Endowing stimuli-responsive materials with micro-nano structures is an intriguing strategy for the fabrication of superwetting surfaces;however,its application is limited by poor chemical/mechanical stability.Herein,a...Endowing stimuli-responsive materials with micro-nano structures is an intriguing strategy for the fabrication of superwetting surfaces;however,its application is limited by poor chemical/mechanical stability.Herein,a simple and versatile strategy was developed to fabricate durable polymeric superwetting surfaces with photoswitchable wettability on hierarchically structured metallic substrates.Inspired by nature,a novel functional terpolymer incorporating mussel-inspired catechol groups,photoresponsive azobenzene groups,and low-surface-energy fluorine-containing groups was synthesized via solution radical polymerization.The azobenzene-containing terpolymer possesses outstanding photoresponsiveness in both the solution and film states because of the trans-cis isomerization of the azobenzene moieties.After dip-coating with the mussel-inspired azo-copolymer,the as-prepared smart surfaces exhibited a photo-triggered change in wettability between high hydrophobicity and superhydrophilicity.More importantly,these superwetting surfaces with enhanced adhesion properties can tolerate harsh environmental conditions and repeated abrasion tests,thereby demonstrating excellent chemical robustness and mechanical durability.This study paves a new avenue for the convenient and large-scale fabrication of robust smart surfaces that could find widespread potential applications in microfluidic devices,water treatment,and functional coatings.展开更多
This work proposes a bioinspired hierarchical actuation strategy based on liquid crystal elastomers(LCEs),inspired by the helical topological dynamic adaptation mechanism of plant tendrils,to overcome the bottleneck o...This work proposes a bioinspired hierarchical actuation strategy based on liquid crystal elastomers(LCEs),inspired by the helical topological dynamic adaptation mechanism of plant tendrils,to overcome the bottleneck of precise anisotropic control in LCEs.Mechanically pre-programmed hierarchical LCE structures responsive to near-infrared(NIR)light were fabricated:the oriented constrained actuator achieves asymmetric contraction under NIR irradiation,enabling reversible switching between helix and planar morphologies with multi-terrain grasping capability;the biomimetic vine-like helical actuator,composed of Ag nanowire photothermal layers combined with helical LCE,utilizes temperaturegradient-induced phase transition wave propagation to achieve NIR-controlled climbing motion;the M?bius topology actuator realizes reversible deformation or self-locking states by tuning the twist angle(180°/360°);based on these,a bioinspired koala-like concentric soft robot was constructed,successfully demonstrating tree trunk climbing.This study reveals that artificial helical stretching significantly enhances the molecular chain orientation of LCEs(surpassing uniaxial stretching),reaching up to 1000%pre-strain,and the Ag NWs/LCE/PI(Polyimide)tri-layer structure achieves efficient photothermal-mechanical energy conversion via localized surface plasmon resonance(LSPR).This study provides a new paradigm for soft robotics material design and topological programming,demonstrating the potential for remote operation and adaptive grasping.展开更多
The regulation of the interfacial electric field plays a pivotal role in magnifying the electromagnetic en-ergy attenuation capability during the design and synthesis of efficient and tunable absorbers for elec-tromag...The regulation of the interfacial electric field plays a pivotal role in magnifying the electromagnetic en-ergy attenuation capability during the design and synthesis of efficient and tunable absorbers for elec-tromagnetic waves(EMW).Herein,a rational and universally applicable two-step hydrothermal method strategy was proposed to effectively control the electronic structure of Mott-Schottky EMW absorbing materials derived from Co-MOF.The as-synthesized Co_(3)S_(4)@MoS_(2)/NC ensures efficient electron transfer,while the change redistribution leads to the emergence of additional electric dipoles under an external EMM field.In addition,the hierarchical Co_(3)S_(4)@MoS_(2)/NC nano-architecture with a hierarchical arrange-ment in 2D and 3D offers more polarization sites,thereby extending the path for EMW transmission through multiple reflections and scattering.The potential to enhance the EMW absorption performance of Co_(3)S_(4)@MoS_(2)/NC lies in its unique microstructure and substantial surface area,which optimize impedance matching properties through a synergistic effect of dipole and interfacial polarization induced by Mott-Schottky heterointerfaces.As anticipated,the Co_(3)S_(4)@MoS_(2)/NC exhibits a maximum EMW absorption ca-pacity with an RLmin value of-41.97 dB and a broad EAB of 4.24 GHz at a thickness of 2.0 mm.This study provides insights for designing highly efficient Mott-Schottky EMW absorbing materials at the molecular level rationally.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
Switchable radiative cooling/heating holds great promise for mitigating the global energy and environmental crisis.Here,we reported a cost-effective,high-strength Janus film through surface optical engineering waste p...Switchable radiative cooling/heating holds great promise for mitigating the global energy and environmental crisis.Here,we reported a cost-effective,high-strength Janus film through surface optical engineering waste paper with one side decorated by a hydrophobic polymeric cooling coating consisting of micro/nanopore/particle hierarchical structure and the other side coated with hydrophilic MXene nanosheets for heating.The cooling surface demonstrates high solar reflectivity(96.3%)and infrared emissivity(95.5%),resulting in daytime/nighttime sub-ambient radiative cooling of 6℃/8℃with the theoretical cooling power of 100.6 and 138.5Wm^(−2),respectively.The heating surface exhibits high solar absorptivity(83.7%)and low infrared emissivity(15.2%),resulting in excellent radiative heating capacity for vehicle charging pile(~6.2℃)and solar heating performance.Impressively,the mechanical strength of Janus film increased greatly by 563%compared with that of pristine waste paper,which is helpful for its practical applications in various scenarios for switchable radiative thermal management through mechanical flipping.Energy-saving simulation results reveal that significant total energy savings of up to 32.4MJm^(−2) can be achieved annually(corresponding to the 12.4%saving ratio),showing the immense importance of reducing carbon footprint and promoting carbon neutrality.展开更多
Hierarchical micro/nanograting structures have attracted increasing attention owing to their significant applications in the fields of structural coloring,anti-counterfeiting,and decoration.Thus,the fabrication of hie...Hierarchical micro/nanograting structures have attracted increasing attention owing to their significant applications in the fields of structural coloring,anti-counterfeiting,and decoration.Thus,the fabrication of hierarchical micro/nanograting structures is important for these applications.In this study,a strategy for machining hierarchical micro/nanograting structures is developed by controlling the tool movement trajectory.A coupling Euler-Lagrange finite element model is established to simulate the machining process.The effect of the machining methods on the nanograting formation is demonstrated,and a suitable machining method for reducing the cutting force is obtained.The height of the nanograting decreases with an increase in the tool edge radius.Furthermore,optical variable devices(OVDs)are machined using an array overlap machining approach.Coding schemes for the parallel column unit crossover and column unit in the groove crossover are designed to achieve high-quality machining of OVDs.The coloring of the logo of the Harbin Institute of Technology and the logo of the centennial anniversary of the Harbin Institute of Technology on the surface of metal samples,such as aluminum alloys,is realized.The findings of this study provide a method for the fabrication of hierarchical micro/nanograting structures that can be used to prepare OVDs.展开更多
