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1.
The influence of small (lower than 0.02) molar fractions of water on the rate of ammonia decomposition on platinum wires was studied for ammonia pressures varying between 6.7 and 93.3 kPa and temperatures between 800 and 1700 K. The presence of water strongly inhibited the rate of reaction in all experiments.
( 0,02) , 6,7 93,3 , 800 1700 K. .相似文献
2.
Kinetics of the reactions of WCl6 with Ph4Sn, Ph3SnCl and Ph2SnCl2 have been studied by UV-VIS spectroscopy. Approximate values of the corresponding rate constants in benzene have been obtained.
WCl6 Ph4Sn, Ph3SnCl Ph2SnCl2, , - . .相似文献
3.
Kinetic analysis of the simple reaction scheme of the heterogeneously catalyzed reaction AB has been made for the classical Langmuir adsorption and the Ipateev displacement adsorption. It has been shown that the only kinetic consequence of displacement adsorption is the different physical meaning of the parameters of the rate equation. Its form remains the same for both adsorption modes. This conclusion seems to be general also for other reaction schemes.
AB . , . . .相似文献
4.
A. I. Trokhimetz 《Reaction Kinetics and Catalysis Letters》1979,12(4):547-552
A kinetic equation is derived for the bimolecular isotope exchange reaction between AX
n
*
and BX
m
o
, all atoms of element X in each molecule being equivalent. The equation can be generalized for homogeneous and heterogeneous catalytic isotope exchange.
, AX n * BX m o , X . , - .相似文献
5.
The activity of modified Fe/Al2O3 catalysts in the hydrocondensation of CO has been studied in terms of the selectivity for light olefins and of repartition of the hydrocarbon products.
Fe/Al2O3 CO, .相似文献
6.
D. J. Morgan 《Journal of Thermal Analysis and Calorimetry》1977,12(2):245-263
A DTA apparatus has been linked to non-dispersive infrared H2O and CO2 analyzers and an SO2 analyzer based on an electrochemical cell, enabling evolution profiles of these three volatiles to be recorded simultaneously with the DTA curve. Examples are given of the use of the combined DTA-EGA method in the determination of the quantitative mineralogical composition of potential industrial raw materials.
Zusammenfassung Ein DTA-Gerät wurde mit nicht-dispersiven Infrarot-Analysatoren für H2O und CO2 sowie mit einem auf einer elektrochemischen Zelle beruhenden SO2-Analysator gekoppelt, welche die gleichzeitige Registrierung der Entwicklungsprofile dieser drei flüchtigen Substanzen und der DTA-Kurve gestatten. Beispiele zum Einsatz der kombinierten DTA-EGA-Methode bei der Bestimmung der quantitativen mineralogischen Zusammensetzung potentieller Rohstoffe der Industrie werden gegeben.
Résumé On a couplé un appareil d'analyse thermique différentielle avec un spectromètre infrarouge non dispersif pour l'analyse d'H2O et CO2 et avec une cellule électrochimique pour l'analyse de SO2, afin d'enregistrer simultanément la courbe ATD et le profil de dégagement de ces trois composés volatils. On donne des exemples d'application de ce couplage dans la détermination de la composition minéralogique quantitative de matières premières potentielles de l'industrie.
H2O 2, - SO2 , . - .相似文献
7.
A. Kamińska S. Sanyal H. Kaczmarek 《Journal of Thermal Analysis and Calorimetry》1989,35(7):2135-2141
The influence of some irregularities in polystyrene (PS) and polyvinyl chloride (PVC) chains on their thermal stability was investigated. UV irradiation caused an increase in the content of these irregularities in the polymers. It was found that the presence of carbonyl groups and crosslinking of the polymer chains hamper the thermal dehydrochlorination of PVC and the total decomposition of both polymers. On the other hand, weak peroxy linkages (which facilitate degradation processes) and conjugated double bonds decrease the temperature of total decomposition of PS and PVC blends.
Zusammenfassung Es wurde der Einfluß von Unregmlmäßigkeiten in Polystyrol (PS)- und Polyvinylchlorid (PVC)-Ketten auf deren thermische Stabilität untersucht. UV-Bestrahlung verursacht ein Ansteigen des Gehaltes an Unregelmäßigkeiten in den Polymeren. Es wurde festgestellt, daß die Gegenwart von Carbonylgruppen und Querverbindungen der Polymerketten die thermische Dehydrochlorierung von PVC und eine vollständige Zersetzung beider Polymere verhindern. Andererseits senken Peroxidverknüpfungen (die die Degradierungsvorgänge erleichtern) und konjugierte Doppelbindungen die Temperatur für eine vollständige Zersetzung von PS und PVC Gemischen.
. - . , . , , , .相似文献
8.
The activity of vanadia/titania catalysts in CO oxidation has been tested and found to be of the same order as that observed for unsupported vanadia; the simultaneous presence of vanadium-sodium compounds cancels the activity, probably because of the elimination of labile V=0 species at surface defects.
