To meet the market requirements for Flexible Transf er Line (FTL), which consists of modular NC machining tools of high quality and co st saving, the methodologies and technologies of client-oriented FTL rapid resp on...To meet the market requirements for Flexible Transf er Line (FTL), which consists of modular NC machining tools of high quality and co st saving, the methodologies and technologies of client-oriented FTL rapid resp onse schematic design CAPP-based, one of the key techniques, are presented in t his paper. In order to achieve this purpose, an integrated system for integrated design of CAD/CAPP/FTL with box-type parts is realized. In this paper, firstly the theory of the conceptual design of FTL based on CAPP is established and the software architecture is developed. The global-domain pr oduct model is put forward to meet with data representation. After the manufactu ring feature is analyzed and decomposed for machining operations, the feature-b ased part unified data model object-oriented is built. Secondly the knowledge- based CAPP system data model is established. The process planning unit model is formed by work element (WE), which is tool-cell based function abstraction meth od, and has unified layers with respect to designing and manufacturing. With WEs through dynamic response and simultaneous structure in process planning, the pr inciple solution for CAPP function system can be implemented. Lastly the mapping from process domain to module design domain is built. The unidirectional select ion process based on fuzzy matching technology is easily dealt with computer. Th e algorithm of decision with fuzzy synthetic evaluation method and technology is applied to estimate the feasibility of the results in local working procedure o f modular NC machine tools and make decision of designs in overall FTL, which co nsists of many different factors. The example shows that the rapid response desi gn in bidding-based FTL scheme design is realized.展开更多
The frequency response design method for PDFSV (Pseudo Derivative Feedback Subvariable) control of electrohydraulic servo system is introduced. Theoretical analysis and computer simulation show that PDFSV con...The frequency response design method for PDFSV (Pseudo Derivative Feedback Subvariable) control of electrohydraulic servo system is introduced. Theoretical analysis and computer simulation show that PDFSV control is a high robust system, and a very good performance can be obtained when this theory is employed in electrohydraulic servo system.展开更多
[Objectives] To optimize the extraction process of total flavonoids in stems of Mallotus apelta. [Methods]On the basis of singlefactor test,with volume fraction of ethanol,extraction time and ratio of solvent as indep...[Objectives] To optimize the extraction process of total flavonoids in stems of Mallotus apelta. [Methods]On the basis of singlefactor test,with volume fraction of ethanol,extraction time and ratio of solvent as independent variables,the content of total flavonoids as dependent variables,the completely secondary response surface regression fitting was conducted on the independent and dependent variables,and the Response Surface Method was used to optimize the optimum extraction process of total flavonoids in Mallotus apelta stems and predict the optimum process. [Results] The optimum extraction process of total flavonoids in Mallotus apelta was determined as follows: ethanol concentration of 71. 5%; extraction time of 154. 6 min; solid-liquid ratio of 1∶19. 2; total flavonoids content of 7. 060 mg/g; fitted binomial squared correlation coefficient R^2= 0. 8751.[Conclusions]Composite Design/Response Surface Method could be used in the extraction process optimization of total flavonoids in Mallotus apelta stems,the mathematical model established had high prediction accuracy,the method was simple and operability was good.展开更多
It was shown from the study on the recently near-fault earthquake ground motions that the near-fault effects were seldom considered in the existing Chinese seismic code. Referring to the UBC97 design concept for near-...It was shown from the study on the recently near-fault earthquake ground motions that the near-fault effects were seldom considered in the existing Chinese seismic code. Referring to the UBC97 design concept for near-fault factors, based on the collected world-widely free-site records of near-fault earthquakes ground motions classified by earthquake magnitude and site condition, the attenuation relationship expressions of the acceleration spectrum demand at the key points within the long period and moderate period were established in term of the earthquake magnitude and the site condition. Furthermore, the near-fault factors' expressions about the earthquake magnitude and the fault distance were deduced for the area lack of near-fault strong earthquake records. Based on the current Chinese Building Seismic Design Code, the near-fault effect factors and the modified design spectral curves, which were valuable for the seismic design, were proposed to analyze the seismic response of structures.展开更多
To obtain the peak response at 532nm, narrow-band response GaA1As photocathodes with two GaAIAs ac- tive layers of different aluminum compositions are designed in consideration of the maximum absorptivity and quantum ...To obtain the peak response at 532nm, narrow-band response GaA1As photocathodes with two GaAIAs ac- tive layers of different aluminum compositions are designed in consideration of the maximum absorptivity and quantum efficiency. The transmission-mode and the corresponding reflective-mode photocathodes are grown by metalorganic chemical vapor deposition. The results indicate that the peak response and the cut-off wavelength occur at 532nm for the two kinds of photocathodes respectively. The response of the reflection-mode photoeath- ode is an order of magnitude higher than that of the transmission-mode photocathode, whereas the better growth quality and the thicker second GaAIAs active layer can improve the transmission-mode response.展开更多
Characteristic period is an important parameter of the seismic design response spectrum. There is important theoretical significance and engineering application value to the study of the characteristic period of seism...Characteristic period is an important parameter of the seismic design response spectrum. There is important theoretical significance and engineering application value to the study of the characteristic period of seismic design response spectrum of ultra high voltage (UHV) electrical equipment. In this paper, 1448 horizontal earthquake records within the world scope including the United States and Japan for Site Class m were analyzed. Results show that both magnitude and epicentral distance have great influence on the characteristic period. About 80 % of characteristic periods of strong earthquake records are about 0. 9s. Statistical analysis was conducted on the seismic hazard assessment results of 312 projects of China in recent years, and it is found that about 70 % of characteristic periods are about 0. 9s. Combined with the related code comparison and analysis, it is suggested that the characteristic period of the seismic design response spectrmn of UHV electrical equipment should select 0. 9s in order to effectively guarantee the seismic safety of UHV electrical equipment.展开更多
