Integrating wave energy converters(WECs)with offshore platforms offers numerous advantages,such as reducing wave loads,supplying energy to the platform,and cost-sharing in construction.This paper reports an experiment...Integrating wave energy converters(WECs)with offshore platforms offers numerous advantages,such as reducing wave loads,supplying energy to the platform,and cost-sharing in construction.This paper reports an experimental investigation focusing on the hydrodynamic characteristics of a proposed modular floating structure system integrated with WEC-type floating artificial reefs.The proposed system comprises several serially arranged hexagonal floating structures,anchored by tension legs,and integrated with outermost WEC-type floating artificial reefs.A simplified wave energy converter utilizing the relative pitch motion between adjacent modules for energy conversion was constructed in the scale model test.The effects of chain-type modular expansion on the multi-body motion response,mooring tension response,and WEC performance of the system have been thoroughly investigated.The experimental results indicate that increasing the number of hexagonal modules can notably reduce the system’s surge response,particularly under survival sea conditions.The connection of the outermost reef modules slightly increases the tension leg load of the adjacent module,whereas the tension leg load remains relatively consistent across the inner hexagonal modules.Furthermore,through a comparison of the dynamic responses of the hexagonal module connected and unconnected outermost reefs,the good performance in terms of energy conversion and wave attenuation of the WECtype floating artificial reef modules was effectively validated.The main results from this work can provide useful references for engineering applications involving modular floating structures integrated with WECs.展开更多
In this paper, we propose a novel anomaly detection method for data centers based on a combination of graphstructure and abnormal attention mechanism. The method leverages the sensor monitoring data from targetpower s...In this paper, we propose a novel anomaly detection method for data centers based on a combination of graphstructure and abnormal attention mechanism. The method leverages the sensor monitoring data from targetpower substations to construct multidimensional time series. These time series are subsequently transformed intograph structures, and corresponding adjacency matrices are obtained. By incorporating the adjacency matricesand additional weights associated with the graph structure, an aggregation matrix is derived. The aggregationmatrix is then fed into a pre-trained graph convolutional neural network (GCN) to extract graph structure features.Moreover, both themultidimensional time series segments and the graph structure features are inputted into a pretrainedanomaly detectionmodel, resulting in corresponding anomaly detection results that help identify abnormaldata. The anomaly detection model consists of a multi-level encoder-decoder module, wherein each level includesa transformer encoder and decoder based on correlation differences. The attention module in the encoding layeradopts an abnormal attention module with a dual-branch structure. Experimental results demonstrate that ourproposed method significantly improves the accuracy and stability of anomaly detection.展开更多
A launching system with a filter cartridge structure was proposed to improve the muzzle velocity of the projectile.The combustion chamber of the launching system is divided into two fixed chambers,one is located in th...A launching system with a filter cartridge structure was proposed to improve the muzzle velocity of the projectile.The combustion chamber of the launching system is divided into two fixed chambers,one is located in the breech chamber,and the other is arranged in the barrel.The breech chamber charge was ignited first,and the charges in the auxiliary chambers were ignited by the high-temperature,highpressure combustible gas trailing the projectile.In this way,the combustible gas in the auxiliary chambers could compensate for the pressure drop caused by the movement of the projectile.The proposed device features the advantage of launching a projectile with high muzzle velocity without exceeding the maximum pressure in the chamber.In order to obtain some internal ballistic characteristics of the launch system,some critical structure,such as the length of the filter cartridge auxiliary charge,the combustion degree of the propellant in the chamber,and the length of the barrel,are discussed.The experimental results show that with the increased auxiliary charge length,a pressure plateau or even a secondary peak pressure can be formed,which is less than the peak pressure.The projectile velocity increased by 23.57%,14.64%,and 7.65%when the diaphragm thickness was 0 mm,1 mm,and2 mm,respectively.The muzzle velocity of the projectile can be increased by 13.42%by increasing the length of the barrel.Under the same charge condition,with the increase of barrel length,the energy utilization rate of propellant increases by 28.64%.展开更多
In an effort to clarify the formation mechanism of LPSO structure in Mg-Y-Zn alloy,the chemical environment and structural ordering in liquid Mg-rich Mg-Y-Zn system are investigated with the aid of ab-initio molecular...In an effort to clarify the formation mechanism of LPSO structure in Mg-Y-Zn alloy,the chemical environment and structural ordering in liquid Mg-rich Mg-Y-Zn system are investigated with the aid of ab-initio molecular dynamics simulation.In liquid Mg-rich Mg-Y alloys,the strong Mg-Y interaction is determined,which promotes the formation of fivefold symmetric local structure.For Mg-Zn alloys,the weak Mg-Zn interaction results in the fivefold symmetry weakening in the liquid structure.Due to the coexistence of Y and Zn,the strong attractive interaction is introduced in liquid Mg-Y-Zn ternary alloy,and contributes to the clustering of Mg,Y,Zn launched from Zn.What is more,the distribution of local structures becomes closer to that in pure Mg compared with that in binary Mg-Y and Mg-Zn alloys.These results should relate to the origins of the Y/Zn segregation zone and close-packed stacking mode in LPSO structure,which provides a new insight into the formation mechanism of LPSO structure at atomic level.展开更多
In this study,a novel equivalent damping ratio model that is suitable for reinforced concrete(RC)structures considering cyclic degradation behavior is developed,and a new equivalent linearization analysis method for i...In this study,a novel equivalent damping ratio model that is suitable for reinforced concrete(RC)structures considering cyclic degradation behavior is developed,and a new equivalent linearization analysis method for implementing the proposed equivalent damping ratio model for use in seismic damage evaluation is presented.To this end,Ibarra’s peak-oriented model,which incorporates an energy-based degradation rule,is selected for representing hysteretic behavior of RC structure,and the optimized equivalent damping for predicting the maximum displacement response is presented by using the empirical method,in which the effect of cyclic degradation is considered.Moreover,the relationship between the hysteretic energy dissipation of the inelastic system and the elastic strain energy of the equivalent linear system is established so that the proposed equivalent linear system can be directly integrated with the Park-Ang seismic model to implement seismic damage evaluation.Due to the simplicity of the equivalent linearization method,the proposed method provides an efficient and reliable way of obtaining comprehensive insight into the seismic performance of RC structures.The verification demonstrates the validity of the proposed method.展开更多
