We focus on Mei symmetry for time scales nonshifted mechanical systems within Lagrangian framework and its resulting new conserved quantities.Firstly,the dynamic equations of time scales nonshifted holonomic systems a...We focus on Mei symmetry for time scales nonshifted mechanical systems within Lagrangian framework and its resulting new conserved quantities.Firstly,the dynamic equations of time scales nonshifted holonomic systems and time scales nonshifted nonholonomic systems are derived from the generalized Hamilton’s principle.Secondly,the definitions of Mei symmetry on time scales are given and its criterions are deduced.Finally,Mei’s symmetry theorems for time scales nonshifted holonomic conservative systems,time scales nonshifted holonomic nonconservative systems and time scales nonshifted nonholonomic systems are established and proved,and new conserved quantities of above systems are obtained.Results are illustrated with two examples.展开更多
OPENING up Human Clothing and Ornament Culturology, a recently. published academic work, is like entering a comprehensive museum of the history of apparel. Readers will marvel at the extensive knowledge of clothing co...OPENING up Human Clothing and Ornament Culturology, a recently. published academic work, is like entering a comprehensive museum of the history of apparel. Readers will marvel at the extensive knowledge of clothing contained in each chapter of the thick volume, which is filled with numerous photos and illustrations. Its author is Hua Mei, a professor at the Tianjin Academy of Fine Arts. Born in 1951 to an intellectual family,展开更多
基金supported by the National Natural Science Foundation of China(Grants 11972241 and 11572212)the Natural Science Foundation of Jiangsu Province of China(Grant BK20191454).
文摘We focus on Mei symmetry for time scales nonshifted mechanical systems within Lagrangian framework and its resulting new conserved quantities.Firstly,the dynamic equations of time scales nonshifted holonomic systems and time scales nonshifted nonholonomic systems are derived from the generalized Hamilton’s principle.Secondly,the definitions of Mei symmetry on time scales are given and its criterions are deduced.Finally,Mei’s symmetry theorems for time scales nonshifted holonomic conservative systems,time scales nonshifted holonomic nonconservative systems and time scales nonshifted nonholonomic systems are established and proved,and new conserved quantities of above systems are obtained.Results are illustrated with two examples.
文摘OPENING up Human Clothing and Ornament Culturology, a recently. published academic work, is like entering a comprehensive museum of the history of apparel. Readers will marvel at the extensive knowledge of clothing contained in each chapter of the thick volume, which is filled with numerous photos and illustrations. Its author is Hua Mei, a professor at the Tianjin Academy of Fine Arts. Born in 1951 to an intellectual family,
