奇观

《午夜巴黎》(2011·美国)导演:伍迪·艾伦主演:欧文·威尔逊,瑞秋·麦克亚当斯故事梗概:吉尔是好莱坞编剧和蹩脚作家,与未婚妻伊内兹订婚的时候他正困在自己的长篇小说创作中不得出路。婚前他们俩和准岳父岳母来到法国办事会朋友,但周遭的人和他都不是很谈得来。于是,就在他独自一个人在法国的小道上逡巡之时,一辆来自1920年的老爷车带他回到了毕加索的艺术之年,改变他人生的奇妙之旅就此展开。     

Life science research in space brings health on Earth

Leading scientists and physicians review groundbreaking research that is leading the way to better health care for astronauts and new treatments for medical problems on Earth. This research includes the development and testing of a new Ventricular Assist Device for patients with heart failure awaiting heart transplantation; advancements in telemedicine that bring medical care to remote areas on Earth and aid in the diagnosis and treatment of illness during space flight; advanced technologies, such as a miniature mass spectrometer, cardiac ultrasound equipment, bone imaging, non-invasive High-Intensity Focused Ultrasound, non-invasive techniques for blood and tissue chemistry measurements; and advances in the treatment of spinal cord injuries.     

Biomedical support of man in space

In its broadest sense, biomedical support of man in space must not be limited to assisting spacecraft crew during the mission; such support should also ensure that flight personnel be able to perform properly during landing and after leaving the craft. Man has developed mechanisms that allow him to cope with specific stresses in his normal habitat; there is indisputable evidence that, in some cases, the space environment, by relieving these stresses, has also allowed the adaptive mechanisms to lapse, causing serious problems after re-entry. Inflight biomedical support must therefore include means to simulate some of the normal stresses of the Earth environment. In the area of cardiovascular performance, we have come to rely heavily on complex feedback mechanisms to cope with two stresses, often combined: postural changes, which alter the body axis along which gravitational acceleration acts, and physical exercise, which increases the total load on the system. Unless the appropriate responses are reinforced continuously during flight, crew members may be incapacitated upon return. The first step in the support process must be a study of the way in which changes in g, even of short duration, affect these responses. In particular we should learn more about effects of g on the "on" and "off" dynamics, using a variety of approaches: increased acceleration on one hand at recumbency, immersion, lower body positive pressure, and other means of simulating some of the effects of low g, on the other. Once we understand this, we will have to determine the minimal exposure dose required to maintain the response mechanisms. Finally, we shall have to design stresses that simulate Earth environment and can be imposed in the space vehicle. Some of the information is already at hand; we know that several aspects of the response to exercise are affected by posture. Results from a current series of studies on the kinetics of tilt and on the dynamics of readjustment to exercise in different postures will be presented and discussed.     

自适应机载雷达的杂波模拟

众所周知，自适应波束形成装置可有效地消除进入相控阵雷达天线旁瓣的强干扰信号。机载雷达受人为干扰的影响时，如果允许杂波进入自适应处理机，则会显著影响自适应波束方向图的形状，进而影响雷达影响。在缺少测试数据的情况下，先行建立了一个分布杂波模型，从而能够通过模拟，就前视机载雷达的情况对杂波出现时自适应算法的性能进行评价。本文概述了相挥阵雷达各输出通道产生杂波时间序列的方法，这种方法可以确保通道间的相关符     

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.     

Sugar synthesis from a gas-phase formose reaction

Prebiotic possibilities for the synthesis of interstellar ribose through a protic variant of the formose reaction under gas-phase conditions were studied in the absence of any known catalyst. The ion-molecule reaction products, diose and triose, were sought by mass spectrometry, and relevant masses were observed. Ab initio calculations were used to evaluate protic formose mechanism possibilities. A bilateral theoretical and experimental effort yielded a physical model for glycoaldehyde generation whereby a hydronium cation can mediate formaldehyde dimerization followed by covalent bond formation leading to diose and water. These results advance the possibility that ion-molecule reactions between formaldehyde (CH(2)O) and H(3)O(+) lead to formose reaction products and inform us about potential sugar formation processes in interstellar space.     

Radiolytic hydrogen and microbial respiration in subsurface sediments

Radiolysis of water may provide a continuous flux of an electron donor (molecular hydrogen) to subsurface microbial communities. We assessed the significance of this process in anoxic marine sediments by comparing calculated radiolytic H(2) production rates to estimates of net (organic-fueled) respiration at several Ocean Drilling Program (ODP) Leg 201 sites. Radiolytic H(2) yield calculations are based on abundances of radioactive elements (uranium, thorium, and potassium), porosity, grain density, and a model of water radiolysis. Net respiration estimates are based on fluxes of dissolved electron acceptors and their products. Comparison of radiolytic H(2) yields and respiration at multiple sites suggests that radiolysis gains importance as an electron donor source as net respiration and organic carbon content decrease. Our results suggest that radiolytic production of H(2) may fuel 10% of the metabolic respiration at the Leg 201 site where organic-fueled respiration is lowest (ODP Site 1231). In sediments with even lower rates of organic-fueled respiration, water radiolysis may be the principal source of electron donors. Marine sedimentary ecosystems may be useful models for non-photosynthetic ecosystems on early Earth and on other planets and moons, such as Mars and Europa.     

Astrobiological considerations for the selection of the geological filters on the ExoMars PanCam instrument

The Panoramic Camera (PanCam) instrument will provide visible-near IR multispectral imaging of the ExoMars rover's surroundings to identify regions of interest within the nearby terrain. This multispectral capability is dependant upon the 12 preselected "geological" filters that are integrated into two wide-angle cameras. First devised by the Imager for Mars Pathfinder team to detect iron oxides, this baseline filter set has remained largely unchanged for subsequent missions (Mars Exploration Rovers, Beagle 2, Phoenix) despite the advancing knowledge of the mineralogical diversity on Mars. Therefore, the geological filters for the ExoMars PanCam will be redesigned to accommodate the astrobiology focus of ExoMars, where hydrated mineral terrains (evidence of past liquid water) will be priority targets. Here, we conduct an initial investigation into new filter wavelengths for the ExoMars PanCam and present results from tests performed on Mars analog rocks. Two new filter sets were devised: one with filters spaced every 50?nm ("F1-12") and another that utilizes a novel filter selection method based upon hydrated mineral reflectance spectra ("F2-12"). These new filter sets, along with the Beagle 2 filter set (currently the baseline for the ExoMars PanCam), were tested on their ability to identify hydrated minerals and biosignatures present in Mars analog rocks. The filter sets, with varying degrees of ability, detected the spectral features of minerals jarosite, opaline silica, alunite, nontronite, and siderite present in these rock samples. None of the filter sets, however, were able to detect fossilized biomat structures and small (<2?mm) mineralogical heterogeneities present in silica sinters. Both new filter sets outperformed the Beagle 2 filters, with F2-12 detecting the most spectral features produced by hydrated minerals and providing the best discrimination between samples. Future work involving more extensive testing on Mars analog samples that exhibit a wider range of mineralogies would be the next step in carefully evaluating the new filter sets.     

共焦扫描光学显微镜的工业应用

共焦扫描光学显微镜开拓了点探针光学扫描系统三个独特的功能:差分相衬、共焦剖面和光束感生电流(OBIC)像。本文叙述了这些功能在材料显微术、半导体失效分析、生物显微术上的应用,概述了激光扫描共焦显微镜的设计特点。