共查询到20条相似文献，搜索用时 46 毫秒
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The mathematical modeling of most physical systems, such as aerospace systems, heat processes, telecommunication systems, transmission lines and chemical reactors, results in complex high order models. The complexity of the models imposes a lot of difficulties in analysis, simulation and control designs. Several analytical model reduction techniques have been proposed in literature over the past few decades to reduce these difficulties. However, most of the optimal techniques follow computationally demanding, time consuming, iterative procedures that usually result in non-robustly stable models with poor frequency response resemblance to the original high order model in some frequency ranges. Genetic Algorithm (GA) has proved to be an excellent optimization tool in the past few years. Therefore, the aim of this paper will be to use GA to solve H2 and H∞ norm model reduction problems, and help obtain globally optimized nominal models. 相似文献
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The inherent brittleness and low sustainability of YBa2Cu3O7-x(YBCO) bulk superconductor seriously impede its wide applications.It is a great challenge to achieve toughening of this material and maintain its invariable superconductivity at the same time.Here,we fabricate bulk YBCO composite superconductor with a density of 2.15 g cm-3,which consists of interlocking dual network construction and shows high toughness and durability.The results show that ... 相似文献
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We consider robust optimization equilibrium for the bimatrix game based on robust optimization method. In this paper, each player may neither exactly estimate his opponent's strategies nor evaluate his own cost matrix accurately while may estimate a bounded uncertain set. We obtain that the robust optimization equilibrium problem can be formulated as a mixed complementarity problem (MCP) under l1∩l∞-norm. Some numerical examples are presented to illustrate the behavior of robust optimization equilibrium. 相似文献
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基于2000-2019年江西省相关时间序列数据,运用VAR模型分析农业科技创新、技术效率与农业经济发展之间的动态关系。研究结果表明：农业科技创新对农业经济发展的相互效果是正向的,而技术进步对农业经济发展的相互作用结果复杂,在不同时期的作用和方向不一致。相对于技术进步,农业科技创新对农业经济发展的贡献率较大。农业科技创新、农业技术效率与农业经济增长之间存在长期稳定均衡的关系,但农业科技创新投入对农业经济增长的短期影响更为显著。因此,要发挥农业科技创新与技术效率之间的相互促进作用,以科技创新促进农业经济发展,推动农业可持续发展。 相似文献
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化学灾害发生后,个体风险感知水平和客观风险水平之间的差距会进一步影响其行为倾向和后续决策,运用系统动力学软件Vensim构建模型来研究二者之间差值的拟合过程,可以更为清晰的看出风险地传播过程,特别是化学事故所引发的舆情风险和污染风险的传播情况,进而得出控制风险的几个关键时间点以及相关措施。 相似文献
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针对广东省能源发展及碳排放现状进行分析,认为在碳中和目标下,氢能开发利用在保障能源安全及低碳转型中扮演重要角色.广东省氢能利用及产业发展在全国居于领先水平,主要体现在氢能产业链布局已具雏形、氢能推广应用规模领先全国,但同时也存在氢源保障不足、绿氢比例偏低、应用场景有待拓展等问题.结合广东省产业特色及优势,建议采用可再生能源电力电解水制氢、工业副产氢提纯等方式解决氢源问题,并积极探索氢能在工业领域深度脱碳、交通行业低碳转型、天然气掺氢等领域应用发展,减少工业、交通、建筑等领域对化石能源依赖,帮助难以减排领域深度脱碳,助力碳中和目标实现. 相似文献
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我国作为碳排放大国,面临着碳达峰、碳中和（以下简称“双碳”）目标任务和国际碳减排压力。因此,准确的碳排放数据对于评估“双碳”目标和国际履约非常重要。联合国政府间气候变化专门委员会（IPCC）报告推荐将二氧化碳（CO2）观测与大气反演结合来“自上而下”地校验“自下而上”的碳排放清单,并指出加入大气14CO2观测可以更准确地校验碳排放清单。放射性碳同位素（ 14C）是化石源CO2最准确的示踪剂,已被国际社会广泛推荐用于碳排放评估。文章基于大气14CO2观测的国际发展趋势和国内的紧迫状况,建议加大支持力度,建立大气14CO2观测网络;开展培训,统一相关标准,积极参与国际交流;尽快开展14CO2观测与大气反演相结合的研究。以此使我国的碳排放研究水平与国际接轨,并提高碳排放数据的可靠性,进而服务国家的“双碳”目标和气候外交谈判。 相似文献
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Jipeng Li Linhan Du Xian Kong Jianzhong Wu Diannan Lu Lei Jiang Wei Guo 《国家科学评论(英文版)》2023,(12):193-202
A biological potassium channel is> 1000 times more permeable to K+than to Na+ and exhibits a giant permeation rate of ～108 ions/s.It is a great challenge to construct artificial potassium channels with such high sele ctivity and ion conduction rate.Herein,we unveil a long-overlo oked structural feature that underpins the ultra-high K+/Na+ selectivity.By carrying out massive molecular dynamics simulation for ion transport through carbonyl-... 相似文献
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Reza Hashemian 《Journal of The Franklin Institute》1973,295(5):383-394
A class of matrices with 1, -1 and 0 entries, called the H-matrices, is introduced and properties of such matrices are investigated. It is shown that for an H-matrix K the matrix G = KDKT, where D is a diagonal matrix with nonnegative diagonal entries, has certain properties applicable to topological synthesis of networks. A technique for decomposing a particular symmetrical matrix G, called the Q-matrix, into KDKT, where K is an H-matrix and D is a diagonal matrix with positive diagonal entries, is also developed. 相似文献