Results 11 to 20 of about 1,047,854 (148)
Jianzhu Gangjiegou Jinzhan, 2021 现行《建筑钢结构防火技术规范》(GB 51249—2017)未给出火灾下钢结构的局部稳定设计方法,为了获得轴心受压焊接H形高强Q690钢柱高温下的局部稳定性能,考虑钢材高温下力学性能退化、截面高温下焊接残余应力降低及初始几何缺陷,采用ABAQUS软件建立经试验验证的高温局部稳定分析有限元模型,得到焊接H形高强Q690钢柱在不同温度下的局部屈曲应力和极限应力。研究表明:当温度低于550℃时,钢柱在高温下和常温下屈曲应力具有相同的变化趋势;高温下的残余应力值和初始几何缺陷对屈曲应力有较大的影响 ...
李翔, 王卫永, 于克强
doaj
, 2019 介绍了大温差温湿度独立控制动态冰蓄冷系统的系统原理和运行状态,并以广东省东莞市某超高层建筑为例,对空调系统设备选型、设备配电和运行节能经济性进行了分析,指出动态冰蓄冷系统的应用为新风深度除湿和大温差供冷创造了条件,送风含湿量低于6 g/kg,且年转移电量占比达39.40%;指出大温差低温供冷和高温供冷的应用为超高层建筑带来显著的节能、节费效果,年节省运行电量120.19万kWh,在东莞市优惠峰谷电价差下运行2 ...
王志强, 董凯军, 孙钦, 苏林
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PLANTS, PEOPLE, PLANET, EarlyView.Climate change is intensifying heat, drought, and food insecurity, threatening dryland farming and carbon management worldwide. We reviewed research on sorghum, a drought‐adapted C4 crop, covering physiology, roots, biomass allocation, soil carbon, bioenergy, breeding, phenotyping, management, and policy.
Monir Idres Yahya Ahmed +4 more
wiley +1 more source
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
Plant invasion in mountain ecosystems reduces soil micro‐food web complexity at higher elevations
Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract Anthropogenic activities have accelerated plant invasions in mountain ecosystems, impacting the structure and functions of native plant communities. Changes in above‐ground vegetation can drive shifts in below‐ground biota, yet the effects of plant invasions on soil ...
Runjie Jiao +8 more
wiley +1 more source
Effects of restoration practices on biodiversity in temperate and boreal forests
Conservation 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
Intact coastal nursery rearing amid climate‐driven phenological shifts in threatened salmon
Conservation Biology, EarlyView.Abstract Literature linking phenology to climate has proliferated in recent decades and shows that climate change has reorganized seasonal opportunities worldwide. However, this literature often quantifies changes in point measures of timing (e.g., beginnings and peaks) without context about duration (e.g., rearing season length) or performance (e.g ...
Stuart H. Munsch +8 more
wiley +1 more source
Jianzhu 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
Subspecies taxonomy reflects social and geographic patterns of taxonomic effort in tetrapods
Conservation Biology, EarlyView.Abstract Subspecies have been used in conservation biology to account for intraspecific patterns in genetic diversity, which is crucial to long‐term population viability. Although over 3200 subspecies are currently assessed by the International Union for Conservation of Nature Red List, their biological relevance remains controversial.
Jhonny J. M. Guedes +3 more
wiley +1 more source
, 2010 本发明公开了一种多功能传感器及高温下测量热流与温度的方法，其中多功能传感器包括外壳和热流测头，外壳上设置热流测头，热流测头包括热流探头和热沉，热沉与热流探头相连容置在外壳内部与热流探头组成热电偶，所述外壳内还设置有用于冷却热流测头的冷却装置和用于测量热沉温度的另一热电偶，两热电偶与检测仪相连，通过测量出两热电偶的电压信号实现热流和温度的检测。本发明公开的测量方法通过测量低温的温度，建立数学模型推导得出高温处的所测温度。本发明的多功能热传感器能够在高温环境下测量热流和温度 ...
王晶, 李龙, 范学军, 仲峰泉
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