With the continuous expansion of digital infrastructures,malicious behaviors in host systems have become increasingly sophisticated,often spanning multiple processes and employing obfuscation techniques to evade detec...With the continuous expansion of digital infrastructures,malicious behaviors in host systems have become increasingly sophisticated,often spanning multiple processes and employing obfuscation techniques to evade detection.Audit logs,such as Sysmon,offer valuable insights;however,existing approaches typically flatten event sequences or rely on generic graph models,thereby discarding the natural parent-child process hierarchy that is critical for analyzing multiprocess attacks.This paper proposes a structure-aware threat detection framework that transforms audit logs into a unified two-dimensional(2D)spatio-temporal representation,where process hierarchy is modeled as the spatial axis and event chronology as the temporal axis.In addition,entropy-based features are incorporated to robustly capture obfuscated and non-linguistic strings,overcoming the limitations of semantic embeddings.The model’s performance was evaluated on publicly available datasets,achieving competitive results with an accuracy exceeding 95%and an F1-score of at least 0.94.The proposed approach provides a promising and reproducible solution for detecting attacks with unknown indicators of compromise(IoCs)by analyzing the relationships and behaviors of processes recorded in large-scale audit logs.展开更多
Gas adsorption remains an attractive area of research.The hierarchical structure can reduce diffusion limitations and facilitate molecular transport,while acid sites can be used as adsorption sites.These make zeolites...Gas adsorption remains an attractive area of research.The hierarchical structure can reduce diffusion limitations and facilitate molecular transport,while acid sites can be used as adsorption sites.These make zeolites widely used in the field of gas adsorption.How to obtain zeolite adsorbents with better adsorption properties by modulating the hierarchical structure and acid sites is a pressing issue nowadays.This review highlights the strategies to modulate the hierarchical structure as well as the acid sites;and then explains how these strategies are achieved.The mechanism of zeolite adsorption on gases is then described in terms of these two properties.Lastly,the adsorption properties of zeolites for certain gases under specific conditions are summarised.An outlook of zeolite hierarchical structures and acid site modulation strategies is given.展开更多
Conducting polymers(CPs),including poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS),are promising coating materials for neural electrodes.However,the weak adhesion of CP coatings to substrates such a...Conducting polymers(CPs),including poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS),are promising coating materials for neural electrodes.However,the weak adhesion of CP coatings to substrates such as platinum-iridium is a significant challenge that limits their practical application.To address this issue,we used femtosecond laser-prepared hierarchical structures on platinum-iridium(Pt-Ir)substrates to enhance the adhesion of PEDOT:PSS coatings.Next,we used cyclic voltammetry(CV)stress and accelerated aging tests to evaluate the stability of both drop cast and electrodeposited PEDOT:PSS coatings on Pt-Ir substrates,both with and without hierarchical structures.Our results showed that after 2000 CV cycles or five weeks of aging at 60℃,the morphology and electrochemical properties of the coatings on the Pt-Ir substrates with hierarchical structures remained relatively stable.In contrast,we found that smooth Pt-Ir substrate surfaces caused delamination of the PEDOT:PSS coating and exhibited both decreased charge storage capacity and increased impedance.Overall,enhancing the stability of PEDOT:PSS coatings used on common platinum-iridium neural electrodes offers great potential for improving their electrochemical performance and developing new functionalities.展开更多
Currently,the hierarchical structure is one of the most effective means to enhance the strength and plasticity of metal materials,since the strain localization can be effectively delayed by the coordination of the uni...Currently,the hierarchical structure is one of the most effective means to enhance the strength and plasticity of metal materials,since the strain localization can be effectively delayed by the coordination of the unique microstructure.In this study,a hierarchical structure of Mg-15Gd-1Zn-0.4Zr(GZ151K)alloys containing grain,twin,and precipitation structural units was prepared by ultrasonic surface rolling process(USRP)and recrystallization annealing(RU).The results showed that the stress gradient generated by USRP formed a twin gradient structure,which will activate the twin-assisted precipitation(TAP)effect and twin-induced recrystallization(TIR)effect during RU.Then,the twin gradient structure transformed into a twin-precipitation gradient structure,and finally into a hierarchical structure with grain-twinprecipitation as the increasement of recrystallization degree.Besides,the dual gradient structure with twin and precipitation structural units had the highest strength and microhardness owing to the precipitation strengthening.However,the hierarchical structure with grain,twin,and precipitation structural units exhibited the most excellent combination of strength and plasticity under grain refinement and precipitation strengthening.展开更多
SiBCN ceramic aerogel is an ideal potential candidate for ultra-high temperature thermal insulation due to its unique microscopic pore structure combined with the excellent thermal stability of SiBCN ce-ramic.Here,red...SiBCN ceramic aerogel is an ideal potential candidate for ultra-high temperature thermal insulation due to its unique microscopic pore structure combined with the excellent thermal stability of SiBCN ce-ramic.Here,reduced graphene oxide(rGO)modified SiBCN aerogels(rGO/SiBCN)were prepared through solvothermal,freeze-casting and pyrolysis,and the dimension of the aerogel is up toΦ130 mm×28 mm.The density of the rGO/SiBCN aerogel is as low as 0.024 g/cm^(3) and the microstructural regulation is achieved by controlling the rGO content in the aerogel.The hierarchical cellular structure endows the aerogel with a high specific surface area(148.6 m^(2)/g)and low thermal conductivity(0.057 W m^(-1) K^(-1)).The 10 mm-thick sample exhibits excellent thermal insulation and ablation resistance,as evidenced by its ability to reduce the temperature from~1100℃to~180℃under the intense heat of a butane flame.Moreover,benefiting from the ultrahigh-temperature stability of SiBCN,the rGO/SiBCN aerogel exhibits good thermal stability up to 1200℃in argon and short-oxidation resistance at 800℃in air.There-fore,the rGO/SiBCN aerogel with superior overall performance could expand its practical application in high-temperature thermal insulation under extreme environments.展开更多
