共查询到20条相似文献，搜索用时 31 毫秒
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灯盏花是云南省的特色中草药之一,有重要的药用价值,并为地方经济做出了重要贡献．对灯盏花中有效成分灯盏花乙素的提取和分离检测进行全面报道,包括溶剂浸提、索氏提取、超声提取、微波提取、超临界流体萃取等提取方法,以及紫外分光光度法、薄层色谱法、高效液相色谱法、毛细管电泳法、液质联用法等分离检测方法,旨在为相关研究提供参考． 相似文献
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[目的]优化微波辐射下紫甘薯中花青素的提取工艺和含量测定方法.[方法]采用单因素实验,,确定最佳提取工艺;通过误差分析,对两种测定方法进行比较.[结论]最佳提取条件是：盐酸水溶液与物料的液固比为20∶1、盐酸浓度为0.5%、微波辐射功率为700 W、提取温度为70℃、提取时间为6 m in;pH示差法比单一pH法测定结果稳定,准确度更高. 相似文献
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文中对近年来用色谱法分析酚类内分泌干扰物质的研究进展进行了综合评述．介绍了固相萃取、固相微萃取、加速溶剂萃取、微波萃取四种样品预处理方法以覆利用气相色谱、液相色谱对样品进行测定的方法,从而,对酚类内分泌干扰物的研究前景进行了展望． 相似文献
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溶剂萃取过程新技术进展 总被引：2，自引：0，他引：2
阐述了近年来溶剂萃取的新进展.认为反胶团溶剂萃取、超临界流体萃取、微波萃取、电泳萃取、超声萃取、预分散萃取、磁场协助溶剂萃取、液膜萃取、内耦合萃取反交替分离过程、离子液体萃取等是溶剂萃取发展的新方向.溶剂萃取已成为一项得到广泛应用的分离提纯技术. 相似文献
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以国内发表的相关文献为依据,综述了叶下珠提取实验的溶剂选择、提取方法及化学成分的分离和测定方法等方面的研究成果,基于文献中有机溶剂的普遍使用,提出了实验过程应体现绿色化学理念的观点。 相似文献
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正交试验法优选叶下珠有效成分水提工艺 总被引：1，自引：0，他引：1
以优选叶下珠有效成分水提工艺为目的,以黄酮提取率为考察指标,用分光光度法对黄酮进行定量,在单因素试验的基础上,采用正交试验设计法,考察液料比、温度、提取时间三个因素对提取效果的影响。试验结果表明,叶下珠水提最佳工艺条件为：液料比为20：1,温度为80℃,提取时间为120min,用该条件进行试验,黄酮提取率达1.467%。 相似文献
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Michael J. Jacobson 《Journal of Experimental Education》2020,88(3):375-381
AbstractThis article is premised on the observation that in educational research there is an increasing use of terminology and concepts related to the field of complexity and the study of complex physical, biological, and social systems. As we are at an early stage in this cross-fertilization of complex systems ideas and methods in educational research, this article provides an overview of key complex systems conceptual perspectives and research methods in conjunction with a discussion of why educational researchers should consider their use. It is hoped that this overview of complex systems concepts and nomenclature used to describe research that views education as a complex system will help promote a broader awareness and acceptance of this work in the educational research community. 相似文献
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教学方法是课程取得良好效果的关键因素。从英语语言学课程的特殊性出发,依据语言学相关理论,探讨总结了该课程的教学方法,即如何帮助学生构建语言学理论的框架、怎样导入学习具体的理论、运用方法记忆纷繁的术语以及怎样运用多元化的机制考核学生。这些方法在实践中反复应用解决了语言学课堂的实践性难题。 相似文献
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紫色马铃薯Bora valley花青素的提取与含量的测定 总被引：2，自引：0，他引：2
用马铃薯的全薯、薯皮、薯肉作为实验材料,采用溶剂浸提（95％乙醇,0．1mol／L盐酸）法、超声波破碎提取法以及液氮-丙酮提取法这三种不同的实验方法对其花青素进行了提取,并使用分光光度计比色及pH示差法计算了花青素的含量．结果显示,不同的提取方法所测得的花青素相对浓度存在着一定的差异．其中,通过溶液浸提法得到的Bora的花青素含量为全薯为0．041mg·g^-1鲜重,薯皮0．109mg·g。鲜重,薯肉为0．030mg·g^-1鲜重．通过超声波破碎提取法得到的花青素的含量为全薯0．055mg·g^-1鲜重,薯皮0．156mg·g^-1鲜重,薯肉为0．038mg·g^-1鲜重．而通过液氮-丙酮提取法得到的花青素的含量为全薯0．028mg·g^-1鲜重,薯皮0．064mg·g^-1鲜重,薯肉为O．028mg·g^-1鲜重．其中,通过超声波破碎法得到的花青素的量较高．实验结果表明,Bora中较高的花青素含量可使其在天然抗氧化剂的提取及制备方面拥有更广阔的前景和应用价值． 相似文献
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李荣 《忻州师范学院学报》2012,28(2):28-30
AOR(快速超松弛法)和USSOR(非对称逐次超松弛法)的迭代矩阵中都含有两参数,且这两种迭代更具广泛性。文章首先论证了当ω1=γ,ω2=ω,且0≤γ≤ω≤1(ω≠0)时,USSOR迭代优于AOR迭代;其次证明了预条件矩阵Pm下这种结论也成立。由于USSOR法的迭代矩阵形式较复杂,计算麻烦,要直接判别其敛散性是比较困难的,因此可通过AOR迭代矩阵的谱半径来判断USSOR迭代的敛散性,这样就简单多了。最后通过两个数值例子进行验证。 相似文献
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以清除亚硝酸盐及阻断亚硝胺合成的百分率为综合评价指标,研究了半仿生法下龙胆草提取液体外清除亚硝酸盐和阻断亚硝胺合成的能力．研究结果表明,半仿生法下在70℃,用1：15的料液比提取3次,每次1．5h,所得结果最佳,对亚硝酸盐最大清除率可达90．79％,亚硝胺合成的阻断率最大达65．23％,分别是常规提取方法的4倍、1．5倍． 相似文献
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综述了近年发展起来的发酵液后处理新技术,包括双水相萃取技术、超临界二氧化碳萃取技术、细胞过滤培养技术、反胶团提取分离技术,经过不断的研究、改进,已有些达到商业规模,有非常诱人的前景 相似文献
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Donna Koller Valerie San Juan 《International journal of qualitative studies in education》2013,26(5):610-631
