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171.
We studied the population growth of two rotifer (Brachionus calyciflorus and Brachionus rubens) and two cladoceran (Ceriodaphnia dubia and Moina macrocopa) species fed three diets (Chlorella vulgaris (Ch), Scenedesmus acutus (Sc) and yeast (Saccharomyces cerevisiae) (Y) in seven combinations (alone or mixed in equal proportions (on dry weight basis): Ch+Sc, Ch+Y, Sc+Y and Ch+Sc+Y). In general, the cladocerans were more adversely affected than the rotifers on the diet of yeast alone. The population growth curves of B. calyciflorus and B. rubens revealed that algal diets were superior to yeast. Regardless of diet, B. rubens had a longer lag phase and delayed peak density compared to B. calyciflorus. Both M. macrocopa and C. dubia had higher peak abundances when fed mixed algae than on either alga offered separately. B. rubens, C. dubia and M. macrocopa reached significantly lower maximal densities on diets containing yeast, S. acutus or both. When the data on the eggs/female (egg ratio) were plotted as function of population density, we found an inverse relation, which was curvilinear for B. calyciflorus and linear for B. rubens. In general, we found that yeast could effectively supplement algal diets in all the test species, thereby reducing costs in large scale production of zooplankton. 相似文献
172.
173.
Photoelectric observations of the RS CVn type non-eclipsing binary UX Arietis obtained at Nizamiah Observatory during the
observing seasons of 1975–76, 1981–82 and 1982–83 are presented. The light curve of UX Ari showed a distortion wave with an
amplitude inV varying from 0.02 mag during 1975–76 to 0.15 mag during 1982–83. An analysis of the available data shows that the light maximum
is almost constant. It is also evident that the light-curve minimum decreases as the wave amplitude increases. The constant
light at maximum,V = 6.51 ± 0.03 indicates the unspotted photospheric brightness. It is also suggested that the variation in meanV brightness is mainly due to spot activity and not due to intrinsic variation. 相似文献
174.
Natural occurrences and recent experimental work show that a low-friction inclusion/matrix boundary can be responsible for antithetical rotation and development of stable shape preferred orientations in simple shear. The flow of a viscous matrix around a rigid inclusion to which it may or may not be adherent is still not well studied, but it is relevant to the understanding of the behaviour of structural elements in mylonite zones. We used two-dimensional (2-D) analogue experiments to address these issues. The experimental results with a permanent low-friction inclusion/matrix boundary (nonadherent mode) show the following. (1) The rotation behaviour of inclusions in this mode is markedly different from the theoretical predictions and experimental results for the adherent mode. (2) Inclusions with aspect ratio equal to 1 rotate synthetically at a rate that depends upon inclusion shape and orientation. (3) Ellipse-, rectangle- and lozenge-shaped inclusions rotate antithetically when starting with their greatest axis parallel to the shear direction. (4) Back rotation is limited in all cases studied, and the angle between the inclusion greatest axis and the shear direction represents a stable orientation, which depends on inclusion aspect ratio and shape. (5) A metastable orientation exists, which is strongly dependent upon inclusion shape and aspect ratio, and separates fields of antithetic and synthetic rotation.Our experimental results show that the overall flow pattern is bow tie-shaped in adherent and nonadherent modes. However, there are major differences in the way the matrix flows near the inclusion. (i) In the nonadherent mode, the nearby matrix flows past the inclusion, whereas in the adherent mode, the nearby matrix flows with and follows the inclusion. Therefore, in the adherent mode, passive marker lines parallel to the shear direction and streamlines show considerable deflections at the inclusion crests, in marked contrast with their straight character in the nonadherent mode. (ii) Stagnation points or closed flow lines near the inclusion were not observed in the nonadherent mode, which means that there is no closed separatrix around the inclusion in this mode, despite the fact that the overall flow shape is bow tie. (iii) In the adherent mode, the line of flow reversal is stable throughout deformation, but in the nonadherent mode, it changes position and orientation with progressive shearing. This shifting of the line of flow reversal can be an important factor controlling rotation behaviour in the nonadherent mode. (iv) In the nonadherent mode, the inclusion behaviour is similar to that observed in confined flow. (v) The flow pattern in the nonadherent mode provides an explanation for the observed lack of drag folds associated with small-scale rigid inclusions in mylonites. 相似文献
175.
S B S S Sarma 《Journal of Earth System Science》1991,100(3):307-307
The online version of the original article can be found at 相似文献
176.
177.
Ground-Water Recharge from Rectangular Areas 总被引:1,自引:0,他引:1
178.
The study of thermal expansion by a dilatometer technique on a few granitic rocks from the Peninsular shield and Himalayan regions of India confirms that the linear coefficient of thermal expansion (α) is a function of heating rate, crack porosity, thermal cycling, mineral composition and grain orientation. Permanent set in the samples occurs at the limiting temperature (Tp) and restricts the validity of the apparent thermal-expansion coefficient with rise in temperature. Values of α are determined for a heating rate of ?2°C min?1 in order to calculate the volume coefficient of expansion (αv) and the temperature dependence of density (ρT). 相似文献
179.
D. D. Sarma 《Mineralium Deposita》1979,14(3):263-279
An approach to prospecting for minerals which quantifies the risk involved in exploration ventures is suggested in this paper. This approach is based on three factors viz., (a) the probability of the occurrence of an economic prospect (P1), (b) the probability of its actual discovery (P2) and (c) the probability that it is of sufficient economic value to compensate costs. An operational equation which takes into account the number of ventures, probability factors P1, P2, P3 and the estimated mining costs for a given region has been employed to assess the likely returns. Three case situations in respect of copper prospects at Ingladhal have been analysed and the probability and pay off ratios have been worked out in each of these situations. In respect of the actual case situation (situation 3), the profitability and the pay off ratios have been found to be approximately equal to 6.3 and 0.22 respectively. A comparison of this study with other similar earlier studies has also been made. 相似文献
180.
R. S. Ayyangar P. M. Sarma P. P. Nageswara Rao S. S. Budwal 《Journal of the Indian Society of Remote Sensing》1982,10(1):35-44
The size and reliability of the training sets or sample area for the classification of airborne multispectral scanner data obtained over an agricultural area with the help of an interactive computer system have been examined in this study. The experiment reported herein suggests that a training set of not less than 50 pixels would adequately represent all the likely variations in any particular field. The evaluation of the results further reveals that if the training sets can adequately represent the field variations characteristic of the region, the corresponding training statistics can be utilized both on scanline and pixel directions. 相似文献