In order to shorten the design period, the paper describes a new optimization strategy for computationally expensive design optimization of turbomachinery, combined with design of experiment (DOE), response surface mo...In order to shorten the design period, the paper describes a new optimization strategy for computationally expensive design optimization of turbomachinery, combined with design of experiment (DOE), response surface models (RSM), genetic algorithm (GA) and a 3-D Navier-Stokes solver(Numeca Fine). Data points for response evaluations were selected by improved distributed hypercube sampling (IHS) and the 3-D Navier-Stokes analysis was carried out at these sample points. The quadratic response surface model was used to approximate the relationships between the design variables and flow parameters. To maximize the adiabatic efficiency, the genetic algorithm was applied to the response surface model to perform global optimization to achieve the optimum design of NASA Stage 35. An optimum leading edge line was found, which produced a new 3-D rotor blade combined with sweep and lean, and a new stator one with skew. It is concluded that the proposed strategy can provide a reliable method for design optimization of turbomachinery blades at reasonable computing cost.展开更多
Limited by the poor transient response performance of turbochargers,the dynamic performance of aviation piston engines tends to deteriorate.In a bid to enhance the turbocharger’s acceleration capabilities,this study ...Limited by the poor transient response performance of turbochargers,the dynamic performance of aviation piston engines tends to deteriorate.In a bid to enhance the turbocharger’s acceleration capabilities,this study scrutinizes various factors impacting its performance.Based on the operational principles and transient response process of the turbocharger,three types of in-ertiadnamely,aerodynamic inertia(ADI),thermal inertia(TI),and mechanical inertia(MI)d are identified and addressed for design.To begin,this paper pioneers the innovative definition of a method for evaluating the transient response performance of the turbocharger.This method incor-porates the introduction of an ADI parameter,inspired by the definition of MI.Subsequently,a thin-walled volute design with a low Biot number and a lightweight turbine impeller is introduced to reduce the turbocharger’s TI and MI.The simulation results of theflowfield distribution within the volute and diffuser demonstrate the comprehensive design method’s effectiveness in improving gas pressure and temperature distributions in these components.Notably,the pressure distributionfluctuation in the constant moment-of-momentum volute(CMV)is 62.8%lower than that in the constant velocity moment volute(CVMV).The low-TI thin-walled volute not only en-hances the turbocharger’s response speed but also reduces its weight by approximately 40%.The impact of three types of inertia on the engine’s response speed is quantified as follows:ADI(94%)>MI(5%)>TI(1%).This conclusion has been verified through test results of both the turbocharger and the engine.This design method not only significantly improves the turbo-charger’s response performance but also offers valuable insights for the optimal design of other blade mechanical systems.展开更多
Morchella septimelata polysaccharide(MSP)possesses multiple biological activities.In this study,double enzyme method was used to extract polysaccharides from Morchella septimelata.The basis of single factor experiment...Morchella septimelata polysaccharide(MSP)possesses multiple biological activities.In this study,double enzyme method was used to extract polysaccharides from Morchella septimelata.The basis of single factor experiment and response surface design was used to optimize the extraction process of polysaccharides.The optimal extraction conditions of polysaccharide were as follows:extraction time 2 h,extraction temperature 40.5℃,solid-liquid ratio 1:15(w/v),and the amount of double enzyme(cellulase:β-glucanase,mass ratio 1:2)2.0%.Under these conditions,the extraction yield of polysaccharide reached(14.86±0.12)%.展开更多
Response surface (RSM) methodology based on a three-level three-factor Box-Behnkendesign of experiment was used to optimize the exopolysaccharide content (EPC) and themycelium biomass in submerged cultivation by Clito...Response surface (RSM) methodology based on a three-level three-factor Box-Behnkendesign of experiment was used to optimize the exopolysaccharide content (EPC) and themycelium biomass in submerged cultivation by Clitocybe sp. AS 5.112. The criticalfactors selected for the investigation were cultivation temperature, time and volume ofmedium, based on the results of previous Plackett-Burman design. By analyzing theresponse surface plots, the optimum ranges of cultivation temperature, time and mediumvolume for obtaining over 1 253.00gmL-1 of EPC lie in 24.325.8℃, 9.710.2d and 76.090.0mL, respectively. While for obtaining over 8.32 mg mL-1 of dry cell weight (DCW), theabove variables would be in the range of 23.824.8℃, 9.610.3d and 71.098.0mL,respectively. By solving the inverse matrix from the quadratic regression equations, theoptimal conditions to gain 1 265.45gmL-1 of EPC were 25.0℃, 9.9d and 83.4mL, to gain8.50mg mL-1 of DCW were 24.4℃, 9.9d and 87.1mL. In order to obtain the maximum yield ofEPC and DCW at the same time, the above conditions would be 24.5℃, 9.9d and 84.7mL,respectively, in this situation, the maximum predicted EPC and DCW were 1 261.60gmL-1and 8.47mgmL-1, respectively. The experimental data under various conditions have validatedthe theoretical values.展开更多
Objective:The Box-Behnken response surface method combined with fingerprints was used to optimize the extraction process of total anthraquinone from Cassia seeds.Methods:A three-factor,three-level response surface tes...Objective:The Box-Behnken response surface method combined with fingerprints was used to optimize the extraction process of total anthraquinone from Cassia seeds.Methods:A three-factor,three-level response surface test was conducted based on the single-factor test with comprehensive evaluation as the measurement index.The comprehensive evaluation indexes included the extraction rate of total anthraquinone of Cassia seeds or the equivalent amount of herbs per gram of total anthraquinone of Cassia seeds,the normalized value of peak areas of 5 index components such as aurantio obtusin in the fingerprint of each sample to 16 shared peaks and the similarity of fingerprints(the reference fingerprint was established by the extraction solvent for the determination of Cassia seeds content in the Chinese Pharmacopoeia 2020 edition)with the weights of 0.2,0.5 and 0.3,respectively.Results:The best extraction process was obtained:the liquid-to-material ratio was 20:1(mL·g-1),the extraction solvent was mixture of 60%ethanol-ethyl acetate(2:1),and the extraction time was 15.12 min.The results of five sets of validation experiments showed that the overall evaluation of total anthraquinone of cassia seeds by the best process was 0.528(RSD=0.45%),and the prediction result of response surface method model was 0.531,and the relative error with the prediction result was 0.531.The relative error of the predicted results was 0.56%,and the best extraction process was consistent with the model prediction,and the obtained best process could be used for the extraction of total anthraquinone from Cassia seeds.Conclusion:The Box-Behnken response surface method combined with the fingerprint technique can be used to find the best reaction conditions and examine the interactions among the factors in a comprehensive and accurate manner,which can provide reference for the optimization and evaluation of the extraction process of Chinese medicine.展开更多