Internal polyhedral structures of a granular system can be investigated using the Voronoi tessellations.This technique has gained increasing recognition in research of kinetic properties of granular flows.For systems ...Internal polyhedral structures of a granular system can be investigated using the Voronoi tessellations.This technique has gained increasing recognition in research of kinetic properties of granular flows.For systems with mono-sized spherical particles,Voronoi tessellations can be utilized,while radial Voronoi tessellations are necessary for analyzing systems with multi-sized spherical particles.However,research about polyhedral structures of non-spherical particle systems is limited.We utilize the discrete element method to simulate a system of ellipsoidal particles,defined by the equation(x/a)^(2)+(y/1)^(2)+(z/1/a)^(2)=1,where a ranges from 1.1 to 2.0.The system is then dissected by using tangent planes at the contact points,and the geometric quantities of the resulting polyhedra in different shaped systems,such as surface area,volume,number of vertices,number of edges,and number of faces,are calculated.Meanwhile,the longitudinal and transverse wave velocities within the system are calculated with the time-of-flight method.The results demonstrate a strong correlation between the sound velocity of the system and the geometry of the dissected polyhedra.The sound velocity of the system increases with the increase in a,peaking at a=1.3,and then decreases as a continues to increase.The average volume,surface area,number of vertices,number of edges,and number of faces of the polyhedra decrease with the increase in sound velocity.That is,these quantities initially decrease with the increase in a,reaching minima at a=1.3,and then increase with further increase of a.The relationship between sound velocity and the geometric quantities of the dissected polyhedra can serve as a reference for acoustic material design.展开更多
Triboelectric nanogenerators(TENG),renowned for their remarkable capability to harness weak mechanical energy from the environment,have gained considerable attention owing to their cost-effectiveness,high output,and a...Triboelectric nanogenerators(TENG),renowned for their remarkable capability to harness weak mechanical energy from the environment,have gained considerable attention owing to their cost-effectiveness,high output,and adaptability.This review provides a unique perspective by conducting a comprehensive and in-depth analysis of magnetically assisted TENGs that encompass structures,materials,and self-powered sensing systems.We systematically summarize the diverse functions of the magnetic assistance for TENGs,including system stiffness,components of the hybrid electromagnetic-triboelectric generator,transmission,and interaction forces.In the material domain,we review the incorporation of magnetic nano-composites materials,along with ferrofluid-based TENG and microstructure verification,which have also been summarized based on existing research.Furthermore,we delve into the research progress on physical quantity sensing and human-machine interface in magnetic-assisted TENGs.Our analysis highlights that magnetic assistance extends beyond the repulsive and suction forces under a magnetic field,thereby playing multifaceted roles in improving the output performance and environmental adaptability of the TENGs.Finally,we present the prevailing challenges and offer insights into the future trajectory of the magnetic-assisted TENGs development.展开更多
The deep structure,material circulation,and dynamic processes in the Southeast Asia have long been an elusive scientific puzzle due to the lack of systematic scientific observations and recognized theoretical models.B...The deep structure,material circulation,and dynamic processes in the Southeast Asia have long been an elusive scientific puzzle due to the lack of systematic scientific observations and recognized theoretical models.Based on the deep seismic tomography using long-period natural earthquake data,in this study,the deep structure and material circulation of the curved subduction system in Southeast Asia was studied,and the dynamic processes since 100 million years ago was reconstructed.It is pointed out that challenges still exist in the precise reconstruction of deep mantle structures of the study area,the influence of multi-stage subduction on deep material exchange and shallow magma activity,as well as the spatiotemporal evolution and coupling mechanism of multi-plate convergence.Future work should focus on high-resolution land-sea joint 3-D seismic tomography imaging of the curved subduction system in the Southeast Asia,combined with geochemical analysis and geodynamic modelling works.展开更多
Aim: This paper aims to evaluate disparities of type 2 diabetes structured health education programmes that is utilised within the communities. Design: systematic review, (a type of secondary research design) aiming t...Aim: This paper aims to evaluate disparities of type 2 diabetes structured health education programmes that is utilised within the communities. Design: systematic review, (a type of secondary research design) aiming to summarize the results of prior primary research studies on available evidence Community type 2 diabetes structured education (CT2DSHE). Methods: Research question: Type 2 diabetic structured health education within a community how effective is it? Qualitative Systematic review, defined as a way to get reliable and objective picture of current available evidence on the specific topic—(CT2DSHE), (Denscombe, 2021) through reflexivity synthesis of available data as an example. This is valuable in time constraints such as project assignments that must be met within specific time and also to bring together available evidence together [1]. Results: This review has shown that CT2DSHE is effective with seven out of the eleven authors supporting, three authors against and one was neutral, further showed that knowledge and skills acquired can last longer with patient activation improved among T2DM patients ideal for sustaining their self-management of T2DM. Conclusion: This research provides suggestive answers to the research question: “Type 2 diabetic structured health education within a community how effective is it?”, This has demonstrated CT2DSHE effectiveness in knowledge acquisition and improving T2DM awareness among T2DM patients, whilst evidencing long effects beyond the study times of 3 - 9 months period in relation to patient activation. Also Identified diabetes education self-management on newly diagnosed (DESMOND) patient as CT2DSHE program for recommendation. Patient or Public Contribution: This work aspires to contribute to CT2DSHE in these areas;Influencing policy decision-making for community diabetes care within the UK and world at large., Contributing to already vast knowledge on diabetes self-management and reasons why?, Influencing educators on how CT2DSHEP are designed, delivered by putting the patient at the Centre and bringing different perspectives on CT2DSHEP in one place that is serving users time of having to consult several resources especially busy clinicians [2] [3].展开更多
Vision-based measurement technology benefits high-quality manufacturers through improved dimensional precision,enhanced geo-metric tolerance,and increased product yield.The monocular 3D structured light visual sensing...Vision-based measurement technology benefits high-quality manufacturers through improved dimensional precision,enhanced geo-metric tolerance,and increased product yield.The monocular 3D structured light visual sensing method is popular for detecting online parts since it can reach micron-meter depth accuracy.However,the line-of-sight requirement of a single viewpoint vision system often fails when hiding occurs due to the object’s surface structure,such as edges,slopes,and holes.To address this issue,a multi-view 3D structured light vi-sion system is proposed in this paper to achieve high accuracy,i.e.,Z-direction repeatability,and reduce hiding probability during mechani-cal dimension measurement.The main contribution of this paper includes the use of industrial cameras with high resolution and high frame rates to achieve high-precision 3D reconstruction.Moreover,a multi-wavelength(heterodyne)phase expansion method is employed for high-precision phase calculation.By leveraging multiple industrial cameras,the system overcomes field of view occlusions,thereby broadening the 3D reconstruction field of view.Finally,the system achieves a Z-axis repetition accuracy of 0.48µm.展开更多
