Results 11 to 20 of about 93,560 (164)
, 2021 本发明涉及一种线性调频连续波中频接收雷达及信号处理方法，雷达系统包括延时器、发射天线、接收天线、混频器、模拟带通滤波器、模数转换器(ADC)、数字信号处理模块。本发明将线性调频连续波作为一种线性调频连续波中频接收雷达的基准信号，基准信号经过延时器作为发射信号，将接收天线的接收信号与参考信号混频，得到混频后的中频信号；将混频后的中频信号经带通滤波器后，进行离散采样。本发明利用通过设置时延的方式设计一种线性调频连续波中频接收雷达，避免低频噪声对信号的干扰 ...
丛日刚 +5 more
core
, 2023 针对特高压直流闭锁等原因造成的受端电网频率严重跌落问题，提出一种储能紧急频率控制策略。首先，建立储能参与紧急频率控制的数学模型。其次，对于大功率缺额后发电机组惯性响应不足问题，提出了改进的频率变化率（rate of change of frequency，RoCoF）下垂控制策略以提高储能的惯量支撑，根据储能比例分配系数实时调节储能虚拟惯性及下垂控制出力；惯性响应阶段以RoCoF下垂控制为主、虚拟惯性控制为辅，抑制系统频率变化率；结合频率调节需求和储能系统出力特点提出不同区域的调频策略 ...
葛乐, 郝雨辰, 高水朋, 苏大威
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International Journal of Applied Linguistics, EarlyView.ABSTRACT Self‐directed Learning (SDL) is an important skill for learners of all ages and phases of life. Generative AI facilitates self‐directed second language (L2) learning by providing interactive, personalised access to online resources. However, existing research on AI‐assisted self‐directed L2 learning focuses on adult learners in higher ...
Qing Ma +4 more
wiley +1 more source
International Journal of Applied Linguistics, Volume 36, Issue 4, Page 3040-3055, November 2026.ABSTRACT Multilingual students in Anglophone universities often operate in survival mode. While translanguaging supports learning, critical gaps remain in understanding how translanguaging pedagogies transform and sustain motivation in English‐dominant contexts.
Melissa Jufenna Slamet, Julie Choi
wiley +1 more source
Rare Metals, Volume 45, Issue 10, October 2026.ABSTRACT Reflection loss (RL) ≤ −15 dB (corresponding to 96.875% electromagnetic energy absorption), a core metric for moderate‐ to high‐temperature (< 600°C) electromagnetic protection materials, is critical for ensuring the reliability of aerospace high‐temperature structural components.
Chunyan Ding +10 more
wiley +1 more source
He jishu超导腔的频率稳定性是超导质子直线加速器稳定运行的关键。频率调谐器作为超导腔系统的重要组成部分，用于补偿或抑制在超导腔运行过程中由于液氦压力波动、洛伦兹力、束流负载效应和麦克风效应等因素导致的腔体频率失谐，从而确保超导腔的谐振频率与加速器的主参考源频率保持一致。针对HWR010铜铌复合超导腔的高机械强度和大体积特点，以及腔体对频率调谐高精度和快响应的需求，研发了一套氦气驱动的机械频率调谐器，该系统通过脉冲调制控制，实现了在低温、真空和辐射等恶劣环境下的稳定运行。利用ANSYS软件设计了调谐器的机械结构 ...
刘 鲁北 +7 more
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Rare Metals, Volume 45, Issue 10, October 2026.ABSTRACT Magnetic particles coated with carbon shells have been considered as promising electromagnetic wave absorption materials with antibacterial features. However, how to precisely control the monodispersed magnetic nanoparticles on a carbon matrix to manipulate impedance matching and antibacterial performances is still a key challenge.
Xiaofei Li +10 more
wiley +1 more source
Estimating the total mortality of seabirds following a marine heat wave
Conservation Biology, Volume 40, Issue 5, October 2026.Abstract Marine heat waves detrimentally affect a range of marine species, including seabirds, and are increasing in frequency and severity. When thousands of dead seabirds wash up on beaches, the public becomes concerned. However, the number of dead birds recorded on beaches is only a fraction of the total mortality; most birds perish at sea.
Jennifer L. Lavers +3 more
wiley +1 more source
四川大学学报. 自然科学版, 1998 指出了直接和间接锁相调频的缺点，提出了改进措施．采用锁相两点调频，对锁相两点调频的跟踪性能进行了分析．分析表明：锁相两点调频可以扩展调频器的下限调制频率 ...
杨平先
doaj
Neutral interactions among non‐native plants are common
New Phytologist, Volume 252, Issue 1, Page 292-309, October 2026.Global distribution of studies and overall effect of co‐invasion for all metrics of non‐native plant performance combined. Summary Globalization has accelerated the establishment of non‐native plant species, increasing the prevalence of multispecies co‐invasions; yet interactions among co‐invaders remain poorly understood.
Feng He +7 more
wiley +1 more source