Библиотека института физики им. Л.В. Киренского СО РАН

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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ershov A. E., Isaev I. L., Semina P. N., Markel V. A., Karpov S. V.
Заглавие : Effects of size polydispersity on the extinction spectra of colloidal nanoparticle aggregates
Место публикации : Phys. Rev. B: American Physical Society, 2012. - Vol. 85, Is. 4. - Ст.045421. - P. - ISSN 1098-0121, DOI 10.1103/PhysRevB.85.045421
Примечания : Cited References: 41. - This work was supported by grants from the following foundations of the Russian Federation: Presidium of RAS, OFN RAS, and SB RAS.
Предметные рубрики: METAL FRACTAL CLUSTERS
OPTICAL-PROPERTIES
ABSORPTION
NONLINEARITIES
COMPOSITES
SCATTERING
PARTICLES
SPHERES
GRAINS
Аннотация: We investigate the effect of particle polydispersity on the optical extinction spectra of colloidal aggregates of spherical metallic (silver) nanoparticles, taking into account the realistic interparticle gaps caused by layers of stabilizing polymer adsorbed on the metal surface (adlayers). The spectra of computer-generated aggregates are computed using two different methods. The coupled-multipole method is used in the quasistatic approximation and the coupled-dipole method beyond the quasistatics. The latter approach is applicable if the interparticle gaps are sufficiently wide relative to the particle radii. Simulations are performed for two different particle size distribution functions (bimodal and Gaussian), varying the number of particles per aggregate, and different distribution functions of the interparticle gap width. The strong influence of the latter factor on the spectra is demonstrated and investigated in detail.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gurevich Y. L., Mankov Yu.I., Khlebopros R. G.
Заглавие : Self-assembly of superparamagnetic ferrihydrite nanoparticles
Коллективы : Russian Foundation for Basic Research [08-08-00427_a, 10-08-00278_a]; Siberian Branch, Russian Academy of Sciences, Integration project [21]
Место публикации : Dokl. Phys.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2013. - Vol. 58, Is. 11. - P.478-481. - ISSN 1028-3358, DOI 10.1134/S1028335813110104
Примечания : Cited References: 15. - This work was supported by the Russian Foundation for Basic Research, project nos. 08-08-00427_a and 10-08-00278_a, and by the Siberian Branch, Russian Academy of Sciences, Integration project no. 21.
Предметные рубрики: CHAINS
CLUSTERS
Аннотация: A study was conducted to estimate the possibility of formation of chains of superparamagnetic nanoparticles of iron oxyhydroxides synthesized in a bacteria culture. The self-assembly of biogenic nanoparticles distinguished by low values of magnetization and small sizes is assumed to proceed due to the forces of magnetic dipole dipole interaction as an initial mechanism of aggregation and exchange-interaction forces, which provide the stability of chains. The microphotographs demonstrate the self-assembly of anisotropic cobalt-doped ferrihydrite nanoparticles in aggregates of ellipsoidal shape with sizes of about 550 × 300 nm and a platelike shape of 50-100 nm thick. The aggregates, in turn, are combined from blocks, which include a restricted number of nanoparticles of about 5 nm in diameter and have the shape of rods of 50-100 × 12 nm in size. The energy of degaussing fields of chains is reasonably high, which forces them to form two and three dimensional structures in which the compensation of such fields is provided.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Verpekin V. V., Kondrasenko A. A., Chudin O. S., Vasiliev A. D., Burmakina G. V., Pavlenko N. I., Rubaylo A. I.
Заглавие : Chemistry of vinylidene complexes. XXIII. Binuclear rhenium-palladium vinylidene bridged complexes, their reactions with diiron nonacarbonyl
Место публикации : J. Organomet. Chem.: Elsevier Science, 2014. - Vol. 770. - P.42-50. - ISSN 0022-328X, DOI 10.1016/j.jorganchem.2014.07.024. - ISSN 1872-8561
Примечания : Cited References: 56. - This article is dedicated to the memory of Alla B. Antonova.
