Microwave roasting self-leaching is an innovative method for recovering gold from high-sulfur refractory gold concentrates,without using deadly toxic cyanide reagents.However,the mechanism of gold self-leaching,which ...Microwave roasting self-leaching is an innovative method for recovering gold from high-sulfur refractory gold concentrates,without using deadly toxic cyanide reagents.However,the mechanism of gold self-leaching,which relies on lixiviants prepared using volatilized sulfur obtained from roasting,has not been fully elucidated.This study employs the response surface methodology to optimize processing parameters,resulting in an increased gold extraction rate of 96.18%.Analytical factorization and the Tafel curve indicate that CuSO_(4) and NH_(3)·H_(2)O significantly influence the self-leaching process.Furthermore,X-ray photoelectron spectroscopy(XPS)analysis reveals that S^(2−),S_(2)^(2−),polysulfides(S_(n)^(2−)),and thiosulfate(S_(2)O_(3)^(2−))are involved in the gold leaching reaction,with S^(2−),S_(2)^(2−),and S_(n)^(2−) serving as primary ligands for gold complexation.The role of S_(2)O_(3)^(2−) in the early stages of the gold-leaching reaction is also noteworthy.The copper–ammonia complex catalyzes the self-leaching gold reaction;however,an improper addition ratio can lead to copper-sulfur compound precipitates,reducing the extraction rate.展开更多
To enhance the accuracy of path planning of unmanned surface vehicles(USVs),the particle swarm optimization algorithm(PSO)is improved based on species migration strategies observed in ecology.By incorporating the conc...To enhance the accuracy of path planning of unmanned surface vehicles(USVs),the particle swarm optimization algorithm(PSO)is improved based on species migration strategies observed in ecology.By incorporating the concept of particle sight distance,an improved algorithm,called SD-IPSO,is proposed for the real-time autonomous navigation of USVs in marine environments.The algorithm refines the individual behavior pattern of particles in the population,effectively improving both local and global search capabilities while avoiding premature convergence.The effectiveness of the algorithm is validated using standard test functions from CEC-2017 function library,assessing it from multiple dimensions.Sensitivity analysis is conducted on key parameters in the algorithm,including particle sight distance and population size.Results indicate that compared with PSO,SD-IPSO demonstrates significant advantages in optimization accuracy and convergence speed.The application of SD-IPSO in path planning is further investigated through a 14-point traveling salesman problem(TSP)example and navigation autonomous tests of USVs in marine environments.Findings demonstrate that the proposed algorithm exhibits superior optimization capabilities and can effectively address the path planning challenges of USVs.展开更多
Deep coal mining rock support structures using rock bolts face complex geological conditions such as high ground temperatures and groundwater.Rock mass deformation and failure caused by bolt failure frequently occur,m...Deep coal mining rock support structures using rock bolts face complex geological conditions such as high ground temperatures and groundwater.Rock mass deformation and failure caused by bolt failure frequently occur,making it crucial to enhance the anchoring performance of rock bolts.First,the stress state of the anchor rod under axial loading across five stages of any anchored segment is analyzed.The shear stress patterns at the anchoring interface during different stages are elucidated.A refined mechanical model of the anchoring interface incorporating surface rib parameters is established.A failure criterion for the anchoring interface under the influence of ground temperature or groundwater is derived and validated.Second,the influence of anchor rib parameters on anchoring force is abalyzed,and in-situ shear tests are conducted.Results indicate that increasing the rib angle and optimizing rib spacing can enhance anchoring force.To minimize the shear component of axial force at the anchor interface,the rib angle of the anchor bolt should not be less than 70°.When the anchor grout possesses high inherent strength,the spacing between ribs on the anchor bolt surface may be increased(to 24 mm or greater).Finally,methods for enhancing the anchoring performance of bolts in deep complex strata are proposed,providing technical references for the safe and efficient support of tunnel rock masses in similar geological conditions.展开更多
In situ recycling is one of the most effective methods to dispose of earth pressure balance(EPB)shield waste muck with residual foaming agents with high moisture content.In this context,response surface methodology(RS...In situ recycling is one of the most effective methods to dispose of earth pressure balance(EPB)shield waste muck with residual foaming agents with high moisture content.In this context,response surface methodology(RSM)was employed to quantify the effects of independent variables,including flocculant dosage,defoamer dosage,and muck drying mass(MDM)and their interactions on defoaming-flocculation-dewatering indices.The polymeric aluminum chloride(PACL)and hydroxy silicone oil-glycerol polypropylene ether(H-G)were selected as the flocculant and defoamer.The contents of surfactants and foam stabilizers in residual foaming agents were determined using the proposed empirical equation.The defoaming ratio,antifoaming ratio,turbidity,moisture content,filtration loss ratio,and fall cone penetration depth were considered as dependent variables.The accuracy of developed RSM models was verified by the analysis results of variance,residuals,and paired t-test.Combined with the desirability approach,an optimal mixing ratio of 0.078 wt%PACL,0.016 wt%H-G,and 27.882 wt%MDM was recommended,leading to a defoaming ratio of 98.34 vol%for residual foams and a moisture content of 56.72 wt%for pressure-filtration cakes.Our findings were demonstrated to be able to provide useful guidance for prediction and optimization of the in situ recycling indicators of EPB shield waste muck in metro tunnel construction sites.展开更多
[Objectives] To optimize the crystallization process of ceftriaxone sodium using response surface methodology (RSM) for enhancing both the crystallization rate and the quality of the final product. [Methods] Four key ...[Objectives] To optimize the crystallization process of ceftriaxone sodium using response surface methodology (RSM) for enhancing both the crystallization rate and the quality of the final product. [Methods] Four key factors, including crystallization temperature, stirring speed, solvent drop rate, and seed crystal content, were employed as independent variables, while the crystallization rate served as the response variable. The Box-Behnken response surface method was utilized for the optimization design. [Results] The optimal parameters for the crystallization process, determined through optimization, were as follows: a temperature of 10.6 ℃, a stirring rate of 150 rpm, a solvent drop rate of 1.50 mL/min, and a seed crystal content of 0.12 g. Validation tests conducted under these conditions yielded an average crystallization rate of 94.38% for the refined product. [Conclusions] The crystallization efficiency of ceftriaxone sodium is markedly enhanced, thereby offering substantial support for its industrial production and clinical application.展开更多
