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1.
The equilibria and thermodynamics of a number of naturally occuring isolated compounds (e.g. proteins, amino acids, carbohydrates) have recently been studied in several laboraties in different temperature ranges, and thermoanalytical methods have been used to study structural changes of biological materials, among them human tissues.In our investigations we succeeded in appling the derivatograph for the assay of glycosaminoglycans and for the characterization of the stability of crosslinked proteins in intact human and animal tissues. By means of this method age-related and pathological changes and repair reactions were studied in various connective and vascular tissues.Other temperature-dependent techniques (DSC, polarizing microscopy) were used successfully in another series of experiments. Alterations in the characteristic order-disorder transition temperatures of human serum lipoproteins could be demonstrated in pathological conditions; the altered physical structure of lipoproteins might give an additional explanation to the assumed mechanism of different metabolic disorders.
Zusammenfassung Die Gleichgewichte und die Thermodynamik einer Reihe von natürlich vorkommenden isolierten Verbindungen (z. B. Proteine, Aminosäuren, Kohlenhydrate) wurden in verschiedenen Laboratorien in verschiedenen Temperaturbereichen untersucht. Hierbei wurden thermoanalytische Methoden zum Studium der Strukturänderungen von biologischem Material, u. a. von menschlichem Gewebe, eingesetzt.In unseren Untersuchungen gelang es den Derivatographen zur Prüfung von Glycosaminoglycanen und zur Charakterisierung der Stabilität quervernetzter Proteine in intakten menschlichen und tierischen Geweben einzusetzen. Durch diese Methode wurden altersbedingte und pathologische Änderungen sowie Reaktionen zur Wiederherstellung in verschiedenen Binde und Vasculärgeweben studiert.Andere temperaturabhängige Techniken (DSC, Polarisationsmikroskopie) wurden in anderen Versuchsserien mit Erfolg eingesetzt.

, . , , , , . . , . .


Plenary lecture  相似文献   

2.
The liquid-phase catalytic hydrogenation of various organic compounds was carried out using new rhodium catalysts supported on AlPO4–SiO2 (2080 wt. %) system, in methanol as solvent, under low hydrogen pressure (0.55 MPa) and at 293 K. Neither alkene isomerization nor hydrogenolysis products were detected in any of the cases.
AlPO4–SiO2 (2080 . %), , , (0,55 MPa) 293 . , .
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3.
Z-2-benzamido(acetamido)-3-(3-indolyl)-2-propenoic acids were hydrogenated with neutral and cationic rhodium(I) complexes containing the chiral diphosphine (–) or (+)–2,3-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino)-butane [(–) or (+)–DIOP].
Z-2- ()-3-(3-)-2- () (I), (–) (+)-2,3--2,3--1,4- ()-.
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4.
The GC-MS method was used to identify the addition products of methyldichlorosilane to vinyl acetate. Radiation-induced addition of methyldichlorosilane to vinyl acetate produces 2-methyldichlorosilylethyl ethyl ether. The reaction follows a radical-chain mechanism. The ratio of the rate constants of methyldichlorosilyl radical addition to C=C and C=O to vinyl acetate amounts to 0.4±0.1 (303 K).
- . , - 2- . , C=C C=O 0,4±0,1.
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5.
The possibility of describing the kinetics of thermal degradation of PVC samples under both isothermal and nonisothermal conditions with a unique model and using the same set of parameters was investigated. Analysis of the experimental data revealed good agreement at higher temperatures (above 175 °C) when the catalytic action of generated HCl and its distribution in the sample were considered. At lower reaction temperatures, further experimental conditions and/or sample characteristics must be considered, and a modification of the model is necessary.
Zusammenfassung Es wird die Möglichkeit untersucht, die Kinetik des thermischen Abbaus von PVC sowohl unter isothermen wie unter nichtisothermen Bedingungen durch ein einziges Modell und unter Verwendung des gleichen Parametersatzes zu beschreiben. Die Analyse der Messdaten zeigt gute Übereinstimmung bei hohen Temperaturen (über 175 °C), wenn die katalytische Aktivität des entwickelten HCL und seine Verteilung in der Probe berücksichtigt werden. Bei tieferen Temperaturen müssen weitere experimentelle Bedingungen und/oder Probeneigenschaften berücksichtigt werden, was eine Modifizierung des Modells erforderlich macht.

