基于纳米四氧化三铁的光电化学传感器及其对过氧化氢的检测研究

为实现对过氧化氢的高灵敏度检测,合成了表面具有葡聚糖(dextran)配体的纳米四氧化三铁(Fe₃O₄)材料,并将其应用于制备光电化学(photoelectrochemical, PEC)传感器.所合成的Fe₃O₄纳米材料不仅具有光电转换能力,而且表现出传统纳米材料所缺乏的对过氧化氢的直接催化性.同时利用Fe₃O₄纳米材料光电性能和催化特性制作的PEC传感器表现出对过氧化氢良好的传感特性,可以实现过氧化氢的传感检测.最终在0-4 mmol/L的过氧化氢浓度范围内,达到了2.39 nA/mmol·L^-1的灵敏度,以及0.13 mmol/L的最低检测限,实现了对过氧化氢的高灵敏度检测.     

铜/石墨烯新型电化学传感器检测性能的研究

检测水中硝酸根离子和亚硝酸根离子浓度的方法很多，如高效液相色谱、分光光度计、色分析法等。电化学传感器凭借响应速度快、灵敏度高、选择性好等优点成为检测新技术的研究热点之一。很多研究表明，由石墨烯纳米复合功能材料构建的新型电化学传感器性能优异。基于此，一种铜负载于石墨烯表面的纳米材料在室温下被合成，并通过扫描电子显微镜、透射电镜、原子力显微镜和电化学阻抗谱等多种方法对其进行了表征。由该材料制备的一种新型电化学传感器，其检测性能运用循环伏安法和微分脉冲伏安法进行了探究。结果表明：该传感器对硝酸根离子和亚硝酸根离子检测性能好，检测浓度范围宽，由0.1μmol/L到100μmol/L;检出限低：硝酸根离子检出限为0.03μmol/L,亚硝酸根离子检出限为0.05μmol/L。所制备的传感器对实际样品进行了检测，结果令人满意，证明新型电化学传感器具有实际使用价值。     

基于二氧化锆和金纳米粒子的葡萄糖生物传感器

将合成的二氧化锆纳米材料修饰到玻碳电极上面。在此基础上,还修饰了金纳米颗粒,构建了电化学生物传感器用来检测葡萄糖。纳米结构的二氧化锆作为金属氧化物,不仅生物相容性好,而且灵敏度高。此外,修饰的金纳米颗粒可以提高导电性,促进固定化的蛋白质和电极基质之间的电子转移。结果发现葡萄糖的检测范围是0. 01～20. 0 mmol/L,检测线为7. 52μmol/L,并且响应速度快,表明合成的材料对葡萄糖的成功检测。     

石墨烯量子点/钯纳米复合材料直接电化学法检测葡萄糖

通过简单的合成方法制备了氨基功能化石墨烯量子点支撑钯纳米复合材料(GQDs@PEI/Pd)。采用透射电镜(TEM)、循环伏安法(CV)和电流-时间(i-t)等方法对其表征,并证明该纳米材料对葡萄糖有明显的电化学响应。基于该复合材料构建了无酶葡萄糖电化学生物传感器,葡萄糖浓度在1～220μmol/L范围内与电流信号呈现良好的线性关系,其线性方程由高、低浓度两部分组成,最低检测线为0.30μmol/L,其灵敏度最高为1 405.2μA/(mmol/L)/cm~2。因此,该传感器具有高选择性、高灵敏度和长期稳定的优点,可为检测人体血清葡萄糖提供一种新的方法。     

碳纤维-纳米金复合材料修饰电极检测ATP的研究

采用静电纺丝法和高温碳化法制备了碳纤维材料,进一步用水热合成法制备碳纤维-纳米金复合材料.将优化浓度的碳纤维-纳米金复合材料作为修饰剂固定于碳离子液体电极(CILE)的表面制得了碳纤维-纳米金修饰电极(CNF-Au/CILE),采用扫描电子显微镜考察了复合材料的表面形貌.最优实验条件下将该修饰电极用于ATP的检测,结果发现ATP浓度为0.06～0.80 mmol/L和12.0～150.0 mmol/L时,氧化峰电流值与浓度呈现出良好的线性关系,检测限为0.023 mmol/L.常见干扰物质对ATP的测定影响较小,说明该方法具有良好的选择性,并成功应用于三磷酸腺苷二钠注射液中ATP含量的测定.     

