In this study, a multivariate local quadratic polynomial regression(MLQPR) method is proposed to design a model for the sludge volume index(SVI). In MLQPR, a quadratic polynomial regression function is established to ...In this study, a multivariate local quadratic polynomial regression(MLQPR) method is proposed to design a model for the sludge volume index(SVI). In MLQPR, a quadratic polynomial regression function is established to describe the relationship between SVI and the relative variables, and the important terms of the quadratic polynomial regression function are determined by the significant test of the corresponding coefficients. Moreover, a local estimation method is introduced to adjust the weights of the quadratic polynomial regression function to improve the model accuracy. Finally, the proposed method is applied to predict the SVI values in a real wastewater treatment process(WWTP). The experimental results demonstrate that the proposed MLQPR method has faster testing speed and more accurate results than some existing methods.展开更多
The development of defect prediction plays a significant role in improving software quality. Such predictions are used to identify defective modules before the testing and to minimize the time and cost. The software w...The development of defect prediction plays a significant role in improving software quality. Such predictions are used to identify defective modules before the testing and to minimize the time and cost. The software with defects negatively impacts operational costs and finally affects customer satisfaction. Numerous approaches exist to predict software defects. However, the timely and accurate software bugs are the major challenging issues. To improve the timely and accurate software defect prediction, a novel technique called Nonparametric Statistical feature scaled QuAdratic regressive convolution Deep nEural Network (SQADEN) is introduced. The proposed SQADEN technique mainly includes two major processes namely metric or feature selection and classification. First, the SQADEN uses the nonparametric statistical Torgerson–Gower scaling technique for identifying the relevant software metrics by measuring the similarity using the dice coefficient. The feature selection process is used to minimize the time complexity of software fault prediction. With the selected metrics, software fault perdition with the help of the Quadratic Censored regressive convolution deep neural network-based classification. The deep learning classifier analyzes the training and testing samples using the contingency correlation coefficient. The softstep activation function is used to provide the final fault prediction results. To minimize the error, the Nelder–Mead method is applied to solve non-linear least-squares problems. Finally, accurate classification results with a minimum error are obtained at the output layer. Experimental evaluation is carried out with different quantitative metrics such as accuracy, precision, recall, F-measure, and time complexity. The analyzed results demonstrate the superior performance of our proposed SQADEN technique with maximum accuracy, sensitivity and specificity by 3%, 3%, 2% and 3% and minimum time and space by 13% and 15% when compared with the two state-of-the-art methods.展开更多
Additive Manufacturing(AM)can provide customized parts that conventional techniques fail to deliver.One important parameter in AM is the quality of the parts,as a result of the material extrusion 3D printing(3D-P)proc...Additive Manufacturing(AM)can provide customized parts that conventional techniques fail to deliver.One important parameter in AM is the quality of the parts,as a result of the material extrusion 3D printing(3D-P)procedure.This can be very important in defense-related applications,where optimum performance needs to be guaranteed.The quality of the Polyetherimide 3D-P specimens was examined by considering six control parameters,namely,infill percentage,layer height,deposition angle,travel speed,nozzle,and bed temperature.The quality indicators were the root mean square(Rq)and average(Ra)roughness,porosity,and the actual to nominal dimensional deviation.The examination was performed with optical profilometry,optical microscopy,and micro-computed tomography scanning.The Taguchi design of experiments was applied,with twenty-five runs,five levels for each control parameter,on five replicas.Two additional confirmation runs were conducted,to ensure reliability.Prediction equations were constructed to express the quality indicators in terms of the control parameters.Three modeling approaches were applied to the experimental data,to compare their efficiency,i.e.,Linear Regression Model(LRM),Reduced Quadratic Regression Model,and Quadratic Regression Model(QRM).QRM was the most accurate one,still the differences were not high even considering the simpler LRM model.展开更多
The mass loss rate of CaF2-CaO-Al2O3-SiO2-MgO slag system originated from ANF-6 was studied with CaF2, CaO, Al2O3, SiO2 or MgO content as variables. The method of quadratic regression orthogonal design was used for th...The mass loss rate of CaF2-CaO-Al2O3-SiO2-MgO slag system originated from ANF-6 was studied with CaF2, CaO, Al2O3, SiO2 or MgO content as variables. The method of quadratic regression orthogonal design was used for the design and analysis of the experiment. The experimental results indicated that mass loss rate of slag can be increased by 6% with CaF2 changing from 50%to 65%. Mass loss increases with SiO2 , Al2O3 and MgO adding and decreases with CaO content increasing. Because of the reaction between oxide and fluoride in the slag pool, apparent mass loss of CaF2-Al2O3 CaO-SiO2 MgO slag system appears at melting point. This will cause obvious composition change of electroslag. In addition, the segregation occurs in the slag skin forming process. This is another reason causing the composition change of electroslag.展开更多
