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1.
以草莓中原花青素含量为考察指标,研究提取溶剂浓度、提取温度、料液比、提取时间等因素对原花青素提取效果的影响。通过正交试验,确定草莓中原花青素的最佳提取工艺条件为:乙醇浓度70%,料液比1∶20,提取温度50℃,提取时间70 min。在最佳提取条件下原花青素的提取率为24.23%。  相似文献   

2.
葡萄籽中含抗氧化物质——原花青素,具有防癌、抗衰老、防心血管疾病等作用,考察了溶剂种类、乙醇浓度、提取时间、提取温度、料液比等因素对原花青素提取量的影响,最终确立最佳提取条件:乙醇为溶剂、提取浓度为70%、提取时间为60 min、提取温度为50℃、料液比1∶7。  相似文献   

3.
研究以单因素实验结果为依据,采用三元二次旋转组合设计及响应曲面分析法,研究了以时间、温度及料液比三个条件对葡萄籽中原花青素提取率的影响。试验结果显示:最佳提取条件是提取温度44.99℃,料液比1∶12(g/ml),提取时间15.37 min,预测提取率可达19.93%,在此条件下通过实验验证,原花青素的提取率为19.97%。将提取的原花青素纯化,并与标准品通过红外和高效液相检测,峰形和出峰时间基本一致。  相似文献   

4.
为优化杨梅原花青素的提取工艺参数,通过单因素实验,采用响应面法研究乙醇浓度、料液比、提取时间和温度等对杨梅原花青素提取的影响,以原花青素提取率为评价指标,通过Box-Behnken组合,建立杨梅提取的二次回归方程,得到最优提取条件.结果表明,杨梅原花青素提取得率的影响的顺序为:乙醇浓度温度时间料液比;杨梅原花青素的最佳提取工艺条件为:乙醇浓度为92%,提取温度75℃,提取时间57 min,液料比选取25:1(m L/g).该条件下,杨梅原花青素提取率的为30.03 mg/g.  相似文献   

5.
实验以丹桂为试材,对其提取条件进行了研究,考察了温度、液料比、乙醇浓度、提取时间对丹桂花中原花青素提取率的影响。实验结果表明:在50℃水浴中,以35%乙醇和35%丙酮的混合液作为提取液,用7:1的液料比提取45.2min为桂花花青素的最佳提取工艺。  相似文献   

6.
以乙醇为提取剂,采用超声辅助法对地榆根中原花青素提取工艺进行研究.在研究地榆根粒度、液料比、超声功率、超声时间、提取次数等单因素对花青素提取率影响的基础上,运用Box-Behnken中心组合试验和响应曲面法分析了液料比、超声波功率、超声时间3个因素对原花青素提取率的影响,并优化了提取工艺.结果表明:超声辅助对地榆根中原花青素提取的最佳工艺条件为液料比30.81∶1(m L∶g),功率320 W,时间42.97 min,在此工艺条件下,地榆根原花青素的提取率为4.86%.  相似文献   

7.
蚕豆壳中含有原花青素,本文主要研究了微波功率、微波提取时间、溶剂浓度、料液比、浸泡时间、提取次数等因素对原花青素提取率的影响.  相似文献   

8.
利用溶剂提取法从鱼腥草中提取鱼腥草素.研究了乙醇浓度、固液比、提取时间、提取温度等工艺条件对鱼腥草素提取率的影响,最佳提取工艺条件为:以50%乙醇溶液为溶剂,固液比1:30,温度50℃,时间65min,提取率可达11.0%.  相似文献   

9.
从葡萄籽中分离纯化原花青素的研究   总被引:5,自引:0,他引:5  
研究了从葡萄籽中分离纯化原花青素的最佳浸提条件,经过正交实验,得出最佳浸提条件:乙醇体积分数60%,提取温度50℃,料液比(g:mL)1:7.AB-8树脂较适合精制原花青素粗提物,最佳的柱分离条件:上样液pH=4,上样液流速2.0 BV/h,体积分数为50%醇溶液洗脱,洗脱流速1.0 BV/h.经AB-8树脂吸附精制,原花青素的纯度可达91.2%.  相似文献   

10.
目的:优选黄花倒水莲多糖提取的最佳脱脂工艺条件.方法:用均匀设计方法设计最佳脱脂工艺条件,以提取物中多糖含量为测定指标,考察溶剂、回流时间及料液比三个因素对有效成分多糖提取的影响.结果:最佳脱脂工艺条件为乙醇和乙醚比例为1∶6.1(mL/mL),回流时间3h,料液比1∶20(g/mL),黄花倒水莲茎部多糖的提取率为2.65%.结论:优选的提取工艺提取率高,是一种省时、高效、节能的提取工艺.  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.
何延凌 《科技信息》2008,(4):258-258
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.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
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   

15.
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   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
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   

20.
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   

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