Nucleosynthesis from non-thermal particles

The long-standing problem of nucleosynthesis from non-thermal charged particles is reviewed with emphasis on some novel points. Recent theoretical results predict very efficient acceleration of nuclei (up to GeV range) by violent systems with energy release in the form of multiple shock waves —OB associations and coronae of AGNs and black holes candidates in galactic accretion disks. A detection of gamma-line emission from the Orion complex by theCOMPTEL telescope on board ofGRO could confirm theoretical predictions. Production of lithium by non-thermal particles in Orion-like objects is discussed. The mechanism can be responsible for the observed variations of abundance of isotopes.     

行星际尘粒中锂同位素丰度与太阳星云演化的关系

1引言构成太阳系的大多数元素都经历过恒星演化过程，但3种轻元素Li，Be和B极为脆弱，在绝大多数恒星内部的高温、高密度和剧烈变动的条件下，很快就会分解．太阳系的早期阶段，太阳星云可能是由大爆炸产生的1H、2H、3He、4He和7Li及附近超新星爆发产生的C、N、O等构成[1]，而6Li、Be、B是以后由宇宙射线粒子轰击附近星际和行星际的C、N、O等的核产生[2]．因为Li的同位素丰度的一部分是由大爆炸生成，一部分是由宇宙射线与星际介质核反应产生，因此它的丰度与宇宙射线暴露时间有关．1991年，文献间报导过在行星际尘粒中发现Li、Be和…     

采用串列静电加速器进行单粒子效应模拟试验研究

本文描述了采用ＨＩ－１３串列静电加速器进行单粒子效应模拟试验的试验系数、试验方法和试验条件，给出了８０Ｃ３１单片机单粒子效应模拟试验结果；根据试验结果，采用ＣＲＥＭＥ程序对８０Ｃ３１单片机在三类不同轨道卫星上的单粒子翻转率进行了预计。     

一种全息滤波用于粒子场层析的方法

本文介绍用4F傅里叶透镜系统和全息滤波器对粒子场分布作全息记录的原理和方法。理论和实验结果表明,这种记录方法能同时准确记录位于输入平面和在其前、后相同距离平面上的粒子分布,并能根据清晰的粒子像直接判读出粒子尺寸和空间位置。若应用不同的全息滤波器,就能在输出平面上记录与滤波器相匹配的三个层次平面上的粒子分布。这种用4F系统的全息滤波记录方法,实质上是用全息术测量粒子场分布的层析法。文中还介绍了制作这种全息滤波器的原理和方法。     

Reverse shock acceleration of electrons and protons at mid-heliolatitudes from 5.3-3.8 AU

We examine the intensity, anisotropy and energy spectrum of 480–966 keV protons and 38–315 keV electrons observed by the HI-SCALE instrument on Ulysses associated with Corotating Interaction Regions (CIR) from mid-1992 to early 1994. The particle events are most clearly ordered by the reverse shocks bounding the CIRs. The bulk of the ion fluxes appear either straddling, or with their maximum intensity following, the reverse shock. The electron intensities rise sharply to their maximum upon the passage of the reverse shock, and are delayed with respect to the protons. We believe that following acceleration at the reverse shock the electrons re-enter the inner heliosphere and mirror, to return to the reverse shock for repeated acceleration. This process is more effective for electrons (vc/2) than for ions, and also favours the higher velocity electrons, which accounts for the observed spectral hardening with latitude.     

直升机粒子分离器三维两相流场的数值模拟

本文以某型直升机粒子分离器为研究对象, 在三维非正交曲线坐标系下计算湍流分叉流动和砂粒运动, 结合边界条件特殊处理, 采用分块计算来考虑叶片对流场的影响, 首次对有叶片粒子分离器三维两相流动进行了数值模拟。      

垂直激波条件下能量粒子加速机制的模拟研究

在具有湍动的磁场和垂直激波条件下对大量测试粒子的轨迹进行了数值计算,研究了激波强度和粒子初始能量对于粒子穿越激波的平均能量变化的影响,分析了漂移加速(SDA)在不同条件下对粒子加速的贡献,并给出了一个与数值结果相符合的漂移加速理论公式△E=amvivup(1-1/s).结果表明,加入磁场湍流后,垂直激波条件下粒子仍主要受到漂移加速作用,而基于粒子引导中心的耗散漂移加速理论在此条件下失效.      

喷管流场V3V试验示踪粒子特性研究

采用体3维测试系统(V3V)试验研究了拉伐尔喷管出口的速度场。为了选择适合V3V试验测量气流流场的示踪粒子,对3种不同物理属性的固体微粒进行测试分析,结果表明:二氧化钛粒径为5～10μm,对于激光散射性太差,粒子亮度较弱,在V3V处理软件识别时粒子匹配不成功;滑石粉和聚苯乙烯的粒径分别为20～25μm和30～35μm,在V3V软件处理4副图片时的粒子匹配率分别为30%和40%,试验得到的速度场与理论计算值误差分别约为2%和5%。     

Al／TiB_2复合工艺的铝含量研究

采用示差扫描量热法（ＤＳＣ）和Ｘ射线衍射技术（ＸＲＤ）着重研究了不同铝含量对铝、钛、硼混合粉烧结反应生成ＴｉＢ＿２过程的影响。试验结果表明：在Ａｌ－Ｔｉ－Ｂ系中，混合粉中铝的含量是一重要参数。ＴｉＢ＿２相虽可在６４０℃及９５０℃反应生成，但生成的数量与铝含量密切相关。含５０ｗｔ－％铝的混合粉被认为是最佳成分配比。     

Energetic particle signatures of geoeffective coronal mass ejections

We have studied statistically associations of moderate and intense geomagnetic storms with coronal mass ejections (CMEs) and energetic particle events. The goal was to identify specific energetic particle signatures, which could be used to improve the predictions of the geoeffectiveness of full and partial halo CMEs. Protons in the range 1–110 MeV from the ERNE experiment onboard SOHO are used in the analysis. The study covers the time period from August 1996 to July 2000. We demonstrate the feasibility of energetic particle observations as an additional source of information in evaluating the geoeffectiveness of full and partial halo CMEs. Based on the observed onset times of solar energetic particle (SEP) events and energetic storm particle (ESP) events, we derive a proxy for the transit times of shocks driven by the interplanetary counterparts of coronal mass ejections from the Sun to the Earth. For a limited number of geomagnetic storms which can be associated to both SEP and ESP signatures, we found that this transit time correlates with the strength of geomagnetic storms.