Climatic considerations in the architectural design of most contemporary buildings have not been strictly adhered to by building design and construction professionals in the last few decades in the developing world, w...Climatic considerations in the architectural design of most contemporary buildings have not been strictly adhered to by building design and construction professionals in the last few decades in the developing world, with users being denied the inevitable interactions with the natural surroundings offered by climate. The situation leads to utilization of energy-based equipment such as air conditioner that is environmentally unsustainable. The study aimed to evaluate the bioclimatic design features of residential building typologies and to identify features that can enhance the environmental responsiveness of buildings. This study adopted the Mahoney Tables to undertake a climatic analysis to develop appropriate design guidelines for the climate context. The developed design guidelines were then used to evaluate the bio-climatic design features of a sampled number of residential building types. The study revealed that features of the buildings reflect the recommended design guidelines, but to varied extents among the building typologies that were studied. Occupants generally find their spaces unsatisfactory primarily as a result of the experience of hot discomfort. The findings are expected to engender a renewed interest in the design of buildings in response to prevailing climatic conditions to reduce reliance on energy use and to serve as a useful reference for contemporary architectural design practice and education.展开更多
Glutaminase is used industrially to enhance flavor and aroma and to enrich foodstuffs nutritionally. It also has potential for pharmaceutical application as anti-leukemia agent. The bacteria of Zymomonas mobilis has b...Glutaminase is used industrially to enhance flavor and aroma and to enrich foodstuffs nutritionally. It also has potential for pharmaceutical application as anti-leukemia agent. The bacteria of Zymomonas mobilis has been studied for ethanol production, however, there is no study regarding glutaminase production. The aim of the present study was to establish the influencing factors for the growth of Z mobilis and its relationship with glutaminase production using statistical tools. Analysis of variance in blocks was carried out in a complete block design and the Tukey test demonstrated the importance of the components of the culture medium, absence of agitation and fermentation time. Minimum culture medium was used in the optimization varying the glucose concentrations (10, 30, and 50 g/L), glutamine (0, 0.5 and 1g/L) and culture time (18, 24 and 30 hours). Maximum production was obtained at 8.86 U/L glutaminase. Optimized conditions were used in the growth kinetics, where typical exponential growth was observed. Glutaminase production was shown to be related to biomass production.展开更多
Abstract: Objective To apply the response surface-central composite design to developing and optimizing the oral fastdisintegrating tablets (ODT) formulation for Jiawei Qing’e, a kind of prescription of Chinese herba...Abstract: Objective To apply the response surface-central composite design to developing and optimizing the oral fastdisintegrating tablets (ODT) formulation for Jiawei Qing’e, a kind of prescription of Chinese herbal medicine.Methods The bitterness of Jiawei Qing’e was masked using Eudragit E-100 by solvent evaporation technique.Response surface approach was applied to investigating the interaction of formulation parameters in optimizing theformulation. The independent variables were Eudragit E-100/drug ratio (X1), amount of disintegrants (X2), and theamount of diluents (X3). The disintegration time (Y1), hardness (Y2), and weight variations of the tablets werecharacterized. Results The models predicted levels of X1= 4.63%, X2= 5.25%, and X3= 34.33%, for the optimalformulation having a hardness of 3.0 kg with the disintegration time of 30 s within experimental region. The observedresponse of Y1= 26.5 s and Y2= 3.14 kg reasonably agreed with the predicted response. Conclusion Responsesurface methodology shows the good predictability and reliability in optimizing the formulation. The optimized ODTof Jiawei Qing’e has acceptable taste, rapid disintegrating ability, and good mechanical strength.展开更多
Strong-motion site effect was checked for four sites at comparable epicentral distances from the March 11, 2011 Mw9.0 Tohoku earthquake in Japan. The result showed that site condition had a significant impact on peak ...Strong-motion site effect was checked for four sites at comparable epicentral distances from the March 11, 2011 Mw9.0 Tohoku earthquake in Japan. The result showed that site condition had a significant impact on peak acceleration, and on maximal amplitude and characteristic period of its response spectrum. Shorter-period seismic waves were amplified mainly in shallower soils, while longer-period waves in deeper soft rocks and soils, where the characteristic periods of response spectra were longer than those on ground surface.展开更多
Fusarium head blight(FHB),caused primarily by Fusarium graminearum,is a destructive disease of wheat throughout the world.However,the mechanisms of host resistance to FHB are still largely unclear.Deoxynivalenol(DO...Fusarium head blight(FHB),caused primarily by Fusarium graminearum,is a destructive disease of wheat throughout the world.However,the mechanisms of host resistance to FHB are still largely unclear.Deoxynivalenol(DON)produced by F graminearum which enhances the pathogen to spread could be converted into inactive form D3 G by UDP-glycosyltransferases(UGTs).A DON responsive UGT gene,designated as TaUGT4,was first cloned from wheat in this study.The putative open reading frame(ORF) of TaUGT4 was 1386 bp,encoding 461 amino acids protein.TaUGT4 was placed on chromosome 2D using a set of nulli-tetrasomic lines of wheat cultivar Chinese Spring(CS).When fused with eGFP at C terminal,TaUGT4 was shown to localize in cytoplasm of the transformed tobacco cells.The transcriptional analysis revealed that TaUGT4 was strongly induced by F graminearum or DON in both of FHB-resistant cultivar Sumai 3 and susceptible cultivar Kenong 199,especially in Sumai 3 under DON treatment.Similar increase of TaUGT4 expression was observed in Sumai 3 and Kenong 199 in response to salicylic acid(SA) treatment.But interestingly,the transcripts level of TaUGT4 in Sumai 3 showed significantly higher than that in Kenong 199 after treated with methyl jasmonate(MeJA).According to the expression patterns,TaUGT4 might lead to different effects between FHB-resistant genotype and susceptible genotype in the process against F graminearum inoculation.It had also been discussed in this paper that JA signaling pathway might play a significant role in the resistance against F.graminearum compared to SA signaling pathway.展开更多
[Objectives]This study was conducted to confirm the existence of anthocyanins in pitaya(Hylocereus undatus)pericarp and optimize the extraction condition.[Methods]Single-factor tests were carried out on five factors:e...[Objectives]This study was conducted to confirm the existence of anthocyanins in pitaya(Hylocereus undatus)pericarp and optimize the extraction condition.[Methods]Single-factor tests were carried out on five factors:ethanol concentration,extraction temperature,ultrasonic power,solid-to-liquid ratio and extraction time.Based on the single-factor test results,four factors and three levels of process conditions were optimized by Box-Behnken design test.[Results]Anthocyanins exist in the pericarp of pitaya,and the optimum conditions were extraction temperature 49℃,ultrasonic power 120 W,extracted time 2 h and ethanol concentration 60%.Under these conditions,the average yield of anthocyanins was 80 mg/100g.[Conclusions]This study provides a theoretical basis for the extraction of anthocyanins from the pericarp of red-flesh pitaya.展开更多
