On the history of the discovery of nanodiamond synthesis

The history of the discovery of nanodiamond synthesis, the investigation of nanodiamond properties, and the application and organization of their production in the second half of the 20th century is expounded. It is noted that this history is unique, since nanodiamond synthesis was discovered in the USSR three times over 19 years: first by K.V. Volkov, V.V. Danilenko, and V.I. Elin at the VNIITF (Snezhinsk) in 1963 and then, in 1982, by A.M. Staver and A.I. Lyamkin at the Institute of Hydrodynamics, Siberian Division, Academy of Sciences of the USSR (Novosibirsk), and by G.I. Savvakin at the Institute of Problems of Materials Science, Academy of Sciences of the UkSSR (Kiev). All of these researchers discovered nanodiamond synthesis accidentally while studying diamond synthesis by shock compression of nondiamond carbon modifications in blast chambers. The priority of work by Russian scientists in this field is demonstrated.     

Intermittency and the passive nature of the magnitude of the magnetic field

It is shown that the statistical properties of the magnitude of the magnetic field in turbulent electrically conducting media resemble, in the inertial range, those of passive scalars in fully developed three-dimensional fluid turbulence. This conclusion, suggested by the data from the Advanced Composition Explorer, is supported by a brief analysis of the appropriate magnetohydrodynamic equations.     

On the predictability of the positions of the convergence zones in the ocean

The disagreement between the experimental and calculated positions of the first convergence zone are known from many publications. The most probable cause for such a disagreement, namely, the incorrect specification of the input data for the calculations, is considered. The lack of simultaneity between the hydrological surveys of the region and the acoustic experiments is emphasized. The experimental data obtained by the author in five ocean regions are presented. These data characterize the diurnal variability of the distance from the source to the nearest boundary of the convergence zone. The relations proposed by different researchers for calculating the sound speed from the temperature, salinity, and hydrostatic pressure are analyzed. It is shown that these relations lead to a substantial difference in the estimated depth dependence of the hydrostatic gradient of the sound speed. The position of the first convergence zone is calculated for the propagation conditions determined by vertical temperature and salinity profiles with the subsequent recalculation of these profiles into sound speed profiles by using eight different formulas known from the literature. It is shown that different formulas lead to different values of the distance to the first zone; this difference is substantially greater than that between the calculations and experiment. The necessity of improving the recalculation relations in view of the experimental data on sound propagation in natural oceanic waveguides, including the data on the actual positions of the convergence zones, is emphasized.     

Republication of: On the gravitational stability of the expanding universe

This is the republished English edition of a paper by E. Lifshitz, first published in 1946, in which the author investigates the gravitational stability of the non–stationary isotropic models of the universe. The paper has been selected by the Editors of General Relativity and Gravitation for re-publication in the Golden Oldies series of the journal. This republication is accompanied by an editorial note written by George F. R. Ellis, and by a brief biography of Evgenii Mikhailovich Lifshitz, written by Andrzej Krasiński.     

Chemical composition of the primary cosmic rays near the top of the atmosphere

Summary A stack of CR-39 (HCB 0.5%) passive solid-state nuclear track detectors were irradiated by primary cosmic rays near the top of the atmosphere. The stack of detectors were flown by balloons launched from Alice Springs, Australia in 1983. After 16 h 41 min flight exposure at an atmospheric pressure of 9.5 mb the plates were collected and chemically etched in 6.7 N NaOH aqueous solution at 70°C for 27 hours. The diameter distribution of the 1208 etch pits caused by the presence of heavy ions in primary cosmic rays was measured by a transmitted light Leitz Ortholux microscope having an objective×10 and a×15 filar micrometer eyepiece attachment. The diameter distribution was standardised and calibrated against the conventional cosmic-ray results found by Tasakaet al. The estimated charge spectrum is in accord with the nuclear emulsion data of Daniel and Durgaprasad, Kristianssonet al., Saito and Chohanet al.     

Distribution of the probability of oscillations of the surface of liquid hydrogen in the turbulent regime

The probability distribution density of the deviation of the surface of liquid hydrogen from the equilibrium plane state in the system of capillary waves has been analyzed. It has been shown that this probability distribution density for the case of the excitation of the surface oscillations by low-frequency noise in the turbulent regime is well reproduced by a Gaussian. When the oscillations are excited by a low-frequency harmonic force, the stochastization of the waves occurs after several scattering events.     

Republication of: On the initial value problem of the equations of gravitation

This is an English translation of a paper by Karl Stellmacher, first published in German in 1938, in which he presented the first, correct and successful, formulation of the initial value problem for Einstein’s equations in vacuum and with a dust source. The paper has been selected by the Editors of General Relativity and Gravitation for re-publication in the Golden Oldies series of the journal. This republication is accompanied by an editorial note written by Helmut Friedrich and Stellmacher’s brief biography written by Hubert Goenner.     

