The filling mining method is important in realizing the green mining of mineral resources.Aiming at the problems of land resource occupation,environmental pollution,and rational utilization of coal-based solid wastes ...The filling mining method is important in realizing the green mining of mineral resources.Aiming at the problems of land resource occupation,environmental pollution,and rational utilization of coal-based solid wastes such as coal gangue,fly ash,and desulfurization gypsum,a new paste filling material was developed with coal gangue,fly ash,and desulfurization gypsum as raw materials.The microstructure of the raw materials was analyzed by XRD and SEM.Combined with the Box-Behnken experimental design,the effect of each component on the fluidity of the filling slurry was analyzed through the response surface analysis.The significance of each component on its bleeding and fluidity was determined,and the optimal ratio of the filling slurry was obtained.Experimental results show that the microcosmic morphology of coal gangue,desulfurization gypsum,and gasification slag presents an irregular block and rough particle surface;the microcosmic morphology of fly ash and bottom slag presents first out spherical or quasi spherical particles.Moreover,obvious sintering traces exist on the surface of the bottom slag.The main crystal mineral of coal gangue and fly ash is SiO_(2),the desulfurization gypsum is composed of Ca(SO_(4))(H_(2)O)and Ca(CO_(3))crystal minerals,the gasification slag is composed of carbon and nitrogen compounds,and the main crystal mineral components in the bottom slag sample are SiO_(2) and Al_(x)Si_(y)O_(z) compounds.The order of significance of each key factor on slurry fluidity is as follows:C(desulfurization gypsum)>D(gasification slag and bottom slag 1:1)>A(coal gangue)>B(fly ash).The order of the significance of each key factor on slurry bleeding is as follows:B(fly ash)>C(desulfurization gypsum)>D(gasification slag and bottom slag 1:1)>A(coal gangue).Considering the material preparation,field application,and other conditions,the mass percentage of each factor content of the new paste filling material is as follows:49.5%coal gangue,8.3%fly ash,4.1%desulfurization gypsum,6.2%gasification slag,and 6.2%bottom slag.展开更多
We calculate the multicomponent responses of surface-hole transient electromagnetic method. The methods and models are unsuitable as geoelectric models of conductive surrounding rocks because they are based on regular...We calculate the multicomponent responses of surface-hole transient electromagnetic method. The methods and models are unsuitable as geoelectric models of conductive surrounding rocks because they are based on regular local targets. We also propose a calculation and analysis scheme based on numerical simulations of the subsurface transient electromagnetic fields. In the modeling of the electromagnetic fields, the forward modeling simulations are performed by using the finite-difference time-domain method and the discrete image method, which combines the Gaver–Stehfest inverse Laplace transform with the Prony method to solve the initial electromagnetic fields. The precision in the iterative computations is ensured by using the transmission boundary conditions. For the response analysis, we customize geoelectric models consisting of near-borehole targets and conductive wall rocks and implement forward modeling simulations. The observed electric fields are converted into induced electromotive force responses using multicomponent observation devices. By comparing the transient electric fields and multicomponent responses under different conditions, we suggest that the multicomponent-induced electromotive force responses are related to the horizontal and vertical gradient variations of the transient electric field at different times. The characteristics of the response are determined by the varying the subsurface transient electromagnetic fields, i.e., diffusion, attenuation and distortion, under different conditions as well as the electromagnetic fields at the observation positions. The calculation and analysis scheme of the response consider the surrounding rocks and the anomalous field of the local targets. It therefore can account for the geological data better than conventional transient field response analysis of local targets.展开更多
This research introduces a novel approach to enhancing bucket elevator design and operation through the integration of discrete element method(DEM)simulation,design of experiments(DOE),and metaheuristic optimization a...This research introduces a novel approach to enhancing bucket elevator design and operation through the integration of discrete element method(DEM)simulation,design of experiments(DOE),and metaheuristic optimization algorithms.Specifically,the study employs the firefly algorithm(FA),a metaheuristic optimization technique,to optimize bucket elevator parameters for maximizing transport mass and mass flow rate discharge of granular materials under specified working conditions.The experimental methodology involves several key steps:screening experiments to identify significant factors affecting bucket elevator operation,central composite design(CCD)experiments to further explore these factors,and response surface methodology(RSM)to create predictive models for transport mass and mass flow rate discharge.The FA algorithm is then applied to optimize these models,and the results are validated through simulation and empirical experiments.The study validates the optimized parameters through simulation and empirical experiments,comparing results with DEM simulation.The outcomes demonstrate the effectiveness of the FA algorithm in identifying optimal bucket parameters,showcasing less than 10%and 15%deviation for transport mass and mass flow rate discharge,respectively,between predicted and actual values.Overall,this research provides insights into the critical factors influencing bucket elevator operation and offers a systematic methodology for optimizing bucket parameters,contributing to more efficient material handling in various industrial applications.展开更多
Due to the size effects of rockfill materials, the settlement difference between numerical simulation and in situ monitoring of rockfill dams is a topic of general concern.The constitutive model parameters obtained fr...Due to the size effects of rockfill materials, the settlement difference between numerical simulation and in situ monitoring of rockfill dams is a topic of general concern.The constitutive model parameters obtained from laboratory triaxial tests often underestimate the deformation of high rockfill dams.Therefore, constitutive model parameters obtained by back analysis were used to calculate and predict the long-term deformation of rockfill dams.Instead of using artificial neural networks (ANNs), the response surface method (RSM) was employed to replace the finite element simulation used in the optimization iteration.Only 27 training samples were required for RSM, improving computational efficiency compared with ANN, which required 300 training samples.RSM can be used to describe the relationship between the constitutive model parameters and dam settlements.The inversion results of the Shuibuya concrete face rockfill dam (CFRD) show that the calculated settlements agree with the measured data, indicating the accuracy and efficiency of RSM.展开更多
