the healing of the wound,especially when infected with multi-drug resistant strains.This demands novel bioactive materials to combat bacterial infections.In this study,gallium oxide nanoparticles(Ga_(2)O_(3)NPs)were successfully synthesized through high-temperature thermal decomposition,exhibiting excellent biocompatibility and photocatalytic antimicrobial activity.The Ga_(2)O_(3)NPs were crosslinked into chitosan hydrogel to create a light-responsive multilayered 3D porous hydrogel(Ga_(2)O_(3)NPs hydrogel)for use in photocatalytic antimicrobial therapy(PCAT).The prepared Ga_(2)O_(3)NPs hydrogel exhibits broad-spectrum photocatalytic activity and remarkable antibacterial efficacy against E.coli and S.aureus.It effectively eradicates biofilms,promotes reactive oxygen species production,disrupts bacterial cell membranes,and induces nucleic acid leakage,ultimately resulting in bacterial death.Additionally,it exhibits excellent biosafety.Both in vitro pigskin and in vivo mouse wound infection models have confirmed the remarkable efficacy of Ga_(2)O_(3)NPs hydrogel in PCAT.Notably,Ga_(2)O_(3)NPs hydrogel created a moist environment for the wound in an MDR S.aureus-infected mouse wound model,demonstrating significant potential to facilitate wound healing and minimize scar formation.This study introduces a novel hydrogel dressing without antibiotic components for resistant bacterial-infected wounds.展开更多
Articular cartilage,which plays a vital role in joint structure,is susceptible to damage from trauma and degenerative joint diseases.Traditional methods for cartilage treatment often involve complex surgical procedure...Articular cartilage,which plays a vital role in joint structure,is susceptible to damage from trauma and degenerative joint diseases.Traditional methods for cartilage treatment often involve complex surgical procedures with limited efficacy.Alternatively,implantable drug-loaded scaffolds are an increasingly attractive cartilage treatment option.To address the challenges of structural and functional compatibility between scaffolds and native cartilage,as well as issues related to drug loading,we design a novel cartilage scaffold with a four-region hollow porous fiber network structure.Using an extrusion-based 3D printing platform,a biphasic silicone ink composed primarily of liquid-phase silicone and solid particles was employed to construct the hollow porous fiber network.Mechanical compression tests demonstrate that the cartilage scaffold has mechanical characteristics similar to those of native cartilage tissue,and ultraviolet spectrophotometry measurements confirm its ability to control drug release.These results showcase the feasibility and effectiveness of the proposed cartilage substitute structure.展开更多
Hierarchical porous structure,which include macropores,minor pores,and micropores in scaffolds,are essential in the multiple biological functions of bone repair and regeneration.In this study,patientcustomized calcium...Hierarchical porous structure,which include macropores,minor pores,and micropores in scaffolds,are essential in the multiple biological functions of bone repair and regeneration.In this study,patientcustomized calcium-deficient hydroxyapatite(CDHA)scaffolds with three-level hierarchical porous structure were fabricated by indirect 3D printing technology and particulate leaching method.The sacrificial template scaffolds were fabricated using a photo-curing 3D printer,which provided a prerequisite for the integral structure and interconnected macropores of CDHA scaffolds.Additionally,20 wt%pore former was incorporated into the slurry to enhance the content of smaller pores within the CDHA-2 scaffolds,and then the CDHA-2 scaffolds were sintered to remove the sacrificial template scaffolds and pore former.The obtained CDHA-2 scaffolds exhibited interconnected macropores(300-400μm),minor pores(∼10-100μm),and micropores(<10μm)distributed throughout the scaffolds,which could promote bone tissue ingrowth,increase surface roughness,and enhance protein adsorption of scaffolds.In vitro studies identified that CDHA-2 scaffolds had nanocrystal grains,high specific surface area,and outstanding protein adsorption capacity,which could provide a microenvironment for cell adhesion,spreading,and proliferation.In addition,the murine intramuscular implantation experiment suggested that CDHA-2 scaffolds exhibited excellent osteoinductivity and were superior to traditional BCP ceramics under conditions without the addition of live cells and exogenous growth factors.The rabbit calvarial defect repair results indicated that CDHA-2 scaffolds could enhance in situ bone regeneration.In conclusion,these findings demonstrated that the hierarchical porous structure of CDHA scaffolds was a pivotal factor in modulating osteoinductivity and bone regeneration,and CDHA-2 scaffolds were potential candidates for bone regeneration.展开更多
Flexible piezoresistive sensors based on carbon nanomaterials have attracted significant attention with regard to their application to wearable electronics.The enhanced performance of these sensors is primarily due to...Flexible piezoresistive sensors based on carbon nanomaterials have attracted significant attention with regard to their application to wearable electronics.The enhanced performance of these sensors is primarily due to the integration of microstructures and conductive coatings.In this study,a flexible sandwich-shaped piezoresistive pressure sensor is fabricated by adopting microstructured electrodes and a porous sensing layer of carbon nanocomposite.The microtextured electrodes are obtained from a template by three-dimensional printing using digital light processing(DLP),and the porous structure is obtained by scarification of an NaCl crystal template.Multiwalled carbon nanotubes(MWCNTs)and graphene nanoparticles(GNPs),composited with polydimethylsiloxane and silica(ESSIL 296),are used to fabricate the functional structures,including the upper and lower electrode layers and a sandwiched porous sensing layer.The sensor exhibits a rapid response and recovery speed(-80 ms),a high sensitivity(0.437 kPa^(−1))within a range of 0–1.08 kPa,and excellent stability.In addition,such sensors demonstrate potential applications for finger motion monitoring and information encryption.展开更多