The combination of structural health monitoring and vibration control is of great importance to provide components of smart structures.While synthetic algorithms have been proposed,adaptive control that is compatible ...The combination of structural health monitoring and vibration control is of great importance to provide components of smart structures.While synthetic algorithms have been proposed,adaptive control that is compatible with changing conditions still needs to be used,and time-varying systems are required to be simultaneously estimated with the application of adaptive control.In this research,the identification of structural time-varying dynamic characteristics and optimized simple adaptive control are integrated.First,reduced variations of physical parameters are estimated online using the multiple forgetting factor recursive least squares(MFRLS)method.Then,the energy from the structural vibration is simultaneously specified to optimize the control force with the identified parameters to be operational.Optimization is also performed based on the probability density function of the energy under the seismic excitation at any time.Finally,the optimal control force is obtained by the simple adaptive control(SAC)algorithm and energy coefficient.A numerical example and benchmark structure are employed to investigate the efficiency of the proposed approach.The simulation results revealed the effectiveness of the integrated online identification and optimal adaptive control in systems.展开更多
Currently,the Al_(2)O_(3)content in the high-alumina slag systems within blast furnaces is generally limited to 16wt%–18.5wt%,making it challenging to overcome this limitation.Unlike most studies that concentrated on...Currently,the Al_(2)O_(3)content in the high-alumina slag systems within blast furnaces is generally limited to 16wt%–18.5wt%,making it challenging to overcome this limitation.Unlike most studies that concentrated on managing the MgO/Al_(2)O_(3)ratio or basicity,this paper explored the effect of equimolar substitution of MgO for CaO on the viscosity and structure of a high-alumina CaO-MgO-Al_(2)O_(3)-SiO_(2)slag system,providing theoretical guidance and data to facilitate the application of high-alumina ores.The results revealed that the viscosity first decreased and then increased with higher MgO substitution,reaching a minimum at 15mol%MgO concentration.Fourier transform infrared spectroscopy(FTIR)results found that the depths of the troughs representing[SiO_(4)]tetrahedra,[AlO_(4)]tetrahedra,and Si-O-Al bending became progressively deeper with increased MgO substitution.Deconvolution of the Raman spectra showed that the average number of bridging oxygens per Si atom and the X_(Q^(3))/X_(Q^(2))(X_(Q^(i))is the molar fraction of Q^(i) unit,and i is the number of bridging oxygens in a[SiO_(4)]tetrahedral unit)ratio increased from 2.30 and 1.02 to 2.52 and 2.14,respectively,indicating a progressive polymerization of the silicate structure.X-ray photoelectron spectroscopy(XPS)results highlighted that non-bridging oxygen content decreased from 77.97mol% to 63.41mol% with increasing MgO concentration,whereas bridging oxygen and free oxygen contents increased.Structural analysis demonstrated a gradual increase in the polymerization degree of the tetrahedral structure with the increase in MgO substitution.However,bond strength is another important factor affecting the slag viscosity.The occurrence of a viscosity minimum can be attributed to the complex evolution of bond strengths of non-bridging oxygens generated during depolymerization of the[SiO_(4)]and[AlO_(4)]tetrahedral structures by CaO and MgO.展开更多
To analyze the seismic response of steel structure isolation systems under long-period seismic motion,a 9-story steel frame building was selected as the subject.Five steel structure finite element models were establis...To analyze the seismic response of steel structure isolation systems under long-period seismic motion,a 9-story steel frame building was selected as the subject.Five steel structure finite element models were established using SAP2000.Response spectrum analysis was conducted on the seismic motion to determine if it adhered to the characteristics of long-period seismic motion.Modal analysis of each structural model revealed that the isolation structure significantly prolonged the structural natural vibration period and enhanced seismic performance.Base reactions and floor displacements of various structures notably increased under long-period seismic motion compared to regular seismic activity.Placing isolation bearings in the lower part of the structure proved more effective under long-period seismic motion.In seismic design engineering,it is essential to consider the impact of long-period seismic motion on structures and the potential failure of isolation bearings.展开更多
The rapid development of 5G communication technology and smart electronic and electrical equipment will inevitably lead to electromagnetic radiation pollution.Enriching heterointerface polarization relaxation through ...The rapid development of 5G communication technology and smart electronic and electrical equipment will inevitably lead to electromagnetic radiation pollution.Enriching heterointerface polarization relaxation through nanostructure design and interface modifica-tion has proven to be an effective strategy to obtain efficient electromagnetic wave absorption.Here,this work implements an innovative method that combines biomimetic honeycomb superstructure to constrain hierarchical porous heterostructure composed of Co/CoO nano-particles to improve the interfacial polarization intensity.The method effectively controlled the absorption efficiency of Co^(2+)through de-lignification modification of bamboo,and combined with the bionic carbon-based natural hierarchical porous structure to achieve uniform dispersion of nanoparticles,which is conducive to the in-depth construction of heterogeneous interfaces.In addition,the multiphase struc-ture brought about by high-temperature pyrolysis provides the best dielectric loss and impedance matching for the material.Therefore,the obtained bamboo-based Co/CoO multiphase composite showed excellent electromagnetic wave absorption performance,achieving excel-lent reflection loss(RL)of-79 dB and effective absorption band width of 4.12 GHz(6.84-10.96 GHz)at low load of 15wt%.Among them,the material’s optimal radar cross-section(RCS)reduction value can reach 31.9 dB·m^(2).This work provides a new approach to the micro-control and comprehensive optimization of macro-design of microwave absorbers,and offers new ideas for the high-value utiliza-tion of biomass materials.展开更多
Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic efficiency.The introduction of defects emerges as a promising strategy,effectively modifying the e...Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic efficiency.The introduction of defects emerges as a promising strategy,effectively modifying the electronic structure of active sites.This optimization influences the adsorption energy of intermediates,thereby mitigating reaction energy barriers,altering paths,enhancing selectivity,and ultimately improving the catalytic efficiency of electrocatalysts.To elucidate the impact of defects on the electrocatalytic process,we comprehensively outline the roles of various point defects,their synthetic methodologies,and characterization techniques.Importantly,we consolidate insights into the relationship between point defects and catalytic activity for hydrogen/oxygen evolution and CO_(2)/O_(2)/N_(2) reduction reactions by integrating mechanisms from diverse reactions.This underscores the pivotal role of point defects in enhancing catalytic performance.At last,the principal challenges and prospects associated with point defects in current electrocatalysts are proposed,emphasizing their role in advancing the efficiency of electrochemical energy storage and conversion materials.展开更多
Recent progress in microwave absorption materials stimulates the extensive exploration of rare earth oxide materials.Herein,we report the synthesis of a hollow sphere-based carbon material compounded with rare earth o...Recent progress in microwave absorption materials stimulates the extensive exploration of rare earth oxide materials.Herein,we report the synthesis of a hollow sphere-based carbon material compounded with rare earth oxides.Hollow N-doped carbon nano-spheres loaded ceria composites(H-NC@CeO_(2))were designed and prepared by the template method,combined with in-situ coating,pyrolysis and chemical etching.By controlling the loading content of H-NC@CeO_(2)and adjusting the impedance matching of the material,the H-NC@CeO_(2)/PS(polystyrene)composite exhibited a minimum reflection loss(RL)of-50.8 dB and an effective absorption band-width(EAB)of 4.64 GHz at a filler ratio of 20wt%and a thickness of 2 mm.In accordance with measured electromagnetic parameters,simulations using the high frequency structure simulator(HFSS)software were conducted to investigate the impact of the honeycomb structure on the electromagnetic wave performance of H-NC@CeO_(2)/PS.By calculating the surface electric field and the material’s bulk loss density,the mechanism of electromagnetic loss for the honeycomb structure was elaborated.A method for structural design and man-ufacturing of broadband absorbing devices was proposed and a broadband absorber with an EAB of 11.9 GHz was prepared.This study presents an innovative approach to designing advanced electromagnetic(EM)wave absorbing materials with broad absorption band-widths.展开更多
Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and...Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and hierarchical.Due to their porous nature,interfacial compatibility,and electrical conductivity,biomass materials hold significant potential as EMI shielding materials.Despite concerted efforts on the EMI shielding of biomass materials have been reported,this research area is still relatively new compared to traditional EMI shielding materials.In particular,a more comprehensive study and summary of the factors influencing biomass EMI shielding materials including the pore structure adjustment,preparation process,and micro-control would be valuable.The preparation methods and characteristics of wood,bamboo,cellulose and lignin in EMI shielding field are critically discussed in this paper,and similar biomass EMI materials are summarized and analyzed.The composite methods and fillers of various biomass materials were reviewed.this paper also highlights the mechanism of EMI shielding as well as existing prospects and challenges for development trends in this field.展开更多
This paper reviews the applications of the multi degree-of-freedom(MDOF)equivalent linear system in seismic analysis and design of planar steel and reinforced concrete framed structures.An equivalent MDOF linear struc...This paper reviews the applications of the multi degree-of-freedom(MDOF)equivalent linear system in seismic analysis and design of planar steel and reinforced concrete framed structures.An equivalent MDOF linear structure,analogous to the original MDOF nonlinear structure,is constructed,which has the same mass and elastic stiffness as the original structure and modal damping ratios that account for the effects of geometrical and material nonlinearities.The equivalence implies a balance between the viscous damping work of the equivalent linear structure and that of the nonlinearities in the original nonlinear structure.This work balance is established with the aid of a transfer function in the frequency domain.Thus,equivalent modal damping ratios can be explicitly determined in terms of the period and deformation levels of the structure as well as the soil types.Use of these equivalent modal damping ratios can help address a variety of seismic analysis and design problems associated with planar steel and reinforced concrete framed structures in a rational and accurate manner.These include force-based seismic design with the aid of acceleration response spectra characterized by high amounts of damping,improved direct displacement-based seismic design and the development of advanced seismic intensity measures.The equivalent modal damping ratios are also utilized in the context of linear modal analysis for the definition and construction of the MDOF response spectrum.Furthermore,the equivalent modal damping ratios are employed in a seismic retrofit method for steel-framed structures with viscous dampers.Finally,it is demonstrated that modal behavior(or strength reduction)factors can be easily constructed based on these modal damping ratios for a more rational and accurate force-based seismic design,including the determination of inelastic displacement profiles.展开更多
Layer-structured Ruddlesden–Popper(RP)perovskites(RPPs)with decent stability have captured the imagination of the photovoltaic research community and bring hope for boosting the development of perovskite solar cell(P...Layer-structured Ruddlesden–Popper(RP)perovskites(RPPs)with decent stability have captured the imagination of the photovoltaic research community and bring hope for boosting the development of perovskite solar cell(PSC)technology.However,two-dimensional(2D)or quasi-2D RP PSCs are encountered with some challenges of the large exciton binding energy,blocked charge transport and poor film quality,which restrict their photovoltaic performance.Fortunately,these issues can be readily resolved by rationally designing spacer cations of RPPs.This review mainly focuses on how to design the molecular structures of organic spacers and aims to endow RPPs with outstanding photovoltaic applications.We firstly elucidated the important roles of organic spacers in impacting crystallization kinetics,charge transporting ability and stability of RPPs.Then we brought three aspects to attention for designing organic spacers.Finally,we presented the specific molecular structure design strategies for organic spacers of RPPs aiming to improve photovoltaic performance of RP PSCs.These proposed strategies in this review will provide new avenues to develop novel organic spacers for RPPs and advance the development of RPP photovoltaic technology for future applications.展开更多
Hydrogel scaffolds have numerous potential applications in the tissue engineering field.However,tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and hi...Hydrogel scaffolds have numerous potential applications in the tissue engineering field.However,tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and high mechanical properties.Inspired by Chinese ramen,we propose a universal fabricating method(printing-P,training-T,cross-linking-C,PTC&PCT)for tough hydrogel scaffolds to fill this gap.First,3D printing fabricates a hydrogel scaffold with desired structures(P).Then,the scaffold could have extraordinarily high mechanical properties and functional surface structure by cycle mechanical training with salting-out assistance(T).Finally,the training results are fixed by photo-cross-linking processing(C).The tough gelatin hydrogel scaffolds exhibit excellent tensile strength of 6.66 MPa(622-fold untreated)and have excellent biocompatibility.Furthermore,this scaffold possesses functional surface structures from nanometer to micron to millimeter,which can efficiently induce directional cell growth.Interestingly,this strategy can produce bionic human tissue with mechanical properties of 10 kPa-10 MPa by changing the type of salt,and many hydrogels,such as gelatin and silk,could be improved with PTC or PCT strategies.Animal experiments show that this scaffold can effectively promote the new generation of muscle fibers,blood vessels,and nerves within 4 weeks,prompting the rapid regeneration of large-volume muscle loss injuries.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.52161041)the Natural Science Foundation of Hainan Province(Grant No.520RC552).
文摘Integrating wave energy converters(WECs)with offshore platforms offers numerous advantages,such as reducing wave loads,supplying energy to the platform,and cost-sharing in construction.This paper reports an experimental investigation focusing on the hydrodynamic characteristics of a proposed modular floating structure system integrated with WEC-type floating artificial reefs.The proposed system comprises several serially arranged hexagonal floating structures,anchored by tension legs,and integrated with outermost WEC-type floating artificial reefs.A simplified wave energy converter utilizing the relative pitch motion between adjacent modules for energy conversion was constructed in the scale model test.The effects of chain-type modular expansion on the multi-body motion response,mooring tension response,and WEC performance of the system have been thoroughly investigated.The experimental results indicate that increasing the number of hexagonal modules can notably reduce the system’s surge response,particularly under survival sea conditions.The connection of the outermost reef modules slightly increases the tension leg load of the adjacent module,whereas the tension leg load remains relatively consistent across the inner hexagonal modules.Furthermore,through a comparison of the dynamic responses of the hexagonal module connected and unconnected outermost reefs,the good performance in terms of energy conversion and wave attenuation of the WECtype floating artificial reef modules was effectively validated.The main results from this work can provide useful references for engineering applications involving modular floating structures integrated with WECs.