V2O5/TiO2 CO, V2O5; - , , V=0 .相似文献
9.
E. Alabiso P. Ciambelli V. De Simone C. Porcellu R. Valentino 《Reaction Kinetics and Catalysis Letters》1979,12(4):451-456
The catalytic activity of a chabazite tuff in the partial oxidation of H2S to sulfur has been determined. The effects of temperature, feed concentration and chemical composition of the tuff on H2S conversion and selectivity to sulfur have been investigated. Encouraging results in view of a possible use in H2S removal processes have been obtained.
H2S . , H2S . H2S.相似文献
10.
I. Labádi K. Burger G. Liptay M. Czugler A. Kálmán 《Journal of Thermal Analysis and Calorimetry》1986,31(5):1171-1181
Eleven copper(II)-ethylene glycol-sulphate complexes of different compositions were prepared, one of them-CuGl2(H2O)2SO4-in single-crystal form. A thermoanalytical study of these complexes revealed three types of thermal decomposition pattern. The X-ray structure of the single-crystal demonstrated the presence of ethylene glycol bridges resulting in endless chains in the crystal.
Zusammenfassung Elf Kupfer(II)-äthylenglykol-sulfat-Komplexe unterschiedlicher Zusammensetzung wurden dargestellt, einer davon — CuGl2(H2O)2SO4 — in Form von Einkristallen. Die thermoanalytische Untersuchung dieser Komplexe ergab drei Typen der thermischen Zersetzung. Die röntgendiffraktometrische Bestimmung der Struktur des in Form von Einkristallen erhaltenen Komplexes zeigte, daß den Kristall endlose Ketten von Äthylenglykolbrücken durchziehen.
() — , — CuGl2(H2O)2SO4 — . . , , .相似文献
11.
G. K. Bratspies J. F. Smith J. O. Hill P. J. Derrick 《Journal of Thermal Analysis and Calorimetry》1979,16(2):369-379
A new tin dithiocarbamate containing sulphur bridges, di--sulphidobis [bis(N,N-diethyldithiocarbamato)tin(IV)], has been isolated from the thermal decomposition of tetrakis(N,N-diethyldithiocarbamato)tin(IV). A dimeric structure is proposed on the basis of results from mass spectrometry, infrared spectroscopy, thermal analysis and vapour pressure osmometry.
The authors gratefully acknowledge the assistance given by Dr. A. G. Wedd with the vacuum sublimation technique. One of us, G. K. B., is grateful for a research scholarship provided by La Trobe University. 相似文献
Zusammenfassung Ein neues, Schwefelbrücken enthaltendes Zinn-Dithiocarbamat, Di--sulfidobis[bis(N,N-diäthyldithiocarbamato)Zinn(IV)], wurde bei der Zersetzung von Tetrakis(N,N-diäthyl-dithiocarbamato)Zinn(IV) isoliert. Aufgrund der Ergebnisse der Massenspektrometrie, der Infrarotspektroskopie, der Thermoanalyse und der Dampfdruck-Osmometrie wird eine Dimerstruktur vorgeschlagen.
Résumé Un nouveau dithiocarbamate d'étain contenant des ponts de soufre, le di--sulfidobis[bis(N,N-diéthyl-dithiocarbamato)é tain(IV)], a été isolé lors de la décomposition thermique du tétrakis(N,N-diethyl-dithiocarbamato) étain(IV). Une structure dimère est proposéeà partir des résultats obtenus par spectrométrie de masse, spectroscopie infrarouge, analyse thermique et osmométrie sous pression de vapeur.
—-- [/N,N- (/IV)], [/N,N- (/IV)], , (N,N- ) (IV). - , , .
The authors gratefully acknowledge the assistance given by Dr. A. G. Wedd with the vacuum sublimation technique. One of us, G. K. B., is grateful for a research scholarship provided by La Trobe University. 相似文献
12.
Acid-base and radical properties of two sets of MgO–Na catalysts have been studied. The catalysts were prepared (I) by impregnation of MgO with NaOH in aqueous solution, and (II) by evaporation of metallic sodium onto a MgO surface. The catalyst prepared by the second method was much more basic than pure MgO (Ho=35) and showed a high activity in olefin isomerization.
- MgO–Na. 1) MgO (NaOH) 2) MgO. , , , MgO(H0=35), .相似文献
13.
M. I. Zaki G. A. M. Hussien R. B. Fahim 《Journal of Thermal Analysis and Calorimetry》1985,30(1):129-134
The kinetics of the solid-state reaction between alumina and strontium carbonate were studied by thermogravimetry. The effects of the structure ( or) and/or doping (with Li+ or Cd2+) of the alumina on the kinetics of the reaction were examined. The results obtained were correlated with the phase composition and structural changes, followed by a number of physicochemical analyses (DTA, XRA and IRA) throughout the course of the reaction.
