[Objectives]The ultrasound-assisted aqueous two-phase extraction of sweet potato leaf polysaccharides was studied.[Methods]With the yield of sweet potato leaf polysaccharides as the index,the aqueous two-phase extract...[Objectives]The ultrasound-assisted aqueous two-phase extraction of sweet potato leaf polysaccharides was studied.[Methods]With the yield of sweet potato leaf polysaccharides as the index,the aqueous two-phase extraction system was determined,and the optimal extraction conditions were optimized by single-factor experiments and response surface methodology.[Results]The optimal parameters were ethanol concentration 25.68%,liquid-to-material ratio 55.83,and ultrasonic treatment time 38.33 min.Under these conditions,the yield of sweet potato leaf polysaccharides could reach 20.646 mg/g.[Conclusions]The ethanol/ammonium sulfate aqueous system is a rapid and efficient method for extracting sweet potato leaf polysaccharides,which is of great significance for the application of sweet potato leaf extract as a natural food additive.展开更多
“Dendrite-free”deposition behavior of Mg^(2+)is expected to achieve planar and dense Mg growth for long-life and safe Mg batteries.However,in practice,the Mg electrode still suffers from uneven stripping/deposition ...“Dendrite-free”deposition behavior of Mg^(2+)is expected to achieve planar and dense Mg growth for long-life and safe Mg batteries.However,in practice,the Mg electrode still suffers from uneven stripping/deposition in Cl-based electrolytes.Here,we reveal the low Pilling-Bedworth(P-B)ratio(0.81,the ratio of the molar volume of a metal oxide to that of the corresponding metal)of Mg metal intrinsically results in a contractive,unprotective,and inhomogeneous electrode surface,subsequently making it vulnerable in Cl-based electrolytes and inducing uneven stripping/deposition.By constructing an Al nanolayer with a high P-B ratio(1.28)to the surface of the Mg-metal electrode,we protect the electrode from corrosion,homogenize Mg stripping,and regulate planar Mg deposition.Symmetric cells with Al-Mg electrodes show a 15-fold increase in cycle life,and a Mg||Al-Cu half cell achieves an average Coulombic efficiency of 99.8%for 300 cycles at 5 mA cm^(-2)and 5 mAh cm^(-2).A long-life Al-Mg||Mo_(6)S_(8)pouch cell is also demonstrated with stable cyclability of up to 1200 cycles.This work provides a simple yet effective strategy to enhance the practical prospects of Mg batteries in terms of cycle life and safety.展开更多
【Objective】To optimize the steam explosion process condition for extracting polysaccharides from Pseudostellaria heterophylla.【Method】The effects of steam pressure,pressure-maintaining time and material moisture c...【Objective】To optimize the steam explosion process condition for extracting polysaccharides from Pseudostellaria heterophylla.【Method】The effects of steam pressure,pressure-maintaining time and material moisture content on the extraction of polysaccharides from Pseudostellaria heterophylla were studied by response surface methodology based on Box-Behnken design.【Result】The findings showed that each factor could significantly affect the test index,and the optimum condition was as follows:steam pressure 1.50 Mpa,pressuremaintaining time 46 s and material moisture content 46%.Under this condition,the verified experimental value of polysaccharides from Pseudostellaria heterophylla was 39.32%,indicating a relative standard deviation of 2.73%from the predictive value.Meanwhile,scanning electron microcopy(SEM)images showed that the surface physical structure of Pseudostellaria heterophylla was irregularly broken and cracked,which means the physical structure of Pseudostellaria heterophylla was changed and destroyed at the cellular level.【Conclusion】This experiment provides a new approach for the extraction of polysaccharides from Pseudostellaria heterophylla,as well as a reference for the resource utilization of Pseudostellaria heterophylla.展开更多
Taking refined flour,matsutake powder,and highland barley powder as main raw materials,this experiment studied the optimal formula of matsutake highland barley biscuit. Besides,single factor experiment was carried out...Taking refined flour,matsutake powder,and highland barley powder as main raw materials,this experiment studied the optimal formula of matsutake highland barley biscuit. Besides,single factor experiment was carried out for the amount of highland barley powder,white granulated sugar,and shortening. Then,the response surface optimization analysis was made on crispness and sensory score of the biscuit. The experiment indicates that taking the refined flour as the base 100 g( 100%),the formula of 20% highland barley powder,25% white granulated sugar,and 26% shortening can bake crisp biscuit with complete shape,pure flavor and high quality.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
The scalable production of high grade activated carbon from abundant coal for supercapacitors application is an efficient way to achieve high value-added utilization of coal sources.However,this technology is challeng...The scalable production of high grade activated carbon from abundant coal for supercapacitors application is an efficient way to achieve high value-added utilization of coal sources.However,this technology is challenging due to lack of comprehensive understanding on the mechanism of activation process and effect of external factors.In this paper,the effect of activating temperature and time on the specific capacitance of coal-based activated carbon prepared by H2O steam activation was studied using the response surface method.Under optimal conditions,coal-based activated carbon exhibits the largest specific capacitance of 194.35 F·g^(−1),thanks to the appropriate pore/surface structure and defect degree.Density functional theory calculations explain in detail the mechanism of contraction of aromatic rings and overflow of H2 and CO during the activation.Meanwhile,oxygen-containing functional groups are introduced,contributing to the pseudocapacitance property of coal-based activated carbon.This mechanism of reactions between aromatic carbon and H2O vapor provides understanding on the role of water during coal processing at the molecular level,offering great potential to regulate product distribution and predict rate of pore generation.This insight would contribute to the advancement of other coal processing technology such as gasification.展开更多
