褪色光度法测定Fenton体系中产生的羟自由基

建立一种丽春红2R作显色剂分光光度法测定Fenton反应产生的羟自由基的方法,所产生的羟自由基与丽春红2R作用后使其吸光度降低,利用吸光度值的变化可间接测定所产生的羟自由基,确定了体系最佳实验条件;同时测定抗氧化剂清除羟自由基的实验,证明该体系可作为筛选抗氧化剂的方法之一.     

溴甲酚绿测定Fenton产生的羟基自由基

利用Fenton反应产生的羟基自由基与染料试剂溴甲酚绿(Bromocresol green,BG)发生氧化反应后使其吸光度值降低,建立了一种可间接测定羟基自由基的新方法.确定了体系的最佳实验条件,采用抗坏血酸和硫脲为羟基自由基清除剂测定了其羟基自由基清除率D%及其与清除剂的线性回归方程.用拟定羟基自由基测定新方法应用于光催化降解孔雀绿(Malachite green,MG)体系中的羟自由基含量测定,表明该方法可作为测定羟基自由基和筛选抗氧化剂的方法之一.     

甲基紫光度法测定Fenton体系中产生的羟自由基

提出了检测Fenton反应产生羟自由基的新方法.羟自由基与甲基紫发生反应后,甲基紫褪色,用分光光度计测定其ΔA值的变化,可间接测定羟自由基的产生量.通过对测定条件的研究,得到最佳测定方案:λ=580nm,pH=3.0,[H2O2] [Fe2+]=4～6.甲基紫光度法可作为一种简便的筛选羟自由基清除剂的方法.     

罗丹明B-Mn2+-H2O2体系光度法测定水果的抗氧化性

在稀硫酸介质中,B-Mn^2＋ - H2O2体系产生的羟自由基迅速氧化罗丹明B使其褪色．在558啪处测定吸光度的变化,可间接测定羟自由基的生成量．水果提取物可以消除溶液中的羟自由基,从而使溶液的吸光度下降程度减弱．据此建立了一种测定水果对羟自由基的清除率的新方法．测定了9种常见水果的抗氧化性,其中桃子、橙子的抗氧化性较强．     

茜素紫光度法检测超声波辐照水体系产生的羟自由基

为了了解超声作用与羟自由基产量的关系,利用茜素紫能被羟自由基及过氧化氢(H2O2)所氧化而改变颜色的性质,用紫外-可见分光光度计测定超声作用后茜素紫溶液在515 nm波长处吸光度的变化,从而间接地检测羟自由基的产量.研究结果表明,羟自由基的产量随单位体积超声输出功率增加而增加.在输出体积功率约为12 W/cm3时羟自由基的产量基本达到饱和,同时,在该输出功率下超声波作用产生的羟自由基与超声作用时间呈良好的线性关系.     

茜素紫光度法检测H2 O2／CO2+产生的羟自由基

研究了用茜素紫的氧化来显色测定Co2+-H2O2体系产生羟自由基(·OH)的方法,提出CO2+-H2O2-茜素紫分析新体系并用于羟自由基(·OH)的测定．本方法利用Co2+与H2O2反应,类似Fenton试剂产生羟自由基(·OH),并加入茜素紫显色剂,使茜素紫的颜色发生变化,采用紫外．可见分光光度计测定其△A值的变化,可间接测定羟自由基的含量,且灵敏度高．研究结果表明：在最大吸收波长560nm处,茜素紫的吸光度与·OH产生量成良好的线性关系;此外,抗氧化荆药物甘露醇、苯甲酸、硫脲与羟自由基清除率具有明显的量效关系,方法稳定性好。操作简便,测定快速,是一种简便的筛选抗羟自由基的清除剂和有效抗氧化剂药物的方法     

光度法测定常见蔬菜的抗氧化活性

在稀硫酸介质中,羟自由基迅速氧化丁基罗丹明B,使其褪色.在558 nm处测定吸光度的变化,可间接测定羟自由基的生成量;蔬菜提取物可以清除溶液中的羟自由基,从而使溶液的吸光度下降程度减弱.由此建立了一种测定蔬菜对羟自由基的清除率的新方法.测试了菠菜、油菜、香菜等10种蔬菜的抗氧化活性,其中菠菜、油菜、香菜的抗氧化活性较强.     

分光光度法测定胆红素对羟自由基的体外清除作用

次甲基蓝在662 nm处有强烈吸收,它与·OH反应后,使体系的吸光度降低.胆红素可以清除溶液中的·OH,从而使溶液吸光度下降的程度降低.据此原理建立了一种测定胆红素对·OH清除率的新方法.确定了体系最佳实验条件为pH 8.5,次甲基蓝浓度1.6×10-5 mol·L-1,Fe2 浓度4.0×10-5mol·L-1,H2O22.56×10-5 mol·L-1,反应时间15 min以上.测定胆红素、抗坏血酸、苯甲酸清除·OH的效果,结果表明:三者对羟自由基均有较好的清除率;浓度相同时,它们对羟自由基的清除效果,苯甲酸>胆红素>抗坏血酸.     

分光光度法测定中药对羟自由基的清除率

三苯甲烷碱性染料结晶紫在紫外有强烈吸收,它与·OH反应生成无色物质,使体系的吸光度降低.中药提取物可以清除溶液中的·OH,从而使溶液吸光度下降的程度降低.据此原理建立了一种测定中药对·OH清除率的新方法.确定了体系最佳实验条件为pH5.5,结晶紫浓度2.8×10-6mol·L-1,Fe2+浓度5×10-4mol·L-1,1%H2O2用量0.4mL,反应时间5min以上.测得天然银杏叶和其药剂舒血宁片清除·OH的效果,结果表明:(1)在0.6～3.6g L的浓度范围内,两者对羟自由基均有较好的清除率;(2)浓度相同时,前者对羟自由基的清除效果较好.     

孔雀绿褪色光度法检测Fenton反应产生的羟自由基

建立了Fe2++H2O2-孔雀绿的分析新体系 ,用于羟自由基的测定.该法利用Fenton反应产生羟自由基,并加入孔雀绿显色剂,羟自由基使孔雀绿褪色.采用分光光度法测定其ΔA617值的变化,可间接测定羟自由基的产生量.通过对测定条件的研究,分别确定最佳的酸度、孔雀绿显色剂、EDTA-Fe2+ ,H2O2以及缓冲溶液的用量,显色的稳定性等,得出最佳的实验条件.对苯甲酸和五倍子等中草药的抗羟自由基氧化性能作了比较,以验证本法的有效性,得到较好的清除结果,并采用超声波提取法和传统的水煎法的清除率作了比较,二者均与抗氧化剂用量成量效关系,超声波提取法优于传统的水煎法.     

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