弹-架间隙的非线性模拟与特性分析

以大长径比低速旋转火箭为例,探讨弹-架间隙非线性特性对不同发射装置系统的动力响应的影响,当飞行器以S个定心部沿发射装置滑移时,根据弹、架横向相对位移确定其定心部处接触刚度和支承特性,模拟弹-架间隙效应。分别就刚性和柔性两种发射装置,分析了间隙量、支承刚度和转速等因素对飞行器发射中的姿态和系统动力特性的影响,算例与实际情况的相吻合证明了该方法的有效性。     

情报研究成果的AHP-F评价

本文采用层次分析法与模糊数学综合译判法相结合的方法——AHP-F法,提出了综合情报评判研究成果指标体系和方法,旨在实现对情报研究成果的科学有效的管理。     

以中等职业教育为平台培育外出务工的新型农民

中等职业教育是以培养专业技术人才为目的,以就业为导向的一种教育。培育千千万万高素质的新型农民依赖于中等职业教育为其提供培训平台。中等职业教育要立足于外出务工新型农民的培训需求,进一步提升其培训平台功能,推动实现以新型农民为主体的社会主义新农村建设。     

Composition of Light Solar Wind Noble Gases in the Bulk Metallic Glass flown on the Genesis Mission

We discuss data of light noble gases from the solar wind implanted into a metallic glass target flown on the Genesis mission. Helium and neon isotopic compositions of the bulk solar wind trapped in this target during 887 days of exposure to the solar wind do not deviate significantly from the values in foils of the Apollo Solar Wind Composition experiments, which have been exposed for hours to days. In general, the depth profile of the Ne isotopic composition is similar to those often found in lunar soils, and essentially very well reproduced by ion-implantation modelling, adopting the measured velocity distribution of solar particles during the Genesis exposure and assuming a uniform isotopic composition of solar wind neon. The results confirm that contributions from high-energy particles to the solar wind fluence are negligible, which is consistent with in-situ observations. This makes the enigmatic “SEP-Ne” component, apparently present in lunar grains at relatively large depth, obsolete. ²⁰Ne/ ²²Ne ratios in gas trapped very near the metallic glass surface are up to 10% higher than predicted by ion implantation simulations. We attribute this superficially trapped gas to very low-speed, current-sheet-related solar wind, which has been fractionated in the corona due to inefficient Coulomb drag.     

3He-Rich Solar Energetic Particle Events

³He-rich solar energetic particle (SEP) events show huge enrichments of ³He and association with kilovolt electrons and Type-III radio bursts. Observations from a new generation of high resolution instruments launched on the Wind, ACE, Yohkoh, SOHO, TRACE, and RHESSI spacecraft have revealed many new properties of these events: the particle energy spectra are found to be either power-law or curved in shape, with the ³He spectrum often being distinctly different from other species. Ultra-heavy nuclei up to >200 amu are found to be routinely present at average enrichments of >200 times solar-system abundances. The high ionization states previously observed near ∼1 MeV/nucleon have been found to decrease towards normal solar coronal values in these events. The source regions have been identified for many events, and are associated with X-ray jets and EUV flares that are associated with magnetic reconnection sites near active regions. This paper reviews the current experimental picture and theoretical models, with emphasis on the new insights found in the last few years.     

The dynamics of chromospheric spicules

We present the observational results on chromospheric spicules obtained at the Sayan observatory 50 cm coronograph. To investigate the evolution of chromospheric spicules, we analysed spicule spectra of strong chromospheric lines measured simultaneously at three altitudes above the solar limb during 5–60 min with a time resolution of 10 to 20 s. The spatial resolution was better than 1, and the spectral resolution was 0.03Å in 6563Å. The appearance of a spicule at a given altitude is preceded by an sharp increase in line-of-sight velocity and/or in line half-width at a lower level. Generally, the evolution has a non-monotonous impulsive character. Changes of line-of-sight velocities and other parameters of the line profile can be represented as the superposition of slow, evolutionary changes and fluctuations with periods of about 80 to 120 s. The amplitude of line-of-sight velocity fluctuations is 2–3 km/sec and tends to increase with height. By studying the phase delays of the fluctuations at different heights, we found that the propagation velocity exceeds 300 km s^–1, and that the disturbances do not necessarily propagate upwards.     

Imaging diagnostics of solar non-thermal particles

Non-thermal hard X-ray, gamma-ray and radio emission are the most direct signatures of the presence of energetic particles in the solar atmosphere. This paper lays emphasis on hard X-ray and radio imaging data, obtained during and outside flares, which reveal the sites where particles interact with the ambient medium. These observations, which provide more or less direct information on the topology and dynamics of the magnetic structures in which particles are accelerated and propagate, are discussed in the framework of the statistical flare scenario.     

Current dissipation within the chromosphere-corona transition

Studies of sporadic outbursts, ranging from flares to nano-flares, invariably endow the solar corona with steady plasma conditions, prior to seeking a current-flow (or the associated magnetic structure) which induces instability. Such an approach does not incorporate a crucial feature of the natural configuration, namely, that the material is of chromospheric origin, and only resides at coronal altitudes for as long as it can acquire adequate energy. There is clearly a feedback loop involved, which allows plasma to moderate the transfer of energy from the field while making use of this heat to permeate coronal altitudes. An examination of the whole procedure is necessary if the location and threshold-conditions for the energy-conversion mechanism are to be identified.A critical step in the feedback procedure mentioned involves the supply line which links the corona to the chromosphere. Because the solar atmosphere has such large vertical dimensions, even a modest change in average temperature and/or density can place heavy demands on this artery: the problem is that a conventional conduction-dominated transition layer cannot readily accommodate a rapid increase in current-density or plasma-flow. (Restructuring of the temperature gradient, to provide the carriers with extra heat, is a very slow process.) A transition layer of this type is unable to endure for long at the base of a sporadically-heated atmosphere in any case, since it becomes the target for plasma falling in the gravitational field during each intermediate cooling phase. As a result, the gap between the chromosphere and corona is more abrupt than is usually considered, endowing the region with thermo-electric characteristics which allow energy to be extracted when modest current-densities arise. Energy-conversion at this region fulfills two rôles: it supplies at least part of the heat required by the overlying corona, and maintains contact between the chromosphere and corona via non-thermal transport processes.     

1983年2月3日双带耀斑爆发事件的综合分析

本文在统一模型的考虑下,对1983年2月3日太阳3B级Hα双带耀斑和共生的爆发事件进行了综合分析研究.探讨了其中主要的共生辐射的物理过程和内在联系,并讨论了Ⅲ型、Ⅳ型和微波射电爆发源的非热电子束流对产生Hα双带耀斑和硬X射线爆发所起的重要作用.