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1.
The effect of substituted hydroxybenzophenone, benzotriazole and organic metal complexes on the photooxidation of PP films has been studied. It has been established that NiDBTC added in 1.0 wt. % is the most effective photostabilizer.While in the case of other stabilizers there is a slight increase in the Co content even during the induction period, with the application of NiDBTC practically no oxidation can be observed before the stabilizer completely disappears. This means that NiDBTC inhibits the photooxidation of the polymer even in low concentration.
, - . , Ni, 1,0 . %. . , Ni , . , Ni .相似文献
2.
T. Borowiecki 《Reaction Kinetics and Catalysis Letters》1987,33(2):429-434
Experiments on the coking rates of variously prepared nickel catalysts on TiO2, Al2O3 and MgO in n-butane steam reforming show that changes in the relative coking rate at a rising steam excess in the gas phase depend mainly on the kind of support. The results obtained are accounted for by changes in the electron density at the site of nickel crystallite contact with the surface of various supports.
, TiO2, Al2O3 MgO, - , , , , , . .相似文献
3.
V. N. Romannikov N. V. Klueva N. N. Bobrov K. G. Ione 《Reaction Kinetics and Catalysis Letters》1976,5(2):217-222
The dependence of palladium distribution in zeolites on the temperature of thermal treatment has been established from the data on oxygen chemisorption and the statistical processing of electron micrographs. The influence of palladium distribution in zeolites on their catalytic activity towards the complete oxidation of benzene has been shown.
- . .相似文献
4.
T. Paryjczak J. Rynkowski K. Krzyzanowski 《Reaction Kinetics and Catalysis Letters》1982,21(3):295-298
Reducibility of NiO/Al2O3 and CuO–NiO/Al2O3 catalysts has been studied by the TPR method within the temperature range 293–873 K. The results suggest that the copper content essentially does not influence the reducibility of NiO/Al2O3.
NiO/Al2O3 CuO–NiO/Al2O3 TPR 293–873 . , NiO/Al2O3.相似文献
5.
Radical intermediates formed at 25°C in the presence and absence of oxygen during the photolysis of anthraquinone in aromatic, cyclic and aliphatic hydrocarbon solvents were trapped by 2,6-dichloronitrosobenzene, 2,6-dibromonitrosobenzene and 2,4,6-tribromonitrosobenzene. The resulting nitroxide radicals have been characterized in situ by ESR spectra.
: 2,6-, 2,6- 2,4,6-— , , 25°C. .相似文献
6.
P. V. Srinivasulu M. Adinarayana B. Sethuram T. Navaneeth Rao 《Reaction Kinetics and Catalysis Letters》1985,27(1):167-172
Kinetics of OsO4 catalyzed oxidation of chalcones by Ce4+ has been studied in aqueous acetic-sulfuric acid medium in the temperature range 313 to 338 K. The order in [oxidant] is zero while the order with respect to [substrate] and [catalyst] are each fractional. The rate of the reaction decreased with increase in percentage of acetic acid while [H+] had practically no effect on the rate The rates of various substituted chalcones (with substituents in the phenyl. ring attached to the moiety) are in the orderp-CH3>m-CH3>H>p-Cl>m-Cl>m-NO2>p-NO2. A mechanism in which formation of a cyclic ester between chalcone and OsO4 in a fast step followed by its decomposition in a rate-determining step is envisaged.
Ce4+, OsO4, - 313–338 . —, —. , [H+] . ( , : -CH3>-CH3>H>-Cl>-NO2>-NO2. , OsO4 , , .相似文献
7.
《Reaction Kinetics and Catalysis Letters》1981,16(4):359-364
,- (ZnO, Al2O3, B2O3, ThO2, MgO, HfO2).
The selectivity of an osmium catalyst for hydrogenation of carbonyl groups in ,-unsaturated aldehydes can be increased by modification with oxides (ZnO, Al2O3, B2O3, ThO2, MgO, HfO2).相似文献
8.
