Experimental design was applied in the optimization of crude oil adsorption from saline waste water using raw bagasse.The application of response surface methodology(RSM) was presented with temperature,salinity of wat...Experimental design was applied in the optimization of crude oil adsorption from saline waste water using raw bagasse.The application of response surface methodology(RSM) was presented with temperature,salinity of water,pH,adsorbent dose,and initial oil content as factors.A quadratic model could be used to approximate the mathematical relationship of crude oil removal on the five significant independent variables.Predicted values and experimental values are found to be in good agreement with R2 of 97.44%.The result of optimization shows that the maximum crude oil removal is equal to 67.38% under the optimal condition of temperature of 46.53 °C,salinity of 37.2 g/L,pH of 3,adsorbent dose of 9 g/L and initial oil content of 300×10-6.展开更多
Iterated local search(ILS)is used to construct the optimal experimental designs for multi-dimensional constrained spaces,in which the inner loop is based on the stochastic coordinate-exchange(SCE)algorithm.Every time ...Iterated local search(ILS)is used to construct the optimal experimental designs for multi-dimensional constrained spaces,in which the inner loop is based on the stochastic coordinate-exchange(SCE)algorithm.Every time a local optimal solution is found by the SCE algorithm,the perturbation operator is applied to it,and then a new solution is explored in the areas where the exchange of coordinates may produce improvement,so as to retain the features and attributes of the current optimal solution and avoid the defects of random restart.We implement the iterated local coordinate-exchange algorithm for experimental designs in the multi-dimensional constrained spaces.In addition,sensitivity analysis was conducted to analyze the impacts of the parameters on the performance of the proposed algorithm.Also we compared the performance of the proposed algorithm to the SCE algorithm using the random restart strategy.The analysis shows that the proposed algorithm is better than the SCE algorithm in terms of efficiency and quality,especially in the experimental designs for high-dimensional constrained space.展开更多
A new multi-species particle swarm optimization with a two-level hierarchical topology and the orthogonal learning strategy(OMSPSO) is proposed, which enhances the global search ability of particles and increases thei...A new multi-species particle swarm optimization with a two-level hierarchical topology and the orthogonal learning strategy(OMSPSO) is proposed, which enhances the global search ability of particles and increases their convergence rates. The numerical results on 10 benchmark functions demonstrated the effectiveness of our proposed algorithm. Then, the proposed algorithm is presented to design a butterfly-shaped microstrip patch antenna. Combined with the HFSS solver, a butterfly-shaped patch antenna with a bandwidth of about 40.1% is designed by using the proposed OMSPSO. The return loss of the butterfly-shaped antenna is greater than 10 d B between 4.15 and 6.36 GHz. The antenna can serve simultaneously for the high-speed wireless computer networks(5.15–5.35 GHz) and the RFID systems(5.8 GHz).展开更多
An optimal configuration of the flux-reversal linear synchronous motor (FRLSM) with the optimal number of attachment permanent magnets (PMs) was presented. The optimal model of 2 000 N was designed to reduce the deten...An optimal configuration of the flux-reversal linear synchronous motor (FRLSM) with the optimal number of attachment permanent magnets (PMs) was presented. The optimal model of 2 000 N was designed to reduce the detent force by redesigning the air-gap structure and skewing. The design parameters,mover PMs and stator core,were selected for optimal design by DOE. The thrust and the detent force of the designed optimal models were compared by finite element analysis (FEA). As a result,the thrust of the optimal model is slightly decreased by 1.97% compared with the basic model,and the detent force of the optimal model is greatly decreased by 88.47% compared with the basic model.展开更多
The order-of-addition experiments are widely used in many fields,including food and industrial production,but the relative research under prior constraints is limited.The purpose of this paper is to select an optimal ...The order-of-addition experiments are widely used in many fields,including food and industrial production,but the relative research under prior constraints is limited.The purpose of this paper is to select an optimal sequence under the restriction that component i is added before component j,while it is unachievable to compare all sequences when the number of components m is large.To achieve this,a constrained PWO model is first provided,and then the D-optimal designs for order-of addition experiments with minimal-points via the modified threshold accepting algorithm is established.The effectiveness of the proposed method is demonstrated through a job scheduling problem with a prior constraint for teaching cases.展开更多
