密度泛函理论对ZrnPd团簇结构和性质的研究

用B3LYP/LANL2DZ方法对Zr_nPd(n =1—13)团簇的平衡几何结构、能量、频率、电子性质和磁性进行了计算.研究表明,Pd原子位于表面的异构体更为稳定,其中Zr₇Pd,Zr₁₂Pd团簇稳定性高,是幻数团簇;此外,相对于Zr_nCo与Zr_nFe团簇,Zr_nPd团簇参与化学反应的能力较弱,化学稳定性更     

渤海海域莱州湾凹陷KL11-2地区盐构造特征

本文主要利用最新的钻井和三维地震资料对渤海海域莱州湾凹陷盐构造几何形态、形成演化及其控制机理进行分析。莱州湾凹陷沙河街组四段含有较厚的岩盐和膏盐层,并在KL11-2地区发生聚集隆起,形成典型的盐底辟(盐枕)构造。KL11-2地区盐构造外部形态在不同地区发生了明显变化,从南向北,逐渐由过成熟底辟向成熟底辟和盐枕变化,南部的盐构造已进入底辟后演化阶段,而北部的盐构造仍处于盐枕阶段。受盐体塑性流动影响,盐构造周缘还发育有盐撤凹陷和阶状反向断层等盐相关构造。KL11-2地区盐构造的形成主要受伸展作用、重力滑动、浮力、沉积差异负载、基底构造以及郯庐断裂带的走滑作用等因素影响,主控因素为伸展作用背景下的重力滑动作用,但郯庐断裂带的走滑作用对盐体的塑性流动及其最终定位也有重要的影响。     

Unification Of Non-Dimensional Solutions To Asymptotic Equations For Plumes Of Different Shape

A model of buoyant fluid rise is developed in aLagrangian framework. Results from the model arevalidated by comparison with laboratory and fieldexperiments. The model is sufficiently general toinclude geometries of any cross-sectional shape. Exact solutions to the asymptotic equations forcontinuous discharges from line and point sources andfor an instantaneous discharge from a point source areconsidered. Prismatic, cylindrical andspherical shapes approximate these three geometries,respectively. Accommodation of these shapes withinthe same general model allows for direct comparison. It is shown that, for discharges into a cross-flowthat may be stratified or unstratified, thenon-dimensional trajectory, thickness and dilution canbe uniquely specified using three parameters. Theseare the non-dimensional size of the source, therelative importance of the initial fluxes of momentumand buoyancy and the number of orthogonal axes throughwhich entrainment can occur. Such non-dimensionalresults are particularly useful for examining thosescenarios for which there are limited experimentaldata.     

Non‐uniqueness and symmetry in stratigraphic interpretations: A quantitative approach for determining stratal controls

Different combinations of stratal controls could produce identical sequence architectures. Consequently, interpretations of the stratigraphic record, for example to infer palaeo‐climate and eustatic sea‐level history, suffer from non‐uniqueness. However, variations in the multiple controls can be encapsulated through discovery of all possible solutions to an interpretation. As this paper demonstrates, a single solution can be directly transformed into an alternative solution that leaves the expected geological outcomes unaltered, which can be regarded as the existence of symmetry in the interpretation. Repetitive application of the symmetry method can therefore allow additional solutions to be rapidly derived given an existing solution. The proposed method has been adapted to a stratigraphic forward model for interpreting the Baltimore Canyon (USA) stratigraphy. Modelling results have indicated the ranges of changes in relative sea‐level, sediment supply and subaerial erosion from Oligocene to Mid‐Miocene. Using these limits, it is possible to determine what appears to be true in the palaeo‐history, even when a solution is not unique.