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1.
| 1. | The relation of the adsorption values of standard benzene vapor at 293 K to the parameters of the Dubinin-Stokley adsorption equation was considered for the case of model microporous carbon adsorbents. |
| 2. | Active carbons with low characteristic standard-vapor adsorption energies and a wide micropore-volume size distribution are characterized by higher filling of the micropore volume at low equilibrium pressures in comparison with active carbons with homogeneous microporous structure. |
| 3. | Fillings were calculated for micropores under various adsorption conditions for estimation of the adsorption properties of active carbons and selection of adsorbents with parameters most suitable for practical use. |
2.
A. M. Voloshchuk M. M. Dubinin T. A. Moskovskaya G. K. Ivakhnyuk N. F. Fedorov 《Russian Chemical Bulletin》1988,37(2):204-209
| 1. | A standard adsorption isotherm (CAI) was plotted from the isotherms of adsorption of N2 on nonporous and mesoporous carbon adsorbents for analyzing the pore structure of carbon adsorbents. |
| 2. | The analysis of the pore structure of active carbon with a relatively large area of mesopores and predominantly microporous active carbon shows that the CAI obtained adequately describes the adsorption of N2 on the surface of the mesopores of these samples. |
3.
A. M. Voloshchuk M. M. Dubinin T. A. Moskovskaya A. O. Larionova L. A. Shilkova 《Russian Chemical Bulletin》1988,37(10):1979-1983
| 1. | The adsorption isotherms of N2 at 77 K on the surface of carbonaceous adsorbents in the region of low relative pressures are satisfactorily described by the Dubinin-Radushkevich (DR) equation. However, the a0 parameter of the DR equation is not related to the monolayer capacity, and for samples with the most homogeneous surface the quantity a0 substantially exceeds the BET monolayer capacity. |
| 2. | The adsorption isotherms calculated per unit surface area of adsorbent can be grouped in terms of the E0 value of the DR equation; this can be regarded as a measure of the degree of energetic heterogeneity of the samples. |
| 3. | For samples with E0 < 15.5="" kj/mole,="" the="" specific="" surface="" areas="" calculated="" by="" the="" bet="" method="" and="" by="" the=""> and methods are similar. |
| 4. | The samples of carbonaceous adsorbents with E0 > 15.5 kJ/mole are characterized by surface heterogeneity associated with the presence of micropores. |
4.
| 1. | The potential energy of the interaction of one water molecule with the walls of a micropore E(Zc) as a function of the distance to its lower surface has one or two minima, determined by the half-width of the micropore d. |
| 2. | The height of the barrier U between the minima of E(Zc) and distance R between these minima for a given model potential of the water-carbon interaction increase linearly with an increase in the slit half-width. The values of the coefficients of these linear dependences were obtained empirically. |
| 3. | The dependence of the transverse diffusion coefficient on d for one molecule of water has one distinct maximum at d 0.41 nm. For this micropore, the height of the barrier gDU between the minima of E(Zc) is kT. For a cluster of six water molecules, there is also a maximum, but at d 0.35 nm, which is due to the formation of hydrogen bonds between the molecules of water. |
| 4. | Note that with a micropore half-width of d > 0.375 nm, for a cluster of 19 molecules of water, the number of hydrogen bonds is 18 per cluster and increases monotonically with an increase in d from 0.36 to 0.46 nm. In the 0.47–0.5 nm region, the average number of hydrogen bonds is almost independent of d. |
| 5. | When d < 0.42="" nm,="" the="" hydrogen="" bonds="" prevents="" the="" optimum="" orientation="" of="" the="" molecules="" with="" respect="" to="" the="" nearest="" surface="" of="" the="" pore="" and="" when="" d=""> 0.425 nm, they favor localization of the water near the walls of the micropore. |
5.
