Results 81 to 90 of about 621,014 (218)
, 2015 本文针对相变储热材料的潜在大规模应用,对低温,中温,和高温无机盐复合相变材料的热稳定性进行研究。以103.5 oC的Li NO3-Na NO3-KNO3-Ca(NO3)2/硅酸钙相变材料,306oC的Na NO3/硅藻土相变材料,500oC的Li CO3-Na CO3/Mg O相变材料这三种材料为例,通过热重-质谱(TG-MS)联用分别研究了这三种材料在空气和氩气气氛下的分解温度及分解产物。进一步考虑到尺度效应的影响,本文将材料放大到工业应用的相变材料单元进行测试。通过自搭建实验平台 ...
姜竹 +5 more
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International Journal of Applied Linguistics, EarlyView.ABSTRACT Understanding learners’ English speaking self‐efficacy is essential for promoting effective oral communication in EFL contexts. However, variable‐centered research on English speaking self‐efficacy often overlooks heterogeneity among learners.
Cha Li, Lawrence Jun Zhang
wiley +1 more source
Gaoya dianqi, 2010 断路器在随机关合空载变压器时会产生幅值、频率很高的励磁涌流,这种操作暂态可能导致微机继保装置误动作,降低用户电能质量和系统可靠性。根据空载变压器涌流产生的机理,采用选相关合技术消除变压器励磁涌流,研究了铁心剩磁和最佳关合相位关系;分析了断路器截流和暂态恢复电压对铁心剩磁影响,并给出了剩磁测量方法。在空载变压器选相关合原理基础上,采用ATP-EMTP软件建立空载变压器关合模型,对暂态过程进行了仿真。仿真结果表明,选相关合技术能有效消除空载变压器合闸时产生的励磁涌流,为空载变压器选相关合提供了理论基础。
李伟 +4 more
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International Journal of Applied Linguistics, EarlyView.ABSTRACT Grounded in social cognitive theory, this study investigated how high‐evidence factors jointly contribute to Chinese‐as‐a‐foreign‐language (CFL) speaking self‐efficacy. Data from 236 CFL learners in Beijing revealed a multifaceted pattern of associations.
Peijian Paul Sun +3 more
wiley +1 more source
一种平面相变存储器的制备方法，包括：在衬底上依次生长一层电热绝缘材料层，相变材料层和基底材料层；去除基底材料层的四边，形成基底；在相变材料层的上面和基底材料层的表面及侧面淀积侧墙材料层；去除基底材料层上表面的和相变材料层表面的侧墙材料层，在基底材料层的侧面将形成高和宽均为纳米尺寸的侧墙；去除基底材料层，只保留纳米尺寸的侧墙；去掉除了侧墙底部以外的所有相变材料，从而形成由侧墙和相变材料层构成的叠层侧墙；在该侧墙的一条边上搭上一条制作电极的金属层；去除侧墙以及侧墙表面上的金属层 ...
马慧莉 +5 more
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New Phytologist, EarlyView.Design of the VPDrought experiment in a Scots pine (Pinus sylvestris) forest at the Pfynwald research platform. Summary Atmospheric and soil drought are major, yet typically confounded, drivers of tree stress. Rising vapor pressure deficit (VPD) may impair forest function independently of soil moisture decline, yet stand‐scale experimental separation ...
Marcus Schaub +9 more
wiley +1 more source
四川大学学报. 自然科学版, 2011 本文主要是研究金属铁经历冲击—卸载到熔化压力区,其内部发生熔化相变时,铁/蓝宝石界面的辐亮度和温度随时间演化特性,发现辐亮度随时间持续增强而界面却经历了一个慢降温过程,该特征与无相变或瞬时相变的热传导模型结论不一致,即无熔化相变或瞬时相变时,界面温度是一个稳定值.本文结合熔化相变动力学模型与热传导方程对实验现象给出一种理论解释.模型计算所给出的温度历史与观测结果一致,由此可以校对其它测量或者计算熔化温度的方法和模型计算的结果,并能够初步限定出该压力下铁的熔化成核速率和径向长大速率.
张世来 +5 more
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Journal of Critical Infrastructure Policy, Volume 8, Issue 1, Spring/Summer 2027.ABSTRACT Epistemic orphaning, responsibility drift, loss of institutional memory, and non‐stationarity are not new problems in infrastructure governance—they have accompanied long‐life infrastructure throughout its history. What artificial intelligence changes is not the existence of these problems but their scale, opacity, and the structural ...
Priscilla P. Nelson
wiley +1 more source
Governing for Digital Resilience: Rethinking Inclusion for WSIS+20 and Beyond
Policy &Internet, Volume 18, Issue 4, December 2026.ABSTRACT At the WSIS+20 juncture, this article asks what conditions enable individuals to participate meaningfully in digital life, and how governance arrangements should be assessed accordingly. Multistakeholder governance has distributed authority across actors, but not necessarily the capacity to shape or respond to digital conditions. We argue that
Audrey Yue, Jun Yu, Renae Sze Ming Loh
wiley +1 more source
Shiyou jixie, 2015 采用有限元仿真方法，根据结构失稳理论分析六级分支井分岔装置在20 MPa内压作用下相贯线部分出现鼓包变形问题。首先，模拟双相钢和IF钢不同壁厚、管径的六级分支井分岔装置在内压作用下的变形及应力分布，并测量分岔装置最大鼓包变形量与位置。然后，通过未加压分岔装置相贯线截面与加压变形后相同位置截面对比分析，发现相贯线截面存在的结构几何缺陷与厚度缺陷导致分岔装置变形，得出六级分支井分岔装置结构失稳极值点位置和导致最大鼓包变形的最大几何缺陷；在内压作用下 ...
邓治国 +7 more
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