The hard target smart fuse of penetration ammunition is developing to be smaller, lighter, smarter and multifunction. After analyzing the characteristics of high-g accelerating signals and the penetration algorithms, ...The hard target smart fuse of penetration ammunition is developing to be smaller, lighter, smarter and multifunction. After analyzing the characteristics of high-g accelerating signals and the penetration algorithms, this paper provides a solution of penetration ammunition fuse system based on embedded technology. This fuse system realizes acquisition of the high-g accelerating signals and uses the appropriate penetration algorithms to process them. The fuse system can not only make the same type of penetration ammunition to attack different kinds of objects accurately, but also meet the other requirements of the function of penetration ammunition fuse system.展开更多
The Fused Modified Grasshopper Optimization Algorithm has been proposed,which selects the most specific feature sets from images of the disease of plant leaves.The Proposed algorithm ensures the detection of diseases ...The Fused Modified Grasshopper Optimization Algorithm has been proposed,which selects the most specific feature sets from images of the disease of plant leaves.The Proposed algorithm ensures the detection of diseases during the early stages of the diagnosis of leaf disease by farmers and,finally,the crop needed to be controlled by farmers to ensure the survival and protection of plants.In this study,a novel approach has been suggested based on the standard optimization algorithm for grasshopper and the selection of features.Leaf conditions in plants are a major factor in reducing crop yield and quality.Any delay or errors in the diagnosis of the disease can lead to delays in the management of plant disease spreading and damage and related material losses.Comparative new heuristic optimization of swarm intelligence,Grasshopper Optimization Algorithm was inspired by grasshopper movements for their feeding strategy.It simulates the attitude and social interaction of grasshopper swarm in terms of gravity and wind advection.In the decision on features extracted by an accelerated feature selection algorithm,popular approaches such as ANN and SVM classifiers had been used.For the evaluation of the proposed model,different data sets of plant leaves were used.The proposed model was successful in the diagnosis of the diseases of leaves the plant with an accuracy of 99.41 percent(average).The proposed biologically inspired model was sufficiently satisfied,and the best or most desirable characteristics were established.Finally,the results of the research for these data sets were estimated by the proposed Fused Modified Grasshopper Optimization Algorithm(FMGOA).The results of that experiment were demonstrated to allow classification models to reduce input features and thus to increase the precision with the presented Modified Grasshopper Optimization Algorithm.Measurement and analysis were performed to prove the model validity through model parameters such as precision,recall,f-measure,and precision.展开更多
Bridges designed following a conventional approach minimize the risk of collapse,but often require challenging,costly,and time-consuming restoration after an earthquake occurs.The new seismic design philosophy require...Bridges designed following a conventional approach minimize the risk of collapse,but often require challenging,costly,and time-consuming restoration after an earthquake occurs.The new seismic design philosophy requires bridges to maintain functionality even after severe earthquakes.In this context,this paper proposes a controlled rocking pile foundation(CRPF)system and numerically evaluates bridges′degree of seismic resilience.The CRPF system allows a pile cap to rock on a pile foundation and dissipate seismic energy through inelastic deformations of replaceable bar fuses that connect a pile cap and piles.Following the conceptual design of the CRPF system,two analytical models were developed for a bridge pier utilizing the CRPF system and a pier designed to develop a plastic hinge in its column.The analytical results indicate that,after experiencing a severe earthquake,a conventionally designed bridge pier sustained substantial damage in its column and exhibited significant residual displacement.In contrast,a pier using the CRPF system showed negligible residual displacement and maintained elastic behavior except,as expected,for bar fuses.The damaged fuses can be rapidly replaced to recover bridge seismic resistance following an earthquake.Therefore,the CRPF system helps to achieve the desired postearthquake performance objectives.展开更多