Fe-N-C single-atom catalysts are considered among the most promising non-precious metal-based catalysts for oxygen reduction reaction(ORR),but issues such as low utilization of active sites and the easy aggregation of...Fe-N-C single-atom catalysts are considered among the most promising non-precious metal-based catalysts for oxygen reduction reaction(ORR),but issues such as low utilization of active sites and the easy aggregation of single atoms severely hinder their application in fuel cells and metal-air batteries.Herein,a single-atom Fe-embedded hierarchical porous hollow carbon fiber catalyst(Fe S AC/HCNF) is reported for ORR.The hollow channels and the porous structure of the fibers facilitate the exposure of single-atom active sites,and offer multidimensional mass transfer pathways to promote the transport of reactants,thus significantly enhancing catalytic performance.Additionally,the abundant micropores exert spatial confinement,which is beneficial for preventing the aggregation of single atoms.Leveraging its unique structural advantages,the Fe S AC/HCNF catalyst demonstrates outstanding ORR activity with low metal loading,boasting a high half-wave potential of 0.905 V,a substantial double-layer capacitance(C_(d1)) of 41.1 mF cm^(-2),and a notable kinetic current density of 45.2 mA cm^(-2)in alkaline media.Furthermore,the liquid Zn-air battery(ZAB) using Fe SAC/HCNF catalyst as the air cathode exhibits excellent battery performance and long-term cycling durability nearly 600 h.And the flexible quasi-solid-state ZAB can be stably cycled in various flat/bent states,which is promising for applications in flexible electronic devices.展开更多
The development of high-performance lithium-ion batteries(LIBs)hinges on searching for advanced anode materials with large specific capacities as well as high cycling stability.However,traditional graphite anodes have...The development of high-performance lithium-ion batteries(LIBs)hinges on searching for advanced anode materials with large specific capacities as well as high cycling stability.However,traditional graphite anodes have not met the demand for higher energy storage owing to the deficiency of low lithium storage capacity.In the current work,we focus on designing one composite anode material with multiscale porous(MP)structure and phosphorus(P)doping.The coupling effects of three-dimensional(3D)interconnected skeleton,hollow pore channels,and P doping can facilitate the electrolyte diffusion and the mass transfer,as well as accommodate the volume changes during lithiation/delithiation processes.As expected,the as-prepared MP-SiGeSnSbPAl composite exhibits superior lithium storage performance,achieving a specific capacity of 827.9 mAh/g after 150 cycles at 200 mA/g and maintaining the high capacity of 456.7 mAh/g after 400 cycles at 1 A/g.Contrastively,the corresponding surplus capacities are only 590.3 and 225.7 mAh/g for the non-doped counterparts,respectively.In particular,MP-SiGeSnSbPAl displays much more stable cycling performances under the measurement of high areal mass loading of~3 mg/cm^(2)and the full-cell tests with the lithium iron phosphate as the cathode.This work witnesses one scalable protocol for preparing multinary Si-based composite in terms of facile operation and high lithium storage performances.展开更多
Faced with complex operational environments,liquid metal divertors are considered alternative solutions to traditional solid divertors.Experiments have been conducted using a self-designed embedded multichannel capill...Faced with complex operational environments,liquid metal divertors are considered alternative solutions to traditional solid divertors.Experiments have been conducted using a self-designed embedded multichannel capillary porous structure(EM-CPS)for plasma irradiation of lithium(Li)-prefilled EM-CPS in the high-density linear plasma device(SCU-PSI).The optical image analysis of the interaction region between the plasma and Li vapor shows that the region is not a regular geometric shape and the point of strongest light emission appears 1–2 cm in front of the target rather than on its surface.The irregularity is due to the uneven distribution and density of the Li vapor,as well as the radial and axial attenuation of the plasma.As the plasma discharge parameters increase,the vapor profile initially expands globally and then contracts locally,with the point of the strongest light emission gradually moving towards the target surface.The spectral lines of Li 670.78 nm and Ar 763.51 nm in the interaction region are produced by deexcitation.These lines gradually decrease in intensity along the axial direction,which is close to the trend of light emission intensity that initially increases and then decreases along the same direction.These findings provide a reference for studying the interaction mechanism between plasma and liquid Li capillary porous structures in linear plasma devices and future tokamak.展开更多