Various field investigations of earthquake disaster cases have confirmed that earthquake-induced liquefaction is a main factor causing significant damage to dyke,research on seismic performances of dyke is thus of gre...Various field investigations of earthquake disaster cases have confirmed that earthquake-induced liquefaction is a main factor causing significant damage to dyke,research on seismic performances of dyke is thus of great importance.In this paper,seismic responses of dyke on liquefiable soils were investigated by means of dynamic centrifuge model tests and three-dimensional(3D) effective stress analysis method which is based on a multiple shear mechanism model and a liquefaction front.For the prototype scale centrifuge tests,sine wave input motions with peak accelerations 0.806 m/s2,1.790 m/s2 and 3.133 m/s2 of varied amplitudes were adopted to study the seismic performances of dyke on the saturated soil layer foundation with relative density of approximately 30%.Then,corresponding numerical simulations were conducted to investigate the distribution and variations of deformation,acceleration,excess pore-water pressure(EPWP),and behaviors of shear dilatancy in the dyke and the liquefiable soil foundation.Moreover,detailed discussions and comparisons between numerical simulations and centrifuge tests were also presented.It is concluded that the computed results have a good agreement with the measured results by centrifuge tests.The physical and numerical models both indicate that the dyke hosted on liquefiable soils subjected to earthquake motions has exhibited larger settlement and lateral spread:the stronger the motion is,the larger the dyke deformation is.Compared to soils in the deep ground under the dyke and the free field,the EPWP ratio is much smaller in the shallow liquefiable soil beneath the dyke in spite of large deformation produced.For the same overburden depth soil from free site and the liquefiable foundation beneath dyke,the characteristics of effective stress path and stress-strain relations are different.All these results may be of theoretical and practical significance for seismic design of the dyke on liquefiable soils.展开更多
In this paper,size and shape optimization problem of a machine gun system is addressed with an efficient hybrid method,in which a novel and flexible mesh morphing technique is employed to achieve fast parameterization...In this paper,size and shape optimization problem of a machine gun system is addressed with an efficient hybrid method,in which a novel and flexible mesh morphing technique is employed to achieve fast parameterization and modification of complexity structure without going back to CAD for reconstruction of geometric models or to finite element analysis( FEA) for remodeling. Design of experiments( DOE) and response surface method( RSM) are applied to approximate the constitutive parameters of a machine gun system based on experimental tests. Further FEA,secondary development technique and genetic algorithm( GA) are introduced to find all the optimal solutions in one go and the optimal design of the demonstrated machine gun system is obtained. Results of the rigid-flexible coupling dynamic analysis and exterior ballistics calculation validate the proposed methodology,which is relatively time-saving,reliable and has the potential to solve similar problems.展开更多
Parabens are antimicrobial preservatives with extensive applications in cosmetics,toiletries,pharmaceuticals,and food.Considering the legitimate concerns relating to their potential to disrupt multiple endocrine funct...Parabens are antimicrobial preservatives with extensive applications in cosmetics,toiletries,pharmaceuticals,and food.Considering the legitimate concerns relating to their potential to disrupt multiple endocrine functions,it becomes imperative to prioritize the development of innovative bioanalytical techniques for effectively monitoring their presence in biological samples.In this study,an efficient solvent bar microextraction(SBME)was established,utilizing new hydrophobic deep eutectic solvents(DEs)to determine methylparaben and propylparaben in urine and plasma samples.The DEs comprising menthol and tris(2-ethylhexyl)phosphate(M-TEHP)at various molar ratios were synthesized for the first time to enhance the extraction capacity and promote the eco-friendliness of the DE used as an extraction solvent.Fourier-transform infrared(FT-IR)and proton nuclear magnetic resonance(1H NMR)spectroscopies were employed to confirm and investigate the properties of the successful synthesis(M-TEHP)DE at a molar ratio of 1:1.The synthesized DE exhibits low microbial toxicity and can be considered an eco-friendly solvent for extraction.Furthermore,quantum-chemical calculations were utilized to predict synthesized DE's structure and interaction energy with selected parabens.The influential operational factors of DE-SBME on the extraction efficiency(EE%)of both parabens were evaluated using response surface methodology based on central composite design,and a total of 30 extraction tests were conducted to determine the optimal conditions.The optimized DE-SBME,in combination with HPLC-DAD,exhibited low detection limits(0.54–0.91μg L^(−1)),excellent linearity(R^(2)≥0.9993),precise results(RSDs≤7.6%),satisfactory recoveries(92–97%)and negligible matrix effects.Hence,it had remarkable effectiveness and applicability in determining selected parabens in real urine and plasma samples.展开更多
文摘To meet the market requirements for Flexible Transf er Line (FTL), which consists of modular NC machining tools of high quality and co st saving, the methodologies and technologies of client-oriented FTL rapid resp onse schematic design CAPP-based, one of the key techniques, are presented in t his paper. In order to achieve this purpose, an integrated system for integrated design of CAD/CAPP/FTL with box-type parts is realized. In this paper, firstly the theory of the conceptual design of FTL based on CAPP is established and the software architecture is developed. The global-domain pr oduct model is put forward to meet with data representation. After the manufactu ring feature is analyzed and decomposed for machining operations, the feature-b ased part unified data model object-oriented is built. Secondly the knowledge- based CAPP system data model is established. The process planning unit model is formed by work element (WE), which is tool-cell based function abstraction meth od, and has unified layers with respect to designing and manufacturing. With WEs through dynamic response and simultaneous structure in process planning, the pr inciple solution for CAPP function system can be implemented. Lastly the mapping from process domain to module design domain is built. The unidirectional select ion process based on fuzzy matching technology is easily dealt with computer. Th e algorithm of decision with fuzzy synthetic evaluation method and technology is applied to estimate the feasibility of the results in local working procedure o f modular NC machine tools and make decision of designs in overall FTL, which co nsists of many different factors. The example shows that the rapid response desi gn in bidding-based FTL scheme design is realized.