M. M. Dubinin M. V. Degtyarev K. M. Nikolaev N. S. Polyakov E. A. Ustinov 《Russian Chemical Bulletin》1988,37(11):2197-2201
| 1. | The use of the existing methods of calculation of the specific mesopore surface area was analyzed on the example of carbon adsorbents with a different pore structure. |
| 2. | The calculations with the method based on the improved theory of Broekhoff and de Boer with consideration of the effect of the curvature of the liquid meniscus on the surface tension and mercury porosimetry give the closest values of the mesopore surface area for all of the adsorbents studied. |
6.
| 1. | A new type of sorbents, containing SH groups, was obtained by the modification of aminooxy adsorbents. |
| 2. | The obtained sorbents were used for the covalent immobilization of biologically active compounds with the formation of C-S, C-Hg-S, and S-S bonds. |
7.
V. I. Avdeev I. I. Zakharov G. M. Zhidomirov N. M. Neshev E. I. Proinov 《Journal of Structural Chemistry》1992,33(2):179-185
| 1. | Upon interaction of OH with Ni(100)m Ni(111), and Ni(110), stable, many-center forms of OH adsorption are produced. One-center and bridge forms of OH adsorption on nickel are kinetically unstable for the lowest surface coverages. |
| 2. | On Ni(100) and Ni(111), a linear form of adsorption of OH is realized; on Ni(110), an angular form is realized, with a polar angle 0 = 20°. |
| 3. | In the course of adsorption, there is a significant transfer of electron density from the metal to the OH, leading to an increase in the work function of the electrons and a decrease in the frequency of the (O–H) vibration. For the angular forms of adsorption, bending vibrations (O–H–Ni) are active. |
| 4. | Upon adsorption of OH, a strong -bond Ni(110)–OH is formed, as manifested in the UV photoelectron spectra by absorption in the 9.2 eV energy region. |
8.
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. |
9.
A. A. Fomkin N. I. Regent V. Yu. Gusev S. G. Tkachenko V. A. Eroshenko V. V. Serpinskii 《Russian Chemical Bulletin》1989,38(6):1268-1270
| 1. | The absolute differential calorimetric heats of adsorption were measured for Xe and Kr on NaX zeolite at 304.5 K and pressures up to 10 MPa. |
| 2. | Good agreement was found between the measured heats of adsorption and the calculated isosteric heats within experimental error. |
10.
R. G. Kostyanovskii V. P. Leshchinskaya R. K. Alekperov G. K. Kadorkina L. L. Shustova Yu. I. Él'natanov G. L. Gromova A. É. Aliev I. I. Chervin 《Russian Chemical Bulletin》1988,37(11):2315-2323
| 1. | An efficient method of aziridine dimer synthesis is presented involving reaction of aziridine with esters of strong organic acids followed by alkaline hydrolysis of the resultant N-acyl derivatives. |
| 2. | New N-acyl and carbamoyl derivatives of aziridine dimer and trimer were synthesized. |
| 3. | Linear and branched isomers of aziridine tetramer and also diastereomers of 2-methylaziridine dimer were isolated and characterized. |
| 4. | An efficient regiospecific synthesis of 2,2-dimethylaziridine dimer and trimer was developed. |
11.
A. Teies Gonsalo A. I. Donskikh V. N. Kulagin Yu. V. Moiseev G. M. Tseitlin 《Russian Chemical Bulletin》1976,25(5):1156-1158
| 1. | The hydrolysis rate of N-benzoylanthranilic acid was studied at a KOH concentration of 2.2–44.6% and a temperature of 25–95°. |
| 2. | The limiting step of the process is the reaction of the singly ionized form of the reagent with a molecule of water. |
| 3. | The equilibrium constant for the addition of hydroxyl ion to the carbonyl atom of the amido group of N-benzoylanthranilic acid is 267, and the true rate constant for the reaction of the ionized form with a molecule of H2O at 25° is 0.13 min–1. |
12.
| 1. | The (Cp2TiCl)2-LiAlH4 system with Al/Ti from 0.25 to 1.5 catalyzes both the homogeneous hydrogenation and isomerization of allylbenzene. |
| 2. | In an argon atmosphere, allylbenzene is isomerized to trans-propenylbenzene with 90–92% selectivity when Al/Ti=1–1.5. |
| 3. | The possibility was demonstrated for reactivation of this catalytic system by its retreatment with LiAlH4. |
13.
