大扩张通道超音高载荷对转涡轮动叶三维设计方法研究

 为设计一种SRR结构具有大扩张通道的超音高载荷对转涡轮高压动叶，论文提出了一种更符合三维真实流动状态的S1流面三维造型法，详细阐述了三维造型方法基本原理，并用之设计了一个出口马赫数1.33，通道扩张角37.3°的超音高载荷对转涡轮动叶。三维数值模拟结果显示对转涡轮动叶流场参数分布合理，没有出现分离，滞止效率达到92.57%。实例表明三维造型法由于充分考虑涡轮流场三维性，对于通道扩张度大，流线曲率变化剧烈的涡轮叶片，比传统二维柱面造型法更精确、更实效。     

氪气和氙气中四氟化碳杂质分析

介绍了CF4定性定量分析方法,探讨了CF4的来源及清除.     

Deep Impact: The Anticipated Flight Data

A comprehensive observational sequence using the Deep Impact (DI) spacecraft instruments (consisting of cameras with two different focal lengths and an infrared spectrometer) will yield data that will permit characterization of the nucleus and coma of comet Tempel 1, both before and after impact by the DI Impactor. Within the constraints of the mission system, the planned data return has been optimized. A subset of the most valuable data is planned for return in near-real time to ensure that the DI mission success criteria will be met even if the spacecraft should not survive the comet’s closest approach. The remaining prime science data will be played back during the first day after the closest approach. The flight data set will include approach observations spanning the 60 days prior to encounter, pre-impact data to characterize the comet at high resolution just prior to impact, photos from the Impactor as it plunges toward the nucleus surface (including resolutions exceeding 1 m), sub-second time sampling of the impact event itself from the Flyby spacecraft, monitoring of the crater formation process and ejecta outflow for over 10 min after impact, observations of the interior of the fully formed crater at spatial resolutions down to a few meters, and high-phase lookback observations of the nucleus and coma for 60 h after closest approach. An inflight calibration data set to accurately characterize the instruments’ performance is also planned. A ground data processing pipeline is under development at Cornell University that will efficiently convert the raw flight data files into calibrated images and spectral maps as well as produce validated archival data sets for delivery to NASA’s Planetary Data System within 6 months after the Earth receipt for use by researchers world-wide.     

电离层峰下结构的数值模拟

在考虑由扩散与中性风引起的动力学输运与有原子离子Ｏ＾＋（＾４Ｓ），Ｏ＾＋（＾２Ｄ）与Ｏ＾＋（＾２Ｐ）以及分子离子Ｏ２＾＋，ＮＯ＾＋，Ｎ２＾＋参加光化学反应的电离层－热层体系中，提出一个一维时变的电离层剖面数值模型，通过数值计算着重讨论了武昌地区Ｆ２层峰以下，尤其是Ｅ／Ｆ与Ｆ１／Ｆ２谷区的电离层形态与有关过程，得到如下结论：（１）对于原子离子，单一成分Ｏ＾＋（＾４Ｓ）的光化学反应与输运，也有助于形成     

嫦娥一号卫星紫外月球敏感器

探月工程是我国航天领域的又一项重大工程项目,嫦娥一号卫星是探月工程的第一步。嫦娥一号卫星首次采用了一种全新的光学姿态敏感器——紫外月球敏感器,实现在卫星环月飞行期间的姿态测量任务。紫外月球敏感器是一种以月球为姿态参考源的大视场成像式光学姿态敏感器,本文介绍其工作原理、功能与组成以及在轨飞行试验的相关情况。     

面向任务的单武器系统平均修复时间模型

平均修复时间(MTTR,Mean Time To Repair)作为一个重要的维修性定量指标,目前其预计方法及算法立足于大量的试验结果和经验估计.通过对任务—装备—维修组成的面向任务的队列模型的研究,将任务需求、武器系统的可靠性及维修性综合考虑,针对故障率和修复率均服从指数分布的可修系统,建立了一种基于M/G/1可修排队模型的武器系统MTTR的模型,并给出了定量预计方法.此模型符合基于可靠性基础上的维修理论的基本结论,避免了设计初期对大量维修统计数据的依赖,为订购方在装备采购中提出维修性定量的要求提供了依据.      