In this paper,the residue from bamboo factory has been used to design photo-Fenton catalyst,which has the advantages of low cost and magnetic recycling.The photo-Fenton catalytic performance of the biocarbon-based cat...In this paper,the residue from bamboo factory has been used to design photo-Fenton catalyst,which has the advantages of low cost and magnetic recycling.The photo-Fenton catalytic performance of the biocarbon-based catalyst was excellent and its optimal preparation process was also explored by response surface methodology.First,bamboo-carbon fiber was selected as the photo-Fenton catalyst carrier.Subsequently,the surface of the car-bon fiber was modified,with which dopamine,nano-Fe_(3)O_(4) and nano-TiO_(2) were successively loaded by hydro-thermal method.After the single factor tests,four factors including dopamine concentration,ferric chloride mass,P25 titanium dioxide mass and liquid-solid ratio were selected as the characteristic values.The degradation efficiency of photo-Fenton catalyst to methylene blue(MB)solution was treated as the response value.After the analysis of the response surface optimization,it was shown that the significance sequence of the selected 4 factors in terms of the MB degradation efficiency was arranged as follows:dopamine concentration>liquid-solid ratio>P25 titanium dioxide quality>ferric chloride quality.The optimal process parameters of fiber-carbon catalyst were affirmed as follows:the 1.7 mg/mL concentration of dopamine,the 1.2 g mass of ferric chloride,the 0.2 g mass of P25 titanium dioxide and the liquid-solid ratio of 170 mL/g.The experiment-measured average MB degra-dation efficiency performed by the optimized catalyst was 99.3%,which was nearly similar to the model-predicted value of 98.9%.It showed that the prediction model and response surface model were accurate and reliable.The results from response surface optimization could provide a good reference to design bamboo-based Fenton-like catalyst with excellent catalytic performance.展开更多
Atrazine, a widely used herbicide, is increasing the agricultural production effectively, while also causing great environmental concern. Efficient atrazine-degrading bacterium is necessary to removal atrazine rapidly...Atrazine, a widely used herbicide, is increasing the agricultural production effectively, while also causing great environmental concern. Efficient atrazine-degrading bacterium is necessary to removal atrazine rapidly to keep a safe environment. In the present study, a new atrazine-degrading strain ZXY-1, identified as Pseudomonas, was isolated. This new isolated strain has a strong ability to biodegrade atrazine with a high efficiency of 9.09 mg/L/hr.Temperature, p H, inoculum size and initial atrazine concentration were examined to further optimize the degradation of atrazine, and the synthetic effect of these factors were investigated by the response surface methodology. With a high quadratic polynomial mathematical model（R^2= 0.9821） being obtained, the highest biodegradation efficiency of 19.03 mg/L/hr was reached compared to previous reports under the optimal conditions（30.71°C, pH 7.14, 4.23%（V/V） inoculum size and 157.1 mg/L initial atrazine concentration）.Overall, this study provided an efficient bacterium and approach that could be potentially useful for the bioremediation of wastewater containing atrazine.展开更多
The colloidal properties of biogenic elemental sulfur（S^0）cause solid–liquid separation problems,such as poor settling and membrane fouling.In this study,the separation of S^0 from bulk liquids was performed using ...The colloidal properties of biogenic elemental sulfur（S^0）cause solid–liquid separation problems,such as poor settling and membrane fouling.In this study,the separation of S^0 from bulk liquids was performed using flocculation.Polyaluminum chloride（PAC）,polyacrylamide（PAM）and microbial flocculant（MBF）were compared to investigate their abilities to flocculate S^0 produced during the treatment of sulfate-containing wastewater.A novel approach with response surface methodology（RSM）was employed to evaluate the effects and interactions of flocculant dose,pH and stirring intensity,on the treatment efficiency in terms of the S^0 flocculation and the supernatant turbidity removal.The dose optimization results indicated that the S^0 flocculation efficiency decreased in the following order PAC〉MBF〉PAM.Optimum S^0 flocculation conditions were observed at pH 4.73,a stirring speed of 129 r/min and a flocculant dose of 2.42 mg PAC/mg S.During optimum flocculation conditions,the S^0f locculation rate reached 97.53%.Confirmation experiments demonstrated that employing PAC for S^0 flocculation is feasible and RSM is an efficient approach for optimizing the process of S^0 flocculation.The results provide basic parameters and conditions for recovering sulfur during the treatment of sulfate-laden wastewaters.展开更多
In order to shorten the design period, the paper describes a new optimization strategy for computationally expensive design optimization of turbomachinery, combined with design of experiment (DOE), response surface mo...In order to shorten the design period, the paper describes a new optimization strategy for computationally expensive design optimization of turbomachinery, combined with design of experiment (DOE), response surface models (RSM), genetic algorithm (GA) and a 3-D Navier-Stokes solver(Numeca Fine). Data points for response evaluations were selected by improved distributed hypercube sampling (IHS) and the 3-D Navier-Stokes analysis was carried out at these sample points. The quadratic response surface model was used to approximate the relationships between the design variables and flow parameters. To maximize the adiabatic efficiency, the genetic algorithm was applied to the response surface model to perform global optimization to achieve the optimum design of NASA Stage 35. An optimum leading edge line was found, which produced a new 3-D rotor blade combined with sweep and lean, and a new stator one with skew. It is concluded that the proposed strategy can provide a reliable method for design optimization of turbomachinery blades at reasonable computing cost.展开更多
[Objectives]To explore the saponins resources in fibrous roots of Pseudostellaria heterophylla and optimize the SEP technology for extracting saponins.[Methods]Saponins contents in fibrous roots and root tubers of P.h...[Objectives]To explore the saponins resources in fibrous roots of Pseudostellaria heterophylla and optimize the SEP technology for extracting saponins.[Methods]Saponins contents in fibrous roots and root tubers of P.heterophylla were compared;with the fibrous roots as host materials,this experiment applied Box-Behnken design to analyze the influence of steam pressure,maintenance pressure time,moisture content of host materials on the content of saponins extracts.[Results]Saponins content was higher in fibrous roots than in tuberous roots of P.heterophylla;the response surface optimization showed that SEP(steam explosion pretreatment)promoted the contents of saponins and extracts in fibrous roots,and the optimal extracting conditions were stream pressure 1.50 Mpa,maintenance pressure time 54 s,and moisture content of host materials 30%.Under this extracting conditions,the verification value of saponins content experiment was 0.441%,36.53%higher than the untreated control group.[Conclusions]This research offered a new method of exploring saponins resources from fibrous roots of P.heterophylla,and provided a reference for developing new medicinal parts of P.heterophylla.展开更多