Determination of the aggregation degree of zinc-phthalocyanines derivatives into polymeric films via the characterization of the linear-optical absorption

We investigated the aggregation effects in films composed by zinc-phtalocyanine and its derivative, dispersed into a poly(methyl methacrylate) matrix, by analyzing the absorption coefficient at an increasing concentration. The ratio by weight of the compound to the host polymer was varied within two different ranges in order to extrapolate the solubility limit for both molecules. Measurements performed by spectroscopic analysis, allowed the calculation of the linear-optical absorption coefficient. Experimental data were interpolated by adopting a set of three Lorentzian oscillators characterized by three different sets of parameters, i.e., the intensity factor, resonance frequency, and line width, respectively. With the obtained data, the degree of monomer and dimer concentration in the films was evaluated. Within the investigated concentration range, the maximum solubility was found to be very different for the two investigated molecules, where the substituted phthalocyanine was very efficient in reducing the aggregation tendency.     

Dependence of the anomalous fading of the TL and blue-OSL of fluorapatite on the occupancy of the tunnelling recombination sites

The anomalous fading (AF) of thermoluminescence (TL) and optically stimulated luminescence (OSL) signals in Durango apatite is attributed to tunnelling effects. Electrons from the TL and OSL traps in this material are transferred, via a tunnelling effect, to the recombination sites. The availability of recombination sites for tunnelled electrons is of major importance for the degree of AF rate observed in this material. It is expected that a variation of the number of the electron recombination sites will be reflected in the experimentally measured AF rate. In the present work an investigation of the recombination sites for the tunnelled electrons is attempted by studying the AF effect using a special technique, in which the anomalously faded TL (OSL) is replaced by an equal amount of TL (OSL) induced by a beta dose.     

From the Solution of the Tsarev System to the Solution of the Whitham Equations

We study the Cauchy problem for the Whitham modulation equations for increasing smooth initial data. The Whitham equations are a collection of one-dimensional quasi-linear hyperbolic systems. This collection of systems is enumerated by the genus g=0,1,2, ... of the corresponding hyperelliptic Riemann surface. Each of these systems can be integrated by the so-called hodograph transformation introduced by Tsarev. A key step in the integration process is the solution of the Tsarev linear overdetermined system. For each g>0, we construct the unique solution of the Tsarev system, which matches the genus g+1 and g–1 solutions on the transition boundaries.     

测量可溶性物质的密度

常规方法测量可溶性物质（如食盐）的密度遇到了困难,经过分析研究和实验检测,本文给出的3种实验方法的确可行,实验结果误差较小。     

Analysis of the effects of geometry on the fluorescence radiation field in the frame of transport theory

In x‐ray fluorescence spectroscopy, a photon beam is focused on the sample to stimulate the emission of characteristic radiation. Even if a qualitative interpretation of the measurements is simple, a quantitative analysis is not straightforward because the primary photons are produced deep in the target and the properties of the radiation that reaches the detector are modified significantly by the interactions undergone before leaving the specimen. Understanding how the emission spectra are influenced by interactions with matter is a central problem in fluorescence analysis. In this work, by using the 3D transport equation, we found that not only the composition of the specimen but also the geometry of the system plays an important role in determining the properties of the radiation field, denoting by geometry the shape of the target, the direction of the incoming beam and the observation angle. Copyright © 2004 John Wiley & Sons, Ltd.     

On the concept of time and the origin of the cosmological temperature

Time arises in the theory of gravity through the semiclassical approximation of the gravitational part of the solution of the Wheeler-De Witt equation in the manner shown by Banks (SCAG). We generalize Banks' procedure by grafting a Born-Oppenheimer type approximation onto SCAG. This allows for the feedback of matter onto gravity, wherein the latter is driven by the (quantum) mean energy-momentum tensor of matter. The wave function is nonvanishing in classically forbidden configurations of gravity. In SCAG this is described by the evolution of matter in imaginary time. This is interpreted as an inverse temperature, and the norm of the matter wave function, no longer conserved for these gravitational configurations, is a partition function. A simple cosmological model is worked out to illustrate these ideas. In this model it is shown that the temperature of the matter which emerges into the classically permitted region is the inverse bounce time of the bounce executed by the system in the forbidden region (behind the horizon).Time present and time past are both perhaps present in time future. And time future contained in time past. If all time is eternally present All time is unredeemable.—T. S. Eliot, Burnt Norton,Four Quartets, 1943.In honor of Ilya Prigogine on the occasion of his 70th birthday.     

Republication of: On the physical significance of the Riemann tensor

This Golden Oldie is a reprinting of a paper by F. A. E. Pirani first published in 1956. It is accompanied by a reprinting of a paper by J. L. Synge first published in 1934. Together these papers pointed the way to the interpretation of geodesic deviation and its relation to the curvature tensor. These two Golden Oldies are accompanied by an Golden Oldie Editorial containing an editorial note written by A. Trautman, and by the biography of F. Pirani written by himself and commented by A. Trautman. An editorial note to this paper and a biography can be found in this issue preceding this Golden Oldie and online via doi:. Original paper: F. A. E. Pirani, Acta Physica Polonica 15, 389–405 (1956). Reprinted with the kind permission of the Editors of Acta Physica Polonica, and of Felix Pirani.     

