Results 11 to 20 of about 13,466 (118)

高温蠕变对冷弯薄壁型钢柱抗火性能的影响

open access: yesJianzhu Gangjiegou Jinzhan, 2021
钢材高温蠕变是钢材在高温和应力作用下的塑性应变。高温蠕变会导致钢柱变形增大,耐火极限降低。为了考察高温蠕变对冷弯薄壁型钢柱抗火性能的影响程度,建立了考虑高温蠕变的抗火分析有限元模型,通过试验结果对有限元模型进行验证。利用模型研究了在不同荷载比、轴向约束刚度比、升温速率和火灾场景下,高温蠕变对冷弯薄壁型钢柱抗火性能的影响。研究表明,在有限元模型中考虑蠕变因素后,对于钢柱抗火性能的预测更为准确,更符合真实情况;在中等升温速率的火灾场景中,荷载比为0 ...
杨竞杰, 王卫永
doaj  

Seasonal Spatial Population Density Distribution Dynamics of Lynx and Ungulate Prey in Cold‐Temperate Coniferous Forests 寒温带针叶林猞猁和有蹄类猎物种群密度空间分布的季节性动态研究

open access: yesIntegrative Conservation, EarlyView.
This study used camera trap data from 6 years between 2016 and 2021 and generalized linear mixed models to explore the factors that influence the spatial density distribution of lynx and its prey populations in warm and cold seasons in Inner Mongolia Hanma National Nature Reserve, China.
Wentao Zhang   +11 more
wiley   +1 more source

Changes of Potential Suitable Areas for Lynx Under Climate Change in Mohe Area, Daxing'anling Mountains, China 气候变化下中国大兴安岭漠河地区猞猁潜在适宜区的变化

open access: yesWildlife 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

Habitat and spatial trends of U.K. wintering waterbird populations over 50 years

open access: yesConservation Biology, EarlyView.
Abstract The United Kingdom is an important wintering ground for millions of waterbirds. Most U.K. wintering waterbird populations increased between 1970 and the mid‐1990s, but declined thereafter. We examined U.K. population indices in 46 wintering waterbird species in two 25‐year periods, 1970–1994 and 1995–2019, to identify which waterbird groups ...
Blaise Martay   +8 more
wiley   +1 more source

Uncovering correlates of decline and critical refuges for a threatened terrestrial mammal

open access: yesConservation Biology, EarlyView.
Abstract Globally, the geographic ranges of numerous species are contracting. Identifying spatiotemporal patterns of threat impact can illuminate why species decline in some parts of their range but persist in others. We developed a correlative approach to identify species’ response thresholds and locate ecological refuge areas associated with ...
Natalya M. Maitz   +5 more
wiley   +1 more source

Effects of restoration practices on biodiversity in temperate and boreal forests

open access: yesConservation Biology, EarlyView.
Abstract Several restoration practices are used to mitigate and compensate for the negative effects of large‐scale forestry on biodiversity in temperate and boreal forests. A comprehensive synthesis of the benefits of these practices across taxa is missing. We conducted a systematic review and meta‐analysis on this topic.
Malin Tälle   +2 more
wiley   +1 more source

非正弦激励下高频变压器的温度分布计算与分析

open access: yesGaoya dianqi, 2022
高频变压器是DC/DC变换器的重要电气元件,其内部温度过高会加速绝缘老化,准确预测高频变压器的温度分布有助于其散热设计。文中考虑温度对高频变压器材料电磁特性和空气热物理特性的影响,利用Infolytica有限元软件建立高频变压器的瞬态磁场—温度场双向耦合模型,通过仿真分析,得到高频变压器的磁密分布、损耗分布和温度分布。在此基础上,根据高频变压器的散热路径建立其等效热路模型,计算出稳态温度分布。通过比较分析可知分别使用有限元法和等效热路法得到的计算结果相吻合 ...
孙晨茜, 李琳
doaj  

From Affect to Values: A Lexical Approach

open access: yesJournal of Personality, EarlyView.
ABSTRACT Introduction Personal values act as guiding principles in life and are thought to be connected to affective experiences; however, past research has primarily examined the direction from values to affect rather than the reverse. This study identified theoretical frameworks suggesting a causal pathway from affect to values and tested this ...
Xi Chen, Shengquan Ye
wiley   +1 more source

Visible‐Light‐Excited Optical Thermometry in Ca3Sc2Si3O12: Er3+ via an Efficient Eu2+ Bridge

open access: yesRare Metals, Volume 45, Issue 7, July 2026.
ABSTRACT Er3+ ions are promising for optical thermometry due to their thermally coupled levels. However, their parity‐forbidden transitions result in weak and narrowband absorption, which restricts excitation to infrared lasers (e.g., 808, 980, or 1550 nm). Moreover, the single emission center inherently limits temperature sensitivity. In this work, we
Yi Liu   +6 more
wiley   +1 more source

Q690高强钢板梁火灾后剩余承载性能研究

open access: yesJianzhu Gangjiegou Jinzhan, 2022
开展高温后水冷Q690高强钢的材性试验研究,明确高温对Q690高强钢力学性能的影响规律。在考虑材料非线性和几何非线性的基础上,将高温后水冷Q690高强钢的材性引入数值分析模型,在ABAQUS有限元软件中实现考虑屈曲后性能的Q690高强钢板梁的火灾后剩余承载性能分析。研究结果表明:暴露温度700 ℃为Q690高强钢力学性能变化的分界点。随着暴露温度的升高,fy和fu都表现出先减小后增大的规律。暴露温度对Q690高强钢弹性模量的影响较小。当暴露温度为800 ℃和900 ℃时 ...
华建民   +5 more
doaj  

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