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1.
槲皮素与锆形成二元荧光络合物,SDS对体系有强烈的增敏作用,研究并建立了测定槲皮素的荧光光度法。在0.48mol/LHCl介质中,槲皮素浓度在0.072~7.76μg/mL范围内与其荧光强度呈良好的线性关系,其线性回归方程为γ=7.1829x+5.4025,相关系数r=0.9958,检出限为0.046μg/mL。该法用于银杏叶片制剂中总黄酮醇苷含量(以槲皮素计)的测定,其回收率为97.60%-102.2%,结果较为理想。  相似文献   

2.
沙枣叶中提取的总黄酮化合物对羟基自由基的清除作用   总被引:6,自引:0,他引:6  
以青海本地沙枣叶为原料,利用水作为提取介质对黄酮类化合物进行了提取,并对提取液中黄酮类化合物对羟基自由基的清除作用进行了研究。结果表明:当黄酮浓度为400μg/mL时,对羟基自由基的清除率为22.3%;黄酮浓度在50~400μg/mL范围内其清除率与浓度剂量呈正相关。  相似文献   

3.
提出了在六次甲基四胺一盐酸缓冲溶液(pH5.5)中,硝酸铅与磷酸根反应生成磷酸氯化铅复盐沉淀,运用方波伏安法快速测定过量的铅离子从而间接测定无机磷含量。在最佳实验测定条件下方波伏安峰高ip(μA)与磷的浓度在0.2~20μg/mL内有良好的线性关系,回归方程为ip=54.82—2.39c,相关系数r=0.9876,检出限为0.085μg/mL,相对标准偏差(RSD)为2.44%,加标回收率在95%~99%。方法具有准确性好,操作简便的特点,用于饲料中磷含量的测定,结果满意。  相似文献   

4.
毛细管色谱法测定头孢美唑中的有机溶剂残留量   总被引:1,自引:0,他引:1  
采用毛细管气相色谱法,以叔丁基甲醚为内标,用Agilent DB-200毛细管气相色谱柱和氢焰离子化检测器.同时测定了头孢美唑中甲醇、乙醇、二氯甲烷、三乙胺、乙酸乙酯、苯甲醚等6种有机溶剂残留量.6种溶剂的线性范围分别为0~480μg/mL(r=0.9996)、0—800μg/mL(r=0.9994)、0~96μg/mL(r=0.9990)、0~800μg/mL(r=0.9993)、0~800μg/mL(r=0.9995)、0~800μg/mL(r=0.9993);平均回收率分别为100.1%、100.5%、101.2%、100.1%、100.7%和100.4%;相对标准偏差分别为0.90%、1.30%、1.18%、1.23%、1.52%、1.41%(n=9).  相似文献   

5.
银杏叶提取物中总黄酮含量的分析方法研究   总被引:2,自引:0,他引:2  
提出了一种简便、灵敏地测定银杏叶提取物中总黄酮含量的新方法。实验结果表明银杏叶提取物经酸性条件下加热水解,使黄酮苷转化为苷元再与Al3+配位,所形成的配合物具有较强的荧光,可以槲皮素为标准品,采用荧光光度法测定其总黄酮含量。在选定条件下,槲皮素的浓度与荧光强度成线性关系,线性范围:0000?75~050?μg/mL, 检测限:045?g/mL(S/N=3),回归方程: If=7799?48+63210?86ρ×107(μg/mL),相关系数R=0999?9(P<0000?1),并用标准加入法进行回收实验和银杏叶提取物(GBE)中的总黄酮含量的测定,结果令人满意。  相似文献   

6.
酸性高锰酸钾化学发光体系测定针剂中的头孢噻肟钠   总被引:3,自引:1,他引:3  
头孢噻肟钠碱性水解产物与高锰酸钾反应可产生微弱的化学发光,多聚磷酸对其有强烈的增敏作用,据此建立了一种简单、快捷、灵敏的流动注射化学发光测定头孢噻肟钠的新方法.化学发光信号ICL与头孢噻肟钠质量浓度C在0.02-20μg/mL和20~120μg/mL范围内呈良好的线性关系,回归方程分别表示为ICL=3.169+20.961C(r=0.9998,n=9);ICL=147.5+14.752C(r=0.9994,n=9),方法的检出限为20ng/mL.对5μg/mL头孢噻肟钠进行11次平行测定,相对标准偏差为0.8%,用本法对针剂中头孢噻肟钠的含量进行了测定,得出了令人满意的结果.  相似文献   

7.
高锰酸钾在酸性介质中能氧化扑尔敏并产生弱的化学发光,甲醛的存在能大大增强化学发光强度。基于此发现,建立了一种测定扑尔敏的流动注射化学发光分析法。测定扑尔敏的线性范围为0.4~50μg/mL,方法的检出限为0.2μg/mL。对浓度为4.0μg/mL的扑尔敏溶液进行11次平行测定的相对标准偏差为1.4%,样品测定频率达到120h^-1。该方法用于药物制剂中扑尔敏含量的测定。并与药典标准方法进行了对照,结果一致。  相似文献   

8.
新疆红景天中红景天苷含量的测定   总被引:1,自引:0,他引:1  
用反相高效液相色谱法,流动相为甲醇-0.1mol/L磷酸二氢钠(15:85),紫外检测波长为280nm,流速1.0mL/min,测定新疆产红景天中红景天苷含量,结果表明,红景天苷对照品在10~320μg/mL内线性关系良好,r=0.999。平均加样回收率为96.5%;RSD为3.4%。稳定性良好。该法简便,分离完全,结果可靠,适用于红景天苷的含量测定。  相似文献   

9.
基于六价铬与碘化钾反应生成了单质碘,碘可以使罗丹明B发生荧光猝灭,从而间接测定六价铬的含量.六价铬浓度在0.01~0.5μg/mL围内,荧光强度差值与六价铬浓度呈线形关系,线性回归方程为△F=121.58CCr(VI)(μg/mL)+16.17,相关系数r=0.9990,检测限为2.4ng/mL.该方法简便,快速,灵敏度高,已用于环境样品中六价铬的测定,回收率在99.8%~104.2%,结果满意.  相似文献   

10.
用HF—HNO3—HClO4溶解样品,在0.6mol/L盐酸介质中,用ICP—AES法对铀矿石中钪(Sc)、硒(Se)、铼(Re)进行了测定.测得各元素的测定下限分别为:Sc0.03μg/mL、Se0.03μg/mL、Re0.016μg/mL.低、中、高3种浓度的平均标准加入回收率为96%~106%,相对标准偏差小于8%。  相似文献   

11.
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   

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

14.
Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to  相似文献   

15.
Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications (up to 574.8 km/ h test speeds or 380 km/h commercial speeds) in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.  相似文献   

16.
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.
Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.  相似文献   

19.
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   

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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