. ( 175°), . , .
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6.
The chlorination kinetics of pure vanadia was studied via isothermal thermogravimetric measurements, with CCl4, CoCl2 and Cl2 as chlorinating agents. At temperatures where chemical control was predominant, apparent activation energies of 77, 48 and 126 kJ: mol–1 were obtained for chlorination by CCl4, COCl4 and Cl2, respectively. For interpretation of the conversion vs. time curves in the whole conversion range, a non-uniform particle size distribution was assumed, where the reacting solid phase was considered to be composed of thin plates of different thicknesses. With this model, a fairly good correspondence was obtained between the measured and calculated kinetic curves. Selected thermodynamic calculation data on the V2O5 + CCl4, V2O5 + COCl2 and V2O5 + Cl2 systems are presented.
Zusammenfassung Mittels isothermen Thermogravimetriemessungen wurde die Kinetik der Chlorierung von reinem Vanadiumoxid mit CCl4, COCl2 und Cl2 als Chlorierungsmittel untersucht. Bei Temperaturen mit vorherrschender chemischer Kontrolle wurde für die Chlorierung mit CCl4, COCl2 bzw. Cl2 Bruttoaktivierungsenergien von 77, 48 bzw. 126 kJ/mol erhalten. Zur Interpretation der Konversion-Zeit-Diagramme im gesamten Conversionsbereich wurde eine nichteinheitliche Teilchengrösseverteilung angenommen, namentlich den Bestand der reagierenden Festphase aus dünnen Plättchen unterschiedlicher Dicke. Mit diesem Modell konnte eine recht gute Übereinstimmung zwischen errechneten und ermittelten kinetischen Kurven erhalten werden. Einige thermodynamische Rechenbeispiele für die Systeme V2O5 + CCl4, V2O5 + COCl2 und V2O5+Cl2 wurden gegeben.

, l4, l2 l2. , l4, l2 l2, 77, 48 126 ·–1. — , . , . - . V2O5+CCl4, V2O5+COCl2 V2O5+Cl2.
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7.
It is shown that, in contrast to classical impregnation methods, in bimetallic catalyst production the texture of the carrier is stabilized by introducing the promoting ion on the surface of Pt/Al2O3 with vapors of CrO2Cl2 or SnCl4. This is shown by a relatively slower decrease of the specific area and the volume of the pores upon calcination.
, Pt/Al2O3- CrO2Cl2 SnCl4 . .
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8.
    
2--4--2 -2. , .
The kinetics of intramolecular condensation of 2-methyl-4-phenylbutanol-2 have been studied in the presence of the strongly acidic cation exchanger KU-2. The reaction is first order with respect to the catalyst. A linear relationship is found between the rate constant and the extent of modification by sodium ions of the cation exchanger.
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9.
Iron(II) tartrate two and a half hydrate (FeC4H4O6·2.5H2O) was prepared and its thermal dehydration and decomposition were studied with a simultaneous thermal analyser (TG/DTA/DTG) under atmospheres of static air, dynamic dry nitrogen and dynamic air. This study was supplemented with the two-probe d.c. electrical conductivity technique under the same atmospheres. Under all the above atmospheres, the thermal dehydration was found to be a two-step process. However, the thermal decomposition process was quite complicated, involving the formation of various metastable intermediates, including-Fe2O3. The final product of decomposition under all atmosphere was-Fe2O3.Studies on the physical properties of-Fe2O3 were also undertaken.
Zusammenfassung Es wurde Eisen(II)-tartrathydrat (FeC4H4O6 · 2,5H2O) hergestellt und seine thermische Dehydratation bzw. Zersetzung in statischer Luftatmosphäre bzw. im Stickstoff- und Luftstrom mittels eines Simultanthermoanalysators (TG/DTA/DTG) untersucht, ergänzt durch Untersuchungen nach dem Gleichstromleitfähigkeitsverfahren in den gleichen Atmosphären. Die thermische Dehydratation wurde in jedem Falle als zweistufig befunden. Der thermische Zersetzungsprozeß ist jedoch wegen der Bildung verschiedener metastabiler Zwischenprodukte, z. B.-Fe2O3, recht kompliziert. Das Endprodukt der Zersetzung war in allen Fällen-Fe2O3. Weiterhin wurden die physikalischen Eigenschaften von-Fe2O3 untersucht.