文摘The frequency response design method for PDFSV (Pseudo Derivative Feedback Subvariable) control of electrohydraulic servo system is introduced. Theoretical analysis and computer simulation show that PDFSV control is a high robust system, and a very good performance can be obtained when this theory is employed in electrohydraulic servo system.
基金Supported by Chinese Medicine Science and Technology Project of Guangxi Administration of Traditional Chinese Medicine(GZLC14-31)Science and Technology Research and Development Program of Guilin Bureau of Technology(20130403-4)+1 种基金Guangxi"2011 Collaborative Innovation Center"-Zhuang and Yao Medicine Collaborative Innovation Center(Gui201320)the Autonomous Region-Level College Students’ Innovation and Entrepreneurship Training Program(201710601082)
文摘[Objectives] To optimize the extraction process of total flavonoids in stems of Mallotus apelta. [Methods]On the basis of singlefactor test,with volume fraction of ethanol,extraction time and ratio of solvent as independent variables,the content of total flavonoids as dependent variables,the completely secondary response surface regression fitting was conducted on the independent and dependent variables,and the Response Surface Method was used to optimize the optimum extraction process of total flavonoids in Mallotus apelta stems and predict the optimum process. [Results] The optimum extraction process of total flavonoids in Mallotus apelta was determined as follows: ethanol concentration of 71. 5%; extraction time of 154. 6 min; solid-liquid ratio of 1∶19. 2; total flavonoids content of 7. 060 mg/g; fitted binomial squared correlation coefficient R^2= 0. 8751.[Conclusions]Composite Design/Response Surface Method could be used in the extraction process optimization of total flavonoids in Mallotus apelta stems,the mathematical model established had high prediction accuracy,the method was simple and operability was good.
基金National Natural Science Foundation of China (50278002)Dalian Nationalities University Ph D Foundation (20066104)
文摘It was shown from the study on the recently near-fault earthquake ground motions that the near-fault effects were seldom considered in the existing Chinese seismic code. Referring to the UBC97 design concept for near-fault factors, based on the collected world-widely free-site records of near-fault earthquakes ground motions classified by earthquake magnitude and site condition, the attenuation relationship expressions of the acceleration spectrum demand at the key points within the long period and moderate period were established in term of the earthquake magnitude and the site condition. Furthermore, the near-fault factors' expressions about the earthquake magnitude and the fault distance were deduced for the area lack of near-fault strong earthquake records. Based on the current Chinese Building Seismic Design Code, the near-fault effect factors and the modified design spectral curves, which were valuable for the seismic design, were proposed to analyze the seismic response of structures.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61171042 and 61301023the Introducing Talent Scientific Initial Foundation of Nanjing Institute of Technology of China under Grant Nos YKJ201320,YKJ201322,and YKJ201323
文摘To obtain the peak response at 532nm, narrow-band response GaA1As photocathodes with two GaAIAs ac- tive layers of different aluminum compositions are designed in consideration of the maximum absorptivity and quantum efficiency. The transmission-mode and the corresponding reflective-mode photocathodes are grown by metalorganic chemical vapor deposition. The results indicate that the peak response and the cut-off wavelength occur at 532nm for the two kinds of photocathodes respectively. The response of the reflection-mode photoeath- ode is an order of magnitude higher than that of the transmission-mode photocathode, whereas the better growth quality and the thicker second GaAIAs active layer can improve the transmission-mode response.
基金founded by the Earthquake Science and Technology Spark Plan of China(XH12063)
文摘Characteristic period is an important parameter of the seismic design response spectrum. There is important theoretical significance and engineering application value to the study of the characteristic period of seismic design response spectrum of ultra high voltage (UHV) electrical equipment. In this paper, 1448 horizontal earthquake records within the world scope including the United States and Japan for Site Class m were analyzed. Results show that both magnitude and epicentral distance have great influence on the characteristic period. About 80 % of characteristic periods of strong earthquake records are about 0. 9s. Statistical analysis was conducted on the seismic hazard assessment results of 312 projects of China in recent years, and it is found that about 70 % of characteristic periods are about 0. 9s. Combined with the related code comparison and analysis, it is suggested that the characteristic period of the seismic design response spectrmn of UHV electrical equipment should select 0. 9s in order to effectively guarantee the seismic safety of UHV electrical equipment.
