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1.
This research examined the typical flavor compounds in the commonest type of Khat called Harari Khat grown in the region of
Ethiopia. Twenty-eight compounds, which includes 1,2-Propanedione, 1-Phenyl, Hexanol, Hexanal compounds, Limonene, Benzaldehyde
with other flavors, were extracted by polydimethylsiloxane at room temperature for 30 min from Khat samples, and identified
by solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). This method needs no organic solvents and
required minimal sample.
Project supported by scholarship from China 相似文献
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INTRODUCTIONKhat,achemicalextractedfromaplantCathaEdulis,belongingtothefamilyCelastraceae,isusedasanaturalstimulantinEastAfricaandbor-deringArabicstates.OthernamesbywhichKhatisknowninclude:Catha,qat,kat,chat,kuses-salahin,mirra,tohai,tschat,quat,africanteaandafricansalad.TheplantofCathaedulisisanevergreenfloweringtreeorlargeshrubfoundinEthiopiaandspreadwidelyinKenya,Nyasalnd(nowMalawi),Uganda,Tanganyika,Tanzania,Somalia,Djibouti,andYemen.Itattainsaheightrangingfrom3to4m(Lewis,1931… 相似文献
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德·青格乐图 《内蒙古师范大学学报(哲学社会科学版)》2003,32(4):10-14
笔者以分类法和属性描述的方法,对蒙古语复合词的语法属性进行详细的描述,使复合词的各种语法属性更加具体化、条理化,作为语法属性字段附在每一个词语后面,以便为研制电子版蒙古语复合词语法信息词典提供理论依据。 相似文献
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配位聚合物通常是指以金属离子或金属簇为中心,以有机配体为联结体,通过金属离子与有机配体之间的配位作用而形成的具有周期性网络结构的一类化合物.为了能得到结构新颖、功能独特的晶体材料,一些非常规的合成方法诸如原位合成法被发现和采用,本论文着重综述了配位聚合物的原位合成策略. 相似文献
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As many as 90 % of incarcerated children and young people enter the secure setting disengaged from education. The nature of the secure custodial setting compounds the complex and challenging needs of the children, though efforts to understand this are limited. This paper reports on an ethnographic case study in one secure children’s home in England. Findings show that children can be re-engaged with education, relatively easily within a short space of time, given the right conditions. However, the secure setting was a defining feature, shaping the extent of this engagement. The implications of these findings are discussed and recommendation made. 相似文献
7.
胡继明 《西南师范大学学报(人文社会科学版)》2010,(6):141-145
颜师古在训诂著作中,常用注释用语＂今＂来指称唐代通语,说明从东汉到唐代汉语词语的演变发展轨迹。这些唐代通语与被释词相比较,在形态上,主要有一成不变、貌合神离、改头换面、面目全非等四种变化,而以后两种为主。在构词法上,单音词演变为复音词,以合成词为主且偏正式最多。今天仍有一部分唐代通语作为现代汉语基本词汇、一般词汇或方言词汇在沿用。 相似文献
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本文从七个方面阐述了汉俄两种语言中数词的不同特点及其用法，提出了数词在汉译俄的翻译中常碰到的一些问题，并针对这些问题提出解决办法。 相似文献
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千山侧柏叶挥发性化学成分分析 总被引：7，自引：0，他引：7
报道了用水蒸气蒸馏-萃取法提取千山侧柏叶中挥发性物质，测得提取的千山侧柏叶挥发油含量为2.0％。用GC／MS法从千山侧柏叶挥发油中分离并确定出30种化学成分，占总挥发油总检出量的98．67％．用峰面积归—化法通过化学工作站数据处理系统，得出各化学成分在挥发油中的相对百分含量． 相似文献
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本文采用化学软件Chem3D ultra 8.0,计算了24种含氮杂环化合物分子的11种结构参数,将这些结构参数作为描述符与其毒性LgBR进行多元回归分析并构建方程.该方程的构建能够准确地预测含氮杂环化合物的活（毒）性.通过回归模型可以看出含氮杂环化合物的毒性与其电子能、最高占据轨道能密切相关. 相似文献
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目的：研究地瓜藤（Ficus tikoua Bur）石油醚及乙酸乙酯提取部分的化学成分。方法：地瓜藤经乙醇渗漉提取,采用溶剂提取法进行分离纯化,得到的单体化合物,根据理化方法及气相色谱-质谱联用分析鉴定法鉴定其结构。结果：分离出穿贝海绵甾醇、邻苯二甲酸二丁酯、4-羟基-3-甲氧基苯甲酸、邻苯二甲酸二异丁酯、邻苯二甲酸二乙基己基酯、十八酸等33种化学成分,其中32种化合物是首次从该种植物中提取得到的。 相似文献
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本文根据美学原理阐述了商标翻译的美学原则,并结合商标翻译的基本准则和实例分析了翻译商标时,如何使译名具有形美、音美、意美等美学特征。 相似文献
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郑厚尧 《荆州师范学院学报》2008,(3):86-88
通过计量的方式从微观层面来研究多义词,即多义复合词的词义与其构成成分——语素义之间的关系,结果表明：语素的多义性使复合词也具有多义性。或者说复合词的多义性来源于构词语素的多义性。由语素的多义性产生的多义复合词,其词义基本上可以由语素的字面意义获得。 相似文献
15.