Tooth modification technique is widely used in gear industry to improve the meshing performance of gearings. However, few of the present studies on tooth modification considers the influence of inevitable random error...Tooth modification technique is widely used in gear industry to improve the meshing performance of gearings. However, few of the present studies on tooth modification considers the influence of inevitable random errors on gear modification effects. In order to investigate the uncertainties of tooth modification amount variations on system's dynamic behaviors of a helical planetary gears, an analytical dynamic model including tooth modification parameters is proposed to carry out a deterministic analysis on the dynamics of a helical planetary gear. The dynamic meshing forces as well as the dynamic transmission errors of the sun-planet 1 gear pair with and without tooth modifications are computed and compared to show the effectiveness of tooth modifications on gear dynamics enhancement. By using response surface method, a fitted regression model for the dynamic transmission error(DTE) fluctuations is established to quantify the relationship between modification amounts and DTE fluctuations. By shifting the inevitable random errors arousing from manufacturing and installing process to tooth modification amount variations, a statistical tooth modification model is developed and a methodology combining Monte Carlo simulation and response surface method is presented for uncertainty analysis of tooth modifications. The uncertainly analysis reveals that the system's dynamic behaviors do not obey the normal distribution rule even though the design variables are normally distributed. In addition, a deterministic modification amount will not definitely achieve an optimal result for both static and dynamic transmission error fluctuation reduction simultaneously.展开更多
In order to present a new method for analyzing the reliability of a two-link flexible robot manipulator,Lagrange dynamics differential equations of the two-link flexible robot manipulator were established by using the...In order to present a new method for analyzing the reliability of a two-link flexible robot manipulator,Lagrange dynamics differential equations of the two-link flexible robot manipulator were established by using the integrated modal method and the multi-body system dynamics method.By using the Monte Carlo method,the random sample values of the dynamic parameters were obtained and Lagrange dynamics differential equations were solved for each random sample value which revealed their displacement,speed and acceleration.On this basis,dynamic stresses and deformations were obtained.By taking the maximum values of the stresses and the deformations as output responses and the random sample values of dynamic parameters as input quantities,extremum response surface functions were established.A number of random samples were then obtained by using the Monte Carlo method and then the reliability was analyzed by using the extremum response surface method.The results show that the extremum response surface method is an efficient and fast reliability analysis method with high-accuracy for the two-link flexible robot manipulator.展开更多
An approach of limit state equation for surrounding rock was put forward based on deformation criterion. A method of symmetrical sampling of basic random variables adopted by classical response surface method was mend...An approach of limit state equation for surrounding rock was put forward based on deformation criterion. A method of symmetrical sampling of basic random variables adopted by classical response surface method was mended, and peak value and deflection degree of basic random variables distribution curve were took into account in the mended sampling method. A calculation way of probability moment, based on mended Rosenbluth method, suitable for non-explicit performance function was put forward. The first, second, third and fourth order moments of functional function value were calculated by mended Rosenbluth method through the first, second, third and fourth order moments of basic random variable. A probability density the function(PDF) of functional function was deduced through its first, second, third and fourth moments, the PDF in the new method took the place of the method of quadratic polynomial to approximate real functional function and reliability probability was calculated through integral by the PDF for random variable of functional function value in the new method. The result shows that the improved response surface method can adapt to various statistic distribution types of basic random variables, its calculation process is legible and need not itemtive circulation. In addition, a stability probability of surrounding rock for a tunnel was calculated by the improved method, whose workload is only 30% of classical method and its accuracy is comparative.展开更多
Levulinic acid(LA) has been identified as a promising green,biomass derived platform chemical.Response surface analysis(RSA) with a four-factor-five-level central composite design(CCD) was applied to optimize th...Levulinic acid(LA) has been identified as a promising green,biomass derived platform chemical.Response surface analysis(RSA) with a four-factor-five-level central composite design(CCD) was applied to optimize the hydrolysis conditions for the conversion of bamboo(Phyllostachys Praecox f.preveynalis) shoot shell(BSS) to LA catalyzed with ionic liquid [C4mim]HSO4.The effects of four main reaction parameters including temperature,time,C[C4mim]HSO4(initial [C4mim]HSO4 concentration) and XBSS(initial BSS intake) on the hydrolysis reaction for yield of LA were analyzed.A quadratic equation model for yield of LA was established and fitted to the data with an R2 of 0.9868,and effects of main factors and their corresponding relationships were obtained with RSA.Model validation and results of CCD showed good correspondence between actual and predicted values.The analysis of variance(ANOVA) of the results indicated that the yield of LA in the range studied was significantly(P<0.05) affected by the four factors.The optimized reaction conditions were as follows:temperature of 145 ℃,time of 103.8 min,C[C4mim]HSO4 of 0.9 mol.L-1 and XBSS of 2.04%(by mass),respectively.A high yield [(71±0.41)%(by mol),triplicate experiment] was obtained at the optimum conditions of temperature of 145 ℃,time of 104 min,C[C4mim]HSO4 of 0.9 mol.L-1 and XBSS of 2%(by mass),which obtained from the real experiments,concurred with the model prediction [73.8%(by mol) based on available C6 sugars in BSS or 17.9%(by mass) based on the mass of BSS],indicating that the model was adequate for the hydrolysis process.展开更多
To overcome excessive computation errors and convergence failures encountered in an iterative calculation of the reliability index using the response surface method (RSM) for some nonlinear limit state functions, th...To overcome excessive computation errors and convergence failures encountered in an iterative calculation of the reliability index using the response surface method (RSM) for some nonlinear limit state functions, this study investigates an essential factor based on chaotic dynamics theory. The bifurcation diagrams of the reliability index are presented for some typical nonlinear limit state functions, and the computation results from the mapping functions due to the RSM iterations show the complicated dynamic phenomena such as the periodic oscillation, as well as bifurcation and chaos. From the numerical examples, it is concluded that the parameter of selection range fplays an important role in the convergence of the RSM iteration, and an improved RSM iterative algorithm is proposed with regard to the incorporation of the iterative sequential function of selection rangef The proposed method is shown to be efficient and to yield accurate results.展开更多