The rapid growth in data generation and increased use of computer network devices has amplified the infrastructures of internet.The interconnectivity of networks has brought various complexities in maintaining network...The rapid growth in data generation and increased use of computer network devices has amplified the infrastructures of internet.The interconnectivity of networks has brought various complexities in maintaining network availability,consistency,and discretion.Machine learning based intrusion detection systems have become essential to monitor network traffic for malicious and illicit activities.An intrusion detection system controls the flow of network traffic with the help of computer systems.Various deep learning algorithms in intrusion detection systems have played a prominent role in identifying and analyzing intrusions in network traffic.For this purpose,when the network traffic encounters known or unknown intrusions in the network,a machine-learning framework is needed to identify and/or verify network intrusion.The Intrusion detection scheme empowered with a fused machine learning technique(IDS-FMLT)is proposed to detect intrusion in a heterogeneous network that consists of different source networks and to protect the network from malicious attacks.The proposed IDS-FMLT system model obtained 95.18%validation accuracy and a 4.82%miss rate in intrusion detection.展开更多
Replaceable flexural and shear fuse-type coupling beams are used in hybrid coupled shear wall(HCSW)systems,enabling concrete buildings to be promptly recovered after severe earthquakes.This study aimed to analytically...Replaceable flexural and shear fuse-type coupling beams are used in hybrid coupled shear wall(HCSW)systems,enabling concrete buildings to be promptly recovered after severe earthquakes.This study aimed to analytically evaluate the seismic behavior of flexural and shear fuse beams situated in short-,medium-and high-rise RC buildings that have HCSWs.Three building groups hypothetically located in a high seismic hazard zone were studied.A series of 2D nonlinear time history analyses was accomplished in OpenSees,using the ground motion records scaled at the design basis earthquake level.It was found that the effectiveness of fuses in HCSWs depends on various factors such as size and scale of the building,allowable rotation value,inter-story drift ratio,residual drift quantity,energy dissipation value of the fuses,etc.The results show that shear fuses better meet the requirements of rotations and drifts.In contrast,flexural fuses dissipate more energy,but their sectional stiffness should increase to meet other requirements.It was concluded that adoption of proper fuses depends on the overall scale of the building and on how associated factors are considered.展开更多
Recently,there has been an investigation of polishing processes that has considered new ultra-precision polishing technology for micro parts and optical parts such as those with aspheric and complex shapes.One suitabl...Recently,there has been an investigation of polishing processes that has considered new ultra-precision polishing technology for micro parts and optical parts such as those with aspheric and complex shapes.One suitable means of polishing complex shapes is to use a jet of abrasive fluid.However,aerodynamic disturbances and radial spreading are generated by the unstable polishing process of the jet on the surface of the workpiece when it is being polished.A method of jet stabilization has been proposed in which the original nozzle form of a jet of magnetorheological(MR)fluid contains abrasive particles that are magnetized using a magnetic.This paper details the design of an MR jet polishing system that uses an electromagnet,a nozzle,and a hydraulic unit to stabilize a slurry jet based on MR fluid, Second,for silica glass,the polishing spot and section profile are analyzed and the effect of the MR fluid jet polishing process is evaluated.The results of the experiment show that the removal profile is W-shaped and that,in this case,a stable can be proof of a distance of several tens of millimeters from the nozzle.Such results show the possibility of applying the proposed polishing method using MR fluids in ultra-precision micro and optical parts production processes. MR jet polishing shows great potential for use as a new type of precision surface polishing technology.In particular,this is a highly valuable process for the polishing of complex shapes such as micro parts,concaves parts,and cavities.展开更多
A simple route to synthesize novel fluorinated fused hetero-polycyclic nitrogen systems containing a pyrazolotriazine moiety (5,8,11) have been deduced from cyclization of 2-aminothiocarbonyl-5-arylidene-3-phenyl-1,2,...A simple route to synthesize novel fluorinated fused hetero-polycyclic nitrogen systems containing a pyrazolotriazine moiety (5,8,11) have been deduced from cyclization of 2-aminothiocarbonyl-5-arylidene-3-phenyl-1,2,4-triazin-6(1H)one (2) with diethoxy-phosphine, diethyl carbonate and/or diethyl oxalate in boil THF followed by cyclo condensation with aryl sulfonic acid hydrazide in EtOH/piperidine and finally fluorination with trifluoroethyl acetate. Structures of the products have been established from their elemental analysis and spectral measurements. The antimicrobial activity of the targets has also been evaluated.展开更多
