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911.
912.
The purpose of this paper is the semi-analytical computation of the bounded orbits of Hill’s equations, describing the relative
motion of two particles in their Keplerian motion around a central body. We have considered the case in which one of the particles
moves along a circular reference orbit. The solutions obtained are the generalisation of the usual periodic orbits obtained
for the linearised equations and also of the third-order solution computed by D.L. Richardson and J.W. Mitchell (2003). With
the algorithm presented, those orbits can be computed in a fast and efficient way up to a high-order in the in-plane and out-of-plane
amplitudes. 相似文献
913.
Licandro J. Bellot Rubio L. R. Casas R. Gómez A. Kidger M. R. Sabalisk N. Santos-Sanz P. Serra-Ricart M. Torres-Chico R. Oscoz A. Jorda L. Denicolo G. 《Earth, Moon, and Planets》1997,77(3):199-206
Monitoring of the near-nucleus activity of C/1995 O1 (Hale-Bopp) began in Teide Observatory in August 1995. During 1996 the
comet was observed on 72 nights between March 26 and November 13. A permanent fan structure was observed towards the north
during the whole period of observation. The position angle of the axis of this fan was measured and its variations with time
were used to determine the position of the North Pole of the cometary nucleus.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
914.
Dr. József Szakály 《Theoretical and Applied Climatology》1965,14(1):94-113
Zusammenfassung Seit mehr als 110 Jahren werden in Ungarn systematische pflanzenphänologische Beobachtungen durchgeführt. Da die überwiegende Mehrheit der phänologischen Arbeiten nur in ungarischer Sprache erschienen ist, soll hier ein Überblick über das vorhandene Beobachtungsmaterial und über die Ergebnisse der pflanzenphänologischen Forschung in Ungarn geboten werden. Es sollen dabei nur die wichtigeren Publikationen über Pflanzenphänologie und ihre Grenzgebiete angeführt, ihre Ergebnisse bewertet und die Quellen bezeichnet werden, die Beobachtungsmaterial zur weiteren Bearbeitung und Forschung liefern.
Summary Since more than 110 years systematic plant-phenological observations are made in Hungary. As the overwhelming majority of the phenological papers has been published in Hungarian language a survey over the existing data and over the results of the plant-phenological research in Hungary shall be given here. Only the more important publications on the subject of plant-phenology and its border areas are cited here. Their results are discussed and the sources are specified where one can find observational data for further work and research.
Résumé On effectue depuis plus de 110 ans des observations phénologiques systématiques en Hongrie. Vu que la grande majorité des travaux effectués en phénologie ont été publiés en hongrois, on donne ici un aperçu du materiel d'observation existant et des résultats des recherches effectuées dans ce domaine en Hongrie. On n'a indiqué que les publications principales en phénologie et sciences connexes. On discute en outre les résultats obtenus et on en indique les sources qui pourraient fournir du matériel pour de nouvelles études et recherches.相似文献
915.
Fernando Comerón 《Astrophysics and Space Science》2004,289(3-4):395-403
While the importance of merging, accretion, and infall processesin determining galactic evolution is well established boththeoretically and observationally, details on how such processesare taking place nowadays even in our own Galaxy are stillrelatively poorly known, especially due to large remaininguncertainties on the location and origin of high velocity clouds.In this paper we focus on the possible role that galacticoutflows and gas infall may have on directly triggering starformation in the halo and in galactic disks. While compellingevidence has been accumulating in recent years suggesting thatsome level of star formation directly triggered by outflows isvery likely to exist in the halo of some galaxies, the evidencefor star formation dynamically triggered by infall is far moreelusive due to confusion with other, more efficient large-scalestar forming mechanisms operating in the galactic disk. Despite ofincreasingly realistic simulations of the gas circulation betwenthe gas and the halo and of high velocity cloud impacts ongalactic disks, the efficiency of star formation directlytriggered by such impacts remains an open question. 相似文献
916.
