共查询到20条相似文献,搜索用时 156 毫秒
1.
V. P. Sokolov N. M. Zaidman N. V. Elokhina N. V. Savostina E. V. Kuznetsova 《Reaction Kinetics and Catalysis Letters》1982,20(3-4):313-316
General forms of the kinetic equations for the conversion of various hydrocarbons in reforming of multicomponent gasoline fractions on platinum/alumina catalysts have been confirmed experimentally by using a gradientless method.
.相似文献
2.
V. A. Dyachenko E. M. Kuramshin S. S. Zlotskii D. L. Rakhmankulov 《Reaction Kinetics and Catalysis Letters》1987,33(1):63-66
Liquid phase oxidation of cycloalkane diheteroanalogs catalyzed by compounds of Cu2+, Ni2+, Co2+, Cr3+, Fe3+ has been studied. It has been established that these catalysts can be applied to intensify, oxidize and increase the selectivity of this process.
: Cu2, Ni2+, Co2+, Cr3+, Fe3+. .相似文献
3.
Jan Adamiec 《Reaction Kinetics and Catalysis Letters》1986,30(1):143-147
Hydrogen adsorption on chromia supported Pd, Rh and Pt was studied under various pretreatment conditions. The reduction temperature influences strongly the hydrogen uptake for all these metals. Platinum supported on chromia shows an unusually high hydrogen adsorption stoichiometry.
Pd, Rh Pt, Cr2O3, . , . Cr2O3 .相似文献
4.
V. F. Anufrienko T. M. Yurieva F. S. Hadzhieva T. P. Minyukova S. Yu. Burylin 《Reaction Kinetics and Catalysis Letters》1985,27(1):201-205
ESR and electronic spectroscopy have reveled that in low-temperature ZnO the copper ions form Cu–O–Cu type cluster structures with highly covalent bonds and strong exchange interaction between the ions. The nearer environment of the Cu2+ ions is an octahedron with distortion towards square planar coordination.
, ZnO Cu–O–Cu . Cu2+- , .相似文献
5.
J. G. Konrad G. Chesters D. R. Keeney 《Journal of Thermal Analysis and Calorimetry》1970,2(2):199-208
A microcombustion procedure specific for the determination of total-, organic- and carbonate-C in freshwater lake sediments is described. The procedure involves combustion of the sample at 650° to obtain organic-C. Total-C is obtained by combustion at 950° and carbonate-C calculated by difference. The procedure was evaluated by differential thermal analyses of representative sediments and known carbonate minerals. A procedure for the identification of dolomite in lake sediments by differential thermal analysis under CO2 is also described.
Zusammenfassung Es wurde über ein zur Bestimmung des Gesamt-, Karbonat- und organischen Kohlenstoffgehaltes von Süßwasserrückständen geeigneten Mikroverbrennungsverfahren berichtet. Durch Verbrennen bei 650° erhält man den organischen Kohlenstoff, durch Verbrennen bei 950° den Gesamtkohlenstoff. Der Karbonatkohlenstoff ergibt sich aus der Differenz. Die Methode wurde durch differentialthermoanalytische Prüfung von charakteristischen Sedimenten und bekannten Karbonatmineralien getestet. Ein Verfahren zur Identifizierung von Dolomit in Seesedimenten durch Differentialthermoanalyse unter CO2 wurde ebenfalls beschrieben.
Résumé On décrit une méthode spécifique de microcombustion pour déterminer la teneur en carbone total, organique et carbonate dans des sédiments des lacs à eau froide. On reçoit le C organique par combustion à 650°, le C total par combustion à 950° et le carbone à l'état de carbonate, par la différence. On a évalué le procédé par ATD des sédiments représentatifs et de minérais de carbonate connus. On a décrit une méthode pour identifier le dolomite dans les sédiments des lacs, par ATD sous CO2.
, , C . C 650° 950°C, , C . . , , CO2.相似文献
6.
V. M. Zelenkovskii P. P. Mardilovich G. M. Zhidomirov 《Reaction Kinetics and Catalysis Letters》1989,38(1):73-77
The non-empirical LCAO SCF MO method on the STO-3G basis was applied to calculate adsorption of H2O, NH3 and CO molecules on paired Lewis acid sites (LAS) of alumina formed as a result of the removal of the OH groups which are common for two aluminium atoms.
, STO-3G, H2O, NH3, CO () Al2O3, OH. , H2O, NH3, CO .相似文献
7.