This study employed the Box-Behnken design in response surface methodology(RSM)to optimize predistillation and pressurized distillation column parameters in methanol distillation.Statistical and fittinganalyses demons...This study employed the Box-Behnken design in response surface methodology(RSM)to optimize predistillation and pressurized distillation column parameters in methanol distillation.Statistical and fittinganalyses demonstrated the effects of operational parameters and their interactions on product purity and operating costs.Results showed that for methanol mass fraction in the product,the top distillate of the predistillation column(D_(1)),the interaction between D_(1) and the top distillate of the pressurized distillation column(D_(2)),and the interaction between the theoretical plates of the pressurized distillation column(N_(2))and its refluxratio(R_(2))significantlyaffected the outcome,in addition to pressurized distillation column parameters.Acetone mass fraction was mainly influencedby predistillation column parameters and their interactions,with minimal relation to the pressurized distillation column.Operating costs were primarily affected by the refluxratio(R),withdrawal(D)of both columns,and their interactions.Optimization strategies involved increasing theoretical plates and reducing refluxratios compared to the initial plan,achieving energy-saving and consumption-reduction goals.The process required the pressurized distillation column‘s methanol mass fraction to exceed 99.80%,acetone mass fraction below 2×10^(-8),and formaldehyde mass fraction below 5×10^(-9),with a feed rate of 6100 kg·h^(-1).Plans A,B,and C achieved energy-savings of 29.80%,21.78%,and 25.50%respectively,while ensuring separation efficiencyand product quality.This research provides theoretical and practical guidance for optimizing the methanol distillation process,helping to reduce energy consumption and production costs,thereby enhancing corporate competitiveness.展开更多
To solve the problems of deformation,micro-cracks,and residual tensile stress in laser cladding coatings,the technique of laser cladding with Fe-based memory alloy can be considered.However,the process of in-situ synt...To solve the problems of deformation,micro-cracks,and residual tensile stress in laser cladding coatings,the technique of laser cladding with Fe-based memory alloy can be considered.However,the process of in-situ synthesis of Fe-based memory alloy coatings is extremely complex.At present,there is no clear guidance scheme for its preparation process,which limits its promotion and application to some extent.Therefore,in this study,response surface methodology(RSM)was used to model the response surface between the target values and the cladding process parameters.The NSGA-2 algorithm was employed to optimize the process parameters.The results indicate that the composite optimization method consisting of RSM and the NSGA-2 algorithm can establish a more accurate model,with an error of less than 4.5%between the predicted and actual values.Based on this established model,the optimal scheme for process parameters corresponding to different target results can be rapidly obtained.The prepared coating exhibits a uniform structure,with no defects such as pores,cracks,and deformation.The surface roughness and microhardness of the coating are enhanced,the shaping quality of the coating is effectively improved,and the electrochemical corrosion performance of the coating in 3.5%NaCl solution is obviously better than that of the substrate,providing an important guide for engineering applications.展开更多
[Objectives]This study was conducted to efficiently extract loganin from Viburnum erosum Thunb.[Methods]Ultrasound-assisted extraction coupled with response surface methodology was employed.The extraction was carried ...[Objectives]This study was conducted to efficiently extract loganin from Viburnum erosum Thunb.[Methods]Ultrasound-assisted extraction coupled with response surface methodology was employed.The extraction was carried out with 60%methanol as the solvent and loganin extraction rate as the evaluation index.The effects of liquid-to-solid ratio,extraction temperature,and extraction time on loganin extraction rate were investigated through single-factor experiments.Subsequently,a Box-Behnken experimental design was implemented based on the single-factor results to optimize the extraction process.[Results]Under the conditions of liquid-to-solid ratio of 6 ml/g,extraction temperature of 39℃,and extraction time of 88 min,the loganin extraction rate was 4.199%,which agreed with the predicted value of 4.271%.The order of three factors affecting the extraction rate of loganin in V.erosum Thunb was liquid-to-solid ratio>extraction time>extraction temperature.The response surface methodology demonstrates high stability and feasibility for optimizing the extraction process,and the proposed protocol achieves efficient loganin extraction from V.erosum Thunb.[Conclusions]This study provides a novel approach for extracting iridoid glycosides from V.erosum Thunb.and expands the plant sources of loganin.展开更多
Background:Polygonati cyrtonema Hua(PC)has many pharmacological effects such as immune regulation,hypoglycemic and lipid-lowering,anti-oxidation and anti-tumor.Oligosaccharide is one of the main active components of P...Background:Polygonati cyrtonema Hua(PC)has many pharmacological effects such as immune regulation,hypoglycemic and lipid-lowering,anti-oxidation and anti-tumor.Oligosaccharide is one of the main active components of PC.At present,the research on Polygonatum cyrtonema oligosaccharides(PCOS)is not deep,and there is a lack of systematic research on the optimization of extraction process of pcos and the change of pcos and Polygonatum cyrtonema polysaccharide content before and after wine steaming.Methods:The optimum extraction process of oligosaccharides from PC was optimized,and the content of oligosaccharides before and after wine steaming of PC was investigated.The single factor experiment was carried out with the ratio of liquid to material,extraction temperature and extraction time as the investigation factors.The extraction process of PCOS was optimized by Box Behnken design-response surface methodology,and the changes of total oligosaccharides and total polysaccharides before and after wine steaming were studied.Results:The optimal extraction process for the PCOS was 32:1 mL/g,85℃,and 1.5 h.The total PCOS decreased slightly after steaming,but the percentage of the total sugar increased.Conclusion:The extraction process of PCOS optimized by response surface method is reasonable and feasible.The changes of total oligosaccharides and total polysaccharides during the steaming process of PC can reveal the processing mechanism of PC to a certain extent,and provide scientific basis and technical support for better in-depth excavation and development and utilization of PCOS.展开更多
