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1.
探讨用醇提法提取竹叶中黄酮类成分的最佳工艺,为竹叶的开发利用提供理论依据。以竹叶为试材,以乙醇为溶剂,采用分光光度法对竹叶中的黄酮类化合物的含量进行测试。通过单因素实验研究乙醇浓度、料液比、提取温度、提取时间对总黄酮提取率的影响,再采用正交试验法优化提取总黄酮的最佳工艺条件。单因素实验和正交试验表明:影响黄酮提取率的因素主次顺序是:料液比〉乙醇浓度〉提取温度〉提取时间。最佳实验条件为料液比1:20,60%的乙醇,60℃提取4h,竹叶中黄酮的含量为7.88mg.g-1。  相似文献   

2.
黄酮类化合物是一类功能性化合物,具有广泛的应用价值。本文采用超声波法提取陈皮中的黄酮,通过正交试验对工艺条件进行优化,并对提取的黄酮进行抑菌性能研究。通过实验确定,超声波法提取陈皮黄酮的最佳工艺条件为料液比1:30、乙醇体积分数80%、提取20 min。在此条件下,陈皮黄酮的提取率为1.467%。希望通过本研究,为陈皮黄酮的提取工艺优化提供借鉴。  相似文献   

3.
水芹黄酮提取工艺的研究   总被引:20,自引:0,他引:20  
利用正交试验法,探讨从水芹中提取黄酮类化合物的最佳工艺条件,结果表明:在40倍于样重的80%乙醇中浸泡24h,超声波提取30min,连续提取2次,黄酮浸出率为94.6%。  相似文献   

4.
采用微波法对山楂中黄酮类化合物进行提取,探讨了山楂中黄酮类化合物提取工艺的影响因素.通过正交实验,得出微波法提取山楂黄酮的优化条件为:功率为300w,时间为3min,料液比为1:15(g/ml),在此条件下,提取黄酮类化合物得率为8.02%.山楂黄酮有较强的清除自由基能力,表现出明显的抗氧化性.  相似文献   

5.
研究超声波辅助提取蕤核叶中黄酮类化合物的工艺.通过单因素试验确定黄酮得率的主要因素和最佳范围,运用正交设计确定出最佳组合工艺条件.结果显示:利用超声波提取蕤核叶黄酮类化合物的最佳提取工艺条件是60%乙醇溶液,料液比为1∶30,在40℃提取70 min,该条件下的提取量为4.970 mg·g~(-1).  相似文献   

6.
为了研究羊耳菊最佳工艺,试验采用超声的方法来提取羊耳菊中黄酮类化合物,确定最佳的提取工艺条件。试验采用单因素和正交试验,分析乙醇浓度、料液比、提取时间及提取温度等四个因素对黄酮类化合物含量的影响,优化提取工艺条件。结果表明:乙醇浓度60%,料液比为1:10、提取时间为10min、提取温度为60℃,黄酮含量可以达到69.82mg/g。优选提取工艺简单可行,速度快,可提高葛花人参中有效成分的收率。  相似文献   

7.
本实验采用正交设计法对银线莲黄酮类化合物提取工艺参数进行优化.以黄酮提取率为指标,以乙醇浓度、提取时间、料液比、提取温度、萃取液比为考察因素,采用正交试验优选最佳提取工艺.结果表明最佳提取工艺应为在80℃条件下提取,乙醇浓度90%,提取时间为2.0h,料液比1:20,萃取液用量为提取液的0.75倍,最后黄酮得率为1.697%.  相似文献   

8.
研究了浸提温度、时间、乙醇浓度、料液比等因素对金银木叶中黄酮类化合物提取效果的影响,确定了最佳单因素水平。正交实验确定了以乙醇为浸提剂的最佳提取工艺条件为:体积分数为0.60的乙醇,料液比1∶30,70℃,浸提4h。金银木叶中富含黄酮类化合物,颜色反应试验和紫外光谱分析初步表明,其主要成分为黄酮类和黄酮醇类。  相似文献   

9.
柚皮黄酮类化合物的微波辅助萃取工艺研究   总被引:2,自引:0,他引:2  
采用微波辅助萃取法,通过单因素实验和正交试验对柚皮中黄酮类化合物提取工艺进行研究.研究结果表明,在中火温度、乙醇浓度60%、提取时间50 min、料液比1∶25的最佳条件下,黄酮得率达到2.308 mg.g-1.微波辅助萃取法提取柚皮黄酮类化合物不仅操作简单,而且是一种快速、高效、节能且实用的新型工艺.  相似文献   

10.
杨丹  宋萌 《科技信息》2009,(18):67-67
本文对橙皮中黄酮类化合物的超声提取工艺进行了研究。采取L9(34)正交试验,探讨了乙醇浓度、料液比、超声时间和提取温度对橙皮黄酮提取效果的影响。结果表明提取温度对提取效果的影响最为显著,最佳提取工艺条件为:乙醇浓度70%,提取温度70℃,超声时间30min,料液比1:30。  相似文献   

11.
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   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
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   

14.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

15.
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   

16.
17.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

18.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

19.
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   

20.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

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