The use of additive manufacturing techniques in the development of unconventional materials can help reduce the environmental impact of traditional construction materials.In this paper,the properties of a 3D-printed b...The use of additive manufacturing techniques in the development of unconventional materials can help reduce the environmental impact of traditional construction materials.In this paper,the properties of a 3D-printed biocomposite were evaluated.Biofilaments obtained by mixing pulverized bamboo fibers with polylactic acid(PLA)resin were extruded during the manufacturing process.To assess the effect of incorporating plant fibers,an analysis was conducted on the morphology,elemental chemical composition,crystallinity index,principal functional groups,thermal stability,surface roughness,microhardness,density,tensile strength,elastic modulus,and strain percentage of reinforced samples.The results were comparedwith those obtained from the characterization of standard PLAfilaments(unreinforced).The fused deposition modeling(FDM)technique was employed to print biocomposite specimens.Additionally,the influence of the printing parameters(infill density,build orientation,and layer thickness)on the physical,tribological,andmechanical properties of the biocomposites was analyzed.These results were compared with those obtained for specimens printed with pure PLA.The findings indicate that incorporating 10%vegetable filler into PLA filaments enhanced the strength and stiffness of the biocomposite under axial loads.Finally,the strength of the biocomposite subjected to axial loads was compared with the standardized values for wood-plastic composites,demonstrating the feasibility of its use for non-structural purposes in civil construction.展开更多
Fused silica(SiO_(2)glass),a key amorphous component of Earth’s silicate minerals,undergoes coordination and phase transformations under high pressure.Although extensive studies have been conducted,discrepancies betw...Fused silica(SiO_(2)glass),a key amorphous component of Earth’s silicate minerals,undergoes coordination and phase transformations under high pressure.Although extensive studies have been conducted,discrepancies between theoretical and experimental studies remain,particularly regarding strain rate effects during compression.Here,we examine strain rate influences on the shock-induced amorphous–amorphous phase transitions in fused silica by measuring its Hugoniot equation of state and longitudinal sound velocity(CL)up to 7 GPa at strain rates of 10^(6)–10^(7)s^(-1)using a one-stage light-gas gun.A discontinuity in the relationship between shock velocity(US)and particle velocity(UP)and a significant softening in C_(L)of fused silica were observed near~5 GPa under shock loading.Our results indicate that high strain rates restrict Si–O–Si rotation in fused silica,modifying their bonds and increasing silicon coordination.The transition pressure by shock compression is significantly higher than that under static high-pressure conditions(2–3 GPa),which agrees with some recent theoretical predictions with high compression rates,reflecting the greater pressure needed to overcome energy barriers with the strain rate increase.These findings offer insights into strain rate-dependent phase transitions in fused silica and other silicate minerals(e.g.,quartz,olivine,and forsterite),bridging gaps between theoretical simulations and experiments.展开更多
Transparent sand is a special material to realize visualization of concealed work in geotechnical engineering. To investigate the dynamic characteristics of transparent sand, a series of undrained cyclic simple shear ...Transparent sand is a special material to realize visualization of concealed work in geotechnical engineering. To investigate the dynamic characteristics of transparent sand, a series of undrained cyclic simple shear tests were conducted on the saturated transparent sand composed of fused quartz and refractive index-matched oil mixture. The results reveal that an increase in the initial shear stress ratio significantly affects the shape of the hysteresis loop, particularly resulting in more pronounced asymmetrical accumulation. Factors such as lower relative density, higher cyclic stress ratios and higher initial shear stress ratio have been shown to accelerate cyclic deformation, cyclic pore water pressure and stiffness degradation. The cyclic liquefaction resistance curves decrease as the initial shear stress ratio increases or as relative density decreases. Booker model and power law function model were applied to predict the pore water pressure for transparent sand. Both models yielded excellent fits for their respective condition, indicating a similar dynamic liquefaction pattern to that of natural sands. Finally, transparent sand displays similar dynamic characteristics in terms of cyclic liquefaction resistance and Kα correction factor. These comparisons indicate that transparent sand can serve as an effective means to mimic many natural sands in dynamic model tests.展开更多