The escalating production of industrial solid waste,combined with the dwindling availability of natural resources,has intensified the focus on waste recycling.However,the heterogeneity and complexity of waste pose sig...The escalating production of industrial solid waste,combined with the dwindling availability of natural resources,has intensified the focus on waste recycling.However,the heterogeneity and complexity of waste pose significant challenges to determining process parameters.In this study,burnt coal cinder(BCC),granite powder(GP),and high-calcium fly ash(Class-C FA)were used as raw materials,and the response surface methodology(RSM)and single-factor experiments were applied to optimize the process parameters for geopolymer preparation.The optimized precursor powder composition was determined to be a mass ratio of 1.6:0.9:7.3 for BCC,GP,and Class-C FA.The NaOH-precursor powder ratio and liquid-solid ratio were adjusted to 0.084 and 0.222,respectively.The curing condition was set at 80℃ for 24 h.The resulting 28 d-aged multi-solid wastes-based geopolymer exhibited a high compressive strength of61.34 MPa.The microstructure,mineral phase,and atomic bonding of geopolymers were investigated using X-ray diffraction(XRD),thermal analysis(TA),Fourier transform infrared spectroscopy(FTIR),and scanning electron microscopy with energy dispersive spectroscopy(SEM-EDS).Findings indicate that the compressive strength of geopolymer is most significantly influenced by the Class-C FA,followed by BCC.Furthermore,a minor addition of GP can optimize the structural density of the geopolymer.The Ca present in the Class-C FA participates in the geopolymerization,forming a hybrid N-(C)-A-S-H gel.RSM optimization facilitates the synergistic utilization of multi-solid wastes,ensuring an even distribution of gel and filler.This research establishes a theoretical framework for optimizing the preparation parameters of multi-solid wastes-based geopolymer and its subsequent applications;it holds significant scientific implications for the circular economy,resource transformation,and environmental conservation.展开更多
[Objectives]This study was conducted to improve the poor water-holding capacity(WHC)and high syneresis rate of fermented soy milk by optimizing fermentation process conditions.[Methods]Based on the results of single f...[Objectives]This study was conducted to improve the poor water-holding capacity(WHC)and high syneresis rate of fermented soy milk by optimizing fermentation process conditions.[Methods]Based on the results of single factor experiments,response surface methodology was employed to optimize the fermentation temperature,fermentation time,and starter culture addition for enhancing WHC.The physicochemical properties of fermented soybean milk were analyzed.[Results]The optimal process parameters were determined as follows:fermentation temperature 36℃,fermentation time 8 h,and starter culture addition 5%.Under these conditions,WHC reached(77.18±0.08)%,which was consistent with the theoretical prediction value of(76.75±0.15)%.During fermentation,the pH decreased from(6.6±0.11)to(4.65±0.09),while acidity increased from(16.5±0.04)°T to(81.5±0.08)°T.The viable cell count rose from 1×10^(7)to 29×10^(7)cfu/ml,and WHC was improved significantly from(10.50±0.18)%to(77.40±0.13)%.[Conclusions]This study optimized the fermentation process parameters and revealed physicochemical characteristic changes during soybean milk fermentation,providing a theoretical foundation for industrial production.展开更多
In order to improve the quality of 3D printed raspberry preserves after post-processing,microwave ovens combining infrared and microwave methods were utilized.The effects of infrared heating temperature,infrared heati...In order to improve the quality of 3D printed raspberry preserves after post-processing,microwave ovens combining infrared and microwave methods were utilized.The effects of infrared heating temperature,infrared heating time,microwave power,microwave heating time on the center temperature,moisture content,the chroma(C*),the total color difference(ΔE*),shape fidelity,hardness,and the total anthocyanin content of 3D printed raspberry preserves were analyzed by response surface method(RSM).The results showed that under combining with the two methods,infrared heating improved the fidelity and quality degradation of printed products,while microwave heating enhanced the efficiency of infrared heating.Infrared-microwave combination cooking could maintain relatively stable color appearance and shape of 3D printed raspberry preserves.The AHP–CRITIC hybrid weighting method combined with the response surface test to determine the comprehensive weights of the evaluation indicators optimized the process parameters,and the optimal process parameters were obtained:infrared heating temperature of 190℃,infrared heating time of 10 min and 30 s,microwave power of 300 W,and microwave heating time of 2 min and 6 s.The 3D printed raspberry cooking methods obtained under the optimal conditions seldom had color variation,porous structure,uniform texture,and high shape fidelity,which retained the characteristics of personalized manufacturing by 3D printing.This study could provide a reference for the postprocessing and quality control of 3D cooking methods.展开更多
Safety,high protein content,and the numerous health benefits make Spirulina an outstanding source of bioactive peptides.Peptides from Spirulina,which exhibit antioxidant,anti-inflammatory,and antihypertensive effects,...Safety,high protein content,and the numerous health benefits make Spirulina an outstanding source of bioactive peptides.Peptides from Spirulina,which exhibit antioxidant,anti-inflammatory,and antihypertensive effects,may assist in the management of cardiovascular diseases(CVDs).Here,we present the optimization of enzyme-digested hydrolysates derived from Spirulina sp.by using response surface methodology(RSM).We also evaluated the biological activity of Spirulina protein hydrolysates(SPHs)in contributing to the amelioration of hypertension and associated cardiovascular diseases.Our findings suggest that Spirulina protein extracts contain a complex proteinaceous composition with phycocyanin being the dominant protein,as evidenced by both SDS-PAGE and LC-MS/MS profiling.Alkaline protease,protease K,andα-chymotrypsin exhibited a substantial hydrolytic effect on Spirulina protein,taking into account their degree of hydrolysis(DH),peptide yield,and molecular weight distribution.Single-factor experiments identified pH,temperature,and enzyme/substrate ratio as the key factors influencing DH.Moreover,optimal hydrolysis conditions for the proteases were determined via RSM,leading to a considerable enhancement of the actual DH.Bioassays showed that SPHs have strong antioxidant activity against various free radicals,with a higher ability to scavenge hydroxyl radicals.Furthermore,SPHs inhibited macrophage nitric oxide secretion and significantly inhibited angiotensin I-converting enzyme in vitro at 400μg/mL.It is worth noting that SPHs prepared with protease K exhibited a potent anti-hypertensive effect in vivo.The findings indicate the potential usefulness of including dietary SPHs in preventing hypertension and associated CVDs.This research could be valuable in guiding the development of health-promoting foods within the Spirulina industry.展开更多
