Production of high fidelity lunar agglutinate simulant

As space faring nations consider manned and unmanned missions to the Moon, there is a growing need to develop high fidelity lunar regolith simulants that can accurately reproduce the properties and behavior of lunar regolith. Such simulants will be employed to verify the performance of equipment, mechanisms, structures and processes to be used on the lunar surface. One of the significant limitations of current terrestrial-based simulants, such as the popular mare simulant, JSC-1A, is the lack of agglutinates. This paper investigates the production of a lunar mare agglutinate simulant based on JSC-1A. A modified plasma processing technique was used to expose the JSC-1A regolith simulant to high temperatures and transform it to predominantly a glassy phase. Detailed characterization results are presented to confirm that the agglutinate simulant material produced during this investigation reasonably satisfies the primary requirements of an agglutinate simulant such as amorphous/crystalline content, particle size, morphology, vesicular structure, chemistry, and presence of nanophase elemental Fe.     

Comparing ionospheric models with mid-latitude ionosonde observations

The purpose of this research work is to validate the ionospheric models (IRI and CHIU) to assess its suitability and usefulness as an operational tool. The ionospheric model is a computer model designed to predict the state of the global ionosphere for 24 h. The scope was limited to conduct comparisons between the predicted F₂ layer critical frequencies (f₀F₂) against observed ionosonde data. The ionospheric prediction model (IPM) was designed to predict by using monthly median sunspot number, while the observation data are taken from two digital ionospheric sounding stations (Okinawa, 26.28N, 127.8E and Wakkanai, 45.38N, 141.66E) which lies within the mid-latitude region of the globe. Analysis of the f₀F₂ data from stations for year (2001) with high solar activity and year (2004) with low solar activity, four months (March, June, September and December) chosen based primarily on data availability. From results it seen that the ratio between monthly median predicted and observed f₀F₂ values for each model used in this research work and for the chosen months was nonlinear with local time, so the empirical formula for applying correction factors were determined, these formula can be used to correct the error occurred in predicted f₀F₂ value.     

会议筹备优化设计

根据代表回执的住房要求数据,通过曲线拟合估计出本届与会代表人数,定义了距离数量指标和代表满意数量指标,并对指标赋予权重,再利用线性规划,建立优化模型,得到应预定的宾馆及每个宾馆应预定的房间;对会议室的租借问题,将各分组会议分为三个级别,并根据其重要性赋予相应的权重,再结合与会代表总人数,求得各级别会议的与会代表人数,选定会议室;对租车方案,以租车总费用最少为目标函数,以租借三种类型作为约束条件,建立优化模型,利用Lingo软件编程求解。     

T cell regulation in microgravity – The current knowledge from in vitro experiments conducted in space,parabolic flights and ground-based facilities

Dating back to the Apollo and Skylab missions, it has been reported that astronauts suffered from bacterial and viral infections during space flight or after returning to Earth. Blood analyses revealed strongly reduced capability of human lymphocytes to become active upon mitogenic stimulation. Since then, a large number of in vitro studies on human immune cells have been conducted in space, in parabolic flights, and in ground-based facilities. It became obvious that microgravity affects cell morphology and important cellular functions. Observed changes include cell proliferation, the cytoskeleton, signal transduction and gene expression. This review gives an overview of the current knowledge of T cell regulation under altered gravity conditions obtained by in vitro studies with special emphasis on the cell culture conditions used. We propose that future in vitro experiments should follow rigorous standardized cell culture conditions, which allows better comparison of the results obtained in different flight- and ground-based experiment platforms.     

