Главная
Авторизация
Фамилия
Пароль
 

Базы данных


Труды сотрудников ИФ СО РАН - результаты поиска

Вид поиска

Область поиска
в найденном
Формат представления найденных документов:
полный информационныйкраткий
Отсортировать найденные документы по:
авторузаглавиюгоду изданиятипу документа
Поисковый запрос: (<.>K=compound<.>)
Общее количество найденных документов : 62
Показаны документы с 1 по 10
 1-10    11-20   21-30   31-40   41-50   51-60      
1.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kovel E. S., Sachkova A. S., Vnukova N. G., Churilov G. N., Knyazeva E. M., Kudryasheva N. S.
Заглавие : Antioxidant Activity and Toxicity of Fullerenols via Bioluminescence Signaling: Role of Oxygen Substituents
Место публикации : Int. J. Mol. Sci. - 2019. - Vol. 20, Is. 9. - Ст.2324. - ISSN 14220067 (ISSN) , DOI 10.3390/ijms20092324
Примечания : Cited References: 74. - This work was supported by PRAN-32, Program: 'Nanostructures: physics, chemistry, biology, technological basis'; RFBR 18-29-19003; RFBR-Krasnoyarsk Regional Foundation 18-44-240004, Tomsk Polytechnic University CE Program.
Аннотация: Fullerenols are nanosized water-soluble polyhydroxylated derivatives of fullerenes, a specific allotropic form of carbon, bioactive compounds, and perspective basis for drug development. Our paper analyzes the antioxidant activity and toxicity of a series of fullerenols with different number of oxygen substituents. Two groups of fullerenols were under investigation: (1) C60Oy(OH)(x), C60,70Oy(OH)(x), where x+y = 24-28 and (2) C60,70Oy(OH)(x), Fe0,5C60Oy(OH)(x), Gd@C82Oy(OH)(x), where x+y = 40-42. Bioluminescent cellular and enzymatic assays (luminous marine bacteria and their enzymatic reactions, respectively) were applied to monitor toxicity in the model fullerenol solutions and bioluminescence was applied as a signaling physiological parameter. The inhibiting concentrations of the fullerenols were determined, revealing the fullerenols' toxic effects. Antioxidant fullerenol' ability was studied in solutions of model oxidizer, 1,4-benzoquinone, and detoxification coefficients of general and oxidative types (D-GT and D-OxT) were calculated. All fullerenols produced toxic effect at high concentrations (0.01 g L-1), while their antioxidant activity was demonstrated at low and ultralow concentrations (0.001 g L-1). Quantitative toxic and antioxidant characteristics of the fullerenols (effective concentrations, concentration ranges, D-GT, and D-OxT) were found to depend on the number of oxygen substituents. Lower toxicity and higher antioxidant activity were determined in solutions of fullerenols with fewer oxygen substituents (x+y ⋍ 24-28). The differences in fullerenol properties were attributed to their catalytic activity due to reversible electron acceptance, radical trapping, and balance of reactive oxygen species in aqueous solutions. The results provide pharmaceutical sciences with a basis for selection of carbon nanoparticles with appropriate toxic and antioxidant characteristics. Based on the results, we recommend, to reduce the toxicity of prospective endohedral gadolinium-fullerenol preparations Gd@C82Oy(OH)(x), decreasing the number of oxygen groups to x+y ⋍ 24-28. The potential of bioluminescence methods to compare toxic and antioxidant characteristics of carbon nanostructures were demonstrated.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
2.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aplesnin S. S.
Заглавие : Existence of massive singlet excitations in an antiferromagnetic alternating chain with S=1/2
Место публикации : Phys. Rev. B: AMERICAN PHYSICAL SOC, 2000. - Vol. 61, Is. 10. - P6780-6784. - ISSN 1098-0121, DOI 10.1103/PhysRevB.61.6780
Примечания : Cited References: 26
Предметные рубрики: PEIERLS COMPOUND CUGEO3
SPIN SYSTEMS
TRANSITION
Аннотация: The one-dimensional Heisenberg model with alternating antiferromagnetic bond and spin-1/2 has been studied by the Monte Carlo method. The thermodynamic characteristics, spin-spin, and four spin-correlation function have been calculated. From several maxima of the correlation radius of the four spin-correlation function and sharp slopes of the dimer order parameter, a longitudinal component of the total spin square as a function of temperature and magnetic field, the existence of two mass singlet excitation branches with Delta S-z=0 and one triplet with Delta S-z=1 is suggested. Critical temperatures and fields related to singlet filled bands have been estimated. From these results low-temperature (TT-SP) properties of spin-Peierls (SP) compounds CuGeO3 and NaV2O5 have been explained.
