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871.
Yang Song Lingwei Li Yuanqing Chen Fengzhu Li Wenwen Qu Huimin Wu Aditya S. Yerramilli T. L. Alford Haiwu Zheng 《Journal of Sol-Gel Science and Technology》2018,86(2):285-292
In this paper, we reported the design and preparation of a double-layer antireflective (AR) coating, which possessed relatively high transmittance at 351, 527, and 1053?nm. The refractive indices and film thicknesses of the under layer and upper layer of the simulated AR coating were determined as 1.27, 95?nm and 1.18, 106?nm, respectively. The under layer of the double-layer coating dip-coated from a mixture of base-catalyzed and acid-catalyzed silica sols had a refractive index of 1.27. The upper layer fabricated by the deposition of methylated silica nanoparticles by simply adding methyltriethoxysilane into the base-catalyzed silica sols possessed a refractive index of 1.18. The hydrophobicity of coatings could be dramatically improved with the water contact angle increasing from 23.4° to 150.0°, and the refractive indices of the pure base-catalyzed silica coatings were easily decreased from 1.20 to 1.12 through the surface treatment of silica nanoparticles. Thus, we have successfully prepared a double-layer AR coating, which had a high transmittance of 99.8%, 96.1%, and 99.7% at 351, 527, and 1053?nm, respectively. 相似文献
872.
Haohua Chen Lei Zhu Kangbao Zhong Xiaoyu Yue Ling-Bo Qu Ruopeng Bai Yu Lan 《中国化学快报》2018,29(8):1237-1241
A theoretical investigation of the mechanism and origin of enantioselectivity for phosphoric acid-catalyzed asymmetric conjugate addition of indolizines to α,β-unsaturated ketones. 相似文献
873.
Zhijun Luo Lingling Qu Jianzhong Jia Jing Wang Suying Jiang Zhiren Wu Xiangyang Wu 《中国化学快报》2018,29(3):547-550
TiO2/EDTA-rich carbon composites exhibits excellent photoreduction of Cr(VI) activity via ligand-to-metal charge transfer process. 相似文献
874.
Total Syntheses of Crinipellins Enabled by Cobalt‐Mediated and Palladium‐Catalyzed Intramolecular Pauson–Khand Reactions
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Zhihui Huang Dr. Jun Huang Yongzheng Qu Weibin Zhang Prof. Dr. Jianxian Gong Prof. Dr. Zhen Yang 《Angewandte Chemie (International ed. in English)》2018,57(28):8744-8748
Efficient total syntheses of the naturally occurring, potent antibiotic compounds (?)‐crinipellin A and (?)‐crinipellin B are described. The key advanced intermediate, a fully functionalized tetraquinane core, was constructed by a novel thiourea/palladium‐catalyzed Pauson–Khand reaction. This intermediate can serve as a common intermediate for the collective total synthesis of other members of the crinipellin family. 相似文献
875.
Dr. Hanjun Sun Ya Zhou Prof. Jinsong Ren Prof. Xiaogang Qu 《Angewandte Chemie (International ed. in English)》2018,57(30):9224-9237
Nanozymes have advantages over natural enzymes, such as facile production on large scale, long storage time, low costs, and high stability in harsh environments. Carbon nanomaterials (CNMs), including fullerenes, carbon nanotubes, graphene, carbon quantum dots, and graphene quantum dots, have become a star family in materials science. As a new class of nanozymes, the catalytic activity of CNMs and their hybrids has been extensively reported. In this Minireview, recent progress of CNMs based artificial enzymes, focusing on those with peroxidase‐like activity, has been summarized. The enzymatic properties, catalytic mechanisms, and novel applications of CNM nanozymes in sensing, therapy, and environmental engineering are discussed in detail. Additionally, we also highlight the remaining challenges and unsolved problems. With the fast development of bionanotechnology, the unique enzymatic properties and advantages of CNM nanozymes have received much attention and will continue to be an active and challenging field for the years to come. 相似文献
876.
Thermo‐Driven Controllable Emulsion Separation by a Polymer‐Decorated Membrane with Switchable Wettability
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Dr. Weifeng Zhang Dr. Na Liu Dr. Qingdong Zhang Dr. Ruixiang Qu Dr. Yanan Liu Dr. Xiangyu Li Prof. Yen Wei Prof. Lin Feng Prof. Lei Jiang 《Angewandte Chemie (International ed. in English)》2018,57(20):5740-5745
A thermoresponsive Poly(N‐isopropylacrylamide) (PNIPAAm)‐modified nylon membrane was fabricated via hydrothermal route. Combining rough structure, proper pore size, and thermoresponsive wettability, the membrane can separate at least 16 types of stabilized oil‐in‐water and water‐in‐oil emulsions at different temperatures. Below the LCST (ca. 25 °C), the material exhibits hydrophilicity and underwater superoleophobicity, which can be used for the separation of various kinds of oil‐in‐water emulsions. Above the LCST (ca. 45 °C), the membrane shows the opposite property with high hydrophobicity and superoleophilicity, and it can then separate stabilized water‐in‐oil emulsions. The material exhibits excellent recyclability and high separation efficiency for various kinds of emulsions and the hydrothermal method is facile and low‐cost. The membrane shows good potential in real situations such as on‐demand oil‐spill cleanup, industrial wastewater treatment, remote operation of oil/water emulsion separation units, and fuel purification. 相似文献
877.
