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111.
Reaction of Ni2+ and SnS as a Way to Form Ni@SnS and Sn2Ni3S2 Nanocrystals: Control of Product Formation and Shape
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Stefan Michael Rommel Dr. Richard Weihrich 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(27):9863-9867
Reductive diffusion of Ni2+ into SnS particles was shown to selectively form Sn2Ni3S2, hybrid, or even core‐shell Ni@SnS, Ni1.523Sn, and Ni3S2, by tuning the reaction conditions at low temperatures. The mechanism of Ni2+ reduction and diffusion into SnS was observed in ethylene glycol, which served both as solvent and reducing agent. Tuning of reaction temperature and duration, morphology of the template SnS, and the application of ethylenediamine as supporting chelating agent, influence the formation of the final products. Their formation was controlled by carefully adjusting redox and equilibrium reactions. The products were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X‐ray spectroscopy analysis (EDX). 相似文献
112.
“Grafting through” polymerization represents copolymerization of free monomers in solution and polymerizable units bound to a substrate. Free polymer chains are formed initially in solution and can incorporate the surface-bound monomers, and thereby, get covalently bonded to the surface during the polymerization process. As more growing chains attach to the surface-bound monomers, an immobilized polymer layer is formed on the surface. We use a combination of computer simulation and experiments to comprehend this process for monomers bound to a flat impenetrable substrate. We concentrate specifically on addressing the effect of spatial density of the surface-bound monomers on the formation of the surface-attached polymers. We employ a lattice-based Monte Carlo model utilizing the bond fluctuation model scheme to provide molecular-level insight into the grafting process. For experimental validation, we create gradients of density of bound methacrylate units on flat silicon wafers using organosilane chemistry and carry out “grafting through” free radical polymerization initiated in bulk. We report that the proximity of the surface-bound polymerizable units promotes the “grafting through” process but prevents more free growing chains to “graft through'' the polymerizable units. The “grafting through” process is self-limiting in nature and does not affect the overall density of the surface-bound polymer layer, except in case of the highest theoretical packing density of surface-bound monomers. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 263–274 相似文献
113.
A graph with at least vertices is said to be distance -extendable if, for any matching of with edges in which the edges lie at distance at least pairwise, there exists a perfect matching of containing . In this paper we prove that every 5-connected triangulation on the projective plane of even order is distance 3 7-extendable and distance 4 -extendable for any . 相似文献
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115.
《Biomedical chromatography : BMC》2018,32(6)
A molecularly imprinted polymer was synthesized and applied as a sorbent in the solid‐phase extraction device. The imprinted polymer was characterized by fourier‐transform infrared spectroscopy and scanning electron microscope. The results revealed that imprinted polymer possess sensitive selectivity and reliable adsorption properties for five NSAIDs. The imprinted polymer was successfully applied to the pre‐concentration for five NSAIDs in different water samples prior to UPLC‐MS/MS. In the early studies, several factors were investigated, including pH adjustment, the kind of elution solvent and the volume of elution solvent. Finally, we found that the pH 5 and an aliquot of 2 mL methanol were suitable for the water samples. The limits of detection and limits of quantitation of five nonsteroidal anti‐inflammatory drugs varied from 0.007 to 0.480 μg L−1 and 0.03 to 1.58 μg L−1, respectively. The spiking recoveries of the target analytes were 50.33‐127.64% at the levels of 0.2 μg L−1, 2 μg L−1 and 5 μg L−1. The precision and accuracy of this method showed a great increase compared with traditional solid‐phase extraction. The developed method was successfully applied to extraction and analysis of NSAIDs in different water samples with satisfactory results which could help us better understand their environmental fate and risk to ecological health. 相似文献
116.
Inside Cover: Lipid Nanotube Tailored Fabrication of Uniquely Shaped Polydopamine Nanofibers as Photothermal Converters (Chem. Eur. J. 13/2016)
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Yu Na Lim Soo Kyung Chae Woongbin Yim Ji‐Yong Park Woojin Yoon Hoseop Yun Eunha Kim Seung Uk Son Hye‐Young Jang 《应用有机金属化学》2019,33(3)
The reaction of [(domppp) Pd (OAc)2] [domppp = 1,3‐bis (di‐o‐methoxyphenylphosphino)propane] and imidazolium‐functionalized carboxylic acids containing various anions (Br?, PF6?, SbF6? and BF4?) resulted in the formation of nano‐sized Pd (II) aggregates under template‐free conditions. The rate of formation of aggregates can be modulated by changing the anion, affecting the rate of polymerization of CO and olefins without fouling. Herein, we describe the analysis of Pd (II) catalysts by dynamic light scattering, atomic force microscopy, X‐ray photoelectron spectroscopy and X‐ray crystallography, and co‐ and terpolymerization results including the catalytic activity, and bulk density and molecular weight of polymers. 相似文献
119.
With the deepening of social information, the panoramic image has drawn a significant interest of viewers and researchers as it can provide a very wide field of view (FoV). Since panoramic images are usually obtained by capturing images with the overlapping regions and then stitching them together, image stitching plays an important role in generating panoramic images. In order to effectively evaluate the quality of stitched images, a novel quality assessment method based on bi-directional matching is proposed for stitched images. Specifically, dense correspondences between the testing and benchmark stitched images are first established by bi-directional SIFT-flow matching. Then, color-aware, geometric-aware and structure-aware features are respectively extracted and fused via support vector regression (SVR) to obtain the final quality score. Experiments on our newly constructed database and ISIQA database demonstrate that the proposed method can achieve comparable performance compared with the conventional blind quality metrics and the quality metrics specially designed for stitched images. 相似文献
120.
如何根据患者的差异化需求,撮合医生与患者双方形成合理有效的医疗服务供需匹配,是医疗服务运作管理中重要的研究问题。本文针对医疗服务中医生与患者的实际需求,提出了一种考虑患者预约行为的匹配决策方法。在该方法中,首先依据患者的预约行为及特征分类;然后,通过计算不同情形下医患双方的差异度,获得了医患双方的满意度矩阵;在此基础上,提出了匹配预约患者与医生的E-HR算法,并进一步构建了匹配剩余患者和医生的多目标优化模型,通过模型求解得到最优匹配结果;最后,通过算例说明了本文提出方法的可行性和实用性。 相似文献