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美空军重新考虑GPS-3卫星的发射日期
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作者 赵颖 《遥测遥控》 2003年第3期27-27,共1页
关键词 发射日 美空军 美国空军 GPS卫星 参议院 拨款申请 项目开支 空间计划 抗干扰能力 推迟到
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美国火箭公司的火箭在发射台上烧毁
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作者 姚昕 《固体火箭技术》 EI CAS CSCD 1989年第4期38-38,共1页
美国火箭公司实验性的工业研究大箭于上周进行了首次试射。点火17s后,发射停止,当时控制液氧流入主燃烧室的阀门未能完全打开。当发射控制器试图使垂直支架回到原位时,大火吞没了火箭,助推器落到了它的侧边。火箭几乎被完全烧毁。
关键词 主燃烧室 液氧箱 工业研究 试射 大箭 侧边 发射日 程曾 范登堡 聚丁二烯
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GLONASS星座在轨卫星一览表
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作者 赵颖 《遥测遥控》 2000年第6期62-62,共1页
关键词 GLONASS 卫星 星座 宇宙 开始运转 系统编号 发射日 开始运行 轨道面 览表
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GLONASS卫星星座最新状态
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作者 赵颖 《遥测遥控》 2001年第5期37-37,共1页
关键词 卫星星座 GLONASS 宇宙 系统编号 最新状态 发射日 停止使用 开始运行 轨道面 莫斯科
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GLONASS卫星星座最新状态
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作者 赵颖 《遥测遥控》 2002年第1期31-31,共1页
关键词 GLONASS 卫星星座 系统编号 最新状态 发射日 停止使用 开始运行 轨道面 莫斯科 星位
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电联京都大会18号决议有关问题的综述
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作者 徐小超 《中国无线电》 1996年第6期28-31,共4页
电联京都大会18号决议有关问题的综述国家无委办公室频率二处徐小超电联京都大会18号决议旨在对现行的卫星网路国际协调和规划的某些重要议题进行复审。因为随着卫星通信需求的急剧增长,卫星轨道和频率资源日趋紧张,现行(无线电... 电联京都大会18号决议有关问题的综述国家无委办公室频率二处徐小超电联京都大会18号决议旨在对现行的卫星网路国际协调和规划的某些重要议题进行复审。因为随着卫星通信需求的急剧增长,卫星轨道和频率资源日趋紧张,现行(无线电视则)中有关卫星轨道/频率的国际法... 展开更多
关键词 主管部门 卫星网路 卫星设计 有关问题 卫星系统 频率资源 无线电规则 现行规则 抵押金 发射日
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Development of a Cross-Flow Fish Smoking Kiln Fired by Biomass Material
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作者 Ajiboye Solomon Oyerinde Agboola Simeon Ogunlowo Olawale John Olukunle 《Journal of Agricultural Science and Technology(A)》 2013年第7期531-541,共11页
Traditional smoking of fish in Nigeria is often carried out in open and unsanitary environment. In addition, the current process does not result in uniformly smoked fish and uses wood (an increasingly scarce material... Traditional smoking of fish in Nigeria is often carried out in open and unsanitary environment. In addition, the current process does not result in uniformly smoked fish and uses wood (an increasingly scarce material) as heat source. The fish smoking kiln designed and fabricated in this study addresses these problems. The kiln (700 × 800 × 1,500 mm) is made of stainless steel on the inside and mild steel on the outside with glass fiber insulation separating the inside and outside covers. The sample to be smoked is totally enclosed by the kiln with a latchable door provided at one of the sides for placing of samples to be smoked. In addition, the kiln was designed to use waste biomass resource as fuels (sawdust and/or maizecob). Bonga fish (Ethmalosafimbriata) and African catfish (Clarias gariepinus) were used as test samples for the kiln. The temperature of the chamber increased to about 120 ℃ to 160 ℃ when fueled with sawdust and about 150 ℃ to 200 ℃ for maizecob. The total heat transfer resistance through the kiln walls was determined to be 1.0 ℃/W. About 6-8 h was required to smoke-dry 16 kg of fish samples from initial moisture content of 75% to about 25% or 20% moisture level. 展开更多
关键词 Smoking kiln SAWDUST maizecob Bonga CATFISH biomass material.
