南非卫星通信应用现状

由于南非人口居住分散,发展固定通讯很不经济,因而卫星通讯则以其特有的技术优势成为南非政府解决边远地区通讯落后现状、带动地区经济发展的理想手段。南非电信公司门elkom）是目前南非唯一的公共电信运营公司,主要使用国际通信卫星组织和国际海事卫星组织的地球静止轨道通信卫星,通过由分布在全国的930个VAST卫星接收站组成的卫星数据传输网向全国提供卫星图像、话音及数据传输和国际电话连接服务。Telkom通过建在比勒陀利亚附近的国际通信卫星地面站与国际通信卫星组织万个地球静止轨道的卫星中的13个建立通讯联系,同时还使用国际…     

日本宇宙开发计划

运用、开发、研究计划 　　1.地球观测、地球科学领域 　　①运用 　　·静止气象 5号卫星 (GMS－ 5)。为了提高气象业务水平和卫星气象技术,继续运用 1995年发射的静止气象 5号卫星 (GMS－ 5)--"向日葵 5号",进行气象观测。 　　·热带雨林观测卫星 (TRMM)。运用 1997年发射的热带雨林观测卫星上搭载的降雨雷达,观测热带雨林变化,解析全球规模的能源收支机理 (该卫星由日、美两国合作完成,日本负责制造卫星上搭载的降雨雷达及发射用的 H－ II火箭;美国负责卫星本体和其他传感器 )。 　　·资源探查传感器 (ASTER)。为了进一…     

英国的航天业

概况英国是世界上少数几个掌握航天科技的国家之一。１９５７年英国成功发射了它的首枚“云雀”式亚轨道火箭；１９７１年英国在其南部的怀特岛上发射成功了英国第一颗人造地球卫星Prospero；１９７４年英国发射了第一枚地球同步轨道军用卫星Skynet－２B，这是在美国和苏联之外     

遥感技术在法国农业中的应用

法国继1986年2月发射运行的遥感卫星SPOT1型之后,于1990年1月23日又将搭乘阿利亚娜Ⅳ型火箭的 SPOT2型地球观测卫星送入运行轨道。该卫星极地轨道离地面高度为832公里,与赤道倾角为98.7°,轨道运行周期为26天。可从侧面拍摄到双重立体图象,并可在二周飞行中对同一位置进行观测。观测的方     

美国的SDI早期部署是什么?

据报道,美国的 SDI 早期部署共分三个构成部分:1.推进器阶段利用卫星上的运动能迎击武器(SBKKV),从离地球540—900公里高度的地球轨道上摧毁在发射塔进入发射状态的多弹头收藏部分还没有从火箭本体脱离时的敢方导弹。每个卫星装载5～10个 SBKKV,     

太空广告牌96年将上天

光亮度等同满月的“太空广告牌”将于九六年发射升空。 最近,美国乔治亚洲的太空推广公司,联邦政府一间核子武器实验室,及科罗拉多大学达成了一项协议,进行一项名为“环境太空月台”的计划,于九六年把一个一里长的广告卫星发射到环绕地求的轨道。该卫星以薄胶片制造,写在其表面字体及徽号将于地求上空一百八十里轨道运行,肉眼能仅见。发展商谓,从地球上     

苏联成立测绘外贸公司

苏联部长会议测绘总局从今年开始有权独立对外开展业务。为此成立了“苏联测绘对外贸易公司”,出售地图、地图集及测绘总局的其他产品,其中包括从卫星摄制的地球照片。据报道,苏联“礼炮”号航天站轨道摄制的照片已在苏联国民经济各部门得到广泛应用。苏卫星摄影可从300公里高空清晰地拍摄出地面长6米的物体。目前,只有美国和法国在世界市场出售卫     

中国航天之路

1975年11月26日,发射了一颗返回式人造卫星。1980年发射远程运载火箭。1982年,潜艇水下发射运载火箭。1984年4月8日,发射第一颗地球静止轨道试验通信卫星。1986年2月,发射实用通信广播卫星。1988年9月7日,发射试验气象卫星“风云1号”。1999年11月20日,用运载火箭发射第一艘“神舟号”试验飞船。2000年,“神舟”二号无人飞船按照预定轨道在太空飞行近7天。2002年3月25日,发射“神舟”号无人飞船。它在太空留轨运行了180天,环绕地球飞行2821圈,成功进行了一系列空间科学实验。2002年12月30日,发射“神舟”号无人飞船(“神舟”四号),进行了第…     

在电视直播卫星问题上法国面临的困难抉择

根据法国和联邦德国间电视卫星合作协议,两国共同研制的法国第一颗电视直播卫星TDF-1应该于今年下半年初由阿里亚娜火箭的第24次发射送入离地面36000公里的地球轨道。它比联邦德国的同类型的第一颗电视直播卫星晚发射半年左右。就在有关各方面正紧锣密鼓     

航天工业涉外产品投标报价研究

当今，航天技术已成为发达国家的一种重要产业，是国家经济发展、科学技术先进的象征，也是文明和昌盛的一个窗口。我国的航天技术、航天产品经过四十多年的努力和奋斗，已经跨入世界的先进行列。我国的运载火箭是具有先进水平的高技术产业，能够发射近地轨道、极地轨道和地球同步轨道的载荷；我国返回型卫星已经提供国际搭载，进行微重力环境的科学实验。这表明我国的空间技术已经取得了国际信誉，具有参与国际航天市场竟争的相对优势．摆在我们面前一个亟待解决的问题，就是如何提高我国航天涉外产品在国际市场上的中标率，既保证我们的产…     

John Stuart Mill's Theory Of Justice

John Stuart Mill has traditionally been portrayed as self-contradictory and failing to construct a unified social theory. Recent scholarship, however, has challenged this view, finding Mill's work to be creatively synthetic in bridging the antinomies inherent in liberal democratic thought. This revisionist interpretation of Mill is advanced by an understanding of his theory of justice and its role in shaping his policy positions on issues such as welfare, education, voting rights, property rights, taxation, government intervention, and the future of capitalism.     