The size-dependent effect on the biaxial and shear nonlinear buckling analysis of an isotropic and orthotropic micro-plate based on the surface stress, the modified couple stress theory (MCST), and the nonlocal elas...The size-dependent effect on the biaxial and shear nonlinear buckling analysis of an isotropic and orthotropic micro-plate based on the surface stress, the modified couple stress theory (MCST), and the nonlocal elasticity theories using the differential quadrature method (DQM) is presented. Main advantages of the MCST over the classical theory (CT) are the inclusion of the asymmetric couple stress tensor and the consideration of only one material length scale parameter. Based on the nonlinear von Karman assumption, the governing equations of equilibrium for the micro-classical plate consid- ering midplane displacements are derived based on the minimum principle of potential energy. Using the DQM, the biaxial and shear critical buckling loads of the micro-plate for various boundary conditions are obtained. Accuracy of the obtained results is validated by comparing the solutions with those reported in the literature. A parametric study is conducted to show the effects of the aspect ratio, the side-to-thickness ratio, Eringen's nonlocal parameter, the material length scale parameter, Young's modulus of the surface layer, the surface residual stress, the polymer matrix coefficients, and various boundary conditions on the dimensionless uniaxial, biaxial, and shear critical buckling loads. The results indicate that the critical buckling loads are strongly sensitive to Eringen's nonlocal parameter, the material length scale parameter, and the surface residual stress effects, while the effect of Young's modulus of the surface layer on the critical buckling load is negligible. Also, considering the size dependent effect causes the increase in the stiffness of the orthotropic micro-plate. The results show that the critical biaxial buckling load increases with an increase in G12/E2 and vice versa for E1/E2. It is shown that the nonlinear biaxial buckling ratio decreases as the aspect ratio increases and vice versa for the buckling amplitude. Because of the most lightweight micro-composite materials with high strength/weight and stiffness/weight ratios, it is anticipated that the results of the present work are useful in experimental characterization of the mechanical properties of micro-composite plates in the aircraft industry and other engineering applications.展开更多
[Objectives] This study was conducted to optimize the extraction process of protocatechuic acid from Emilia sonchifolia DC. [Methods] The optimal extraction conditions were determined by single factor,response surface...[Objectives] This study was conducted to optimize the extraction process of protocatechuic acid from Emilia sonchifolia DC. [Methods] The optimal extraction conditions were determined by single factor,response surface analysis and variance analysis,and the content of protocatechuic acid was determined by HPLC. [Results] The protocatechuic acid standard curve equation was: y = 1 435 x + 8 403,R^2= 0. 999 8,indicating a good linear relationship. The optimal extraction conditions were as follows: a temperature at 80 ℃,an extraction time of 1 h,a material-to-liquid ratio at 1:10 and an ultrasonic power of 600 W,and the content of protocatechuic acid extracted was 1. 93 mg/g. The method showed a RSD of 0. 41%,less than 2%,and the detection limit was 0. 0000047261 g/ml.The experimental sample X1 was the low-level 0. 1 mg/ml standard solution,which showed recovery of protocatechuic acid between 100.8% and 105.2%,with a RSD of 0. 013%;and the sample X2 was the high-level 1. 0 mg/ml standard solution,which exhibited recovery between 100. 6% and 102. 2%,with a RSD of 0.076%. Thus,the recovery was high,and the requirements of the performance index were met. [Conclusions] The detection method is stable and reliable and can produce satisfactory results.展开更多
[Objectives]To study the optimal extraction process of total flavonoids in Rhodiola rosea L.,and further facilitate the development and utilization of Rhodiola rosea L. [Methods]With Rhodiola crenulata as raw material...[Objectives]To study the optimal extraction process of total flavonoids in Rhodiola rosea L.,and further facilitate the development and utilization of Rhodiola rosea L. [Methods]With Rhodiola crenulata as raw material,ethanol as extractant,ultrasonic extraction as the extraction method,the single factor method was first used for preliminary investigation of effect of ethanol volume fraction,solid-liquid ratio,extraction temperature and extraction time on the flavonoids extraction rate,and then the Box-Behnken response surface method was used to optimize the extraction process of total flavonoids in R. crenulata. [Results] The optimal extraction conditions: ethanol concentration of 72%;solid-liquid ratio of 1∶ 43; extraction temperature of 66℃; extraction time of 50 min. Under these conditions,the extraction rate of total flavonoids from R. crenulata was 2. 591%. [Conclusions] The results showed that the method of response surface was reasonable and feasible for the optimization of ultrasonic extraction of total flavonoids from R. crenulata.展开更多
This paper aimed to optimize extracting conditions of SOD in Sedum aizoon by response surface method. First,the single factor optimization tests were carried out. Three single factors were time,p H and liquid-solid ra...This paper aimed to optimize extracting conditions of SOD in Sedum aizoon by response surface method. First,the single factor optimization tests were carried out. Three single factors were time,p H and liquid-solid ratio respectively. By Design expert 8. 0. 5 software,17 kinds of test scheme were designed. The protein yield of each scheme was obtained,and Design expert 8. 0. 5 software was used to conduct variance analysis and interactive analysis among factors,to obtain the corresponding mathematical model. The results showed that in single factor experiments,the optimal time was 1 h,p H was 7. 8,and liquid-solid ratio was 15:1. The interactive analysis indicated that the optimal scheme for extracting SOD in Sedum aizoon was time of 0. 98 h,p H of 7. 79,liquid-solid ratio of 13. 71:1. By the method of pyrogallol autoxidation,the extracted SOD enzyme activity was measured,namely 12 U/g. The results could provide a reference for further utilization and research of Sedum aizoon resource.展开更多
In the present work, the response surface method software was used with five measurement levels with three factors.These were applied for the optimization of operating parameters that affected gas separation performan...In the present work, the response surface method software was used with five measurement levels with three factors.These were applied for the optimization of operating parameters that affected gas separation performance of polyurethane–zeolite 3A, ZSM-5 mixed matrix membranes.The basis of the experiments was a rotatable central composite design(CCD).The three independent variables studied were: zeolite content(0–24 wt%), operating temperature(25–45 ℃) and operating pressure(0.2–0.1 MPa).The effects of these three variables on the selectivity and permeability membranes were studied by the analysis of variance(ANOVA).Optimal conditions for the enhancement of gas separation performances of polyurethane–3A zeolite were found to be 18 wt%, 30 ℃ and 0.8 MPa respectively.Under these conditions, the permeabilities of carbon dioxide, methane, oxygen and nitrogen gases were measured at 138.4, 22.9, 15.7 and 6.4 Barrer respectively while the CO_2/CH_4, CO_2/N_2 and O_2/N_2 selectivities were 5.8, 22.5 and 2.5, respectively.Also, the optimal conditions for improvement of the gas separation performance of polyurethane–ZSM 5 were found to be 15.64 wt%, 30 ℃ and 4 bar.The permeabilities of these four gases(i.e.carbon dioxide, methane, oxygen and nitrogen) were 164.7, 21.2, 21.5 and 8.1 Barrer while the CO_2/CH_4, CO_2/N_2 and O_2/N_2 selectivities were 7.8, 20.6 and 2.7 respectively.展开更多
