The work takes a new liquid-cooling plate in a power battery with pin fins inside the channel as the object.A mathematical model is established via the central composite design of the response surface to study the rel...The work takes a new liquid-cooling plate in a power battery with pin fins inside the channel as the object.A mathematical model is established via the central composite design of the response surface to study the relationships among the length,width,height,and spacing of pin fins;the maximum temperature and temperature difference of the battery module;and the pressure drop of the liquid-cooling plate.Model accuracy is verified via variance analysis.The new liquid-cooling plate enables the power battery to work within an optimal temperature range.Appropriately increasing the length,width,and height and reducing the spacing of pin fins could reduce the temperature of the power battery module and improve the temperature uniformity.However,the pressure drop of the liquid-cooling plate increases.The structural parameters of the pin fins are optimized to minimize the maximum temperature and the temperature difference of the battery module as well as the pressure drop of the liquid-cooling plate.The errors between the values predicted and actual by the simulation test are 0.58%,4%,and 0.48%,respectively,which further verifies the model accuracy.The results reveal the influence of the structural parameters of the pin fins inside the liquid-cooling plate on its heat dissipation performance and pressure drop characteristics.A theoretical basis is provided for the design of liquid-cooling plates in power batteries and the optimization of structural parameters.展开更多
Platycodon grandiflorum A.DC.(PAl)C)root was taken as experiment material to extract polysaccharide.On the base of single factor tests(extraction time,extraction temperature,liquid-solid ratio,solvent pH value and NaC...Platycodon grandiflorum A.DC.(PAl)C)root was taken as experiment material to extract polysaccharide.On the base of single factor tests(extraction time,extraction temperature,liquid-solid ratio,solvent pH value and NaCl concentration),the study concluded the main factors affecting the extraction of PADC polysaccharide,which are liquid-solid ratio,extraction time and extraction temperature.Then through central-composite test design,the extraction conditions were concluded as liquid-solid ratio 34.43,extraction time 89.83 min and extraction temperature 52.47℃.By means of validation experiments,the adequacy of this model was confirmed.展开更多
A new method for optimizing a butterfly-shaped linear ultrasonic motor was proposed to maximize its mechanical output. The finite element analysis technology and response surface methodology were combined together to ...A new method for optimizing a butterfly-shaped linear ultrasonic motor was proposed to maximize its mechanical output. The finite element analysis technology and response surface methodology were combined together to realize the optimal design of the butterfly-shaped linear ultrasonic motor. First, the operation principle of the motor was introduced. Second, the finite element parameterized model of the stator of the motor was built using ANSYS parametric design language and some structure parameters of the stator were selected as design variables. Third, the sample points were selected in design variable space using latin hypercube Design. Through modal analysis and harmonic response analysis of the stator based on these sample points, the target responses were obtained. These sample points and response values were combined together to build a response surface model. Finally, the simplex method was used to find the optimal solution. The experimental results showed that many aspects of the design requirements of the butterfly-shaped linear ultrasonic motor have been fulfilled. The prototype motor fabricated based on the optimal design result exhibited considerably high dynamic performance, such as no-load speed of 873 ram/s, maximal thrust of 27.5 N, maximal efficiency of 43%, and thrust-weight ratio of 45.8.展开更多
The response surface methodology(RSM)was used to optimize the operating parameters during the bioleaching of Jinchuan high-magnesium nickel sulfide ore.The particle size,acid addition,pulp density and inoculation amou...The response surface methodology(RSM)was used to optimize the operating parameters during the bioleaching of Jinchuan high-magnesium nickel sulfide ore.The particle size,acid addition,pulp density and inoculation amount were chosen as the investigated parameters.To maximize the leaching efficiency of nickel,copper,cobalt and minimize the dissolution of magnesium and iron ions,the model suggested a combination of optimal parameters of particles less than 0.074 mm being 72.11%,sulfuric acid addition being 300 kg/t,pulp density being 5%and inoculation amount being 12.88%.Under the conditions,the average results of three parallel experiments were 89.43%of nickel leaching efficiency,36.78%of copper leaching efficiency,84.07%of cobalt leaching efficiency,49.19%of magnesium leaching efficiency and 0.20 g/L of iron concentration.The model indicated that the most significant factor in response of the leaching efficiency of valuable metal is the particle size,and the most significant factor in response to the leaching efficiency of harmful ions(Mg2+)is the amount of sulfuric acid addition.And according to the suggested models,no significance of the interaction effect between particle size and acid addition was shown.Under the optimized parameters suggested by models,the valuable metals could be separated from harmful ions during the bioleaching process.展开更多
Deformation prediction and the analysis of underground goaf are important to the safe and efficient recovery of residual ore when shifting from open-pit mining to underground mining.To address the comprehensive proble...Deformation prediction and the analysis of underground goaf are important to the safe and efficient recovery of residual ore when shifting from open-pit mining to underground mining.To address the comprehensive problem of stability in the double mined-out area of the Tong-Lv-Shan(TLS)mine,which employed the dry stacked gangue technology,this paper applies the function fitting theory and a regression analysis method to screen the sensitive interval of four influencing factors based on single-factor experiments and the numerical simulation software FLAC3D.The influencing factors of the TLS mine consist of the column thickness(d),gob area span(D),boundary pillar thickness(h)and height of tailing gangue(H).The fitting degree between the four factors and the displacement of the gob roof(W)is reasonable because the correlation coefficient(R2)is greater than0.9701.After establishing29groups that satisfy the principles of Box-Behnken design(BBD),the dry gangue tailings process was re-simulated for the selected sensitive interval.Using a combination of an analysis of variance(ANOVA),regression equations and a significance analysis,the prediction results of the response surface methodology(RSM)show that the significant degree for the stability of the mined-out area for the factors satisfies the relationship of h>D>d>H.The importance of the four factors cannot be disregarded in a comparison of the prediction results of the engineering test stope in the TLS mine.By comparing the data of monitoring points and function prediction,the proposed method has shown promising results,and the prediction accuracy of RSM model is acceptable.The relative errors of the two test stopes are1.67%and3.85%,respectively,which yield satisfactory reliability and reference values for the mines.展开更多
