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1.
The diffusion-segregation boron distribution in the silicon dioxide-silicon system upon oxidation in different environments is studied by secondary-ion mass spectrometry and numerical simulation. The coefficient of boron segregation at the SiO2/Si interface and the enhancement of boron diffusion in silicon as functions of the type of oxidizing environment (dry oxygen, wet oxygen, and the presence of hydrochloric acid vapor), the orientation of the silicon surface, and the temperature of oxidizing annealing are obtained. A qualitative model is proposed based on the assumption that the segregation mass transfer of boron through the SiO2/Si interface is associated with the generation of nonequilibrium intrinsic interstitials. 相似文献
2.
I. A. Zyryanova L. V. Baikalova O. A. Tarasova A. V. Afonin V. A. Kukhareva M. A. Maksimova B. A. Trofimov 《Russian Journal of General Chemistry》2005,75(8):1283-1289
With respect to Co2+, Ni2+, Zn2+,Cd2+, Cu2+, Pd2+, and Sn4+ salts, 1-isopropenyl-substituted imidazole, 2-methylimidazole, and pyrazole behave as monodentate ligands with only one coordination center on the N1 and N2 atoms, respectively; 1-isopropenylpyrazole under complex-formation conditions is dealkylated to form pyrazole complexes. The reaction with HCl leaves the unsaturated substituent in 1-isopropenylimidazole intact and yields corresponding hydrochlorides by the N3 atom of the heterocycle. The least basic 1-isopropenylpyrazole takes up HCl also by the double bond of the alkenyl group. 相似文献
3.
Reaction of benzothiazole-2-thione and benzothiazole-2-one with acetylene in the presence of potassium hydroxide or cadmium acetate gives 2-vinylthiobenzothiazole and 3-vinylbenzothiazol-2-one, respectively. Benzothiazole-2-thione is partially convened to benzothiazol-2-one by the action of Cd(OAc)2. Under vinylation conditions the latter also forms 2-vinylthioaniline.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 270–271, February, 1991. 相似文献
4.
Powder X-ray diffraction study of sodium salts of 1-hydroxyethane-1'1-diphosphonic acid (H4L)of the compositions NaH3L·H2O, Na2H2L·4H2O, Na3HL·5.5H2O showed that these compounds aresingle-phase. Some of their properties were determined. The possibility of preparing salts of other compositionswas examined. 相似文献
5.
S. F. Malysheva N. K. Gusarova N. A. Belogorlova A. V. Afonin S. N. Arbuzova B. A. Trofimov 《Russian Chemical Bulletin》1997,46(10):1799-1801
Diorganylvinylphosphine oxides were synthesized in 31–38% yields on heating (50°C) diorganylphosphine oxides with vinyl sulfoxides
or divinyl sulfone in the presence of KOH.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1895–1896, October, 1997. 相似文献
6.
Andriyankova L. V. Zhivet'ev S. A. Mal'kina A. G. Kudryakova P. N. Kositsyna E. I. Il'icheva L. N. Ushakov I. A. Afonin A. V. Trofimov B. A. 《Russian Journal of Organic Chemistry》2002,38(11):1681-1685
Reactions of nucleophilic addition of 2- and 4-mercaptopyridines to 3-phenyl-2-propynonitrile, 4-hydroxy-4-alkyl-2-alkynonitriles, and methyl 2-butynoate (triethylamine, 20-25 or 100°C) give rise to the corresponding S-adducts with Z-configuration (for cyanoethylenes), or to a mixture of E- and Z-isomers in 60:40 ratio for methyl 2-butynoate. 相似文献
7.
N. A. Nedolya N. P. Papsheva A. V. Afonin B. A. Trofimov 《Russian Chemical Bulletin》1990,39(8):1724-1725
Previously unreported N,N-bis(2-vlnyloxyethyl)carbodiimide was synthesized by the reaction of N,N -bis(2-vinyloxyethyl)thiourea with yellow mercuric oxide in CH2Cl2 at room temperature.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1897–1898, August, 1990. 相似文献
8.
Baikalova L. V. Zyryanova I. A. Tarasova O. A. Chipanina N. N. Shmidt E. Yu. Kashik T. V. Afonin A. V. Sinegovskaya L. M. Vashchenko A. V. Trofimov B. A. 《Russian Journal of General Chemistry》2003,73(10):1634-1640
1-Allenylpyrazole and 1-allenyl-1,2,4-triazole react with hydrogen chloride via proton addition at the pyridine-like nitrogen atom (N2 and N4, respectively). In the reaction with 1-allenylpyrazole, 1-[(E)-3-chloro-1-propenyl]pyrazole is also formed via regio- and stereoselective addition of hydrogen chloride to the propadienyl group. 1-Allenylpyrazole and 1-allenyl-1,2,4-triazole act as unidentate ligands with respect to Co, Ni, Cu, Zn, Cd, Pd, and Sn, the donor centers being N2 and N4, respectively. Apart from mononuclear coordination compounds, 1-allenylpyrazole gives rise to polymeric complexes which contain units and blocks formed by the free ligand. 相似文献
9.
Sergii Afonin Alexander Frey Sybille Bayerl Dahlia Fischer Parvesh Wadhwani Sevil Weinkauf Anne S Ulrich 《Chemphyschem》2006,7(10):2134-2142
Cell-penetrating peptides (CPPs) are short polycationic sequences that can translocate into cells without disintegrating the plasma membrane. CPPs are useful tools for delivering cargo, but their molecular mechanism of crossing the lipid bilayer remains unclear. Here we study the interaction of the HIV-derived CPP TAT (48-60) with model membranes by solid-state NMR spectroscopy and electron microscopy. The peptide induces a pronounced isotropic (31)P NMR signal in zwitterionic DMPC, but not in anionic DMPG bilayers. Octaarginine and to a lesser extent octalysine have the same effect, in contrast to other cationic amphiphilic membrane-active peptides. The observed non-lamellar lipid morphology is attributed to specific interactions of polycationic peptides with phosphocholine head groups, rather than to electrostatic interactions. Freeze-fracture electron microscopy indicates that TAT(48-60) induces the formation of rodlike, presumably inverted micelles in DMPC, which may represent intermediates during the translocation across eukaryotic membranes. 相似文献
10.
A. V. Afonin 《Russian Chemical Bulletin》1991,40(6):1282-1285
1H and13C NMR spectroscopy indicates the low efficiency of specific intramolecular C-H...Hal (Hal=F, Cl, Br) interactions in comparison with analogous C-H...Y (Y=N, O, S) interactions despite their formal similarity. This is seen in the absence of anomalous downfield PMR shifts of the hydrogen atom and increase in the corresponding direct13C-1H coupling.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1442–1446, June, 1991. 相似文献