Pomegranate pomace is the solid waste of the pomegranate juice industry which accounts for approximately 50%of the quantity of the fruits,which is processed into juice and is a good raw material for production of high...Pomegranate pomace is the solid waste of the pomegranate juice industry which accounts for approximately 50%of the quantity of the fruits,which is processed into juice and is a good raw material for production of high added value products with diverse uses.Pomegranate pomace is rich in polyphenols and flavonoids which could substitute the potentially hazardous synthetic antioxidants/antimicrobials used in agro-food and cosmetics sectors.In this work,eco-friendly aqueous microwave assisted extraction of pomegranate pomace was investigated and optimized in order to produce effectively novel natural antioxidant/antimicrobial extracts.A three-factorial response surface optimization methodology with centered Box&Behnken experimental design was used to obtain the predictive models and the maximum values of total polyphenols,total flavonoids and total antioxidant capacity(TAC).The three optimization factors involved were:(a)water/solid ratio;(b)extraction temperature;(c)extraction time and the effectiveness and robustness of the three models were statistically verified by ANOVA.展开更多
Orange pomace is the solid waste of the orange juice industry which accounts for approximately 50%of the quantity of the fruits processed into juice and is a good raw material for production of high added value produc...Orange pomace is the solid waste of the orange juice industry which accounts for approximately 50%of the quantity of the fruits processed into juice and is a good raw material for production of high added value products with diverse uses.Orange pomace is rich in polyphenols and flavonoids which can substitute the potentially hazardous or less desirable chemical antioxidants/antimicrobials used in agro-food and cosmetics industry.In this work,an eco-friendly aqueous microwave assisted extraction of orange pomace was investigated and optimized in order to produce aqueous bioactive antioxidant/antimicrobial extracts.A three factorial Response Surface Optimization methodology with centered Box&Behnken experimental design was used to obtain optimum values of total polyphenols and total flavonoids and build predictive models for their optimal extraction conditions.The three optimization factors in terms of applied process parameters were(a)water/solid ratio,(b)extraction temperature and(c)extraction time.The effectiveness and statistical soundness of the two corresponding models regarding optimal total polyphenols and flavonoids were verified by Analysis of Variance(ANOVA).展开更多
In order to design the press bend forming path of aircraft integral panels,a novel optimization method was proposed, which integrates FEM equivalent model based on previous study,the artificial neural network response...In order to design the press bend forming path of aircraft integral panels,a novel optimization method was proposed, which integrates FEM equivalent model based on previous study,the artificial neural network response surface,and the genetic algorithm.First,a multi-step press bend forming FEM equivalent model was established,with which the FEM experiments designed with Taguchi method were performed.Then,the BP neural network response surface was developed with the sample data from the FEM experiments.Furthermore,genetic algorithm was applied with the neural network response surface as the objective function. Finally,verification was carried out on a simple curvature grid-type stiffened panel.The forming error of the panel formed with the optimal path is only 0.098 39 and the calculating efficiency has been improved by 77%.Therefore,this novel optimization method is quite efficient and indispensable for the press bend forming path designing.展开更多
In this paper,size and shape optimization problem of a machine gun system is addressed with an efficient hybrid method,in which a novel and flexible mesh morphing technique is employed to achieve fast parameterization...In this paper,size and shape optimization problem of a machine gun system is addressed with an efficient hybrid method,in which a novel and flexible mesh morphing technique is employed to achieve fast parameterization and modification of complexity structure without going back to CAD for reconstruction of geometric models or to finite element analysis（ FEA） for remodeling. Design of experiments（ DOE） and response surface method（ RSM） are applied to approximate the constitutive parameters of a machine gun system based on experimental tests. Further FEA,secondary development technique and genetic algorithm（ GA） are introduced to find all the optimal solutions in one go and the optimal design of the demonstrated machine gun system is obtained. Results of the rigid-flexible coupling dynamic analysis and exterior ballistics calculation validate the proposed methodology,which is relatively time-saving,reliable and has the potential to solve similar problems.展开更多
This study presents the use of chicken eggshells waste utilizing palm kernel shell based activated carbon（PKSAC） through the modification of their surface to enhance the adsorption capacity of H2S. Response surface ...This study presents the use of chicken eggshells waste utilizing palm kernel shell based activated carbon（PKSAC） through the modification of their surface to enhance the adsorption capacity of H2S. Response surface methodology technique was used to optimize the process conditions and they were found to be： 500 mg/L for H2S initial concentration, 540 min for contact time and 1 g for adsorbent mass. The impacts of three arrangement factors（calcination temperature of impregnated activated carbon（IAC）, the calcium solution concentration and contact time of calcination） on the H2S removal efficiency and impregnated AC yield were investigated. Both responses IAC yield（IACY, %） and removal efficiency（RE, %） were maximized to optimize the IAC preparation conditions. The optimum preparation conditions for IACY and RE were found as follows： calcination temperature of IAC of 880 ℃, calcium solution concentration of 49.3% and calcination contact time of 57.6 min, which resulted in 35.8% of IACY and 98.2% RE. In addition, the equilibrium and kinetics of the process were investigated. The adsorbent was characterized using TGA, XRD, FTIR, SEM/EDX, and BET. The maximum monolayer adsorption capacity was found to be 543.47 mg/g. The results recommended that the composite of PKSAC and Ca O could be a useful material for H2S containing wastewater treatment.展开更多