Предметные рубрики: TRANSITION-METAL-COMPLEXES
CATIONIC CARBYNE COMPLEXES
RAY CRYSTAL-STRUCTURE
MOLECULAR-STRUCTURE
HETEROBIMETALLIC COMPLEXES
LIGANDS
MANGANESE
CLUSTERS
DINUCLEAR
PD2CL2(MU-PH2PCH2PPH2)2
Ключевые слова (''Своб.индексиров.''): rhenium--palladium--iron--vinylidene complexes--heterometallic complexes
Аннотация: The reaction of [Cp(CO)2ReCCHPh] (1) with [Pd(PPh3)4] followed by the treatment of resulting [Cp(CO)2RePd(μ-CCHPh)(PPh3)2] (2) with diphosphines (dppe, dppp) gave new complexes [Cp(CO)2RePd(μ-CCHPh)(dppe)] (3) and [Cp(CO)2RePd(μ-CCHPh)(dppp)] (4). Treatment of the synthesized complexes with [Fe2(CO)9] led to mixtures of [Cp(CO)2ReFe(μ-CCHPh)(CO)4] (5), [(dppe)PdFe2(CO)8] (6), [CpReFe2(μ3-CCHPh)(CO)8] (7), [CpReFePd(μ3-CCHPh)(CO)5(dppe)] (8) and of 5, [(dppp)PdFe2(CO)8] (9), [CpReFePd(μ3-CCHPh)(CO)5(dppp)] (10), respectively. The main products of both reactions were trinuclear μ3-vinylidene clusters 8 and 10. Reactions of the trinuclear μ3-vinylidene ReFePd clusters 8 and 10 with Fe2(CO)9 were also studied. New complexes were characterized by IR, 1H, 13C, 31P NMR spectroscopy and cyclic voltammetry. The structure of [CpReFe2(μ3-CCHPh)(CO)8] was determined by single-crystal X-ray diffraction.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kveglis L. I., Dzhes A. V., Volochaev M. N., Cherkov A. G., Noskov F. M.
Заглавие : The clusters self-assembled crystal and magnetic structure during the martensite transition in Fe86Mn13C alloy
Место публикации : J. Sib. Fed. Univ. Eng. Technol. - 2015. - Vol. 8, Is. 1. - P.48-56. - ISSN 1999-494X; Журн. СФУ. Сер. "Техника и Технологии"
Примечания : Cited References: 14. - The authors thank to Zhigalov V.S., Kirensky Institute of Physics Russian Academy of Sciences Siberian Branch, V.N. Cherepanov, A.V. Nyavro Tomsk State University for assistance.This work is supported by a grant # 278 from the Ministry of Science and Education of the Republic of Kazakhstan.
Ключевые слова (''Своб.индексиров.''): тонкие магнитные пленки--сплав fe86mn13c--кластеры с плотноупакованной структурой--магнитная структура--плотность электронных состояний--волны пластической деформации--мартенситные превращения--thin magnetic films--fe86mn13c alloy--close packed structure clusters--magnetic structure--martensite transitions--density of electronic states--waves of plastic deformation
Аннотация: In bulk and thin ﬁlm state Fe86Mn13C alloy observed experimentally self-assembly of the crystal and magnetic structures on multiscale levels. Offered self-assembly cluster model of atomic structure based on the concept of a liquid-like state of the material in localized areas, formed in the waves of plastic deformation.В массивных и тонкопленочных образцах сплава Fe86Mn13C экспериментально наблюдается самоорганизация кристаллической и магнитной структур на разномасштабных уровнях. Предлагается кластерная модель атомной самоорганизации, основанная на концепции жидкоподобного состояния материала в локальных участках, образованных волнами пластической деформации.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kveglis L. I., Dzhes A. V., Volochaev M. N., Cherkov A. G., Noskov F. M.
Заглавие : Кластерная самоорганизация кристаллической и магнитной структур в процессе мартенситного превращения в сплаве Fe86Mn13C
Место публикации : Журн. СФУ. Сер. "Техника и Технологии". - 2015. - Т. 8, № 1. - С. 48-56. - ISSN 1999-494X; J. Sib. Fed. Univ. Eng. Technol.