Supersaturated design is essentially a fractional factorial design in which the number of potential effects is greater than the number of runs. In this article, the supersaturated design is applied to a computer exper...Supersaturated design is essentially a fractional factorial design in which the number of potential effects is greater than the number of runs. In this article, the supersaturated design is applied to a computer experiment through an example of steady current circuit model problem. A uniform mixed-level supersaturated design and the centered quadratic regression model are used. This example shows that supersaturated design and quadratic regression modeling method are very effective for screening effects and building the predictor. They are not only useful in computer experiments but also in industrial and other scientific experiments.展开更多
By means of the quadratic regression combination design process, the regression equations of nugget diameter and tensile shear load of spot welded joint were established. Effects of welding parameters on the nugget di...By means of the quadratic regression combination design process, the regression equations of nugget diameter and tensile shear load of spot welded joint were established. Effects of welding parameters on the nugget diameter and the tensile shear load were investigated. The results show that effect of welding current on nugget diameter is the most evident. And higher welding current will result in bigger nugget diameter. Besides, interaction effect of electrode force and welding current on tensile shear load is the most evident compared with others. The optimum welding parameters corresponding to the maximum of tensile shear load have been obtained by programming using Matlab software, which is 4, 7 kN electrode force, 28 kA welding current and 4 cycle welding time. Under the condition of the optimum welding parameters, the joint having no visible defects can be obtained, nugget diameter and tensile shear load being 6. 8 mm and 3 256 N, respectively.展开更多
Background:Blood stasis syndrome is one of the major syndromes in the development of chronic conditions in traditional Chinese medicine.Blood stasis syndrome is closely related to microcirculation dysfunction and thro...Background:Blood stasis syndrome is one of the major syndromes in the development of chronic conditions in traditional Chinese medicine.Blood stasis syndrome is closely related to microcirculation dysfunction and thrombosis.Trigonaceae,as a representative traditional Chinese medicine for promoting blood circulation and removing blood stasis,there are many studies on its anticoagulant,antiplatelet aggregation and antithrombotic effects.Methods:Optimization of sparganin compounds,comprising sparganin A,sparganin B,and sparganin C for the characterization of drug pair effects against blood stasis syndrome was carried out.Ternary quadratic regression orthogonal combination design was carried out in a mouse model of blood stasis syndrome.The concentrations of thromboxane B2,plasminogen activator inhibitor 1,fibrinogen,and endothelin 1 were evaluated by enzyme linked immunosorbent assay.Thymus,hepatic,and spleen indices were also assessed.The outcomes of the evaluations aided in identifying optimum parameter values for the most favorable precipitation against blood stasis syndrome.Subsequently,Cytoscape 3.7.1 was used for network pharmacology to predict the key targets of sparganins and disease.Results:After sparganin A,sparganin B,and sparganin C treatment,hepatic had a downward trend,while spleen indices and thymus had an upward trend.Compared with the model group,thromboxane B2,endothelin 1,plasminogen activator inhibitor 1,and fibrinogen were decreased(P<0.05).The blood stasis syndrome model regression equation was extremely significant,and the correlation coefficient of R was 0.939,indicating that sparganin A,sparganin B and sparganin C were positively correlated at all levels.According to the dosage of these three factors and test results,the equation was fitted and the maximum values of the three sparganin in the corresponding dose range were obtained as follows:A=0.2982 mg/10g,B=0.1438 mg/10g,C=0.0417 mg/10g.Thus,the optimum parameters were found to be 0.298:0.144:0.042 for synergistic drug combinations of sparganin compounds sparganin A,sparganin B,and sparganin C in blood stasis syndrome.The possible key targets of sparganins included matrix metalloproteinase 9,plasminogen,proto-oncogene tyrosine-protein kinase src,and akt serine/threonine kinase 1 in blood stasis syndrome.Conclusion:Our study for the first time found two novel cyclic peptide compounds sparganin B and sparganin C have an anti-blood stasis effect,and speculated sparganins key targets included matrix metalloproteinase 9,plasminogen,proto-oncogene tyrosine-protein kinase src,and akt serine/threonine kinase 1 in blood stasis syndrome.展开更多