The q-profile control problem in the ramp-up phase of plasma discharges is consid- ered in this work. The magnetic diffusion partial differential equation （PDE） models the dynamics of the poloidal magnetic flux prof...The q-profile control problem in the ramp-up phase of plasma discharges is consid- ered in this work. The magnetic diffusion partial differential equation （PDE） models the dynamics of the poloidal magnetic flux profile, which is used in this work to formulate a PDE-constrained op-timization problem under a quasi-static assumption. The minimum surface theory and constrained numeric optimization are then applied to achieve suboptimal solutions. Since the transient dy- namics is pre-given by the minimum surface theory, then this method can dramatically accelerate the solution process. In order to be robust under external uncertainties in real implementations, PID （proportional-integral-derivative） controllers are used to force the actuators to follow the computational input trajectories. It has the potential to implement in real-time for long time discharges by combining this method with the magnetic equilibrium update.展开更多
The rapid urbanization underscores the urgency of efficient treatment and resource utilization of municipal sludge for environmental conservation.To address this,a novel pH-responsive dual network polyvinyl alcohol/so...The rapid urbanization underscores the urgency of efficient treatment and resource utilization of municipal sludge for environmental conservation.To address this,a novel pH-responsive dual network polyvinyl alcohol/sodium alginate sludge hydrogel was devised by integrating municipal sludge with acrylic acid monomers,ammonium persulphate initiator,N,N’-methylene bisacrylamide crosslinking agent,reinforced by polyvinyl alcohol and sodium alginate through free radical cross-linking polymerization.The hydrogel’s optimal formulation was identified by adjusting the monomer,crosslinking agent,and initiator dosage while assessing its swelling behavior across various pH environments.Results revealed excellent swelling capacity,notably exhibiting a remarkable swelling capacity of up to 7265.64% at pH 11.0,suggesting the hydrogel’s potential in environmental remediation and innovative material design.This research presents a pioneering approach to harnessing municipal sludge and developing intelligent hydrogels,fostering sustainable resource management.展开更多
Recent years have witnessed a booming interest in grid-scale electrochemical energy storage,where much attention has been paid to the aqueous zinc ion batteries(AZIBs).Among various cathode materials for AZIBs,mangane...Recent years have witnessed a booming interest in grid-scale electrochemical energy storage,where much attention has been paid to the aqueous zinc ion batteries(AZIBs).Among various cathode materials for AZIBs,manganese oxides have risen to prominence due to their high energy density and low cost.However,sluggish reaction kinetics and poor cycling stability dictate against their practical application.Herein,we demonstrate the combined use of defect engineering and interfacial optimization that can simultaneously promote rate capability and cycling stability of MnO_(2) cathodes.β-MnO_(2) with abundant oxygen vacancies(VO)and graphene oxide(GO)wrapping is synthesized,in which VO in the bulk accelerate the charge/discharge kinetics while GO on the surfaces inhibits the Mn dissolution.This electrode shows a sustained reversible capacity of~129.6 mAh g^(−1) even after 2000 cycles at a current rate of 4C,outperforming the state-of-the-art MnO_(2)-based cathodes.The superior performance can be rationalized by the direct interaction between surface VO and the GO coating layer,as well as the regulation of structural evolution ofβ-MnO_(2) during cycling.The combinatorial design scheme in this work offers a practical pathway for obtaining high-rate and long-life cathodes for AZIBs.展开更多
Based on the Canadian Standards Association (CSA) criteria,105 pullout specimens were tested to investigate the effect of different rib geometries on bond strength of glass fiber reinforced polymer (GFRP) rebars embed...Based on the Canadian Standards Association (CSA) criteria,105 pullout specimens were tested to investigate the effect of different rib geometries on bond strength of glass fiber reinforced polymer (GFRP) rebars embedded in concrete. Two kinds of conventional reinforcing rebars were also studied for comparison. Each rebar was embedded in a 150 mm concrete cube,with the embedded length being four times the rebar diameter. The experimental parameters were the rebar type,rebar component,rebar diameter,rebar surface texture,rib height,rib spacing and rib width. Theoretical analysis was also carried out to explain the experimental phenomena and results. The experimental and theoretical results indicated that the bond strength of GFRP rebars was about 13%～35% lower than that of steel rebars. The bond strength and bond-slip behavior of the specially machined rebars varied with the rebar type,rebar diameter,rebar surface texture,rib height,rib spacing and rib width. Using the results,design recom-mendations were made concerning optimum rib geometries of GFRP ribbed rebars with superior bond-slip characteristics,which concluded that the optimal rib spacing of ribbed rebars is the same as the rebar diameter,and that the optimal rib height is 6% of the rebar diameter.展开更多
文摘[Objectives]The ultrasound-assisted aqueous two-phase extraction of sweet potato leaf polysaccharides was studied.[Methods]With the yield of sweet potato leaf polysaccharides as the index,the aqueous two-phase extraction system was determined,and the optimal extraction conditions were optimized by single-factor experiments and response surface methodology.[Results]The optimal parameters were ethanol concentration 25.68%,liquid-to-material ratio 55.83,and ultrasonic treatment time 38.33 min.Under these conditions,the yield of sweet potato leaf polysaccharides could reach 20.646 mg/g.[Conclusions]The ethanol/ammonium sulfate aqueous system is a rapid and efficient method for extracting sweet potato leaf polysaccharides,which is of great significance for the application of sweet potato leaf extract as a natural food additive.