Примечания : Cited References:14
Ключевые слова (''Своб.индексиров.''): thin magnetic films--fe86mn13c alloy--close packed structure clusters--magnetic structure--martensite transitions--density of electronic--states--waves of plastic deformation
Аннотация: In bulk and thin ﬁlm state Fe86Mn13C alloy observed experimentally self-assembly of the crystal and magnetic structures on multiscale levels. Offered self-assembly cluster model of atomic structure based on the concept of a liquid-like state of the material in localized areas, formed in the waves of plastic deformation.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Edel'man I. S., Petrov D. A., Ivantsov R. D., Zharkov S. M., Khaibullin R. I., Valeev V. F., Nuzhdin V. I., Stepanov A. L.
Заглавие : Microstructure and Magnetooptics of Silicon Oxide with Implanted Nickel Nanoparticles
Разночтения заглавия :авие SCOPUS: Microstructure and magnetooptics of silicon oxide with implanted nickel nanoparticles
Место публикации : J. Exp. Theor. Phys.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2011. - Vol. 113, Is. 6. - P1040-1049. - ISSN 1063-7761, DOI 10.1134/S1063776111160035
Примечания : Cited References: 44. - This work was supported by the Russian Foundation for Basic Research (project nos. 11-02-00972, 11-02-90420, 11-02-91341) and the program Research and Scientific-Pedagogical Brainpower of Innovated Russia (State contract 02.740.11.0797).
Предметные рубрики: SIMPLE METAL-CLUSTERS
OPTICAL-PROPERTIES
ION-IMPLANTATION
FARADAY-ROTATION
KERR SPECTRA
GLASS
RESONANCE
PHYSICS
ENERGY
FE
Ключевые слова (''Своб.индексиров.''): disperse structure--effective medium model--implanted samples--irradiation dose--magnetic circular dichroisms--magnetic nickel--magneto-optical faraday effect--magneto-optical measurements--matrix--metal nanoparticles--metallic nickel--nickel nanoparticles--nickel particles--optical range--spectral dependences--surface plasma resonances--tensor components--thin near-surface layers--amorphous silicon--crystal microstructure--dichroism--faraday effect--ion implantation--magnetoplasma--metallic compounds--nanomagnetics--nanoparticles--nickel--silicon compounds--silicon oxides--spectroscopy--tensors--transmission electron microscopy--nickel oxide
Аннотация: Metallic nickel nanoparticles of various sizes are formed in a thin near-surface layer in an amorphous SiO2 matrix during 40-keV Ni+ ion implantation at a dose of (0.25-1.0) x 10(17) ions/cm(2). The micro-structure of the irradiated layer and the crystal structure, morphology, and sizes of nickel particles formed at various irradiation doses are studied by transmission electron microscopy and electron diffraction. The magnetooptical Faraday effect and the magnetic circular dichroism in an ensemble of nickel nanoparticles are studied in the optical range. The permittivity (epsilon) over cap tensor components are calculated for the implanted samples using an effective medium model with allowance for the results of magnetooptical measurements. The spectral dependences of the tensor (epsilon) over cap components are found to be strongly different from those of a continuous metallic nickel film. These differences are related to a disperse structure of the magnetic nickel phase and to a surface plasma resonance in the metal nanoparticles.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zobov V. E.
Заглавие : THE critical exponent of the tree lattice generating function in the eden model
Разночтения заглавия :авие SCOPUS: The critical exponent of the tree lattice generating function in the eden model
Место публикации : Theor. Math. Phys.: SPRINGER, 2010. - Vol. 165, Is. 2. - P1443-1455. - ISSN 0040-5779, DOI 10.1007/s11232-010-0120-5
Примечания : Cited References: 14
Предметные рубрики: GROWTH PARAMETER
CLUSTERS
DIMENSIONS
SYSTEMS
Ключевые слова (''Своб.индексиров.''): number of lattice trees--tree perimeter--generating function--critical exponent--hypercubic lattice--bethe lattice--eden model--bethe lattice--critical exponent--eden model--generating function--hypercubic lattice--number of lattice trees--tree perimeter
Аннотация: We consider the increase in the number of trees as their size increases in the Eden growth model on simple and face-centered hypercubic lattices in different space dimensions. We propose a first-order partial differential equation for the tree generating function, which allows relating the exponent at the critical point of this function to the perimeter of the most probable tree. We estimate tree perimeters for the lattices considered. The theoretical values of the exponents agree well with the values previously obtained by computer modeling. We thus explain the closeness of the dimension dependences of the exponents of the simple and face-centered lattices and their difference from the results in the Bethe lattice approximation.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zobov V. E., Lundin A. A.
