Results 21 to 30 of about 77,688 (168)

新型环保绝缘气体1-C3F6与CO2混合气体的绝缘性能研究

open access: yesGaoya dianqi, 2021
文中介绍了一种新型环保绝缘气体六氟丙烯(1-C3F6),并重点研究了1-C3F6与CO2混合气体在不同电极结构和电压特性下的绝缘特性。研究表明:在均匀电场中,1-C3F6/CO2混合气体的50%击穿电压随着电极间距、气压的增加而增加,工频击穿电压随着充气压力的升高而近似线性升高,纯1-C3F6气体在1.25 bar(1 bar=100 k Pa)时的工频击穿电压与SF6接近。此外,在各个充气压力下,1-C3F6/CO2混合气体的工频击穿电压都比C5F10O/Air混合气体高。在稍不均匀电场中,1 ...
周永言   +4 more
doaj  

Biodiversity‐driven spatial conservation planning to delineate temporally stable regions

open access: yesConservation Biology, Volume 40, Issue 3, June 2026.
Abstract The accelerating loss of biodiversity underscores the critical need for effective conservation strategies, particularly in the face of climate change and anthropogenic pressures. We devised a conservation planning framework that adopts a temporal stacking approach to species distribution models and landscape connectivity analyses. These models
Mattia Iannella   +5 more
wiley   +1 more source

CF3I/N2混合气体中绝缘子沿面闪络特性的研究

open access: yesGaoya dianqi, 2016
文中以SF6/N2混合气体作为比较,研究了CF3I/N2混合气体中绝缘子在工频电压和正、负极性雷电冲击电压下的沿面闪络特性。结果表明:在0.10.3 MPa下,CF3I/N2混合气体中绝缘子的工频闪络电压和雷电冲击闪络电压均随气压升高而增大;在较低气压下,CF3I/N2混合气体中绝缘子的负雷电冲击闪络电压比正极性下要低,而当气压高于某临界值时,负极性下闪络电压又会高于正极性;绝缘子在含30%CF3I气体的CF3I/N2混合气体中的绝缘性能基本介于含20%/30%SF6气体的SF6 ...
张辉, 肖登明, 赵谡, 李冰
doaj  

高压自能式SF6断路器空载分闸过程中阀运动特性的仿真分析

open access: yesGaoya dianqi, 2023
高压自能式SF6断路器单向阀、回气阀和泄压阀的运动特性对灭弧室气流场计算结果的准确性具有重要影响。基于3个阀片实际的运动规律,运用牛顿第二定律,建立阀片运动的数学模型,并结合真实气体物性参数,对自能式SF6断路器灭弧室冷态气流场进行仿真,准确获得了3个阀片的运动特性,同时分析了3个阀片的受力特性及阀片周围的压力分布。研究表明,空载情况下,单向阀将对拉杆产生相对运动,这是引起单向阀由闭合到开启状态变化的主要原因,而回气阀移动的主要原因是压气室压力的建立 ...
赵伟涛   +4 more
doaj  

Mechanism of Selective Arsenic Purification via Reductive Vacuum Sublimation: From Oxygenated Crude Arsenic to High‐Purity Arsenic

open access: yesRare Metals, Volume 45, Issue 5, May 2026.
ABSTRACT Arsenic presents a critical duality as both a hazardous environmental pollutant and an indispensable material for advanced semiconductor technologies. This study proposes an integrated reductive vacuum sublimation strategy, assisted by carbon and lead additives, to purify crude arsenic containing high oxygen (7.4%) and antimony (1326 mg kg−1).
Hongrui Xiang   +6 more
wiley   +1 more source

内凹式负压磁头气体动力特性

open access: yes, 1993
本文给出了一种用于磁盘机读/写功能的非接触起停式负压磁头滑块模型。通过求解修正Reynolds方程,计算出其稳态气动力特性。给出了磁头滑块与磁盘之间润滑气膜压强分布的立体图,滑块工作曲线及压力载荷随磁盘线速度、气膜厚度 ...
孙征, 傅仙罗
core   +1 more source

基于SRK状态方程的SF6/CF4混合气体物性参数计算

open access: yesGaoya dianqi, 2016
采用混合气体是解决气体开关设备低温运行的有效途径之一。文中基于真实气体模型,建立SRK状态方程的迭代形式,给出了SF6与CF4气体压力值在0.11 MPa,温度在223323 K范围内压缩因子曲线,分析了温度与压力对压缩因子的影响,给出了不同压力与温度下,SF6与CF4真实气体与理想气体压缩因子的偏离情况,确定混合气体的压缩因子的混合规则,分析了温度与压力对压缩因子的影响,确定混合气体的混合规则,获得了SF6、CF4及混合气体饱和蒸汽压与等密度曲线,得到了混合气体在不同使用条件下的充气与补气方案 ...
钟建英   +4 more
doaj  

Trends and Challenges in Water Governance Systematic Review and Bibliographic Study of Scientific Publications (2018–2025)

open access: yesWorld Water Policy, Volume 12, Issue 2, May 2026.
ABSTRACT Water governance has emerged as a critical analytical framework for addressing the complexity of socioecological water systems in contexts of increasing climate vulnerability and anthropogenic pressure. This study presents a systematic review and bibliometric analysis of 50 scientific articles indexed on water governance published between 2018
Roger Pichis‐García   +1 more
wiley   +1 more source

不同型号气管导管对小儿产生内源性呼气末正压的影响

open access: yesZhongguo shiyan zhenduanxue, 2017
内源性呼气末正压(PEEPi)是指由于呼气气流受限或有效呼气时间不足导致呼气末时肺容积未能回到正常功能残气状态,呼气末时肺泡内压力大于大气压,所产生的正压称为PEEPi[1-6]。目前有相关研究表明 ...
朱冬雪, 杨俏, 金立民, 宋雪松
doaj  

Æ E Æ Å – Reshaping the Role of Træna Fishermen

open access: yes, 2022
This diploma project aims to strengthen the viability of Træna’s community by proposing an ocean research facility in the archipelago, enabling the next generation of local fishermen to collect oceanographic data while working at sea. The idea of the fisherman as oceanographer is inextricably linked to the architectural program on the island of ...
openaire   +1 more source

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