Formal structures,the concepts of covariance,invariance, equivalent reference frames,and the principle Relativity

In this paper a given spacetime theoryT is characterized as the theory of a certainspecies of structure in the sense of Bourbaki [1]. It is then possible to clarify in a rigorous way the concepts ofpassive andactive covariance ofT under the action of the manifold mapping groupG _M . For eachT, we define also aninvariance groupG _I T and, in general,G _I T ≠G _M . This group is defined once we realize that, for eachτ ∈ModT, each explicit geometrical object defining the structure can be classified as absolute or dynamical [2]. All spacetime theories possess alsoimplicit geometrical objects that do not appear explicitly in the structure. These implicit objects are not absolute nor dynamical. Among them there are thereference frame fields, i.e., “timelike” vector fieldsX ∈TU, \(U \subseteq M\) M, whereM is a manifold which is part ofST, a substructure for eachτ ∈ModT, called spacetime. We give a physically motivated definition of equivalent reference frames and introduce the concept of theequivalence group of a class of reference frames of kind X according to T, G _X T. We define thatT admits aweak principle of relativity (WPR) only ifG _X T ≠ identity for someX. IfG _X T =G _I T for someX, we say thatT admits a strong principle of relativity (PR). The results of this paper generalize and clarify several results obtained by Anderson [2], Scheibe [3], Hiskes [4], Recami and Rodrigues [5], Friedman [6], Fock [7], and Scanavini [8]. Among the novelties here, there is the realization that the definitions ofG _I T andG _X T can be given only when certain boundary conditions for the equations of motion ofT can be physically realizable in the domainU \(U \subseteq M\) M, where a given reference frame is defined. The existence ofphysically realizable boundary conditions for eachτ ∈ModT (in ?U), in contrast with the mathematically possible boundary condition, is then seen to be essential for the validity of a principle of relativity forT. The methodology of the present paper has been applied to several topics of spacetime physics with very interesting results. Here we mention:

1. The Newtonian concepts of absolute space and absolute time can be presented in a very elegant way as “species of structure”. One of the surprising results is that we succeeded in finding a Lorentzian structure [9] in Newtonian spacetime without introducing any new explict geometrical object in the original structure. The Newtonian spacetime structure and its relation to the relativistic spacetime structure and to the structure of the spacetime of the so-called Lorentz aether theories [11,12] is fully discussed in [13].
2. It is possible to present in a novel and unified way the question concerning experiments designed to detect a possible breakdown of Lorentz invariance, a subject we already dedicated attention to in Rodrigues and Tiomno [11,12] and Rodrigues [14,15]. A full account of this subject will be published elsewhere.
3. In Rodrigues and Scanavini [16], we proved that there are models of General Relativity that contain a canonical privileged locally inertial reference frame that can be physically distinguished from any other frame by experiments doneinside the frame.

Although the formalism of this paper may at first sight look very abstract, actually it is easy to aplly it to specific theories. We present an example at the end of the paper which is sufficiently general to show “in action” almost all concepts introduced in this paper.     

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.     

Torsion,wormholes, and the problem of the Cosmological constant

We consider the effect of torsion in the early universe to see if it is possible to explain the small value (if not zero) of the Cosmological constant at the present time. For the gauge-theoretic formulation of the Einstein-Cartan theory, we find a wormhole instanton solution which has a minimum (baby universe) radius of the Planck length. The basic difficulty with the wormhole approach is stressed. Finally, we give an explicit calculation from the expression for the evolution of the scale factor, which shows that the spin-dominated interaction term in the very early universe can cancel the Cosmological constant term at that epoch.     

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.     

Invention,development, and status of the blue light-emitting diode,the enabler of solid-state lighting

The realization of the first high-brightness blue-light-emitting diodes (LEDs) in 1993 sparked a more than twenty-year period of intensive research to improve their efficiency. Solutions to critical challenges related to material quality, light extraction, and internal quantum efficiency have now enabled highly efficient blue LEDs that are used to generate white light in solid-state lighting systems that surpass the efficiency of conventional incandescent lighting by 15–20×. Here we discuss the initial invention of blue LEDs, historical developments that led to their current state-of-the-art performance, and potential future directions for blue LEDs and solid-state lighting.     

Planck, the Quantum, and the Historians

In late 1900, the German theoretical physicist Max Planck derived an expression for the spectrum of black-body radiation. That derivation was the first step in the introduction of quantum concepts into physics. But how did Planck think about his result in the early years of the twentieth century? Did he assume that his derivation was consistent with the continuous energies inherent in Maxwellian electrodynamics and Newtonian mechanics? Or did he see the beginnings, however tentative and uncertain, of the quantum revolution to come? Historians of physics have debated this question for over twenty years. In this article, I review that debate and, at the same time, present Planck's achievement in its historical context.     

