Heating of nanoparticles and their environment by laser radiation and applications

This review considers the fundamental dynamic processes involved in the laser heating of metal nanoparticles and their subsequent cooling.Of particular interest are the absorption of laser energy by nanoparticles,the heating of a single nanoparticle or an ensemble thereof,and the dissipation of the energy of nanoparticles due to heat exchange with the environment.The goal is to consider the dependences and values of the temperatures of the nanoparticles and the environment,their time scales,and other parameters that describe these processes.Experimental results and analytical studies on the heating of single metal nanoparticles by laser pulses are discussed,including the laser thresholds for initiating subsequent photothermal processes,how temperature influences the optical properties,and the heating of gold nanoparticles by laser pulses.Experimental studies of the heating of an ensemble of nanoparticles and the results of an analytical study of the heating of an ensemble of nanoparticles and the environment by laser radiation are considered.Nanothermometry methods for nanoparticles under laser heating are considered,including changes in the refractive indices of metals and spectral thermometry of optical scattering of nanoparticles,Raman spectroscopy,the thermal distortion of the refractive index of an environment heated by a nanoparticle,and thermochemical phase transitions in lipid bilayers surrounding a heated nanoparticle.Understanding the sequence of events after radiation absorption and their time scales underlies many applications of nanoparticles.The applicationfields for the laser heating of nanoparticles are reviewed,including thermochemical reactions and selective nanophotothermolysis initiated in the environment by laser-heated nanoparticles,thermal radiation emission by nanoparticles and laser-induced incandescence,electron and ion emission of heated nanoparticles,and optothermal chemical catalysis.Applications of the laser heating of nanoparticles in laser nanomedicine are of particular interest.Significant emphasis is given to the proposed analytical approaches to modeling and calculating the heating processes under the action of a laser pulse on metal nanoparticles,taking into account the temperature dependences of the parameters.The proposed models can be used to estimate the parameters of lasers and nanoparticles in the various applicationfields for the laser heating of nanoparticles.

Discipline Impact Factor: Some of Its History, Some of the Author's Experience of Its Application, the Continuing Reasons for Its Use and… Next Beyond

Purpose: This work aims to consider the role and some of the 42-year history of the discipline impact factor(DIF) in evaluation of serial publications. Also, the original "symmetric" indicator called the "discipline susceptibility factor" is to be presented. Design/methodology/approach: In accordance with the purpose of the work, the methods are analytical interpretation of the scientific literature related to this problem as well as speculative explanations. The information base of the research is bibliometric publications dealing with impact, impact factor, discipline impact factor, and discipline susceptibility factor.Findings: Examples of the DIF application and modification of the indicator are given. It is shown why research and university libraries need to use the DIF to evaluate serials in conditions of scarce funding for subscription to serial publications, even if open access is available. The role of the DIF for evaluating journals by authors of scientific papers when choosing a good and right journal for submitting a paper is also briefly discussed. An original indicator "symmetrical" to the DIF(the "discipline susceptibility factor") and its differences from the DIF in terms of content and purpose of evaluation are also briefly presented.Research limitations: The selection of publications for the information base of the research did not include those in which the DIF was only mentioned, used partially or not for its original purpose. Restrictions on the length of the article to be submitted in this special issue of the JDIS also caused exclusion even a number of completely relevant publications. Consideration of the DIF is not placed in the context of describing other derivatives from the Garfield impact factor. Practical implications: An underrated bibliometric indicator, viz. the discipline impact factor is being promoted for the practical application. An original indicator "symmetrical" to DIF has been proposed in order of searching serial publications representing the external research fields that might fit for potential applications of the results of scientific activities obtained within the framework of the specific research field represented by the cited specialized journals. Both can be useful in research and university libraries in their endeavors to improve scientific information services. Also, both can be used for evaluating journals by authors of scientific papers when choosing a journal to submit a paper.Originality/value: The article substantiates the need to evaluate scientific serial publications in library activities—even in conditions of access to huge and convenient databases(subscription packages) and open access to a large number of serial publications. It gives a mini-survey of the history of one of the methods of such evaluation, and offers an original method for evaluating scientific serial publications.