In the non-linear microwave drying process, the incremental improved back-propagation （BP） neural network and response surface methodology （RSM） were used to build a predictive model of the combined effects of ind...In the non-linear microwave drying process, the incremental improved back-propagation （BP） neural network and response surface methodology （RSM） were used to build a predictive model of the combined effects of independent variables （the microwave power, the acting time and the rotational frequency） for microwave drying of selenium-rich slag. The optimum operating conditions obtained from the quadratic form of the RSM are： the microwave power of 14.97 kW, the acting time of 89.58 min, the rotational frequency of 10.94 Hz, and the temperature of 136.407 ℃. The relative dehydration rate of 97.1895% is obtained. Under the optimum operating conditions, the incremental improved BP neural network prediction model can predict the drying process results and different effects on the results of the independent variables. The verification experiments demonstrate the prediction accuracy of the network, and the mean squared error is 0.16. The optimized results indicate that RSM can optimize the experimental conditions within much more broad range by considering the combination of factors and the neural network model can predict the results effectively and provide the theoretical guidance for the follow-up production process.展开更多
To reduce the fuel consumption and emissions and also enhance the molten aluminum quality, a mathematical model with user-developed melting model and burning capacity model, were established according to the features ...To reduce the fuel consumption and emissions and also enhance the molten aluminum quality, a mathematical model with user-developed melting model and burning capacity model, were established according to the features of melting process of regenerative aluminum melting furnaces. Based on validating results by heat balance test for an aluminum melting furnace, CFD （computational fluid dynamics） technique, in association with statistical experimental design were used to optimize the melting process of the aluminum melting furnace. Four important factors influencing the melting time, such as horizontal angle between burners, height-to-radius ratio, natural gas mass flow and air preheated temperature, were identified by PLACKETT-BURMAN design. A steepest descent method was undertaken to determine the optimal regions of these factors. Response surface methodology with BOX-BEHNKEN design was adopted to further investigate the mutual interactions between these variables on RSD （relative standard deviation） of aluminum temperature, RSD of furnace temperature and melting time. Multiple-response optimization by desirability function approach was used to determine the optimum melting process parameters. The results indicate that the interaction between the height-to-radius ratio and horizontal angle between burners affects the response variables significantly. The predicted results show that the minimum RSD of aluminum temperature （12.13%）, RSD of furnace temperature （18.50%） and melting time （3.9 h） could be obtained under the optimum conditions of horizontal angle between burners as 64°, height-to-radius ratio as 0.3, natural gas mass flow as 599 m3/h, and air preheated temperature as 639 ℃. These predicted values were further verified by validation experiments. The excellent correlation between the predicted and experimental values confirms the validity and practicability of this statistical optimum strategy.展开更多
The technology that waste activated carbon after extracting gold is regenerated with steam under microwave heating was studied. The influence of the activation temperature, activation duration and steam flow rate on i...The technology that waste activated carbon after extracting gold is regenerated with steam under microwave heating was studied. The influence of the activation temperature, activation duration and steam flow rate on iodine adsorption value and regeneration yield of activated carbon was investigated. The response surface methodology （RSM） technique was utilized to optimize the process conditions. The optimum conditions for the preparation of activated carbon are identified to be activation temperature of 831 ℃, activation duration of 40 min and steam flow rate of 2.67 mL/min. The optimum conditions result in an activated carbon with an iodine number of 1048 mg/g and a yield of 40%, and the BET surface area evaluated using nitrogen adsorption isotherm is 1493 m2/g, with total pore volume of 1.242 cm3/g. And the pore structure of activated carbon regenerated is mainly composed of micropores and a small amount of mesopores.展开更多
Some effective parameters on the copper extraction from Kiire chalcopyrite concentrate were optimized by using response surface methodology （RSM）. Experiments designed by RSM were carried out in the presence of ammo...Some effective parameters on the copper extraction from Kiire chalcopyrite concentrate were optimized by using response surface methodology （RSM）. Experiments designed by RSM were carried out in the presence of ammonium persulfate （APS） and different types of impeller in an autoclave system. Ammonium persulfate concentration and leaching temperature were defined numerically and three types of impellers were defined categorically as independent variables using experimental design software. The optimum condition for copper extraction from the chalcopyrite concentrate is found to be ammonium persulfate concentration of 277.77 kg/m3, leaching temperature of 389.98 K and wheel type of impeller. The proposed model equation using RSM has shown good agreement with the experimental data, with correlation coefficients R2 and RaZaj for the model as 0.89 and 0.84, respectively.展开更多