Acrylonitrile–butadiene–styrene(ABS)is the main material used in fused deposition modeling(FDM),which has good toughness and strength,but the single ABS material has poor heat resistance,which tends to cause warping...Acrylonitrile–butadiene–styrene(ABS)is the main material used in fused deposition modeling(FDM),which has good toughness and strength,but the single ABS material has poor heat resistance,which tends to cause warping and deformation during the printing process.Polycarbonate(PC)exhibits good performance in heat resistance,allowing it to maintain stable performance at higher temperatures.In this work,PC was used as a blending modifier to prepare five kinds of ABS/PC composite filaments,and the mechanical and thermal properties of the ABS/PC(Acrylonitrile-butadiene-styrene/Polycarbonate)composite filaments were studied and analyzed.Results showed that the glass transition temperature(Tg)of the blend increased continuously as the PC content increased.When the mass fraction of ABS/PC was 50/50,the glass transition temperature of the blend increased by 21.21%,and the tensile strength of the composites reached 40.23 MPa,which was an increase of 36.47% compared with that of pure ABS.However,the impact strength of the composites decreased with the addition of PC.Moreover,with the increase in the mass fraction of PC,the printing accuracy error increased from 0.02 to 0.18 mm.The results of this paper will promote the improvement of ABS printing performance and enrich the available materials for FDM.展开更多
Fluorinated fused azobenzene boron(FBAz)is a novel electron-deficient building block for polymer electron acceptors in all-polymer solar cells(all-PSC).The B←N bridging units impart a fixed configuration and low-lyin...Fluorinated fused azobenzene boron(FBAz)is a novel electron-deficient building block for polymer electron acceptors in all-polymer solar cells(all-PSC).The B←N bridging units impart a fixed configuration and low-lying LUMO/HOMO energy.Three polymer acceptor materials(P2f,P3f and P5f)with different fluorine substitution positions by copolymerizing FBAz with indacenodithiophene(IDT),are synthesized and investigated to study the influence of fluorinated forms on the all-polymer solar cell performance.The FBAz units are synthesized in just three steps,facilitating the straightforward production of polymer acceptors P2f,P3f,and P5f.These acceptors exhibit strong light absorption in the visible to near-infrared range of 500-1000nm and possess suitable LUMO/HOMO energy levels of-3.99/-5.66 eV which are very complementary to that(E_(LUMO/HOMO)=-3.59/-5.20 eV)of the widely-used polymer donor poly[(ethylhexylthiophenyl)-benzodithiophene-(ethylhexyl)-thienothiophene](PTB7-Th).All-polymer solar cells(all-PSCs)with PTB7-Th as electron donor and P3f as electron acceptor exhibits highest power conversion efficiencies(PCE)2.70%.When PC_(61)BM is added as the third component,the device efficiency can reach 5.36%.These preliminary results indicate that FBAz is a promising strong electron acceptor for the development of n-type polymer semiconductors,especially in organic photovoltaics(OPVs).To the best of our knowledge,this is the first example demonstrating the unique photovoltaic properties of the N=N double bond as an acceptor material.展开更多
We demonstrate a new polarization smoothing(PS)approach utilizing residual stress birefringence in fused silica to create a spatially random polarization control plate(SRPCP),thereby improving target illumination unif...We demonstrate a new polarization smoothing(PS)approach utilizing residual stress birefringence in fused silica to create a spatially random polarization control plate(SRPCP),thereby improving target illumination uniformity in inertial confinement fusion(ICF)laser systems.The fundamental operating mechanism and key fabrication techniques for the SRPCP are systematically developed and experimentally validated.The SRPCP converts a linearly polarized 3ω incident laser beam into an output beam with a spatially randomized polarization distribution.When combined with a continuous phase plate,the SRPCP effectively suppresses high-intensity speckles at all spatial frequencies in the focal spot.The proposed PS technique is specifically designed for high-fluence large-aperture laser systems,enabling novel polarization control regimes in laser-driven ICF.展开更多
Based on analyzing the influences of a slicing scheme on stair-stepping effect, supporting structure, efficiency and deformation, etc. , analytical hierarchical process （AHP） combining with fuzzy synthetic evaluatio...Based on analyzing the influences of a slicing scheme on stair-stepping effect, supporting structure, efficiency and deformation, etc. , analytical hierarchical process （AHP） combining with fuzzy synthetic evaluation is introduced to make decision in slicing schemes for a processing part. The application in determining the slicing scheme for a computer mouse during prototyping shows that the method increases the rationality during decision- making and improves quality and efficiency for the prototyping part.展开更多
文摘The hard target smart fuse of penetration ammunition is developing to be smaller, lighter, smarter and multifunction. After analyzing the characteristics of high-g accelerating signals and the penetration algorithms, this paper provides a solution of penetration ammunition fuse system based on embedded technology. This fuse system realizes acquisition of the high-g accelerating signals and uses the appropriate penetration algorithms to process them. The fuse system can not only make the same type of penetration ammunition to attack different kinds of objects accurately, but also meet the other requirements of the function of penetration ammunition fuse system.
