Ⅰ.Quick cuppingMake the cup sucking to the skin with theflash-fire method,and then remove it swiftlyupon its sucking.This quick sucking-and-removing art is applied repeated 30-50 timesover the same area until the loc...Ⅰ.Quick cuppingMake the cup sucking to the skin with theflash-fire method,and then remove it swiftlyupon its sucking.This quick sucking-and-removing art is applied repeated 30-50 timesover the same area until the local skin becomeshyperemic so as to produce a specific physicalstimulation of drawing-pulling and relaxationsensation.As a result,the blood circulation ofthe local skin can be improved by this pouring-展开更多
Objective To establish a reliable platform for screening glucokinase activators （GKAs） in vitro. Methods Pancreatic glucokinase （PGK） protein expressed in a prokaryotic expression system as a histidine-tagged fusi...Objective To establish a reliable platform for screening glucokinase activators （GKAs） in vitro. Methods Pancreatic glucokinase （PGK） protein expressed in a prokaryotic expression system as a histidine-tagged fusion protein from Homo sapiens was produced. Then, response surface methodology （RSM） was used to optimize the microplate-based GKA screening platform. In the f＇trst step of optimization with Plackett-Burman design （PBD）, initial pH, reaction time and MgC12 were found to be important factors affecting the activity ratio of GKA （RO-28-1675） significantly. In the second step, a 23 full factorial central composite design （CCD） and RSM were applied to the optimal condition determination of each significant variable. A second-order polynomial was determined by a multiple regression analysis of the experimental data. Results The following optimal values for the critical factors were obtained： initial pH 0 （7.0）, reaction time-0.63 （13.7 min） and MgC12 0.11 （2.11 mmol/L） with a predicted value of the maximum activity ratio of 34.1%. Conclusion Under the optimal conditions, the practical activity ratio is 34.8%. The determination coefficient （R2） is 0.9442, ensuring adequate credibility of the model. LLAE3, extracted from Folium nelumbinis in our laboratory, has prominently activated effects on PGK.展开更多
Flexible roll forming is a new roll forming process that produces parts with variable cross sections. This forming process is proposed to meet the demand of weight reduction of automobile industry. In order to study t...Flexible roll forming is a new roll forming process that produces parts with variable cross sections. This forming process is proposed to meet the demand of weight reduction of automobile industry. In order to study the mechanisms and material flow rules in this new forming process,the finite element mothod( FEM) model of a nine-step flexible roll forming of an ultra-high-strength steel bumper is established based on deep understanding and reasonable simplification of the process.Given that the material model is an important factor that influences the simulation accuracy,three material models which consist of different yield criteria and hardening models are adopted in the FEM models. Sheet thickness and springback amount calculated with three material models are studied comparatively. According to sheet thickness reduction and springback amounts,it is found that the MKi( Mises yield criterion and kinematic hardening law) model's result is larger than MI( Mises yield criterion and isotropic hardening law) model and HI( Hill's yield criterion and isotropic hardening law) model. Therefore,it is concluded that material models do have influences on the flexible roll forming simulation and need to be determined carefully.展开更多
The stability of buildings on the surface will be influenced by underground mining. For the purposes of safe mining and buildings protecting around mining area, the rock and sod distortion should be forecasted. By usi...The stability of buildings on the surface will be influenced by underground mining. For the purposes of safe mining and buildings protecting around mining area, the rock and sod distortion should be forecasted. By using the results of the elastic-finite-element method simulation, we can calculate the tilting, horizontal deformation and curvature of the surface and the strata. Wushan Copper Mine was taken as an example to analyze the reasons of accident and beyond standard limit, and the influence on the safety of the packed volumn.展开更多
Numerical simulations are presented about the effects of gas rarefaction on hypersonic flow field.Due to the extremely difficult experiment,limited wind-tunnel conditions and high cost,most problems in rarefied flow r...Numerical simulations are presented about the effects of gas rarefaction on hypersonic flow field.Due to the extremely difficult experiment,limited wind-tunnel conditions and high cost,most problems in rarefied flow regime are investigated through numerical methods,in which the direct simulation Monte-Carlo(DSMC)method is widely adopted.And the unstructured DSMC method is employed here.Flows around a vertical plate at a given velocity 7 500 m/s are simulated.For gas rarefaction is judged by the free-stream Knudsen number(Kn),two vital factors are considered:molecular number density and the plate′s length.Cases in which Kn varies from 0.035 to13.36 are simulated.Flow characters in the whole rarefied regime are described,and flow-field structure affected by Knis analyzed.Then,the dimensionless position D*of a certain velocity in the stagnation line is chosen as the marker of flow field to measure its variation.Through flow-field tracing and least-square numerical method analyzing,it is proved that hypersonic rarefied flow field expands outward linearly with the increase of 1/2Kn.An empirical method is proposed,which can be used for the prediction of the hypersonic flow-field structure at a given inflow velocity,especially the shock wave position.展开更多
In this paper we prove that a class of trust region methods presented in part I is superlinearly convergent. Numerical tests are reported thereafter. Results by solving a set of typical problems selected from literatu...In this paper we prove that a class of trust region methods presented in part I is superlinearly convergent. Numerical tests are reported thereafter. Results by solving a set of typical problems selected from literatures have demonstrated that our algorithm is effective.展开更多
In this paper, the stability of nonlinear time-delay discrete systems is investigated bymeans of the Gauss-Seidel iteration method. Some algebraic criteria of the stability are obtained. Theconstruction of Lyapunov fu...In this paper, the stability of nonlinear time-delay discrete systems is investigated bymeans of the Gauss-Seidel iteration method. Some algebraic criteria of the stability are obtained. Theconstruction of Lyapunov function is avoided.展开更多
This paper believes that complex feedback systems are very common and important in the modern engineering technology. It is very difficult to resolve the optimum problem of the complex feedback system. But it has impo...This paper believes that complex feedback systems are very common and important in the modern engineering technology. It is very difficult to resolve the optimum problem of the complex feedback system. But it has important practical value. This paper decomposed the complex feedback system into many subsystems by means of the decomposing method. First, optimize each subsystem on the optimization basis. Second optimize the whole system step by step. Finally, we provide an example of the optimal design of the heat-exchanger used in chemical processes.展开更多
文摘Ⅰ.Quick cuppingMake the cup sucking to the skin with theflash-fire method,and then remove it swiftlyupon its sucking.This quick sucking-and-removing art is applied repeated 30-50 timesover the same area until the local skin becomeshyperemic so as to produce a specific physicalstimulation of drawing-pulling and relaxationsensation.As a result,the blood circulation ofthe local skin can be improved by this pouring-
基金supported by the Program for Changjiang Scholars and Innovative Research Team in University,PCSERT(No.IRT0540).
