Experience in polyharmonic analysis of the parameters of the earth’s rotation

A method for approximating time series by an nth degree trigonometric polynomial for a series of parameters of the Earths rotation, calculated from GPS and GLONASS measurements, is tested. Satisfactory agreement is obtained between the model and experimental data. The results can be used for complex modeling and forecasting of the parameters of the Earths rotation.Translated from Izmeritelnaya Tekhnika, No. 12, pp. 40–42, December, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Yesterday’s dreams and today’s reality in telecommunications

Twenty-five years ago the telecommunications industry had its vision of the future. There were three dreams that, given the right technology, they could achieve: (1) the Dick Tracy wristwatch phone; (2) the Picturephone; and (3) the set-top box for the home television which could access an information store maintained by the telephone company. None of these dreams turned out as planned, but it is interesting to compare the original concepts with what has actually transpired in the last quarter-century. Today, having achieved some form of each of these three dreams, it seems as if, looking ahead to tomorrow’s technology, the industry has no similar vision.     

Estimates of the annual average indoor radon concentration in Telecí in the Czech Republic

Indoor radon concentrations are subject to diurnal and seasonal variations. In order to obtain an unbiased estimate of the annual mean radon concentration, measurements made over periods less than 12 months have to be adjusted accordingly. In this paper, hourly radon measurements from one uninhabited rural house in Telecí in the Czech Republic have been analysed. The data were collected over a period of 1 y. The behaviour of the radon concentration with time and its relationship with the outdoor temperature, wind speed and atmospheric pressure have been studied. Different estimates of the annual mean radon concentration based on short-term continuous measurements have been assessed.     

Mendeleev’s Periodic System of Elements: Between Past and Future

Measurement Techniques - In the present paper, current possibilities for further research into the structure of Mendeleev’s Periodic System are considered. The four-valued logic of quantum...     

Structural behaviour of earthen corbelled domes in the Aleppo’s region

The paper illustrates the results of a study aimed at understanding the structural behaviour of earthen corbelled domes, used as roofs in several villages in the Aleppo??s region. The materials and the shape of the domes suggested the hypothesis of a ??monolithic?? structural behaviour, justified by the very good bond between earthen bricks and earthen mortar, and by the use of very low values of thickness, which would have otherwise lead to collapse during the construction. Thanks to this hypothesis, although the dome is built with corbelled layers (??false dome??), the membrane theory can be applied to analyze the stresses in the domes under investigation. The results of this analysis, that were compared also to those obtained by a finite element analysis with shell elements, show that the dome is subjected to biaxial compression only; moreover, the dome shape seems close to the funicular surface due to its own weight, i.e. a dome shape is the optimal geometrical choice for that material.     

Radiation of strong shock waves propagating in the earth’s atmosphere

Radiation of a strong shock wave propagating in air at heights H ≤ 50 km with velocity D=20–50 km/sec is investigated. From the solution of a self-consistent radiation-gasdynamic problem with real thermodynamic and optical properties of air the distributions of gasdynamic parameters and radiant fluxes in the heating region ahead of the front and in the relaxation zone behind a viscous shock are obtained. The characteristics of radiation generated by the shock wave and going to “infinity” are determined. Calculations of integral and spectral radiation fluxes on the earth’s surface at different stages of the motion of a large asteroid in the atmosphere are given.     

China’s emerging centrality in the contemporary international scientific collaboration network

In this paper we analyze the evolution of China’s growing importance in international scientific collaboration over the past 15 years. Using co-authored publications indexed in Clarivate Analytics’s Web of Science Core Collection we develop novel weighted and unweighted centrality measures to quantify China’s emerging role in the global scientific research network. We analyze the networks formed by international co-authorship in three 5-year periods: 2001–2005, 2006–2010, and 2011–2015. This analysis highlights China’s sharp increase in prominence in international scientific collaborations. The analysis of China’s co-authored, highly cited papers also illustrates China’s rising importance in scientific research and collaboration from a different perspective. The impact of multilaterally co-authored papers to the centrality measure is also analyzed both theoretically and empirically. The results show that multilateral collaboration is also a key factor that influences the centrality of a country beyond simply the scale of international co-authorship. We further contextualize our work in a discussion of international scientific collaboration as both a key driver of China’s economy and its emerging perception as a first-world innovator and intellectual power. Finally, we suggest directions for further research including more granular analysis by academic discipline and an alternative investigation based on the fractional counting method.     

The drunkard’s search: Looking for ‘HRM’ in all the wrong places

Abstract and Key Results

What’s in a name?

