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1.
Summary In addition to pinostilbene and resveratrol, two new stilbene glycosides have been isolated from the phloem ofPinus sibirica R. Mayr, and their structures have been established as 3,4-dihydroxy-5-methoxy-stilbene 4--D-glycopyranoside (pinostilbenoside) and 3,4,5-trihydroxystilbene 4--D-glycopyranoside (resveratroloside).Irkutsk Institute of Organic Chemistry, Siberian Branch of the Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 677–682, November–December, 1975.  相似文献   

2.
The catalytic activity of some solid acidic catalysts was tested in the depolymerization of paraldehyde. It was found that the activities of sulfonated ion exchange resin and mounted phosphotungstic acid strongly exceed the activity of silica-alumina and other oxide catalysts. By means of Brönsted relationship, the differences in HO of the surfaces were estimated.
. , - - . HO .
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3.
Benzene alkylation by C2–C4 olefins in the presence of hydrogen over a steam-treated zeolite catalyst containing lanthanum and nickel, has been studied. The promoting action of hydrogen on benzene alkylation by propylene has been established.
C2–C4 , . .
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4.
An intumescent fire retardant coating can effectively control fire spread and damage. Its dual purpose is to confine the surface spread of flame to the boundaries of an already established fire, and to retard the penetration of heat and flame to and through the coated surface. Our composition expanded and provided an insulation layer between the flame source and the combustion substrate, and liberated a quantity of primarily non-flammable decomposition products which tended to extinguish the flame. The main ingredients of the coating were cellulose acetate butyrate and HMDI (Desmodur N) for Polyurethane, and Chlorowax-70 (chlorinated paraffins) as fire retardant component. This fire retardant coating was applied to wood panels, and tested in a 2-foot tunnel, its flame spread rating being measured. The effects of three parameters of interest were investigated: the type of wood used, the percentage of Chlorowax, and the coating thickness. It was found of interest to study the oxidation of the coating using different techniques, e.g. flash pyrolysis under oxygen and GC/MS for analysis of the decomposed products. Combustion studies of the coating were also conducted using DSC and thermogravimetry, either with the scanning mode or under isothermal conditions. Comparisons were made between the results obtained from pyrolysis and combustion.
Zusammenfassung Ein schwellender feuerhemmender Überzug kann Ausbreitung und Schäden von Feuer wirksam einschränken und wird zwei Zwecken gerecht: Verhinderung der Ausbreitung von ausgebrochenem Feuer und Schutz der überzogenen Oberfläche vor Hitze- und direkter Flammeneinwirkung. Die beschriebene Komposition quillt und bildet eine Isolationsschicht zwischen der Flammenquelle und dem brennbaren Material, liefert zugleich aber auch eine gewisse Menge von nichtbrennbaren, die Flamme erstickenden primären Zersetzungsprodukten. Die Hauptbestandteile des Überzugs sind Celluloseacetat und -butyrat und HMDI (Desmodur N) für Polyurethan sowie Chlorowax-70 (chlorierte Paraffine) als feuerhemmende Komponente. Dieser feuerhemmende Überzug wurde auf Holzplatten aufgebracht und in einem 2ft-Tunnel getestet, wobei die Flammenausbreitungsgeschwindigkeit gemessen wurde. Der Einfluß von drei interessierenden Parametern wurde untersucht: Typ des benutzten Holzes, Anteil von Chlorowax und Überzugsschichtdicke. Es erwies sich als interessant, die Oxydation des Überzugmaterials mit verschiedenen Techniken zu untersuchen, z.B. durch Schnellpyrolyse und Analyse der Zersetzungsprodukte mittels GC/MS. Verbrennungsuntersuchungen des Überzugmaterials wurden auch mittels DSC und Thermogravimetrie entweder nach der scanning-Arbeitsweise oder unter isothermen Bedingungen ausgeführt. Die bei Pyrolyse und Verbrennung erhaltenen Ergebnisse werden miteinander verglichen.