Enhancing both the number of active sites available and the intrinsic activity of Co-based electrocatalysts simultaneously is a desirable goal.Herein,a ZIF-67-derived hierarchical porous cobalt sulfide decorated by Au...Enhancing both the number of active sites available and the intrinsic activity of Co-based electrocatalysts simultaneously is a desirable goal.Herein,a ZIF-67-derived hierarchical porous cobalt sulfide decorated by Au nanoparticles(NPs)(denoted as HP-Au@CoxSy@ZIF-67)hybrid is synthesized by low-temperature sulfuration treatment.The well-defined macroporous-mesoporous-microporous structure is obtained based on the combination of polystyrene spheres,as-formed CoxSy nanosheets,and ZIF-67 frameworks.This novel three-dimensional hierarchical structure significantly enlarges the three-phase interfaces,accelerating the mass transfer and exposing the active centers for oxygen evolution reaction.The electronic structure of Co is modulated by Au through charge transfer,and a series of experiments,together with theoretical analysis,is performed to ascertain the electronic modulation of Co by Au.Meanwhile,HP-Au@CoxSy@ZIF-67 catalysts with different amounts of Au were synthesized,wherein Au and NaBH4 reductant result in an interesting“competition effect”to regulate the relative ratio of Co^(2+)/Co^(3+),and moderate Au assists the electrochemical performance to reach the highest value.Consequently,the optimized HP-Au@CoxSy@ZIF-67 exhibits a low overpotential of 340 mV at 10 mA cm^(-2)and a Tafel slope of 42 mV dec-1 for OER in 0.1 M aqueous KOH,enabling efficient water splitting and Zn-air battery performance.The work here highlights the pivotal roles of both microstructural and electronic modulation in enhancing electrocatalytic activity and presents a feasible strategy for designing and optimizing advanced electrocatalysts.展开更多
Flexible attachment actuators are popular in a wide range of applications,owing to their flexibility and highly reliable attachment.However,their reversible adhesion performance depends on the actual effective contact...Flexible attachment actuators are popular in a wide range of applications,owing to their flexibility and highly reliable attachment.However,their reversible adhesion performance depends on the actual effective contact area and peel angle during operation.Therefore,a good actuator must ensure a uniform and reliable pre-pressure load on an adhesive surface,to increase the effective contact area of the attached surface,thereby maximizing adhesion.This study was inspired by fusion bionics for designing a hierarchical attachment structure with vacuum-adsorption and dry-adhesion mechanisms.The designed structure used the normal force under the negative pressure of a suction cup as a stable source of a pre-pressure load.By optimizing the rigid and flexible structural layers of the attachment structure,a load was applied uniformly to the adhesion area;thus,reliable attachment was achieved by self-preloading.The structure achieved detachment by exploiting the large deformation of a pneumatic structure under a positive pressure.The hierarchical attachment structure achieved up to 85%of the optimal performance of the adhesive surface.Owing to its self-preloading and reliable attachment characteristics,the designed structure can be used as an attachment unit in various complex scenarios,such as small,lightweight climbing platforms and the transport of objects in long,narrow pipelines.展开更多
Some living organisms with hierarchical structures in nature have received extensive attention in various fields.The hierarchical structure with multiple pores,a large number of solid-gas interfaces and tortuous condu...Some living organisms with hierarchical structures in nature have received extensive attention in various fields.The hierarchical structure with multiple pores,a large number of solid-gas interfaces and tortuous conduction paths provide a new direction for the development of thermal insulation materials,making the living creatures under these extreme conditions become the bionic objects of scientific researchers.In this review,the research progress of bionic hierarchical structure in the field of heat insulation is highlighted.Polar bears,cocoons,penguin feathers and wool are typical examples of heat preservation hierarchy in nature to introduce their morphological characteristics.At the same time,the thermal insulation mechanism,fractal model and several preparation methods of bionic hierarchical structures are emphatically discussed.The application of hierarchical structures in various fields,especially in thermal insulation and infrared thermal stealth,is summarised.Finally,the hierarchical structure is prospected.展开更多
Amplifying the intrinsic wettability of substrate material by changing the solid/liquid contact area is considered to be the main mechanism for controlling the wettability of rough or structured surfaces.Through theor...Amplifying the intrinsic wettability of substrate material by changing the solid/liquid contact area is considered to be the main mechanism for controlling the wettability of rough or structured surfaces.Through theoretical analysis and experimental exploration,we have found that in addition to this wettability structure amplification effect,the surface structure also simultaneously controls surface wettability by regulating the wetting state via changing the threshold Young angles of the Cassie-Baxter and Wenzel wetting regions.This wetting state regulation effect provides us with an alternative strategy to overcome the inherent limitation in surface chemistry by tailoring surface structure.The wetting state regulation effect created by multi-scale hierarchical structures is quite significant and plays is a crucial role in promoting the superhydrophobicity,superhydrophilicity and the transition between these two extreme wetting properties,as well as stabilizing the Cassie-Baxter superhydrophobic state on the fabricated lotus-like hierarchically structured Cu surface and the natural lotus leaf.展开更多
When a human lands from a high drop,there is a high risk of serious injury to the lower limbs.On the other hand,cats can withstand jumps and falls from heights without being fatally wounded,largely due to their impact...When a human lands from a high drop,there is a high risk of serious injury to the lower limbs.On the other hand,cats can withstand jumps and falls from heights without being fatally wounded,largely due to their impact-resistant paw pads.The aim of the present study was to investigate the biomechanism of impact resistance in cat paw pads,propose an optimal hierarchical Voronoi structure inspired by the paw pads,and apply the structure to bionic cushioning shoes to reduce the impact force of landing for humans.The microstructure of cat paw pads was observed via tissue section staining,and a simulation model was reconstructed based on CT to verify and optimize the structural cushioning capacity.The distribution pattern,wall thickness of compartments,thickness ratio of epidermis and dermis,and number of compartments in the model were changed and simulated to achieve an optimal composed structure.A bionic sole was 3D-printed,and its performance was evaluated via compression test and a jumping-landing experiment.The results show that cat paw pads are a spherical cap structure,divided from the outside to the inside into the epidermis,dermis,and compartments,each with different cushioning capacities.A finite element simulation of different cushioning structures was conducted in a cylinder with a diameter of 20 mm and a height of 10 mm,featuring a three-layer structure.The optimal configuration of the three layers should have a uniform distribution with 0.3–0.5 mm wall thickness,a 1:1–2 thickness ratio of epidermis and dermis,and 100–150 compartments.A bionic sole with an optimized structure can reduce the peak impact force and delay the peak arrival time.Its energy absorption rate is about 4 times that of standard sole.When jumping 80,100,and 120 cm,the normalized ground reaction force is also reduced by 8.7%,12.6%and 15.1%compared with standard shoes.This study provides theoretical and technical support for effective protection against human lower limb landing injuries.展开更多
