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M.R.Li B.Z.Bian 《山东海洋学院学报》1986,16(4):215-216
From a stock culture of Cylindrotheca sp., non-motile colony-forming cells were observed and isolated.Colony-forming cells produced both single cells and colony-forming cells in liquid medla.the rate of single cell production varied among clones. 相似文献
105.
An experimental investigation on the initiation and development of bed forms on a bed of fine silica sand was conducted under alluvial flow conditions in a laboratory flume with a diverging channel. The main aims of the study were to assess: i) the steepness of bed forms in the transition stage of development; and ii) the threshold height of wavelets (ηt) that triggered the start of ripple development. Detailed bed profile measurements were carried out using an acoustic Doppler probe, traversed longitudinally over the sediment bed at various experimentation times. The bed form dimensions were extracted from such bed profile records and analysed for the wavelet, transition and equilibrium stages. It was found that the steepness of ripples in the transition and equilibrium stages were similar, confirming predictions of previous mathematical model simulations. A lognormal distribution fitted the wavelet length data. The wavelet threshold height was estimated as ηt ≈ 7 mm, or ηt≈ 80 in wall units. Such a height magnitude suggested that ripple development could be triggered by the wavelets reaching the outer flow zone of a turbulent boundary layer. The ηt value obtained corresponded generally to the intersection point between two predictive equations for bed form dimensions. A formulation was developed to predict ηt as a function of the sediment grain size, which was confirmed for the fine sand used in this study. 相似文献
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J.M.ANDRADE D.PRADA S.MUNIATEGUI Department of Analytical Chemistry Universidade da Corun La Zapateir E- Corun Spain B.GOMEZ M.PAN Analytical Laboratory Complejo Industrial Repsol Petróleo S.A.de La Corun Poligono Bens Corun Spain Author to whom correspondence should be addressed. 《地理学报(英文版)》1993,(5)
This paper deals with a typical question encountered in all industrial analytical laboratories:are all thetests performed in the laboratory to characterize the final product really necessary?In this work the cross-validation technique,Procrustes rotation techniques and statistical variable selection have been used toreduce the 26 initial British Petroleum and ASTM kerosene specification tests to ten'essential'ones.Statistical as well as chemical considerations were used to select the optimum subset of original variablesto be retained from all the possible ones. 相似文献
108.
The paper presents the 3D finite element simulation of tidal flow and sediment transport in the estuarine region of the Haihe river. The proposed model adopts sigma-transformation of the hydrodynamic and sediment transport equations. The hydrodynamic and sediment transport models are verified in case of a simple test problem for which analytical solutions are available. Finally the models are applied to muddy Haihe river estuary of North China and it is claimed that hydrodynamic and sediment… 相似文献
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