第九届全国日地空间物理学术讨论会

由空间物理专业委员会主办的第九届全国日地空间物理学术讨论会将于今年10月在山东曲阜召开,涉及内容有:空间物理各分支学科的科研成果,空间物理发展动向,空间天气和空间环境的理论和应用研究,发展我国空间物理的措施和发展方向的建议,有关空间探测方案、仪器设计、探测方法和原理的概念研究.     

基于脑电信号相位传递熵的谎言机制研究

说谎是复杂的认知过程,其执行控制功能需要不同脑区的共同参与,相关研究证实了这些脑区之间存在相互作用。针对当前脑电信号特征提取方法有限及谎言机制尚不明确的问题,利用相位传递熵构建了谎言实验过程中脑电信号的脑网络,并分析了诚实组和说谎组不同脑区间的效应连接差异。采用标准的三刺激实验模式对60名受试者进行说谎检测实验,同步采集所有受试者的脑电信号并进行预处理;利用相位传递熵构建效应连接矩阵,通过统计方法对矩阵中的每一条边进行2组间的熵值差异分析,选取具有显著性差异的导联对上的熵值作为全连接神经网络的分类特征,结果显示,分类准确率为96.75%,说明相位传递熵指标可以有效区分说谎者和诚实者2类人群的脑电信号;对2类人群大脑功能网络的分析结果显示,与诚实者相比,说谎类人群的额叶、顶叶和颞叶之间存在更强的信息流动,表明说谎行为需要协调和使用更多的大脑资源。研究结果有助于揭示说谎状态下大脑的神经活动机制。      

幅度调制稳态听觉刺激脑电信号响应及选择性注意力分析

闭锁症患者不能自主控制眼球运动，无法使用视觉刺激脑-机接口（BCI）技术实现意识交流，听觉刺激脑-机接口技术不受视觉限制，可实现这类患者的意识交流，具有重要意义。首先，对不同受试者在幅度调制频率变化的听觉诱发刺激下的响应特征进行研究，获得人体大脑听觉通频带的幅频特性。然后，基于受试者的听觉通频带频率特征，设计了全新的听觉选择注意力实验范式，选择响应幅值较强的刺激频率作为受试者的刺激频率，并提出了改进的空间相干脑电（EEG）信号解算方法，提高了算法的鲁棒性，获得了相对更高的准确率，受试者通过注意力选择实现脑-机接口的二分类控制。实验获得了不同受试者的大脑听觉通频带频率特征，得到了人体大脑在35~94 Hz调制频率范围内的听觉幅频特性曲线，发现了响应幅值在35~44 Hz调制频率范围最强。利用改进的空间相干算法，将提出的基于通频带特征的实验范式和固定频率组合的实验范式进行比较，由3名受试者的对比实验表明，所提实验范式和改进的空间相干算法获得了更高的准确率。      

学术动态

中国空间科学学会成立20周年纪念会今年是中国空间科学学会成立20周年，届时将举办隆重的纪念及庆祝活动．时间定于10月，地点为北京，规模150－200人．第九届全国日地空间物理学术讨论会由空间物理专业委员会主办的第九届全国日地空间物理学术讨论会将于今年10月在山东曲阜召开，涉及内容有：空间物理各分支学科的科研成果，空间物理发展动向，空间天气和空间环境的理论和应用研究，发展我国空间物理的措施和发展方向的建议，有关空间探测方案、仪器设计、探测方法和原理的概念研究．空间探测第十三次学术会议由空间探测专业委员会主办的空…     

脑-机接口技术在载人航天任务中的应用研究

1脑-机接口技术概述
　　脑-机接口技术概念
　　脑-机接口（BCI）是以脑电信号或其他相关技术为基础，将大脑活动特征转化为预定义的命令，从而实现与外界交流或者控制其他外部设备的先进技术，是一种不依赖身体肌肉组织系统和控制神经系统的新型智能接口技术。因此，我们可以把BCI定义为一个非肌肉通信系统，它可以使人体的大脑意图和外界环境进行直接的沟通交流，在计算机和大脑之间建立一个新的通信通道。     