. -, , — . , . - ( ) ( ) . , . : , . , , , - . . , .
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5.
A method is proposed for the evaluation of quantum yields of photochemical reactions studied in the presence of absorbing additives using cylindrical sample tubes.
.
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6.
It has been found that carbohydrates naturally present in ppm quantities in paraformaldehyde are the cause of the autocatalysis in the formose reaction of paraformaldehyde solutions. Paraformaldehyde sublimed into Ca(OH)2 suspension was not transformed to sugars by formose reaction, only to methanol and formate by Cannizzaro reaction. A minute trace of glycolaldehyde — 3 ppm — was sufficient to initiate conventional autocatalysis. A formose reaction scheme in which formaldehyde reacts only with sugars by aldol condensation but not with itself is proposed.
, , .. . , Ca(OH)2, , , . — 3 .. — . , , .
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7.
The activity of platinum/alumina catalysts in cyclopropane hydrogenation has been investigated. Catalysts heated in exhaust gases are considerably less active in cyclopropane hydrogenation as compared to samples calcined in air. A relatively stable modification of the metallic surface is formed, probably as a result of coke or poison deposition.
- . , , , , , . , , .
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8.
Structural and morphological investigations of the solid state decomposition process of Ni(SCN)2(C5H5N)4 single crystals to microcrystalline Ni(SCN)2(C5H5N)2 reveal a contracting sphere reaction mechanism. Reconsidering possible artefacts registered by quantitative thermoanalytical measurements a pathway for the determination of specific and reproducible kinetic parameters for the rate-limiting step is described.
Zusammenfassung Strukturelle und morphologische Untersuchungen der Zersetzung von Ni(SCN)2(C5H5N)4-Einkristallen zu polykristallinem Ni(SCN)2(C5H5N)2 haben gezeigt, da\ diese Festkörperreaktion nach einem Kugelkontraktions-Reaktionsmechanismus verlÄuft. Unter Berücksichtigung der bei quantitativen thermoanalytischen Messungen möglicherweise auftretenden Artetakte wurde ein Weg zur Bestimmung der spezifischen und reproduzierbaren kinetischen Parameter für den geschwindigkeitsbestimmenden Schritt aufgezeigt.

Ni(SCN)2(C5H5N)4 Ni(SCN)2(C5H5N)2 . , , , .
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9.
It is shown that the oxidative condensation of ethane on CoMo/-Al2O3 catalysts is in principle possible. The conceivable paths of this reaction are analyzed.
- .
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10.
Chromium catalysts were prepared on monolith supports, some of them with radioactive Cr-51 in the surface. The dehydrogenation-hydrogenation reaction of cyclohexene was used to compare the catalytic activities of the radioactive and inactive catalysts. Differences were observed in the distribution of the main products at low temperatures and of the byproducts also at high temperatures.
, Cr-51. - . , — , .
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11.
The uptake of sulfur reduces the overall activity of PtMo/Al2O3 and enhances that of CoMo/Al2O3 in conversion of cyclohexanol. Significant changes in selectivity indicate the existence of different active sites of the initial catalyst for hydro-dehydrogenation and dehydration. The differences in catalytic activity expressed in terms of overall TOF decrease with increasing sulfur treatment like for Ru and Ir promoted catalysts.
PtMo/Al2O3 CoMo/Al2O3. - . Ru .
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12.
The adsorption of phenol, anisole, o-cresol and methanol on MgO was studied by infrared spectroscopy. The surface species of phenol, anisole and o-cresol were of the phenolate type and for methanol of the methoxide type.
, , - MgO . , - , — .
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13.
Several samples of Egyptian cotton fabric strips were subjected to various caustic mercerization conditions, varying in temperature and time. On these samples extensive measurements were undertaken, comprising X-ray diffraction, IR absorption spectra and the temperature-dependence of DC-electric conductivity.The phase constitution, % crystallinity, IR band assignment, activation energies for conduction and energy gap were evaluated as a function of caustic mercerization. The results obtained were correlated and discussed in detail, leading to valuable information of use in the cotton fabric strip industries.
Zusammenfassung Verschiedene Proben von ägyptischen Baumwollstreifen wurden unter verschiedenen Bedingungen (Temperatur, Zeit) einer Laugung unterworfen. Die gelaugten Proben wurden eingehend durch Röntgendiffraktometrie, IR-Absorptionsspektroskopie und Messungen der Temperaturabhängigkeit der elektrischen Gleichstromleitfähigkeit untersucht. Phasenstruktur, Kristallinität, Zuordnung der Banden, Aktivierungsenergien für die Leitfähigkeit und verbotene Bänder wurden in Abhängigkeit von der Laugung ermittelt. Die erhaltenen Ergebnisse wurden miteinander verglichen und in Einzelheiten diskutiert, wobei für die Baumwollverarbeitungsindustrie wertvolle und empfehlenswerte Informationen erhalten wurden.