于洁 《连云港师范高等专科学校学报》2001,(3):51-52
本文从三个方面浅析连云港地区民间小调的基本特征：一、小调的内容涉及到不同的历史时期社会各个方面，显示其内容的丰富性。二、演唱时，可连续演唱多种小调，调式间相互转换十分灵活，施用于一般的业务伴奏者。三、小调的旋律受到周边地区民歌的影响，优美而明快，同时又被其它剧种所吸收，可塑性强。 相似文献
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A method of screening assay is demonstrated. The approach is based on the affinity ofantitumor candidates for topoisomerases. In this method, antitumor candidates are fished out using topoisomerases as targets. Traditional analysis of complex compounds typically encounters signal suppression due to the relatively low concentrations, but enzyme-affinity screening for the active compounds can effectively concentrate the desired analysts into a small volume of high concentration. Active compounds are separated from non-affinity compounds by ultrafiltration. The molecules-enzymes complexes that are retained on the filter are subsequently separated by acidification to obtain the topoisomerases-affinity compounds for analysis on High Performance Liquid Chromatography coupled with electrospray ionization mass spectrometric detection (ESI-MS). This enzyme-affinity based screening assay provides a highly specific and efficient method that can directly screen, identify, and acquire drug candidates thus improving the accuracy and speed of high-throughput screening activities. 相似文献
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INTRODUCTION Variety of scientific advances and economicpressures in recent years called for improved drugdiscovery screening technology (Burbaum, 1998;Major, 1998). In response to that call, a number ofpotential therapeutic targets from the field offunctional genomics have emerged and largecompound libraries derived from parallel andcombinatorial chemical synthesis techniques havebeen developed. These new advances have helpedthe pharmaceutical industry reduce developmentcosts and e… 相似文献
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本论文通过核磁共振实验技术,对吐昔烯盘状液晶化合物的结构特征进行了详细的研究.通一维的1HNMR、13CNMR、DEPT,二维核磁共振gHMBC、gHSQC等实验技术对化合物的碳氢进行了归属;为该化合物结构的解析提供了有利的依据. 相似文献
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英语复合词的述谓结构与语义格研究 总被引：2，自引：0，他引：2
邹霞 《邵阳学院学报(社会科学版)》2007,6(3):89-91
英语复合词不但有着显性的句法关系,还有着隐性的语义关系。文章通过对英语复合词的述谓结构和语义格的分析和描写,揭示出英语复合词复杂的隐性语义结构关系,提出英语复合词的结构模式,并且发现,英语复合词的造字过程实际上也是句子结构的词化和结构压缩的过程。 相似文献
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Nicos Papadouris 《课程研究杂志》2013,45(4):521-538
This paper demonstrates a methodology for effectively integrating computer‐based learning tools in science teaching and learning. This methodology provides a means of systematic analysis to identify the capabilities of particular software tools and to formulate a series of competencies relevant to physical science that could be developed by means of these capabilities. This analysis could inform the transition to technology‐rich learning environments by helping to deflect reliance on computer‐based tools for objectives they cannot meet, while encouraging the design of activity sequences that make the most of the educationally useful capabilities of available computer‐based tools. This methodology is demonstrated by means of two software tools widely used in science learning, namely modelling and simulation tools. 相似文献