On the basis of the alloying theory of bonding assistant coat （BAC）, taking into account of the interaction of alloy elements, the regressive equation, which relates the wetting ability of bonding assistant coat wit...On the basis of the alloying theory of bonding assistant coat （BAC）, taking into account of the interaction of alloy elements, the regressive equation, which relates the wetting ability of bonding assistant coat with the contents of Mn, Ni, Si, Sn, and B, was es- tablished by using quadratic regression orthogonal design of five factors. The influence of elements and their interaction on the wetting ability was analyzed. The ranges of alloy elements were optimized. The melting point of bonding assistant coat was measured by using differential thermal analysis. The results show that the interactions of Ni and Mn, Ni, and Sn can increase the wetting ability obviously and the melting point of bonding assistant coat has been decreased.展开更多
On the basis of the uniform design method, six kinds of martensitic hot work die steels were designed. The phase transformation temperatures including Ac1 , Ac3 , and Ms were measured by DIL805A quenching dilatometer....On the basis of the uniform design method, six kinds of martensitic hot work die steels were designed. The phase transformation temperatures including Ac1 , Ac3 , and Ms were measured by DIL805A quenching dilatometer. The influences of the main elements on phase transformation temperatures were analyzed by quadratic stepwise regression analysis, and three corresponding equations were obtained. These equations, in which the interactions of the elements were considered, showed more effectiveness than the traditional ones. In addition, the thermal expansion coefficients of these steels in annealed state and quenched state were also obtained during the tests. The influences of chemical composition and temperature on the thermal expansion coefficient were analyzed; the equations obtained were verified by using several kinds of steels. The predicted values were in accordance with the results of the experiments.展开更多
Globalization and informatization promote the evolution of urban spatial organization from a hierarchical structure mode to a network structure mode,forming a complex network system.This study considers the coupling o...Globalization and informatization promote the evolution of urban spatial organization from a hierarchical structure mode to a network structure mode,forming a complex network system.This study considers the coupling of“space of flows”and“spaces of places”as the core and“embeddedness”as the link and a relevant theoretical basis;then we construct a conceptual model of urban networks and explore the internal logic of enterprise networks and city networks.Using the interlocking-affiliate network model and data from China’s top 500 listed companies,this study constructs a directed multi-valued relational matrix between cities in western China from 2005 to 2015.Using social network analysis and the multiple regression of quadratic assignment program model(MRQAP),this study adopts a“top-down”research perspective to analyze the spatio-temporal evolution and growth mechanism of the city network in western China from three nested spatial scales:large regions,intercity agglomerations,and intracity agglomerations.The results show the following:(1)Under the large regional scale,the city network has good symmetry,obvious characteristics of hierarchical diffusion,neighborhood diffusion,and cross-administrative regional connection,presenting the“core-periphery”structural pattern.(2)The network of intercity agglomerations has the characteristics of centralization,stratification,and geographical proximity.(3)The internal network of each urban agglomeration presents a variety of network structure modes,such as dual-core,single-core,and multicore modes.(4)Administrative subordination and economic system proximity have a significant positive impact on the city network in western China.The differences in internet convenience,investment in science and technology,average time distance,and economic development have negative effects on the growth and development of city networks.(5)The preferential attachment is the internal driving force of the city network development.展开更多
For the general fixed effects linear model: Y = X_T+ε, ε～N(0, V), V≥0, weobtain the necessary and sufficient conditions for LY +a to be admissible for a linear estimablefunction S_r in the class of all estimators ...For the general fixed effects linear model: Y = X_T+ε, ε～N(0, V), V≥0, weobtain the necessary and sufficient conditions for LY +a to be admissible for a linear estimablefunction S_r in the class of all estimators under the loss function (d -- Sr)'D(d --Sr), whereD≥0 is known. For the general random effects linear model: Y = Xβ+ε,(βε)～N((Aα 0), (V_(11)V_(12)V_(21)V_(22))), ∧= XV_(11)X'+XV_(12)+ V_(21)X+V_(22)≥0, we also get the necessaryand sufficient conditions for LY+a to be admissible for a linear estimable function Sα+Qβin the class of all estimators under the loss function (d-Sα-Qβ)'D(d-Sα-Qβ).whereD≥0 is known.展开更多