Practical applications of desulfurization gypsum are limited owing to its brittleness and low strength.To overcome these challenges,researchers have developed engineered desulfurization gypsum composites(EDGCs)by inco...Practical applications of desulfurization gypsum are limited owing to its brittleness and low strength.To overcome these challenges,researchers have developed engineered desulfurization gypsum composites(EDGCs)by incorporating ultrahigh molecular weight polyethylene(UHMWPE)fiber and sulfoaluminate cement(SAC).The mix ratio was optimized using response surface methodology(RSM).Experimental testing of EDGC under compressive and tensile loads led to the creation of a regression model that investigates the influence of variables and their interactions on the material’s compressive and tensile strengths.Additionally,microscopic morphology and hydration product composition were analyzed to explore the influence mechanism.The results indicated that EDGC’s compressive strength increased by up to 38.4%owing to a decreased water-binder ratio and higher SAC content.Similarly,tensile strength increased by up to 38.6%owing to increased SAC and fiber content.Moreover,EDGC demonstrated excellent strain-hardening behavior and multiple cracking characteristics,achieving a maximum tensile strain of nearly 3%.The research findings provide valuable insights for optimizing the performance of desulfurization gypsum.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 reduction roasting processes for low-grade pyrolusite using bagasse as the reducing agent was statistically analyzed. The central composite rotatable design （CCD） was used to optimize this reduction roasting pro...The reduction roasting processes for low-grade pyrolusite using bagasse as the reducing agent was statistically analyzed. The central composite rotatable design （CCD） was used to optimize this reduction roasting processes. The three process parameters studied were the mass ratio of bagasse to ore, the roasting temperature and the roasting time. Analysis of variance （ANOVA） was used to analyze the experimental results. The interactions between the process parameters were done by using the linear and quadratic model. The results revealed that the linear and quadratic effects as well as the interaction are statistically significant for the mass ratio and roasting temperature but insignificant for the roasting time. The optimal conditions of 0.9：10 of mass ratio, the roasting temperature of 450 ~C, the roasting time of 30 min were obtained. Under these conditions, the predicted leaching recovery rate for manganese was 98.1%. And the satisfied experimental result of 98.2% confirmed the validity of the model.展开更多
Parameters of technique to prepare vanadium pentoxide by calcination from ammonium metavanadate were optimized using central composite design of response surface methodology. A quadratic equation model for decompositi...Parameters of technique to prepare vanadium pentoxide by calcination from ammonium metavanadate were optimized using central composite design of response surface methodology. A quadratic equation model for decomposition rate was built and effects of main factors and their corresponding relationships were obtained. The results of the statistical analysis show that the decomposition rate of ammonium metavanadate is significantly affected by calcination temperature and calcination time. The optimized calcination conditions are as follows： calcination temperature 669.71 K, calcination time 35.9 min and sample mass 4.25 g. The decomposition rate of ammonium metavanadate is 99.71%,which coincides well with experimental value of 99.27% under the optimized conditions, suggesting that regressive equation fits the decomposition rates perfectly. XRD reveals that it is feasible to prepare the V2O5 by calcination from ammonium metavanadate using response surface methodology.展开更多
Microwave was applied to roasting the zinc oxide fume obtained from fuming furnace for the removal of F and Cl. The effects of important parameters, such as roasting temperature, holding time and stirring speed, were ...Microwave was applied to roasting the zinc oxide fume obtained from fuming furnace for the removal of F and Cl. The effects of important parameters, such as roasting temperature, holding time and stirring speed, were investigated and the process conditions were optimized using response surface methodology (RSM). The results show that the effects of roasting temperature and holding time on the removal rate of F and Cl are the most significant, and the effect of stirring speed is the second. The defluorination rate reaches 92.6% while the dechlorination rate reaches 90.2%, under the process conditions of roasting temperature of 700 °C, holding time of 80 min and stirring speed of 120 r/min. The results indicate that the removal of F and Cl from fuming furnace production of zinc oxide fumes using microwave roasting process is feasible and reliable.展开更多
[Objective] Ginger essential oil （GEO） is widely used in food production and medical field in recent years due to its prominent biological functions, and this study was conducted to obtain high-quality and high-puri...[Objective] Ginger essential oil （GEO） is widely used in food production and medical field in recent years due to its prominent biological functions, and this study was conducted to obtain high-quality and high-purity ginger essential oil from the fresh ginger. [Method] GEO was extracted from ginger roots by supercritical fluid extraction （SFE） method. The effects of flow rate of CO2, mesh size of ginger powder and volume of entrainer were investigated by single-factor experiments and response surface method. The content and extraction rate of 6-gingerol represented the extraction index of GEO. [Result] The conditions were optimized as follows： flow rate of CO2 at 25 L/h, mesh size of ginger power of 80 mesh, and volume of anhydrous ethanol as entrainer of 92.46 ml. The optimal extraction rate of 6-gingerol was 3.21%, which was predicted by RSM. [Conclusion] The optimal process of supercritical carbon dioxide extraction of ginger essential oil was identified by singlefactor experiments and response surface method. The present study provides a satisfactory method for purifying GEO from ginger for industrial purpose.展开更多
The uniform design and response surface methodology （RSM） are applied to the multi-objective optimization of a 2-D mixed compression scramjet inlet. The set of experimental design points on the design space is selec...The uniform design and response surface methodology （RSM） are applied to the multi-objective optimization of a 2-D mixed compression scramjet inlet. The set of experimental design points on the design space is selected by the uniform design, and the inlet performance is analyzed by computational fluid dynamics （CFD）. Then complete quadratic polynomial response surface approximation models are constructed based on the performance analysis results and then used to replace theoriginal complex inlet performance model. The optimization is conducted using a multi-objective genetic algorithm NSGA-Ⅱ, and the Pareto optimal solution set is obtained. Results show that the uniform design and RSM can reduce the computational complexity of numerical simulation and improve the optimization efficiency.展开更多
基金supported by the National Natural Science Foundation of China(No.51974016).
