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131.
C.E. Epifanio 《Aquaculture (Amsterdam, Netherlands)》1979,16(3):187-192
Four species of bivalve molluscs were fed diets consisting of varying proportions of the yeast Candida utilis and the diatom Thalassiosira pseudonana. Juvenile Argopecten irradians, Mercenaria mercenaria, and Mytilus edulis grew as fast or faster than controls when fed diets containing as much as 50% yeast. Growth of soft tissue in Crassostrea virginica, however, decreased with the amount of yeast in the diet. The relative food values of the different diets were not closely correlated with gross chemical composition or amino acid composition. 相似文献
132.
Relations between stratigraphy,geomorphology and soils in Coastal Plain areas of Southeastern U.S.A.
Small infiltrometers were used to measure infiltration rates into strongly and maderately developed compound prisms, sampled individually from surface layers of two dry clay soils. Initially, both rates were equally high but after three hours a higher rate was measured for the moderately developed compound prisms. These data were used to interpret adsorption and outflow phenomena of water in undisturbed, large and initially dry soil cores (diameter 20 cm) sampled from the upper 20 cm of the two soils, following application rates of about 8 mm/h and 28 mm/h. The two soils adsorbed an average of 6.4 mm water before the start of discharge, independent of the applied intensity. They discharged water at a constant and high rate for several hours, allowing adsorption of about 10% of the applied water. This represents a high degree of “short-circuiting” for all treatments, except one: adsorption was 40% at the 28 mm/h rate for the soil with the moderately developed prisms. The moisture content in the transmission zone was not constant as it would have been in homogeneous soil but increased regularly as a function of time. Slow wetting of both soils through a crust, followed by rain with an intensity of 30 mm/h, resulted in the adsorption of only about 3% of the applied rain in both soils.In general, more effective wetting of a dry clay surface soil at a given rainfall intensity is initially associated with less “short-circuiting” to deeper horizons. However, the resulting higher moisture content allows less adsorption in the surface layer and is therefore associated with increased “short-circuiting” thereafter, as long as large vertical pores have not been closed by swelling. 相似文献
133.
A proton magnetic resonance spectroscopic method for determining disulfiram in the bulk drug product and in the formulated material was collaboratively studied. The method depends on the use of chloroform-d as a solvent and hexamethylcyclotrisiloxane as the internal standard. No interference from tablet excipients was observed. The method is rapid and specific. Eighteen laboratories analyzed duplicate samples of a bulk drug product, a 250 mg tablet composite, and a 500 mg tablet composite. The average per cent results and standard deviations were 99.7 +/- 1.4, 100.9 +/- 2.0, and 99.9 +/- 2.2, respectively. 相似文献
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E J de Vries J Zeeman R J Esser B Borsje F J Mulder 《Journal of the Association of Official Analytical Chemists》1979,62(6):1285-1291
Vitamin D is determined in preparations containing other fat-soluble vitamins by high performance liquid chromatography (HPLC). The unsaponifiable residue is extracted and separated from interferences by reverse phase chromatography; the fraction corresponding to vitamin D3 is collected and quantitated using normal phase chromatography (amylalcohol-n-hexane as mobile phase) by measuring the vitamin D3 and pre-vitamin D3 peaks at 254 nm. Previtamin D3 content is calculated as vitamin D3 with a conversion factor (determined on the equipment used). Application of the method to vitamin AD3 mixtures in oils gives 98-102% recovery. The reproducibility, using an external standard, is 2-3%, calculated as the coefficient of variation; with an internal standard, the coefficient of variation is 1-1.5%. The method measures potential vitamin D3 content in preparations containing greater than or equal to 200 IU/g in the presence of all known vitamin D3 isomers, vitamin A, and vitamin E. 相似文献
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