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Ecological Investigations on the Ciliated Protozoa Associated with the Self-purification Process under Laboratory Conditions The environmental conditions and the associations of ciliates occurring within the process of self-purification were investigated using a series of 7 laboratory ecosystems connected mutually by means of tubes. The first ecosystem of the series received periodically a certain amount of artificial sewage which required about a fortnight to pass through the whole system. The individual ecosystems, therefore, reflect different stages of increasing self-purification.  相似文献   

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Oil plants in Middle Europe Renewable resources have an increasing impact on industry and technology. Oil plants supply vegetable oil, which is important for our nutrition but can also be used as an industrial resource. Plant oils have many non‐food uses. They are not only used as Biofuels, but can also be found in many technical products including industrial lubricants, hydraulic oils, washing agents, paints and varnishes, and much else. In Europe rapeseed, sunflower, and olive are the primary oil plants. Rapeseed oil is newly recommended for infant nutrition, as it contains a high concentration of α‐linolenic acid, which is an important building block in brain development.  相似文献   

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The splitting of vegetable and animal oils used as antifoam agents and the metabolization of fatty acids released were analysed during fermentation of T. vulgaris in a 30 l jar fermenter. During cultivation time of 22 hours the oil amount decreased by 60 to 70%. The metabolization of fatty acids is 50 to 90% of the starting level depending on the kind of acid. The eventual effect of the fatty acids released from antifoam oils on the protease production is discussed.  相似文献   

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Das Boetzelaerer Meer, ein alter Rheinmäander, gehört dem eutrophen Gewässertypus an und befindet sich zur Zeit noch in einem völlig unbeeinflußten Zustand. Stärkere Eingriffe sind jedoch in absehbarer Zeit durch Industrieansiedlung und Straßenbau zu erwarten. Das Gewässer hat eine Länge von 1500 m und eine größte Tiefe von 300 cm; im Uferbereich legen Steil- und Flachufertypen mit entsprechenden Übergängen die Verbreitung der Verlandungszonen fest. Die Wasserstände des ?Meeres” werden durch die monatliche Niederschlagsverteilung und über das Grundwasser auch durch den Rheinwasserstand modifiziert und gesteuert. Die Verlandungszonen zeichnen sich durch ein Fehlen von Bruchwaldgürteln und durch eine sehr starke Differenzierung der Glycerieten aus. Teichschlammbestände finden sich vornehmlich in Flachuferbereichen als junge Pionierstadien oder auf höherliegenden Sedimentationsflächen als Zwischenstadien zum Glycerietum maximae. Die Wasserpflanzengesellschaften sind ausgesprochen artenarm und zeigen eine hohe Vitalität. Unterwasserpflanzenbestände fehlen mit Ausnahme einer für den Niederrhein neuen Enteromorpha intestinalis-Gesellschaft. Hydrochemische Untersuchungen ergaben, daß das Meer weitgehend abwasserfrei ist bis auf einige kleinere Zuflüsse im Ostteil, die sich jedoch nicht nachteilig auswirken. Im Gewässerschlamm dominieren die minerogenen Bestandteile; die Sedimente sind als Amphisapropele anzusprechen.  相似文献   

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Faunistic Investigations of the Hyporheic Interstitial of the River Mur (Styria, Austria) Two distinct sections of the River Mur (Styria, Austria), one almost unpolluted and the other heavily polluted by domestic and industrial waste waters, were investigated for two years. Faunistic, hydrographic, and ecological investigations were carried out at the river bottom, including particularly the hyporheic interstitial zone. All species found were investigated qualitatively and quantitatively, and ecological factors are stressed. The composition of the fauna of the unpolluted area differs markedly from that in the polluted section.  相似文献   

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《当今生物学》2018,48(1):62-68
Biomimetic approaches for the dental plaque control Tooth and gum diseases are widespread and are primarily based on the presence of bacterial biofilms. The characterization of biofilms can be carried out by means of state‐of‐the‐art microbiome analysis that can provide information on bacterial composition and diversity. Modern oral care products mostly contain different antimicrobial agents for biofilm control. These include chlorhexidine, metal salts, and quaternary ammonium compounds, which, however, often kill harmful (dysbiotic) and useful bacteria (homeostatic) (unspecific antimicrobial effect). Recent developments show that innovative concepts shift the ecological balance of plaque in the oral cavity to “physiological commensal bacteria” (homeostasis) or minimize the bacterial colonization on enamel surfaces without having pronounced antimicrobial properties. Examples are biomimetic approaches, i.e. based on selected salivary enzymes or hydroxyapatite.  相似文献   

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Aquatic ecosystems have the ability to compensate for oscillations of the inputs (substrate concentration, dilution rate, temperature). The mechanisms of this buffering capacity are studied in this paper (see fig. 7). The inputs exert an influence on the biomass and the activity of the organisms (activity = specific rate of RNA-synthesis or specific P-removal rate [μ/mg biomass day]). The activity is regulated either directly by the inputs and/or indirectly by the biomass. The activity decreases with an increase of the biomass (see fig. 5 and 6). The product of biomass and activity determines the transient response (= effective performance) of the system which is better buffered than biomass or activity alone. Considering the theory developed in this paper the effect of shock loadings on the phosphate removal in preimpoundment basins of drinking water reservoirs is discussed.  相似文献   

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