Heterogeneous solid/gas chemistry of organic compounds related to comets,meteorites, Titan,and Mars: Laboratory and in lower Earth orbit experiments

To understand the evolution of organic molecules involved in extraterrestrial environments and with exobiological implications, many experimental programs in the laboratory are devoted to photochemical studies in the gaseous phase as well as in the solid state. The validity of such studies and their applications to extraterrestrial environments can be questioned as long as experiments conducted in space conditions, with the full solar spectrum, especially in the short wavelength domain, have not been implemented. The experiments that are described here will be carried out on a FOTON capsule, using the BIOPAN facility, and on the International Space Station, using the EXPOSE facility. Vented and sealed exposition cells will be used, which will allow us to study the chemical evolution in the gaseous phase as well as heterogeneous processes, such as the degradation of solid compounds and the release of gaseous fragments.     

An estimation of the cooling process by infrared radiation in the atmosphere

Two procedure are presented for quantitative estimation of cloud cover (N), type of clouds (C), as well as base of clouds (C_b) and top of clouds (C^t) by using radiosonde data as well as satellite cloud pictures and radiation data. The data obtained in this way can be used as input data in the model for the estimation of the vertical profile of longwave radiative cooling.     

Low cost training in remote sensing applications for developing countries

This presentation introduces the Polish Remote Sensing Centre /OPOLiS/, which offers various types of training possibilities in remote sensing techniques and applications. It deals with a wide range of applications and experiences reached by OPOLiS for various branches of national economy, as well as introduction to analog and digital satellite data processing possibilities with the existing equipment.The offered training possibilities include analog and digital data handling and its interpretation such as visual and computer assisted integration of multiple data sets, as well as image processing, enhancements, mosaics etc.It also includes training and applications of interpretations results for exploration of minerals, energy, and ground water resources, as well as inventories, monitoring and forecasting for agriculture, forest, and natural environmental purposes.The cost factor of the offered training possibilities includes a reasonable input from the Polish Government, which results in low cost input by the participants from developing countries. It also accepts the participation fee in non - convertible currency.     

On the dynamics of the heliosphere on intermediate and long time-scales

A time-dependent, three-dimensional model of the dynamics of the heliosphere as a result of solar activity and a time-varying local interstellar medium is presented. The model is based on a recent version of the well known ZEUS code and employs parallel processing. It includes the solar and interstellar plasma components as well as neutral atoms, and contains the heliospheric magnetic field in a kinematic fashion. We study the dynamics of the heliosphere due to solar activity on periods of months to years up to the so-called Schwabe (11-year) cycle as well as due to time variations of the local interstellar medium, all of which have drawn increasing attention during recent years, as the significance of their direct or indirect effect on the Earth and its environment is under lively debate.     

我国氢钟研制现状与用于卫星导航的可行性

介绍了我国氢钟的研制现状以及国产氢钟的应用情况 ,指出它们在我国卫星导航系统的潜在应用前景。对目前氢钟小型化国内外研究现状 ,我国进行星载氢钟的研制方案 ,拟解决的关键问题的可行性分析进行了论述。同时给出了星载氢钟的预期性能指标和应用前景     

Recent developments in ultraviolet filters and coatings

A number of new high efficiency optical coatings have recently been developed at wavelengths in the ultraviolet and vacuum ultraviolet for use in space science experiments. The development of these coatings has resulted in the design and manufacture of wavelength selective filters used in reflectance at near normal incidence that have high VUV reflectance with little near-UV and visible reflectance. Very narrow band transmission filters are now available at wavelengths as short as 1500Å with bandwidths as narrow as 35–40Å. In addition, high efficiency anti-reflection coatings as well as neutral density filters are now available at many wavelengths in this region.Material limitations, more severe than those in the visible, place certain restrictions on the size, wavelength, and degree of selectivity that is achievable with present technology. A summary of the current commercial technology along with the material limitations is presented.     

