International School on Spectroscopy of Molecules and Crystals最新文献

{"title":"Rayleigh light scattering by large-scale inhomogeneities in filled liquid crystals","authors":"Mikhailo F. Lednei, I. Pinkevich, V. Reshetnyak, T. Sluckin","doi":"10.1117/12.486662","DOIUrl":"https://doi.org/10.1117/12.486662","url":null,"abstract":"This paper presents a theoretical study of differential and total light scattering cross-sections in liquid crystals containng small hard macroscopic spherical or cylindrical particles, using the naomalous-diffraction approach. The light scattering is normally governed by director inhomogeneity around teh separate particles. When the particles form a network the scattering is controlled by the director domain structure. We consider the influence of particle shape and size, the type of director anchoring on the particle surface and light polarization. Our principal findings are that: (a) for a so-called 'dipole' director configuration around the particle, the light scattering is predicted to be approximately two orderes of value stronger than for a so-called 'Saturn ring' configuration; (b) incident light polarizred parallel to the scattering plane gives rise to a stronger scattered angular dependnece than light polarized perpendicular to it; (c) when the inclusions are cylindrical the light scattering is relatively stronger at lwo scattering angles than when the inclusions are spherical; (d) for a particle network, the nature of the network domain orientational distribution influences the intenstiy of light scattering, but has little effect on its angular dependence.","PeriodicalId":205850,"journal":{"name":"International School on Spectroscopy of Molecules and Crystals","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126870971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Peculiarities of fluctuations in glass-forming liquids","authors":"I. V. Blazhnov, N. P. Malomuzh","doi":"10.1117/12.486682","DOIUrl":"https://doi.org/10.1117/12.486682","url":null,"abstract":"The present work is devoted to the investigation of the peculiarities of fluctuations in glass-forming liquids. To justify our reasons we will anlayze the character of molecular light scattering in silicate glass, that was the object of experimental study. Our approach to the problem of fluctuations in glasses and liquids near the glassification point is based on the following general motivations. Highly-viscous and glass-like states of glass-forming liquids are in the metastable region, which correspond to the crystal state of a system in the equilibrium. The behavior of a system is determined by relations between two characteristic times: τw(T) and τe, where the former is the waiting time for the critical nucleus and τe is the time for cooling the system from the melting temperature to the spinodal temperature Ts at the same pressure. If τe <(<<) τw(Ts) the system smoothly passes to the glass-like state. Here two factors are very important. In metastable region of a system the nuclei of the new phase (crystal) appear. The fraction volume φ(T), occupied by them, depends on the cooling rate. The value of φ is the less the more quick cooling the system is. However, below the spinodal in accordance with thermodynamics the homogeneous states of a system are impossible. The existence of the lasts contradicts the stabilty conditons. From here we conclude that typical glass-like states in a system should be microinhomogeneous. Similar conclusion is confirmed by the results of experimental study of the structure. Now we should note that the strongly anisotropic interaction between nonspyherical molecules of glass-forming liquids leads to considerable coupling between the translational and orientational degrees of freedom in a system. In other words the changes of density is accompanied by the corresponding modulation of molecular orientations. Due to strong increasing the shear viscosity at approaching the glassification point some configurations of the centers of mass and the orientations of molecules froze. More exactyly, only weak thermal deviations of coordinates of molecules from their local equilibrium values are possible. The radical change of the global molecular configuration requires exponentially large time. Thus, the combination of frozen and thermal fluctuations is the distinctive feature of glass-like state of a system. It is necessary to note that different ways of cooling of a system lead to nonequivalent frozen fluctuations.","PeriodicalId":205850,"journal":{"name":"International School on Spectroscopy of Molecules and Crystals","volume":"248 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115755389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectral and generating properties of active laser media based on dye-doped elastomers","authors":"V. Bezrodnyi, N. Derevyanko, A. Ishchenko, Valeriy V. Slobodin, L. V. Karabanova","doi":"10.1117/12.486644","DOIUrl":"https://doi.org/10.1117/12.486644","url":null,"abstract":"The advantages of a polyurethane matrix over other polymers, which are widely used as active media for dye lasers, are analzyed. This matrix exhibits the photostability, service life, radiation resistance, conversion efficiency, and homogeneity of the dye distribution that surpass these properties for active media based on polyurethane acrylate, which has close physical and operation properties. These advantages result not only from the milder polymerization conditions but also from a lower probability of the formation of ion pairs and dye aggregates. A substantial suppression of these processes in polyurethane is explained by its greater polarity and solvation ability compared to polyurathane acrylate.","PeriodicalId":205850,"journal":{"name":"International School on Spectroscopy of Molecules and Crystals","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116801227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface waves on a strong-coupling superconductor","authors":"M. Glumova, V. Lozovski, D. Reznik","doi":"10.1117/12.486673","DOIUrl":"https://doi.org/10.1117/12.486673","url":null,"abstract":"A theory of electromagnetic surface wave propagation on a plane superconductor-vacuum interface is presented for superconductor with strong-coupling. The resutls of self-consistent euqation for eneryg of elementary excitations obtined in the framework of modified u-v transformation method.On the basis of a non-local description taknig into account the finite size of the pair-bound state, the linear resopnse tensor is analyzed. Within the framework of semi-classifcal infinite-barrier model the surface waves dispersion relations are the analyztically and numerically calculated for teh case of strong-coupling superconductor.","PeriodicalId":205850,"journal":{"name":"International School on Spectroscopy of Molecules and Crystals","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115030162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of alkyl chain length on the FTIR spectra