WOS,
Читать в сети ИФ
Найти похожие
3.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aplesnin S. S.
Заглавие : Modeling a dimer state in CuGeO3 in the two-dimensional anisotropic Heisenberg model with alternated exchange interaction
Место публикации : J. Exp. Theor. Phys.: AMER INST PHYSICS, 1997. - Vol. 85, Is. 6. - P1196-1203. - ISSN 1063-7761, DOI 10.1134/1.558393
Примечания : Cited References: 33
Предметные рубрики: SPIN-PEIERLS TRANSITION
HIGH MAGNETIC-FIELDS
COMPOUND CUGEO3
GROUND-STATE
SYSTEMS
NEUTRON
Аннотация: The two-dimensional Heisenberg spin-1/2 model with alternated exchange interaction along the c axis and an anisotropic distribution of the exchange interaction in the lattice, J(b)/J(c)=0.1, is examined. A quantum Monte Carlo method is used to calculate the phase diagrams of the antiferromagnet, the dimer state in a plane, the value of the alternation delta of the exchange interaction, and the anisotropy Delta=1-J(xy)/J(z) of the exchange interaction, Delta similar to delta(0.58(6)). The following characteristics are calculated for Delta=0.25: the dependence of the temperature of the dimer-state-paramagnet transition on the alternation of the exchange interaction, T-c(delta)=0.55(4(delta-0.082(6))(0.50(3)), the singlet-triplet energy gap, and the dependence of the magnetization on the external field for some values of delta. The value of the exchange interaction, J(c)=127 K, the alternation of the exchange interaction, delta=0.11J(c), and the correlation radius along the c axis, xi(c) approximate to 28c, are determined. Finally, it is found that the temperature dependence of the susceptibility and the specific heat are in good agreement with the experimental data. (C) 1997 American Institute of Physics. [S1063-7761(97)01912-4].
WOS,
Scopus
Найти похожие
4.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aplesnin S. S.
Заглавие : Quantum Monte Carlo investigation of the magnetic properties of weakly interacting antiferromagnetic chains with an alternating exchange interaction with spin S=1/2
Место публикации : J. Exp. Theor. Phys.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2000. - Vol. 90, Is. 1. - P194-201. - ISSN 1063-7761, DOI 10.1134/1.559075
Примечания : Cited References: 35
Предметные рубрики: PEIERLS COMPOUND CUGEO3
MAGNON DISPERSION
BI2CUO4
EXCITATIONS
RESONANCE
SYSTEMS
SCATTERING
DYNAMICS
NEUTRON
PHASE
Аннотация: An approximation dependence of the spontaneous magnetic moment at a site, sigma/sigma(0) - 1 = 0.71(6)delta(2.5(2)), and the antiferromagnet-singlet state phase boundary, J(2)/J(1) = 0.52(3)delta, are determined by the quantum Monte Carlo method in the self-consistent sublattice molecular field approximation for weakly interacting (J(2)) antiferromagnetic chains with spin S = 1/2 and alternating exchange interaction (J(1) +/- delta). The Neel temperature and a number of critical temperatures which could be related with the filling energy of two singlets (Delta S-z = 0) and one triplet (Delta S-z= 1) spin bands, each of which is split by the sublattice field (h(x,y)not equal h(z)) into two subbands, are determined on the basis of the computed correlation radii of the two- and four-spin correlation function, the squared total spin (S-z)(2) with respect to the longitudinal components, the dimerization parameter, and the correlation functions between the nearest neighbors with respect to longitudinal and transverse spin components. On the basis of the Monte Carlo calculations, the critical temperatures and possible energy gaps at the band center are determined for the antiferromagnets CuWO4 and Bi2CuO4 and for the singlet compounds (VO)(2)P2O7 and CuGeO3 , agreeing satisfactorily with existing results, and new effects are also predicted. (C) 2000 MAIK "Nauka / Interperiodica".
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
5.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aver'yanov E. M.
