نتایج جستجو برای: acetylene

تعداد نتایج: 3543  

Journal: :Dalton transactions 2018
De-Ming Rao Shi-Tong Zhang Chang-Ming Li Yu-Di Chen Min Pu Hong Yan Min Wei

Intermetallic compounds (IMCs) have shown excellent catalytic performance toward the selective hydrogenation of acetylene, but the theoretical understanding on this reaction over Ni-based IMCs is rather limited. In this work, the adsorptions of the C2 species, Bader charge, projected density of states (PDOS) and the reaction pathways were calculated by the density functional theory (DFT) method...

2016
Jing Hou Ming-Lei Yuan Jian-Hua Xie Qi-Lin Zhou

Acrylic acid is an important commodity chemical and is widely used as a base material for the industrial production of paints, plastics, superabsorbent polymers, rubber, and so on. Currently acrylic acid is produced by partial oxidation of propene, which is refined from petroleum. Catalytic hydrocarboxylation of acetylene with CO is another way to synthesize acrylic acid with high atom-economy....

Journal: :Journal of bacteriology 1983
L S Privalle R H Burris

Heterocysts isolated from Anabaena sp. strain 7120 with lysozyme plus sonication were permeabilized with the cationic detergent cetyltrimethylammonium bromide, and they then exhibited comparable acetylene reduction activity in the light and dark with an ATP-regenerating system plus dithionite. The detergent diminished the effect of H2 in enhancing acetylene reduction.

Journal: :Philosophical transactions. Series A, Mathematical, physical, and engineering sciences 2013
M Tian B S Liu M Hammonds N Wang P J Sarre A S-C Cheung

Polycyclic aromatic hydrocarbons (PAHs) are known to be present in many astrophysical objects and environments, but our understanding of their formation mechanism(s) is far from satisfactory. In this paper, we describe an investigation of the catalytic conversion reaction of acetylene gas to PAHs over pyroxene and alumina. Crystalline silicates such as pyroxenes (with general formula [Mg, Fe]Si...

Journal: :Journal of the American Chemical Society 2008
Takahiro Nishimura Xun-Xiang Guo Nanase Uchiyama Taisuke Katoh Tamio Hayashi

Rhodium-catalyzed asymmetric conjugate addition to R,âunsaturated ketones and related compounds is now well-recognized to be one of the most efficient methods of introducing aryl and alkenyl groups with high enantioselectivity.1 On the other hand, asymmetric conjugate addition of alkynyl groups has not been welldeveloped in spite of its high synthetic utility.2 A most straightforward and conven...

Journal: :The Journal of chemical physics 2004
Mark D Marshall James B Davey Margaret E Greenslade Marsha I Lester

The entrance channel leading to the addition reaction between the hydroxyl radical and acetylene has been examined by spectroscopic characterization of the asymmetric CH stretching band of the pi-hydrogen bonded OH-acetylene reactant complex. The infrared action spectrum observed at 3278.6 cm(-1) (origin) consists of seven peaks of various intensities and widths, and is very different from thos...

Journal: :Chemical communications 2011
Michal Juríček Paul H J Kouwer Alan E Rowan

Over the past 50 years, numerous roads towards carbon-based materials have been explored, all of them being paved using mainly one functional group as the brick: acetylene. The acetylene group, or the carbon-carbon triple bond, is one of the oldest and simplest functional groups in chemistry, and although not present in any of the naturally occurring carbon allotropes, it is an essential tool t...

Journal: :Microbiology 2001
I Schmidt E Bock M S Jetten

The effect of acetylene ((14)C(2)H(2)) on aerobic and anaerobic ammonia oxidation by Nitrosomonas eutropha was investigated. Ammonia monooxygenase (AMO) was inhibited and a 27 kDa polypeptide (AmoA) was labelled during aerobic ammonia oxidation. In contrast, anaerobic, NO(2)-dependent ammonia oxidation (NO(2)/N(2)O(4) as oxidant) was not affected by acetylene. Further studies gave evidence that...

Journal: :The Biochemical journal 1977
R N Thorneley R R Eady

Non-linear rates of acetylene reduction and concomitant H2 evolution were observed for the nitrogenase of Klebsiella pneumoniae at 10 degrees C. A lag phase of 1-4 min, dependent on the ratio of Mo-Fe protein to Fe protein present, occurred before linear rates of acetylene reduction were achieved. A complementary burst phase for concomitant H2 evolution in the presence of acetylene was also obs...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1972
P N Raju H J Evans R J Seidler

Examination of root systems and adhering soil associated with unusually green corn plants from nitrogen-deficient areas in fields has revealed higher acetylene-reducing activities than comparable root systems of chlorotic plants that appeared to be nitrogen deficient. From the root systems with acetylene-reducing activity, N(2)-fixing Enterobacter cloacae were isolated. Pure cultures of the org...

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