Hard carbon (HC) is perceived as an anode candidate for sodium-ion batteries and potassium-ion batteries due to its disordered structure and cost-effectiveness,yet its capacity is restricted by limited active sites.He...Hard carbon (HC) is perceived as an anode candidate for sodium-ion batteries and potassium-ion batteries due to its disordered structure and cost-effectiveness,yet its capacity is restricted by limited active sites.Heteroatom-induced defect engineering of HC is commonly applied for enhancing its reversible capacity,but high heteroatom doping (>14 at%) is challenging due to the absence of heteroatoms in most biomasses.Not only that,the heteroatom doping strategy is also bothered with high diffusion barriers toward Na^(+)/K^(+).Herein,based on a rationally selected low-cost precursor (sodium alginateDmelamineDNaCl),a new HC with high-level N,O heteroatom dopants (21.4 at%) and well-regulated porous structure has been constructed via acylating and controllable pore engineering.Experimental proof and theoretical calculations have been conducted to clarify the influence of heteroatom dopants and porous structures on the ion storage behavior of the designed HC.The rich N,O co-doping could enable efficient Na+/K+adsorption and enhanced electron transfer behavior.Besides,benefiting from the hierarchical porous structures (micro to macropores),the interfacial reaction kinetics and electrochemical behavior can be boosted.Particularly,the optimized N,O dualdoped hierarchical porous HC (NO-HPHC-1,0.285 mol L-1NaCl in precursor) with abundant defects from macropores and moderate micropores make it exhibit excellent Na^(+)storage:127 mAh g^(-1)at 0.5 A g^(-1)even after 2000 cycles.Meanwhile,the superiority of NO-HPHC-1 can be well maintained for K^(+)storage with a reversible capacity of 199 mAh g^(-1)at 0.1 A g^(-1).More importantly,the diverse Na^(+)/K^(+)storage behaviors have been elucidated.展开更多
Flexible piezoresistive sensors based on biomimetic microstructures are prospective for broad application in motion monitoring.However,the design and preparation processes of most biomimetic microstructures in the exi...Flexible piezoresistive sensors based on biomimetic microstructures are prospective for broad application in motion monitoring.However,the design and preparation processes of most biomimetic microstructures in the existing studies are complicated,and there are few studies on pore size control.Herein,the porous structure of human bones was used as a biomimetic prototype,and optimally designed by creating a theoretical equivalent sensor model and a finite element model.Soluble raw materials such as sugar and salt in different particle sizes were pressed into porous templates.Based on the template method,porous structures in different pore sizes were prepared using polydimethylsiloxane(PDMS)polymer as the substrate.On this basis,graphene oxide conductive coating was prepared with the modified Hummers method and then deposited via dip coating onto the substrate.Finally,a PDMS-based porous structure biomimetic flexible piezoresistive sensor was developed.Mechanically,the deformation of the sensor under the same load increased with the pore size rising from 0.3 to 1.5 mm.Electrically,the resistance rang of the sensor was enlarged as the pore size rose.The resistance variation rates of samples with pore sizes of 0.3,1.0,and 1.5 mm at approximately the 200th cycle were 63%,79%,and 81%,respectively;at the 500th cycle,these values were 63%,77%,and 79%;and at the 1000th cycle,they stabilized at 63%,74%,and 76%.These results indicate that the fabricated sensor exhibits high stability and fatigue resistance.At the pressure of 0–25 kPa,the sensitivity rose from 0.0688 to 0.1260 kPa−1,and the performance was enhanced by 83%.After 1,000 cycles of compression testing,the signal output was stable,and no damage was caused to the substrate.Further application tests showed the biomimetic sensor accurately and effectively identified human joint motions and gestures,and has potential application value in human motion monitoring.展开更多
A molten salt method was developed to prepare porous La1‐xSrxMn0.8Fe0.2O3 （0≤ x ≤ 0.6） micro‐spheres using hierarchical porous δ‐MnO2 microspheres as a template in eutectic NaNO3‐KNO3. X‐ray diffraction patt...A molten salt method was developed to prepare porous La1‐xSrxMn0.8Fe0.2O3 （0≤ x ≤ 0.6） micro‐spheres using hierarchical porous δ‐MnO2 microspheres as a template in eutectic NaNO3‐KNO3. X‐ray diffraction patterns showed that single phase LaMn0.8Fe0.2O3 with good crystallinity was syn‐thesized at 450℃ after 4 h. Transmission electron microscope images exhibited that the LaMn0.8Fe0.2O3 sample obtained at 450？？ after 4 h possessed a porous spherical morphology com‐posed of aggregated nanocrystallites. Field emission scanning electron microscope images indicated that the growth of the porous LaMn0.8Fe0.2O3 microspheres has two stages. SEM pictures showed that a higher calcination temperature than 450？？ had an adverse effect on the formation of a po‐rous spherical structure. The LaMn0.8Fe0.2O3 sample obtained at 450？？ after 4 h displayed a high BET surface area of 55.73 m2/g with a pore size of 9.38 nm. Fourier transform infrared spectra suggested that Sr2＋ions entered the A sites and induced a decrease of the binding energy between Mn and O. The CO conversion with the La1‐xSrxMn0.8Fe0.2O3 （0≤x≤0.6） samples indicated that the La0.4Sr0.6Mn0.8Fe0.2O3 sample had the best catalytic activity and stability. Further analysis by X‐ray photoelectron spectroscopy demonstrated that Sr2＋doping altered the content of Mn4＋ions, oxygen vacancies and adsorbed oxygen species on the surface, which affected the catalytic performance for CO oxidation.展开更多
基金Project(51146010)supported by the National Natural Science Foundation of ChinaProject(S2011040003189)supported by the Doctoral Research Fund of Guangdong Natural Science Foundation,ChinaProject supported by the Fundation of Key Laboratory of Surface Functional Structure Manufacturing of Guangdong Higher Education Institutes,South China University of Technology
文摘A solid-phase sintering process for the low-cost fabrication of composite micro-channels was developed. Three kinds of composite micro-channels with metallic porous structures were designed. The sintering process was studied and optimized to obtain porous-structured micro-channels with high porosity. The flow resistance and heat transfer performance in the composite micro-channels were investigated. The composite micro-channels show acceptable flow resistance, significant enhancement of heat transfer and dramatic improvement of flow boiling stability, which indicates a promising prospect for the application in forced convective heat transfer.
