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叙述了利用D-甘露醇为手性源合成白三烯B_3(LTB_3)的10-C~20-C片断的新方法。 相似文献
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白三烯类化合物发现以后短短几年中即引起了生理、生化以及有机化学界的特别关注,对此作者曾就白三烯的化学工作,从代谢、分类、结构和化学合成等几个方面,作了较系统的介绍。自此以后又有不少文献发表,尤其对白三烯及其类似物的合成作了不少出色的工作,现择其要者作一简介,以飨读者。 相似文献
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The spatial resolution and the relative density resolution are the two most critical indicators in CT system. The method recommended in the ASTM E1695-95 and GJB 5311-2004 is only suitable to the fan-beam CT system. In this paper, for industrial cone-beam micro CT system, we will adopt the edge response function (ERF) created by the step edges of a steel ball to measure the system 3D PSF and MTF. To describe the contrast discrimination function more accurately, we will first propose to extend the two-dimensional measurement region to the three-dimensional space. Our experimental spatial resolution is (55.56±0.56) lp/mm and the relative density resolution is 1% within 300 μm×300 μm×300 μm according to the 3σ rule. 相似文献
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