基金the Science and Technology Project of China Southern Power Grid Company,Ltd.(031200KK52200003)the National Natural Science Foundation of China(Nos.62371253,52278119).
文摘In this paper, we propose a novel anomaly detection method for data centers based on a combination of graphstructure and abnormal attention mechanism. The method leverages the sensor monitoring data from targetpower substations to construct multidimensional time series. These time series are subsequently transformed intograph structures, and corresponding adjacency matrices are obtained. By incorporating the adjacency matricesand additional weights associated with the graph structure, an aggregation matrix is derived. The aggregationmatrix is then fed into a pre-trained graph convolutional neural network (GCN) to extract graph structure features.Moreover, both themultidimensional time series segments and the graph structure features are inputted into a pretrainedanomaly detectionmodel, resulting in corresponding anomaly detection results that help identify abnormaldata. The anomaly detection model consists of a multi-level encoder-decoder module, wherein each level includesa transformer encoder and decoder based on correlation differences. The attention module in the encoding layeradopts an abnormal attention module with a dual-branch structure. Experimental results demonstrate that ourproposed method significantly improves the accuracy and stability of anomaly detection.
基金financially supported by the National Natural Science Foundation of China under Project No.51874267 and No.12272374the Fundamental Research Funds for the Central Universities under Project Nos.WK2480000008,WK2480000007,and WK2320000049。
文摘A launching system with a filter cartridge structure was proposed to improve the muzzle velocity of the projectile.The combustion chamber of the launching system is divided into two fixed chambers,one is located in the breech chamber,and the other is arranged in the barrel.The breech chamber charge was ignited first,and the charges in the auxiliary chambers were ignited by the high-temperature,highpressure combustible gas trailing the projectile.In this way,the combustible gas in the auxiliary chambers could compensate for the pressure drop caused by the movement of the projectile.The proposed device features the advantage of launching a projectile with high muzzle velocity without exceeding the maximum pressure in the chamber.In order to obtain some internal ballistic characteristics of the launch system,some critical structure,such as the length of the filter cartridge auxiliary charge,the combustion degree of the propellant in the chamber,and the length of the barrel,are discussed.The experimental results show that with the increased auxiliary charge length,a pressure plateau or even a secondary peak pressure can be formed,which is less than the peak pressure.The projectile velocity increased by 23.57%,14.64%,and 7.65%when the diaphragm thickness was 0 mm,1 mm,and2 mm,respectively.The muzzle velocity of the projectile can be increased by 13.42%by increasing the length of the barrel.Under the same charge condition,with the increase of barrel length,the energy utilization rate of propellant increases by 28.64%.
基金supported by National Natural Science Foundation of China,China(No.51901117,51801116)Youth Innovation and Technology Support Program of Shandong Provincial Colleges and Universities,China(No.2020KJA002)+2 种基金Youth Fund of Shandong Academy of Sciences,China(2020QN0021)Innovation Pilot Project for Fusion of Science,Education and Industry(International Cooperation)from Qilu University of Technology(Shandong Academy of Sciences),China(No.2020KJC-GH03)Several Policies on Promoting Collaborative Innovation and Industrialization of Achievements in Universities and Research Institutes,China(No.2019GXRC030)。
文摘In an effort to clarify the formation mechanism of LPSO structure in Mg-Y-Zn alloy,the chemical environment and structural ordering in liquid Mg-rich Mg-Y-Zn system are investigated with the aid of ab-initio molecular dynamics simulation.In liquid Mg-rich Mg-Y alloys,the strong Mg-Y interaction is determined,which promotes the formation of fivefold symmetric local structure.For Mg-Zn alloys,the weak Mg-Zn interaction results in the fivefold symmetry weakening in the liquid structure.Due to the coexistence of Y and Zn,the strong attractive interaction is introduced in liquid Mg-Y-Zn ternary alloy,and contributes to the clustering of Mg,Y,Zn launched from Zn.What is more,the distribution of local structures becomes closer to that in pure Mg compared with that in binary Mg-Y and Mg-Zn alloys.These results should relate to the origins of the Y/Zn segregation zone and close-packed stacking mode in LPSO structure,which provides a new insight into the formation mechanism of LPSO structure at atomic level.
基金National Natural Science Foundation of China under Grant No.51978125Open Fund Project of Research Center for Geotechnical and Structural Engineering Technology of Liaoning Province under Grant No.DLSZD2023[007]。
文摘In this study,a novel equivalent damping ratio model that is suitable for reinforced concrete(RC)structures considering cyclic degradation behavior is developed,and a new equivalent linearization analysis method for implementing the proposed equivalent damping ratio model for use in seismic damage evaluation is presented.To this end,Ibarra’s peak-oriented model,which incorporates an energy-based degradation rule,is selected for representing hysteretic behavior of RC structure,and the optimized equivalent damping for predicting the maximum displacement response is presented by using the empirical method,in which the effect of cyclic degradation is considered.Moreover,the relationship between the hysteretic energy dissipation of the inelastic system and the elastic strain energy of the equivalent linear system is established so that the proposed equivalent linear system can be directly integrated with the Park-Ang seismic model to implement seismic damage evaluation.Due to the simplicity of the equivalent linearization method,the proposed method provides an efficient and reliable way of obtaining comprehensive insight into the seismic performance of RC structures.The verification demonstrates the validity of the proposed method.
基金Supported by the National Natural Science Foundation of China(Grant Nos.12262005,11962003,and 11602062)the Postgraduate Education Reform and Quality Improvement Project of Henan Province(Grant No.YJS2024AL138)the Graduate Education Reform Project of Henan Province(Grant No.2023SJGLX096Y).