3D-printed Porous Titanium Alloy Implants(pTi),owing to their biologically inertness and relatively smooth surface morphology,adversely affect the biological functions of surrounding cells.To address the challenges,co...3D-printed Porous Titanium Alloy Implants(pTi),owing to their biologically inertness and relatively smooth surface morphology,adversely affect the biological functions of surrounding cells.To address the challenges,constructing a bioinspired interface that mimics the hierarchical structure of bone tissue can enhance the cellular functions of cells.In this context,Hollow Mesoporous Silica Nanoparticles(HMSNs),renowned for their unique physicochemical properties and superior biocompatibility,offer a promising direction for this research.In this research,the initially synthesized HMSNs were used to construct a“hollow-mesoporous-macroporous”hierarchical bioinspired coating on the pTi surface through the Layer-by-Layer technique.Simultaneously,diverse morphologies of coatings were established by adjusting the deposition strategy of PDDA/HMSNs on the pTi surface(pTi-HMSN-2,pTi-HMSN-4,pTi-HMSN-6).A range of techniques were employed to investigate the physicochemical properties and regulation of cellular biological functions of the diverse HMSN coating strategies.Notably,the pTi-HMSN-4 and pTi-HMSN-6 groups exhibited the uniform coatings,leading to a substantial enhancement in surface roughness and hydrophilicity.Meantime,the coating constructed strategy of pTi-HMSN-4 possessed commendable stability.Based on the aforementioned findings,both pTi-HMSN-4 and pTi-HMSN-6 facilitated the adhesion,spreading,and pseudopodia extension of BMSCs,which led to a notable upsurge in the expression levels of vinculin protein in BMSCs.Comprehensive analysis indicates that the coating,when PDDA/HMSNs are deposited four times,possesses favorable overall performance.The research will provide a solid theoretical basis for the translation of HMSN bioinspired coatings for orthopedic implants.展开更多
Development of metal oxide semiconductors-based methane sensors with good response and low power consumption is one of the major challenges to realize the real-time monitoring of methane leakage.In this work,a self-as...Development of metal oxide semiconductors-based methane sensors with good response and low power consumption is one of the major challenges to realize the real-time monitoring of methane leakage.In this work,a self-assembled mulberry-like ZnO/SnO_(2)hierarchical structure is constructed by a two-step hydrothermal method.The resultant sensor works at room temperature with excellent response of~56.1%to 2000 ppm CH_(4)at 55%relative humidity.It is found that the strain induced at the ZnO/SnO_(2)interface greatly enhances the piezoelectric polarization on the ZnO surface and that the band bending results in the accumulation of chemically adsorbed O_(2)^(-)ions close to the interface,leading to significant improvement in the sensing performance of the methane gas sensor at room temperature.展开更多
With vigorous developments in nanotechnology,the elaborate regulation of microstructure shows attractive potential in the design of electromagnetic wave absorbers.Herein,a hierarchical porous structure and composite h...With vigorous developments in nanotechnology,the elaborate regulation of microstructure shows attractive potential in the design of electromagnetic wave absorbers.Herein,a hierarchical porous structure and composite heterogeneous interface are constructed successfully to optimize the electromagnetic loss capacity.The macro–micro-synergistic graphene aerogel formed by the ice template‑assisted 3D printing strategy is cut by silicon carbide nanowires(SiC_(nws))grown in situ,while boron nitride(BN)interfacial structure is introduced on graphene nanoplates.The unique composite structure forces multiple scattering of incident EMWs,ensuring the combined effects of interfacial polarization,conduction networks,and magnetic-dielectric synergy.Therefore,the as-prepared composites present a minimum reflection loss value of−37.8 dB and a wide effective absorption bandwidth(EAB)of 9.2 GHz(from 8.8 to 18.0 GHz)at 2.5 mm.Besides,relying on the intrinsic high-temperature resistance of SiC_(nws) and BN,the EAB also remains above 5.0 GHz after annealing in air environment at 600℃ for 10 h.展开更多
K–Se batteries have been identified as promising energy storage systems owing to their high energy density and cost-effectiveness.However,challenges such as substantial volume changes and low Se utilization require f...K–Se batteries have been identified as promising energy storage systems owing to their high energy density and cost-effectiveness.However,challenges such as substantial volume changes and low Se utilization require further investigation.In this study,novel N-doped multichannel carbon nanofibers(h-NMCNFs)with hierarchical porous structures were successfully synthesized as efficient cathode hosts for K–Se batteries through the carbonization of two electrospun immiscible polymer nanofibers and subsequent chemical activation.Mesopores originated from the decomposition of the polymer embedded in the carbon nanofibers,and micropores were introduced via KOH activation.During the activation step,hierarchical porous carbon nanofibers with enhanced pore volumes were formed because of the micropores in the carbon nanofibers.Owing to the mesopores that enabled easy access to the electrolyte and the high utilization of chain-like Se within the micropores,the Se-loaded hierarchical porous carbon nanofibers(60 wt%Se)exhibited a high discharge capacity and excellent rate performance.The discharge capacity of the nanofibers at the 1,000th cycle was 210.8 mA.h.g^(-1)at a current density of 0.5C.The capacity retention after the initial activation was 64%.In addition,a discharge capacity of 165 mA.h.g^(-1)was obtained at an extremely high current density of 3.0C.展开更多
基金supported by the Natural Science Foundation of Shandong Province(No.ZR2022MB034)the Development Program Project of the Young Innovation Team of Institutions of Higher Learning in Shandong Province。
文摘Endowing stimuli-responsive materials with micro-nano structures is an intriguing strategy for the fabrication of superwetting surfaces;however,its application is limited by poor chemical/mechanical stability.Herein,a simple and versatile strategy was developed to fabricate durable polymeric superwetting surfaces with photoswitchable wettability on hierarchically structured metallic substrates.Inspired by nature,a novel functional terpolymer incorporating mussel-inspired catechol groups,photoresponsive azobenzene groups,and low-surface-energy fluorine-containing groups was synthesized via solution radical polymerization.The azobenzene-containing terpolymer possesses outstanding photoresponsiveness in both the solution and film states because of the trans-cis isomerization of the azobenzene moieties.After dip-coating with the mussel-inspired azo-copolymer,the as-prepared smart surfaces exhibited a photo-triggered change in wettability between high hydrophobicity and superhydrophilicity.More importantly,these superwetting surfaces with enhanced adhesion properties can tolerate harsh environmental conditions and repeated abrasion tests,thereby demonstrating excellent chemical robustness and mechanical durability.This study paves a new avenue for the convenient and large-scale fabrication of robust smart surfaces that could find widespread potential applications in microfluidic devices,water treatment,and functional coatings.