基金supported by the National Natural Science Foundation of China(Grant No.52075119)。
文摘Flexible pressure sensors play an important role in the field of monitoring, owing to their inherent safety and the fact that they are embedded at the material level. Capacitive pressure sensors have been proven to be quite versatile, with the ability to change the sensitivity and monitoring range by modifying the pore structure of the dielectric layer(elastic modulus). In this paper, capacitive pressure sensors are devised, comprising hierarchical porous polydimethylsiloxane. Due to the inherent hollow and hierarchical micropore structure, the capacitive pressure sensor allows operation at a wider pressure range(~1000 kPa) while maintaining sensitivity(6.33 MPa-1) in the range of 0–300 k Pa. Subsequently, the capacitance output model of the sensor is optimized, which provides an overall approximation of the experimental values for the sensor performance. Additionally, the signal response of the“break up the whole into parts”(by analysis of the whole sensor in parts) is simulated and outputted by the finite element analysis. The simplified analysis model provides a good understanding of the relationship between the local pressure and the signal response of the pressure sensor. For practical applications, seal monitoring and rubber wheel pressure array system are tested, and the proposed sensor shows sufficient potential for application in large deformation elastomer products.
基金supported by the National Natural Science Foundation of China (51203071,51363014,51463012,and 51763014)China Postdoctoral Science Foundation (2014M552509 and 2015T81064)+2 种基金Natural Science Funds of the Gansu Province (1506RJZA098)the Program for Hongliu Distinguished Young Scholars in Lanzhou University of Technology (J201402)Joint fund between Shenyang National Laboratory for Materials Science and State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals (18LHPY002)
文摘Transition-metal nitrides exhibit wide potential windows and good electrochemical performance, but usually experience imbalanced practical applications in the energy storage field due to aggregation, poor circulation stability, and complicated syntheses. In this study, a novel and simple multiphase polymeric strategy was developed to fabricate hybrid vanadium nitride/carbon(VN/C) membranes for supercapacitor negative electrodes, in which VN nanoparticles were uniformly distributed in the hierarchical porous carbon 3D networks. The supercapacitor negative electrode based on VN/C membranes exhibited a high specific capacitance of 392.0 F g^(-1) at 0.5 A g^(-1) and an excellent rate capability with capacitance retention of 50.5% at 30 A g^(-1). For the asymmetric device fabricated using Ni(OH)_2//VN/C membranes, a high energy density of 43.0 Wh kg^(-1) at a power density of800 W kg^(-1) was observed. Moreover, the device also showed good cycling stability of 82.9% at a current density of 1.0 A g^(-1) after 8000 cycles. This work may throw a light on simply the fabrication of other high-performance transition-metal nitridebased supercapacitor or other energy storage devices.
基金Supported by National Natural Science Foundation of China (No.51002095)Innovation Foundation of Shanghai Education Committee (No.11YZ86)
文摘Hierarchically nanostructured porous carbonated hydroxyapatite coatings (HNPCs) on Ti6Al4V substrate were fabricated by a two-stage application route: fabrication of nacre coatings (NCs) on Ti6Al4V substrate by electrophoretic technique, and conversion of NCs to HNPCs in a phosphate buffer solution (PBS) by microwave irradiation method. Their samples were characterized by using XRD, FT-IR, SEM, TEM, and N2 adsorption-desorption isotherms. The results show that the microwave irradiation technique improves obviously the conversion rate of NCs to HNPCs as compared with conventional method. After soaking the NCs in the PBS, calcium ions are released from the nacre particles and react with phosphate ions to form carbonated hydroxyapatite nanoparticles. These nanoparticles aggregate to form the plate-like carbonated apatite. The mesopores with a size of about 3.9 nm and macropores with the diameters of 1~4μm exist within and among the carbonated apatite plates, respectively. Simulated body fluid immersion tests reveal that the HNPCs have a good in vitro bioactivity.
基金supported by the National Key R&D Program of China(Grant No.2021YFC2501700).
文摘The current artificial bone is unable to accurately replicate the inhomogeneity and anisotropy of human cancellous bone.To address this issue,we proposed a personalized approach based on clinical CT images to design mechanical equivalent porous structures for artificial femoral heads.Firstly,supported by Micro and clinical CT scans of 21 bone specimens,the anisotropic mechanical parameters of human cancellous bone in the femoral head were characterized using clinical CT values(Hounsfield unit).After that,the equivalent porous structure of cancellous bone was designed based on the gyroid surface,the influence of its degree of anisotropy and volume fraction on the macroscopic mechanical parameters was investigated by finite element analysis.Furthermore,a mapping relationship between CT values and the porous structure was established by jointly solving the mechanical parameters of the porous structure and human cancellous bone,allowing the design of personalized gradient porous structures based on clinical CT images.Finally,to verify the mechanical equivalence,implant press-in tests were conducted on 3D-printed artificial femoral heads and human femoral heads,the influence of the porous structure’s cell size in bone-implant interaction problems was also explored.Results showed that the minimum deviations of press-in stiffness(<15%)and peak load(<5%)both occurred when the cell size was 20%to 30%of the implant diameter.In conclusion,the designed porous structure can replicate the human cancellous bone-implant interaction at a high level,indicating its effectiveness in optimizing the mechanical performance of 3D-printed artificial femoral head.
基金supported by the National Key R&D Program of China(No.2022YFB3707700)National Natural Science Foundation of China(No.52302121)+3 种基金Shanghai Sailing Program(No.23YF1454700)Shanghai Natural Science Foundation(No.23ZR1472700)Shanghai Post-doctoral Excellent Program(No.2022664)Shanghai Science and Technology Innovation Action Plan(No.21511104800).