Заглавие : On the Second Moment of the Multiquantum NMR Spectrum of a Solid
Место публикации : Russ. J. Phys. Chem. B: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2008. - Vol. 2, Is. 5. - P676-683. - ISSN 1990-7931, DOI 10.1134/S1990793108050035
Примечания : Cited References: 39
Предметные рубрики: MULTIPLE-QUANTUM NMR
DEPENDENT BEHAVIOR
MAGNETIC-MOMENTS
SPIN CLUSTERS
LINE-SHAPE
DYNAMICS
COHERENCES
SYSTEMS
CRYSTAL
GROWTH
Аннотация: New experimental data on the time dependence of an increase in the number of correlated spins under the conditions of the observation of the multiquantum NMR spectrum of a solid are processed on the basis of a microscopic theory for describing the growth of the second moment of multiquantum NMR developed by us earlier. As follows from the theory, the growth is an exponential function of time for crystals with quite diverse structures. The results are discussed on the basis of semiphenomenological models.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Frolov G. I., Bachina O. I., Zav'yalova M. M., Ravochkin S. I.
Заглавие : Magnetic properties of nanoparticles of 3d metals
Коллективы :
Место публикации : Tech. Phys.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2008. - Vol. 53, Is. 8. - P1059-1064. - ISSN 1063-7842, DOI 10.1134/S1063784208080136
Примечания : Cited References: 19. - This study was supported by the targeted program "Development of the Research Potential of Higher Education Institutions," grant no. RNP.2.1.1.7376.
Предметные рубрики: CLUSTERS
IRON
PARTICLES
Аннотация: The influence of size effects on the coercive force, magnetization, and Curie temperature in nanoparticles of 3d metals is considered. It is shown that experimental results obtained during the last two decades provide new information on peculiar magnetic properties of these particles.
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10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kliava J., Malakhovskii A. V., Edelman I. S., Potseluyko A. M., Petrakovskaja E. A., Bruckental I., Yeshurun Y., Zarubina T.
Заглавие : Unusual magnetic phase transitions in Gd3+ clusters in multicomponent oxide glasses
Разночтения заглавия :авие SCOPUS: Unusual magnetic phase transitions in Gd 3+ clusters in multicomponent oxide glasses
Место публикации : J. Supercond. Nov. Magn.: SPRINGER, 2007. - Vol. 20, Is. 2. - P149-153. - ISSN 1557-1939, DOI 10.1007/s10948-006-0116-4
Примечания : Cited References: 7
Предметные рубрики: GADOLINIUM
RESONANCE
Ключевые слова (''Своб.индексиров.''): oxide glasses--gadolinium--magnetic clusters--superparamagnetism--gadolinium--magnetic clusters--oxide glasses--superparamagnetism--magnetic clusters--magnetic phase transitions--oxide glasses--weiss constant--antiferromagnetic materials--ferromagnetic materials--gadolinium--magnetic anisotropy--magnetic susceptibility--paramagnetic resonance--phase transitions--positive ions--superparamagnetism--glass
Аннотация: Magnetic susceptibility, EPR and optical properties have been studied in a glass system {20La(2)O(3) - 22Al(2)O(3) - 23B(2)O(3) - 35(SiO2 + GeO2)} with a part of La2O3 substituted by Gd2O3 in different concentrations. Positive Weiss constants have been found in more heavily doped glasses; two magnetic transitions at 55 and 12 K have been detected and ascribed, respectively, to ferromagnetic and antiferromagnetic clusters of Gd3+ ions. The EPR spectra confirm the clustering at higher Gd contents. At low temperatures the cluster-related resonance indicates an onset of magnetic anisotropy. The clustering, depending on the Gd concentration, correlates with a shift to lower energies of the strong optical absorption band edge.
