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101.
Water turbidity, surface temperature and circulation of Barton and Wroxham Broads, two of the Norfolk Broads, were studied using one reflective (TM1) and the thermal (TM6) TM band. The results indicated that the through-flowing path of the River Ant in Barton Broad is the major influence on the distribution of these parameters. In Wroxham Broad, both turbidity and surface temperature displayed a uniform distribution. This could be explained by the absence of a predominant direction of flow. 相似文献
102.
The compressive stress-strain relationships of two puffed cereals, rice and corn based, in bulk were determined using a Universal Testing Machine. The general sigmoid shape of the relationship could be described by a four parameter empirical model originally developed for cellular solids. Jaggedness could be expressed in terms of an apparent fractal dimension and/or the mean magnitude of the power spectrum determined using the Fast Fourier Transform. Both measures as well as a particular parameter of the empirical model were sensitive indicators of the changes in the stress-strain relationships resulting from exposure to different relative humidities. Although the stress strain relationship, especially of dry samples, had an irregular, irreprodu-cible shape, the magnitude of the two roughness measures was highly reproducible. 相似文献
103.
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105.
水下灌浆隧道围岩应力与位移分析 总被引:1,自引:0,他引:1
目前对隧道围岩的应力与位移分析,其前提都是以围岩为均质材料,而灌浆隧道的围岩是由两层不同力学性能材料构成的夏合结构,其应力与位移特点不同于均质围岩。基于岩体的弹脆塑性模型及非关联流动法则,考虑地下水压力的作用,对灌浆隧道围岩的应力与位移进行理论分析,获得了围岩位移曲线。 相似文献
106.
榆树林油田砂岩储层敏感性研究 总被引:16,自引:10,他引:6
榆树林油田储层粘土矿物含量较高,各种注入条件和施工条件都会对该储层造成相应的伤害,应采取相应的防护措施,为防止速敏的发生,储层的注水速度应控制在临界流速(1.0mL/min)以下,在油井转注时,可先注入1.09PV的含粘土稳定剂的进行处理,以提高产量或注入量,注入阴离子表面活性剂配置的活性水再注入地层水,不能增加地层水的渗透率,该项试验研究对指导榆树林油田的开发具有重要的意义。 相似文献
107.
The causes of lightning outage are subdivided into direct lightning strokes and induced lightning strokes, which are identified by the characteristics of the lightning overvoltage. In the past, lightning protection devices were directed mainly toward the latter, and attention has been focused on the installation of lightning protection devices, ground wires, and reinforcement of insulators. However, lightning outages continue to occur. Thus it is extremely important to clarify the fault characteristics of lightning surges and to study the effectiveness of various lightning protection devices by considering both direct lightning stroke and induced lightning stroke in order to prevent lightning outage in the future. In this research, the electromagnetic transients program (EMTP) has been applied to the direct lightning stroke, and the induced lightning outage analysis program for multiple conductor systems has been applied to the induced lightning stroke to study the effectiveness of lightning protection devices provided by combination of various lightning protection devices. The most effective lightning protection schemes are analyzed and evaluated based on verification tests on the full scale models as well as economic considerations. 相似文献
108.
M. Aigner M. Zeilinger H. Hofbauer 《Chemical Engineering and Processing: Process Intensification》1995,34(6):515-520
The hydrolysis of isocyanic acid in the gaseous phase has been investigated at temperatures between 553 and 613 K by mass spectrometry and evaluated to obtain the corresponding kinetic data. The reaction order and reaction constant have been determined. Finally, the influence of water on the catalysed formation of melamine from isocyanic acid under the operating conditions employed has been investigated in order to determine whether there is a need to try the process gas. 相似文献
109.
110.
基于STEP的零件加工工艺计划模型 总被引:1,自引:0,他引:1
为了满足CIMS环境下工艺系统与其它系统集成的需要,建立了标准工艺计划模型具十分重要的意义。本文描述了一个基于STEP的零件加工工艺计划模型,介绍了建立这一模型的关键技术,给出了参照STEP建立工艺计划模型的方法。 相似文献