首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
采用高效液相色谱法(HPLC)对大叶种红茶英红九号的春、夏、秋三季茶产品进行测定,对所得HPLC色谱图中的相对保留时间、相对峰面积、共有峰进行了分析。结果表明,HPLC色谱法具有良好的精密度,各样品色谱峰的相对保留时间稳定,可作为指纹图谱的相对时间,并确定了7个共有峰。以各色谱峰的峰面积为因子,用相关系数、聚类分析等方法构建了数字化的英红九号红茶HPLC指纹图谱。在本研究的实验范围内,该方法在区分不同季节生产的英红九号红茶、以及英红九号红茶与其他品种红茶的差异性等方面具有可行性。  相似文献   

2.
研究不同开封时间的乙酸铵对糖精钠、山梨酸保留时间的影响。采用高效液相色谱法,以二极管阵列检测器(DAD)检测,色谱柱为Waters Sunfine C18(250mm×4.6mm,5μm),流动相甲醇-乙酸铵溶液(5:95),柱温35℃,用不同时间开封的同一厂家的乙酸铵配置乙酸铵溶液进行试验,糖精钠和山梨酸的相对保留时间和出峰顺序发生改变。不同开封时间的乙酸铵对糖精钠、山梨酸保留时间和出峰顺序有影响,进而影响峰形及峰纯度。  相似文献   

3.
本文阐述了建立何首乌药材色谱定性分析方法。采用HPLC测定法,色谱柱phnomenex C18,4.6×250 mm,5μm;流动相:甲醇-水梯度洗脱;流速1.2 ml/min;检测波长280 nm;柱温40℃。对何首乌有效部位进行指纹图谱定性分析,从18个批次不同产地何首乌药材的指纹图谱中可检出4个相对位置稳定的色谱峰,作为定性鉴别的指标峰。利用何首乌药材指纹图谱可以作为对何首乌药材的定性分析和质量控制。  相似文献   

4.
目的:采用共有峰率和变异峰率双指标序列分析法分析不同产地半夏药材紫外指纹图谱。方法:以石油醚、氯仿、无水乙醇、水4种溶剂分别提取半夏药材不同极性区间成分,测定其紫外指纹图谱,研究各样品之间的异同。结果:采用该方法可以对不同产地半夏药材进行区分。结论:本方法操作简单,应用范围广,为半夏药材质量评价提供了简便的方法。  相似文献   

5.
为建立以1种对照品同时检测垂盆草中槲皮素、山柰素、异鼠李素3个成分的"一测多评"方法,随机从药材市场收集12批垂盆草样品,以外标法测定其中各有效成分的含量;以槲皮素为内标物,确定山柰素、异鼠李素的相对校正因子及相对保留时间;另取8批样品,对实验结果加以验证.得到山柰素、异鼠李素的相对校正因子分别为0.960、0.918,山柰素、异鼠李素的相对保留时间分别为1.85、2.15.验证试验表明"一测多评"法检测结果与外标法相比无明显差异,利用"一测多评"法同时检测垂盆草药材中槲皮素、山柰素、异鼠李素3个成分含量所得结果准确度高,具有良好的重现性、稳定性和精密度,"一测多评"法可用于垂盆草药材的质量控制.  相似文献   

6.
目的:建立抗肝炎药走胆草药材的HPLC指纹图谱.方法:反相高效液相色谱法,流动相为甲醇-水(含0.1%磷酸),梯度洗脱,流速为1.0ml·min-1,检测波长为270nm,柱温为30℃.结果:精密度、重复性、稳定性试验中共有峰的峰面积小于5%、保留时间的RSD值均小于3%;不同产地的走胆草的相似度大于0.90.结论:该方法简便、可靠,可作为走胆草药材的质量标准.  相似文献   

7.
该文旨在研究并建立罗汉果甜苷的指纹图谱,采用高效液相色谱法对广西不同产地不同品种的罗汉果进行分析,色谱条件为:色谱柱Lichrospher NH,250×4.6mm,流动相:乙腈和异丙醇水溶液(体积比75∶2.5∶22.5),流速为1.0ml/min,检测波长为205nm.该研究建立的分析方法有较好的重复性,不同产地不同品种的罗汉果色谱峰相对保留时间一致,为加强罗汉果的质量控制提供实验基础.  相似文献   

8.
快速测定废水中苯胺、硝基苯方法研究   总被引:4,自引:0,他引:4  
选用分析纯正己烷,对兰州石化公司化肥厂苯胺装置苯胺废水塔(T-601)馏出口废水、硝基苯废水塔(T-401)馏出口废水、污水池废水、污水处理废水中的苯胺、硝基苯进行萃取,采用大口径毛细管柱气相色谱分离技术,对萃取液中苯胺、硝基苯进行分离,用FID检测器进行检测,用标样中苯胺、硝基苯的保留时间与样品中色谱峰保留时间相对照的方法定性,峰面积标准曲线法定量,进行废水中苯胺、硝基苯气相色谱法快速测定的方法研究,方法最低检测下限为:苯胺0.91mg/L、硝基苯0.98mg/L,分析时间为15min,分析结果的相对标准偏差RSD4.0%。  相似文献   

9.
用高效液相色谱法建立了红景天药材的色谱指纹图谱.固定相采用ODS-C18(4.6mm×250mm×5μm)色谱柱,流动相为乙腈-0.08%磷酸水溶液梯度洗脱,检测波长为278nm,体积流量为1.0mL/min.结果表明,11个红景天样品共有10个共有峰,可作为鉴定红景天药材的主要依据.该方法简便快捷,可为红景天药材的鉴定、质量标准的建立及控制提供一定的参考.  相似文献   

10.
青海道地药材秦艽色谱指纹图谱的研究   总被引:3,自引:0,他引:3  
利用高效液相色谱法建立了青海道地药材秦艽的色谱指纹图谱.色谱条件:Kromasil C18柱(250mm×4.6mm5μm),甲醇:0.04%磷酸水梯度洗脱,流速为1 mL/min,检测波长222nm.通过比较发现秦艽样品的13个主要共有峰,可作为鉴别秦艽药材的主要依据.对12批秦艽药材进行了相似度计算和聚类分析,结果表明,所建立的秦艽指纹图谱可用于秦艽药材的真伪鉴别和质量评价.  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.
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   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
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   

15.
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   

16.
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   

17.
18.
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   

19.
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   

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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号