To obtain the optimal process parameters of stamping forming, finite element analysis and optimization technique were integrated via transforming multi-objective issue into a single-objective issue. A Pareto-based gen...To obtain the optimal process parameters of stamping forming, finite element analysis and optimization technique were integrated via transforming multi-objective issue into a single-objective issue. A Pareto-based genetic algorithm was applied to optimizing the head stamping forming process. In the proposed optimal model, fracture, wrinkle and thickness varying are a function of several factors, such as fillet radius, draw-bead position, blank size and blank-holding force. Hence, it is necessary to investigate the relationship between the objective functions and the variables in order to make objective functions varying minimized simultaneously. Firstly, the central composite experimental(CCD) with four factors and five levels was applied, and the experimental data based on the central composite experimental were acquired. Then, the response surface model(RSM) was set up and the results of the analysis of variance(ANOVA) show that it is reliable to predict the fracture, wrinkle and thickness varying functions by the response surface model. Finally, a Pareto-based genetic algorithm was used to find out a set of Pareto front, which makes fracture, wrinkle and thickness varying minimized integrally. A head stamping case indicates that the present method has higher precision and practicability compared with the "trial and error" procedure.展开更多
An integer linear bilevel programming problem is firstly transformed into a binary linear bilevel programming problem, and then converted into a single-level binary implicit programming. An orthogonal genetic algorith...An integer linear bilevel programming problem is firstly transformed into a binary linear bilevel programming problem, and then converted into a single-level binary implicit programming. An orthogonal genetic algorithm is developed for solving the binary linear implicit programming problem based on the orthogonal design. The orthogonal design with the factor analysis, an experimental design method is applied to the genetic algorithm to make the algorithm more robust, statistical y sound and quickly convergent. A crossover operator formed by the orthogonal array and the factor analysis is presented. First, this crossover operator can generate a smal but representative sample of points as offspring. After al of the better genes of these offspring are selected, a best combination among these offspring is then generated. The simulation results show the effectiveness of the proposed algorithm.展开更多
In this research work, extraction and purification of germanium from zinc leach residues(ZLR) were investigated. The results of ICP, XRF, and atomic adsorption spectroscopy(AAS) tests show that contents of germanium, ...In this research work, extraction and purification of germanium from zinc leach residues(ZLR) were investigated. The results of ICP, XRF, and atomic adsorption spectroscopy(AAS) tests show that contents of germanium, iron, lead, and zinc within the leaching residue were 105×10^(-6), 3.53%, 10.35%, and 8.8%, respectively. XRD results indicate that the main minerals were in different forms of sulfates(CaSO_4·2H_2O, PbSO_4 and ZnSO_4·6H__2O), silicate(SiO_2), and oxide(Fe_2O_3). Dissolution of leaching filter cake was carried out using 5 parameters and each in 4 levels(acid concentration, temperature, time, liquid-to-solid ratio, and stirring speed) by Taguchi method(L_(16)), and then optimization of the effective parameters by response surface method. Under optimum conditions, zinc and germanium dissolution efficiencies were 88.71% and 8%, respectively. Leaching tests with sulfuric acid(added di-ammonium oxalate monohydrate) and hydrochloric acid(HCl) on the residues obtained from previous-stage sulfuric acid dissolution, yielded germanium and iron recoveries of 83%, 88%, 40%, and 90%, respectively. Thus, leaching experiment with sulfuric acid(added di-ammonium oxalate monohydrate) was superior to that with hydrochloric acid due to high and low extraction amounts of germanium and iron, respectively. Precipitation experiments revealed that germanium purification with tannic acid presented a better result compared to sodium hydroxide and ammonia. Under optimum conditions, contents of germanium and iron in the solution after precipitation were 0.1505% and 14.7% with precipitation yields of 91% and 52%, respectively.展开更多
A quadratic bilevel programming problem is transformed into a single level complementarity slackness problem by applying Karush-Kuhn-Tucker（KKT） conditions.To cope with the complementarity constraints,a binary encod...A quadratic bilevel programming problem is transformed into a single level complementarity slackness problem by applying Karush-Kuhn-Tucker（KKT） conditions.To cope with the complementarity constraints,a binary encoding scheme is adopted for KKT multipliers,and then the complementarity slackness problem is simplified to successive quadratic programming problems,which can be solved by many algorithms available.Based on 0-1 binary encoding,an orthogonal genetic algorithm,in which the orthogonal experimental design with both two-level orthogonal array and factor analysis is used as crossover operator,is proposed.Numerical experiments on 10 benchmark examples show that the orthogonal genetic algorithm can find global optimal solutions of quadratic bilevel programming problems with high accuracy in a small number of iterations.展开更多