, FeC4H4O6 · 2,52. . , . , y-Fe2O3. -Fe2O3. -Fe2O3.


Now deceased.

Financial assistance for this work was given by Grants-in-aid (Defence Ministry), Govt. of India. One of the authors (A.V.R.) is grateful to the Head, Dept. of Chemistry, Sardar Patel University, for his interest and encouragement.  相似文献   

10.
By means of thin-layer and gas chromatography the reaction products have been determined in the oscillation system of aniline, KBrO3 and H2SO4. These products include: 2-bromoaniline, 4-bromoaniline, 2,4-dibromoaniline, 2,4,6-tribromoaniline, 1,4-benzoquinone, 2-bromo-1,4-benzoquinone, 2,6-dibromo-1,4-benzoquinone and a brominated oxidation product. The brominated aniline derivatives do not exhibit an oscillating behavior, and the addition of these substances to an oscillating mixture damps the course of other oscillations.
, KBrO3 H2SO4. : 2-, 4-, 2,4-, 2,4,6-, 1,4-, 2--1,4-, 2,6--1,4- . , , , .
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11.
Ni(II), Ni(I) Ni(O) . , , , Ni(O) Ni(I) - Ni(I) Ni(II) Ni(O).
The interaction of organoaluminium compounds with phosphine complexes of Ni(II), Ni(I) and Ni(0) has been studied under the conditions of catalytic propylene dimerization. The active complexes are formed from Ni(II) compounds, the regeneration of the latter is ensured by repeated reduction, oxidation of Ni(0) to Ni(I), and by disproportionation of Ni(I) into Ni(II) and Ni(0).
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12.
Liquid (aqueous) phase catalytic hydrogenation of compounds containing two oxo-groups in -position (biacetyl, glyoxal, alloxan) was studied in the presence of tungsten carbide catalyst. It has been shown that only one of the oxo-groups is affected in the course of the process and is transformed into a >CH–OH group. Comparative studies carried out in the presence of platinum catalyst attest the selective behaviour of tungsten carbide.
- - (, , ). , >C=O >CH–OH, . .
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13.
The kinetics of thermal dehydration of [Ni2Al(OH)6]2SO4.nH2O has been studied through the analysis of isothermal weight loss data. The results obtained seem to indicate that the process is governed by a diffusion mechanism up to an value which is dependent on the temperature. An explanation is provided for this behaviour on the basis of the structural properties of the compound and the nature of the water loss.
Zusammenfassung Die Kinetik der thermischen Dehydratisierung von [Ni2Al(OH)6]2SO4.nH2O wurde mittels isothermer TG untersucht. Die Ergebnisse scheinen darauf hinzudeuten, daß der Prozeß bis zu einem von der Temperatur abhängigen -Wert von einem Diffusionsmechanismus bestimmt wird. Für dieses Verhalten wird basierend auf den strukturellen Eigenschaften der Verbindung und der Natur der Wasserabgabe eine Erklärung gegeben.