文摘Microwave roasting self-leaching is an innovative method for recovering gold from high-sulfur refractory gold concentrates,without using deadly toxic cyanide reagents.However,the mechanism of gold self-leaching,which relies on lixiviants prepared using volatilized sulfur obtained from roasting,has not been fully elucidated.This study employs the response surface methodology to optimize processing parameters,resulting in an increased gold extraction rate of 96.18%.Analytical factorization and the Tafel curve indicate that CuSO_(4) and NH_(3)·H_(2)O significantly influence the self-leaching process.Furthermore,X-ray photoelectron spectroscopy(XPS)analysis reveals that S^(2−),S_(2)^(2−),polysulfides(S_(n)^(2−)),and thiosulfate(S_(2)O_(3)^(2−))are involved in the gold leaching reaction,with S^(2−),S_(2)^(2−),and S_(n)^(2−) serving as primary ligands for gold complexation.The role of S_(2)O_(3)^(2−) in the early stages of the gold-leaching reaction is also noteworthy.The copper–ammonia complex catalyzes the self-leaching gold reaction;however,an improper addition ratio can lead to copper-sulfur compound precipitates,reducing the extraction rate.
文摘To enhance the accuracy of path planning of unmanned surface vehicles(USVs),the particle swarm optimization algorithm(PSO)is improved based on species migration strategies observed in ecology.By incorporating the concept of particle sight distance,an improved algorithm,called SD-IPSO,is proposed for the real-time autonomous navigation of USVs in marine environments.The algorithm refines the individual behavior pattern of particles in the population,effectively improving both local and global search capabilities while avoiding premature convergence.The effectiveness of the algorithm is validated using standard test functions from CEC-2017 function library,assessing it from multiple dimensions.Sensitivity analysis is conducted on key parameters in the algorithm,including particle sight distance and population size.Results indicate that compared with PSO,SD-IPSO demonstrates significant advantages in optimization accuracy and convergence speed.The application of SD-IPSO in path planning is further investigated through a 14-point traveling salesman problem(TSP)example and navigation autonomous tests of USVs in marine environments.Findings demonstrate that the proposed algorithm exhibits superior optimization capabilities and can effectively address the path planning challenges of USVs.
基金The Natural Science Research Project of Anhui Educational Committee(No.2022AH050814)Open Fund of State Key Laboratory of Nuclear Resources and Environment(East China Universityof Technology)(No.2022NRE07)+1 种基金the National Natural Science Foundation of China(No.51964002,52174104)Open Fund of Engineering Research Center of Underground Mine Construction of Ministry of Education(No.JYBGCZX2022105).
文摘Deep coal mining rock support structures using rock bolts face complex geological conditions such as high ground temperatures and groundwater.Rock mass deformation and failure caused by bolt failure frequently occur,making it crucial to enhance the anchoring performance of rock bolts.First,the stress state of the anchor rod under axial loading across five stages of any anchored segment is analyzed.The shear stress patterns at the anchoring interface during different stages are elucidated.A refined mechanical model of the anchoring interface incorporating surface rib parameters is established.A failure criterion for the anchoring interface under the influence of ground temperature or groundwater is derived and validated.Second,the influence of anchor rib parameters on anchoring force is abalyzed,and in-situ shear tests are conducted.Results indicate that increasing the rib angle and optimizing rib spacing can enhance anchoring force.To minimize the shear component of axial force at the anchor interface,the rib angle of the anchor bolt should not be less than 70°.When the anchor grout possesses high inherent strength,the spacing between ribs on the anchor bolt surface may be increased(to 24 mm or greater).Finally,methods for enhancing the anchoring performance of bolts in deep complex strata are proposed,providing technical references for the safe and efficient support of tunnel rock masses in similar geological conditions.
基金supported by the National Youth Top-notch Talent Support Program of China(Grant No.00389335)the National Natural Science Foundation of China(Grant No.52378392)the“Foal Eagle Program”Youth Top-notch Talent Project of Fujian Province(Grant No.00387088).
文摘In situ recycling is one of the most effective methods to dispose of earth pressure balance(EPB)shield waste muck with residual foaming agents with high moisture content.In this context,response surface methodology(RSM)was employed to quantify the effects of independent variables,including flocculant dosage,defoamer dosage,and muck drying mass(MDM)and their interactions on defoaming-flocculation-dewatering indices.The polymeric aluminum chloride(PACL)and hydroxy silicone oil-glycerol polypropylene ether(H-G)were selected as the flocculant and defoamer.The contents of surfactants and foam stabilizers in residual foaming agents were determined using the proposed empirical equation.The defoaming ratio,antifoaming ratio,turbidity,moisture content,filtration loss ratio,and fall cone penetration depth were considered as dependent variables.The accuracy of developed RSM models was verified by the analysis results of variance,residuals,and paired t-test.Combined with the desirability approach,an optimal mixing ratio of 0.078 wt%PACL,0.016 wt%H-G,and 27.882 wt%MDM was recommended,leading to a defoaming ratio of 98.34 vol%for residual foams and a moisture content of 56.72 wt%for pressure-filtration cakes.Our findings were demonstrated to be able to provide useful guidance for prediction and optimization of the in situ recycling indicators of EPB shield waste muck in metro tunnel construction sites.
基金Supported by Central Guided Local Science and Technology Development Funds(ZY20230102)Guilin Scientific Research and Technology Development Programme Project(2023010301-1,20220104-4)+1 种基金Guangxi Science and Technology Programme Project(GK AB24010263)Guangxi Innovation Driving Development Special Funds Project(GK AA22096020).
文摘[Objectives] To optimize the crystallization process of ceftriaxone sodium using response surface methodology (RSM) for enhancing both the crystallization rate and the quality of the final product. [Methods] Four key factors, including crystallization temperature, stirring speed, solvent drop rate, and seed crystal content, were employed as independent variables, while the crystallization rate served as the response variable. The Box-Behnken response surface method was utilized for the optimization design. [Results] The optimal parameters for the crystallization process, determined through optimization, were as follows: a temperature of 10.6 ℃, a stirring rate of 150 rpm, a solvent drop rate of 1.50 mL/min, and a seed crystal content of 0.12 g. Validation tests conducted under these conditions yielded an average crystallization rate of 94.38% for the refined product. [Conclusions] The crystallization efficiency of ceftriaxone sodium is markedly enhanced, thereby offering substantial support for its industrial production and clinical application.
