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51.
不同实验装置测定粉尘湿润剂的湿润效果相关性 总被引:7,自引:1,他引:7
采用滴液法、正向渗透法和反渗湿润法分别研究了3种阴离子型湿润剂对10种硫化矿粉尘的湿润效果,比较了不同实验装置研究湿润剂湿润粉尘的相关性.结果表明:温度约20℃时,使用上述3种实验方法对相同的试剂和粉尘做湿润实验没有相关性,许多情况下还出现完全相反的结果;而对于相同的实验装置,3种湿润剂都具有较好的相关性.由此可以看出,实验室研究湿润剂所采用的方法在原理上要与应用现场的特征相适应,否则就将适得其反. 相似文献
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1 INTRODUCTIONAtpresent ,zincisproducedbythehydrometallurgy electroanalysismethodinmostzincsmeltingplants .Eachyear,millionstonsofhydrometallurgicalzincresiduesaredischargedfromChinesesmeltingplants ,whicharehighlyacidicandconsistofgreatdealofsilverandot… 相似文献
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针对传统相位一致算法提取裂缝连续性差的缺点,提出改进的相位一致算法.首先对岩心图像进行预提取,增大目标和背景区域的对比度,并标记疑似目标像素点;然后,利用双圆投影断点检测算子判定并重建岩心图像裂缝中的断点;最后利用相位一致算法延伸裂缝走向的特性,再次对岩心图像中的裂缝目标进行提取,并进行图像去噪处理.实验结果表明,改进后的相位一致算法,能够保留提取效果不受光照亮度影响、对目标区域敏感度高的传统相位一致算法的优点,并且有效改善所提取裂缝的连续性. 相似文献
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Yangqing Dou 《International Journal for Computational Methods in Engineering Science and Mechanics》2017,18(4-5):266-276
This article provides a combined computational and analytical study to investigate the lateral impact behavior of pressurized pipelines and inspect all the parameters such as the outside diameter and internal pressure and evaluate how they affect such behavior. In this study, quartic polynomial functions are applied to formulate the maximum crushing force (Fmax), maximum permanent displacement (W), and absorbed energy (E) of the pressurized pipelines during the impact problem. The effects of the diameter and pressure on Fmax, W, and E are therefore illustrated through analyzing these functions. Response surfaces are also plotted based on the generated quartic polynomial functions and the quality (accuracy) of these functions are verified through several techniques. 相似文献
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A sweeping window method for detection of flaws using an explicit dynamic XFEM and absorbing boundary layers 下载免费PDF全文
Hao Sun Haim Waisman Raimondo Betti 《International journal for numerical methods in engineering》2016,105(13):1014-1040
We present a sweeping window method in elastodynamics for detection of multiple flaws embedded in a large structure. The key idea is to measure the elastic wave propagation generated by a dynamic load within a smaller substructural detecting window domain, given a sufficient number of sensors. Hence, rather than solving the full structure, one solves a set of smaller dynamic problems quickly and efficiently. To this end, an explicit dynamic extended FEM with circular/elliptical void enrichments is implemented to model the propagation of elastic waves in the detecting window domain. To avoid wave reflections, we consider the window as an unbounded domain with the option of full‐infinite/semi‐infinite/quarter‐infinite domains and employ a simple multi‐dimensional absorbing boundary layer technique. A spatially varying Rayleigh damping is proposed to eliminate spurious wave reflections at the artificial model boundaries. In the process of flaw detection, two phases are proposed: (i) pre‐analysis—identification of rough damage regions through a data‐driven approach, and (ii) post‐analysis‐–identification of the true flaw parameters by a two‐stage optimization technique. The ‘pre‐analysis’ phase considers the information contained in the ‘pseudo’ healthy structure and the scattered wave signals, providing an admissible initial guess for the optimization process. Then a two‐stage optimization approach (the simplex method and a damped Gauss–Newton algorithm) is carried out in the ‘post‐analysis’ phase for convergence to the true flaw parameters. A weighted sum of the least squares, of the residuals between the measured and simulated waves, is used to construct the objective function for optimization. Several benchmark examples are numerically illustrated to test the performance of the proposed sweeping methodology for detection of multiple flaws in an unbounded elastic domain. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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D. Jude Hemanth J. Anitha Valentina Emilia Balas 《International journal of imaging systems and technology》2016,26(3):188-195
Fuzzy theory based intelligent techniques are widely preferred for medical applications because of high accuracy. Among the fuzzy based techniques, Fuzzy C‐Means (FCM) algorithm is popular than the other approaches due to the availability of expert knowledge. But, one of the hidden facts is that the computational complexity of the FCM algorithm is significantly high. Since medical applications need to be time effective, suitable modifications must be made in this algorithm for practical feasibility. In this study, necessary changes are included in the FCM approach to make the approach time effective without compromising the segmentation efficiency. An additional data reduction approach is performed in the conventional FCM to minimize the computational complexity and the convergence rate. A comparative analysis with the conventional FCM algorithm and the proposed Fast and Accurate FCM (FAFCM) is also given to show the superior nature of the proposed approach. These techniques are analyzed in terms of segmentation efficiency and convergence rate. Experimental results show promising results for the proposed approach. © 2016 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 26, 188–195, 2016 相似文献
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利用改良座滴法研究了高真空条件下熔融6061和4043铝合金在600,650,700℃分别与纯钛(TA2)的反应润湿行为。结果表明:Al/Ti体系属于典型的反应润湿,铝合金中微量的Si元素在界面上产生了明显富集且满足热力学条件;界面上形成了富Si的致密的层片状Ti_7Al_5Si_(12)相,致密层产生后阻碍熔体润湿母材;Ti_7Al_5Si_(12)相的分解及三相线附近疏松的粒状Al_3Ti相产生后能够破除钛表面的氧化膜,进而促进润湿;6061/TA2和4043/TA2两润湿体系铺展动力学均可由反应产物控制(Reaction Product Model)模型描述,整个润湿铺展过程分为两个阶段,即先呈指数铺展、后呈线性铺展;6061铝合金对应两个阶段的铺展活化能分别为56kJ/mol和112kJ/mol,4043铝合金以指数铺展为主,铺展活化能为47kJ/mol,Ti_7Al_5Si_(12)相的分解对应于指数铺展阶段。 相似文献