Estimation of Q and inverse Q filtering for prestack reflected PP-and converted PS-waves

Multi-component seismic exploration technology, combining reflected PP- and converted PS-waves, is an effective tool for solving complicated oil and gas exploration problems. The improvement of converted wave resolution is one of the key problems. The main factor affecting converted wave resolution is the absorption of seismic waves in overlying strata. In order to remove the effect of absorption on converted waves, inverse Q filtering is used to improve the resolution. In this paper, we present a method to estimate the S-wave Q values from prestack converted wave gathers. Furthermore, we extend a stable and effective poststack inverse Q filtering method to prestack data which uses wave field continuation along the ray path to compensate for attenuation in prestack common shot PP- and PS-waves. The results of theoretical modeling prove that the method of estimating the S-wave Q values has high precision. The results from synthetic and real data prove that the stable inverse Q filtering method can effectively improve the resolution of prestack PP- and PS-waves.

用双光子电离探测技术研究奇宇称的Eu原子光谱（英文）

利用双光子电离探测技术系统地研究了Eu原子的奇宇称态的光谱。双光子电离探测技术利用两步激发获得Eu原子奇宇称态的光谱:首先将第一步激光的波长固定,而最后一步激光的波长在35 500～35 650cm^(-1),36 200～36 600 cm^(-1)和46 650～46 950 cm^(-1)三个能域范围扫描,对处于奇宇称激发态的Eu原子进行双光子电离,以实现探测其光谱信息的目的。本文系统地研究了35 500～35 650 cm^(-1),36 200～36 600 cm^(-1)和46 650～46 950 cm^(-1)能域内的光谱特征,报道了这些能域内具有特殊寿命的高激发态。通过对采用3种不同的激发路径获得的高激发态的光谱进行拟合,不仅获得了这些高激发态能级位置、线宽和线型的信息,而且还观察到奇宇称态光谱中的q反转现象。此外,通过分析所获得的3张奇宇称态的光谱,首次证明了4f壳层的电子被激发的可能性,该结果为检测新量子理论提供了可靠的实验依据。