, [Ni2Al(OH)6]2SO4.nH2O. , , . , .
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14.
Studies of the interaction of hydrotrioxides ROOOH of ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1,1-dimetoxyethane, 1,1-diethoxyethane, benzaldehyde and tetrahydrofuran with trimethyl triisopropyl, tributyl, triallyl, triphenyl and tri-o-chresyl phosphites (RO)3P have revealed that in mild conditions ROOOH rapidly and selectively oxidizes (RO)3P to the corresponding phosphates. The reaction stoichiometry has been established. Aromatic phosphites are shown to be of inferior reactivity to ROOOH as compared with aliphatic phosphites.
, 1-, 2-, 1-, 2-, 1,1-, 1,1-, -, -, -, -, -, -, -- (RO)3P. ROOOH (RO)3P . . , ROOOH .
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15.
The synthesis of some new and economical BPO4 catalysts is described. The chemical and textural properties and the thermogravimetric analysis (TGA) of these catalysts is given. The dehydration of cyclohexanol, cycloheptanol and cyclooctanol catalyzed by these new BPO4 catalysts is studied using the microcatalytic pulse technique.
BPO4. , (). , , BPO4, .
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16.
The kinetics of isothermal dehydration of LiKC4H4O6.H2O single-crystals was investigated in the [001] crystallographic direction under a dynamic vacuum of 6.7×10–5 Pa with a quartz crystal microbalance. The removal of H2O molecules may be described by a diffusion equation for a semi-infinite medium. The diffusion coefficients vary from 2.13×10–11 cm2 s–1 at 391.7 K to 9.9×10–9 cm2 s–1 at 453.2 K. The scanning electron microscope data provide some evidence that the dehydration is not a topochemical reaction. From the experimental data it is concluded that the anhydrous product is in the state of premelting. This explains the anomalous diffusion energyE D=37±1 kcal mol–1 and preexponential factorD 0=5×109 cm2 s–1.
Zusammenfassung Die Kinetik der Entwässerung von LiKC4H4O6.H2O in [001] — Richtung unter dynamischem Vakuum wurde mit einer Quarzkristall-Mikrowaage verfolgt. Die Abgabe von Wasser kann mit einer Diffusionsgleichung für ein halb-unendliches Medium beschrieben werden, die Diffusionskoeffizienten variieren von 2, 13 · 10–11 cm2s–1 bei 391,7 K bis 9,9 · 10–9 cm2 s–1 bei 453,2 K. Rasterelektronenmikroskopische Aufnahmen zeigen, daß die Entwässerung nicht topochemisch abläuft. Nach dem experimentellen Ergebnis befindet sich das entwässerte Produkt in einem Vorschmelz-Stadium. Daraus erklären sich die anomalen Werte für die DiffusionsenergieE D=(37±1) kcal mol–1 und den präexponentiellen FaktorD 0=5 · 109 cm2 s–1.

6,7 · 10. LiKC4H4O6.H2O [001]. . 2,13·10–11 2 –1 391,7 9,9·10–9 2 –1 453,2 . , . , «», E =37±1 ·– 1 0=5·1092·–1.
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17.
Effect of silylation with hexamethyldisilazane on adsorption and catalytic properties of porous glass-supported platinum catalysts has been studied. Catalytic activity decreases markedly with an increase in surface coverage by trimethylsilyl groups for all the following reactions examined: hydrogenation of benzene, dehydrogenation of cyclohexane and dehydrocyclization of n-hexane.
, . , : , -.
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18.
    
Syngas reactions have been performed under pressure (6 MPa) on Co–Y and Co–Cu–Y catalysts with the intent to obtain good conversions and high C2–C5 alcohol selectivities. The addition of MoOx promotes the alcohol production and stabilizes the catalysts. TPR experiments indicate clearly the strong interaction between Co, Cu and Mo and XRD data show that MoOx prevents structural damage during the ageing.
Co–Y Co–Cu–Y 6 MPa C2–C5. MoOx . Co, Cu Mo, , MoOx .
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19.
The temperature of the polymerizing system was measured with a thermistor during the bulk polymerization of acrylonitrile initiated by azoisobutyronitrile. The temperature of self-heating suddenly rises at a conversion of about 2%. This jump of temperature is presumably caused by the formation of a gel structure and, consequently, the outfall of thermal convection within the system.
, -- . , - . - , .
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20.
[Cu(-C2H2)2]+, [Cu(-CCH2)2]+ and [Cu(-C2H2) (-CCH2]+ complexes have been studied by the ab initio double-zeta basis set method. It has been established that all calculated compounds are stable to decomposition into two C2H2 molecules and Cu+ cation and into one C2H2 molecules and the respective monocomplex. Calculation results suggest the possibility of intramolecular acetylene-vinylidene rearrangement in the coordination sphere of Cu+.
ab initio : [Cu(-C2H2)2]+, [Cu(-CCH2)2]+, [Cu(-C2H2) (-CCH2)]+. C2H2 Cu+ C2H2 . - Cu+.
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