Numerical simulation in the frequency-space domain has inherent advantages, such as： it is possible to simulate wave propagation from multiple sources simultaneously; there are no cumulative errors; only the interest...Numerical simulation in the frequency-space domain has inherent advantages, such as： it is possible to simulate wave propagation from multiple sources simultaneously; there are no cumulative errors; only the interesting frequencies can be selected; and it is more suitable for wave propagation in viscoelastic media. The only obstacle to using the method is the requirement of huge computer storage. We extend the compressed format for storing the coefficient matrix. It can reduce the required computer storage dramatically. We get the optimal coefficients by least-squares method to suppress the numerical dispersion and adopt the perfectly matched layer （PML） boundary conditions to eliminate the artificial boundary reflections. Using larger grid intervals decreases computer storage requirements and provides high computational efficiency. Numerical experiments demonstrate that these means are economic and effective, providing a good basis for elastic wave imaging and inversion.展开更多
In this paper,we give the explicit expressions of the differential operator representations of the exceptional Lie superalgebra D(2,1;α).Based on these expressions,we construct free field realizations of the currents...In this paper,we give the explicit expressions of the differential operator representations of the exceptional Lie superalgebra D(2,1;α).Based on these expressions,we construct free field realizations of the currents associated with D(2,1;α) at an arbitrary level k.展开更多
基金supported by the 863 Program (Grant no.2006AA09Z323)the 973 Program (Grant No.2006CB202402)
文摘Numerical simulation in the frequency-space domain has inherent advantages, such as： it is possible to simulate wave propagation from multiple sources simultaneously; there are no cumulative errors; only the interesting frequencies can be selected; and it is more suitable for wave propagation in viscoelastic media. The only obstacle to using the method is the requirement of huge computer storage. We extend the compressed format for storing the coefficient matrix. It can reduce the required computer storage dramatically. We get the optimal coefficients by least-squares method to suppress the numerical dispersion and adopt the perfectly matched layer （PML） boundary conditions to eliminate the artificial boundary reflections. Using larger grid intervals decreases computer storage requirements and provides high computational efficiency. Numerical experiments demonstrate that these means are economic and effective, providing a good basis for elastic wave imaging and inversion.
基金Support from the National Natural Science Foundation of China under Grant Nos.10931006,10975180,and 11075126the Ministry of Education of China under Grant No.20116101110017Northwest University Graduate Cross-Discipline Fund (10YJC15)
文摘In this paper,we give the explicit expressions of the differential operator representations of the exceptional Lie superalgebra D(2,1;α).Based on these expressions,we construct free field realizations of the currents associated with D(2,1;α) at an arbitrary level k.
