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131.
The evolution of surface defects during shape rolling of high‐speed steel billets is studied using longitudinal surface defects prepared by machining and welding. The reduction of the defects during rolling in a production mill is compared to the total area reduction of the billets. Samples are collected after pass 4, 6, 8, 14, 19 and the final pass, 28, representing the finished 5.5mm wire. By inspecting the cross sections, the rotation of the billets from pass to pass is evaluated. Results from FE simulations on solid billets are compared to the experimental results. Generally, simulations predict less reduction than observed experimentally. In most cases cracks reduce most effectively followed by carbon steel welds and stainless steel welds. 相似文献
132.
The authors of this paper investigated the influence of esters of rapeseed oil fatty acids on the lubricating properties of
mineral lubricants containing chosen AW/EP additives. Methyl esters, ethylene glycol esters, and glycerol esters as well as
some commercial AW/EP packages based on zinc dialkyldithiophosphate, S–P organic compounds, and sulphurized esters of fatty
acids were tested. The tribological tests were carried out with the use of a four-ball machine. Antiwear (AW) properties of
tested compositions were determined using their limiting load of wear (Goz(40)). It appears that the AW action of esters of rapeseed oil fatty acids depends on their structure. The best AW action is shown
by compositions of mineral oil lubricants containing AW/EP additives and methyl esters of rapeseed oil fatty acids. The SEM/EDS
analysis of the scar surface layer indicated that the presence of these esters in lubricants causes a change in the interaction
between AW/EP additives and the metal surface. These observations were confirmed by the XPS surface analysis. 相似文献
133.
通过分析甲壳素纤维各项性能,将其引入山羊绒产品中,对双层织物的设计进行探讨,并经过纺纱和织物试制,提出了设计与生产中应注意的问题,开发出了具有永久抗菌性的表层为羊绒、里层为甲壳素与改性羊毛混纺的系列产品. 相似文献
134.
从原材料的控制、配合比设计控制、施工阶段控制三方面探讨了热拌沥青混凝土面层的施工,重点对施工阶段的控制进行了详细阐述,以提高行车的安全性、舒适性及路面使用的耐久性等,从而延长路面的使用寿命。 相似文献
135.
In this paper we present a new radiosity algorithm, based on the notion of a well distributed ray set (WDRS). A WDRS is a set of rays, connecting mutually visible points and patches, that forms an approximate representation of the radiosity operator and the radiosity distribution. We propose an algorithm that constructs an optimal WDRS for a given accuracy and mesh. The construction is based on discrete importance sampling as in previously proposed stochastic radiosity algorithms, and on quasi Monte Carlo sampling. Quasi Monte Carlo sampling leads to faster convergence rates and the fact that the sampling is deterministic makes it possible to represent the well distributed ray set very efficiently in computer memory. Like previously proposed stochastic radiosity algorithms, the new algorithm is well suited for computing the radiance distribution in very complex diffuse scenes, when it is not feasible to explicitly compute and store form factors as in classical radiosity algorithms. Experiments show that the new algorithm is often more efficient than previously proposed Monte Carlo radiosity algorithms by half an order of magnitude and more. 相似文献
136.
Speed-up fractal image compression with a fuzzy classifier 总被引:4,自引:0,他引:4
This paper presents a fractal image compression scheme incorporated with a fuzzy classifier that is optimized by a genetic algorithm. The fractal image compression scheme requires to find matching range blocks to domain blocks from all the possible division of an image into subblocks. With suitable classification of the subblocks by a fuzzy classifier we can reduce the search time for this matching process so as to speedup the encoding process in the scheme. Implementation results show that by introducing three image classes and using fuzzy classifier optimized by a genetic algorithm the encoding process can be speedup by about 40% of an unclassified encoding system. 相似文献
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地层微电阻率成像测井在中原油田的应用 总被引:2,自引:0,他引:2
介绍地层微电阻率测井(FMI)技术以及它在地质构造解释、沉积学解释、裂缝识别、地层分析等方面独特的枝术优势,并详细介绍了FMI在中原油田濮深X井的实际应用,进行了应用效果分析,指出成像测井是未来油田油气勘探开发的重要技术手段。 相似文献