SomerecentsubmissiontoCARBONhaveindicatedatrendtogetcertain“buzz”wordsintothetitle .Themostcommonbeing“nano” ,andmore recently“fullerene like” .Inthelasteightmonthsover 35 %ofallpaperssubmittedtomehavenanointhetitle .WithrespecttotheformerIhavebeenp     

From the Green’s Function in Tight-Binding Representation to Interatomic Many-body Potentials

1.IntroductionCentralpairf0rcemodelsf0rtheinteratomicpo-tentialshavebeenusedextensively,butthestructure-dependenceandthetransferabilityofthesemod-elsaren0tclearbecausethemany-bodyeffectsarenotincludedinthesem0dels.T0overc0metheselimitations,manyinteratomicpotentialmodelshavebeenproposed['~'].F0rexamp1e,theembedded-at0mm0del(EAM)[']hasbeendesignedbased0nthedensity-functi0nal-the0ryandhasbeensuccessfullyappliedtocalculateextensivephysicalpr0pertiesofmaterials,butlitt1efirst-principleguidanceexi…     

Modeling of solar-radiation transfer in the spherical system of atmosphere-earth’s surface

The study gives a characteristic of the developed model of solar-radiation transfer in the spherical system atmosphere-earth’s surface. Account is taken of the vertical profiles of the aerosol and gas components of the atmosphere, the anisotropy of the reflection of the earth’s mantle, the properties of the relief of the earth’s surface, the characteristics of the wind wave, and the optical properties of the aqueous medium. The problem of radiation transfer is considered in the approximation of the small-angle modification of the method of spherical harmonics. The polar and azimuthal distributions of the components of the Stokes vector are obtained. The integral radiation characteristics and the temperature and rate of heating of the medium at various levels are determined within the framework of a general calculation scheme.     

Use of the Bohm’s formula and its analogues in probe diagnostics

Simple algorithms are developed to proceed the probe characteristics in a number of limiting regimes when the characteristic probe size, r _p, is relatively large (r _p > 10³rD). It relates both to steady plasmas and to movement with the directed velocity, u. We consider the cases of collision-free (the Knudsen number, Kn?1) and collisional (Kn?1) plasmas. The majority of the proposed algorithms are tested in practice and confirm their reliability.     

Mechanical Alloying of Immiscible Elements in the Fe–Mg System

Mechanical alloying of immiscible elements in the Fe–Mg system (32 at % Mg) is achieved by grinding in a planetary ball mill. The process is studied by x-ray diffraction, Mössbauer spectroscopy, and magnetic measurements. The results attest to the formation of supersaturated solid solutions of Mg in -Fe. The highest Mg content of the solid solutions is 5–7 at %. Mössbauer results are used to evaluate the changes in the hyperfine magnetic field at Fe nuclei associated with the presence of one Mg atom among the nearest neighbors and next nearest neighbors of Fe in the solid solutions: H ₁ = –1760 kA/m and H ₂ = –800 kA/m, respectively. Increasing the Mg content of the starting mixture reduces Mg solubility in Fe. Thermodynamic analysis indicates that the driving force for the formation of solid solutions may be associated with the excess energy of coherent interfaces in the Fe–Mg nanocomposite resulting from mechanical alloying. The elastic strain arising from the lattice mismatch between Fe and Mg facilitates incorporation of Mg into -Fe. Above a certain Mg content, no coherent interfaces are formed, and the thermodynamic driving force for Mg dissolution disappears. As a result, the system becomes immiscible.     

Enhancing the Precision of Measurements of a Ship’s Magnetic Moment in the Far Field

Measurement Techniques - Measurements of the magnetic moment of a ship are necessary for monitoring safety from magnetic mines and from stealth, by the magnetic field. A modification of the method...     

Characterization of the Thermal-Wave Field in a Wedge-Shaped Solid Using the Green’s Function Method

In this study, a theoretical model is established for a wedge-like solid with an open sector surrounded by walls of radius $R$ of a cylindrical rod illuminated by a modulated circular Gaussian incident beam by means of the Green’s function method in cylindrical coordinates. An analytical expression for the thermal-wave field in such a sample is presented. The theory is validated by reducing the arbitrary geometrical structure of the wedge to simpler geometries. It is shown that the frequency dependence of the thermal-wave field near the edge exhibits a large phase lag compared with that at a location far from the edge. The theory provides a foundation for quantitatively characterizing wedge-shaped industrial samples, such as metals with sintered edges, using photothermal methods in a non-contact and non-destructive manner.     

Dynamics of Plasma in a Plasma-Microwave Amplifier under the Action of the Miller’s Force

High Temperature - In this paper, we consider the dynamics of plasma in a high-power plasma-microwave amplifier with a submicrosecond pulse duration. It is shown that, in the case of a linear mode...     

An EU without the UK: mapping the UK’s changing roles in the EU scientific research

In science, technology and innovation, the consequences of Britain’s exit (Brexit) for both Britain and the Europe Union (EU) are still uncertain. However, there is no doubt that in the years to come, the UK will need to re-calibrate its scientific collaborations with other EU countries. In this research, we aim to identify which EU countries would suffer the greatest loss and which research fields would be most affected by Brexit. Based on the scientific output of each EU country, as indexed by the Web of Science, we demonstrate that international scientific collaboration frequently involves the UK. We also define four types of roles according to the UK’s performance in production and collaboration; these roles are of great significance to our understanding of the status of the UK in the EU. In this sense, the UK acted as a leader in health sciences, a pioneer in social sciences, an assistant in physical sciences, and a participant in engineering.