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排序方式: 共有172条查询结果,搜索用时 31 毫秒
1.
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S. A. Shiryaev M. V. Atamanov M. I. Guseva Yu. V. Martynenko A. V. Mitin V. S. Mitin P. G. Moskovkin 《Technical Physics》2002,47(2):238-243
It is suggested to produce metal-carbon composite coatings by magnetron sputtering of mosaic cathodes, which are Group IV,
V, and VI metals. The mosaic structure of the cathode elements are computer-optimized for each of the metals. Reflection electron
diffraction studies show that the coatings have the amorphous or nanocrystalline structures, which are thermally stable. The
coatings offer specific physical properties, in particular, low friction factor and high hardness. 相似文献
3.
A. A. Gavriliuk A. L. Semenov A. Yu. Mokhovikov D. V. Prudnikov D. A. Shiryaev 《Technical Physics》2006,51(6):746-751
The magnetic and magnetoelastic parameters of Fe64Co21B15 and Fe81.5B13.5Si3C2 amorphous ferromagnetic alloys treated by direct electric current in air are studied as functions of the applied magnetic field and current density. The samples of the alloy have the form of narrow strips with different lengths. It is found that the magnetoelastic parameters of the dc-treated alloys depend on the magnetic field in a qualitatively different way. From the behavior of the magnetic and magnetoelastic parameters of the alloys in the magnetic field a model of magnetization nonuniform distribution in amorphous ferromagnetic alloys subjected to dc treatment is proposed. 相似文献
4.
5.
A. V. Belyakov A. V. Golubinskii L. V. Vilkov V. I. Shiryaev E. M. Styopina E. A. Kovalyova V. S. Nikitin 《Russian Chemical Bulletin》1993,42(2):346-349
The molecular structure of gaseous Br2Sn(CH2SiMe2)2O was studied by electron diffraction. The six-membered ring has a chair conformation whereas the entire molecule possessesC
s
symmetry. The existence of a boat conformer cannot be completely excluded. The results of theoretical calculations for a twisted-boat conformation are at variance with the experimental data. Steric strain caused by mutual repulsion of the two axial methyl groups is reduced to the tilt of the Me2Si fragments in opposite directions. This results in an increase (up to 26°C) in the angle formed by the bisector of the CM-Si-CM angle with the CcSiO plane. The main geometrical parameters are as follows:r
g (Å): Si-O 1.708(20); Si-CM 1.862(20); Si-Cc 1.882(9); Sn-C 2.108(26); Sn-Br 2.456(3); C-H 1.099(30); (degr.): C-Sn-C 105(2); Br-Sn-Br 107.9(1.2); Si-O-Si 129.6(3); CM-Si-CM 112; Si-C-H 113 (fixed value in accordance with experiment); Cc-Si-O 107(2); Sn-C-Si 109(2); torsion angles: (Si-C) 52(2); (Si-O) 62(1); (Cc-Sn) 54(1). The average amplitudes were fixed at the values calculated from the force field. Structural parameters of molecules with similar structures were analyzed and compared.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 384–387, February, 1993. 相似文献
6.
V. N. Tsarev S. E. Lyubimov S. V. Zheglov A. A. Shiryaev V. A. Davankov K. N. Gavrilov 《Russian Chemical Bulletin》2004,53(9):2025-2028
A chiral P,N-bidentate aryl phosphite ligand containing peripheral (R)-(+)-camphor-derived ketimine and its rhodium(I) and palladium(II) chelate complexes were synthesized for the first time. These compounds were found to be suitable for asymmetric allylic substitution. The Pd-catalyzed sulfonylation of 1,3-diphenylallyl acetate with sodium p-toluenesulfinate gave the product in 73% ee; in the alkylation of the same substrate with dimethyl malonate, the ee was 94%. These ee values are higher than the enantioselectivity achieved with the known phosphine analogs.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1942–1945, September, 2004. 相似文献
7.
Konstantin N. Gavrilov Alexei A. Shiryaev Ilya V. Chuchelkin Sergey V. Zheglov Eugenie A. Rastorguev Vadim A. Davankov Armin Börner 《Tetrahedron: Asymmetry》2012,23(14):1052-1057
New P,P-bidentate diastereomeric diphosphoramidite chiral ligands with mixed stereogenic elements and a C1 backbone symmetry have been prepared from (Sa)- and (Ra)-1,1′-binaphthyl-2,2′-diol (BINOL) and (S)-N-benzyl-1-(pyrrolidin-2-yl)methanamine and are fully characterized. The use of these ligands provides up to 84% ee in the Pd-catalyzed asymmetric allylic substitution of (E)-1,3-diphenylallyl acetate and up to 95% ee in the Rh-catalyzed asymmetric hydrogenation of α-dehydrocarboxylic acid esters. The results indicate that the catalytic performance is highly affected by the axial chirality of the binaphthyl moieties of the ligand and the nature of the solvent. 相似文献
8.
A. Ya. Fridman A. Yu. Tsivadze E. M. Morozova N. P. Sokolova A. A. Shiryaev G. A. Petukhova A. M. Voloshchuk I. I. Bardyshev A. M. Gorbunov I. Ya. Polyakova A. K. Novikov V. N. Titova A. A. Yavich N. V. Petrova 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2016,90(12):2453-2458
A material with porous structures formed by jointed aza- and oxa-aza-crowns with peripheral OHgroups is synthesized on the basis of cellulose fabric and PVC transformed into hydroxyethylcyclam. Mesopores are mainly observed on the fiber surface. The specific surface of the material is 6 m2/g; the volume of free space is 0.112 cm3/g. Assuming the internal pores have a disk-like shape, their width is estimated at 2 nm. The material sorbs vapors of aliphatic and aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, amides, nitriles, and sulfoxides. It also swells to a limited degree in organic solvents. When sulfuric acid or sodium hydroxide is sorbed in the pores, compounds of them with H+- and OH–-conducting systems of hydrogen bonds are formed. 相似文献
9.
P. A. Storozhenko A. A. Grachev A. O. Klochkov V. I. Shiryaev 《Russian Journal of Applied Chemistry》2013,86(3):387-393
Continuous organomagnesium synthesis of a number of organic derivatives of 14th group elements of the periodic table was examined in a column apparatus with an agitator. An effect of a molar ratio of reactants, temperature in a reaction zone, and other factors was studied on the yield and composition of the products. 相似文献
10.
A. A. Safronov O. B. Vasil’eva Yu. D. Dudnik V. E. Kuznetsov V. N. Shiryaev D. I. Subbotin N. V. Obraztsov A. V. Surov V. E. Popov 《High Energy Chemistry》2018,52(4):319-323
The decomposition of tetrachloromethane and tetrafluoromethane by air plasma in the presence of methane has been studied using an ac plasma torch of up to 500 kW power with rail electrodes. Methane reacts with air in the partial oxidation mode to form hydrogen, which reacts with a halogen to produce the hydrogen halide. 相似文献