台湾舰队进行环岛航训

2004年台湾“海军年敦睦舰队”进行远洋航训和本岛环航训，从3月21日开始，至5月29日结束。2004年本岛航训较以往略有不同，首先进行远洋航训，结束后再进行本岛航训。2004年远洋航训从3月21日开始，至5月10日返回左营，远航支队曾访问马歇尔，图瓦卢、索罗门等。完成远洋航训后，5月15日     

航天飞机遇冰雹袭击 外贮箱被砸出小坑

据2007年2月28日报道，美国航空航天局2月27日作出决定，由于26日傍晚肯尼迪航天中心上空发生雷暴夹带冰雹，导致阿特兰蒂斯号航天飞机的外贮箱和一个机翼被砸出上百个凹痕，原定于3月15日的发射将至少被推迟到5月中旬进行。     

中国军队缴获的日本轻武器（上）

近代以来，帝国主义列强入侵中国，致使中国沦为了半封建半殖民地社会。日本帝国主义就是其中之一。1894年的中日甲午战争，1900年八国联军侵略中国。1931年9月18日日本侵略东北，1932年1月28日入侵上海，1937年7月7日发动卢沟桥事变，发动了全面的侵华战争，妄图将中国变成日本的殖民地，中国人民团结一致，抵御外辱，     

创新振兴中国国防 第六届珠海航空航天博览会散记

金秋时节，丹桂飘香，10月31日至11月5日，珠海迎来了第六届中国国际航空航天博览会的召开。2006年10月30日下午，珠海航展正式开幕，中共中央政治局委员，国务院副总理曾培炎出席开幕式并宣布开幕，中共中央政治局委员广东省委书记张德江出席开幕式，航天科技集团公司副总经理马兴瑞，航天科工集团公司总经理殷兴良出席了开幕式。     

天下珠海 蓝天盛会——第五届中国国际航空航天博览会

第五届的中国国际航空航天博览会于2004年11月1—7日在珠生活经验国际机场展览馆举行，前4日为专业日，后3日为公众日，本次珠海航展绝大部分的实机展品皆由俄罗斯提供，包括2架IL-76运输机、Su-27SMK战机、“雨燕”特技小组的MiG-39战机，An-72运输机与An-38-120运输机，其次就是中国人民解放军空军的“八一”特技飞行小组的歼-7M改战机，除此之外，皆为英国民间特技飞行表演小组的飞机、美国商用机与直升机。     

假如地球刚刚1岁

据科学２家的研究，地球诞生已经４６亿年了，人类的起源也可以追溯到３００万年以前，而人类的现代文明只有几百年的时间。几百年与４６亿年相比较是一个什么概念呢？假设地球刚刚只有１岁，也就是说将４６亿年压缩为３６５天，那么我们来看看地球上在几月几日有哪些变化吧。１月１日零时，地球诞生；２月２４日１３时，地球上出现了原始的海洋；４月５日５时，海洋中出现了最原始的生命；９月１８日２０时，有细胞核的真核生物出现了；１１月１３日９时，海洋中出现藻类；１１月２１日８时，海洋中出现三叶虫；１１月３０日６时，身长２米…     

空间扫描

印度“地球静止卫星运载火箭”于2006年7月10日发射失败，美国太空旅馆试验舱于2006年7月12日凌晨由俄罗斯“第聂伯”火箭顺利送入预定轨道，俄罗斯于2006年7月21日发射宇宙-2422军用卫星，俄罗斯“轰鸣”火箭于7月28日成功将韩国卫星阿里郎-2送入预定轨道，美国航空航天局欲叫停空间站实验，第36届世界空间科学大会7月17—22日在北京举行，第八次国际月球探测与利用大会于7月25日在北京召开，第五届美洲空间大会强调加强空间技术合作[编者按]     

“嫦娥”计划后的话题

截至2008年8月1日14日，“嫦娥1”号卫星已正常工作9个月零9天，绕月飞行3042圈，卫星曾经安全度过2008年2月21日的月食，目前整星剩余燃料量约270千克。按计划，8月4日，“嫦娥1”号卫星将由现在约正飞姿态转入侧飞姿态。8月16日，“嫦娥1”号卫星将迎来第二次月食。有关专家表示，根据前一次度过月食的经验和对目前卫星状态的确认，“嫦娥1”号卫星能够安全度过第二次月食.     