文摘The Fused Modified Grasshopper Optimization Algorithm has been proposed,which selects the most specific feature sets from images of the disease of plant leaves.The Proposed algorithm ensures the detection of diseases during the early stages of the diagnosis of leaf disease by farmers and,finally,the crop needed to be controlled by farmers to ensure the survival and protection of plants.In this study,a novel approach has been suggested based on the standard optimization algorithm for grasshopper and the selection of features.Leaf conditions in plants are a major factor in reducing crop yield and quality.Any delay or errors in the diagnosis of the disease can lead to delays in the management of plant disease spreading and damage and related material losses.Comparative new heuristic optimization of swarm intelligence,Grasshopper Optimization Algorithm was inspired by grasshopper movements for their feeding strategy.It simulates the attitude and social interaction of grasshopper swarm in terms of gravity and wind advection.In the decision on features extracted by an accelerated feature selection algorithm,popular approaches such as ANN and SVM classifiers had been used.For the evaluation of the proposed model,different data sets of plant leaves were used.The proposed model was successful in the diagnosis of the diseases of leaves the plant with an accuracy of 99.41 percent(average).The proposed biologically inspired model was sufficiently satisfied,and the best or most desirable characteristics were established.Finally,the results of the research for these data sets were estimated by the proposed Fused Modified Grasshopper Optimization Algorithm(FMGOA).The results of that experiment were demonstrated to allow classification models to reduce input features and thus to increase the precision with the presented Modified Grasshopper Optimization Algorithm.Measurement and analysis were performed to prove the model validity through model parameters such as precision,recall,f-measure,and precision.
基金Supported by:National Natural Science Foundation of China under Grant Nos.52008092,U1934205,51908123the China Postdoctoral Science Foundation under Grant No.2021M690034+1 种基金the International Postdoctoral Exchange Fellowship Program of Chinathe Zhishan Postdoctoral Fellowship Program。
文摘Bridges designed following a conventional approach minimize the risk of collapse,but often require challenging,costly,and time-consuming restoration after an earthquake occurs.The new seismic design philosophy requires bridges to maintain functionality even after severe earthquakes.In this context,this paper proposes a controlled rocking pile foundation(CRPF)system and numerically evaluates bridges′degree of seismic resilience.The CRPF system allows a pile cap to rock on a pile foundation and dissipate seismic energy through inelastic deformations of replaceable bar fuses that connect a pile cap and piles.Following the conceptual design of the CRPF system,two analytical models were developed for a bridge pier utilizing the CRPF system and a pier designed to develop a plastic hinge in its column.The analytical results indicate that,after experiencing a severe earthquake,a conventionally designed bridge pier sustained substantial damage in its column and exhibited significant residual displacement.In contrast,a pier using the CRPF system showed negligible residual displacement and maintained elastic behavior except,as expected,for bar fuses.The damaged fuses can be rapidly replaced to recover bridge seismic resistance following an earthquake.Therefore,the CRPF system helps to achieve the desired postearthquake performance objectives.
