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排序方式: 共有162条查询结果,搜索用时 15 毫秒
11.
Yincai Xu Dr. Chenglong Li Dr. Zhiqiang Li Qingyang Wang Xinliang Cai Dr. Jinbei Wei Prof. Yue Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(40):17595-17599
The design and synthesis of organic materials with a narrow emission band in the longer wavelength region beyond 510 nm remain a great challenge. For constructing narrowband green emitters, we propose a unique molecular design strategy based on frontier molecular orbital engineering (FMOE), which can integrate the advantages of a twisted donor–acceptor (D-A) structure and a multiple resonance (MR) delayed fluorescence skeleton. Attaching an auxiliary donor to a MR skeleton leads to a novel molecule with twisted D-A and MR structure characteristics. Importantly, a remarkable red-shift of the emission maximum and a narrowband spectrum are achieved simultaneously. The target molecule has been employed as an emitter to fabricate green organic light-emitting diodes (OLEDs) with Commission Internationale de L'Eclairage (CIE) coordinates of (0.23, 0.69) and a maximum external quantum efficiency (EQE) of 27.0 %. 相似文献
12.
Chenglong Sun Jiuming He Hongbo Wu Xiaowei Song Jiangshuo Li Luojiao Huang Xiaoyu Xu Manjiangcuo Wang Ruiping Zhang Zeper Abliz 《中国化学快报》2018,29(8):1284-1286
A rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC–MS/MS) method was developed and fully validated for determination of arformoterol in rat plasma, lung and trachea tissues. 相似文献
13.
Zhixia Zhuang Chenglong Yang Xioaru Wang Pengyuan Yang Benli Huang 《Fresenius' Journal of Analytical Chemistry》1996,355(3-4):277-280
Palladium salts can be used as a coprecipitation carrier for the preconcentration of trace elements from natural water prior to their measurement by atomic spectrometry (AAS). The palladium is subsequently reduced by the introduction of hydrogen gas into the sample solution. The procedure is applied to the determination of Cu, Pb and Cd in seawater (enrichment factor 50) and synthetic water samples. Operating conditions have been optimized for the analysis of real samples. With the technique established an enrichment factor (500 fold) is feasible in synthetic samples. The recoveries of Cu, Cd and Pb from seawater are 95, 103 and 100%, respectively. This simple and rapid method can be applied in a wide pH-range and with complex matrices. 相似文献
14.
Chenglong Yu a b Xin Hao a Hongtao Jiang a Lili Wang a a School of Materials Science Engineering Shaanxi University of Science & Technology Xi’an China b Research Laboratory of Hydrothermal Chemistry Faculty of Science Kochi University Kochi Japan 《中国颗粒学报》2011,9(1)
Fe 3 O 4 nano-whiskers were synthesized via ultrasonic-aided reduction of FeCl 2 ·4H 2 O with N 2 H 4 ·H 2 O in concentrated NaOH solution. Phase identification and morphology observation were conducted by X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM). Face scanning energy dispersive spectrum (face scanning EDS) and two-dimensional fast Fourier transform (2DFFT) for element distribution were carried out for confirming compos... 相似文献
15.
Synthesis of Discrete Alkyl‐Silica Hybrid Nanowires and Their Assembly into Nanostructured Superhydrophobic Membranes 下载免费PDF全文
Dr. Deliang Yi Chenglong Xu Ruidie Tang Assoc. Prof. Xuehua Zhang Prof. Frank Caruso Prof. Yajun Wang 《Angewandte Chemie (International ed. in English)》2016,55(29):8375-8380
We report the synthesis of highly flexible and mechanically robust hybrid silica nanowires (NWs) which can be used as novel building blocks to construct superhydrophobic functional materials with three‐dimensional macroporous networks. The hybrid silica NWs, with an average diameter of 80 nm and tunable length of up to 12 μm, are prepared by anisotropic deposition of the hydrolyzed tetraethylorthosilicate in water/n‐pentanol emulsions. A mechanistic investigation reveals that the trimethoxy(octadecyl)silane introduced to the water‐oil interface in the synthesis plays key roles in stabilizing the water droplets to sub‐100 nm and also growing a layer of octadecyl groups on the NW surface. This work opens a solution‐based route for the one‐pot preparation of monodisperse, hydrophobic silica NWs and represents an important step toward the bottom‐up construction of 3D superhydrophobic materials and macroporous membranes. 相似文献
16.