ICP-AES同时测定铝合金中Fe,Si,Cu,Mg,Mn,Ni,Zn,Ti,Cr,Sr等杂质元素

本文通过基体干扰和操作条件的试验研究，分别用基体匹配法和干扰系数法校正基体干扰和待测元素间的干扰，建立了以氢氧化钠溶样，ICP－AES同时测定铝合金中铁、锰、铜、锌、镁、钛、硅、镍、铬、锶等杂质元素的方法。方法快速、简便、可靠，回收率93％－102％，适用于进出口铝合金的快速检验。     

Effect of Helium ion irradiation on the structure,the phase stability,and the microhardness of TiN,TiAlN, and TiAlYN nanostructured coatings

The radiation resistance of nanostructured TiN, TiAlN, and TiAlYN coatings is studied after 500-keV He⁺ ion irradiation in the fluence range 5 × 10¹⁶–3 × 10¹⁷ ions/cm². The radiation-induced changes in the phase composition, the structure, the lattice parameters, the morphology, and the mechanical properties of coatings are investigated. Blistering is found to be absent, and the radiation fluence is shown to affect the strength properties of the thin coatings nonlinearly. A significant decrease in the grain sizes is detected upon ion irradiation, which causes an increase in the microhardness and the radiation resistance of the coatings. The TiN, TiAlN, and TiAlYN coatings are found to be radiation-resistant coatings, which do not undergo serious degradation during high-fluence ion irradiation.     

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...     

对图像信息学(PI)算法的一个回溯性预测检验:四川芦山7.0级地震

文章针对中强地震预测的图像信息学(PI)算法,对2013年4月20日芦山Ms7.0地震的预测效果进行了回溯性震例分析.结果表明,在芦山地震的震中附近存在“PI热点”.在与2008年汶川地震的PI算法预测进行比较后建议,在以后的“PI热点”计算中,也许还应把背景形变速率作为一个权重因素考虑在内.     

ICP-AES法直接测定地热温泉水样中的钾、钠、钙、镁、硅、锂、硼的研究

采用顺序扫描式ＩＣＰ光谱仪,直接测定了地热温泉水样中的７种元素,并对最佳测试条件的选择进行了探讨,方法简便,快速、准确,检出限及精密度均可满足分析要求。     

Irreversibility,evolution,Evolution,and the process of local concentration

We suggest that some general questions of irreversibility and of quasi-Equilibrium vs. non-Equilibrium configurations (terminology is explained in the text), with respect to both biophysical and physical structures, can be clarified by generalizing results from investigations of stellar structure in relation to its environment. Such work has evolved from considerations of the stellar atmosphere as a transition zone between the quasi-Equilibrium stellar interior and the non-Equilibrium interstellar medium. As opposed to suggestions of irreversibility originating in the large (Gal-Or, e.g.), we suggest that the origin is local, in coupling between different storage modes for matter and energy. In contract to suggestions of non-Equilibrium biophysical structures arising in fluctuations from a quasi-Equilibrium state (Prigogineet al.), we suggest that they arise via condensations within a non-Equilibrium, steady-state, unstable environment. Generalization from stellar prototype studies of the process of such concentration indicates that the general process of forming structures in the Universe follows a hierarchy of such greater degree ofEquilibrium concentrations formed in lower degree ofEquilibrium environments.     

On the Masses of the W,Z, and H Bosons

Russian Physics Journal -     

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.     

Maximal acceleration,Mach's principle,and the mass of the electron

Recent arguments for an upper limit to the proper acceleration of extended massive bodies are briefly reviewed. A transient mass shift in accelerated objects with non-constant proper mass density, expected in all locally Lorentz-invariant theories of gravitation which satisfy Mach's principle, is considered. This effect affects arguments for a maximal proper acceleration. It is shown that, while the widely discussed upper limit to proper acceleration obtains for rigid bodies with constant proper mass density, the limit ceases to obtain generally if this effect is taken into consideration. Applicability of maximal acceleration arguments to elementary particles is briefly considered in the context of a plausible classical model of the electron (one where the mass of the electron follows from the electronic charge).     

Chiral extrapolation, renormalization, and the viability of the quark model

The relationship of the quark model to the known chiral properties of QCD is a long-standing problem in the interpretation of low-energy QCD. In particular, how can the pion be viewed as both a collective Goldstone-boson quasiparticle and as a valence-quark-antiquark bound state? A comparison of the many-body solution of a simplified model of QCD to the constituent-quark model demonstrates that the quark model is sufficiently flexible to describe meson hyperfine splitting provided proper renormalization conditions and correct degrees of freedom are employed consistently.     

Estimation of the Optimum Concentration Interval of the Contents of Praseodymium, Neodymium, Europium, Holmium, and Erbium in a Solution

Based on the electronic absorption spectra of Pr³⁺, Nd³⁺, Eu³⁺, Ho³⁺, and Er³⁺ ions in 1 M aqueous solutions of chloric acid, calibration graphs have been constructed in a concentration of metals–optical density of a solution format for different frequencies. The band for praseodymium was used at 22,520 cm^–1, for neodymium at 17,380, 13,480, and 12,560 cm^–1, for europium at 25,380 cm^–1, for holmium at 18,580 and 15,580 cm^–1, and for erbium at 39,160, 26,480, and 19,160 cm^–1. The errors in determining the concentration of the indicated elements as a function of their content have been calculated. It is shown that for perchloric solutions of praseodymium it is possible to correctly determine its contents within the concentration range 0.1–1.5% at a frequency of 22,520 cm^–1; for neodymium the ranges are 0.4–1.0, 0.3–1.0, and 0.5–1.0% at 17,380, 13,480, and 12,560 cm^–1, respectively; for europium 0.4–1.5% at 25,380 cm^–1; for holmium — 0.2–1.5 and 0.4–1.5% at 15,580 and 18,580 cm^–1, and for erbium the range is 0.4–1.0% at frequencies of 39,160, 26,480, and 19,160 cm^–1.