The hydrodesulfurization (HDS) of thiophene by nickel-molybdenum catalysts supported on alumina-zirconia has been investigated. The effect of varying the ratios of oxides in the support is to produce a minimum in the activity for HDS, and the coimpregnated catalysts are shown to be more active than the analogous co-precipitated catalysts.
(HDS) -, . HDS. , .相似文献
9.
The H/D isotope exchange of C2D4 adsorbed on an Ir surface has been studied by the thermal desorption method. Only deuterium atoms detached from the molecule after its adsorption on the metal surface participate in the exchange with a relatively high rate.
H/D C2D4, Ir, . , , .相似文献
10.
E. G. Antsiferov B. M. Kaganovich G. S. Yablonskii 《Reaction Kinetics and Catalysis Letters》1988,37(1):57-61
An algorithm of searching for optimal nonequilibrium reaction mixture compositions accounting for thermodynamic limitations is suggested. It is exemplified by the analysis of a steam conversion of hydrocarbons.
, . .相似文献
11.
A. I. Vagin V. I. Erofeev I. V. Kalechits 《Reaction Kinetics and Catalysis Letters》1982,21(3):309-314
According to kinetic studies on the reduction of commercial Co–Mo/Al2O3 and model catalysts in H2 at 523–773 K, the kinetic curves for the reduction process have been determined. The reduction rate is shown to be higher for the commercial catalyst. Activation energies Eact for the reduction of several forms of Mo and Co in Co–Mo/Al2O3 catalysts are presented.
H2 523–773 . , : Mo Co .相似文献
12.
O. V. Klimov E. A. Krivoshchekova A. N. Startsev 《Reaction Kinetics and Catalysis Letters》1991,43(1):19-23
New highly active catalysts for metathesis of olefins were obtained through the interaction of bis(acetylacetonato)dioxymolybdenum(VI) with surface OH groups of -Al2O3 and subsequent reduction in H2 or CO.
()(VI) OH -Al2O3 H2 CO .相似文献
13.
V. V. Goncharuk Yu. D. Pankratiev N. E. Shcherbatyuk 《Reaction Kinetics and Catalysis Letters》1981,16(1):69-72
Differential heats of cumene adsorption at 293 K on Ca-, Sr- and Ba-substituted metakaolinites at surface coverages up to 0.1 have been measured on a Calvet microcalorimeter. The presence of two energetically different adsorption centers are shown to be determined by the nature of the exchanged cation; the adsorption heats decrease in the sequence Ba, Sr, Ca, Mg.
293 Ca-, Sr, Ba- 0.1. . , Ba, Sr, Ca, Mg.相似文献
14.
Hexenes give large amounts of hexane and isomeric hexenes over EUROPT-1. A constant hydrocarbon coverage can be assumed in the steady-state period of the reaction; the direction of reactions of these surface species depends on the hydrogen excess and also on the structure of starting hydrocarbon.
Based on the diploma work of Mr. M. Räth and Ms. B. Brose. 相似文献
EUROPT-1 , . , . , .
Based on the diploma work of Mr. M. Räth and Ms. B. Brose. 相似文献
15.
E. M. Sadovskaya S. A. Pokrovskaya Y. A. Yabrov A. A. Ivanov 《Reaction Kinetics and Catalysis Letters》1989,39(2):431-436
Based on numerical analysis of experimental data, the main ideas of the reaction mechanism have been confirmed and kinetic principles of the non-steady=state reaction have been determined.
, .相似文献
16.
The conditions of thermal decomposition of the thiodiglycolates of Y, La and light lanthanides from Ce to Gd have been studied. On heating, these complexes decompose in various ways. Hydrated thiodiglycolates of La,Ce(III), Pr(III) and Gd lose crystallization water in one step, while those of Y, Nd, Sm and Eu(III) do so in two steps. The anhydrous complexes subsequently decompose in several steps to the oxysulfates Ln2O3–x((SO4)x.
