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1.
极谱法连续测定痕量铅和镉   总被引:1,自引:0,他引:1  
研究了Pb2+和Cd2+与KCI-酒石酸钠-三乙醇胺-明胶体系的二次导数极谱波.在pH=4.5的HAc-NaAc介质中,Pb2+和Cd2+分别于-0.46V和-0.64V电位处产生一良好的极谱波.峰电流与Pb2+和Cd2+的浓度分别在1×10-5~3×10-1 g·L-1和5×10-5~6×10-3 g·L-1范围内呈线性关系.Pb2+和Cd2+的检出限分别为1×10-7 g·L-1和5×10-7 g·L-1.本法准确、简便、快速、选择性高.已直接用于饮料中铅和镉的连续测定,同时也对酒及面粉样品进行了测定,回收率分别为99.9%~100.1%和97.0%~104.8%.  相似文献   

2.
在弱酸性条件下,盐酸阿米替林和固绿依靠静电作用形成离子缔合物,使体系的共振光散射明显增强.据此建立了一种测定盐酸阿米替林的共振光散射法.研究了体系的紫外-可见吸收光谱和共振光散射光谱,并考察了各因素对体系的影响.在最佳条件下,体系的最大散射峰位于344 nm处.共振光散射增强的程度与盐酸阿米替林的浓度在7.50×10-3~3.75×10-2mg.mL-1之间呈良好的线性关系.该方法的检测限为1.81×10-4mg.mL-1.将方法用于片剂中盐酸阿米替林的测定,并与药典法进行了对照,经t-检验证明两种方法无显著性差异.  相似文献   

3.
将毛细管区带电泳(CZE)与微透析采样技术联用,研究了盐酸雷尼替丁在家兔血液中的代谢过程.首先研究了毛细管电泳的pH值、缓冲液浓度、分离电压、进样时间等电泳条件对盐酸雷尼替丁与法莫替丁分离的影响.结果采用pH6.2磷酸缓冲液,分离电压为10kV,进样压力2758Pa,4s的条件,能够使盐酸雷尼替丁与法莫替丁达到基线分离,据此以法莫替丁为内标建立了一种测定盐酸雷尼替丁的方法,峰面积比与相应的盐酸雷尼替丁浓度在1.5×10-7g·mL-1~8.0×10-6g·mL-1范围内成线性关系(r=0.998),最低检测限9.0×10-8g·mL-1.药物代谢动力学参数由“NDST21”计算软件求得,代谢符合一室开放模型,其半衰期为89.8min.  相似文献   

4.
在弱酸性条件下,核固红,Cu(Ⅱ)与盐酸吡硫醇共存时,导致体系共振光散射强度明显增强.据此建立了测定盐酸吡硫醇的共振光散射分析法.在最佳条件下,Cu(Ⅱ)-核固红-盐酸吡硫醇体系的最大散射峰位于364nm处.共振光散射增强的程度与盐酸吡硫醇的浓度在0.5~11.5μg.mL-1之间呈良好的线性关系.方法的检出限为1.5×10-2μg.mL-1.将方法用于片剂中盐酸吡硫醇的测定,并与药典法进行对照,经t检验证明2种方法无显著性差异.  相似文献   

5.
在pH 10.8的含NO-2的NH3/NH4Cl缓冲液中,使用单扫描示波极谱仪测定了α-联呋喃甲醛二肟与钴(Ⅱ)在-1.18 V处形成的灵敏的络合吸附波,此方法用于测定维生素B12针剂中痕量钴的含量,结果满意.其一阶导数峰峰电流与Co2+浓度在4×10-10 g·mL-1~4×10-8 g·mL-1范围内呈线性关系,检出限为2×10-10 g·mL-1.使用不同电化学方法对该极谱波的性质进行了研究,表明该极谱波是一具有催化作用的络合吸附波,电极过程不可逆.  相似文献   

6.
有机磷农药——敌敌畏时间分辨化学发光分析的研究   总被引:1,自引:0,他引:1  
文中根据鲁米诺-H2O2体系中敌敌畏与Co2+化学发光动力学性质的不同,建立了敌敌畏的时间分辨化学发光分析法.该法可对存在于一些金属离子的混合溶液中的敌敌畏进行测定,在最优条件下,混和溶液中的敌敌畏浓度在2×10-8~3×10-6g@mL-1范围内(Co2+浓度小于3.0×10-2μg·mL-1)呈较好的线性关系.  相似文献   

7.
采用硫化铵快速分解硫磺试样,在16.56 mol·L-1NH3·H2O-0.21 mol·L-1酒石酸钠-3.01×10-4mol·L-1Pb-1.50×10-2mol·L-1EDTA-0.12mol·L-1Na2SO3-3.2×10-4mol·L-1HNO3体系中以催化极谱法测定微量碲.极谱峰电位为-1.10V(VS·SCE).碲浓度在4~100ng/mL-1范围内与峰电流有良好的分段线性关系.检出下限为4ng·mL-1.方法的RSD为1.9%~2.3%,加标回收率为90.10%~96.00%.该法操作简便快速,用于硫磺样品的测定结果满意.  相似文献   

8.
催化动力学光度法测定痕量铁   总被引:3,自引:0,他引:3  
基于酸性介质中三价铁离子对过氧化氢氧化百里香酚蓝褪色的催化作用 ,提出了催化动力学光度法测定痕量铁的新方法 .该方法的线性范围为 0~ 372 μg·L- 1 .检测限为 4 .7× 10 - 3μg·mL- 1 .将本法用于自来水、大米和玉米中铁的测定 ,获得满意结果 .  相似文献   

9.
研究了在磷酸介质中,钒(Ⅴ)对KIO4氧化偶氮胂(Ⅲ)褪色反应的催化作用及柠檬酸的活化作用,测定了体系的动力学性质,确定了反应的最佳条件,建立了测定痕量钒的新方法.实验表明,无柠檬酸时体系为准一级反应,表观速率常量为3.7×10-4s-1,表观活化能为99.4kJ·mol-1,钒的量在0~9.0×10-5g·L-1范围内与log(A0/A)呈线性关系,检出限为1.3×10-7g·L-1.有柠檬酸时为准零级反应,表观速率常量为1.6×10-3s-1,表观活化能为82.9kJ·mol-1,钒的量在0~5.0×10-5g·L-1范围内与ΔA呈线性关系,检出限为7.8×10-8g·L-1.本法简单快速,灵敏度较高,用于钢样中痕量钒的测定,结果较满意.  相似文献   

10.
邻菲罗啉的电化学性质研究   总被引:1,自引:0,他引:1  
0.5 mol·L-1的一氯乙酸和0.1 g·L-1的十二烷基磺酸钠溶液中,邻菲啰啉有一灵敏极谱峰,其峰电位是-0.75 V(vs.SCE).峰电流与邻菲啰啉的浓度在4.0×10-7~3.8×10-5mol·L-1范围内呈线性关系(r=0.998 5),检测下限为2.0×10-7mol·L-1.利用线性扫描极谱法和循环伏安法研究了邻菲啰啉的电化学性质.  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   

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