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星状嵌段偶氮苯类肽的自组装与光响应性 被引量:1
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作者 陈阳 姚文倩 +2 位作者 丁明宇 靳海宝 林绍梁 《功能高分子学报》 北大核心 2025年第1期33-41,共9页
星状聚合物因其独特的物理化学性质和拓扑结构而备受关注。然而,开发刺激响应型序列可控星状聚合物仍然是一项重大挑战。本文利用固相亚单体合成技术设计并制备了一种新型的具有特定序列结构、光响应性的两亲性星状嵌段偶氮苯类肽Star-[... 星状聚合物因其独特的物理化学性质和拓扑结构而备受关注。然而,开发刺激响应型序列可控星状聚合物仍然是一项重大挑战。本文利用固相亚单体合成技术设计并制备了一种新型的具有特定序列结构、光响应性的两亲性星状嵌段偶氮苯类肽Star-[(N_(AZO4)-b-NME4-b-NCOOH)]_(3),并通过溶液自组装制备了尺寸均一的球形胶束。由于偶氮苯基团的光致异构化特性,在紫外光和可见光的交替照射下,该球形胶束能够实现光控的尺寸可逆转变。此外,铂纳米颗粒修饰的球形胶束对硼氢化钠介导的4-硝基苯酚还原反应具有良好的催化能力和可逆的光控催化活性。此研究工作为刺激响应型序列可控星状聚合物的制备及其在纳米催化领域中的应用提供了理论指导。 展开更多
关键词 特定序列聚合物 星状嵌段偶氮苯类肽 自组装 可逆结构转变 光控催化
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标签推荐Top-N列表优化算法 被引量:2
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作者 朱小兵 丁明玉 肖玉 《计算机应用与软件》 北大核心 2022年第11期281-287,共7页
针对标签推荐算法推荐列表长度常为固定值,进而导致推荐精度下降的问题,提出一种优化标签推荐算法Top-N推荐列表长度的算法。该算法对Top-N推荐列表进行重排序;再对排序以后的Top-N标签推荐列表进行列表长度的优化,进而计算出最优的标... 针对标签推荐算法推荐列表长度常为固定值,进而导致推荐精度下降的问题,提出一种优化标签推荐算法Top-N推荐列表长度的算法。该算法对Top-N推荐列表进行重排序;再对排序以后的Top-N标签推荐列表进行列表长度的优化,进而计算出最优的标签推荐列表长度。在多个真实数据集之上进行了多次对比实验,结果表明,标签Top-N推荐列表优化算法具有较好的推荐性能。 展开更多
关键词 标签推荐 Top-N列表 标签推荐系统 列表优化
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Combination of dynamic hollow fiber liquid-phase microextraction with HPLC analysis for the determination of UV filters in cosmetic products 被引量:2
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作者 YANG HongYun LI HaiFang +3 位作者 Masahito Ito LIN Jin-Ming GUO GuangSheng ding mingyu 《Science China Chemistry》 SCIE EI CAS 2011年第10期1627-1634,共8页
A simple method based on hollow fiber liquid-phase microextraction (HF-LPME) followed by high performance liquid chro-matography (HPLC) analysis was successfully developed for the determination of UV filters in cosmet... A simple method based on hollow fiber liquid-phase microextraction (HF-LPME) followed by high performance liquid chro-matography (HPLC) analysis was successfully developed for the determination of UV filters in cosmetic products. A canular extractor was assembled by mounting a hollow fiber inside an external tube with a tee-connector. The organic solvent was immobilized into the fiber to form a liquid membrane as the acceptor phase. The sample was continuously injected into the extractor and the UV filters were extracted from the aqueous sample into organic acceptor phase. The main parameters affecting HF-LPME including extraction solvent, sample volume, sample flow rate, pH values and ionic strength were investigated. Toluene has been verified to be suitable as the acceptor phase. Under the optimized HF-LPME conditions, the enrichment factors of five UV filters varying from 24 to 57 were achieved. The limits of detection for the five UV filters were in the range of 1-100 μg L-1 .The relative standard deviations (RSDs) of HF-LPME and HPLC analysis were lower than 5.2%. The proposed method has been successfully applied to the analysis of the varied cosmetic products. 展开更多
关键词 hollow fiber liquid-phase microextraction UV filter high performance liquid chromatography COSMETICS
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