大型低温抽气技术

大型低温抽气技术是大型空间环境试验中获得真空的主要手段，在真空科学与技术中是发展最快的一项技术，文章对大型低温抽气技术的原理和理论计算方法进行了研究探讨，并利用改进和计算方法对KM6大型空间环境试验设备中的低温抽气设备进行了理论计算和优化设计，取得了满意的结果。     

基于先进量子测量技术的雷达发展动态

传统雷达方案是基于电磁波信号传输理论,通过探测空间中物体反射的电磁波回波信号,来实现目标定位及其他参数的测量。相比于传统雷达方案,量子技术框架下的量子雷达方案旨在提高雷达探测精度和反应速度,同时在抗干扰能力和反隐身功能等方面也具有更加明显的优势。该雷达发展动态研究阐述了量子技术的原理、发展及量子测量技术在雷达中的应用研究动态,着重叙述国内现有最新基于先进量子测量技术的三种量子雷达技术方案,通过案例分析其原理,为未来量子雷达的进一步发展提供可以借鉴的新思路。     

拓扑数据分析在复杂脑网络分析中的应用

针对复杂脑网络分析中网络结构变化阈值选择中没有公认的标准确定合适阈值这一问题，基于拓扑分析中的持续同调性理论，本文提出一种多尺度大脑网络建模分析方法，该方法在大脑全尺度距离范围之内，通过不断增加阈值，运用Rips过滤算法捕获网络的动态持续拓扑特征，并用条形码和持续图对拓扑特征可视化，最后通过计算持续图之间的Bottleneck距离和Wasserstein距离分析持续特征的稳定性。实验结果表明，该方法能更准确地提取大脑网络的拓扑结构特征并提高诊断分类的准确性。     

基于类脑模型与深度神经网络的目标检测与跟踪技术研究

目标检测与跟踪技术广泛应用于交通、医疗、安保和航天等领域.目前，目标检测与跟踪技术面临目标微弱、背景复杂、目标被遮挡等挑战.同时，随着脑科学研究的不断深入，人们对人脑视觉系统的理解逐渐透彻，利用类脑计算解决复杂背景下高精度目标检测与跟踪问题成为相关领域的重要研究方向.本文结合神经工程导向的类脑模型和计算机工程导向的深度神经网络(Deep Neural Networks, DNNs)，提出多种基于类脑模型与深度神经网络的目标检测与跟踪算法，包括：基于演算侧抑制的目标检测算法，基于结构 对比度(Structure Contrast, SC)视觉注意模型的弱小目标检测算法和基于记忆机制与分层卷积特征的目标跟踪算法.实验结果表明，将类脑模型和深度神经网络应用于目标检测和跟踪领域，有利于实现复杂条件下的高精度目标检测和鲁棒性目标跟踪.     

太空行走时间最长纪录

据光明网-光明日报，由英国和德国等国家的一批世界顶尖级神经系统科学家组成的一个研究小组已经研制出能够洞察人脑、解读出人在“事成”前之“心想”的大脑扫描仪。这些科学家用高清晰脑扫描仪对人脑进行扫描，用计算机找出人脑活动的独特模式或不同思维活动的独特信号，然后扫描大脑寻找这些信号，再将扫描到的信息转化为具体的思维，从而解读出一个人想要干什么。这是科学家们第一次以这种方式成功解读人的思维。     

Exobiology research on Space Station Freedom.

The Gas-Grain Simulation Facility (GGSF) is a multidisciplinary experiment laboratory being developed by NASA at Ames Research Center for delivery to Space Station Freedom in 1998. This facility will employ the low-gravity environment of the Space Station to enable aerosol experiments of much longer duration than is possible in any ground-based laboratory. Studies of fractal aggregates that are impossible to sustain on Earth will also be enabled. Three research areas within exobiology that will benefit from the GGSF are described here. An analysis of the needs of this research and of other suggested experiments has produced a list of science requirements which the facility design must accommodate. A GGSF design concept developed in the first stage of flight hardware development to meet these requirements is also described.     

