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1.
分别采用微波提取法、碱液提取法、60%丙酮提取法、55%乙醇提取法提取庐山石韦中的黄酮类化合物,并以芦丁为标准品,测定各提取物中的总黄酮含量,并比较它们的黄酮得率和含量。结果表明,60%丙酮提取法、55%乙醇提取法明显优于碱液提取法和微波提取法,而且55%乙醇为提取溶剂时效果最佳。 相似文献
2.
从毛泡桐叶中提取、分离熊果酸的新工艺研究 总被引:13,自引:0,他引:13
以天然产物毛泡桐叶为原料。采用正交试验法筛选出其有效成分熊果酸的最佳提取及精制工艺条件为:提取次数2次,每次lh;温度85℃;乙醇浓度90%-95%;石油醚3次除杂,每次18—24h,加入量为沉淀的l5—20倍;乙醇反复溶解浓缩2—3次,用量宜为沉淀量的3倍左右;精制3—4次。所得熊果酸晶体用红外、紫外、质谱进行了表征,HPLC测定熊果酸含量为96.9%。 相似文献
3.
薛晓丽 《长春师范学院学报》2007,(12)
将现代的超临界CO2流体提取工艺与传统的乙醇浸出提取工艺相比较,利用高效液相色谱法、HP6890GC/5973MSD气—质联用分析仪对两种方法的提取物进行检测。结果表明:两种方法都有利于蜂胶有效化学成分的提取,乙醇浸出提取工艺有利于提取蜂胶中黄酮类物质,超临界CO2流体提取工艺有利于蜂胶中化学成分的分析,应根据提取活性成分的主次及具体情况进行选择。 相似文献
4.
薛晓丽 《长春师范学院学报》2007,26(6):54-57
将现代的超临界CO2流体提取工艺与传统的乙醇浸出提取工艺相比较,利用高效液相色谱法、HP6890GC/5973MSD气一质联用分析仪对两种方法的提取物进行检测.结果表明:两种方法都有利于蜂胶有效化学成分的提取,乙醇浸出提取工艺有利于提取蜂胶中黄酮类物质,超临界CO2流体提取工艺有利于蜂胶中化学成分的分析,应根据提取活性成分的主次及具体情况进行选择. 相似文献
5.
黄芩苷提取工艺的研究 总被引:2,自引:0,他引:2
采用正交实验从黄芩中提取黄芩苷,利用液相色谱仪测浸膏中黄芩苷的含量。分析得到最佳提取的工艺条为40%的乙醇,乙醇用量为黄芩根的10倍,提取时间为1.5h,在此条件下对黄芩苷进行4次提取得干浸膏得率为72%,黄芩苷含量为26.5%。 相似文献
6.
利用95%的乙醇对蜂胶润喉片中黄酮类化合物进行提取、采用分光光度法进行含量分析,蜂胶润喉片中黄酮类化合物的含量达0.68%.为保健品蜂胶润喉片的质量检测提供了一种切实有效的检测方法. 相似文献
7.
对精制冠心系列制剂提取工艺进行再评价研究,为改进该系列制剂的生产工艺提供实验依据.以有效成分提取转移率和出膏率的综合评分为指标,利用单因素试验及正交试验全面试验考察精制冠心系列制剂提取工艺的可优化参数和未明确参数,并确定其最佳提取工艺.精制冠心系列的最佳提取工艺为改进后的精制冠心片提取工艺,具体为:丹参、赤芍、川芎、红花用70%乙醇回流提取2次,第一次加入10倍量70%乙醇提取3h,第二次加入8倍量70%乙醇提取2 h.结果表明,改进后的精制冠心系列提取工艺稳定可行,有效成分提取转移率较高,可用于工业大生产. 相似文献
8.
黄颖华 《贵州工业大学学报(自然科学版)》1987,(1)
猪、牛、羊胆汁中含有胆红素、胆汁酸、酯类、糖类、无机盐等。根据胆红素分子结构中含有丙酸基官能团,将胆汁和石灰水反应,得固体颗粒(胆钙盐),经酸化、乙醇处理、氯仿提取、浓缩、精制,得胆红素。目前国外用猪胆生产胆红素,收率为0.03%左右,纯度为70%左右。而用本文工艺生产胆红素的收率为0.0 6—0.07%左右,纯度可达75% 相似文献
9.
用甲醇提取法和乙醇提取法从罗氏海盘车提取了海星总皂甙,其产率分别为0.09%和0.11%。产品绠化实验、溶血实验及紫外和红外光谱分析鉴定,证明提取物为海星总皂甙;总皂甙经薄层层析及柱层析分离出五种主要组分,其中两种初步断明为海星皂A和海星皂甙B。 相似文献
10.
正交实验法优选无叶假木贼生物碱的提取工艺 总被引:1,自引:0,他引:1
本章采用正交实验法,以提取物中生物碱的光吸收值为指标进行检测。优选出从无叶假木贼碱中提取出生物碱的最佳工艺为:用70%的乙醇,提取2h,浸提温度为50℃,物料配比为1:15。结论:该工艺提取出的生物碱含量可达1.012%。 相似文献
11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness. 相似文献
12.
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly. 相似文献
13.
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well. 相似文献
14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation. 相似文献
15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。 相似文献
16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death. 相似文献
17.
Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula- 相似文献
18.
Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re- 相似文献
19.
Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that 相似文献
20.
《上海师范大学学报(自然科学版)》2014,(5):550
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with 相似文献