固相萃取-高效液相色谱法快速测定生活用水中痕量苯并[a]芘

针对国家标准GB/T 5750.8(9.1)-2006生活用水中苯并[a]芘测定方法进行改进,采用固相萃取-高效液相色谱荧光检测法,通过全自动盘氏固相萃取仪对生活用水中的苯并[a]芘进行富集,可以快速准确测定其含量.实验结果表明苯并[a]芘在0.00μg/L～5.00μg/L的浓度范围内呈现良好的线性关系,相关系数为0...     

高效液相色谱法测定辣条中苯并[a]芘的含量

使用C18反相色谱柱,高效液相色谱检测仪,甲醇与水的混合溶液作为流动相,比例为90∶10,流速2.0 mL/min,检测波长260 nm,进样量为20μL,紫外检测器对样品中苯并[a]芘的含量进行定量检测。检出限为36.04μg/L,辣条中苯并[a]芘的平均加标回收率为102.5%,实验相对标准偏差为1.20%(n=9)。方法步骤简单、溶剂与试样消耗少、样品分析时间短,具有良好的精密度以及高回收率,适合于对辣条中苯并[a]芘浓度的有效检测。     

高效液相色谱荧光法测定贵阳市市售腊肉中苯并[a]芘含量

建立高效液相色谱法测定腊肉中苯并[α]芘(简称BaP)的测定方法。通过先超声提取,后皂化的处理,采用迪马C18色谱柱(250mm×4.6mm,5μm);乙腈-水为流动相;荧光检测器,激发波长为385 nm;检测波长为405nm;苯并[a]芘在(0.005-1.0μg/mL)范围呈线性,其线性回归方程为:Y=1.8×107x+11012;相关系数R=0.9992;苯并[a]芘在0.0035、0.0070、0.0105μg 3个添加浓度水平上的回收率为(83.08%、88.67%、84.54%)。本法色谱条件易于掌握,测得数据重复性好,线性关系好,精密度和准确度均能满足分析要求。同时本文对贵阳市主要市售腊肉中苯并[α]芘(BaP)含量进行了测定,结果含量在1.04~4.16μg?kg之间,表明传统的油炸食品安全性使人的健康受到不同程度的影响。     

离子液体-中空纤维膜液相微萃取-高效液相色谱法快速测定卷烟烟气中的苯并[a]芘

将中空纤维膜液相微萃取技术与高效液相色谱-荧光检测器相结合,建立卷烟烟气中苯并[a]芘的分析检测新方法.以疏水性离子液体1-辛基-3-甲基咪唑六氟磷酸盐([OMIM]PF6)作萃取剂,十一烷酸乙腈溶液作为液膜支持相溶剂,在最佳实验条件下,萃取平衡可在3 min内完成.苯并[a]芘浓度在0.1~20.0ng/mL范围内与其色谱峰面积呈良好的线性关系,相关系数R2=0.999 4,检出限为0.05ng/mL.该方法已成功应用于卷烟烟气中苯并[a]芘的分析检测,回收率为93.6%~102.4%,相对标准偏差为2.7%~4.8%.     

GPC-气相色谱质谱法测定卷烟主流烟气中的苯并[a]芘

建立了用凝胶渗透色谱(GPC)联用GC-SIM-MS法测定卷烟主流烟气中苯并[a]芘的方法.卷烟烟气样品经环己烷超声萃取,GPC系统分离纯化后,经浓缩后用GC-SIM-MS分析测定.与经固相萃/R(SPE)分离纯化的样品相比,通过GPC系统处理后,卷烟烟气样品的干扰烽大大减小,样品谱图干净.该方法测定苯并[a]芘的线性范围为:10.00ng/mL～130.00ng/mL;相关系数R2为O.999 1,检出限为0.99ng/mL,加标回收率为91.70%-103.40%.GPC系统在处理卷烟烟气样品上有独特的优势,该方法适宜应用于卷烟主流烟气中苯并[a]芘含量检测.     

