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21.
This paper addresses the food distribution decision from a wholesaler's perspective, as the wholesalers are often faced with thorny issues such as when, where, how to deliver products at the lowest costs to best satisfy the retailers’ changing needs. This research relies on a distribution problem encountered at Northern Grocery Company in Beijing as an example to develop a two-stage solution procedure and subsequent computer-enabled programs for identifying efficient vehicle routing alternatives. The solution process, which integrates heuristic search algorithms and an integer programming model, can be applied to a wide range of distribution problems with specified route durations and a circular transportation network structure as exemplified by City of Beijing. 相似文献
22.
本文所阐述的水下无线技术即基于跳频技术和同步捕获技术的水声通信,由于声波在海水中的传播特性显著优越于电磁波和可见光,使得水声技术成为海洋高技术的主要研究领域之一 ,在国防领域也具有十分重要的研究意义.本文主要论述了水声通信中跳频技术和同步捕获技术的原理、具体算法的实现方案以及部分硬件设施的使用简述,并通过展示实验结果验证算法的可行性. 相似文献
23.
介绍了将LIGA技术及其与牺牲层技术相结合 ,制造可动微结构的工艺方法。并给出了可实现摆动、转动的可动微结构———微执行器、微传感器和三维加速度传感器的制造过程等应用实例 相似文献
24.
Examined V. Axlines's book, Play Therapy (1947) which includes 8 basic principles on non-directive play therapy. Student responses to learning these principles in play therapy classes were also examined. Each student was assigned a play therapy client and was observed and assisted directly by the instructor, a licensed clinical psychologist. Clients were mildly trouble children (aged 5–10 yrs) and were selected from a referral base by the instructor as appropriate for the course. As the semester progressed and students gained direct experience, weekly small (3–4 student) group discussions were held to explore in-depth understanding of play therapy principles and how these principles are put into practice. It is concluded that Axline's book remains a classic text and a foremost resource in the field. Coupling it with experiential learning is an invaluable basis for teaching play therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
25.
溶胶—凝胶法制备有机改性硅酸盐的研究进展 总被引:3,自引:0,他引:3
综述了有机改性硅酸盐的溶胶-凝胶合成路线,并简要介绍它们的结构、性能及应用 相似文献
26.
本文介绍一种新的膜分离技术-渗透蒸发的原理和特点,及操作条件对分离性质的影响,并对其关键构件和设备即渗蒸发膜和渗透池作了专门叙述,结合具体实例从有机溶剂的脱水及水溶液中回收有机溶剂两个方面介绍了该技术在工业上应用的效果。 相似文献
27.
《国际计算机数学杂志》2012,89(9):1542-1555
In this paper, the upper and lower solution method and monotone iterative technique are employed to study the boundary value problem for a class of first-order impulsive ordinary differential equations with Carathéodory condition on infinite intervals. Several existence theorems are obtained. 相似文献
28.
We review, unify and extend work pertaining to evaluating mode mixity of interfacial fracture utilizing the virtual crack
closure technique (VCCT). From the VCCT, components of the strain energy release rate (SERR) are obtained using the forces
and displacements near the crack tip corresponding to the opening and sliding contributions. Unfortunately, these components
depend on the crack extension size, Δ, used in the VCCT. It follows that a mode mixity based upon these components also will
depend on the crack extension size. However, the components of the strain energy release rate can be used for determining
the complex stress intensity factors (SIFs) and the associated mode mixity. In this study, we show that several—seemingly
different—suggested methods presented in the literature used to obtain mode mixity based on the stress intensity factors are
indeed identical. We also present an alternative, simpler quadratic equation to this end. Moreover, a Δ-independent strain
energy release based mode mixity can be defined by introducing a “normalizing length parameter.” We show that when the reference
length (used for the SIF-based mode mixity) and the normalizing length (used for Δ-independent SERR-based mode mixity) are
equal, the two mode mixities are only shifted by a phase angle, depending on the bimaterial parameter ε. 相似文献
29.