Using solid waste as a substitute for conventional cement has become an important way to reduce carbon emissions.This paper attempted to utilize steel slag(SS)and fly ash(FA)as supplementary cementitious material by u...Using solid waste as a substitute for conventional cement has become an important way to reduce carbon emissions.This paper attempted to utilize steel slag(SS)and fly ash(FA)as supplementary cementitious material by utilizing CO_(2)mineralization curing technology.This study examined the dominant and interactive influences of the residual water/cement ratio,CO_(2)pressure,curing time,and SS content on the mechanical properties and CO_(2)uptake rate of CO_(2)mineralization curing SS-FA-Portland cement ternary paste specimens.Additionally,microstructural development was analyzed.The findings demonstrated that each factor significantly affected compressive strength and CO_(2)uptake rate,with factor interactions becoming more pronounced at higher SS dosages(>30%),lower residual water/cement ratios(0.1-0.15),and CO_(2)pressures of 0.1-0.3 MPa.Microscopic examinations revealed that mineralization primarily yielded CaCO_(3)and silica gel.The residual w/c ratio and SS content significantly influenced the CaCO_(3)content and crystallinity of the mineralization products.Post-mineralization curing,the percentage of pores larger than 50 nm significantly decreased,the proportion of harmless pores smaller than 20 nm increased,and pore structure improved.This study also found that using CO_(2)mineralization curing SS-FA-Portland cement solid waste concrete can significantly reduce the negative impact on the environment.展开更多
In the present study,the effect of reduction of cutting fluid consumption on the surface quality and tool wear was studied.Mathematical models were developed to predict the surface roughness using response surface met...In the present study,the effect of reduction of cutting fluid consumption on the surface quality and tool wear was studied.Mathematical models were developed to predict the surface roughness using response surface methodology(RSM).Analysis of variance(ANOVA)was used to investigate the significance of the developed regression models.The results showed that the coefficient of determination values(R^2)for the developed models was 97.46%for dry,89.32%for flood mode(FM),and 99.44%for MQL,showing the high accuracy of fitted models.Also,under the minimum quantity lubrication(MQL)condition,the surface roughness improved by 23%−44%and 19%−41%compared with dry and FM,respectively,and the SEM images of machined surface proved the statement.The prepared SEM images of tool rake face also showed a considerable decrease in adhesion wear.Built-up edge and built-up layer were the two main products of the adhesion wear,and energy-dispersive X-ray spectroscopy(EDX)analysis of specific points on the tool faces helped to discover the chemical compositions of adhered materials.By changing dry and FM to MQL mode,dominant mechanism of tool wear in machining aluminum alloy was significantly decreased.Breakage wear that led to early failure of cutting edge was also controlled by MQL technique.展开更多
The novelty of this research lies in the successful fabrication of a 3D-printed honeycomb structure filled with nanofillers for acoustic properties,utilizing an impedance tube setup in accordance with ASTM standard E ...The novelty of this research lies in the successful fabrication of a 3D-printed honeycomb structure filled with nanofillers for acoustic properties,utilizing an impedance tube setup in accordance with ASTM standard E 1050-12.The Creality Ender-3,a 3D printer,was used for printing the honeycomb structures,and polylactic acid(PLA)material was employed for their construction.The organic,inorganic,and polymeric compounds within the composites were identified using fourier transformation infrared(FTIR)spectroscopy.The structure and homogeneity of the samples were examined using a field emission scanning electron microscope(FESEM).To determine the sound absorption coefficient of the 3D printed honeycomb structure,numerous samples were systematically developed using central composite design(CCD)and analysed using response surface methodology(RSM).The RSM mathematical model was established to predict the optimum values of each factor and noise reduction coefficient(NRC).The optimum values for an NRC of 0.377 were found to be 1.116 wt% carbon black,1.025 wt% aluminium powder,and 3.151 mm distance between parallel edges.Overall,the results demonstrate that a 3Dprinted honeycomb structure filled with nanofillers is an excellent material that can be utilized in various fields,including defence and aviation,where lightweight and acoustic properties are of great importance.展开更多
The high aerodynamic noise induced by automotive air conditioning systems has important effects on the ride comfort, and the centrifugal fan is the largest noise source in these systems. It is very important to reduce...The high aerodynamic noise induced by automotive air conditioning systems has important effects on the ride comfort, and the centrifugal fan is the largest noise source in these systems. It is very important to reduce the aerodynamic noise generated by the centrifugal fan. The flow field and the sound field on the whole centrifugal fan configuration have been carried out using the computational fluid dynamics. Simulation results show that the sound pressure level near the outlet of the centrifugal fan is too high. Based on the relationship between flow characteristics and the aerodynamic noise, four parameters of the centrifugal fan, i.e., impeller blade＇s outlet angle 0, volute tongue＇s gap t, collector inclination angle fl, and rotating speed n, were selected as design variables and optimized using response surface methodology. While keeping the function of flow rate unchanged, the peak noise level is reduced by 8 dB or 10.8%. The noise level is satisfactorily reduced.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
