Neue Ungarische geoelektrische Instrumente     

Dr. Ing. Antal Ádám  Dipl. Geophys. András Erkel  Lászlò Szabadváry 《Pure and Applied Geophysics》1962,52(1):127-138

Zusammenfassung Die Einleitung gibt einige Gesichtspunkte der heutigen geoelektrischen Instrumentenentwicklung in Ungarn. Dann werden zwei neue ungarische geoelektrische Instrumente u.z.w.: 1) ein den spezifischen Widerstand unmittelbar lieferndes Instrument und 2) ein isolationsfehlerloses geophysikalisches Fotoregistrier-instrument mit ihren theoretischen Grundlagen behandelt. Am Ende des Artikels werden einige technische Daten der Instrumenten mitgeteilt.

---

Summary The introduction deals with the general aspects of the development of modern geoelectrical instruments in Hungary. Then two hungarian geoelectrical instruments: 1) an instrument giving directly the value of the resistivity and 2) a geophysical recording instrument free from isolation errors are discussed from the point of view of the theoretical problems of the instrument-constructions. Finally some technical data of the instruments are presented.

  相似文献   

Assessment of three-dimensional physical-biological ECOHAM1 simulations by quantified validation for the North Sea with ICES and ERSEM data     

Moll  Andreas 《ICES Journal of Marine Science》2000,57(4):1060-1068

  相似文献   

Gravity analysis offshore the Canary Islands from a systematic survey     

A. Carbó  A. Muñoz-Martín  P. Llanes  J. Álvarez 《Marine Geophysical Researches》2003,24(1-2):113-127

  相似文献   

Spatial variability of phytoplankton absorption coefficients and pigments off Baja California during November 2002     

Óscar A. Barocio-León  Roberto Millán-Núñez  Eduardo Santamaría-del-Ángel  Adriana González-Silvera  Charles C. Trees 《Journal of Oceanography》2006,62(6):873-885

We have estimated the spatial variability of phytoplankton specific absorption coefficients (a* _ph ) in the water column of the California Current System during November 2002, taking into account the variability in pigment composition and phytoplankton community structure and size. Oligotrophic conditions (surface Chl < 0.2 mg m⁻³) dominated offshore, while mesotrophic conditions (surface Chl 0.2 to 2.0 mg m⁻³) where found inshore. The specific absorption coefficient at 440 [a* _ph (440)] ranged from 0.025–0.281 m²mg⁻¹ while at 675 nm [a* _ph (675)] it varied between 0.014 and 0.087 m²mg⁻¹. The implementation of a size index based on HPLC data showed the community structure was dominated by picoplankton. This would reduce the package effect in the variability of a* _ph (675). Normalized a _ph curves were classified in two groups according to their shape, separating all spectra with peaks between 440 and 550 nm as the second group. Most samples in the first group were from surface layers, while the second group were from the deep chlorophyll maximum or deeper. Accessory photoprotective pigments (APP) tended to decrease with depth and accessory photosynthetic pigments (APS) to increase, indicating the importance of photoprotective mechanisms in surface layers and adaptation to low light at depth. Samples with higher ratios of APP:APS (>0.4) were considered as phytoplankton adapted to high irradiances, and lower ratios (<0.26) as adapted to low irradiances. We found a good relationship between APP:APS and a* _ph (440) for the deeper layer (DCM and below), but no clear evidence of the factors causing the variability of a* _ph (440) in the upper layer.  相似文献   

Cosmological parameters and redshift periodicity     

Ágnes Holba  I. Horváth  B. Lukács  G. Paál 《Astrophysics and Space Science》1992,198(1):111-120

This work is the continuation of the search for such a cosmological model using which the observed redshift distribution of galaxies in the sample of Broadhurstet al. (1990) turns out to be maximally periodic in the calculated spatial distance. In a previous work, Paálet al. (1992) have demonstrated that among theflat models with non-negative cosmological constant (e.e., vacuum density) the one with a vacuum: dust ratio 2:1 provides the optimum. Now we extend that study to the case of arbitrary space curvature and find equally good periodicity in a surprisingly wide range of models. By use of the dimensionless parameters ₀= ₀/ _crit and ₀=/3H ₀ ² acceptable periodicity is obtained forall points of the parameter plane within the strip between the parallel lines 0.83₀–0.30< ₀(₀)<0.83₀+0.85(₀<1.8), whilst the best periodicities appear along the line ₀=0.83₀+0.39 fitting to the previous optimum at ₀=1/3, ₀=2/3. Any nonpositive value of ₀ gives bad periodicity unless the space curvature is strongly negative and ₀<0.4. Fairly good periodicity is observed only in the range of the deceleration parameter –1.2q ₀<0.2, corresponding to a small or even negative total gravitational attraction and an expansion time-scale longer than usually expected.  相似文献   

Evaluation of 2D models for the prediction of surface depression storage using realistic reference values          下载免费PDF全文