文摘The rapid growth in data generation and increased use of computer network devices has amplified the infrastructures of internet.The interconnectivity of networks has brought various complexities in maintaining network availability,consistency,and discretion.Machine learning based intrusion detection systems have become essential to monitor network traffic for malicious and illicit activities.An intrusion detection system controls the flow of network traffic with the help of computer systems.Various deep learning algorithms in intrusion detection systems have played a prominent role in identifying and analyzing intrusions in network traffic.For this purpose,when the network traffic encounters known or unknown intrusions in the network,a machine-learning framework is needed to identify and/or verify network intrusion.The Intrusion detection scheme empowered with a fused machine learning technique(IDS-FMLT)is proposed to detect intrusion in a heterogeneous network that consists of different source networks and to protect the network from malicious attacks.The proposed IDS-FMLT system model obtained 95.18%validation accuracy and a 4.82%miss rate in intrusion detection.
文摘Replaceable flexural and shear fuse-type coupling beams are used in hybrid coupled shear wall(HCSW)systems,enabling concrete buildings to be promptly recovered after severe earthquakes.This study aimed to analytically evaluate the seismic behavior of flexural and shear fuse beams situated in short-,medium-and high-rise RC buildings that have HCSWs.Three building groups hypothetically located in a high seismic hazard zone were studied.A series of 2D nonlinear time history analyses was accomplished in OpenSees,using the ground motion records scaled at the design basis earthquake level.It was found that the effectiveness of fuses in HCSWs depends on various factors such as size and scale of the building,allowable rotation value,inter-story drift ratio,residual drift quantity,energy dissipation value of the fuses,etc.The results show that shear fuses better meet the requirements of rotations and drifts.In contrast,flexural fuses dissipate more energy,but their sectional stiffness should increase to meet other requirements.It was concluded that adoption of proper fuses depends on the overall scale of the building and on how associated factors are considered.
基金Item Sponsored by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of EducationScience and Technology[No.2009-0074199+1 种基金2012R1A1A2008399]the Ministry of Knowledge Economy (MKE) and Korea Institute for Advancement of Technology (KIAT) through the Workforce Development Program in Strategic Technology
文摘Recently,there has been an investigation of polishing processes that has considered new ultra-precision polishing technology for micro parts and optical parts such as those with aspheric and complex shapes.One suitable means of polishing complex shapes is to use a jet of abrasive fluid.However,aerodynamic disturbances and radial spreading are generated by the unstable polishing process of the jet on the surface of the workpiece when it is being polished.A method of jet stabilization has been proposed in which the original nozzle form of a jet of magnetorheological(MR)fluid contains abrasive particles that are magnetized using a magnetic.This paper details the design of an MR jet polishing system that uses an electromagnet,a nozzle,and a hydraulic unit to stabilize a slurry jet based on MR fluid, Second,for silica glass,the polishing spot and section profile are analyzed and the effect of the MR fluid jet polishing process is evaluated.The results of the experiment show that the removal profile is W-shaped and that,in this case,a stable can be proof of a distance of several tens of millimeters from the nozzle.Such results show the possibility of applying the proposed polishing method using MR fluids in ultra-precision micro and optical parts production processes. MR jet polishing shows great potential for use as a new type of precision surface polishing technology.In particular,this is a highly valuable process for the polishing of complex shapes such as micro parts,concaves parts,and cavities.
文摘A simple route to synthesize novel fluorinated fused hetero-polycyclic nitrogen systems containing a pyrazolotriazine moiety (5,8,11) have been deduced from cyclization of 2-aminothiocarbonyl-5-arylidene-3-phenyl-1,2,4-triazin-6(1H)one (2) with diethoxy-phosphine, diethyl carbonate and/or diethyl oxalate in boil THF followed by cyclo condensation with aryl sulfonic acid hydrazide in EtOH/piperidine and finally fluorination with trifluoroethyl acetate. Structures of the products have been established from their elemental analysis and spectral measurements. The antimicrobial activity of the targets has also been evaluated.
基金a derivative product of the project INV-ING-3788 financed by the Vicerectory of Research of the Universidad Militar Nueva Granada,validity 2023.
