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  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Microchimica acta 57 (1969), S. 1292-1296 
    ISSN: 1436-5073
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Summary The C-methyl determination in substituted toluidines was studied. The yield of acetic acid is excellently reproducible. The influence of the position and kind of substitution in these substances was followed and discussed.
    Notizen: Zusammenfassung Die C-Methylbestimmung in substituierten Toluidinen wurde untersucht. Die Ausbeute an Essigsäure ist gut reproduzierbar. Der Einfluß der Stellung und Art der Substituenten in diesen Substanzen wurde verfolgt und diskutiert.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    ISSN: 1436-5073
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Summary Too high hydrogen values were obtained in the C-H-determinations, with external absorption of the nitrogen oxides, in a series of nitrogenous substances, whereas a second series with the same atom groups gave correct results. To explain these divergent behaviors, additional substances were prepared and analyzed. It was then observed that substances with the group yielded too high hydrogen values in general, while the presence of phenyl rings or OH-groups in the α andβ-position led again to uniform hydrogen values. The preparation of the new compounds of this kind is described. In the case of the compounds that gave too high hydrogen values in the C-H-determination, identification was made on one hand by determining the nitrogen, on the other hand by determining the carbon and hydrogen by another method that provides for the reduction of the nitrogen oxides. The latter is described.
    Notizen: Zusammenfassung Bei der C-H-Bestimmung mit Außenabsorption der Stickoxide wurden bei einer Serie stickstoffhaltiger Substanzen zu hohe Wasserstoffwerte erhalten, während sich bei einer zweiten Serie, mit gleichen Atomgruppen, richtige Werte ergaben. Um dieses verschiedene Verhalten erklären zu können, wurden weitere Substanzen dieser Art dargestellt und analysiert. Dabei konnte beobachtet werden, daß Substanzen mit der Atomgruppe bei der Analyse im allgemeinen zu hohe Wasserstoffwerte geben, während die Anwesenheit von Phenylringen oder OH-Gruppen, inα undβ Stellung wieder zu regelmäßigen Wasserstoffwerten führen. Die Darstellung neuer Verbindungen dieser Art wurde beschrieben. In den Verbindungen, die bei der C-H-Bestimmung zu hohe Wasserstoffwerte gaben, wurden zur Identifizierung einerseits der Stickstoff, anderseits C und H nach einer Methode bestimmt, die die Reduktion der Stickoxide vorsieht. Diese wird beschrieben.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Microchimica acta 59 (1971), S. 63-65 
    ISSN: 1436-5073
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Summary The C-methyl determination in substituted pyridines was studied. The influence of the amino-, hydroxyl-, carboxyl-, nitrilo- and hydroxymethyl groups on the yield of acetic acid was investigated and discussed.
    Notizen: Zusammenfassung Die C-Methylbestimmung in substituierten Pyridinen wurde untersucht. Der Einfluß der Amino-, Hydroxyl-, Carboxyl-, Nitril- und Hydroxymethylgruppen auf die Ausbeute an Essigsäure wurde verfolgt und diskutiert.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    ISSN: 1432-1793
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The structure of megabenthic decapod crustacean assemblages on the Galician (north-west Spain) continental shelf (100 to 200 depth) and upper slope (200 to 500 m) was analyzed based on surveys carried out in autumn and spring, from 1980 to 1987. Forty species belonging to 19 families were caught. The portunid crab Polybius henslowii, a species with pelagic phases, was the most abundant species, but displayed strong spatial and temporal fluctuations. Other dominant species were the Norway lobster Nephrops norvegicus, the portunid Liocarcinus depurator, the galatheids Munida intermedia and M. sarsi, and the shrimps Solenocera membranacea, Plesionika heterocarpus, Pasiphaea sivado and Dichelopandalus bonnieri. Total abundance and biomass (average values excluding Polybius henslowii = 255 individuals and 2.06 kg/30 min tow) and species richness and diversity, H′ (6.85 species and H′ = 1.45 per tow) displayed a significant positive correlation with depth, and strong interannual fluctuations. The factors determining community organization were depth and, to a lesser extent, spatial structure. There was clear evidence of bathymetric zonation, differentiating between species characteristic of the slope (D. bonnieri and Pasiphaea sivado), shelf-slope edge (Macropipus tuberculatus, Pontophilus spinosus, Munida sarsi, S. membranacea, Processa spp.) and shelf (L. depurator, Macropodia tenuirostris, Paguridae and Chlorotocus crassicornis). The spatial zonation was related to changes in oceanography and sediment along the continental margin. Goneplax rhomboides, N. norvegicus, C. crassicornis and Alpheus glaber are benthic species which generally exhibit burrowing behaviour, and they were found mainly in the southern area where there are fine sediments due to the outwelling from the Rías Baixas. Different benthopelagic shrimps (Pontophilus spinosus, Plesionika heterocarpus,Processa spp. and Pasiphaea sivado) were typical of the zone just north of Fisterra, characterized by a convergence of water masses bringing about an increase in productivity due to upwelling. The benthic anomuran and brachyuran crabs Munida intermedia, M.