在直升机平台上进行高分辨率SAR／ISAR成像

海上监视对高分辨率雷达成像模式特别感兴趣。在海上监视应用中，可以使用高分辨率雷达成像模式来支持对已经用传统搜索功能和跟踪功能检测到的海面目标的分类和可能的识别。     

Ozone concentrations and ultraviolet fluxes on Earth-like planets around other stars

Coupled radiative-convective/photochemical modeling was performed for Earth-like planets orbiting different types of stars (the Sun as a G2V, an F2V, and a K2V star). O(2) concentrations between 1 and 10(-5) times the present atmospheric level (PAL) were simulated. The results were used to calculate visible/near-IR and thermal-IR spectra, along with surface UV fluxes and relative dose rates for erythema and DNA damage. For the spectral resolution and sensitivity currently planned for the first generation of terrestrial planet detection and characterization missions, we find that O(2) should be observable remotely in the visible for atmospheres containing at least 10(-2) PAL of O(2). O(3) should be visible in the thermal-IR for atmospheres containing at least 10(-3) PAL of O(2). CH(4) is not expected to be observable in 1 PAL O(2) atmospheres like that of modern Earth, but it might be observable at thermal-IR wavelengths in "mid-Proterozoic-type" atmospheres containing approximately 10(-1) PAL of O(2). Thus, the simultaneous detection of both O(3) and CH(4) - considered to be a reliable indication of life - is within the realm of possibility. High-O(2) planets orbiting K2V and F2V stars are both better protected from surface UV radiation than is modern Earth. For the F2V case the high intrinsic UV luminosity of the star is more than offset by the much thicker ozone layer. At O(2) levels below approximately 10(-2) PAL, planets around all three types of stars are subject to high surface UV fluxes, with the F2V planet exhibiting the most biologically dangerous radiation environment. Thus, while advanced life is theoretically possible on high-O(2) planets around F stars, it is not obvious that it would evolve as it did on Earth.     

Blood volume regulating hormones response during two space related simulation protocols: four-week confinement and head-down bed-rest

The volume of regulating hormones (renin, aldosterone, arginine vasopressin and atrial natriuretic factor), electrolytes and creatinine concentrations, and blood pressure were measured in two different four-week experimental protocols: respectively -6 degrees head-down bed-rest (5 subjects) and confinement (6 subjects). We observed a significant increase (P < 0.01 at D2 vs D-5) of systolic blood pressure during confinement and a different level of response for some hormones, especially for arginine vasopressin (300% increase during confinement instead of 50% during bed-rest). The renin-angiotensin-aldosterone system was enhanced during confinement and head-down bed-rest. In both conditions, we obtained a similar pattern of response for blood volume regulating hormones. During confinement, two main factors were inactivity and stress activation of the sympathetic nervous system. In the bed-rest study the response is principally due to the fluid shift and blood volume adaptation but it is not possible to exclude the role of inactivity and stress.     

Cosmic dosimetry using TLD aboard spacecrafts of the "Cosmos" series

Thermoluminescent (TL) detectors were used for dosimetric investigations on the outer surface as well as inside Soviet spacecrafts of the "Cosmos" series. At the outer surface, ultrathin TL detectors, based on CaF2-PTFE and LiF, were arranged in special stacks and exposed to unshielded cosmic radiation. The strong decrease of dose within a few mg/cm2 demonstrates that weakly penetrating radiation is dominating in the radiation field under investigation. On the basis of glow curve analysis of LiF thermoluminescent detectors it could be shown, that the high doses are caused by electrons.     

Japanese telescience technology development for JEM and its utilization

Recognizing the importance of the telescience technology for the efficient and improved space environment utilization in JEM, we have undertaken telescience technology development since 1987. The purpose of this paper is to introduce the recent status of our telescience activity, the results of the testbed experiments in these years, and the new activities for the initial JEM operation and its future utilization.     

NUMERICAL SIMULATION OF FLOW PATTERNS IN PLANAR JETS

INTRODUCTIONTurbulent jet flow is the most widely usedflow type in engineering applications especiallyfor combustion engines which provide most ener-gy sources for industrial production and trans-portation,and a large proportion of energy trans-portation and conversion processes is dominatedby transient evolution of large- scale structures,or so called coherent structures,in turbulentjets.As the flow control and optimization pro-cesses are closely related to the understanding ofdetailed in…     

一个包括气相和亚表面反应的过氯酸铵复合推进剂的点火模型

本文提出了 Ap 基复合推进剂点火的一个综合模型及其数值解。这一分析模拟位于滞止区的推进剂试样在快速加压条件下的点火过程。本模型的特点包括:a)考虑了 Ap 基复合推进剂点火的详细的化学动力学资料;b)推进剂几何形状是二维(轴对称)的;c)考虑了气相中压力迅速增加对点燃过程的影响。使用隐式有限差分格式求解瞬态二阶联立、非齐次、非线性偏微分控制方程组。数值解揭示在点火阶段顺序发生的一系列重要事件,包括:点火器气体流入接近样品表面的区域;压缩波到达处未燃成份的燃烧;向推进剂传热;氧化剂和燃烧剂的高温分解;气相反应导致点燃。这个模型正确地预测了实验观察到的现象:随着增压速率提高,点火延迟时间缩短。采用文中考虑的不同点火准则都得到和试验一样的趋势。     

CMOS 集成硅压力传感器特性的线性分析

作者对最新设计的具有方形硅膜片的 CMOS 集成硅压力传感器的特性进行了理论的和实验的分析。结果表明:传感器的非线性是由硅膜片的大幅度偏折(deflecti-on)和压阻元件的非线性压阻特性所引起的。文章还指出了将非线性减至最小程度时传感器的最佳结构形式。对所制得的压力传感器的非线性作了测量,其值与数学分析值十分吻合。     

Early renal changes in 45 degrees HDT rats

Background: Both microgravity and simulated microgravity models, such as the 45HDT (45 degrees head-down tilt), cause a redistribution of body fluids indicating a possible adaptive process to the microgravity stressor. Understanding the physiological processes that occur in microgravity is a first step to developing countermeasures to stop its harmful effects, i.e., (edema, motion sickness) during long-term space flights. Hypothesis: Because of the kidneys' functional role in the regulation of fluid volume in the body, it plays a key role in the body's adaptation to microgravity. Methods: Rats were injected intramuscularly with a radioactive tracer and then lightly anesthetized in order to facilitate their placement in the 45HDT position. They were then placed in the 45HDT position using a specially designed ramp (45HDT group) or prone position (control group) for an experimental time period of 1 h. During this period, the 99mTc-DTPA (technetium-labeled diethylenepentaacetate, MW=492 amu, physical half-life of 6.02 h) radioactive tracer clearance rate was determined by measuring gamma counts per minute. The kidneys were then fixed and sectioned for electron microscopy. A point counting method was used to quantitate intracellular spaces of the kidney proximal tubules. Results: 45HDT animals show a significantly (p=0.0001) increased area in the interstitial space of the proximal tubules. Conclusions: There are significant changes in the kidneys during a 1 h exposure to a simulated microgravity environment that consist primarily of anatomical alterations in the kidney proximal tubules. The kidneys also appear to respond differently to the initial periods of head-down tilt.     

Psychophysiological reactivity under Mir-simulation and real micro-G

A complex psychophysiological test battery (ECG, blood pressure, SCL, finger temperature e.t.c.) was applied on two subjects in space. It could be shown that the subjects react under space conditions differently than on earth. The data received could be classified into four types of regulation. The subjects changed this type of regulation during the flight and returned to their former pattern after the flight.