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1.
1.  When silicas are modified with amines, not all surface silanol groups participate in the chemical reaction.
2.  When amine-modified silica gels are heated, water is produced; the maximum rate of the formation of gas occurs at 625 and 750 K. Destruction of the modifying layer begins with the liberation of ammonia at T > 640 K.
3.  Adsorption of SO2 and CO2 on aminated silicas is determined by the surface concentration of amino groups, by their nature, and by their mutual position.
Translated from Izvestiya Akademiya Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 983–990, May, 1989.  相似文献   

2.
1.  CO2 interacts with the hydrogen forms of type Y zeolites, erionite, and mordenite without experiencing any loss in symmetry.
2.  The adsorption of CO2 at 20°C on zeolites containing monovalent cations involves ion-dipole cation interaction in the case of A, X, and Y zeolites, erionite, and mordenite, and the formation of more stable carbonate structures in the case of the A, X, and Y zeolites. Transition between the bidentate coordinated carbonate structure and the carbonate ion proceeds through adsorbed forms of CO2 resulting from ion-dipole interactions.
3.  The symmetry of stable carbonate structures established on the Ca forms of zeolites A, X, and Y can alter under the action of various adsorbates.
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3.
The energy metabolism of a mammalian cell line grown in vitro was analyzed by substrate consumption rates and metabolic flux measurements. The data allowed the determination of the relative importance of the pathways of glucose and glutamine metabolism to the energy requirements of the cell. Changes in the substrate concentrations during culture contributed to the changing catalytic activities of key enzymes, which were determined.
1.  A murine B-lymphocyte hybridoma (PQXB1/2) was grown in batch culture to a maximum cell density of 1–2×106 cells/mL in 3–4 d. The intracellular protein content showed a maximum value during the exponential growth phase of 0.55 mg/106 cells. Glutamine was completely depleted, but glucose only partially depleted to 50% of its original concentration when the cells reached a stationary phase following exponential growth.
2.  The specific rates of glutamine and glucose utilization varied during culture and showed maximal values at the midexponential phase of 2.4-nmol/min/106 cells and 4.3 nmol/min/106 cells, respectively.
3.  A high proportion of glucose (96%) was metabolized by glycolysis, but only limited amounts by the pentose phosphate pathway (3.3%) and TCA cycle (0.21%).
4.  The maximum catalytic activity of hexolinase approximates to the measured flux of glycolysis and is suggested as a rate-limiting step. In the stationary phase, the hexokinase activity reduced to 11% of its original value and may explain the reduced glucose utilization at this stage.
5.  The maximal activities of two TCA cycle enzymes were well above the measured metabolic flux and are unlikely to pose regulatory barriers. However, the activity of pyruvate dehydrogenase was undetectable by spectrophotometric assay and explains the low level of flux of glycolytic metabolites into the TCA cycle.
6.  A significant proportion of the glutamine (36%) utilized by the cells was completely oxidized to CO2.
7.  The measured rate of glutamine transport into the cells approximated to the metabolic flux and is suggested as a rate-limiting step.
8.  Glutamine metabolism is likely to occur via glutaminase and amino transaminase, which have significantly higher activities than glutamate dehydrogenase.
9.  The calculated potential ATP production suggests that, overall, glutamine is the major contributor of cellular energy. However, at the midexponential phase, the energy contribution from the catabolism of the two substrates was finely balanced—glutamine (55%) and glucose (45%).
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4.
1.  The complexes of Pd(acac)2 and Pd(OAc)2 with triphenylphosphine catalyze the telomerization of isoprene with water in the presence of CO2, which leads to the formation of isomeric dimethyloctadienols.
2.  The complexes of Pd(acac)2 and Pd(OAc)2 with tricresyl phosphite catalyze the formation of the isomeric dimethyloctadienol acetates from isoprene and CH3COOH.
3.  In acetone the complexes of Pd(acac)2, Pd(OAc)2 with triphenylphosphine smoothly and almost completely dimerize isoprene to 2,7-dimethyl-1,3,7-octatriene.
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5.
Ethylene-olefin copolymers differ from other polyethylenes in that:
-  there is no long chain branching;
-  short chain branching is determined by the comonomer unit;
-  the molecular mass distribution is sharp;
-  the side chain distribution on different molecules is broad;
-  the sequential distribution of branching is very broad along the molecular chains, which becauses a multi-peak lamella distribution, and a multi-peak melting heat.
With the help of a cross-fractionation method we interpreted the differences of the experimental data, according to the molecular mass fractionation and the branching received.  相似文献   

