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Carthamin potassium salt isolated from Carthamus tinctorius L. was purified by an improved traditional Japanese method, without using column chromatography. The 1H and 13C nuclear magnetic resonance (NMR) signals of the pure product were fully assigned using one- and two-dimensional NMR spectroscopy, while the high purity of the potassium salt and deprotonation at the 3′ position of carthamin were confirmed by atomic adsorption spectroscopy and nano-electrospray ionization mass spectrometry. 相似文献
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This paper provides the uniform enumerative functional equation of orientable (nonori-entable) rooted petal bundles with more parameters, and deduces two recursion formulas for calculation. Accordingly, an explicit expression of rooted petal bundles with up to two parameters on nonorientable surface of genus 4 is also obtained. 相似文献
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高分子自组装Mn2O3花瓣状纳米带、纳米线的研究 总被引:1,自引:0,他引:1
通过控制热处理工艺条件, 利用Mn(CH3COO)2和具有特殊空间构型的聚乙烯醇(PVA), 在600 ℃合成了类花瓣状Mn2O3纳米带和纳米线结构. SEM, XRD表征分析证明Mn2O3纳米带结构为方铁锰矿晶型结构, 沿(222)方向择优生长. 分析了热处理工艺对一维纳米结构的影响机制. 初步探讨了Mn2O3一维纳米结构的生长机理. 相似文献
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玫瑰花花瓣微观结构与水滴黏附性质的关系 总被引:1,自引:0,他引:1
利用环境扫描电镜(ESEM)分别观察了新鲜、枯萎的玫瑰花花瓣正、反两面的微观形貌,并通过测量样品的表观接触角表征了其浸润性,采用高敏感性微电力学天平测试了样品表面的粘附力,分析了玫瑰花花瓣微观结构与水滴粘附性质的关系.实验结果表明,微米结构主要影响玫瑰花花瓣的超疏水性,而纳米结构则是导致玫瑰花花瓣具有高粘附力的关键原因. 相似文献
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Graecia Lugito Eamor M. Woo Shih‐Min Chang 《Journal of Polymer Science.Polymer Physics》2017,55(7):601-611
Using in‐house synthesized poly(dodecamethylene terephthalate) (P12T) as a model, periodic extinction‐banded spherulites melt‐crystallized at high Tcs (100–115 °C) are expounded in terms of growth mechanism. The extinction‐banded spherulites wildly differing from the usual blue/orange double ring‐banded spherulites are composed of all flat‐on discrete single‐crystalline lamellae packed like roof shingles (or fish scales) along the circularly curved bands and the lamellae in the extinction bands are flat with a lozenge shape with no continuous twisting at all. For P12T films of more than 10 µm crystallized at Tc = 105–115 °C, no periodic bands were seen, and all spherulites were ringless, where periodic growth precipitation of crystals to extinction does not occur until impingement. Extinction bands in the P12T spherulites with the inter‐ring spacing steadily decrease with decreasing film thickness, because for thinner films (submicrons to 2 µm), draining or depletion of available molten species takes place more frequently, leading to bands of smaller inter‐ring spacing. The petal‐like extinction bands are discussed and analyzed in detail using 3D AFM imaging. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 601–611 相似文献