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11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Karpov S. V., Gerasimov V. S., Isaev I. L., Markel V. A.
Заглавие : Local anisotropy and giant enhancement of local electromagnetic fields in fractal aggregates of metal nanoparticles
Место публикации : Phys. Rev. B: AMER PHYSICAL SOC, 2005. - Vol. 72, Is. 20. - Ст.205425. - ISSN 1098-0121, DOI 10.1103/PhysRevB.72.205425
Примечания : Cited References: 56
Предметные рубрики: SMALL-PARTICLE COMPOSITES
DIFFUSION-LIMITED AGGREGATION
OPTICAL-PROPERTIES
SELECTIVE PHOTOMODIFICATION
NUMERICAL-SIMULATION
DISORDERED CLUSTERS
ABSORPTION-SPECTRUM
PARTICULATE MATTER
NONLINEAR OPTICS
LIGHT-SCATTERING
Аннотация: We have shown within quasistatic approximation that the giant fluctuations of a local electromagnetic field in random fractal aggregates of silver nanospheres are strongly correlated with a local anisotropy factor S which is defined in this paper. The latter is a purely geometrical parameter which characterizes the deviation of local environment of a given nanosphere in an aggregate from spherical symmetry. Therefore, it is possible to predict the sites with anomalously large local fields in an aggregate without explicitly solving the electromagnetic problem. We have also demonstrated that the average (over nanospheres) value of S does not depend noticeably on the fractal dimension D, except when D approaches the trivial limit D=3. In this case, as one can expect, the average local environment becomes spherically symmetrical and S approaches zero. This corresponds to the well-known fact that in trivial aggregates, fluctuations of local electromagnetic fields are much weaker than in fractal aggregates. Thus, we find that, within the quasistatics, the large-scale geometry does not have a significant impact on local electromagnetic responses in nanoaggregates in a wide range of fractal dimensions. However, this prediction is expected not to be correct in aggregates which are sufficiently large for the intermediate- and radiation-zone interaction of individual nanospheres to become important.
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12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zobov V. E., Popov M. A.
Заглавие : Tree growth parameter in the Eden model on face-centered hypercubic lattices
Место публикации : Theor. Math. Phys. - 2005. - Vol. 144, Is. 3. - P.1361-1371. - ISSN 0040-5779, DOI 10.1007/s11232-005-0165-z
Примечания : Cited References: 19
Предметные рубрики: BRANCHED POLYMERS
HIGH-TEMPERATURES
EXPANSION
CLUSTERS
SYSTEMS
TIME
Ключевые слова (''Своб.индексиров.''): eden model--number of lattice trees--monte carlo method--growth parameter--singular points of generating function--large-dimension expansion--face-centered hypercubic lattice--eden model--face-centered hypercubic lattice--growth parameter--large-dimension expansion--monte carlo method--number of lattice trees--singular points of generating function
Аннотация: In the Eden model, we investigate how the tree growth parameter depends on the space dimension d for face-centered hypercubic lattices. We find the first three terms of the 1/d-expansion for this parameter directly from the generating function without calculating the number of trees because the growth parameter is the reciprocal coordinate of the singular point of the tree generating function. The same growth parameter was calculated by computer experiment where the ratios between the numbers of trees without intersections and trees without restrictions in the dimensions 3, 4, 6, 8, and 10 were estimated by the Monte Carlo method on face-centered cubic lattices. The results of the two methods agree well. Comparing with the previously performed computer experiment for simple hypercubic lattices, we observe that the values of the singular exponents for the tree generating functions are close for two different types of lattices.
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13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gorban A., Popova T., Zinovyev A.