基金financially supported by the National Natural Science Foundation of China(Nos.52275290 and 51905222)the Research Project of the State Key Laboratory of Mechanical System and Oscillation(No.MSV202419)+2 种基金Major Program of the National Natural Science Foundation of China for Basic Theory and Key Technology of Tri-Co Robots(No.92248301)Opening Project of the Key Laboratory of Bionic Engineering(Ministry of Education),Jilin University(No.KF2023006)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCX23_2091)。
文摘This work proposes a bioinspired hierarchical actuation strategy based on liquid crystal elastomers(LCEs),inspired by the helical topological dynamic adaptation mechanism of plant tendrils,to overcome the bottleneck of precise anisotropic control in LCEs.Mechanically pre-programmed hierarchical LCE structures responsive to near-infrared(NIR)light were fabricated:the oriented constrained actuator achieves asymmetric contraction under NIR irradiation,enabling reversible switching between helix and planar morphologies with multi-terrain grasping capability;the biomimetic vine-like helical actuator,composed of Ag nanowire photothermal layers combined with helical LCE,utilizes temperaturegradient-induced phase transition wave propagation to achieve NIR-controlled climbing motion;the M?bius topology actuator realizes reversible deformation or self-locking states by tuning the twist angle(180°/360°);based on these,a bioinspired koala-like concentric soft robot was constructed,successfully demonstrating tree trunk climbing.This study reveals that artificial helical stretching significantly enhances the molecular chain orientation of LCEs(surpassing uniaxial stretching),reaching up to 1000%pre-strain,and the Ag NWs/LCE/PI(Polyimide)tri-layer structure achieves efficient photothermal-mechanical energy conversion via localized surface plasmon resonance(LSPR).This study provides a new paradigm for soft robotics material design and topological programming,demonstrating the potential for remote operation and adaptive grasping.
基金supported by the National Natural Science Foundation of China(Nos.22271178,22301239)Science and Technology New Star in Shaanxi Province(No.2023KJXX-045)+3 种基金the Youth Talent Promotion Project of Science and Technology Association of Universities of Shaanxi Province(No.20240601)Shaanxi Provincial Department of Education service local special project,industrialization cultivation project(No.23JC007)the Research Program of the Shaanxi Provincial Department of Education(Nos.23JK0596,23JP135)the Open Foundation of Xi’an Key Laboratory of Functional Supramolecular Structure and Materials(No.CFZKFKT23003).
文摘The regulation of the interfacial electric field plays a pivotal role in magnifying the electromagnetic en-ergy attenuation capability during the design and synthesis of efficient and tunable absorbers for elec-tromagnetic waves(EMW).Herein,a rational and universally applicable two-step hydrothermal method strategy was proposed to effectively control the electronic structure of Mott-Schottky EMW absorbing materials derived from Co-MOF.The as-synthesized Co_(3)S_(4)@MoS_(2)/NC ensures efficient electron transfer,while the change redistribution leads to the emergence of additional electric dipoles under an external EMM field.In addition,the hierarchical Co_(3)S_(4)@MoS_(2)/NC nano-architecture with a hierarchical arrange-ment in 2D and 3D offers more polarization sites,thereby extending the path for EMW transmission through multiple reflections and scattering.The potential to enhance the EMW absorption performance of Co_(3)S_(4)@MoS_(2)/NC lies in its unique microstructure and substantial surface area,which optimize impedance matching properties through a synergistic effect of dipole and interfacial polarization induced by Mott-Schottky heterointerfaces.As anticipated,the Co_(3)S_(4)@MoS_(2)/NC exhibits a maximum EMW absorption ca-pacity with an RLmin value of-41.97 dB and a broad EAB of 4.24 GHz at a thickness of 2.0 mm.This study provides insights for designing highly efficient Mott-Schottky EMW absorbing materials at the molecular level rationally.
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National Natural Science Foundation of China,Grant/Award Number:52003248Henan Province Youth Health Science and Technology Innovation Talent Training Program,Grant/Award Number:YQRC2023007+1 种基金Henan Province Excellent Youth Science Fund,Grant/Award Number:242300421064Joint Fund Predominant Discipline Cultivation Project of Henan Province,Grant/Award Number:232301420036.
文摘Switchable radiative cooling/heating holds great promise for mitigating the global energy and environmental crisis.Here,we reported a cost-effective,high-strength Janus film through surface optical engineering waste paper with one side decorated by a hydrophobic polymeric cooling coating consisting of micro/nanopore/particle hierarchical structure and the other side coated with hydrophilic MXene nanosheets for heating.The cooling surface demonstrates high solar reflectivity(96.3%)and infrared emissivity(95.5%),resulting in daytime/nighttime sub-ambient radiative cooling of 6℃/8℃with the theoretical cooling power of 100.6 and 138.5Wm^(−2),respectively.The heating surface exhibits high solar absorptivity(83.7%)and low infrared emissivity(15.2%),resulting in excellent radiative heating capacity for vehicle charging pile(~6.2℃)and solar heating performance.Impressively,the mechanical strength of Janus film increased greatly by 563%compared with that of pristine waste paper,which is helpful for its practical applications in various scenarios for switchable radiative thermal management through mechanical flipping.Energy-saving simulation results reveal that significant total energy savings of up to 32.4MJm^(−2) can be achieved annually(corresponding to the 12.4%saving ratio),showing the immense importance of reducing carbon footprint and promoting carbon neutrality.
基金Supported by National Natural Science Foundation of China(Grant Nos.52035004,52105434).
文摘Hierarchical micro/nanograting structures have attracted increasing attention owing to their significant applications in the fields of structural coloring,anti-counterfeiting,and decoration.Thus,the fabrication of hierarchical micro/nanograting structures is important for these applications.In this study,a strategy for machining hierarchical micro/nanograting structures is developed by controlling the tool movement trajectory.A coupling Euler-Lagrange finite element model is established to simulate the machining process.The effect of the machining methods on the nanograting formation is demonstrated,and a suitable machining method for reducing the cutting force is obtained.The height of the nanograting decreases with an increase in the tool edge radius.Furthermore,optical variable devices(OVDs)are machined using an array overlap machining approach.Coding schemes for the parallel column unit crossover and column unit in the groove crossover are designed to achieve high-quality machining of OVDs.The coloring of the logo of the Harbin Institute of Technology and the logo of the centennial anniversary of the Harbin Institute of Technology on the surface of metal samples,such as aluminum alloys,is realized.The findings of this study provide a method for the fabrication of hierarchical micro/nanograting structures that can be used to prepare OVDs.