基金jointly supported by the National Key Research and Development Program of China(2022YFC2106300)the National Nature Science Foundation of China(U2267226).
文摘This study employed the Box-Behnken design in response surface methodology(RSM)to optimize predistillation and pressurized distillation column parameters in methanol distillation.Statistical and fittinganalyses demonstrated the effects of operational parameters and their interactions on product purity and operating costs.Results showed that for methanol mass fraction in the product,the top distillate of the predistillation column(D_(1)),the interaction between D_(1) and the top distillate of the pressurized distillation column(D_(2)),and the interaction between the theoretical plates of the pressurized distillation column(N_(2))and its refluxratio(R_(2))significantlyaffected the outcome,in addition to pressurized distillation column parameters.Acetone mass fraction was mainly influencedby predistillation column parameters and their interactions,with minimal relation to the pressurized distillation column.Operating costs were primarily affected by the refluxratio(R),withdrawal(D)of both columns,and their interactions.Optimization strategies involved increasing theoretical plates and reducing refluxratios compared to the initial plan,achieving energy-saving and consumption-reduction goals.The process required the pressurized distillation column‘s methanol mass fraction to exceed 99.80%,acetone mass fraction below 2×10^(-8),and formaldehyde mass fraction below 5×10^(-9),with a feed rate of 6100 kg·h^(-1).Plans A,B,and C achieved energy-savings of 29.80%,21.78%,and 25.50%respectively,while ensuring separation efficiencyand product quality.This research provides theoretical and practical guidance for optimizing the methanol distillation process,helping to reduce energy consumption and production costs,thereby enhancing corporate competitiveness.
基金financial supports from the National Natural Science Foundation of China-Youth Project(51801076)the Provincial Colleges and Universities Natural Science Research Project of Jiangsu Province(18KJB430009)+1 种基金the Postdoctoral Research Support Project of Jiangsu Province(1601055C)the Senior Talents Research Startup of Jiangsu University(14JDG126)。
文摘To solve the problems of deformation,micro-cracks,and residual tensile stress in laser cladding coatings,the technique of laser cladding with Fe-based memory alloy can be considered.However,the process of in-situ synthesis of Fe-based memory alloy coatings is extremely complex.At present,there is no clear guidance scheme for its preparation process,which limits its promotion and application to some extent.Therefore,in this study,response surface methodology(RSM)was used to model the response surface between the target values and the cladding process parameters.The NSGA-2 algorithm was employed to optimize the process parameters.The results indicate that the composite optimization method consisting of RSM and the NSGA-2 algorithm can establish a more accurate model,with an error of less than 4.5%between the predicted and actual values.Based on this established model,the optimal scheme for process parameters corresponding to different target results can be rapidly obtained.The prepared coating exhibits a uniform structure,with no defects such as pores,cracks,and deformation.The surface roughness and microhardness of the coating are enhanced,the shaping quality of the coating is effectively improved,and the electrochemical corrosion performance of the coating in 3.5%NaCl solution is obviously better than that of the substrate,providing an important guide for engineering applications.
基金Supported by Natural Science Foundation Project of Hubei Province(RZ2300001603)Open Fund of Key Laboratory of Biologic Resources Protection and Utilization of Hubei Province(Hubei Institute for Nationalities)(PT012017).
文摘[Objectives]This study was conducted to efficiently extract loganin from Viburnum erosum Thunb.[Methods]Ultrasound-assisted extraction coupled with response surface methodology was employed.The extraction was carried out with 60%methanol as the solvent and loganin extraction rate as the evaluation index.The effects of liquid-to-solid ratio,extraction temperature,and extraction time on loganin extraction rate were investigated through single-factor experiments.Subsequently,a Box-Behnken experimental design was implemented based on the single-factor results to optimize the extraction process.[Results]Under the conditions of liquid-to-solid ratio of 6 ml/g,extraction temperature of 39℃,and extraction time of 88 min,the loganin extraction rate was 4.199%,which agreed with the predicted value of 4.271%.The order of three factors affecting the extraction rate of loganin in V.erosum Thunb was liquid-to-solid ratio>extraction time>extraction temperature.The response surface methodology demonstrates high stability and feasibility for optimizing the extraction process,and the proposed protocol achieves efficient loganin extraction from V.erosum Thunb.[Conclusions]This study provides a novel approach for extracting iridoid glycosides from V.erosum Thunb.and expands the plant sources of loganin.
基金sponsored by National Key Research and Development Program of China(Grant No.2023YFC3504200)High Level Key Discipline Construction of Traditional Chinese Medicine Program(Grant No.zyyzdxk-2023272).
文摘Background:Polygonati cyrtonema Hua(PC)has many pharmacological effects such as immune regulation,hypoglycemic and lipid-lowering,anti-oxidation and anti-tumor.Oligosaccharide is one of the main active components of PC.At present,the research on Polygonatum cyrtonema oligosaccharides(PCOS)is not deep,and there is a lack of systematic research on the optimization of extraction process of pcos and the change of pcos and Polygonatum cyrtonema polysaccharide content before and after wine steaming.Methods:The optimum extraction process of oligosaccharides from PC was optimized,and the content of oligosaccharides before and after wine steaming of PC was investigated.The single factor experiment was carried out with the ratio of liquid to material,extraction temperature and extraction time as the investigation factors.The extraction process of PCOS was optimized by Box Behnken design-response surface methodology,and the changes of total oligosaccharides and total polysaccharides before and after wine steaming were studied.Results:The optimal extraction process for the PCOS was 32:1 mL/g,85℃,and 1.5 h.The total PCOS decreased slightly after steaming,but the percentage of the total sugar increased.Conclusion:The extraction process of PCOS optimized by response surface method is reasonable and feasible.The changes of total oligosaccharides and total polysaccharides during the steaming process of PC can reveal the processing mechanism of PC to a certain extent,and provide scientific basis and technical support for better in-depth excavation and development and utilization of PCOS.
