Solar-Blind Diamond Detectors for Lyra, the Solar VUV Radiometer on Board Proba II     

A. Benmoussa  J.-F. Hochedez  W. K. Schmutz  U. SchÜhle  M. NeslÁdek  Y. Stockman  U. Kroth  M. Richter  A. Theissen  Z. Remes  K. Haenen  V. Mortet  S. Koller  J. P. Halain  R. Petersen  M. Dominique  M. D’Olieslaeger 《Experimental Astronomy》2003,16(3):141-148

Fabrication, packaging and experimental results on the calibration of metal-semiconductor-metal (MSM) photodetectors made on diamond are reported. LYRA (Lyman- RAdiometer onboard PROBA-2) will use diamond detectors for the first time in space for a solar physics instrument. A set of measurement campaigns was designed to obtain the XUV-to-VIS responsivity of the devices and other characterizations. The measurements of responsivity in EUV and VUV spectral ranges (40–240 nm) have been carried out by the Physkalisch-Technische Bundesanstalt (PTB) in Germany at the electron storage ring BESSY II. The longer wavelength range from 210 to 1127 nm was measured with monochromatic light by using a Xe-lamp at IMO-IMOMEC. The diamond detectors exhibit a photoresponse which lie in the 35–65 mA/W range at 200 nm (corresponding to an external quantum efficiency of 20–40%) and indicate a visible rejection ratio (200–500 nm) higher than four orders of magnitude.  相似文献   

A Comparative Analysis of Transpiration and Bare Soil Evaporation   总被引：4，自引：0，他引：4  

Ferenc Ács 《Boundary-Layer Meteorology》2003,109(2):139-162

Transpiration E^v and bare soil evaporation E^b processes are comparatively analysed assuming homogeneous and inhomogeneous areal distributions of volumetric soil moisture content . For a homogeneous areal distribution of we use a deterministic model, while for inhomogeneous distributions a statistical-deterministic diagnostic surface energy balance model is applied. The areal variations of are simulated by Monte-Carlo runs assuming normal distributions of .The numerical experiments are performed for loam. In the experiments we used different parameterizations for vegetation and bare soil surface resistances and strong atmospheric forcing. According to the results theE^v()-^Eb() differences are great, especially in dry conditions. In spite of this, the available energy flux curves of vegetation A^v() and bare soil A^b() surfaces differ much less than the E^v() and ^Eb() curves. The results suggest that E^v is much more non-linearly related to environmental conditions than ^Eb. Both E^v and ^Eb depend on the distribution of , the wetness regime and the parameterization used. With the parameterizations, ^Eb showed greater variations than E^v. These results are valid when there are no advective effects or mesoscale circulation patterns and the stratification is unstable.  相似文献   

A record of pre-Variscan Barrovian regional metamorphism in the eastern part of the Slavonian Mountains (NE Croatia)     

D. Balen  P. Horváth  B. Tomljenović  F. Finger  B. Humer  J. Pamic  P. Árkai 《Mineralogy and Petrology》2006,87(1-2):143-162

Summary Petrological investigations and monazite dating are carried out on medium-grade metamorphic rocks (micaschist, gneiss and amphibolite) from the Kutjevačka Rijeka transect in the Slavonian Mts., Tisia Unit (NE Croatia). Field, mesoscopic and microstructural observations, as well as the preserved mineral chemistry, point to a single metamorphic event during peak assemblage growth reaching amphibolite facies conditions of ca. 600–650 °C and 8–11 kbar. Th, U and Pb contents of yttrium-rich accessory monazites indicate a pre-Variscan, i.e. Ordovician-Silurian age (444 ± 19 and 428 ± 25 Ma) for the medium-grade metamorphism of garnet-bearing micaschist.  相似文献   

Functional and Physical Parameters of HII Galaxies     

Ángeles I. Díaz 《Astrophysics and Space Science》1998,263(1-4):143-146

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Petrology of a new basalt occurrence in Hungary     

Dr. A. Embey-Isztin  G. Dobosi  Dr. G. Noske-Fazekas  E. Árva-Sós 《Mineralogy and Petrology》1989,40(3):183-196

Summary A new occurrence of basalt (minimum K/Ar age 57.9 ± 2.2 m.y.) is reported from Budaliget, near Budapest. Major and minor element concentrations show that the basalts are alkaline and potassic in nature ranging from olivine tholeiite to moderately undersaturated basanite. High mg-values and concentrations of Ni and Cr indicate that some of the samples may represent primary compositions. High pressure accidental xenoliths, xenocrysts and cognate megacrysts are frequent and the chemical zoning patterns of olivine and pyroxene phenocrysts indicate a complex evolution and polibaric conditions for the crystallization. The discovery of the new basalt occurrence is important from a geodynamical point of view: prior to the last two major geodynamical events (Plio-Pleistocene rifting with associated alkali basaltic volcanism and collision of microplates with associated Miocene calk-alkaline volcanism) the continental lithosphere below NE Transdanubia may have experienced another rifting period in the Paleocene or Upper Cretaceous.With 7 Figures  相似文献   