文摘The research on high-performance electromagnetic wave absorption materials with high-temperature and oxidative stability in extreme environments is gaining popularity.Herein,the lightweight silicon carbide nanowires(SiC_(nws))/SiC composites are fabricated with in-situ SiC interface on one-dimensional oriented SiC_(nws)skeleton,which collaborative configuration by 3D printing and freeze casting assembly.The con-structed porous structure optimizes the impedance matching degree and scattering intensity,the maximum effective absorption bandwidth(EAB_(max))of 5.9 GHz and the minimum reflection loss(RL_(min))of−41.4 dB can be realized.Considering the inherent oxidation resistance of SiC,the composites present well-maintained absorption performance at 600℃.Even at 1100℃,the EAB_(max)of 4.9 GHz and RLmin of−30.4 dB also demonstrate the high-temperature absorption stability of the composites,indicating exceptional wave absorption properties and thermal stability.The slight attenuation can be attributed to the decrease in impedance matching capability accompanying the elevated dielectric constant.This work clarifies the impact of structure and component synergy on wave absorption behavior,and offers a novel approach to producing high-performance and high-temperature resistance ceramic-based electromagnetic wave absorption materials suitable for extreme environments.
文摘Porous spherical MnCo_(2)S_(4) was synthesized by a simple solvothermal method.Thanks to the well-designedbimetallic composition and the unique porous spherical structure,the MnCo_(2)S_(4) electrode exhibited an exceptionalspecific capacitance of 190.8 mAh·g^(-1)at 1 A·g^(-1),greatly higher than the corresponding monometallic sulfides MnS(31.7 mAh·g^(-1))and Co_(3)S_(4)(86.7 mAh·g^(-1)).Impressively,the as-assembled MnCo_(2)S_(4)||porous carbon(PC)hybridsupercapacitor(HSC),showed an outstanding energy density of 76.88 Wh·kg^(-1)at a power density of 374.5 W·kg^(-1),remarkable cyclic performance with a capacity retention of 86.8% after 10000 charge-discharge cycles at 5 A·g^(-1),and excellent Coulombic efficiency of 99.7%.
基金supported by the National Natural Science Foundation of China(grant no.52273044,52373092)the Opening Project of State Key Laboratory of Polymer Materials Engineering(Sichuan University)(grant no.sklpme2023-3-4)+1 种基金the Key Research Program of Zhejiang Province(grant no.2023C01101,2023C01210,2022C01049,2022C01205)the Natural Science Foundation of Zhejiang Province(grant no.LY20E030008).
文摘The increasingly serious electromagnetic(EM)radiation and related pollution effects have gradually attracted people's attention in the information age.Hence,it's crucial to develop adaptive shielding materials with minimum EM waves(EMW)reflection.In this paper,Ag nanoparticles loaded mesoporous carbon hollow spheres(MCHS@Ag)were synthesized by chemical reduction method,and cellulose nanofibers(CNF)/MXene/MCHS@Ag homogeneous composites were prepared.The total EM interference shielding efficiency(SET)of CNF/MXene/MCHS@Ag composite film was 32.83 dB(at 12.4 GHz),and the absorption effectiveness(SEA)was improved to 26.6 dB,which was 63.1%and 195.5%higher than that of CNF/MXene/MCHS composite film.The low dielectric property of MCHS effectively optimized the impedance matching between the composites and air.The hollow porous structure prolonged the transmission path of EMW and increased the absorption loss of the composites.At the same time,Ag nanoparticles located the MCHS were helpful to construct the internal conductive path overcoming the damage of the conductive property caused by the low dielectric of MCHS.This research adopts a straightforward method to construct a lightweight,pliable,and mesoporous composites for EMI shielding,which serves a crucial role in the current era of severe EM pollution.
基金Funded by the National Natural Science Foundation of China(Nos.22068021 and 52064030)the Yunnan Young and Middle-aged Academic and Technical Leaders Reserve Talent Program of China(No.202305AC160064)the Yunnan Major Scientific and Technological Program of China(Nos.202402AB080004,202202AG050011,and 202202AG050007)。
文摘To efficiently address the current high cost associated with preparing pseudo-boehmite from organic aluminum,a low-cost alternative,AlCl_(3),is employed as the raw material.The sol-gel method is utilized,and H_(2)O_(2)is incorporated for the modification of pseudo-boehmite.The modification mechanism is thoroughly investigated through the use of X-ray powder diffractometer,scanning electron microscope,and BET data analysis,as well as molecular dynamics simulations.Under specific conditions(temperature at 80°C,pH=7,and H_(2)O_(2)volume ratios of 0.5:1,1:1,and 2:1),mesoporous pseudo-boehmite is synthesized with a specific surface area of 227 m^(2)/g,a pore volume of 0.281 cm^(3)/g,a pore size of 6.78 nm,and a peptizing index of 99.47%.A novel and innovative methodology for the cost-effective production of high-performance alumina is offered through the approach.
基金financial support by the National Natural Science Foundation of China(No.21805017)。
文摘With the impact of energy crisis and environmental problems,it is urgent to develop green sustainable energy.Osmotic energy stored in the salinity difference between seawater and river water is one of the sustainable,abundant,and renewable energy.However,the membranes used to capture osmotic energy by reverse electrodialysis(RED)always suffer from low ion selectivity,low stability and low power.Hydrogels with three-dimensional(3D)networks have shown great potential for ion transportation and energy conversion.In this work,based on the homogeneity and porosity characteristics of acrylamide(AM)hydrogel,as well as the remarkable stability and abundant negative charge of 3-sulfopropyl acrylate potassium salt(SPAK),a high-performance AM/SPAK cation-selective hydrogel membrane was successfully developed for harvesting osmotic energy.Compared to AM hydrogels,utilizing AM/SPAK as a monomer mixture greatly facilitated the preparation of homogeneous polymers,exhibiting a porous structure,exceptional ion selectivity,and remarkable stability.A maximum output power density of 13.73 W/m^(2)was achieved at a 50-fold NaCl concentration gradient,exceeding the commercial requirement of 5 W/m^(2).This work broadens the idea for the construction and application of composite hydrogel in high efficiency osmotic energy conversion.
