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991.
粘接结构超声信号的小波分解与特征提取 总被引:1,自引:0,他引:1
粘接结构因其独特的物理、机械和声学特性在诸多领域具有非常广泛的应用,对于铝合金-橡胶这样一种金属-非金属粘接结构的超声检测信号,本文利用了小波变换的多分辨率分析(时频分析)的方法,有效地提取出了反映多层材料粘接状况的信号特征,该特征提取方法可用在粘接结构的无损检测中。 相似文献
992.
M. M. I. HAMMOUDA I. G. EL-BATANONY H. E. M. SALLAM 《Fatigue & Fracture of Engineering Materials & Structures》2003,26(7):627-639
An understanding into the macro kinetic and kinematic behaviour of fretted surfaces is provided. Making use of a modified version of a previously developed in‐house two‐dimensional elastic–plastic finite element analysis numerically simulates flat contact pad fretting fatigue tests. Basic macro mechanics concepts are adopted to idealise two bodies with rough contact surfaces and loaded at two different sites with arbitrary axial loading profiles. A time scale factor is devised to recognise the earliest candidate out of the events possibly accommodated at each loading increment. The present analysis utilises a relevant experimental set up developed in the Structural Integrity Research Institute of the University of Sheffield as an application. Computational results accurate to within 1.2% and corresponding to one contact pad span and six constant normal loads acting individually with four amplitudes of two sinusoidal axial load cycles are presented. The present computations include (1) the development of the global and local normal and tangential reactions and relative sliding displacement acting along the fretting surfaces and (2) contact pad deformation, generated stress fields and plasticity development within the neighbouring region of the fretted area. 相似文献
993.
曲流河沉积亚相的地震识别方法 总被引:7,自引:1,他引:6
本文提出利用三维地震资料相干数据分析研究曲流河沉积相的方法,其优点是在地质分析的基础上,对沉积体系有较为明显的识别特征,且在钻井较少的地区尤为实用。该方法在济阳拗陷东北部上第三系应用中取得了较为明显的效果。 相似文献
994.
995.
996.
Feng‐Ge Wu Fu‐Chun Sun Ke Yu Chang‐Wen Zheng 《International Journal of Satellite Communications and Networking》2005,23(6):359-371
How to evaluate the performance of satellite networks is a prerequisite to the construction of satellite networks, and is also one of challenges in the researches on satellite networks. In this paper, generalized stochastic Petri net (GSPN) models are presented to carry out the performance analysis of a double‐layered satellite network. Firstly, the GSPN model of a double‐layered satellite network is simplified by proper analysis. Then, two sets of experiments are conducted to analyse the performance of the satellite networks, and show that the double‐layered satellite network outperforms single‐layered ones on the heavy traffic load. Finally, the feasibility and effectiveness of the proposed approach is verified by simulation experiments. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
997.
锰在有色金属中的应用 总被引:3,自引:2,他引:1
对常见的含锰有色合金的性能及其应用作了较为系统的介绍,锰作为一种重要的合金元素,与铁,铝,镁,钛等构成了极其广泛地合金系列。 相似文献
998.
999.
C. D. Singh S. K. Dhua M. Kumar A. K. Jha T. Mrinal K. Sharma R. R. Abhyuday Y. Kumar 《Journal of Failure Analysis and Prevention》2007,7(4):292-301
A concentric reducer tube, which was a part of the top exit roughing hydraulic descaler in a hot strip mill failed prematurely
under working pressure. A detailed metallurgical investigation comprising physical examination, optical microscopy, scanning
electron microscopy, and electron probe microanalysis was carried out to find out the genesis of the failure. Physical examination
revealed cracks located symmetrically around the circumference of the tube that ran along its full length, up to the weld
beads at both ends. Optical microscopy of etched samples revealed a banded ferrite-pearlite structure and the existence of
forging folds near the change-in-section(160° fillets). Cracks were found to initiate from these forging folds. No structural
abnormalities were found in the weld beads and heat-affected zones. 相似文献
1000.
ABSTRACT Bulgur cooked in soymilk of 6% and 9% solid content had significantly ( P < 0.05) higher bulk density compared with bulgur cooked in soymilk of 3% solid content and control bulgur cooked in water. As the soymilk solid content increased, pilav bulgur yield increased whereas fine bulgur yield decreased. The SDS-extractability of bulgur proteins increases with the increase in soymilk solid content. Water absorption capacity of fine bulgur samples was affected by soymilk incorporation, and variations in oil absorption capacity were not significant ( P > 0.05). Soymilk incorporation improved color and sensory properties of pilav and fine bulgur. The results of this study suggest that soymilk can be successfully applied to bulgur production. 相似文献