In order to optimize plastic viscosity of 18 mPa·s circulating micro-bubble drilling fluid formula,orthogonal and uniform experimental design methods were applied,and the plastic viscosities of 36 and 24 groups o...In order to optimize plastic viscosity of 18 mPa·s circulating micro-bubble drilling fluid formula,orthogonal and uniform experimental design methods were applied,and the plastic viscosities of 36 and 24 groups of agent were tested,respectively.It is found that these two experimental design methods show drawbacks,that is,the amount of agent is difficult to determine,and the results are not fully optimized.Therefore,multiple regression experimental method was used to design experimental formula.By randomly selecting arbitrary agent with the amount within the recommended range,17 groups of drilling fluid formula were designed,and the plastic viscosity of each experiment formula was measured.Set plastic viscosity as the objective function,through multiple regressions,then quadratic regression model is obtained,whose correlation coefficient meets the requirement.Set target values of plastic viscosity to be 18,20 and 22 mPa·s,respectively,with the trial method,5 drilling fluid formulas are obtained with accuracy of 0.000 3,0.000 1 and 0.000 3.Arbitrarily select target value of each of the two groups under the formula for experimental verification of drilling fluid,then the measurement errors between theoretical and tested plastic viscosity are less than 5%,confirming that regression model can be applied to optimizing the circulating of plastic-foam drilling fluid viscosity.In accordance with the precision of different formulations of drilling fluid for other constraints,the methods result in the optimization of the circulating micro-bubble drilling fluid parameters.展开更多
A design method based on tip to tail streamline tracing and osculating inward cone methods is discussed for designing the integrated Osculating Inward Cone Waverider Inlet（OICWI）. A practical geometrical constrained...A design method based on tip to tail streamline tracing and osculating inward cone methods is discussed for designing the integrated Osculating Inward Cone Waverider Inlet（OICWI）. A practical geometrical constrained experimental model of OICWI is designed based on the validated design method. It has a total contraction ratio of 4.61 and inner contraction ratio is 2.0. Wind-tunnel tests have been conducted for the OICWI model at free stream Mach number（Ma） of 4.0, 3.5 and 3.0 respectively. The experimental results show that the OICWI has high flow capture ratio and compression abilities. It can self-start at Ma= 3.5 and 4.0 and its flow capture ratio is 0.73 at Ma= 4.0, and Angle of Attack（AOA） 0°. The research results show that the OICWI has advantages of inward cone waverider and streamline tracing inlet. Present OICWI is a novel approach for waverider inlet integration studies and it will promote the use of waverider inlet integration configuration in the studies of airbreathing hypersonic vehicles.展开更多
A new ion-imprinted polymer （liP） was synthesized by copolymerization of 4-vinylpyridine （monomer）, ethyleneglycoldimethacrylate （cross-linker） and 2,2-azobis-isobutyronitrile （initiator） in the presence of Cd...A new ion-imprinted polymer （liP） was synthesized by copolymerization of 4-vinylpyridine （monomer）, ethyleneglycoldimethacrylate （cross-linker） and 2,2-azobis-isobutyronitrile （initiator） in the presence of Cd2＋ and quinaldic acid （complexing agent）. It was found that the adsorption capacity of IIP and blank polymer were 45.0 and 6.2 mg g-l, respectively. The relative selectivity coefficients of the imprinted polymer for different binary mixture were also calculated. Compared to non-imprinted polymer （NIP）, the IIP had higher selectivity for Cd（II）. The IIP was used as a sorbent for cadmium extraction from water samples by using a simple batch extraction procedure. The effect of different parameters on Cd2＋ extraction and its recovery from the IIP were evaluated and optimized by using experimental design methodology. The optimized adsorption/desorption procedure was applied for cadmium removal from the real water samples. The obtained recoveries proved that this IIP could be used for removal of trace cadmium ions from water samples.展开更多
The energy conversion efficiency of a multistage synchronous induction coilgun(MSSICG) has become one of the key factors that restricts its industrialization. To improve the launch efficiency of medium-and high-veloci...The energy conversion efficiency of a multistage synchronous induction coilgun(MSSICG) has become one of the key factors that restricts its industrialization. To improve the launch efficiency of medium-and high-velocity MSSICG,we propose an optimization design scheme combining orthogonal experimental design(OED) and self-consistent design method in this paper. The OED is introduced to reduce the number of iterations and improve the identification accuracy and efficiency. A self-consistent design model is established to overcome a defect that the parameters that need to be optimized will multiply as the number of coil stages increases. The influence of six factors(radial thickness of armature, axial length of armature, axial length of coil, capacitance, wire diameter, and slip speed) on the launch efficiency are then evaluated by range analysis. This work presents a valuable reference for optimizing medium-and high-velocity MSSICG.展开更多
The inverse heat conduction method is one of methods to identify the casting simulation parameters. A new inverse method was presented according to the Tikhonov regularization theory. One appropriate regularized funct...The inverse heat conduction method is one of methods to identify the casting simulation parameters. A new inverse method was presented according to the Tikhonov regularization theory. One appropriate regularized functional was established, and the functional was solved by the sensitivity coefficient and Newtonaphson iteration method. Moreover, the orthogonal experimental design was used to estimate the appropriate initial value and variation domain of each variable to decrease the number of iteration and improve the identification accuracy and efficiency. It illustrated a detailed case of AlSiTMg sand mold casting and the temperature measurement experiment was done. The physical properties of sand mold and the interracial heat transfer coefficient were identified at the meantime. The results indicated that the new regularization method was efficient in overcoming the ill-posedness of the inverse heat conduction problem and improving the stability and accuracy of the solutions.展开更多