6.
1.  By14C labeling, it has been shown that carbon dioxide will adsorb differently on various synthetic Ca2+-ion-containing zeolites (CaNaY, and dealuminated CaNaY and CaNdNaY) on which benzene is being alkylated by ethylene. The promoting action of CO2 is due to the presence of a weakly adsorbed form of the compound which can be readily displaced by N2 at the reaction temperature.
2.  The CO2 content of the catalyst and its time variation are dependent on the zeolite composition, the re-action temperature, and the moisture content of the CO2.
3.  Under fixed operating conditions, the CO2 content of zeolite 0.67CaNaY and its time variation are the same for C6H6 alkylation by ethylene and for toluene disproportionation.
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7.
1.  In NaA zeolite a homocharge is formed by charges deposited on the surface of the zeolite from the gas gap between the electrode and the specimen.
2.  The existence of thermoelectret effects has been found in the systems NaA-zeolite -air, NaA-helium, NaA-nitrogen, and NaA-oxygen.
3.  The thermoelectret effects are caused by both the accumulation of charges in the specimen and the adsorption of molecules in the electric field.
4.  A low mobility has been noted for adsorbed molecules in the electret state of the system.
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8.
1.  The kinetics of reactions of alkali metal salts of 9-carbomethoxy- and 9-cyanofluorene with para-nitrofluorobenzene and of Me3SnM with pentafluoropyridine have been studied.
2.  In the case of carbanions the free anions are more reactive, while in the case of Me3SnM the corresponding tight (contact) ion pairs are more reactive.
3.  The effect of the leaving group (on reactivity) was investigated using the reactions of pentafluorochlorobenzene with the K salts of 9-carbomethoxyfluorene and cyclopentadienylirondicarbonyl anions as examples.
4.  The reaction mechanism has been shown to depend on the nature of the nucleophile.
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2826–2832, December, 1988.  相似文献   

9.
1.  The condensation of 1,2-hydroxylamino oximes with biacetyl leads to 1-hydroxy-2-acetyl-2,4,5,5-tetrasubstituted 3-imidazoline 3-oxides.
2.  When 1-hydroxy-2-acetyl-2,5,5-trimethyl-4-phenyl-3-imidazoline 3-oxide is oxidized the CH3CO group is cleaved to give the 5H-imidazole 1,3-dioxide.
3.  Stable nitroxyl radicals were obtained when the 1-hydroxy-2-oximiaoethyl-2,4,5,5-tetrasubstituted 3-imidazoline 3-oxides are oxidized.
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10.
1.  It has been shown that 2-bromo-l,3,2-dioxaarsenanes exist in chair conformation with axially oriented As-Br bonds.
2.  Polarity and polarizability parameters have been found for the As-O and As-Br bonds in 2-bromo-l,3,2-dioxaarsenanes.
3.  The so-called -effect is stronger in the O2AsBr group than in the O2AsCl group.
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11.
1.  Methanol, containing 10–20 mole % of CH3I, is carbonylated to methyl acetate in the presence of impregnated Eh-zeolite NaX catalyst at 230–250° and atmospheric pressure.
2.  The specific (per gram of Rh) rate of methyl acetate formation is antibatic to the Rh content in the catalyst, it increases with increase in the methanol contact time, and shows little change in the range 230–250°.
3.  The rate of forming the sole secondary product, namely dimethyl ether, decreases with increase in the amount of Rh and the methanol contact time.
4.  CH2I is an astoichiometric component of the reaction.
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12.
1.  A method has been developed for the intercalation of solid substances from solutions in organic solvents into graphite fluoride C2Fx.
2.  Molecules of inserted paramagnetic copper complexes and nitroxyl radicals assume oriented positions between the structural layers in graphite fluoride.
3.  The planes of molecules of bis-chelate Cu(II) complexes with acetylacetone, o-hydroxyquinoline, and phenylsalicylaldimine were determined to lie parallel to the C2Fx planes.
4.  A method has also been suggested for the preparation of samples from C2Fx·yA compounds with a higher degree of texturizing (more nearly complete orientation) than can be achieved by pelletizing.
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 272–276, February, 1988.  相似文献   

