Results 51 to 60 of about 506,383 (198)
, 2008 多元醇类相变材料是相变材料中质量储热密度大、过冷度低、具有固－固相变的一类相变材料。本论文采用精密绝热量热法、燃烧量热法和近代热分析技术对多元醇类相变材料的热容、相变、燃烧热、标准摩尔生成焓和热稳定性等基础热力学性质进行了系统的研究，并对多元醇－中空纤维复合相变材料做了探索性研究，取得了如下结果： 首先，利用精密自动绝热量热仪测量了多元醇类固－固、固－液相变材料，天然多元醇类固－液相变材料等11种相变材料的热容。利用相变温区的热容数据，计算出化合物的相变温度、相变焓和相变熵 ...
童 波
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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
, 2011 相位误差的校正是傅里叶变换成像光谱仪数据处理的重要环节之 一。针对干涉曲线的对称性特征,利用相位相关性计算方法,提出一种新的傅里叶变换光谱数据的相位校正的方法。将相位相关性拟合为Sinc函数,计算亚像素 的偏移量,采用离散余弦变换转换到光谱域。使用标准光谱库中的源光谱数据作为原始数据,将通过离散余弦变换仿真的干涉数据与该方法得到的结果进行比较和验 证,并与Mertz方法进行了对比。结果表明:该方法精度优于Mertz方法,并且计算简单。
李玉山 +3 more
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Psychometric framework for coexistence with large carnivores
Conservation Biology, EarlyView.Abstract Human–carnivore coexistence is essential for biodiversity conservation, yet measuring the attitudes and behaviors that support it remains methodologically challenging. We developed psychometric scales to assess willingness to coexist with carnivores and the underlying beliefs of this coexistence through an iterative expert elicitation process ...
Benjamin Ghasemi +14 more
wiley +1 more source
四川大学学报. 自然科学版, 1985 用倒扭摆法测试了18 Ni马氏体时效钢的低频内耗.发现在降温中于165℃附近出现正马氏体相变内耗峯.在升温中于700℃附近出现反马氏体相变内耗峯.内耗峯的高度与T/f(T—温度变化速率,f—振动频率)成线性关系,恒温测量时,相变内耗降为背景值.还观察到相变过程中,切变模量发生软化.我们认为这个内耗是由外加切应力促进或加速接近临界的马氏体胚芽的界面位错滑移所引起.
何思明 +3 more
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Modeling seed germination data to meet biodiversity conservation needs in the Mediterranean
Conservation Biology, EarlyView.Workflow to assess the availability and quality of germination data and assign species' thermal risk in the Mediterranean. (a) Assessment of data availability, including the phylogenetic distribution of the number of records (i.e. available germination data); (b) data quality assessment; and (c) assignment of climate risk categories for species that ...
Diana María Cruz‐Tejada +2 more
wiley +1 more source
四川大学学报. 自然科学版, 1980 这是熟知的,两个相互等价的(即可经行列式为±1的整系数齐次线性变换互变的)实系数n元二次型f和g,对变元的所有整数值来说,表数相同(即凡能由f以整变元表出之数均可由型g以整变元表出,反之亦真).但是,相反的结论是否能够成立呢?亦即是否表数相同的二次型一定是等价的呢?这是基本而古老的问题.1830年,Legendre曾未加证明地断言,表数相同的二元恒定二次型必等价.1895年,Bauer曾就有相同行列式的真本原整系数恒定二元二次型这一特殊情形证明了Legendre的断言.
柯召, 郑德勋
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, 2014 本发明涉及一种相变控温防晒薄膜及其制备方法。其特征在于相变控温防晒薄膜是以微胶囊复合相变材料为智能控温成分，采用氧化锌、二氧化钛、银、氧化铝等纳米颗粒作为抗紫外线材料，以PVC、PET、PE等薄膜为基体材料塑化复合而成。本发明首先将基体材料的树脂粉，塑料助剂通过高速搅拌混炼成均匀稳定的增塑糊，然后加入微胶囊复合相变材料和纳米颗粒，继续搅拌混合均匀，最后通过涂敷成形、高温固化制备出具有较好相变储能特性和较高抗紫外线性能的新型相变控温防晒薄膜，该薄膜在可见光区的透过率可达65%，在紫外光区的透过率仅为10%
徐芬 +4 more
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Learning Styles, Engagement and Anxiety in AI‐Mediated Writing: A Multimodal Feedback Study
International Journal of Applied Linguistics, EarlyView.ABSTRACT Artificial intelligence (AI) tools now permeate English academic writing. However, evidence on how feedback modalities align with student differences and with psychological mechanisms remains limited. Prior work often reduced learning styles to simple matches with delivery modes and treated learning engagement and writing anxiety as peripheral.
Yi Ren +3 more
wiley +1 more source
Gaoya dianqi, 2010 单相自动重合闸是保证电力系统安全稳定的重要举措,在国内外超高压/特高压电力系统中得到了广泛的应用。笔者分析了相电流突变量选相原理及在高压输电线路单相自动重合闸中的应用。用MATLAB7.0仿真了相电流差突变量选相和相电流突变量选相方法,并结合继电保护模块和单相重合闸模块进行仿真分析。结果表明,应用MATLAB对单相自动重合闸故障选相进行仿真分析可获得很好的效果,对理解单相自动重合闸的原理很有帮助。
胥杰 +5 more
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