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991.
W B?cher 《Canadian Metallurgical Quarterly》1994,31(6):356-366
The paper deals with the fundamental problem: How does the brain (in the way it is and the way it functions) influence human experience, behaviour and social interaction? Deriving from this question, there's the matter of how all this influences people as road users. After some epistemological considerations the following subjects are dealt with the article: the human perception and human "reality", the limits of human imagination, the basis of human learning, the complexity of processes within the brain, the reaction to changes and the ability to concentrate as well as McLean's theory of the triune brain. The subjects are complemented by aspects of biological and socio-cultural evolution of man, starting from evolutionary ethics going right up to the problem of responsibility. 相似文献
992.
M. J. Annen R. Kizhappali P. W. Carr A. McCormick 《Journal of Materials Science》1994,29(23):6123-6130
Polymerization-induced colloid aggregation is used to synthesize spheres of narrow size distribution which are porous aggregates of ZrO2 colloids. Variation of the reaction pH has been investigated to determine the optimum rate of polymerization of the urea-formaldehyde resin. At the optimum rate, a colloid packing structure is formed where a balance of high porosity and high strength of the aggregates is achieved. This optimum coincides with the maximum yield of the 5 m sintered (polymer-free) particles. Particles synthesized at pH values below the optimum are mechanically weak; some are hollow spheres. Variation of the pore structure, and thus colloid packing structure, is elucidated by nitrogen adsorption and apparent density measurements. Differences on either side of the optimum pH are related to the efficiency of polymer-bridge formation between colloids. 相似文献
993.
We have shown that dicyanogold(I), [Au(CN)(2)](-) is a common metabolite found in blood and urine samples of patients treated with different gold based drugs. Some patients have high levels of gold within their red blood cells (RBCs). Size exclusion and C18 reversed phase chromatography show that the majority of the gold in RBC lysates is bound to protein, but small molecules such as dicyanogold(I) and gold-glutathione complexes are also present. Dicyanogold incubation with red blood cells in vitro leads to a rapid and complete uptake of gold. This uptake is unaffected by DIDS, an inhibitor of the anion channel, but is blocked by the addition of external cyanide. Dicyanogold is also readily taken up by H9 cells, a continuous CD(4+) cell line. This uptake is significantly inhibited by N-ethylmaleimide, suggesting a requirement for sulfhydryl groups. Dicyanogold inhibits the replication of the AIDS virus, HIV, in a cell culture model. 相似文献
994.
I. ledziska J. Sotysiak W. Staczyk 《Journal of Inorganic and Organometallic Polymers》1994,4(2):199-204
The synthesis and properties of individual liquid crystal oligo(cyclosiloxanes),, wherex=4–8 andR is a 4-methoxyphenyl-4-alkyloxybenzoate type of mesogenic group, is described. Preliminary results concerning the effect of ring size on the mesophase formation are included. X-ray diffraction studies have shown that the cyclosiloxanes form a smectic A1 phase. 相似文献
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Wang W 《Applied optics》1994,33(13):2567-2573
The reflection and transmission properties of holographic mirrors (HM's) under partially coherent illumination are investigated with emphasis on the properties of reflected light. The effects of a HM on the spectrum and on the coherence properties of partially coherent incident light are studied. We show that within angular and frequency-selectivity ranges of HM's (where their reflectivities are nearly uniform), the changes in the spectrum and in the coherence properties are negligible. Yet changes are expected when the spectrum of the incident light falls beyond frequency-selectivity ranges of the HM's or when the spectrum of the reflected light is observed beyond the angular-selectivity ranges of the mirrors. We illustrate the results by considering in detail the performance of HM's when the incident light is produced by planar secondary Gaussian Schell-model sources. Some computed curves are presented. 相似文献