Notes on Hori Method for Non-Canonical Systems     

Sandro da Silva Fernandes 《Celestial Mechanics and Dynamical Astronomy》2003,87(3):307-315

In this paper the new approach for the integration theory of the canonical version of Hori method recently proposed is extended to the non-canonical one. It will be shown that the non-homogeneous ordinary differential equation with an auxiliary parameter t* associated with the mth order equation of the algorithm can also be replaced by a non-homogeneous partial differential equation in the time t. Using a generalized canonical approach, the general algorithm proposed by Sessin is then revised; as well as the Lagrange variational equations for the non-canonical version of Hori method. A simplified algorithm derived from Sessin's algorithm is presented for non-linear oscillations problem.  相似文献   

A homogeneous sample of sub-damped Lyman     systems – IV. Global metallicity evolution     

Céline Péroux  Miroslava Dessauges-Zavadsky  Sandro D'Odorico  Tae-Sun Kim  Richard G. McMahon 《Monthly notices of the Royal Astronomical Society》2007,382(1):177-193

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Counts, Sizes and Colours of Faint Infrared-Selected Galaxies     

Paolo Saracco  Sandro D'Odorico  Alan Moorwood  Jean G. Cuby 《Astrophysics and Space Science》2001,276(2-4):991-998

Deep J- and K _s-band images covering a 5 × 5 arcmin area centred on the NTT Deep Field have been obtained during the Science Verification of SOFI at the NTT. These images were made available via the Web in early June, 1998. The preliminary results we have obtained by the analysis of these data are the following: (i) the counts continue to rise with no evidence of a turnover or of a flattening down to the limits of the survey (K _s = 22.5 and J = 24 mag); (ii) we find a slope d log(N)/dm≈ 0.37, in agreement with most of the faintest surveys but much steeper than the Hawaii survey; (iii) fainter than K _s ≈ 19and J ≈ 20 mag, the median J-K colour of galaxies shows a break in its reddening trend turning toward bluer colours; (iv) faint bluer galaxies also display a larger compactness index, and a smaller apparent size. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

List of papers from other journals     

Luciano Baresi  Sebastiano Colazzo  Luca Mainetti  Sandro Morasca 《Solar physics》1992,140(2):397-410

List of papers from other journals  相似文献   

List of papers from other journals     

Luciano Baresi  Sebastiano Colazzo  Luca Mainetti  Sandro Morasca 《Solar physics》1991,135(1):199-209

List of papers from other journals  相似文献   

Lithium speciation in aqueous fluids at high P and T studied by ab initio molecular dynamics and consequences for Li-isotope fractionation between minerals and fluids     

Sandro Jahn  Bernd Wunder 《Geochimica et cosmochimica acta》2009,73(18):2797-6123

Ab initio molecular dynamics simulations are performed to study the speciation changes in lithium bearing aqueous fluids at high temperature (T = 1000 K) and high pressures, P, between about 0.3 and 6.0 GPa. The simulations show a linear increase in Li coordination with fluid density, from 3.2 to about five in the considered pressure range. Towards low densities, associated LiF complexes are becoming increasingly stable, which is quantified by evaluating the dynamic behavior of the respective species. In the high-density region, HF complexes are observed. The differences in speciation may be related to structural changes of the solvent under compression. At a fluid density of 1.2 g/cm³, kinks in the pressure dependences of the oxygen–oxygen nearest neighbor distance and the oxygen–oxygen coordination are observed, which indicates a change in compaction mechanism. Assuming that the Li coordination difference between crystal and fluid is a major determinant for the isotopic fractionation between minerals and fluids, we expect only a small pressure dependence of the Li isotopic fractionation between Li bearing fluids and minerals. Our simulation results are consistent with experimental data that show reverse fractionation of ⁷Li between fluid and mineral, when Li is in tetrahedral instead of octahedral coordination in the crystal.  相似文献   

The strongest cosmic magnets: soft gamma-ray repeaters and anomalous X-ray pulsars     

Sandro Mereghetti 《Astronomy and Astrophysics Review》2008,15(4):225-287

Two classes of X-ray pulsars, the anomalous X-ray pulsars and the soft gamma-ray repeaters, have been recognized in the last decade as the most promising candidates for being magnetars: isolated neutron stars powered by magnetic energy. I review the observational properties of these objects, focussing on the most recent results, and their interpretation in the magnetar model. Alternative explanations, in particular those based on accretion from residual disks, are also considered. The possible relations between these sources and other classes of neutron stars and astrophysical objects are also discussed.  相似文献   

An atmosphere–ocean regional climate model for the Mediterranean area: assessment of a present climate simulation     

Vincenzo Artale  Sandro Calmanti  Adriana Carillo  Alessandro Dell’Aquila  Marine Herrmann  Giovanna Pisacane  Paolo M. Ruti  Gianmaria Sannino  Maria Vittoria Struglia  Filippo Giorgi  Xunqiang Bi  Jeremy S. Pal  Sara Rauscher 《Climate Dynamics》2010,35(5):721-740

We present an atmosphere–ocean regional climate model for the Mediterranean basin, called the PROTHEUS system, composed by the regional climate model RegCM3 as the atmospheric component and by a regional configuration of the MITgcm model as the oceanic component. The model is applied to an area encompassing the Mediterranean Sea and compared to a stand-alone version of its atmospheric component. An assessment of the model performances is done by using available observational datasets. Despite a persistent bias, the PROTHEUS system is able to capture the inter-annual variability of seasonal sea surface temperature (SST) and also the fine scale spatio-temporal evolution of observed SST anomalies, with spatial correlation as high as 0.7 during summer. The close inspection of a 10-day strong wind event during the summer of 2000 proves the capability of the PROTHEUS system to correctly describe the daily evolution of SST under strong air–sea interaction conditions. As a consequence of the model’s skill in reproducing observed SST and wind fields, we expect a reliable estimation of air–sea fluxes. The model skill in reproducing climatological land surface fields is in line with that of state of the art regional climate models.  相似文献   

Interactive effects of cadmium and zinc pollution on PGI and PGM polymorphisms in Idotea baltica     

Marina De Nicola  Carmela Gambardella  Sandro M. Guarino 《Marine pollution bulletin》1992,24(12):619-621

Separate and interactive pollution effects of Cd and Zn on electrophoretically-detected allozyme frequencies of the different genotypes at PGI and PGM loci were studied in Idotea baltica.

Differential survivorship of PGM genotypes was detected in the presence of the single or combined pollutants, while no effect was observed for PGI. Cadmium decreased heterozygosity while zinc or Cd + Zn increased it, suggesting an antithetic action of the two metals and the prevalence of zinc.  相似文献   

The Kleiner Feldberg Cloud Experiment 1990: Introduction     

Sandro Fuzzi 《Journal of Atmospheric Chemistry》1994,19(1-2):1-2

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