A series of high oil-absorption resins with low cross-linking degree were synthesized by suspension polymerization using stearyl methacrylate(SMA),2-Ethylhexyl methacrylate(EHMA),and styrene(St)as monomers.Response su...A series of high oil-absorption resins with low cross-linking degree were synthesized by suspension polymerization using stearyl methacrylate(SMA),2-Ethylhexyl methacrylate(EHMA),and styrene(St)as monomers.Response surface methodology(RSM)with central composite design(CCD)was also applied to determine the optimal parameters that are mainly known to affect their synthesis.Thus,the effects of the monomer mass ratio(EHMA:SMA),the rigid monomer(St)dosage,the porous agent(acetone)dosage,and their pairwise interaction on the resin's oil-absorption capacity were analyzed,highlighting PSES-R_(2) as the resin with the optimum performance.The pure oil-absorption rates of PSES-R_(2) for gasoline,diesel,and kerosene were 11.19 g·g^(-1),16.25 g·g^(-1),and 14.84 g·g^(-1),respectively,while the oil removal rates from oily wastewater were 98.82%,65.11%,and 99.63%,respectively.展开更多
An effective optimization method for the shape/sizing design of composite wing structures is presented with satisfying weight-cutting results. After decoupling, a kind of two-layer cycled optimization strategy suitabl...An effective optimization method for the shape/sizing design of composite wing structures is presented with satisfying weight-cutting results. After decoupling, a kind of two-layer cycled optimization strategy suitable for these integrated shape/sizing optimization is obtained. The uniform design method is used to provide sample points, and approximation models for shape design variables. And the results of sizing optimization are construct- ed with the quadratic response surface method (QRSM). The complex method based on QRSM is used to opti- mize the shape design variables and the criteria method is adopted to optimize the sizing design variables. Compared with the conventional method, the proposed algorithm is more effective and feasible for solving complex composite optimization problems and has good efficiency in weight cutting.展开更多
The methods of modifying dimension and shape of structure, or covering damping material are effective to reduce structure-borne noise, while these methods are based on the knowledge of qualitative and quantitative rel...The methods of modifying dimension and shape of structure, or covering damping material are effective to reduce structure-borne noise, while these methods are based on the knowledge of qualitative and quantitative relationship between sound radiation and design parameters. In order to decrease the complexity of the problem, response surface method(RSM) was utilized to analyze and optimize the vibro-acoustic properties of the damping structure. A simple case was illustrated to demonstrate the capabilities of the developed procedure. A structure-born noise problem was approximated by a series of polynomials using RSM. Three main performances were considered, i.e. sound radiation power, first order modal frequency and total mass. Consequently, the response surface model not only gives the direction of design modification, it also leads to an optimal design of complex systems.展开更多
In this paper,the effects of different influencing factors and factor interaction on the compressive strength and permeability of recycled aggregate pervious concrete(RAPC)were studied based on the response surface me...In this paper,the effects of different influencing factors and factor interaction on the compressive strength and permeability of recycled aggregate pervious concrete(RAPC)were studied based on the response surface method(RSM).By selecting the maximum aggregate size,water cement ratio and target porosity as design variables,combined with laboratory tests and numerical analysis,the influences of three factors on the compressive strength and permeability coefficient of RAPC were revealed.The regression equation of compressive strength and permeability coefficient of recycled aggregate pervious concrete were established based on RSM,and the response surface model was optimized to determine the optimal ratio of RAPC under the conditions of meeting the mechanical and permeability properties.The results show that the mismatch item of the model is not significant,the model is credible,and the accuracy and reliability of the test are high,but the degree of uncorrelation between the test data and the model is not obvious.The sensitivity of the three factors to the compressive strength is water cement ratio>maximum coarse aggregate particle size>target porosity,and the sensitivity to the permeability coefficient is target porosity>maximum coarse aggregate particle size>water cement ratio.The absolute errors of the model prediction results and the model optimization results are 1.28 MPa and 0.19 mm/s,and the relative errors are 5.06%and 4.19%,respectively.With high accuracy,RSM can match the measured results of compressive strength and permeability coefficient of RAPC.展开更多
Objective:The Box-Behnken response surface method combined with fingerprints was used to optimize the extraction process of total anthraquinone from Cassia seeds.Methods:A three-factor,three-level response surface tes...Objective:The Box-Behnken response surface method combined with fingerprints was used to optimize the extraction process of total anthraquinone from Cassia seeds.Methods:A three-factor,three-level response surface test was conducted based on the single-factor test with comprehensive evaluation as the measurement index.The comprehensive evaluation indexes included the extraction rate of total anthraquinone of Cassia seeds or the equivalent amount of herbs per gram of total anthraquinone of Cassia seeds,the normalized value of peak areas of 5 index components such as aurantio obtusin in the fingerprint of each sample to 16 shared peaks and the similarity of fingerprints(the reference fingerprint was established by the extraction solvent for the determination of Cassia seeds content in the Chinese Pharmacopoeia 2020 edition)with the weights of 0.2,0.5 and 0.3,respectively.Results:The best extraction process was obtained:the liquid-to-material ratio was 20:1(mL·g-1),the extraction solvent was mixture of 60%ethanol-ethyl acetate(2:1),and the extraction time was 15.12 min.The results of five sets of validation experiments showed that the overall evaluation of total anthraquinone of cassia seeds by the best process was 0.528(RSD=0.45%),and the prediction result of response surface method model was 0.531,and the relative error with the prediction result was 0.531.The relative error of the predicted results was 0.56%,and the best extraction process was consistent with the model prediction,and the obtained best process could be used for the extraction of total anthraquinone from Cassia seeds.Conclusion:The Box-Behnken response surface method combined with the fingerprint technique can be used to find the best reaction conditions and examine the interactions among the factors in a comprehensive and accurate manner,which can provide reference for the optimization and evaluation of the extraction process of Chinese medicine.展开更多
基金We acknowledge the financial support for this work provided by the National Natural Science Foundation of China(Grant No.51774010)National Key R&D Program of China(Grant No.2019YF1904304).