基金supported by the Fundamental Research Funds for the Central Universities,China(No.104972025RSCrc0005)the Science and Technology Project of Shaanxi Yanchang Petroleum(Group)Co.,LTD,China(No.yc-whlg-2023ky-03)。
文摘The escalating production of industrial solid waste,combined with the dwindling availability of natural resources,has intensified the focus on waste recycling.However,the heterogeneity and complexity of waste pose significant challenges to determining process parameters.In this study,burnt coal cinder(BCC),granite powder(GP),and high-calcium fly ash(Class-C FA)were used as raw materials,and the response surface methodology(RSM)and single-factor experiments were applied to optimize the process parameters for geopolymer preparation.The optimized precursor powder composition was determined to be a mass ratio of 1.6:0.9:7.3 for BCC,GP,and Class-C FA.The NaOH-precursor powder ratio and liquid-solid ratio were adjusted to 0.084 and 0.222,respectively.The curing condition was set at 80℃ for 24 h.The resulting 28 d-aged multi-solid wastes-based geopolymer exhibited a high compressive strength of61.34 MPa.The microstructure,mineral phase,and atomic bonding of geopolymers were investigated using X-ray diffraction(XRD),thermal analysis(TA),Fourier transform infrared spectroscopy(FTIR),and scanning electron microscopy with energy dispersive spectroscopy(SEM-EDS).Findings indicate that the compressive strength of geopolymer is most significantly influenced by the Class-C FA,followed by BCC.Furthermore,a minor addition of GP can optimize the structural density of the geopolymer.The Ca present in the Class-C FA participates in the geopolymerization,forming a hybrid N-(C)-A-S-H gel.RSM optimization facilitates the synergistic utilization of multi-solid wastes,ensuring an even distribution of gel and filler.This research establishes a theoretical framework for optimizing the preparation parameters of multi-solid wastes-based geopolymer and its subsequent applications;it holds significant scientific implications for the circular economy,resource transformation,and environmental conservation.
基金Supported by Postgraduate Research Innovation Project of Shaoyang University(CX2023SY026)Natural Science Foundation of Hunan Province(2022JJ50232)Horizontal Scientific Research Project of Shaoyang University(2023HX43).
文摘[Objectives]This study was conducted to improve the poor water-holding capacity(WHC)and high syneresis rate of fermented soy milk by optimizing fermentation process conditions.[Methods]Based on the results of single factor experiments,response surface methodology was employed to optimize the fermentation temperature,fermentation time,and starter culture addition for enhancing WHC.The physicochemical properties of fermented soybean milk were analyzed.[Results]The optimal process parameters were determined as follows:fermentation temperature 36℃,fermentation time 8 h,and starter culture addition 5%.Under these conditions,WHC reached(77.18±0.08)%,which was consistent with the theoretical prediction value of(76.75±0.15)%.During fermentation,the pH decreased from(6.6±0.11)to(4.65±0.09),while acidity increased from(16.5±0.04)°T to(81.5±0.08)°T.The viable cell count rose from 1×10^(7)to 29×10^(7)cfu/ml,and WHC was improved significantly from(10.50±0.18)%to(77.40±0.13)%.[Conclusions]This study optimized the fermentation process parameters and revealed physicochemical characteristic changes during soybean milk fermentation,providing a theoretical foundation for industrial production.
基金Supported by the National Natural Science Foundation of China(32072352)。
文摘In order to improve the quality of 3D printed raspberry preserves after post-processing,microwave ovens combining infrared and microwave methods were utilized.The effects of infrared heating temperature,infrared heating time,microwave power,microwave heating time on the center temperature,moisture content,the chroma(C*),the total color difference(ΔE*),shape fidelity,hardness,and the total anthocyanin content of 3D printed raspberry preserves were analyzed by response surface method(RSM).The results showed that under combining with the two methods,infrared heating improved the fidelity and quality degradation of printed products,while microwave heating enhanced the efficiency of infrared heating.Infrared-microwave combination cooking could maintain relatively stable color appearance and shape of 3D printed raspberry preserves.The AHP–CRITIC hybrid weighting method combined with the response surface test to determine the comprehensive weights of the evaluation indicators optimized the process parameters,and the optimal process parameters were obtained:infrared heating temperature of 190℃,infrared heating time of 10 min and 30 s,microwave power of 300 W,and microwave heating time of 2 min and 6 s.The 3D printed raspberry cooking methods obtained under the optimal conditions seldom had color variation,porous structure,uniform texture,and high shape fidelity,which retained the characteristics of personalized manufacturing by 3D printing.This study could provide a reference for the postprocessing and quality control of 3D cooking methods.
基金Supported by the Science and Technology Project of Fujian Province(Nos.2023T3034,2020N3011)the Innovation Academy for Drug Discovery and DevelopmentChinese Academy of Sciences。
文摘Safety,high protein content,and the numerous health benefits make Spirulina an outstanding source of bioactive peptides.Peptides from Spirulina,which exhibit antioxidant,anti-inflammatory,and antihypertensive effects,may assist in the management of cardiovascular diseases(CVDs).Here,we present the optimization of enzyme-digested hydrolysates derived from Spirulina sp.by using response surface methodology(RSM).We also evaluated the biological activity of Spirulina protein hydrolysates(SPHs)in contributing to the amelioration of hypertension and associated cardiovascular diseases.Our findings suggest that Spirulina protein extracts contain a complex proteinaceous composition with phycocyanin being the dominant protein,as evidenced by both SDS-PAGE and LC-MS/MS profiling.Alkaline protease,protease K,andα-chymotrypsin exhibited a substantial hydrolytic effect on Spirulina protein,taking into account their degree of hydrolysis(DH),peptide yield,and molecular weight distribution.Single-factor experiments identified pH,temperature,and enzyme/substrate ratio as the key factors influencing DH.Moreover,optimal hydrolysis conditions for the proteases were determined via RSM,leading to a considerable enhancement of the actual DH.Bioassays showed that SPHs have strong antioxidant activity against various free radicals,with a higher ability to scavenge hydroxyl radicals.Furthermore,SPHs inhibited macrophage nitric oxide secretion and significantly inhibited angiotensin I-converting enzyme in vitro at 400μg/mL.It is worth noting that SPHs prepared with protease K exhibited a potent anti-hypertensive effect in vivo.The findings indicate the potential usefulness of including dietary SPHs in preventing hypertension and associated CVDs.This research could be valuable in guiding the development of health-promoting foods within the Spirulina industry.
