Begriff und Bedeutung der Intrusionstektonik     

Franz Ed. Suess 《International Journal of Earth Sciences》1927,18(2):149-154

Ohne Zusammenfassung  相似文献   

Zur Deutung der Vertikalbewegungen der Festländer und Meere     

Franz E. Sueß 《International Journal of Earth Sciences》1921,11(7-8):361-406

Ohne Zusammenfassung  相似文献   

Die Vereisung des Lilliehöökfjordes (Spitzbergen) in den Jahren 1941/42 und 1942/43     

Nusser  Franz 《Ocean Dynamics》1950,3(5-6):286-293

Ocean Dynamics - Die Eisbeobachtungen, die während der Überwinterungen 1941/42 und 1942/43 in dem Lilliehöökfjord gemacht wurden, werden mitgeteilt und daraus der Ablauf der...  相似文献   

Die Eisverhältnisse des Winters 1948/49 an den deutschen Küsten     

Franz Nusser 《Ocean Dynamics》1949,2(6):251-255

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猿,巨人及人     

魏敦瑞  刘东生 《地质论评》1949,14(Z1):75-79

全书共分五章,每章专论一题目,各自独立,但其总旨仍互相连贯。第一章人及其猿猴类之祖先此章由解剖学各方面证明在分类学上人与人猿最为相近,因其相差之程度,远较人猿与其他低等猿类为小。而在研究人类演化之过程  相似文献   

Symbiotic Relations of Sediment-Agglutinating Nematodes and Bacteria in Detrital Habitats: The Enzyme-Sharing Concept   总被引：2，自引：0，他引：2  

Franz Riemann  & Elisabeth Helmke 《Marine Ecology》2002,23(2):93-113

Abstract. A new concept (‘enzyme sharing’) concerning the interaction of marine nematodes and microbes in the degradation of sedimentary detritus is presented. Elements of this concept are (1) the notorious tendency of many aquatic nematodes to agglutinate detrital particles by mucus secretions, (2) new observations on the stimulation of microbial growth by nematodes in agar plates, and (3) literature data on limited endogenous proteolytic capacities of aquatic nematodes.
Observations on nematode‐microbe associations in agar plates prompted the conceptual synthesis. In agar medium without the addition of any nutrients a spectacular growth of bacteria was visible on the sinusoidal crawling trails of nematodes only 2 – 3 days after introduction of the worms (species of Adoncholaimus, Anoplostoma and Sabatieria). Juveniles of Anoplostoma that hatched in the agar cultures left their minute trails in the medium and these were rapidly occupied by bacteria. The nematodes repeatedly visited their bacterial trails, which persisted as a peculiar biotic structure for more than one year and survived the nematodes.
In sterile agar preparations containing the fluorogenic methylumbelliferyl‐β‐glucoside in the presence of the nematode Adoncholaimus, an enhanced fluorescence of the medium was visible, indicating β‐glucosidase activity. We therefore assume that oncholaimid nematodes discharge enzymes that alone, or in concert with microbial activities, contribute to the hydrolytic cleavage of refractory polysaccharides containing β‐glucosidic bonds such as agar components and cellulose. The sugars thus produced may then be taken up by the nematodes and concomitantly support the conspicuous growth of microbes. Since we did not observe any feeding of the nematodes on the associated microbes in agar plates, we question the nutritive potential of intact microbial cells for a number of nematodes abounding in detrital habitats, and call attention to the significance of ambient dissolved or adsorbed organic monomeric nutrients.
Consequently, we perceive the puzzling perpetual accretion of detrital organic particles to sediment agglutinations by nematodes as an adaptation for operating an ‘enzymatic reactor’ for the production of dissolved nutrients. We hypothesise a relationship of mutual commensalism of nematodes and heterotrophic microbes in detrital habitats and propose the term ‘enzyme sharing’ for this relationship. Both parties invest in a common enzyme pool that decomposes organic detritus for their nutrition. We present here evidence that nematodes contribute β‐glucosidase, which is involved in the cellulase system. Data from the literature suggest that microbial enzymatic processing of detrital proteins yields amino acids available to nematodes, which apparently have no efficient proteolytic enzyme system in their intestines.  相似文献   