[ Objective] To study the effects of combined application of different elements on alfalfa hay yield. [ Medthod] Potassium sulfate, ammonium chloride, superphosphate and magnesium oxide were applied to alfalfa field i...[ Objective] To study the effects of combined application of different elements on alfalfa hay yield. [ Medthod] Potassium sulfate, ammonium chloride, superphosphate and magnesium oxide were applied to alfalfa field in the experiment, and quaternary quadratic regression orthogonal combination was used to examine the effects of the experiment factors on hay yield of alfalfa. [ Result] The order of targets based on the effects on hay yield is as follows： potassium sulfate 〉 ammonium chloride 〉 magnesium oxide 〉 superphosphate. Among them, the potassium sulfate had a significant impact on alfalfa hay yield. The interaction between potassium sulfate and magnesium oxide also had a significant impact on alfalfa hay yield. [ Conclusion] The optimal cultivation measures for alfalfa hay yield of more than 19 224.6 kg/hm^2 are as follows： potassium sulfate, 163.253 - 181.679 kg/hm^2 ; ammonium chloride, 155.877 - 174.258 kg/hm^2 ; superphosphate, 566.177 - 632.924 kg/hm^2 ; and magnesium oxide, 30.060 - 33.628 kg/hm^2.展开更多
Effects of Mg^2＋, NTPs and Taq DNA polymerase in pear SSR-PCR system were analyzed by quadratic regressive orthogonal rotational combinational design. Results showed： absolute IOD （Integrated OD of each band） valu...Effects of Mg^2＋, NTPs and Taq DNA polymerase in pear SSR-PCR system were analyzed by quadratic regressive orthogonal rotational combinational design. Results showed： absolute IOD （Integrated OD of each band） value of target band reduced with concentration rising of Mg^2＋ and Taq DNA polymerase, but heightened with concentration rising of dNTPs. The decay rate of absolute IOD value increased progressively with rising Mg^2＋ concentration, decreased gradually with rising Taq DNA polymerase concentration; the rising speed would be slower than the dNTPs increase. Absolute IOD value would reduce with concentration rising of dNTPs at a low level of Mg^2＋ concentration. Conversely it would rise with the increase of dNTPs while high Mg^2＋ concentration. Absolute IOD value would generally rise with concentration rising of Taq DNA polymerase while low Mg^2＋ concentration. On the contrary it would reduce with concentration rising of Taq DNA polymerase while high Mg^2＋ concentration.展开更多
Atomizers were designed with different atomization parameters to obtain droplets that satisfy optimal particle size requirements for an impinging-type low-speed centrifugal atomizing sprayer.The main factors affecting...Atomizers were designed with different atomization parameters to obtain droplets that satisfy optimal particle size requirements for an impinging-type low-speed centrifugal atomizing sprayer.The main factors affecting droplet size are turntable speed,the number of teeth and the tooth shape of the toothed disc.Winner318 software was used to evaluate droplet sizes for different structures and the working parameters of the atomizer.The response surface method and Design-Expert were used to analyze the effect of each factor.The response surface analysis of the effect of structural and working parameters of the atomizer on the interaction between the volume medium diameter of the droplet and the spectral width of the droplet size was used to establish the atomizer droplet Granular spectrum prediction model.Optimal design fitting formulas are obtained,and the droplet sizes required for pesticides to control flying insect pests,to control the growth of reptile larvae,and the use of spraying fungicides to prevent crop damage were determined.This research provides a product not only similar to those in the market,but also the theoretical basis and references for innovation,development,and optimization of centrifugal atomization technology.展开更多
In order to optimize the parameters of bowl-tray rice precision seeder and improve its performance,three major factors respectively at five levels,including shaped hole diameter,vertical displacement of rice seeds and...In order to optimize the parameters of bowl-tray rice precision seeder and improve its performance,three major factors respectively at five levels,including shaped hole diameter,vertical displacement of rice seeds and rotating speed of cam,were tested,the quadratic orthogonal rotational regression experiments were conducted,and the effects on seeding rate,leakage sowing rate and the injury rate were investigated.The test results show that factors affecting rice seeding rate are in the order of shaped hole diameter,rotating speed of cam and vertical displacement of rice seeds.The factors affecting rice planting leakage rate are in the order of shaped hole diameter,vertical displacement of rice seeds and rotating speed of cam,and the factors affecting rice injury rate are in the order of rotating speed of cam,vertical displacement of rice seeds and shaped hole diameter.Optimal parameters(shaped hole diameter:10 mm,vertical displacement of rice seeds:27 mm,rotating speed of cam:13 r/min)and performance index(seeding rate:95.43%,leakage sowing rate:0.37%,injury rate:0.58%)provided the basis for design and performance improvement of the bowl-tray rice precision seeder.展开更多
文摘In this study, a multivariate local quadratic polynomial regression(MLQPR) method is proposed to design a model for the sludge volume index(SVI). In MLQPR, a quadratic polynomial regression function is established to describe the relationship between SVI and the relative variables, and the important terms of the quadratic polynomial regression function are determined by the significant test of the corresponding coefficients. Moreover, a local estimation method is introduced to adjust the weights of the quadratic polynomial regression function to improve the model accuracy. Finally, the proposed method is applied to predict the SVI values in a real wastewater treatment process(WWTP). The experimental results demonstrate that the proposed MLQPR method has faster testing speed and more accurate results than some existing methods.
