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21.
在实验室对WXS凹陷的W3地层岩芯样品进行了地层压力和温度条件下的密度、孔隙度和声波速度测试,基于岩石物理模型提出一种集成目标储层孔隙度、厚度和饱和流体信息的AVO响应模板制作方法。该方法以砂岩孔隙度与干燥状态下的密度和纵、横波阻抗的线性关系为核心,利用Gassmann流体替换技术构建岩石物理模型,通过正演模拟获得不同... 相似文献
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研究了度量G?空间中拓扑共轭不变性和映射迭代不变性,给出了度量G?空间中强G?跟踪性的概念,并举例说明了强G?跟踪性与G?跟踪性的不同,利用拓扑共轭和映射迭代的性质,得到(1)若f1拓扑G?共轭于f2,则f1具有强G?跟踪性当且仅当f2具有强G?跟踪性;(2)对任意的n∈N+,映射f具有强G?跟踪性当且仅当fn具有强G?跟踪性。所得结果是对度量G?空间中拓扑共轭不变性和映射迭代不变性理论的补充。 相似文献
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对Cn中某一Reinhardt域上以及复Hilbert空间单位球上推广的Roper-Suffridge算子保持α(0<α<1)次的β(-π/2<β<π/2)型螺形性进行了讨论.所得的结果推广了以前相应的结论. 相似文献
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Xiaoqing Jin Zhanjiang Wang Qinghua Zhou Leon M. Keer Qian Wang 《Journal of Elasticity》2014,114(1):1-18
Stress analysis of an elliptical inhomogeneity in an infinite isotropic elastic plane is a classical elasticity problem, which is usually solved by means of the complex variable formulation. In this work, we demonstrate that an alternative method of solution for such a problem, via the equivalent inclusion method, may be more convenient and straightforward without recourse to complex potentials or curvilinear coordinates. The explicit analytical solution can be derived through simple algebraic manipulation, although the longitudinal eigenstrain component should be handled with care in the case of plane strain. Since the exterior Eshelby tensor for an elliptical inclusion is available in closed-form, the present study provides a full field stress solution expressed in Cartesian coordinates. Furthermore, the in-plane stress components are represented in terms of Dundurs’ parameters. The solution methodology and the convenient formulae of the stress concentration may be of practical use to the engineers in developing benchmarks for design evaluation. 相似文献
26.
Effects of water treatments on the activation of soil seed banks – A case study on the lower reaches of the Tarim River 总被引:1,自引:0,他引:1
Evaluation of seedling emergence is a common method used to investigate the vegetation restoration potential of soil seed banks. Previous studies have primarily been conducted in the laboratory using a single water treatment. However, when this method is used, it is difficult to optimize the water conditions for the needs of the individual species of seeds. Additionally, the germination conditions
for seedlings in the laboratory are different from those in nature. To avoid these issues, we conducted experiments to activate soil seed banks in the field using different water treatments. The results revealed that: (1) generally, the number of species and quantity of seedlings decrease gradually as the water supply decreases, but that for several species most seedlings did not appear when they were provided with the greatest amount of water, and (2) different species present different germination characteristics. According to the rate of seedling emergence, the species were classified into two germination types: fast and slow. In addition, each species also had a unique climax period of emergence, which was delayed with a decrease in water supply. Therefore, the amount of water provided is vital to seedling emergence, and various water treatments should be evaluated when studying the characteristics of different species in soil seed banks. For the lower reaches of the Tarim River, the optimal soil moisture for seedling emergence ranged from 23% to 28%, and seedling conservation should be strengthened during the climax period of emergence (9–15 days from the day when water became available). These results highlight the importance of the use of an optimal water treatment and demonstrate the danger of using a single treatment method. Our results also emphasize the need for a preliminary study prior to conducting studies to evaluate seed banks. 相似文献
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图像边缘检测是机器视觉和目标提取的重要步骤,直接决定目标检测的准确性,传统边缘检测方法大都只利用像素的梯度信息和局部邻域信息,使提取的图像目标边缘存在断点,文中引入像素的概率密度分布函数描述像素在整个图像空间的全局分布信息,提出一种新的图像边缘检测方法。仿真试验结果表明,与传统方法相比,新方法具有较好的图像边缘检测效果。 相似文献