Sediment mobility in the Pomeranian Bight (Baltic Sea): a case study based on sidescan-sonar images and hydrodynamic modelling     

Franz Tauber  Kay-Christian Emeis 《Geo-Marine Letters》2005,25(4):221-229

Sidescan-sonar surveys were performed on a 2×4 km area of seafloor in the southern Baltic Sea (Pomeranian Bight) in 1996 and 1998. Overlapping sub-areas of the individual surveys showing characteristic details were processed into geographically referenced mosaics. Sediment types were identified from echo characteristics and by comparison with granulometric data. The sea bottom covered by the mosaics consists predominantly of sand, with subordinate lag sediments with stones and small ripple fields consisting of coarse sand to fine gravel. A comparison of the two mosaics did not reveal any significant changes of the sea bottom over the 2-year period. Characteristic sedimentary features remained almost unchanged over this period on detailed sonar images of smaller sub-areas. Substantial transport of sandy sediments can thus be excluded in the course of the observation period. Grid files of advective velocity components and orbital velocity of wave motion of a three-dimensional hydrodynamical model for the period from September 1996 to October 1997 were used to estimate the current regime in the study area for the interval between the two sidescan surveys. Comparing critical velocities for the dominant sediment types with the results of the numerical bottom current simulations and the observations from sidescan images, it is apparent that strong current events during the modelled time interval were still too weak to resuspend and transport sand of any grain size, even though maximum current velocities of 30 cm/s at the seafloor were modelled. Only a few patches of newly accumulated (acoustically soft) material (mud, fluff and/or soft plant remnants), with a horizontal extension of about 10 m at a terrain step feature, were recognised in the 1998 mosaic. Our results imply that sand deposits in the southern Baltic Sea can remain stationary over time periods of several years, and that the transport of organic material, nutrients and associated pollutants to depositional areas in deeper water is predominantly accomplished by the movement of material finer than sand. A significant portion of this fine material is evidently transported in the bottom boundary layer under conditions of moderate hydrodynamical forcing.  相似文献   

Distribution of population-based indicators across multiple taxa to assess the status of Gulf of Alaska and Bering Sea groundfish communities     

Mueter  Franz J.; Megrey  Bernard A. 《ICES Journal of Marine Science》2005,62(3):344-352

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The Bering Sea—A dynamic food web perspective     

Kerim Aydin  Franz Mueter   《Deep Sea Research Part II: Topical Studies in Oceanography》2007,54(23-26):2501

The Bering Sea is a high-latitude, semi-enclosed sea that supports extensive fish, seabird, marine mammal, and invertebrate populations and some of the world's most productive fisheries. The region consists of several distinct biomes that have undergone wide-scale population variation, in part due to fisheries, but also in part due to the effects of interannual and decadal-scale climatic variation. While recent decades of ocean observation have highlighted possible links between climate and species fluctuations, mechanisms linking climate and population fluctuations are only beginning to be understood. Here, we examine the food webs of Bering Sea ecosystems with particular reference to some key shifts in widely distributed, abundant fish populations and their links with climate variation. Both climate variability and fisheries have substantially altered the Bering Sea ecosystem in the past, but their relative importance in shaping the current ecosystem state remains uncertain.  相似文献   

A search for posteclipse brightening of Io in 1973. II     

O.G. Franz  R.L. Millis 《Icarus》1974,23(3):431-436

Four eclipse reappearances of Io were observed with an area-scanning photometer during the 1973 apparition of Jupiter. The results of these observations and of the ones reported in the preceding paper are discussed in the context of recent physical models for posteclipse brightening. An evaluation of the relative merits and deficiencies of all observational techniques which have been used to search for posteclipse brightening of Io leads to the conclusion that the reality of this phenomenon remains very much in doubt.  相似文献