基金supported by the National Key R&D Program of China(grant no.2022YFB3803500)the National Natural Science Foundation of China(grant no.52272203)the Fundamental Research Funds for the Central Universities(grant no.2021GCRC001).
文摘“Dendrite-free”deposition behavior of Mg^(2+)is expected to achieve planar and dense Mg growth for long-life and safe Mg batteries.However,in practice,the Mg electrode still suffers from uneven stripping/deposition in Cl-based electrolytes.Here,we reveal the low Pilling-Bedworth(P-B)ratio(0.81,the ratio of the molar volume of a metal oxide to that of the corresponding metal)of Mg metal intrinsically results in a contractive,unprotective,and inhomogeneous electrode surface,subsequently making it vulnerable in Cl-based electrolytes and inducing uneven stripping/deposition.By constructing an Al nanolayer with a high P-B ratio(1.28)to the surface of the Mg-metal electrode,we protect the electrode from corrosion,homogenize Mg stripping,and regulate planar Mg deposition.Symmetric cells with Al-Mg electrodes show a 15-fold increase in cycle life,and a Mg||Al-Cu half cell achieves an average Coulombic efficiency of 99.8%for 300 cycles at 5 mA cm^(-2)and 5 mAh cm^(-2).A long-life Al-Mg||Mo_(6)S_(8)pouch cell is also demonstrated with stable cyclability of up to 1200 cycles.This work provides a simple yet effective strategy to enhance the practical prospects of Mg batteries in terms of cycle life and safety.
文摘【Objective】To optimize the steam explosion process condition for extracting polysaccharides from Pseudostellaria heterophylla.【Method】The effects of steam pressure,pressure-maintaining time and material moisture content on the extraction of polysaccharides from Pseudostellaria heterophylla were studied by response surface methodology based on Box-Behnken design.【Result】The findings showed that each factor could significantly affect the test index,and the optimum condition was as follows:steam pressure 1.50 Mpa,pressuremaintaining time 46 s and material moisture content 46%.Under this condition,the verified experimental value of polysaccharides from Pseudostellaria heterophylla was 39.32%,indicating a relative standard deviation of 2.73%from the predictive value.Meanwhile,scanning electron microcopy(SEM)images showed that the surface physical structure of Pseudostellaria heterophylla was irregularly broken and cracked,which means the physical structure of Pseudostellaria heterophylla was changed and destroyed at the cellular level.【Conclusion】This experiment provides a new approach for the extraction of polysaccharides from Pseudostellaria heterophylla,as well as a reference for the resource utilization of Pseudostellaria heterophylla.
基金Supported by Agricultural Product Processing Technology and Product Development Project of the 13th Five-Year Plan of Tibet
文摘Taking refined flour,matsutake powder,and highland barley powder as main raw materials,this experiment studied the optimal formula of matsutake highland barley biscuit. Besides,single factor experiment was carried out for the amount of highland barley powder,white granulated sugar,and shortening. Then,the response surface optimization analysis was made on crispness and sensory score of the biscuit. The experiment indicates that taking the refined flour as the base 100 g( 100%),the formula of 20% highland barley powder,25% white granulated sugar,and 26% shortening can bake crisp biscuit with complete shape,pure flavor and high quality.
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support by Shaanxi Province Technological Innovation Guidance Special (Grant No.2021QFY04-01)technical support by Analytical Instrumentation Center of XUST.
文摘The scalable production of high grade activated carbon from abundant coal for supercapacitors application is an efficient way to achieve high value-added utilization of coal sources.However,this technology is challenging due to lack of comprehensive understanding on the mechanism of activation process and effect of external factors.In this paper,the effect of activating temperature and time on the specific capacitance of coal-based activated carbon prepared by H2O steam activation was studied using the response surface method.Under optimal conditions,coal-based activated carbon exhibits the largest specific capacitance of 194.35 F·g^(−1),thanks to the appropriate pore/surface structure and defect degree.Density functional theory calculations explain in detail the mechanism of contraction of aromatic rings and overflow of H2 and CO during the activation.Meanwhile,oxygen-containing functional groups are introduced,contributing to the pseudocapacitance property of coal-based activated carbon.This mechanism of reactions between aromatic carbon and H2O vapor provides understanding on the role of water during coal processing at the molecular level,offering great potential to regulate product distribution and predict rate of pore generation.This insight would contribute to the advancement of other coal processing technology such as gasification.
基金funding from Hunan Provincial Key Research and Development Program(2020WK2018)Hunan Provincial Forestry Technological Innovation Funds(XLK202107-3)+2 种基金Scientific Research Project of Hunan Education Department(19A505,21B0242)National Natural Science Foundation of China(No.21908251)Hunan Provincial Natural Science Foundation of China(No.2020JJ2058).