HgCl2与CdCl2对河蟹精子DNA损伤的单细胞凝胶电泳检测研究

采用单细胞凝胶电泳技术，研究了HgCl2和CdCl2对河蟹（Eriocheir sinensis）精子DNA损伤的影响.HgCl2和CdCl2各设置6个相同的浓度梯度，分别为0 mmol/L，0.01 mmol/L，0.05 mmol/L，0.1 mmol/L，1 mmol/L，5 mmol/L，处理温度为37 ℃（水浴），处理时间为1 h；SCGE的检测指标为DNA拖尾长度和DNA损伤率.结果表明，对照组DNA未受损伤，在电场中核DNA几乎不泳动，染色后呈圆形的荧光团，无拖尾现象；各处理组精子DNA均不同程度受损，电泳染色后均呈现彗星状荧光团，且随着HgCl2和CdCl2浓度的升高，河蟹精子DNA迁移距离和损伤率亦随之增加，DNA损伤程度与其浓度之间存在明显的“剂量-效应”关系.此外，本实验亦证实SCGE可用于河蟹精子DNA损伤的检测.     

石墨烯/银纳米壳复合材料用作过氧化氢传感器的研究

以石墨烯作为载体负载银纳米壳获得新型复合纳米材料,利用透射电镜等技术对复合材料的形貌及组成进行了表征.将复合材料修饰用在玻碳电极表面制作非酶电化学传感器,并采用循环伏安法研究了其对过氧化氢的电化学性质.电化学测试结果表明,该非酶传感器在磷酸缓冲溶液中对过氧化氢的还原有着稳定且快速的响应,检测限可低至1.5μmol/L.     

固定化E.coliBL21（pTc—gsh）细胞催化合成谷胱甘肽

分别以卡拉胶、明胶、海藻酸钠包埋E.coliBL21（pTrc-gsh)细胞催化合成谷胱甘肽（GSH）。从酶活收率及机械强度方面进行比较，选择卡拉胶为包埋载体，其最适PH为7.0，最适温度为40℃。相关物质对GSH的合成均有影响：半胱氨酸、甘氨酸的最达浓度为20mmol/L，谷氨酸的最适浓度为60mmol/L；Mg^2 /ATP为1-5（V/V）较合适；腺苷二磷酸（ADP）浓度为5mmol/L时对酶活的抑制为20%。优化条件下罐式反应器中GSH的产量为0.84g/L，操作稳定性较好；延迟加入甘氨酸时GSH产量可提高17.5%；与酵母生产ATP体系相耦联的共固定化体系在填充床中反应，GSH合成量达1.24g/L，收率比直接加入ATP提高24.2%。     

血浆中与运动相关的同型半胱氨酸含量分析检测的新方法

基于氯乙酸修饰的荧光素设计了一种新型荧光化学传感器(CACFC),该荧光传感器通过巯基和胺基的双分子识别来选择性检测同型半胱氨酸和半胱氨酸。结果表明:在水-乙醇(V/V,1/10)体系溶液中,CACFC的荧光强度与Hcy(40~280μmol/L)和Cys(20~280μmol/L)存在良好的线性关系。此传感器不仅成功实现了对活细胞中Hcy的荧光成像检测,而且可以有效用于动脉粥样硬化患者有氧运动前后血浆中同型半胱氨酸浓度水平的检测,为拓展其在生物医学领域的应用提供了新的研究思路。     

基于石墨烯和Fe_3O_4@TiO_2@AuNPs纳米复合材料修饰电极用于检测洋蓟素

基于石墨烯(GR)和Fe_3O_4@TiO_2@AuNPs磁性核壳纳米粒子复合材料修饰金电极,构建了一种电化学传感器用于洋蓟素(cynarin)的定量检测.采用化学合成法制备了石墨烯二维纳米材料和Fe_3O_4@TiO_2@AuNPs磁性核壳纳米粒子,并利用扫描电镜(SEM)和透射电镜(TEM)对其形貌和结构进行了表征.考察了洋蓟素在传感器上的电化学行为,石墨烯具有大的比表面积和良好的导电性,与Fe_3O_4@TiO_2@AuNPs核壳纳米粒子复合后,改善了石墨烯的分散性,并产生协同效应,导致传感器对洋蓟素表现出显著的电流响应.该电化学传感器对洋蓟素的线性响应范围为50 nmol/L～0.3 mmol/L,线性方程为I(μA)=5.14lgc(μmol/L)+1.37,检出限为17 nmol/L (信噪比S/N=3).制备的电化学传感器具有线性范围宽、检出限低、选择性和稳定性高等特点,用于实际样品中洋蓟素的测定,结果令人满意.     

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.     

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.     

A computer generator for randomly layered structures

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

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

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     

Advances in broadband wireless communications under high-mobility scenarios

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.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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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。     

Scale-based spatial data model for GIS

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.     

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