Results 31 to 40 of about 70,094 (168)
Dianci bileiqi, 2022 输电线路在运行过程中容易受到风力作用而发生风偏，特高压紧凑型输电线路由于本身相间距离较小，更易受风偏影响出现电气或机械事故。线路在自然环境中运行受到的风载荷具有脉动成分，其对导线风偏的影响不可忽略。因此，有必要研究在包含脉动成分的风载荷作用下线路的运动特性，从而采取有针对性的抑制措施。本研究通过自编程软件仿真计算了稳态风和脉动风作用下三相导线发生风偏不同期摆动时的最小相间距离、不平衡张力和悬挂点张力，研究了风偏特性与风速、档距和冰厚之间的关系。结果表明 ...
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Zhejiang Daxue xuebao. Lixue ban, 2014 利用舟山浮标站和海岛自动站2011年全年测风数据资料，对舟山海域浮标风力和附近非遮蔽高海拔海岛站以及不同海域无遮蔽海岛站、遮蔽海岛站的风力进行了对比分析，结果表明：1）浮标站大风日数比非遮蔽海拔较高海岛站以及传统大风指标站嵊泗明显偏少，比遮蔽海区海岛站多.2）浮标站年平均风速小于非遮蔽高海拔站，同嵊泗、西磨盘接近，大于遮蔽海区海岛站.3）浮标站大风日数和平均风速具有明显的月际变化特征，秋冬季明显多于春夏季.4）对比不同风向的大风过程可得：浮标站与其他海岛站的风速差值不仅与季节变化、海拔高度有关 ...
LIYun(李云) +3 more
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Using online reports of seahorse seizures to track their illegal trade
Conservation Biology, Volume 39, Issue 5, October 2025.Abstract Illegal wildlife trade (IWT) is a persistent and extensive threat to global biodiversity. Hundreds of marine fish species are subject to regulation under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), but it is unclear how much protection species gain from CITES because information on marine fish ...
Sarah J. Foster +3 more
wiley +1 more source
Dianci bileiqi, 2018 采用刚体直杆模型,计算绝缘子串风偏角,分别研究了水平档距、垂直档距、风速、风向、风压不均匀系数、地形以及加重锤等主要因素对绝缘子风偏特性的影响程度。研究结果表明:水平档距与绝缘子串风偏角呈正相关,垂直档距与绝缘子风偏角呈负相关;在风速一定的情况下,风向的主要影响区间在垂直于线路约±60°区间内。
唐子峰, 廖志雄, 袁翔
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Integrative Conservation, Volume 4, Issue 3, Page 442-463, September 2025.In this study, we analyze the conservation status of Ethiopia's amphibian and reptile diversity in terms of coverage with protected areas and global representation in conservation breeding facilities. We identify conservation gaps and suggest priorities for improvement.
Kolja Sperling +3 more
wiley +1 more source
Gaoya dianqi, 2019 为研究特高压输电线路的风偏机理,文中以1 000kV南荆Ⅰ线风偏闪络事故为基础,开展故障点的风偏分析。采用规范给定的刚性直棒法进行验算,在风压不均匀系数取0.61和0.75的情况下,计算结果均小于发生事故的阈值。在已有研究基础上确定了分裂导线的阻力系数取值;同时进行了风洞试验,确定了绝缘子串的阻力系数。在Ansys建立导线—绝缘子有限元模型,通过谐波叠加法模拟得到风速时程,在此基础上,进行事故线路导线风偏的动态计算,得到了设计风速下的风偏角大小。结果表明,脉动效应对计算结果的放大作用不可忽略 ...
吕中宾, 白航, 杨晓辉, 楼文娟
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Ultrasound in Obstetrics &Gynecology, Volume 66, Issue 3, Page 271-281, September 2025.ABSTRACT Objective To evaluate the impact of endometrial thickness on the reproductive outcomes of embryo transfer (ET) treatments using both cut‐off‐based meta‐analysis and meta‐analysis of proportions. Methods This was a systematic review and meta‐analysis of comparative studies (randomized controlled trials, cohort studies, case–control studies) and
F. Pérez‐Milán +10 more
wiley +1 more source
Ultrasound in Obstetrics &Gynecology, Volume 66, Issue 2, Page 135-146, August 2025.ABSTRACT Objective To derive pooled estimates of maternal, fetal and pediatric outcomes up to the age of 30 months in patients undergoing pre‐ or postnatal surgery for open spina bifida (OSB). Methods A systematic search was conducted in MEDLINE, PubMed (non‐MEDLINE records), Embase, Web of Science, ClinicalTrials.gov, Cochrane Central Register of ...
Y. Kunpalin +10 more
wiley +1 more source
±1100 kV昌吉换流站与±800 kV天山换流站共同作用的直流偏磁问题研究
Gaoya dianqi, 2020 针对±800 kV天山—中洲特高压直流输电工程和±1 100 kV昌吉—古泉特高压直流输电工程同时以单极大地方式运行时,新疆电网内厂站面临的变压器直流偏磁风险,提出了研究方法和应对策略:首先,利用电磁测深对两接地极周边土壤进行了冬夏两季实测,在实测的土壤电阻率基础上构建了两接地极同时作用下的电网直流电流分布模型;其次,对新疆电网直流偏磁风险进行仿真计算分析,发现不同季节土壤电阻率不同,且冬季直流偏磁风险较大,两双接地极同时注入直流时,原本没有直流偏磁风险的厂站也会存在风险;最后 ...
孙冰 +5 more
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Wildlife Letters, Volume 3, Issue 2, Page 73-83, June 2025.Blue sheep in Dhorpatan Hunting Reserve prefer alpine grasslands at 3800–4200 m on south‐facing slopes near water resources, favoring areas with low tree cover and dense ground cover, particularly rhododendrons, junipers, and Cyperaceae grasses. Their habitat significantly overlaps with livestock.
Amit Adhikari +4 more
wiley +1 more source