基金supported by the Nuclear Safety Research Program through Korea Foundation of Nuclear Safety(KoFONS)using the financial resource granted by the Nuclear Safety and Security Commission(NSSC)of the Republic of Korea(Grant number:2106061,50%)supported by the Institute of Information&Communications Technology Planning&Evaluation(IITP)grant funded by the Korea government(MSIT)(RS-2025-25394739,Development of Security Enhancement Technology for Industrial Control Systems Based on S/HBOM Supply Chain Protection,50%).
文摘With the continuous expansion of digital infrastructures,malicious behaviors in host systems have become increasingly sophisticated,often spanning multiple processes and employing obfuscation techniques to evade detection.Audit logs,such as Sysmon,offer valuable insights;however,existing approaches typically flatten event sequences or rely on generic graph models,thereby discarding the natural parent-child process hierarchy that is critical for analyzing multiprocess attacks.This paper proposes a structure-aware threat detection framework that transforms audit logs into a unified two-dimensional(2D)spatio-temporal representation,where process hierarchy is modeled as the spatial axis and event chronology as the temporal axis.In addition,entropy-based features are incorporated to robustly capture obfuscated and non-linguistic strings,overcoming the limitations of semantic embeddings.The model’s performance was evaluated on publicly available datasets,achieving competitive results with an accuracy exceeding 95%and an F1-score of at least 0.94.The proposed approach provides a promising and reproducible solution for detecting attacks with unknown indicators of compromise(IoCs)by analyzing the relationships and behaviors of processes recorded in large-scale audit logs.
基金supported by“Shanghai Science and Technology Innovation Action Plan”-Baoshan Transformation Development Science and Technology Special Project (No.21SQBS01100)the National Natural Science Foundation of China (Nos.22276137 and52170087)。
文摘Gas adsorption remains an attractive area of research.The hierarchical structure can reduce diffusion limitations and facilitate molecular transport,while acid sites can be used as adsorption sites.These make zeolites widely used in the field of gas adsorption.How to obtain zeolite adsorbents with better adsorption properties by modulating the hierarchical structure and acid sites is a pressing issue nowadays.This review highlights the strategies to modulate the hierarchical structure as well as the acid sites;and then explains how these strategies are achieved.The mechanism of zeolite adsorption on gases is then described in terms of these two properties.Lastly,the adsorption properties of zeolites for certain gases under specific conditions are summarised.An outlook of zeolite hierarchical structures and acid site modulation strategies is given.
基金supported by the National Key Research and Development Program of China(No.2021YFC2400201)the National Natural Science Foundation of China(No.81830033)+1 种基金the Natural Science Foundation of Fujian Province,China(No.2023J05097)the Young and Middle-aged Teacher Education Research Project of the Education Department of Fujian Province,China(No.JAT220004)。
文摘Conducting polymers(CPs),including poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS),are promising coating materials for neural electrodes.However,the weak adhesion of CP coatings to substrates such as platinum-iridium is a significant challenge that limits their practical application.To address this issue,we used femtosecond laser-prepared hierarchical structures on platinum-iridium(Pt-Ir)substrates to enhance the adhesion of PEDOT:PSS coatings.Next,we used cyclic voltammetry(CV)stress and accelerated aging tests to evaluate the stability of both drop cast and electrodeposited PEDOT:PSS coatings on Pt-Ir substrates,both with and without hierarchical structures.Our results showed that after 2000 CV cycles or five weeks of aging at 60℃,the morphology and electrochemical properties of the coatings on the Pt-Ir substrates with hierarchical structures remained relatively stable.In contrast,we found that smooth Pt-Ir substrate surfaces caused delamination of the PEDOT:PSS coating and exhibited both decreased charge storage capacity and increased impedance.Overall,enhancing the stability of PEDOT:PSS coatings used on common platinum-iridium neural electrodes offers great potential for improving their electrochemical performance and developing new functionalities.
基金supported by the National Key Research and Development Program of China(No.2021YFB3501001)the National Natural Science Foundation of China(Nos.52061028,and 52061039)+1 种基金the Natural Science Foundation of Jiangxi Province(No.20212BAB204049)the Interdisciplinary Innovation Fund of Nanchang University(IIFNCU),China(No.9166–27060003-ZD05).
文摘Currently,the hierarchical structure is one of the most effective means to enhance the strength and plasticity of metal materials,since the strain localization can be effectively delayed by the coordination of the unique microstructure.In this study,a hierarchical structure of Mg-15Gd-1Zn-0.4Zr(GZ151K)alloys containing grain,twin,and precipitation structural units was prepared by ultrasonic surface rolling process(USRP)and recrystallization annealing(RU).The results showed that the stress gradient generated by USRP formed a twin gradient structure,which will activate the twin-assisted precipitation(TAP)effect and twin-induced recrystallization(TIR)effect during RU.Then,the twin gradient structure transformed into a twin-precipitation gradient structure,and finally into a hierarchical structure with grain-twinprecipitation as the increasement of recrystallization degree.Besides,the dual gradient structure with twin and precipitation structural units had the highest strength and microhardness owing to the precipitation strengthening.However,the hierarchical structure with grain,twin,and precipitation structural units exhibited the most excellent combination of strength and plasticity under grain refinement and precipitation strengthening.
基金National Natural Science Foundation of China(No.52173261).
文摘SiBCN ceramic aerogel is an ideal potential candidate for ultra-high temperature thermal insulation due to its unique microscopic pore structure combined with the excellent thermal stability of SiBCN ce-ramic.Here,reduced graphene oxide(rGO)modified SiBCN aerogels(rGO/SiBCN)were prepared through solvothermal,freeze-casting and pyrolysis,and the dimension of the aerogel is up toΦ130 mm×28 mm.The density of the rGO/SiBCN aerogel is as low as 0.024 g/cm^(3) and the microstructural regulation is achieved by controlling the rGO content in the aerogel.The hierarchical cellular structure endows the aerogel with a high specific surface area(148.6 m^(2)/g)and low thermal conductivity(0.057 W m^(-1) K^(-1)).The 10 mm-thick sample exhibits excellent thermal insulation and ablation resistance,as evidenced by its ability to reduce the temperature from~1100℃to~180℃under the intense heat of a butane flame.Moreover,benefiting from the ultrahigh-temperature stability of SiBCN,the rGO/SiBCN aerogel exhibits good thermal stability up to 1200℃in argon and short-oxidation resistance at 800℃in air.There-fore,the rGO/SiBCN aerogel with superior overall performance could expand its practical application in high-temperature thermal insulation under extreme environments.
