5,453 research outputs found
Peculiarities of spectra of induced emission of polymethine dye solutions at low temperatures
Results from studying the induced emission spectra with monochromatic excitation (superluminescent regime) within a temperature range of 300 K - 5.2 K are presented. The significant feature of such operations is the appearance of quasi-lines whose minimum width is realized at 4.2 K. The frequency distribution of the quasi-lines unambiguously characterizes the dye investigated. When interpreting these results, the idea of an inhomogeneous broadening of the polymethine dye spectra in the solution being studied experimentally was used for the first time. The quasi-lines observed are interpreted as a manifestation of the electron vibration structure of singlet states of a complex molecule
Structure And Properties of Nanoparticles Formed under Conditions of Wire Electrical Explosion
Structure and properties of nanoparticles formed under conditions of wire
electrical explosion were studied. It was shown that the state of WEE power
particles can be characterized as a metastable state. It leads to an increased
stability of nanopowders at normal temperatures and an increased reactivity
during heating, which is revealed in the form of threshold phenomena.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
lassopack: Model selection and prediction with regularized regression in Stata
This article introduces lassopack, a suite of programs for regularized
regression in Stata. lassopack implements lasso, square-root lasso, elastic
net, ridge regression, adaptive lasso and post-estimation OLS. The methods are
suitable for the high-dimensional setting where the number of predictors
may be large and possibly greater than the number of observations, . We
offer three different approaches for selecting the penalization (`tuning')
parameters: information criteria (implemented in lasso2), -fold
cross-validation and -step ahead rolling cross-validation for cross-section,
panel and time-series data (cvlasso), and theory-driven (`rigorous')
penalization for the lasso and square-root lasso for cross-section and panel
data (rlasso). We discuss the theoretical framework and practical
considerations for each approach. We also present Monte Carlo results to
compare the performance of the penalization approaches.Comment: 52 pages, 6 figures, 6 tables; submitted to Stata Journal; for more
information see https://statalasso.github.io
Efficient solar light harvesting device based on multilayer photonic crystal films
We fabricate, characterize and calculate photonic-colloidal crystals. We propose to use wave guiding
properties of photonic crystal films [1] to concentrate large amount of sunlight onto a small area of solar
photovoltaic (PV) cells
“Financial bubbles” and monetary policy
The relevance of this research is caused by the need of strengthening a role of monetary regulators to prevent financial bubbles in the financial markets. The aim of the article is the analysis of a problem of crisis phenomena in the markets of financial assets owing to an inadequate growth of their cost, owing to subjective reasons. The leading approach to mechanism research of crisis phenomena in the market of financial assets is the approach based on a balance effect. Results: authors developed offers to prevent the crisis phenomena in the financial markets due to credit expansion. There is proved the necessity to develop a risk assessment system on existing and new financial instruments, with their obligatory application by commercial banks and rating agencies. The materials of the article can be useful at further studying the reasons for financial bubbles, development of actions for their prevention, and also in an educational process when studying certain subjects. © 2016 Tikhonov, Pudovkina and Permjakova
The motion of two masses coupled to a massive spring
We discuss the classical motion of a spring of arbitrary mass coupled to two
arbitrary massive blocks attached at its ends. A general approach to the
problem is presented and some general results are obtained. Examples for which
a simple elastic function can be inferred are discussed and the normal modes
and normal frequencies obtained. An approximation procedure to the evaluation
of the normel frequencies in the case of uniform elastic function and mass
density is also discussed.Comment: Standard Latex file plus three eps figure
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