共查询到20条相似文献，搜索用时 78 毫秒
1.
对乌药叶中黄酮类化合物的含量进行了测定,并对其成分进行了定性分析。结果表明,乌药叶中黄酮类化合物的含量为2.1％,叶片中可能主要含有黄酮醇类化合物。 相似文献
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以70%乙醇为溶剂,采用索氏提取仪提取九香虫中黄酮类化合物,用分光光度法测定含量.结果测得样品中总黄酮的含量为1 122mg/100g,平均回收率为98.8%.九香虫中含有一定量的黄酮类化合物,但含量较少. 相似文献
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石榴叶中总黄酮含量的测定 总被引：7，自引：0，他引：7
用分光光度法对石榴叶中总黄酮含量进行了初步测定,结果表明,石榴叶中黄酮类物质含量非常高,可达3.59mg/g,这将为开发利用石榴叶资源提供依据. 相似文献
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采用超声波法提取黄柏中的黄酮类化合物,并用紫外分光光度法测定了黄酮含量.本方法的回收率为95.3%~101.1%,变异系数小于0.35%.用流动注射化学发光分析法测定了黄柏的抗氧化性,结果表明黄柏中所含的黄酮类化合物具有较强的抗氧化性. 相似文献
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犁头草中化学成分及总黄酮含量的研究 总被引：1，自引：0，他引：1
目的:研究犁头草中的化学成分,测定犁头草中总黄酮的含量.方法:以鉴别法对犁头草提取物中的化学成分进行定性,以芦丁为对照品,采用紫外分光光度法在274nm处测定犁头草中总黄酮类化合物的含量.结果:犁头草提取物中含有大量黄酮,总黄嗣含量为15.5%,芦丁对照品在0.800～16μg/mL浓度范围内线性良好,R=0.9997,总黄酮平均回收率为99.5%,RSD为1.76%.结论:该研究首次报道了犁头草中的化学成分及总黄酮含量的测定,此方法仪器要求低、灵敏度高,操作简便、快速,结果准确,可作为犁头草总黄酮研究及含量测定的方法. 相似文献
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本文根据黄酮类化合物与铝盐反应可生成黄色络合物(λmax=415nm)其颜色深浅与溶液的浓度在一定范围内成线性关系的特点,采用分光光度法测定山楂片中的黄酮含量. 相似文献
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皂苷和黄酮类化合物广泛存在于植物体内,国内外对二者的研究十分活跃.研究表明,皂苷和黄酮类化合物均具有较强的生理活性及多种多样的药理功能.为了研究豌豆中的皂苷和黄酮类化合物及其各自的含量,本研究采用水提皂苷做定性实验研究来鉴别豌豆中皂苷的类别,并利用热乙醇冷却的方法对皂苷进行提取、分离和测定;还进一步利用碱溶酸沉法对皂苷滤液中的黄酮类化合物进行提取和测定.研究结果表明,豌豆中皂苷类型为三萜皂苷,其含量为碗豆干粉的3.86%,黄酮类化合物含量为碗豆干粉的2.11%. 相似文献
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对芹菜不同部位黄酮化合物进行提取,采用光谱法对其含量进行分析.测定波长为510 nm,线性范围为0.2557～0.7670 mg/mL,方法的回收率为101.5％～104.6％,变异系数小于0.27％.用流动注射化学发光法分析了芹菜不同部位的抗氧化性,实验结果表明芹菜中含有丰富的黄酮类化合物.芹菜不同部位中黄酮化合物含量不同,芹菜叶中黄酮含量最高,芹菜根中黄酮含量次之,而芹菜茎中黄酮含量最低.芹菜具有较强的抗氧化性,芹菜不同部位抗氧化性不同,芹菜叶的抗氧化性最强,芹菜根次之,而芹菜茎中抗氧化性最低.芹菜不同部位即根、茎、叶中黄酮类化合物含量与抗氧化性增加趋势相同.芹菜根、茎、叶的黄酮含量与抗氧化性呈现明显的量效关系. 相似文献
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桃红四物汤水提液中总酚酸含量测定 总被引：2，自引：0，他引：2
目的:测定桃红四物汤水提液中总酚酸(TPA)的含量.方法:总酚酸的含量测定采用可见分光光度法,以没食子酸为对照品,0.6%FeCl3～0.9%K3\(1∶0.9)混合液为显色剂,在720nm波长处进行测定.结果:分光光度法测定总酚酸在所试浓度范围内(0.1756～0.8780μg/mL)线性关系良好,r=0.9968.总酚酸的平均回收率为99.96%,RSD为4.1%. 结论:本法简单快捷,重现性好,可作为桃红四物汤中总酚酸的质控方法. 相似文献
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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
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Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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陈美曦 《山东教育学院学报》2008,23(2):103-107
Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language. 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献