We focus on Swiss earthquakes in antiquity and the early medieval period before A.D. 1000. We have information on less than
half a dozen earthquakes within this era, since written records for the first half of the first millennium A.D. are minimal,
and there is little hope of finding more written evidence for earthquakes. Furthermore, interpreting the documents at hand
is somewhat complex. For the 6th century Gregory of Tours in Historia Francorum gives hints of a rockslide near the castle Tauredunum (Le Grammont) in the Swiss canton Valais, an event that has been considered in the literature as caused by an earthquake. The Carolingian period (ca. 750–950) included the rise of some very important cultural centers in various parts of today’s Switzerland. For
instance, the ecclesiastical culture in St. Gallen generated a remarkable number of written records, which survived for our
use in a unique manner. From the 9th and 10th centuries, we have evidence for earthquakes in the years 849, 867, 902, and
944. However, information on them remains so scarce that their location and intensity are generally difficult to assess. Nevertheless,
the finding of a new document - a memoir written by the abbot of Reichenau - offers some insight into the A.D. 849 event and
its reportedly aftershocks.
相似文献
Monika GislerEmail: |
917.
J.A. Ramos-Leal J. Moran-Ramírez U. Rodríguez-Robles G. Santacruz-De León P.D. Roy R.M. Fuentes-Rivas R.M.G. Fonseca-Montes de Oca 《Chemie der Erde / Geochemistry》2022,82(2):125872
This work addresses hydrogeochemical processes in shallow aquifers, represented by the Quaternary alluvial deposits, from a part of the semi-arid Mexican Highlands through the evaluations of physicochemical parameters as well as the δ18O and δ2H compositions of groundwater. Mifflin diagram separates the Na-bicarbonate, sulphate and mixed groundwater into one group showing interactions with volcanic lithology in the recharge zones and another group interacting with the evaporite rich sedimentary formation. In the Gibbs diagram, the samples with Cl?/(Cl? + HCO3?) < 0.4 showed higher influence of ion exchange and the samples with Cl?/(Cl? + HCO3?) > 0.4 showed higher effects of evaporation. All of them were oversaturated with carbonate minerals (i.e., calcite and dolomite) and unsaturated with evaporites (i.e., gypsum and halite). Evaporation (earlier stage) occurred before the water-rock interactions (later stage). Evolution occurs through three different routes such as up to 7.5‰ enrichment in δ18O caused by the infiltration with a certain delay and subsequently, the water-rock interaction became dominant. Ternary mixing models revealed dominant influence of local recharge (C1) on the water system, contributing 70.4%. Water-rock interaction (C3) with 18% and evaporation (C2) with 11.6% had comparatively less influences. The presence of nitrate (2–60 mg/L) in the groundwater indicated variable degrees of anthropogenic pollution. 相似文献
918.
Santosh Sapkota Saurav Sarup Khadka Gautam Sabin Karki Monika Adhikari Binod Mishra Roshan Kumar Klausner Virginia Dhungana Beni Madhav 《Geomagnetism and Aeronomy》2022,62(1-2):125-137
Geomagnetism and Aeronomy - Electrodynamical coupling between the solar wind’s plasma and the Earth’s magnetosphere creates geomagnetic disturbances recorded on the ground. This work... 相似文献
919.
Leguizamón-Barreto Luis C. Ramos-Cañón Alfonso M. Andrade José E. 《Acta Geotechnica》2021,16(10):3041-3059
Acta Geotechnica - This work proposes a criterion for the detection of undrained instability under multiaxial stress conditions at elemental level. To do so, it develops the application of the... 相似文献
920.
Chen Zi Xu Teng Gómez-Hernández J. Jaime Zanini Andrea 《Mathematical Geosciences》2021,53(7):1587-1615
Mathematical Geosciences - The joint identification of the parameters defining a contaminant source and the heterogeneous distribution of the hydraulic conductivities of the aquifer where the... 相似文献