基金The National Natural Science Foundation of China(No.51978504).
文摘Practical applications of desulfurization gypsum are limited owing to its brittleness and low strength.To overcome these challenges,researchers have developed engineered desulfurization gypsum composites(EDGCs)by incorporating ultrahigh molecular weight polyethylene(UHMWPE)fiber and sulfoaluminate cement(SAC).The mix ratio was optimized using response surface methodology(RSM).Experimental testing of EDGC under compressive and tensile loads led to the creation of a regression model that investigates the influence of variables and their interactions on the material’s compressive and tensile strengths.Additionally,microscopic morphology and hydration product composition were analyzed to explore the influence mechanism.The results indicated that EDGC’s compressive strength increased by up to 38.4%owing to a decreased water-binder ratio and higher SAC content.Similarly,tensile strength increased by up to 38.6%owing to increased SAC and fiber content.Moreover,EDGC demonstrated excellent strain-hardening behavior and multiple cracking characteristics,achieving a maximum tensile strain of nearly 3%.The research findings provide valuable insights for optimizing the performance of desulfurization gypsum.
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.
基金Projects (20866001, 21166003, 51164002) supported by the National Natural Science Foundation of ChinaProject (20114501110004)supported by the Ph.D. Programs Foundation of Ministry of Education of China
文摘The reduction roasting processes for low-grade pyrolusite using bagasse as the reducing agent was statistically analyzed. The central composite rotatable design （CCD） was used to optimize this reduction roasting processes. The three process parameters studied were the mass ratio of bagasse to ore, the roasting temperature and the roasting time. Analysis of variance （ANOVA） was used to analyze the experimental results. The interactions between the process parameters were done by using the linear and quadratic model. The results revealed that the linear and quadratic effects as well as the interaction are statistically significant for the mass ratio and roasting temperature but insignificant for the roasting time. The optimal conditions of 0.9：10 of mass ratio, the roasting temperature of 450 ~C, the roasting time of 30 min were obtained. Under these conditions, the predicted leaching recovery rate for manganese was 98.1%. And the satisfied experimental result of 98.2% confirmed the validity of the model.
基金Project (50734007) supported by the National Natural Science Foundation of ChinaProject (2007GA002) supported by Science and Technology Planning of Yunnan Province, ChinaProject (2008-16) supported by Analysis and Testing Foundation of Kunming University of Science and Technology, China
文摘Parameters of technique to prepare vanadium pentoxide by calcination from ammonium metavanadate were optimized using central composite design of response surface methodology. A quadratic equation model for decomposition rate was built and effects of main factors and their corresponding relationships were obtained. The results of the statistical analysis show that the decomposition rate of ammonium metavanadate is significantly affected by calcination temperature and calcination time. The optimized calcination conditions are as follows： calcination temperature 669.71 K, calcination time 35.9 min and sample mass 4.25 g. The decomposition rate of ammonium metavanadate is 99.71%,which coincides well with experimental value of 99.27% under the optimized conditions, suggesting that regressive equation fits the decomposition rates perfectly. XRD reveals that it is feasible to prepare the V2O5 by calcination from ammonium metavanadate using response surface methodology.
基金Project(51104073)supported by the National Natural Science Foundation of ChinaProject(2013AA064003)supported by the High-tech Research and Development Program of China+1 种基金Project(2014CB643404)supported by the National Basic Research Program of ChinaProject(2012HB008)supported by Yunnan Province Young Academic Technology Leader Reserve Talents,China
文摘Microwave was applied to roasting the zinc oxide fume obtained from fuming furnace for the removal of F and Cl. The effects of important parameters, such as roasting temperature, holding time and stirring speed, were investigated and the process conditions were optimized using response surface methodology (RSM). The results show that the effects of roasting temperature and holding time on the removal rate of F and Cl are the most significant, and the effect of stirring speed is the second. The defluorination rate reaches 92.6% while the dechlorination rate reaches 90.2%, under the process conditions of roasting temperature of 700 °C, holding time of 80 min and stirring speed of 120 r/min. The results indicate that the removal of F and Cl from fuming furnace production of zinc oxide fumes using microwave roasting process is feasible and reliable.
基金Supported by the Natural Science Foundation of Higher Education Institutions of Jiangsu Province(16KJA550001)~~
文摘[Objective] Ginger essential oil （GEO） is widely used in food production and medical field in recent years due to its prominent biological functions, and this study was conducted to obtain high-quality and high-purity ginger essential oil from the fresh ginger. [Method] GEO was extracted from ginger roots by supercritical fluid extraction （SFE） method. The effects of flow rate of CO2, mesh size of ginger powder and volume of entrainer were investigated by single-factor experiments and response surface method. The content and extraction rate of 6-gingerol represented the extraction index of GEO. [Result] The conditions were optimized as follows： flow rate of CO2 at 25 L/h, mesh size of ginger power of 80 mesh, and volume of anhydrous ethanol as entrainer of 92.46 ml. The optimal extraction rate of 6-gingerol was 3.21%, which was predicted by RSM. [Conclusion] The optimal process of supercritical carbon dioxide extraction of ginger essential oil was identified by singlefactor experiments and response surface method. The present study provides a satisfactory method for purifying GEO from ginger for industrial purpose.
文摘The uniform design and response surface methodology （RSM） are applied to the multi-objective optimization of a 2-D mixed compression scramjet inlet. The set of experimental design points on the design space is selected by the uniform design, and the inlet performance is analyzed by computational fluid dynamics （CFD）. Then complete quadratic polynomial response surface approximation models are constructed based on the performance analysis results and then used to replace theoriginal complex inlet performance model. The optimization is conducted using a multi-objective genetic algorithm NSGA-Ⅱ, and the Pareto optimal solution set is obtained. Results show that the uniform design and RSM can reduce the computational complexity of numerical simulation and improve the optimization efficiency.
