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Lughawiyah: Journal of Arabic Education and Linguistics, 2020 Ïú┘çϻϺ┘ü ┘çÏ░Ϻ Ϻ┘äϿϡϽ ┘äÏÑ┘åϬϺϼ Ϻ┘ä┘êÏ│┘è┘äÏ® Ϻ┘äϬÏ╣┘ä┘è┘à┘èÏ® Ï¿┘åϩϺ┘à Ϻ┘äÏÑ┘åϼ┘ä┘èÏ▓┘èÏ® Ï¿Ï»┘ê┘å ÏÁÏ╣┘êÏ¿Ï® ϿϺÏ│ϬϫϻϺ┘à ϬÏÀÏ¿┘è┘é Ïú┘åÏ»Ï▒┘ê┘èÏ» ┘äϬÏ▒┘é┘èÏ® ┘à┘çϺÏ▒Ï® Ϻ┘ä┘â┘äϺ┘à ┘ü┘ë Ϻ┘ä┘äÏ║Ï® Ϻ┘äÏ╣Ï▒Ï¿┘èÏ®Ïî ┘ê┘ä┘àÏ╣Ï▒┘üÏ® ϬÏÁÏ¡┘èÏ¡ Ϻ┘ä┘à┘åϬϼ ┘ê ┘ä┘àÏ╣Ï▒┘üÏ® ┘å┘à┘êÏ░Ï¡ Ϻ┘äϬÏ╣┘ä┘à Ϻ┘ä┘à┘åϺÏ│Ï¿ ┘äϬÏÀÏ¿┘è┘é Ϻ┘ä┘à┘
Robby Arinil Asror +2 more
openaire +2 more sources
基于逐次变分模态分解的飞轮-火电一次调频控制策略 [PDF]
全球能源互联网随着新型电力系统的大力建设与推广，火电机组面临的调频压力增大，提出一种逐次变分模态分解的飞轮-火电一次调频控制策略。首先，以飞轮储能和火电机组为研究对象，建立考虑新能源占比的飞轮-火电一次调频模型；其次，将一次调频功率指令利用逐次变分模态方法分解，由火电机组响应分解后的低频功率指令，同时设计飞轮储能下垂优化控制方法，实现飞轮储能与火电机组响应频率变化的协同控制；最后在不同工况下仿真验证，结果表明所提策略可有效避免火电机组一次调频时的频繁出力，减小火电机组响应频率变化时的调控要求 ...
张萍, 刘海涛
doaj +1 more source
全球能源互联网, 2019 由于柔直电网“隔离”了频率信号，互联多区域协同调频问题亟待研究。现有研究大多利用换流站的下垂控制以及直流电压偏差实现频率信号的传递，但忽略了风电集群接入后由风电功率正常波动引起的直流电压偏差干扰，可能导致风电集群在无需调频时频繁地调整出力。对此，提出了基于直流电压偏差及其特征量的多区域协同调频策略，分别针对电网频率偏移和风电功率波动两种场景提取直流电压偏差特征量，包含电压变化量、电压变化率和滤波后的电压分量幅值3个特征，并基于二者的差异设置换流站启动下垂控制的判据。仿真结果验证了所提方法的有效性。
崔阳 +5 more
doaj +1 more source
Conservation Biology, EarlyView.Abstract Knowledge of species distributions is essential for informing policies on nature conservation and restoration. However, updating them on a regular basis and doing so in a harmonized manner at the international level is difficult. The European Bird Census Council integrated national monitoring data covering 5 years to update farmland bird ...
Sergi Herrando +54 more
wiley +1 more source
Estimating the total mortality of seabirds following a marine heat wave
Conservation Biology, EarlyView.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
Uncovering correlates of decline and critical refuges for a threatened terrestrial mammal
Conservation Biology, EarlyView.Abstract Globally, the geographic ranges of numerous species are contracting. Identifying spatiotemporal patterns of threat impact can illuminate why species decline in some parts of their range but persist in others. We developed a correlative approach to identify species’ response thresholds and locate ecological refuge areas associated with ...
Natalya M. Maitz +5 more
wiley +1 more source
, 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
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
doaj +1 more source
International Journal of Applied Linguistics, EarlyView.ABSTRACT This study investigates how the learner‐related factors of language dominance, encompassing language history, proficiency, use, and attitude, modulate congruency effects in multi‐word unit (MWU) processing among early bilinguals. Seventy Cantonese–Putonghua bilinguals completed lexical decision tasks measuring reaction time and accuracy for ...
Mingjia Cai, Yuan Liang
wiley +1 more source
International Journal of Applied Linguistics, EarlyView.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