␣sarsi, L.␣depurator and Macropipus tuberculatus were characteristic of the northwestern zone between Fisterra and Estaca, where the infauna reaches high biomass despite coarser sediments with a lower concentration of organic material than in the southern area. Lastly, both the Paguridae and Macropodia tenuirostris were species typically found in the waters in the northern shelf. Based on interannual changes in assemblage structure, two periods could be distinguished: between 1980 and 1984, when Polybius henslowii, D. bonnieri and Pasiphaea sivado had abundance peaks; and another period from 1985 to 1987 when L. depurator, Munida intermedia, M.␣sarsi and Macropipus tuberculatus increased in abundance.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Publikationsdatum: 2016-06-24
    Beschreibung: Using a specialized technique sensitive to the presence of expanding ionized gas, we have detected a set of three concentric expanding shells in an H ii region in the nearby spiral galaxy M33. After mapping the kinematics in Hα with Fabry–Perot spectroscopy, we used slit spectra to measure the intensities of the [S ii ] doublet at 671.9, 673.1 nm and the [N ii ] doublet at 645.8, 658.3 nm to corroborate the kinematics and apply diagnostic tests using line ratios. These showed that the expanding shells are shock dominated as would be the case if they had originated with supernova explosions. Estimating their kinetic energies, we find fairly low values, indicating a fairly advanced stage of evolution. We obtain density, mass and parent star mass estimates, which, along with the kinetic energies, are inconsistent with the simplest models of shock–interstellar medium interaction. We propose that the presence and properties of an inhomogeneous medium offer a scenario which can account for these observations, and discuss the implications. Comparing our results with data from the literature supports the combined presence of an H ii region and supernova remnant material at the observed position.
    Print ISSN: 1745-3925
    Digitale ISSN: 1745-3933
    Thema: Physik
    Publiziert von Oxford University Press
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Publikationsdatum: 2015-06-07
    Beschreibung: We have observed 12 interacting galaxy pairs using the Fabry–Perot interferometer GH αFaS (Galaxy H α Fabry–Perot system) on the 4.2-m William Herschel Telescope at the Observatorio del Roque de los Muchachos, La Palma. We present here the Hα surface brightness, velocity and velocity dispersion maps for the 10 systems we have not previously observed using this technique, as well as the physical properties (sizes, Hα luminosities and velocity dispersion) of 1259 H ii regions from the full sample. We also derive the physical properties of 1054 H ii regions in a sample of 28 isolated galaxies observed with the same instrument in order to compare the two populations of H ii regions. We find a population of the brightest H ii regions for which the scaling relations, for example the relation between the Hα luminosity and the radius, are clearly distinct from the relations for the regions of lower luminosity. The regions in this bright population are more frequent in the interacting galaxies. We find that the turbulence, and also the star formation rate (SFR), are enhanced in the H ii regions in the interacting galaxies. We have also extracted the Hα equivalent widths for the H ii regions of both samples, and we have found that the distribution of H ii region ages coincides for the two samples of galaxies. We suggest that the SFR enhancement is brought about by gas flows induced by the interactions, which give rise to gravitationally bound gas clouds which grow further by accretion from the flowing gas, producing conditions favourable to star formation.
    Print ISSN: 0035-8711
    Digitale ISSN: 1365-2966
    Thema: Physik
    Publiziert von Oxford University Press
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Publikationsdatum: 2015-01-31
    Beschreibung: We present a new method for the detection and characterization of expansion in galaxy discs based on Hα Fabry-Perot spectroscopy, taking advantage of the high spatial and velocity resolution of our instrument (GHαFaS). The method analyses multipeaked emission line profiles to find expansion along the line of sight on a point-by-point basis. At this stage we have centred our attention on the large-scale structures of expanding gas associated with H ii regions which show a characteristic pattern of expansion velocities, of the order of 100 km s –1 , as a result of both bubble shape and projection effects. We show an example of the expansion map obtained with our method from a superbubble detected in the Antennae galaxies. We use the information obtained from the method to measure the relevant physical parameters of the superbubbles, including their ages which can be used to date young star clusters.
