空值环境下关系数据库的更新 Ⅰ：扩展关系模型及基本运算

本文从空值语义及更新操作的关系出发，提出了一种新的扩展关系模型，用以组织更新操作下的含有空值的关系数据库中的信息．同时，定义了这种模型下的基本关系代数运算．为实现空值环境下关系数据库的数据更新奠定了基础。

空值环境下关系数据库的更新 Ⅱ：更新处理的插入、删除和修改操作算法

本文的这部分是以扩展模型为基础，以五种运算为工具，对空值环境下关系数据库的更新处理策略做了深入研究，并给出了相应的算法及算法分析。

叠前地震数据规则化、重建及噪音压制

I address of reconstruction of spatial irregular sampling seismic data to regular grids. Spatial irregular sampling data impairs results of prestack migration, multiple attenuations, spectra estimation. Prestack 5-D volumes are often divided into sub-sections for further processing. Shot gathers are easy to obtain from irregular sampling volumes. My strategy for reconstruction is as follows: I resort irregular sampling gathers into a form of easy to bin and perform bin regularization, then utilize F-K inversion to reconstruct seismic data. In consideration of poor ability of F-K regularization to fill in large gaps, I sort regular sampling gathers to CMP and proposed high-resolution parabolic Radon transform to interpolate data and extrapolate offsets. To strong interfering noise--multiples, I use hybrid-domain high-resolution parabolic Radon transform to attenuate it. F-K regularization demand ultimately for lower computing costs. I proposed several methods to further improve efficiency of F-K inversion: first I introduce 1D and 2D NFFT algorithm for a rapid calculation of DFT operators; then develop fast 1D and 2D CG method to solve least-square equations, and utilize preconditioner to accelerate convergence of CG iterations; what’s more, I use Delaunay triangulation for weight calculation and use bandlimit frequency and varying bandwidth technique for competitive computation. Numerical 2D and 3D examples are offered to verify reasonable results and more efficiency. F-K regularization has poor ability to fill in large gaps, so I rearrange data as CMP gathers and develop hybrid-domain high-resolution parabolic Radon transforms which be used ether to interpolate null traces and extrapolate near and far offsets or suppress a strong interfere noise: multiples. I use it to attenuate multiples to verify performances of our algorithm and proposed routines for industrial application. Numerical examples and field data examples show a nice performance of our method.

贵州将军洞上覆土层对滴水水化学特征的影响

对贵州安顺将军洞4 个滴水点进行为期1a 的动态监测. 将军洞滴水对大气降雨的响应极快(0～9d) . 滴水的物质来源于土壤. 由于滴水点上覆土壤厚度的差异,极大地影响到滴水水化学特点. 水通过的土壤较薄时,溶解的物质量少,降低了滴水点发生稀释作用的可能,也使得岩石对滴水化学组成的贡献增大. 样点JJD21 、JJD24 滴水在一定程度上受到稀释作用的影响,而JJD21 滴水运移过程中还受到不同源来水的影响产生了“活塞效应”,JJD22 滴水也受到不同源来水的影响而产生滴率的跳跃式变化,这些作用只在次一级作用强度上对滴水水化学产生影响. 岩石的溶解作用以及方解石的沉淀作用控制了洞穴4 个滴水点水运移过程中所发生的地球化学作用. 因此,土壤作为一个重要的岩溶环境因素决定和控制了洞穴滴水的水化学特点,应该给予必要的重视.

贵州七星洞滴水的水文水化学特征及其意义

本文对贵州都匀七星洞9 个滴水点进行了为期1 年的动态监测,结果显示滴水的物质组成直接源自于洞穴环境,即土壤和岩石,而大气降雨携带的物质成分较少。洞穴滴水的化学组成中元素含量变化主要由水运移过程中水- 土、水- 岩作用导致的岩石溶解- 方解石沉淀过程所控制。QXD21 # 、QXD22 # 、QXD26 # 、QXD27 # 、QXD28 # 由于水运移过程中经过的土壤较薄,水- 岩作用对滴水化学特性的贡献略大。稀释作用发生在干旱条件下的QXD22 # 滴水点,活塞作用在雨季对QXD27 # 、QXD29 # 滴水产生影响,在不同的季节, QXD21 # 、QXD23 # 、QXD28 # 滴水点的滴率产生跳跃式变化。这些作用均受控于水的来源差异,所有这些过程对滴水点水化学产生影响但其效果较弱。滴水的MgPCa 指示了大气降雨的变化,其值受控于洞穴顶板内水运移过程中水- 土、水- 岩作用下的水文地球化学过程即岩石的溶解、方解石沉淀过程及土壤物理、化学、生物学过程等。