广州地磁Z分量日变幅的谱特征

利用1972—1993年广州地磁资料，分析了Z分量日变幅的年平均、年变化和半年变化等低频成分的逐年变化，以及小于60天的短周期变化特征．同时对1972—1993年的F10.7日均值进行了谱分析．结果指出，广州地磁Z分量日变幅的年平均与太阳活动指数F10．7的年平均存在良好的线性相关；具有幅度大约5nT夏季极大的年变化，与太阳活动没有明显相关，是一种季节效应；存在春秋分极大的半年变化，幅度与太阳活动有关，高年的幅度明显大于低年；具有明显的与太阳自转相关的27天左右的变化和明显的与行星波有关的接近16日、10日、5日、2日等短周期变化．广州地磁Z分量日变幅的这些谱特征，有助于更深入地了解中低层大气对电离层影响的物理机制．     

最新消息

美航天飞机又一次飞行　２月２３日哥伦比亚号航天飞机在肯尼迪航天中心发射升空。２月２４日因航天飞机上两台计算机出现故障，绳系卫星发射未能进行。２月２５日航天飞机释放绳系卫星，但因缆绳突然断裂，卫星丢失，实验失败。３月４日美纽约伦塞勒综合技术研究所的科研...     

The Comet Halley flyby I.R. sounder “I.K.S.”

An infrared sounder is being developed in France to observe in 1986 Comet Halley from the Soviet “VEGA” flyby probes. The instrument, called “I.K.S.”, has three measuring channels. Two of these channels will provide the spectrum of the comet emission in the spectral intervals 2.5–5.0 μ and 6–12 μ, at a constant resolution λ/Δλ = 50.The third channel analyzes the comet I.R. image at a spatial frequency of about 1 arc minute^?1; two I.R. colours are used in this channel: 7–10 μ and 10–14 μ. From the results expected, it is hoped that (1) most primary simple molecules emitted by the nucleus will be identified; (2) the chemical composition and perhaps crystalline structure of the dust grains and ices released by the comet will be derived; and (3) the diameter of the nucleus and its brightness temperatures will be measured.     

Indirect search for Dark Matter with H.E.S.S.

Observations of the Galactic center region with the H.E.S.S. telescopes have established the existence of a steady, extended source of gamma-ray emission coinciding with the position of the super massive black hole Sgr A^*. This is a remarkable finding given the expected presence of dense self-annihilating Dark Matter in the Galactic center region. The self-annihilation process is giving rise to gamma-ray production through hadronization including the production of neutral pions which decay into gamma-rays but also through (loop-suppressed) annihilation into final states of almost mono-energetic photons. We study the observed gamma-ray signal (spectrum and shape) from the Galactic center in the context of Dark Matter annihilation and indicate the prospects for further indirect Dark Matter searches with H.E.S.S.     

The C.E.B.A.S.-Minimodule: behaviour of an artificial aquatic ecological system during spaceflight.

The C.E.B.A.S.-Minimodule, a closed aquatic ecosystem integrated into a middeck locker and consisting of a Zoological (animal tanks), a Botanical (plant bioreactor), a Microbial (bacteria filter) and an Electronic Component (data acquisition/control system) was flown on the STS-89 spaceshuttle mission in January 1998 for 9 days. Preflight the plant bioreactor was loaded with 53 g of Ceratophyllum demersum (coontail) and the animal tanks with 4 adult pregnant females of the fish, Xiphophorus helleri (sword-tails), 200 juveniles of the same species less than 1 week of age, 38 large and 30 juvenile Biomphalaria glabrata water snails. The filter compartment was filled with 200 g of lava grain inoculated with laboratory strains of ammonia-oxidizing bacteria. A ground reference was undertaken with the same biological setup with a delay of 4 d. After an adaptation period of 5 d the system was closed and integrated into the spaceshuttle one day before launch. Video recordings of the animals were automatically taken for 10 minutes in 2-hour periods; the tapes were changed daily by the astronauts. The chemical and physical data for the aquatic system were within the expected range and were closely comparable in comparison to the ground reference. After 9 d under space conditions, the plant biomass increased to 117 g. The plants were all found in very good condition. All 4 adult female fish were retrieved in a good physiological condition. The juvenile fishes had a survival rate of about 33%. Almost 97% of the snails had survived and produced more than 250 neonates and 40 spawning packs. All samples were distributed according to a defined schedule and satisfied all scientific needs of the involved 12 principal investigators. This was the first successful spaceflight of an artificial aquatic ecosystem containing vertebrates, invertebrates, higher plants and microorganisms self-sustained by its inhabitants only. C.E.B.A.S. in a modified form and biological setup is a promising candidate for the early space station utilization as a first midterm experiment.     

Mechanisms underlying cellular radiosensitivity and R.B.E.: introductory remarks.

