Results 61 to 70 of about 18,571 (176)
Numerical Study on the Environment of Shenhu and Quanzhou Bays [PDF]
本文以福建中部的两个半封闭的海湾——深沪湾和泉州湾为研究对象,通过数值模拟的方法再现了当地的潮汐潮流,浅滩干湿变化,污染物的输运,百年一遇的台风过境引起的增水现象和台风生成的波浪特征,在此基础上进一步探讨了不同动力机制对当地泥沙动力特性的影响。 结果发现:福建沿岸的潮汐潮流以规则半日潮为主,由于潮差较大,一些浅滩、湿地和暗礁在低潮时会露出水面,在高潮时又重新被海水淹没,形成周期性的干湿变化过程。模拟结果还显示:当天文分潮由外海传入海湾时 ...
刘浩
core
Unpacking Welfare Deservingness Theory: Evidence From the Perceived Deservingness of Gig Workers
ABSTRACT The theory of welfare deservingness provides valuable insights into the social legitimacy of welfare programs and the principles underlying policy design. In examining the question of who deserves what and why, established deservingness criteria emphasize that individuals demonstrating motivation to work (“reciprocity”) are typically perceived
Juhyun Bae
wiley +1 more source
随着电网系统的快速发展,大容量、高电压电力变压器不断增多,其振动与噪声对设备自身及周边居民的健康造成的影响日益凸显,因此变压器振动与噪声及其控制受到了国内外学者的广泛关注。文中从变压器振动噪声机理、特性、影响因素以及控制措施等方面对国内外研究进展进行综述。分析了硅钢片的磁致伸缩特性及Maxwell应力特性,得出铁心振动噪声的主要来源及数学模型;根据绕组磁场分布及受力分布,分析了绕组轴向及幅向振动特性及数学模型;总结了冷却设备等部件的振动特性。从振动产生、传递到噪声辐射等过程分析了变压器传播特性。从激励 ...
汲胜昌, 师愉航, 张凡, 陆伟锋
doaj
[The study on the characteristics of active force of neck muscles under rapid braking conditions]. [PDF]
Yuan X, Li F, Lei K, Liu Q.
europepmc +1 more source
Designing Integrated Policies for the Twin Transition: Challenges and Tradeoffs
ABSTRACT Democratic governance faces the intertwined imperatives of managing the transformative risks and opportunities of digitalization, particularly stemming from artificial intelligence (AI), while achieving environmental sustainability within planetary boundaries.
Martino Maggetti
wiley +1 more source
真空断路器的动触头运动特性对其开断能力和寿命影响很大。介绍了一种控制分闸运动特性的方法,通过控制永磁机构的分、合闸线圈的接入时间,控制分闸的的运动特性。在实验室进行了试验,验证了该方法的可行性。
黄瑜珑 +3 more
doaj
ABSTRACT Background Advances in transcriptomics have driven the demand for minimally invasive, reproducible and high‐yield skin sampling methods, particularly for studying inflammatory skin diseases in companion animals. Hypothesis/Objectives We tested tolerability, feasibility and RNA quantity and quality of three minimally invasive skin sampling ...
Ina Herrmann +2 more
wiley +1 more source
碟簧作为储能元件是高压断路器用液压操动机构的重要核心部件,其优点是能在很小变形的条件下,承受范围变化很大的载荷。储能碟簧的可靠性直接影响着液压操动机构及高压断路器的整体可靠性。笔者通过碟簧力学特性分析、碟簧应力计算、碟簧力学特性曲线试验、碟簧力学时效性试验及单片碟簧断裂后对整组碟簧性能的影响试验,验证了某高压断路器用液压操动机构储能碟簧的可靠性。
周仙娥 +3 more
doaj
Investigation on Aerodynamic Characteristics of Long-Grouped High Speed Train Subjected to Crosswind [PDF]
采用定常RANS方法,对长大编组高速列车的横风气动特性进行分析,从流场特性和气动力特性两个方面开展研究。结果表明,横风条件下,列车表面流动现象非常丰富,列车首尾流线型存在较多流动分离、再附等现象,且受横风侧偏角影响较大。在列车背风侧出现两个以上的复杂分离涡系,从列车头车下部开始,向列车下游发展并逐渐远离列车车体。分离涡系是列车承受非定常气动力的根源。列车头车是侧向力、滚转力矩最严峻的车厢,且随着横风侧偏角增大,侧向力、滚转力矩逐渐增大 ...
孙振旭, 尚克明, 杜健
core
ABSTRACT Rapid urbanisation and persistent socio‐economic inequality continue to entrench multidimensional poverty within South Africa's urban informal settlements, with women and female‐headed households experiencing disproportionate deprivation. This study analysed primary household survey data collected in 2023 from 322 households across three ...
Adrino Mazenda +3 more
wiley +1 more source