文摘Internal polyhedral structures of a granular system can be investigated using the Voronoi tessellations.This technique has gained increasing recognition in research of kinetic properties of granular flows.For systems with mono-sized spherical particles,Voronoi tessellations can be utilized,while radial Voronoi tessellations are necessary for analyzing systems with multi-sized spherical particles.However,research about polyhedral structures of non-spherical particle systems is limited.We utilize the discrete element method to simulate a system of ellipsoidal particles,defined by the equation(x/a)^(2)+(y/1)^(2)+(z/1/a)^(2)=1,where a ranges from 1.1 to 2.0.The system is then dissected by using tangent planes at the contact points,and the geometric quantities of the resulting polyhedra in different shaped systems,such as surface area,volume,number of vertices,number of edges,and number of faces,are calculated.Meanwhile,the longitudinal and transverse wave velocities within the system are calculated with the time-of-flight method.The results demonstrate a strong correlation between the sound velocity of the system and the geometry of the dissected polyhedra.The sound velocity of the system increases with the increase in a,peaking at a=1.3,and then decreases as a continues to increase.The average volume,surface area,number of vertices,number of edges,and number of faces of the polyhedra decrease with the increase in sound velocity.That is,these quantities initially decrease with the increase in a,reaching minima at a=1.3,and then increase with further increase of a.The relationship between sound velocity and the geometric quantities of the dissected polyhedra can serve as a reference for acoustic material design.
基金supported by the General Program of the National Natural Science Foundation of China(NSFC,No.52075061)the Key Program of the National Natural Science Foundation of China(NSFC,No.U22B2089)the Science Fund for Distinguished Young Scholars of Chongqing(No.CSTB2022 NSCQ-JQX0006).
文摘Triboelectric nanogenerators(TENG),renowned for their remarkable capability to harness weak mechanical energy from the environment,have gained considerable attention owing to their cost-effectiveness,high output,and adaptability.This review provides a unique perspective by conducting a comprehensive and in-depth analysis of magnetically assisted TENGs that encompass structures,materials,and self-powered sensing systems.We systematically summarize the diverse functions of the magnetic assistance for TENGs,including system stiffness,components of the hybrid electromagnetic-triboelectric generator,transmission,and interaction forces.In the material domain,we review the incorporation of magnetic nano-composites materials,along with ferrofluid-based TENG and microstructure verification,which have also been summarized based on existing research.Furthermore,we delve into the research progress on physical quantity sensing and human-machine interface in magnetic-assisted TENGs.Our analysis highlights that magnetic assistance extends beyond the repulsive and suction forces under a magnetic field,thereby playing multifaceted roles in improving the output performance and environmental adaptability of the TENGs.Finally,we present the prevailing challenges and offer insights into the future trajectory of the magnetic-assisted TENGs development.
基金Support by the National Natural Science Foundation of China(No.92258303)the Project of Donghai Laboratory(No.DH-2022ZY0005)。
文摘The deep structure,material circulation,and dynamic processes in the Southeast Asia have long been an elusive scientific puzzle due to the lack of systematic scientific observations and recognized theoretical models.Based on the deep seismic tomography using long-period natural earthquake data,in this study,the deep structure and material circulation of the curved subduction system in Southeast Asia was studied,and the dynamic processes since 100 million years ago was reconstructed.It is pointed out that challenges still exist in the precise reconstruction of deep mantle structures of the study area,the influence of multi-stage subduction on deep material exchange and shallow magma activity,as well as the spatiotemporal evolution and coupling mechanism of multi-plate convergence.Future work should focus on high-resolution land-sea joint 3-D seismic tomography imaging of the curved subduction system in the Southeast Asia,combined with geochemical analysis and geodynamic modelling works.
文摘Aim: This paper aims to evaluate disparities of type 2 diabetes structured health education programmes that is utilised within the communities. Design: systematic review, (a type of secondary research design) aiming to summarize the results of prior primary research studies on available evidence Community type 2 diabetes structured education (CT2DSHE). Methods: Research question: Type 2 diabetic structured health education within a community how effective is it? Qualitative Systematic review, defined as a way to get reliable and objective picture of current available evidence on the specific topic—(CT2DSHE), (Denscombe, 2021) through reflexivity synthesis of available data as an example. This is valuable in time constraints such as project assignments that must be met within specific time and also to bring together available evidence together [1]. Results: This review has shown that CT2DSHE is effective with seven out of the eleven authors supporting, three authors against and one was neutral, further showed that knowledge and skills acquired can last longer with patient activation improved among T2DM patients ideal for sustaining their self-management of T2DM. Conclusion: This research provides suggestive answers to the research question: “Type 2 diabetic structured health education within a community how effective is it?”, This has demonstrated CT2DSHE effectiveness in knowledge acquisition and improving T2DM awareness among T2DM patients, whilst evidencing long effects beyond the study times of 3 - 9 months period in relation to patient activation. Also Identified diabetes education self-management on newly diagnosed (DESMOND) patient as CT2DSHE program for recommendation. Patient or Public Contribution: This work aspires to contribute to CT2DSHE in these areas;Influencing policy decision-making for community diabetes care within the UK and world at large., Contributing to already vast knowledge on diabetes self-management and reasons why?, Influencing educators on how CT2DSHEP are designed, delivered by putting the patient at the Centre and bringing different perspectives on CT2DSHEP in one place that is serving users time of having to consult several resources especially busy clinicians [2] [3].
基金supported by the 2023 Guangdong Basic and Applied Basic Research Fund Regional Joint Fund Key Project under Grant No. 2023B15151200172023 Key Project of Guangdong Provincial Department of Education for General Universities under Grant No. 2023ZDZX3024ZTE Industry-University-Institute Cooperation Funds under Grant No. K2133Z167
文摘Vision-based measurement technology benefits high-quality manufacturers through improved dimensional precision,enhanced geo-metric tolerance,and increased product yield.The monocular 3D structured light visual sensing method is popular for detecting online parts since it can reach micron-meter depth accuracy.However,the line-of-sight requirement of a single viewpoint vision system often fails when hiding occurs due to the object’s surface structure,such as edges,slopes,and holes.To address this issue,a multi-view 3D structured light vi-sion system is proposed in this paper to achieve high accuracy,i.e.,Z-direction repeatability,and reduce hiding probability during mechani-cal dimension measurement.The main contribution of this paper includes the use of industrial cameras with high resolution and high frame rates to achieve high-precision 3D reconstruction.Moreover,a multi-wavelength(heterodyne)phase expansion method is employed for high-precision phase calculation.By leveraging multiple industrial cameras,the system overcomes field of view occlusions,thereby broadening the 3D reconstruction field of view.Finally,the system achieves a Z-axis repetition accuracy of 0.48µm.