A general outline of the symposium titled "Mechanisms underlying cellular radiosensitivity and R.B.E." will be given in the introduction. The essential topics of molecular radiation biology are described with respect to the damage, repair and mutagenesis caused by high-LET irradiation to cellular DNA. The importance of clustered DNA lesions (locally multiply damaged sites) formed in vivo is discussed. This symposium is devoted to the mechanisms of the biological effects of radiation with high LET, especially with regard to the effects of heavy ions and neutrons which may cause possible risks in space flight, (e.g. carcinogenesis and mutagenesis). Detailed understanding of these risks, however, demands knowledge of the molecular mechanisms involved in the biological effects of high-LET radiations. Thus, it was the organizers' idea to hold a symposium dealing with primary physical and chemical events caused in cellular deoxyribonucleoproteins by densely-ionizing radiations and to relate them to track structures and energy transfer processes. The mechanisms of DNA damage were regarded from different points of view including those considering DNA repair and mutagenesis. Problems associated with cell survival and radiation protection were discussed as well. Our knowledge of the molecular mechanisms of high-LET radiation actions, however, is limited compared to what we know about low-LET radiation effects (e.g. from gamma-rays or X-rays). To emphasize this statement, I would like to summarize briefly the open questions in molecular radiation biology, what we know already about low-LET effects and what is lacking describing the effect of high-LET radiation.     

The "C.E.B.A.S. MINI-MODULE": a self-sustaining closed aquatic ecosystem for spaceflight experimentation.

The C.E.B.A.S. MINI-MODULE is the miniaturized space flight version of the Closed Equilibrated Biological Aquatic System (C.E.B.A.S.). It fits into a large middeck locker tray and is scheduled to be flown in the STS 85 and in the NEUROLAB missions. Its volume is about 9 liters and it consists of two animal tanks, a plant cultivator, and a bacteria filter in a monolithic design. An external sensor unit is connected to a data acquisition/control unit. The system integrates its own biological life support. The CO2 exhaled by the consumers (fishes, snails, microorganisms) is assimilated by water plants (Ceratophyllum demersum) which provide them with oxygen. The products of biomass degradation and excretion (mainly ammonia ions) are converted by bacteria into nitrite and nitrate. The latter is taken up by the plants as a nitrogen source together with other ions like phosphate. The plants convert light energy into chemical energy and their illumination is regulated via the oxygen concentration in the water by the control unit. In ground laboratory tests the system exhibited biological stability up to three month. The buffer capacity of the biological filter system is high enough to eliminate the degradation products of about one half of the dead animal biomass as shown in a "crash test". A test series using the laboratory model of the flight hardware demonstrated the biological stability and technical reliability with mission-identical loading and test duration. A comprehensive biological research program is established for the C.E.B.A.S. MINI-MODULE in which five German and three U.S.-American universities as well as the Russian Academy of Sciences are involved.     

C.E.B.A.S. MINI MODULE: test results of an artificial (man-made) aquatic ecosystem.

The original Closed Equilibrated Biological Aquatic System (C.E.B.A.S.) is a long-term multi-generation research facility for experiments with aquatic animals and plants in a space station the development of which is surrounded by a large international scientific program. In addition, a miniaturized laboratory prototype, the C.E.B.A.S. MINI MODULE, with a total volume of about 10-12 liters for a Spacelab middeck locker was developed and a first version was tested successfully for two weeks with a population of fishes (Xiphophorus helleri) in the animal tank and a Ceratophyllum spec. in the illuminated higher plant growth chamber. The water recycling system consisted of a bacteria filter and a mechanical filter and the silastic tubing gas exchanger was separated by valves for the utilization in emergency cases only. Data were collected with the acquisition module of the original C.E.B.A.S. process control system. In addition, an optimized version was tested for 7 weeks with fishes and plants and thereafter with fish and with plants only for 2 and 1 weeks, resp.. The paper presents the relevant water parameters (e.g., pH, pressure, temperature, oxygen saturation, flow rate, ion concentrations) during the test period as well as morphological and physiological data of the enclosed animals and plants. On the basis of the given results the possible role of the C.E.B.A.S. system as a scientific tool in artificial ecosystem research and for the development of a combined animal-plant intensive aquaculture system and its utilization in bioregenerative life support is discussed.     

Aquatic modules for bioregenerative life support systems: developmental aspects based on the space flight results of the C.E.B.A.S. MIN-MODULE.

