Two new types of conserved quantities directly deduced by Mei symmetry of holonomic mechanical system are studied. The definition and criterion of Mei symmetry for holonomic system are given. A coordination function i...Two new types of conserved quantities directly deduced by Mei symmetry of holonomic mechanical system are studied. The definition and criterion of Mei symmetry for holonomic system are given. A coordination function is introduced, the conditions under which the Mei symmetry can directly lead to the two types of conserved quantities and the forms of the two types of conserved quantities are obtained. An illustrative example is given. The result indicates that the coordination function can be selected properly according to the demand of the gauge function, thereby the gauge function can be found out more easily. Furthermore, since the choice of the coordination function has multiformity, much T more conserved quantity of Mei symmetry for holonomic mechanical system can be obtained.展开更多
The development of modern science and technology has promoted the overlapping and mutual penetration among different disciplines, which led to the technological innovations in the field of mechanical engineering. The ...The development of modern science and technology has promoted the overlapping and mutual penetration among different disciplines, which led to the technological innovations in the field of mechanical engineering. The mechatronics technology conforms to the law of development of science and technology in today, and combines the mechanical technology and electronic technology together to integrate the logistics, energy flow and information flow. This paper briefly describes the concept of mechatronics and the elements of mechatronics technology, and elaborates on the application of mechatronics technology in three different areas of the Machinery Industry in the form of living examples, finally introduces the future developing direction of mechatronics technology.展开更多
Mechanoluminescent(ML)materials can directly convert external mechanical stimulation into light without the need for excitation from other forms of energy,such as light or electricity.This alluring characteristic make...Mechanoluminescent(ML)materials can directly convert external mechanical stimulation into light without the need for excitation from other forms of energy,such as light or electricity.This alluring characteristic makes ML materials potentially applicable in a wide range of areas,including dynamic imaging of force,advanced displays,information code,storage,and anti-counterfeiting encryption.However,current reproducible ML materials are restricted to sulfide-and oxide-based materials.In addition,most of the reported ML materials require pre-irradiation with ultraviolet(UV)lamps or other light sources,which seriously hinders their practical applications.Here,we report a novel ML material,MgF_(2):Mn^(2+),which emits bright red light under an external dynamic force without the need for pre-charging with UV light.The luminescence properties were systematically studied,and the piezophotonic application was demonstrated.More interestingly,unlike the well-known zinc sulfide ML complexes reported previously,a highly transparent ML film was successfully fabricated by incorporating MgF_(2):Mn^(2+)into polydimethylsiloxane(PDMS)matrices.This film is expected to find applications in advanced flexible optoelectronics such as integrated piezophotonics,artificial skin,athletic analytics in sports.展开更多
文摘Two new types of conserved quantities directly deduced by Mei symmetry of holonomic mechanical system are studied. The definition and criterion of Mei symmetry for holonomic system are given. A coordination function is introduced, the conditions under which the Mei symmetry can directly lead to the two types of conserved quantities and the forms of the two types of conserved quantities are obtained. An illustrative example is given. The result indicates that the coordination function can be selected properly according to the demand of the gauge function, thereby the gauge function can be found out more easily. Furthermore, since the choice of the coordination function has multiformity, much T more conserved quantity of Mei symmetry for holonomic mechanical system can be obtained.
文摘The development of modern science and technology has promoted the overlapping and mutual penetration among different disciplines, which led to the technological innovations in the field of mechanical engineering. The mechatronics technology conforms to the law of development of science and technology in today, and combines the mechanical technology and electronic technology together to integrate the logistics, energy flow and information flow. This paper briefly describes the concept of mechatronics and the elements of mechatronics technology, and elaborates on the application of mechatronics technology in three different areas of the Machinery Industry in the form of living examples, finally introduces the future developing direction of mechatronics technology.
基金financial support from the Advanced Talents Incubation Program of Hebei University (521100221006)financial support from the National Natural Science Foundation of China (11974097)+2 种基金the Natural Science Foundation of Hebei Province (A2019201073)support from the National Natural Science Foundation of China (61875136)the Fundamental Research Project of Guangdong Province (2020A1515011315)
文摘Mechanoluminescent(ML)materials can directly convert external mechanical stimulation into light without the need for excitation from other forms of energy,such as light or electricity.This alluring characteristic makes ML materials potentially applicable in a wide range of areas,including dynamic imaging of force,advanced displays,information code,storage,and anti-counterfeiting encryption.However,current reproducible ML materials are restricted to sulfide-and oxide-based materials.In addition,most of the reported ML materials require pre-irradiation with ultraviolet(UV)lamps or other light sources,which seriously hinders their practical applications.Here,we report a novel ML material,MgF_(2):Mn^(2+),which emits bright red light under an external dynamic force without the need for pre-charging with UV light.The luminescence properties were systematically studied,and the piezophotonic application was demonstrated.More interestingly,unlike the well-known zinc sulfide ML complexes reported previously,a highly transparent ML film was successfully fabricated by incorporating MgF_(2):Mn^(2+)into polydimethylsiloxane(PDMS)matrices.This film is expected to find applications in advanced flexible optoelectronics such as integrated piezophotonics,artificial skin,athletic analytics in sports.
