The measurement of the magnetic susceptibility of some elements (Fe,Co, Ni,Ge, Sn,Te) in the liquid state

A magnetic balance was used for measuring the susceptibility of metals and alloys, in an atmosphere of purified argon, up to 1800°c.

Comparison of the susceptibilities of liquid Fe, Co and Ni gives information on the liquid state. The changes in the susceptibilities of Ge, Sn and Te on melting are typical of semi-metallic elements and semiconductors, but their behaviour differs according to the degree of symmetry in the solid state.     

Change in the Shape of Nuclei in the Chains of Krypton,Strontium, Zirconium,Molybdenum, and Ruthenium Isotopes in the Relativistic-Mean-Field Approximation

Physics of Atomic Nuclei - Changes in the shape of nuclei in the chains of even—even crypton, strontium, zirconium, molybdenum, and ruthenium isotopes are studied on the basis of the...     

The Interaction Vector Model and the Intensity of the Secondary Transition of the Benzene Chromophore in Strained Natural Molecules: Sesamol,Melacacidin, Tetrahydropapaverolin,Renifolin, Pterocarpin,Peltogynol

A method (the New Vector Model : NVM) designed to approach the intensity of the secondary transition of the benzene chromophore with-CH3 and-OR substituents, has been recently published ¹ This method is based on MNDO calculations. It has been applied to strained chromophores with fused rings, ² assuming that it is possible to take into account the incidence of strain on intensity in introducing a strain vector in the vector scheme used to calculate the transition moment vector. In another step it has been derived a much simpler method which avoids the quantum calculations. It can be brought into play using graphically simple vector addition rules. ³ This method is based on a new concept : the interaction vector (underneath, the method is called the Interaction Vector Model : IVM). It has been designed to study alkyl and-OR substituents, since we are mainly involved in the study of natural products and many natural products display such substituents. This IVM has not been designed to take into account the perturbations induced by the strain on intensity. The present work is devoted to the adaptation of the IVM to strained benzene chromophores. It is given several examples on the way it can be used on strained natural molecules.     

Stability of bipolarons, electron-electron correlations, the variational principle, and the virial theorem

For bipolaron states, a relation is established between the variational principle and the virial theorem optimizing the electronic wave functions. It is shown that a bipolaron one-center state is unstable under any conditions that do not violate basic physical principles. It is established that a stage-by-stage increase in the flexibility of the electronic wave function due to the electron-electron correlations does not stabilize a one-center bipolaron. It is argued that the results of calculations based on the one-center bipolaron model are incorrect.     

Superheavy matter, strange matter, antimatter and the structure of the vacuum

The extension of the periodic system into various new areas is investigated. Experiments for the synthesis of superheavy elements and the predictions of magic numbers are reviewed. Further on, investigations on hypernuclei and the possible production of antimatter clusters in heavy-ion collisions are reported. Various versions of the meson field theory serve as effective field theories at the basis of modern nuclear structure and suggest structure in the vacuum which might be important for the production of hyper- and antimatter.     

Analysis of the applicability of Ni,Cu, Au,Pt, and Pd nanoclusters for data recording

The applicability of individual Ni, Cu, Au, Pt, and Pd nanoclusters as data bits in next generation memory devices constructed on the phase-change carrier principle is studied. To this end, based on the modified tight-binding potential (TB-SMA), structure formation from the melt of nanoparticles of these metals to 10 nm in diameter was simulated by the molecular dynamics method. The effect of various crystallization conditions on the formation of the internal structures of Ni, Cu, Au, Pt, and Pd nanoclusters is studied. The stability boundaries of various crystalline isomers are analyzed. The obtained systematic features are compared for nanoparticles of copper, nickel, gold, platinum, and palladium of identical sizes. It is concluded that platinum nanoclusters of diameter D > 8 nm are the best materials among studied metals for producing memory elements based on phase transitions.

     

Neutrinos,supernovae, and the origin of the heavy elements

Stars of～8-100 M_⊙end their lives as core-collapse supernovae(SNe). In the process they emit a powerful burst of neutrinos,produce a variety of elements, and leave behind either a neutron star or a black hole. The wide mass range for SN progenitors results in diverse neutrino signals, explosion energies, and nucleosynthesis products. A major mechanism to produce nuclei heavier than iron is rapid neutron capture, or the r process. This process may be connected to SNe in several ways. A brief review is presented on current understanding of neutrino emission, explosion, and nucleosynthesis of SNe.     

Quantization of the anomalous,chiral, Schwinger model

We implement the recent proposal of Faddeev [6] and present a quantization of the anomalous, chiral, Schwinger model. We carry out a Schrödinger representation, hamiltonian formulation quantization, on a circle. We expose the structure of the fermionic Hilbert bundle as a functional of the background gauge fields. We find that, although a unitary and consistent quantum field theory is obtained, Lorentz invariance is lost.     

