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31.
32.
S. V. Shishkina S. M. Desenko K. G. Nazarenko O. V. Shishkin 《Journal of Structural Chemistry》2005,46(1):191-194
X-ray diffraction investigation showed that protonation of 4H-benzo-[1,4]-oxazin-3-ylidene-cyclohexylamine occurs at the exocyclic nitrogen atom. In crystal, the cation has a structure with a distinct exocyclic C=N bond. 相似文献
33.
34.
35.
Kateryna O. Znovjyak Olesia V. Moroz Vladimir A. Ovchynnikov Tatyana Yu. Sliva Svitlana V. Shishkina Vladimir M. Amirkhanov 《Polyhedron》2009,28(17):3731-3738
Coordination compounds with general formula [Ln(L1)3phen], where Ln = Nd, Eu, Er, Yb, HL1 = N,N′-dipyrrolidine-N′′-trichloracetylphosphortriamide, phen = 1,10-phenanthroline; [Ln(L1)3bpm], where Ln = La, Nd, Eu, Gd, Er, Y, bpm = 2,2′-bipyrimidine and [{Ln(L2)3}2(μ-bpm)], where Ln = La, Nd, Eu, Gd, Er, Y, HL2 = dimethyl-N-trichloracetylamidophosphate have been synthesized and characterized by means of IR and UV–Vis spectroscopy. Crystal structures of [Nd(L1)3phen] (1), [Nd(L1)3bpm] (2) and [{Nd(L2)3}2(μ-bpm)] (3) have been determined. It was found, that in the deprotonated form the phosphoryl ligands (L1)? and (L2)? are coordinated to the neodymium atoms in a bidentate manner via the oxygen atoms of the phosphoryl and the carbonyl groups with formation of six-membered metallocycles. In the case of compounds 1 and 2 the 1,10-phenanthroline (or 2,2′-bipyrimidine) molecules are coordinated to the metals in a bidentate manner via the nitrogen atoms. In contrast 2,2′-bipyrimidine acts in the bidentate-bridge mode forming binuclear complex 3. Variable-temperature magnetic susceptibility measurements of 3 and [{Gd(L2)3}2(μ-bpm)] (4) reveal a weak antiferromagnetic interaction between the two magnetic centres, whereas in the case of [{Eu(L2)3}2(μ-bpm)] (5) the presence of spin–orbit coupling leads to a deviation from the Curie and Curie–Weiss laws. 相似文献
36.
Lipson V. V. Svetlichnaya N. V. Borodina V. V. Shirobokova M. G. Shishkina S. V. Shishkin O. V. Musatov V. I. 《Russian Journal of Organic Chemistry》2010,46(9):1388-1398
Three-component condensation of 5(3)-amino-3(5)-methylpyrazole with aromatic aldehydes and 1,3-cyclohexanedione afforded mixtures
of 3-methyl-4-aryl-2,4,6,7,8,9-hexa hydro-5H-pyrazolo[3,4-b]quinolin-5-ones and 2-methyl-9-aryl-5,6,7,9-tetrahydro pyrazolo[5,1-b]quinazolin-8(4H)-ones. The reaction of 3-aminopyrazolo-4-carbonitrile and ethyl 3-aminopyrazolo-4-carboxylate with aldehydes and cyclo hexanedione
or dimedome is regioselective and leads to the formation of partially hydrogenated pyrazolo [5,1-b]quinazolin-8-one systems.
In all compounds the dihydroazine ring exists in the enamine tautomeric form. 相似文献
37.
Agata L. Starosta Viktoriya V. Karpenko Anna V. Shishkina Aleksandra Mikolajka Natalia V. Sumbatyan Frank Schluenzen Galina A. Korshunova Alexey A. Bogdanov Daniel N. Wilson 《Chemistry & biology》2010,17(5):504-514
Highlights? Macrolides exhibit nascent polypeptide chain–dependent inhibition ? Peptides can form specific interactions with the ribosomal tunnel ? A covalent bond between tylosin and the ribosome is necessary for inhibitory activity 相似文献
38.
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Resonant generation of a solitary wave in a thermocline 总被引:1,自引:0,他引:1
O. D. Shishkina 《Experiments in fluids》1996,21(5):374-379
The resonant generation of a second-mode internal solitary wave, resulting from a ship internal waves system damping in a thermocline, is studied experimentally. The source of the stationary internal waves was provided by an oblong ellipsoid of revolution towed horizontally and uniformly at the depth of the thermocline center. The ranges of the Reynolds and Froude numbers were 500Re=Ul/v 15000 and 0.3Fi=U/N
max
D1.0, respectively. When the body's speed and the linear long-wave second-mode phase speed were equal, an internal solitary wave of the bulge type was observed. The shape of the wave satisfied the Korteweg-de Vries equation. The Urcell parameter was equal to 10.2.List of Symbols
L, B, H
towing tank length, breadth and height respectively
-
z
vertical coordinate
-
D
characteristic vertical dimension of the body
-
a
minor semiaxis of an ellipsoid
-
b
major semiaxis of an ellipsoid (maximum ellipsoid diameter D=2a)
-
l
length of the body ( =2b)
-
U
velocity of the body
-
t
temperature
-
g
acceleration due to gravity
-
i
fresh water density at ith level
-
4°
fresh water density for temperature t=4°C
-
o
water density at the center of the thermocline
-
i
density variation due to the temperature variation at the ith horizon
-
N
Brunt-Väisälä frequency
-
N
max
maximum value of Brunt-Väisälä frequency
-
Re
Reynolds number
-
Fi
internal Froude number
-
f
n
eigenfunction of the boundary-value problem for the nth mode
-
n
nth mode frequency
-
k
n
nth mode horizontal wavenumber
-
C
n
limiting phase speed of a linear nth mode interval wave (=
n/kn;kn
0)
-
Ur
Urcell parameter
-
v
fresh water kinematic viscosity
-
conventional density
-
half-length of a solitary wave
-
0
solitary wave height
-
time
This work was partially supported by the INTAS (grant no. 94-4057) and by the Russian Foundation of Basic Research under grant no. 94-05-17004-a.A version of this paper was presented at the Second International Conference on Experimental Fluid Mechanics, Torino, Italy, 4–8 July, 1994. 相似文献
40.
Semenenko A. N. Babak N. L. Gella I. M. Musatov V. I. Shishkina S. V. Sofronov D. S. Lipson V. V. 《Russian Journal of Organic Chemistry》2017,53(2):282-289
Russian Journal of Organic Chemistry - Crotone condensation of allobetulone with fluorine-containing benzaldehydes afforded new α,β-unsaturated ketones of lupane series. Their... 相似文献