文摘In order to shorten the design period, the paper describes a new optimization strategy for computationally expensive design optimization of turbomachinery, combined with design of experiment (DOE), response surface models (RSM), genetic algorithm (GA) and a 3-D Navier-Stokes solver(Numeca Fine). Data points for response evaluations were selected by improved distributed hypercube sampling (IHS) and the 3-D Navier-Stokes analysis was carried out at these sample points. The quadratic response surface model was used to approximate the relationships between the design variables and flow parameters. To maximize the adiabatic efficiency, the genetic algorithm was applied to the response surface model to perform global optimization to achieve the optimum design of NASA Stage 35. An optimum leading edge line was found, which produced a new 3-D rotor blade combined with sweep and lean, and a new stator one with skew. It is concluded that the proposed strategy can provide a reliable method for design optimization of turbomachinery blades at reasonable computing cost.
基金funded by the Basic Research Program of the National Nature Science Foundation of China (Grant number[52206131],[U2233213],[51775025]and[U2333217])National Key R&D Program of China,grant number[2022YFB2602002]and[2018YFB0104100]+1 种基金Zhejiang Provincial Natural Science Foundation of China,grant number[LQ22E060004]Science Center of Gas Turbine Project[P2022-A-I-001-001].
文摘Limited by the poor transient response performance of turbochargers,the dynamic performance of aviation piston engines tends to deteriorate.In a bid to enhance the turbocharger’s acceleration capabilities,this study scrutinizes various factors impacting its performance.Based on the operational principles and transient response process of the turbocharger,three types of in-ertiadnamely,aerodynamic inertia(ADI),thermal inertia(TI),and mechanical inertia(MI)d are identified and addressed for design.To begin,this paper pioneers the innovative definition of a method for evaluating the transient response performance of the turbocharger.This method incor-porates the introduction of an ADI parameter,inspired by the definition of MI.Subsequently,a thin-walled volute design with a low Biot number and a lightweight turbine impeller is introduced to reduce the turbocharger’s TI and MI.The simulation results of theflowfield distribution within the volute and diffuser demonstrate the comprehensive design method’s effectiveness in improving gas pressure and temperature distributions in these components.Notably,the pressure distributionfluctuation in the constant moment-of-momentum volute(CMV)is 62.8%lower than that in the constant velocity moment volute(CVMV).The low-TI thin-walled volute not only en-hances the turbocharger’s response speed but also reduces its weight by approximately 40%.The impact of three types of inertia on the engine’s response speed is quantified as follows:ADI(94%)>MI(5%)>TI(1%).This conclusion has been verified through test results of both the turbocharger and the engine.This design method not only significantly improves the turbo-charger’s response performance but also offers valuable insights for the optimal design of other blade mechanical systems.
基金Supported by The Key Research and Development Program of Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization(202141204)The 2024 Huanggang Municipal Level Science and Technology Innovation Special Fund(YBXM20240031).
文摘Morchella septimelata polysaccharide(MSP)possesses multiple biological activities.In this study,double enzyme method was used to extract polysaccharides from Morchella septimelata.The basis of single factor experiment and response surface design was used to optimize the extraction process of polysaccharides.The optimal extraction conditions of polysaccharide were as follows:extraction time 2 h,extraction temperature 40.5℃,solid-liquid ratio 1:15(w/v),and the amount of double enzyme(cellulase:β-glucanase,mass ratio 1:2)2.0%.Under these conditions,the extraction yield of polysaccharide reached(14.86±0.12)%.
文摘Response surface (RSM) methodology based on a three-level three-factor Box-Behnkendesign of experiment was used to optimize the exopolysaccharide content (EPC) and themycelium biomass in submerged cultivation by Clitocybe sp. AS 5.112. The criticalfactors selected for the investigation were cultivation temperature, time and volume ofmedium, based on the results of previous Plackett-Burman design. By analyzing theresponse surface plots, the optimum ranges of cultivation temperature, time and mediumvolume for obtaining over 1 253.00gmL-1 of EPC lie in 24.325.8℃, 9.710.2d and 76.090.0mL, respectively. While for obtaining over 8.32 mg mL-1 of dry cell weight (DCW), theabove variables would be in the range of 23.824.8℃, 9.610.3d and 71.098.0mL,respectively. By solving the inverse matrix from the quadratic regression equations, theoptimal conditions to gain 1 265.45gmL-1 of EPC were 25.0℃, 9.9d and 83.4mL, to gain8.50mg mL-1 of DCW were 24.4℃, 9.9d and 87.1mL. In order to obtain the maximum yield ofEPC and DCW at the same time, the above conditions would be 24.5℃, 9.9d and 84.7mL,respectively, in this situation, the maximum predicted EPC and DCW were 1 261.60gmL-1and 8.47mgmL-1, respectively. The experimental data under various conditions have validatedthe theoretical values.
基金2018 Anhui Provincial Quality Engineering Project(No.2018jyxm1273)Major Provincial Natural Science Research Project of Anhui Universities(No.KJ2016SD60)2021 Anhui University Students’Innovation and Entrepreneurship Plan Project。
文摘Objective:The Box-Behnken response surface method combined with fingerprints was used to optimize the extraction process of total anthraquinone from Cassia seeds.Methods:A three-factor,three-level response surface test was conducted based on the single-factor test with comprehensive evaluation as the measurement index.The comprehensive evaluation indexes included the extraction rate of total anthraquinone of Cassia seeds or the equivalent amount of herbs per gram of total anthraquinone of Cassia seeds,the normalized value of peak areas of 5 index components such as aurantio obtusin in the fingerprint of each sample to 16 shared peaks and the similarity of fingerprints(the reference fingerprint was established by the extraction solvent for the determination of Cassia seeds content in the Chinese Pharmacopoeia 2020 edition)with the weights of 0.2,0.5 and 0.3,respectively.Results:The best extraction process was obtained:the liquid-to-material ratio was 20:1(mL·g-1),the extraction solvent was mixture of 60%ethanol-ethyl acetate(2:1),and the extraction time was 15.12 min.The results of five sets of validation experiments showed that the overall evaluation of total anthraquinone of cassia seeds by the best process was 0.528(RSD=0.45%),and the prediction result of response surface method model was 0.531,and the relative error with the prediction result was 0.531.The relative error of the predicted results was 0.56%,and the best extraction process was consistent with the model prediction,and the obtained best process could be used for the extraction of total anthraquinone from Cassia seeds.Conclusion:The Box-Behnken response surface method combined with the fingerprint technique can be used to find the best reaction conditions and examine the interactions among the factors in a comprehensive and accurate manner,which can provide reference for the optimization and evaluation of the extraction process of Chinese medicine.