文摘The filling mining method is important in realizing the green mining of mineral resources.Aiming at the problems of land resource occupation,environmental pollution,and rational utilization of coal-based solid wastes such as coal gangue,fly ash,and desulfurization gypsum,a new paste filling material was developed with coal gangue,fly ash,and desulfurization gypsum as raw materials.The microstructure of the raw materials was analyzed by XRD and SEM.Combined with the Box-Behnken experimental design,the effect of each component on the fluidity of the filling slurry was analyzed through the response surface analysis.The significance of each component on its bleeding and fluidity was determined,and the optimal ratio of the filling slurry was obtained.Experimental results show that the microcosmic morphology of coal gangue,desulfurization gypsum,and gasification slag presents an irregular block and rough particle surface;the microcosmic morphology of fly ash and bottom slag presents first out spherical or quasi spherical particles.Moreover,obvious sintering traces exist on the surface of the bottom slag.The main crystal mineral of coal gangue and fly ash is SiO_(2),the desulfurization gypsum is composed of Ca(SO_(4))(H_(2)O)and Ca(CO_(3))crystal minerals,the gasification slag is composed of carbon and nitrogen compounds,and the main crystal mineral components in the bottom slag sample are SiO_(2) and Al_(x)Si_(y)O_(z) compounds.The order of significance of each key factor on slurry fluidity is as follows:C(desulfurization gypsum)>D(gasification slag and bottom slag 1:1)>A(coal gangue)>B(fly ash).The order of the significance of each key factor on slurry bleeding is as follows:B(fly ash)>C(desulfurization gypsum)>D(gasification slag and bottom slag 1:1)>A(coal gangue).Considering the material preparation,field application,and other conditions,the mass percentage of each factor content of the new paste filling material is as follows:49.5%coal gangue,8.3%fly ash,4.1%desulfurization gypsum,6.2%gasification slag,and 6.2%bottom slag.
基金supported by the Young Scientists Fund of the National Natural Science Foundation of China(No.41304082)the China Postdoctoral Science Foundation(No.2016M590731)+2 种基金the Young Scientists Fund of the Natural Science Foundation of Hebei Province(No.D2014403011)the Program for Young Excellent Talents of Higher Education Institutions of Hebei Province(No.BJ2016046)the Geological survey project of China Geological Survey(No.1212011121197)
文摘We calculate the multicomponent responses of surface-hole transient electromagnetic method. The methods and models are unsuitable as geoelectric models of conductive surrounding rocks because they are based on regular local targets. We also propose a calculation and analysis scheme based on numerical simulations of the subsurface transient electromagnetic fields. In the modeling of the electromagnetic fields, the forward modeling simulations are performed by using the finite-difference time-domain method and the discrete image method, which combines the Gaver–Stehfest inverse Laplace transform with the Prony method to solve the initial electromagnetic fields. The precision in the iterative computations is ensured by using the transmission boundary conditions. For the response analysis, we customize geoelectric models consisting of near-borehole targets and conductive wall rocks and implement forward modeling simulations. The observed electric fields are converted into induced electromotive force responses using multicomponent observation devices. By comparing the transient electric fields and multicomponent responses under different conditions, we suggest that the multicomponent-induced electromotive force responses are related to the horizontal and vertical gradient variations of the transient electric field at different times. The characteristics of the response are determined by the varying the subsurface transient electromagnetic fields, i.e., diffusion, attenuation and distortion, under different conditions as well as the electromagnetic fields at the observation positions. The calculation and analysis scheme of the response consider the surrounding rocks and the anomalous field of the local targets. It therefore can account for the geological data better than conventional transient field response analysis of local targets.
基金This research was funded by the Faculty of Engineering,King Mongkut’s University of Technology North Bangkok.Contract No.ENG-NEW-66-39.
文摘This research introduces a novel approach to enhancing bucket elevator design and operation through the integration of discrete element method(DEM)simulation,design of experiments(DOE),and metaheuristic optimization algorithms.Specifically,the study employs the firefly algorithm(FA),a metaheuristic optimization technique,to optimize bucket elevator parameters for maximizing transport mass and mass flow rate discharge of granular materials under specified working conditions.The experimental methodology involves several key steps:screening experiments to identify significant factors affecting bucket elevator operation,central composite design(CCD)experiments to further explore these factors,and response surface methodology(RSM)to create predictive models for transport mass and mass flow rate discharge.The FA algorithm is then applied to optimize these models,and the results are validated through simulation and empirical experiments.The study validates the optimized parameters through simulation and empirical experiments,comparing results with DEM simulation.The outcomes demonstrate the effectiveness of the FA algorithm in identifying optimal bucket parameters,showcasing less than 10%and 15%deviation for transport mass and mass flow rate discharge,respectively,between predicted and actual values.Overall,this research provides insights into the critical factors influencing bucket elevator operation and offers a systematic methodology for optimizing bucket parameters,contributing to more efficient material handling in various industrial applications.
基金supported by the National Natural Science Foundation of China(Grant No.51579193)the Science and Technology Planning Project of Guizhou Province(Grant No.[2016]1154)
文摘Due to the size effects of rockfill materials, the settlement difference between numerical simulation and in situ monitoring of rockfill dams is a topic of general concern.The constitutive model parameters obtained from laboratory triaxial tests often underestimate the deformation of high rockfill dams.Therefore, constitutive model parameters obtained by back analysis were used to calculate and predict the long-term deformation of rockfill dams.Instead of using artificial neural networks (ANNs), the response surface method (RSM) was employed to replace the finite element simulation used in the optimization iteration.Only 27 training samples were required for RSM, improving computational efficiency compared with ANN, which required 300 training samples.RSM can be used to describe the relationship between the constitutive model parameters and dam settlements.The inversion results of the Shuibuya concrete face rockfill dam (CFRD) show that the calculated settlements agree with the measured data, indicating the accuracy and efficiency of RSM.
