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A plasma reactor that has a transient traveling arc has been used to study hydrogen in relation to in-flight reduction of metal oxide particles. Experiments were done to determine the nature of the arc and its interaction with the reactor gas. The lifetime of the excited atomic hydrogen was measured and it was found to be more than 4 ms after the arc had ceased. Powders and tablets of oxides were exposed to the pulsed-arc treated hydrogen and found to react much more rapidly and intensely than when exposed to hot molecular hydrogen. The results suggest that atomic hydrogen will exist throughout the volume of such a reactor for a period that is sufficient to reduce particles of FeO, Cr2O3, and TiO2.  相似文献   
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White biotechnology is a fast emerging area that concerns itself with the use of biotechnological approaches in the production of bulk and fine chemicals, biofuels, and agricultural products. It is a truly multidisciplinary area and further progress depends critically on the role of chemists. This article outlines the emerging contours of white biotechnology and encourages chemists to take up some of the challenges that this area has thrown up.  相似文献   
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Smita Rai 《Tetrahedron》2007,63(11):2455-2465
Three porphyrin building blocks with N4, N3S and N2S2 cores having three meso-furyl groups and one meso-iodophenyl group were synthesized and characterized. The porphyrin building blocks were used to synthesize six porphyrin dyads such as N4-N4, N3S-N3S, N2S2-N2S2, N4-N3S, N4-N2S2 and N3S-N2S2 containing meso-tolyl and meso-furyl porphyrin sub-units under mild Pd(0) mediated coupling conditions. Steady state fluorescence studies indicated an efficient energy transfer from the meso-tolyl porphyrin sub-unit to the meso-furyl porphyrin sub-unit in all six dyads. This study supported the argument that the meso-furyl porphyrins can be used as good energy acceptors when meso-aryl porphyrins act as energy donors in their metal free form.  相似文献   
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The DNA binding characteristics of mixed ligand complexes of the type [Co(en)2(L)]Br3 where en = N,N′-ethylenediamine and L = 1,10-phenanthroline (phen), 2,2′-bipyridine (bpy), 1,10-phenanthroline-5,6-dione (phendione), dipyrido[3,2-a:2′,3′-c]phenazine (dppz) have been investigated by absorption titration, competitive binding fluorescence spectroscopy and viscosity measurements. The order of intercalative ability of the coordinated ligands is dppz > phen > phendione > bpy in this series of complexes.  相似文献   
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N-((2-chloroquinolin-3-yl)methylene)aniline (CQM) and N-((2-chloroquinolin-3-yl)methylene)-5-methylthiazol-2-amine (CQMA) were synthesized. The effect of CQM and CQMA have been investigated against mild steel (MS) in 1 N HCl solutions using conventional weight loss, potentiodynamic polarization, linear polarization, electrochemical impedance spectroscopy, UV–Vis spectroscopy and scanning electron microscopic studies. The losses in the weights of MS samples have proved that both CQM and CQMA are efficient inhibitors. The mixed mode of inhibition was confirmed by electrochemical polarizations. The adsorptions of these inhibitors are found to follow the Langmuir adsorption isotherm. CQM and CQMA adsorbs on the MS sample by chemisorptions.  相似文献   
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