Excitation parameter preferences are key factors a ecting the performance of magnetic frequency mixing detection.A uniform experimental design method was used to analyze this influence.Using fuzzy theory,a comprehensi...Excitation parameter preferences are key factors a ecting the performance of magnetic frequency mixing detection.A uniform experimental design method was used to analyze this influence.Using fuzzy theory,a comprehensive model is established for evaluating the e ect of magnetic frequency mixing.A polynomial is selected as the regression function to express explicitly the correlation between the excitation parameters and the frequency-mixing e ect.The excitation parameters were then optimized using genetic algorithm.Magnetic frequency mixing experiments were conducted to measure the surface hardness of some ferromagnetic materials.Frequency mixing is further enhanced under the optimal settings,resulting in an improvement in the measurement sensitivity.The results of this study support the application of the magnetic frequency mixing technique in non-destructive testing.展开更多
Quenching and partitioning(Q&P)which provides a balance between toughness and strength is a promising heat treatment in iron and steel industry.However,there are three parameters(quenching temperature,partitioning...Quenching and partitioning(Q&P)which provides a balance between toughness and strength is a promising heat treatment in iron and steel industry.However,there are three parameters(quenching temperature,partitioning temperature and partitioning time)which affect the properties dramatically.As a result,it remains a challenge to get the best parameters in a low-cost way for Q&P process.Here,the orthogonal experimental design combined with a local optimization was adopted to optimize the quenching and partitioning parameters of 65Si2MnWA steel.By using this method,the combination between strength and ductility was optimized;meanwhile,the number of experiments was reduced significantly.When treated by quenching at 180℃followed by partitioning at 330℃for 20 min,the steel reached the best combination between strength and ductility.In detail,the product of ultimate tensile strength and reduction in area was 1.36 times(from 64.9 to 88.8 GPa%)that treated by quenching and tempering.In addition,owing to the grain refinement,the strength and ductility increase simultaneously.Specifically,the reduction in area increased by 27.4%(from 35.8%to 45.6%)coupled with a little improvement in ultimate tensile strength(7.4%).展开更多
The current study was to understand how process variables of high shear wet granulations affect physical properties of granules and tablets. The knowledge gained was intended to be used for Quality-by-Design based pro...The current study was to understand how process variables of high shear wet granulations affect physical properties of granules and tablets. The knowledge gained was intended to be used for Quality-by-Design based process design and optimization. The variables were selected based on the risk assessment as impeller speed, liquid addition rate, and wet massing time. Formulation compositions were kept constant to minimize their influence on granules properties. Multiple linear regression models were built providing understanding of the impact of each variable on granule hardness, Carr’s index, tablet tensile strength, surface mean diameter of granules, and compression behavior. The experimental results showed that the impact of impeller speed was more dominant compared to wet massing time and water addition rate. The results also revealed that quality of granules and tablets could be optimized by adjusting specific process variables(impeller speed 1193 rpm, water spray rate 3.7 ml/min, and wet massing time 2.84 min). Overall desirability was 0.84 suggesting that the response values were closer to the target one. The SEM image of granules showed that spherical and smooth granules produced at higher impeller speed, whereas rough and irregular shape granules at lower speed. Moreover, multivariate data analysis demonstrated that impeller speed and massing time had strong correlation with the granule and tablet properties. In overall, the combined experimental design and principal component analysis approach allowed to better understand the correlation between process variables and granules and tablet attributes.展开更多
The catalytic performance of Mo supported on hierarchical alumina–silica(Si/Al = 15) with Mo loadings of 3, 6 and 15 wt% was investigated for the oxidative desulfurization(ODS) of model and real oil samples. Hierarch...The catalytic performance of Mo supported on hierarchical alumina–silica(Si/Al = 15) with Mo loadings of 3, 6 and 15 wt% was investigated for the oxidative desulfurization(ODS) of model and real oil samples. Hierarchical alumina–silica(h Al–Si) was synthesized by economical and ecofriendly silicate-1 seed-induced route using cetyltrimethylammonium bromide(CTAB) as mesoporogen. The effect of CTAB on the structure of catalyst was studied by characterization techniques. The results revealed that 6%Mo/h Al–Si had the highest sulfur removal compared to the other catalyst loadings. The effect of operating parameters was evaluated using Box–Behnken experimental design. The optimal desulfurization conditions with the 6%Mo/h Al–Si catalyst were determined at oxidation temperature of 67 ℃, oxidation time of 42 min, H2O2/S molar ratio of 8 and catalyst dosage of 0.008 g·ml^-1 for achieving a conversion of 95%. Under optimal conditions, different sulfur-containing compounds with initial concentration of 1000 ppm, Dibenzothiophene(DBT), Benzothiophene(BT) and Thiophen(Th), showed the catalytic oxidation reactivity in the order of DBT > BT>Th. According to the regeneration experiments, the 6%Mo/h Al–Si catalyst was reused 4 times with a little reduction in the performance. Also, the total sulfur content of gasoline and diesel after ODS process reached 156.6 and 4592.2 ppm, respectively.展开更多
