Database of molecular masers and variable stars     

Andrej M.Sobolev  Dmitry A.Ladeyschikov  Jun-ichi Nakashima 《天文和天体物理学研究(英文版)》2019,(3)

We present the database of maser sources in H2 O, OH and Si O lines that can be used to identify and study variable stars at evolved stages. Detecting the maser emission in H2 O, OH and Si O molecules toward infrared-excess objects is one of the methods for identifing long-period variables(LPVs, including miras and semiregulars), because these stars exhibit maser activity in their circumstellar shells. Our sample contains 1803 known LPV objects. Forty-six percent of these stars(832 objects) manifest maser emission in the line of at least one molecule: H2 O, OH or Si O. We use the database of circumstellar masers in order to search for LPVs which are not included in the General Catalogue of Variable Stars(GCVS). Our database contains 4806 objects(3866 objects without associations in GCVS) with maser detection in at least one molecule. Therefore it is possible to use the database in order to locate and study the large sample of LPV stars. The database can be accessed at http://maserdb.net.  相似文献   

Integrated Rhaetian foraminiferal and conodont biostratigraphy from the Slovenian Basin, eastern Southern Alps     

Luka Gale  Tea Kolar-Jurkov?ek  Andrej ?muc  Bo?tjan Ro?i? 《Swiss Journal of Geoscience》2012,105(3):435-462

Conodonts and re-deposited shallow-water benthic foraminifera co-occur in the Upper Norian-Rhaetian Slatnik Formation of the Slovenian Basin (Southern Alps). The Mt. Kobla and Mt. Slatnik sections were investigated in order to give the first direct correlation between these two groups. The Norian-Rhaetian boundary (NRB) is placed at the First Appearance Datum of the conodont Misikella posthernsteini and is approached with the First Occurrence of the foraminifer Involutina turgida. An association of Trocholina turris with duostominids is a good marker for the Rhaetian. Careful revision of literature combined with our data culminated in reambulation of stratigraphical ranges for several foraminiferal species. The foraminiferal Triassic-Jurassic boundary (TJB) can be defined with the Last Occurrence of Galeanella tollmanni, ??Sigmoilina?? schaeferae or duostominids. The absence of the uppermost Rhaetian Misikella ultima conodont zone and the close coincidence of foraminiferal and conodont TJB could point to the presence of hiati in the upper part of the Slatnik Formation. Consequently, the exact pattern of disappearance of Late Triassic foraminifera at the boundary could not be observed. It is clear, however, that the foraminiferal assemblage was decimated for reef-dwelling foraminifera, duostominids and most of the platform-dwelling foraminifera. Biotic changes at the TJB are best explained as a result of a biocalcification crisis.  相似文献   

Deductions from the Indication of Eclipses of Nova V1493 Aql     

Michael Friedjung  Andrej Dobrotka  Alon Retter  Ladislav Hric  Rudolf Novák 《Astrophysics and Space Science》2006,304(1-4):317-319

Our mainly R band photometry of V1493 Aql (1999) during its outburst, indicates periodic variations with a period of 0.156 days, seen only 5 days after the maximum in V. This period can be orbital. The light curve indicates in addition, the presence of a faint eclipse like feature. We try to explain its extremely low amlitude, as being due to the eclipse of an expanded white dwarf component of the binary below an optically thick wind. We discuss what conditions would be required for such an interpretation to work.  相似文献   

Relativistic emission lines from accretion discs around black holes     

Andrej &#;ade&#;  Massimo Calvani 《Monthly notices of the Royal Astronomical Society》2005,363(1):177-182

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Factors that contributed to recent eutrophication of two Slovenian mountain lakes     

Gregor Muri  Branko Čermelj  Radojko Jaćimović  Tina Ravnikar  Andrej Šmuc  Janja Turšič  Polona Vreča 《Journal of Paleolimnology》2018,59(4):411-426

Increased eutrophication was recently observed in the 5th (5J) and 6th (6J) Triglav Lakes, two remote Slovenian mountain lakes. Sediment phosphorus (P) pools were analysed and potential external P sources affecting the lakes (atmospheric deposition, terrestrial export and nearby hut) evaluated, to assess the effects of internal and external changes on the lakes. A sequential extraction procedure was used to quantify five P fractions from the sediments: adsorbed (NH₄Cl–P), redox-sensitive (BD–P), aluminium- (NaOH–P) and calcium- (HCl–P) bound, and refractory organic (Res–P) P. Total phosphorus (TP) contents in surface sediment of 5J and 6J were 1430 and 641 µg P g^?1 dry weight sediment (dw), respectively. TP varied with depth in 5J sediments, but displayed no discernible pattern, whereas it decreased steadily downcore in 6J. Contents of all P forms were distinctly higher in 5J than 6J, but their rank order and relative abundances were similar in the two lakes. Res–P was the most abundant P fraction, followed by HCl–P. Together, the two P forms accounted for nearly 80 and 90% of TP in 5J and 6J sediments, respectively. BD–P and NaOH–P were less abundant, with each fraction accounting for 3 to 9% of TP, whereas NH₄Cl–P was least abundant. Atmospheric deposition and terrestrial export were substantial sources of P for the lakes. Delivery of the former was estimated to be at least 7.5 mg P m^?2 yr^?1 and the latter around 20 mg P m^?2 yr^?1. We concluded that P was not retained in the catchment effectively, likely because of only slightly acidic soil pH (5.9), relatively low aluminium content and high organic matter content (53%) in soils, resulting in higher vulnerability of the studied lakes to eutrophication. The mountain hut could also be a significant source of P for the lakes. Each year, it could potentially contribute ~12 kg of soluble P to the environment, but the true impact of the hut on lake trophic status remains unclear.  相似文献   