    Print ISSN: 0035-8711
    Digitale ISSN: 1365-2966
    Thema: Physik
    Publiziert von Oxford University Press
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    Publikationsdatum: 2015-06-12
    Beschreibung: We have observed 12 interacting galaxy pairs using the Fabry–Perot interferometer GH αFaS (Galaxy H α Fabry–Perot system) on the 4.2-m William Herschel Telescope at the Observatorio del Roque de los Muchachos, La Palma. We present here the Hα surface brightness, velocity and velocity dispersion maps for the 10 systems we have not previously observed using this technique, as well as the physical properties (sizes, Hα luminosities and velocity dispersion) of 1259 H ii regions from the full sample. We also derive the physical properties of 1054 H ii regions in a sample of 28 isolated galaxies observed with the same instrument in order to compare the two populations of H ii regions. We find a population of the brightest H ii regions for which the scaling relations, for example the relation between the Hα luminosity and the radius, are clearly distinct from the relations for the regions of lower luminosity. The regions in this bright population are more frequent in the interacting galaxies. We find that the turbulence, and also the star formation rate (SFR), are enhanced in the H ii regions in the interacting galaxies. We have also extracted the Hα equivalent widths for the H ii regions of both samples, and we have found that the distribution of H ii region ages coincides for the two samples of galaxies. We suggest that the SFR enhancement is brought about by gas flows induced by the interactions, which give rise to gravitationally bound gas clouds which grow further by accretion from the flowing gas, producing conditions favourable to star formation.
    Print ISSN: 0035-8711
    Digitale ISSN: 1365-2966
    Thema: Physik
    Publiziert von Oxford University Press
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    Publikationsdatum: 2012-02-17
    Beschreibung: Cañás, L., Stransky, C., Schlickeisen, J., Sampedro, M. P., and Fariña, A. C. 2012. Use of the otolith shape analysis in stock identification of anglerfish ( Lophius piscatorius ) in the Northeast Atlantic. – ICES Journal of Marine Science, 69: 250–256. The geographical variability in the anglerfish Lophius piscatorius otolith shape was investigated to examine biological evidence for the current separation into Northern and Southern stocks of L. piscatorius established in the Southwest European waters (Southern Shelf area) by the International Council for the Exploration of the Sea (ICES). In all, 629 otoliths of L. piscatorius (12–90 cm total length) from commercial fishing and research surveys were collected in two consecutive years, 2008 and 2009. The otolith shape was compared between stocks for differences in univariate descriptors using non-parametric analysis of covariance, as well as elliptical Fourier shape descriptors, through a metric multidimensional scaling and a linear discriminant analysis (LDA). The differences found in the otolith shape between Northern and Southern stocks were not large enough to hold the current status of L. piscatorius regarding stock definition in the Southern Shelf area, although homogeneous mixing between both stocks is not expected as there were significant differences between three univariate descriptors and the LDA was significant. These results are in agreement with the previous L. piscatorius stock identification studies (genetics, body morphology, and migratory behaviour), which do not support the current separation of these stocks but found substructures within the area.
    Print ISSN: 1054-3139
    Digitale ISSN: 1095-9289
    Thema: Biologie , Geologie und Paläontologie , Physik
    Publiziert von Oxford University Press
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Publikationsdatum: 2011-12-23
    Beschreibung: Semistatic word-based byte-oriented compressors are known to be attractive alternatives to compress natural language texts. With compression ratios around 30–35%, they allow fast direct searching of compressed text. In this article, we reveal that these compressors have even more benefits. We show that most of the state-of-the-art compressors benefit from compressing not the original text, but the compressed representation obtained by a word-based byte-oriented statistical compressor. For example, p7zip with a dense-coding preprocessing achieves even better compression ratios and much faster compression than p7zip alone. We reach compression ratios below 17% in typical large English texts, which was obtained only by the slow prediction by partial matching compressors. Furthermore, searches perform much faster if the final compressor operates over word-based compressed text. We show that typical self-indexes also profit from our preprocessing step. They achieve much better space and time performance when indexing is preceded by a compression step. Apart from using the well-known Tagged Huffman code, we present a new suffix-free Dense-Code-based compressor that compresses slightly better. We also show how some self-indexes can handle non-suffix-free codes. As a result, the compressed/indexed text requires around 35% of the space of the original text and allows indexed searches for both words and phrases.
    Print ISSN: 0010-4620
    Digitale ISSN: 1460-2067
    Thema: Informatik
    Publiziert von Oxford University Press
    Standort Signatur Erwartet Verfügbarkeit
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