The Closed Equilibrated Biological Aquatic System (C.E.B.A.S.) is an artificial aquatic ecosystem which contains teleost fishes, water snails, ammonia oxidizing bacteria and edible non-gravitropic water plants. It serves as a model for aquatic food production modules which are not seriously affected by microgravity and other space conditions. Its space flight version, the so-called C.E.B.A.S. MINI-MODULE was already successfully tested in the STS-89 and STS-90 (NEUROLAB) missions. It will be flown a third time in space with the STS-107 mission in January 2003. All results obtained so far in space indicate that the basic concept of the system is more than suitable to drive forward its development. The C.E.B.A.S. MINI-MODULE is located within a middeck locker with limited space for additional components. These technical limitations allow only some modifications which lead to a maximum experiment time span of 120 days which is not long enough for scientifically essential multi-generation-experiments. The first necessary step is the development of "harvesting devices" for the different organisms. In the limited space of the plant bioreactor a high biomass production leads to self-shadowing effects which results in an uncontrolled degradation and increased oxygen consumption by microorganisms which will endanger the fishes and snails. It was shown already that the latter reproduce excellently in space and that the reproductive functions of the fish species are not affected. Although the parent-offspring-cannibalism of the ovoviviparous fish species (Xiphophorus helleri) serves as a regulating factor in population dynamics an uncontrolled snail reproduction will also induce an increased oxygen consumption per se and a high ammonia concentration in the water. If harvesting locks can be handled by astronauts in, e. g., 4-week intervals their construction is not very difficult and basic technical solutions are already developed. The second problem is the feeding of the animals. Although C.E.B.A.S.-based aquaculture modules are designed to be closed food loop systems (edible herbivorous fish species and edible water plants) which are already verified on Earth this will not be possible in space without devices in which the animals are fed from a food storage. This has to be done at least once daily which would waste too much crew time when done by astronauts. So, the development of a reliable automated food dispenser has highest priority. Also in this case basic technical solutions are already elaborated. The paper gives a comprehensive overview of the proposed further C.E.B.A.S.-based development of longer-term duration aquatic food production modules.     

V.L.A. observations of flare build-up in coronal loops

Very Large Array (V.L.A.) measurements at 20 cm wavelength map emission from coronal loops with second-of-arc angular resolution at time intervals as short as 3.3 seconds. The total intensity of the 20 cm emission describes the evolution and structure of the hot plasma that is detected by satellite X-ray observations of coronal loops. The circular polarization of the 20 cm emission describes the evolution, strength and structure of the coronal magnetic field. Preburst heating and magnetic changes that precede burst emission on time scales of between 1 and 30 minutes are discussed. Simultaneous 20 cm and soft X-ray observations indicate an electron temperature $\text{T}{}_{\mathrm{e}}\textcolor{red}{}\text{2.5 × 10}{}^7\text{K}$ and electron density $\text{N}{}_{\mathrm{e}}\textcolor{red}{}\text{10}{}^{10}\text{cm}{}^{\mathrm{?3}}$ during preburst heating in a coronal loop that was also associated with twisting of the entire loop in space. We also discuss the successive triggering of bursts from adjacent coronal loops; highly polarized emission from the legs of loops with large intensity changes over a 32 MHz change in observing frequency; and apparent motions of hot plasma within coronal loops at velocities V > 2,000 kilometerspersecond.     

美国的战斧巡航导弹

3月19日,美英法三国开始对利比亚实行军事打击。在当天进行的空袭行动中,部署在地中海的美军和英军军舰与潜艇就向利比亚首都的黎波里郊区和东部城市米苏拉塔等地发射了110多枚战斧巡航导弹,袭击了20多处防空设施和民事目标。在随后的几天里,每天又都发射了一批这种导弹。截止到4月1日,美军共发射了221枚、英军共发射了7枚战斧巡航导弹。那么,战斧巡航导弹究竞     

Pigment composition and concentrations within the plant (Ceratophyllum demersum L.) component of the STS-89 C.E.B.A.S. Mini-Module spaceflight experiment.

The Closed Equilibrated Biological Aquatic System (C.E.B.A.S.) Mini-Module, a Space Shuttle middeck locker payload which supports a variety of aquatic inhabitants (fish, snails, plants and bacteria) in an enclosed 8.6 L chamber, was tested for its biological stability in microgravity. The aquatic plant, Ceratophyllum demersum L., was critical for the vitality and functioning of this artificial mini-ecosystem. Its photosynthetic pigment concentrations were of interest due to their light harvesting and protective functions. "Post-flight" chlorophyll and carotenoid concentrations within Ceratophyllum apical segments were directly related to the quantities of light received in the experiments, with microgravity exposure (STS-89) failing to account for any significant deviation from ground control studies.