共查询到7条相似文献,搜索用时 93 毫秒
1.
2.
本文闸明了地球站天线产生极化夹角的原理;导出了计算极化夹角的公式;给出了全国各地具有代表性的一些地球站极化夹角值,供有关研制人员和操作人员调整地球站天线消除极化夹角影响之参考。 相似文献
3.
本文简述了AsiaSatl号卫星(105.5°E)的情况,根据AsiaSat/EM/So**/Issue 01系列文件,介绍了地球站天线系统入亚洲卫星通信网的技术规范及配备的测试系统。 相似文献
4.
5.
本文主要论述了微波、卫星通信局站为了抑制来自外界空间电视、广播信号的干扰,在抗干扰过程中,根据不同的干扰引入渠道,查找干扰入口的途径,采用接地、屏蔽和滤波来解决于扰的方法。 相似文献
6.
Tendai Chikweche Richard Fletcher 《International Review of Retail, Distribution & Consumer Research》2013,23(4):343-360
Bottom of the Pyramid (BOP) markets provide distinct marketing challenges to firms either serving these markets or intending to enter these markets. BOP markets have often been criticised for having weak supporting infrastructure such as inefficient or non-existence of distribution systems which hinder firms' ability to distribute products to consumers. Franchising is one distribution strategy which firms can use to enhance distribution at the BOP. Using findings from research conducted in Zimbabwe, this article demonstrates how firms can use franchising as a distribution strategy to facilitate distribution of products to those at the BOP. Both consumers and firms derive benefits from the use of franchising. Firms face distinct challenges in using this strategy and need to re-invent the way they do business. 相似文献
7.
海内外各界对新四军抗战的经济支援 总被引:1,自引:0,他引:1
新四军之所以能在艰苦的环境里不断发展起来,并且没有发生八路军1941~1942年间出现的严重困难局面,除了新四军所在的华中地区比较富庶外,还得力于海内外各界对新四军的巨大经济支援。海内外各界的经济支援,保障了新四军最迫切的医药、衣被、器械等方面的急需,为新四军坚持华中敌后抗战提供了强有力的物质支撑。 相似文献