文摘The development of defect prediction plays a significant role in improving software quality. Such predictions are used to identify defective modules before the testing and to minimize the time and cost. The software with defects negatively impacts operational costs and finally affects customer satisfaction. Numerous approaches exist to predict software defects. However, the timely and accurate software bugs are the major challenging issues. To improve the timely and accurate software defect prediction, a novel technique called Nonparametric Statistical feature scaled QuAdratic regressive convolution Deep nEural Network (SQADEN) is introduced. The proposed SQADEN technique mainly includes two major processes namely metric or feature selection and classification. First, the SQADEN uses the nonparametric statistical Torgerson–Gower scaling technique for identifying the relevant software metrics by measuring the similarity using the dice coefficient. The feature selection process is used to minimize the time complexity of software fault prediction. With the selected metrics, software fault perdition with the help of the Quadratic Censored regressive convolution deep neural network-based classification. The deep learning classifier analyzes the training and testing samples using the contingency correlation coefficient. The softstep activation function is used to provide the final fault prediction results. To minimize the error, the Nelder–Mead method is applied to solve non-linear least-squares problems. Finally, accurate classification results with a minimum error are obtained at the output layer. Experimental evaluation is carried out with different quantitative metrics such as accuracy, precision, recall, F-measure, and time complexity. The analyzed results demonstrate the superior performance of our proposed SQADEN technique with maximum accuracy, sensitivity and specificity by 3%, 3%, 2% and 3% and minimum time and space by 13% and 15% when compared with the two state-of-the-art methods.
文摘Additive Manufacturing(AM)can provide customized parts that conventional techniques fail to deliver.One important parameter in AM is the quality of the parts,as a result of the material extrusion 3D printing(3D-P)procedure.This can be very important in defense-related applications,where optimum performance needs to be guaranteed.The quality of the Polyetherimide 3D-P specimens was examined by considering six control parameters,namely,infill percentage,layer height,deposition angle,travel speed,nozzle,and bed temperature.The quality indicators were the root mean square(Rq)and average(Ra)roughness,porosity,and the actual to nominal dimensional deviation.The examination was performed with optical profilometry,optical microscopy,and micro-computed tomography scanning.The Taguchi design of experiments was applied,with twenty-five runs,five levels for each control parameter,on five replicas.Two additional confirmation runs were conducted,to ensure reliability.Prediction equations were constructed to express the quality indicators in terms of the control parameters.Three modeling approaches were applied to the experimental data,to compare their efficiency,i.e.,Linear Regression Model(LRM),Reduced Quadratic Regression Model,and Quadratic Regression Model(QRM).QRM was the most accurate one,still the differences were not high even considering the simpler LRM model.
基金Item Sponsored by National Natural Science Foundation of China(50644040)
文摘The mass loss rate of CaF2-CaO-Al2O3-SiO2-MgO slag system originated from ANF-6 was studied with CaF2, CaO, Al2O3, SiO2 or MgO content as variables. The method of quadratic regression orthogonal design was used for the design and analysis of the experiment. The experimental results indicated that mass loss rate of slag can be increased by 6% with CaF2 changing from 50%to 65%. Mass loss increases with SiO2 , Al2O3 and MgO adding and decreases with CaO content increasing. Because of the reaction between oxide and fluoride in the slag pool, apparent mass loss of CaF2-Al2O3 CaO-SiO2 MgO slag system appears at melting point. This will cause obvious composition change of electroslag. In addition, the segregation occurs in the slag skin forming process. This is another reason causing the composition change of electroslag.
