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81.
Hammond AL 《Science (New York, N.Y.)》1977,195(4281):862-863
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Computer graphics as an aid to learning 总被引:3,自引:0,他引:3
K R Hammond 《Science (New York, N.Y.)》1971,172(986):903-908
Departing from the traditional model for teaching and learning, this article deals with the problem of teaching and learning the effective application of knowledge already acquired. To this end, a model for the process of exercising judgment was outlined, and the results of an empirical study of judgmental learning were employed to show the inadequacy of the traditional outcome feedback procedures. Computer graphics techniques were used to provide new forms of information to the learner; the results are promising for the rapid learning of a task that would otherwise be difficult to learn. 相似文献
85.
The level of the plasma prothrombin in the circulating blood is decreased during its passage through the pulmonary capillaries. In 85 per cent. of samples, plasma prothrombin has been found to be less in the blood of the left ventricle than in that from the right ventricle. This difference averaged 10.6 per cent. and ranged from 4 to 19 per cent. In no instance was the level in the right ventricle lower than that in the left. In samples of blood taken from the arterial and venous supply of the head, liver, spleen, intestine, kidney and hind limbs, no significant difference in plasma prothrombin levels was found. A possible explanation of this role of the lung in the loss of plasma prothrombin is thought to be the production of blood platelets in this organ, as demonstrated by Howell and Donahue. Platelets, as they undergo disintegration, initiate the first stage of the clotting process by releasing thromboplastin, which, in the presence of calcium, changes prothrombin to thrombin. 相似文献
86.
The relative rates of racemization for amino acid residues at the NH(2) and COOH ends of 37 different dipeptides were determined. In nine dipeptides containing alanine, leucine, phenylalanine, aspartic acid, and methionine, the amino acid residue racemized faster at the COOH-terminal position than at the NH(2)-terminal position (COOH > NH(2)). The sterically hindered amino acids isoleucine and valine showed NH(2) > COOH. Six proline dipeptides showed NH(2) > COOH. Intramolecular effects have been invoked to explain these surprising results. 相似文献
87.
Hammond AL 《Science (New York, N.Y.)》1971,173(3996):511-512
88.
Cimino G DE Rosa S DE Stefano S Sodano G Villani G 《Science (New York, N.Y.)》1983,219(4589):1237-1238
A biosynthetic experiment with mevalonic acid labeled with carbon-14 showed that the nudibranch Dendrodoris limbata elaborates polygodial, a sesquiterpenoid dialdehyde stored in the mantle, which constitutes its chemical defense against predators. Previously described nudibranchs drew defensive chemicals from their preys. 相似文献
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Hammond AL 《Science (New York, N.Y.)》1974,186(4168):1011-1013