Axiomatic,or model-independent,approach to the symmetries of the elementary particles

The usual model-building approach to the symmetries of the elementary particles is supplemented by a slightly more abstract, or axiomatic, approach. In this approach stress is laid on the algebraic structure of the gauge theory, and the consequences of various postulates which can be made within this structure are investigated in a direct, model-free, manner. The main problems considered are the relationship of the weak and electromagnetic interactions to, and the breakdown of, flavour symmetry.Invited talk at the Symposium on Mathematical Methods in the Theory of Elementary Particles, Liblice castle, Czechoslovakia, June 18–23, 1978.The author wishes to thank Professor H.Leutwyler for some very useful discussions and comments.     

Effect of the dissipation, dispersion, and diffraction on the amplitude and the transverse stability of solitons

The transverse stability and the amplitude variations of soliton-like wave motions in the presence of nonlinearity, dispersion, diffraction, and dissipation in the medium are studied. The wave process is described by a quintic nonlinear evolution equation. It is demonstrated that the stability of the solution does not depend on the dissipation when the dissipation, diffraction, and dispersion are of the same order of magnitude. It depends on the sign of the ratio of the diffraction and dispersion coefficients. When the sign is positive, the soliton is stable. This result coincides with the stability condition for a nonlinear modulation wave. For the case of strong dissipation, an expression describing the soliton amplitude is obtained and the dissipation is shown to have no effect on the soliton stability.     

Smoothed Wigner-distributions, decoherence, and the temperature-dependence of the classical-quantum frontier

We discuss the strange behavior at T = 0 of the phase-space Wigner distribution of the harmonic oscillator with the help of the purely quantal concepts of participation ratio of a mixed state and decoherence parameter. We also show that Wigner distribution-smoothing yields interesting insights, specially in the pathological instance in which the Wigner-Fano factor diverges. The associated decoherence parameter also sheds some light on temperature-dependence of the classical-quantum frontier.     

Occupational noise exposure—The laws in the EEC,Sweden, Norway,Australia, Canada and the USA

The aim of this paper is to investigate which of the EEC member states use the equal energy rule for occupational noise exposure limits, and how many of these countries have taken legislative action on these scientific standards. Declaration of industrial diseases caused by noise, and medical surveillance are only mandatory in four EEC countries. Furthermore, limitation of both the level and number of high intensity impulses per day is virtually ignored in the EEC countries, apart from Belgium. For comparison purposes, the laws on the protection of workers' hearing, as they apply in Sweden, Norway, the USA, Canada and Australia, are also reviewed.Legislation on workers' compensation for occupational deafness is examined, a distinction being drawn between the adversary and clinical systems. The role being played by the trade unions in checking the effectiveness of hearing conservation measures in Canada, Germany and the USA is also discussed.     

Influence of alloying elements introduced into copper upon the specific electrical resistance,the adhesion to the substrate,the thermal stability,and the welding characteristics of vacuum-condensed films

The electrical resistance, adhesion to sital, thermal stability, and welding characteristics of certain pure metals and copper-base alloys are studied in relation to the composition of the original alloy, the conditions of production, and the subsequent heat treatment. Films based on certain copper alloys have an advantage over those based on pure metals of the kind widely employed in microelectronics. Recommendations are made as to the optimum composition of the original alloy so as to be able to manufacture film elements of high electrical conductivity. These elements respond excellently to the demands made by microelectronic technology on the internal switching of hybrid film circuits.Translated from Izvestiya VUZ. Fizika, No. 12, pp. 25–31, December, 1973.     

Maxwell, Mechanism, and the Nature of Electricity

Maxwell aimed to reduce electromagnetism to the mechanics of an ether and even proposed a detailed ether model of electromagnetic phenomena that could accommodate light waves. I argue in this paper that Maxwell's undoubted successes in electromagnetism came about in spite, rather than because of his attempts to reduce electromagnetism to mechanics. By the end of the nineteenth century it had become clear that electric charge and the electromagnetic field were primitives on a par with, and not to be reduced to mechanical entities such as mass.     

Decoherence,the Density Matrix,the Thermal State and the Classical World

Decoherence has been the basis for understanding the emergence of the classical world from its quantum underpinnings. Unfortunately the calculations establishing decoherence overshoot and, based on assumptions that break down, predict that with the passage of time the off-diagonal elements of the density matrix become arbitrarily small. It has been recognized by some authors that the thermal state, assumed to hold for systems in equilibrium, places a bound on off diagonal terms. In this article we establish—preserving the conservation of energy, as is not the case for previous work—that indeed the thermal state is an attractor under scattering. Moreover, the bound on the off-diagonal terms present in the thermal state does not contradict everyday experience.     