Zusammenfassung Bedingungen der thermischen Zersetzung der Thiodiglycolate von Y, La und den leichten Lanthaniden von Ce bis Gd wurden untersucht. Beim Erhitzen zersetzen sich diese Komplexe auf verschiedene Weise. Hydratisierte Thiodiglycolate von La, Ce(III), Pr(III) und Gd verlieren das Kristallwasser in einem Schritt, die von Y, Nd, Sm, und Eu(III) dagegen in zwei Schritten. Die wasserfreien Komplexe zersetzen sich in mehreren Schritten zu den Oxysulfaten Ln2O3–x(SO4)x.
. . . , , , , , . Ln2O3–x(SO4)x.相似文献
17.
St. Veleva 《Reaction Kinetics and Catalysis Letters》1980,13(4):351-356
Some characteristics of the kinetic equation of dissolution are discussed, bearing in mind that in the course of the process, along with the concentration of the solution, the surface of the soluble substance is also changed. The opportunity for the appication of an exponential kinetic equation is pointed out. Methods are proposed for calculating the solubility and also for using the integral forms of the exponential equation. The meaning of the coefficient of proportionality is explained.
, , ◹ . . , . .相似文献
18.
P. K. Sinhamahapatra S. Sinhamahapatra T. K. Mukherjee S. K. Bhattacharyya 《Reaction Kinetics and Catalysis Letters》1977,7(4):473-479
Electron spin resonance absorptions have been studied in bismuth tungstate catalysts with Bi/W ratios of 2/3, 1/1, 2/1 and 6/1. The first three systems exhibit a mean g value of 2.07±0.04 while the last one does not show any ESR signal. All the systems are diamagnetic. The signals at g=2.03–2.11 are attributed to oxygen ion-radicals chemisorbed (O
2
–
) on W6+. An attempt has been made to correlate these whith the catalytic activities of the bismuth tungstates in the oxidation of propylene and 1-butene.
Bi/W=2/3, 1/1, 2/1 6/1. g=2,07±0,04, . . g=2,03 2,11 - (O2 –), W+6. 1-.相似文献
19.
The thermal decompositions of natural and synthetic andersonites were studied. Two partly overlapping dehydration steps and three partly overlapping decarbonation steps were observed. The second dehydration and the first decarbonation steps also partly overlap. During decarbonation, the gradual formation of sodium diuranate and monoclinic and hexagonal phases in the Na2U2O7-CaUO4–x
system was proved. The results were correlated with measured infrared spectra using site and factor group analysis and X-ray structure analysis. The chemical formula inferred for natural andersonite, Na2Ca[UO2(CO3)3] 5.6H2O, agrees with that proposed for its synthetic analogue.
Zusammenfassung Die thermische Zersetzung von natürlichem und synthetischem Andersonit wurde untersucht. Sie umfasst zwei teilweise überlappende Entwässerungs- und drei teilweise überlappende Decarboxylierungsstufen. Der zweite Entwässerungs- und der erste Decarboxylierungsschritt überlagern einander ebenfalls teilweise. Während der Decarboxylierung wird die allmähliche Bildung von Natriumdiuranat und monoklinen und hexagonalen Phasen des Systems Na2U2C7-CaUO4–x nachgewiesen. Die Ergebnisse wurden mit den gemessenen IR-Spektren unter Benutzung der site- und Faktor-Gruppenanalyse sowie Röntgenbeugungsuntersuchungen korreliert. Die für natürlichen Andersonit abgeleitete Formel Na2Ca[UO2(CO3)3].5,6H2O stimmt mit der für synthetischen Andersonit vorgeschlagenen überein.
. . . , Na2U2O7-CaUO4–x. . Na2Ca[UO2(CO3)3] 5,62, ** , .相似文献
20.
C. Karunakaran K. Ganapathy P. Ramasasamy 《Reaction Kinetics and Catalysis Letters》1989,40(2):369-374
The perborate oxidation of quinol in aqueous acetic acid is first order with respect to perborate, zero order with respect to quinol, and first order with respect to H+. The oxidation is faster than H2O2 oxidation. Breakdown of protonated perboric acid is suggested as the rate-limiting step.
, H+. . , , , .相似文献