文摘Climatic considerations in the architectural design of most contemporary buildings have not been strictly adhered to by building design and construction professionals in the last few decades in the developing world, with users being denied the inevitable interactions with the natural surroundings offered by climate. The situation leads to utilization of energy-based equipment such as air conditioner that is environmentally unsustainable. The study aimed to evaluate the bioclimatic design features of residential building typologies and to identify features that can enhance the environmental responsiveness of buildings. This study adopted the Mahoney Tables to undertake a climatic analysis to develop appropriate design guidelines for the climate context. The developed design guidelines were then used to evaluate the bio-climatic design features of a sampled number of residential building types. The study revealed that features of the buildings reflect the recommended design guidelines, but to varied extents among the building typologies that were studied. Occupants generally find their spaces unsatisfactory primarily as a result of the experience of hot discomfort. The findings are expected to engender a renewed interest in the design of buildings in response to prevailing climatic conditions to reduce reliance on energy use and to serve as a useful reference for contemporary architectural design practice and education.
文摘Glutaminase is used industrially to enhance flavor and aroma and to enrich foodstuffs nutritionally. It also has potential for pharmaceutical application as anti-leukemia agent. The bacteria of Zymomonas mobilis has been studied for ethanol production, however, there is no study regarding glutaminase production. The aim of the present study was to establish the influencing factors for the growth of Z mobilis and its relationship with glutaminase production using statistical tools. Analysis of variance in blocks was carried out in a complete block design and the Tukey test demonstrated the importance of the components of the culture medium, absence of agitation and fermentation time. Minimum culture medium was used in the optimization varying the glucose concentrations (10, 30, and 50 g/L), glutamine (0, 0.5 and 1g/L) and culture time (18, 24 and 30 hours). Maximum production was obtained at 8.86 U/L glutaminase. Optimized conditions were used in the growth kinetics, where typical exponential growth was observed. Glutaminase production was shown to be related to biomass production.
基金Major Projects of National Science and Technology on"New Drug Creation and Development"(2012ZX09103201-0462012ZX09101212)
文摘Abstract: Objective To apply the response surface-central composite design to developing and optimizing the oral fastdisintegrating tablets (ODT) formulation for Jiawei Qing’e, a kind of prescription of Chinese herbal medicine.Methods The bitterness of Jiawei Qing’e was masked using Eudragit E-100 by solvent evaporation technique.Response surface approach was applied to investigating the interaction of formulation parameters in optimizing theformulation. The independent variables were Eudragit E-100/drug ratio (X1), amount of disintegrants (X2), and theamount of diluents (X3). The disintegration time (Y1), hardness (Y2), and weight variations of the tablets werecharacterized. Results The models predicted levels of X1= 4.63%, X2= 5.25%, and X3= 34.33%, for the optimalformulation having a hardness of 3.0 kg with the disintegration time of 30 s within experimental region. The observedresponse of Y1= 26.5 s and Y2= 3.14 kg reasonably agreed with the predicted response. Conclusion Responsesurface methodology shows the good predictability and reliability in optimizing the formulation. The optimized ODTof Jiawei Qing’e has acceptable taste, rapid disintegrating ability, and good mechanical strength.
基金supported by the National Natural Science Foundation of China(41004020)the Director Foundation of Institute of Seismology,China Earthquake Administration(IS200926044)
文摘Strong-motion site effect was checked for four sites at comparable epicentral distances from the March 11, 2011 Mw9.0 Tohoku earthquake in Japan. The result showed that site condition had a significant impact on peak acceleration, and on maximal amplitude and characteristic period of its response spectrum. Shorter-period seismic waves were amplified mainly in shallower soils, while longer-period waves in deeper soft rocks and soils, where the characteristic periods of response spectra were longer than those on ground surface.
基金supported by the National Natural Science Foundation of China(31071405 and 31171553)the National High-Tech R&D Program of China(863 Program,2011AA100102 and 2012AA101105)+3 种基金the Transgenic Special Item,China(2011ZX08002-004 and 2011ZX08009-003)the International Collaboration Program(948 Project,2013-S19)the Doctoral Fund of Ministry of Education of China(20133702120002)the Promotive Research Fund for Young and Middle-Aged Scientisits of Shandong Province,China(BS2013NY006)
文摘Fusarium head blight(FHB),caused primarily by Fusarium graminearum,is a destructive disease of wheat throughout the world.However,the mechanisms of host resistance to FHB are still largely unclear.Deoxynivalenol(DON)produced by F graminearum which enhances the pathogen to spread could be converted into inactive form D3 G by UDP-glycosyltransferases(UGTs).A DON responsive UGT gene,designated as TaUGT4,was first cloned from wheat in this study.The putative open reading frame(ORF) of TaUGT4 was 1386 bp,encoding 461 amino acids protein.TaUGT4 was placed on chromosome 2D using a set of nulli-tetrasomic lines of wheat cultivar Chinese Spring(CS).When fused with eGFP at C terminal,TaUGT4 was shown to localize in cytoplasm of the transformed tobacco cells.The transcriptional analysis revealed that TaUGT4 was strongly induced by F graminearum or DON in both of FHB-resistant cultivar Sumai 3 and susceptible cultivar Kenong 199,especially in Sumai 3 under DON treatment.Similar increase of TaUGT4 expression was observed in Sumai 3 and Kenong 199 in response to salicylic acid(SA) treatment.But interestingly,the transcripts level of TaUGT4 in Sumai 3 showed significantly higher than that in Kenong 199 after treated with methyl jasmonate(MeJA).According to the expression patterns,TaUGT4 might lead to different effects between FHB-resistant genotype and susceptible genotype in the process against F graminearum inoculation.It had also been discussed in this paper that JA signaling pathway might play a significant role in the resistance against F.graminearum compared to SA signaling pathway.
