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Self-control is demonstrated when a less desirable immediate outcome is chosen to ensure a substantially better future. In a novel animal analogue of this situation, primary reinforcement was delivered in both the initial and terminal links of a concurrent chain schedule. Rats made initial link choices between equal amounts of ethanol-free or ethanol-containing milk. Choosing the ethanol-free reinforcer resulted in delivery of the larger terminal link reinforcer and was thus analogous to self-control. Self-control decreased as the delay between initial and terminal links increased. The results have implications for human choice situations where decisions are made between two immediately available reinforcement alternatives each associated with a different delayed outcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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K. Y. Sze W. K. Chan T. H. H. Pian 《International journal for numerical methods in engineering》2002,55(7):853-878
This paper presents eight‐node solid‐shell elements for geometric non‐linear analysis of elastic shells. To subdue shear, trapezoidal and thickness locking, the assumed natural strain method and an ad hoc modified generalized laminate stiffness matrix are employed. A selectively reduced integrated element is formulated with its membrane and bending shear strain components taken to be constant and equal to the ones evaluated at the element centroid. With the generalized stresses arising from the modified generalized laminate stiffness matrix assumed to be independent from the ones obtained from the displacement, an extended Hellinger–Reissner functional can be derived. By choosing the assumed generalized stresses similar to the assumed stresses of a previous solid element, a hybrid‐stress solid‐shell element is formulated. Commonly employed geometric non‐linear homogeneous and laminated shell problems are attempted and our results are close to those of other state‐of‐the‐art elements. Moreover, the hybrid‐stress element converges more readily than the selectively reduced integrated element in all benchmark problems. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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The relation between the initial unbalance and the output signal of bridge circuits when acted upon simultaneously by the
physical factor being measured and the temperature of the surroundings when the bridge is supplied from a voltage or current
source is investigated. Analytic relations are obtained which explain the temperature dependence of the useful output voltage
under external physical action.
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Translated from Izmeritel’naya Tekhnika, No. 1, pp. 48–49, 2007. 相似文献
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由于具有初曲率板弯曲问题的控制微分方程较复杂,直接求解原问题基本解推导边界积分方程较为困难。本文通过引入等效荷载,将此问题的控制微分方程化成与普通板弯曲基本方程形式相同的微分方程,利用一般求解板弯曲问题的边界元法迭代求解,建立了分析具有初曲率板弯曲问题的边界元法。算例表明本方法理论准确、精度良好。 相似文献
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Atilla Bilgin 《国际能源研究杂志》2002,26(11):987-1000
Flame front surface area and enflamed volume (the volume enclosed with flame front) is theoretically analysed for a spark‐ignition engine, having cylindrical disc‐shaped combustion chamber with two spark plugs located axisymmetrically on cylinder head, between cylinder axis and cylinder wall. Spherical flame front assumption is used. A computer code is developed based on purely geometric consideration of the flame development process in combustion chamber, and is used to investigate the effects of variations of spark plugs' locations on geometric features of the flame front. A comparison has also been made with a spark‐ignition engine having one spark plug at the same location. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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本文对代数曲面的几何连续拼接作了研究,给出了多个代数曲面的几何连续过渡方法,同时给出了一种基于分片的曲面过渡方法。 相似文献
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