Results 81 to 90 of about 1,435,259 (250)
International Journal of Applied Linguistics, EarlyView.ABSTRACT In English medium instruction (EMI), students face cognitive and emotional demands in second language (L2) communication, which may hamper their motivation and willingness to communicate (WTC). Adopting a mixed‐methods design, this study explores how growth mindsets affected student motivation (e.g., ideal L2 self and ideal disciplinary self ...
Pengzhan Yang +2 more
wiley +1 more source
, 2003 一种由合成气选择合成汽、柴油馏分(＜C20)用的催化剂由活性组分、助剂和载体三部分组成。活性组分是金属铁，助剂是来自第IB、IIIB、IA族金属元素，如Cu、Ce、K等，或加入第二活性组分第VIII族金属元素，如Co、Ru等。载体选用杏核活性炭或椰壳活性炭，活性炭的比表面积为200m2/g-2000m2/g，孔容0.3-1.5cm3/g，孔径分布为4-1000。金属铁在催化剂总重量中占4-40％，助剂元素在催化剂总重量占0.01-20.0％，第二活性组分在催化剂总重量点0.01-10 ...
林培滋 +4 more
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International Journal of Applied Linguistics, EarlyView.ABSTRACT While English‐medium instruction (EMI) and English for Academic Purposes (EAP) courses are designed to promote language and content learning, their prevailing English‐only approaches often undermine students’ learning motivation. Against this backdrop, translanguaging has gained recognition as an effective pedagogical practice to support ...
Yihai Wen, Fan Fang
wiley +1 more source
酶促立体有择合成(1R,3S,5S)-1-乙炔基3-二苯叔丁硅氧基双环[3.1.0]己烷
四川大学学报. 自然科学版, 2002 (1R,3S,5S) 1 乙炔基 3 二苯叔丁硅氧基双环[3.1.0]己烷(3)是合成19 失碳 1α,25 二羟基维生素D3(2)的重要合成子.为了寻找更有效的可用于工业化生产的合成(3)的方法,作者以(±)外向 1 溴双环[3.1.0] 3 己醇(±4)为原料,经酶促立体有择反应得到光学活性的(1S,3S,5S) 1 溴 双环 [3.1.0] 3 己醇(4),再经羟基保护等3步反应得到目标物(3).实验结果表明,该合成方法实验操作简单、收率较高,所合成的(3)的光学纯度可达99 ...
郭丽, 伍晓春, 李佩杰, 吴勇
doaj
, 2009 本发明公开了一种聚酰亚胺及其合成方法，其特征在于聚酰亚胺聚合物合成分为二步完成，分别是第一步2，5-二(对羟基)-1，3，4-噁二唑单体的制备；第二步，聚酰亚胺的合成，与现有技术相比，本发明的优点在于：采用先合成2，5-二(对羟基)-1，3，4-噁二唑单体，再合成新型的聚酰亚胺聚合物，合成方法简单有效，合成成本比较低；使用催化剂 KI。由于2，5-二(对羟基)-1，3，4-噁二唑单体中噁二唑基团吸电子作用的影响，使苯氧负离子的电子密度相对降低，亲核性相对减弱，故反应中，通过加入催化剂KI来加快反应的进程；
严庆, 严 庆, 禇怡春
core
The Impact of AI‐Assisted L2 Learning on Learners’ Emotions: A Meta‐Analysis
International Journal of Applied Linguistics, EarlyView.ABSTRACT The scope of research on AI‐assisted second/foreign language (L2/FL) learning has expanded beyond learning outcomes to focus on learners’ emotional experiences. Despite their proliferation, existing empirical findings are inconsistent, and few studies have systematically synthesized the impacts of AI‐assisted L2 learning on learners’ emotional
Jiaqi Jing +4 more
wiley +1 more source
Zhongshan Daxue xuebao. Yixue kexue ban, 2001 【目的】探讨积雪草甙治疗增生性瘢痕的作用机制。【方法】采用光镜、电镜、3H-TdR、3H 脯氨酸掺入及MTT 比 色等方法检测成纤维细胞核DNA 合成和胶原蛋白的合成。【结果】积雪草甙不仅能影响成纤维细胞的超微结构, 而且能抑 制成纤维细胞增殖及胶原蛋白的合成。【结论】积雪草在预防和治疗增生性瘢痕中有重要作用, 其机制可能与抑制成纤维细 胞增殖和胶原蛋白合成有关。
谢举临, 利天增, 黎志明
doaj
, 2008 由生物质气化合成液体燃料（甲醇、二甲醚和低碳烃类），是理想的碳中性绿色燃料，将其用作城市交通和民用燃料，已经引起全世界的广泛关注，也是可再生能源中唯一能转化为液体燃料和化学品的碳资源。通过生物质气化得到合成气的缺点主要是H2／CO比低，CO2含量高等。随着气化和重整技术的提高，通过水蒸气气化后得到的合成气，或者经过重整调整H2／CO，最终的合成气H2／CO比组成可以达到2．20以上，已经达到合成气合成液体燃料的最佳比例要求（合成甲醇合成气最佳组成f=（H2-CO2）／（CO＋CO2）=2．05～2．10）
王铁军 +4 more
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International Journal of Applied Linguistics, EarlyView.ABSTRACT Collaborative writing has attracted increasing attention in English as a Foreign Language (EFL) instruction due to its potential to enhance learners’ writing competence. However, few studies have examined the comparative effects of collaborative versus independent writing on EFL learners’ individual performance, especially in higher‐order ...
Ting Huang, Chenze Wu, Wenkang Zhang
wiley +1 more source