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51.
Christian Bigler Evastina Grahn Isabelle Larocque Adam Jeziorski Roland Hall 《Journal of Paleolimnology》2003,29(4):509-510
Volume Contents
Volume contents 相似文献52.
Peter Brack Hans Rieber Roland Mundil Wolfgang Blendinger Florian Maurer 《Swiss Journal of Geoscience》2007,100(3):327-348
The depositional architecture and the geometric relationships between platform-slope deposits and basinal sediments along
with paleontological evidence indicate the time interval of the younger Anisian Reitziites reitzi ammonoid zone to largely represent the main stage of platform aggradation at the Cernera and Bivera/Clapsavon carbonate platforms.
Published and new U-Pb age data of zircons from volcaniclastic layers bracketing the stratigraphic interval of platform growth
constrain the duration of platform evolution to a time span shorter than 1.8±0.7m.y., probably in the order of 0.5-1m.y.,
reflecting fast rates of vertical platform aggradation exceeding 500 m/m.y. In the range of growth potentials for shallow-water
carbonate systems estimated in relation to the time span of observation, this high rate is in agreement with values for short
intervals of 105-106yrs (e.g., Schlager 1999).
After drowning, the platforms at Cernera and Bivera/Clapsavon were blanketed by thin pelagic carbonates. On the former platform
flanks the draping sediments in places comprise red nodular pelagic limestones (Clapsavon Limestone) similar in facies to
the Han Bulog Limestones occurring elsewhere in Middle Triassic successions of the Mediterranean Tethys. The drowning of vast
areas of former carbonate platforms possibly triggered the onset of bottom-water circulation in adjacent basins as suggested
by the abrupt transition from laminated to bioturbated pelagic nodular limestones in the Buchenstein Formation which occurred
close to the time of initial platform submergence. During the Late Ladinian the topographic features of the drowned platforms
were onlapped by rapidly deposited, predominantly clastic successions including coarse breccias and volcanic rocks sealing
and preserving the peculiar stratigraphic setting. 相似文献
53.
Matthias Mauder Steven P. Oncley Roland Vogt Tamas Weidinger Luis Ribeiro Christian Bernhofer Thomas Foken Wim Kohsiek Henk A. R. De Bruin Heping Liu 《Boundary-Layer Meteorology》2007,123(1):29-54
The eddy-covariance method is the primary way of measuring turbulent fluxes directly. Many investigators have found that these
flux measurements often do not satisfy a fundamental criterion—closure of the surface energy balance. This study investigates
to what extent the eddy-covariance measurement technology can be made responsible for this deficiency, in particular the effects
of instrumentation or of the post-field data processing. Therefore, current eddy-covariance sensors and several post-field
data processing methods were compared. The differences in methodology resulted in deviations of 10% for the sensible heat
flux and of 15% for the latent heat flux for an averaging time of 30 min. These disparities were mostly due to different sensor
separation corrections and a linear detrending of the data. The impact of different instrumentation on the resulting heat
flux estimates was significantly higher. Large deviations from the reference system of up to 50% were found for some sensor
combinations. However, very good measurement quality was found for a CSAT3 sonic together with a KH20 krypton hygrometer and
also for a UW sonic together with a KH20. If these systems are well calibrated and maintained, an accuracy of better than
5% can be achieved for 30-min values of sensible and latent heat flux measurements. The results from the sonic anemometers
Gill Solent-HS, ATI-K, Metek USA-1, and R.M. Young 81000 showed more or less larger deviations from the reference system.
The LI-COR LI-7500 open-path H2O/CO2 gas analyser in the test was one of the first serial numbers of this sensor type and had technical problems regarding direct
solar radiation sensitivity and signal delay. These problems are known by the manufacturer and improvements of the sensor
have since been made.
The National Center for Atmospheric Research is supported by the National Science Foundation. 相似文献
54.
