MD-SLAG-MELT Software Package for Simulating the Nanostructure and Properties of Multicomponent Melts
The possibilities of computer experiments performed with the MDSLAGMELT v. 10.0 information-research system (IRS) with remote access are described. The main classes of mathematical models and methods and the sets of properties obtained in computer experiments are considered. An information model is developed for an oxide melt to study multidimensional composition–temperature–property–structure relations. A nanostructural model based on generalized graph network descriptors is considered in detail. The results of simulating the structure-sensitive properties of the SiO2–Na2O system using IRS are presented.
The conference was held in the form of lectures by leading scientists, oral and poster presentations of young scientists and students of physical specialties, as well as leaders of innovative structures for the purpose of mutual acquaintance with the new results of fundamental research on a wide range of areas in physics, the prospects and challenges in the expansion of relations between science , education and high technologies. SECTION (heads): I. LASERS (Fundam. Probl., Computer ...) (prof. A.A.Ionin) II. OPTICS (quant., And nano materials and new sources) (d.f.m.n.A.V.Masalov) III. Solid state physics, INCLUDING Nanostructures ELEM. BASE UNIT (Corresponding Member of RAS N.N.Sibeldin) IV. Nuclear physics, high energy physics (prof. O.D.Dalkarov, Head: Prof. V.A.Ryabov) V. PLASMA PHYSICS and particle beams (Head: Prof. A.V.Agafonov) VI. Astrophysics (Head: Prof. S.A.Bogachev) VII. PHYSICS IN THE MODERN INSTRUMENT AND TECHNOLOGY (prof. V.N.Nevolin)
We report on broad-area lasers, mode-locked lasers (MLLs), and superluminescent light-emitting diodes (SLDs) based on a recently developed novel type of nanostructures that we refer to as quantum well-dots (QWDs). The QWDs are intermediate in properties between quantum wells and quantum dots and combine some useful properties of both. 1.08 μm InGaAs/GaAs QWDs broad area edge-emitting lasers based on coupled large optical cavity waveguides show high internal quantum efficiency of 92%, low internal loss of 0.9 cm-1 and material gain of ~1.1∙104 cm-1 per one QWD layer. CW output power of 14.2 W is demonstrated at room temperature. Superluminescent light-emitting diodes with one QWD layer in the active region exhibit stimulated emission spectra centered at 1050 nm with the maximal full width at half maximum of 36 nm and the output power of 17 mW. First results on mode-locked operation in QWD lasers are also presented. 2 mm long two-section devices demonstrate the pulse repetition rate of 19.3 GHz and the pulse duration of 3.5 ps. The width of the radio frequency spectrum is 0.2 MHz.
A theoretical model is suggested to determine the critical conditions for generation of circular prismatic misfit dislocation loops in hollow core-shell nanoparticles. Based on a strict solution of the linear elasticity boundary-value problem for a circular prismatic dislocation loop in a free-surface shell, we examine the loop formation energy in the nanoparticle and show a potential opportunity to fabricate hollow coherently bonded, i.e. dislocation-free, core-shell nanoparticles by using thin-wall shells with inner-to-outer radii ratio larger than 0.8 as supporting cores.
We demonstrate evidence of coherent magnetic flux tunneling through superconducting nanowires patterned in a thin highly disordered NbN film. The phenomenon is revealed as a superposition of flux states in a fully metallic superconducting loop with the nanowire acting as an effective tunnel barrier for the magnetic flux, and reproducibly observed in different wires. The flux superposition achieved in the fully metallic NbN rings proves the universality of the phenomenon previously reported for InOx .We perform microwave spectroscopy and study the tunneling amplitude as a function of the wire width, compare the experimental results with theories, and estimate the parameters for existing theoretical models.
This book presents research dedicated to solving scientific and technological problems in many areas of electronics, photonics and renewable energy. Progress in information and renewable energy technologies requires miniaturization of devices and reduction of costs, energy and material consumption. The latest generation of electronic devices is now approaching nanometer scale dimensions; new materials are being introduced into electronics manufacturing at an unprecedented rate; and alternative technologies to mainstream CMOS are evolving. The low cost of natural energy sources have created economic barriers to the development of alternative and more efficient solar energy systems, fuel cells and batteries.
Nanotechnology is widely accepted as a source of potential solutions in securing future progress for information and energy technologies. Nanoscale Materials and Devices for Electronics, Photonics and Solar Energy features chapters that cover the following areas: atomic scale materials design, bio- and molecular electronics, high frequency electronics, fabrication of nanodevices, magnetic materials and spintronics, materials and processes for integrated and subwave optoelectronics, nanoCMOS, new materials for FETs and other devices, nanoelectronics system architecture, nano optics and lasers, non-silicon materials and devices, chemical and biosensors,quantum effects in devices, nano science and technology applications in the development of novel solar energy devices, and fuel cells and batteries.
A model for organizing cargo transportation between two node stations connected by a railway line which contains a certain number of intermediate stations is considered. The movement of cargo is in one direction. Such a situation may occur, for example, if one of the node stations is located in a region which produce raw material for manufacturing industry located in another region, and there is another node station. The organization of freight traﬃc is performed by means of a number of technologies. These technologies determine the rules for taking on cargo at the initial node station, the rules of interaction between neighboring stations, as well as the rule of distribution of cargo to the ﬁnal node stations. The process of cargo transportation is followed by the set rule of control. For such a model, one must determine possible modes of cargo transportation and describe their properties. This model is described by a ﬁnite-dimensional system of diﬀerential equations with nonlocal linear restrictions. The class of the solution satisfying nonlocal linear restrictions is extremely narrow. It results in the need for the “correct” extension of solutions of a system of diﬀerential equations to a class of quasi-solutions having the distinctive feature of gaps in a countable number of points. It was possible numerically using the Runge–Kutta method of the fourth order to build these quasi-solutions and determine their rate of growth. Let us note that in the technical plan the main complexity consisted in obtaining quasi-solutions satisfying the nonlocal linear restrictions. Furthermore, we investigated the dependence of quasi-solutions and, in particular, sizes of gaps (jumps) of solutions on a number of parameters of the model characterizing a rule of control, technologies for transportation of cargo and intensity of giving of cargo on a node station.
Event logs collected by modern information and technical systems usually contain enough data for automated process models discovery. A variety of algorithms was developed for process models discovery, conformance checking, log to model alignment, comparison of process models, etc., nevertheless a quick analysis of ad-hoc selected parts of a journal still have not get a full-fledged implementation. This paper describes an ROLAP-based method of multidimensional event logs storage for process mining. The result of the analysis of the journal is visualized as directed graph representing the union of all possible event sequences, ranked by their occurrence probability. Our implementation allows the analyst to discover process models for sublogs defined by ad-hoc selection of criteria and value of occurrence probability
Existing approaches suggest that IT strategy should be a reflection of business strategy. However, actually organisations do not often follow business strategy even if it is formally declared. In these conditions, IT strategy can be viewed not as a plan, but as an organisational shared view on the role of information systems. This approach generally reflects only a top-down perspective of IT strategy. So, it can be supplemented by a strategic behaviour pattern (i.e., more or less standard response to a changes that is formed as result of previous experience) to implement bottom-up approach. Two components that can help to establish effective reaction regarding new initiatives in IT are proposed here: model of IT-related decision making, and efficiency measurement metric to estimate maturity of business processes and appropriate IT. Usage of proposed tools is demonstrated in practical cases.