便携式多功能校准仪在专用测试设备现场校准中的应用

航天工程专用测试设备具有系统复杂、参数多、不易移动的特点,常用校准方法复杂度高、效率低、成本高。为保证航天工程科研生产的顺利进行,专用测试设备的准确可靠及可溯源性越来越受到研制、生产和使用方的重视,并介绍了五种常用的专用测试设备校准方法。并针对目前常用校准方法的不足,提出将便携式多功能校准仪应用在专用测试设备现场校准的新方法,给出了不确定度分析。     

Severe disruption of the cytoskeleton and immunologically relevant surface molecules in a human macrophageal cell line in microgravity—Results of an in vitro experiment on board of the Shenzhou-8 space mission

During spaceflight the immune system is one of the most affected systems of the human body. During the SIMBOX (Science in Microgravity Box) mission on Shenzhou-8, we investigated microgravity-associated long-term alterations in macrophageal cells, the most important effector cells of the immune system. We analyzed the effect of long-term microgravity on the cytoskeleton and immunologically relevant surface molecules. Human U937 cells were differentiated into a macrophageal phenotype and exposed to microgravity or 1g on a reference centrifuge on-orbit for 5 days. After on-orbit fixation, the samples were analyzed with immunocytochemical staining and confocal microscopy after landing. The unmanned Shenzhou-8 spacecraft was launched on board a Long March 2F (CZ-2F) rocket from the Jiuquan Satellite Launch Center (JSLC) and landed after a 17-day-mission. We found a severely disturbed actin cytoskeleton, disorganized tubulin and distinctly reduced expression of CD18, CD36 and MHC-II after the 5 days in microgravity. The disturbed cytoskeleton, the loss of surface receptors for bacteria recognition, the activation of T lymphocytes, the loss of an important scavenger receptor and of antigen-presenting molecules could represent a dysfunctional macrophage phenotype. This phenotype in microgravity would be not capable of migrating or recognizing and attacking pathogens, and it would no longer activate the specific immune system, which could be investigated in functional assays. Obviously, the results have to be interpreted with caution as the model system has some limitations and due to numerous technical and biological restrictions (e.g. 23 °C and no CO₂ supply during in-flight incubation). All parameter were carefully pre-tested on ground. Therefore, the experiment could be adapted to the experimental conditions available on Shenzhou-8.     

空间目标距离像畸变分析及运动参数估计

针对卫星目标的宽带雷达回波信号,从理论上详细分析了目标运动产生的多项式相位模型,指出三次以上的相位对一维距离像的畸变可以忽略。以频谱主瓣的展宽程度为判据,推导了二次相位需补偿时的目标速度边界条件。结果表明,在典型参数条件下卫星目标的径向速度远大于该临界速度（约560m/s）,需在成像前予以补偿。最后,结合雷达目标散射中心的稀疏分布特性,提出了基于L1范数的空间目标运动参数估计算法。结果表明,该算法对速度的估计误差接近克拉美-罗下界,且远小于临界速度,可用于卫星目标成像。     

定向片模型描述的“天绘一号”卫星影像区域网平差

针对三线阵相机的成像特点,文章利用卫星辅助数据建立了"天绘一号"卫星三线阵影像的严密成像模型,在常规定向片模型描述外方位元素变化特征的基础上,考虑定向片间的连续平滑制约条件,并将其引入摄影测量光束法平差中,从而构建"天绘一号"卫星三线阵影像光束法平差模型,最后利用真实影像数据进行实验验证。结果表明,在一定数量地面控制点参与条件下,合适的定向片数目选取并顾及定向片间的连续平滑制约条件,检查点能够达到平面方向约为1.5个像元、高程方向优于1个像元的定位精度,验证了该文所建模型的正确性和有效性。