A new process of AlN removal from secondary aluminum dross(SAD)by pyrometallurgical treatment with added cryolite was applied for solving the problem of recycling the secondary aluminum dross.The response surface meth...A new process of AlN removal from secondary aluminum dross(SAD)by pyrometallurgical treatment with added cryolite was applied for solving the problem of recycling the secondary aluminum dross.The response surface methodology(RSM)was used to design experiments and optimize parameters.The results show that adding the appropriate amount of cryolite can effectively promote the oxidation of AlN in the SAD,and too much cryolite will reduce the promotion effect.The effects of roasting temperature and cryolite on the denitrification rate are the most significant(p<0.0001)followed by holding time.Predicted values of the denitrification rate are found to be in good agreement with experimental values(R^(2)=0.9894 and R_(adj)^(2)=0.9775),which confirms the validity of the model employed.The optimum conditions of roasting temperature of 750°C,holding time of 194 min,mass fraction of cryolite of 17.7%are obtained according to the quadratic model.Under these conditions,the maximum actual denitrification rate reaches 94.71%and the AlN content in the SAD is only 0.55 wt%.The unfired brick with compressive strength of 18.62 MPa(GB/T 2542−2012)was prepared based on the roasted SAD.展开更多
A reliable ultrasound-assisted extraction （UAE） method combined with HPLC-UV for quantification of eight active alkaloids in fruits of Macleaya cordata （Willd） R. Br. was developed. The optimization conditions of ...A reliable ultrasound-assisted extraction （UAE） method combined with HPLC-UV for quantification of eight active alkaloids in fruits of Macleaya cordata （Willd） R. Br. was developed. The optimization conditions of UAE were obtained by using Box-Behnken design of response surface methodology. Chromatography was carried out using a Kromasil C18 column by gradient elution with 0.1% phosphoric acid aqueous solution for HPLC-UV. All calibration curves showed good linear correlation coefficients （R^2〉0.999 6） and recoveries （from 97.3% to 104.9%） were acceptable. 1,1-diphenyl-2-picrylhydrazyl （DPPH） method was employed to test the antioxidant activity of the extract from the samples. The proposed method was successfully applied to quantifying eight components in nine samples of M.cordata, and significant variations of alkaloid contents and antioxidant aetivity of the samples from different habitats were demonstrated. It presents a powerful proof for the selection of the best sources to extract eight kinds of alkaloids.展开更多
Process parameters of microwave assisted extraction （MAE） of the polysaccharides from pumpkin viz. extraction temperature, time and liquid-solid ratio were studied by using single factor and response surface methodo...Process parameters of microwave assisted extraction （MAE） of the polysaccharides from pumpkin viz. extraction temperature, time and liquid-solid ratio were studied by using single factor and response surface methodology method. The results showed that the liquid-solid ratio was the most important factor in polysaccharides yield, followed the extraction temperature was the least important factor. The optimum microwave assisted extraction co by ndi extraction time, and tions for the highest polysaccharides yield from pumpkin （16.76%-4-0.38%） were obtained by using the response surface methodology with extraction time of 29 min, an extraction temperature of 79 ℃ and a liquid-solid ratio of 22 mL·g^-1. Validation experiment result well agreed with predicted value.展开更多
To provide theoretical basis for square honeycombs used as crashworthy structures, energy-absorption properties of metal square honeycombs and the size optimization were performed. Specific energy absorption(SEA) was ...To provide theoretical basis for square honeycombs used as crashworthy structures, energy-absorption properties of metal square honeycombs and the size optimization were performed. Specific energy absorption(SEA) was defined as the energy absorbed by the honeycomb structure per unit volume. This parameter was often used for determining the crashworthiness of thin-walled structures. In order to find the most optimized metal square honeycomb structure with the maximum SEA and the lowest peak stress, the cell length and the foil thickness of the metal honeycombs were optimized, with a low peak stress and a high SEA set as the two primary objectives. The pre-processing software Patran was used to build FE models, and the explicit solver LS-DYNA was employed to perform the crashworthiness analyses. The results show that the square honeycomb exhibits good energy absorption performance in some cases. The geometry is effective using 16.8% less buffer structure volume than the hexagonal honeycombs with a peak stress limitation of 1.21 MPa.展开更多
Combining the optimization and FEM technology,crashworthiness of aluminum extrusions was studied for an automobile safety plan.The effects of longitudinal stiffeners on the crushing of stiffened square columns were st...Combining the optimization and FEM technology,crashworthiness of aluminum extrusions was studied for an automobile safety plan.The effects of longitudinal stiffeners on the crushing of stiffened square columns were studied considering the damage evolution.The numerical analysis was carried out by ABAQUS software.Subsequently,the collapse behavior of aluminum extrusion damage was validated by comparing against solution published in literature.Finally,in order to find more efficient and lighter crush absorber and achieving minimum peak crushing force,response surface methodology(RSM) has been applied for optimizing the aluminum extrusion tube.展开更多
Effects of dilute acid and acid steam pretreatments were inspected for cellulose production of Eucalyptus leaves through Box-Behenken design, a three variable factors for response surface methodology by Bacillus subti...Effects of dilute acid and acid steam pretreatments were inspected for cellulose production of Eucalyptus leaves through Box-Behenken design, a three variable factors for response surface methodology by Bacillus subtilus K-18. Maximum cellulose production performed in 250 mL erlenmeyer flask with submerged fermentation attained at 50＂C, pH 5, 140 r· min-1 for 24 h. Results showed the efficient cellulose production from acid steam pretreatrnent （being autoclaved at 15 Psi for 15 rain） than acid pretreatment. The optimum condition for maximum carboxymethyl cellulas （CMCase） was 1.811 IU·mL-1·min-1 （0.8% acid cone., 10 g biomass loading, 6 h reaction time） and filter paper activity （FPase） was 2.255 IU·mL·-1·min-1 （1% acid conc., 10 g biomass loading, 8 h reaction time）. Whereas, the acid steam maximum CMCase activity recorded was 2.585 IU·mL-1·min-1 （0.8% acid cone., 15 g substrate loading and 8 h reaction time） and the highest FPase activity was 2.055 IU·mL-1·min-1 （0.8% cone., 10 g biomass, 6 h reaction time then autoclaved）. Results revealed that acid pretreated Eucalyptus leaves were better lignocellulosic biomass for cellulose production by submerged fermentation.展开更多
基金supported by the Education and Teaching Research Project of Universities in Fujian Province(FBJY20230167).
