نتایج جستجو برای: symmetric catalyst

تعداد نتایج: 124781  

Journal: :Chemical communications 2005
Lijin Xu Kim Hung Lam Jianxin Ji Jing Wu Qing-Hua Fan Wai-Hung Lo Albert S C Chan

An air-stable catalyst system Ir-(P-Phos) catalyst was found to be highly effective in the asymmetric hydrogenation of quinoline derivatives. The catalyst immobilized in DMPEG was efficiently recovered and reused eight times, retaining reactivity and enantioselectivity.

Journal: :journal of nanostructures 2013
a. a. hosseini f. doustan m. akbarzadeh pasha

monometallic and bimetallic ni and co catalytic nanoparticles supported on titanium dioxide (rutile phase) substrate were prepared by wet impregnation method. these nanoparicles were used as catalysts for synthesis of multiwalled carbon nanotubes (mwcnts) from acetylene decomposition at 700°c by the catalytic chemical vapor deposition (ccvd) technique. the nanomaterials (catalyst and cnts) were...

2016

The simultaneous esterification and transesterification of Jatropha curcas oil (JCO) was carried out in the presence of Bi2O3 (1–7 wt.%) modified La2O3 catalyst at atmospheric pressure. The catalyst were characterized by X-ray diffraction (XRD), BET surface area, desorption of CO2 (TPD-CO2) and NH3 (TPD-NH3). Under the optimal reaction condition of methanol/oil molar ratio of 15:1, 2 wt.% of ca...

Journal: :تحقیقات اقتصاد و توسعه کشاورزی ایران 0
فهیمه زمانی دانشجوی کارشناسی ارشد بخش اقتصاد کشاورزیف دانشگاه شهید باهنر کرمان حسین مهرابی بشرآبادی استاد بخش اقتصاد کشاورزی دانشگاه شهید باهنر کرمان

the effect of symmetric (non-symmetric) foreign exchange rate shocks on iranian agricultural import and exports was explored throughout the current research.. time series of 1973-2007 along with hodrick and prescott filter method were employed. the results as obtained through vector error correction and johnson model indicated that positive (negative) shocks introduce positive (negative) effect...

2004
Kenneth R. Muske James C. Peyton Jones

This work presents model-based strategies for on-board catalyst monitoring and fault detection using a simplified catalyst oxygen storage and reversible deactivation model. The performance of the catalyst is inferred from the error between the post-catalyst exhaust gas oxygen sensor measurement and the model predicted value. Each of these strategies is based on the use of some test statistic th...

2017
Huoxin Luan Yunqiang Wu Wenxiang Wu Quansheng Chen Hailing Zhang Kang Liu Guangmiao Qu Wei Ding

Based on starch and series of alkyl benzene sulfonic acid as the materials, a novel carbon-based solid acid catalyst is synthesized using hydrothermal method. This catalyst exhibits much higher catalytic activity in the reaction of esterification of Mono-fatty alcohol polyoxyethylene maleate esters with 1,4-butanediol. The structure of carbon-based solid acid catalyst was charactered by IR and ...

Journal: :Journal of Physics: Conference Series 2021

Journal: :Chemical communications 2011
Antoine Buchard Michael R Kember Karl G Sandeman Charlotte K Williams

A novel di-iron(III) catalyst for the copolymerisation of cyclohexene oxide and CO(2) to yield poly(cyclohexene carbonate), under mild conditions, is reported. The catalyst selectivity was completely changed on addition of an ammonium co-catalyst to yield only the cis-isomer of the cyclic carbonate, also under mild conditions. Additionally, the catalyst was active for propylene carbonate and st...

Journal: :Organic letters 2009
Martin T Mwangi Michael D Schulz Ned B Bowden

Incompatible Grubbs catalyst and an osmium dihydroxylation catalyst were site-isolated from each other using polydimethylsiloxane thimbles. The Grubbs catalyst was added to the interior of the thimbles, and AD-mix-alpha/beta was added to the exterior. Organic substrates readily fluxed through the walls of the thimbles and reacted with each catalyst. A series of cascade reactions were developed ...

Journal: :Differential Geometry and its Applications 2002

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