The residue drying area(RDA)is the major source of fugitive red sand(RS)dust emissions in the bauxite mining industry and causes serious environmental and safety detriments.Polymer stabilizer(PS)is one of the promisin...The residue drying area(RDA)is the major source of fugitive red sand(RS)dust emissions in the bauxite mining industry and causes serious environmental and safety detriments.Polymer stabilizer(PS)is one of the promising non-traditional stabilizers to mitigate such issues.This research investigated the unconfined compressive strength(UCS)of RS using synthetic polymer stabilizer(SPS)and natural polymer stabilizer(NPS),and to determine the optimum application concentration and mixing ratio of the PAM and Guar gum mixture.Results illustrated that PAM apparently outperform Guar gum in stabilizing sand particles.The mixture of PAM and Guar gum is more effective than individual use.The optimum polymer concentration and the mixing ratio are 0.94 wt.%and 0.6(PAM:total(PAM+Guar gum)),respectively.A rigorous regression model was developed to predict the UCS value based on application concentration and mixing ratio for the purpose of cost and time efficiency.展开更多
Aiming at the independent development of tracked vehicles,it is urgent to improve its mobility,passability and ride comfort,a new type of flexible road wheel with a“wheel-hinge-hub”combined structure is proposed in ...Aiming at the independent development of tracked vehicles,it is urgent to improve its mobility,passability and ride comfort,a new type of flexible road wheel with a“wheel-hinge-hub”combined structure is proposed in this study.The vibration model characteristics of the flexible road wheel were studied by the combination of numerical simulation and experiments.The superelasticity of rubber is obtained through uniaxial tensile experiment of the material and a detail three-dimensional nolinear finite element model of the flexible road wheel is established through finite element software ABAQUS.The free vibration equation of the flexible road wheel is solved by Lanczos vector direct superposition method,and its predicted modes and natural frequencies are compared with experimental results,which verifies the accuracy and reliability of the established finite element model.On this basis,the effects of various key structural or material factors on the natural frequencies of the flexible road wheel are studied using orthogonal experimental design method.Besides,the vibration modal characteristics of the flexible road wheel are also compared with those of the rigid road wheel.The research results provide a theoretical basis for the vibration and noise reduction of flexible road wheel.展开更多
Surface-enhanced Raman scattering(SERS) has been widely used as an effective technique for lowconcentration molecules detections in the past decades. This work proposes a rapid and accessible process to fabricate SERS...Surface-enhanced Raman scattering(SERS) has been widely used as an effective technique for lowconcentration molecules detections in the past decades. This work proposes a rapid and accessible process to fabricate SERS-active substrates with high uniformity and controllability based on two-step laser ablation. Laser beams directly ablate the surface of Si, concurrently creating microstructures and ejecting molten materials caused by the thermal effect that nucleate in ambient air. The nuclei grow into nanoparticles and deposit over the surface. These nanoparticles,together with microstructures, improve the light collection efficiency of the SERS-active substrates. Especially after Au thin film deposition, these nanoparticles can provide nanogaps as hotspots for SERS. By orthogonal experiment design,laser processing parameters for better performances are determined. Compared with substrates fabricated by single 1064 nm master oscillator power amplifier(MOPA) laser ablation, substrates ablated by the primary 1064 nm MOPA laser and secondary UV pulsed laser show more uniform nanoparticles’ deposition over the surface. The optimized largearea substrate has a SERS detection limit of 10^(-8)mol/L for 4-aminothiophenol(4-ATP), indicating the potential realworld applications for trace detection.展开更多
