Eine Methode zur Bestimmungdes wahren Winkelsder optischen Achsen und des mittleren Hauptbrechungsquotienten zweiachsiger Minerale im Dünnschliff     

Prof. Dr. Rudolf Mosebach 《Contributions to Mineralogy and Petrology》1951,2(5):432-436

Zusammenfassung Eine früher mitgeteilte Bestimmungsmethode des wahren Winkels der optischen Achsen und des mittleren Hauptbrechungsquotienten /ß mit Hilfe von Drehtischmessungen am Dünnschliff wird auf ihre Brauchbarkeit an Mineralien der Olivingruppe praktisch erprobt. Für senkrechten der nahezu senkrechten Austritt der Mittellinien werden einfache Berechnungsformeln abgeleitet und ihr Anwendungsbereich geprüft. An Olivinen verschiedener Herkunft wird der Fayalitgehalt optisch ermittelt und mit dem Ergebnis der quantitativen chemischen Analyse verglichen.Die Anwendbarkeit der Methode für ähnliche Bestimmungen an anderen, optisch zweiachsigen Mineralgruppen wird erwogen und in Ergänzung einer Methode von BuRRI besonders für rhombische Pyroxene vorgeschlagen.  相似文献   

Die Bestimmung des optischen Schwerpunktes von Glühlicht-Filter-Kombinationen     

Prof. Dr. Rudolf Mosebach 《Contributions to Mineralogy and Petrology》1951,2(5):437-442

Zusammenfassung Ein Verfahren zur mikroskopischen Bestimmung des optischen Schwerpunktes von Glühlicht-Filter-Kombinationen mit Hilfe von Drehkompensatoren wird entwickelt und praktisch erprobt. Bei genügend engem spektralen Durchlässig-keitsbereich (z. B. Lifa-Filter Nr. 215 rot und Nr. 391 blau) ist die Bestimmung der Schwerpunktswellenlänge () bis auf Bruchteile von m möglich. Das Verfahren kann prinzipiell auf alle Lichtquellen ausgedehnt werden; deren Wellenlängen sich in genügend engen Spektralbereichen halten. Erforderlich ist lediglich die genaue Kenntnis der Kompensatorkonstanten für Na-Licht, welche am besten durch Eichung mit einer Na-Dampflampe bestimmt wird.  相似文献   

Ecology of Nematodes in the Mediterranean Seagrass Posidonia oceanica (L.) Delile 1. General Part and Faunistics of the Nematode Community     

Rudolf Novak 《Marine Ecology》1989,10(4):335-363

Abstract. The nematode fauna of the phytal region of a stand of the Mediterranean seagrass Posidonia oceanica (L.) Delile was studied in a shallow subtidal location (5 m) at the island of Ischia (Gulf of Naples, Italy). During a one year's growth-cycle of the seagrass, abundance and faunal composition of the nematode community were investigated in a stratified sampling survey. Ninety seven species of nematodes were found. Nematode density and biomass ranged from 1.3 · 10⁵ indiv. · m^-2 (0.02g dwt · m^-2) in winter to 5.5 · 10⁵ indiv. · m^-2 (0.08 g dwt · m^-2) in early autumn. Density and biomass of nematodes were much lower and showed more marked seasonal fluctuations in the leaf strata than in the stem stratum of the seagrass. Diversity and seasonal homogeneity (expressed with Riedl 's index) were much lower in the two leaf strata (25–36 species, 29.6 ho%) than in the stem stratum (60–70 species, 42.5 ho%). The nematode community of the leaf stratum can be characterized as a Chromadora nudicapitata – Monhystrella sp. –Symplocostoma tenuicolle– community and is clearly set off from the stem stratum community (9.2% Riedl 's ho%), which is characterized as a Molgolaimus sp. 1 –Epsilonema sp. 1 –Chromadora nudicapitata– community. In the seasonal succession, the leaf stratum fauna shifts from a chromadorid-dominated community (from winter to summer) to a monhysterid-dominated community in early autumn. The stem stratum fauna shifts from a epsilonematid-dominated fauna in winter to a molgolaimid-dominated fauna in summer and early autumn. The distribution of nematode size classes showed a clear selection toward small animals (< 1 mm lenght), although marked seasonal fluctuations in size class distribution were observed. A modified approach for describing the trophic structure of the nematode fauna is presented. The observed abundance patterns and changes of community composition are discussed in relation to the development of habitat complexity and in relation to trophic conditions in the scagrass stand according to the seasonal growth rhythm of the plants and their aufwuchs-community.  相似文献   