文摘In this paper,the residue from bamboo factory has been used to design photo-Fenton catalyst,which has the advantages of low cost and magnetic recycling.The photo-Fenton catalytic performance of the biocarbon-based catalyst was excellent and its optimal preparation process was also explored by response surface methodology.First,bamboo-carbon fiber was selected as the photo-Fenton catalyst carrier.Subsequently,the surface of the car-bon fiber was modified,with which dopamine,nano-Fe_(3)O_(4) and nano-TiO_(2) were successively loaded by hydro-thermal method.After the single factor tests,four factors including dopamine concentration,ferric chloride mass,P25 titanium dioxide mass and liquid-solid ratio were selected as the characteristic values.The degradation efficiency of photo-Fenton catalyst to methylene blue(MB)solution was treated as the response value.After the analysis of the response surface optimization,it was shown that the significance sequence of the selected 4 factors in terms of the MB degradation efficiency was arranged as follows:dopamine concentration>liquid-solid ratio>P25 titanium dioxide quality>ferric chloride quality.The optimal process parameters of fiber-carbon catalyst were affirmed as follows:the 1.7 mg/mL concentration of dopamine,the 1.2 g mass of ferric chloride,the 0.2 g mass of P25 titanium dioxide and the liquid-solid ratio of 170 mL/g.The experiment-measured average MB degra-dation efficiency performed by the optimized catalyst was 99.3%,which was nearly similar to the model-predicted value of 98.9%.It showed that the prediction model and response surface model were accurate and reliable.The results from response surface optimization could provide a good reference to design bamboo-based Fenton-like catalyst with excellent catalytic performance.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment(No.2012ZX07212001)the National Natural Science Foundation of China(No.31570505)the State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.2014TS05)
文摘Atrazine, a widely used herbicide, is increasing the agricultural production effectively, while also causing great environmental concern. Efficient atrazine-degrading bacterium is necessary to removal atrazine rapidly to keep a safe environment. In the present study, a new atrazine-degrading strain ZXY-1, identified as Pseudomonas, was isolated. This new isolated strain has a strong ability to biodegrade atrazine with a high efficiency of 9.09 mg/L/hr.Temperature, p H, inoculum size and initial atrazine concentration were examined to further optimize the degradation of atrazine, and the synthetic effect of these factors were investigated by the response surface methodology. With a high quadratic polynomial mathematical model（R^2= 0.9821） being obtained, the highest biodegradation efficiency of 19.03 mg/L/hr was reached compared to previous reports under the optimal conditions（30.71°C, pH 7.14, 4.23%（V/V） inoculum size and 157.1 mg/L initial atrazine concentration）.Overall, this study provided an efficient bacterium and approach that could be potentially useful for the bioremediation of wastewater containing atrazine.
基金supported by the National High-Tech Research and Development Program(863)of China(No.2011AA060904)the National Science Foundation for Distinguished Young Scholars(No.51225802)+3 种基金the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(No.51121062)the National Key Technology Research and Development Program of the Ministry of Science and Technology of China(No.2010BAC67B02)the Fundamental Research Funds for Central Universities(No.AUGA5710055514)the National Natural Science Foundation of China(Nos.51176037,1308147,51308147 and 51408591)
文摘The colloidal properties of biogenic elemental sulfur（S^0）cause solid–liquid separation problems,such as poor settling and membrane fouling.In this study,the separation of S^0 from bulk liquids was performed using flocculation.Polyaluminum chloride（PAC）,polyacrylamide（PAM）and microbial flocculant（MBF）were compared to investigate their abilities to flocculate S^0 produced during the treatment of sulfate-containing wastewater.A novel approach with response surface methodology（RSM）was employed to evaluate the effects and interactions of flocculant dose,pH and stirring intensity,on the treatment efficiency in terms of the S^0 flocculation and the supernatant turbidity removal.The dose optimization results indicated that the S^0 flocculation efficiency decreased in the following order PAC〉MBF〉PAM.Optimum S^0 flocculation conditions were observed at pH 4.73,a stirring speed of 129 r/min and a flocculant dose of 2.42 mg PAC/mg S.During optimum flocculation conditions,the S^0f locculation rate reached 97.53%.Confirmation experiments demonstrated that employing PAC for S^0 flocculation is feasible and RSM is an efficient approach for optimizing the process of S^0 flocculation.The results provide basic parameters and conditions for recovering sulfur during the treatment of sulfate-laden wastewaters.
文摘In order to shorten the design period, the paper describes a new optimization strategy for computationally expensive design optimization of turbomachinery, combined with design of experiment (DOE), response surface models (RSM), genetic algorithm (GA) and a 3-D Navier-Stokes solver(Numeca Fine). Data points for response evaluations were selected by improved distributed hypercube sampling (IHS) and the 3-D Navier-Stokes analysis was carried out at these sample points. The quadratic response surface model was used to approximate the relationships between the design variables and flow parameters. To maximize the adiabatic efficiency, the genetic algorithm was applied to the response surface model to perform global optimization to achieve the optimum design of NASA Stage 35. An optimum leading edge line was found, which produced a new 3-D rotor blade combined with sweep and lean, and a new stator one with skew. It is concluded that the proposed strategy can provide a reliable method for design optimization of turbomachinery blades at reasonable computing cost.