A new approach which adopted the idea of coupling bionics to improve erosion resistance was presented, by taking the desert scorpion as the research object. The anti-erosion characteristic rules and mechanism of deser...A new approach which adopted the idea of coupling bionics to improve erosion resistance was presented, by taking the desert scorpion as the research object. The anti-erosion characteristic rules and mechanism of desert scorpion＇s surface under the dynamics effect of gas/solid mixed media were researched, especially the comprehensive influence mechanism of surface morphology, microstructure, creature flexibility and many other factors was studied. Simulation by CFD software was applied to predict the relative erosion severity. Samples with the coupled bionic configurations and flexibility were produced. Experiment optimum design theory was employed to design experiment scheme. Silica sand of particle size of 105-830 ~tm was used as the erodent. The erosion tests were carried out to validate the simulation results obtained. It is shown that the predicted results are in agreement with those obtained from the experiment. And contrast tests were carried out at the best and worst test points of erosion resistance for four samples. Contrast tests show that the erosion resistance trend occurs in such order with the best erosion resistance as coupling sample, groove, smooth and flexibility, and smooth, and the increasing rate of erosion resistances in sequence of 12.08%, 8.87%, 6.03% in the best test point. But in the poorest point, the increasing rate of erosion resistance is in sequence of 15.64%, 9.53%, 6.59%. The morphologies of eroded surface were examined by the scanning electron microscope, and the possible wear mechanism was discussed.展开更多
The effectiveness of optimizing electrical conductivity of carbon fiber/carbon nanotube （CNT）/epoxy hybrid composites via Taguchi method was demonstrated. CNTs were induced on carbon fabric by electrophoretic deposi...The effectiveness of optimizing electrical conductivity of carbon fiber/carbon nanotube （CNT）/epoxy hybrid composites via Taguchi method was demonstrated. CNTs were induced on carbon fabric by electrophoretic deposition （EPD） technique. The essential deposition parameters were identified as l） the deposition time, 2） the deposition voltage, 3） the mass fraction of CNTs in suspension, and 4） the distance between the electrodes. An experimental design was then performed to establish the appropriate levels for each factor. An orthogonal array of L9 （34） was designed to conduct the experiments. Electrical conductivity results were collected as the response. The relative influences of design parameters on the response were discussed. Using the model, signal to noise （S/N） ratio and response characteristics for the optimized deposition parameter combination were predicted. The results show clearly that the optimum condition of electrophoretic deposition （EPD） process improves the electrical conductivity of carbon/epoxy hybrid composites.展开更多
文摘Experimental design was applied in the optimization of crude oil adsorption from saline waste water using raw bagasse.The application of response surface methodology(RSM) was presented with temperature,salinity of water,pH,adsorbent dose,and initial oil content as factors.A quadratic model could be used to approximate the mathematical relationship of crude oil removal on the five significant independent variables.Predicted values and experimental values are found to be in good agreement with R2 of 97.44%.The result of optimization shows that the maximum crude oil removal is equal to 67.38% under the optimal condition of temperature of 46.53 °C,salinity of 37.2 g/L,pH of 3,adsorbent dose of 9 g/L and initial oil content of 300×10-6.
基金This work was supported by the National Natural Science Foundation of China(72171231).
文摘Iterated local search(ILS)is used to construct the optimal experimental designs for multi-dimensional constrained spaces,in which the inner loop is based on the stochastic coordinate-exchange(SCE)algorithm.Every time a local optimal solution is found by the SCE algorithm,the perturbation operator is applied to it,and then a new solution is explored in the areas where the exchange of coordinates may produce improvement,so as to retain the features and attributes of the current optimal solution and avoid the defects of random restart.We implement the iterated local coordinate-exchange algorithm for experimental designs in the multi-dimensional constrained spaces.In addition,sensitivity analysis was conducted to analyze the impacts of the parameters on the performance of the proposed algorithm.Also we compared the performance of the proposed algorithm to the SCE algorithm using the random restart strategy.The analysis shows that the proposed algorithm is better than the SCE algorithm in terms of efficiency and quality,especially in the experimental designs for high-dimensional constrained space.
基金Project(61105067)supported by the National Natural Science Foundation of China
文摘A new multi-species particle swarm optimization with a two-level hierarchical topology and the orthogonal learning strategy(OMSPSO) is proposed, which enhances the global search ability of particles and increases their convergence rates. The numerical results on 10 benchmark functions demonstrated the effectiveness of our proposed algorithm. Then, the proposed algorithm is presented to design a butterfly-shaped microstrip patch antenna. Combined with the HFSS solver, a butterfly-shaped patch antenna with a bandwidth of about 40.1% is designed by using the proposed OMSPSO. The return loss of the butterfly-shaped antenna is greater than 10 d B between 4.15 and 6.36 GHz. The antenna can serve simultaneously for the high-speed wireless computer networks(5.15–5.35 GHz) and the RFID systems(5.8 GHz).
