Results 31 to 40 of about 791,805 (159)
Digital Futures Between Participatory Digital Democracy and Participatory Digital Fascism
ABSTRACT This paper explores one of the defining political questions of the twenty‐first century: will digital technologies strengthen democracy or accelerate new forms of authoritarianism and fascism? Against the backdrop of platform capitalism, AI‐driven communication, surveillance infrastructures, disinformation and democratic crisis, the study asks
Christian Fuchs +2 more
wiley +1 more source
为评估双地网对配电变压器反变换过电压的抑制效果,推导了单双地网接地方式下低压侧不安装和安装避雷器时配电变压器的反变换过电压简化计算公式,根据推导的理论公式,分析了在配电变压器低压侧不安装和安装避雷器时双地网接地方式相比单地网接地方式对反变换过电压的抑制效果,并分析了双地网接地方式下高低压侧地网间距对配电变压器反变换过电压的影响,同时采用ATPdraw仿真建模,验证并修正了由理论公式推导得到的结论。研究表明:对于低压侧没有安装避雷器的配电变压器,双地网接地方式相比单地网接地方式对反变换过电压的抑制效果明显;
郭婷婷, 杨琪, 文习山
doaj
The End of the Observable Infodemic: Privatised Observability and Public Health Monitoring
ABSTRACT Infodemiology and infodemic management rest on a premise so foundational that it is rarely stated: health information behaviour leaves traces that researchers and public institutions can observe. This paper argues that the premise is dissolving.
Christoph Dockweiler
wiley +1 more source
风机地网由于受腐蚀等因素影响可能会产生连接断点,需要分析断点对地网雷击暂态特性的影响。本研究首先分析电流频率对土壤电参数的影响,通过矢量匹配法结合最小二乘法拟合风机地网电路模型参数,导入ATP软件建立暂态电路仿真模型,计算雷电流作用下地网地电位抬升,分析不同地网断点方式对地网雷击地点位抬升和冲击阻抗的影响。研究结果表明:土壤电参数受周围流经电流频率影响明显,土壤电阻率和相对介电常数随着频率的增大而显著减小,在地网雷击暂态特性分析中必须予以考虑;低频范围内地网谐波阻抗近似等于工频电阻,随着频率的进一步增大,
doaj
Migratory shorebirds traveling the East Asian–Australasian Flyway face systemic policy fragmentation and habitat disconnection between China (coordination challenges and renewable energy conflicts) and Australia (federal governance fragmentation). This study proposes a transboundary conservation framework to fill this gap.
Yarui Wang
wiley +1 more source
为确保风电场电气设备和工作人员人身安全,接地设计需要有合格的接地电阻值、接触电压和跨步电压值。在接地电阻满足安全值的情况下,如果接地设计不合理,地面上还是可能产生超过允许值的接触电压和跨步电压。降低接触和跨步电压的一般方法是增设水平接地网和在地表铺设高阻率土壤层,但风电机组所处自然环境特殊,受地形限制,不易过多扩大接地网面积。在不增加接地网总长度的情况下采用不等间距法布置地网导体,或者改变地基与接地网的相对位置可显著降低地表最大接触电压,提高地网安全水平 ...
宋景博 +4 more
doaj
变电站接地网腐蚀断点的缺陷对变电站造成潜在的安全隐患,然而目前能用于实际的接地网腐蚀检测系统十分缺乏,为了提高大型接地网导体腐蚀断点检测的效率和精度,使用了诊断接地网地表面电磁感应密度的方法。首先在对接地网磁场分布仿真计算的基础上研制了磁场信号激励源,并结合现场实际电磁干扰特征,研制了信号采集、处理、分析系统。然后利用该系统检测大型接地网地表面磁场分布,依据磁场分布特征和规律快速确定接地网导体的断点故障及部位。最后根据仿真计算分析、试验接地网实验测试和现场应用,表明了该方法诊断接地网断点的有效性和准确性。
张树亮 +6 more
doaj
ABSTRACT Lithium–sulfur (Li–S) batteries are promising for next‐generation high‐energy‐storage systems but are hindered by polysulfide shuttle, sluggish kinetics, and volume expansion. Conventional carbon hosts struggle to simultaneously anchor and convert polysulfides efficiently.
Ling Chen, Peng Xu, Jiaojing Shao
wiley +1 more source
本申请公开了一种接地网故障诊断方法,包括:根据接地网中的激励电流和采集参数采集接地网多个导体的磁场数据;每个磁场数据带有对应接地网导体的标识;对采集到的磁场数据进行处理;将处理后的磁场数据通过无线通信方式发送给变电站服务器;变电站服务器根据所述接地网导体的标识,确认处理后的接地网第一导体的磁场数据小于第一预设阈值时,诊断出所述接地网第一导体发生故障。本申请对接地网的故障定位精确,检测效率高 ...
邵帅 +4 more
core
ABSTRACT The electrocatalytic co‐reduction of CO2 and nitrate (NO3− ${\text{NO}}_{3}^{-}$) to synthesize urea presents a sustainable alternative to traditional industrial processes, yet its efficiency is fundamentally limited by the kinetically mismatched activation and coupling of CO2 and NO3− ${\text{NO}}_{3}^{-}$.
Jiayu Liu +9 more
wiley +1 more source