基金Instructive Project of Fujian Provincial Science and Technology Plan(2019Y6005)Innovation Funding Program of Fujian Provincial Department of Science and Technology。
文摘[Objectives]To explore the saponins resources in fibrous roots of Pseudostellaria heterophylla and optimize the SEP technology for extracting saponins.[Methods]Saponins contents in fibrous roots and root tubers of P.heterophylla were compared;with the fibrous roots as host materials,this experiment applied Box-Behnken design to analyze the influence of steam pressure,maintenance pressure time,moisture content of host materials on the content of saponins extracts.[Results]Saponins content was higher in fibrous roots than in tuberous roots of P.heterophylla;the response surface optimization showed that SEP(steam explosion pretreatment)promoted the contents of saponins and extracts in fibrous roots,and the optimal extracting conditions were stream pressure 1.50 Mpa,maintenance pressure time 54 s,and moisture content of host materials 30%.Under this extracting conditions,the verification value of saponins content experiment was 0.441%,36.53%higher than the untreated control group.[Conclusions]This research offered a new method of exploring saponins resources from fibrous roots of P.heterophylla,and provided a reference for developing new medicinal parts of P.heterophylla.
文摘Pomegranate pomace is the solid waste of the pomegranate juice industry which accounts for approximately 50%of the quantity of the fruits,which is processed into juice and is a good raw material for production of high added value products with diverse uses.Pomegranate pomace is rich in polyphenols and flavonoids which could substitute the potentially hazardous synthetic antioxidants/antimicrobials used in agro-food and cosmetics sectors.In this work,eco-friendly aqueous microwave assisted extraction of pomegranate pomace was investigated and optimized in order to produce effectively novel natural antioxidant/antimicrobial extracts.A three-factorial response surface optimization methodology with centered Box&Behnken experimental design was used to obtain the predictive models and the maximum values of total polyphenols,total flavonoids and total antioxidant capacity(TAC).The three optimization factors involved were:(a)water/solid ratio;(b)extraction temperature;(c)extraction time and the effectiveness and robustness of the three models were statistically verified by ANOVA.
基金co-financed by the European Regional Development Fund of the European Union and Greek national funds through the Operational Program Competitiveness,Entrepreneurship and Innovation,under the call Research-Create-Innovate(project code:T1EDK-03942).
文摘Orange pomace is the solid waste of the orange juice industry which accounts for approximately 50%of the quantity of the fruits processed into juice and is a good raw material for production of high added value products with diverse uses.Orange pomace is rich in polyphenols and flavonoids which can substitute the potentially hazardous or less desirable chemical antioxidants/antimicrobials used in agro-food and cosmetics industry.In this work,an eco-friendly aqueous microwave assisted extraction of orange pomace was investigated and optimized in order to produce aqueous bioactive antioxidant/antimicrobial extracts.A three factorial Response Surface Optimization methodology with centered Box&Behnken experimental design was used to obtain optimum values of total polyphenols and total flavonoids and build predictive models for their optimal extraction conditions.The three optimization factors in terms of applied process parameters were(a)water/solid ratio,(b)extraction temperature and(c)extraction time.The effectiveness and statistical soundness of the two corresponding models regarding optimal total polyphenols and flavonoids were verified by Analysis of Variance(ANOVA).
基金Project(20091102110021)supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China
文摘In order to design the press bend forming path of aircraft integral panels,a novel optimization method was proposed, which integrates FEM equivalent model based on previous study,the artificial neural network response surface,and the genetic algorithm.First,a multi-step press bend forming FEM equivalent model was established,with which the FEM experiments designed with Taguchi method were performed.Then,the BP neural network response surface was developed with the sample data from the FEM experiments.Furthermore,genetic algorithm was applied with the neural network response surface as the objective function. Finally,verification was carried out on a simple curvature grid-type stiffened panel.The forming error of the panel formed with the optimal path is only 0.098 39 and the calculating efficiency has been improved by 77%.Therefore,this novel optimization method is quite efficient and indispensable for the press bend forming path designing.
基金Supported by the National Natural Science Foundation of China(51376090,51676099)
文摘In this paper,size and shape optimization problem of a machine gun system is addressed with an efficient hybrid method,in which a novel and flexible mesh morphing technique is employed to achieve fast parameterization and modification of complexity structure without going back to CAD for reconstruction of geometric models or to finite element analysis（ FEA） for remodeling. Design of experiments（ DOE） and response surface method（ RSM） are applied to approximate the constitutive parameters of a machine gun system based on experimental tests. Further FEA,secondary development technique and genetic algorithm（ GA） are introduced to find all the optimal solutions in one go and the optimal design of the demonstrated machine gun system is obtained. Results of the rigid-flexible coupling dynamic analysis and exterior ballistics calculation validate the proposed methodology,which is relatively time-saving,reliable and has the potential to solve similar problems.
基金Funded by the Faculty of Chemical&Natural Resources Engineering,Universiti Malaysia Pahang through a Local Research Grant Scheme
文摘This study presents the use of chicken eggshells waste utilizing palm kernel shell based activated carbon（PKSAC） through the modification of their surface to enhance the adsorption capacity of H2S. Response surface methodology technique was used to optimize the process conditions and they were found to be： 500 mg/L for H2S initial concentration, 540 min for contact time and 1 g for adsorbent mass. The impacts of three arrangement factors（calcination temperature of impregnated activated carbon（IAC）, the calcium solution concentration and contact time of calcination） on the H2S removal efficiency and impregnated AC yield were investigated. Both responses IAC yield（IACY, %） and removal efficiency（RE, %） were maximized to optimize the IAC preparation conditions. The optimum preparation conditions for IACY and RE were found as follows： calcination temperature of IAC of 880 ℃, calcium solution concentration of 49.3% and calcination contact time of 57.6 min, which resulted in 35.8% of IACY and 98.2% RE. In addition, the equilibrium and kinetics of the process were investigated. The adsorbent was characterized using TGA, XRD, FTIR, SEM/EDX, and BET. The maximum monolayer adsorption capacity was found to be 543.47 mg/g. The results recommended that the composite of PKSAC and Ca O could be a useful material for H2S containing wastewater treatment.