The aim of the present investigation was to model the experimental conditions of tin bronze patination using full factorial experimental design. In this sense, a full factorial design approach was developed to model t...The aim of the present investigation was to model the experimental conditions of tin bronze patination using full factorial experimental design. In this sense, a full factorial design approach was developed to model the corrosion behavior of patinated tin bronze alloy in sulfate electrolyte. Three experimental factors (the immersion time in the chloride electrolyte, the potential limit for the anodic sweep Elim, and the potential scan rate) were chosen to identify the significant factor on the patina growth process at the bronze substrate. The experimental responses were the kinetic parameters extracted from the electro-chemical spectra (EIS) for eight different experiments. An equivalent electrical circuit containing an electrolyte resistance (Re), a double layer capacitance (CPEdl), a charge transfer resistance (Rt) and Gerischer element (G), was developed to model the patinated bronze corrosion process. The electro-chemical spectra (EIS) show that the corrosion process of the patinated bronze alloy occurred from a chemical reaction is followed by an electrochemical one. Analysis of the experimental responses showed that while the scan rate is the most influent factor for the corrosion potential (Ecorr), the electrolyte resistance (Re), and the double layer capacitance CPEdl variation, the potential limit is the significant factor for charge transfer resistance Rt, reciprocal of the admittance parameter Y0 and the effective transfer rate of the chemical reaction k variation.展开更多
Experimental design was applied in the optimization of crude oil adsorption from saline waste water using raw bagasse.The application of response surface methodology(RSM) was presented with temperature,salinity of wat...Experimental design was applied in the optimization of crude oil adsorption from saline waste water using raw bagasse.The application of response surface methodology(RSM) was presented with temperature,salinity of water,pH,adsorbent dose,and initial oil content as factors.A quadratic model could be used to approximate the mathematical relationship of crude oil removal on the five significant independent variables.Predicted values and experimental values are found to be in good agreement with R2 of 97.44%.The result of optimization shows that the maximum crude oil removal is equal to 67.38% under the optimal condition of temperature of 46.53 °C,salinity of 37.2 g/L,pH of 3,adsorbent dose of 9 g/L and initial oil content of 300×10-6.展开更多
As one of the main load-carrying components of cable-stayed bridges,bridge towers are typically required to remain elastic even when subjected to severe ground motions with a 2%-3%probability of exceedance in 50 years...As one of the main load-carrying components of cable-stayed bridges,bridge towers are typically required to remain elastic even when subjected to severe ground motions with a 2%-3%probability of exceedance in 50 years.To fulfill this special requirement imposed by current seismic design codes,reinforcement ratios in the bridge towers have to be kept significantly higher than if limited ductility behavior of the tower is allowed.In addition,since the foundation capacity is closely related to the moment and shear capacities of the bridge tower,a large increase in bridge construction cost for elastically designed cable-stayed bridge is inevitable.To further investigate the possibility of limited ductility bridge tower design strategies,a new 1/20-scale cable-stayed bridge model with H-shaped bridge towers designed according to strong strut-weak tower column design was tested.The shake table experimental results are compared with a previous strong tower column-weak strut designed full bridge model.A comparison of the results show that ductility design with plastic hinges located on tower columns,i.e.,strong strut-weak tower column design,is another effective seismic design strategy that results in only small residual displacement at the top of the tower column,even under very severe earthquake excitations.展开更多
Iterated local search(ILS)is used to construct the optimal experimental designs for multi-dimensional constrained spaces,in which the inner loop is based on the stochastic coordinate-exchange(SCE)algorithm.Every time ...Iterated local search(ILS)is used to construct the optimal experimental designs for multi-dimensional constrained spaces,in which the inner loop is based on the stochastic coordinate-exchange(SCE)algorithm.Every time a local optimal solution is found by the SCE algorithm,the perturbation operator is applied to it,and then a new solution is explored in the areas where the exchange of coordinates may produce improvement,so as to retain the features and attributes of the current optimal solution and avoid the defects of random restart.We implement the iterated local coordinate-exchange algorithm for experimental designs in the multi-dimensional constrained spaces.In addition,sensitivity analysis was conducted to analyze the impacts of the parameters on the performance of the proposed algorithm.Also we compared the performance of the proposed algorithm to the SCE algorithm using the random restart strategy.The analysis shows that the proposed algorithm is better than the SCE algorithm in terms of efficiency and quality,especially in the experimental designs for high-dimensional constrained space.展开更多
A large model of the screen was mounted in the laboratory for studying its modal performance. The model is suspended with steel ropes. Modal test was carried out with artificially exciting by 500 g impacting hammer an...A large model of the screen was mounted in the laboratory for studying its modal performance. The model is suspended with steel ropes. Modal test was carried out with artificially exciting by 500 g impacting hammer and 100 kg exciting force shaker respectively. Synthesis and correction of the modal parameters are obtained from both testing methods. Design faults of vibrating screen were determined based on the analy-sis and dynamic correction of structure approaches about the screen was put forward finally.展开更多