基金Supported by National Natural Science Foundation of China(Grant No.51375013)Anhui Provincial Natural Science Foundation of China(Grant No.1208085ME64)
文摘Tooth modification technique is widely used in gear industry to improve the meshing performance of gearings. However, few of the present studies on tooth modification considers the influence of inevitable random errors on gear modification effects. In order to investigate the uncertainties of tooth modification amount variations on system's dynamic behaviors of a helical planetary gears, an analytical dynamic model including tooth modification parameters is proposed to carry out a deterministic analysis on the dynamics of a helical planetary gear. The dynamic meshing forces as well as the dynamic transmission errors of the sun-planet 1 gear pair with and without tooth modifications are computed and compared to show the effectiveness of tooth modifications on gear dynamics enhancement. By using response surface method, a fitted regression model for the dynamic transmission error(DTE) fluctuations is established to quantify the relationship between modification amounts and DTE fluctuations. By shifting the inevitable random errors arousing from manufacturing and installing process to tooth modification amount variations, a statistical tooth modification model is developed and a methodology combining Monte Carlo simulation and response surface method is presented for uncertainty analysis of tooth modifications. The uncertainly analysis reveals that the system's dynamic behaviors do not obey the normal distribution rule even though the design variables are normally distributed. In addition, a deterministic modification amount will not definitely achieve an optimal result for both static and dynamic transmission error fluctuation reduction simultaneously.
基金Project(2006AA04Z405) supported by the National High Technology Research and Development Program of ChinaProject(3102019) supported by Beijing Municipal Natural Science Foundation,China
文摘In order to present a new method for analyzing the reliability of a two-link flexible robot manipulator,Lagrange dynamics differential equations of the two-link flexible robot manipulator were established by using the integrated modal method and the multi-body system dynamics method.By using the Monte Carlo method,the random sample values of the dynamic parameters were obtained and Lagrange dynamics differential equations were solved for each random sample value which revealed their displacement,speed and acceleration.On this basis,dynamic stresses and deformations were obtained.By taking the maximum values of the stresses and the deformations as output responses and the random sample values of dynamic parameters as input quantities,extremum response surface functions were established.A number of random samples were then obtained by using the Monte Carlo method and then the reliability was analyzed by using the extremum response surface method.The results show that the extremum response surface method is an efficient and fast reliability analysis method with high-accuracy for the two-link flexible robot manipulator.
基金Project(50378036) supported by the National Natural Science Foundation of China Project (200503) supported by the Foundation ofCommunications Department of Hunan Province, China
文摘An approach of limit state equation for surrounding rock was put forward based on deformation criterion. A method of symmetrical sampling of basic random variables adopted by classical response surface method was mended, and peak value and deflection degree of basic random variables distribution curve were took into account in the mended sampling method. A calculation way of probability moment, based on mended Rosenbluth method, suitable for non-explicit performance function was put forward. The first, second, third and fourth order moments of functional function value were calculated by mended Rosenbluth method through the first, second, third and fourth order moments of basic random variable. A probability density the function(PDF) of functional function was deduced through its first, second, third and fourth moments, the PDF in the new method took the place of the method of quadratic polynomial to approximate real functional function and reliability probability was calculated through integral by the PDF for random variable of functional function value in the new method. The result shows that the improved response surface method can adapt to various statistic distribution types of basic random variables, its calculation process is legible and need not itemtive circulation. In addition, a stability probability of surrounding rock for a tunnel was calculated by the improved method, whose workload is only 30% of classical method and its accuracy is comparative.
基金Supported by the National Natural Science Foundation of China(30940058,31170672)the Natural Science Foundation of Zhejiang Province of China(Y3110025)+1 种基金Key Laboratory for Physical Processing of Agricultural Products(JAPP2010-4)Key Laboratory of Exploitation and Preservation of Coastal Bio-resource(2010F30003)
文摘Levulinic acid(LA) has been identified as a promising green,biomass derived platform chemical.Response surface analysis(RSA) with a four-factor-five-level central composite design(CCD) was applied to optimize the hydrolysis conditions for the conversion of bamboo(Phyllostachys Praecox f.preveynalis) shoot shell(BSS) to LA catalyzed with ionic liquid [C4mim]HSO4.The effects of four main reaction parameters including temperature,time,C[C4mim]HSO4(initial [C4mim]HSO4 concentration) and XBSS(initial BSS intake) on the hydrolysis reaction for yield of LA were analyzed.A quadratic equation model for yield of LA was established and fitted to the data with an R2 of 0.9868,and effects of main factors and their corresponding relationships were obtained with RSA.Model validation and results of CCD showed good correspondence between actual and predicted values.The analysis of variance(ANOVA) of the results indicated that the yield of LA in the range studied was significantly(P<0.05) affected by the four factors.The optimized reaction conditions were as follows:temperature of 145 ℃,time of 103.8 min,C[C4mim]HSO4 of 0.9 mol.L-1 and XBSS of 2.04%(by mass),respectively.A high yield [(71±0.41)%(by mol),triplicate experiment] was obtained at the optimum conditions of temperature of 145 ℃,time of 104 min,C[C4mim]HSO4 of 0.9 mol.L-1 and XBSS of 2%(by mass),which obtained from the real experiments,concurred with the model prediction [73.8%(by mol) based on available C6 sugars in BSS or 17.9%(by mass) based on the mass of BSS],indicating that the model was adequate for the hydrolysis process.
基金National Hi-Tech Research and Development Program of China (863 Program) Under Grant No. 2006AA04Z416Nation Natural Science Foundation of China Under Grant No. 50725828
文摘To overcome excessive computation errors and convergence failures encountered in an iterative calculation of the reliability index using the response surface method (RSM) for some nonlinear limit state functions, this study investigates an essential factor based on chaotic dynamics theory. The bifurcation diagrams of the reliability index are presented for some typical nonlinear limit state functions, and the computation results from the mapping functions due to the RSM iterations show the complicated dynamic phenomena such as the periodic oscillation, as well as bifurcation and chaos. From the numerical examples, it is concluded that the parameter of selection range fplays an important role in the convergence of the RSM iteration, and an improved RSM iterative algorithm is proposed with regard to the incorporation of the iterative sequential function of selection rangef The proposed method is shown to be efficient and to yield accurate results.