Effect of gravity field on the nonequilibrium/nonlinear chemical oscillation reactions.

Biological systems have evolved for a long time under the normal gravity. The Belousov-Zhabotinsky (BZ) reaction is a nonlinear chemical system far from the equilibrium that may be considered as a simplified chemical model of the biological systems so as to study the effect of gravity. The reaction solution is comprised of bromate in sulfuric acid as an oxidizing agent, 1,4-cyclohexanedione as an organic substrate, and ferroin as a metal catalyst. Chemical waves in the BZ reaction-diffusion system are visualized as blue and red patterns of ferriin and ferroin, respectively. After an improvement to the tubular reaction vessels in the experimental setup, the traveling velocity of chemical waves in aqueous solutions was measured in time series under normal gravity, microgravity, hyper-gravity, and normal gravity using the free-fall facility of JAMIC (Japan Microgravity Center), Hokkaido, Japan. Chemical patterns were collected as image data via CCD camera and analyzed by the software of NIH image after digitization. The estimated traveling velocity increased with increasing gravity as expected. It was clear experimentally that the traveling velocity of target patterns in reaction diffusion system was influenced by the effect of convection and correlated closely with the gravity field.     

The MELISSA pilot plant facility as as integration test-bed for advanced life support systems.

The different advances in the Micro Ecological Life Support System Alternative project (MELISSA), fostered and coordinated by the European Space Agency, as well as in other associated technologies, are integrated and demonstrated in the MELISSA Pilot Plant laboratory. During the first period of operation, the definition of the different compartments at an individual basis has been achieved, and the complete facility is being re-designed to face a new period of integration of all these compartments. The final objective is to demonstrate the potentiality of biological systems such as MELISSA as life support systems. The facility will also serve as a test bed to study the robustness and stability of the continuous operation of a complex biological system. This includes testing of the associated instrumentation and control for a safe operation, characterization of the chemical and microbial safety of the system, as well as tracking the genetic stability of the microbial strains used. The new period is envisaged as a contribution to the further development of more complete biological life support systems for long-term manned missions, that should be better defined from the knowledge to be gained from this integration phase. This contribution summarizes the current status of the Pilot Plant and the planned steps for the new period.     

空间薄膜结构刚柔耦合非线性动力学分析

空间薄膜结构经历大范围刚体运动时,刚柔高度耦合的非线性动态响应极易发生,这将会降低结构几何精度,甚至影响设备正常工作.针对平面张拉式空间薄膜天线,建立了大范围运动的空间薄膜天线刚柔耦合非线性动力学有限元模型,描述了二阶效应与刚柔耦合效应对结构刚度特性、阻尼特性以及载荷的作用.通过对模型的数值解算,讨论了刚体运动规律(初...     

Formation of oligopeptides on the surface of small bodies in solar system by cosmic radiation.

The present experiment indicates that oligopeptides are easily produced in solid state from mixtures of simple amino acids by irradiating with high energy charged particles. We investigated such amino acids and their mixtures as tryptophan, tyrosine and glycine. The thin films was irradiated with protons (6.6 MeV). Such dipeptides as Trp-Trp, Gly-Tyr, Tyr-Gly, and Tyr-Tyr have been detected as products of irradiation. Cosmic rays might be an effective energy source for abiotic formation of bioorganic compounds on the surface of small bodies in the solar system on early stage of formation of planets as well as at present day.     

Modeling ground and space based cosmic ray observations

After entering our local astrosphere (called the heliosphere), galactic cosmic rays, as charged particles, are affected by the Sun’s turbulent magnetic field. This causes their intensities to decrease towards the inner heliosphere, a process referred to as modulation. Over the years, cosmic ray modulation has been studied extensively at Earth, utilizing both ground and space based observations. Moreover, modelling cosmic ray modulation and comparing results with observations, insight can be gained into the transport of these particles, as well as offering explanations for observed features. We review some of the most prominent cosmic ray observations made near Earth, how these observations can be modelled and what main insights are gained from this modelling approach. Furthermore, a discussion on drifts, as one of the main modulation processes, are given as well as how drift effects manifest in near Earth observations. We conclude by discussing the contemporary challenges, fuelled by observations, which are presently being investigated. A main challenge is explaining observations made during the past unusual solar minimum.     

