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1.
Results of numerical calculations of the flow in a double-diaphragm shock tube with a tailored contact surface are reported.
The calculations were carried out using a model of an ideal shock tube allowing for the real properties of the driver gas
at high pressures and equilibrium thermodynamics of the processes behind the shock waves at Mach numbers M
s1 of the shock wave in the working gas varying in the range 5–25. Flow regimes with a tailored contact surface were obtained
for Mach numbers M
s1=6.3, 11, and 15 using the double-diaphragm shock tube at the Ioffe Physicotechnical Institute. Under these conditions, the
parameters of the working gas were kept constant for more than 1 ms. The calculated data were compared with the experimental
results and it was shown that the calculated data may be used to determine the section lengths in a double-diaphragm shock
tube and to estimate its operating time. The calculated values of the initial pressure in the sections of the tube were substantially
lower than those achieved experimentally. Measurements were made of the static pressure along the axis of a conical nozzle
during the expansion of hydrogen (initial temperature T
0=293 K) and shock-heated nitrogen (T
0=4000 K). It is found that the expansion of hydrogen is accompanied by deactivation of the rotational degrees of freedom,
and that partial freezing of the vibrational degrees of freedom takes place in the nitrogen stream.
Zh. Tekh. Fiz. 67, 88–95 (November 1997) 相似文献
2.
3.
Piskunov A. V. Maslennikov S. V. Cherkasov V. K. Spirina I. V. Maslennikov V. P. 《Russian Journal of General Chemistry》2002,72(6):933-938
Kinetic regularities of zinc and cadmium oxidation in systems comprising 3,5-di-tert-butyl-1,2-benzoquinone and dimethylformamide or dimethyl sulfoxide are studied. Thermodynamic parameters of oxidant and ligand adsorption on metal surface are estimated. The oxidation of Group II metals (Be, Ca, Mg, Zn, Cd) with 3,5-di-tert-butyl-1,2-benzoquinone gives metal bis-o-semiquinolates. In the presence of excess metal in the medium of coordinating solvents, diradical products convert to the corresponding catecholate derivatives. It is shown that the dependence of the rates of metal reactions with 3,5-di-tert-butyl-1,2-benzoquinone on the donor number of solvent passes through a maximum. With less active metals, the maximum shifts to more basic ligands. 相似文献
4.
5.
Batenin V. M. Maslennikov V. M. Shterenberg V. Ya. Gordin K. A. 《Doklady Physics》2018,63(12):533-536
6.
F. David A. G. Maslennikov V. P. Peretrukhin 《Journal of Radioanalytical and Nuclear Chemistry》1990,143(2):415-426
Electrochemical reduction of heavy elements from aqueous solution to amalgams was studied by radiopolarography and radiocoulometry. Mechanism of actinide reduction on a mercury pool is discussed through simulation techniques. Special emphasis is placed on redox reactions and potentials, kinetics of the process and effect of acetate and citrate ions as complexing agents. Three groups of actinides have been found. The first group represents actinium and from uranium to berkelium. Reduction occurs in the experimental conditions via an irreversible 3–0 process. The second group consists of the elements from fermium to nobelium, which are reduced in non-complexing solutions, or with acetate ions, similarly as barium and radium, via a reversible 2–0 reaction. Finally, californium and einsteinium behave as intermediate elements. It is noticeable that such groups are also observed in the actinide series by studying the structure of the trivalent aqua ions. On the basis of the above mentioned investigations of actinides and lanthanides several examples of electrochemical application are presented. Californium has been separated from preceding transuranium and lanthanide elements (except europium) by electrochemical reduction to amalgams in acetic solution. Separation factors from 25–90 are achieved with appropriate cathodic potentials. Similarly, this element could be separated from several heavier actinides with citric media. The electrochemical preparation of mixed uranium-nickel and uranium-tin amalgams from aqueous acetate solutions is investigated. The dependence of redox potentials of mixed amalgams on different atomic ratio UNi and USn in amalgams is measured. The large shift of redox potentials of mixed amalgams to the positive direction is detected when the atomic ratio UNi or USn in amalgams reaches 15. The thermal distillation of mercury from mixed amalgams with different UNi and USn atomic ratios was carried out and the products were identified by chemical analysis and X-ray diffraction. The intermetallics UNi5 and USn3 were prepared from mixed amalgams with the atomic ratios UNi=15 and USn=13. The uranium and neptunium amalgams are prepared by electrolysis of aqueous acetate solutions and are processes into metals or nitrides U2N3, NpN by thermal distillation of mercury in vacuum or in nitrogen atmosphere. 相似文献
7.
Maslennikov S. V. Piskunov A. V. Spirina I. V. Chekhonina O. Yu. 《Russian Journal of General Chemistry》2002,72(10):1495-1497
Oxidation of magnesium with dicarbonyl(cyclopentadienyl)iron(II) chloride in dimethylformamide gives rise to 5-C5H5Fe(CO)2MgCl. Kinetic regularities of the process were determined. Thermodynamic parameters of adsorption of the reagents on the metal surface were calculated. 相似文献
8.
Ignat'ev R. A. Maslennikov S. V. Spirina I. V. Artemov A. N. Maslennikov V. P. Lineva A. N. 《Russian Journal of General Chemistry》2002,72(6):882-885
Chlorides of Ti(IV), V(III), Nb(V), and Mo(VI), in contrast to Cr(III) and Zr(IV) chlorides, catalyze oxidation of magnesium with cyclopentadiene to magnesium cyclopentadienide. The kinetic features of the process were revealed, and the composition and yield of reaction products were determined. Certain details of the reaction mechanism were discussed. 相似文献
9.
10.