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Carbon black (CB) without micropores was functionalized by mixed acid and used to explore the surface chemistry effect on the production of hydrogen peroxide (H2O2). The CB materials were characterized by N2 adsorption‐desorption, XRD, SEM, FTIR, and TPD. The results of different characterization methods indicated that both the textural features and the surface chemical properties of CB were significantly modified by the acidic treatment. The catalytic performance of the modified CBs for hydroxylamine (NH2OH) oxidation increased with increasing the surface oxygen‐containing species. The yield of H2O2 approached 30% with the corresponding concentration of 73.9 mmol·L?1 (w=0.25%) over the most promising CB catalyst, which was much superior to the results obtained on supported noble metals. Correlations between catalytic activity and concentration of different surface functional groups on the CB samples confirmed that the quinonoid species might be the active species. 相似文献
996.
Marino Vega‐Vazquez Juan Carlos Cobas Manuel Martin‐Pastor 《Magnetic resonance in chemistry : MRC》2010,48(10):749-752
A parallel localized spectroscopy (PALSY) method is presented to speed up the acquisition of multidimensional NMR (nD) spectra. The sample is virtually divided into a discrete number of nonoverlapping slices that relax independently during consecutive scans of the experiment, affording a substantial reduction in the interscan relaxation delay and the total experiment time. PALSY was tested for the acquisition of three experiments 2D COSY, 2D DQF‐COSY and 2D TQF‐COSY in parallel, affording a time‐saving factor of 3–4. Some unique advantages are that the achievable resolution in any dimension is not compromised in any way: it uses conventional NMR data processing, it is not prone to generate spectral artifacts, and once calibrated, it can be used routinely with these and other combinations of NMR spectra. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Javier Ramos Víctor L. Cruz Javier Martínez‐Salazar Mikael Brasse Pilar Palma Juan Campora 《Journal of polymer science. Part A, Polymer chemistry》2010,48(5):1160-1165
The present computational study was designed to study the polymerization of ethylene catalyzed by a new Ni‐based PymNox organometallic compound. Recently, we have synthesized and tested the behavior of this type of catalyst in olefin polymerization. It has been experimentally observed that the unsubstituted catalyst Ni2 (aldimino PymNox catalyst ) is less active than the methyl substituted Ni1 (acetaldimino PymNox catalyst ) analogue. The reactivity of both catalysts was examined using density functional theory (DFT) models. Our results indicate that the methyl substituted Ni1 introduces some additional steric hindrance that probably renders a more suitable catalyst conformation for the monomer incorporation. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1160–1165, 2010 相似文献
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Xi Rong HUANG * Yue Zhong LI Guo Liang YANG Li Li LIU Yin Bo QU Wen Juan ZHANG State Key Lab of Microbial Technology of China Shandong University Jinan Key Lab for Colloid Inferface Chemistry of the Education Ministry of Chin 《中国化学快报》2001,(5)
Lipase is one of the hydrolases. It catalyzes the hydrolysis of triglycerides, liberating fat acids. Based on its catalysis and the response of a glass electrode to the acids, a glass-electrode-based lipase sensor can be fabricated1, which has great potential in clinical medicine for the detection of blood fat in human serum samples.The immobilization of lipase on the bulb of a glass electrode is the key to the development of the sensor. In addition to its response time, which has a lot to do … 相似文献
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Probabilistically induced domain decomposition methods for elliptic boundary-value problems 总被引:1,自引:0,他引:1
Juan A. Acebrn Maria Pia Busico Piero Lanucara Renato Spigler 《Journal of computational physics》2005,210(2):421-438
Monte Carlo as well as quasi-Monte Carlo methods are used to generate only few interfacial values in two-dimensional domains where boundary-value elliptic problems are formulated. This allows for a domain decomposition of the domain. A continuous approximation of the solution is obtained interpolating on such interfaces, and then used as boundary data to split the original problem into fully decoupled subproblems. The numerical treatment can then be continued, implementing any deterministic algorithm on each subdomain. Both, Monte Carlo (or quasi-Monte Carlo) simulations and the domain decomposition strategy allow for exploiting parallel architectures. Scalability and natural fault tolerance are peculiarities of the present algorithm. Examples concern Helmholtz and Poisson equations, whose probabilistic treatment presents additional complications with respect to the case of homogeneous elliptic problems without any potential term and source. 相似文献