基金financially supported by the Advanced Fiber Materials Engineering Research Center of Anhui Province(No.2023AFMC20)the Scientific Research Foundation for Advanced Talents of Anhui Polytechnic University(No.2022YQQ072)+5 种基金the Anhui Province Key Research and Development Program(No.2022i01020002)the Key Project Foundation of Anhui Higher Education Institutes of China(No.2023AH050941)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.22KJB180020)the Transversal Project(No.KH10004443),the Anhui Provincial Natural Science Foundation(No.2308085Y45)the Program for Excellent Sci-tech Innovation Teams of Universities in Anhui Province(No.2023AH010073)Wuhu Science and Technology Department project(No.2023jc22).
文摘The skin wound is susceptible to bacterial invasion,which hinders the healing of the wound,especially when infected with multi-drug resistant strains.This demands novel bioactive materials to combat bacterial infections.In this study,gallium oxide nanoparticles(Ga_(2)O_(3)NPs)were successfully synthesized through high-temperature thermal decomposition,exhibiting excellent biocompatibility and photocatalytic antimicrobial activity.The Ga_(2)O_(3)NPs were crosslinked into chitosan hydrogel to create a light-responsive multilayered 3D porous hydrogel(Ga_(2)O_(3)NPs hydrogel)for use in photocatalytic antimicrobial therapy(PCAT).The prepared Ga_(2)O_(3)NPs hydrogel exhibits broad-spectrum photocatalytic activity and remarkable antibacterial efficacy against E.coli and S.aureus.It effectively eradicates biofilms,promotes reactive oxygen species production,disrupts bacterial cell membranes,and induces nucleic acid leakage,ultimately resulting in bacterial death.Additionally,it exhibits excellent biosafety.Both in vitro pigskin and in vivo mouse wound infection models have confirmed the remarkable efficacy of Ga_(2)O_(3)NPs hydrogel in PCAT.Notably,Ga_(2)O_(3)NPs hydrogel created a moist environment for the wound in an MDR S.aureus-infected mouse wound model,demonstrating significant potential to facilitate wound healing and minimize scar formation.This study introduces a novel hydrogel dressing without antibiotic components for resistant bacterial-infected wounds.
基金supported by the National Natural Science Foundation of China(No.52175278).
文摘Articular cartilage,which plays a vital role in joint structure,is susceptible to damage from trauma and degenerative joint diseases.Traditional methods for cartilage treatment often involve complex surgical procedures with limited efficacy.Alternatively,implantable drug-loaded scaffolds are an increasingly attractive cartilage treatment option.To address the challenges of structural and functional compatibility between scaffolds and native cartilage,as well as issues related to drug loading,we design a novel cartilage scaffold with a four-region hollow porous fiber network structure.Using an extrusion-based 3D printing platform,a biphasic silicone ink composed primarily of liquid-phase silicone and solid particles was employed to construct the hollow porous fiber network.Mechanical compression tests demonstrate that the cartilage scaffold has mechanical characteristics similar to those of native cartilage tissue,and ultraviolet spectrophotometry measurements confirm its ability to control drug release.These results showcase the feasibility and effectiveness of the proposed cartilage substitute structure.
基金supported by the National Key Research and Development Program of China(No.2019YFA0110600)the Science and Technology Support Program of Sichuan Province(No.2019YJ0161).
文摘Hierarchical porous structure,which include macropores,minor pores,and micropores in scaffolds,are essential in the multiple biological functions of bone repair and regeneration.In this study,patientcustomized calcium-deficient hydroxyapatite(CDHA)scaffolds with three-level hierarchical porous structure were fabricated by indirect 3D printing technology and particulate leaching method.The sacrificial template scaffolds were fabricated using a photo-curing 3D printer,which provided a prerequisite for the integral structure and interconnected macropores of CDHA scaffolds.Additionally,20 wt%pore former was incorporated into the slurry to enhance the content of smaller pores within the CDHA-2 scaffolds,and then the CDHA-2 scaffolds were sintered to remove the sacrificial template scaffolds and pore former.The obtained CDHA-2 scaffolds exhibited interconnected macropores(300-400μm),minor pores(∼10-100μm),and micropores(<10μm)distributed throughout the scaffolds,which could promote bone tissue ingrowth,increase surface roughness,and enhance protein adsorption of scaffolds.In vitro studies identified that CDHA-2 scaffolds had nanocrystal grains,high specific surface area,and outstanding protein adsorption capacity,which could provide a microenvironment for cell adhesion,spreading,and proliferation.In addition,the murine intramuscular implantation experiment suggested that CDHA-2 scaffolds exhibited excellent osteoinductivity and were superior to traditional BCP ceramics under conditions without the addition of live cells and exogenous growth factors.The rabbit calvarial defect repair results indicated that CDHA-2 scaffolds could enhance in situ bone regeneration.In conclusion,these findings demonstrated that the hierarchical porous structure of CDHA scaffolds was a pivotal factor in modulating osteoinductivity and bone regeneration,and CDHA-2 scaffolds were potential candidates for bone regeneration.
基金supported by the Science and Technology Cooperation and Exchange Special Project of Shanxi Province(Grant No.202204041101006)the Shanxi Provincial Patent Transformation Special Plan Project(Grant No.202403003)+4 种基金a research project supported by the Shanxi Scholarship Council of China(Grant No.2023-130)the Aeronautical Science Foundation of China(Grant No.2023Z0560U0001)the Fundamental Research Program of Shanxi Province(Grant No.202203021222077)the Science and Technology Project of the North University of China(Grant No.20231914)the National Natural Science Foundation of China(Grant Nos.52405633 and 62404208).