A pulse-chromatographic method has been developed for the estimation of molybdenum surface by selective adsorption of oxygen at –78°C in cobalt-molybdenum-alumina catalysts. The surface concentrations of molybdenum in a series of catalysts of different compositions were compared with the activities for cyclohexene hydrogenation and for thiophene hydrogenolysis.
- –78°C -- . - .相似文献
8.
A. Maubert G. A. Martin H. Praliaud P. Turlier 《Reaction Kinetics and Catalysis Letters》1984,24(1-2):183-186
An increase of the reduction temperature of a Ni/CeO2 solid results in a continuous decrease of the catalytic activity toward C2H6 hydrogenolysis and of the quantity of adsorbed H2. O2 treatments with subsequent reduction at low temperature restore a part of the initial properties. This behavior, typical of a strong metal support interaction, is similar to that of Ni/TiO2, Ni/SiO2 and Ni/ZrO2 solids and shows that the SMSI phenomenon is general.
Ni/CeO2 C2H6 H2. . , (), Ni/TiO2, Ni/SiO2 Ni/ZrO2 , .相似文献
9.
N. A. Samoilov 《Reaction Kinetics and Catalysis Letters》1986,30(2):311-319
Catalytic deactivation dynamics of zeolites in multicycle processes has been calculated. It has been revealed that in naphthalene sorption on NaX zeolites surface deactivation is predominant with its similarity criterion close to unity and a high fraction of deactivation. Calculated data for several multicycle processes are given.
. , NaX . .相似文献
10.
Nonsteady state activity during the gas phase oxidation of ethanol in a simple flow reactor and its dependence on pretreatment and reaction conditions can be explained utilizing the previously presented model of possible surface vanadia phases on silica.
.相似文献
11.
R. I. Soltanov E. A. Paukshtis E. N. Yurchenko 《Reaction Kinetics and Catalysis Letters》1985,28(1):139-144
Influence of the strength and concentration of non protic centers on the catalytic activity of metal-zeolite catalysts in isomerization of n-butane has been studied. A relationship between the specific activity and the center strength is suggested.
-. , .相似文献
12.
The influence of the Na2O/Al2O3 mole ratio in sodium aluminate, the pH and the temperature of precipitation upon physicochemical properties of pseudoboehmite obtained from sodium aluminate has been studied. A mole ratio of 11 and low pH are favorable for the preparation of pure alumina.
Na2O/Al2O3 , pH , . , Na2 O/Al2O3=1 , pH, .相似文献
13.
P. Pomonis 《Reaction Kinetics and Catalysis Letters》1982,18(1-2):247-251
The catalytic activity of rare earth oxides for simple catalytic reactions show patterns which broadly resemble each other and also reactions in which the number of 4f-electrons changes. If simple concepts of electron transfer are augmented, it emerges that any rate controlling step which involves the adsorption of a species by electron transfer to it, leads to an activity pattern with maxima for f0 and f7 and f14 structures.
, , 4f-. , , , , f1 f8 f0, f7 f14 .相似文献
14.
V. B. Jordanovska 《Journal of Thermal Analysis and Calorimetry》1989,35(5):1331-1337
Double sulphates of trivalent aluminium and chromium with dimethylammonium, with general formula (CH3NH2M(SO4
2·6H2O, were synthesized and studied by means of thermogravimetry and differential thermal analysis over the range 20–600 °C under dynamic conditions in a flow of dry nitrogen or air, and with the methods of chemical analysis. An X-ray powder diffraction study of the above compound was also undertaken. It is assumed that dimethylammonium aluminium sulphate hexahydrate and dimethylammonium chromium sulphate hexahydrate are isostructural. The mechanism of thermal decomposition of these double salts is also suggested.
Zusammenfassung Verbindungen der Formel (CH3)2NH2M(SO4)2·6H2O mit M=Al(III) oder Cr(III) wurden synthetisiert und mittels TG und DTA im Intervall 20–600 °C unter dynamischen Bedingungen in bewegtem trockenen Stickstoff-oder Luftstrom sowie mittels chemischer Analyse untersucht. Auf Grund einer ebenfalls durchgeführten röntgenografischen Pulvermethode wurde festgestellt, daß Dimethylammonium-aluminiumsulfat-hexahydrat sowie Dimethylammoniumchromsulfat-hexahydrat isostrukturell sind. Ein Mechanismus für die thermische Zersetzung dieser Doppelsalze wird ebenfalls vorgeschlagen.