S. P. Freidman N. I. Medvedeva G. S. Nazarova V. A. Gubanov 《Journal of Structural Chemistry》1991,32(5):631-636
| 1. | The Al–O and P–O chemical bonds in variscite are mainly covalent in nature. The degree of covalency of the P–Ob chemical bond is substantially greater than that of Al–Ob. |
| 2. | The presence of nonequivalent bonds of oxygen atoms in water molecules in variscite (H–OW–H) and bonds of bridge oxygen atoms (P–Ob–Al) leads to splitting of the 02s and 02p states of the OW and Ob atoms amounting to 7 eV. |
| 3. | The strength of the Al–OW bond is considerably lower than that of the Al–Ob bond. |
| 4. | The H11, H21, and H22 hydrogen atoms form hydrogen bonds with the bridge oxygen atoms, but H12 does not participate in hydrogen bonding. |
| 5. | The results from cluster calculations of the electronic structure of variscite provide a basis for interpreting the experimental x-ray photoelectron spectrum and for determining the influence of structural molecules of water on the XPS line shape and structure. |
14.
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. |
15.
| 1. | The authors suggest a model to explain the axial symmetry of the hole center V– in magnesium oxide. |
| 2. | Using the model they consider the possible alternatives for localization of the hydroxyl groups of the hole center. |
| 3. | In analytic form, they express the values of the g factors for the V– center in terms of the parameters of the method of molecular orbits. The experimental values of the g factors can be explained if we assume localization of one or two hydroxyl groups in the first or second layer from the O– radical ion in the MgO lattice. |
16.
L. F. Chertanova G. A. Marchenko A. A. Gazikasheva Yu. T. Struchkov V. F. Sopin L. N. Punegova A. S. Mukhametzyanov 《Russian Chemical Bulletin》1989,38(2):250-253
| 1. | The planar alkoxydiazinoxide fragments are shown to have the Z-configuration and be orthogonal to each other by an x-ray structure study of a series of alkoxydiazinoxides. |
| 2. | In the oxydiazinoxide fragments, p- conjugation occurs. |
| 3. | The molecules of the compounds in the crystals studied are joined by hydrogen bonds. |
17.
O. S. Morozova A. A. Kadushin V. A. Khalif E. L. Aptekar' L. Ya. Margolis O. V. Krylov 《Russian Chemical Bulletin》1976,25(4):722-725
| 1. | The surface of a SnO2-Sb2O4 catalyst is uniformly homogeneous with respect to the heats of adsorption of isobutylene. The heats vary from 50 to 20 kcal/mole as the degree of coverage is increased to 18% of a monolayer. |
| 2. | Isobutylene is adsorbed on SnO2-Sb2O4 in two forms: reversible (desorbed in the range 79–100° with Edes=21 kcal/mole) and irreversible. |
| 3. | Irreversibly chemisorbed isobutylene exists on the surface primarily in the form of the-methallyl complex. |
18.
V. A. Smit S. O. Simonyan V. A. Tarasov A. S. Gybin G. S. Mikaélyan A. S. Shashkov S. S. Mamyan I. I. Ibragimov R. Kéipl 《Russian Chemical Bulletin》1988,37(12):2526-2535
| 1. | The intramolecular Khand-Pauson reaction is substantially accelerated when it is carried out on the surface of a Chromatographic adsorbent in the absence of a solvent. |
| 2. | A method has been developed for the preparation of substituted 3-oxabicyclo[3.3.0]-oct-5-en-7-ones, by cyclization of the dicobalt hexacarbonyl complexes of allyl propargyl ethers. |
| 3. | A novel cyclization reaction of dicobalt hexacarbonyl complexes has been found, which provides a convenient synthetic route to 4-hydroxymethylcyclopent-2-en-1-ones. |
19.
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. |
20.
Presently, a large variety of layered materials are synthesized that are able to intercalate neutral guest molecules or to exchange inorganic and organic ions for interlayer ions. Several of these materials are also found as minerals.The intracrystalline reactivity of a few selected compounds will be described and compared to clay minerals:
相似文献
| – | - intercalation into crystalline silicic acids; |
| – | - reactions of phosphates, arsenates, and sulfates; |
| – | - reactions of titanates, niobates, and molybdates with long chain alkylammonium ions, and |
| – | - anion exchange properties of double hydroxides. |