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991.
992.
G. F. Volodina V. F. Zhitar’ S. P. Muntyan D. Z. Grabko O. A. Shikimaka 《Inorganic Materials》2007,43(7):720-723
Multilayer ZnO/In2O3 structures prepared by annealing Zn x In2S3+x (x = 1, 5) single crystals have been studied by x-ray diffraction and optical microscopy. The results indicate limited texturing of the endotaxial oxide layers. The orientation relationships between the ZnO and In2O3 crystallites in neighboring layers are shown to be analogous to those between similar unit cells of single-crystal layers and substrates in epitaxial systems. 相似文献
993.
An optimised structure is one which uses the smallest quantity of the best material to perform its function, with adequate
safety factor or margin for error. Structural optimisation occurs not only in mechanical engineering, but also in nature:
plants with hollow stems or stalks gain a height advantage, and are thus more efficient, by approaching the optimum shape.
Here we consider the optimisation of orthotropic tubes, typifying, in a mechanical sense, stalk and stem. The stiffness and
strength of orthotropic tubes of initially circular section are reviewed, and diagrams are proposed which allow the optimum
section shape to be selected. 相似文献
994.
This study presents the first application of a high-resolution magic angle spinning 1H NMR approach to elucidate the metabolic effects of a hypercholesterolemic condition and two high-fiber diets based on rye and wheat bread, respectively, in intact pig liver biopsy samples. Standard 1D and spin-echo 1H spectra were acquired on a total of 20 biopsy samples, and 2D total correlation spectroscopy experiments were carried out on selected samples for assignment of the observed resonances. Principal component analyses and partial least-squares regression discriminant analysis revealed differences in the hepatic lipid content and choline-containing compounds between normal and hypercholesterolemic pigs. In addition, the results demonstrated that the liver metabolite profile of hypercholesterolemic pigs fed a high-fiber rye bread differed from that of pigs fed high-fiber wheat bread with respect to both the lipoprotein fractions and the choline-containing compounds. These findings suggest that earlier reports on high-fiber rye diet-induced effects on plasma HDL/LDL content partially can be ascribed to effects on liver cholesterol metabolism and that the hepatic phospholipase pathways of phosphatidylcholine breakdown are affected by the high-fiber rye diet. 相似文献
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999.
Ward Joseph E. Carlson F. Paul Heywood J. David 《IEEE transactions on bio-medical engineering》1974,(1):12-20
A coherent optical data-processing system for identifying and counting blood cells has been developed. Optical Weiner-Kolmogorov (minimum mean-square error) linear filtering is employed to estimate the density per unit area of a given cell type present in a sample blood smear. The Weiner filter is designed to recognize the characteristics of an ensemble of cells of a type rather than specific individual cells. In this way the system is made insensitive to minor variations in shape, size, or orientation of the cells. A Poisson shot-noise model for blood cells as a spatial random process is employed to calculate the far-field scattering from the cells. Results of experiments in which the percentage of reticulated (immature) red cells present in a smear has been determined are presented. The identification and counting accuracies compare favorably with those obtained by laboratory technicians with a microscope. The potential time saving of instantaneous estimation for the entire smear is significant. 相似文献
1000.
CF2 Cl2 is found to cause passiveQ switching on practically all of the lines in theR branch of the00deg1-02deg0 vibrational-rotational band of CO2 . 相似文献