发展了一条1,2,6,7-四氢-8H-茚并[5,4-b]呋喃-8-酮的新合成方法,以价廉、易得的对溴苯酚为原料,在无水碳酸钾作用下与2-溴乙醛缩二乙醇缩合后用多聚磷酸(PPA)环合得5-溴苯并呋喃,该中间体与丙烯酸甲酯在Pd(OAc)2催化下,经Heck偶合反应得3-(苯并呋喃-5-基)丙酸甲酯,在氢氧化钠水溶液中经Raney Ni催化氢化和水解一锅反应得3-(2,3-二氢苯并呋喃-5-基)丙酸,再经二溴代、Friedel-Crafts酰化反应和氢解脱溴,得1,2,6,7-四氢-8H-茚并[5,4-b]呋喃-8-酮,7步反应总收率49.9%.该方法原料易得、反应条件温和、操作简便、产物分离纯化容易,收率良好,适合大规模制备1,2,6,7-四氢-8H-茚并[5,4-b]呋喃-8-酮. 相似文献
17.
Present docking methodologies simulate only one single ligand at a time during docking process. In reality, the molecular recognition process always involves multiple molecular species. Typical protein–ligand interactions are, for example, substrate and cofactor in catalytic cycle; metal ion coordination together with ligand(s); and ligand binding with water molecules. To simulate the real molecular binding processes, we propose a novel multiple ligand simultaneous docking (MLSD) strategy, which can deal with all the above processes, vastly improving docking sampling and binding free energy scoring. The work also compares two search strategies: Lamarckian genetic algorithm and particle swarm optimization, which have respective advantages depending on the specific systems. The methodology proves robust through systematic testing against several diverse model systems: E. coli purine nucleoside phosphorylase (PNP) complex with two substrates, SHP2NSH2 complex with two peptides and Bcl‐xL complex with ABT‐737 fragments. In all cases, the final correct docking poses and relative binding free energies were obtained. In PNP case, the simulations also capture the binding intermediates and reveal the binding dynamics during the recognition processes, which are consistent with the proposed enzymatic mechanism. In the other two cases, conventional single‐ligand docking fails due to energetic and dynamic coupling among ligands, whereas MLSD results in the correct binding modes. These three cases also represent potential applications in the areas of exploring enzymatic mechanism, interpreting noisy X‐ray crystallographic maps, and aiding fragment‐based drug design, respectively. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010 相似文献
18.
通过Hypercarb色谱柱分离,建立了四极杆静电场轨道阱高分辨质谱平行反应监测(PRM)模式检测聚丙烯酰胺(PAM)中单体残留量的方法。PAM经水稀释,高速搅拌溶解均匀,过0.22μm水相滤膜后,直接用高分辨质谱Q Exactive采集数据。以Hypercarb色谱柱为分析柱,水和甲醇为流动相,柱温为20℃,采用PRM模式,提取目标化合物及其二级子离子的精确质量数,并对二级特征碎片进行同位素匹配,推测碎裂规律,以强化定性效果。结果表明:在2~50μg/L范围内线性关系良好(相关系数为0.999 8),方法检出限(LOD)可达到1.5μg/kg,满足食品级PAM的检测要求。通过加标验证,回收率为101.3%~107.1%,相对标准偏差为3.1%~4.1%。实际样品验证结果表明,PAM中丙烯酰胺(AM)单体的残留质量分数范围为0~0.43%,存在一定的安全风险。该方法简单、准确、高效,可作为快检和确证检测技术广泛使用。 相似文献
19.
20.
Yawei Jia Pengfei Li Kanglei Liu Chenglong Li Meiyan Liu Jiaqi Di Nan Wang Xiaodong Yin Niu Zhang Pangkuan Chen 《Chemical science》2022,13(39):11672
π-Conjugated macrocycles involving electron-deficient boron species have received increasing attention due to their intriguing tunable optoelectronic properties. However, most of the reported B(sp2)-doped macrocycles are difficult to modify due to the synthetic challenge, which limits their further applications. Motivated by the research of non-strained hexameric bora- and aza-cyclophanes, we describe a new class of analogues MC-BN5 and MC-ABN5 that contain charge-reversed triarylborane (Ar3B) units and oligomeric triarylamines (Ar3N) in the cyclics. As predicted by DFT computations, the unique orientation of the donor–acceptor systems leads to an increased dipole moment compared with highly symmetric macrocycles (M1, M2 and M3), which was experimentally represented by a significant solvatochromic effect with large Stokes shifts up to 12 318 cm−1. Such a ring-structured design also allows the easy peripheral modification of aza-boracyclophanes with tetraphenylethenyl (TPE) groups, giving rise to a change in the luminescence mechanism from aggregation-caused quenching (ACQ) in MC-BN5 to aggregation-induced emission (AIE) in MC-ABN5. The open-shell characteristics have been chemically enabled and were characterized by UV-Vis-NIR spectroscopy and electron paramagnetic resonance (EPR) for MC-BN5. The present study not only showed new electronic properties, but also could expand the research of B/N doped macrocycles into the future scope of supramolecular chemistry, as demonstrated in the accessible functionalization of ring systems.We have achieved the synthesis of new B/N doped macrocycles by stitching oligoarylamine pentamers using arylborane acceptor segments. They exhibit open-shell radical species and AIE under ambient conditions. 相似文献