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41.
Sergey A. Nazarov Iryna L. Pankratova Andrey L. Piatnitski 《Archive for Rational Mechanics and Analysis》2011,200(3):747-788
The paper deals with the asymptotic behaviour of spectra of second order self-adjoint elliptic operators with periodic rapidly
oscillating coefficients in the case when the density function (the factor on the spectral parameter) changes sign. We study
the Dirichlet problem in a regular bounded domain and show that the spectrum of this problem is discrete and consists of two
series, one of them tending towards +∞ and another towards −∞. The asymptotic behaviour of positive and negative eigenvalues
and their corresponding eigenfunctions depends crucially on whether the average of the weight function is positive, negative
or equal to zero. We construct the asymptotics of eigenpairs in all three cases. 相似文献
42.
Anja Kastell Iryna Smetanska Christian Ulrichs Zhenzhen Cai Inga Mewis 《Applied biochemistry and biotechnology》2013,169(2):624-635
Although some study have established hairy root cultures from brassicaceous plants with glucosinolates (GS) as characteristic secondary metabolite, studies are missing which compare hairy roots with the corresponding mother plants. Therefore, two different plant species—Sinapis alba and Brassica rapa subsp. rapa pygmeae teltoviensis—were transformed with the Agrobacterium rhizogenes strain A4. Aliphatic and indolyl GS were present in B. rapa, exhibiting larger quantities in leaves than in roots. Aromatic p-hydroxybenzyl GS were found particularly in the leaves of S. alba. However, the proportion of indolyl GS increased suddenly in transformed hairy roots of S. alba and B. rapa. Cultivation with the phytohormone kinetin (0.5 mg?L?1) enhanced GS accumulation in B. rapa hairy roots, however not in S. alba, but 2,4-D (0.4 mg?L?1) induced de-differentiation of roots in both species and reduced GS levels. GS levels especially of 1-methoxyindol-3ylmethyl GS increased in hairy roots in response to JA, but root growth was inhibited. While 2 weeks of cultivation in 100 to 200 μM JA were determined at optimum for maximum GS yield in S. alba hairy root cultures, 4 weeks of cultivation in 50 to 100 μM JA was the optimum for B. rapa. 相似文献
43.
Porphyrin heteroaggregates composed of meso-tetrakis(N-methylpyridinium-4-yl)porphinatocopper(II) and meso-tetrakis(4-sulfonatophenyl)porphyrin formed in the presence of a polyglutamic matrix possess chiral memory and an ability to self-replicate their supramolecular structures. By means of electronic circular dichroism spectroscopy, it has been shown that the self-replication process is not influenced by changes in pH or ionic strength. The average molecular weight of the polyglutamic matrix used for porphyrin aggregate preparation plays a crucial role with regard to the form of the resulting CD spectrum. In the second part of our study, a complex composed of polylysine and bilirubin as a model system for a structured homoaggregate formed on the chiral matrix has been tested for chiral memory phenomena. The results indicate that the bilirubin homoaggregate shows chiral memory. 相似文献
44.
Stepanenko IN Krokhin AA John RO Roller A Arion VB Jakupec MA Keppler BK 《Inorganic chemistry》2008,47(16):7338-7347
Reactions of (H 2azole) 2[OsCl 6], where Hazole = pyrazole, Hpz, ( 1), indazole, Hind, ( 2), imidazole, Him, ( 3) and benzimidazole, Hbzim, ( 4) with the corresponding azole heterocycle in 1:4 molar ratio in boiling isoamyl alcohol or hexanol-1 afforded novel water-soluble osmium(III) complexes of the type trans-[OsCl 2(Hazole) 4]Cl, where Hazole = Hpz ( 5a), Hind ( 6a), Him ( 7a), and Hbzim ( 9a) in 50-70% ( 5a, 7a, 9a) and 5% ( 6a) yields. The synthesis of 7a was accompanied by a concurrent reaction which led to minor formation (<4%) of cis-[OsCl 2(Him) 4]Cl ( 8). The complexes were characterized by elemental analysis, IR spectroscopy, UV-vis spectroscopy, ESI mass spectrometry, cyclic voltammetry, and X-ray crystallography. 5a, 7a, and 9a were found to possess remarkable antiproliferative activity in vitro against A549 (non-small cell lung carcinoma), CH1 (ovarian carcinoma), and SW480 (colon carcinoma) cells, which was compared with that of related ruthenium compounds trans-[RuCl 2(Hazole) 4]Cl, where Hazole = Hpz (5b), Hind (6b), Him (7b), and Hbzim (9b). 相似文献
45.
On the basis of combined studies of the acoustic and optical properties of Sn2P2(Se x S1– x )6 solid solutions with x?=?0 and 0.28 it is shown that two special points exist on the x,T-phase diagram of these ferroelectric crystals, a tricritical point and a triple one. With increasing Se concentration, the phase transition changes its character at x?≈?0.28 from second-order to first-order. The phase transition becomes split at x?≈?0.4, with the appearance of an intermediate incommensurate phase. 相似文献
46.
The problem of classification of Jordan bimodules over (non-semisimple) finite dimensional Jordan algebras with respect to their representation type is considered. The notions of diagram of a Jordan algebra and of Jordan tensor algebra of a bimodule are introduced and a mapping Qui is constructed which associates to the diagram of a Jordan algebra J the quiver of its universal associative enveloping algebra S(J). The main results are concerned with Jordan algebras of semi-matrix type, that is, algebras whose semi-simple component is a direct sum of Jordan matrix algebras. In this case, criterion of finiteness and tameness for one-sided representations are obtained, in terms of diagram and mapping Qui, for Jordan tensor algebras and for algebras with radical square equals to 0. 相似文献
47.
Chepurna I Smotraev R Kanibolotsky V Strelko V 《Journal of colloid and interface science》2011,356(2):404-411
The processes of coagulation and gelation of sols in zirconium oxychloride aqueous solutions and the properties of hydrated zirconium dioxide sols (pH, particles size, dynamic viscosity) depending on the aging conditions of partially neutralized zirconium oxychloride feedstock solution-zirconyl hydroxychloride used for the synthesis and molar ratio of initial reagents (Zr/NaOH, Zr/CH(3)COO(-)) were first studied in the paper. The concentration and temperature limits of hydrated zirconium dioxide sols stability were determined. The coagulation constant, gelation activation energy, and gelation thermal effect values were found. 相似文献
48.
49.
Iryna O. LebedyevaVictor V. Dotsenko Vladimir V. Turovtsev Sergey G. KrivokolyskoV'yacheslav M. Povstyanoy Mikhaylo V. Povstyanoy 《Tetrahedron》2012,68(47):9729-9737
3-Cyanopyridine-2(1H)-thiones have been shown to react with Biginelli-type ethyl 4-aryl-6-(bromomethyl)-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates upon heating in DMF giving rise to ethyl 4-aryl-6-{[(3-cyanopyridin-2-yl)thio]methyl}-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates. The latter upon treatment with an excess of NaH or t-BuOK in boiling DMF undergo a tandem Thorpe-Ziegler-type heterocyclization to give pyrido[3″,2″:4′,5′]thieno[2′,3′:5,6]pyrido[4,3-d]pyrimidine derivatives in good yields. Selected compounds were tested for antibacterial and antifungal activity. 相似文献
50.
Iryna Egorova Leonid Golinskii 《Journal of Difference Equations and Applications》2013,19(14):1185-1203
We study spectrum inclusion regions for complex Jacobi matrices, which are compact perturbations of real periodic Jacobi matrix. The condition sufficient for the lack of the discrete spectrum for such matrices is given. 相似文献