文摘The use of additive manufacturing techniques in the development of unconventional materials can help reduce the environmental impact of traditional construction materials.In this paper,the properties of a 3D-printed biocomposite were evaluated.Biofilaments obtained by mixing pulverized bamboo fibers with polylactic acid(PLA)resin were extruded during the manufacturing process.To assess the effect of incorporating plant fibers,an analysis was conducted on the morphology,elemental chemical composition,crystallinity index,principal functional groups,thermal stability,surface roughness,microhardness,density,tensile strength,elastic modulus,and strain percentage of reinforced samples.The results were comparedwith those obtained from the characterization of standard PLAfilaments(unreinforced).The fused deposition modeling(FDM)technique was employed to print biocomposite specimens.Additionally,the influence of the printing parameters(infill density,build orientation,and layer thickness)on the physical,tribological,andmechanical properties of the biocomposites was analyzed.These results were compared with those obtained for specimens printed with pure PLA.The findings indicate that incorporating 10%vegetable filler into PLA filaments enhanced the strength and stiffness of the biocomposite under axial loads.Finally,the strength of the biocomposite subjected to axial loads was compared with the standardized values for wood-plastic composites,demonstrating the feasibility of its use for non-structural purposes in civil construction.
基金supported by the National Natural Science Foundation of China(Grant Nos.42422201,12175211,and 12350710177)the Sichuan Science and Technology Program(Grant No.2023NSFSC1910).
文摘Fused silica(SiO_(2)glass),a key amorphous component of Earth’s silicate minerals,undergoes coordination and phase transformations under high pressure.Although extensive studies have been conducted,discrepancies between theoretical and experimental studies remain,particularly regarding strain rate effects during compression.Here,we examine strain rate influences on the shock-induced amorphous–amorphous phase transitions in fused silica by measuring its Hugoniot equation of state and longitudinal sound velocity(CL)up to 7 GPa at strain rates of 10^(6)–10^(7)s^(-1)using a one-stage light-gas gun.A discontinuity in the relationship between shock velocity(US)and particle velocity(UP)and a significant softening in C_(L)of fused silica were observed near~5 GPa under shock loading.Our results indicate that high strain rates restrict Si–O–Si rotation in fused silica,modifying their bonds and increasing silicon coordination.The transition pressure by shock compression is significantly higher than that under static high-pressure conditions(2–3 GPa),which agrees with some recent theoretical predictions with high compression rates,reflecting the greater pressure needed to overcome energy barriers with the strain rate increase.These findings offer insights into strain rate-dependent phase transitions in fused silica and other silicate minerals(e.g.,quartz,olivine,and forsterite),bridging gaps between theoretical simulations and experiments.
基金Project(U2268213) supported by the National Natural Science Foundation of ChinaProject(2024YFHZ0121) supported by the Sichuan Science and Technology Program,China。
文摘Transparent sand is a special material to realize visualization of concealed work in geotechnical engineering. To investigate the dynamic characteristics of transparent sand, a series of undrained cyclic simple shear tests were conducted on the saturated transparent sand composed of fused quartz and refractive index-matched oil mixture. The results reveal that an increase in the initial shear stress ratio significantly affects the shape of the hysteresis loop, particularly resulting in more pronounced asymmetrical accumulation. Factors such as lower relative density, higher cyclic stress ratios and higher initial shear stress ratio have been shown to accelerate cyclic deformation, cyclic pore water pressure and stiffness degradation. The cyclic liquefaction resistance curves decrease as the initial shear stress ratio increases or as relative density decreases. Booker model and power law function model were applied to predict the pore water pressure for transparent sand. Both models yielded excellent fits for their respective condition, indicating a similar dynamic liquefaction pattern to that of natural sands. Finally, transparent sand displays similar dynamic characteristics in terms of cyclic liquefaction resistance and Kα correction factor. These comparisons indicate that transparent sand can serve as an effective means to mimic many natural sands in dynamic model tests.
基金the Natural Science Foundation of Shandong Province(grant no.ZR2020KF024)Yantai City Science and Technology Plan Project(grant no.2022ZDCX016)+1 种基金the University Research Project of Shandong Province(grant no.J17KB007)Natural Science Foundation of Shandong Jiaotong University(grant no.Z201937).
