共查询到20条相似文献，搜索用时 500 毫秒
1.
K. K. Kalnin'sh 《Russian Chemical Bulletin》1988,37(9):1768-1773
| 1. | A new method of analysis of autocatalytic reactions was developed which permits determining the rate constants of noncatalytic and catalytic reaction pathways with the data from one kinetic curve. |
| 2. | The reverse reaction of acylation has an autocatalytic character. |
| 3. | In comparison to CHCl3, in CH3CN, all of the rate constants increase by 2–4 times, and the noncatalytic reaction pathways are more sensitive to the nature of the solvent. |
2.
| 1. | The spectra of the charge-transfer complexes of mesoionic 1,3,4-oxa, thia, and triazoles with various exocyclic groups and tetracyanoethylene have been obtained. |
| 2. | The position of the charge-transfer band provides information on the relative donor capacity of the exocyclic groups. |
3.
L. D. Belyakova G. A. Gerasimova L. T. Zhuravlev G. V. Kudryavtsev G. V. Lisichkin N. S. Ovchinnikova N. P. Platonova T. I. Shevchenko 《Russian Chemical Bulletin》1989,38(5):885-891
| 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. |
4.
| 1. | Rhodium complexes [RhCl(COD)]2, RhCl(PPh3)3, and RhCl3 immobilized on silica gel modified by aminophosphine groups catalyze the transfer of hydrogen from 2-propanol to cyclohexanone, styrene, and 2-cyclohexenone and the isomerization of allylbenzene in an argon atmosphere. |
| 2. | The reduction of cyclohexanone to cyclohexanol is promoted by alkali. The reaction rate is proportional to the amount of catalyst, 2-propanol concentration, and cyclohexanone. The reaction rate decreases at high ketone concentrations. |
| 3. | Styrene is reduced to ethylbenzene extremely slowly. Under these conditions, allylbenzene is not reduced, but rather undergoes isomerization with the predominant formation of trans-propenylbenzene. |
| 4. | The reduction of 2-cyclohexenone to cyclohexanol occurs by the initial reduction of the C=C bond and the subsequent reduction of the C=O group. |
5.
M. Gaft 《Journal of Thermal Analysis and Calorimetry》1992,38(10):2281-2290
The photoluminescence (PL) of zircon is characterized by a broad structureless spectral band down to 4.6 K, which does not enable correct interpretation of the nature of the luminescence centres (LC). By applying step-like thermal treatment, a radiation treatment and timeresolved spectroscopy, seven pure bands were separated and their individual spectral-kinetic properties were determined.The yellow PL is connected with three LC:
相似文献
| 1. | Intrinsic defects of the (SiOm)n– type, which are generated by radioactive decay of U and Th; |
| 2. | Impurity defects (MeOm)n– (Me–Mo, V) associated with charge compensators, probably the Fe3+ and Ti3+ (clusters of these LC generate a yellow-orange shoulder); |
| 3. | Impurity defects (UO2)2+. |
6.
Ya. T. Éidus A. L. Lapidus V. I. Mashinskii L. L. Krasnova 《Russian Chemical Bulletin》1976,25(6):1261-1264
| 1. | The activity of cobalt-group II metal oxide catalysts in the hydropolymerization reactions of C2-C4 olefins, initiated by CO at 190°, depends on the nature of the oxide and decreases when going from BeO to BaO. |
| 2. | In their reactivity the olefins fall into the order: C2 > C3H6 >-C4H8 > i-C4H8. |
| 3. | The degree of reduction of the cobalt found in the catalyst depends on the nature of the employed oxide and (toes not determine its activity. |
7.
D. N. Kravtsov V. D. Vil'chevskaya P. V. Petrovskii Yu. Yu. Gorelikova 《Russian Chemical Bulletin》1988,37(5):991-994
| 1. | Ferrocene reacts with bromoadmantane in the presence of A1Cl3 to give mono- and 1,1-diadamantylferrocene. |
| 2. | Acylation of adamantylferrocene with raonoethyl o-phthaloyl chloride takes place in the 3-position of the substituted ferrocene ring, and to some extent in the free cyclopentadienyl ring. |
8.
G. A. Artamkina A. Yu. Mil'chenko I. P. Beletskaya O. A. Reutov 《Russian Chemical Bulletin》1988,37(12):2550-2556
| 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. |
9.
