欺骗干扰能够获得距离和方位向压缩增益,使用较小功率即可实现对合成孔径雷达(SAR)的有效干扰。针对SAR的欺骗干扰抑制问题,提出了基于多个互正交多相编码在脉间捷变的抗干扰方法。利用加权循环算法,优化多相编码,提高自相关峰值,降低...欺骗干扰能够获得距离和方位向压缩增益,使用较小功率即可实现对合成孔径雷达(SAR)的有效干扰。针对SAR的欺骗干扰抑制问题,提出了基于多个互正交多相编码在脉间捷变的抗干扰方法。利用加权循环算法,优化多相编码,提高自相关峰值,降低自相关旁瓣和互相关峰值,提高抗转发式欺骗干扰性能。通过仿真比较了模拟退火算法、遗传算法优化多相编码与本文优化所得多相编码的自相关和互正交性能,并从多个不同干扰功率入手,对研究的多相编码抗欺骗干扰性能与二相编码进行了对比,20 d B干扰时该方法仍可达到88%的检测概率,证明了方法有效性。展开更多
Anthropogenic aluminum cycle in China was analyzed by the aluminum flow diagram based on the life cycle of aluminum products. The whole anthropogenic aluminum cycle consists of four stages: alumina and aluminum produ...Anthropogenic aluminum cycle in China was analyzed by the aluminum flow diagram based on the life cycle of aluminum products. The whole anthropogenic aluminum cycle consists of four stages: alumina and aluminum production, fabrication and manufacture, use and reclamation. Based on the investigation on the 2003-2007 aluminum cycles in China, a number of changes can be found. For instance, resources self-support ratio (RSR) in alumina production dropped from 95.42%to 55.50%, while RSR in the aluminum production increased from 52.45%to 79.25%. However, RSR in the Chinese aluminum industry leveled off at 50%in the period of 2003-2007. The respective use ratios of domestic and imported aluminum scrap in the aluminum industry of 2007 were 5.38% and 9.40%. In contrast, both the net imported Al-containing resources and the lost quantity of Al-containing materials in aluminum cycle increased during the same period, as well as the net increased quantity of Al-containing materials in social stock and recycled Al-scrap. Proposals for promoting aluminum cycle were put forward. The import/export policy and reducing the loss of Al-containing materials for the aluminum industry in China in the future were discussed.展开更多
文摘欺骗干扰能够获得距离和方位向压缩增益,使用较小功率即可实现对合成孔径雷达(SAR)的有效干扰。针对SAR的欺骗干扰抑制问题,提出了基于多个互正交多相编码在脉间捷变的抗干扰方法。利用加权循环算法,优化多相编码,提高自相关峰值,降低自相关旁瓣和互相关峰值,提高抗转发式欺骗干扰性能。通过仿真比较了模拟退火算法、遗传算法优化多相编码与本文优化所得多相编码的自相关和互正交性能,并从多个不同干扰功率入手,对研究的多相编码抗欺骗干扰性能与二相编码进行了对比,20 d B干扰时该方法仍可达到88%的检测概率,证明了方法有效性。
基金Projects (71003018,71373003) supported by the National Natural Science Foundation of ChinaProjects (N110402003,N120302004) supported by the Fundamental Research Funds for the Central Universities,ChinaProject (13YJCZH172) supported by the Ministry of Education of China of Humanities and Social Sciences
文摘Anthropogenic aluminum cycle in China was analyzed by the aluminum flow diagram based on the life cycle of aluminum products. The whole anthropogenic aluminum cycle consists of four stages: alumina and aluminum production, fabrication and manufacture, use and reclamation. Based on the investigation on the 2003-2007 aluminum cycles in China, a number of changes can be found. For instance, resources self-support ratio (RSR) in alumina production dropped from 95.42%to 55.50%, while RSR in the aluminum production increased from 52.45%to 79.25%. However, RSR in the Chinese aluminum industry leveled off at 50%in the period of 2003-2007. The respective use ratios of domestic and imported aluminum scrap in the aluminum industry of 2007 were 5.38% and 9.40%. In contrast, both the net imported Al-containing resources and the lost quantity of Al-containing materials in aluminum cycle increased during the same period, as well as the net increased quantity of Al-containing materials in social stock and recycled Al-scrap. Proposals for promoting aluminum cycle were put forward. The import/export policy and reducing the loss of Al-containing materials for the aluminum industry in China in the future were discussed.