加强企业固定资产经济安全管理探究

对于企业来说固定资产是企业的核心,那么固定资产的安全管理对于企业来说是十分重要的一个环节。固定资产的多少决定了该企业的规模的大小,也是企业的地基,因而固定资产的管理就显得十分重要了。固定资产管理得好,那么企业可以以此为基础,更好地经营企业,发展企业,赚更多的钱。我们从固定资产的支出标准、账本的真实以及固定资产的核算方法这三个方面分析了在管理固定资产时出现的问题,并且以此为基础提出解决方案,希望以此更好地解决在固定资产的管理上出现的问题。

Regularities of Nanofocusing of the Electromagnetic Field of a Fractal Rough Surface

A consistent physical and mathematical model of the propagation of electromagnetic waves in an inhomogeneous medium with strong discontinuities of the electromagnetic field at the interface of two media, which is a rough surface, was developed. Mathematical modeling of rough surfaces and their profiles was carried out using fractal geometry, which allows us to display the topology of the object as close as possible to reality. For real heterogeneous rough structures, we have developed a through-counting method that takes into account the continuity of the total current at the interfaces of adjacent media, the effect of induced surface charge and surface current. This approach lets one avoid the necessity to set surface impedances depending on the structure of the field being determined and on the material properties.

Mathematical Modeling of Shock Waves in Inhomogeneous Viscoelastic Two-Component Media

Mathematical modeling of two-component media with a saturated liquid began over 90 years with studies of the consolidation of soils. Two-component must be taken into account when solving a significant number of applied problems arising in various areas of human activity (soils, foams, various cement mortars, sand, porous ceramics, porous sintered composite materials, etc.). Two-component media are widely used in the national economy. For example, in the construction of new airfields and the restoration of destroyed, where the building materials used contain a significant number of voids. The study of wave processes is also very important for the development of new diagnostic methods, new technologies for creating two-component environments that could be applied in the field of engineering, construction, instrumentation, metallurgy, nuclear power and the defense capability of the country. However, the complexity of describing the effects of the interaction of components, heat transfer, and other related processes has led to the fact that until now the generally accepted models (elastic medium-liquid) for a fluid-saturated two-component medium have not been fully developed. Therefore, it is of interest to develop a mathematical two-component model when one of the components represents an inhomogeneous viscoelastic medium and the other is a compressible fluid. The presence and degree of porosity in materials is accounted for by a porosity coefficient equal to the ratio of the pore volume to the total volume occupied by the medium.

Upconversion Luminescence of Er^3＋ and Co-Doped Er^3＋/Yb^3＋ Novel Transparent Oxyfluoride Glasses and Glass Ceramics： Spectral and Structural Properties

Transparent oxyfluoride silicate precursor glasses and glass ceramics with the novel composition （1） SiO2-PbO-PbFE-Er2O3, （2） SiO2-GeOE-PbO-PbFE-Er2O3 （3） SiO2-Al2O3-Y2O3-Na2O-NaF-LiF-Er2O3-YbF3 doped with Er^3＋ and co-doped with Er^3＋/Yb^3＋ ions were synthesized. X-ray diffraction analysis （XRD） and Er3＋ absorption spectra revealed precipitation of PbF2 nanocrystals dispersed in the glassy matrix. Under 980 nm laser excitation, intense green, red and near IR bands of upconversion luminescence （UCL） were recorded both before and after heat treatment. In the glass ceramics the upconversion intensity increased significantly. To our knowledge, for the first time the composition of the glass ceramics characterized by the small-angle neutron scattering （SANS） showed the cluster organization of PbF2 nanocrystals.

Tailoring properties of reticulated vitreous carbon foams with tunable density

Reticulated vitreous carbon （RVC） foams were manufactured by multiple replications of a polyurethane foam template structure using ethanolic solutions of phenolic resin. The aims were to create an algorithm of fine tuning the precursor foam density and ensure an open-cell reticulated porous structure in a wide density range. The precursor foams were pyrolyzed in inert atmospheres at 700℃, 1100℃and 2000℃, and RVC foams with fully open cells and tunable bulk densities within 0.09-0.42 g/cm3 were synthesized. The foams were characterized in terms of porous structure, carbon lattice parameters, mechanical properties, thermal conductivity, electric conductivity, and corrosive resistance. The reported manufacturing approach is suitable for designing the foam microstructure, including the strut design with a graded microstructure.

Synthesis,Characteristics and Applications of Fibrous Composites with Immobilized Nanomolecular Layers of Ferrocyanides and Phosphates of Some d-Elements

1 Results The general principle of the synthesis of fibrous inorganic ion-exchanging composites, containing the combination of polymer analogous conversion reactions of the fibres and cycles of ion-molecular layering is advanced. Synthesis of thin nanomolecular layers of the acid Ti(Ⅳ) and Zr(Ⅳ) phosphates on surface of the cotton fibres and Cu(Ⅱ) and Fe(Ⅲ) ferrocyanides-on polyacrylonitrile fibres was performed on the basis of this principle. By the method of X-ray analysis it was stated that the forme...