Prospects for astronomical development in South Africa     

R. S. Stobie 《Astrophysics and Space Science》1995,230(1-2):9-15

Because of its geographical location and (astronomically) excellent climate South Africa can make an unique contribution to international astronomical research. An assessment of recent developments in telescope technology has shown that an advanced technology telescope of 4m-class can be constructed which will out-perform most existing 4m-class telescopes. Detailed consideration is given to the construction of such a telescope for optical/infrared astronomy, the new science that this will enable and the selection of a site of sufficiently good quality to justify the erection of such a telescope. If a telescope of this nature is sited in southern Africa it would provide the premier astronomical facility in Africa for decades to come.  相似文献   

卫星授时技术控制方案     

Liang Shuangyou 《时间频率学报》1995,(1)

根据我国同步广播卫星的现状，本文提出在不专门占用卫星信道的情况下，保留现有的ＣＣＴＶ中的时间信号，并将卫星轨道参数以及其它参数插入到ＣＣＴＶ信号中去的技术问题以及控制方法，完成同步卫星的高精度授时工作。  相似文献   

一种实用于无线半双工信道的ARQ差错控制方案     

杨家仕 《成都信息工程学院学报》1996,(Z1)

介绍一种适用于无线半双工信道数据传输系统，旨在提高报文通过享的改进的混合二型ＡＲＱ差错控制方案。方案中，采用了缩短的半速可逆ＢＣＨ编码（２ｍ，ｍ）和交织技术，分析了差错控制方案的性能。  相似文献   

BOOK REVIEWS     

《The Professional geographer》1985,37(2):226-262

Book Reviewed in this article: The City in Cultural Context . John Agnew, John Mercer, David Sopher, eds. Soils and Geomorphology Peter W. Birkeland. Urbanization and Settlement Systems, International Perspectives . L. S. Bourne, R. Sinclair, and K. Dziewoński. eds. An Introduction to Urban Historical Geography . Harold Carter. Overshoot, The Ecological Basis of Revolutionary Change . William J. Catton, Jr. Rivers of the World . Eberhard Czaya. Jewish Communities in Frontier Societies: Argentina, Australia and South Africa . Daniel J. Elazar with Peter Medding. Color in Public Spaces: Toward a Communication-Based Theory of the Urban Built Environment. Kenneth E. Foote. Spatial Statistics and Models. Gary L. Gaile and Cort J. Willmott, eds. Mega-Geomorphology. Rita Gardner and Helen Scoging, eds. Technological Change and Regional Development. Gillespie, ed. The Arid Lands: Their Use and Abuse. R. L. Heathcote. The Location of Industry in Britain. A. G. Hoare. Groundwater as a Geomorphic Agent . R. G. LaFleur, ed. Rural Public Services: International Comparisons. Richard E. Lonsdale and Gyorgy Enyedi, eds. Saving Water in a Desert City. William E. Martin, Helen M. Ingram, Nancy K. Laney, and Adrian H. Griffin. Water Resources: Distribution, Use and Management. John R. Mather. Transnationals and the Third World: The Struggle for Culture. Armand Mattelart. South Hadley, MA: USGS Digital Cartographic Data Standards. R. B. McEwen, R. E. Witmer, and B. S. Ramey, eds. The Ecosystem Concept in Anthropology. Emilio F. Moran, ed. Boulder, CO: Women, Men, and the International Division of Labor. June Nash and Maria Patricia Fernandez-Kelly, eds. Nuclear Power: Assessing and Managing Hazardous Technology. Martin J. Pasqualetti and K. David Pijawka, eds. Mary Somerville and the Cultivation of Science 1815-1840. Elizabeth Chalmers Patterson. An Introduction to Coastal Geomorphology. John Pethick. Late Quaternary Environments of the United States , Vol. 1, The Late Pleistocene. Stephen C. Porter, ed. Planning and Ecology. R. D. Roberts and T. M. Roberts, eds. Regionalism and the Pacific Northwest. William G. Robbins, Robert J. Frank, and Richard E. Ross, eds. Environment and Health. Anthony J. Rowland and Paul Cooper. Sunbelt/Snowbelt: Urban Development and Regional Restructuring. Larry Sawers and William K. Tabb, eds. The Bad Earth. Environmental Degradation in China. Vaclav Smil. Armonk, NY: Voyage into Substance: Art, Science, Nature, and the Illustrated Travel Account, 1760–1840. Barbara Maria Stafford. The Institute of British Geographers: The First Fifty Years. Robert W. Steel. Visions of the Past. Christopher Taylor and Richard Muir. Glacial Lake Agassiz. J. T. Teller and Lee Clayton, eds. The Tule Breakers: The Story of the California Dredge. John Thompson and Edward A. Dutra. The Balkan City 1400–1900. Nikolai Todorov. Explanation, Prediction and Planning: the Lowry model. Michael J. Webber. Mercedes Reales: Hispanic Land Grants of the Upper Rio Grande Region. Victor Westphall. The World Atlas of Revolutions. Andrew J. M. Wheatcroft. The West European City, A Social Geography. Paul White. Urban Elites and Mass Transportation. J. Allen Whitt. Princeton, NJ: Urban Life In Contemporary China. Martin King Whyte and William L. Parish. The Demand for Energy in the Soviet Union. David Wilson. London and Canberra: Rethinking Geographical Inquiry. J. David Wood, ed.  相似文献   

