Results 21 to 30 of about 7,536 (172)
随着土地资源的紧缺,往往需要在有限的土地资源条件下选取合适的土壤模型并设计相应的符合参数要求的接地网方案。建立了垂直分层的土壤模型,用以模拟在山脚、江(河)两岸等的情况下的土壤电阻率分布。运用CDEGS仿真软件计算接地网的接地电阻、接触电压及跨步电压等参数,通过增设双层地网、增加垂直或倾斜接地体及改变网格密度等方式研究更加优越且经济的接地网优化方案。研究结果表明:对于垂直分层土壤下的接地网,可在低土壤电阻率侧错位的铺设双层接地网;而在高土壤电阻率侧铺设双层接地网对降低接地电阻的作用较小 ...
王继来
doaj
ABSTRACT Bangladesh's goal of achieving high‐income status by 2041 requires dependable, low‐emission, and affordable energy. With near‐universal grid coverage and increasing demand, nuclear energy is a strategic asset for long‐term baseload supply. However, the existing financing model, typified by the country's most expensive $12.65 billion Rooppur ...
Hafiz Ahmed
wiley +1 more source
Abstract Short‐term policy (STP) has attracted considerable attention as a form of time‐related public policy and is typically used to solve urgent problems. The objective of this study, which considers STP as policy myopia from an information science perspective, is to discuss the challenges encountered during the STP policymaking process and their ...
Prasongchai Setthasuravich +1 more
wiley +1 more source
Australian Teen Voices on Age Verification and Age Assurance Measures
ABSTRACT Age verification and age assurance technologies, including biometrics, facial recognition software and digital identification, have been explored as potential measures to restrict access of young people to social media and sexually explicit media (SEM), including pornography.
Giselle Woodley +5 more
wiley +1 more source
采用近似分析方法推导出在水平接地网接地导体周围人工改善土壤后水平接地网的等效接地导体半径,结合已有的均匀土壤中水平接地网接地电阻及最大接触电压的计算公式,提出人工改善土壤后水平接地网接地电阻及最大接触电压的计算方法,并通过分析得出:人工改善土壤对降低接地网接地电阻的作用甚微,但能有效降低接地网的最大接触电压。
刘渝根 +3 more
doaj
<p>由于某高速铁路途径山区地带平地资源稀缺,为少占耕地,某220kV 牵引变电所选址于较缓山坡上。所址区域表层覆盖浅薄,基岩<br />为花岗岩,牵引变电所所址接地条件不理想。所址区域采用四极等距法现场实测土壤电阻率数据为516.2Ω·m 及采用三极夹角法实测接地电阻为<br />1.2Ω。根据《铁路电力牵引供电设计规范》TB10009— 2005 的规定,牵引变电所接地电阻一般不大于0.5Ω。结合现场实际情况对接地网整改,并<br /> ...
伟 曾
core +1 more source
US Foreign Policy and the Gulf States: Changing Dynamics in a Multipolar World
ABSTRACT This article focuses on US foreign policy toward the Gulf from Obama's Pivot to Asia to the initial period of the second Trump administration. It situates the role of the US within the broader context of the global energy transition and the Gulf states as geopolitical actors in a multipolar world order.
Steven Wright
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
Predictions of southern migration timing in coastal sharks under future ocean warming
Abstract Projected redistribution of marine species due to ocean warming may undermine current conservation efforts. Yet, there have been few studies on how ocean warming may alter migration timing. Across 5 years of acoustic telemetry data (2018–2022), we determined environmental drivers of southward migration timing for 6 migratory shark species from
Maria H. Manz +16 more
wiley +1 more source
基于接地网小比例模型试验原理,以某水电站为例,在自动化电解槽中采用琼脂和稀释盐溶液作为导电介质进行了接地网小比例模型试验。借助CDEGS软件分析了本试验结果对评估实际接地网接地电阻所起的作用,结果表明,接地网小比例模型试验中导体半径对接地电阻影响较大。本文引入接地网接地电阻小比例模型试验半径修正系数概念,从导体半径、模拟地网面积以及模拟地网网孔数目等方面分析对其的影响,根据分析结果,对本次模拟试验测量得到的接地电阻进行修正,修正后得到的原接地网接地电阻与实际接地网接地电阻较符合 ...
彭永晶 +4 more
doaj