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Solar Forcing on Makkah AI-Mukaramah Flash Floods
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作者 Shahinaz Yousef Yasser H.O. Algafari +1 位作者 Zaki AI-Mostafa Mutaz Kordi 《Journal of Earth Science and Engineering》 2012年第2期77-83,共7页
Severe solar events manifested by highly energetic X-Ray events accompanied by coronal mass ejections and proton flares caused flash floods in Makkah AI-Mukaramab, A1-Madinah AI-Munawarah and Jeddah. The responses can... Severe solar events manifested by highly energetic X-Ray events accompanied by coronal mass ejections and proton flares caused flash floods in Makkah AI-Mukaramab, A1-Madinah AI-Munawarah and Jeddah. The responses can be prompt, delayed or prompt-delayed, suggesting that the protons entered the troposphere either through the opening of a direct gate in the magnetosphere to the location concer.led due to magnetic reconnection, through the polar gates or through those two paths respectively. The authors suggest that there is a magnetic anomaly in Makkah AI-Mukaramah area which makes it liable to be subjected to flash floods. The width of the solar streams determines the width of the gate opened in the magnetosphere via magnetic reconnection and thus narrow streams affect only one location of the three cities while extended width streams can cause flash floods in all of Makkah AI-Mukaramah AI-Madinah AI Munawarah and Jeddah. In addition, the November 24-26 Jeddah flash flood could be attributed to a prompt event due to a moderately fast solar stream that arrived the earth on those days. 展开更多
关键词 Makkah AI-Mukaramah Al-Madinah AI-Munawarah Jeddah coronal mass ejections X-ray events flash floods.
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枪的发展——枪械之王:步枪(二)
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《少年读者》 2007年第11期23-23,共1页
在枪械家族中,步枪属于"元老级别"。细说步枪,自然就得追溯枪械的发展史。在远古时,猿人就用石块当作防卫和狩猎的武器。随着阶极、社会以及战争的产生,武器也迅速发展起来。从石、骨、蚌、竹、木等材质演进到青铜、铁、钢等... 在枪械家族中,步枪属于"元老级别"。细说步枪,自然就得追溯枪械的发展史。在远古时,猿人就用石块当作防卫和狩猎的武器。随着阶极、社会以及战争的产生,武器也迅速发展起来。从石、骨、蚌、竹、木等材质演进到青铜、铁、钢等,并创造出刀、剑、矛、弓、弩、标枪。 展开更多
关键词 用石块 投石 蒙军 突火枪 火绳枪 火门枪 发射日 黑暗时代 蒙古铁骑 人类史
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Origin and structures of solar eruptions Ⅰ: Magnetic flux rope 被引量:13
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作者 CHENG Xin GUO Yang DING MingDe 《Science China Earth Sciences》 SCIE EI CAS CSCD 2017年第8期1383-1407,共25页
Coronal mass ejections(CMEs) and solar flares are the large-scale and most energetic eruptive phenomena in our solar system and able to release a large quantity of plasma and magnetic flux from the solar atmosphere in... Coronal mass ejections(CMEs) and solar flares are the large-scale and most energetic eruptive phenomena in our solar system and able to release a large quantity of plasma and magnetic flux from the solar atmosphere into the solar wind. When these high-speed magnetized plasmas along with the energetic particles arrive at the Earth, they may interact with the magnetosphere and ionosphere, and seriously affect the safety of human high-tech activities in outer space. The travel time of a CME to 1 AU is about 1–3 days, while energetic particles from the eruptions arrive even earlier. An efficient forecast of these phenomena therefore requires a clear detection of CMEs/flares at the stage as early as possible. To estimate the possibility of an eruption leading to a CME/flare, we need to elucidate some fundamental but elusive processes including in particular the origin and structures of CMEs/flares. Understanding these processes can not only improve the prediction of the occurrence of CMEs/flares and their effects on geospace and the heliosphere but also help understand the mass ejections and flares on other solar-type stars. The main purpose of this review is to address the origin and early structures of CMEs/flares, from multi-wavelength observational perspective. First of all, we start with the ongoing debate of whether the pre-eruptive configuration, i.e., a helical magnetic flux rope(MFR), of CMEs/flares exists before the eruption and then emphatically introduce observational manifestations of the MFR. Secondly, we elaborate on the possible formation mechanisms of the MFR through distinct ways. Thirdly, we discuss the initiation of the MFR and associated dynamics during its evolution toward the CME/flare. Finally, we come to some conclusions and put forward some prospects in the future. 展开更多
关键词 Coronal mass ejections Flares Magnetic flux ropes Magnetic field EUV/UV emissions Photosphere Corona Particle acceleration
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