文摘The work takes a new liquid-cooling plate in a power battery with pin fins inside the channel as the object.A mathematical model is established via the central composite design of the response surface to study the relationships among the length,width,height,and spacing of pin fins;the maximum temperature and temperature difference of the battery module;and the pressure drop of the liquid-cooling plate.Model accuracy is verified via variance analysis.The new liquid-cooling plate enables the power battery to work within an optimal temperature range.Appropriately increasing the length,width,and height and reducing the spacing of pin fins could reduce the temperature of the power battery module and improve the temperature uniformity.However,the pressure drop of the liquid-cooling plate increases.The structural parameters of the pin fins are optimized to minimize the maximum temperature and the temperature difference of the battery module as well as the pressure drop of the liquid-cooling plate.The errors between the values predicted and actual by the simulation test are 0.58%,4%,and 0.48%,respectively,which further verifies the model accuracy.The results reveal the influence of the structural parameters of the pin fins inside the liquid-cooling plate on its heat dissipation performance and pressure drop characteristics.A theoretical basis is provided for the design of liquid-cooling plates in power batteries and the optimization of structural parameters.
文摘Platycodon grandiflorum A.DC.(PAl)C)root was taken as experiment material to extract polysaccharide.On the base of single factor tests(extraction time,extraction temperature,liquid-solid ratio,solvent pH value and NaCl concentration),the study concluded the main factors affecting the extraction of PADC polysaccharide,which are liquid-solid ratio,extraction time and extraction temperature.Then through central-composite test design,the extraction conditions were concluded as liquid-solid ratio 34.43,extraction time 89.83 min and extraction temperature 52.47℃.By means of validation experiments,the adequacy of this model was confirmed.
基金Projects(51275235, 50975135) supported by the National Natural Science Foundation of ChinaProject(U0934004) supported by the Natural Science Foundation of Guangdong Province, ChinaProject(2011CB707602) supported by the National Basic Research Program of China
文摘A new method for optimizing a butterfly-shaped linear ultrasonic motor was proposed to maximize its mechanical output. The finite element analysis technology and response surface methodology were combined together to realize the optimal design of the butterfly-shaped linear ultrasonic motor. First, the operation principle of the motor was introduced. Second, the finite element parameterized model of the stator of the motor was built using ANSYS parametric design language and some structure parameters of the stator were selected as design variables. Third, the sample points were selected in design variable space using latin hypercube Design. Through modal analysis and harmonic response analysis of the stator based on these sample points, the target responses were obtained. These sample points and response values were combined together to build a response surface model. Finally, the simplex method was used to find the optimal solution. The experimental results showed that many aspects of the design requirements of the butterfly-shaped linear ultrasonic motor have been fulfilled. The prototype motor fabricated based on the optimal design result exhibited considerably high dynamic performance, such as no-load speed of 873 ram/s, maximal thrust of 27.5 N, maximal efficiency of 43%, and thrust-weight ratio of 45.8.
基金Projects(51704028,51574036)supported by the National Natural Science Foundation of China。
文摘The response surface methodology(RSM)was used to optimize the operating parameters during the bioleaching of Jinchuan high-magnesium nickel sulfide ore.The particle size,acid addition,pulp density and inoculation amount were chosen as the investigated parameters.To maximize the leaching efficiency of nickel,copper,cobalt and minimize the dissolution of magnesium and iron ions,the model suggested a combination of optimal parameters of particles less than 0.074 mm being 72.11%,sulfuric acid addition being 300 kg/t,pulp density being 5%and inoculation amount being 12.88%.Under the conditions,the average results of three parallel experiments were 89.43%of nickel leaching efficiency,36.78%of copper leaching efficiency,84.07%of cobalt leaching efficiency,49.19%of magnesium leaching efficiency and 0.20 g/L of iron concentration.The model indicated that the most significant factor in response of the leaching efficiency of valuable metal is the particle size,and the most significant factor in response to the leaching efficiency of harmful ions(Mg2+)is the amount of sulfuric acid addition.And according to the suggested models,no significance of the interaction effect between particle size and acid addition was shown.Under the optimized parameters suggested by models,the valuable metals could be separated from harmful ions during the bioleaching process.