R. Giménez  I. Mezkiritz  M.A. Campo  J. Álvarez‐Mozos  M. González‐Audicana  A. Martinez‐Agirre  J. Casalí 《水文研究》2016,30(18):3197-3209

Depression storage (DS) is the maximum storage of precipitation and runoff in the soil surface at a given slope. The DS is determined by soil roughness that in agricultural soils is largely affected by tillage. The direct measurement of DS is not straightforward because of the natural permeability of the soil. Therefore, DS has generally been estimated from 2D/3D empirical relationships and numerical algorithms based on roughness indexes and height measurements of the soil surface, respectively. The objective of this work was to evaluate the performance of some 2D models for DS, using direct and reliable measurements of DS in an agricultural soil as reference values. The study was carried out in experimental microplots where DS was measured in six situations resulting from the combination of three types of tillage carried out parallel and perpendicular to the main slope. Those data were used as reference to evaluate four empirical models and a numerical method. Longitudinal altitudinal profiles of the relief were obtained by a laser profilometer. Infiltration measurements were carried out before and after tillage. The DS was largely affected by tillage and its direction. Highest values of DS are found on rougher surfaces mainly when macroforms cut off the dominant slope. The empirical models had a limited performance while the numerical method was the most effective, even so, with an important variability. In addition, a correct hydrological management should take into account that each type of soil tillage affects infiltration rate differently. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Younger Dryas – early Holocene transition in the south‐eastern Iberian Peninsula: insights from land snail shell middens     

YURENA YANES  MAGDALENA GÓMEZ‐PUCHE  MARCO A. ESQUEMBRE‐BEBIA  JAVIER FERNÁNDEZ‐LÓPEZ‐DE‐PABLO 《第四纪科学杂志》2013,28(8):777-788

  相似文献   

Markovian characteristics of dry spells over the Iberian Peninsula under present and future conditions using ESCENA ensemble of regional climate models     

Noelia López-Franca  Enrique Sánchez  Teresa Losada  Marta Domínguez  Raquel Romera  Miguel Ángel Gaertner 《Climate Dynamics》2015,45(3-4):661-677

  相似文献   

13e SESSION DU COMITÉ CONSULTATIF KARACHI 4–15 NOVEMBRE 1957     

L. ALFÖLDI  J. GÁLFI 《水文科学杂志》2013,58(1):8-12

Abstract

Event-based methods are used in flood estimation to obtain the entire flood hydrograph. Previously, such methods adopted in the UK have relied on pre-determined values of the input variables (e.g. rainfall and antecedent conditions) to a rainfall–runoff model, which is expected to result in an output flood of a particular return period. In contrast, this paper presents a method that allows all the input variables to take on values across the full range of their individual distributions. These values are then brought together in all possible combinations as input to an event-based rainfall–runoff model in a Monte Carlo simulation approach. Further, this simulation strategy produces a long string of events (on average 10 per year), where dependencies from one event to the next, as well as between different variables within a single event, are accounted for. Frequency analysis is then applied to the annual maximum peak flows and flow volumes.

Citation Svensson, C., Kjeldsen, T.R., and Jones, D.A., 2013. Flood frequency estimation using a joint probability approach within a Monte Carlo framework. Hydrological Sciences Journal, 58 (1), 1–20.  相似文献   

In two waters: contemporary evolution of lagoonal and marine white seabream (Diplodus sargus) populations     

Mercedes González-Wangüemert  Ángel Pérez-Ruzafa 《Marine Ecology》2012,33(3):337-349

Brackish water ecosystems are often exposed to wide variations in environmental variables, including temperature and salinity, which may cause strong selective pressures on organisms modifying the genetic patterns of species. The aim of this work was to test whether there is a ‘divergence-with-gene flow’ in coastal lagoon populations of white seabream (Diplodus sargus) (Ria Formosa, S Portugal and Mar Menor, SE Spain) respect to four marine populations, by using partial sequences of cyt b mitochondrial gene and information from nine microsatellite loci. Genetic diversity was highest in both coastal lagoons (Mar Menor and Ria Formosa) considering mitochondrial and nuclear markers. Although some of F_ST population pairwise comparisons were not significant, analyses of molecular variance (AMOVAs) detected differences between groups (coastal lagoon and marine) close to significance. Also, only two haplotypes (Cytb-17 and Cytb-18) were detected in both coastal lagoon sampling sites and these localities (Mar Menor and Ria Formosa) showed the highest number of singletons, some of them with a high number of mutations, as has been already described for other Mar Menor populations (Pomatochistus marmoratus and Holothuria polii). Also, several tests detected significant positive and balancing selection considering mtDNA and microsatellite data. These data support the hypothesis of selection as one of the drivers of the genetic differences found between coastal lagoon and marine populations. The life strategy adopted by Diplodus sargus in coastal lagoons allows it to decrease its mortality rate and improve the heritability of its genes. Also, the increase time spent in coastal lagoons with different temperatures and salinities favours the fitness selection and the maintenance of exclusive haplotypes and genotypes in coastal lagoon inhabitants favouring the ‘divergence-with-gene-flow’.  相似文献