Заглавие : Codon usage trajectories and 7-cluster structure of 143 complete bacterial genornic sequences
Разночтения заглавия :авие SCOPUS: Codon usage trajectories and 7-cluster structure of 143 complete bacterial genomic sequences
Место публикации : Physica A: ELSEVIER SCIENCE BV, 2005. - Vol. 353. - P365-387. - ISSN 0378-4371, DOI 10.1016/j.physa.2005.01.043
Примечания : Cited References: 46
Предметные рубрики: DNA-BASE COMPOSITION
ASYMMETRIC SUBSTITUTION PATTERNS
PROTEIN-CODING REGIONS
MICROBIAL GENOMES
GENE IDENTIFICATION
MARKOV-MODELS
G+C CONTENT
BIAS
PREDICTION
SELECTION
Ключевые слова (''Своб.индексиров.''): genome--cluster--codon usage--correlations--entropy--mean field--cluster--codon usage--correlations--entropy--genome--mean field--approximation theory--correlation methods--database systems--entropy--functions--genes--mathematical models--clusters--codon usage--genomes--mean field--bacteria
Аннотация: Three results are presented. First, we prove the existence of a universal 7-cluster structure in all 143 completely sequenced bacterial genomes available in Genbank in August 2004, and explained its properties. The 7-cluster structure is responsible for the main part of sequence heterogeneity in bacterial genomes. In this sense, our 7 clusters is the basic model of bacterial genome sequence. We demonstrated that there are four basic "pure" types of this model, observed in nature: "parallel triangles", "perpendicular triangles", degenerated case and the flower-like type. Second, we answered the question: how big are the position-specific information and the contribution connected with correlations between nucleotide. The accuracy of the mean-field (context-free) approximation is estimated for bacterial genomes. We show that codon us-age of bacterial genomes is a multi-linear function of their genomic G+C-content with high accuracy (more precisely, by two similar functions, one for eubacterial genomes and the other one for archaea). Description of these two codon-usage trajectories is the third result. All 143 cluster animated 3D-scatters are collected in a database and is made available on our web-site: http://www.ihes.fr/similar to zinovyev/7clusters. (c) 2005 Elsevier B.V. All rights reserved.
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14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aver'yanov E. M.
Заглавие : Dimension of mesogenic molecules as atomic clusters
Место публикации : Phys. Solid State: AMER INST PHYSICS, 2005. - Vol. 47, Is. 2. - P378-389. - ISSN 1063-7834, DOI 10.1134/1.1866424
Примечания : Cited References: 19
Предметные рубрики: LIQUID-CRYSTAL CHEMISTRY
ORIENTATIONAL ORDER
TRANSITION
Аннотация: The problem regarding the mass dimension D of mesogenic molecules as atomic clusters is formulated and solved using computer simulation and analytical calculations. For a large number of compounds belonging to different chemical classes, it is shown that the cores of discotic lacunar (rodlike, lathlike) molecules forming nematic or columnar discotic (calamitic) phases have a fractional dimension 1 D-c 2 (D-c approximate to 1). The dependences of the dimension D-c on the symmetry, the conformation, and the structural-chemical features of the molecular core are determined. It is demonstrated that, in the region of side flexible chains in molecules of both types, the dimension D-ch can be either smaller or larger than unity, depending on the chain conformation. An analytical expression accounting for the results of numerical experiments is obtained for the dimension D-ch. (C) 2005 Pleiades Publishing, Inc.
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15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Markel V. A., Pustovit V. N., Karpov S. V., Obuschenko A. V., Gerasimov V. S., Isaev I. L.
