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11.
The kinetics of oxidation of isopropanol (IPA) by IO 4 in the presence of Os(VIII), Ru(III) and mixture of Os(VIII) and Ru(III) has been studied. The catalytic effect was found to be in the order Os(VIII)
IO 4 Os(VIII), Ru(III) Os(VIII) Ru(III), . : Os(VIII)  相似文献   
12.
The extraction of plutonium(IV), uranium(VI), zirconium(IV), europium(III) and ruthenium(III) with -pre-irradiated n-dodecane solutions of methylbutyl substituted hexanamide (MBHA), octanamide (MBOA) and decanamide (MBDA) from 3.5M HNO3 has been studied as a function of absorbed dose up to 184×104 Gray. The distribution ratios (Kd) of uranium(VI) decreased gradually up to a dose of 50×104 Gray and became almost constant thereafter, while ruthenium(III) and europium(III) were not extracted in the entire dose range studied. The Kd values of Pu(IV) decreased gradually up to 10×104 Gray, for MBOA, and 30×104 Gray for MBHA and MBDA and then increased up to a dose of 72×104 Gray, indicating the synergistic effect of radiolytic products at higher doses. The extraction of zirconium(IV) was found to increase gradually up to 72×104 Gray. However, the steep fall in Kd values of plutonium(IV), zirconium(IV) beyond a dose of 72×104 Gray was atrributed to third phase formation. The radiolytic degradation of amides was monitored by quantitative IR spectroscopy and was found to follow the order MBOA>MBDA>MBHA at 184×104 Gray having the amines and carboxylic acids as the main radiolytic products.  相似文献   
13.
Dimethyl sulfoxide has been used as a solvent in the polymerization of methyl methacrylate and styrene. The chain-transfer coefficients of the solvent and the values of δ [i.e., (2kt)1/2/kp] in solvent-monomer mixtures of various compositions were determined. δ was observed to be dependent on the solvent concentration in the case of methyl methacrylate but remained constant in case of styrene. The lowering of the values of δ with increasing solvent concentration in case of methyl methacrylate has been attributed to an interaction between the solvent and poly(methyl methacrylate) radical resulting in lower termination rate.  相似文献   
14.
DSC measurements in air from 20 to 800° are reported on aged iron(III)-chromium(III) coprecipitated hydroxides (with Fe3+Cr3+ wt% ratios of 91, 73, 11, 37 and 19). A comparison of the DSC profiles of aged coprecipitates with the thermal behaviour of freshly precipitated and well characterized samples provided information on the modification occurring in the structure and reactivity of the coprecipitates on prolonged aging.
Zusammenfassung Es werden DSC-Messungen an gealterten kogefällten Eisen(III)Chrom(III)-hydroxiden (mit Fe3+Cr3+ Gewichtsanteilen von 91, 73, 11, 37 und 19) im Temperaturbereich von 20 bis 800° beschrieben. Ein Vergleich der DSC-Profile von gealterten Kofällungen mit dem thermischen Verhalten frisch gefällter und gut definierbarer Proben lieferte Informationen über die Veränderungen in Struktur und Reaktivität der Koniederschläge bei längerem Altern.


Dedicated to Professor Wahid U. Malik, Founder-President, Indian Council of Chemists, India, with profound regards and fond memories of his youthful enthusiasm and ceaseless and pioneering efforts towards the development of chemical education and research activities at the University of Roorkee, Roorkee, India, on the occasion of his 70th birthday.

Paper presented at the World Conference on Thermal Analysis, Capri (Italy), 1989.

We thank Professor J. Pescia, Dr.G. Ablart and N. Favillier of Laboratoire de Magnétisme et d'Electronique Quantique for their interest in this work. A. C. Vajpei expresses his gratefulness to C.N.R.S. and C.N.O.U.S., Paris, for financial support of this work.  相似文献   
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17.
The first-row transition-metal monosulfides and alkaline-earth chalcogenides were studied by means of X-ray photoelectron spectroscopy. It is shown that the bonding in the alkaline earth compounds is relatively ionic with XPS evidence for significant charge separation. On the other hand, transition metal sulfides, with the exception of MnS, appear to be principally metallic with little or no charge separation. Values for the inner orbital binding energy shifts are reported for a large number of monochalcogenides.  相似文献   
18.
An efficient (in terms of experiment and time) synthetic procedure for chloromethyl methyl ether (MOM-Cl) is described using heteropolyacids as catalysts.  相似文献   
19.
Abstract— We have examined the fluorescence properties of excised intact normal human corneas from over a hundred donors, using synchronous excitation fluorescence spectroscopy. In some of the corneas from the donors, a fluoro-phore with an excitation band centered at 330 nm was observed. This fluorophore does not seem to correspond to the dityrosine moiety or to any photoproducts of tryptophan. Isolated corneas irradiated with light of 295 nm wavelength do not produce any fluorescent photoproducts, suggesting that the intact tissue has endogenous quenchers, radical scavengers and antioxidants that inhibit its photodamage. The non-tryptophan fluorophores that accumulate in some corneas thus appear to arise largely from the nonenzymatic glycosylation (glycation) of the constituent proteins as similar fluorophores are detected in the corneas of rats in which diabetes is induced.  相似文献   
20.
T. Uma  M. Nogami   《Journal of membrane science》2006,280(1-2):744-751
A new class of proton conducting glass membranes for hydrogen fuel cell applications are being developed using phosphotungstic acid. These glasses are being design to yield high proton conductivities could be potential substitutes for electrolytes in H2/O2 fuel cell. P2O5–SiO2–PWA glasses have been non-crystalline phases confirmed by structural studies. The glass materials showed good mechanical and thermal stability, and also found a maximum proton conductivity of 9.1 × 10−2 S/cm at 90 °C and 30% RH. The average pore size less than 5 nm was determined by Barrett–Joyner–Halenda (BJH) desorption method. The electrochemical activity was investigated by polarization curves and current–voltage profiles. A maximum power density value of 10.2 mW/cm2 was obtained using 0.15 mg/cm2 of Pt/C loaded on electrode and 5P2O5–87SiO2–8PWA glasses at 30 °C and 30% humidity.  相似文献   
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