Based on the Weierstrass elliptic function equation, a new Weierstrass semi-rational expansion method and its algorithm are presented. The main idea of the method changes the problem solving soliton equations into ano...Based on the Weierstrass elliptic function equation, a new Weierstrass semi-rational expansion method and its algorithm are presented. The main idea of the method changes the problem solving soliton equations into another one solving the corresponding set of nonlinear algebraic equations. With the aid of Maple, we choose the modified KdV equation, (2+ 1)-dimensional KP equation, and (3+1)-dimensional Jimbo-Miwa equation to illustrate our algorithm. As a consequence, many types of new doubly periodic solutions are obtained in terms of the Weierstrass elliptic function.Moreover the corresponding new Jacobi elliptic function solutions and solitary wave solutions are also presented as simple limits of doubly periodic solutions.展开更多
In this study,we propose valley phononic crystals that consist of a hexagonal aluminum plate with six chiral arrangements of ligaments.Valley phononic crystals were introduced into a topological insulator(TI)system to...In this study,we propose valley phononic crystals that consist of a hexagonal aluminum plate with six chiral arrangements of ligaments.Valley phononic crystals were introduced into a topological insulator(TI)system to produce topologically protected edge waves(TPEW s)along the topological interfaces.The implementation of chiral topological edge states is different from the implementation of topological edge states of systems with symmetry.Unlike the conventional breaking of mirror symmetry,a new complete band with topological edge modes gap was opened up at the Dirac point by tuning the difference in lengths of the ligaments in the chiral unit cells.We investigated the dispersion properties in chiral systems and applied the dispersion properties to waveguides on the interfaces to achieve designable route systems.Furthermore,we simulated the robust propagation of TPEWs in different routes and demonstrated their immunity to backscattering at defects.Finally,the existence of the valley Hall effect in chiral systems was demonstrated.The study findings may lead to the further study of the topological states of chiral materials.展开更多
That whether unidirectional tension changes the influence of incident angle on FSS's(frequency selective surface) electromagnetic(EM) property and whether incident angle changes the effect of unidirectional intens...That whether unidirectional tension changes the influence of incident angle on FSS's(frequency selective surface) electromagnetic(EM) property and whether incident angle changes the effect of unidirectional intension on FSS's EM property is researched.The pattern and magnitude of these changes are revealed.Firstly,the analyses for the mechanism of unidirectional tension's influence and the mechanism of the coupling between the influences of unidirectional tension and incident angle are conducted.Then,according to the mechanism of these influences,Mechanics-Electromagnetics co-analysis is conducted based on mechanics finite element method and electromagnetics finite element method.The frequency responses of the FSS which is under different unidirectional tensions and illuminated by EM wave incident at different angles are gained.The concept"unidirectional tensile sensitivity of FSS"is put forward along with two unidirectional tensile sensitivity factors.By using angular sensitivity-factor and unidirectional tensile sensitivity-factor,the influences of unidirectional tension and incident angle,which are coupled with each other,are expatiated respectively.Research results show that these influences have two sides.Meanwhile,basing on Mode Matching Method and according to the results of numerical investigation,one principle for the layout of FSS with apertures is gained.Several suggestions for further research are given.展开更多
基金National Key Basic Research Project of China under，国家自然科学基金，教育部留学回国人员科研启动基金
文摘Based on the Weierstrass elliptic function equation, a new Weierstrass semi-rational expansion method and its algorithm are presented. The main idea of the method changes the problem solving soliton equations into another one solving the corresponding set of nonlinear algebraic equations. With the aid of Maple, we choose the modified KdV equation, (2+ 1)-dimensional KP equation, and (3+1)-dimensional Jimbo-Miwa equation to illustrate our algorithm. As a consequence, many types of new doubly periodic solutions are obtained in terms of the Weierstrass elliptic function.Moreover the corresponding new Jacobi elliptic function solutions and solitary wave solutions are also presented as simple limits of doubly periodic solutions.
基金supported by the National Natural Science Foundation of China(Grant Nos.11872313 and 12172297).
文摘In this study,we propose valley phononic crystals that consist of a hexagonal aluminum plate with six chiral arrangements of ligaments.Valley phononic crystals were introduced into a topological insulator(TI)system to produce topologically protected edge waves(TPEW s)along the topological interfaces.The implementation of chiral topological edge states is different from the implementation of topological edge states of systems with symmetry.Unlike the conventional breaking of mirror symmetry,a new complete band with topological edge modes gap was opened up at the Dirac point by tuning the difference in lengths of the ligaments in the chiral unit cells.We investigated the dispersion properties in chiral systems and applied the dispersion properties to waveguides on the interfaces to achieve designable route systems.Furthermore,we simulated the robust propagation of TPEWs in different routes and demonstrated their immunity to backscattering at defects.Finally,the existence of the valley Hall effect in chiral systems was demonstrated.The study findings may lead to the further study of the topological states of chiral materials.
基金the Defense Science and Technology Advance-research for Ship Industry
文摘That whether unidirectional tension changes the influence of incident angle on FSS's(frequency selective surface) electromagnetic(EM) property and whether incident angle changes the effect of unidirectional intension on FSS's EM property is researched.The pattern and magnitude of these changes are revealed.Firstly,the analyses for the mechanism of unidirectional tension's influence and the mechanism of the coupling between the influences of unidirectional tension and incident angle are conducted.Then,according to the mechanism of these influences,Mechanics-Electromagnetics co-analysis is conducted based on mechanics finite element method and electromagnetics finite element method.The frequency responses of the FSS which is under different unidirectional tensions and illuminated by EM wave incident at different angles are gained.The concept"unidirectional tensile sensitivity of FSS"is put forward along with two unidirectional tensile sensitivity factors.By using angular sensitivity-factor and unidirectional tensile sensitivity-factor,the influences of unidirectional tension and incident angle,which are coupled with each other,are expatiated respectively.Research results show that these influences have two sides.Meanwhile,basing on Mode Matching Method and according to the results of numerical investigation,one principle for the layout of FSS with apertures is gained.Several suggestions for further research are given.
