针对方波-三角波-正弦波变换电路实验问题,设计了基于NI ELVIS Ⅱ+平台的波形变换电路实验.首先介绍了利用运算放大器进行波形变换电路实验教学的整个过程,通过理论分析确定实验方案,然后在Multisim软件上进行仿真,最后在NI ELVIS Ⅱ+...针对方波-三角波-正弦波变换电路实验问题,设计了基于NI ELVIS Ⅱ+平台的波形变换电路实验.首先介绍了利用运算放大器进行波形变换电路实验教学的整个过程,通过理论分析确定实验方案,然后在Multisim软件上进行仿真,最后在NI ELVIS Ⅱ+平台上搭建电路进行仿真验证和数据测试.展开更多
A new method for receiver function inversion by wavelet transformation is presented in this paper. Receiver func-tion is expanded to different scales with different resolution by wavelet transformation. After an initi...A new method for receiver function inversion by wavelet transformation is presented in this paper. Receiver func-tion is expanded to different scales with different resolution by wavelet transformation. After an initial model be-ing taken, a generalized least-squares inversion procedure is gradually carried out for receiver function from low to high scale, with the inversion result for low order receiver function as the initial model for high order. A neighborhood containing the global minimum is firstly searched from low scale receiver function, and will gradu-ally focus at the global minimum by introducing high scale information of receiver function. With the gradual ad-dition of high wave-number to smooth background velocity structure, wavelet transformation can keep the inver-sion result converge to the global minimum, reduce to certain extent the dependence of inversion result on the initial model, overcome the nonuniqueness of generalized least-squares inversion, and obtain reliable crustal and upper mantle velocity with high resolution.展开更多
基金National Nature Science Foundation of China (49974021).
文摘A new method for receiver function inversion by wavelet transformation is presented in this paper. Receiver func-tion is expanded to different scales with different resolution by wavelet transformation. After an initial model be-ing taken, a generalized least-squares inversion procedure is gradually carried out for receiver function from low to high scale, with the inversion result for low order receiver function as the initial model for high order. A neighborhood containing the global minimum is firstly searched from low scale receiver function, and will gradu-ally focus at the global minimum by introducing high scale information of receiver function. With the gradual ad-dition of high wave-number to smooth background velocity structure, wavelet transformation can keep the inver-sion result converge to the global minimum, reduce to certain extent the dependence of inversion result on the initial model, overcome the nonuniqueness of generalized least-squares inversion, and obtain reliable crustal and upper mantle velocity with high resolution.
