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81.
Dr. Hongjing Wang Shiqian Jiao Songliang Liu Hugang Zhang Dr. You Xu Prof. Xiaonian Li Dr. Ziqiang Wang Prof. Liang Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(58):14472-14477
The optimization of structure and composition is essential to improve the performance of catalysts. Herein, mesoporous nanoparticles assembled PdNi/Ni nanotubes (mPdNi/Ni NTs) are successfully fabricated using nickel nanowires as sacrificial template. The combination of nanotubular structure with mesoporous nanoparticle morphology can provide facilitated transfer channels and sufficient active sites, allowing the full contact and reaction between catalysts and reactants. Therefore, the synthesized mPdNi/Ni NTs exhibite superior ethanol oxidation performance to mesoporous Pd nanotubes and commercial Pd black. This study proposes a rational strategy for the development of nanoparticle assembled nanotubes with surface mesoporous morphology, which can greatly improve catalytic performance in various electrocatalytic fields. 相似文献
82.
In this paper, we construct a new class of finite groups whose common divisor graphs are complete graphs, while there is no prime dividing all the nontrivial degrees. 相似文献
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Shu-jie Miao Yun-fa Qiao Meng-yang You Fu-tao Zhang 《Journal of Thermal Analysis and Calorimetry》2016,123(3):2045-2051
Long-term continuous cropping affects the biochemical quality of soil organic matter (SOM), but whether the effects are relevant with their thermal stability is less clear. In northeast China, long-term continuous cropping occurred frequently owing to higher yield and economic interest requirement. To verify the thermal stability properties of SOM affected by the long-term continuous cropping, the study focused on 23-yr continuous cultivated maize and soybean plots, where the effect of cropping is likely to be detected. Bulk soils sampled in 1991 and 2014 were studied by thermogravimetry and differential scanning calorimetry (DSC). The results showed typical bimodal peaks in DSC curve in bulk Mollisols. A labile fraction peak was observed at 354–366 °C low-temperature zone and recalcitrant fraction one at high temperature of 430–438 °C. Energy density (J mg?1 OM) was greater in soybean plots compared to maize plots; in contrast, long-term continuous maize cultivation also increased energy density, in reverse in soybean plots after 23-yr cultivation. The DSC-T50, temperature at which half of energy release occurred, typically showed larger responses to long-term cultivation than crop species. Results obtained support the hypothesis of a potential link between long-term continuous cropping and the thermal stability of SOM, and a correlation with crop species. 相似文献
87.
Highly dispersed palladium nanoclusters incorporated in amino‐functionalized silica spheres for the selective hydrogenation of succinic acid to γ‐butyrolactone 下载免费PDF全文
Highly dispersed palladium nanoclusters incorporated on amino‐functionalized silica sphere surfaces (Pd/SiO2‐NH2) were fabricated by a simple one‐pot synthesis utilizing 3‐(2‐aminoethylamino)propyltrimethoxysilane (AAPTS) as coordinating agent. Uniform palladium nanoclusters with an average size of 1.1 nm can be obtained during the co‐condensation of tetraethyl orthosilicate and AAPTS owing to the strong interaction between palladium species and amino groups in AAPTS. The palladium particle size can be controlled by addition of AAPTS and plays a significant role in the catalytic performance. The Pd/SiO2‐NH2 catalyst exhibits high catalytic activity for succinic acid hydrogenation with 100% conversion and 94% selectivity towards γ‐butyrolactone using 1,4‐dioxane as solvent at 240°C and 60 bar for 4 h. Moreover, the Pd/SiO2‐NH2 catalyst is robust and readily reusable without loss of its catalytic activity. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
88.
Xue‐qin Zhao Sheng Guo Hui Yan You‐yuan Lu Fang Zhang Da‐wei Qian Han‐qing Wang Jin‐ao Duan 《Biomedical chromatography : BMC》2019,33(8)
The leaves of Lycium barbarum (LLB) have been utilized as crude drugs and functional tea for human health in China and Southeast Asia for thousands of years. To control its quality, a rapid and sensitive ultra‐high‐performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry method was established and validated for the first time for simultaneous determination of 10 phenolic acids and flavonoids (including neochlorogenic acid , protocatechuic aldehyde, p‐hydroxybenzoic acid, chlorogenic acid, cryptochlorogenic acid, caffeic acid, p‐coumaric acid, ferulic acid, rutin and kaempferol‐3‐O‐rutinoside) in LLB. The separation was performed on an Acquity UPLC C18 chromatographic column (100 × 2.1 mm internal diameter, 1.7 μm particle size) with 0.1% formic acid in water (A)–acetonitrile (B) as the mobile phase under gradient elution. Multiple reaction monitoring mode was adopted to simultaneously monitor the target components. The developed method was fully validated in terms of linearity (r2 ≥ 0.9860), precision (RSD ≤ 6.58%), repeatability (RSD ≤ 6.60%), stability (RSD ≤ 6.17%), recovery (95.56–108.06%, RSD ≤ 4.64%) and limit of detection (0.021–0.664 ng/mL) and limit of quantitation (0.069–2.210 ng/mL), and then successfully applied to evaluate the quality of 64 batches of LLB collected from 41 producing areas in four different provinces of China. The results showed that the LLB, especially collected from Inner Mongolia regions, were rich in the phenolic acids and flavonoids. Rutin, kaempferol‐3‐O‐rutinoside and chlorogenic acid are the predominant compounds contained in LLB. The above findings will provide helpful information for the effective utilization of LLB. 相似文献
89.
Luminescent coordination polymers can be potential chemosensors and extensive efforts are being devoted to improve their selectivity and sensitivity. In this work, we report a new kind of fluorene‐based Tb‐CP, Tb4L6·7DMF·5H2O ( Tb 4 L 6 , H2L = 4,4′‐(9,9‐dimethyl‐9H‐fluorene‐2,7‐diyl)dibenzoic acid), showing 2D network and strong blue emission. Meanwhile, Tb 4 L 6 exhibits excellent selectivity and sensitivity for picric acid (PA). The quenching constant (Ksv) of Tb 4 L 6 is equal to 4.5 × 104 L/mol during the concentration range of 0–30 μmol/L, which approaches the best reported CPs‐based on PA sensor up to now. Moreover, we went into depth on the possible mechanisms of luminescence quenching. 相似文献
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