基金Work supported by the Second Stage of Brain Korea 21 Projects
文摘An optimal configuration of the flux-reversal linear synchronous motor (FRLSM) with the optimal number of attachment permanent magnets (PMs) was presented. The optimal model of 2 000 N was designed to reduce the detent force by redesigning the air-gap structure and skewing. The design parameters,mover PMs and stator core,were selected for optimal design by DOE. The thrust and the detent force of the designed optimal models were compared by finite element analysis (FEA). As a result,the thrust of the optimal model is slightly decreased by 1.97% compared with the basic model,and the detent force of the optimal model is greatly decreased by 88.47% compared with the basic model.
基金supported by National Natural Science Foundation of China(Grant Nos.11971204,12271270)Natural Science Foundation of Jiangsu Province of China(Grant No.BK20200108)the Zhongwu Youth Innovative Talent Program of Jiangsu University of Technology and the Third Level Training Object of the Sixth“333 Project”in Jiangsu Province。
文摘The order-of-addition experiments are widely used in many fields,including food and industrial production,but the relative research under prior constraints is limited.The purpose of this paper is to select an optimal sequence under the restriction that component i is added before component j,while it is unachievable to compare all sequences when the number of components m is large.To achieve this,a constrained PWO model is first provided,and then the D-optimal designs for order-of addition experiments with minimal-points via the modified threshold accepting algorithm is established.The effectiveness of the proposed method is demonstrated through a job scheduling problem with a prior constraint for teaching cases.
基金Project(2012ZX04010-081) supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China
文摘To obtain the optimal process parameters of stamping forming, finite element analysis and optimization technique were integrated via transforming multi-objective issue into a single-objective issue. A Pareto-based genetic algorithm was applied to optimizing the head stamping forming process. In the proposed optimal model, fracture, wrinkle and thickness varying are a function of several factors, such as fillet radius, draw-bead position, blank size and blank-holding force. Hence, it is necessary to investigate the relationship between the objective functions and the variables in order to make objective functions varying minimized simultaneously. Firstly, the central composite experimental(CCD) with four factors and five levels was applied, and the experimental data based on the central composite experimental were acquired. Then, the response surface model(RSM) was set up and the results of the analysis of variance(ANOVA) show that it is reliable to predict the fracture, wrinkle and thickness varying functions by the response surface model. Finally, a Pareto-based genetic algorithm was used to find out a set of Pareto front, which makes fracture, wrinkle and thickness varying minimized integrally. A head stamping case indicates that the present method has higher precision and practicability compared with the "trial and error" procedure.
基金supported by the Fundamental Research Funds for the Central Universities(K50511700004)the Natural Science Basic Research Plan in Shaanxi Province of China(2013JM1022)
文摘An integer linear bilevel programming problem is firstly transformed into a binary linear bilevel programming problem, and then converted into a single-level binary implicit programming. An orthogonal genetic algorithm is developed for solving the binary linear implicit programming problem based on the orthogonal design. The orthogonal design with the factor analysis, an experimental design method is applied to the genetic algorithm to make the algorithm more robust, statistical y sound and quickly convergent. A crossover operator formed by the orthogonal array and the factor analysis is presented. First, this crossover operator can generate a smal but representative sample of points as offspring. After al of the better genes of these offspring are selected, a best combination among these offspring is then generated. The simulation results show the effectiveness of the proposed algorithm.