Adaptive Square-Root Cubature–Quadrature Kalman Particle Filter for satellite attitude determination using vector observations

A novel algorithm is presented in this study for estimation of spacecraft?s attitudes and angular rates from vector observations. In this regard, a new cubature–quadrature particle filter (CQPF) is initially developed that uses the Square-Root Cubature–Quadrature Kalman Filter (SR-CQKF) to generate the importance proposal distribution. The developed CQPF scheme avoids the basic limitation of particle filter (PF) with regards to counting the new measurements. Subsequently, CQPF is enhanced to adjust the sample size at every time step utilizing the idea of confidence intervals, thus improving the efficiency and accuracy of the newly proposed adaptive CQPF (ACQPF). In addition, application of the q-method for filter initialization has intensified the computation burden as well. The current study also applies ACQPF to the problem of attitude estimation of a low Earth orbit (LEO) satellite. For this purpose, the undertaken satellite is equipped with a three-axis magnetometer (TAM) as well as a sun sensor pack that provide noisy geomagnetic field data and Sun direction measurements, respectively. The results and performance of the proposed filter are investigated and compared with those of the extended Kalman filter (EKF) and the standard particle filter (PF) utilizing a Monte Carlo simulation. The comparison demonstrates the viability and the accuracy of the proposed nonlinear estimator.     

多相流环境下绝热材料烧蚀试验方法研究

为深入了解高温多相流环境中绝热材料烧蚀规律，以氧-煤油烧蚀试验系统为基础，采用氧化硼(B2O3)粉末为添加粒子，发展了一种用于绝热材料烧蚀性能测试的新方法，并进行了验证测试。结果表明：氧-煤油烧蚀试验系统的温度为500~2700 K，射流速度为200~1500 m/s，可通过调整燃烧室压力、烧蚀距离和粒子浓度等参数适应各种烧蚀工况；B2O3颗粒在高温射流中发生熔化、蒸发等相变，可用于模拟火箭发动机中的凝聚相粒子；验证试验中绝热材料的烧蚀率和烧蚀规律与其他多相流烧蚀试验结果相近。结果证明该装置可用于开展多相流环境下绝热材料烧蚀试验研究。     

基于BU-61580的MIL-STD-1553B远程终端设计

介绍了MIL-STD-1553B总线和BU-61580芯片的特点,给出了基于BU-61580的MIL-STD-1553B远程终端设计思路和方法。最后结合工程实际给出了利用单片机MS1210Y5对BU-61580的初始化、接收、发送过程。     

基于相空间重构的f_0F_2一步预测算法研究

利用低纬度地区某垂测站2005年3月和4月两个月,f0F2参数共5856个数据样奉,对提前15min的一步预测算法进行了研究.基于混沌时间序列的相空间重构方法,以相近邻点轨迹具有相似性为预测理论基础,采用k最近邻点的方法对下一时刻的,f0F2进行预测.对邻点个数的选取采用了训练法和自适应选择法,对选出的邻点采用平均法和自回归两种方法进行处理,并对几种不同方法的预测结果进行了比较.结果证明,基于相空间重构的一步预测算法预测精度较高,并且容易实现,运算速度高,适用于电离层参数准实时预报.     

一种用于实时轨道确定的NPF-SRCKF滤波算法

针对航天器实时轨道确定中建模复杂、计算量大、估计精度低的问题,设计了一种考虑地球J 2 摄动影响的基于NPF-SRCKF的实时轨道确定算法,该算法采用非线性预测滤波(NPF)对模型误差进行补偿修正,利用平方根容积卡尔曼滤波(SRCKF)算法对修正模型误差后的系统进行状态估计。针对单测站、双测站跟踪测量设计了不同的实时轨道确定算法。实验结果显示,将非线性预测滤波和平方根容积卡尔曼滤波结合在一起,运用于简化的实时轨道确定模型,能有效降低计算复杂度,改进数值运算的稳定性,提高状态估计的精度。     

基于傅里叶变换的HY-1B卫星影像条带噪声去除

HY-1B卫星是中国第二颗海洋遥感卫星,水色水温扫描仪（COCTS）是其主要载荷。文章针对COCTS图像条带噪声的特点,采用傅里叶变换方法,设计了一种新的滤波器,对图像进行条带噪声去除．并同传统的低通滤波方法处理结果进行比较。实验结果表明,新的傅里叶变换方法能够有效地去除图像的条带噪声,其去除效果要优于传统的低通滤波方法。