Заглавие : Electromagnetic density of states and absorption of radiation by aggregates of nanospheres with multipole interactions
Место публикации : Phys. Rev. B: AMER PHYSICAL SOC, 2004. - Vol. 70, Is. 5. - Ст.54202. - ISSN 1098-0121, DOI 10.1103/PhysRevB.70.054202
Примечания : Cited References: 81
Предметные рубрики: DISCRETE-DIPOLE APPROXIMATION
ENHANCED RAMAN-SCATTERING
METAL FRACTAL CLUSTERS
OPTICAL-PROPERTIES
SELECTIVE PHOTOMODIFICATION
DISORDERED CLUSTERS
NUMERICAL-SIMULATION
SPECTRAL DEPENDENCE
PARTICULATE MATTER
LIGHT-SCATTERING
Ключевые слова (''Своб.индексиров.''): carbon--iron--palladium--silver--article--dipole--electromagnetic field--geometry--mathematical analysis--molecular interaction--nanoparticle--radiation absorption
Аннотация: We calculate the quasistatic electromagnetic density of states for aggregates of touching spheres, in particular, linear chains and computer-generated random fractal aggregates. Multipole moments with orders of up to L=64 are taken into account for random aggregates with the number of particles of up to N=100 and up to L=8000 for linear chains. Extensive comparisons with the dipole approximation and geometrical cluster renormalization method are performed. Extinction spectra are calculated for several metals and black carbon. Long wavelength electromagnetic properties of fractal aggregates are considered in details.
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16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zobov V. E., Popov M. A.
Заглавие : The coordinate of the singular point of generating functions of clusters in the high-temperature dynamics of spin lattice systems with axially symmetric interaction
Место публикации : Theor. Math. Phys.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2003. - Vol. 136, Is. 3. - P1297-1311. - ISSN 0040-5779, DOI 10.1023/A:1025603416535
Примечания : Cited References: 25
Предметные рубрики: CONSISTENT FLUCTUATING FIELD
NUCLEAR-DOUBLE-RESONANCE
HEISENBERG PARAMAGNET
LINE SHAPE
RELAXATION
SPECTRUM
APPROXIMATION
CRYSTALS
MOMENT
CAF2
Ключевые слова (''Своб.индексиров.''): spin dynamics--singular points--expansion over the reciprocal space dimension--expansion over the reciprocal space dimension--singular points--spin dynamics
Аннотация: We investigate generating functions for equipped trees composed of double bonds of two sorts on a hypercubic lattice of dimension d with built-in fragments. Rules for constructing these clusters are chosen to ensure the estimate for coefficients of power series in time for the longitudinal and transverse autocorrelation functions of the spin system with axially symmetric interaction. We derive a system of two equations for the tree-generating functions and an equation for the generating functions of chains leading from the root to a fragment in a tree using the Bethe approximation and under the condition that mainly bonds of one sort are taken into account. For the face-centered hypercubic lattice, we find the First terms of the 1/d expansion for the coordinate of the singular point of the generating function in both the anisotropic and the isotropic cases taking fragments in the forms of a triangle from four bonds and a four-fold bound pair into account. The obtained result is written in terms of ratios of lattice sums and is generalized to nuclear spin systems with dipole-dipole interaction. The theoretical value of the singular-point coordinate agrees well with the experimental value calculated from the tail of the absorption spectrum of the nuclear magnetic resonance in a barium fluoride monocrystal.
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17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Karpov S. V., Popov A. K., Slabko V. V.
Заглавие : Photochromic reactions in silver nanocomposites with a fractal structure and their comparative characteristics
Место публикации : Tech. Phys.: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2003. - Vol. 48, Is. 6. - P749-756. - ISSN 1063-7842, DOI 10.1134/1.1583830
Примечания : Cited References: 24
Предметные рубрики: SMALL-PARTICLE COMPOSITES
OPTICAL-PROPERTIES
COLLOIDAL SILVER
SELECTIVE PHOTOMODIFICATION
CLUSTERS
LIGHT
Аннотация: Conditions for a change in the polarization selectivity of dips in the plasmon absorption spectra of fractal silver nanocomposites irradiated by pulsed laser radiation are studied. The energy thresholds of the polarization selectivity are evaluated, and the polarization and spectral threshold characteristics are compared. Mechanisms behind the correlation between the fractal structure of the nanocomposites, on the one hand, and their optical and photochromic properties, on the other hand, are discussed. (C) 2003 MAIK "Nauka / Interperiodica".
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18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Churilov G. N., Fedorov A. S., Novikov P. V.