文摘Acrylonitrile–butadiene–styrene(ABS)is the main material used in fused deposition modeling(FDM),which has good toughness and strength,but the single ABS material has poor heat resistance,which tends to cause warping and deformation during the printing process.Polycarbonate(PC)exhibits good performance in heat resistance,allowing it to maintain stable performance at higher temperatures.In this work,PC was used as a blending modifier to prepare five kinds of ABS/PC composite filaments,and the mechanical and thermal properties of the ABS/PC(Acrylonitrile-butadiene-styrene/Polycarbonate)composite filaments were studied and analyzed.Results showed that the glass transition temperature(Tg)of the blend increased continuously as the PC content increased.When the mass fraction of ABS/PC was 50/50,the glass transition temperature of the blend increased by 21.21%,and the tensile strength of the composites reached 40.23 MPa,which was an increase of 36.47% compared with that of pure ABS.However,the impact strength of the composites decreased with the addition of PC.Moreover,with the increase in the mass fraction of PC,the printing accuracy error increased from 0.02 to 0.18 mm.The results of this paper will promote the improvement of ABS printing performance and enrich the available materials for FDM.
基金supported by the National Natural Science Foundation of China(No.22375123)the Shuguang Program of Shanghai Education Development Foundation,the Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(No.2022SXTD012)。
文摘Fluorinated fused azobenzene boron(FBAz)is a novel electron-deficient building block for polymer electron acceptors in all-polymer solar cells(all-PSC).The B←N bridging units impart a fixed configuration and low-lying LUMO/HOMO energy.Three polymer acceptor materials(P2f,P3f and P5f)with different fluorine substitution positions by copolymerizing FBAz with indacenodithiophene(IDT),are synthesized and investigated to study the influence of fluorinated forms on the all-polymer solar cell performance.The FBAz units are synthesized in just three steps,facilitating the straightforward production of polymer acceptors P2f,P3f,and P5f.These acceptors exhibit strong light absorption in the visible to near-infrared range of 500-1000nm and possess suitable LUMO/HOMO energy levels of-3.99/-5.66 eV which are very complementary to that(E_(LUMO/HOMO)=-3.59/-5.20 eV)of the widely-used polymer donor poly[(ethylhexylthiophenyl)-benzodithiophene-(ethylhexyl)-thienothiophene](PTB7-Th).All-polymer solar cells(all-PSCs)with PTB7-Th as electron donor and P3f as electron acceptor exhibits highest power conversion efficiencies(PCE)2.70%.When PC_(61)BM is added as the third component,the device efficiency can reach 5.36%.These preliminary results indicate that FBAz is a promising strong electron acceptor for the development of n-type polymer semiconductors,especially in organic photovoltaics(OPVs).To the best of our knowledge,this is the first example demonstrating the unique photovoltaic properties of the N=N double bond as an acceptor material.
基金supported by the National Natural Science Foundation of China(Grant No.62275235).
文摘We demonstrate a new polarization smoothing(PS)approach utilizing residual stress birefringence in fused silica to create a spatially random polarization control plate(SRPCP),thereby improving target illumination uniformity in inertial confinement fusion(ICF)laser systems.The fundamental operating mechanism and key fabrication techniques for the SRPCP are systematically developed and experimentally validated.The SRPCP converts a linearly polarized 3ω incident laser beam into an output beam with a spatially randomized polarization distribution.When combined with a continuous phase plate,the SRPCP effectively suppresses high-intensity speckles at all spatial frequencies in the focal spot.The proposed PS technique is specifically designed for high-fluence large-aperture laser systems,enabling novel polarization control regimes in laser-driven ICF.
基金Supported by the Science and Technology Support Key Project of Jiangsu Province (DE2008365)~~
文摘Based on analyzing the influences of a slicing scheme on stair-stepping effect, supporting structure, efficiency and deformation, etc. , analytical hierarchical process （AHP） combining with fuzzy synthetic evaluation is introduced to make decision in slicing schemes for a processing part. The application in determining the slicing scheme for a computer mouse during prototyping shows that the method increases the rationality during decision- making and improves quality and efficiency for the prototyping part.