(CH3)2NH2M(SO4)2· 6H2O, 20–600° . , . .相似文献
15.
G. I. Panov G. K. Boreskov A. S. Kharitonov E. M. Moroz 《Reaction Kinetics and Catalysis Letters》1981,16(2-3):247-251
The activity of barium nitride in the isotope exchange of nitrogen is 2–3 orders of magnitude higher than that of Fe and Ru. In the temperature range from 373 to 673 K the activation energy of exchange is 40 kJ/mol.
2–3 Fe Ru. 373–673 40 /.相似文献
16.
T. A. Andreeva V. I. Makarov G. I. Skubnevskaya N. M. Bazhin 《Reaction Kinetics and Catalysis Letters》1982,19(3-4):383-387
The photolysis products of SO2-pentane-NO mixtures are N2O, H2O and a compound designated as RNO. Kinetic data obtained by OC method confirm the previously proposed scheme of photolysis. Also studied was the photolysis of SO2, NO and cyclohexane mixtures. From comparison of spectral characteristics of RNO and its analog 2-methyl-2-nitrosopropane, the probable structure of RNO is suggested.
SO2--NO N2O, H2O , RNO. , , . SO2 NO . RNO 2--2- RNO.相似文献
17.
The pyrolysis of cyclohexyl thiol has been studied in a static system at subambient pressures in the temperature range 420–497°C. It is proposed that in the presence of a large excess of cyclohexene the mechanism is a radical non-chain process.
, , 420–497°C. , .相似文献
18.
It has been shown that NiP catalyst, if fresh, contains a high concentration of the same type acid-base surface centers as those participating in i-PrOH dehydration on -Al2O3. The concentration of these centers diminishes rapidly after a modification of NiP surface in a stream of ethylbenzene (EtPh) oxydehydrogenation products.
, NiP - , , i-PrOH -Al2O3. NiP .相似文献
19.
H. F. Bauer 《Journal of Thermal Analysis and Calorimetry》1989,35(5):1571-1602
The steady local temperature distribution has been determined for arbitrary prolate spheroidal systems with various boundary conditions. The temperature was derived for all possible systems, such as when the temperature was kept constant on the hyperbolic surfaces and variable on the prolate spheroidal surfaces, and vice versa. In'the latter case, roots with respect to the degree of the associated Legendre function for arguments larger than unity had to be determined. Some of the presented solutions have been evaluated numerically, and the isothermal surfaces have been presented.
Zusammenfassung Für beliebig ausgedehnte sphäroide Systeme wurde mit verschiedenen Randbedingungen eine stationäre lokale Temperaturverteilung ermittelt. Die Temperatur wurde für alle möglichen Fälle ermittelt, so auch für den Fall, in dem die Temperatur an der Hyperbeloberfläche konstant gehalten und an den ausgedehnten sphäroiden Flächen veränderlich ist bzw. umgekehrt. Für letzteren Fall mußten für Argumente größer als eins Wurzeln betreffs des Grades der zugehörigen Legendre Funktion ermittelt werden. Einige der dargestellten Lösungen wurden numerisch ermittelt und die isothermen Flächen dargestellt.
. , . , . .相似文献
20.
A new series of complexes of Zn(II), Cd(II) and Hg(II) with phosphoramidothioate (PAT), phosphorodiamidothioate (PDAT) and N,N-diphenylphosphorodiamidothioate (N,N-DPDAT) ligands have been synthesized and studied. The structures of the new compounds are discussed on the basis of their spectroscopic and thermal data. Thermoanalytical studies of these compounds have shown a dependence of the thermal stability on the size of the metal cation; the PAT complexes have greater thermal stability than the others.
Zusammenfassung Komplexe von Zn(II), Cd(II) und Hg(II) mit Phosphoramidothioat (PAT), Phosphorodiamidothioat (PDAT) und N,N-Diphenylphosphorodiamidothioat (N,N-DPDAT) als Liganden wurden synthetisiert und untersucht. Die Strukturen der neuen Verbindungen werden basierend auf deren spektroskopischen und thermischen Daten diskutiert. Die thermoanalytische Untersuchung dieser Verbindungen hat eine Abhängigkeit der thermischen Stabilität von der Größe der Metallkationen ergeben, und zwar sind die PAT-Komplexe thermisch stabiler als die anderen.
, , N,N . N,N . . . .相似文献