为全面准确地描述地震相特征,在地震相分析中引入了时频分析技术,如短时窗傅里叶变换、Cabor 变换、小波变换等。之后发展起来的 S 变换时频分析方法综合了短时窗傅里叶变换和小波变换的优点,具有线性化、无损可逆性以及高时频分辨率等...为全面准确地描述地震相特征,在地震相分析中引入了时频分析技术,如短时窗傅里叶变换、Cabor 变换、小波变换等。之后发展起来的 S 变换时频分析方法综合了短时窗傅里叶变换和小波变换的优点,具有线性化、无损可逆性以及高时频分辨率等特性。阐述了 S 变换的基本理论,并利用 S 变换对理想的地震序列模型以及实际地震资料进行了地震相分析。通过对地震相特征的连续性以及振幅和频率变化特征的分析发现,对于规模较小的地震相体,在时间剖面上很难识别其层序内的地震相特征(特别是频率)随旅行时的变化情况,但在 S 变换的时频域内可以被清楚地体现出来。因此,在进行沉积环境识别时,可以利用 S 变换来提供有效地震信息。展开更多
Let R = k[x1,...,xn], where k is a field. The path ideal （of length t ≥ 2） of a directed graph G is the monomial ideal], denoted by It （G）, whose generators correspond to the directed paths of length t in G. Let ...Let R = k[x1,...,xn], where k is a field. The path ideal （of length t ≥ 2） of a directed graph G is the monomial ideal], denoted by It （G）, whose generators correspond to the directed paths of length t in G. Let F be a directed rooted tree. We characterize all such trees whose path ideals are unmixed and Cohen-Macaulay. Moreover, we show that R/It（F） is Corenstein if and only if the Stanley-Reisner simplicial complex of It（Г） is a matroid.展开更多
The standard Podle′s quantum sphere is Artin-Schelter regular as showed by Kra¨hmer(2012).The non-standard Podle′s quantum spheres are proved to be Auslander-regular,Cohen-Macaulay and Artin-Schelter regular in...The standard Podle′s quantum sphere is Artin-Schelter regular as showed by Kra¨hmer(2012).The non-standard Podle′s quantum spheres are proved to be Auslander-regular,Cohen-Macaulay and Artin-Schelter regular in this paper.展开更多
文摘为全面准确地描述地震相特征,在地震相分析中引入了时频分析技术,如短时窗傅里叶变换、Cabor 变换、小波变换等。之后发展起来的 S 变换时频分析方法综合了短时窗傅里叶变换和小波变换的优点,具有线性化、无损可逆性以及高时频分辨率等特性。阐述了 S 变换的基本理论,并利用 S 变换对理想的地震序列模型以及实际地震资料进行了地震相分析。通过对地震相特征的连续性以及振幅和频率变化特征的分析发现,对于规模较小的地震相体,在时间剖面上很难识别其层序内的地震相特征(特别是频率)随旅行时的变化情况,但在 S 变换的时频域内可以被清楚地体现出来。因此,在进行沉积环境识别时,可以利用 S 变换来提供有效地震信息。
文摘Let R = k[x1,...,xn], where k is a field. The path ideal （of length t ≥ 2） of a directed graph G is the monomial ideal], denoted by It （G）, whose generators correspond to the directed paths of length t in G. Let F be a directed rooted tree. We characterize all such trees whose path ideals are unmixed and Cohen-Macaulay. Moreover, we show that R/It（F） is Corenstein if and only if the Stanley-Reisner simplicial complex of It（Г） is a matroid.
基金supported by National Natural Science Foundation of China (Grant Nos. 10731070 and 11171067)Science and Technology Committee,Shanghai Municipality (Grant No. 11XD1400500)a training program for innovative talents of key disciplines,Fudan University
文摘The standard Podle′s quantum sphere is Artin-Schelter regular as showed by Kra¨hmer(2012).The non-standard Podle′s quantum spheres are proved to be Auslander-regular,Cohen-Macaulay and Artin-Schelter regular in this paper.