基金Research supported by the National Natural Science Foundation of China (10301015)the Science and Technology Innovation Fund of Nankai University, the Visiting Scholar Program at Chern Institute of Mathematicsa Hong Kong Research Grants Council Grant (RGC/HKBU 200804)
文摘Supersaturated design is essentially a fractional factorial design in which the number of potential effects is greater than the number of runs. In this article, the supersaturated design is applied to a computer experiment through an example of steady current circuit model problem. A uniform mixed-level supersaturated design and the centered quadratic regression model are used. This example shows that supersaturated design and quadratic regression modeling method are very effective for screening effects and building the predictor. They are not only useful in computer experiments but also in industrial and other scientific experiments.
文摘By means of the quadratic regression combination design process, the regression equations of nugget diameter and tensile shear load of spot welded joint were established. Effects of welding parameters on the nugget diameter and the tensile shear load were investigated. The results show that effect of welding current on nugget diameter is the most evident. And higher welding current will result in bigger nugget diameter. Besides, interaction effect of electrode force and welding current on tensile shear load is the most evident compared with others. The optimum welding parameters corresponding to the maximum of tensile shear load have been obtained by programming using Matlab software, which is 4, 7 kN electrode force, 28 kA welding current and 4 cycle welding time. Under the condition of the optimum welding parameters, the joint having no visible defects can be obtained, nugget diameter and tensile shear load being 6. 8 mm and 3 256 N, respectively.
基金This work was supported by the National Natural Science Foundation of China(No.81773884,81473413,81274060)the National Science and Technology Major Project(No.2017ZX09301077)+1 种基金Guangzhou Science and Technology Project(No.201803010115)Technology Funds were obtained from the Key Unit of Chinese Medicine Digitalization Quality Evaluation of State Administration of Traditional Chinese Medicine.
文摘Background:Blood stasis syndrome is one of the major syndromes in the development of chronic conditions in traditional Chinese medicine.Blood stasis syndrome is closely related to microcirculation dysfunction and thrombosis.Trigonaceae,as a representative traditional Chinese medicine for promoting blood circulation and removing blood stasis,there are many studies on its anticoagulant,antiplatelet aggregation and antithrombotic effects.Methods:Optimization of sparganin compounds,comprising sparganin A,sparganin B,and sparganin C for the characterization of drug pair effects against blood stasis syndrome was carried out.Ternary quadratic regression orthogonal combination design was carried out in a mouse model of blood stasis syndrome.The concentrations of thromboxane B2,plasminogen activator inhibitor 1,fibrinogen,and endothelin 1 were evaluated by enzyme linked immunosorbent assay.Thymus,hepatic,and spleen indices were also assessed.The outcomes of the evaluations aided in identifying optimum parameter values for the most favorable precipitation against blood stasis syndrome.Subsequently,Cytoscape 3.7.1 was used for network pharmacology to predict the key targets of sparganins and disease.Results:After sparganin A,sparganin B,and sparganin C treatment,hepatic had a downward trend,while spleen indices and thymus had an upward trend.Compared with the model group,thromboxane B2,endothelin 1,plasminogen activator inhibitor 1,and fibrinogen were decreased(P<0.05).The blood stasis syndrome model regression equation was extremely significant,and the correlation coefficient of R was 0.939,indicating that sparganin A,sparganin B and sparganin C were positively correlated at all levels.According to the dosage of these three factors and test results,the equation was fitted and the maximum values of the three sparganin in the corresponding dose range were obtained as follows:A=0.2982 mg/10g,B=0.1438 mg/10g,C=0.0417 mg/10g.Thus,the optimum parameters were found to be 0.298:0.144:0.042 for synergistic drug combinations of sparganin compounds sparganin A,sparganin B,and sparganin C in blood stasis syndrome.The possible key targets of sparganins included matrix metalloproteinase 9,plasminogen,proto-oncogene tyrosine-protein kinase src,and akt serine/threonine kinase 1 in blood stasis syndrome.Conclusion:Our study for the first time found two novel cyclic peptide compounds sparganin B and sparganin C have an anti-blood stasis effect,and speculated sparganins key targets included matrix metalloproteinase 9,plasminogen,proto-oncogene tyrosine-protein kinase src,and akt serine/threonine kinase 1 in blood stasis syndrome.