FRACTURES AS CONDUCTING DYKES AND CORRESPONDING TWO-DIMENSIONAL MODELS*     

A. ÁDÁM 《Geophysical Prospecting》1984,32(4):543-553

A statistical treatment of MT data from the Pannonian Basin, Hungary, based on the distortion theory of the S-effect suggests that the local increase in crustal conductivity is connected with deep fractures. Field model measurements have recently been carried out in a shallow, quasi two-dimensional basin of well known tectonics using MT station distances of 1–3 km. The results of the investigation and numerical modelling of near surface distortions, support the idea that deep fractures (faults) contain the conducting formations. According to 2-D model computations, several conducting dykes at considerable depths can cause anomalies which are indiscernible from an anomaly due to a conducting layer. The significance of these results is discussed from the point of view of geothermal energy exploitation.  相似文献   

Remarks on the one-photon-pair annihilation in strong magnetic fields     

Jorge PÁez  L. Semionova  J. Bonatti 《Astrophysics and Space Science》1994,214(1-2):89-92

We report specifically on a quantum electrodynamic feature of the one-photon-pair annihilation. Most of the calculation related with this process (not excluding other ones) have been carried out usually utilizing the wave functions obtained from the Dirac equation in the Landau gauge A = (0,Bx, 0), where B is oriented along the z-axis (Johnson and Lippman, 1949). Although, the eigenstates of the Dirac Hamiltonian as it was introduced by Johnson and Lippman, do not consider the coupling to the radiation field and consequently they reflect only forp _z = 0 the same linear combination of the two degenerate polarization states.We report the transition rate function for the one-photon-pair annihilation in a strong magnetic field by using the Sokolov and Ternov eigenstate |± as far asp _z = 0 andN > 0 is concerned. The difference between the expression for the transition rate by using the Sokolov and Ternov eigenstates and the one calculated by (Wunneret al., 1986), is just the functionI _s,s which corresponds to the degeneracy of the orbit center of the electrons characterized by the quantum numberss ands. Presented at the 2nd UN/ESA Workshop, held in Bogotá, Colombia, 9-13 November, 1992.  相似文献   

Alpine metamorphism of organic matter in metasedimentary rocks from Mt. Medvednica (Croatia)     

Katalin Judik  Gerd Rantitsch  Thomas M. Rainer  Péter Árkai  Bruno Tomljenović 《Swiss Journal of Geoscience》2008,101(3):605-616

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Variations in the dynamic response of structures founded on piles induced by obliquely incident SV waves     

Cristina Medina  Guillermo M. Álamo  Juan J. Aznárez  Luis A. Padrón  Orlando Maeso 《地震工程与结构动力学》2019,48(7):772-791

Although the seismic actions generally consist of a combination of waves, which propagates with an angle of incidence not necessarily vertical, the common practice when analyzing the dynamic behavior of pile groups is based on the assumption of vertically incident wave fields. The aim of this paper is to analyze how the angle of incidence of SV waves affects the dynamic response of pile foundations and piled structures. A three-dimensional boundary element-finite element coupling formulation is used to compute impedances and kinematic interaction factors corresponding to several configurations of vertical pile groups embedded in an isotropic homogeneous linear viscoelastic half-space. These results, which are provided in ready-to-use dimensionless graphs, are used to determine the effective dynamic properties of an equivalent single-degree-of-freedom oscillator that reproduces, within the range where the peak response occurs, the response of slender and nonslender superstructures through a procedure based on a substructuring model. Results are expressed in terms of effective flexible-base period and damping as well as maximum shear force at the base of the structure. The relevance and main trends observed in the influence of the wavefront angle of incidence on the dynamic behavior of the superstructure are inferred from the presented results. It is found that effective damping is significantly affected by the variations of the wave angle of incidence. Furthermore, it comes out that the vertical incidence is not always the worst-case scenario.  相似文献   

THE Fe  XXV EXCITATION EQUILIBRIUM IN THE SOLAR CORONA FOR THE ELECTRON POWER DISTRIBUTIONS USING A PSEUDO-TEMPERATURE     

DZIFČÁKOVÁ  ELENA  KULINOVÁ  ALENA 《Solar physics》2001,203(1):53-70

The excitation equilibrium of Fexxv in the solar corona for electron power distributions is presented. A parametric form of the distribution function is used to demonstrate the changes in the excitation equilibrium due to the shape of the distribution. A pseudo-temperature is used for better understanding of the changes in the excitation equilibrium. The Fexxv line intensities depend on the shape of the electron distribution and unusual Fe line ratios can be observed for non-thermal distribution. The results can be used in specific applications in the solar corona, especially in diagnostics of the impulsive phase of solar flares, where the deviations from the Maxwellian distribution can be large.  相似文献