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91.
Enrique Portugal Rosa María Barragn Jesús de Len 《Journal of Geochemical Exploration》2006,89(1-3):339
Chemical equilibrium modeling studies of two aquifers in the western part of the Cerro Prieto (CP-I) geothermal field were performed to obtain the activities of the main ions and complexes by using the EQQYAC program. The results provided a pH of 6.44 for the deep aquifer, which is slightly higher than the value of 5.5 found for the shallower reservoir. In the northern part of the field, the reservoir pH has decreased up to 1.5 units compared to that modeled for 1990. Variations of pH with respect to time were also found to occur in the southern part of the field. In spite of the large changes in hydrodynamic conditions occurring in the reservoir due to exploitation, the equilibrium between both K- and Na-feldspars and between K-feldspar and K-mica seems to control the chemical composition of the fluids, in both reservoirs. 相似文献
92.
I. García De La Rosa R. Coziol R.R. De Carvalho S. Zepf 《Astrophysics and Space Science》2001,276(2-4):717-723
We present a study focusing on the nature of compact groups (CGs) through the study of their elliptical (E) galaxies. Parameters describing the internal dynamics and the stellar populations of the galaxies are compared with their counterparts in other environments. Our sample has24 bright E galaxies located in the core of Hickson CGs and 11 bright ‘bona fide’ Es, located in the field or very loose groups. Their spectra were obtained with the 2.1 m Telescope at KPNO and have a 4.1 Å resolution over the wavelength range 3500–7000 Å. We have found that, from the dynamical point of view, E galaxies in CGs are essentially similar to those in dense clusters. Moreover, the stellar populations of Es in CGs seem to be older and less metal rich than those in the field, behaviour which has also been observed by Rose et al. (1994). 相似文献
93.
94.
T.B. Veronese R.R. Rosa M.J.A. Bolzan F.C. Rocha Fernandes H.S. Sawant M. Karlicky` 《Journal of Atmospheric and Solar》2011,73(11-12):1311-1316
High temporal resolution solar observations in the decimetric range (1–3 GHz) can provide additional information on solar active regions dynamics and thus contribute to better understanding of solar geoeffective events as flares and coronal mass ejections. The June 6, 2000 flares are a set of remarkable geoeffective eruptive phenomena observed as solar radio bursts (SRB) by means of the 3 GHz Ondrejov Observatory radiometer. We have selected and analyzed, applying detrended fluctuation analysis (DFA), three decimetric bursts associated to X1.1, X1.2 and X2.3 flare-classes, respectively. The association with geomagnetic activity is also reported. DFA method is performed in the framework of a radio burst automatic monitoring system. Our results may characterize the SRB evolution, computing the DFA scaling exponent, scanning the SRB time series by a short windowing before the extreme event. For the first time, the importance of DFA in the context of SRB monitoring analysis is presented. 相似文献
95.
96.
William R. Stockwell Rosa M. Fitzgerald Duanjun Lu Roberto Perea 《Journal of Atmospheric Chemistry》2013,70(1):91-104
The objective of this study is to present differences in the variability of observed and ozone-mixing ratios simulated by a three-dimensional atmospheric chemical model using two chemical mechanisms. In this study the Comprehensive Air Quality Model with Extensions is used to make ozone simulations with the Carbon Bond mechanism, versions 4 and 5. The Paso del Norte region is used as a test-bed for these simulations. The shared variance between the simulations and measurements is typical for air quality models ranging from 0.51 to 0.86 for both mechanisms. The smallest mean normalized gross error is about 31 % with CB4 but the normalized bias is over 30 % as well. Boundary conditions, emissions and other factors affect the levels of ozone of the simulated mixing ratios and therefore error and bias but these factors have a much less affect on the simulated ozone variability. The differences in the ozone variability of the measurements and the simulations are very large and different for the two chemical mechanisms. There are many more instances of low ozone mixing ratios in the measurements than in the simulated ozone. One possible explanation is that these differences are due to problems associated with comparing point measurements with grid averages. A more disturbing possibility is that the bias could be due to the procedures used in the development and testing of air quality modeling systems. Air quality mechanisms are evaluated against environmental chamber data where the chemistry occurs at high concentrations and this may lead to a systematic positive bias in ozone simulations. 相似文献
97.
98.
J. I. De La Rosa Garcia 《Solar physics》1983,89(1):51-62
According to several properties, the active regions are divided in two groups whose limit is roughly set at 1021 Mx. A statistical analysis indicates that the small regions emerge almost exclusively in the remnant magnetic regions, resulting from the decay of previous active centers. According to these facts, a tentative picture is proposed, where the small active regions and perhaps also the ephemeral ones, are the secondary effects after the decay of the large active regions and complexes of activity. 相似文献
99.
100.
Carlos Roberto Sanquetta Ana Paula Dalla Corte Alexandre Behling Luani Rosa de Oliveira Piva Sylvio Péllico Netto Aurélio Lourenço Rodrigues Mateus Niroh Inoue Sanquetta 《Carbon balance and management》2018,13(1):25