The C-L method was generalized from Liapunov-Schmidt reduction method, combined with theory of singularities, for study of non-autonomous dynamical systems to obtain the typical bifurcating response curves in the syst...The C-L method was generalized from Liapunov-Schmidt reduction method, combined with theory of singularities, for study of non-autonomous dynamical systems to obtain the typical bifurcating response curves in the system parameter spaces. This method has been used, ar an example, to analyze the engineering nonlinear dynamical problems by obtaining the bifurcation programs and response curves which are useful in developing techniques of control to subharmonic instability of large rotating machinery.展开更多
The topological bifurcation diagrams and the coefficients of bifurcation equation were obtained by C_L method.According to obtained bifurcation diagrams and combining control theory,the method of robust control of per...The topological bifurcation diagrams and the coefficients of bifurcation equation were obtained by C_L method.According to obtained bifurcation diagrams and combining control theory,the method of robust control of periodic bifurcation was presented,which differs from generic methods of bifurcation control.It can make the existing motion pattern into the goal motion pattern.Because the method does not make strict requirement about parametric values of the controller,it is convenient to design and make it.Numerical simulations verify validity of the method.展开更多
The oil-film oscillation in dimensional nonlinear problem. In this a large rotating machinery is a complex high- paper, a high pressure rotor of an aero engine with a pair of liquid-film lubricated bearings is modeled...The oil-film oscillation in dimensional nonlinear problem. In this a large rotating machinery is a complex high- paper, a high pressure rotor of an aero engine with a pair of liquid-film lubricated bearings is modeled as a twenty-two-degree-of-freedom nonlinear system by the Lagrange method. This high-dimensional nonlinear system can be reduced to a two-degree-of-freedom system preserving the oil-film oscillation property by introducing the modified proper orthogonal decomposition （POD） method. The effi- ciency of the method is shown by numerical simulations for both the original and reduced systems. The Chen-Longford （C-L） method is introduced to get the dynamical behaviors of the reduced system that reflect the natural property of the oil-film oscillation.展开更多
目的:研究白毛乌蔹莓(Cayratia albifolia C. L. Li)乙醇提取物不同萃取部位抗氧化活性。方法:以VC为阳性对照,选取清除1,1-diphenyl-2-picrylhydrazyl (DPPH)自由基清除能力为抗氧化指标,探究白毛乌蔹莓乙醇提取物不同萃取部位抗氧化...目的:研究白毛乌蔹莓(Cayratia albifolia C. L. Li)乙醇提取物不同萃取部位抗氧化活性。方法:以VC为阳性对照,选取清除1,1-diphenyl-2-picrylhydrazyl (DPPH)自由基清除能力为抗氧化指标,探究白毛乌蔹莓乙醇提取物不同萃取部位抗氧化活性。结果:正丁醇层、乙酸乙酯层、二氯甲烷层、石油醚层DPPH清除能力分别为2.76、0.48、16.99、3.03 (mg/g) VC当量。结论:白毛乌蔹莓乙醇提取物二氯甲烷层的抗氧化能力最强,其次是石油醚层,正丁醇层,乙酸乙酯层活性最弱。展开更多
文摘The C-L method was generalized from Liapunov-Schmidt reduction method, combined with theory of singularities, for study of non-autonomous dynamical systems to obtain the typical bifurcating response curves in the system parameter spaces. This method has been used, ar an example, to analyze the engineering nonlinear dynamical problems by obtaining the bifurcation programs and response curves which are useful in developing techniques of control to subharmonic instability of large rotating machinery.
文摘The topological bifurcation diagrams and the coefficients of bifurcation equation were obtained by C_L method.According to obtained bifurcation diagrams and combining control theory,the method of robust control of periodic bifurcation was presented,which differs from generic methods of bifurcation control.It can make the existing motion pattern into the goal motion pattern.Because the method does not make strict requirement about parametric values of the controller,it is convenient to design and make it.Numerical simulations verify validity of the method.
基金Project supported by the National Natural Science Foundation of China (No. 11072065)
文摘The oil-film oscillation in dimensional nonlinear problem. In this a large rotating machinery is a complex high- paper, a high pressure rotor of an aero engine with a pair of liquid-film lubricated bearings is modeled as a twenty-two-degree-of-freedom nonlinear system by the Lagrange method. This high-dimensional nonlinear system can be reduced to a two-degree-of-freedom system preserving the oil-film oscillation property by introducing the modified proper orthogonal decomposition （POD） method. The effi- ciency of the method is shown by numerical simulations for both the original and reduced systems. The Chen-Longford （C-L） method is introduced to get the dynamical behaviors of the reduced system that reflect the natural property of the oil-film oscillation.
文摘目的:研究白毛乌蔹莓(Cayratia albifolia C. L. Li)乙醇提取物不同萃取部位抗氧化活性。方法:以VC为阳性对照,选取清除1,1-diphenyl-2-picrylhydrazyl (DPPH)自由基清除能力为抗氧化指标,探究白毛乌蔹莓乙醇提取物不同萃取部位抗氧化活性。结果:正丁醇层、乙酸乙酯层、二氯甲烷层、石油醚层DPPH清除能力分别为2.76、0.48、16.99、3.03 (mg/g) VC当量。结论:白毛乌蔹莓乙醇提取物二氯甲烷层的抗氧化能力最强,其次是石油醚层,正丁醇层,乙酸乙酯层活性最弱。