A Study in Ultra-Ecology: Microorganisms on the Seagrass Posidonia oceanica (L.) DELILE     

Rudolf  Novak 《Marine Ecology》1984,5(2):143-190

Abstract. Microbial colonization on the leaves of a shoot of the mediterranean seagrass Posidonia oceanica (L.) DELILE was studied using Scanning Electron Microscopy. Methods of field ecology such as transect, random plot and stratified sampling survey were applied to the microbial niveau to gain both qualitative and quantitative information on the microbial assemblage. While macro-epiphytic growth was significantly greater on the outer leaf sides, microbial colonization density was significantly higher on the inner leaf sides, both on leaf surface and epiphyte surface. Diatoms colonized the surface of incrusting algae and epiphytic animals in significantly lower numbers than the Posidonia leaf surface and were absent on erect epiphytic algae. Bacterial densities on epiphyte surfaces even exceeded values of the corresponding leaf surfaces on algal thalli near the leaf tips and on old leaves. Diatoms reach highest mean density on mature leaves and close to the leaf tips, while bacteria reach their greatest density on the oldest leaf and closer to the leaf base. Diatom density in general increases with exposure time of plant surface, while greatest bacterial density was observed at 7–10 weeks exposure. Basal leaf parts on younger leaves were dominated by rod-shaped bacteria, while distal leaf parts and old leaves were dominated by small coccoid bacteria. Surfaces of epiphytic algae were always distinctly dominated by small coccoid bacteria, and edges of thalli attracted high microbial densities. Microbial biomass (calculated from cell volumes using standard conversion factors) amounts to 2.3 g dry weight m-² in the Posidonia stand where the shoot was sampled. The observed patterns of epiphytic colonization are interpreted as the result of a complex, dynamically changing system of interactions both within the epiphytic community and between the epiphytic community, the host plant, and it's environment. A model of the organization of the epiphytic community on Posidonia leaves is presented. “Ultra-ecology” is a term introduced to denote a type of SEM research in the micro-environment which is analogous to in situ investigation in “macroscopic” ecological work.  相似文献   

Magnetfeldanomalien in der Eifel     

Dr. Rudolf Pucher 《International Journal of Earth Sciences》1992,81(2):429-443

The magnetic anomalies over the Laach volcanics and in adjacent areas were interpreted by comparison with the fields of three-dimensional model bodies. In addition to an aeromagnetic survey, magnetic measurements were carried out on the ground and in the laboratory. Most of the model bodies in the Laach volcanic field require a thickness adjustment of only a few tens of meters to achieve a correlation of the magnetic model fields with the anomalies detected at ground level or at flight altitude.The three-dimensional model calculations did not yield any evidence for the existence of a deep-seated body which might be interpreted as a remnant magma chamber from which magma was explosively extruded during the eruption of the Laacher See volcano.The extensive positive magnetic anomaly near Ahrweiler is interpreted as being caused by a magnetized tabular body located at a depth of 8 km.The sharp bend of the isolines in the northeastern part of the Ahrweiler anomaly is a possible indication of the existence of magnetic rock at a maximum depth of 3–4 km. However, the rock need not necessarily occur in the form of a discrete body. The longitudinal axis of the model body lies on the line connecting the Siebengebirge with the Laach volcanic area.Two model body configurations have been developed for the magnetic anomaly near Kelberg. One of them consists of an upper part corresponding to the magma chamber of the Tertiary volcanics of the Hocheifel (high Eifel), and a lower part that can be regarded as a southern extension of the deep-seated body which is probably the source of the Ahrweiler anomaly. The other configuration represents a magnetized zone formed by thermal metamorphism due to an underlying plutonic body or by magma differentiation, possibly during the Paleozoic.

