无纤维吸声材料研究进展

简要地介绍了吸声材料的基本特点，阐述无纤维性吸声材料（特别是微穿孔板吸声结构）取代传统的纤维性吸声材料的可能性及其重要意义，较详细地介绍了近年来德国以及我国科研人员在纤维吸声材料研究上取所得的进展。     

Charged particle reaction cross sections and nucleosynthesis

The role of proton and α-particle induced reactions in carbon, neon, oxygen and silicon burning in massive stars is surveyed. The problems associated with determining thermonuclear reaction rates for reactions with widely spaced resonances and with closely spaced or overlapping resonances are discussed and the associated experimental approaches are reviewed. Experimental techniques which have been used in the measurement of reaction cross sections are discussed and their strengths and weaknesses are identified. Recent developments in attempts to establish reliable statistical-model codes for calculation of reaction cross sections are presented and discussed. Finally, the results of experimental tests of statistical model codes are summarised and evaluated.     

2002年度诺贝尔物理奖

对2002年度的诺贝尔物理奖和中微子天文学以及一些相关的有趣问题作了比较详细的介绍。介绍了太阳中微子短缺之谜以及长达三四十年的奋斗历程;SN1987A中微子的发现以及最近太阳中微子短缺之谜的解决。还介绍了X射线天文学的发现和进展。现在,X射线天文学已经发展成为可与光学天文学、射电天文学媲美的一门举足轻重的学科。     

De Sitter gauge theories of gravity

The two types of de Sitter gravities are constructed with the fiber bundle technique and some special cases are discussed. Relations among de Sitter, Poincaré, and Lorentz gravity are discussed and the contraction from the de Sitter bundle to the Poincaré bundle is demonstrated. Two types of gravitational gauge field equations are obtained by using the de Sitter-Poincaré and de Sitter-Lorentz actions. The de Sitter effect occurring in the field equations is discussed.     

Equilibrium theory of molecular fluids: Structure and freezing transitions

In this article we review equilibrium theory of molecular fluids which includes structure and freezing transitions. The application of the theory to evaluate the pair correlation functions using Integral Equation methods and Computer Simulations have been discussed. Freezing of classical complex fluids based on the density functional approach is also discussed and compare a variety of its versions. Transitions discussed are sensitive to the value of direct correlation functions of the effective liquid which is required as an input information in the theory. Accurate evaluation of pair correlation functions is emphasized. Calculation of these correlation functions which pose problems in the case of ordered phases is discussed. The pair correlation functions of the ordered phase, which are supposed to be made up of two contributions, one that preserves the symmetry of the isotropic phase and a second that breaks it, are discussed. A new free-energy functional developed for an inhomogeneous system that contains both symmetry conserved and symmetry broken parts of the direct pair correlation function is discussed. The most useful three dimensional reference interaction site model (3D-RISM) and its extension done recently by many workers is discussed. Application of this theory to a large variety of complex systems in combination with the density functional theory method implemented in the Amsterdam density functional software package is discussed. Coupling of the 3D-RISM salvation theory with molecular dynamics in the Amber molecular dynamics package is also given.     

Some analytical aspects in field theories with dynamical mass generation

The consequence of dynamical mass generation on the singularity structure of propagators is discussed. First the phenomena of dynamical mass generation is discussed in the framework of Euclidean gap equations, then a possible Minkowski solution is looked for. The examples are reviewed and studied for several models: Yukawa, QED, QCD and Wess-Zumino. It is argued that the absence of propagator pole goes hand in hand with the nontrivial solution for mass function. The consequences are discussed.     

Some exact solutions of string cosmology in Bianchi III space-time

Following the techniques used by Letelier and Stachel some exact Bianchi III cosmological solutions of massive strings in the presence of magnetic field are obtained and their physical features are discussed. Some string solutions in which magnetic fields are absent are also discussed.     

