Results 11 to 20 of about 2,116 (167)
Dianci bileiqi, 2021 随着我国输电线路向高海拔地区延伸,高海拔输电线路的防雷问题日益突出,由于缺乏选型标准,线路避雷器的高海拔应用存在困难。笔者对电气一次设备外绝缘高海拔修正的基本原则进行了说明,对交流线路避雷器串联间隙电弧距离、本体电弧距离的耐受电压确定原则进行了解释,对不同海拔下的电弧距离修正结果进行了计算。提出了不同电极结构电气距离与电压耐受值的计算公式,结合低海拔避雷器电弧距离典型设计值对计算公式有效性进行了验证,使用计算公式对高海拔情况下线路避雷器的电弧距离进行了近似计算并给出了参考设计值 ...
刘守豹 +5 more
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Gaoya dianqi, 2022 合理设计高海拔地区特高压换流站均压屏蔽装置能够有效避免站内电晕放电，保障系统安全稳定运行。为实现高海拔地区均压屏蔽金具的可靠应用，文中在平原地区（平顶山）和高海拔地区（羊八井）进行了特高压换流站典型电极的起晕试验，计算获得了不同尺寸典型电极的起晕场强，并提出了海拔4 300 m金具的控制场强值。仿真分析了球形、鼓形电极表面电场分布随关键结构参数的变化规律，设计并在羊八井开展了高海拔地区换流站用典型均压屏蔽金具真型试验。结果表明：海拔高度对小尺寸电极起晕场强的影响程度较大尺寸电极高，4 300 ...
张炜 +6 more
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Shuitu Baochi Xuebao, 2021 以贺兰山不同海拔植被下0—20，20—40 cm土层土壤为研究对象，分析不同粒径团聚体含量及团聚体稳定性随海拔升高的变化特征，探讨其与土壤理化性质之间的相关关系。结果表明：0—20 cm土层，0.25~0.053 mm团聚体为主要团聚体类型，随海拔增加，水稳性大团聚体（>0.25 mm）含量增加，高海拔>低海拔，较高含量的大团聚体和土壤养分是团聚体稳定的关键要素。
吴梦瑶 +6 more
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Evaluation and correction of GPM satellite precipitation products during Typhoon "In-Fa" affecting Zhejiang [PDF]
, 2023 To understand and improve the performance and quality of Global Precipitation Measurement (GPM) satellite-derived precipitation products during the typhoon process, with gauge observations from ground meteorological stations, this study used the ...
Haoqing ZHU +4 more
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Jianzhu Gangjiegou Jinzhan, 2022 基于高海拔地区山地和平原两类地貌1.5年的实测脉动风风速数据，确定了两类地貌风剖面指数、湍流强度的均值和98%保证概率值，分析了高海拔风场特性参数对输电线路风压高度变化系数、杆塔风振系数和导地线风振系数的影响规律，高海拔地区风剖面指数不应高于A类场地风剖面指数0.12。确定了高海拔与标准B类地貌下杆塔和导地线风荷载的差异，通过结构受力分析得到了高海拔地区杆塔应力及分布特征，两类地貌风场下杆塔最大应力比较B类地貌均有所增加，且山地地貌风场更为不利，杆件最大应力比达到了1.14 ...
杨风利 +4 more
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Spatiotemporal Variations and Topographic Differentiation of Fractional Vegetation Cover in Changbai Mountain [PDF]
, 2023 [Objective] The dynamic changes of vegetation and its response relationship with topography in Changbai Mountain were explored in order to provide scientific support for ecological environmental protection and management in this mountainous area ...
Li Wen, Shi Song, Yang Ziyi, Yu Ran
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Justice in coexistence: Pastoralism and large carnivores on the Qinghai‐Tibet Plateau
People and Nature, EarlyView.Abstract The conflict between livestock husbandry and large carnivore conservation presents significant challenges in grassland ecosystems worldwide. Achieving sustainable coexistence among herders, livestock and large carnivores requires reconciling diverse perspectives and interests through equitable, inclusive and fair processes that address both ...
Yufang Gao, Yue Yu
wiley +1 more source
Acute ischaemic stroke during short-term travel to high altitude [PDF]
, 2012 This is a case report of a young healthy adult who had acute cerebral infarcts after a short-term visit to high-altitude area. He developed acute onset of right-sided limb weakness and right hemianopia a few hours after arrival at an altitude of 3600 m ...
Chan, JKC +4 more
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Wildlife Letters, EarlyView.Climate change drives shifts in suitable habitats for Eurasian lynx and its prey (hare, roe deer) in Mohe, Daxing'anling Mountains. Under RCP scenarios, moderate warming (RCP4.5) promotes substantial habitat expansion, while high‐emission conditions (RCP8.5) lead to strong expansion in the 2050s but slower gains and partial contraction by the 2070s ...
Binglian Liu +5 more
wiley +1 more source
, 2012 分区边界的确定是生态分区的重要步骤,但目前多数水生态分区的边界确定以定性分析、专家判断为主。本研究以洱海流域为例,建立了一套两级分区体系。该体系基于GIS技术,用子流域作为分区基本单元,并用相关分析法,定量筛选一、二级分区指标。其中,一级分区指标为高程、坡度和植被归一化指数(NDVI),二级分区指标为农田百分比和城镇百分比。通过指标图层的叠加和重分类,合并同质性子流域,从而将洱海流域划分为5个一级区和9个二级区。藻类群落分布的验证结果表明分区合理。本研究将定量分析和子流域边界应用于水生态分区 ...
唐佳 +6 more
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