文摘Flexible piezoresistive sensors based on carbon nanomaterials have attracted significant attention with regard to their application to wearable electronics.The enhanced performance of these sensors is primarily due to the integration of microstructures and conductive coatings.In this study,a flexible sandwich-shaped piezoresistive pressure sensor is fabricated by adopting microstructured electrodes and a porous sensing layer of carbon nanocomposite.The microtextured electrodes are obtained from a template by three-dimensional printing using digital light processing(DLP),and the porous structure is obtained by scarification of an NaCl crystal template.Multiwalled carbon nanotubes(MWCNTs)and graphene nanoparticles(GNPs),composited with polydimethylsiloxane and silica(ESSIL 296),are used to fabricate the functional structures,including the upper and lower electrode layers and a sandwiched porous sensing layer.The sensor exhibits a rapid response and recovery speed(-80 ms),a high sensitivity(0.437 kPa^(−1))within a range of 0–1.08 kPa,and excellent stability.In addition,such sensors demonstrate potential applications for finger motion monitoring and information encryption.
基金financially supported by the National Natural Science Foundation of China(No.22408391)the Fundamental Research Funds for the Central Universities(No.2024ZKPYHH04)
文摘Fe-N-C single-atom catalysts are considered among the most promising non-precious metal-based catalysts for oxygen reduction reaction(ORR),but issues such as low utilization of active sites and the easy aggregation of single atoms severely hinder their application in fuel cells and metal-air batteries.Herein,a single-atom Fe-embedded hierarchical porous hollow carbon fiber catalyst(Fe S AC/HCNF) is reported for ORR.The hollow channels and the porous structure of the fibers facilitate the exposure of single-atom active sites,and offer multidimensional mass transfer pathways to promote the transport of reactants,thus significantly enhancing catalytic performance.Additionally,the abundant micropores exert spatial confinement,which is beneficial for preventing the aggregation of single atoms.Leveraging its unique structural advantages,the Fe S AC/HCNF catalyst demonstrates outstanding ORR activity with low metal loading,boasting a high half-wave potential of 0.905 V,a substantial double-layer capacitance(C_(d1)) of 41.1 mF cm^(-2),and a notable kinetic current density of 45.2 mA cm^(-2)in alkaline media.Furthermore,the liquid Zn-air battery(ZAB) using Fe SAC/HCNF catalyst as the air cathode exhibits excellent battery performance and long-term cycling durability nearly 600 h.And the flexible quasi-solid-state ZAB can be stably cycled in various flat/bent states,which is promising for applications in flexible electronic devices.
基金supported by National Science Foundation of Shandong Province(Nos.ZR2023ME155 and ZR2023ME085)the Taishan Scholar Project of Shandong Province(Nos.tsqn202306226 and tsqn202211171).
文摘The development of high-performance lithium-ion batteries(LIBs)hinges on searching for advanced anode materials with large specific capacities as well as high cycling stability.However,traditional graphite anodes have not met the demand for higher energy storage owing to the deficiency of low lithium storage capacity.In the current work,we focus on designing one composite anode material with multiscale porous(MP)structure and phosphorus(P)doping.The coupling effects of three-dimensional(3D)interconnected skeleton,hollow pore channels,and P doping can facilitate the electrolyte diffusion and the mass transfer,as well as accommodate the volume changes during lithiation/delithiation processes.As expected,the as-prepared MP-SiGeSnSbPAl composite exhibits superior lithium storage performance,achieving a specific capacity of 827.9 mAh/g after 150 cycles at 200 mA/g and maintaining the high capacity of 456.7 mAh/g after 400 cycles at 1 A/g.Contrastively,the corresponding surplus capacities are only 590.3 and 225.7 mAh/g for the non-doped counterparts,respectively.In particular,MP-SiGeSnSbPAl displays much more stable cycling performances under the measurement of high areal mass loading of~3 mg/cm^(2)and the full-cell tests with the lithium iron phosphate as the cathode.This work witnesses one scalable protocol for preparing multinary Si-based composite in terms of facile operation and high lithium storage performances.
基金supported by the National Key Research and Development Program of China(No.2022YFE03130000)。
文摘Faced with complex operational environments,liquid metal divertors are considered alternative solutions to traditional solid divertors.Experiments have been conducted using a self-designed embedded multichannel capillary porous structure(EM-CPS)for plasma irradiation of lithium(Li)-prefilled EM-CPS in the high-density linear plasma device(SCU-PSI).The optical image analysis of the interaction region between the plasma and Li vapor shows that the region is not a regular geometric shape and the point of strongest light emission appears 1–2 cm in front of the target rather than on its surface.The irregularity is due to the uneven distribution and density of the Li vapor,as well as the radial and axial attenuation of the plasma.As the plasma discharge parameters increase,the vapor profile initially expands globally and then contracts locally,with the point of the strongest light emission gradually moving towards the target surface.The spectral lines of Li 670.78 nm and Ar 763.51 nm in the interaction region are produced by deexcitation.These lines gradually decrease in intensity along the axial direction,which is close to the trend of light emission intensity that initially increases and then decreases along the same direction.These findings provide a reference for studying the interaction mechanism between plasma and liquid Li capillary porous structures in linear plasma devices and future tokamak.