Prediction of the incidence of motion sickness from the magnitude, frequency, and duration of vertical oscillation

A method is proposed by which the incidence of motion sickness may be predicted from measurement of the motion exposure. The method is based on data from both field and laboratory studies involving large numbers of people and is applicable to marine and other environments where vertical oscillation occurs at frequencies below 0.5 Hz. The dependence of motion sickness on the frequency of oscillation requires the use of a weighting function between 0.1 and 0.5 Hz. The dependence of sickness on the duration of exposure is incorporated by the use of a cumulative measure of motion dose based on the product of root-mean-square (rms) acceleration magnitude and the square root of stimulus duration. The influence of population variables such as sex, age, and motion experience is discussed. The method enables separate predictions to be made of vomiting incidence and of feelings of illness. The prediction procedure, while not seeking to explain the underlying mechanisms of motion sickness occurrence, provides a generally applicable method which is simple to use and has an accuracy consistent with the experimental data on which it is based.     

Benchmarks for the forward observables at RHIC,the Tevatron-run II,and the LHC

We present predictions on the total cross sections and on the rho parameter for present and future pp and (-)pp colliders, and on total cross sections for gammap-->hadrons at cosmic-ray energies and for gammagamma-->hadrons up to sqrt[s]=1 TeV. These predictions are based on an extensive study of possible analytic parametrizations invoking the largest hadronic dataset available at t=0. The uncertainties on total cross sections reach 1.9% at the Relativistic Heavy Ion Collider, 3.1% at the Tevatron, and 4.8% at the Large Hadron Collider, whereas those on the rho parameter are, respectively, 5.4%, 5.2%, and 5.4%.     

A New Approach to the Intensity of the Secondary Transition of the Benzene Chromophore with-CH3,-OH,-OCH3, Substituents

Since the beginning of the UV absorption spectroscopy, the intensity of the secondary transition of the benzene chromophore in organic derivatives has been a puzzling challenge. The well known vector model has led to some qualitative evaluation of intensity, but accuracy is very low, and sometimes leads to no less than 50% or 100% error. ^1–8 It is designed for very weak perturbations only, as in methylbenzenes. But, even in that latter case, it is not completely satisfactory. Nevertheless, that model is very easy to use; it allows to determine the sensitive positions around the benzene nucleus: those which could enhance or quench intensity for a given pattern of substitution. On that ground it has been of much help for qualitative evaluations. With SCF methods and CI calculations, evaluation of transition moments for several benzene derivatives has been possible on a firmer ground. In fact, such an approach is useful mainly from a theoretical point of view, when accuracy is not the first aim, for some choosen molecules at the same time, since the involvement of computation is far from being negligible, and since the method is not part of the ones that are of common use in organic chemistry ^9,10 (for a recent example on oscillator strength calculations of π systems see:¹¹). In other words, it is not perfectly valuable on a large scale and routine approach and, from that point of view, UV spectroscopy of benzene derivatives appeared sometimes, from 1965 till now, as being in a cul-de-sac, although it was under thorough examination (for example: 12–30). Until recently ab initio calculations have failed to reach a fit with experiment better than 1 eV for the spectrum of the benzene molecule^31–32)     

Simulation of the influence of the polymer conformation,orientation, crystallinity,and stretching on its IR absorption spectrum

Using cis-1,4-polyisoprene as an example, the influence of the conformation and orientation of the polymer chain on its polarization absorption spectra has been simulated. It has been shown that if a change in the orientation of the polymer chain leads to a monotonic change in the intensities of the absorption bands with their maxima positions remaining unchanged, then changes in the polymer chain conformation additionally cause a shift and the appearance of new absorption bands. According to the results of the calculation of the vibrational spectra, the inversion of the IR dichroism of the absorption bands of polymers is associated with the conformation transition. We simulate the influence on the IR absorption spectrum of the degree of crystallinity of cis-1,4-polyisoprene, in which the amorphous and amorphous-crystalline states are considered as a mixture of noninteracting polymer chains, where each state is characterized by a certain ratio of conformers. Likewise, the changes in the IR absorption spectrum of cis-1,4-polyisoprene under its stretching have been investigated. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 6, pp. 727–733, November–December, 2005.     

Studies of fullerenes by the excitation, emission, and scattering of electrons

This paper presents an overview of how electron spectroscopies have contributed to advances in fullerene research. In particular, we illustrate the vital role these techniques have played in improving our understanding of the importance of strong electronic correlation and of electron-phonon coupling in these materials, in the derivation of electron hopping rates, in providing a direct determination of charge transfer and hybridisation in both fullerene salts and adsorbed fullerenes and in determining the optical gap of these systems. We discuss systems of increasing complexity, starting with C₆₀ in the gas phase and in the solid state, and moving on to C₆₀ salts and to C₆₀ adsorbed on surfaces. Finally we look at both higher fullerenes and fullerenes with a heteroatom either on or inside the cage.