. , . , , , . , .
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14.
A thermoanalytical study of estradiol monovalerate (a) and estriol (b) revealed the thermal stability, the decomposition kinetics, and the temperatures and intervals of fusion. The degree of purity was calculated only for estradiol monovalerate: 99.72 ± 0.11 mol %. The fusion enthalpy (29.45±0.47 kJ mol–1) and entropy for this compound were evaluated by differential scanning calorimetry. It was also possible to detect the polymorphism and the pseudopolymorphism of (a) and (b) after recrystallization from several solvents.
Zusammenfassung Die thermische Stabilität, die Zersetzungskinetik sowie die Schmeiztemperaturen und -intervalle von Estradiol-Monovalerianat (a) und Estriol (b) wurden thermoanalytisch ermittelt. Nur der Reinheitsgrad von (a) wurde berechnet (99,72 ± 0,11 mol %). Die Schmelzenthalpie (29,45±0,47 kJ · mol–1) und Schmelzentropie dieser Verbindung wurden mittels DSC bestimmt. Nach Rekristallisation in verschiedenen Lösungsmitteln konnten Polymorphie und Pseudopolymorphie für (a) und (b) nachgewiesen werden.

, . 99,72±0,11 %. (29,45±0,47 · –1) . , .
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15.
High activities and selectivities of Ni on SiO2 catalysts producing CO in the reaction of CH4 with CO2, have been obtained at relatively low temperatures. These aspects are considerably different from the activities or selectivities of other catalysts, and have been explained by assuming that the Ni on SiO2 catalyst markedly suppresses carbon deposition.
CO Ni SiO2 CH4 CO2. , Ni SiO2.
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16.
The Beckmann rearrangement of cyclohexanone oxime p-toluenesulfonate has been studied using several catalysts. The reaction is catalyzed by weakly acidic sites and seems to occur by way of O-(p-toluenesulfonyl)--caprolactim.
- -, . - -(-)--.
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17.
The previously suggested approach to the problem of kinetic system identification /1/ was used for the system of independent first order reactions. The analysis of the curves of CO2 formation in thermal destruction of brown coal indicates that both structure and model parameters of real processs can be identified in terms of the continuity concepts.
(I) ë . CO2 , , .
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18.
Kinetics of the oxidation of D-altrose by Ce(IV) perchlorate has been studied in perchloric acid medium. At equivalent concentrations the overall order of the reaction is two, being unity in each reactant. The reaction is characterized by a primary positive kinetic salt effect. Perchloric acid has been found to enhance the rate, while the addition of the reaction products retards the rate. No evidence for initial complexation has been obtained. Thermodynamic parameters have been determined and a mechanism consistent with the observed results is proposed.
D- Ce(IV) . , . . , . . , .
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19.
The temperature programmed desorption of several bases from a HY zeolite has shown that the activation energy of desorption represents a useful measure for characterizing the acidic properties.
- HY , , .
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20.
Photoinduced adsorption (PIA) of oxygen molecules on AgBr films at 77 K has been experimentally observed and investigated. Lifetimes of PIA centers and desorption activation energies of O2 molecules have been determined. The process is suggested to compete with the ionic step of AgBr photolysis.
- () - AgBr 77 K. - O2. , , - AgBr.
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