The bulk strain induced by excavation of rooms for storage of highly radioactive waste is usually unimportant, but the change in aperture and shear displacement of permeable fractures may be of practical importance. Hence, the normal and shear of such discontinuities have to be considered and are commonly predicted by using special deformation moduli termed “normal” and “shear” stiffnesses in numerical calculations. For the use of some finite element methods, these have to be converted to compression and shear moduli ,which, in turn, requires that the thickness of the discontinuity is known. The normal and shear strain can be expressed in terms of soil mechanical parameters, yielding the compression modulus M and the shear modulus G, with the required form for finite element calculations. By definition they are functions of the normal and shear stiffness Kn and Ks. It is concluded that calculation of the normal and shear strain of discontinuities with clastic fillings by the use of finite element methods and deformation moduli derived from stiffness numbers is very uncertain except when the geometry of the weaknesses can be accurately defined. 相似文献
55.
56.
Roland Doerffer 《Boundary-Layer Meteorology》1980,18(2):221-232
A version of the two-flow radiative transfer model is presented as a simple method to study the relationship between substances in water and the backscattered radiation field. It is shown that under the assumption of a diffuse radiative input into a water body, the irradiance attenuation coefficient k can be regarded as an inherent property. A cuvette system is presented which allows one to measure and calculate the attenuation coefficient k, the absorption coefficient a and the backscattering coefficient Bb of various substances. The model can be used to check the applicability of a remote sensing technique for a specific research area and for specific parameters, and to estimate the expected accuracy, and the signal depth. The inversion of the model can be applied as a technique to estimate concentrations in water from the backscattered radiation. The critical assumption of a diffuse radiative input and transfer, which has to be made when using the model for natural conditions, is discussed.The research work was supported by the Deutsche Forschungsgemeinschaft. 相似文献
57.
58.
WASP-1b and WASP-2b: two new transiting exoplanets detected with SuperWASP and SOPHIE 总被引:1,自引:0,他引:1
A. Collier Cameron F. Bouchy G. Hébrard P. Maxted D. Pollacco F. Pont I. Skillen B. Smalley R. A. Street R. G. West D. M. Wilson S. Aigrain D. J. Christian W. I. Clarkson B. Enoch A. Evans A. Fitzsimmons M. Fleenor M. Gillon C. A. Haswell L. Hebb C. Hellier S. T. Hodgkin K. Horne J. Irwin S. R. Kane F. P. Keenan B. Loeillet T. A. Lister M. Mayor C. Moutou A. J. Norton J. Osborne N. Parley D. Queloz R. Ryans A. H. M. J. Triaud S. Udry P. J. Wheatley 《Monthly notices of the Royal Astronomical Society》2007,375(3):951-957
We have detected low-amplitude radial-velocity variations in two stars, USNO-B1.0 1219–0005465 (GSC 02265–00107 = WASP–1 ) and USNO-B1.0 0964–0543604 (GSC 00522–01199 = WASP–2 ). Both stars were identified as being likely host stars of transiting exoplanets in the 2004 SuperWASP wide-field transit survey. Using the newly commissioned radial-velocity spectrograph SOPHIE at the Observatoire de Haute-Provence, we found that both objects exhibit reflex orbital radial-velocity variations with amplitudes characteristic of planetary-mass companions and in-phase with the photometric orbits. Line-bisector studies rule out faint blended binaries as the cause of either the radial-velocity variations or the transits. We perform preliminary spectral analyses of the host stars, which together with their radial-velocity variations and fits to the transit light curves yield estimates of the planetary masses and radii. WASP-1b and WASP-2b have orbital periods of 2.52 and 2.15 d, respectively. Given mass estimates for their F7V and K1V primaries, we derive planet masses 0.80–0.98 and 0.81–0.95 times that of Jupiter, respectively. WASP-1b appears to have an inflated radius of at least 1.33 R Jup , whereas WASP-2b has a radius in the range 0.65–1.26 R Jup . 相似文献
59.
Roland Walter 《Astrophysics and Space Science》2007,309(1-4):5-9
INTEGRAL is operational since more than three years and producing high quality data that allows to detect fainter new hard
X-ray sources. The new sources, identified until now, are mostly active galactic nuclei and absorbed or transient high mass
X-ray binaries. TeV emission could be expected from the new high mass X-ray binaries accreting dense clumps of stellar wind.
INTEGRAL sources with TeV counterparts are discussed.
Based on observations with INTEGRAL, an ESA project with instruments and science data centre funded by ESA member states (especially
the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), Czech Republic and Poland, and with the participation
of Russia and the USA. 相似文献
60.