文摘The combination of structural health monitoring and vibration control is of great importance to provide components of smart structures.While synthetic algorithms have been proposed,adaptive control that is compatible with changing conditions still needs to be used,and time-varying systems are required to be simultaneously estimated with the application of adaptive control.In this research,the identification of structural time-varying dynamic characteristics and optimized simple adaptive control are integrated.First,reduced variations of physical parameters are estimated online using the multiple forgetting factor recursive least squares(MFRLS)method.Then,the energy from the structural vibration is simultaneously specified to optimize the control force with the identified parameters to be operational.Optimization is also performed based on the probability density function of the energy under the seismic excitation at any time.Finally,the optimal control force is obtained by the simple adaptive control(SAC)algorithm and energy coefficient.A numerical example and benchmark structure are employed to investigate the efficiency of the proposed approach.The simulation results revealed the effectiveness of the integrated online identification and optimal adaptive control in systems.
基金financially supported by the National Natural Science Foundation of China(Nos.52425408 and 52304345)the Fundamental Research Funds for the Central Universities,China(No.2023CDJXY-016)the Postdoctoral Science Foundation of Chongqing(No.CSTB2023NSCQ-BHX0174)。
文摘Currently,the Al_(2)O_(3)content in the high-alumina slag systems within blast furnaces is generally limited to 16wt%–18.5wt%,making it challenging to overcome this limitation.Unlike most studies that concentrated on managing the MgO/Al_(2)O_(3)ratio or basicity,this paper explored the effect of equimolar substitution of MgO for CaO on the viscosity and structure of a high-alumina CaO-MgO-Al_(2)O_(3)-SiO_(2)slag system,providing theoretical guidance and data to facilitate the application of high-alumina ores.The results revealed that the viscosity first decreased and then increased with higher MgO substitution,reaching a minimum at 15mol%MgO concentration.Fourier transform infrared spectroscopy(FTIR)results found that the depths of the troughs representing[SiO_(4)]tetrahedra,[AlO_(4)]tetrahedra,and Si-O-Al bending became progressively deeper with increased MgO substitution.Deconvolution of the Raman spectra showed that the average number of bridging oxygens per Si atom and the X_(Q^(3))/X_(Q^(2))(X_(Q^(i))is the molar fraction of Q^(i) unit,and i is the number of bridging oxygens in a[SiO_(4)]tetrahedral unit)ratio increased from 2.30 and 1.02 to 2.52 and 2.14,respectively,indicating a progressive polymerization of the silicate structure.X-ray photoelectron spectroscopy(XPS)results highlighted that non-bridging oxygen content decreased from 77.97mol% to 63.41mol% with increasing MgO concentration,whereas bridging oxygen and free oxygen contents increased.Structural analysis demonstrated a gradual increase in the polymerization degree of the tetrahedral structure with the increase in MgO substitution.However,bond strength is another important factor affecting the slag viscosity.The occurrence of a viscosity minimum can be attributed to the complex evolution of bond strengths of non-bridging oxygens generated during depolymerization of the[SiO_(4)]and[AlO_(4)]tetrahedral structures by CaO and MgO.
基金Anhui Province Young and Middle-aged Teacher Training Action Excellent Young Teacher Cultivation Project(YQYB2023162)Anhui University Natural Science Research Key Project(KJ2021A1410)Special Topic of the Higher Education Institution Scientific Research Development Center of the Ministry of Education(ZJXF2022080)。
文摘To analyze the seismic response of steel structure isolation systems under long-period seismic motion,a 9-story steel frame building was selected as the subject.Five steel structure finite element models were established using SAP2000.Response spectrum analysis was conducted on the seismic motion to determine if it adhered to the characteristics of long-period seismic motion.Modal analysis of each structural model revealed that the isolation structure significantly prolonged the structural natural vibration period and enhanced seismic performance.Base reactions and floor displacements of various structures notably increased under long-period seismic motion compared to regular seismic activity.Placing isolation bearings in the lower part of the structure proved more effective under long-period seismic motion.In seismic design engineering,it is essential to consider the impact of long-period seismic motion on structures and the potential failure of isolation bearings.
基金supported by the National Key R&D Program of China(Nos.2023YFE0108300 and 2023YFD2202103)the National Natural Science Foundation of China(No.32371972)+2 种基金the Natural Science Foundation of Jiangsu Province,China(No.BK20221336)Jiangsu Agricultural Science and Technology Independent Innovation Fund,China(No.CX(23)3060)Jiangxi Forestry Bureau Forestry Science and Technology Innovation Special Project,China(No.202240).
文摘The rapid development of 5G communication technology and smart electronic and electrical equipment will inevitably lead to electromagnetic radiation pollution.Enriching heterointerface polarization relaxation through nanostructure design and interface modifica-tion has proven to be an effective strategy to obtain efficient electromagnetic wave absorption.Here,this work implements an innovative method that combines biomimetic honeycomb superstructure to constrain hierarchical porous heterostructure composed of Co/CoO nano-particles to improve the interfacial polarization intensity.The method effectively controlled the absorption efficiency of Co^(2+)through de-lignification modification of bamboo,and combined with the bionic carbon-based natural hierarchical porous structure to achieve uniform dispersion of nanoparticles,which is conducive to the in-depth construction of heterogeneous interfaces.In addition,the multiphase struc-ture brought about by high-temperature pyrolysis provides the best dielectric loss and impedance matching for the material.Therefore,the obtained bamboo-based Co/CoO multiphase composite showed excellent electromagnetic wave absorption performance,achieving excel-lent reflection loss(RL)of-79 dB and effective absorption band width of 4.12 GHz(6.84-10.96 GHz)at low load of 15wt%.Among them,the material’s optimal radar cross-section(RCS)reduction value can reach 31.9 dB·m^(2).This work provides a new approach to the micro-control and comprehensive optimization of macro-design of microwave absorbers,and offers new ideas for the high-value utiliza-tion of biomass materials.
基金supported by the National Natural Science Foundation of China(U21A20281)the Special Fund for Young Teachers from Zhengzhou University(JC23557030,JC23257011)+1 种基金the Key Research Projects of Higher Education Institutions of Henan Province(24A530009)the Project of Zhongyuan Critical Metals Laboratory(GJJSGFYQ202336).
文摘Point defect engineering endows catalysts with novel physical and chemical properties,elevating their electrocatalytic efficiency.The introduction of defects emerges as a promising strategy,effectively modifying the electronic structure of active sites.This optimization influences the adsorption energy of intermediates,thereby mitigating reaction energy barriers,altering paths,enhancing selectivity,and ultimately improving the catalytic efficiency of electrocatalysts.To elucidate the impact of defects on the electrocatalytic process,we comprehensively outline the roles of various point defects,their synthetic methodologies,and characterization techniques.Importantly,we consolidate insights into the relationship between point defects and catalytic activity for hydrogen/oxygen evolution and CO_(2)/O_(2)/N_(2) reduction reactions by integrating mechanisms from diverse reactions.This underscores the pivotal role of point defects in enhancing catalytic performance.At last,the principal challenges and prospects associated with point defects in current electrocatalysts are proposed,emphasizing their role in advancing the efficiency of electrochemical energy storage and conversion materials.