A spice formulation study in Burkina Faso was carried out using local ingredients for the benefit of households. The objective of this study was to propose some spice formulations based on local ingredients in order t...A spice formulation study in Burkina Faso was carried out using local ingredients for the benefit of households. The objective of this study was to propose some spice formulations based on local ingredients in order to reduce the use of chemical spices in the preparation of different dishes. The Design of Experiments (DOE) methodology was used for the formulation of the spices and their physicochemical, nutritional and sensory characteristics were evaluated by standardized and standard methods. The results obtained showed lipid contents (g/100 g DM) ranging from 10.41 ± 0.26 to 15.64 ± 0.68, total sugars from 4.39 ± 0.32 to 5.46 ± 0.31, protein from 3.65 ± 0.17 to 12.04 ± 0.35 and ash from 5.83 ± 0.01 to 7.02 ± 0.01. The polyphenol content ranged from 9.09 ± 1.60 to 11.33 ± 0.90, and the flavonoid content ranged from 0.65 ± 0.03 to 1.08 ± 0.13. The sensory analysis carried out showed that the spices have generally satisfactory organoleptic characteristics. These results constitute new information in the diet of populations and are an alternative to the chemical spices used in their cooking.展开更多
Materials that are difficult to cut,such as titanium alloys,are widely used in large load-bearing integral components of aircraft,leading to great challenges for manufacturing.Electrochemical milling is a way for mach...Materials that are difficult to cut,such as titanium alloys,are widely used in large load-bearing integral components of aircraft,leading to great challenges for manufacturing.Electrochemical milling is a way for machining difficult-to-cut materials through Computer Numerical Control(CNC)trajectory motion.Using a tilted large cathode machining surface and the cut-in feed mode,an efficient and low-cost method is obtained for machining the large integral components.A novel crossed and inclined structure of the flow mode is designed to realize electrochemical milling with a large tilted cathode surface.Compared to the vertical flow mode with one inlet,the proposed flow mode has two inlets that independently supply electrolytes,and the inclined channels make the flow field more stable.Flow field simulations are performed for both the vertical and proposed flow modes.The results show that the proposed flow mode avoids the random diversion of electrolytes and the ultralow flow velocity at both ends of the nozzle area,improving the velocity,uniformity,and stability of the electrolytes.The inclination angle of the crossed and inclined flow field is optimized.Finally,limit feed rate experiments are conducted in two modes,and the limit feed rate is 70 mm/min in the proposed mode.A sector workpiece of a large circular surface with approximately 8.77 mm thickness is machined 9 times by the cut-in electrochemical milling,the material removal rate is 4872 mm^(3)/min,and the surface roughness is superior to 1.15μm.展开更多
Method validation presents a detailed investigation of analytical method and provision of the evidence that the method, when correctly applied, produces results that fit to the purpose. In order to achieve the method ...Method validation presents a detailed investigation of analytical method and provision of the evidence that the method, when correctly applied, produces results that fit to the purpose. In order to achieve the method validation scope efficiently, experimental design presents a very useful tool. The greatest benefits of such approach could be seen in robustness testing through the provision of very useful data about the control of the chromatograp6hic system during the routine application. In this paper, robustness testing of the LC method proposed for the determination of raloxifene hydrochloride and its four impurities was done employing Plackett-Burman design. Applying this design, the effect of five real factors （acetonitrile content, sodium dodecyl sulfate content, column temperature, pH of the mobile phase and flow rate） on the corresponding resolution factors was investigated through twelve experiments. Furthermore, the insignificance intervals for significant factors were calculated and the parameters for system suitability tests were defined. Eventually, the other validation parameters were tested and the effectiveness of the proposed analytical method with a high degree of accuracy was confirmed.展开更多
Different Ziegler-Natta catalysts were employed to polymerize ethylene. To investigate the influences of reaction parameters, namely Al/Ti molar ratio, hydrogen and processing parameters, i.e. ethylene pressure and te...Different Ziegler-Natta catalysts were employed to polymerize ethylene. To investigate the influences of reaction parameters, namely Al/Ti molar ratio, hydrogen and processing parameters, i.e. ethylene pressure and temperature, a Taguchi experimental design was worked out. An L27 orthogonal array was chosen to take the above-mentioned parameters and relevant interactions into account. Response surface method was the tool used to analyze the experimental design results. Al/Ti, ethylene pressure and temperature were selected as experimental design factors, and catalyst activity and polymerization yield were the response parameters. Increasing pressure, due to an increment in monomer accessibility, and rising Al/Ti, because of higher reduction in the catalysts, cause an increase in both polymerization yield and catalyst activity. Nonetheless, a higher temperature, thanks to reducing ethylene solubility in the slurry medium and partially catalyst destruction, lead to a reduction in both response parameters. A synergistic effect was also observed between temperature and pressure. All catalyst activities will reduce in the presence of hydrogen. Molecular weight also shows a decline in the presence of hydrogen as a transfer agent. However, the polydispersity index remains approximately intact. Using SEM, various morphologies, owing to different catalyst morphologies, were seen for the polyethylene.展开更多
For mistakes taken in pesticide bioassays, teaching experimental design is improved in the paper, so as to let students explore and analyze in teaching experiments to get a deeper understanding of theoretical knowledg...For mistakes taken in pesticide bioassays, teaching experimental design is improved in the paper, so as to let students explore and analyze in teaching experiments to get a deeper understanding of theoretical knowledge, thereby effectively avoiding frequently-taken mistakes in pesticide bioassays.展开更多