Inclusive education provides learning opportunities for children with disabilities in regular settings with other children. Despite the prevalence of inclusive education, few qualitative studies have adequately explored young children’s perspectives on inclusion. This paper reviews the findings of a preliminary qualitative study where play-based interviews were conducted with 12 typically developing children enrolled in one of two childcare lab schools. Study methods provided an opportunity to assess play-based interview techniques where young children were asked to describe their views on inclusive education. The findings demonstrate that play-based methods allow young children of various ages to identify complex issues related to inclusion. The authors call for additional research that examines research methods in early childhood settings on multi-faceted issues regarding educational policies and practices as a way to attenuate young children’s lack of participation in curriculum development. 相似文献
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生物样品中短链脂肪酸提取测定及其应用进展 总被引：2，自引：0，他引：2
综述了不同样品（尿液、血液、生物培养液等）中短链脂肪酸的测定方法,讨论了气相色谱、高效液相色谱、毛细管电泳、原子吸收分光光度测定方法的优缺点,并讨论了短链脂肪酸在营养生理、疾病以及肠道菌群中的应用研究进展. 相似文献
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Cognitive Load Theory and Complex Learning: Recent Developments and Future Directions 总被引：27，自引：0，他引：27
Traditionally, Cognitive Load Theory (CLT) has focused on instructional methods to decrease extraneous cognitive load so that available cognitive resources can be fully devoted to learning. This article strengthens the cognitive base of CLT by linking cognitive processes to the processes used by biological evolution. The article discusses recent developments in CLT related to the current view in instructional design that real-life tasks should be the driving force for complex learning. First, the complexity, or intrinsic cognitive load, of such tasks is often high so that new methods are needed to manage cognitive load. Second, complex learning is a lengthy process requiring learners motivational states and levels of expertise development to be taken into account. Third, this perspective requires more advanced methods to measure expertise and cognitive load so that instruction can be flexibly adapted to individual learners needs. Experimental studies are reviewed to illustrate these recent developments. Guidelines for future research are provided. 相似文献
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愤怒作为一种普遍情绪和复杂的本能,它以多种方式影响着私人的和社会的各种关系。国内外愤怒情绪研究主要成果集中在愤怒情绪影响因素及其相关因素等方面,所采用的研究方法是实验法和测验法,研究对象为正常人群,存在着实验研究不够精密、理论研究不够深入、被试范围狭窄等不足。未来愤怒情绪的理论研究丰富,被试范围扩展,研究方法改进。 相似文献
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Cheryl Poth 《International Journal of Research & Method in Education》2019,42(3):252-266
ABSTRACTEducational research teams are increasingly recognized as an optimal configuration for addressing more complex mixed methods research problems; however, their development is often approached as a conventional research collaboration rather than an integrative one. An approach informed by complexity theory provides the practical guidance for studying mixed methods research teams as complex adaptive systems with the capacity for generating novel educational research outcomes greater than the sum of individual contributions alone. In this paper, I advance a complexity-sensitive strategy through which to realize the integrative capacity of educational mixed methods research teams comprising of four interrelated elements: membership, contributions, interactions, and performance. These elements embody amalgamations from a decade of my readings of the literature and real-life professional experience. Each element is examined in light of the three key concepts of complex adaptive systems to describe the necessary conditions for emergence, influential challenges illustrating interdependency, and desirable individual and team adaptations. The study’s theoretical and practical implications are discussed. 相似文献