The gravitational field and brain function.

The frontal cortex is recognized as the highest adaptive control center of the human brain. The principle of the "frontalization" of human brain function offers new possibilities for brain research in space. There is evolutionary and experimental evidence indicating the validity of the principle, including it's role in nervous response to gravitational stimulation. The gravitational field is considered here as one of the more constant and comprehensive factors acting on brain evolution, which has undergone some successive crucial steps: "encephalization", "corticalization", "lateralization" and "frontalization". The dominating effects of electrical responses from the frontal cortex have been discovered 1) in experiments under gravitational stimulus; and 2) in processes potentially relating to gravitational adaptation, such as memory and learning, sensory information processing, motor programing, and brain state control. A brain research experiment during space flight is suggested to test the role of the frontal cortex in space adaptation and it's potentiality in brain control.     

Life sciences flight hardware development for the International Space Station.

During the construction phase of the International Space Station (ISS), early flight opportunities have been identified (including designated Utilization Flights, UF) on which early science experiments may be performed. The focus of NASA's and other agencies' biological studies on the early flight opportunities is cell and molecular biology; with UF-1 scheduled to fly in fall 2001, followed by flights 8A and UF-3. Specific hardware is being developed to verify design concepts, e.g., the Avian Development Facility for incubation of small eggs and the Biomass Production System for plant cultivation. Other hardware concepts will utilize those early research opportunities onboard the ISS, e.g., an Incubator for sample cultivation, the European Modular Cultivation System for research with small plant systems, an Insect Habitat for support of insect species. Following the first Utilization Flights, additional equipment will be transported to the ISS to expand research opportunities and capabilities, e.g., a Cell Culture Unit, the Advanced Animal Habitat for rodents, an Aquatic Facility to support small fish and aquatic specimens, a Plant Research Unit for plant cultivation, and a specialized Egg Incubator for developmental biology studies. Host systems (Figure 1A, B: see text), e.g., a 2.5 m Centrifuge Rotor (g-levels from 0.01-g to 2-g) for direct comparisons between g and selectable g levels, the Life Sciences Glovebox for contained manipulations, and Habitat Holding Racks (Figure 1B: see text) will provide electrical power, communication links, and cooling to the habitats. Habitats will provide food, water, light, air and waste management as well as humidity and temperature control for a variety of research organisms. Operators on Earth and the crew on the ISS will be able to send commands to the laboratory equipment to monitor and control the environmental and experimental parameters inside specific habitats. Common laboratory equipment such as microscopes, cryo freezers, radiation dosimeters, and mass measurement devices are also currently in design stages by NASA and the ISS international partners.     

Space Life Science of China

With the human space exploration activities, space life science is an emerging interdiscipline, which covers a wide range of researches. Based on our country's manned space station and recoverable satellite science experimental platform, the development of space life science research is very important to acquire new knowledge or new technological innovation, to give further services to the human space exploration activities, to improve the national economic and social development. Both ground-based and flight applied studies were continuously performed in the previous 2 years. Here, we review and summarize the researches on space life sciences contributed by Chinese scientists.      

Achievements of Space Scientific Experiments Aboard SJ-8 Satellite

As scientific experiment payloads, microgravity experiments of fluid physics, life science,combustion science, physics and accelerator measurement were conducted on board the Chinese recoverable satellite SJ-8 during 18-day orbital flight. The experimental payloads and an experiment support system constituted the microgravity experiment system of the flight mission. This article has presented the briefs of the scientific achievements of these space experiments, the composition and performance of the Microgravity Experimental System (MES) and the general picture of the overall flight mission, respectively.      