文摘In this research work, extraction and purification of germanium from zinc leach residues(ZLR) were investigated. The results of ICP, XRF, and atomic adsorption spectroscopy(AAS) tests show that contents of germanium, iron, lead, and zinc within the leaching residue were 105×10^(-6), 3.53%, 10.35%, and 8.8%, respectively. XRD results indicate that the main minerals were in different forms of sulfates(CaSO_4·2H_2O, PbSO_4 and ZnSO_4·6H__2O), silicate(SiO_2), and oxide(Fe_2O_3). Dissolution of leaching filter cake was carried out using 5 parameters and each in 4 levels(acid concentration, temperature, time, liquid-to-solid ratio, and stirring speed) by Taguchi method(L_(16)), and then optimization of the effective parameters by response surface method. Under optimum conditions, zinc and germanium dissolution efficiencies were 88.71% and 8%, respectively. Leaching tests with sulfuric acid(added di-ammonium oxalate monohydrate) and hydrochloric acid(HCl) on the residues obtained from previous-stage sulfuric acid dissolution, yielded germanium and iron recoveries of 83%, 88%, 40%, and 90%, respectively. Thus, leaching experiment with sulfuric acid(added di-ammonium oxalate monohydrate) was superior to that with hydrochloric acid due to high and low extraction amounts of germanium and iron, respectively. Precipitation experiments revealed that germanium purification with tannic acid presented a better result compared to sodium hydroxide and ammonia. Under optimum conditions, contents of germanium and iron in the solution after precipitation were 0.1505% and 14.7% with precipitation yields of 91% and 52%, respectively.
基金supported by the National Natural Science Foundation of China (60873099)
文摘A quadratic bilevel programming problem is transformed into a single level complementarity slackness problem by applying Karush-Kuhn-Tucker（KKT） conditions.To cope with the complementarity constraints,a binary encoding scheme is adopted for KKT multipliers,and then the complementarity slackness problem is simplified to successive quadratic programming problems,which can be solved by many algorithms available.Based on 0-1 binary encoding,an orthogonal genetic algorithm,in which the orthogonal experimental design with both two-level orthogonal array and factor analysis is used as crossover operator,is proposed.Numerical experiments on 10 benchmark examples show that the orthogonal genetic algorithm can find global optimal solutions of quadratic bilevel programming problems with high accuracy in a small number of iterations.
基金Project(2016YFC0501103)supported by the National Key Research and Development Program of ChinaProject(51574222)supported by the General Program of National Science Foundation of China+1 种基金Project(SKLCRSM15KF01)supported by Independent Research Projects of State Key Laboratory of Coal Resources and Safe Mining,CUMT,ChinaProject(2015)supported by the Mining Education Australia Collaborative Research Grant Scheme
文摘The residue drying area(RDA)is the major source of fugitive red sand(RS)dust emissions in the bauxite mining industry and causes serious environmental and safety detriments.Polymer stabilizer(PS)is one of the promising non-traditional stabilizers to mitigate such issues.This research investigated the unconfined compressive strength(UCS)of RS using synthetic polymer stabilizer(SPS)and natural polymer stabilizer(NPS),and to determine the optimum application concentration and mixing ratio of the PAM and Guar gum mixture.Results illustrated that PAM apparently outperform Guar gum in stabilizing sand particles.The mixture of PAM and Guar gum is more effective than individual use.The optimum polymer concentration and the mixing ratio are 0.94 wt.%and 0.6(PAM:total(PAM+Guar gum)),respectively.A rigorous regression model was developed to predict the UCS value based on application concentration and mixing ratio for the purpose of cost and time efficiency.
基金the National Natural Science Foundation of China[grant numbers 11672127,51605215]the Advance Research Special Technology Project of Army Equipment[grant number AGA19001]+2 种基金the Army Research and Technology Project[grant number AQA19001],the Innovation Fund Project of China Aerospace 1st Academy[grant number CHC20001]the Special funded project of China Postdoctoral Science Foundation[grant number 2019T120450]the Fundamental Research Funds for the Central Universities[grant number NP2020407].
文摘Aiming at the independent development of tracked vehicles,it is urgent to improve its mobility,passability and ride comfort,a new type of flexible road wheel with a“wheel-hinge-hub”combined structure is proposed in this study.The vibration model characteristics of the flexible road wheel were studied by the combination of numerical simulation and experiments.The superelasticity of rubber is obtained through uniaxial tensile experiment of the material and a detail three-dimensional nolinear finite element model of the flexible road wheel is established through finite element software ABAQUS.The free vibration equation of the flexible road wheel is solved by Lanczos vector direct superposition method,and its predicted modes and natural frequencies are compared with experimental results,which verifies the accuracy and reliability of the established finite element model.On this basis,the effects of various key structural or material factors on the natural frequencies of the flexible road wheel are studied using orthogonal experimental design method.Besides,the vibration modal characteristics of the flexible road wheel are also compared with those of the rigid road wheel.The research results provide a theoretical basis for the vibration and noise reduction of flexible road wheel.