New HPLC method was developed for determination of amlodipine and valsartan in their binary mixture as a part of routine control of combined formulations. The method was validated to meet official requirements includi...New HPLC method was developed for determination of amlodipine and valsartan in their binary mixture as a part of routine control of combined formulations. The method was validated to meet official requirements including selectivity, stability, linearity, precision and accuracy. Chromatography was carried out using a LiChrospher RP-18 column, a mixture containing acetonitrile, phosphate buffer of pH 3.5 and methanol (45:45:10, v/v/v) and new fluorescence detection at 255 nm for excitation and 448 nm for emission. The effect of methanol content, pH of the buffer, flow rate, detection wavelengths and column temperature was estimated in robustness study, according to a plan defined by the Plackett-Burman design. For identification of significant effects, both graphical and statistical methods were used. Ro-bustness for dissolution test was checked estimating the effects of paddle speed, temperature and pH of dissolution medium. The method was proved to complying with all official guidelines. Therefore, it is suitable for determination of amlodipine and valsartan in their binary mixtures for different analytical and pharmaceutical purposes.展开更多
基金Project(50304010) supported by the National Natural Science Foundation of China
文摘In order to optimize plastic viscosity of 18 mPa·s circulating micro-bubble drilling fluid formula,orthogonal and uniform experimental design methods were applied,and the plastic viscosities of 36 and 24 groups of agent were tested,respectively.It is found that these two experimental design methods show drawbacks,that is,the amount of agent is difficult to determine,and the results are not fully optimized.Therefore,multiple regression experimental method was used to design experimental formula.By randomly selecting arbitrary agent with the amount within the recommended range,17 groups of drilling fluid formula were designed,and the plastic viscosity of each experiment formula was measured.Set plastic viscosity as the objective function,through multiple regressions,then quadratic regression model is obtained,whose correlation coefficient meets the requirement.Set target values of plastic viscosity to be 18,20 and 22 mPa·s,respectively,with the trial method,5 drilling fluid formulas are obtained with accuracy of 0.000 3,0.000 1 and 0.000 3.Arbitrarily select target value of each of the two groups under the formula for experimental verification of drilling fluid,then the measurement errors between theoretical and tested plastic viscosity are less than 5%,confirming that regression model can be applied to optimizing the circulating of plastic-foam drilling fluid viscosity.In accordance with the precision of different formulations of drilling fluid for other constraints,the methods result in the optimization of the circulating micro-bubble drilling fluid parameters.
基金supported by the National Natural Science Foundation of China (Nos. 51376192 and 91216303)
文摘A design method based on tip to tail streamline tracing and osculating inward cone methods is discussed for designing the integrated Osculating Inward Cone Waverider Inlet（OICWI）. A practical geometrical constrained experimental model of OICWI is designed based on the validated design method. It has a total contraction ratio of 4.61 and inner contraction ratio is 2.0. Wind-tunnel tests have been conducted for the OICWI model at free stream Mach number（Ma） of 4.0, 3.5 and 3.0 respectively. The experimental results show that the OICWI has high flow capture ratio and compression abilities. It can self-start at Ma= 3.5 and 4.0 and its flow capture ratio is 0.73 at Ma= 4.0, and Angle of Attack（AOA） 0°. The research results show that the OICWI has advantages of inward cone waverider and streamline tracing inlet. Present OICWI is a novel approach for waverider inlet integration studies and it will promote the use of waverider inlet integration configuration in the studies of airbreathing hypersonic vehicles.
文摘A new ion-imprinted polymer （liP） was synthesized by copolymerization of 4-vinylpyridine （monomer）, ethyleneglycoldimethacrylate （cross-linker） and 2,2-azobis-isobutyronitrile （initiator） in the presence of Cd2＋ and quinaldic acid （complexing agent）. It was found that the adsorption capacity of IIP and blank polymer were 45.0 and 6.2 mg g-l, respectively. The relative selectivity coefficients of the imprinted polymer for different binary mixture were also calculated. Compared to non-imprinted polymer （NIP）, the IIP had higher selectivity for Cd（II）. The IIP was used as a sorbent for cadmium extraction from water samples by using a simple batch extraction procedure. The effect of different parameters on Cd2＋ extraction and its recovery from the IIP were evaluated and optimized by using experimental design methodology. The optimized adsorption/desorption procedure was applied for cadmium removal from the real water samples. The obtained recoveries proved that this IIP could be used for removal of trace cadmium ions from water samples.
基金Project supported by the National Natural Science Foundation of China(Grant No.5140130)
文摘The energy conversion efficiency of a multistage synchronous induction coilgun(MSSICG) has become one of the key factors that restricts its industrialization. To improve the launch efficiency of medium-and high-velocity MSSICG,we propose an optimization design scheme combining orthogonal experimental design(OED) and self-consistent design method in this paper. The OED is introduced to reduce the number of iterations and improve the identification accuracy and efficiency. A self-consistent design model is established to overcome a defect that the parameters that need to be optimized will multiply as the number of coil stages increases. The influence of six factors(radial thickness of armature, axial length of armature, axial length of coil, capacitance, wire diameter, and slip speed) on the launch efficiency are then evaluated by range analysis. This work presents a valuable reference for optimizing medium-and high-velocity MSSICG.
