Results 41 to 50 of about 275,175 (145)
Fermi Surface Structure Revealed by Quantum Oscillations in Half‐Heusler Semimetal LuAuSn
ABSTRACT The Fermi surface structure in the half‐Heusler semimetallic compound LuAuSn was systematically investigated using quantum oscillation studies of high‐quality single crystals and first‐principles calculations. Clear bulk quantum oscillation signals were observed for multiple complementary physical properties, including magnetization, Hall ...
Yue Lu +12 more
wiley +1 more source
该文回顾了中国振动工程学会随机振动专业委员会成立后的10年间我国学者在随机振动领域所进行的理论、应用技术研究方面取得的一些重要进展。着重介绍了随机非线性响应时域积分方法与空间有限元结合的随机动力有限元方法的发展 ...
欧阳怡 +3 more
core +1 more source
针对机载重型悬臂体的瞬态和稳态抑振问题,提出了基于机械手的主被动分阶段抑振方法。由于机械手动态能力有限,在瞬态阶段,振动时间短振幅大,故采用机械手固定抱夹的被动减振方式;在稳态阶段,振动为周期性小振幅,故采用机械手多臂协同的主动抑振方式。首先,将机械手被动抱夹状态下的悬臂体等效为弹性支撑悬臂梁模型,通过分段构建弹性支撑边界条件,以脉冲激励的形式引入弹性力,获得被动减振模型;其次,在模态空间的基础上得到柔性基础下的振动模型,进一步提出了基于减振因子的主动抑振算法;最后,搭建了小机械手实验平台 ...
doaj +1 more source
气体绝缘金属封闭开关设备(gas insulated switchgear,GIS)运行中时常出现异常机械振动,振动信号检测对GIS运行状态评价与故障诊断具有重要意义。基于电磁感应原理分析了三相分箱型和三相共箱型GIS设备外壳环流特性,从电磁力和磁致伸缩两个方面深入研究了GIS振动机理,基于小波时频变换提取了振动信号频谱分布特征和振动声学指纹,用于振动信号识别与诊断。现场振动检测结果表明,GIS正常振动信号频率主要集中在100 Hz,与理论分析一致,异常振动信号除100 Hz分量外 ...
丁登伟 +7 more
doaj
电力变压器受谐波驱动将产生频率含量丰富的振动和噪声,振动加速度和总体声功率增大将导致变压器机械和绝缘故障概率提高,影响电力系统运行的稳定性,难以满足国家标准要求,因此研究电力变压器的振动特性具有重要意义。文中首先分析电力变压器的振动来源和传递过程,并试验研究变压器整体的模态特性和振动特性,获得其各阶振型;在模态分析的基础上进一步搭建变压器振动信号测量平台,分别对变压器三相进行谐波激励下的负载试验与空载试验,分析谐波激励下变压器振动的传递过程,研究不同频率谐波下变压器的振动特性和相应变化规律。
董家睿, 李基民, 魏铭
doaj
Read the free Plain Language Summary for this article on the Journal blog. Abstract The nested subset pattern (nestedness) has been widely used to explain species distributions in island and fragmented systems. Mountain sky islands serve as critical natural laboratories for understanding the evolutionary consequences of geographic isolation and climate
Caiwen Zhang +5 more
wiley +1 more source
深水钻井作业过程中,管柱在平台升沉振动的作用下产生纵向振动载荷,影响管柱的强度安全。以深水下表层套管作业管柱为例,建立了具有复杂结构的深水作业管柱纵向振动力学模型,并利用振动力学理论分析了管柱的纵向自由振动特性及纵向受迫振动载荷。分析结果表明,在平台升沉振动的作用下,作业管柱的纵向振动以第1阶振型为主;管柱顶端截面上的纵向振动载荷最大,是作业管柱上的危险截面;当钻井平台的升沉振动周期接近作业管柱的固有周期时,将产生极大的纵向振动载荷;当表层套管下入深度较大时 ...
张辉, 柯珂, 王磊
doaj
ABSTRACT Harnessing solar energy for self‐heating presents an effective strategy to suppress surface ice formation. In this paper, we fabricated nano‐silver‐modified multilayer graphene sheets (Ag@MGs) that integrate photothermal and superhydrophobic properties for anti‐icing applications.
Yihan Zhang +7 more
wiley +1 more source
振动法在变压器机械故障诊断中得到了越来越广泛的应用,文中研究了变压器绕组轴向振动特性,为振动法的研究建立必要的理论基础。文中介绍了基于质量—弹簧模型的变压器绕组轴向振动机理,搭建了基于压电式加速度传感器的变压器单绕组模型振动测试平台,探究了变压器绕组轴向振动分布特点,以及负载电流波动和绕组松动对其产生的影响。实验研究发现单绕组模型轴向振动近似呈U型分布,电流波动对绕组的振动分布无明显影响,绕组的松紧程度改变,绕组的振动分布发生明显变化。
余长厅 +3 more
doaj
A Multiagent Reasoning Framework for Classical Chinese Question Answering With Large Language Models
Background Understanding Classical Chinese remains a major challenge in Chinese education, especially in the National College Entrance Examination (NCEE). Although large language models (LLMs) exhibit strong reasoning capabilities, their performance on exam‐style Classical Chinese questions still suffers from instability and limited accuracy.
Qing Liu +6 more
wiley +1 more source

