Preface     

Elisabete M. de Gouveia Dal Pino  Anthony L. Peratt  Gustavo A. Medina Tanco  Abraham C. -L. Chian 《Astrophysics and Space Science》1996,242(1-2):1-2

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Evolution of marine morphodynamic modelling: Time for 3- D?     

H. J. de Vriend 《Ocean Dynamics》1997,49(2-3):331-341

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Climatic changes in areas adjacent to the North Atlantic during the last glacial-interglacial transition (14-9 ka BP): A contribution to IGCP-253     

J. John Lowe  B. Ammann  H. H. Birks  S. Bjrck  G. R. Coope  L. Cwynar  J.-L. de Beaulieu  R. J. Mott  D. M. Peteet  M. J. C. Walker 《第四纪科学杂志》1994,9(2):185-198

This paper presents a summary of the evidence for climatic changes during the last glacial-interglacial transition (14-9 ka BP) in land areas adjacent to the North Atlantic. It is a synthesis of the results of the 12 regional summaries compiled by contributors to the North Atlantic Seaboard Programme of IGCP-253 that are published separately in this issue of Journal of Quaternary Science. Eighteen palaeotemperature curves are compared and arranged in three transects, one from southern Europe to Spitsbergen, a second from Ireland to Poland, and the third from southern New England to the Labrador-Baffin Shelf area. Ten maps are presented that summarise the synoptic climatic conditions of the region in 500-year time periods. The purpose of the exercise is to examine the extent to which any emerging patterns support the Ruddiman and Mclntyre model of large-scale shifts in the position of the oceanice Polar Front during the last glacial-interglacial transition. Some broad agreement emerges, although the influence of oceanic changes is diminished in areas that lay in close proximity to the Laurentide and Fennoscandian ice sheets. Attention is drawn to limitations in the compilations and to the potential for improved models in the future.  相似文献   

SHORT COMMUNICATION SOL1:A PROGRAM FOR THE SIMULATION OF COMPLEX EQUILIBRIA USING A PERSONAL COMPUTER     

ALVAROIZQUIERDO  JOSE-LUISBELTRAN 《地理学报(英文版)》1988,(Z1)

The program SOL1,written in Turbo-PASCAL for use on a personal computers(IBM-PC orcompatible),has been developed for calculating the equilibrium concentrations of the species inmulticomponent ligand-metal mixtures of up to 21 components and 150 species.The main features arethe easy data input system,the possibility of three different tasks(calculating the composition of a singlesolution,simulating titration curves and calculating the species distribution as a function of pH)andprocedures for drawing the calculated curves on Roland DXY plotters.The program has been tested by astudy of six different complex systems.  相似文献   

Astrophysical limits on gauge invariance breaking in electrodynamics with torsion     

C. Sivaram  L. C. Garica de Andrade 《Astrophysics and Space Science》1993,201(1):121-123

General relativistic electrodynamics in a torsion background can give rise to a situation where the photons can ahve a non-zero rest mass and magnetic moment. Astrophysical limits are used to constrain these parameters.  相似文献   

Elementary flare bursts explained by explosive coalescence     

Cornelis de Jager  Jun-ichi Sakai 《Solar physics》1991,133(2):395-398

The observed burst durations of Elementary Flare Bursts (5–25 s), as well as the related other flare characteristics, such as the temperature (30–50 MK), the electron density (log ne = 10 to 11) and the magnetic field strengths (100 G to 200 G) can be explained quantitatively by the mechanism of explosive coalescence.  相似文献   

An observational program for a unified optical-radio reference frame     

C. de Vegt  J. A. Hughes  D. Jauncey  G. White  K. J. Johnston  J. Russell  G. Nicholson 《Astrophysics and Space Science》1991,177(1-2):199-202

An observational pilot program is described which provides a first step towards the construction of an inertial extragalactic reference frame from optical and radio measurements. Candidate objects will be selected from extragalactic compact radio sources which display optical counterparts. Galactic radio stars will be secondary reference objects. The reference frame will be defined by the radio positions of the extragalactic objects. Based on a coordinated effort in both hemispheres, a global homogeneous net of about 400 quasars and 100 radio stars is expected to result from a five year campaign.  相似文献   

The dynamics of velocity fluctuations in the solar wind – I. Coronal mass ejections     

J. Cantó  R. F. González  A. C. Raga  E. M. de Gouveia Dal Pino  A. Lara  J. A. González-Esparza 《Monthly notices of the Royal Astronomical Society》2005,357(2):572-578

In this paper we present a simple, analytic model for the dynamical evolution of supersonic velocity fluctuations at the base of the ambient solar wind. These fluctuations result in the formation of dense working surfaces that travel down the wind. It is shown how the initial parameters of the fluctuations (velocity, density and duration) are related to the characteristics of the working surfaces far from the Sun (for instance at the Earth). We apply the model to the evolution of the coronal mass ejections in the IP medium, finding that the model is in good agreement with satellite observations of these phenomena, thus providing physical insight into their dynamical evolution. Our model may contribute to future 'space weather forecasting' on the Earth, based on detailed satellite monitoring of the solar corona.  相似文献   

A bar signature and central disc in the gaseous and stellar velocity fields of NGC 5448     

Kambiz Fathi  Glenn van de Ven  Reynier F. Peletier  Eric Emsellem  Jesús Falcón-Barroso  Michele Cappellari  Tim de Zeeuw 《Monthly notices of the Royal Astronomical Society》2005,364(3):773-782

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Particulate matter exchange across a Rjord sill     

J.C. Therriault  R. de Ladurantaye  R.G. Ingram 《Estuarine, Coastal and Shelf Science》1984,18(1):51-64

Recent studies have indicated the existence of a considerably higher planktonic biomass in the deep waters of the Saguenay Fjord as compared to corresponding depths in the adjacent St Lawrence Estuary on the other side of a shallow sill. The hypothesis that has been put forward to explain this phenomenon is related to the advection of near surface estuarine waters, at times very rich in particulate matter, over the entrance sill into the deeper waters of the fjord. Mixing processes associated with the development of a density flow, the presence of a hydraulic jump or other mechanisms are assumed to be responsible for the common occurrence of lower density subsurface water within the basin as compared to that penetrating over the sill.The exchange processes between the estuary and the fjord are described and an estimate made of the estuarine water volume that penetrates into the lower layer of the fjord over a semidiurnal tide cycle. From these calculations, the replacement time for the outer basin was estimated to range between one and four days. The biological characteristics of this water were used to establish a budget for particulate matter exchange which showed, in early August, a typical net input of ? 188 t of particulate organic carbon into the deep waters of the fjord over one tide cycle.  相似文献