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81.
Yulu Li Xiao Luo Tao Ding Xin Lu Kaifeng Wu 《Angewandte Chemie (International ed. in English)》2020,59(34):14292-14295
Lead halide perovskite nanocrystals (NCs) hold strong promise for a variety of light‐harvesting, emitting, and detecting applications, all of which, however, could be complicated by multicarrier Auger recombination. Therefore, complete documentation of the size‐ and composition‐dependent Auger recombination rates of these NCs is highly desirable, as it can guide system design in many applications. Herein we report the synthesis and Auger measurements of monodisperse APbX3 (A=Cs and FA; X=Cl, Br, and I) NCs in an extensive size range (ca. 3–9 nm). The biexciton Auger lifetime of all the NCs scales linearly with the NC volume. The scaling coefficient is virtually independent of the cation but rather depends sensitively on the anion, and is 0.035, 0.085, and 0.142 ps nm?3 for Cl, Br, and I, respectively. In all of these nanocrystals the Auger recombination is much faster than in standard CdSe and PbSe NCs (ca. 1 ps nm?3). 相似文献
82.
WANG Jingping ZHAO Junwei & NIU Jingyang Institute of Molecule Crystal Engineering School of Chemistry Chemical Engineering Henan University Kaifeng China 《中国科学B辑(英文版)》2005,(4)
Polyoxometalate chemistry is a very important re- search field in modern inorganic chemistry. Poly- oxometalates have attracted extensive interest owingto their unique physical-chemical and unusual topo- logical properties as well as their great potential… 相似文献
83.
Sol-gel法制备纳米SnO2气敏材料的研究 总被引:14,自引:2,他引:12
用Sol-gel法制备SnO2纳米粒子,并用XRD、紫外吸收光谱和激光Raman光谱进行了表征和分析。XRD实验证实了所制备的粒子具有较理想的纳料尺寸,其粒径随热退火温度升高而增大;Raman光谱表明低温退火时SnO2纳米材料的氧缺位较大;紫外吸收光谱表明退火温度在300-500℃粒径变化很大,但光的吸收稳定不变,可望利用这些性质,提高SnO2气敏器件的性能。 相似文献
84.
Haikun Yue Dong Li Chenre Wang Xiaofei Li Dezhi Chen Kaifeng Liu Chi Zhou Ruimin Pan 《等离子体物理论文集》2015,55(9):658-663
An Radio‐Frequency (RF) Inductively Coupled Plasma (ICP) ion source test facility has been successfully developed at Huazhong University of Science and Technology (HUST). As part of a study on hydrogen plasma, the influence of three main operation parameters on the RF power necessary to ignite plasma was investigated. At 6 Pa, the RF power necessary to ignite plasma influenced little by the filament heating current from 5 A to 9 A. The RF power necessary to ignite plasma increased rapidly with the operation pressure decreasing from 8 Pa to 4 Pa. The RF power necessary to ignite plasma decreased with the number of coil turns from 6 to 10. During the experiments, plasma was produced with the electron density of the order of 1016m–3 and the electron temperature of around 4 eV. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
85.
86.
Gallium Oxide Nanorods: Novel,Template‐Free Synthesis and High Catalytic Activity in Epoxidation Reactions 下载免费PDF全文
Warunee Lueangchaichaweng Dr. Neil R. Brooks Dr. Sonia Fiorilli Dr. Elena Gobechiya Prof. Kaifeng Lin Li Li Dr. Sonia Parres‐Esclapez Dr. Elsa Javon Prof. Sara Bals Prof. Gustaaf Van Tendeloo Prof. Johan A. Martens Prof. Christine E. A. Kirschhock Prof. Pierre A. Jacobs Prof. Paolo P. Pescarmona 《Angewandte Chemie (International ed. in English)》2014,53(6):1585-1589
Gallium oxide nanorods with unprecedented small dimensions (20–80 nm length and 3–5 nm width) were prepared using a novel, template‐free synthesis method. This nanomaterial is an excellent heterogeneous catalyst for the sustainable epoxidation of alkenes with H2O2, rivaling the industrial benchmark microporous titanosilicate TS‐1 with linear alkenes and being much superior with bulkier substrates. A thorough characterization study elucidated the correlation between the physicochemical properties of the gallium oxide nanorods and their catalytic performance, and underlined the importance of the nanorod morphology for generating a material with high specific surface area and a high number of accessible acid sites. 相似文献
87.
Abstract In this article, we extend the definition of uniformly starlike functions and uni- formly convex functions on the unit disk to the unit ball in C^n, give the discriminant criterions for them, and get some inequalities for them. 相似文献
88.
Influence of octadecyl dihydrogen phosphate on the formation of active super-fine calcium carbonate 总被引:4,自引:0,他引:4
Sheng Y Zhou B Zhao J Tao N Yu K Tian Y Wang Z 《Journal of colloid and interface science》2004,272(2):326-329
A carbonation process for the synthesis of active super-fine calcium carbonate particles from Ca(OH)(2) slurry at room temperature using a CO(2)-N(2) gas mixture was investigated. Industrial octadecyl dihydrogen phosphate (A) was added as a size-controlling additive and modifier in different reaction periods according to the pH of the medium. Analysis of the reaction products led to the conclusion that the addition of A in the digestion period could inhibit the crystal growth of calcium carbonate, while the addition of A at pH 7 of the medium could modify the surface character of the calcium carbonate particle, which was found to exhibit hydrophobic properties. From transmission electron microscopy (TEM), the hydrophobic property was attributed to the deposition of calcium alkyl phosphates, produced in the reaction mixture, onto the surface of calcium carbonate particle. IR spectra and TGA analysis of the obtained products indicated that A was bound onto the crystalline CaCO(3). 相似文献
89.
Xuefeng Yan Kaifeng Gan Baozhu Tian Jinlong Zhang Lingzhi Wang Deli Lu 《Research on Chemical Intermediates》2018,44(1):1-11
A yolk–shell-structured sphere composed of a superparamagnetic Fe3O4 core and a carbon shell (Fe3O4@HCS) was etched from Fe3O4@SiO2@carbon by NaOH, which was synthesized through the layer-by-layer coating of Fe3O4. This yolk–shell composite has a shell thickness of ca. 27 nm and a high specific surface area of 213.2 m2 g?1. Its performance for the magnetic removal of tetracycline hydrochloride from water was systematically examined. A high equilibrium adsorption capacity of ca. 49.0 mg g?1 was determined. Moreover, the adsorbent can be regenerated within 10 min through a photo-Fenton reaction. A stable adsorption capacity of 44.3 mg g?1 with a fluctuation <10% is preserved after 5 consecutive adsorption–degradation cycles, demonstrating its promising application potential in the decontamination of sewage water polluted by antibiotics. 相似文献