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911.
912.
Yun Zhi Fu Ping Yang Jin Ru Li Long Jiang 《Journal of Dispersion Science and Technology》2013,34(4):633-637
In this article, a new method which not only can separate hydrophobic Au nanoparticles (NPs), but also obtain highly monodisperse NPs is discussed. A self‐made device of two same burettes, one of which was inserted into the other, was used for separating the nanoparticles by washing the reversal micelle. The effects of separation were characterized and analyzed by micrograph of transmission electron microscope (TEM), UV‐vis spectra, quartz crystal microbalance (QCM), and energy dispersive x‐ray analysis (EDX). It has been shown that, the smaller nanoparticles are, the easier they are to stay at the reversal micelle and the narrower the sizes are. This method can be applied to synthesize highly monodisperse Au NPs. 相似文献
913.
Ying‐Hui Wang Li‐Jing Gong Wen‐Yue Dong Ping Lu Zhi‐Hui Kang Tian‐Hao Huang Yu‐Guang Ma Han‐Zhuang Zhang 《Journal of Polymer Science.Polymer Physics》2013,51(12):992-997
The photoexcitation processes of two donor–acceptor‐type copolymers PCFBT with different ratios between the donor and the acceptor ( PCFBT0.5 and PCFBT0.1 ) in the solution system are systematically studied. If the number of the donor is equal to that of the acceptor in one repeat unit (such as PCFBT0.5 ), intrachain charge transfer (ICT) can occur and participate in the relaxation of the excited state after photoexcitation. When the number of donors is much larger than that of acceptors (such as PCFBT0.1 ) in one repeat unit, the ICT character can disappear, and the localized exciton decay process is dominant in the relaxation of the copolymer, which also involves an excitation intensity‐independent vibrational thermal relaxation process at the initial time. The results further the understanding of the basic structure‐property relationship. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013 , 51, 992–996 相似文献
914.
Du‐Qiang Luo Wen‐Liang Zhu Xiao‐Long Yang Shu‐Juan Liang Zhi‐Ran Cao 《Helvetica chimica acta》2010,93(6):1209-1215
Two new daphniphyllum alkaloids named 2‐hydroxyyunnandaphnine D ( 1 ) and methyl 7‐hydroxyhomodaphniphyllate ( 2 ), together with eight known alkaloids, daphnioldhanin D, calyciphylline F, calyciphylline B, deoxycalyciphylline B, daphnicyclidin H, macropodumine C, 9,10‐epoxycalycine A, and yunnandaphnine A, were isolated from the stems and leaves of Daphniphyllum calycinum. Their structures and relative configurations were established on the basis of spectral evidence (including 2D‐NMR) and subsequently confirmed by a single‐crystal X‐ray crystallographic diffraction analysis. 相似文献
915.
Zhi‐Yong Xiao Xia‐Chang Wang Gui‐Ping Zhang Zhong‐Liang Huang Li‐Hong Hu 《Helvetica chimica acta》2010,93(4):803-810
Five new terpenoids, including four eudesmane‐type sesquiterpenoids, 1 – 4 , and one labdane‐type diterpenoid, 6 , together with ten known compounds, were isolated from the roots of Chloranthus spicatus. The structures and their relative configurations were mainly established by 1D‐ and 2D‐NMR spectra, and MS experiments. 相似文献
916.
Guangmei Xia Linghao He Qiaoling Zhao Weihong Chen Rui Song Zhi Ma 《Colloid and polymer science》2012,290(18):1943-1947
Hydrogen bonds exist in many polymer systems and play a large role in the physical and chemical properties. In this study, nylon-6, which consists of repeated amide groups and contains large number of hydrogen bonds, is chosen as an example. Meanwhile, the oxidized unzipped MWCNTs (μCNTs) with oxygenated species such as carboxyl and hydroxyl groups are used as mediator to regulate the crystallization process of nylon-6 thin films. In-site experimental techniques, including Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy, and polarized optical microscopy were utilized to get more direct insights on the crystallization mechanism of nylon-6 and μCNTs systems. 相似文献
917.
Polyaniline doped with camphor sulfonic acid, poly(2,5-dimethoxyaniline) and their copolymers were synthesized by interfacial method. The FT-IR spectra, UV-Vis absorption spectra and X-ray diffraction patterns were used to characterize the molecular structures of the polymers. The morphology of the polymers was studied by using SEM and TEM. Voltammetric study was done to investigate the electrochemical behavior of these polymers. The results show that the polymers were in microscale with the different shapes such as rod, flake and sphere, respectively. All the homopolymers and copolymers had a poor crystallinity. The conductivity of the copolymers of aniline with 2,5-dimethoxyaniline decreased with increase of 2,5-dimethoxy-aniline molar content. 相似文献
918.
919.
Yong‐Kai Deng Zhi‐Hao Yan Di Sun 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(10):1147-1151
An infinite one‐dimensional cadmium metal–organic chain, namely catena‐poly[aquabis(μ3‐2,2′‐{[1,2‐phenylenebis(methylene)]bis(sulfanediyl)}dibenzoato)dicadmium(II)], [Cd2(C22H16O4S2)2(H2O)]n, was synthesized by solvothermal reaction of Cd(NO3)2·4H2O and 2,2′‐{[1,2‐phenylenebis(methylene)]bis(sulfanediyl)}dibenzoic acid (H2L). The CdII centres have six‐coordinate CdS2O4 and CdSO5 geometries. Due to the flexible –CH2–S– arms, the L2− ligand adopts both syn and anti conformations. Four CdII cations are linked by two syn L2− ligands to form a centrosymmetric planar tetranuclear CdII core, which is further extended through bonding to the anti L2− ligands to form a one‐dimensional metal–organic chain. Adjacent one‐dimensional chains are connected by C—H...π interactions and nonclassical C—H...O hydrogen bonds to form the resultant three‐dimensional supramolecular framework. 相似文献
920.
Zhi‐Yong Guo Pan‐Pan Gai Jing Duan Jin‐Xia Zhai Sha‐Sha Zhao Sui Wang Dan‐Yi Wei 《Biomedical chromatography : BMC》2010,24(10):1094-1099
A gas chromatography–mass spectrometry assay was developed and validated for the simultaneous determination of phthalates and adipates in human serum. The phthalates and adipates studied were dimethyl phthalate, diethyl phthalate, dibutyl phthalate, benzylbutyl phthalate, di‐2‐ethylhexyl phthalate, di‐n‐octyl phthalate, diethyl adipate, dibutyl adipate, diisobutyl adipate, bis(2‐butoxyethyl) adipate and di‐2‐ethylhexyl adipate, with diisooctyl phthalate as internal standard. The extraction and cleaning up procedure was carried out with solid‐phase extraction cartridges containing dimethyl butylamine groups, which showed extraction efficiencies over 88% for each analyte and the internal standard. The calibration curves obtained were linear with correlation coefficients greater than 0.98. For all analytes, the assay gave CV% values for intra‐day precision from 4.9 to 13.3% and mean accuracy values from 91.4 to 108.4%, while inter‐day precision was 5.2–13.4% and mean accuracy 91.0–110.2%. The limits of detection for the assay of phthalates and adipates were in the range 0.7–4.5 ng/mL. The method is simple, sensitive and accurate, and allows for simultaneous determination of nanogram levels of phthalates and adipates in human serum. It was successfully applied to an investigation on the level of phthalates and adipates in a non‐occupationally exposed population. 相似文献