Results 61 to 70 of about 758,549 (212)
Ibis, EarlyView.Anthropogenic factors such as artificial lighting at night (ALAN) and natural factors including temperature and moonlight can affect the dawn chorus pattern in birds. However, most studies are conducted in temperate regions. We investigated the effect of anthropogenic and natural factors on dawn chorus timing in eight species of bird across Hong Kong ...
Ann W. Y. To, Sarah A. Collins
wiley +1 more source
, 2006 为解决龙眼（Dimocarpus Longan Lour）资源浪费，深加工技术水平低等问题，实现龙眼资源综合利用，进行了龙眼多糖、色素的超声强化提取及纯化研究。本文分析了超声提取和神经网络模型的机理，系统研究了影响超声提取龙眼多糖和色素各个因素；同时利用神经网络和单因素试验对提取条件进行了优化，并进行了小规模放大试验。粗多糖和色素经层析分离后，分别得到了纯度和色价较高的纯品。 本文首次系统对超声波功率、作用时间、液固比、温度等影响超声提取龙眼多糖和色素的因素进行了研究 ...
王统一
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四川大学学报. 自然科学版, 2004 瑞香狼毒根的乙醇索氏提取粗膏及粗膏的正己烷索氏提取物和石油醚索氏提取物对柑桔全爪螨的毒力分别是氧乐果原药毒力的0.34倍、12.8倍和11.5倍,其中可能含有更高毒性的物质.乙醇粗膏的乙酸乙酯索氏提取物对正己烷索氏提取物和石油醚索氏提取物有强烈的抑制减效作用.
潘为高 +6 more
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International Journal of Applied Linguistics, EarlyView.ABSTRACT This article examines the language life of young Malaysian Chinese immigrants in Australia and their construction of multi‐membership as reflected in their daily language behaviors. It develops the concept of everyday linguistic citizenship and uses this concept as a theoretical lens to understand how the young adults build, maintain, and ...
Xiaoyi Zhang +2 more
wiley +1 more source
, 2000 为了改变我国海藻多糖依靠水煮及乙醇沉淀法的落后现状，研究开发新的海藻多糖提取分离方法，在海洋863青年基金项目819-Q-15的支持下，本论文以以海带为原料，在浸提方面研究了气升式循环超声破碎浸提工艺及装置；在海藻硫酸酯多糖提取方面进行了絮凝分离和外加电场强化絮凝分离的研究；在分离方面进行了溶剂萃取研究。实验中采用了超声波破碎的方法破碎海带颗粒，从中提取海带多糖。实验所用装置为自制1.2升、8升气升式超声浸提装置。研究结果表明：在1.2升浸提装置中，颗粒的粒度提取率的影响是：随颗粒粒度的增大，提取率下降；
黄猛
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四川大学学报. 自然科学版, 2004 以银杏叶为原料 ,研究了微波技术在银杏黄酮浸提中的应用 .实验通过改变溶剂浓度、提取时间、料液比等条件对产品提取得率的影响进行了探讨 ,并比较了传统浸提法、微波法、微波结合浸提法三种方法的提取 ,结果表明微波法提取银杏黄酮是一种快速、高效、节能的新型提取方法 ,具有一定的实用价值 .
曾里, 刘世贵
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Vocabulary Strategy Instruction in the Argentine EFL Context: Teachers’ Perspectives and Practices
International Journal of Applied Linguistics, EarlyView.ABSTRACT Despite extensive research on vocabulary strategy instruction (VSI), little has been known about teachers’ perspectives on how it is understood and implemented in practice. This study investigated Argentinian EFL teachers’ priorities in vocabulary instruction, their perceived knowledge of learner strategies for spoken vocabulary, and factors ...
Isobel Kai‐Hui Wang, Andrew D. Cohen
wiley +1 more source
, 2013 本发明公开了一种微生物油脂提取方法，属于生物工程下游技术领域。以产油微生物发酵醪液为原料，经过酶解、有机溶剂浸提得到微生物油脂，浸提率最高可达100%。本发明不需要浓缩发酵醪液、回收菌体、干燥菌体等前处理操作，酶解条件温和，处理时间短，浸提温度低，浸提率高，对设备要求低，所用有机溶剂毒性小，大大降低了微生物油脂提取过程中动力和能量的消耗，降低了过程成本，减轻了对环境的污染和人体健康的损害 ...
靳国杰, 赵宗保, 杨帆
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Co‐Teaching in a Virtual Intensive Study Language Programme: Insights From Team Ethnography
International Journal of Applied Linguistics, EarlyView.ABSTRACT As virtual study abroad becomes an increasingly important form of international education, little is known about how transnational teaching is organised and sustained across institutions. Using activity theory as an analytical framework and team ethnography as methodology, this study examines a virtual intensive study (VIS) programme delivered
Zhu Hua +7 more
wiley +1 more source
, 2007 本发明涉及灵芝子实体中三萜类化合物的提取，具体地说是CO2-SFE 在提取灵芝子实体中三萜类物质上的应用，该方法利用超临界二氧化碳作为萃取介质，通过同时控制萃取压力、萃取温度和萃取时间，实现灵芝子实体中三萜类化合物的提取。该方法具有速度快、提取率高、对环境无污染、提取物的有效成分不破坏、无溶剂残留等优点。此外，超临界二氧化碳萃取率和甲醇提取率相当，提取物的组成也基本相似。因此，利用该超临界萃取法得到的灵芝三萜类提取物能够直接加入到各类保健品、食品和饮料等制品中，具有良好的应用前景和经济效益 ...
张 洁 +4 more
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