L. A. Rozov Yu. V. Zeifman N. P. Gambaryan Yu. A. Cheburkov I. L. Knunyants 《Russian Chemical Bulletin》1976,25(12):2560-2566
| 1. | Depending on the nature of the substituent in the 2 position, l-fluoro-l-(-hydrohexafluoroisopropyl)ethylenes are dehydrofluorinated to either allenes or 1,3-dienes. |
| 2. | It was shown that allylic substitution is possible in the reactions of perfluoroisobutylene with carbanions; the mutual transformations of the allyl and vinyl isomers were studied. |
| 3. | The perfluoroalkenylation product was obtained when perfluoroisobutylene is reacted with ketene acetal. |
10.
| 1. | Polarizability parameters have been determined for the selenocyanate group. |
| 2. | Selenobenzene cyanate, and derivatives of this compound with donor substituants in the p position, have planar conformations; introduction of acceptor substituents breaks down the coplanarity of the C6H4-SeCN fragment. |
11.
| 1. | The rate constants were calculated for the abstraction of hydrogen from HCCl3 and of bromine from BrCCl3 by CCl3(CH2CHX)n radicals. |
| 2. | The reactivity of CCl3(CH2CH2)n radicals (n=1, 2) depends on the position of the CCl3 group and the chain transfer step makes the major contribution to the chain transfer constants in the telomerization of ethylene with HCCl3 and BrCCl3. |
| 3. | The reactivity of CCl3(CH3CHX) n . radicals (X=H, Me, Cl) in reactions involving replacement with C-H and C-Hal bond cleavage depends on the nature of X. |
12.
| 1. | The IR and Raman spectra of the methyl selenophosphonates and methyl selenophosphinates: (CH3O)2P(Se)CH3, CH3OP(Se) (C2H5)2, and CH3OP(Se) (C6H5)2 were studied in various phase states and in solvents, and with a variation in the temperature. The vibration bands of the P=Se group were assigned. |
| 2. | A thermodynamic equilibrium of at least two steric forms of the molecule was detected in the first two compounds. The isomers arise as the result of one methoxy group rotating from the gauche position with respect to the P=Se bond to the trans position, with a gauche orientation of the other groupings. |
| 3. | The relative amount of the isomers in the mixture and the thermodynamic parameters of the equilibrium were determined. |
| 4. | The steric conditions created by the two aryl radicals in the third compound lead to a stabilization of one predominant conformer in all of the states of the compound, with a gauche orientation of the OCH3 with respect to the P=Se bond. |
13.
| 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. |
14.
| 1. | According to thermogravimetric data, PrF4, decomposes when heated, with evolution of fluorine, as in the case of CeF4 and TbF4. |
| 2. | The authors have measured the vapor pressure of the fluorine formed by thermolysis of rare-earth tetrafluorides, and have calculated the thermodynamic characteristics of these tetrafluorides. |
15.
B. K. Nefedov N. S. Sergeeva T. V. Zueva E. M. Shutkina Ya. T. Eidus 《Russian Chemical Bulletin》1976,25(3):565-569
| 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. |
16.
| 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. |
17.
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:
相似文献
| 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. |
18.
Carbon dioxide fixation by microalgae photosynthesis using actual flue gas discharged from a boiler 总被引：2，自引：0，他引：2
Matsumoto Hiroyo Shioji Norio Hamasaki Akihiro Ikuta Yoshiaki Fukuda Yoshinori Sato Minoru Endo Noriyoshi Tsukamoto Toshiaki 《Applied biochemistry and biotechnology》1995,(1):681-692
To mitigate CO2 discharged from thermal power plants, studies on CO2 fixation by the photosynthesis of microalgae using actual exhaust gas have been carried out. The results are as follows.
相似文献
| 1. | A method is proposed for evaluating the maximum photosynthesis rate in the raceway cultivator using only the algal physical properties; |
| 2. | Outdoor cultivation tests taking actual flue gas were performed with no trouble or break throughout 1 yr using the strain collected in the test; |
| 3. | The produced microalgae is effective as solid fuel; and |
| 4. | The feasibility studies of this system were performed. The system required large land area, but the area is smaller than that required for other biomass systems, such as tree farms. |
19.
I. V. Anonimova N. A. Chadaeva L. K. Yuldasheva S. G. Vul'fson A. N. Vereshchagin B. A. Arbuzov 《Russian Chemical Bulletin》1976,25(12):2519-2524
| 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. |
20.
A. M. Moiseenkov V. A. Dragan A. V. Lozanova V. V. Veselovskii 《Russian Chemical Bulletin》1988,37(8):1603-1609
| 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. |