文摘The inverse heat conduction method is one of methods to identify the casting simulation parameters. A new inverse method was presented according to the Tikhonov regularization theory. One appropriate regularized functional was established, and the functional was solved by the sensitivity coefficient and Newtonaphson iteration method. Moreover, the orthogonal experimental design was used to estimate the appropriate initial value and variation domain of each variable to decrease the number of iteration and improve the identification accuracy and efficiency. It illustrated a detailed case of AlSiTMg sand mold casting and the temperature measurement experiment was done. The physical properties of sand mold and the interracial heat transfer coefficient were identified at the meantime. The results indicated that the new regularization method was efficient in overcoming the ill-posedness of the inverse heat conduction problem and improving the stability and accuracy of the solutions.
基金Supported by National Key Research and Development Program of China(Grant No.2017YFF0209703)National Natural Science Foundation of China(Grant Nos.11972053,11527801).
文摘Excitation parameter preferences are key factors a ecting the performance of magnetic frequency mixing detection.A uniform experimental design method was used to analyze this influence.Using fuzzy theory,a comprehensive model is established for evaluating the e ect of magnetic frequency mixing.A polynomial is selected as the regression function to express explicitly the correlation between the excitation parameters and the frequency-mixing e ect.The excitation parameters were then optimized using genetic algorithm.Magnetic frequency mixing experiments were conducted to measure the surface hardness of some ferromagnetic materials.Frequency mixing is further enhanced under the optimal settings,resulting in an improvement in the measurement sensitivity.The results of this study support the application of the magnetic frequency mixing technique in non-destructive testing.
基金This work was supported by the National Natural Science Foundation of China(Grant No.51401099).The authors would like to acknowledge Yi Zhou,Rui-yang Li,Zhi-xuan Chen and Lian-bo Luo for useful advice and discussion.
文摘Quenching and partitioning(Q&P)which provides a balance between toughness and strength is a promising heat treatment in iron and steel industry.However,there are three parameters(quenching temperature,partitioning temperature and partitioning time)which affect the properties dramatically.As a result,it remains a challenge to get the best parameters in a low-cost way for Q&P process.Here,the orthogonal experimental design combined with a local optimization was adopted to optimize the quenching and partitioning parameters of 65Si2MnWA steel.By using this method,the combination between strength and ductility was optimized;meanwhile,the number of experiments was reduced significantly.When treated by quenching at 180℃followed by partitioning at 330℃for 20 min,the steel reached the best combination between strength and ductility.In detail,the product of ultimate tensile strength and reduction in area was 1.36 times(from 64.9 to 88.8 GPa%)that treated by quenching and tempering.In addition,owing to the grain refinement,the strength and ductility increase simultaneously.Specifically,the reduction in area increased by 27.4%(from 35.8%to 45.6%)coupled with a little improvement in ultimate tensile strength(7.4%).
基金supported by the National Research Foun-dation of Korea(NRF)grant,funded by the Korean govern-ment(MSIT)(2015R1A1A1A05000942)the National Re-search Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(NRF-2018R1A5A2023127)
文摘The current study was to understand how process variables of high shear wet granulations affect physical properties of granules and tablets. The knowledge gained was intended to be used for Quality-by-Design based process design and optimization. The variables were selected based on the risk assessment as impeller speed, liquid addition rate, and wet massing time. Formulation compositions were kept constant to minimize their influence on granules properties. Multiple linear regression models were built providing understanding of the impact of each variable on granule hardness, Carr’s index, tablet tensile strength, surface mean diameter of granules, and compression behavior. The experimental results showed that the impact of impeller speed was more dominant compared to wet massing time and water addition rate. The results also revealed that quality of granules and tablets could be optimized by adjusting specific process variables(impeller speed 1193 rpm, water spray rate 3.7 ml/min, and wet massing time 2.84 min). Overall desirability was 0.84 suggesting that the response values were closer to the target one. The SEM image of granules showed that spherical and smooth granules produced at higher impeller speed, whereas rough and irregular shape granules at lower speed. Moreover, multivariate data analysis demonstrated that impeller speed and massing time had strong correlation with the granule and tablet properties. In overall, the combined experimental design and principal component analysis approach allowed to better understand the correlation between process variables and granules and tablet attributes.
文摘The catalytic performance of Mo supported on hierarchical alumina–silica(Si/Al = 15) with Mo loadings of 3, 6 and 15 wt% was investigated for the oxidative desulfurization(ODS) of model and real oil samples. Hierarchical alumina–silica(h Al–Si) was synthesized by economical and ecofriendly silicate-1 seed-induced route using cetyltrimethylammonium bromide(CTAB) as mesoporogen. The effect of CTAB on the structure of catalyst was studied by characterization techniques. The results revealed that 6%Mo/h Al–Si had the highest sulfur removal compared to the other catalyst loadings. The effect of operating parameters was evaluated using Box–Behnken experimental design. The optimal desulfurization conditions with the 6%Mo/h Al–Si catalyst were determined at oxidation temperature of 67 ℃, oxidation time of 42 min, H2O2/S molar ratio of 8 and catalyst dosage of 0.008 g·ml^-1 for achieving a conversion of 95%. Under optimal conditions, different sulfur-containing compounds with initial concentration of 1000 ppm, Dibenzothiophene(DBT), Benzothiophene(BT) and Thiophen(Th), showed the catalytic oxidation reactivity in the order of DBT > BT>Th. According to the regeneration experiments, the 6%Mo/h Al–Si catalyst was reused 4 times with a little reduction in the performance. Also, the total sulfur content of gasoline and diesel after ODS process reached 156.6 and 4592.2 ppm, respectively.
