电沉积咖啡酸玻碳修饰电极对抗坏血酸的催化氧化

在pH=7.0的磷酸缓冲溶液中采用电沉积技术将咖啡酸修饰于玻碳电极表面制备了一层稳定的薄膜,该修饰电极制备简单,稳定性良好.用循环伏安法研究了抗坏血酸在修饰电极上的电化学行为,其氧化峰电流与抗坏血酸的浓度和pH值有关,当pH值达到7.7时,抗坏血酸在修饰电极上的氧化峰电流最大,氧化峰电流与抗坏血酸浓度在4.0×10-5～2.0×10-2mol/L范围成良好的线性关系,检测限为1.0×10-5mol/L,方法简单、快速、准确,可应用于抗坏血酸药片的检测.     

酞菁铁-邻苯二甲酸二正辛酯修饰碳糊电极测定抗坏血酸的研究与应用

制备了酞菁铁-邻苯二甲酸二正辛酯修饰碳糊电极,发现该电极对抗坏血酸的电氧化具有催化作用.在最优化条件下,抗坏血酸的氧化峰电流与其浓度在1.0×10-6～3.4×10-4mol/L范围内成良好的线性关系,检测限为3.2×10-7mol/L.初步讨论了电催化机理.该电极已成功用于果汁和药品维生素C片中的抗坏血酸含量的测定.     

多巴胺在纳米金修饰微玻碳电极上的电化学行为研究

用电沉积的方式制备了纳米金修饰微玻碳电极 ,该修饰电极能分开多巴胺和抗坏血酸的氧化峰 .研究了溶液pH值、磷酸缓冲溶液浓度对多巴胺电化学行为的影响 .多巴胺氧化峰电流值与其浓度在 5× 10 - 6～ 1× 10 - 4mol/L范围内成线性关系 .     

聚茜素红薄膜修饰电极测定丹宁酸

以聚茜素红薄膜修饰电极(PARE)为工作电极,0.05 mol/LHAc-NaAc(pH 5.0)为支持电解质,通过差分脉冲伏安法研究了丹宁酸在修饰电极上的伏安行为.结果表明,当丹宁酸浓度在5.0×10-6~5.0×10-3mol/L范围内,丹宁酸的浓度与氧化峰电流成线性关系,线性方程为i(μA)=0.2768c(10-6mol/L)+2.636,r=0.9966,检出限达1.0×10-7mol/L.方法简便,用于茶叶中丹宁酸的测定,7次测定的RSD%为2.1.     

多壁碳纳米管修饰电极对抗坏血酸的电催化作用

对抗坏血酸在多壁碳纳米管修饰电极上的电化学行为的研究表明,与裸玻碳电极相比,抗坏血酸在多壁碳纳米管修饰电极上具有更高的氧化峰电流和更低的氧化电位。实验优化了支持电解质、pH值、扫描速度等测定条件,此法测定抗坏血酸的线性范围为(1.0×10-5~5.0×10-4)mol.L-1,检测下限为8.0×10-7mol.L-1。此修饰电极制作简便,重现性和稳定性较好。     

聚对苯二酚修饰电极的制备及其对抗坏血酸的催化氧化作用

采用电化学方法制备聚对苯二酚薄膜修饰玻碳电极（PHQ/GCE）,并用该电极对抗坏血酸（AA）进行测定.研究发现：在0.2 mol/L Na2HPO4-NaH2PO4（PBS,pH 7.0）缓冲溶液中,以0.1 mol/L KCl作支持电解质,PHQ/GCE对AA有明显的催化氧化作用.同时,应用线性扫描循环伏安法对AA进行定量分析,其氧化峰电流与AA浓度在5.0×10-6～1.0×10-1 mol/L范围内呈现良好的线性关系,检出限为1.0×10-7 mol/L.对此机理进行详细研究,结果表明聚对苯二酚修饰玻碳电极上带有的酚羟基与脱氢抗坏血酸自由基之间形成的氢键是电催化氧化的主要原因.     

聚甲基红膜修饰电极对儿茶酚的测定

用电化学方法制备了聚甲基红膜修饰电极,该电极对儿茶酚有明显的电催化作用,其氧化峰电位负移70mV,峰电流显著增加,儿茶酚的氧化峰电流在2 0×10-6～1 0×10-4mol/L范围内与其浓度成线性关系,该电极性能稳定,重现性好.     

聚吡啰红Y修饰电极上多巴胺的电化学行为及其伏安法检测

在玻碳电极上用电化学方法制备了聚吡 口罗 红Y修饰膜电极 ,并研究了此电极上多巴胺的电化学行为及其检测 聚吡 口罗 红Y修饰电极对多巴胺有良好的电催化能力 ,循环伏安图上出现一对灵敏、可逆的氧化还原峰 在最佳条件下 ,氧化峰电流与多巴胺浓度在 5 6× 10 -7～ 3 2× 10 -3 mol/L范围内呈良好线性关系 ,开路富集 2min ,检测限为 1 2× 10 -8mol/L 用于多巴胺针剂含量的测定 ,结果满意     

Nafion 修饰玻碳电极伏安法测定痕量氧氟沙星的研究

为了探讨氧氟沙星简易的测定方法 ,报道了用Nafion修饰玻碳 (GC)电极测定痕量氧氟沙星的伏安法 .线性扫描过程中 ,在 +1.2 7V处发现一灵敏氧化峰 ,利用该峰可进行氧氟沙星含量的测定 .通过优化测定条件 ,利用该修饰电极测定氧氟沙星的线性范围为 :1× 10 -6～ 3× 10 -5mol/L ,检测限为 1× 10 -8mol/L .用于实际样品溶液中痕量氧氟沙星的测定 ,平均回收率为 99.5 2 % .     

多巴胺在聚磺基水杨酸修饰电极上的电化学测定

研究了聚磺基水杨酸修饰玻碳电极的制备及多巴胺在此修饰电极上的电化学行为.在磷酸盐缓冲溶液中,多巴胺在修饰电极上呈现两个还原峰和两个氧化峰.其峰电位随着pH的增加而负移.多巴胺的氧化峰电流与其浓度分段呈线性关系:在3×10-7～9×10-6mol/L浓度范围内,其回归方程为ipa (10μA) = 0.23548 0.30552c(mol/L),相关系数r=0.9930;在10-5-10-4mol/L浓度范围内,其回归方程为ipa(10μA) =2.35604 0.0685c (mol/L), 相关系数r=0.9913.检出限为3.0×10-7mol/L.实验结果表明:该修饰电极能有效消除抗坏血酸的干扰,用于注射液中多巴胺的检测,其回收率在97.7%-101.6%范围内.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

An Index mechanism for multi-scale view in spatial databases

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.     

A computer generator for randomly layered structures

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

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

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。     

Exciton Seebeck in Molecular Systems

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     

Achieving Unusual States of Matter Under High Pressure

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     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

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.     

An improved R-tree based on childnode''s probability

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).     

Integrating GIS Web services based on mediating architecture

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.