Заглавие : Fullerene C-60 formation in partially ionized carbon vapor
Разночтения заглавия :авие SCOPUS: Fullerene C60 formation in partially ionized carbon vapor
Место публикации : JETP Letters. - 2002. - Vol. 76, Is. 8. - P.522-526. - ISSN 0021-3640, DOI 10.1134/1.1533779
Примечания : Cited References: 15
Предметные рубрики: TOTAL-ENERGY CALCULATIONS
WAVE BASIS-SET
CLUSTERS
GROWTH
Аннотация: The assembling rate of a fullerene C-60 molecule has been theoretically studied as a function of electron concentration and temperature in partially ionized carbon vapor. For C-60 formation via one or two intermediate stages of cluster collisions, it has been shown that there is a region of plasma parameters (the temperature and electron concentration) in which fullerene C-60 is formed more efficiently. The C-60 formation rate versus temperature and electron concentration relationships have been found to correlate with the trends in the collision cross-section of carbon clusters as functions of these parameters. (C) 2002 MAIK "Nauka/Interperiodica".
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19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Myagkov V. G., Bykova L. E.
Заглавие : Fractal clusters and self-propagating high-temperature synthesis in thin Al/Ge films
Место публикации : JETP Letters. - 1998. - Vol. 67, Is. 5. - P.334-338. - ISSN 0021-3640, DOI 10.1134/1.567669
Примечания : Cited References: 14
Предметные рубрики: DENSE BRANCHING MORPHOLOGY
SINGLE-CRYSTAL GROWTH
AL-GE
PHASE-SEPARATION
Аннотация: Fractal clusters in amorphous thin films are examples of growth models. The main models are the Witten-Sander model and its modifications. It is believed that fractal patterns are formed in the course of the crystallization of an amorphous phase. It is shown that self-propagating high-temperature synthesis can be initiated in an Al/Ge film system and fractal patterns are formed in the reaction products. It is conjectured that the transition of an amorphous phase to a crystalline phase does not play a substantial role in the appearance of such patterns, while the formation of fractal clusters is determined by self-propagating high-temperature synthesis. (C) 1998 American Institute of Physics. [S0021-3640(98)00605-7].
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20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Markel V. A., Shalaev V. M., Poliakov E. Y., George T. F.
Заглавие : Numerical studies of second- and fourth-order correlation functions in cluster-cluster aggregates in application to optical scattering
Место публикации : Phys. Rev. E: AMERICAN PHYSICAL SOC, 1997. - Vol. 55, Is. 6. - P7313-7333. - ISSN 1063-651X, DOI 10.1103/PhysRevE.55.7313
Примечания : Cited References: 21
Предметные рубрики: DIFFUSION-LIMITED AGGREGATION
COLLOIDAL AGGREGATION
FRACTAL CLUSTERS
ANTICORRELATION
SIMULATIONS
Аннотация: Two- and four-point density correlation functions p(2)(r) and p(4)(r) are studied numerically and theoretically in computer-generated three-dimensional lattice cluster-cluster aggregates (CCA) with the number of particles N up to 20 000 in application to the light scattering problem. The ''pure'' aggregation algorithm is used, where subclusters of all possible sizes are allowed to collide. We find that large CCA clusters demonstrate pronounced multiscaling. In particular, the fractal dimension determined from the slope of p(2)(r) at small distances differs from that found from the dependence of the radius of gyration on the number of monomers (according to our data, 1.80 and 1.94, respectively). We also consider different functional forms for p(2) and their general properties and applicability. We find that the best fit to the numerical data is provided by the generalized exponential cutoff function with coefficients depending on N. The latter dependence is a manifestation of multiscaling. We propose some theoretical approaches for calculating p(4)(r), assuming p(2)(r) is known. In particular, we find the small-r asymptote for the p(4)(r) and verify it numerically. In addition, we find that p(4)(r) cannot be represented by a scaling dependence with a cutoff function, like p(2)(r) Instead, p(4)(r) is given by an expansion in terms of integer powers of r(2D-3), where D is the fractal dimension (approximate to 1.8 for CCA clusters).
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