The Brain Adaptation to the Color of Illumination and not the Retinal Adaptation to the Color of Objects that Determines the Color Appearance of an Object in the Space

Color appearance was measured for a test patch which was placed in a test room illuminated by the daylight type of illumination and was looked at from the subject room illuminated by one of the four colored illuminations, red, yellow, green, and blue, through a window of three different sizes. When the window was the smallest so that only the test patch was seen within the window the color of the test patch appeared almost opponent to the illumination color, but as soon as something is seen within the window of larger size the color returned to the original color of the test patch to indicate the color constancy. To recognize the test room as a space was essential to perceive the real color of the test patch. This returning to the original colors was not influenced by green color of objects densely placed in the test room or by red color of objects again densely placed in the test room. The results imply that the color appearance of the test patch is not determined by the retinal chromatic adaptation, but by the brain adaptation to color of the illumination in the space.     

On the interpretation of the inverted kinetics equation and space-time calculations of the effectiveness of the VVER-1000 reactor scram system

In the present paper, an attempt is made to analyze the accuracy of calculating the effectiveness of the VVER-1000 reactor scram system by means of the inverted solution of the kinetics equation (ISKE). In the numerical studies in the intellectual ShIPR software system, the actuation of the reactor scram system with the possible jamming of one of the two most effective rods is simulated. First, the connection of functionals calculated in the space-time computation in different approximations with the kinetics equation is considered on the theoretical level. The formulas are presented in a manner facilitating their coding. Then, the results of processing of several such functions by the ISKE are presented. For estimating the effectiveness of the VVER-1000 reactor scram system, it is proposed to use the measured currents of ionization chambers (IC) jointly with calculated readings of IC imitators. In addition, the integral of the delayed neutron (DN) generation rate multiplied by the adjoint DN source over the volume of the reactor, calculated for the instant of time when insertion of safety rods ends, is used. This integral is necessary for taking into account the spatial reactivity effects. Reasonable agreement was attained for the considered example between the effectiveness of the scram system evaluated by this method and the values obtained by steady-state calculations as the difference of the reciprocal effective multiplication factors with withdrawn and inserted control rods. This agreement was attained with the use of eight-group DN parameters.     

Electromagnetic catalysis of the radiative decay of the axion

The radiative decay of the axion a → γγ is investigated in an external electromagnetic field in DFSZ model in which axion couples to both quarks and leptons at tree level. The decay probability is strongly catalyzed by the external field, namely, the field removes the main suppression caused by the smallness of the axion mass.     

On the interactions of the high energy photoelectrons with the fullerene shell

The probability that photoionization of the caged atom in an endohedral system is accompanied by excitation of the fullerene shell is shown to be close to unity in broad intervals of the photoelectron energies. This is obtained by summation of the perturbative series for the interaction between the photoelectron and the fullerene shell. The result can be verified in experiments. As an outcome, interaction between the photoelectron ejected from the caged atom and the fullerene shell cannot be described by a static potential, since inelastic processes become decisively important.     

Numerical study of the oscillatory convergence to the attractor at the edge of chaos

This paper compares three different types of “onset of chaos” in the logistic and generalized logistic map: the Feigenbaum attractor at the end of the period doubling bifurcations; the tangent bifurcation at the border of the period three window; the transition to chaos in the generalized logistic with inflection 1/2 (x_n+1 = 1-μx_n^1/2), in which the main bifurcation cascade, as well as the bifurcations generated by the periodic windows in the chaotic region, collapse in a single point. The occupation number and the Tsallis entropy are studied. The different regimes of convergence to the attractor, starting from two kinds of far-from-equilibrium initial conditions, are distinguished by the presence or absence of log-log oscillations, by different power-law scalings and by a gap in the saturation levels. We show that the escort distribution implicit in the Tsallis entropy may tune the log-log oscillations or the crossover times.     

On the limitations of the equation of state based on the Lennard-Jones potential

It is emphasized that any equation of state (EOS) based on the generalized Lennard-Jones potential or the Mie potential, suffers from two main shortcomings as pointed out by Stacey and Davis [2]. One of the shortcomings viz. the problem related to imaginary numbers for the exponents in the potential function, has been removed recently by Jiuxun [11] by using a relationship between the exponents. However, the modified EOS obtained by Jiuxun suffers from the second shortcoming viz. it gives lower values for −B ₀ B″₀, an important equation of state parameter related to the second pressure derivative of the bulk modulus. Values of B ₀ B″₀ obtained by Jiuxun are not consistent with those reported by Stacey and Davis.