基于人工神经网络的柔性机翼挠度预测

为实现对承载后柔性机翼挠度的准确预测,在全面分析柔性机翼挠度的影响因素基础上,应用正交试验法确定的影响柔性机翼挠度的主要因子作为输入变量,挠度作为输出变量,以大量试验数据为训练样本,通过多次试取隐含层和各隐含单元,并选取trainlm作为最优训练函数,最终建立了预测柔性机翼挠度的BP(Back Propagation)人工神经网络模型.在此基础上,随机选取试验结果中的12组试验样本,连续进行10次挠度预测,预测结果和试验实测值最大相对误差和标准方差分别为4.481%,1.033 7.解析结果表明:柔性机翼挠度预测结果与实验值吻合的较好,建立的人工神经网络预测模型具有较高的预测精度.     

Evolution of activity signatures during the main sequence phase

We review recent work on the decay of magnetic activity signatures, such as chromospheric/transition region/coronal emission as well as mean flare emission, with age for solar and later type stars. Both implicit and explicit evolutionary representations are discussed. In terms of magnetic flux, as measured by excess chromospheric CaII luminosity, we show that a simple dynamo-rotation relation that incorporates both a saturated state with its characteristic critical rotation (or scale factor) as well as an asymptotic linear power law, i.e. a scale free relation, fits the extant data that includes the dMe stars. Introducing the saturated dynamo state, as exemplified by the dMe stars, into activity power-power diagrams, allows us to not only specify the saturated state, but to define evolutionary tracks that represent the decay from the saturated state. Using the quiescent coronal X-ray power (luminosity) as a basic measure of magnetic activity, we find simple monomial relations for both the saturated state (linear) and for the evolutionary tracks governing both quiescent activity and mean flare activity. In particular, the coronal power loss is found to vary quadratically with the chromospheric power loss, hence with magnetic flux.     

Hydrogen cyanide polymers on comets.

The original presence on cometary nuclei of frozen volatiles such as methane, ammonia and water makes them ideal sites for the formation and condensed-phase polymerization of hydrogen cyanide. We propose that the non-volatile black crust of comet Halley consists largely of such polymers. Dust emanating from Halley's nucleus, contributing to the coma and tail, would also arise partly from these solids. Indeed, secondary species such as CN have been widely detected, as well as HCN itself and particles consisting only of H, C and N. Our continuing investigations suggest that the yellow-orange-brown-black polymers are of two types: ladder structures with conjugated -C=N- bonds, and polyamidines readily converted by water to polypeptides. These easily formed macromolecules could be major components of the dark matter observed on the giant planets Jupiter and Saturn, as well as on outer solar system bodies such as asteroids, moons and other comets. Implications for prebiotic chemistry are profound. Primitive Earth may have been covered by HCN polymers either through cometary bombardment or by terrestrial happenings of the kind that brought about the black crust of Halley. The resulting proteinaceous matrix could have promoted the molecular interactions leading to the emergence of life.     

基于在线轨迹迭代的自适应再入制导

针对传统轨迹跟踪制导方法在再入飞行中无法较好适应导航模式切换等突变状况的问题,提出了一种能够有效应对制导系统输入信息不连续性的自适应在线轨迹生成方法。该方法通过实时的多项式拟合以及迭代过程确定满足终端约束条件的高度-速度剖面,并解算出当前飞行状态下所需的攻角与倾侧角指令,从而平稳、精确地将飞行器引导至末端能量管理段。通过对速度与能量、高度、轨迹倾角以及待飞航程等状态量建立解析关系,该方法拥有迭代速度快以及收敛性强的优势。仿真结果显示,该方法对输入信息的误差及跳变等不确定因素的适应性很强,在各类干扰情况下较传统方法拥有更高的制导精度。相较于传统轨迹跟踪制导方法,该方法在实际应用背景下显著地提升了制导的自主性与适应性。      

