Results 101 to 110 of about 16,705 (195)
Latin American Policy, Volume 17, Issue 1, March 2026.ABSTRACT The rise of ride‐hailing platforms has profoundly transformed urban mobility in Latin America over the past decade. Transportation Network Companies such as Uber, DiDi, Cabify, InDrive, and others operating in the region have affected transportation patterns and intensified debates around labor relations, algorithmic management, regulatory ...
Ronald Sáenz‐Leandro
wiley +1 more source
Gaoya dianqi广泛应用于高压换流站的干式空心电抗器承受频率含量丰富的谐波电流作用，产生严重的振动及噪声污染问题。干式空心电抗器通常为多层包封结构，文中以一台双层包封的电抗器为例，对其在不同谐波激励下的振动及噪声特性开展了研究，结合磁场力仿真和模态试验分析，明确了内外层包封之间的振动响应的关系，及整体声场的辐射特性。研究结果表明，空心电抗器在不同谐波电流激励下的振动分布受其模态特性主导，内外层包封的振动形态均呈现明显的波峰波谷分布，且与临近固有频率对应的模态振型相似；内外层包封在同一电流激励下的振动幅值和相位相近 ...
高璐 +5 more
doaj
Design of a six bit full differential successive approximation analog to digital converter with 40M [PDF]
, 2015 当今社会信息产业发展迅猛，性能优良、低成本的片上系统在集成电路设计领域中越来越受到人们的重视，且芯片上能够集成的功能越来越多，这其中就包括各种各样的模数转换器。在通信过程中，电子产品往往依赖强大的大规模集成电路技术在数字域对信号进行高效的分析和处理，而最初输入的信号却是模拟信号，模数转换器能将模拟信号有效转换成与之对应的数字信号，因而起着非常关键的作用，它的性能往往决定着产品的整体性能。 在北斗多模导航片上系统SOC的ADC设计中，我们需要在保证较大的jammer情况下能无失真采样 ...
邹佳
core
Sexuality, Gender &Policy, Volume 9, Issue 1, February 2026.ABSTRACT The purpose of this study is to determine the relationship between productivity and socioeconomic characteristics, as well as the degree to which job satisfaction and engagement can strengthen or moderate this association. With a focus on the mediating roles of job satisfaction and job engagement, this study examines the complex relationship ...
Abdullah Al Masud +6 more
wiley +1 more source
房室结内折返伴有前向传导延缓的旁观者副束所致宽QRS性心动过速
Zhongshan Daxue xuebao. Yixue kexue ban, 1986 本文报道一例非常独特的复发性宽QRS心动过速。窦性心律时PR间期及QRS形态正常,快速心房起搏时出现左束支阻滞伴电轴左偏的预激图型。电生理检查证实其副束具有前向传导延缓及渐减性传导的特性,其心动过速符合房室结折返性心动过速特点。诱发性心动过速的第1个QRS形态正常,其后则为与快速心房起搏形态相同的宽QRS。在心动过速中心室期前刺激能夺获心室及心房而不造成心动过速的中断或节律重整。作者认为此例心动过速的机制最可能是房室结内折返伴有前向传导延缓的旁观者房室副束。文中详细地讨论了本例与结室副束(Mahaim ...
doaj
Gaoya dianqi, 2013 为了研究断路器分、合闸过程的动态特性,笔者针对一台配永磁操动机构的真空断路器,基于虚拟样机技术建立了断路器的动力学模型,推导出模型动作过程所满足的运动方程及电磁方程,对真空断路器的分闸、合闸动态过程进行仿真分析与实验对比。仿真和实验结果表明,模型的动态特性满足断路器的技术参数及实验数据的要求,为研究断路器的优化设计和故障诊断提供了依据。
林莘, 曹辰, 李斌, 徐建源
doaj
Functional Ecology, Volume 40, Issue 2, Page 534-552, February 2026.Read the free Plain Language Summary for this article on the Journal blog. Abstract Non‐structural carbohydrates (NSC) are critical mediators of plant adaptation to fluctuating light environments. They are tightly coordinated with plant economic strategy, that is, leaf economics spectrum (LES) and root economics spectrum (RES).
Lulu Xie +6 more
wiley +1 more source
Dianci bileiqi, 2020 特高压直流极母线避雷器在运行过程中容易出现电流涌动干扰,会对其运行安全性产生不良影响。提出了一种基于直流振荡频率负阻尼特性分析的特高压直流极母线避雷器运行安全测试技术。以电压、基线电流、电磁感应强度等参数为约束参数,模糊相关性融合特征量方程;建立特高压直流极母线避雷器的稳态控制模型;基于直流振荡频率负阻尼特性,采用模糊信息融合方法进行特高压直流极母线避雷器运行状态的稳态模型构造;建立特高压直流极母线避雷器运行稳态特征方程,结合正阻尼重构的的稳定控制方法进行特高压直流极母线避雷器运行状态特征分析 ...
赵珏斐, 芮新花
doaj
A Current Harmonics Detection Method Based on Input Observer Theory [PDF]
, 2016 基于输入观测器理论,对电流谐波在线检测问题进行了研究,得到了一种能够快速准确地提取电流信号中各频率分量的方法。首先,将被测电流信号和其各频率的分量作为状态量,构建线性时变的状态空间模型。然后,设计基于状态空间模型的观测器对未知状态变量进行在线观测,从而实现各频率分量的信息提取。所设计的观测器是时变的,其稳定性和收敛性由Lyapunov定理及Lasalle不变集原理所证明。最后,搭建仿真和实验平台对该方法进行验证,结果表明其具备检测速度快、精度高、动态跟踪性能和抗干扰性好等优点。Based on the ...
张怡茹, 李钷
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Genetic origins and climate‐induced erosion in economically important Asian walnuts
Conservation Biology, Volume 40, Issue 1, February 2026.Abstract The global climate is undergoing unprecedented changes, posing significant threats to species persistence. However, the spatiotemporal impacts on genetic diversity remain poorly understood, hindering species conservation and management. Walnuts, generally referred to as Juglans regia and J. sigillata, are economically vital in Asia, but little
Peng‐Zhen Fan +17 more
wiley +1 more source