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111.
Chao Sun Yaquan Wang Zhao Wang Hengbao Chen Xiao Wang Hongyao Li Liying Sun Chunyang Fan Cui Wang Xu Zhang 《Comptes Rendus Chimie》2018,21(1):61-70
A series of hierarchical ZnSAPO-34 zeolites were synthesized by treatment with different concentrations of tetraethylammonium hydroxide (TEAOH) solutions. The synthesized samples were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), inductively coupled plasma optical emission spectroscopy (ICP-OES), temperature-programmed desorption, Fourier transform infrared, and N2 adsorption and desorption techniques and studied as catalysts for the methanol to olefin reaction. The characterization results reveal that the crystal size of ZnSAPO-34 is greatly reduced compared with the parent SAPO-34 owing to the incorporation of Zn. Hierarchical pores with the sizes up to the macropore level in the ZnSAPO-34 zeolites are created with the post-treatment of TEAOH. The acid strength and the amounts of the strong acid of the hierarchical ZnSAPO-34 zeolites decrease after the post-treatment because TEAOH preferentially extracts Si species from the zeolite. The hierarchical ZnSAPO-34 zeolites exhibit superior catalytic performance than that of the parent ZnSAPO-34, owing to the shortened transportation distance and the appropriate acidity of the treated samples. 相似文献
112.
Liying Xu Wenyan Zhao Ruimiao Chang Guangbin Zhang Hongfen Zhang Anjia Chen 《Journal of the Iranian Chemical Society》2018,15(7):1477-1483
The purpose of this study was to develop a novel, simple and precise ligand-exchange capillary electrophoresis method to separate the diastereomer pairs of four major cinchona alkaloids (quinine/quinidine and cinchonine/cinchonidine). The l-lysine and copper(II) were chosen as the ligand and the central ion, respectively. Optimal separation conditions of four alkaloids were 4.0 mM l-lys, 2.0 mM copper(II) and 30 mM NH4Ac at pH 8.9 and a applied voltage of 15 kV . Meanwhile, the first-order derivative electropherogram was used for resolving the overlapping peaks of cinchonidine and quinidine. Under the optimum condition, good linearities were obtained with correlation coefficients from 0.9908 to 0.9935. The limits of detection (LOD, S/N?=?3) and the limits of quantitation (LOQ, S/N?=?10) ranged from 0.24 to 0.41 μg/mL and from 0.73 to 1.35 μg/mL, respectively. The recoveries ranged between 95.38 and 106.03%. The proposed ligand-exchange capillary electrophoresis method was suitable for the quantitative determination of four cinchona alkaloids in some preparations such as Compound Quinine Injection, Tonic Water and Klorane quinine and Vitamin B complex Shampoo. 相似文献
113.
Hou?Guangjin Wang?Liying Lu?Xiaoming Zheng?Anmin Deng?Feng Ye?ChaohuiEmail author 《中国科学B辑(英文版)》2004,47(3):214-221
13C 2D-PASS spectra of two new cis-dioxo catecholatomolybdenum complexes (NH2CH2NH2CHCH2)2(H+)3[MovO
2(C6H4O2)2] and (NH2CH2CH2CH2NH2)2(H+)3[Mo(v)O2 (C2H2O2)2] have been obtained by solid-state nuclear magnetic resonance (NMR), in which the spinning sidebands were well-separated.
The principal components of the 13C shielding tensors were extracted by theoretically fitting the intensities of 13C spinning sidebands. The effects of counter cations on 13C chemical shift isotropy and shielding tensor of cis-dioxo catecholatomolybdenum complex anion [Mo (v)O2(C6H4O2)2]3− were studied, comparing the 13C CSA of those carbon sites in complex anions with that of the counter cations. Based on the known structure of the molybdenum
complex crystal, theoretical values of 13C shielding tensors were calculated by the ainitio GIAO method, in comparison with the experimental results. 相似文献
114.
郭丽英 《广东微量元素科学》2006,13(4):69-70
基层图书馆应充分利用科技创新的有利时机,使用有限的图书资源和现有阅览条件,从提高馆员专业素质,科学管理,了解读者,增加藏书量等方面考虑,发挥图书服务读者、服务社区的作用。 相似文献
115.
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117.
Dr. Hang He Dr. Xijia Yang Dr. Liying Wang Dr. Xueyu Zhang Dr. Xuesong Li Dr. Wei Lü 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(71):17212-17221
Fiber supercapacitors are promising energy storage devices for potential application in wearable and miniaturized portable electronics, which currently suffer from difficulties in achieving high capacitance and energy density synchronously owing to the limited specific surface area of the electrode materials and material incompatibility between the two electrodes. Herein, a strategy is developed for the manufacture of coaxial asymmetric fiber supercapacitors by wrapping a core of PVA-KOH gel electrolyte-coated Ni(OH)2@NiCo2O4/CNT fibers with MoS2@Fe2O3/CNT paper. The as-prepared coaxial fiber asymmetric supercapacitors exhibit a specific capacitance of 373 mF cm−2 (at a current density of 2 mA cm−2) and energy density of 0.13 mW h cm−2 (at a power density of 3.2 mW cm−2), and also show good rate capability, long cycle life, and excellent flexibility. This work provides the possibility for the practical application of fiber supercapacitors in wearable and portable energy storage equipment. 相似文献
118.
The second order hyperpolarizability of cis azobenzene isomer (γc) was obtained by measuring the third harmonic generation (THG) variation of an azobenzene doped polymer film when the film was optically pumped to create a large amount of cis isomers via photoisomerization. A steady state theory was developed to treat the THG intensity variation by considering the optical pump induced redistribution and reorientation of azobenzene in the polymer film and the contribution of cis isomer to the THG signal. The ratio of γ of cis and trans molecule, (γc/γt), was found to be 0.51. After the γt was obtained from the time-resolved optical Kerr effect (OKE) measurement, γc was deduced to be 5.6 × 10−33 esu. The result shows that the optical nonlinearity of cis isomer is clearly not negligible. 相似文献
119.
Shuaishuai Fan Baolin Li Yurou Tian Wei Feng Liying Niu 《Journal of separation science》2022,45(5):1006-1019
120.
Thomassen proved that every ‐connected graph G contains an induced cycle C such that is k‐connected, establishing a conjecture of Lovász. In general, one could ask the following question: For any positive integers , does there exist a smallest positive integer such that for any ‐connected graph G, any with , and any , there is an induced cycle C in such that and is l‐connected? The case when is a well‐known conjecture of Lovász that is still open for . In this article, we prove and . We also consider a weaker version: For any positive integers , is there a smallest positive integer such that for every ‐connected graph G and any with , there is an induced cycle C in such that is l‐connected? The case when was studied by Thomassen. We prove and . 相似文献