基金National Natural Science Foundation of China,Grant/Award Numbers:52102260,52171211,51972220,61903235,U22A20145Shandong Provincial Natural Science Foundation,Grant/Award Numbers:ZR2020QB069,ZR2022ME051+4 种基金National Key Research and Development Program of China,Grant/Award Number:2022YFB4002004Scientific and Technological Innovation Ability Improvement Project of Minor Enterprises in Shandong Province,Grant/Award Number:2022TSGC1021Announce the List and Take Charge Project in Jinan,Grant/Award Number:202214012Major innovation project for integrating science,education and industry of Qilu University of Technology (Shandong Academy of Sciences),Grant/Award Numbers:2022JBZ01-07,2022PY044China Postdoctoral Science Foundation,Grant/Award Number:2022M711545。
文摘Enhancing both the number of active sites available and the intrinsic activity of Co-based electrocatalysts simultaneously is a desirable goal.Herein,a ZIF-67-derived hierarchical porous cobalt sulfide decorated by Au nanoparticles(NPs)(denoted as HP-Au@CoxSy@ZIF-67)hybrid is synthesized by low-temperature sulfuration treatment.The well-defined macroporous-mesoporous-microporous structure is obtained based on the combination of polystyrene spheres,as-formed CoxSy nanosheets,and ZIF-67 frameworks.This novel three-dimensional hierarchical structure significantly enlarges the three-phase interfaces,accelerating the mass transfer and exposing the active centers for oxygen evolution reaction.The electronic structure of Co is modulated by Au through charge transfer,and a series of experiments,together with theoretical analysis,is performed to ascertain the electronic modulation of Co by Au.Meanwhile,HP-Au@CoxSy@ZIF-67 catalysts with different amounts of Au were synthesized,wherein Au and NaBH4 reductant result in an interesting“competition effect”to regulate the relative ratio of Co^(2+)/Co^(3+),and moderate Au assists the electrochemical performance to reach the highest value.Consequently,the optimized HP-Au@CoxSy@ZIF-67 exhibits a low overpotential of 340 mV at 10 mA cm^(-2)and a Tafel slope of 42 mV dec-1 for OER in 0.1 M aqueous KOH,enabling efficient water splitting and Zn-air battery performance.The work here highlights the pivotal roles of both microstructural and electronic modulation in enhancing electrocatalytic activity and presents a feasible strategy for designing and optimizing advanced electrocatalysts.
基金supported by the National Key R&D program of China(2023YFE0207000)the National Natural Science Foundation of China(Grant No.51975283 and U22B2040)the Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(Grant No.1005-IZD2300225).
文摘Flexible attachment actuators are popular in a wide range of applications,owing to their flexibility and highly reliable attachment.However,their reversible adhesion performance depends on the actual effective contact area and peel angle during operation.Therefore,a good actuator must ensure a uniform and reliable pre-pressure load on an adhesive surface,to increase the effective contact area of the attached surface,thereby maximizing adhesion.This study was inspired by fusion bionics for designing a hierarchical attachment structure with vacuum-adsorption and dry-adhesion mechanisms.The designed structure used the normal force under the negative pressure of a suction cup as a stable source of a pre-pressure load.By optimizing the rigid and flexible structural layers of the attachment structure,a load was applied uniformly to the adhesion area;thus,reliable attachment was achieved by self-preloading.The structure achieved detachment by exploiting the large deformation of a pneumatic structure under a positive pressure.The hierarchical attachment structure achieved up to 85%of the optimal performance of the adhesive surface.Owing to its self-preloading and reliable attachment characteristics,the designed structure can be used as an attachment unit in various complex scenarios,such as small,lightweight climbing platforms and the transport of objects in long,narrow pipelines.
文摘Some living organisms with hierarchical structures in nature have received extensive attention in various fields.The hierarchical structure with multiple pores,a large number of solid-gas interfaces and tortuous conduction paths provide a new direction for the development of thermal insulation materials,making the living creatures under these extreme conditions become the bionic objects of scientific researchers.In this review,the research progress of bionic hierarchical structure in the field of heat insulation is highlighted.Polar bears,cocoons,penguin feathers and wool are typical examples of heat preservation hierarchy in nature to introduce their morphological characteristics.At the same time,the thermal insulation mechanism,fractal model and several preparation methods of bionic hierarchical structures are emphatically discussed.The application of hierarchical structures in various fields,especially in thermal insulation and infrared thermal stealth,is summarised.Finally,the hierarchical structure is prospected.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52105303 and 52025053)Natural Science Foundation of Jilin Province(No.20220101209JC)Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52021003).
文摘Amplifying the intrinsic wettability of substrate material by changing the solid/liquid contact area is considered to be the main mechanism for controlling the wettability of rough or structured surfaces.Through theoretical analysis and experimental exploration,we have found that in addition to this wettability structure amplification effect,the surface structure also simultaneously controls surface wettability by regulating the wetting state via changing the threshold Young angles of the Cassie-Baxter and Wenzel wetting regions.This wetting state regulation effect provides us with an alternative strategy to overcome the inherent limitation in surface chemistry by tailoring surface structure.The wetting state regulation effect created by multi-scale hierarchical structures is quite significant and plays is a crucial role in promoting the superhydrophobicity,superhydrophilicity and the transition between these two extreme wetting properties,as well as stabilizing the Cassie-Baxter superhydrophobic state on the fabricated lotus-like hierarchically structured Cu surface and the natural lotus leaf.
基金approved by the Science and Ethics Committee of the School of Biological Science and Medical Engineering at Beihang University(protocol code:BM201900125).
文摘When a human lands from a high drop,there is a high risk of serious injury to the lower limbs.On the other hand,cats can withstand jumps and falls from heights without being fatally wounded,largely due to their impact-resistant paw pads.The aim of the present study was to investigate the biomechanism of impact resistance in cat paw pads,propose an optimal hierarchical Voronoi structure inspired by the paw pads,and apply the structure to bionic cushioning shoes to reduce the impact force of landing for humans.The microstructure of cat paw pads was observed via tissue section staining,and a simulation model was reconstructed based on CT to verify and optimize the structural cushioning capacity.The distribution pattern,wall thickness of compartments,thickness ratio of epidermis and dermis,and number of compartments in the model were changed and simulated to achieve an optimal composed structure.A bionic sole was 3D-printed,and its performance was evaluated via compression test and a jumping-landing experiment.The results show that cat paw pads are a spherical cap structure,divided from the outside to the inside into the epidermis,dermis,and compartments,each with different cushioning capacities.A finite element simulation of different cushioning structures was conducted in a cylinder with a diameter of 20 mm and a height of 10 mm,featuring a three-layer structure.The optimal configuration of the three layers should have a uniform distribution with 0.3–0.5 mm wall thickness,a 1:1–2 thickness ratio of epidermis and dermis,and 100–150 compartments.A bionic sole with an optimized structure can reduce the peak impact force and delay the peak arrival time.Its energy absorption rate is about 4 times that of standard sole.When jumping 80,100,and 120 cm,the normalized ground reaction force is also reduced by 8.7%,12.6%and 15.1%compared with standard shoes.This study provides theoretical and technical support for effective protection against human lower limb landing injuries.