文摘The aim of the present investigation was to model the experimental conditions of tin bronze patination using full factorial experimental design. In this sense, a full factorial design approach was developed to model the corrosion behavior of patinated tin bronze alloy in sulfate electrolyte. Three experimental factors (the immersion time in the chloride electrolyte, the potential limit for the anodic sweep Elim, and the potential scan rate) were chosen to identify the significant factor on the patina growth process at the bronze substrate. The experimental responses were the kinetic parameters extracted from the electro-chemical spectra (EIS) for eight different experiments. An equivalent electrical circuit containing an electrolyte resistance (Re), a double layer capacitance (CPEdl), a charge transfer resistance (Rt) and Gerischer element (G), was developed to model the patinated bronze corrosion process. The electro-chemical spectra (EIS) show that the corrosion process of the patinated bronze alloy occurred from a chemical reaction is followed by an electrochemical one. Analysis of the experimental responses showed that while the scan rate is the most influent factor for the corrosion potential (Ecorr), the electrolyte resistance (Re), and the double layer capacitance CPEdl variation, the potential limit is the significant factor for charge transfer resistance Rt, reciprocal of the admittance parameter Y0 and the effective transfer rate of the chemical reaction k variation.
文摘Experimental design was applied in the optimization of crude oil adsorption from saline waste water using raw bagasse.The application of response surface methodology(RSM) was presented with temperature,salinity of water,pH,adsorbent dose,and initial oil content as factors.A quadratic model could be used to approximate the mathematical relationship of crude oil removal on the five significant independent variables.Predicted values and experimental values are found to be in good agreement with R2 of 97.44%.The result of optimization shows that the maximum crude oil removal is equal to 67.38% under the optimal condition of temperature of 46.53 °C,salinity of 37.2 g/L,pH of 3,adsorbent dose of 9 g/L and initial oil content of 300×10-6.
基金National Key Research and Development Plan,China under Grant No.2017YFC1500702the National Natural Science Foundation of China under Grant No.51478338。
文摘As one of the main load-carrying components of cable-stayed bridges,bridge towers are typically required to remain elastic even when subjected to severe ground motions with a 2%-3%probability of exceedance in 50 years.To fulfill this special requirement imposed by current seismic design codes,reinforcement ratios in the bridge towers have to be kept significantly higher than if limited ductility behavior of the tower is allowed.In addition,since the foundation capacity is closely related to the moment and shear capacities of the bridge tower,a large increase in bridge construction cost for elastically designed cable-stayed bridge is inevitable.To further investigate the possibility of limited ductility bridge tower design strategies,a new 1/20-scale cable-stayed bridge model with H-shaped bridge towers designed according to strong strut-weak tower column design was tested.The shake table experimental results are compared with a previous strong tower column-weak strut designed full bridge model.A comparison of the results show that ductility design with plastic hinges located on tower columns,i.e.,strong strut-weak tower column design,is another effective seismic design strategy that results in only small residual displacement at the top of the tower column,even under very severe earthquake excitations.
基金This work was supported by the National Natural Science Foundation of China(72171231).
文摘Iterated local search(ILS)is used to construct the optimal experimental designs for multi-dimensional constrained spaces,in which the inner loop is based on the stochastic coordinate-exchange(SCE)algorithm.Every time a local optimal solution is found by the SCE algorithm,the perturbation operator is applied to it,and then a new solution is explored in the areas where the exchange of coordinates may produce improvement,so as to retain the features and attributes of the current optimal solution and avoid the defects of random restart.We implement the iterated local coordinate-exchange algorithm for experimental designs in the multi-dimensional constrained spaces.In addition,sensitivity analysis was conducted to analyze the impacts of the parameters on the performance of the proposed algorithm.Also we compared the performance of the proposed algorithm to the SCE algorithm using the random restart strategy.The analysis shows that the proposed algorithm is better than the SCE algorithm in terms of efficiency and quality,especially in the experimental designs for high-dimensional constrained space.
基金Supported by Provincial Natural Science Foundation of Shanxi(20031046)
文摘A large model of the screen was mounted in the laboratory for studying its modal performance. The model is suspended with steel ropes. Modal test was carried out with artificially exciting by 500 g impacting hammer and 100 kg exciting force shaker respectively. Synthesis and correction of the modal parameters are obtained from both testing methods. Design faults of vibrating screen were determined based on the analy-sis and dynamic correction of structure approaches about the screen was put forward finally.
文摘A spice formulation study in Burkina Faso was carried out using local ingredients for the benefit of households. The objective of this study was to propose some spice formulations based on local ingredients in order to reduce the use of chemical spices in the preparation of different dishes. The Design of Experiments (DOE) methodology was used for the formulation of the spices and their physicochemical, nutritional and sensory characteristics were evaluated by standardized and standard methods. The results obtained showed lipid contents (g/100 g DM) ranging from 10.41 ± 0.26 to 15.64 ± 0.68, total sugars from 4.39 ± 0.32 to 5.46 ± 0.31, protein from 3.65 ± 0.17 to 12.04 ± 0.35 and ash from 5.83 ± 0.01 to 7.02 ± 0.01. The polyphenol content ranged from 9.09 ± 1.60 to 11.33 ± 0.90, and the flavonoid content ranged from 0.65 ± 0.03 to 1.08 ± 0.13. The sensory analysis carried out showed that the spices have generally satisfactory organoleptic characteristics. These results constitute new information in the diet of populations and are an alternative to the chemical spices used in their cooking.