Reduced Two-Field Equations and Anomalous Transport Scaling in Low-Temperature Plasmas

After a review of more or less systematic approaches for normal as well as anomalous particle transport phenomena across a magnetic field, simplified macroscopic models are discussed. A reduced two-field model for collision-dominated low-temperature plasmas is presented. Although it looks similar to its high-temperature analogue (known as the Hasegawa-Wakatani equations), it has significant peculiarities which are discussed in detail. Some basic results following from the reduced two-field model, e.g. anomalous transport scaling close to the onset of collisional driftwave instability, are discussed.     

爱因斯坦坚持场纲领的原因

探讨了爱因斯坦坚持场纲领的物理学认识基础和思想发展过程，分析了其坚持场纲领的目的及未获成功的原因。     

EPR spectroscopy of radiation-induced centers in tooth enamel and its application for retrospective dosimetry in chernobyl case

A specific EPR tooth enamel dosimetry is discussed which appears to have genuine utility in retrospective dosimetry. The sample preparation technology, digital form of the native background and radiation-induced signals, and their separation from the experimentally observed spectrum are discussed. The possibility of dose estimation from the single initial EPR spectrum of randomly irradiated teeth and the uncertainty of such evaluation are discussed. The method has been used for dose reconstruction of a group of people irradiated due to the Chernobyl accident, and some results are presented.     

Two-photon-exchange contribution to proton form factors in both space-like and time-like regions

The two two-photon exchange corrections to the unpolarized cross section and polarized observable PT,PL in elastic ep scattering are discussed in a simple hadronic model.Comparing with previous results,theΔ contribution are re-analysed.And the similar corrections in e+e-→ p(p-)are also discussed.     

Few remarks about hadron resonance and their effects in hadronic atoms

Interactions of antikaons, antiprotons and nucleons at very low energies are discussed in terms of separable potential models. Coulomb interactions are included and formulae for strong shifts of electromagnetic hadronic hydrogen are obtained. These are discussed as a way of determination of scattering amplitudes below thresholds. Applications to hadronic deuterium are mentioned.     

Theory of electrodynamic levitation with a continuous sheet track — Part II

Various approximate expressions for lift and drag forces for null, normal and brake flux systems are developed from the rigorous expressions given in Part I of this work. Physical significance of the approximations used and the limits of validity are discussed. Results previously known in the literature are also discussed critically in this context.     

SL(2,C) gauge theory of gravitation: Conservation laws

Conservation laws in the SL(2,C) gauge theory of gravitation are reviewed and their relation to the ordinary conservation laws in general relativity theory is discussed. The vector currents that were proposed by different authors along the lines of the Yang-Mills conserved vector current are discussed and their interrelation is given. Likewise Lagrangian densitiies, from which one obtains the SL(2,C) gauge theory gravitational field equations, are discussed and related to the conservation laws through Noether's theorem.     

Coherent effects in inverse compton scattering in the high frequency region

The conditions under which a cooperative emission from different friges occurs in the scattering between a relativistic electron beam and two interfering laser beams are discussed. In particular, the conditions to have an electron grating are discussed.     

孤子源啁啾对光孤子传输的影响以及消啁啾的方法

本文提出了一种孤子源非线性啁啾的模型,利用解析和计算机模拟的方法从理论上分析了孤子源啁啾,特别是非线性啁啾对孤子传输的影响,并讨论了消啁啾的两种方法-正色散光纤消啁啾法和Fabry-Perot光谱窗消啁啾法,实验结果与理论分析基本一致.     

Multiplicity and hadron distributions in QCD jets: Non-leading terms

The multiplicity of hadrons and the distribution of produced hadrons in QCD jets are discussed. The leading logarithmic terms are reviewed. A procedure for finding the structure of next-to-leading effects is developed. The next-to-leading terms are calculated and their phenomenological consequences are discussed.     

Experimental aspects of high energy neutrino physics

Neutrino physics from the viewpoint of the high energy results from Fermilab are discussed. The high energy experiments are described and their results are discussed. The status of both the charged current reactions are reviewed in detail. Also, the important observations of topologies indicating new particle production by neutrinos are covered. Comparisons between results of different experiments are made where relevant.