基金Supported by Food Science Innovation Team Project of Guangdong Colleges and Universities(2016KCXTD020)Guangdong Science and Technology Planning Project(2014B090908007).
文摘[Objectives]This study was conducted to confirm the existence of anthocyanins in pitaya(Hylocereus undatus)pericarp and optimize the extraction condition.[Methods]Single-factor tests were carried out on five factors:ethanol concentration,extraction temperature,ultrasonic power,solid-to-liquid ratio and extraction time.Based on the single-factor test results,four factors and three levels of process conditions were optimized by Box-Behnken design test.[Results]Anthocyanins exist in the pericarp of pitaya,and the optimum conditions were extraction temperature 49℃,ultrasonic power 120 W,extracted time 2 h and ethanol concentration 60%.Under these conditions,the average yield of anthocyanins was 80 mg/100g.[Conclusions]This study provides a theoretical basis for the extraction of anthocyanins from the pericarp of red-flesh pitaya.
基金Financial supports provided by Science and Technological Fund of Anhui Province for Outstanding Youth(No.08040106830)National Natural Sciences Foundation of China(No.41172274)
文摘Various field investigations of earthquake disaster cases have confirmed that earthquake-induced liquefaction is a main factor causing significant damage to dyke,research on seismic performances of dyke is thus of great importance.In this paper,seismic responses of dyke on liquefiable soils were investigated by means of dynamic centrifuge model tests and three-dimensional(3D) effective stress analysis method which is based on a multiple shear mechanism model and a liquefaction front.For the prototype scale centrifuge tests,sine wave input motions with peak accelerations 0.806 m/s2,1.790 m/s2 and 3.133 m/s2 of varied amplitudes were adopted to study the seismic performances of dyke on the saturated soil layer foundation with relative density of approximately 30%.Then,corresponding numerical simulations were conducted to investigate the distribution and variations of deformation,acceleration,excess pore-water pressure(EPWP),and behaviors of shear dilatancy in the dyke and the liquefiable soil foundation.Moreover,detailed discussions and comparisons between numerical simulations and centrifuge tests were also presented.It is concluded that the computed results have a good agreement with the measured results by centrifuge tests.The physical and numerical models both indicate that the dyke hosted on liquefiable soils subjected to earthquake motions has exhibited larger settlement and lateral spread:the stronger the motion is,the larger the dyke deformation is.Compared to soils in the deep ground under the dyke and the free field,the EPWP ratio is much smaller in the shallow liquefiable soil beneath the dyke in spite of large deformation produced.For the same overburden depth soil from free site and the liquefiable foundation beneath dyke,the characteristics of effective stress path and stress-strain relations are different.All these results may be of theoretical and practical significance for seismic design of the dyke on liquefiable soils.
基金Supported by the National Natural Science Foundation of China(51376090,51676099)
文摘In this paper,size and shape optimization problem of a machine gun system is addressed with an efficient hybrid method,in which a novel and flexible mesh morphing technique is employed to achieve fast parameterization and modification of complexity structure without going back to CAD for reconstruction of geometric models or to finite element analysis( FEA) for remodeling. Design of experiments( DOE) and response surface method( RSM) are applied to approximate the constitutive parameters of a machine gun system based on experimental tests. Further FEA,secondary development technique and genetic algorithm( GA) are introduced to find all the optimal solutions in one go and the optimal design of the demonstrated machine gun system is obtained. Results of the rigid-flexible coupling dynamic analysis and exterior ballistics calculation validate the proposed methodology,which is relatively time-saving,reliable and has the potential to solve similar problems.
文摘Parabens are antimicrobial preservatives with extensive applications in cosmetics,toiletries,pharmaceuticals,and food.Considering the legitimate concerns relating to their potential to disrupt multiple endocrine functions,it becomes imperative to prioritize the development of innovative bioanalytical techniques for effectively monitoring their presence in biological samples.In this study,an efficient solvent bar microextraction(SBME)was established,utilizing new hydrophobic deep eutectic solvents(DEs)to determine methylparaben and propylparaben in urine and plasma samples.The DEs comprising menthol and tris(2-ethylhexyl)phosphate(M-TEHP)at various molar ratios were synthesized for the first time to enhance the extraction capacity and promote the eco-friendliness of the DE used as an extraction solvent.Fourier-transform infrared(FT-IR)and proton nuclear magnetic resonance(1H NMR)spectroscopies were employed to confirm and investigate the properties of the successful synthesis(M-TEHP)DE at a molar ratio of 1:1.The synthesized DE exhibits low microbial toxicity and can be considered an eco-friendly solvent for extraction.Furthermore,quantum-chemical calculations were utilized to predict synthesized DE's structure and interaction energy with selected parabens.The influential operational factors of DE-SBME on the extraction efficiency(EE%)of both parabens were evaluated using response surface methodology based on central composite design,and a total of 30 extraction tests were conducted to determine the optimal conditions.The optimized DE-SBME,in combination with HPLC-DAD,exhibited low detection limits(0.54–0.91μg L^(−1)),excellent linearity(R^(2)≥0.9993),precise results(RSDs≤7.6%),satisfactory recoveries(92–97%)and negligible matrix effects.Hence,it had remarkable effectiveness and applicability in determining selected parabens in real urine and plasma samples.