基金supported by the Research Funding of Hangzhou International Innovation Institute of Beihang Uni-versity,China(No.2024KQ130)the National Natural Science Foundation of China(Nos.52073010 and 52373259).
文摘Recent progress in microwave absorption materials stimulates the extensive exploration of rare earth oxide materials.Herein,we report the synthesis of a hollow sphere-based carbon material compounded with rare earth oxides.Hollow N-doped carbon nano-spheres loaded ceria composites(H-NC@CeO_(2))were designed and prepared by the template method,combined with in-situ coating,pyrolysis and chemical etching.By controlling the loading content of H-NC@CeO_(2)and adjusting the impedance matching of the material,the H-NC@CeO_(2)/PS(polystyrene)composite exhibited a minimum reflection loss(RL)of-50.8 dB and an effective absorption band-width(EAB)of 4.64 GHz at a filler ratio of 20wt%and a thickness of 2 mm.In accordance with measured electromagnetic parameters,simulations using the high frequency structure simulator(HFSS)software were conducted to investigate the impact of the honeycomb structure on the electromagnetic wave performance of H-NC@CeO_(2)/PS.By calculating the surface electric field and the material’s bulk loss density,the mechanism of electromagnetic loss for the honeycomb structure was elaborated.A method for structural design and man-ufacturing of broadband absorbing devices was proposed and a broadband absorber with an EAB of 11.9 GHz was prepared.This study presents an innovative approach to designing advanced electromagnetic(EM)wave absorbing materials with broad absorption band-widths.
基金National Natural Science Foundation of China(32201491)Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)The authors extend their appreciation to the Deanship of Scientific Research at Northern Border University,Arar,KSA for funding this research work through the project number“NBU-FPEJ-2024-1101-02”.
文摘Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and hierarchical.Due to their porous nature,interfacial compatibility,and electrical conductivity,biomass materials hold significant potential as EMI shielding materials.Despite concerted efforts on the EMI shielding of biomass materials have been reported,this research area is still relatively new compared to traditional EMI shielding materials.In particular,a more comprehensive study and summary of the factors influencing biomass EMI shielding materials including the pore structure adjustment,preparation process,and micro-control would be valuable.The preparation methods and characteristics of wood,bamboo,cellulose and lignin in EMI shielding field are critically discussed in this paper,and similar biomass EMI materials are summarized and analyzed.The composite methods and fillers of various biomass materials were reviewed.this paper also highlights the mechanism of EMI shielding as well as existing prospects and challenges for development trends in this field.
文摘This paper reviews the applications of the multi degree-of-freedom(MDOF)equivalent linear system in seismic analysis and design of planar steel and reinforced concrete framed structures.An equivalent MDOF linear structure,analogous to the original MDOF nonlinear structure,is constructed,which has the same mass and elastic stiffness as the original structure and modal damping ratios that account for the effects of geometrical and material nonlinearities.The equivalence implies a balance between the viscous damping work of the equivalent linear structure and that of the nonlinearities in the original nonlinear structure.This work balance is established with the aid of a transfer function in the frequency domain.Thus,equivalent modal damping ratios can be explicitly determined in terms of the period and deformation levels of the structure as well as the soil types.Use of these equivalent modal damping ratios can help address a variety of seismic analysis and design problems associated with planar steel and reinforced concrete framed structures in a rational and accurate manner.These include force-based seismic design with the aid of acceleration response spectra characterized by high amounts of damping,improved direct displacement-based seismic design and the development of advanced seismic intensity measures.The equivalent modal damping ratios are also utilized in the context of linear modal analysis for the definition and construction of the MDOF response spectrum.Furthermore,the equivalent modal damping ratios are employed in a seismic retrofit method for steel-framed structures with viscous dampers.Finally,it is demonstrated that modal behavior(or strength reduction)factors can be easily constructed based on these modal damping ratios for a more rational and accurate force-based seismic design,including the determination of inelastic displacement profiles.
基金funding from National Science Foundation of China(52202337 and 22178015)the Young Taishan Scholars Program of Shandong Province(tsqn202211082)+1 种基金Natural Science Foundation of Shandong Province(ZR2023MB051)Independent Innovation Research Project of China University of Petroleum(East China)(22CX06023A).
文摘Layer-structured Ruddlesden–Popper(RP)perovskites(RPPs)with decent stability have captured the imagination of the photovoltaic research community and bring hope for boosting the development of perovskite solar cell(PSC)technology.However,two-dimensional(2D)or quasi-2D RP PSCs are encountered with some challenges of the large exciton binding energy,blocked charge transport and poor film quality,which restrict their photovoltaic performance.Fortunately,these issues can be readily resolved by rationally designing spacer cations of RPPs.This review mainly focuses on how to design the molecular structures of organic spacers and aims to endow RPPs with outstanding photovoltaic applications.We firstly elucidated the important roles of organic spacers in impacting crystallization kinetics,charge transporting ability and stability of RPPs.Then we brought three aspects to attention for designing organic spacers.Finally,we presented the specific molecular structure design strategies for organic spacers of RPPs aiming to improve photovoltaic performance of RP PSCs.These proposed strategies in this review will provide new avenues to develop novel organic spacers for RPPs and advance the development of RPP photovoltaic technology for future applications.
基金supported by the Innovative Research Group Project of the National Natural Science Foundation of China(T2121004)Key Programme(52235007)National Outstanding Youth Foundation of China(52325504).
文摘Hydrogel scaffolds have numerous potential applications in the tissue engineering field.However,tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and high mechanical properties.Inspired by Chinese ramen,we propose a universal fabricating method(printing-P,training-T,cross-linking-C,PTC&PCT)for tough hydrogel scaffolds to fill this gap.First,3D printing fabricates a hydrogel scaffold with desired structures(P).Then,the scaffold could have extraordinarily high mechanical properties and functional surface structure by cycle mechanical training with salting-out assistance(T).Finally,the training results are fixed by photo-cross-linking processing(C).The tough gelatin hydrogel scaffolds exhibit excellent tensile strength of 6.66 MPa(622-fold untreated)and have excellent biocompatibility.Furthermore,this scaffold possesses functional surface structures from nanometer to micron to millimeter,which can efficiently induce directional cell growth.Interestingly,this strategy can produce bionic human tissue with mechanical properties of 10 kPa-10 MPa by changing the type of salt,and many hydrogels,such as gelatin and silk,could be improved with PTC or PCT strategies.Animal experiments show that this scaffold can effectively promote the new generation of muscle fibers,blood vessels,and nerves within 4 weeks,prompting the rapid regeneration of large-volume muscle loss injuries.
