Study of the Contributions of Non‐Specific and Specific Interactions during Fluoxetine Adsorption onto Activated Carbons     

Silvia Román  João Manuel Valente Nabais  Juan Félix González  Carmen María González‐García  Angel Luis Ortiz 《洁净——土壤、空气、水》2012,40(7):698-705

The adsorption of fluoxetine onto activated carbons (ACs) prepared from almond tree pruning by steam and CO₂ activation under different temperature conditions (650–950°C), was studied. In both series increasing the temperature caused an increase in the BET apparent surface area, yielding ACs with S_BET up to 870 and 710 m² g^?1 after steam and CO₂ activation, respectively. Also, a slight widening of the porosity was found in both cases. In order to modify the functionality of the ACs, two of them were impregnated with triethylenediamine (TEDA) prior to the adsorption process, which caused a decrease in the AC apparent surface mainly due to micropore blockage. The fluoxetine adsorption isotherms at 25°C showed maximum adsorption capacities between 110 and 224 mg g^?1. The adsorption isotherms were analyzed using Langmuir and Freundlich models. Although the impregnation reduced the pore volume, it did not cause a decrease in the fluoxetine maximum adsorption capacity, but a modification in the adsorption mechanism was observed.  相似文献   

4D Arctic: A Glimpse into the Structure and Evolution of the Arctic in the Light of New Geophysical Maps,Plate Tectonics and Tomographic Models     

Carmen Gaina  Sergei Medvedev  Trond H. Torsvik  Ivan Koulakov  Stephanie C. Werner 《Surveys in Geophysics》2014,35(5):1095-1122

Knowledge about the Arctic tectonic structure has changed in the last decade as a large number of new datasets have been collected and systematized. Here, we review the most updated, publicly available Circum-Arctic digital compilations of magnetic and gravity data together with new models of the Arctic’s crust. Available tomographic models have also been scrutinized and evaluated for their potential to reveal the deeper structure of the Arctic region. Although the age and opening mechanisms of the Amerasia Basin are still difficult to establish in detail, interpreted subducted slabs that reside in the High Arctic’s lower mantle point to one or two episodes of subduction that consumed crust of possibly Late Cretaceous–Jurassic age. The origin of major igneous activity during the Cretaceous in the central Arctic (the Alpha–Mendeleev Ridge) and in the proximity of rifted margins (the so-called High Arctic Large Igneous Province—HALIP) is still debated. Models of global plate circuits and the connection with the deep mantle are used here to re-evaluate a possible link between Arctic volcanism and mantle plumes.  相似文献   

The spatial distribution of galaxies within the cosmic microwave background cold spot in the Corona Borealis supercluster     

Carmen Pilar Padilla-Torres  Carlos M. Gutiérrez  Rafael Rebolo  Ricardo Génova-Santos  José Alberto Rubiño-Martin 《Monthly notices of the Royal Astronomical Society》2009,396(1):53-60

We study the spatial distribution and colours of galaxies within the region covered by the cold spot in the cosmic microwave background recently detected by the Very Small Array interpherometer (VSA) towards the Corona Borealis supercluster (CrB-SC). The spot is in the northern part of a region with a radius  ∼1° (∼5 Mpc  at the redshift of CrB-SC) enclosing the clusters Abell 2056, 2065, 2059 and 2073, and where the density of galaxies, excluding the contribution from those clusters, is approximately two times higher than the mean value in typical intercluster regions of the CrB-SC. Two of such clusters (Abell 2056 and 2065) are members of the CrB-SC, while the other two are in the background. This high-density intercluster region is quite inhomogeneous, being the most remarkable feature a large concentration of galaxies in a narrow filament running from Abell 2065 with a length of ∼35 arcmin (  ∼3 Mpc  at the redshift of CrB-SC) in the SW–NE direction. This intercluster population of galaxies probably results from the interaction of clusters Abell 2065 and 2056. The area subtended by the VSA cold spot shows an excess of faint  (21 < r < 22)  and red  (1.1 < r − i < 1.3)  galaxies as compared with typical values within the CrB-SC intercluster regions. This overdensity of galaxies shows a radial dependence and extends out to ∼15 arcmin. This could be the signature of a previously unnoted cluster in the background.  相似文献   

Combining the standardized precipitation index and climatic water deficit in characterizing droughts: a case study in Romania   总被引：1，自引：1，他引：0  

Cr. Paltineanu  I. F. Mihailescu  Zoia Prefac  Carmen Dragota  Felicia Vasenciuc  Nicola Claudia 《Theoretical and Applied Climatology》2009,97(3-4):219-233

