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1.
微波辅助提取柿叶黄酮   总被引:7,自引:0,他引:7  
通过正交实验探讨了微波辅助法提取柿叶黄酮的最佳条件.利用3种大孔吸附树脂对柿叶黄酮的静态吸附实验筛选了最优的吸附分离树脂,并确定了乙醇洗脱最优体积分数.结果表明:最佳提取条件为料液比1∶30(m∶v),微波强度250 W,提取时间21 min;DA-201型大孔吸附树脂对柿叶黄酮吸附效果最好且70%乙醇解吸率最高.  相似文献   

2.
为了探究柚皮黄酮的提取工艺,采用超声波辅助乙醇提取法对琯溪蜜柚果皮中的黄酮及柚皮苷进行提取,优化了液料比、提取时间、乙醇体积分数及提取次数。优化得到的柚皮黄酮提取工艺为:液料比(m L∶g)为45∶1,超声提取时间为50 min,乙醇体积分数为70%,提取次数为4次。在此条件下,琯溪蜜柚果皮黄酮提取量为70. 69 mg/g,其中柚皮苷的质量分数为64. 27%。  相似文献   

3.
采用微波辅助乙醇-硫酸铵双水相体系,从苦荞麦粉中提取黄酮类化合物.确定乙醇-硫酸铵双水相提取黄酮类化合物的较优乙醇体积分数以及硫酸铵添加量;通过单因素实验确定苦荞麦粉黄酮类化合物的较优萃取条件.结果表明:微波辅助双水相的方法适合用于苦荞麦粉中黄酮类化合物的提取;响应面法优化微波辅助双水相提取苦荞麦粉黄酮的提取条件,较优提取条件为萃取剂含乙醇的体积分数30%,微波功率550 W,提取时间70 s,苦荞麦粉在提取溶剂中的质量浓度0.02 g/m L,苦荞麦粉中提取得到的黄酮类化合物占苦荞麦粉的质量分数为1.38%.  相似文献   

4.
搅拌回流法和微波法从花生壳中提取黄酮   总被引:2,自引:0,他引:2  
以乙醇水溶液为提取剂,选择搅拌回流法和微波法利用正交实验从花生壳中提取黄酮,确定最佳实验条件,并且利用回收的乙醇和滤渣再进行提取实验.研究结果表明:搅拌回流法最佳实验条件是70%乙醇、提取温度70℃、提取时间4 h、料液比为1:40;微波法最佳实验条件是料液比为1:5、提取液pH值为5、提取时间为4min.提取液定性实验证明其中含有黄酮;旋转蒸发回收乙醇可以重复4次用于提取花生壳中的黄酮;新鲜乙醇可以重复3次用于提取滤渣中的黄酮.  相似文献   

5.
为研究从蓝莓中提取花青素的最佳方法,采用微波-乙醇法处理原料蓝莓皮.在单因素设计的基础上,选取提取时间、微波功率、乙醇体积分数为自变量,以蓝莓花青素提取率为响应值,运用响应面法研究各自变量及其交互作用对蓝莓花青素提取率的影响.结果表明:微波-乙醇法提取蓝莓花青素的最佳工艺条件:提取时间4.15 min,乙醇体积分数65.8%,微波功率440 W,料液比为1∶20,在此条件下花青素提取率为87.07%,与预测的相对误差小,回归模型拟合情况较好,预测能力良好.  相似文献   

6.
采用微波辅助提取法考察了乙醇质量分数、微波功率、微波作用时间、质量体积比以及温度对盘龙参多酚提取率的影响.用响应曲面法优化盘龙参多酚的提取工艺,并对优化结果进行方差分析.结果表明,以47%乙醇溶液为提取剂,在48℃下微波提取84 min,多酚提取率达0.551%.  相似文献   

7.
为了研究芍药叶黄酮的可利用性,以芍药叶片为原料,采用有机溶剂水浴法来提取芍药叶中的黄酮。采用单因素实验法和正交实验法,对芍药叶中的黄酮的提取率进行了研究。研究结果显示,芍药叶黄酮的最适提取条件为:固液比是1∶25、乙醇的体积分数是70%、提取温度是70℃、提取时间是1.5 h。提取率达4.687%。  相似文献   

8.
采用响应面优化法对仙草中黄酮的提取工艺进行研究.将乙醇浓度、提取时间及液料比作为影响因子,在单因素试验的基础上,采用响应面Box-Behnken中心组合法,进行试验设计,将仙草中黄酮的提取率作为响应指标值,进行优化试验.试验结果说明各个因素对仙草中黄酮的提取率影响强弱次序为:乙醇体积分数液料比提取时间;仙草黄酮的最佳提取条件:乙醇体积分数60%,提取时间5 h,液料比30∶1(m L/g),该条件下得到的黄酮提取率最大,实际测定值为14.37%,与预测值(14.79%)没有显著性差异.表明响应面优化法分析的结果可信,所得的最佳提取条件为仙草中黄酮的综合利用奠定了基础.  相似文献   

9.
选取红腰豆为原料,采用微波辅助提取技术,观察乙醇体积分数、液固比、微波功率和微波时间对红腰豆中总黄酮提取效果的影响,并运用Box-Behnken中心组合试验设计建立数学模型,进行响应面分析确定微波辅助提取红腰豆中总黄酮的最佳提取工艺.结果表明:最优参数为乙醇体积分数71%,液固比40:1(m L/g),微波功率560W,微波时间8min,该条件下,总黄酮提取率达1.417%,与模型预测值1.442%基本相符.抑菌试验结果显示,红腰豆黄酮对大肠杆菌、枯草芽孢杆菌和金黄色葡萄球菌有较好的抑制作用.  相似文献   

10.
用超声提取法分别对楠竹叶中黄酮类化合物的提取条件进行了研究,通过正交实验得出最佳条件:乙醇体积分数70%、料液比1:10(g/m L)、提取时间20 min,提取4次,总黄酮得率达到5.709%,相比传统的蒸馏法和索氏提取法(提取率3%)提取效率高,所需时间短,耗费溶剂量少.此外还研究了楠竹叶黄酮提取物对羟自由基和DPPH自由基的抗氧化能力,发现均具有较强的抑制作用.  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.
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   

13.
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   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  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.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
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   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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