基金co-supported by National Natural Science Foundation of China(No.52075253)National Natural Science Foundation of China for Creative Research Groups(No.51921003).
文摘Materials that are difficult to cut,such as titanium alloys,are widely used in large load-bearing integral components of aircraft,leading to great challenges for manufacturing.Electrochemical milling is a way for machining difficult-to-cut materials through Computer Numerical Control(CNC)trajectory motion.Using a tilted large cathode machining surface and the cut-in feed mode,an efficient and low-cost method is obtained for machining the large integral components.A novel crossed and inclined structure of the flow mode is designed to realize electrochemical milling with a large tilted cathode surface.Compared to the vertical flow mode with one inlet,the proposed flow mode has two inlets that independently supply electrolytes,and the inclined channels make the flow field more stable.Flow field simulations are performed for both the vertical and proposed flow modes.The results show that the proposed flow mode avoids the random diversion of electrolytes and the ultralow flow velocity at both ends of the nozzle area,improving the velocity,uniformity,and stability of the electrolytes.The inclination angle of the crossed and inclined flow field is optimized.Finally,limit feed rate experiments are conducted in two modes,and the limit feed rate is 70 mm/min in the proposed mode.A sector workpiece of a large circular surface with approximately 8.77 mm thickness is machined 9 times by the cut-in electrochemical milling,the material removal rate is 4872 mm^(3)/min,and the surface roughness is superior to 1.15μm.
基金the Ministry of Education and Science ofthe Republic of Serbia for supporting these investigations through the Project 172052
文摘Method validation presents a detailed investigation of analytical method and provision of the evidence that the method, when correctly applied, produces results that fit to the purpose. In order to achieve the method validation scope efficiently, experimental design presents a very useful tool. The greatest benefits of such approach could be seen in robustness testing through the provision of very useful data about the control of the chromatograp6hic system during the routine application. In this paper, robustness testing of the LC method proposed for the determination of raloxifene hydrochloride and its four impurities was done employing Plackett-Burman design. Applying this design, the effect of five real factors （acetonitrile content, sodium dodecyl sulfate content, column temperature, pH of the mobile phase and flow rate） on the corresponding resolution factors was investigated through twelve experiments. Furthermore, the insignificance intervals for significant factors were calculated and the parameters for system suitability tests were defined. Eventually, the other validation parameters were tested and the effectiveness of the proposed analytical method with a high degree of accuracy was confirmed.
文摘Different Ziegler-Natta catalysts were employed to polymerize ethylene. To investigate the influences of reaction parameters, namely Al/Ti molar ratio, hydrogen and processing parameters, i.e. ethylene pressure and temperature, a Taguchi experimental design was worked out. An L27 orthogonal array was chosen to take the above-mentioned parameters and relevant interactions into account. Response surface method was the tool used to analyze the experimental design results. Al/Ti, ethylene pressure and temperature were selected as experimental design factors, and catalyst activity and polymerization yield were the response parameters. Increasing pressure, due to an increment in monomer accessibility, and rising Al/Ti, because of higher reduction in the catalysts, cause an increase in both polymerization yield and catalyst activity. Nonetheless, a higher temperature, thanks to reducing ethylene solubility in the slurry medium and partially catalyst destruction, lead to a reduction in both response parameters. A synergistic effect was also observed between temperature and pressure. All catalyst activities will reduce in the presence of hydrogen. Molecular weight also shows a decline in the presence of hydrogen as a transfer agent. However, the polydispersity index remains approximately intact. Using SEM, various morphologies, owing to different catalyst morphologies, were seen for the polyethylene.
基金Supported by Construction Project of " National Teaching Team of Plant Protection" in 2008Construction Project of National " Plant Protection Specialty"( TS11138)Provincial Excellent Course Construction Project of Pesticide Science in Yunnan Province
文摘For mistakes taken in pesticide bioassays, teaching experimental design is improved in the paper, so as to let students explore and analyze in teaching experiments to get a deeper understanding of theoretical knowledge, thereby effectively avoiding frequently-taken mistakes in pesticide bioassays.
文摘New HPLC method was developed for determination of amlodipine and valsartan in their binary mixture as a part of routine control of combined formulations. The method was validated to meet official requirements including selectivity, stability, linearity, precision and accuracy. Chromatography was carried out using a LiChrospher RP-18 column, a mixture containing acetonitrile, phosphate buffer of pH 3.5 and methanol (45:45:10, v/v/v) and new fluorescence detection at 255 nm for excitation and 448 nm for emission. The effect of methanol content, pH of the buffer, flow rate, detection wavelengths and column temperature was estimated in robustness study, according to a plan defined by the Plackett-Burman design. For identification of significant effects, both graphical and statistical methods were used. Ro-bustness for dissolution test was checked estimating the effects of paddle speed, temperature and pH of dissolution medium. The method was proved to complying with all official guidelines. Therefore, it is suitable for determination of amlodipine and valsartan in their binary mixtures for different analytical and pharmaceutical purposes.