基金supported by the Iranian Nanotechnology Development Committee and the University of Kashan(No.363452/10)
文摘The size-dependent effect on the biaxial and shear nonlinear buckling analysis of an isotropic and orthotropic micro-plate based on the surface stress, the modified couple stress theory (MCST), and the nonlocal elasticity theories using the differential quadrature method (DQM) is presented. Main advantages of the MCST over the classical theory (CT) are the inclusion of the asymmetric couple stress tensor and the consideration of only one material length scale parameter. Based on the nonlinear von Karman assumption, the governing equations of equilibrium for the micro-classical plate consid- ering midplane displacements are derived based on the minimum principle of potential energy. Using the DQM, the biaxial and shear critical buckling loads of the micro-plate for various boundary conditions are obtained. Accuracy of the obtained results is validated by comparing the solutions with those reported in the literature. A parametric study is conducted to show the effects of the aspect ratio, the side-to-thickness ratio, Eringen's nonlocal parameter, the material length scale parameter, Young's modulus of the surface layer, the surface residual stress, the polymer matrix coefficients, and various boundary conditions on the dimensionless uniaxial, biaxial, and shear critical buckling loads. The results indicate that the critical buckling loads are strongly sensitive to Eringen's nonlocal parameter, the material length scale parameter, and the surface residual stress effects, while the effect of Young's modulus of the surface layer on the critical buckling load is negligible. Also, considering the size dependent effect causes the increase in the stiffness of the orthotropic micro-plate. The results show that the critical biaxial buckling load increases with an increase in G12/E2 and vice versa for E1/E2. It is shown that the nonlinear biaxial buckling ratio decreases as the aspect ratio increases and vice versa for the buckling amplitude. Because of the most lightweight micro-composite materials with high strength/weight and stiffness/weight ratios, it is anticipated that the results of the present work are useful in experimental characterization of the mechanical properties of micro-composite plates in the aircraft industry and other engineering applications.
基金Supported by Basic and Applied Basic Research Plan of Hainan Province in2019 (2019RC245)Natural Science Foundation of Hainan Province in 2017(217157)。
文摘[Objectives] This study was conducted to optimize the extraction process of protocatechuic acid from Emilia sonchifolia DC. [Methods] The optimal extraction conditions were determined by single factor,response surface analysis and variance analysis,and the content of protocatechuic acid was determined by HPLC. [Results] The protocatechuic acid standard curve equation was: y = 1 435 x + 8 403,R^2= 0. 999 8,indicating a good linear relationship. The optimal extraction conditions were as follows: a temperature at 80 ℃,an extraction time of 1 h,a material-to-liquid ratio at 1:10 and an ultrasonic power of 600 W,and the content of protocatechuic acid extracted was 1. 93 mg/g. The method showed a RSD of 0. 41%,less than 2%,and the detection limit was 0. 0000047261 g/ml.The experimental sample X1 was the low-level 0. 1 mg/ml standard solution,which showed recovery of protocatechuic acid between 100.8% and 105.2%,with a RSD of 0. 013%;and the sample X2 was the high-level 1. 0 mg/ml standard solution,which exhibited recovery between 100. 6% and 102. 2%,with a RSD of 0.076%. Thus,the recovery was high,and the requirements of the performance index were met. [Conclusions] The detection method is stable and reliable and can produce satisfactory results.
基金Supported by Tibetan 13th Five-Year Agricultural Product Processing and Product Development Project
文摘[Objectives]To study the optimal extraction process of total flavonoids in Rhodiola rosea L.,and further facilitate the development and utilization of Rhodiola rosea L. [Methods]With Rhodiola crenulata as raw material,ethanol as extractant,ultrasonic extraction as the extraction method,the single factor method was first used for preliminary investigation of effect of ethanol volume fraction,solid-liquid ratio,extraction temperature and extraction time on the flavonoids extraction rate,and then the Box-Behnken response surface method was used to optimize the extraction process of total flavonoids in R. crenulata. [Results] The optimal extraction conditions: ethanol concentration of 72%;solid-liquid ratio of 1∶ 43; extraction temperature of 66℃; extraction time of 50 min. Under these conditions,the extraction rate of total flavonoids from R. crenulata was 2. 591%. [Conclusions] The results showed that the method of response surface was reasonable and feasible for the optimization of ultrasonic extraction of total flavonoids from R. crenulata.
文摘This paper aimed to optimize extracting conditions of SOD in Sedum aizoon by response surface method. First,the single factor optimization tests were carried out. Three single factors were time,p H and liquid-solid ratio respectively. By Design expert 8. 0. 5 software,17 kinds of test scheme were designed. The protein yield of each scheme was obtained,and Design expert 8. 0. 5 software was used to conduct variance analysis and interactive analysis among factors,to obtain the corresponding mathematical model. The results showed that in single factor experiments,the optimal time was 1 h,p H was 7. 8,and liquid-solid ratio was 15:1. The interactive analysis indicated that the optimal scheme for extracting SOD in Sedum aizoon was time of 0. 98 h,p H of 7. 79,liquid-solid ratio of 13. 71:1. By the method of pyrogallol autoxidation,the extracted SOD enzyme activity was measured,namely 12 U/g. The results could provide a reference for further utilization and research of Sedum aizoon resource.
文摘In the present work, the response surface method software was used with five measurement levels with three factors.These were applied for the optimization of operating parameters that affected gas separation performance of polyurethane–zeolite 3A, ZSM-5 mixed matrix membranes.The basis of the experiments was a rotatable central composite design(CCD).The three independent variables studied were: zeolite content(0–24 wt%), operating temperature(25–45 ℃) and operating pressure(0.2–0.1 MPa).The effects of these three variables on the selectivity and permeability membranes were studied by the analysis of variance(ANOVA).Optimal conditions for the enhancement of gas separation performances of polyurethane–3A zeolite were found to be 18 wt%, 30 ℃ and 0.8 MPa respectively.Under these conditions, the permeabilities of carbon dioxide, methane, oxygen and nitrogen gases were measured at 138.4, 22.9, 15.7 and 6.4 Barrer respectively while the CO_2/CH_4, CO_2/N_2 and O_2/N_2 selectivities were 5.8, 22.5 and 2.5, respectively.Also, the optimal conditions for improvement of the gas separation performance of polyurethane–ZSM 5 were found to be 15.64 wt%, 30 ℃ and 4 bar.The permeabilities of these four gases(i.e.carbon dioxide, methane, oxygen and nitrogen) were 164.7, 21.2, 21.5 and 8.1 Barrer while the CO_2/CH_4, CO_2/N_2 and O_2/N_2 selectivities were 7.8, 20.6 and 2.7 respectively.
