Results 21 to 30 of about 52,444 (177)
A link between increased temperature and avian body condition in a logged tropical forest
Conservation Biology, EarlyView.Abstract The combined effects of anthropogenic disturbances, such as logging and climate change, remain poorly understood; yet, they are the main threats to tropical biodiversity. Most tropical African countries lack long‐term climate data, so climate impacts on biodiversity cannot be assessed.
Moreen Uwimbabazi +7 more
wiley +1 more source
Dianci bileiqi, 2021 红外测温凭借其高效、精确等优点,在特高压避雷器带电检测中发挥了重要作用,然而避雷器表面温度会受到风速、光照等外界因素的影响,给红外测温及故障诊断带来了一定的困难。笔者基于有限元原理建立了特高压交流避雷器热电耦合的三维温度场仿真模型,并通过现场温度试验验证了模型的合理性,从而利用该模型对不同风速、光照影响下的避雷器温度分布进行仿真分析,结果表明:风速增大加强了空气对流散热,使得避雷器内部缺陷发热导致的表面最高温度下降,温升减小;避雷器表面温度随太阳辐射强度的增大而升高,且向阳侧高于背阳侧,但温升值变化不大。
史晓航 +4 more
doaj
Distribution, scale, and drivers of mass mortality events in Europe's freshwater bivalves
Conservation Biology, EarlyView.Abstract Mass mortality events (MMEs) are decimating populations and compromising key ecosystem functions around the globe. One taxon particularly vulnerable to MMEs is freshwater bivalve mollusks. This group has important ecosystem engineering capacities and includes highly threatened and highly invasive taxa.
Daniel A. Cossey +39 more
wiley +1 more source
Theoritical investigations of structural stability, mechanical and thermodynamics properties for γ’ precipitates in Co-based superalloys [PDF]
, 2015 随着国防科技的迅猛发展，新一代的航空航天飞机对发动机涡轮叶片材料的承温能力提出更高的要求。传统Ni基高温合金由于熔点的限制，其最高使用温度已不能满足需要。寻找下一代新型高温合金以满足发展更高效率航空发动机的需求是国内外学术界和产业应用领域共同关注的焦点。最近，新型γ’析出相强化型Co基合金的发现在全世界掀起了开发新型钴基高温材料的热潮。类似于γ’-Ni3Al，γ’析出相在新型Co基高温合金中起到了至关重要的作用。γ’相的结构稳定性、弹性力学性质与温度的依存关系直接决定了Co基合金在高温下的性能表现 ...
许伟伟
core
Representation of obligate groundwater‐dwelling copepod diversity in European protected areas
Conservation Biology, EarlyView.Abstract Groundwaters sustain diverse surface ecosystems and are populated by metazoan species, mostly invertebrates, that provide fundamental ecological functions and are often of prominent conservation value due to narrow endemism and high phylogenetic rarity.
Francesco Cerasoli +7 more
wiley +1 more source
Experimental investigation of Phase Equilibria of Partial Ternary systems with Rhenium [PDF]
, 2016 摘要 镍基高温合金具有高强度、优良的耐热性和良好的耐腐蚀性，被广泛应用于航空航天、国防军事、核能等重要领域。迄今为止，镍基高温合金的添加元素达到了十多种，熔点高、原子半径大的元素如Co，Re，Ru，Mo，W等的添加，能起到很好的固溶强化作用，改善高温力学性能。然而高熔点元素的过量添加导致拓扑密排相的产生，降低镍基高温合金的疲劳寿命、塑性、韧性等力学性能。相图作为合金设计的基础，能够很好的指导镍基高温合金的成分设计。然而，由于Re，Ru，W等元素价格贵，熔点高，对其进行实验研究比较困难。截至目前，由Co ...
杨晓锋
core
Conservation Biology, EarlyView.Abstract Human development is a driver of global change and a major threat to biodiversity. Protected areas maintain and support biodiversity, but outside stressors, such as climate change and land use change, can negatively influence natural resources within protected areas.
Leah J. Rudge +2 more
wiley +1 more source
Dianci bileiqi, 2021 因生产中使用的灰蓝釉配方均采用锆系釉,具有高温粘度大,烧成温度高的特点;而坯料烧成温度低,产品烧成温度不能太高,造成灰蓝釉产品因烧成温度低而出现窑后流痕、缩釉,桔釉、表面不平整等现象,影响产品的外观。所以,需研制与坯料烧成温度匹配的低温电瓷灰蓝釉配方。
杨娟
doaj
Kinetic Investigations and Experimental Determination of Phase Equilibria in some Nickle-Based superalloys [PDF]
, 2016 镍基高温合金具有优异的综合性能，能够适应长时间的高温环境服役要求，广泛应用于航空工业中，其中航空发动机中的镍基高温合金用量最高，所用比例达到了40%-50%。随着航空工业的不断发展，航空发动机对工作温度、推重比及使用寿命的要求进一步提高，高温合金的成分设计面临着新的挑战。相图和动力学计算是材料设计的基础，它使材料工作者摆脱了过去低效的“炒菜式”的材料设计理念，对高温合金的设计研发具有重要的意义。本研究采用扩散偶法，对Ni-Co-Al三元体系的扩散行为进行了研究；基于文献中的实验数据，对Ni-W-X(X ...
杨应来
core
Harnessing social media data to track species range shifts
Conservation Biology, EarlyView.Abstract Biodiversity monitoring programs and citizen science data remain heavily biased toward the Global North. Especially in megadiverse countries with limited biodiversity records, incorporating social media data can help address existing data gaps.
Shawan Chowdhury +15 more
wiley +1 more source