解流体动力弥散问题的等参数溶质质量均衡近似有限元法

本文根据流体动力弥散理论,按地下水中溶质局部质量守恒原理,采用非线性基函数,对单元内的渗透速度和弥散系数作了平均化近似处理,导出了求解流体动力弥散问题的另一种新的数值法——等参数溶质质量均衡近似有限元法。与作者在文献〔1〕中给出的较精确的算法相比,虽不甚精细,但计算工作量大为减小,并保持了文献〔1〕中方法的主要优点,比较简便易行。     

三角网数字地面模型与农田平整设计

针对农田水利工程中农田纵横坡度设计与填挖土方计算问题，本文提出了三角网地面模型，推证了地面坐标转化为设计面坐标的坐标转化公式及三角形模型体积计算公式，给出了设计计算的逐步趋近算法。     

A New Symbolic Processor for the Earth Rotation Theory

In this paper we present a new symbolic processor specially suited for the Earth rotation theory. This processor works with a more general kind of Poisson series called Kinoshita series, which has resulted to be very useful in the Earth rotation theory. Its structure is adapted for dealing with the more general analytical expressions that appear in the Earth rotation theory. This new algebraic processor has been successfully used for computing different contributions to the nutation series of the rigid Earth.This revised version was published online in October 2005 with corrections to the Cover Date.     

Orbital Elements of 2004 Perseid Meteoroids Perturbed by Jupiter

Jupiter and Saturn produce important gravitational impulses on meteoroids released by comet 109P/Swift-Tuttle. The meteoroids from this comet once released follow retrograde orbits that during their periodic approaches to these planets (within 1.6 and 0.9 A.U., respectively) are impulsed gaining orbital energy. This perturbation effect is translated into a net inward shift in the node of the perturbed meteoroids. Such geometry with Jupiter occurred in 2004 over a meteoroid trail ejected by this comet during the 1862 A.D. return of the comet to perihelion. In order to study the predicted outburst produced by one-revolution meteoroids, the Spanish Photographic Meteor Network (SPMN) performed an extensive campaign. As a part of this observational effort here are presented 10 accurate meteoroid orbits. We discuss their origin by comparing them with the theoretical orbital elements of the dust trails intercepting the Earth during the 2004 Perseid return.     

Using SHRIMP zircon dating to unravel tectonothermal events in arc environments. The early Palaeozoic arc of NW Iberia revisited

Abstract Dating of zircon cores and rims from granulites developed in a shear zone provides insights into the complex relationship between magmatism and metamorphism in the deep roots of arc environments. The granulites belong to the uppermost allochthonous terrane of the NW Iberian Massif, which forms part of a Cambro‐Ordovician magmatic arc developed in the peri‐Gondwanan realm. The obtained zircon ages confirm that voluminous calc‐alkaline magmatism peaked around 500 Ma and was shortly followed by granulite facies metamorphism accompanied by deformation at c. 480 Ma, giving a time framework for crustal heating, regional metamorphism, deformation and partial melting, the main processes that control the tectonothermal evolution of arc systems. Traces of this arc can be discontinuously followed in different massifs throughout the European Variscan Belt, and we propose that the uppermost allochthonous units of the NW Iberian Massif, together with the related terranes in Europe, constitute an independent and coherent terrane that drifted away from northern Gondwana prior to the Variscan collisional orogenesis.     

山东构造地质调查研究史略及主要学术观点

文章依据文献资料,扼要叙述了历史上著名自然科学家、国内外知名学者对山东构造地质的考察和有关论述。系统的介绍了国内各大地构造学派对山东构造地质的学术观点、重要建树和研究现状,读者可望从中得到有益的启发。     

解流体动力弥散问题的等参数溶质质量均衡有限元法

本文根据流体动力弥散理论,按照地下水中溶质局部质量守恒原理,采用非线性基函数,导出了求解流体动力弥散问题的一种新的数值法,即等参数溶质质量均衡有限元法。该法与采用同样非线性基函数的等参数里茨(Ritz)法或伽辽全法相比,具有物理意义明确、能准确反映局部质量均衡关系、计算公式简单和易于应用等优点。