This paper characterizes droughts in Romania using the approach of both the standardized precipitation index (SPI) and climatic water deficit (WD). The values of the main climatic factors (rainfall, temperature, reference evapotranspiration, etc.) were obtained from 192 weather stations in various regions of Romania. Penman–Monteith reference evapotranspiration (ET_o-PM) was used to calculate WD as the difference between precipitation (P) and ET_o-PM. SPI was calculated from precipitation values. There is a clear difference between drought and aridity. Drought occurrence determines higher WD values for plains and plateaus and lower climatic excess water (EW) values for high mountains in Romania, depending on the aridity of the specific region considered and drought severity. WD calculated as mean values for both normal conditions and, for all locations studied, various types of drought was correlated with mean annual precipitation and temperature, respectively. The combined approach of WD and SPI was mainly carried out for periods of 1 year, but such studies could also be done for shorter periods like months, quarters, or growing season. The most arid regions did not necessarily coincide with areas of the most severe drought, as there were no correlations between WD and SPI and no altitude-based SPI zones around the Carpathian Mountains, as is the case for other climate characteristics, soils and vegetation. Water resource problems arise where both SPI values characterize extremely droughty periods and WD values are greatly below ?200 mm/year. This combined use of SPI and WD characterizes the dryness of a region better than one factor alone and should be used for better management of water in agriculture in Romania and also other countries with similar climate characteristics.  相似文献   

Entropy-based inference of simple physical models for regional flood analysis     

A. Solana-Ortega  V. Solana 《Stochastic Environmental Research and Risk Assessment (SERRA)》2001,15(6):415-446

 Regional flood analysis is formulated as a physical-modelling problem consisting in the inference of meaningful physical models for a set of observable uncertain quantities representing floods, given the observed data separately associated with them. It is argued that physical modelling suitable for representing causality relationships should involve the use of models comprising functional dependences of the observable uncertain quantities with regard to other quantities which are unobservable. The regional physical-modelling problem becomes the selection, from any proposed space of candidate models, of a probability distribution for the unobservable uncertain quantities together with a functional-dependence model connecting the observable to the unobservable uncertain quantities. Due to the need to coherently represent observational data and to express precisely the available evidences, the physical modelling problem is formalized in a plausible logic language, within the logical probability framework. A logical inference procedure called the relative entropy method with fractile constraints (REF) is formulated within this framework and extended to solve the regional physical-modelling problem. Contrary to the current statistical methods, it allows the selection and validation of inferred models and can be applied whatever it is the number of observational data. The complete solution to the problem using the relative entropy procedure is presented. This method is applied to the regional modelling of annual maximum floods of a set of separate rivers in the Iberian Peninsula. For this application the space of candidate models includes several types of two-parameter probability distributions for the unobservable uncertain quantities and the class of linear homogeneous functional-dependence models connecting the observable to the unobservable quantities.  相似文献   

Sporadic breakdowns of stability in the PBL over simple and complex terrain     

Carmen J. Nappo 《Boundary-Layer Meteorology》1991,54(1-2):69-87

Breakdowns of stability in the PBL are examined using one-minute average horizontal wind speeds and temperatures observed over many nights at stations located in simple and complex terrain. The analysis is based on the temporal behavior of the wind speed-temperature covariance, which is obtained by digital bandpass filtering. It is shown that breakdowns are a common feature of the stable PBL over both simple and complex environments. Vertical fluxes of heat during breakdowns are estimated to be a significant fraction of the nighttime average heat flux. It is hypothesized that a major portion of the nighttime vertical transfer of heat, momentum, and atmospheric pollutants occurs during periods of stability breakdowns.  相似文献   

The nature and distribution of organic matter in the surface sediments of world oceans and seas     

Eugene T. Premuzic  Carmen M. Benkovitz  Jeffrey S. Gaffney  John J. Walsh 《Organic Geochemistry》1982,4(2):63-77

Existing data on the distribution of organic carbon and nitrogen in marine sediments have been analyzed in order to better understand the physical and chemical processes involved in this aspect of the global carbon cycle. Maps of the global distribution of organic carbon and nitrogen in the sediments of world oceans and seas are presented.Correlation analyses of the available information dealing with the distribution of marine sedimentary organic matter has revealed that in terms of bulk parameters (%C_Org and %N Kjeldahl), there is an apparent accumulation of organic matter on the continental slope (water column depth 200–2000 m). Specific interactions between clays and organic matter, although indicated in laboratory experiments, have not been detected by these analyses.  相似文献   

Further constraints for Permo-Carboniferous magnetostratigraphy: case study of the sedimentary sequence from San Salvador–Patlanoaya (Mexico)De nouvelles contraintes pour la magnétostratigraphie du Permo-Carbonifères : cas d'étude de la séquence sédimentaire de San Salvador–Patlanoaya (Mexique)     