基金Project(2017YFC0602902) supported by the National Science and Technology Pillar Program during the 13th Five-Year Plan Period,ChinaProject(2015CX005) supported by the Innovation Driven Plan of Central South University,ChinaProject(2016zzts445) supported by the Fundamental Research Funds for the Central Universities,China
文摘Deformation prediction and the analysis of underground goaf are important to the safe and efficient recovery of residual ore when shifting from open-pit mining to underground mining.To address the comprehensive problem of stability in the double mined-out area of the Tong-Lv-Shan(TLS)mine,which employed the dry stacked gangue technology,this paper applies the function fitting theory and a regression analysis method to screen the sensitive interval of four influencing factors based on single-factor experiments and the numerical simulation software FLAC3D.The influencing factors of the TLS mine consist of the column thickness(d),gob area span(D),boundary pillar thickness(h)and height of tailing gangue(H).The fitting degree between the four factors and the displacement of the gob roof(W)is reasonable because the correlation coefficient(R2)is greater than0.9701.After establishing29groups that satisfy the principles of Box-Behnken design(BBD),the dry gangue tailings process was re-simulated for the selected sensitive interval.Using a combination of an analysis of variance(ANOVA),regression equations and a significance analysis,the prediction results of the response surface methodology(RSM)show that the significant degree for the stability of the mined-out area for the factors satisfies the relationship of h>D>d>H.The importance of the four factors cannot be disregarded in a comparison of the prediction results of the engineering test stope in the TLS mine.By comparing the data of monitoring points and function prediction,the proposed method has shown promising results,and the prediction accuracy of RSM model is acceptable.The relative errors of the two test stopes are1.67%and3.85%,respectively,which yield satisfactory reliability and reference values for the mines.
基金Project(50734007) supported by the National Natural Science Foundation of China
文摘In the non-linear microwave drying process, the incremental improved back-propagation （BP） neural network and response surface methodology （RSM） were used to build a predictive model of the combined effects of independent variables （the microwave power, the acting time and the rotational frequency） for microwave drying of selenium-rich slag. The optimum operating conditions obtained from the quadratic form of the RSM are： the microwave power of 14.97 kW, the acting time of 89.58 min, the rotational frequency of 10.94 Hz, and the temperature of 136.407 ℃. The relative dehydration rate of 97.1895% is obtained. Under the optimum operating conditions, the incremental improved BP neural network prediction model can predict the drying process results and different effects on the results of the independent variables. The verification experiments demonstrate the prediction accuracy of the network, and the mean squared error is 0.16. The optimized results indicate that RSM can optimize the experimental conditions within much more broad range by considering the combination of factors and the neural network model can predict the results effectively and provide the theoretical guidance for the follow-up production process.
基金Project(2009BSXT022) supported by the Dissertation Innovation Foundation of Central South University, ChinaProject(07JJ4016) supported by Natural Science Foundation of Hunan Province, ChinaProject(U0937604) supported by National Natural Science Foundation of China
文摘To reduce the fuel consumption and emissions and also enhance the molten aluminum quality, a mathematical model with user-developed melting model and burning capacity model, were established according to the features of melting process of regenerative aluminum melting furnaces. Based on validating results by heat balance test for an aluminum melting furnace, CFD （computational fluid dynamics） technique, in association with statistical experimental design were used to optimize the melting process of the aluminum melting furnace. Four important factors influencing the melting time, such as horizontal angle between burners, height-to-radius ratio, natural gas mass flow and air preheated temperature, were identified by PLACKETT-BURMAN design. A steepest descent method was undertaken to determine the optimal regions of these factors. Response surface methodology with BOX-BEHNKEN design was adopted to further investigate the mutual interactions between these variables on RSD （relative standard deviation） of aluminum temperature, RSD of furnace temperature and melting time. Multiple-response optimization by desirability function approach was used to determine the optimum melting process parameters. The results indicate that the interaction between the height-to-radius ratio and horizontal angle between burners affects the response variables significantly. The predicted results show that the minimum RSD of aluminum temperature （12.13%）, RSD of furnace temperature （18.50%） and melting time （3.9 h） could be obtained under the optimum conditions of horizontal angle between burners as 64°, height-to-radius ratio as 0.3, natural gas mass flow as 599 m3/h, and air preheated temperature as 639 ℃. These predicted values were further verified by validation experiments. The excellent correlation between the predicted and experimental values confirms the validity and practicability of this statistical optimum strategy.
基金Project(2013AA064003)supported by the National High Technology Research and Development Program of ChinaProject(2012HB008)supported by Young and Middle-aged Academic Technology Leader Backup Talent Cultivation Program in Yunnan Province,China
文摘The technology that waste activated carbon after extracting gold is regenerated with steam under microwave heating was studied. The influence of the activation temperature, activation duration and steam flow rate on iodine adsorption value and regeneration yield of activated carbon was investigated. The response surface methodology （RSM） technique was utilized to optimize the process conditions. The optimum conditions for the preparation of activated carbon are identified to be activation temperature of 831 ℃, activation duration of 40 min and steam flow rate of 2.67 mL/min. The optimum conditions result in an activated carbon with an iodine number of 1048 mg/g and a yield of 40%, and the BET surface area evaluated using nitrogen adsorption isotherm is 1493 m2/g, with total pore volume of 1.242 cm3/g. And the pore structure of activated carbon regenerated is mainly composed of micropores and a small amount of mesopores.
基金supported by the TUBITAK(Scientific and Technological Research Council of Turkey) under the Project No:106M177
文摘Some effective parameters on the copper extraction from Kiire chalcopyrite concentrate were optimized by using response surface methodology （RSM）. Experiments designed by RSM were carried out in the presence of ammonium persulfate （APS） and different types of impeller in an autoclave system. Ammonium persulfate concentration and leaching temperature were defined numerically and three types of impellers were defined categorically as independent variables using experimental design software. The optimum condition for copper extraction from the chalcopyrite concentrate is found to be ammonium persulfate concentration of 277.77 kg/m3, leaching temperature of 389.98 K and wheel type of impeller. The proposed model equation using RSM has shown good agreement with the experimental data, with correlation coefficients R2 and RaZaj for the model as 0.89 and 0.84, respectively.