CREAM: 70 days of flight from 2 launches in Antarctica

The Cosmic-Ray Energetics And Mass balloon-borne experiment has been launched twice in Antarctica, first in December 2004 and again in December 2005. It circumnavigated the South Pole three times during the first flight, which set a flight duration record of 42 days. A cumulative duration of 70 days within 13 months was achieved when the second flight completed 28 days during two circumnavigations of the Pole on 13 January 2006. Both the science instrument and support systems functioned extremely well, and a total 117 GB of data including 67 million science events were collected during these two flights. Preliminary analysis indicates that the data extend well above 100 TeV and follow reasonable power laws. The payload recovered from the first flight has been refurbished for the third flight in 2007, whereas the payload from the second flight is being refurbished to be ready for the fourth flight in 2008. Each flight will extend the reach of precise cosmic-ray composition measurements to energies not previously possible.     

Changes in the central nervous system during long-duration space flight: implications for neuro-imaging.

The purpose of this paper is to review the potential functional and morphological effects of long duration space flight on the human central nervous system (CNS) and how current neuroimaging techniques may be utilized to study these effects. It must be determined if there will be any detrimental changes to the CNS from long term exposure to the space environment if human beings are to plan interplanetary missions or establish permanent space habitats. Research to date has focused primarily on the short term changes in the CNS as the result of space flight. The space environment has many factors such as weightlessness, electromagnetic fields, and radiation, that may impact upon the function and structure of the CNS. CNS changes known to occur during and after long term space flight include neurovestibular disturbances, cephalic fluid shifts, alterations in sensory perception, changes in proprioception, psychological disturbances, and cognitive changes. Animal studies have shown altered plasticity of the neural cytoarchitecture, decreased neuronal metabolism in the hypothalamus, and changes in neurotransmitter concentrations. Recent progress in the ability to study brain morphology, cerebral metabolism, and neurochemistry in vivo in the human brain would provide ample opportunity to investigate many of the changes that occur in the CNS as a result of space flight. These methods include positron emission tomography (PET), single photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI).     

簇飞行网络雷达几何构型对模糊函数的影响

提出了集分离航天器与网络雷达为一体的簇飞行网络雷达概念.通过引入双基地雷达模糊函数，给出簇飞行网络雷达模糊函数定义和计算步骤，研究了雷达几何构型和簇飞行雷达之间相对有界基线对模糊函数的影响.数值计算结果表明:与单基地雷达模糊函数相比，网络雷达模糊函数主瓣宽度明显变窄，簇飞行模式下可变基线对雷达模糊函数的影响不大；雷达模糊函数应主要考虑目标飞行速度和接收距离变化的影响.最后，给出了簇飞行网络雷达模糊函数的一种上界.      

新兴的人机与环境工程技术科学

围绕人-机-环境系统、飞行器环境控制和生命保障系统、环境模拟技术、空气调节技术4个方面,对国内外人机与环境工程科学研究进展情况作了综述;着重介绍了人-机-环境系统的计算机仿真、ECS制冷系统、航天器的生命保障系统、地面、空中及空间环境模拟技术、空气调节技术的最新发展方向和需要进一步研究的问题等,以期进一步推动该技术学科的研究和发展.     

ESA microgravity payloads for the 1990s

Analysis of flight opportunities of existing and new microgravity multi-user facilities on Eureca and Spacelab and design studies of new experimental facilities for Columbus are presently in progress.

The materials and fluid sciences research community is likely to be a major user of the permanently manned Space Station/Columbus elements such as the European Attached Pressurised Module (APM) and the Man-Tended Free Flyer (MTFF).

In metallurgy, crystal growth and bioengineering initial research will be performed in the manned laboratory, whereas later on the processing will be automated and executed on unmanned platforms.

At present ESA prepares - in close cooperation with the scientific community - the hardware development of microgravity experimental facilities/laboratories for all Columbus elements through design studies. Preliminary studies which have been carried out to date are the following : Crystallisation Laboratory, Fluid Sciences Laboratory, Containerless Processing Laboratory, Thermophysical Properties Measurement Facility, Metallurgy Laboratory.

In 1998 it is planned to deepen these studies covering laboratories for the APM and for the MTFF. Details on flight opportunities in the pre-Columbus period will also be provided.