基金This work was financially supported by the National High-Tech Research and Development Program of China (863 Program) (No.2002AA334070).
文摘On the basis of the alloying theory of bonding assistant coat （BAC）, taking into account of the interaction of alloy elements, the regressive equation, which relates the wetting ability of bonding assistant coat with the contents of Mn, Ni, Si, Sn, and B, was es- tablished by using quadratic regression orthogonal design of five factors. The influence of elements and their interaction on the wetting ability was analyzed. The ranges of alloy elements were optimized. The melting point of bonding assistant coat was measured by using differential thermal analysis. The results show that the interactions of Ni and Mn, Ni, and Sn can increase the wetting ability obviously and the melting point of bonding assistant coat has been decreased.
基金Item Sponsored by Shanghai Leading Academic Discipline Project(T0101)Science and Technology Commission of Shanghai Municipality(065211028)
文摘On the basis of the uniform design method, six kinds of martensitic hot work die steels were designed. The phase transformation temperatures including Ac1 , Ac3 , and Ms were measured by DIL805A quenching dilatometer. The influences of the main elements on phase transformation temperatures were analyzed by quadratic stepwise regression analysis, and three corresponding equations were obtained. These equations, in which the interactions of the elements were considered, showed more effectiveness than the traditional ones. In addition, the thermal expansion coefficients of these steels in annealed state and quenched state were also obtained during the tests. The influences of chemical composition and temperature on the thermal expansion coefficient were analyzed; the equations obtained were verified by using several kinds of steels. The predicted values were in accordance with the results of the experiments.
基金National Natural Science Foundation of China(41501176)National Natural Science Foundation of China(41961030)。
文摘Globalization and informatization promote the evolution of urban spatial organization from a hierarchical structure mode to a network structure mode,forming a complex network system.This study considers the coupling of“space of flows”and“spaces of places”as the core and“embeddedness”as the link and a relevant theoretical basis;then we construct a conceptual model of urban networks and explore the internal logic of enterprise networks and city networks.Using the interlocking-affiliate network model and data from China’s top 500 listed companies,this study constructs a directed multi-valued relational matrix between cities in western China from 2005 to 2015.Using social network analysis and the multiple regression of quadratic assignment program model(MRQAP),this study adopts a“top-down”research perspective to analyze the spatio-temporal evolution and growth mechanism of the city network in western China from three nested spatial scales:large regions,intercity agglomerations,and intracity agglomerations.The results show the following:(1)Under the large regional scale,the city network has good symmetry,obvious characteristics of hierarchical diffusion,neighborhood diffusion,and cross-administrative regional connection,presenting the“core-periphery”structural pattern.(2)The network of intercity agglomerations has the characteristics of centralization,stratification,and geographical proximity.(3)The internal network of each urban agglomeration presents a variety of network structure modes,such as dual-core,single-core,and multicore modes.(4)Administrative subordination and economic system proximity have a significant positive impact on the city network in western China.The differences in internet convenience,investment in science and technology,average time distance,and economic development have negative effects on the growth and development of city networks.(5)The preferential attachment is the internal driving force of the city network development.
文摘For the general fixed effects linear model: Y = X_T+ε, ε～N(0, V), V≥0, weobtain the necessary and sufficient conditions for LY +a to be admissible for a linear estimablefunction S_r in the class of all estimators under the loss function (d -- Sr)'D(d --Sr), whereD≥0 is known. For the general random effects linear model: Y = Xβ+ε,(βε)～N((Aα 0), (V_(11)V_(12)V_(21)V_(22))), ∧= XV_(11)X'+XV_(12)+ V_(21)X+V_(22)≥0, we also get the necessaryand sufficient conditions for LY+a to be admissible for a linear estimable function Sα+Qβin the class of all estimators under the loss function (d-Sα-Qβ)'D(d-Sα-Qβ).whereD≥0 is known.