基金supported partially by the US NSF CAREER award program (ECCS-0645086)National Natural Science Foundation of China (No.F030119)+2 种基金Zhejiang Provincial Natural Science Foundation of China (Nos.Y1110354, Y6110751)the Fundamental Research Funds for the Central Universities of China (No.1A5000-172210101)the Natural Science Foundation of Ningbo (No.2010A610096)
文摘The q-profile control problem in the ramp-up phase of plasma discharges is consid- ered in this work. The magnetic diffusion partial differential equation （PDE） models the dynamics of the poloidal magnetic flux profile, which is used in this work to formulate a PDE-constrained op-timization problem under a quasi-static assumption. The minimum surface theory and constrained numeric optimization are then applied to achieve suboptimal solutions. Since the transient dy- namics is pre-given by the minimum surface theory, then this method can dramatically accelerate the solution process. In order to be robust under external uncertainties in real implementations, PID （proportional-integral-derivative） controllers are used to force the actuators to follow the computational input trajectories. It has the potential to implement in real-time for long time discharges by combining this method with the magnetic equilibrium update.
基金the Hubei Provincial Key Scientific Research Project on Water Resources“Study on the Distribution and Characteristics of Sediment Siltation in the Key Waters of Zhanghe Reservoir(HBSLKY202302)”Wuhan Municipal Bureau of Science and Technology 2023 Knowledge and Innovation Special Project,“Research on key technology for fine traceability of total phosphorus in urban lakes in Wuhan”(No.2023020201010119)+1 种基金the National Visiting Scholar Program for Key Young Teachers of Central and Western Universities,and the Ministry of Education(19042)Science and Technology Tackling Projects in Henan Province in 2025(Research on key technology for removing microdust from the surface of photovoltaic power generation panels by spray coating with high-efficiency hydrogel coatings prepared from multi-source solid wastes).
文摘The rapid urbanization underscores the urgency of efficient treatment and resource utilization of municipal sludge for environmental conservation.To address this,a novel pH-responsive dual network polyvinyl alcohol/sodium alginate sludge hydrogel was devised by integrating municipal sludge with acrylic acid monomers,ammonium persulphate initiator,N,N’-methylene bisacrylamide crosslinking agent,reinforced by polyvinyl alcohol and sodium alginate through free radical cross-linking polymerization.The hydrogel’s optimal formulation was identified by adjusting the monomer,crosslinking agent,and initiator dosage while assessing its swelling behavior across various pH environments.Results revealed excellent swelling capacity,notably exhibiting a remarkable swelling capacity of up to 7265.64% at pH 11.0,suggesting the hydrogel’s potential in environmental remediation and innovative material design.This research presents a pioneering approach to harnessing municipal sludge and developing intelligent hydrogels,fostering sustainable resource management.
基金This work is financially supported by the Stable Support Funding for Universities in Shenzhen(Nos.GXWD20201231165807007-20200807111854001).
文摘Recent years have witnessed a booming interest in grid-scale electrochemical energy storage,where much attention has been paid to the aqueous zinc ion batteries(AZIBs).Among various cathode materials for AZIBs,manganese oxides have risen to prominence due to their high energy density and low cost.However,sluggish reaction kinetics and poor cycling stability dictate against their practical application.Herein,we demonstrate the combined use of defect engineering and interfacial optimization that can simultaneously promote rate capability and cycling stability of MnO_(2) cathodes.β-MnO_(2) with abundant oxygen vacancies(VO)and graphene oxide(GO)wrapping is synthesized,in which VO in the bulk accelerate the charge/discharge kinetics while GO on the surfaces inhibits the Mn dissolution.This electrode shows a sustained reversible capacity of~129.6 mAh g^(−1) even after 2000 cycles at a current rate of 4C,outperforming the state-of-the-art MnO_(2)-based cathodes.The superior performance can be rationalized by the direct interaction between surface VO and the GO coating layer,as well as the regulation of structural evolution ofβ-MnO_(2) during cycling.The combinatorial design scheme in this work offers a practical pathway for obtaining high-rate and long-life cathodes for AZIBs.
基金Project (No. 200431882021) supported by the Western Communi-cation Construction and Science & Technological Project,China
文摘Based on the Canadian Standards Association (CSA) criteria,105 pullout specimens were tested to investigate the effect of different rib geometries on bond strength of glass fiber reinforced polymer (GFRP) rebars embedded in concrete. Two kinds of conventional reinforcing rebars were also studied for comparison. Each rebar was embedded in a 150 mm concrete cube,with the embedded length being four times the rebar diameter. The experimental parameters were the rebar type,rebar component,rebar diameter,rebar surface texture,rib height,rib spacing and rib width. Theoretical analysis was also carried out to explain the experimental phenomena and results. The experimental and theoretical results indicated that the bond strength of GFRP rebars was about 13%～35% lower than that of steel rebars. The bond strength and bond-slip behavior of the specially machined rebars varied with the rebar type,rebar diameter,rebar surface texture,rib height,rib spacing and rib width. Using the results,design recom-mendations were made concerning optimum rib geometries of GFRP ribbed rebars with superior bond-slip characteristics,which concluded that the optimal rib spacing of ribbed rebars is the same as the rebar diameter,and that the optimal rib height is 6% of the rebar diameter.
