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91.
泡沫铝的动态压缩性能和吸能性研究 总被引:9,自引:0,他引:9
通过测量泡沫铝在动态和准静态压缩条件下的应力 -应变曲线 ,研究了泡沫铝的准静态和动态压缩行为以及不同应变条件下的吸能性 ,并对其应变率效应进行了分析。结果表明 ,在高应变速率和准静态压缩下 ,泡沫铝的σ -ε曲线均表现出弹性变形段、平缓段和密实段三阶段特征 ;泡沫铝的压缩性能具有明显的应变速率敏感性 ,随应变速率的提高 ,流动应力上升 ,吸能性升高 相似文献
92.
Learning a sequence of target locations when the sequence is uncorrelated with a sequence of responses and target location is not the response dimension (pure perceptual-based sequence learning) was examined. Using probabilistic sequences of target locations, the author shows that such learning can be implicit, is unaffected by distance between target locations, and is mostly limited to first-order transition probabilities. Moreover, the mechanism underlying learning affords processing of information at anticipated target locations and appears to be attention based. Implications for hypotheses of implicit sequence learning are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
93.
小儿的心理状态与成人有着明显的差异,在其住院和接受医疗期间可出现严重的心理反应,导致植物神经功能紊乱,使机体低抗力下降,而削弱机体对麻药的耐受力,不利于麻醉诱导及管理,而且还会造成小儿的精神创伤。文章初步探讨了小儿麻醉心理学的有关问题。 相似文献
94.
采用美国PDI公司开发的PDI-S软件,对不同缺陷基桩的反射波法低应变动测曲线进行数值模拟,对动测曲线的特征进行归纳与总结,以便在解释反射波法曲线时作为参考与借鉴,提高基桩质量检测的可靠度。 相似文献
95.
George Grant Fiona Greer Norma H. McKenzie Arpad Pusztai 《Journal of the science of food and agriculture》1985,36(5):409-414
In a series of 10-day pair feeding experiments it was found that the nutritional value of diets containing beans was essentially the same for rats aged between 30 and 123 days. Thus net protein utilisation (NPU) values of 25–39 on diets containing Processor bean (35 g protein kg?1) + egg albumin (65g protein kg?1) were obtained. As food intakes were considerably reduced when rats were fed diets containing more than 35g protein kg?1 of Processor bean, the measurement of protein utilisation became increasingly more difficult. The severe disruption of the brush borders of duodenal and jejunal enterocytes, originally observed when bean-containing diets were fed to young (30-day-old) rats was also found with rats up to the age of 120 days on similar diets. Similarly, the development of circulating anti-lectin antibodies in the animals showed no age dependence within the age limits investigated. It was also shown that oral immunisation did not protect the rats from the effects of toxicity and that the immune response was a result of continuous absorption of lectin throughout the feeding period. Thus the extent and the mechanism of toxicity of Phaseolus vulgaris bean lectins were found not to be dependent on the age or maturity of the animal. 相似文献
96.
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98.
Stefan Kasapis 《International Journal of Food Science & Technology》2002,37(4):403-413
The structural properties of mixtures of pectin, oxidized starch and glucose syrup were investigated using small deformation dynamic oscillation. In the absence of added calcium, preparations of low methoxy pectin with glucose syrup formed viscous solutions, which remained crystal-free at subzero temperatures. Samples of oxidized starch and glucose syrup, on the other hand, exhibited solid-like behaviour because of the crystalline nature of the amylose-like helices. Mixtures of the two polysaccharides with the co-solute clearly showed phase inversion from liquid to solid-like behaviour with increasing amounts of starch in the formulation. The transformation was reflected in the textural properties of samples, which varied from thick solutions to firm gels. The viscoelasticity of the system was modified further by the introduction of high methoxy pectin. Preparations of high methoxy pectin and glucose syrup formed rubbery gels whose amorphous nature underwent a glass transition during cooling. 相似文献
99.
S. M. Fitzpatrick D. Miller I. Weatherston J. N. McNeil 《Journal of chemical ecology》1985,11(2):207-215
Levels of benzaldehyde recovered from virginPseudaletia unipuncta (Haw.) males were not influenced by (1) the time hairpencils remained in the solvent (1-72 hr), (2) anesthetization or agitation of males prior to excision of hairpencils, or (3) the time (photophase or scotophase) that hairpencils were excised. Thus the interindividual variability observed is not a methodological artifact. Most males had similar concentrations in both hairpencils, although in some cases only one hairpencil contained pheromone. In one case, a male with partially extruded hairpencils had no benzaldehyde at all. Neither pupal weight nor hairpencil length proved to be reliable indicators of pheromone content.Contribution No. 373, Département de biologie, Université Laval. 相似文献
100.