Discontinuous and long-duration thunderstorm weather, which occurred at Guanghan in Sichuan Province, was analyzed and predicted using structural conversion of irregular information in phase-space from self-recording ...Discontinuous and long-duration thunderstorm weather, which occurred at Guanghan in Sichuan Province, was analyzed and predicted using structural conversion of irregular information in phase-space from self-recording “time sequence” records for predicting rain areas, as described in the “Non Destructive Information” method proposed by Professor OuYang Shoucheng. The results show that this method can reveal important changes of weather as well as, by using irregular self-recording information recorded every ten minutes, predict local thunderstorms with durations of only half an hour, and even predict intense convections 12 hours in advance. This is significant for civil and military aviation. It shows the necessity of full utilization of information from automatic weather stations and the necessity of improvements in recording modes in current automatic stations.展开更多
To investigate the buckling and post buckling behaviors of elastic thin plate under frictionless unilateral restraint, enduring the coupling action of lognitudinal and transverse loads, the principle of minimum poten...To investigate the buckling and post buckling behaviors of elastic thin plate under frictionless unilateral restraint, enduring the coupling action of lognitudinal and transverse loads, the principle of minimum potential energy and variational method are used and series functions with unknown coefficients are taken as trial functions of functional to solve the large deflection and non linear bending problem of a thin plate and find relation curves between deflection of plate and loads. The proposed method can capture the buckling and post buckling behaviors of a thin plate in different geometrical and load boundary conditions. The analysis confirms that there occur snap and bifurcation behaviors in the post buckling stage of the plate. And these results show the validity of the variational method for solving buckling problems of thin plate.展开更多
A finite element algorithm combined with divergence condition was presented for computing three-dimensional(3D) magnetotelluric forward modeling. The finite element equation of three-dimensional magnetotelluric forwar...A finite element algorithm combined with divergence condition was presented for computing three-dimensional(3D) magnetotelluric forward modeling. The finite element equation of three-dimensional magnetotelluric forward modeling was derived from Maxwell's equations using general variation principle. The divergence condition was added forcedly to the electric field boundary value problem, which made the solution correct. The system of equation of the finite element algorithm was a large sparse, banded, symmetric, ill-conditioned, non-Hermitian complex matrix equation, which can be solved using the Bi-CGSTAB method. In order to prove correctness of the three-dimensional magnetotelluric forward algorithm, the computed results and analytic results of one-dimensional geo-electrical model were compared. In addition, the three-dimensional magnetotelluric forward algorithm is given a further evaluation by computing COMMEMI model. The forward modeling results show that the algorithm is very efficient, and it has a lot of advantages, such as the high precision, the canonical process of solving problem, meeting the internal boundary condition automatically and adapting to all kinds of distribution of multi-substances.展开更多
基金The project is funded by Youth Scientific Research Foundation of CAFUC (Q2003-23).
文摘Discontinuous and long-duration thunderstorm weather, which occurred at Guanghan in Sichuan Province, was analyzed and predicted using structural conversion of irregular information in phase-space from self-recording “time sequence” records for predicting rain areas, as described in the “Non Destructive Information” method proposed by Professor OuYang Shoucheng. The results show that this method can reveal important changes of weather as well as, by using irregular self-recording information recorded every ten minutes, predict local thunderstorms with durations of only half an hour, and even predict intense convections 12 hours in advance. This is significant for civil and military aviation. It shows the necessity of full utilization of information from automatic weather stations and the necessity of improvements in recording modes in current automatic stations.
文摘To investigate the buckling and post buckling behaviors of elastic thin plate under frictionless unilateral restraint, enduring the coupling action of lognitudinal and transverse loads, the principle of minimum potential energy and variational method are used and series functions with unknown coefficients are taken as trial functions of functional to solve the large deflection and non linear bending problem of a thin plate and find relation curves between deflection of plate and loads. The proposed method can capture the buckling and post buckling behaviors of a thin plate in different geometrical and load boundary conditions. The analysis confirms that there occur snap and bifurcation behaviors in the post buckling stage of the plate. And these results show the validity of the variational method for solving buckling problems of thin plate.
基金Project(60672042) supported by the National Natural Science Foundation of China
文摘A finite element algorithm combined with divergence condition was presented for computing three-dimensional(3D) magnetotelluric forward modeling. The finite element equation of three-dimensional magnetotelluric forward modeling was derived from Maxwell's equations using general variation principle. The divergence condition was added forcedly to the electric field boundary value problem, which made the solution correct. The system of equation of the finite element algorithm was a large sparse, banded, symmetric, ill-conditioned, non-Hermitian complex matrix equation, which can be solved using the Bi-CGSTAB method. In order to prove correctness of the three-dimensional magnetotelluric forward algorithm, the computed results and analytic results of one-dimensional geo-electrical model were compared. In addition, the three-dimensional magnetotelluric forward algorithm is given a further evaluation by computing COMMEMI model. The forward modeling results show that the algorithm is very efficient, and it has a lot of advantages, such as the high precision, the canonical process of solving problem, meeting the internal boundary condition automatically and adapting to all kinds of distribution of multi-substances.
