Appearance of neutron stars in the state of subsonic propeller

The state of subsonic propeller is intermediate between the states of supersonic propeller and accretor in the evolutionary tracks of magnetized compact stars. The rotational rate of a star at this stage decelerates due to the interaction between its magnetosphere and the surrounding hot, quasi-static plasma envelope. The magnetospheric radius is smaller than the corotation radius and the boundary of the magnetosphere is stable with respect to interchange instabilities. The rate of the mass flux from the inner radius of the envelope to the stellar surface is limited by the rate of plasma diffusion into the magnetic field of the star. As a result, the subsonic propeller would appear as a low-luminosity accretion-powered pulsar with a soft X-ray spectrum.     

用Visual FoxPro进行动态界面的设计

本文介绍用 Visual FoxPro的定时器。标签、按钮等控件和控件的属性、方法、事件等在界面上设计动态字幕、动态按钮等若干动态效果的方法。     

TC4钛合金的微动磨损及防护

对Ｔｉ－６Ａｌ－４Ｖ合金在１８℃，１００℃２５０℃下的微动磨损特性及防护工艺进行了研究。表明：该合金微动磨损的主要磨损形式是疲劳脱层，其磨损量随温度升高而下降，高渐微动磨损量与磨损区表面所形成的氧化层的性质及厚度有关。     

离散系统仿真输出数据的统计分析

概括了分析仿真产生的数据的方法，讨论了离散系统仿真输出分析的目的以及应用统计方法的要求，对单变量情形，给出了有关估计来自终态仿真和和稳态仿真参数的技术。对多变量情形，以终态仿真为例，给出了用于分析离散系统的仿真输出的某些多变量统计技术，并提出均值向量的估计方法。     

The population of massive stars in R136 from HST/FOC UV observations

New ultraviolet (1300 A, 3400 A),HST FOC observations have been used to derive the UV color-magnitude diagram (CMD) of R136, with the main scientific goal of studying the upper end of the stellar mass function at ultraviolet wavelengths where the color degeneracy encountered in visual CMDs is less severe. The CMD has been compared to a set of theoretical isochrones, which have been computed using the latest generation of evolutionary models and model atmospheres for early type stars. Wolf-Rayet stars are included. Comparison of theTheoretical andobserved CMD suggests that there are no stars brighter than M₁₃₀–11. We use the observed main sequence turn-off and the known spectroscopic properties of the stellar population to derive constraints on the most probable age of R136. The presence of WNL stars and the lack of red supergiants suggests a most likely age of 3±1 Myr. A theoretical isochrone of 3±1 Myr is consistent with the observed stellar content of R136 if the most massive stars have initial masses around 50 M.Bases on Observations with the NASA/ESA Hubble Space Telescope, obtained at the STScI, which is operated by AURA, Inc., under NASA contract NAS5-26555.Astrophysics Division, Space Science Department, ESA     

Wind asymmetries in massive stars

We are in the process of surveying the linear polarization in luminous, early-type stars. We here report on new observations of the B [e] stars S 18 and R 50, and of the Luminous Blue Variables HR Car, R 143, and HD 160529. Together with previously published data, these observations provide clear evidence for the presence of intrinsic polarization in 1 B[e] star (HD 34664) and in 5 LBVs ( Car, P Cyg, R 127, AG Car, and HR Car). The data indicate that anisotropic stellar winds are a common occurrence among massive stars in these particular evolutionary stages. For such stars, mass-loss rates estimated using the assumption of a spherical, homogeneous and stationary outflow may be in error.     

Urca processes in dense matter and neutron star cooling

Urca-processes were introduced into astrophysics by Gamow and Schoenberg in 1941. Neutrino cooling resulting from urca-processes plays an important role at the latest stages of evolution of massive stars. Recent work on neutrino emissivity of dense matter shows that neutrino cooling via urca-processes could determine the thermal evolution of young neutron stars and depends dramatically on the composition of the neutron star core. In particular, if a neutron star contains a central core in which the direct urca-process is operative, the cooling timescale shortens by many orders of magnitude.     

建立民航维修专家系统的分析

简要介绍了专家系统的原理及构成.分析了“设计民航维修专家系统”的过程,目前加拿大正着手研制的“先进的维修软件系统”的概况.最后提出专家系统需要解决的关键技术问题及发展情况.     

High Excitation ISM and Gas

An overview is given of ISO results on regions of high excitation ISM and gas, i.e. HII regions, the Galactic Centre and Supernova Remnants. IR emission due to fine-structure lines, molecular hydrogen, silicates, polycyclic aromatic hydrocarbons and dust are summarised, their diagnostic capabilities illustrated and their implications highlighted. Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, The Netherlands, and the United Kingdom), and with the participation of ISAS and NASA.     

逻辑分析仪部分参数测量结果的不确定度评定

介绍了逻辑分析仪部分参数测量结果的不确定度分析评定方法，评定过程及结论，可应用在对于计量标准进行相应指标的不确定度评定分析上。