气相色谱-质谱法检测卷烟烟气中的苯并[a]芘

通过固相萃取方法去除卷烟烟气中杂质对分析物苯并[a]芘的影响,建立了气相色谱-选择离子(SIM)质谱方法分析卷烟烟气中有害物质苯并[a]芘的量,该方法的相对标准偏差为3.2%,回收率为96.3%,检测限可达到0.07ng/支卷烟.检测了国内外卷烟烟气中苯并[a]芘的量,结果显示国产烤烟型卷烟烟气中苯并[a]芘的量明显高于国外混合型卷烟.     

GC-MS/MS法快速测定卷烟主流烟气中苯并[a]芘的含量

建立了一种使用GC-MS/MS法测定卷烟主流烟气中苯并[a]芘含量的方法,以内标法定量.将捕集了20支卷烟主流烟气的总粒相物的剑桥滤片用40 mL含有内标物的环己烷振荡萃取,过滤后检测.苯并[a]芘的检出限、定量限分别可达0.056 4 ng/cig和0.094 0 ng/mL,线性相关系数达0.999 4;日内重复性和日间重现性分别为2.39%和3.97%;在3种不同添加浓度下,加标回收率分别在93.00%~109.00%之间.该方法操作简便、重复性好、分析通量大、受环境和人为因素干扰较小,可以作为一种准确、快速测定卷烟主流烟气中苯并[a]芘含量的改进方法加以推广.对无烟气烟草制品质量控制具有重要意义.     

高效液相色谱法测定间苯二甲醛含量在工业上的应用

建立了工业生产中测定间苯二甲醛含量的高效液相色谱方法.采用Kromasil C18(150mm×4.6mm,5μm);流动相:水-乙腈(65∶35按0.1%加入三氟乙酸);流速:1.0mL/min;在220nm波长处检测.间苯二甲醛在4.0～160.0μg/mL的浓度范围内呈线性关系,r=0.9999.高效液相色谱法简单、准确、快速,可精确测定间苯二甲醛的有效含量,适用于药品的出厂分析.     

液液萃取-高效液相色谱法测定水体中的阿特拉津

为建立检测水体中阿特拉津的高效液相色谱法,以Kromasil-C18(250 m×4.6 mm×5μm)为色谱柱,以甲醇∶水=7∶3为流动相,流速0.8 mL/min,采用紫外检测器,用外标法测定水体中阿特拉津含量。结果表明,方法线性范围为0.030~1.96μg/ml,相关系数达0.999 4;采样体积为100 mL时,方法的最低检测浓度为0.30μg/L;对不同加标浓度水样的回收率为87.9%~93.0%,相对标准偏差为1.2%~3.4%。该方法适用于水体中痕量和常量阿特拉津的测定。     

食用油中苯并[α]芘净化技术的优化及高效液相检测方法的建立

针对我国国标中食用油中苯并[a]芘检测方法的不足,建立高效液相色谱法-FLD检测方法,通过优化检测条件得到的最佳操作条件:检测波长:激发波长384nm,发射波长406nm;流动相为乙腈:水(梯度洗脱),在最佳实验条件下,苯并[a]芘得到良好的分离,对苯并芘标准溶液的检测分析的相对标准偏差小于5.5%,方法的检出限(3倍信噪比)和定量下限(10倍信噪比)分别为0.046μg/kg和0.155μg/kg。选用花生油、辣椒油、煎炸油为本底,通过比较中性氧化铝柱、HLB小柱、分子印迹技术、GPC凝胶色谱净化技术、QuEChERS提取净化几种不同前处理在三种食用油中苯并芘的提取效果,确定了食用油中苯并[a]芘检测的前处理技术,建立了分子印迹柱净化-效液相色谱仪联用的检测方法,优化分子印迹技术各影响因素。并考察了日常食用油和油炸油中苯并[a]芘含量情况。     

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