Zusammenfassung Die Kinetik der Festkörperreaktion zwischen Aluminiumoxid und Strontium-carbonat wurde thermogravimetrisch untersucht. Die Effekte der Struktur ( und) und/oder des Dopens des Aluminiumoxids (mit Li+ oder Cd2+) auf die Kinetik der Reaktion wurde untersucht. Die erhaltenen Ergebnisse wurden mit der Phasenzusammensetzung und mit durch physikalisch-chemische Analysenverfahren (DTA, XRA und IRA) während des Reaktionsverlaufs verfolgten strukturellen Veränderungen in Beziehung gebracht.
. ( ) Li+ Cd2+ . , , - .相似文献
14.
15.
C. N. Koshelev A. V. Mashkina N. G. Kalinina 《Reaction Kinetics and Catalysis Letters》1989,39(2):367-372
The catalytic decomposition of dimethyl sulfide has been studied over the temperature range of 400–500 °C. The main reaction products are methylmercaptane, H2S and methane. Catalyst deactivation is due to its coking during the reaction. The possibility of oxidative catalyst regeneration at 550 °C has been shown.
400–500°C. , . , . 550°C.相似文献
16.
The objective of the work was to study the influence of external factors (changes in composition, load and temperature) on the regimes of heterogeneous catalytic reactors. As shown, a rather fast change in external parameters causes an internal reorganization of the CSTR thus leading to an increase in average conversion.
( , , ). , , , .相似文献
17.
《Reaction Kinetics and Catalysis Letters》1982,21(3):327-333
- () SiAl. , - 125 /–1. SiAl - .
Studies of the acidic and catalytic properties of superhigh silica (SHS) zeolites with different SiAl ratios on a vacuum-circulation reactor indicate that n-hexane cracking is a first order reaction with the effective activation energy of 125 kJ/mol–1. With increasing the SiAl ratio the acidity and activity of SHS-zeolites decrease.相似文献
18.
G. Goswami B. P. Padhy J. D. Panda 《Journal of Thermal Analysis and Calorimetry》1989,35(4):1129-1136
A number of samples from the pre-burning zone of a wet-process cement rotary kiln were examined by combined DTA/TG and XRD for estimation of spurrite (2Ca2SiO4·CaCO3). It was found that decarbonation temperatures of spurrite range from 1130 to 1190 K and they are 45 to 75 K higher than that of calcite occurring in the same sample. In the TG curves calcite and spurrite can be easily distinguished and accordingly both can be estimated from the same TG scan. Combined DTA/TG, supplemented by XRD, is a very effective method for qualitative and quantitative estimation of spurrite in cement rotary kiln materials.
The authors are very grateful to Mr. A. H. Dalmia, president, M/s. Orissa Cement Limited, Rajgangpur for allowing to collect the samples during the stoppage of the kiln and also for his permission to publish the paper. 相似文献
Zusammenfassung Unter kombinierter Anwendung von DTA/TG und Röntgendiffraktionsverfahren wurde eine Anzahl Proben aus einem Vorkalzinator eines Drehrohrofens zur Zementherstellung nach dem Naßverfahren auf Spurrit (2Ca2SiO4·CaCO3) untersucht. Es wurde festgestellt, daß die Temperatur für das Austreiben von CO2 bei Spurrit zwischen 1130 und 1190 K und somit um 45–75 °C höher als bei in derselben Probe vorliegenden Kalzit liegt. Aufgrund der TG-Kurven können Kalzit und Spurrit leicht voneinander unterschieden und demzufolge mit einem einzigen TG-Scan bestimmt werden. Kombinierte DTA/TG, ergänzt durch Röntgendiffraktionsverfahren ist eine sehr leistungsstarke Methode zur qualitativen und quantitativen Bestimmung von Spurrit in Stoffen aus Zementdrehrohröfen.
(2Ca2SiO4 · CaCO3), / , , . , 1130– 1190 , 46–75 , . . /, , .
The authors are very grateful to Mr. A. H. Dalmia, president, M/s. Orissa Cement Limited, Rajgangpur for allowing to collect the samples during the stoppage of the kiln and also for his permission to publish the paper. 相似文献
19.
T. G. Alkhazov A. E. Lisovskii T. Kh. Gulakhmedova 《Reaction Kinetics and Catalysis Letters》1979,12(2):189-193
The oxidative dehydrogenation of ethylbenzene over a charcoal catalyst has been studied by the pulse technique. The styrene yields for the oxidation of ethylbenzene by gaseous oxygen and upon the interaction of ethylbenzene with oxygen adsorbed on charcoal are shown to be the same.
. , , , .相似文献
20.
A common type of rate equations for hydrocarbon conversions under reforming conditions has been shown, resulting from the features of the hydrocarbons and hydrogen adsorption on the Pt/Al2O3 catalyst. This has been confirmed by variations in the rate of cyclohexane conversion observed upon the introduction of methane into the reaction mixture. Methane does not react but is strongly adsorbed on the catalyst surface.
, . , , .相似文献