Results 51 to 60 of about 17,412 (176)
Dynamical Mechanisms of Upper Oceanic Response to Tropical Cyclones [PDF]
海洋对热带气旋的响应和反馈机理是海洋与大气科学的研究热点,也是准确预报热带气旋强度和相关海洋环境变化的关键所在。本文结合现场观测、数值模拟和理论分析,着重研究上层海洋对热带气旋的响应特征和机制。首先采用2014年和2016年两组南海北部的浮标/潜标实测资料,针对几个过境的热带气旋(特别是台风海鸥)开展个例分析和数值模拟;在此基础上,再从理论上进一步探讨一般情况下海洋对热带气旋的动力学响应机制。 台风海鸥于2014年9月经过南海观测阵列上空,导致局地风速迅速增加并伴随着大气压强降低、路径右侧(左侧 ...
张翰
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Emerging applications of large language models in ecology and conservation science
Abstract Large language models (LLMs) mark a major development in artificial intelligence, with potentially transformative implications for ecology and conservation science. Built on advanced deep‐learning architectures, these models can support a wide range of tasks. We reviewed emerging applications of LLMs, drawing on the wider scientific literature
Christos Mammides +5 more
wiley +1 more source
强台风下高压输电线路塔—线耦联体系的力学行为仿真分析二:动力响应分析
风载荷是影响高压架空输电线路安全运行的重要因素,为分析塔—线耦联体系的动力响应规律,以广东湛江某220 kV输电线路为背景,在ANSYS有限元开发环境下,建立三基塔两回线塔—线耦联体系有限元模型。基于Davenport脉动风速功率谱,考虑湛江当地气象条件,模拟生成风速时程,在风速时程作用下,对耦联体系进行风致动力响应分析,并将铁塔动力响应结果与拟静力计算结果进行对比。分析发现,动力分析铁塔顺线路位移是规范拟静力的5.2倍左右,垂直线路位移是静力分析的1.3倍左右 ...
贺博 +5 more
doaj
Surface Sediment Grain-Size Characteristic and Its Indicative Significance on Quanzhou Sea Area in the Taiwan Strait [PDF]
沉积物粒度是沉积地质学中一项重要的动力指标,不同物质来源和沉积环境具有不同的沉积物粒度参数特征及其组合。本文通过分析台湾海峡泉州幅609个表层沉积物类型、粒度含量及粒度参数分布特征,利用粒度数据提取粒级组分信息,其中包括EMMA法、Weibull密度函数拟合法及粒度-标准方差法的运用与对比,并运用粒度趋势分析方法对泉州幅沉积物净运移趋势进行分析,结合浙闽沿岸流、台湾暖流、台湾岛西岸及闽东河流物质的输入背景,反演台湾海峡泉州幅的沉积环境,同时区分不同海域主要物质来源 ...
梁群峰
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ABSTRACT Generative artificial intelligence (GenAI) has emerged as a powerful tool in the Informal Digital Learning of English (IDLE) environment, offering personalized, interactive, and innovative language learning experiences that may enhance learning engagement.
Jin Liu, Meilu Liu, Yuan Yao, Dechao Li
wiley +1 more source
Synthesizing Empirical Research on Learner Metacognition in Second Language Writing
ABSTRACT Despite considerable research interest in learner metacognition in second language (L2) writing, there is not yet a review that synthesizes the existing empirical findings and discusses their implications. To fill the void, this systematic review synthesized 39 empirical studies on learner metacognition in L2 writing and examined their salient
Chen Li, Icy Lee, Zhicheng Mao
wiley +1 more source
ABSTRACT This study examines how foreign language teachers’ beliefs about the medium of instruction and translanguaging evolve over time by revisiting three in‐service teachers twelve years after their initial interviews. Using a qualitative longitudinal design, the study traces how translanguaging was initially framed as pedagogically deficient but ...
Danping Wang
wiley +1 more source
文中通过在动力学仿真软件中建立断路器运动仿真模型,设置不同程度的合闸弹簧应力松弛故障,分析了合闸弹簧应力松弛对断路器操动机构运动特性的影响;采集了断路器操动机构合闸弹簧在正常及应力松弛故障下的振动信号,提出一套基于小波包敏感频段能量法的断路器合闸弹簧应力松弛故障的诊断方法。试验表明,该方法能够有效地区分弹簧是否发生应力松弛故障。
杨韧 +7 more
doaj
为探究网侧设备对±800 kV换流变地震响应的影响,以某典型换流变—套管体系为对象,建立其单体有限元模型以及考虑网侧设备连接的耦联模型。网侧套管顶部滑动连接金具采用滑动接触单元进行了模拟,计算分析了地震作用下模型前20阶模态以及套管加速度、位移、应力响应。结果表明:①特高压换流变—套管体系前20阶频率接近地震卓越周期,震中易发生类共振;②网侧设备对换流变阀侧套管地震响应无影响,但会显著放大网侧套管顶部位移响应和根部应力响应;③地震作用下,网侧套管顶部连接金具内部的相对滑移响应显著。因此 ...
杨旭 +5 more
doaj
Real-time identification of time-varying structures and integration with vibration control based on extended Kalman Filter with unknown inputs [PDF]
建筑结构的参数识别与损伤诊断是结构健康监测领域中的一项重要课题。在过去的数十年内,业内许多专家与学者给出了理论各异的,基于结构振动响应的参数识别与损伤诊断方法。然而,这其中的许多方法,大都是针对于时不变系统的。但在重大荷载发生时(如高烈度地震等),结构单元发生损伤,它的物理参数(如刚度等)在荷载作用中是随时间变化的。为了实时地捕捉这一变化,结构健康监测系统应该具备在线地识别时变结构参数的能力。 因此本论文在第二章,在前人基础上得到了基于改进的自适应卡尔曼滤波的时变系统在线识别方法。与现有文献相比 ...
王龙飞
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