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381.
382.
L. A. BARRIE Y. YI W. R. LEAITCH U. LOHMANN P. KASIBHATLA G.J. ROELOFS J. WILSON F. McGOVERN C. BENKOVITZ M. A. MÉLIÈRES K. LAW J. PROSPERO M. KRITZ D. BERGMANN C. BRIDGEMAN M. CHIN J. CHRISTENSEN R. EASTER J. FEICHTER C. LAND A. JEUKEN E. KJELLSTRÖM D. KOCH P. RASCH 《Tellus. Series B, Chemical and physical meteorology》2001,53(5):615-645
383.
DAVID LEE DUEWER 《地理学报(英文版)》1990,(4)
The Free-Wilson paradigm is an established and powerful tool for quantitatively relating activity withchemical structure.Current implementations of the paradigm,however,are flawed both conceptually andin execution.As part of an attempt to more fully realize the promise of the paradigm,it was necessaryto examine these limitations in detail.This report introduces a robust,theory-founded Free-Wilson implementation:stepwise principalcomponents regression analysis(SPCRA).SPCRA is computationally superior to previousimplementations but does not in itself correct their conceptual flaws.The development of SPCRA did,however,facilitate derivation of a simple and chemically significantinterpretation of the Free-Wilson structure-activity model.A number of statistical aspects of this modelcommonly misused in previous applications are discussed at length.These discussions provide criticalbackground for the development of an alternative implementation of the Free-Wilson paradigm. 相似文献
384.
385.
K. U. Lu 《Astrophysics and Space Science》1995,225(2):227-235
A non-static General Relativistic mathematical solution for the gravitational field around a star is obtained. From this mathematical solution, the orbits of the planets around the Sun are calculated and compared with Bode's law and the mean distances of the orbits, the origin of the Moon is deduced, and a theory for quantilization of gravity is concluded. 相似文献
386.
387.
The paper deals with the propagation of shock waves at the surface of soils. Heterogeneity and damping are introduced into analytical half-space solutions. The suggested model explains two phenomena, often observed with shock propagation in actual soils, that differ from the behaviour of the homogeneous half-space: the pronounced decay of the disturbances with distance and the elongation of the disturbance into a train of waves. The effects of heterogeneity and damping are discussed quantitatively. The response of footings on heterogeneous soils has been investigated by several authors. Awojobi4 considered the Gibson soil in which the shear modulus increases linearly with depth. Luco5 and Gazetas and Roesset6 investigated a multi-layered soil, the shear modulus being constant within each layer. Gazetas7, using a technique suggested by Gupta8 extended this method to layers with linearly varying shear modulus. Little work is available on the propagation of waves in heterogeneous bodies. Some results concerning the modes and the mode shapes in heterogeneous soils were reported by Ewing, Jardetzky and Press9 and Bath.10 The modes have to be superposed in an appropriate way to obtain the displacement field at the surface. This has been approximately achieved by the finite element formulations of Lysmer, 11, Lysmer and Waas12 and Waas.13 Auersch14 applied this method to a homogeneous layer on a rigid base. He found some dispersion of the Rayleigh wave within a narrow frequency range. Finite elements combined with discrete Laplace transforms, however, consume much computer time. Rao and Goda15 and Rao16 calculated surface vibrations of a half-space with exponentially varying shear modulus and density. Their method is similar to Lamb'S1 procedure for the homogeneous half-space. Only one mode–the Rayleigh wave–occurs in their heterogeneous half-space. The examples show the considerable effect of heterogeneity on wave propagation. In the present paper, more general variations of the shear modulus are considered. 相似文献
388.
U. De Angelis L. De Cesare A. Forlani G. Platania 《Astrophysics and Space Science》1974,27(1):217-225
The evolution of the central stars of planetary nebulae, interpreted as hot white dwarfs with liquefying cores, towards the cold white dwarf stage is discussed and theoretical (non-computational) evolutionary tracks are built for such central stars as they cool towards the crystallizing region. The conclusions seem to hint a picture in which crystalline white dwarfs can be looked at as final stages of the central stars of planetary nebulae. 相似文献
389.
N.BRATCHELL 《地理学报(英文版)》1989,(3)
Analysis of multivariate response data by modelling the principal components of the response has beenapplied to two sets of data. In both cases principal components analysis revealed the relationships amongthe response variables and exploited them to simplify the problem of modelling and optimizing themultivariate response. The models and optima obtained from the principal components comparedfavourably with the individual models and simultaneous optima. 相似文献
390.
Abstract A detailed field and petrological study of rocks from nappes cut by the Valle dell'Orco (Italian Western Alps), in particular the Sesia–Lanzo composite unit, has revealed geological and metamorphic histories which started in pre-alpine times and lasted up to the alpine subduction-collisional processes. During these processes the nappes sustained an early high P–low T stage and a later low P greenschist facies stage, but followed partly distinctive P–T–time trajectories. This paper discusses the kinematic evolution and the thermal history of the alpine belt from the early subduction/underthrust to the later exhumation stage. The metamorphic crystallization is often governed by incomplete and/or local equilibrium, and the pervasive syn-metamorphic deformation and the composition of the syn-metamorphic fluid phase (if present) have exerted an effective local control on reaction kinetics. 相似文献