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Zusammenfassung Die Magnetfeldanomalien im Raum der Laacher Vulkanite und deren Umgebung wurden durch Vergleich mit den Feldern von dreidimensionalen Modellkörpern interpretiert. Dazu wurden außer der aeromagnetischen Vermessung auch ergänzende Magnetfeldmessungen am Boden sowie gesteinsmagnetische Messungen herangezogen. Für die Mehrzahl der Modellkörper im Laacher Vulkanfeld reicht eine Mächtigkeit von einigen Zehnermetern aus, um die magnetischen Modellfelder den gemessenen Anomalien in Boden- und Flugniveau anzugleichen.Die dreidimensionalen Modellrechnungen haben keinen Hinweis auf die Existenz eines tiefreichenden Körpers ergeben, der als Restkörper einer Magmenkammer, die bei der Eruption des Laacher Sees z. T. ausgeblasen wurde, gedeutet werden könnte.Der weiträumigen magnetisch positiven Anomalie bei Ahrweiler wird eine magnetisierte Platte in ca. 8 km Tiefe zugeordnet.In der engräumigen Krümmung der Isolinien im NE-Teil der Ahrweiler-Anomalie deutet sich magnetisches Gestein in maximal 3–4 km Tiefe an, das aber nicht unbedingt als ein kompakter Körper vorliegen muß. Die Längsachse des betreffenden Modellkörpers liegt in der Verbindungslinie von Siebengebirge und Laacher Vulkangebiet.Fur die magnetische Anomalie bei Kelberg sind zwei Modellkörperkonfigurationen erarbeitet worden — die eine besteht aus einem oberen Modellkörper, welcher der Magmenkammer des tertiären Hocheifelvulkanismus entspricht und aus einem unteren Körper, der als Erweiterung nach Süden des für die Ahrweiler-Anomalie angenommenen tiefen Körpers betrachtet werden kann. Die andere Konfiguration stellt eine magnetisierte Zone dar, die durch thermischen Kontakt mit einem darunterliegenden plutonischen Körper oder auch durch Magmendifferenzierung, möglicherweise im Paläozoikum, entstanden ist.

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Résumé Les anomalies magnétiques dans les volcanites du Laacher See et dans les régions avoisinantes ont été interprétées par comparaison avec les champs qu'engendreraient des corps-modèles tridimensionnels. Outre un levé aéromagnétique, des mesures complémentaires ont été effectuées sur le terrain et sur des échantillons de roches. Dans la région volcanique de Laach, la plupart des corps-modèles utilisés requièrent un ajustement en épaisseur qui ne dépasse pas quelques dizaines de mètres pour assurer la corrélation entre les champs magnétiques du modèle et les anomalies mesurées.Le calcul du modèle tridimensionnel n'a fourni aucune indication de l'existence d'un corps profond qui pourrait s'interpréter comme le reste d'une chambre magmatique, partiellement vidée par l'éruption du Laacher See.L'anomalie magnétique positive qui affecte une grande surface près d'Ahrweiler est interprétée comme due à un corps magnétique tabulaire situé à 8 km de profondeur.La courbure prononcée des isogrades dans la partie nord-est de l'anomalie d'Ahrweiler pourrait traduire la présence d'une roche magnétique à une profondeur maximale de 3 à 4 km. Cette roche ne doit cependant pas nécessairement se présenter sous la forme d'un corps individualisé. Le grand axe du corps magnétique modèle correspond à la ligne qui relie le Siebengebirge à la région de Laach.En ce qui concerne l'anomalie magnétique de Kelberg, deux configurations de corps-modèles ont été envisagées. La première consiste en un corps peu profond correspondant à la chambre magmatique du volcanisme tertiaire du Haut Eifel et en un corps plus profond qui pourrait être le prolongement vers le sud de celui qui serait responsable de l'anomalie d'Ahrweiler. L'autre configuration fait appel à une zone magnétique formée soit par le métamorphisme thermique engendré par une masse plutonique sousjacente, soit par une différenciation magmatique d'âge paléozoïque probable.

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Engineering Geological Properties of Building Stones from the North-Eastern Part of the Vienna Basin in the Western Carpathians     

Bednarik  Martin  Holzer  Rudolf  Pivko  Daniel  Tornyai  Rudolf  Hornáčková  Alžbeta 《Geotechnical and Geological Engineering》2022,40(6):3287-3305

Geotechnical and Geological Engineering - This research focuses on assessing the most important physical and mechanical properties of rocks that were quarried from the north-eastern part of the...  相似文献   

Lipid biomarkers in suspended particles from a subtropical estuary: assessment of seasonal changes in sources and transport of organic matter   总被引：1，自引：0，他引：1  

Xu Y  Jaffé R 《Marine environmental research》2007,64(5):666-678

Temporal and spatial variations in the composition of particulate organic matter (POM) from Florida Bay, USA were examined. The predominance of short-chain homologues for n-alkanes, n-alcohols and n-fatty acids as well as relatively high abundance of C(27) and C(28) sterols suggested that an autochthonous/marine source of OM was dominant bay-wide. Several biomarker proxies such as P(aq) [(C(23)+C(25))/(C(23)+C(25)+C(29)+C(31)) n-alkanes], short/long chain n-alkanes, (C(29)+C(31)) n-alkanes and taraxerol indicated a spatial shift in OM sources, where terrestrial OM rapidly decreased while seagrass and microbial OM markedly increased along a northeastern to southwestern transect. Regarding seasonal variations, POM collected during the dry season was enriched in terrestrial constituents relative to the wet season, likely as a result of reduced primary productivity of planktonic species and seagrasses during the dry season. Principal component analysis (PCA) classified the sample set into sub-groups based on PC1 which seemed to be spatially controlled by OM origin (terrestrial-mangrove vs. marine-planktonic/seagrass). The PC2 seemed to be more seasonally controlled suggesting that hydrological fluctuations and seasonal primary productivity are the drivers controlling the POM composition in Florida Bay.  相似文献   