基金supported by the National Natural Science Foundation of China(Grant No.82372391,82001971,82102358,82202698,52105343,U21A2099 and U23A20523)Project of“Medical+X”interdisciplinary innovation team of Norman Bethune Health Science Center of Jilin University(Grant No.2022JBGS06)+5 种基金Project of youth interdisciplinary innovation team of Jilin University(Grant No.419070623054)China Postdoctoral Science Foundation(Grant No.2021M701384)Bethune Plan of Jilin University(Grant No.2022B27,2022B03)Wu Jieping Medical Foundation(Grant No.320.6750.18522)Scientific Development Program of Jilin Province(Grant No.20220402067GH)Jilin Province Development and Reform Commission(Grant No.2022C044-2).
文摘3D-printed Porous Titanium Alloy Implants(pTi),owing to their biologically inertness and relatively smooth surface morphology,adversely affect the biological functions of surrounding cells.To address the challenges,constructing a bioinspired interface that mimics the hierarchical structure of bone tissue can enhance the cellular functions of cells.In this context,Hollow Mesoporous Silica Nanoparticles(HMSNs),renowned for their unique physicochemical properties and superior biocompatibility,offer a promising direction for this research.In this research,the initially synthesized HMSNs were used to construct a“hollow-mesoporous-macroporous”hierarchical bioinspired coating on the pTi surface through the Layer-by-Layer technique.Simultaneously,diverse morphologies of coatings were established by adjusting the deposition strategy of PDDA/HMSNs on the pTi surface(pTi-HMSN-2,pTi-HMSN-4,pTi-HMSN-6).A range of techniques were employed to investigate the physicochemical properties and regulation of cellular biological functions of the diverse HMSN coating strategies.Notably,the pTi-HMSN-4 and pTi-HMSN-6 groups exhibited the uniform coatings,leading to a substantial enhancement in surface roughness and hydrophilicity.Meantime,the coating constructed strategy of pTi-HMSN-4 possessed commendable stability.Based on the aforementioned findings,both pTi-HMSN-4 and pTi-HMSN-6 facilitated the adhesion,spreading,and pseudopodia extension of BMSCs,which led to a notable upsurge in the expression levels of vinculin protein in BMSCs.Comprehensive analysis indicates that the coating,when PDDA/HMSNs are deposited four times,possesses favorable overall performance.The research will provide a solid theoretical basis for the translation of HMSN bioinspired coatings for orthopedic implants.
基金financially supported by the National Natural Science Foundation of China(No.12174092,21902046,U21A20500)Overseas Expertise Introduction Center for Discipline Innovation(D18025)+1 种基金Hubei Provincial Department of Science and Technology(No.2019CFA079)Wuhan Science and Technology Bureau(2020010601012163)
文摘Development of metal oxide semiconductors-based methane sensors with good response and low power consumption is one of the major challenges to realize the real-time monitoring of methane leakage.In this work,a self-assembled mulberry-like ZnO/SnO_(2)hierarchical structure is constructed by a two-step hydrothermal method.The resultant sensor works at room temperature with excellent response of~56.1%to 2000 ppm CH_(4)at 55%relative humidity.It is found that the strain induced at the ZnO/SnO_(2)interface greatly enhances the piezoelectric polarization on the ZnO surface and that the band bending results in the accumulation of chemically adsorbed O_(2)^(-)ions close to the interface,leading to significant improvement in the sensing performance of the methane gas sensor at room temperature.
基金sponsored by National Natural Science Foundation of China(No.52302121,No.52203386)Shanghai Sailing Program(No.23YF1454700)+1 种基金Shanghai Natural Science Foundation(No.23ZR1472700)Shanghai Post-doctoral Excellent Program(No.2022664).
文摘With vigorous developments in nanotechnology,the elaborate regulation of microstructure shows attractive potential in the design of electromagnetic wave absorbers.Herein,a hierarchical porous structure and composite heterogeneous interface are constructed successfully to optimize the electromagnetic loss capacity.The macro–micro-synergistic graphene aerogel formed by the ice template‑assisted 3D printing strategy is cut by silicon carbide nanowires(SiC_(nws))grown in situ,while boron nitride(BN)interfacial structure is introduced on graphene nanoplates.The unique composite structure forces multiple scattering of incident EMWs,ensuring the combined effects of interfacial polarization,conduction networks,and magnetic-dielectric synergy.Therefore,the as-prepared composites present a minimum reflection loss value of−37.8 dB and a wide effective absorption bandwidth(EAB)of 9.2 GHz(from 8.8 to 18.0 GHz)at 2.5 mm.Besides,relying on the intrinsic high-temperature resistance of SiC_(nws) and BN,the EAB also remains above 5.0 GHz after annealing in air environment at 600℃ for 10 h.
基金financially supported by the Materials/Parts Technology Development Program(No.RS-202400456324)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)by the National Research Foundation(NRF)of Korea grant(No.RS-2024-00454367)funded by the Ministry of Science and ICT(MSIT,Korea)。
文摘K–Se batteries have been identified as promising energy storage systems owing to their high energy density and cost-effectiveness.However,challenges such as substantial volume changes and low Se utilization require further investigation.In this study,novel N-doped multichannel carbon nanofibers(h-NMCNFs)with hierarchical porous structures were successfully synthesized as efficient cathode hosts for K–Se batteries through the carbonization of two electrospun immiscible polymer nanofibers and subsequent chemical activation.Mesopores originated from the decomposition of the polymer embedded in the carbon nanofibers,and micropores were introduced via KOH activation.During the activation step,hierarchical porous carbon nanofibers with enhanced pore volumes were formed because of the micropores in the carbon nanofibers.Owing to the mesopores that enabled easy access to the electrolyte and the high utilization of chain-like Se within the micropores,the Se-loaded hierarchical porous carbon nanofibers(60 wt%Se)exhibited a high discharge capacity and excellent rate performance.The discharge capacity of the nanofibers at the 1,000th cycle was 210.8 mA.h.g^(-1)at a current density of 0.5C.The capacity retention after the initial activation was 64%.In addition,a discharge capacity of 165 mA.h.g^(-1)was obtained at an extremely high current density of 3.0C.
