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71.
M. D. Reed D. M. Terndrup R. Østensen S. Geier J. Gilker P. G. Beck P. Degroote J. Vanautgaerden C. Waelkens 《Astrophysics and Space Science》2010,328(1-2):83-86
During our campaign of acquiring follow-up photometric data to resolve short period pulsating sdB (EC14026 or V361 Hya) stars, we obtained data on the known pulsator KUV 04421+1416 and discovered that it is also in a reflection-effect binary. Here we present preliminary results of the pulsation analysis and provide some constraints on the companion, which is most likely an MV star. This makes KUV 04421+1416 only the second known system with an EC14026-type pulsator in a reflection-effect binary. 相似文献
72.
Sonja Schuh Roberto Silvotti Ronny Lutz Björn Loeptien Elizabeth M. Green Roy H. Østensen Silvio Leccia Seung-Lee Kim Gilles Fontaine Stéphane Charpinet Myriam Francœur Suzanna Randall Cristina Rodríguez-López Valerie van Grootel Andrew P. Odell Margit Paparó Zsófia Bognár Péter Pápics Thorsten Nagel Benjamin Beeck Markus Hundertmark Thorsten Stahn Stefan Dreizler Frederic V. Hessman Massimo Dall’Ora Dario Mancini Fausto Cortecchia Serena Benatti Riccardo Claudi Rimvydas Janulis 《Astrophysics and Space Science》2010,329(1-2):231-242
In 2007, a companion with planetary mass was found around the pulsating subdwarf B star V391 Pegasi with the timing method, indicating that a previously undiscovered population of substellar companions to apparently single subdwarf B stars might exist. Following this serendipitous discovery, the EXOTIME (http://www.na.astro.it/~silvotti/exotime/) monitoring program has been set up to follow the pulsations of a number of selected rapidly pulsating subdwarf B stars on time scales of several years with two immediate observational goals:
- determine $\dot{P}$ of the pulsational periods P
- search for signatures of substellar companions in O–C residuals due to periodic light travel time variations, which would be tracking the central star’s companion-induced wobble around the centre of mass
73.
74.
In connection with the construction of a tunnel collecting water beneath a glacier (Bondhusbreen/Folgefonni) in SW Norway the amount of sediments transported by meltwater has been investigated. According to the values obtained the volume of the sedimentation chamber which has to take a one-years-amount of sediment was fixed at 5000 m3. In 1978 there has been a sedimentation of 3000 m3 of coarse material. The results obtained are not only of practical value, but also of scientific interest. 相似文献
75.
Christian Christiansen Henning Christoffersen JØrgen Dalsgaard Per NØrnberg 《Sedimentary Geology》1981,28(3):163-173
The die-back of eel-grass (Zostera marina, L.) is found to have played an important role with regard to near-shore sedimentation and coastal changes.In a natural harbour at Kyholm, Denmark a hiatus is found between silty sediments that date from about 4000 BC and overlying modern sandy sediments. It is suggested that this is a consequence of the die-back of eel-grass in the nineteen-thirties, resulting in mobilisation and disturbance of nearshore sediments and the shoreward movement of mobilised sandy material into the harbour. The coastal morphology of Kyholm was relatively stable from 1802 to 1933, but between 1933 and 1978 there have been two periods of drastic progradation correlated with die-back of eel-grass. 相似文献
76.
øystein Hov Asgeir Sorteberg Norbert Schmidbauer Sverre Solberg Frode Stordal David Simpson Anne Lindskog Hans Areskoug Pedro Oyola Heikki Lättilä Niels Z. Heidam 《Journal of Atmospheric Chemistry》1997,28(1-3):173-193
Observations and model calculations of the concentration of hydrocarbonsat five Scandinavian rural sites during March–June 1993are reported.Decreasing concentrations from March to June are observedat all sites. The highest concentrations of hydrocarbons were found in air massescoming in from the southwest to southeast, indicating that long rangetransport fromcontinental Europe and the U.K. is important in pollution episodes. An episode of elevated concentrations of hydrocarbons observed at three of the sites in the middle of Marchis described and discussed in relation to the synoptic situation and thepresenceof other chemical compounds (NO2, PAN, total nitrate andozone).A Lagrangian numerical model is used to calculate the concentrations of theindividual hydrocarbons at the fivesites and comparison with observations is made.The calculated concentrations for nonmethane hydrocarbons with quite longchemicallifetimes agree well with the observations.For the sum of observed and calculated hydrocarbons the correlationcoefficientsare in the range of 0.65–0.88 for the five sitesand the ratio between calculated and measured concentrations was0.72–0.97, indicating thatthe European VOC emission inventory is quite well estimated. 相似文献
77.
Trond Reitan Asgeir Petersen-Øverleir 《Stochastic Environmental Research and Risk Assessment (SERRA)》2006,20(6):445-453
Practical application of the power-law regression model with an unknown location parameter can be plagued by non-finite least squares parameter estimates. This presents a serious problem in hydrology, since stream flow data is mainly obtained using an estimated stage–discharge power-law rating curve. This study provides a set of sufficient requirements for the data to ensure the existence of finite least squares parameter estimates for a power-law regression with an unknown location parameter. It is shown that in practice, these requirements act as necessary for having a finite least squares solution, in most cases. Furthermore, it is proved that there is a finite probability for the model to produce data having non-finite least squares parameter estimates. The implications of this result are discussed in the context of asymptotic predictions, inference and experimental design. A Bayesian approach to the actual regression problem is recommended. 相似文献
78.
The nature of thin, highly inclined threads observed in quiescent prominences has puzzled solar physicists for a long time. When assuming that the threads represent truly inclined magnetic fields, the supporting mechanism of prominence plasma against gravity has remained an open issue. This paper examines the levitation of prominence plasma exerted by weakly damped MHD waves in nearly vertical magnetic flux tubes. It is shown that the wave damping, and resulting `radiation pressure', caused predominantly by ion-neutral collisions in the `cold' prominence plasma, may balance the acceleration of gravity provided the oscillation frequency is 2 rad s–1 (f0.5 Hz). Such short wave periods may be the result of small-scale magnetic reconnections in the highly fragmentary magnetic field of quiescent prominences. In the proposed model, the wave induced levitation acts predominantly on plasma – neutral gas mixtures. 相似文献
79.
80.
Øyvind Breivik Jose Henrique Alves Diana Greenslade Kevin Horsburgh Val Swail 《Ocean Dynamics》2017,67(3-4):551-556
Following the 14th International Workshop on Wave Hindcasting and Forecasting and 5th Coastal Hazards Symposium in November 2014 in Key West, Florida, a topical collection has appeared in recent issues of Ocean Dynamics. Here, we give a brief overview of the 16 papers published in this topical collection as well as an overview of the widening scope of the conference in recent years. A general trend in the field has been towards closer integration between the wave and ocean modelling communities. This is also seen in this topical collection, with several papers exploring the interaction between surface waves and mixed layer dynamics and sea ice. 相似文献