A cross-border regional earthquake early warning system: PRESTo@CE3RN     

Pesaresi  Damiano  Picozzi  Matteo  &#;iv&#;i&#;  Mladen  Lenhardt  Wolfgang  Mucciarelli  Marco  Elia  Luca  Zollo  Aldo  Gosar  Andrej 《Natural Hazards》2016,84(2):431-436

Since 2002 the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS) in Udine (Italy), the Agencija Republike Slovenije za Okolje (ARSO) in Ljubljana (Slovenia) and the Zentralanstalt für Meteorologie und Geodynamik (ZAMG) in Vienna (Austria), are collecting, analyzing, archiving and exchanging seismic data in real time, initially in the framework of the EU Interreg IIIa Italia-Austria project “Trans-national seismological networks in the South-Eastern Alps”. As outcome of the successful cooperation, in the 2013 OGS, ARSO and ZAMG decided to officially merge their seismic monitoring efforts into the “Central and Eastern European Earthquake Research Network—CE³RN”. This work reports the results of a nine-month real-time test of the earthquake early warning (EEW) algorithm probabilistic and evolutionary early warning system carried out at the CE³RN. The study allowed identifying the actions to be implemented in order to let the CE³RN become in the next future an efficient cross-border EEW system.

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第纳尔(Dinaric)喀斯特台地的一些大型漏斗     

Andrej KRANJC  黄保健  张远海 《中国岩溶》2006,25(Z1):67-70

Dinaric喀斯特的主要特征是各种各样的洼地,包括坡立谷、漏斗、塌陷漏斗及其它类似塌陷漏斗的洼地.这类地形的一些大尺度洼地分布于高喀斯特台地(如斯洛文尼亚的Pokljuka,Jelovica和Sne(z)nik)、喀斯特接触带(如(S)kocjanske溶洞)、坡立谷上的基面(如Imotski坡立谷上的红湖)和大型喀斯特泉群之后(如Malni泉群上的Un(s)ka koli(s)evka漏斗).喀斯特洼地的许多术语都是依据据斯洛文尼亚的地貌定义的.  相似文献   

Fermat's principle for seismic rays in elastic media     

Andrej Bna  Michael A. Slawinski 《Journal of Applied Geophysics》2003,54(3-4):445

We prove that rays in linearly elastic anisotropic nonuniform media obey Fermat's principle of stationary traveltime. First, we formulate the concept of rays, which emerges from the Hamilton equations. Then, we show that these rays are solutions of the variational problem stated by Fermat's principle. This proof is valid for all rays except the ones associated with infection points on the phase-slowness surface.  相似文献   

Line emission from accretion discs around black holes: the analytic approach     

Andrej ?ade?  Claudio Fanton  Massimo Calvani 《New Astronomy》1998,3(8):528-654

The broad X-ray iron line observed in many active galactic nuclei spectra is thought to originate from the accretion disc surrounding the putative supermassive black hole. We show here how to perform the analytical integration of the geodesic equations that describe the photon trajectories in the general case of a rotating black hole (Kerr metric), in order to write a fast and efficient numerical code for modelling emission line profiles from accretion discs.  相似文献   

Determination of masonry building fundamental frequencies in five Slovenian towns by microtremor excitation and implications for seismic risk assessment     

Andrej Gosar 《Natural Hazards》2012,62(3):1059-1079

Site effects studies using microtremor free-field measurements were performed recently in five Slovenian towns characterized by increased seismic hazard to determine resonance frequency of soft sediments. In this study, microtremor investigations were extended to the measurements inside buildings to determine their fundamental frequencies and to assess the possible occurrence of soil-structure resonance. Measurements were performed in 66 buildings, and by spectral analysis, it was possible to determine reliably fundamental frequencies (longitudinal and transverse) for 58 buildings. Residential masonry houses with two or three floors prevail, but some buildings of up to six-floor height were also surveyed. Microtremor measurements have proved to be an effective tool for assessment of fundamental frequencies of buildings. Such experimental approach is very valuable, as analytical seismic evaluation of an existing building is usually very difficult. Statistical analysis of the fundamental frequency versus number of floors (height) was performed to generalize identification of potential soil-structure resonance. The difference in average fundamental frequency is very clear between buildings with two and three floors. The average value of both horizontal components for two-floor buildings is 9.11?±?1.94?Hz, and for three-floor buildings, 7.03?±?1.46?Hz. On the other hand, the difference in frequencies between three- and four-floor buildings (average for later is 6.52?±?0.80?Hz) is very small. The average fundamental frequencies for five- and six-floor buildings are lower, 4.62?±?0.64?Hz and 5.30?±?0.70?Hz, respectively, with no statistically significant difference between both types. Most Slovenian towns are located in shallow sedimentary basins where the free-field soft covers frequencies are in the range 2?C20?Hz. On the other hand, houses with two and three floors represent the large majority of the building stock. To assess the possible occurrence of soil-structure resonance in general, an average fundamental frequency?±?one standard deviation interval is obtained for these two building heights, which gives the range 5.6?C11.1?Hz. The free-field data show that this frequency range occupies from 22?% of the surveyed area in the Kobarid basin to up to 59?% in the Bovec basin and is in between for other three basins. This leads to the conclusion that the possible occurrence of soil-structure resonance is a serious issue for typical geological situations, in which towns are located.  相似文献