Заглавие : Structural and thermodynamic consequencies of the interaction of conformational degrees of freedom of azomethines in the nematic phase
Место публикации : J. Struct. Chem.: Springer, 2014. - Vol. 55, Is. 4. - P.605-611. - ISSN 0022-4766, DOI 10.1134/S0022476614040039. - ISSN 1573-8779
Примечания : Cited References: 21
Предметные рубрики: CONJUGATED POLY(AZOMETHINE)S
TERMINAL SUBSTITUENTS
ELECTRONIC-STRUCTURES
FLUORINATED ANALOGS
INTERNAL-ROTATION
MOLECULES
COMPOUND
ANGLES
STATE
NMR
Ключевые слова (''Своб.индексиров.''): azomethines--benzylideneaniline--conformation--steric effects of substituents--nematic-isotropic liquid transition--conformational polymorphism
Аннотация: The interaction of the conformational degrees of freedom of azomethines in the nematic phase, which is induced by electronic donor-acceptor properties of the terminal substituents of the benzylideneaniline core is studied. These degrees of freedom related to the rotation angles phi (k) around the bonds between the substituent and the aniline ring (phi(1)) and also between the CH=N bridge and the aniline ring (omega(2)) are characterized by the parameters Q (k) = aOE (c) cos(2)phi (k) . It is found that the interaction of these degrees of freedom is manifested in the linear dependence Q (2)(Q (1)). Within the phenomenological theory the effect of this interaction on changes delta (k) in the Q (k) values during the nematic liquid crystal-isotropic liquid phase transition is revealed along with the temperature T (NI) and character of this transition. The derivation of previously established empirical dependences T (NI)(Q (k) ) is presented in the presence of direct and indirect steric effects of side substituents affecting the Q (k) values. A diverse combination of delta (k) signs in the nematic phase, which is a prerequisite for the conformational polymorphism of the nematic phases of azomethines, is shown.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
6.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Barinov G. I., Babkin Y. V.
Заглавие : Influence of high-pressure thermal-treatment on the phase compound and phase-transformation kinetics of a system magnetite-wustite
Место публикации : Izvestiya vysshikh uchebnykh zavedenii Fizika. - 1990. - Vol. 33, Is. 5. - P.95-96. - ISSN 0021-3411; \b Russian Physics Journal; \b Известия высших учебных заведений. Физика
Примечания : Cited References: 4
WOS
Найти похожие
7.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bayukov O. A., Petrakovskii G. A., Savitskii A. F.
Заглавие : Orbital ordering in CuGeO3
Место публикации : Phys. Solid State: AMER INST PHYSICS, 1998. - Vol. 40, Is. 9. - P1534-1539. - ISSN 1063-7834, DOI 10.1134/1.1130602
Примечания : Cited References: 25
Предметные рубрики: SPIN-PEIERLS TRANSITION
COMPOUND CUGEO3
DIMERIZATION
STATE
SUSCEPTIBILITY
(VO)2P2O7
LADDER
Аннотация: The combined effect of the ligand crystal field and the exchange interaction on the Cu2+ cation in CuGeO3 is examined. It is shown that, if the magnitude of the exchange interaction exceeds the splitting of the energy levels of the d(x2-y2) and d(xy) orbitals, then an alternate filling of the d orbitals along a chain (orbital ordering) is possible. This effect creates an antiferromagnetic interaction between Cu2+ pairs in 90 degrees exchange and a doubling of the lattice period. A Jahn-Teller pseudoeffect causes singletization of the ground state of the antiferromagnetic chain of Cu2+ spins. (C) 1998 American Institute of Physics. [S1063-7834(98)02609-4].
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
8.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Solovyov L. A., Golovnev N. N., Molokeev M. S., Lesnikov M. K.
Заглавие : Bis(μ3-barbiturato−O,O,O′)-(μ2-aqua)- aqua-barium(II): crystal structure, spectroscopic and thermal properties
Место публикации : J. Coord. Chem.: Taylor & Francis, 2017. - Vol. 70, Is. 12. - P.1984-1993. - ISSN 00958972 (ISSN), DOI 10.1080/00958972.2017.1319943
Примечания : Cited References: 21
Ключевые слова (''Своб.индексиров.''): barbituric acid--barium--coordination compound--x-ray diffraction--infrared spectroscopy--thermal analysis
Аннотация: A polymeric coordination compound, [Ba(H2O) 2(Hba)2] (1) (H2ba – barbituric acid, C4H4N2O3), was obtained. The structure of 1 was solved using powder X-ray diffraction methods. The Ba2+ ion in 1 formed a three-capped trigonal prism. The BaO9 polyhedra, connected with each other by the edges and faces, formed a chain. Several 4- and 12-membered cycles due to the bridging μ2-H2O and bridging μ3-Hba– also formed implementing a 3-D polymer structure. The structures of 1 and other thiobarbiturate complexes were compared. The replacement of a S atom by an O atom in the heterocyclic ligand Htba− (thiobarbiturate ion) of the compound Ba(H2O)2(Htba)2 resulted in changes of the coordination number Ba(II) and supramolecular structure. The intermolecular hydrogen bonds O–H⋯O and N–H⋯O formed a 3-D net where pronounced 2-D layers of Hba– ions could be found. A new topological net in 1 was observed. The IR and thermal stability were investigated.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
9.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Boehm M., Roessli B., Schefer J., Ouladdiaf B., Kulda J., Petrakovskii G. A.