基金Project(2020H0006) supported by the Fujian Provincial Science and Technology ProgrammeChina+2 种基金Project(62175203) supported by the National Natural Science Foundation of ChinaProject(RD2020050301) supported by the Innovation Laboratory for Science and Technology of Energy Materials of Fujian Province Applied Research ProjectChina。
文摘Surface-enhanced Raman scattering(SERS) has been widely used as an effective technique for lowconcentration molecules detections in the past decades. This work proposes a rapid and accessible process to fabricate SERS-active substrates with high uniformity and controllability based on two-step laser ablation. Laser beams directly ablate the surface of Si, concurrently creating microstructures and ejecting molten materials caused by the thermal effect that nucleate in ambient air. The nuclei grow into nanoparticles and deposit over the surface. These nanoparticles,together with microstructures, improve the light collection efficiency of the SERS-active substrates. Especially after Au thin film deposition, these nanoparticles can provide nanogaps as hotspots for SERS. By orthogonal experiment design,laser processing parameters for better performances are determined. Compared with substrates fabricated by single 1064 nm master oscillator power amplifier(MOPA) laser ablation, substrates ablated by the primary 1064 nm MOPA laser and secondary UV pulsed laser show more uniform nanoparticles’ deposition over the surface. The optimized largearea substrate has a SERS detection limit of 10^(-8)mol/L for 4-aminothiophenol(4-ATP), indicating the potential realworld applications for trace detection.
基金Projects(51205161, 51175220, 51290292) supported by the National Natural Science Foundation of ChinaProjects(20120061120051, 20100061110023) supported by Specialized Research Fund for the Doctoral Program of Higher Education of China+3 种基金Project(OSR-04-04) supported by Cooperation and Innovation to National Potential Oil and Gas for Production and Research, ChinaProject(200905016) supported by Ten Outstanding Youth Fund Project of Jilin University, ChinaProject(2012M511345) supported by China Postdoctoral Science FoundationProject(450060481176) supported by Basic Scientific Research Expenses of Jilin University, China
文摘A new approach which adopted the idea of coupling bionics to improve erosion resistance was presented, by taking the desert scorpion as the research object. The anti-erosion characteristic rules and mechanism of desert scorpion＇s surface under the dynamics effect of gas/solid mixed media were researched, especially the comprehensive influence mechanism of surface morphology, microstructure, creature flexibility and many other factors was studied. Simulation by CFD software was applied to predict the relative erosion severity. Samples with the coupled bionic configurations and flexibility were produced. Experiment optimum design theory was employed to design experiment scheme. Silica sand of particle size of 105-830 ~tm was used as the erodent. The erosion tests were carried out to validate the simulation results obtained. It is shown that the predicted results are in agreement with those obtained from the experiment. And contrast tests were carried out at the best and worst test points of erosion resistance for four samples. Contrast tests show that the erosion resistance trend occurs in such order with the best erosion resistance as coupling sample, groove, smooth and flexibility, and smooth, and the increasing rate of erosion resistances in sequence of 12.08%, 8.87%, 6.03% in the best test point. But in the poorest point, the increasing rate of erosion resistance is in sequence of 15.64%, 9.53%, 6.59%. The morphologies of eroded surface were examined by the scanning electron microscope, and the possible wear mechanism was discussed.
基金Project supported by the Second Stage of Brain Korea 21 Projects and the National Research Foundation of Korea (2011-0030804) Funded by the Korea Government (MEST)
文摘The effectiveness of optimizing electrical conductivity of carbon fiber/carbon nanotube （CNT）/epoxy hybrid composites via Taguchi method was demonstrated. CNTs were induced on carbon fabric by electrophoretic deposition （EPD） technique. The essential deposition parameters were identified as l） the deposition time, 2） the deposition voltage, 3） the mass fraction of CNTs in suspension, and 4） the distance between the electrodes. An experimental design was then performed to establish the appropriate levels for each factor. An orthogonal array of L9 （34） was designed to conduct the experiments. Electrical conductivity results were collected as the response. The relative influences of design parameters on the response were discussed. Using the model, signal to noise （S/N） ratio and response characteristics for the optimized deposition parameter combination were predicted. The results show clearly that the optimum condition of electrophoretic deposition （EPD） process improves the electrical conductivity of carbon/epoxy hybrid composites.