Luis M Alva-Valdivia  Avto Goguitchaichvili  Manuel Grajales  Antonio Flores de Dios  Jaime Urrutia-Fucugauchi  Carmen Rosales  Juan Morales 《Comptes Rendus Geoscience》2002,334(11):811-817

We report rock-magnetic and magnetostratigraphic results from one of the best exposed Permo-Carboniferous outcrops in Mexico, in order to determine some decisive magnetostratigraphy constraints. Some spinels, most probably titanomagnetites, seem to be responsible for aimantation, although greigite may also exist judging from thermal desaimantation of isothermal remanence. Remanence analyses indicate that only one remanent component could be recognized with minor secondary overprint, which were easily removed applying 100–180 °C. Six normal and four reverse magnetozones were recognized from bottom to top in Patlanoya section between 340 and 280 Myr. Both normal and reverse polarity rocks were found in Carboniferous time around 340 Myr, in agreement with previous paleomagnetic works. Our record revealed two normal subchrons within PCRS (Kiaman), the dominantly reverse superchron, at 305 and 280 Myr, respectively. These, which may be speculatively correlated to normal aimantation, occasionally occurred during PCRS interval. More detailed studies are needed in order to establish a more precise magnetostratigraphy for Permo-Carboniferous time. To cite this article: L.M. Alva-Valdivia et al., C. R. Geoscience 334 (2002) 811–817.  相似文献   

Ground Motion Zoning of Santiago de Cuba: An Approach by SH Waves Modelling   总被引：3，自引：0，他引：3  

Leonardo Alvarez  Julio García  Franco Vaccari  Giuliano F. Panza  Bertha González  Carmen Reyes  Bárbara Fernández  Ramón Pico  José A. Zapata  Enrique Arango 《Pure and Applied Geophysics》2004,161(5-6):1041-1059

— The expected ground motion in Santiago de Cuba basin from earthquakes which occurred in the Oriente fault zone is studied. Synthetic SH-waves seismograms have been calculated along four profiles in the basin by the hybrid approach (modal summation for the path source-profile and finite differences for the profile) for a maximum frequency of 1 Hz. The response spectra ratio (RSR) has been determined in 49 sites, distributed along all considered profiles with a spacing of 900 m. The corresponding RSR versus frequency curves have been classified using a logical-combinatorial algorithm. The results of the classification, in combination with the uppermost geological setting (geotechnical information and geological geometry of the subsoil) are used for the seismic zoning of the city. Three different main zones are identified, and a small sector characterized by major resonance effects, due to the particular structural conditions. Each zone is characterized in terms of its expected ground motion parameters for the most probable strong earthquake (M_S=7), and for the maximum possible (M_S=8).  相似文献   

Influence of Mediterranean sea-level changes on the Dacic Basin (Eastern Paratethys) during the late Neogene: the Mediterranean Lago Mare facies deciphered   总被引：2，自引：0，他引：2  

Georges Clauzon  Jean-Pierre Suc†  Speranta-Maria Popescu†  Mariana Marunteanu‡  Jean-Loup Rubino¶  Florian Marinescu‡  Mihaela Carmen Melinte§ 《Basin Research》2005,17(3):437-462

A recently published scenario viewing the Messinian salinity crisis as two evaporitic steps rather than one has led to a search for new indices of the crisis in the Eastern Paratethys. Fluvial processes characterized the southwestern Dacic Basin (Southern Romania, i.e. the Carpathian foredeep) whereas brackish sediments were continuously deposited in its northern part. This is consistent with previously evidenced responses of the Black Sea to the Messinian salinity crisis. High sea‐level exchanges between the Mediterranean Sea and Eastern Paratethys are considered to have occurred just before and just after desiccation of the Mediterranean. This accounts for two successive Mediterranean nannoplankton‐dinocyst influxes into the Eastern Paratethys that, respectively, belong to zones NN 11 and NN 12. Meanwhile, two separate events that gave rise to Lago Mare facies (with Paratethyan Congeria, ostracods and/or dinoflagellate cysts) arose in the Mediterranean Basin in response to these high sea‐level exchanges and located 5.52 and 5.33 Ma (isotopic stages TG 11 and TG 5, respectively), i.e. just before and just after the almost complete desiccation of the Mediterranean). These Lago Mare facies formed independently of lakes with ostracods of the Cyprideis group that developed in the central basins during the final stages of desiccation. The gateway faciliting these water exchanges is not completely identified. A proto‐Bosphorus strait seems unlikely. A plausible alternative route extends from the northern part of the Thessaloniki region up to the Dacic Basin and through Macedonia and the Sofia Basin. The expression ‘Lago Mare’ is chronostratigraphically ambiguous and should be discontinued for this purpose, although it might remain useful as a palaeoenvironmental term.  相似文献