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排序方式: 共有249条查询结果,搜索用时 140 毫秒
71.
Russian Journal of Applied Chemistry - A dumbbell-like Al doped ZnO(AZO) microstructure was successfully synthesized via a facile, controllable and one-pot hydrothermal method. The samples were... 相似文献
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Ziyun Wei Xiaomin Yu Yu Zhang Yanan Wang Haotian Zhang Sijie Wang Zan Zhang Wenwen Sui Xin Zhang Fei Han 《Journal of separation science》2022,45(2):477-491
Alcoholic liver disease is currently the most clinically concerning liver disease, which occurs from chronic alcohol abuse. Flos Puerariae and Semen Hoveniae have been used to treat alcohol drinking excessively for thousands of years in China. In this study, the ethanol extract of the medicine pair was qualitatively and quantitatively analyzed by high-performance liquid chromatography and Fourier transform ion cyclotron resonance mass spectrometry. First, the high-performance liquid chromatography fingerprint was established to obtain the overall chromatographic data of its chemical constituents. Next, high-performance liquid chromatography-mass spectrometry was applied to identify its chemical constituents. Then, the characteristic constituents were simultaneously quantified by high-performance liquid chromatography. In addition, the chemical constituents that were absorbed into rat plasma were identified by high-performance liquid chromatography-mass spectrometry. As a result, a total of 48 chemical constituents in the medicine pair were detected and identified in vitro. Meanwhile, the content of seven representative constituents, including dihydromyricetin, glycitin, genistin, tectoridin, glycitein, genistein, and tectorigenin were simultaneously determined. Furthermore, a total of 19 chemical constituents were detected in rat plasma after oral administration. In short, the chemical constituents of the medicine pair were initially investigated in this study, which will lay the foundation for the discovery of its pharmacodynamic substances in further works. 相似文献
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Tao Hu Hao Fu Zan Zheng Ning Ma Piyi Du 《Applied Physics A: Materials Science & Processing》2014,117(3):1171-1177
(100) Oriented Pb x Sr1?x TiO3 (PSTO) thin films are prepared on indium tin oxide (ITO)/glass substrates by sol–gel technique while inserting doped PbTiO3 (PTO)-inducing layer in between. The effect of tensile stress in PSTO on tunability and (100) orientation of the thin films was investigated using X-ray diffraction, scanning electron microscopy, transmission electron microscope, and atomic force microscope, respectively. Results show that PSTO thin film deposited on doped PTO has (100) oriented structure while it is randomly oriented when deposited directly on the ITO/glass substrate. Lattice mismatch between PSTO and PTO appears, in which the in-plane lattice constant c is 0.3922–0.3924 nm in the former and 4.02–4.07 nm in the latter, respectively, contributing tensile stress in the PSTO due to different lattice constants between them. The stress in the PSTO thin film is 3.04, 3.15, 3.59 and 4.47 GPa when the doped PTOs are Fe–PTO, Tb–PTO, Co–PTO and Zn–PTO, respectively. The orientation degrees of PSTO thin films are from 89.63, 90.31, 91.92 to 93.29 % with increasing stress of PSTO on Fe–PTO, Tb–PTO, Co–PTO and Zn–PTO, respectively. Tunabilities of the well-oriented PSTO thin films increase in ascending order of 63 < 65 < 69 < 73 % when induced by oriented PTO layers of Fe–PTO, Tb–PTO, Co–PTO and Zn–PTO, respectively, which is in accordance with the degree of (100) orientation appearing in the thin films. The high tunability appears in the PSTO thin film while high (100) orientation is derived from the tensile stress. It is much higher than that of randomly oriented PSTO thin film. 相似文献
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The branching generation during the free radical copolymerization of chain transfer monomer p-vinyl benzene sulfonyl chloride (VBSC) with styrene was investigated by a simple mathematic model. Chain transfer constant of VBSC was determined to be around 0.3 by fitting the 1H-NMR monitored experimental results with a mathematic model. According to the theoretical analysis, the obtained poly(VBSC) and its copolymers were substantiated to have a grafting-like main chain with residual pendent sulfonyl chloride groups after consuming most of the vinyl groups. The copolymerization results of VBSC with styrene at varied feed ratios demonstrated that conversion of sulfonyl chloride groups was lower than that of the monomer, which was in agreement with the theoretical results. The glass transition temperature, number average molecular weight and distribution of those obtained polymers were primarily investigated. Comparing with other chain transfer monomers, VBSC has a chain transfer constant much closer to unity therefore a more branched polymer is expected. Additionally, the branched polystyrene with residual sulfonyl chloride groups is hopefully to be further used as ATRP macroinitiators or reactive intermediates to synthesize functional polymers with complex structure. 相似文献
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TiO2 nanocrystals modified by ethoxy groups were prepared by a facile nonhydrolytic solvothermal method and characterized by XRD, TEM, TG-DTA and XPS, which showed an enhanced visible-light photocatalytic activity on the degradation of Rhodamine B compared with TiO2 modified by benzyloxy groups and the “naked” TiO2. The adsorption and degradation pathway of Rhodamine B on TiO2 modified by ethoxy groups were also investigated. The zeta-potential (ζ) results showed that the TiO2 modified by ethoxy groups had high negative surface charge, which incited the positive -N(Et)2 group of RhB absorbing on the TiO2 surface and preferably led the N-dealkylation pathway under visible light irradiation. 相似文献
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蒸发冷却模式以及微换热器,是最具有潜力的冷却高热流密度电子器件的方法之一。总结和研究微尺度蒸发冷凝相变机理,是本文研究目的。我们在参阅大量文献和提取大量精确数据的基础上,发现了新的区分常规通道与微通道的临界准则Bo×Re1^0.5=200;在此基础上,我们归纳出了新的预测微通道压降、传热系数和临界热流量的关联式,与以前... 相似文献
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We have demonstrated a facile approach for the low‐temperature synthesis of crystalline inorganic/metallic nanocrystal‐halloysite composite nanotubes by employing the bulk controlled synthesis of inorganic/metallic nanocrystals on halloysite nanotubes. The halloysite clay nanotubes can adsorb the target precursor and induce inorganic/metallic nanocrystals to grow in situ. The crystalline phase and morphology of the composite clay nanotubes is tunable. By simply tuning the acidity of the titania sol, the crystalline titania‐clay nanotubes with tunable crystalline phases of anatase, a mixture of anatase and rutile or rutile are achieved. The approach is general and has been extended to synthesize the representative perovskite oxide (barium and strontium titanate)‐halloysite composite nanotubes. Metallic nickel nanocrystal can also be grown on the surface of halloysite nanotubes at low temperature. The traditional thermal treatment for crystallite transformation is not required, thus intact contour of halloysite nanotubes and the crystallinity structure of halloysite nanotubes can be guaranteed. The combined properties from inorganic/metallic nanocrystal (high refractive index, high dielectric constant and catalytic ability) and the halloysite clay nanotubes are promising for applications such as photonic crystals, high‐k‐gate dielectrics, photocatalysis and purification. 相似文献