a two-dimensional nanolayered polyoxomolybdate, [4,4´-h2bipy] [mo7o22].h2o (1), where 4,4´-bipy = 4,4´-bipyridine, was prepared and characterized by ft-ir and atomic absorption spectroscopies, transmission electron microscopy (tem), x-ray single crystal and powder diffraction (xrd), and thermogravimetric analysis. the catalytic performance of 1 was assessed in the epoxidation of some olefins em...

Relating individual differences in cognitive abilities to neural substrates in older adults is of significant scientific and clinical interest, but remains a major challenge. Previous functional magnetic resonance imaging (fMRI) studies of cognitive aging have mainly focused on the amplitude of fMRI response, which does not measure neuronal selectivity and has led to some conflicting findings. ...

Achieving selective C–H functionalization is a significant challenge that requires discrimination between many similar C–H bonds. Yet, reaction systems employing Rh2(DOSP)4 and Rh2(BPCP)4 were recently demonstrated to afford high levels of selectivity in the C–H insertion of carbenes into toluene-derived substrates. Herein, we explore the origin of this selectivity through a systematic analysis...

the catalytic oxidation of toluene over copper oxide supported on natural diatomite was investigated. the catalyst was prepared by the wet impregnation method and characterized by using the brunauer emmett teller (bet), field emission scanning electron microscopy (fesem), x-ray diffraction (xrd), x-ray fluorescence (xrf) and temperature-programmed reduction (tpr) analysis. the highest catalytic ...

the possibility of selective leaching process was investigated during molybdenite flue dust leaching to recover its rhenium content. the results show that addition of alcohols to water makes the medium less favorable for molybdenum transfer into aqueous phase. on the other hand, addition of small amounts of alcohols (5-15%) makes a noticeable separation of rhenium over molybdenum, but by increa...

in a novel dual bed reactor fischer-tropsch synthesis was studied by using two diffrent cobalt catalysts. an alkali-promoted cobalt catalyst was used in the first bed of a fixed-bed reactor followed by a rutenuim promoted cobalt catalyst in the second bed. the activity, product selectivity and accelerated deactivation of the system were assessed and compared with a conventional single bed react...

an extensive study of fischer-tropsch synthesis (fts) on alumina-supported cobalt catalysts with different amounts of cobalt is reported. up to 40 wt % of cobalt, is added to the catalysts by impregnation method. the effect of the cobalt loading on the reducibility of the cobalt oxide species, dispersion of the cobalt, average clusters size, water-gas shift (wgs) activity and activity and selec...

The macroevolutionary effects of extinction derive from both intensity of taxonomic losses and selectivity of losses with respect to ecology, physiology and/or higher taxonomy. Increasingly, palaeontologists are using logistic regression to quantify extinction selectivity because the selectivity metric is independent of extinction intensity and multiple predictor variables can be assessed simul...

Ion selectivity of transport systems is an essential property of membranes from living organisms. These entities are used to regulate multifarious biological processes by virtue of selective participation of specific ions in transport processes. To understand this process, we studied the phosphate selectivity of the OprP porin from Pseudomonas aeruginosa using all-atom free-energy molecular dyn...