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221.
The main question of this research is: Who should undertake promotional and brand-image advertising if the franchisor and franchisees act so as to maximize their respective profits? To address this question, we study a two-stage advertising game between a franchisor and two adjacent franchisees. In the first stage of the game, the franchisor chooses between three advertising models – centralizing or delegating the two types of advertising to the franchisees or delegating only promotional advertising. In the second stage, given the franchisor’s choice of an advertising model, the two franchisees decide whether or not to cooperate. Our main findings are that (1) the franchisees should cooperate if the franchisor delegates either both brand-image and promotional advertising or promotional advertising, although cooperation between franchisees does not necessary improve the franchisor’s profits. (2) The choice of an advertising arrangement critically depends on the margins as well as the costs of performing both promotional and brand-image advertising. We also discuss the conditions under which the three advertising models should be implemented.  相似文献   
222.
苏超  姜弘道  钱向东 《力学学报》2001,9(3):267-271
采用考虑三维接触非线性的结构温度徐变仿真计算方法, 针对三峡永久船闸 (全衬式和混合式)闸室墙整体和分缝两种结构形式进行了计算分析, 研究表明:闸室墙分水平缝可以有效地降低全衬式和混合式结构混凝土铅直向拉应力, 但使最大锚杆拉应力值和平均锚杆拉应力值增加, 分布的离散性增大, 在横缝和纵缝交点附近出现锚杆拉应力集中现象。  相似文献   
223.
The interactions of benzalkonium chloride (BC)with components of stratum corneum, a model system of intercellular lipids in human stratum corneum and homogenized rat stratum corneum were characterized in terms of thermodynamics at pH 7.5 and 37°C. BC was strongly bound to cholesterol and cholesterol sulfate with higher affinities (105~106 M-1) than to any other components of the stratum corneum by hydrophobic interaction and ionic interaction, respectively. BC binding to the model system of intercellular lipids significantly decreased only in the absence of cholesterol. It is indicated that cholesterol and its derivatives play an important role in the penetration and/or accumulation of BC in stratum corneum. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
224.
Stability for basic system of equations of atmospheric motion   总被引:1,自引:1,他引:0  
The topological characteristics for the basic system of equations of atmospheric motion were analyzed with the help of method provided by stratification theory. It was proved that in the local rectangular coordinate system the basic system of equations of atmospheric motion is stable in infinitely differentiable function class. In the sense of local solution, the necessary and sufficient conditions by which the typical problem for determining solution is well posed were also given. Such problems as something about "speculating future from past" in atmospheric dynamics and how to amend the conditions for determining solution as well as the choice of underlying surface when involving the practical application were further discussed. It is also pointed out that under the usual conditions, three motion equations and continuity equation in the basic system of equations determine entirely the property of this system of equations.  相似文献   
225.
Hydrazones based on mono- and bicyclic terpenoids (verbenone, menthone and carvone) have been investigated in vitro as potential biomembrane penetration enhancers. In this regard, liposomes composed of lecithin or cardiolipin as phospholipid phase components with incorporated fluorescence probes have been prepared using the thin-film ultrasonic dispersion method. The mean particle size of the obtained liposomes, established using laser diffraction, was found to be 583 ± 0.95 nm, allowing us to categorize them as multilamellar vesicles (MLVs) according to their morphology. Pursuant to fluorescence analysis, we may assume a reduction in microviscosity and, consequently, a decrease in the packing density of lecithin and cardiolipin lipids to be the major mechanism of action for terpenoid hydrazones 1–15. In order to determine the molecular organization of the lipid matrix, lipids were isolated from rat strata cornea (SCs) and their interaction with tested compounds was studied by means of Fourier transform infrared spectroscopy. FT-IR examination suggested that these hydrazones fluidized the SC lipids via the disruption of the hydrogen-bonded network formed by polar groups of SC constituents. The relationship between the structure of terpenoid hydrazones and their ability to enhance biomembrane penetration is discussed.  相似文献   
226.
雷电电磁脉冲对架空电力线的耦合效应   总被引:5,自引:0,他引:5       下载免费PDF全文
 从传输线模型出发,通过建立雷电回击通道、大地和电力线系统一体化模型,采用时域有限差分法计算得出雷电回击电流的近场分布,将场值代入离散的传输线方程后,计算了架空电力线终端的感应过电压。通过对多导体架空线和单导体线终端感应过电压的分析,发现由于其它导体的存在,多导体系统中单根导体两端的感应电压峰值比相同高度处单一导体两端的感应电压峰值低10%~20%;并且对于垂直导体结构,最小感应电压产生在距离地面最近的导体上;而对于水平导体结构,最小感应电压产生在中间导体上。  相似文献   
227.
砂泥岩薄互层电阻率准确测量是提高泥质砂岩储层计算的一项重要工作。为了解决薄互层电阻率准确测量问题,该文提出一种三维感应成像测井仪的设计与实现方法。首先,基于感应电磁测量方法,设计由1个三轴发射器、4个单轴接收阵列和3个三轴的接收阵列组成的三维探测器。在此基础上,通过三维线圈系参数与结构创新设计、多频循环发射、高精度多道同步采集、高性能发射接收一体化集成等技术实现,在每一个深度点可获取78个电导率测量值。最后,利用数据校正与处理技术来消除各种环境影响,经过理论模型和实际资料的处理结果均证实,该仪器处理得到5条不同径向探测深度的水平电阻率与垂向电阻率、地层倾角等曲线,实现了对薄互层电阻率的准确测量。  相似文献   
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