排序方式: 共有38条查询结果,搜索用时 9 毫秒
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仿生非光滑表面45#钢模具的热疲劳性能 总被引:5,自引:1,他引:4
利用动物体表仿生学原理制备45#钢模具非光滑表面试样,通过自约束冷热疲劳试验方法,对比研究了光滑与非光滑试样的热疲劳特性,观察分析了热疲劳裂纹在仿生非光滑表面上扩展的形貌和内部机理.结果表明,非光滑单元体对热疲劳裂纹有阻断作用,仿生非光滑表面使模具的热疲劳抗力显著提高,模具表面的热疲劳性能在非光滑单元体的某一密度范围内达到最佳状态.在细晶强化、合金强化等强化机制下,由仿生非光滑单元体构筑的"桩钉"效应是导致模具抗热疲劳性提高的主要原因. 相似文献
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超声波拖尾电路的研究 总被引:3,自引:0,他引:3
围绕超声波测距的主要问题是传感器的尺寸、结构、功率、工作频率和设备的最大量程等,着重阐述了超声波测距中减小盲区的几种方法. 相似文献
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针对碎屑岩中正断层侧向封堵性评价的10种研究方法,文中从各方法的基本原理入手,分析其优缺点及适用范围,从而进行了全面的论述和评价。断层侧向封堵性评价方法可概括成4类:Ⅰ类是断层岩封闭法;Ⅱ类是断层两侧流体相关参数对比法;Ⅲ类是岩性对接封闭法;Ⅳ类是综合法。每个断层侧向封堵性评价方法都有一定的局限性,具体选用何种评价方法,要具体情况具体分析确定。总的来说,岩性对接分析和断层两侧流体分析是对地质特征的基本描述,是评价或预测断层侧向封堵性的基础。若是砂砂对接,则SGR法是目前比较成熟的评价方法。 相似文献
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Abstract Reservoir simulation is an approach of recreating the occurring phenomena of the reservoir by solving the general governing equations that describe the reservoir processes. Finite difference technique is an effective method to get the solution out of the reservoir models for different scenarios. In light of many benefits of using course grid models rather than fine grid and simplification, using the same relative permeability curves from laboratory cannot be applied in the fields having large grid dimensions because of numerical dispersion (smearing) of finite difference modeling. Thus, the relative permeability curves must be modified based on the grid size and then applied into the simulator. The authors introduce a methodology to demonstrate how the lab relative permeability curves can be modified based on coarse grid sizes to honor the same anticipated rock behavior. Thus, an objective function is developed to minimize the numerical dispersion in a synthetic tilted reservoir by automatically changing the relative permeability and comparing the results with the equivalent fine model. By this method, modified relative permeability curves can be obtained and introduced to the coarse model. This modification workflow is almost inevitable for reservoir simulation models with very coarse grids and it eases the history-matching process by approaching more realistic solution. 相似文献
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从活动图像运动响应的定义出发,分析种种运动伪像成因,提出描述运动伪像的5个实用参数,阐明选择其中亮拖尾时间和暗拖尾时间作为电视机指标参数的理由,并就它们一种低成本的实用测量方法做了介绍和说明。 相似文献