微型计算机与卡片输入机联机通信中疑难问题的解决     

王晋成 《成都信息工程学院学报》1989,(3)

本文强调了解决微机与卡片输入机联机通信疑难问题的社会经济效益及迫切性。介绍了分析解决问题的全过程:首先为提高硬件的可靠牲作了改进与优化,进而对驱动软件的结构和功能作了细致地分析,最后再把二者的联系作为一个整体加以系统考虑并对二者的时间关系作了计算,采用较为简单的办法解决了这一表面上显得复杂的问题。从而大大提高了工作效率,仅用三个月就完成了一年的卡片转换任务。  相似文献   

用苹果机实现24路气象电报自动转报系统     

自动转报系统课题组 《成都信息工程学院学报》1987,(1)

本文介绍了用两台苹果机实现的气象电报自动转报系统的硬件组成,软件组成和实现的功能。  相似文献   

水泥搅拌桩施工技术浅谈     

周海成 《中国勘察设计》2006,(3):56-59

通过工程实践，从施工角度对水泥搅拌桩施工技术进行全过程分析总结。  相似文献   

基于移动通信/GPS/GIS技术的智能公交系统技术和功能     

兰燕  刘珊红  戴晓爱 《四川测绘》2007,30(4):155-158

本文针对国内公共交通拥堵、效率低的现状,提出了基于移动通信/GPS/GIS技术的智能公交系统的解决方案,该系统能在很大程度上缓解目前公共交通拥堵的现状。本文主要介绍了智能公交系统的关键技术以及系统构成。  相似文献   

 国土资源遥感技术进展与展望   总被引：2，自引：2，他引：2  

熊盛青 《国土资源遥感》2007,18(4):1-6

本文简要回顾了中国国土资源航空物探遥感中心的遥感技术发展历程，着重介绍新一轮国土资源大调查实施以来的主要技术进展与应用成果，并对今后我国国土资源遥感技术的发展方向进行分析。  相似文献   

Review on researchesof nitrous oxide inthe Southern Oceanand relative new technologies   总被引：1，自引：0，他引：1  

Zhang Jiexia  Zhan Liyang  Chen Liqi 《地球科学进展》2013,28(11):1201-1208

Nitrous oxide is an important greenhouse gas,which has a long lifetime of about 120 years and has a 310 times greenhouse effect than CO₂. Since the industrial revolution, the atmospheric N₂O concentration has increased significantly by 20%. Ocean is a net source, about 1/3 of total oceanic souce. Southern Ocean is an important part of the global ocean system, has a unique hydrological characteristics. So far it is regarded as a significant natural source to the global N₂O flux according to the model studies. However,the field work is very limit, due to the fierce in situ conditions. The importance of N₂O reseaches of Southern Ocean, progresses of nitrous oxide researches, especially new technologies applied to underway N₂O measurements in the Southern Ocean are reviewed. The advance of field, model studies and their problems or uncertainties that need to be resolved are also discussed. The using of stable isotope methods will provide powerful tools for marine N₂O mechanism. Development of high precision monitoring technology is generally the driving force of future research. Developing techniques of laser spectroscopy in marine N₂O studies and measurment of N₂O in sea ice will provide powerful tools to differeciate the N₂O source sink characteristic, constrain their budget and formation mechanism in region such as Southern Ocean.  相似文献