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一种大周期新型漏波天线设计
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作者 左丽 《天线学报》 2021年第4期35-43,共9页
传统周期漏波天线所支持的工作波长与周期间距相比拟,天线设计自由度很有限。基于主模一致性,本文提出一种大周期漏波天线,其基本周期由三个不同的物理单元通过中线一致的原则排列组成,通过设计调整天线尺寸使三个周期单元的波数相同,... 传统周期漏波天线所支持的工作波长与周期间距相比拟,天线设计自由度很有限。基于主模一致性,本文提出一种大周期漏波天线,其基本周期由三个不同的物理单元通过中线一致的原则排列组成,通过设计调整天线尺寸使三个周期单元的波数相同,一致的主模保证了每个单元对电磁波相位延迟相同,这使天线的工作波长仅为物理周期间距的三分之一,因此该天线展示出更大的电尺寸。另一方面,由于单元结构及排列具有较高的设计自由度,天线更易于集成在表面路径复杂的共形系统中。最后制作并测试了天线实物,实测结果表明该天线工作在6.4 GHz到9.55 GHz频率范围内,实测S11在工作频段内基本都小于−10 dB,最大增益为14.1 dBi。测试结果与仿真结果相一致,证实了该设计的有效性。 展开更多
关键词 主模一致 大周期 电尺寸 设计自由度
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Three Elements That Affect the Realisation of Subject-Verb Agreement in the Speech Production of L2 Speakers of English with L1 Chinese 被引量:1
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作者 Yi MA Yige Zou 《Chinese Journal of Applied Linguistics》 2018年第3期376-395,398,共21页
The experiment presented in this research is targeting a 'positional' stage of a 'modular' model of speech production originally proposed by Levelt (1989), Bock & Levelt (1994), where selected lemmas are inse... The experiment presented in this research is targeting a 'positional' stage of a 'modular' model of speech production originally proposed by Levelt (1989), Bock & Levelt (1994), where selected lemmas are inserted into syntactic frames. Results suggest a difference between L1 and L2 English speakers at the positional stage. While this might suggest that the speech planning process is different in native and non-native speakers, an alternative view is also proposed that the observed differences are the result of differences in the way that linguistic forms are stored, rather than a fundamental difference in the way that speech is planned. This result indicates main verb, copula be & local dependency effect are the three elements that affect the realization of English subject-verb agreement, and helps us locate the phase where L2 subject-verb agreement errors happen. 展开更多
关键词 second language production speech production model L2 subject-verb agreement local dependency effect
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Perturbative Treatment for Stationary State of Local Master Equation
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作者 aian-Ying Du Fu-Lin Zhang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2018年第7期38-42,共5页
The local approach to construct master equation for a composite open system with a weak internal coupling is simple and seems reasonable. However, it is thermodynamic consistent only when the subsystems are resonantly... The local approach to construct master equation for a composite open system with a weak internal coupling is simple and seems reasonable. However, it is thermodynamic consistent only when the subsystems are resonantly coupled. Efforts are being made to understand the inconsistency and test the validity of the local master equation. We present a perturbative method to solve the steady-state solutions of linear local master equations, which are demonstrated by two simple models. The solving process shows the stationary state as the result of competition between incoherent operations and the unitary creating quantum coherence, and consequently relate quantum coherence with thermodynamic consistency. 展开更多
关键词 perturbation theory stationary state local master equation quantum coherence thermodynanficconsistency
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