of alkyl-cyanobiphenyls compounds","authors":"N. Ponikwicki, I. Gnatyuk, J. Kukielski","doi":"10.1117/12.486663","DOIUrl":"https://doi.org/10.1117/12.486663","url":null,"abstract":"Fourier transform IR spectra of flexible biphenyl molecules as well as their 4-n-alkyl-4'-cyanobiphenyl derivatives with 2, 3, 4, 5, 6 and 7 carbon in alkyl chain, all in solid crystalline state in KBr pellet, were investigated. In order to determine and characterize all vibrations in the range of 400-4000 cm-1, Fourier transform IR spectrosocpy were applied. The different number of bands, their shapes and frequencies for alkyl-cyano-derivatives of biphenyl has been found. But the most essential changes were observed in the range 800-900 cm-1 and 2700-3000 cm-1. Few bands have been found in these regino while biphenyl does not display any bands in these two regions. It is shown that the changes observed in the spectra are not directly dependant on the relation of aromatic cyano core and length of the alkyl tail of the molecule.","PeriodicalId":205850,"journal":{"name":"International School on Spectroscopy of Molecules and Crystals","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124688390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Light scattering by a sample with polished surface","authors":"A. Makarenko, I. A. Shaykevich","doi":"10.1117/12.486669","DOIUrl":"https://doi.org/10.1117/12.486669","url":null,"abstract":"The use of spectrophotometric references under conditions that differ from CIE recommended illumination and viewing geometries is possible only if the bidirectional reflectance function is known. One of the materials used for realization spectrophotometric primary transfer standard is milky glass with polished surfaces. A model that describes scattering of light by a similar object is proposed in this study. The comparison between theoretical results and experimental data is carried out. In view of the results of modeling, a perspective of creating a method of goniophotometric calibration of Russian opal glass for any illumination and viewing condition is discussed.","PeriodicalId":205850,"journal":{"name":"International School on Spectroscopy of Molecules and Crystals","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130104170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of the mm-range electromagnetic radiation on the rheologic properties of aqueous NADH solution","authors":"Y. Barabash, M. Zabolotny, T. Zabolotnaya","doi":"10.1117/12.486665","DOIUrl":"https://doi.org/10.1117/12.486665","url":null,"abstract":"This work studies the influence of the electromagnetic radiation of low intesity on the rheologic parameters of water and water solutions of biologically active substance, which plays an important role in energy transforming processes in living organisms. The power spectrum of the thermal fluctuations of the free surface of liquid has been measured using optical heterodyning method which makes it possible to detect the changes in frequency of the light scattered by moving liquid surface. The amplitude, the spectrum of spatial and time frequencies of thermal fluctuations of free surface of a water solution was investigated using optical heteodyning method. The viscosity and the surface tensions in the micro layer of water solution were determined from the obtained results. Water solution was dealt with as a low-viscosity Newtonian liquid in this analysis and was modeled by Navier-Stokes equation and incompressibility equation.","PeriodicalId":205850,"journal":{"name":"International School on Spectroscopy of Molecules and Crystals","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130573168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Excitonic states of liquid and solid orientationally disordered solutions","authors":"M. U. Bilyi, G. I. Gaididei, Y. Gaididei, V. P. Sakun","doi":"10.1117/12.486664","DOIUrl":"https://doi.org/10.1117/12.486664","url":null,"abstract":"Excitonic states in liquid and solid orientationally disordered solutions are considered. It is shown that collective properties of excitations depend essentially on correlation properites of orientational degrees of freedom of the solution. Specifically, this dependence is exponentially stronger in liquid solutions compared with solid solutions. It is also shown that energy level shift caused by exciton interactions linearly with the concentration of molecules.","PeriodicalId":205850,"journal":{"name":"International School on Spectroscopy of Molecules and Crystals","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123871750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reorientation of nematic liquid crystal under the action of light with stygmatic and astygmatic Gaussian profile","authors":"S. Subota, V. Reshetnyak, M. Soskin","doi":"10.1117/12.486652","DOIUrl":"https://doi.org/10.1117/12.486652","url":null,"abstract":"We report on theoretical study of optical singularity birth in a wave front of light beam with stigmatic and astigmatic Gaussian profile with intially smooth wave front passing through a homeotropically aligned nematic liquid crystal (NLC) cell. When a linearly polarized astigmatic Gaussian light beam illuminates the cell, the light induced Frederick's transition can be observed. Strong director anchoring at the cell walls is assumed. Ritz's variational method is used, i.e. the profile of director reorientation is considered to be similar to astigmatic Gaussian profile. Parameters of the trial function are calculated numerically. The threshold intensity of light beam is appeared to increase with increasing of asymmetry of the beam under the constant value of laser beam area and cell thickness. Utilizing the Huygens-Fresnel principle and geometrical optics approximation we calculate the amplitude distribution in space for different distances from the cell. It is obtained that in the case of stygmatic Gaussian beam incidence on NLC cell the circular edge dislocation is born.","PeriodicalId":205850,"journal":{"name":"International School on Spectroscopy of Molecules and Crystals","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123952982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Complex formation between polyaniline and some transition metal ions observed by optical absorption spectroscopy","authors":"B. V. Lozovski, O. Dimitriev","doi":"10.1117/12.486672","DOIUrl":"https://doi.org/10.1117/12.486672","url":null,"abstract":"Interaction of the transition metal salts and polyaniline in the form of a solution has been studied. It was found that addition of some salts to the polyaniline solution gives rise to formation of a precipitates formed have been studied and molecular model of the polyaniline-transition metal ion compelx has been proposed.","PeriodicalId":205850,"journal":{"name":"International School on Spectroscopy of Molecules and Crystals","volume":"50 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130759012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}