A Rich Vein for “Reality Mining”北大核心CSSCISSCI

Arik Hesseldahl In the aftermath of the September 11 attacks, U.S. officials quickly turned their attention to other potential targets, including California's Golden Gate Bridge. What would happen if terrorists took down the bridge between San Francisco and Marin County? How much of the region would be affected and for how long?     

John Stuart Mill's Theories of Wealth and Income Distribution

Although he was much influenced by David Ricardo when he wrote the classical part of his Principles , John Stuart Mill was not a Ricardian when he penned his theories of wealth and distribution. They are based on a triple foundation. First, a belief that economics is a moral discipline. Second a theory of custom-driven human behavior. Third, an empirically formed conviction that the institutions of state, education and business cooperate to structure the distribution of income. On the basis of these presuppositions, Mill formulated 1) an institutional theory of the formation of human and non-human wealth and 2) an even more institutional theory of distribution demonstrating how the aforementioned institutions malignantly skew the distribution of income to the advantage of the propertied classes and to the extreme disadvantage of the working class. As a social economist, Mill recommended institutional reforms designed to eradicate the poverty of the working class.     

中国养活自己能力的长期预测:技术和政策分析

中国拥有世界五分之一强的人口 ,收入又在迅速增长。因此 ,国际上很自然地会考虑或推测她在今后的几十年是否有能力养活自己。中国的人口预计将从 2 0 0 0年的 1 2 8亿增长到 2 0 2 0年的 1 4 6亿 ,和 2 0 3 0年的 1 4 9亿。与此同时 ,人均收入的增长将导致对家畜和鱼类产品更大的需求 ,因而对饲料的需求也将有很大的增长     

Toward a Phylogenetic Reconstruction of Organizational Life

Synopsis Classification is an important activity that facilitates theory development in many academic disciplines. Scholars in fields such as organizational science, management science and economics and have long recognized that classification offers an approach for ordering and understanding the diversity of organizational taxa (groups of one or more similar organizational entities). However, even the most prominent organizational classifications have limited utility, as they tend to be shaped by a specific research bias, inadequate units of analysis and a standard neoclassical economic view that does not naturally accommodate the disequilibrium dynamics of modern competition. The result is a relatively large number of individual and unconnected organizational classifications, which tend to ignore the processes of change responsible for organizational diversity. Collectively they fail to provide any sort of universal system for ordering, compiling and presenting knowledge on organizational diversity. This paper has two purposes. First, it reviews the general status of the major theoretical approaches to biological and organizational classification and compares the methods and resulting classifications derived from each approach. Definitions of key terms and a discussion on the three principal schools of biological classification (evolutionary systematics, phenetics and cladistics) are included in this review. Second, this paper aims to encourage critical thinking and debate about the use of the cladistic classification approach for inferring and representing the historical relationships underpinning organizational diversity. This involves examining the feasibility of applying the logic of common ancestry to populations of organizations. Consequently, this paper is exploratory and preparatory in style, with illustrations and assertions concerning the study and classification of organizational diversity.     

Information infrastructure: Who builds broadband networks?

This paper examines the essential difference between the U.S. and Japan, when one considers information infrastructure. There are seven perception gaps between the U.S. and Japan concerning Information Infrastructure policies. These gaps must be understood in order to compare the countries' governmental policies in this area. In looking at the present circumstances, the essential question to answer concerns who is to build, own and operate the network(s) of the infrastructure. Liberalization is certain to be a central factor in the ongoing telecommunications debates. Now that customers have had a taste of the liberalized market-place, the movement toward more open markets will be difficult to stop. When considering options, it is necessary to pay close attention to standardized network access and the increasingly important role software plays. These issues are causing us to take a new approach to the traditional role played by regulators. They also force a closer look at the appropriate structure of utility companies. This paper addresses the above issues in hopes of stimulating dialog on the new telecommunications infrastructure paradigm.     

Nonlinearity in Stock Exchange Markets: The Case of Bist 100 Indices

In this paper,using data for the Bist 100 index,we investigate the presence of nonlinearities by employing several nonlinearity tests.The Brock,Dechert,and Sche...     

Solidified Branding Function: How the Urban Brand Affects a Small Town’s Development? Case Study of Wangqingtuo,Tianjin, China

Chinese small towns are usually developed with single core industry,and the urban brand is the identity of a town that formed with the development of its indust...     

海岛地区产业演替及资源基础分析--以舟山群岛为例

改革开放以来,舟山市产业构成发生了显著变化,其经济发展过程可以划分为三个阶段。1992年前,是以产业结构渔业占绝对地位的单一结构阶段;1993—1998年,以旅游业为主的第三产业快速发展阶段;上世纪末以来,又进入了新一轮的经济发展时期,即工业产值比重快速增加阶段。根据海岛的自然资源基础和特点,在新世纪的经济发展过程中,舟山市应定位为生态型的港口旅游城市。以港口及临港工业为主导,以海岛旅游和海洋经济为特色,大力发展第二产业和第三产业。海岛地区的主导产业应体现海岛资源优势及区位优势,以集群性环保型产业为主。同时由于海岛地区淡水资源缺乏,主导产业也应着重选择低耗水型产业。