基金Project(52479115)supported by the National Natural Science Foundation of ChinaProject(2024SF-YBXM-615)supported by the Key Research and Development Program of Shaanxi Province,China+1 种基金Project(2022943)supported by the Youth Innovation Team of Shaanxi Universities,ChinaProject(300102283721)supported by the Fundamental Research Funds for the Central Universities,China。
文摘Using solid waste as a substitute for conventional cement has become an important way to reduce carbon emissions.This paper attempted to utilize steel slag(SS)and fly ash(FA)as supplementary cementitious material by utilizing CO_(2)mineralization curing technology.This study examined the dominant and interactive influences of the residual water/cement ratio,CO_(2)pressure,curing time,and SS content on the mechanical properties and CO_(2)uptake rate of CO_(2)mineralization curing SS-FA-Portland cement ternary paste specimens.Additionally,microstructural development was analyzed.The findings demonstrated that each factor significantly affected compressive strength and CO_(2)uptake rate,with factor interactions becoming more pronounced at higher SS dosages(>30%),lower residual water/cement ratios(0.1-0.15),and CO_(2)pressures of 0.1-0.3 MPa.Microscopic examinations revealed that mineralization primarily yielded CaCO_(3)and silica gel.The residual w/c ratio and SS content significantly influenced the CaCO_(3)content and crystallinity of the mineralization products.Post-mineralization curing,the percentage of pores larger than 50 nm significantly decreased,the proportion of harmless pores smaller than 20 nm increased,and pore structure improved.This study also found that using CO_(2)mineralization curing SS-FA-Portland cement solid waste concrete can significantly reduce the negative impact on the environment.
文摘In the present study,the effect of reduction of cutting fluid consumption on the surface quality and tool wear was studied.Mathematical models were developed to predict the surface roughness using response surface methodology(RSM).Analysis of variance(ANOVA)was used to investigate the significance of the developed regression models.The results showed that the coefficient of determination values(R^2)for the developed models was 97.46%for dry,89.32%for flood mode(FM),and 99.44%for MQL,showing the high accuracy of fitted models.Also,under the minimum quantity lubrication(MQL)condition,the surface roughness improved by 23%−44%and 19%−41%compared with dry and FM,respectively,and the SEM images of machined surface proved the statement.The prepared SEM images of tool rake face also showed a considerable decrease in adhesion wear.Built-up edge and built-up layer were the two main products of the adhesion wear,and energy-dispersive X-ray spectroscopy(EDX)analysis of specific points on the tool faces helped to discover the chemical compositions of adhered materials.By changing dry and FM to MQL mode,dominant mechanism of tool wear in machining aluminum alloy was significantly decreased.Breakage wear that led to early failure of cutting edge was also controlled by MQL technique.
文摘The novelty of this research lies in the successful fabrication of a 3D-printed honeycomb structure filled with nanofillers for acoustic properties,utilizing an impedance tube setup in accordance with ASTM standard E 1050-12.The Creality Ender-3,a 3D printer,was used for printing the honeycomb structures,and polylactic acid(PLA)material was employed for their construction.The organic,inorganic,and polymeric compounds within the composites were identified using fourier transformation infrared(FTIR)spectroscopy.The structure and homogeneity of the samples were examined using a field emission scanning electron microscope(FESEM).To determine the sound absorption coefficient of the 3D printed honeycomb structure,numerous samples were systematically developed using central composite design(CCD)and analysed using response surface methodology(RSM).The RSM mathematical model was established to predict the optimum values of each factor and noise reduction coefficient(NRC).The optimum values for an NRC of 0.377 were found to be 1.116 wt% carbon black,1.025 wt% aluminium powder,and 3.151 mm distance between parallel edges.Overall,the results demonstrate that a 3Dprinted honeycomb structure filled with nanofillers is an excellent material that can be utilized in various fields,including defence and aviation,where lightweight and acoustic properties are of great importance.
基金Project(50975083) supported by the National Natural Science Foundation of ChinaProject(61075001) supported by China State Key Laboratory of Advanced Design and Manufacturing for Vehicle BodyProject(201-IV-068) supported by the Fundamental Research Funds for the Central Universities,China
文摘The high aerodynamic noise induced by automotive air conditioning systems has important effects on the ride comfort, and the centrifugal fan is the largest noise source in these systems. It is very important to reduce the aerodynamic noise generated by the centrifugal fan. The flow field and the sound field on the whole centrifugal fan configuration have been carried out using the computational fluid dynamics. Simulation results show that the sound pressure level near the outlet of the centrifugal fan is too high. Based on the relationship between flow characteristics and the aerodynamic noise, four parameters of the centrifugal fan, i.e., impeller blade＇s outlet angle 0, volute tongue＇s gap t, collector inclination angle fl, and rotating speed n, were selected as design variables and optimized using response surface methodology. While keeping the function of flow rate unchanged, the peak noise level is reduced by 8 dB or 10.8%. The noise level is satisfactorily reduced.
