Results 31 to 40 of about 167,960 (336)
Interactions of rare earth elements with living organisms and emerging biotechnical applications
PLANTS, PEOPLE, PLANET, EarlyView.Rare earth elements (REEs) are critical resources required to achieve net‐zero carbon emission targets and energy security. However, rising demand for REEs coupled with significant extraction and processing challenges and geopolitical risks restricts access to REE resources.
Samantha A. McGaughey +6 more
wiley +1 more source
有色冶炼厂房事故坑附近工字型钢柱在炉料热作用下的耐火稳定性验算
Jianzhu Gangjiegou Jinzhan, 2009 为了评估有色冶炼厂房事故坑附近钢柱在炉料热作用下的耐火稳定性,本文以热辐射理论为基础,采用数值计算方法研究了钢柱9m高度内的温度分布。钢柱温度取决于炉料面积、柱翼缘厚度、柱的计算截面位置、炉料与柱相对位置。炉料面积越大,钢柱越处在炉料中部,钢柱的温度越高;柱翼缘厚度越大,炉料与柱距离越大,钢柱的温度越低。本文以弹性理论为基础,给出了钢柱耐火稳定性验算与评估方法。由于钢柱之间存在较大温差,当钢柱所支承的梁的线刚度较大,两端与柱刚接且设置隅撑时,较强的端部约束作用使柱产生较高水平的温度内力 ...
屈立军, 刘红雅, 刘效铎, 高帅
doaj
Jianzhu Gangjiegou Jinzhan, 2022 钢框架结构在强震作用下易形成薄弱层破坏。在结构中布置连续柱可有效改善结构在地震作用下的侧向变形模式，使结构层间位移角分布更均匀。为研究连续柱的布置方式对钢框架整体抗震性能产生的影响，分别采用Pushover分析和IDA方法对内置式连续柱钢框架结构、外置式连续柱钢框架结构和纯钢框架结构的抗震性能和易损性进行了研究。结果表明：内置式连续柱与外置式连续柱均能有效改善结构的层间位移的分布模式；设置连续柱可使结构的塑性铰分布更均匀，降低损伤的集中程度，但无法遏制柱端塑性铰的产生；当刚度系数相等时，布置内 ...
李成玉 +5 more
doaj
Incidental pollination by passing animals: An overlooked mechanism?
PLANTS, PEOPLE, PLANET, EarlyView.The conservation of pollinators is essential for sustaining the ecosystem services of pollen transfer, which support crop production, biodiversity conservation and ecosystem health. While primary pollinators have been the focus of most conservation efforts, subordinate or incidental pollinators have been largely overlooked.
Kazuo Yamazaki
wiley +1 more source
On the Æ of the floral Envelopes inHelianthemum vulgare [PDF]
Transactions of the Botanical Society of Edinburgh, 1883 n ...
openaire +1 more source
PLANTS, PEOPLE, PLANET, EarlyView.Crop genetic resources, particularly seeds held in ex situ germplasm collections, have enormous value in breeding climate‐resilient crops. Much of this value accrues from information associated with germplasm accessions. Here, we argue that flavor, culinary attributes, and other traditional ecological knowledge (TEK) are important characteristics ...
Eric J. B. von Wettberg +14 more
wiley +1 more source
Jianzhu Gangjiegou Jinzhan, 2019 通过对多层钢框架进行增量动力分析,研究柱脚转动刚度、底层破坏模式以及钢柱宽厚比对多层钢框架抗震性能的影响,具体从结构倒塌储备系数、地震易损性以及结构局部响应考察各影响因素对结构抗震性能的影响。分析结果表明,当破坏模式由钢柱破坏控制时,随着钢柱宽厚比的增大结构抗震性能减弱,考虑柱脚刚度的半刚接柱脚钢框架地震易损性与刚接柱脚钢框架差别较小,当柱脚与柱刚度比为2.0时,框架地震易损性与刚接柱脚钢框架非常接近;当破坏模式由柱脚破坏控制时,可以明显降低钢柱宽厚比的要求。
崔瑶, 刘浩, 王枫智, 山田哲
doaj
PLANTS, PEOPLE, PLANET, EarlyView.The advancement of digital technologies has brought a rapid global information exchange, impacting all areas of our lives. This also applies to science. Knowledge, conservation and scientific innovation on global biodiversity are being strengthened and disseminated at unprecedented scales.
Ana Flávia Alves Versiane +9 more
wiley +1 more source
Jianzhu Gangjiegou Jinzhan, 2003 本文通过沪东造船厂船体装焊车间大跨度、大柱距钢管混凝土柱的设计研究,论述了在大吊车荷载作用下,钢管混凝土柱比其他形式的柱更为经济,更为合理;对柱脚、牛腿、肩粱以及钢管混凝土组合柱的节点构造与受力性能提出了新的看法;并简单介绍了钢管混凝土组合柱的计算要点。
吴建林, 姚永
doaj
Chemical constituent and biological activity research of the small polar substances from Vitis thunbergii var. taiwaniana [PDF]
, 2015 小叶山葡萄(Vitisthunbergiivar.taiwaniana)是葡萄科葡萄属植物，主要分布于台湾，本文对小叶山葡萄的化学成分以及其抗氧化、抗炎和抗肿瘤活性进行了研究。 利用大孔吸附树脂、正相硅胶柱色谱、ODS中低压柱色谱、SephadexLH-20凝胶柱色谱、薄层色谱、分析型和制备型高效液相色谱等分离方法，从小叶山葡萄60%乙醇提取部位大孔树脂柱95%乙醇洗脱部位共分得20个单体化合物，通过理化性质的分析比较、核磁共振波谱以及高分辨质谱等对化合物的结构进行了鉴定 ...
姜超
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