基金financially supported by the National Natural Science Foundation of China(Nos.52072193,U22A20131,U22A20250,and 52361165657)Shandong Provincial Natural Science Foundation(Nos.ZR2021JQ16 and ZR2023YQ040)the State Key Laboratory for Modification of Chemical Fibers and Polymer Materials(No.KF2217)
文摘Hard carbon (HC) is perceived as an anode candidate for sodium-ion batteries and potassium-ion batteries due to its disordered structure and cost-effectiveness,yet its capacity is restricted by limited active sites.Heteroatom-induced defect engineering of HC is commonly applied for enhancing its reversible capacity,but high heteroatom doping (>14 at%) is challenging due to the absence of heteroatoms in most biomasses.Not only that,the heteroatom doping strategy is also bothered with high diffusion barriers toward Na^(+)/K^(+).Herein,based on a rationally selected low-cost precursor (sodium alginateDmelamineDNaCl),a new HC with high-level N,O heteroatom dopants (21.4 at%) and well-regulated porous structure has been constructed via acylating and controllable pore engineering.Experimental proof and theoretical calculations have been conducted to clarify the influence of heteroatom dopants and porous structures on the ion storage behavior of the designed HC.The rich N,O co-doping could enable efficient Na+/K+adsorption and enhanced electron transfer behavior.Besides,benefiting from the hierarchical porous structures (micro to macropores),the interfacial reaction kinetics and electrochemical behavior can be boosted.Particularly,the optimized N,O dualdoped hierarchical porous HC (NO-HPHC-1,0.285 mol L-1NaCl in precursor) with abundant defects from macropores and moderate micropores make it exhibit excellent Na^(+)storage:127 mAh g^(-1)at 0.5 A g^(-1)even after 2000 cycles.Meanwhile,the superiority of NO-HPHC-1 can be well maintained for K^(+)storage with a reversible capacity of 199 mAh g^(-1)at 0.1 A g^(-1).More importantly,the diverse Na^(+)/K^(+)storage behaviors have been elucidated.
基金supported by the National Natural Science Foundation of China(52175270)the Project of Scientifc and Technological Development Plan of Jilin Province(20220508130RC)+3 种基金the Science and Technology Development Program of Jilin Province(YDZJ202501ZYTS370)the Scientific Research Project of Education Department of Jilin Province(JJKH20251196KJ)the Scientific Research Project of Education Department of Jilin Province(JJKH20251195KJ)the Key Project of State Key Laboratory of Changchun City(23GZZ14).
文摘Flexible piezoresistive sensors based on biomimetic microstructures are prospective for broad application in motion monitoring.However,the design and preparation processes of most biomimetic microstructures in the existing studies are complicated,and there are few studies on pore size control.Herein,the porous structure of human bones was used as a biomimetic prototype,and optimally designed by creating a theoretical equivalent sensor model and a finite element model.Soluble raw materials such as sugar and salt in different particle sizes were pressed into porous templates.Based on the template method,porous structures in different pore sizes were prepared using polydimethylsiloxane(PDMS)polymer as the substrate.On this basis,graphene oxide conductive coating was prepared with the modified Hummers method and then deposited via dip coating onto the substrate.Finally,a PDMS-based porous structure biomimetic flexible piezoresistive sensor was developed.Mechanically,the deformation of the sensor under the same load increased with the pore size rising from 0.3 to 1.5 mm.Electrically,the resistance rang of the sensor was enlarged as the pore size rose.The resistance variation rates of samples with pore sizes of 0.3,1.0,and 1.5 mm at approximately the 200th cycle were 63%,79%,and 81%,respectively;at the 500th cycle,these values were 63%,77%,and 79%;and at the 1000th cycle,they stabilized at 63%,74%,and 76%.These results indicate that the fabricated sensor exhibits high stability and fatigue resistance.At the pressure of 0–25 kPa,the sensitivity rose from 0.0688 to 0.1260 kPa−1,and the performance was enhanced by 83%.After 1,000 cycles of compression testing,the signal output was stable,and no damage was caused to the substrate.Further application tests showed the biomimetic sensor accurately and effectively identified human joint motions and gestures,and has potential application value in human motion monitoring.
基金supported by the National Science Foundation for Young Scientists of China (51202171)~~
文摘A molten salt method was developed to prepare porous La1‐xSrxMn0.8Fe0.2O3 （0≤ x ≤ 0.6） micro‐spheres using hierarchical porous δ‐MnO2 microspheres as a template in eutectic NaNO3‐KNO3. X‐ray diffraction patterns showed that single phase LaMn0.8Fe0.2O3 with good crystallinity was syn‐thesized at 450℃ after 4 h. Transmission electron microscope images exhibited that the LaMn0.8Fe0.2O3 sample obtained at 450？？ after 4 h possessed a porous spherical morphology com‐posed of aggregated nanocrystallites. Field emission scanning electron microscope images indicated that the growth of the porous LaMn0.8Fe0.2O3 microspheres has two stages. SEM pictures showed that a higher calcination temperature than 450？？ had an adverse effect on the formation of a po‐rous spherical structure. The LaMn0.8Fe0.2O3 sample obtained at 450？？ after 4 h displayed a high BET surface area of 55.73 m2/g with a pore size of 9.38 nm. Fourier transform infrared spectra suggested that Sr2＋ions entered the A sites and induced a decrease of the binding energy between Mn and O. The CO conversion with the La1‐xSrxMn0.8Fe0.2O3 （0≤x≤0.6） samples indicated that the La0.4Sr0.6Mn0.8Fe0.2O3 sample had the best catalytic activity and stability. Further analysis by X‐ray photoelectron spectroscopy demonstrated that Sr2＋doping altered the content of Mn4＋ions, oxygen vacancies and adsorbed oxygen species on the surface, which affected the catalytic performance for CO oxidation.