基金This work was funded by Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges under Beijing Municipality(IDHT20180508)Scientific Research Common Program of Beijing Municipal Commission of Education(KM202010017006)+2 种基金the Talents Project of Beijing Organization Department(2018000020124G091)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA21021101)the National Key Research and Development Program of China(2019YFA0705803).
文摘A series of high oil-absorption resins with low cross-linking degree were synthesized by suspension polymerization using stearyl methacrylate(SMA),2-Ethylhexyl methacrylate(EHMA),and styrene(St)as monomers.Response surface methodology(RSM)with central composite design(CCD)was also applied to determine the optimal parameters that are mainly known to affect their synthesis.Thus,the effects of the monomer mass ratio(EHMA:SMA),the rigid monomer(St)dosage,the porous agent(acetone)dosage,and their pairwise interaction on the resin's oil-absorption capacity were analyzed,highlighting PSES-R_(2) as the resin with the optimum performance.The pure oil-absorption rates of PSES-R_(2) for gasoline,diesel,and kerosene were 11.19 g·g^(-1),16.25 g·g^(-1),and 14.84 g·g^(-1),respectively,while the oil removal rates from oily wastewater were 98.82%,65.11%,and 99.63%,respectively.
文摘An effective optimization method for the shape/sizing design of composite wing structures is presented with satisfying weight-cutting results. After decoupling, a kind of two-layer cycled optimization strategy suitable for these integrated shape/sizing optimization is obtained. The uniform design method is used to provide sample points, and approximation models for shape design variables. And the results of sizing optimization are construct- ed with the quadratic response surface method (QRSM). The complex method based on QRSM is used to opti- mize the shape design variables and the criteria method is adopted to optimize the sizing design variables. Compared with the conventional method, the proposed algorithm is more effective and feasible for solving complex composite optimization problems and has good efficiency in weight cutting.
文摘The methods of modifying dimension and shape of structure, or covering damping material are effective to reduce structure-borne noise, while these methods are based on the knowledge of qualitative and quantitative relationship between sound radiation and design parameters. In order to decrease the complexity of the problem, response surface method(RSM) was utilized to analyze and optimize the vibro-acoustic properties of the damping structure. A simple case was illustrated to demonstrate the capabilities of the developed procedure. A structure-born noise problem was approximated by a series of polynomials using RSM. Three main performances were considered, i.e. sound radiation power, first order modal frequency and total mass. Consequently, the response surface model not only gives the direction of design modification, it also leads to an optimal design of complex systems.
基金supported by the Jiangsu Water Conservancy Science and Technology Project of China(2016036).
文摘In this paper,the effects of different influencing factors and factor interaction on the compressive strength and permeability of recycled aggregate pervious concrete(RAPC)were studied based on the response surface method(RSM).By selecting the maximum aggregate size,water cement ratio and target porosity as design variables,combined with laboratory tests and numerical analysis,the influences of three factors on the compressive strength and permeability coefficient of RAPC were revealed.The regression equation of compressive strength and permeability coefficient of recycled aggregate pervious concrete were established based on RSM,and the response surface model was optimized to determine the optimal ratio of RAPC under the conditions of meeting the mechanical and permeability properties.The results show that the mismatch item of the model is not significant,the model is credible,and the accuracy and reliability of the test are high,but the degree of uncorrelation between the test data and the model is not obvious.The sensitivity of the three factors to the compressive strength is water cement ratio>maximum coarse aggregate particle size>target porosity,and the sensitivity to the permeability coefficient is target porosity>maximum coarse aggregate particle size>water cement ratio.The absolute errors of the model prediction results and the model optimization results are 1.28 MPa and 0.19 mm/s,and the relative errors are 5.06%and 4.19%,respectively.With high accuracy,RSM can match the measured results of compressive strength and permeability coefficient of RAPC.
基金2018 Anhui Provincial Quality Engineering Project(No.2018jyxm1273)Major Provincial Natural Science Research Project of Anhui Universities(No.KJ2016SD60)2021 Anhui University Students’Innovation and Entrepreneurship Plan Project。
文摘Objective:The Box-Behnken response surface method combined with fingerprints was used to optimize the extraction process of total anthraquinone from Cassia seeds.Methods:A three-factor,three-level response surface test was conducted based on the single-factor test with comprehensive evaluation as the measurement index.The comprehensive evaluation indexes included the extraction rate of total anthraquinone of Cassia seeds or the equivalent amount of herbs per gram of total anthraquinone of Cassia seeds,the normalized value of peak areas of 5 index components such as aurantio obtusin in the fingerprint of each sample to 16 shared peaks and the similarity of fingerprints(the reference fingerprint was established by the extraction solvent for the determination of Cassia seeds content in the Chinese Pharmacopoeia 2020 edition)with the weights of 0.2,0.5 and 0.3,respectively.Results:The best extraction process was obtained:the liquid-to-material ratio was 20:1(mL·g-1),the extraction solvent was mixture of 60%ethanol-ethyl acetate(2:1),and the extraction time was 15.12 min.The results of five sets of validation experiments showed that the overall evaluation of total anthraquinone of cassia seeds by the best process was 0.528(RSD=0.45%),and the prediction result of response surface method model was 0.531,and the relative error with the prediction result was 0.531.The relative error of the predicted results was 0.56%,and the best extraction process was consistent with the model prediction,and the obtained best process could be used for the extraction of total anthraquinone from Cassia seeds.Conclusion:The Box-Behnken response surface method combined with the fingerprint technique can be used to find the best reaction conditions and examine the interactions among the factors in a comprehensive and accurate manner,which can provide reference for the optimization and evaluation of the extraction process of Chinese medicine.