关于"太阳在银河系中所受引力与到银心距离r的关系"的讨论

讨论了银道面内的引力场强分布和太阳在银河系中所受引力与到银心距离r的关系，指出引力场强g并不是与r的平方成反比，这是由于银河系的大小和形状不能忽略造成的．强调了万有引力定律的适用条件．     

Angular response characteristic of pyramid shape fast neutron dosimeter using CR-39 films

CR-39 is a highly sensitive etched track detector for neutron monitoring and dosimetry applications but its dose equivalent response is strongly direction dependent with respect to the incident neutrons. This is considered to be a major drawback for their use. In the present study, an attempt has been made to develop a pyramid shaped dosimeter, which consists of polyethylene material of thickness 1 mm with the provision to hold three CR-39 films at an angle of 35° to each other. The response of CR-39 in this configuration under optimum electrochemical etching at elevated temperature have been found nearly angular independent and therefore the dosimeter can be used for neutron monitoring, i.e. personnel as well as area monitoring.     

Almost automorphic solutions for abstract functional differential equations

For abstract linear functional differential equations with an almost automorphic forcing term, we establish a result on the existence of almost automorphic solutions, which extends the classical theorem due to Massera on the existence of periodic solutions for linear periodic ordinary differential equations.     

Determination of the rheological behavior of epoxy–amine thermosets by dynamic mechanical analysis: Isothermal methods versus nonisothermal methods

The reticulation process of an epoxy resin using an amine as a cure agent was studied at different temperatures and concentrations of the cure agent with dynamic mechanical thermal analysis. The study was performed under both isothermal and nonisothermal conditions, and a temperature–time–transformation diagram was obtained. The measurements from the two modes gave similar results, although the nonisothermal mode required fewer experiments. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1965–1977, 2003     

Coherent quantum transport in normal-metal/d-wave superconductor/normal-metal double tunnel junctions

Taking into account the effects of quantum interference and interface scattering, combining the electron current with hole current contribution to tunnel current,we study the coherent quantum transport in normal-metal/d-wave superconductor/normal-metal (NM/d-wave SC/NM) double tunnel junctions by using extended Blonder-Tinkham-Klapwijk (BTK) approach. It is shown that all quasiparticle transport coefficients and conductance spectrum exhibit oscillating behavior with the energy, in which periodic vanishing of Andreev reflection (AR) above superconducting gap is found.In tunnel limit for the interface scattering strength taken very large, there are a series of bound states of quasiparticles formed in SC.     

Simultaneous Pseudo-Timestepping for PDE-Model Based Optimization Problems

In this paper we present a new method for the solution of optimization problems with PDE constraints. It is based on simultaneous pseudo-time stepping for evolution equations. The new method can be viewed as a continuous reduced SQP method in the sense that it uses a preconditioner derived from that method. The reduced Hessian in the preconditioner is approximated by a pseudo-differential operator, whose symbol can be investigated analytically. We apply our method to a boundary control model problem. The new optimization method needs 3.2-times the overall computational effort of the solution of simulation problem alone.     

耦合双原子Jaynes-Cummings模型的腔场谱H

研究了处于激发态的两原子与高Q腔场相互作用单光子过程的腔场谱,给出了初始光场为光子数态、相干态、压缩真空态时的腔场谱数值计算结果,分析了原子间偶极-偶极相互作用强度gα对腔场谱结构的影响.发现真空场Rabi峰,当gα较弱时为4峰,gα较强时为3峰结构;弱场数态(n＞0)时为5峰,强场时为3峰结构.相干态和压缩真空态时,谱结构与光子数分布有关,一般为复杂的多峰结构.结果表明,gα对峰位峰高都有影响,破坏了谱结构的对称性,但这种影响只在真空场和弱场时才较明显.     

光照与彩陶俑表面色变关系的实验研究

本文以秦彩俑表面色彩为研究对象,通过光照实验与色彩变化的色度测量,分析了光照引起彩俑颜料色变的规律,为秦彩俑这一大型重点文物的色彩保护提供了科学理论依据.