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41.
建立了固相萃取-HPLC法同时测定滇龙胆中抗老年痴呆的7种主要成分gentiside G,gentiside H,gentiside I,gentiside A,gentiside J,gentiside B,gentiside K的含量的方法。滇龙胆样品经乙醇提取环己烷萃取后,用硅胶固相萃取小柱净化,HPLC-DAD对7种苯甲酸酯进行定量检测。7种苯甲酸酯类化合物在一定范围内线性关系良好,相关系数均大于0.999,加样回收率为92.8%~104.6%,RSD为0.8%~4.7%。不同产地龙胆样品中云南产滇龙胆苯甲酸酯含量高于其他产地龙胆,7种化合物中,gentiside B含量最高达0.3425μg/g,gentiside G含量最低只有8.5μg/g。方法为滇龙胆药材的质量控制和资源开发利用提供科学依据。 相似文献
42.
A rigid supramolecular polymer was constructed in aqueous solution via cucurbit[8]uril(CB[8]) host recognition with a rigid monomer containing an azobenzene unit and two 4,4'-bipyridin-1-ium(BP)moieties in the two ends, which also exhibited photo-responsiveness owing to the photoinduced trans–cis isomerization of azobenzene group. 相似文献
43.
Dr. Ling‐Yun Yang Dr. Xiao‐Bin Fu Dr. Tai‐Qiang Chen Prof. Li‐Kun Pan Dr. Peng Ji Prof. Ye‐Feng Yao Prof. Qun Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(17):6346-6349
Highly conductive, crystalline, polymer electrolytes, β‐cyclodextrin (β‐CD)–polyethylene oxide (PEO)/LiAsF6 and β‐CD–PEO/NaAsF6, were prepared through supramolecular self‐assembly of PEO, β‐CD, and LiAsF6/NaAsF6. The assembled β‐CDs form nanochannels in which the PEO/X+ (X=Li, Na) complexes are confined. The nanochannels provide a pathway for directional motion of the alkali metal ions and, at the same time, separate the cations and the anions by size exclusion. 相似文献
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Preparation of coatings from a series of silicone/fluorine‐functionalized polyacrylates via electrophoretic deposition 下载免费PDF全文
Weiming Yao Zhengping Wang Xu Wu Bingbing Li Ximing Zhong Jing Lin Jingyuan Chen Yanghong Lai 《先进技术聚合物》2015,26(9):1148-1154
Silicone/fluorine‐functionalized polyacrylates were synthesized and subsequently used to prepare corrosion‐resistant transparent coatings via electrophoretic deposition. The coated tin plate with the functionalized polyacrylate had a gloss value higher than 95.0 GU and resisted rust after immersion in a 5 wt% NaCl solution for 10 days. In addition, these coatings remained adhered strongly to the tin plates even after they were bent. It is hoped that this work will provide useful experimental data and assist researchers with the design of applicable coatings with desirable properties. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
46.
In this paper, we study some properties of composition operators on Hilbert spaces of Dirichlet series, which include the Fredholmness, Hilbert-Schmidtness, spectra, cyclic and hypercyclic phenomenons, and also answer a norm question raised by Cowen and MacCluer. 相似文献
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This review is mainly focused on the optoelectronic properties of diamond-based one-dimensional-metal-oxide heterojunction. First, we briefly introduce the research progress on one-dimensional (1D)-metal-oxide heterojunctions and the features of the p-type boron-doped diamond (BDD) film; then, we discuss the use of three oxide types (ZnO, TiO2 and WO3) in diamond-based-1D-metal-oxide heterojunctions, including fabrication, epitaxial growth, photocatalytic properties, electrical transport behavior and negative differential resistance behavior, especially at higher temperatures. Finally, we discuss the challenges and future trends in this research area. The discussed results of about 10 years’ research on high-performance diamond-based heterojunctions will contribute to the further development of photoelectric nano-devices for high-temperature and high-power applications. 相似文献
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Prof. Dr. Xiaoqing Liu Xue Li Prof. Dr. Xiaoqian Yao Prof. Dr. Weizhen Zhao Prof. Dr. Lei Liu 《Chemphyschem》2021,22(10):968-974
Nowadays, hydrogen activation by frustrated Lewis pairs (FLPs) and their applications are one of the emerging research topics in the field of catalysis. Previous studies have shown that the thermodynamics of this reaction is determined by electronic structures of FLPs and solvents. Herein, we investigated systems consisting of typical FLPs and ionic liquids (ILs), which are well known by their large number of types and excellent solvent effects. The density functional theory (DFT) calculations were performed to study the thermodynamics for H2 activation by both inter- and intra-molecular FLPs, as well as the individual components. The results show that the computed overall Gibbs free energies in ILs are more negative than that computed in toluene. Through the thermodynamics partitioning, we find that ILs favor the H−H cleavage elemental step over the elemental steps of proton attachment, hydride attachment and zwitterionic stabilization. Moreover, the results show that these effects are strongly dependent on the type of FLPs, where intra-molecular FLPs are more affected compared to the inter-molecular FLPs. 相似文献