捕捉快速波形的时间拦伸法时间拉促预处理：第二部分

时间拉伸预处理法有助于克服慢采样速率模拟－数字转换器（ＡＤＣ０在捕捉信号方面的不足，本文的第一部分已对此技术作了介绍，该技术通过控制输入模拟信号的时间量程（扩大或放慢），大大地提高了ＡＤＣ的有效采样速率和车入带宽，我们将以时间拉伸波分多路采样（ＷＤＳ）为例对这种还可用于数字－模拟转换器（ＤＡＣ）的处理方法做进一步的说明。     

用EM算法解决多目标／多传感器的跟踪问题

采用我种精度不同和特性不同的传感器的输出来跟踪杂波噪声环境中的多个运动目标是监视和侦察系统中的一个重要问题。人们提出了许多解决多目标／多传感器跟踪问题的方案，从难度适中（针对特定应用的方案）的到得复杂的、理论上是最佳的方案均有。本文描述了一种基于最大期望（ＥＭ）算法的时间递归多目标／多传感器的迭代跟踪方法。更具体地说，我们把多目标／多传感器跟踪问题当作是利用可观测传感器的输出表示不完全数据的不完全     

An Investigation of Near-Equatorial Geomagnetic Pi2 Pulsations

There is understanding to date that Pi2 pulsations have two sources. One source is a high-latitude one and is due to fluctuations of electrojet parameters. The other source is a mid-latitude one and is driven by a global mode excited in the Earths plasmasphere. There is experimental evidence that in the near-equatorial regions the character of Pi2 excitation is different from high and mid-latitudes. In this connection, we investigated the amplitude-spectral-polarization characteristics of Pi2 pulsations using the date from near-equatorial Chinese stations. The detected regularities in the excitation of near-equatorial Pi2 pulsations are used in the discussion of the possible physical mechanism that is responsible for the generation of these pulsations.     

Deuterium-free water (1H2O) in complex life-support systems of long-term space missions

Heavy water containing deuterium displays toxic property. It is stated that any quantity of a heavy isotope of hydrogen--deuterium--is undesirable to animals and plants. It was earlier shown by us that physical-chemical life support systems on board the "MIR" station fractionate (change) isotopes of hydrogen, oxygen and carbon. Therefore, the problem of regenerative systems in habitable space objects should include removal, from water, of a heavy stable isotope of hydrogen--deuterium. In this article we consider one method of obtaining deuterium-free water--decomposition of distillate water in an electrolyser to hydrogen and oxygen with subsequent synthesis in a catalytic or high-temperature reactor. The influence of deuterium-free water on the growth and development of Arabidopsis thaliana and Japanese quail is investigated. It is shown that with the help of the electrolysis method it is possible to fabricate water containing 80% less deuterium in comparison with SMOW. Experimentally, it is proved on a culture of Arabidopsis thaliana and Japanese quail that water with reduced contents of deuterium (80%) displays positive biological activity.     

Human characteristics of pair assembly work in a microgravity environment

This research focuses on analyzing the human characteristics of pair assembly work in a microgravity environment. To obtain the necessary data, two groups of test subjects participated in an experiment in a pseudomicrogravity environment, and how such factors as work allotment, sizes of assembled objects, and conditions of parts influence the work efficiency were studied. The results show when the assembled object is smaller that it is easier to change the object's position and that workers can move it to an appropriate site and work easily. If the assembly object is attached to an object with very large mass, the work allotment does not result in a difference in work time. As for positioning the objects, step-saving processes can shorten the work time. For instance, if a part can be put so that both ends automatically touch the proper spots, time can be shortened.     

Changes in mood status and neurotic levels during a 20-day bed rest

This study evaluated changes of mood status and depressive and neurotic levels in nine young male subjects during a 20-day 6 degrees head-down tilting bed rest and examined whether exercise training modified these changes. Participants were asked to complete psychometrical inventories on before, during, and after the bed rest experiment. Depressive and neurotic levels were enhanced during bed rest period according to the Japanese version of Zung's Self-rating Depression Scale and the Japanese version of the General Health Questionnaire. Mood state "vigor" was impaired and "confusion" was increased during bed rest and recumbent control periods compared to pre-bed rest and ambulatory control periods according to the Japanese version of Profiles of Mood State, whereas the mood "tension-anxiety", "depression-dejection", "anger-hostility" and "fatigue" were relatively stable during experiment. Isometric exercise training did not modify these results. Microgravity, along with confinement to bed and isolation from familiar environments, induced impairment of mental status.     

美国七种军用雷达研发动态

首型在空军服役的有源相控阵多功能火控雷达AN／APG-63（V）2 1．1 APG-63／70雷达的改进AN／APG-63（V）2是雷声公司制造的多功能火控有源相控阵雷达，是APG-63／70雷达的改进型，用于装备F-15C战斗机。它是世界上进人空军服役的首型战斗机AESA雷达，已全部交付。该雷达消除了原来F-15雷达笨重的液压天线驱动系统，雷达的快速扫描和多目标跟踪能力得到了改善，提高了飞行员对战场环境的感知能力。