文摘Objective To establish a reliable platform for screening glucokinase activators （GKAs） in vitro. Methods Pancreatic glucokinase （PGK） protein expressed in a prokaryotic expression system as a histidine-tagged fusion protein from Homo sapiens was produced. Then, response surface methodology （RSM） was used to optimize the microplate-based GKA screening platform. In the f＇trst step of optimization with Plackett-Burman design （PBD）, initial pH, reaction time and MgC12 were found to be important factors affecting the activity ratio of GKA （RO-28-1675） significantly. In the second step, a 23 full factorial central composite design （CCD） and RSM were applied to the optimal condition determination of each significant variable. A second-order polynomial was determined by a multiple regression analysis of the experimental data. Results The following optimal values for the critical factors were obtained： initial pH 0 （7.0）, reaction time-0.63 （13.7 min） and MgC12 0.11 （2.11 mmol/L） with a predicted value of the maximum activity ratio of 34.1%. Conclusion Under the optimal conditions, the practical activity ratio is 34.8%. The determination coefficient （R2） is 0.9442, ensuring adequate credibility of the model. LLAE3, extracted from Folium nelumbinis in our laboratory, has prominently activated effects on PGK.
基金Supported by the National Natural Science Foundation of China(No.51205004)Beijing Natural Science Foundation(No.3164041)the National Key Technology R&D Program(No.2011BAG03B03)
文摘Flexible roll forming is a new roll forming process that produces parts with variable cross sections. This forming process is proposed to meet the demand of weight reduction of automobile industry. In order to study the mechanisms and material flow rules in this new forming process,the finite element mothod( FEM) model of a nine-step flexible roll forming of an ultra-high-strength steel bumper is established based on deep understanding and reasonable simplification of the process.Given that the material model is an important factor that influences the simulation accuracy,three material models which consist of different yield criteria and hardening models are adopted in the FEM models. Sheet thickness and springback amount calculated with three material models are studied comparatively. According to sheet thickness reduction and springback amounts,it is found that the MKi( Mises yield criterion and kinematic hardening law) model's result is larger than MI( Mises yield criterion and isotropic hardening law) model and HI( Hill's yield criterion and isotropic hardening law) model. Therefore,it is concluded that material models do have influences on the flexible roll forming simulation and need to be determined carefully.
文摘The stability of buildings on the surface will be influenced by underground mining. For the purposes of safe mining and buildings protecting around mining area, the rock and sod distortion should be forecasted. By using the results of the elastic-finite-element method simulation, we can calculate the tilting, horizontal deformation and curvature of the surface and the strata. Wushan Copper Mine was taken as an example to analyze the reasons of accident and beyond standard limit, and the influence on the safety of the packed volumn.
文摘Numerical simulations are presented about the effects of gas rarefaction on hypersonic flow field.Due to the extremely difficult experiment,limited wind-tunnel conditions and high cost,most problems in rarefied flow regime are investigated through numerical methods,in which the direct simulation Monte-Carlo(DSMC)method is widely adopted.And the unstructured DSMC method is employed here.Flows around a vertical plate at a given velocity 7 500 m/s are simulated.For gas rarefaction is judged by the free-stream Knudsen number(Kn),two vital factors are considered:molecular number density and the plate′s length.Cases in which Kn varies from 0.035 to13.36 are simulated.Flow characters in the whole rarefied regime are described,and flow-field structure affected by Knis analyzed.Then,the dimensionless position D*of a certain velocity in the stagnation line is chosen as the marker of flow field to measure its variation.Through flow-field tracing and least-square numerical method analyzing,it is proved that hypersonic rarefied flow field expands outward linearly with the increase of 1/2Kn.An empirical method is proposed,which can be used for the prediction of the hypersonic flow-field structure at a given inflow velocity,especially the shock wave position.
文摘In this paper we prove that a class of trust region methods presented in part I is superlinearly convergent. Numerical tests are reported thereafter. Results by solving a set of typical problems selected from literatures have demonstrated that our algorithm is effective.
文摘In this paper, the stability of nonlinear time-delay discrete systems is investigated bymeans of the Gauss-Seidel iteration method. Some algebraic criteria of the stability are obtained. Theconstruction of Lyapunov function is avoided.
文摘This paper believes that complex feedback systems are very common and important in the modern engineering technology. It is very difficult to resolve the optimum problem of the complex feedback system. But it has important practical value. This paper decomposed the complex feedback system into many subsystems by means of the decomposing method. First, optimize each subsystem on the optimization basis. Second optimize the whole system step by step. Finally, we provide an example of the optimal design of the heat-exchanger used in chemical processes.