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Project(2017YFB0306001)supported by National Key R&D Program of China。
文摘A new process of AlN removal from secondary aluminum dross(SAD)by pyrometallurgical treatment with added cryolite was applied for solving the problem of recycling the secondary aluminum dross.The response surface methodology(RSM)was used to design experiments and optimize parameters.The results show that adding the appropriate amount of cryolite can effectively promote the oxidation of AlN in the SAD,and too much cryolite will reduce the promotion effect.The effects of roasting temperature and cryolite on the denitrification rate are the most significant(p<0.0001)followed by holding time.Predicted values of the denitrification rate are found to be in good agreement with experimental values(R^(2)=0.9894 and R_(adj)^(2)=0.9775),which confirms the validity of the model employed.The optimum conditions of roasting temperature of 750°C,holding time of 194 min,mass fraction of cryolite of 17.7%are obtained according to the quadratic model.Under these conditions,the maximum actual denitrification rate reaches 94.71%and the AlN content in the SAD is only 0.55 wt%.The unfired brick with compressive strength of 18.62 MPa(GB/T 2542−2012)was prepared based on the roasted SAD.
基金Project(20576142) supposed by the National Natural Science Foundation of China Project(2009DFA31270) supported by the International Cooperation Project of Ministry of Science and Technology of China
文摘A reliable ultrasound-assisted extraction （UAE） method combined with HPLC-UV for quantification of eight active alkaloids in fruits of Macleaya cordata （Willd） R. Br. was developed. The optimization conditions of UAE were obtained by using Box-Behnken design of response surface methodology. Chromatography was carried out using a Kromasil C18 column by gradient elution with 0.1% phosphoric acid aqueous solution for HPLC-UV. All calibration curves showed good linear correlation coefficients （R^2〉0.999 6） and recoveries （from 97.3% to 104.9%） were acceptable. 1,1-diphenyl-2-picrylhydrazyl （DPPH） method was employed to test the antioxidant activity of the extract from the samples. The proposed method was successfully applied to quantifying eight components in nine samples of M.cordata, and significant variations of alkaloid contents and antioxidant aetivity of the samples from different habitats were demonstrated. It presents a powerful proof for the selection of the best sources to extract eight kinds of alkaloids.
基金Supported by National Natural Science Foundation (31071579)Key Program of Heilongjiang Province Science Foundation (ZP201013)
文摘Process parameters of microwave assisted extraction （MAE） of the polysaccharides from pumpkin viz. extraction temperature, time and liquid-solid ratio were studied by using single factor and response surface methodology method. The results showed that the liquid-solid ratio was the most important factor in polysaccharides yield, followed the extraction temperature was the least important factor. The optimum microwave assisted extraction co by ndi extraction time, and tions for the highest polysaccharides yield from pumpkin （16.76%-4-0.38%） were obtained by using the response surface methodology with extraction time of 29 min, an extraction temperature of 79 ℃ and a liquid-solid ratio of 22 mL·g^-1. Validation experiment result well agreed with predicted value.
基金Project(07018) supported by the College Discipline Innovation Wisdom Plan in China
文摘To provide theoretical basis for square honeycombs used as crashworthy structures, energy-absorption properties of metal square honeycombs and the size optimization were performed. Specific energy absorption(SEA) was defined as the energy absorbed by the honeycomb structure per unit volume. This parameter was often used for determining the crashworthiness of thin-walled structures. In order to find the most optimized metal square honeycomb structure with the maximum SEA and the lowest peak stress, the cell length and the foil thickness of the metal honeycombs were optimized, with a low peak stress and a high SEA set as the two primary objectives. The pre-processing software Patran was used to build FE models, and the explicit solver LS-DYNA was employed to perform the crashworthiness analyses. The results show that the square honeycomb exhibits good energy absorption performance in some cases. The geometry is effective using 16.8% less buffer structure volume than the hexagonal honeycombs with a peak stress limitation of 1.21 MPa.
文摘Combining the optimization and FEM technology,crashworthiness of aluminum extrusions was studied for an automobile safety plan.The effects of longitudinal stiffeners on the crushing of stiffened square columns were studied considering the damage evolution.The numerical analysis was carried out by ABAQUS software.Subsequently,the collapse behavior of aluminum extrusion damage was validated by comparing against solution published in literature.Finally,in order to find more efficient and lighter crush absorber and achieving minimum peak crushing force,response surface methodology(RSM) has been applied for optimizing the aluminum extrusion tube.
文摘Effects of dilute acid and acid steam pretreatments were inspected for cellulose production of Eucalyptus leaves through Box-Behenken design, a three variable factors for response surface methodology by Bacillus subtilus K-18. Maximum cellulose production performed in 250 mL erlenmeyer flask with submerged fermentation attained at 50＂C, pH 5, 140 r· min-1 for 24 h. Results showed the efficient cellulose production from acid steam pretreatrnent （being autoclaved at 15 Psi for 15 rain） than acid pretreatment. The optimum condition for maximum carboxymethyl cellulas （CMCase） was 1.811 IU·mL-1·min-1 （0.8% acid cone., 10 g biomass loading, 6 h reaction time） and filter paper activity （FPase） was 2.255 IU·mL·-1·min-1 （1% acid conc., 10 g biomass loading, 8 h reaction time）. Whereas, the acid steam maximum CMCase activity recorded was 2.585 IU·mL-1·min-1 （0.8% acid cone., 15 g substrate loading and 8 h reaction time） and the highest FPase activity was 2.055 IU·mL-1·min-1 （0.8% cone., 10 g biomass, 6 h reaction time then autoclaved）. Results revealed that acid pretreated Eucalyptus leaves were better lignocellulosic biomass for cellulose production by submerged fermentation.
