掺Ce^3＋的碱土氟化物的紫外发光特性研究

研究了掺杂稀土离子Ce^3＋的碱土氟化物发光体LiXAlF6：Ce^3＋（X=Ca^2＋,Sr^2＋或Ba^2＋）,XBaAlF6：Ce^3＋（X=Li6＋,Na^＋或K^＋）及LiBaXF6：Ce^3＋（X=Al^3＋,Ga^3＋或In^3＋）的紫外发光特性。实验发现,在LiXAlF6=Ce^3＋中,随着X元素原子序数的增大,Ce^3＋的发光峰就向短波方向移动。首次研究了在XBaAlF6：Ce^3＋与LiBaXF6：Ce^3＋中的X元素的一价与三价离子对Ce^3＋发光的影响,发现这些一价与三价离子的原子序数的变化并不影响Ce^3＋的发射光谱的峰值,它们只在晶格中起着填隙和电荷补偿作用,这有利于Ce^3＋的发光,使发光强度有所增强。这些紫外发光可用来增强X射线影像板中所包含的储存辐射的发光体BaFBr：Eu“的发光,使X射线影像板的显像增强。     

一种数据残缺时的三星时差定位目标跟踪算法

三星座时差定位是一个非线性定位问题,利用定位点进行跟踪得到目标航迹的方法具有一定的局限性。给出了能够适应大量时差数据残缺情况的基于EKF的目标航迹跟踪算法,仿真分析表明该算法在大量时差数据残缺时具有比前者更好的性能,有效地解决了工程问题。     

MSC．Dytran在坠撞仿真中的应用

介绍了MSC．Dytran在坠撞仿真中的应用。从国外和国内的案例可以看出，用MSC．Dytran能较快较好地解决飞机坠撞问题。     

Protein expression profile changes in human fibroblasts induced by low dose energetic protons

Extrapolation of known radiation risks to the risks from low dose and low dose-rate exposures of human population, especially prolonged exposures of astronauts in the space radiation environment, relies in part on the mechanistic understanding of radiation induced biological consequences at the molecular level. While some genomic data at the mRNA level are available for cells or animals exposed to radiation, the data at the protein level are still lacking. Here, we studied protein expression profile changes using Panorama antibody microarray chips that contain antibodies to 224 proteins (or their phosphorylated forms) involved in cell signaling that included mostly apoptosis, cytoskeleton, cell cycle and signal transduction. Normal human fibroblasts were cultured until fully confluent and then exposed to 2 cGy of 150 MeV protons at high-dose rate. The proteins were isolated at 2 or 6 h after exposure and labeled with Cy3 for the irradiated cells and with Cy5 for the control samples before loading onto the protein microarray chips. The intensities of the protein spots were analyzed using ScanAlyze software and normalized by the summed fluorescence intensities and the housekeeping proteins. The results showed that low dose protons altered the expression of more than 10% of the proteins listed in the microarray analysis in various protein functional groups. Cell cycle (24%) related proteins were induced by protons and most of them were regulators of G1/S-transition phase. Comparison of the overall protein expression profiles, cell cycle related proteins, cytoskeleton and signal transduction protein groups showed significantly more changes induced by protons compared with other protein functional groups.     

空间光学遥感器光机结构材料应用情况及展望

介绍了空间光学遥感器的技术特点,综述了近年来空间光学遥感器光机结构材料的应用状况,对空间光学遥感器的光机结构材料发展趋势进行了展望。     

基于阻力加速度倒数剖面的再入轨迹规划与制导方法

针对升力式飞行器再入制导问题,提出了一种基于阻力加速度倒数剖面的在线解析规划与制导方法。首先将过程和终端约束转换成阻力加速度倒数形式的飞行走廊,采用三次样条函数描述倒数剖面。然后通过解析计算航程上下界,利用待飞航程在倒数剖面内的近似线性关系,以满足待飞航程为目标,迭代计算得到阻力加速度倒数剖面;在飞行过程中根据当前状态和实际待飞航程,周期性更新阻力加速度倒数剖面。通过对阻力加速度剖面的跟踪进行纵向制导,解算倾侧角指令;通过倾侧角反向来进行侧向制导,限制航向角偏差。实现了再入轨迹的在线快速生成与更新,并利用阻力加速度动态特性,将其与跟踪制导结合,提出的方法效率高,适应性强,有工程应用的潜力。     

激光焊接夹层喷管的技术现状

激光焊接冷却通道壁技术是适应商业需要(降低制造费用和缩短开发时间)开发的科研成果.沃尔沃公司(VOLVO)已经研究出其核心技术,即应用于焊接通道壁技术的激光焊接法和X射线辅助连接系统.此项技术最初的开发目的是应用于一次性使用发动机,但是现在发现其应用于可重复使用发动机上也很有优势.使用寿命、热负荷、最小内壁厚度和材料疲劳特性等综合决定了此项技术的适用范围.目前,已经进行了夹层喷管热试,并且制造出了具有典型尺寸的用于演示的夹层喷管.正在研究应用于非再生冷却系统的激光焊接夹层技术.研究成果表明,这项技术可用于各种发动机,即从助推级到上面级均适用.现在,欧洲和美国正在讨论应用此项技术加工Vulcain和RL60发动机的喷管夹层结构.本文对下面内容进行了叙述激光焊接夹层技术概况;目前激光焊接夹层技术在一次性使用发动机上的应用情况;可重复使用发动机用激光焊接夹层技术的一些特性.     

TypeⅡ试验下ε（λ,μ）分布位置参数的EB估计

讨论了在ＴｙｐｅⅡ（无替换定数截尾）试验方案下，当产品寿命为双参数指数分布时，位置参数μ的经验Ｂａｙｅｓ（简记ＥＢ）估计及其收敛速度问题。设受试验产品有ｎ个，试验中前ｒ个产品依次出现的失效时间为     

Up-to-date observations of space energetic particles made by the Chinese satellite Fengyun-1 (B).

This paper presents the observational results of space energetic particles obtained by the Cosmic Ray Composition Monitor (CRCM) onboard the Chinese satellite, Fengyun-1(B). These results, including those of a few solar proton events, the geomagnetically trapped particles and the anomalous cosmic ray components, were obtained from 3 September 1990 to 15 February 1991. The observed elements include H, He, C, N, O and Fe of energies from 4-23 MeV/u. It was found that the proton fluxes of the inner Radiation Belt (IRB) increased obviously during the period of solar proton event (SPE). A few kinds of heavy ions (Z > or = 6) were also detected in the IRB. As to the anomalous cosmic ray component (ACRC), in addition to C, N and O, anomalous iron particles were also recorded.