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利用X射线衍射技术分析黄藤材微纤丝角、结晶度及γ射线的影响 被引量:12
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作者 汪佑宏 刘杏娥 +2 位作者 江泽慧 费本华 任海青 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2010年第5期1404-1407,共4页
为了解棕榈藤材基本材性、提高我国棕榈藤资源高附加值加工利用水平,以我国特有的黄藤为研究对象,应用X射线衍射法测定黄藤材微纤丝角、结晶度,并就γ射线辐照处理对微纤丝角、结晶度有何影响进行了分析。结果表明:纤维微纤丝角在33.4&#... 为了解棕榈藤材基本材性、提高我国棕榈藤资源高附加值加工利用水平,以我国特有的黄藤为研究对象,应用X射线衍射法测定黄藤材微纤丝角、结晶度,并就γ射线辐照处理对微纤丝角、结晶度有何影响进行了分析。结果表明:纤维微纤丝角在33.4°~38.7°范围内,平均为36.1°;藤皮处微纤丝角不比藤芯处的大。当标准剂量率为2.5×103Gy.h-1、辐射剂量分别为3,9和15kGy三个水平时,辐照处理前后对应微纤丝角分别为36.2°和35.8°,35.9°和35.4°,36.2°和35.4°,较处理前分别减小了1.10%,1.39%和2.21%。纤维素结晶度在24.8%~32.0%范围内,平均为28.6%,藤皮处结晶度均比藤芯处高。辐照处理前后对应结晶度分别为28.1%和26.0%,28.1%和26.9%,28.5%和27.1%,较处理前分别减小了7.58%,4.34%和4.70%,其中当辐射剂量为3kGy时,辐照导致结晶度差异在0.001水平上极显著。 展开更多
关键词 黄藤 X射线衍射 微纤丝角 结晶度 辐照处理
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SYNTHESIS AND CHARACTERIZATION OF A NOVEL BLUE LIGHT EMITTING ROD-COIL DIBLOCK OLIGOMER 被引量:1
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作者 Lifang Yang Haifeng He +2 位作者 Hongqing Cao Xinhua Wan Qi-feng Zhou Department of Polymer Science & Engineering College of Chemistry & Molecular Engineering Peking University Beijing 100871, China 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2002年第5期401-407,共7页
Four new rod-coil diblock molecules, which had well-defined para-phenylene oligomers (PPP, from biphenyl to quinquephenyl) as rigid segments and poly(ethylene oxide) (PEO, M-w ca. 750) as flexible segments, were synth... Four new rod-coil diblock molecules, which had well-defined para-phenylene oligomers (PPP, from biphenyl to quinquephenyl) as rigid segments and poly(ethylene oxide) (PEO, M-w ca. 750) as flexible segments, were synthesized. The chemical structure and the number of repeating unit in PEO coil and PPP rod were characterized by H-1-NMR and MALDI-TOF mass spectrometry. The diblock oligomers showed good solubility in common organic solvents and aggregated in water as characterized by a blue shift in UV-vis absorption spectra, a red shift in emission spectra, quenching of the fluorescence and formation of the microfibrilla and fractal-like structures. The formation of different supramolecular structures meant that this effort might lead to commercial important highly organized functional materials. 展开更多
关键词 rod-coil diblock oligomer MALDI-TOF mass spectrometry microfibrilla aggregate fractal-like pattern
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