基金funded by the National Key Technology R&D Program (2006BAD04A10)the Major Scientific and Technological Innovation Projects of Hebei Province (07227146Z)the Earmarked Fund for Modern Agro-industry (Dairy Industry) Technology Research System (nycytx-10)
文摘[ Objective] To study the effects of combined application of different elements on alfalfa hay yield. [ Medthod] Potassium sulfate, ammonium chloride, superphosphate and magnesium oxide were applied to alfalfa field in the experiment, and quaternary quadratic regression orthogonal combination was used to examine the effects of the experiment factors on hay yield of alfalfa. [ Result] The order of targets based on the effects on hay yield is as follows： potassium sulfate 〉 ammonium chloride 〉 magnesium oxide 〉 superphosphate. Among them, the potassium sulfate had a significant impact on alfalfa hay yield. The interaction between potassium sulfate and magnesium oxide also had a significant impact on alfalfa hay yield. [ Conclusion] The optimal cultivation measures for alfalfa hay yield of more than 19 224.6 kg/hm^2 are as follows： potassium sulfate, 163.253 - 181.679 kg/hm^2 ; ammonium chloride, 155.877 - 174.258 kg/hm^2 ; superphosphate, 566.177 - 632.924 kg/hm^2 ; and magnesium oxide, 30.060 - 33.628 kg/hm^2.
文摘Effects of Mg^2＋, NTPs and Taq DNA polymerase in pear SSR-PCR system were analyzed by quadratic regressive orthogonal rotational combinational design. Results showed： absolute IOD （Integrated OD of each band） value of target band reduced with concentration rising of Mg^2＋ and Taq DNA polymerase, but heightened with concentration rising of dNTPs. The decay rate of absolute IOD value increased progressively with rising Mg^2＋ concentration, decreased gradually with rising Taq DNA polymerase concentration; the rising speed would be slower than the dNTPs increase. Absolute IOD value would reduce with concentration rising of dNTPs at a low level of Mg^2＋ concentration. Conversely it would rise with the increase of dNTPs while high Mg^2＋ concentration. Absolute IOD value would generally rise with concentration rising of Taq DNA polymerase while low Mg^2＋ concentration. On the contrary it would reduce with concentration rising of Taq DNA polymerase while high Mg^2＋ concentration.
基金This work was financially supported by National Key Research and Development Program of China(2017YFD0200303)China Agriculture Research System(CARS-25).
文摘Atomizers were designed with different atomization parameters to obtain droplets that satisfy optimal particle size requirements for an impinging-type low-speed centrifugal atomizing sprayer.The main factors affecting droplet size are turntable speed,the number of teeth and the tooth shape of the toothed disc.Winner318 software was used to evaluate droplet sizes for different structures and the working parameters of the atomizer.The response surface method and Design-Expert were used to analyze the effect of each factor.The response surface analysis of the effect of structural and working parameters of the atomizer on the interaction between the volume medium diameter of the droplet and the spectral width of the droplet size was used to establish the atomizer droplet Granular spectrum prediction model.Optimal design fitting formulas are obtained,and the droplet sizes required for pesticides to control flying insect pests,to control the growth of reptile larvae,and the use of spraying fungicides to prevent crop damage were determined.This research provides a product not only similar to those in the market,but also the theoretical basis and references for innovation,development,and optimization of centrifugal atomization technology.
基金This work was supported by Science and Technology Research Projects of Education of the Heilongjiang Province of China(12531439)Natural Science Foundation of Heilongjiang Province of China(E201331)Heilongjiang Province Agricultural Reclamation Administration Science and Technology Projects(HNk11A-09-11-02).
文摘In order to optimize the parameters of bowl-tray rice precision seeder and improve its performance,three major factors respectively at five levels,including shaped hole diameter,vertical displacement of rice seeds and rotating speed of cam,were tested,the quadratic orthogonal rotational regression experiments were conducted,and the effects on seeding rate,leakage sowing rate and the injury rate were investigated.The test results show that factors affecting rice seeding rate are in the order of shaped hole diameter,rotating speed of cam and vertical displacement of rice seeds.The factors affecting rice planting leakage rate are in the order of shaped hole diameter,vertical displacement of rice seeds and rotating speed of cam,and the factors affecting rice injury rate are in the order of rotating speed of cam,vertical displacement of rice seeds and shaped hole diameter.Optimal parameters(shaped hole diameter:10 mm,vertical displacement of rice seeds:27 mm,rotating speed of cam:13 r/min)and performance index(seeding rate:95.43%,leakage sowing rate:0.37%,injury rate:0.58%)provided the basis for design and performance improvement of the bowl-tray rice precision seeder.