Заглавие : Coexisting 1D and 3D magnetic interactions in the insulating copper-oxygen compound CuB2O4
Разночтения заглавия :авие SCOPUS: Coexisting 1D and 3D magnetic interactions in the insulating copper-oxygen compound CuB2 O4
Место публикации : Physica B: ELSEVIER SCIENCE BV, 2006. - Vol. 378-80: International Conference on Strongly Correlated Electron Systems (SECES 05) (JUL 26-30, 2005, Vienna, AUSTRIA). - P1128-1129. - ISSN 0921-4526, DOI 10.1016/j.physb.2006.01.540
Примечания : Cited References: 8
Предметные рубрики: SPIN-WAVE SPECTRUM
PHASE 10 K
METABORATE
Ключевые слова (''Своб.индексиров.''): cuprates--magnetic soliton lattice--heisenberg exchange--low-dimensional excitations--cuprates--heisenberg exchange--low-dimensional excitations--magnetic soliton lattice--dispersions--insulating materials--magnetic properties--neutron scattering--positive ions--cuprates--heisenberg exchange--low-dimensional excitations--magnetic soliton lattice--copper compounds
Аннотация: We performed inelastic neutron scattering measurements on CuB2O4 with a magnetic field applied in the tetragonal basal plane. The spin dynamics in this cuprate is determined by the interplay of two magnetic Cu2+ subsystems, the magnetic cage with predominant 3d Heisenberg exchange and quasi Id zig-zag chains. The comparison of the dispersion spectra along the chain direction in zero field and under applied field suggests a decoupling of the two magnetic sublattices under field. (c) 2006 Elsevier B.V. All rights reserved.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Klauss H. H., Luetkens H., Klingeler R., Hess C., Litterst F. J., Kraken M., Korshunov M. M., Eremin I., Drechsler S. L., Khasanov R., Amato A., Hamann-Borrero J. E., Leps N., Kondrat A., Behr G., Werner J., Buchner B.
Заглавие : Commensurate spin density wave in LaFeAsO: A local probe study
Место публикации : Phys. Rev. Lett.: AMER PHYSICAL SOC, 2008. - Vol. 101, Is. 7. - Ст.77005. - ISSN 0031-9007, DOI 10.1103/PhysRevLett.101.077005
Примечания : Cited References: 28
Предметные рубрики: LAYERED QUATERNARY COMPOUND
SUPERCONDUCTIVITY
Ключевые слова (''Своб.индексиров.''): arsenic compounds--chlorine compounds--ferromagnetism--magnetic materials--magnetic properties--magnetization--magnets--molybdenum--phase transitions--spin density waves--commensurate spin density wave--external fields--magnetic orders--muon spin relaxations--order parameter--ordered moments--probe measurements--ssbauer spectroscopy--structural phase transition--sublattice magnetizations--temperature dependences--spin dynamics
Аннотация: We present a detailed study on the magnetic order in the undoped mother compound LaFeAsO of the recently discovered Fe-based superconductor LaFeAsO(1-x)F(x). In particular, we present local probe measurements of the magnetic properties of LaFeAsO by means of (57)Fe Mossbauer spectroscopy and muon-spin relaxation in zero external field along with magnetization and resistivity studies. These experiments prove a commensurate static magnetic order with a strongly reduced ordered moment of 0.25(5)mu(B) at the iron site below T(N)=138 K, well separated from a structural phase transition at T(S)=156 K. The temperature dependence of the sublattice magnetization is determined and compared to theory. Using a four-band spin density wave model both, the size of the order parameter and the quick saturation below T(N) are reproduced.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
 1-10    11-20   21-30   31-40   41-50   51-60      
 

Другие библиотеки

© Международная Ассоциация пользователей и разработчиков электронных библиотек и новых информационных технологий
(Ассоциация ЭБНИТ)