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排序方式: 共有1662条查询结果,搜索用时 984 毫秒
81.
P.E. Petersson 《Cement and Concrete Research》1981,11(1):51-56
A new type of clamping grips for direct tensile tests on concrete is presented. The grips make it possible to use prismatic specimens without inducing stress concentrations of too high a magnitude and this significantly simplifies the manufacturing of specimens and the performance of direct tensile tests.Test results of the direct tensile strength determined by the new clamping grips are presented for a number of concrete types. These results are compared with test results of the flexural tensile strength and the ratio flexural tensile strength/tensile strength seems to agree well with the theoretical estimations. 相似文献
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KH Naifeh PH Heller F Perry NC Gordon JD Levine 《Canadian Metallurgical Quarterly》1983,16(3):277-283
We used certain physiologic maneuvers to perturb the autonomic nervous system (ANS) in an attempt to detect a link between the ANS and pain. In the unperturbed state, we found no difference in the electrodermal response among normal controls, preoperative patients (increased stress without pain) and postoperative patients (increased stress and pain). The electrodermal response elicited by autonomic maneuvers was significantly attenuated in postoperative patients but not in preoperative patients or in normal control subjects. 相似文献
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In Biomphalaria glabrata with a strong natural resistance, Schistosoma mansoni sporocysts are rapidly encapsulated by granulocytes and killed, mainly by the strong phagocytic activity of the cells. Irradiated Echinostoma paraensei sporocysts seem able to suppress the function of the granulocytes. Tissue reactions in snails with self-cure demonstrate: involvement of two types of cells, granulocytes and hyalinocyte-like cells; formation of amoeba-fibrous capsules; limited tendency of granulocytes to become attracted to the parasites; a slow process of parasite destruction; and a possible involvement of humoral factors. It seems that there is partial suppression of the granulocyte function in smails with self-cure. 相似文献
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The immune profile was controlled in 50 patients with breast cancer over a period of 5 years. No useful method for early detection, prognosis or exacerbation of disease could be developed from these findings for routine clinical work. 相似文献
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Surface oxide layers on CVD films of amorphous silicon can cause the metallic contacts to the films to be non-ohmic. Dipping an amorphous silicon sample in a solution of hydrofluoric acid prior to electrode deposition removes the oxide layer and permits the formation of ohmic contacts. 相似文献
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