13.
1.  The thermal decomposition of N,N-dinitroamines is homogeneous and unimolecular in the gas phase. The limiting step of the process is the rupture of the N-NO2 bond.
2.  The activation parameters of the process imply that the dinitroamine group is more reactive than the mononitroamine group in thermal decomposition. The energy of dissociation of the N-NO2 bond in dinitroamines is 42 kJ/mole less than in mononitroamines.
3.  Nitrogen dioxide and acetaldehyde do not influence the kinetics of thermal decomposition of dinitroamines due to their high reactivity.
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 790–793, April, 1989.  相似文献   

14.
Time- and temperature-dependent SAXS-experiments were used to determine the effect of octene and butene co-units on the lamellar structure and the melting properties of polyethylene. As expected, melting points decrease with increasing co-unit content, but crystal thicknesses are not affected and depend on the crystallization temperature only. Results can be cast into some simple equations which describe the dependence:
1. Of the melting point Tf on the crystal thickness dc and the co-unit content xB
2. Of the equilibrium melting point on xB
3. Of dc on the crystallization temperature Tc
4. Of the long spacing L on Tc, xB and the molar mass
5. Of Tf on Tc.
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15.
1.  The absorption of electromagnetic radiation ( 1.05 mm) by solutions of DMSO in water and DMSO and water in dioxane has been measured in the whole interval of relative concentrations.
2.  The additivity of the absorption in systems containing dioxane, and its absence in the system H2O-DMSO, have been demonstrated.
3.  The possibility of using the absorption of radiation in the millimeter range for the study of solvation in solutions has been shown.
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16.
1.  Indium atoms have been obtained in aqueous solutions of univalent indium by pulse radiolysis.
2.  In0 reacts with In+ to form the dimer In 2 + .
3.  The optical characteristics of these particles, the rate constants for their formation and loss, as well as the oxidation-reduction potentials have been determined.
We thank A. G. Egorova for providing the InBr salt.  相似文献   

17.
1.  Complexes of the REE, Y, and Sc with hydroxyethylethylenediaminetriacetic acid have been isolated in solid form. The hydrate compositions of the complexes have been determined.
2.  The La and Pr complexes form hydrates of different compositions. The LnL hydrates form slightly nonisostructural groups in the series La-Lu.
3.  According to thermographic analysis data, the hydrate water in the LnL·nH2O complexes of different hydrate compositions is not bonded with the same firmness.
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18.
1.  Dimethyl, diphenyl, and tetramethylene sulfoxide hydrochlorides react with methylheptenyl, citronellyl, and geranyl acetates to give predominantly the allylic chlorination products.
2.  These findings are preferably to be regarded as involving AdE reactions between the weakly electrophlic hydroxy and (or) chlorosulfonium cation and the trisubstituted C=C bond in these olefins at the key stage.
3.  The addition of lithium perchlorate has been found to accelerate this reaction.
4.  Sulfoxide hydrobromides are highly selective brominating agents for the terminal grouping in isopropenoid oligoolefins.
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1797–1803, August, 1988.  相似文献   

19.
1.  The authors have studied the formation of electron and hole paramagnetic centers in gamma-irradiated magnesium hydroxide and oxide with various degrees of dehydration.
2.  Rise in the temperature of preliminary heat treatment of the magnesium oxide causes an increase in the radiation-chemical yield of FS + centers and a decrease in that of V su – centers.
3.  The thermal stability of paramagnetic centers in magnesium oxide increases as the hydroxyl group content decreases.
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20.
1.  The adducts of N-benzenesulfonylbis(trifluoromethyl)ketenimine with either KF or KHF2 are formed when perfluoroisobutylene is reacted with the K salt of benzenesulfonamide.
2.  N-Benzenesulfonylbis(trifluoromethyl)ketenimine was synthesized and some of its properties were studied.
  相似文献   

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