两种增强泡沫塑料静动态力学性能的比较

通过静、动态压缩实验对两种增强聚氨酯泡沫塑料的压缩力学性能进行了研究，分析了两种材料应力－应变曲线的特点，并比较它们的应变率敏感性和动态加载时的能量吸收特性，实验结果表明：玻璃纤维束增强聚氨酯泡沫塑料具有不同于单丝玻璃纤维增强泡沫塑料的力学性能和变形破坏机制，单丝玻璃纤维增强泡沫塑料具有较好的增强效果。     

控制力矩陀螺驱动的空间机器人轨迹跟踪控制

提出一种新的空间机器人设计概念,并研究其轨迹跟踪控制问题.系统中的各机械臂以自由球铰连接,在机器人平台和每节机械臂上均安装有一组控制力矩陀螺（CMGs,Control Moment Gyroscopes）作为控制力矩执行机构.采用改进的罗格里得斯参数（MRPs,Modified Rodrigues Parameters）描述平台和各节机械臂的姿态,利用Kane方程建立了系统的动力学模型.在此基础上,用逆动力学方法设计了系统的轨迹跟踪控制律,用以实现卫星平台的位置/姿态和机械臂末端作用器位置的轨迹跟踪控制.采用带有零运动的CMGs操纵律以使CMGs准确输出力矩并回避构型奇异.基于两关节机械臂系统和金字塔构型CMGs的数值仿真结果验证了所设计的控制律和操纵律的有效性,以及自由球铰连接方式在提高末端作用器运动自由度和降低系统动力学耦合方面的优越性.      

HP8902A自动检定系统的研制

介绍了以HP8902A测量接收机为主构成信号源、调制测量仪等仪器的自动检定系统，详细讲述了该系统的构成和软件的实现。     

一种高超声速滑翔再入在线轨迹规划算法

为了提高滑翔再入飞行器响应动态任务的能力并提高其制导系统的鲁棒性，建立了高超声速滑翔再入轨迹规划问题的一种在线求解算法。该算法以一列凸子问题来逼近原问题。通过选择以弧长为自变量并引入对数速度代替速度作为状态，使得动力学方程的非线性大为减弱，同时使动压和热流约束完全成为线性约束。通过使用类似于混合整数规划中割平面的思想处理禁飞区约束，尽可能避免了不必要的计算。通过直接以气动系数和大气密度的乘积作为控制量，构造伪线性控制模型，进一步减弱非线性。非凸约束被适当松弛，以保证子问题的可行性。为了避免过度松弛，利用离线给定的高度和速度上下边界估计对应的参数，以加速收敛。以X-33再入任务为例验证了所提算法的有效性。该算法可以以简单的常值函数为初值并在数次迭代后收敛。      

一种保留几何及属性边界的网格简化方法

在实际应用领域,三维模型除包含由三角形网格构成的几何、拓扑信息外,还包含颜色、纹理、法矢量等属性信息,因此数据量较大,且不可避免地存在边界和孔洞.基于三角形折叠的方法,对误差矩阵的计算和误差控制方法进行了改进,并提出了几何及属性边界三角形的概念,给出了一种保留原始模型边界及属性信息的简化算法.该算法针对不同的边界情况将原始三角形网格划分为边界三角形、角点三角形、内部三角形及特征三角形,并采取相应的约束策略,在减小模型数据量的同时,较好地保留了边界和属性信息,并且生成递进网格文件,为包含属性的非封闭网格模型提供了连续多分辨率的模型重现.实验结果证明该方法快速有效,已成功应用于基于Web的三维递进传输和发布.