Results 31 to 40 of about 833,358 (231)
, 2005 建立了微囊藻毒素的一种新的测定方法。在Ni2 + 硼砂为支持电解质的体系中 ,微囊藻毒素 RR在 -1 5 5V产生一个极谱波。在此实验条件下 ,微囊藻毒素在 1 5 0～8 0 0mg L浓度范围内 ,极谱波高与微囊藻毒素浓度有良好的线性关系 ,线性相关系数为 0 998,检测限为 0 0 7mg L。同时对测定条件进行了研究 ,并探讨了极谱电流的性质 ,认为该极谱波是一个催化氢波 ;常见无机物和有机物不干扰本法测定 ,具有良好的选择性。该方法用于实际水样测定 ...
刘斌,周培疆,宋立荣
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, 2013 测量不确定度是评定测量结果的重要参数.超声波检测是最常用的无损检测方法之一,探头是超声波探伤仪的重要组成部分,它的性能是检测工作得以顺利进行的关键.在检测工作进行之前,对其各性能参数进行准确测试,是提高缺陷定位准确性的重要手段.以超声波检测用斜探头性能参数测试实验为例,说明不确定度评定在无损检测定量分析中的作用.实验依据专业标准JB/T10062-1999的规定,对探头的前沿长度、K值、偏离角度进行了测试,从仪器、方法等方面,对测试结果进行了不确定度评定,试图提出一些建设性改进方案 ...
中国科学院新疆生态与地理研究所,新疆乌鲁木齐,830011 +1 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
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Dianci bileiqi, 2019 为了对直流盘形悬式绝缘子体积电阻测量进行不确定度评定并优化测量方法及不确定度评定方法,基于经验模型法对UD420B205/550H28R（XZP1-420）型直流盘形悬式瓷绝缘子体积电阻试验测量结果进行不确定度评定。绝缘子体积电阻测量结果为3. 157×109Ω,扩展不确定度为0. 594×109Ω,包含因子k=2。测量结果的不确定度主要由铁帽温度引入的不确定度决定,温度系数引入的不确定度为体积电阻合成不确定度的三千分之一,可忽略不计。只要关键影响因素受控就无需对每次得到的结果都重新评定 ...
张勤
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, 2006 一种定量测定样品中内毒素浓度的判断方法，其特征在于：将内毒素标准品和待测样品做系列稀释；与鲎试剂反应，测得浊度值达到一预设浊度时的特征反应时间；将特征反应时间的对数与稀释浓度的对数作曲线，并进而得到标准曲线的斜率bs和样品稀释曲线的斜率b；将二者比值b/bs 的大小作为能否进行定量测定的判断依据，要求b/bs在133-80％之间。本发明提出了定量测定样品中内毒素浓度的判断方法，定量给出了通过标准曲线来计算样品中内毒素浓度的试验误差，也可以与内毒素测定仪、动态比浊定量法配合使用 ...
邵英光 +3 more
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International Journal of Applied Linguistics, EarlyView.ABSTRACT With the increasing number of Chinese international students in Australian universities, intercultural competence has become a critical factor influencing their interactions with Australian tutors in university classroom settings. Existing research often examines students’ intercultural competence from a single‐method or single‐perspective ...
Jiangyu Han, Linda Tsung
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, 1996 本发明公开了一种测定水中溶解氧的试剂，它由碳酸盐、硫酸盐、糖、氯化物、淀粉、钾盐、镁盐、亚硫酸盐组成，按一定比例配制，混合均匀，研磨呈粉状，放入干燥箱内１０５℃４小时，分装入胶囊中。该发明制备工艺简易，测试操作简便，成本低 ...
徐小清, 张晓华, 孙兴湘
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The Effects of Gen‐AI on Situated and Future‐Driven Academic Writing Motivation
International Journal of Applied Linguistics, EarlyView.ABSTRACT Despite the increasing use of Generative Artificial Intelligence (Gen‐AI) in education, there is still a significant gap in understanding its effects on the situated‐ and future‐driven motivation in academic writing. This longitudinal design‐based research sought to explore variations in academic writing motivation of 110 Chinese university ...
Xiao Hu +3 more
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, 1985 <正> 漂白粉中的有效成分——含氯量极不稳定,在使用时,往往由于含氯量的消失而无效。中国科学院水生生物研究所研究制成的“水生”漂白粉有效氯快速测定器,可在15分钟内测出漂白粉中的含氯量,误差数约为千分之四。市售漂白粉有效氯含量为30—35%,该仪器根据含氯量为30%,以碘量法的原理设计而成,采用目测比色法测定,操作容易,设备简单 ...
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Exploring English Language Learners’ Vocabulary Knowledge and Usage When Speaking
International Journal of Applied Linguistics, EarlyView.ABSTRACT Vocabulary forms a fundamental component of speaking ability, as it enables speakers to convey meaning accurately, fluently, and effectively. Although the relationship between vocabulary and speaking has been investigated to some extent, gaps remain in understanding the link between learners’ vocabulary knowledge and their speaking proficiency,
Junyan Guo, Martin East
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