Preface     

Rudolf Dvorak  Sylvio Ferraz-Mello 《Celestial Mechanics and Dynamical Astronomy》2009,104(1-2):1-2

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Comparative study of dissolved organic matter from groundwater and surface water in the Florida coastal Everglades using multi-dimensional spectrofluorometry combined with multivariate statistics   总被引：2，自引：0，他引：2  

Meilian Chen  René M. Price  Youhei Yamashita  Rudolf Jaffé 《Applied Geochemistry》2010

Dissolved organic matter (DOM) in groundwater and surface water samples from the Florida coastal Everglades were studied using excitation–emission matrix fluorescence modeled through parallel factor analysis (EEM-PARAFAC). DOM in both surface and groundwater from the eastern Everglades S332 basin reflected a terrestrial-derived fingerprint through dominantly higher abundances of humic-like PARAFAC components. In contrast, surface water DOM from northeastern Florida Bay featured a microbial-derived DOM signature based on the higher abundance of microbial humic-like and protein-like components consistent with its marine source. Surprisingly, groundwater DOM from northeastern Florida Bay reflected a terrestrial-derived source except for samples from central Florida Bay well, which mirrored a combination of terrestrial and marine end-member origin. Furthermore, surface water and groundwater displayed effects of different degradation pathways such as photodegradation and biodegradation as exemplified by two PARAFAC components seemingly indicative of such degradation processes. Finally, Principal Component Analysis of the EEM-PARAFAC data was able to distinguish and classify most of the samples according to DOM origins and degradation processes experienced, except for a small overlap of S332 surface water and groundwater, implying rather active surface-to-ground water interaction in some sites particularly during the rainy season. This study highlights that EEM-PARAFAC could be used successfully to trace and differentiate DOM from diverse sources across both horizontal and vertical flow profiles, and as such could be a convenient and useful tool for the better understanding of hydrological interactions and carbon biogeochemical cycling.  相似文献   

European temperature records of the past five centuries based on documentary/instrumental information compared to climate simulations     

Eduardo Zorita  Anders Moberg  Lotta Leijonhufvud  Rob Wilson  Rudolf Brázdil  Petr Dobrovolný  Jürg Luterbacher  Reinhard Böhm  Christian Pfister  Dirk Riemann  Rüdiger Glaser  Johan Söderberg  Fidel González-Rouco 《Climatic change》2010,101(1-2):143-168

Two European temperature reconstructions for the past half-millennium, January-to-April air temperature for Stockholm (Sweden) and seasonal temperature for a Central European region, both derived from the analysis of documentary sources and long instrumental records, are compared with the output of climate simulations with the model ECHO-G. The analysis is complemented by comparisons with the long (early)-instrumental record of Central England Temperature (CET). Both approaches to study past climates (simulations and reconstructions) are burdened with uncertainties. The main objective of this comparative analysis is to identify robust features and weaknesses in each method which may help to improve models and reconstruction methods. The results indicate a general agreement between simulations obtained with temporally changing external forcings and the reconstructed Stockholm and CET records for the multi-centennial temperature trend over the recent centuries, which is not reproduced in a control simulation. This trend is likely due to the long-term change in external forcing. Additionally, the Stockholm reconstruction and the CET record also show a clear multi-decadal warm episode peaking around AD 1730, which is absent in the simulations. Neither the reconstruction uncertainties nor the model internal climate variability can easily explain this difference. Regarding the interannual variability, the Stockholm series displays, in some periods, higher amplitudes than the simulations but these differences are within the statistical uncertainty and further decrease if output from a regional model driven by the global model is used. The long-term trend of the CET series agrees less well with the simulations. The reconstructed temperature displays, for all seasons, a smaller difference between the present climate and past centuries than is seen in the simulations. Possible reasons for these differences may be related to a limitation of the traditional ‘indexing’ technique for converting documentary evidence to temperature values to capture long-term climate changes, because the documents often reflect temperatures relative to the contemporary authors’ own perception of what constituted ‘normal’ conditions. By contrast, the amplitude of the simulated and reconstructed inter-annual variability agrees rather well.  相似文献