One‐step Synthesis and Enhanced Thermoelectric Properties of Polymer–Quantum Dot Composite Films
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Wei Shi Dr. Sanyin Qu Hongyi Chen Yanling Chen Prof. Qin Yao Prof. Lidong Chen 《Angewandte Chemie (International ed. in English)》2018,57(27):8037-8042
Conventional syntheses of polymer–inorganic composite thermoelectric materials suffer major problems such as inhomogeneity, large particle size, and oxidation that result in ineffective loading. Now a one‐step synthesis can be used to fabricate high‐quality small‐sized anions codoped poly(3,4‐ethylenedioxythiophene):dodecylbenzenesulfonate/Cl‐tellurium (PEDOT:DBSA/Cl‐Te) composite films using a series of novel TeIV‐based oxidants. The synchronized production of PEDOT and Te results in thick and homogeneous films containing evenly distributed and well‐protected Te quantum dots. Owing to the heavily doped crystalline polymer matrix as well as the <5 nm unoxidized Te quantum dot loading, at low Te concentrations as 2.1–5.8 wt %, the films exhibits high power factors of about 100 μW m?1 K?2, which is 50 % higher compared to a pure PEDOT:DBSA film. 相似文献
878.
Gu Hua Lin Kaiwen Liu Ximei Jian Nannan Qu Kai Xu Jingkun 《Journal of Solid State Electrochemistry》2018,22(2):599-611
Journal of Solid State Electrochemistry - A series of poly(selenophene-co-3-methylthiophene) films were synthesized by electrochemical copolymerization of selenophene and 3-methylthiophene under... 相似文献
879.
Highly Sensitive Silver Nanorod Arrays for Rapid Surface Enhanced Raman Scattering Detection of Acetamiprid Pesticides
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Cai-qin Han Yue Yao Wen Wang Liu-qian Tao Wen-xin Zhang Whitney Marvella Ingram Kang-zhen Tian Ying Liu Ai-xia Lu Ying Wu Chang-chun Yan Lu-Lu Qu Hai-tao Li 《化学物理学报(中文版)》2018,31(2):152-158
The determination of pesticide residue on agricultural products is increasingly important.Exposure to pesticides can cause severe acute reactions in humans, including aplastic anemia and leukemia.In this work, we developed a rapid and sensitive method to detect acetamiprid pesticide residue based on surface-enhanced Raman scattering.Silver nanorod (AgNR) arrays were fabricated by oblique angle deposition technology and were used as SERS substrates.Prior to detection, the AgNR arrays were cleaned with nitric acid solution or a mixture of methanol and acetone.Compared to the unwashed AgNR arrays, the AgNR arrays washed with methanol and acetone shows a signal enhancement 1000 times greater than the unwashed AgNR array due to the effective removal of the impurities on its surface.The limit of detection of acetamiprid was determined to be 0.05 mg/L.In addition, the molecular structure of acetamiprid was simulated and the corresponding vibration modes of the characteristic bands of acetamiprid were calculated by density function theory.To demonstrate its practical application, the AgNRs array substrates were applied successfully to the rapid identification of acetamiprid residue on a cucumber's surface.These results confirmed possibility of utilizing the AgNRs SERS substrates as a new method for highly sensitive pesticide residue detection. 相似文献
880.
Insights into the N‐Heterocyclic Carbene (NHC)‐Catalyzed Intramolecular Cyclization of Aldimines: General Mechanism and Role of Catalyst
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Xue Li Dr. Mingsheng Tang Dr. Yanyan Wang Dr. Yang Wang Dr. Zhongjun Li Dr. Ling‐Bo Qu Dr. Donghui Wei 《化学:亚洲杂志》2018,13(13):1710-1718
One of the most challenging questions in the Lewis base organocatalyst field is how to predict the most electrophilic carbon for the complexation of N‐heterocyclic carbene (NHC) and reactant. This study provides a valuable case for this issue. Multiple mechanisms (A, B, C, D, and E) for the intramolecular cyclization of aldimine catalyzed by NHC were investigated by using density functional theory (DFT). The computed results reveal that the NHC energetically prefers attacking the iminyl carbon (AIC mode, which is associated with mechanisms A and C) rather than attacking the olefin carbon (AOC mode, which is associated with mechanisms B and D) or attacking the carbonyl carbon (ACC mode, which is associated with mechanism E) of aldimine. The calculated results based on the different reaction models indicate that mechanism A (AIC mode), which is associated with the formation of the aza‐Breslow intermediate, is the most favorable pathway. For mechanism A, there are five steps: (1) nucleophilic addition of NHC to the iminyl carbon of aldimine; (2) [1,2]‐proton transfer to form an aza‐Breslow intermediate; (3) intramolecular cyclization; (4) the other [1,2]‐proton transfer; and (5) regeneration of NHC. The analyses of reactivity indexes have been applied to explain the chemoselectivity, and the general principles regarding the possible mechanisms would be useful for the rational design of NHC‐catalyzed chemoselective reactions. 相似文献