沙地濒危植物长柄扁桃仁中维生素E含量分析

目的 研究高效液相色谱快速测定沙地濒危植物长柄扁桃仁中α-维生素E(α-生育酚)含量的方法.方法 采用色谱柱为Shim-pack VP-ODS柱(150 mm×4.6mm,5μm);流动相为甲醇-水(体积比为98:2),流速1.2 mL/min;检测波长为300 nm;柱温为室温.以保留时间定性,峰面积定量,标准曲线法计算样品中α-维生素E(α-VE)的含量.结果 方法的线性范围为1.298～103.84μg/mL,线性相关系数为0.999 9;检出限为0.19μg/mL;精密度为1.21%～3.26%;方法回收率为84.93%～90.53%,平均回收率为88.15%(RSD=2.68%).测得长柄扁桃仁中α-VE含量为2.82μg/g,α-VE,δ-VE,β,γ-VE的相对百分含量分别为0.94%,92.78%,6.28%.结论 长柄扁桃仁具有一定的经济价值,从中提取的天然维生素E为低α型混合生育酚,在医药、食品、饲料、化妆品方面可作为一种抗氧化剂,为全面评价长柄扁桃仁的营养品质及为产品开发利用提供科学依据.     

六六六在海河沉积物中的自然生物降解

为了解天然水体沉积物中六六六(HCHs)的自然生物降解行为,采集海河沉积物进行了实验室研究.结果表 明:HCHs在海河表层沉积物及水/沉积物界面层中的生物降解均符合一级动力学方程,α-HCH、β-HCH、γ-HCH和δ-HCH的生物降解速率常数分别为1.45×10-2～6.02×10-2d-1、9.8×10-3～3.39×10-2 d-1、2.00×10-2～8.58×10-2 d-1和1.42×10-2～5.40×10-2d-1;4种HCH异构体的降解顺序为γ-HCH>α-HCH>δ-HCH>β-HCH;厌氧条件下HCHs的降解速率高于好氧条件,温度升高降解速率增大;水/沉积物界面层中HCHs的生物降解速率,除好氧条件Tα-HCH和γ-HCH外,均高于表层沉积物.     

高效液相色谱法测定联苯甲酸异构体的含量

建立了3位和4位联苯甲酸同分异构体混合物的高效液相色谱法(HPLC)含量测定.色谱柱为Symmetry C18,检测波长254 nm,流动相为甲醇-磷酸二氢钾(1.2 mol/L),流速1 mL/min.3-联苯甲酸的线性范围是48～720 mg/L,4-联苯甲酸线性范围是21～685 mg/L;最低检出质量浓度均为0.01 mg/L,相关系数分别为0.999 2和0.999 8;平均回收率分别是99.4 %和98.8 %(n=6),RSD分别为0.87 %和0.93 %.     

毛细管气相色谱法测定几种中草药中啶虫眯的痕量残留

建立毛细管气相色谱法测定几种中草药中啶虫眯痕量残留的方法.样品经甲醇超声提取、Florisil硅土层析柱净化后,采用不分流进样方式,DB-1弹性石英毛细管柱(30 m×0.25 mm×0.25 ?m)经柱程序升温技术,并用电子捕获检测器检测,该方法的线性范围为6.70 ? 10-4～1.50 mg/L,相关系数为0.999 1。检测限为6.0×10-4mg/L,最低检出量为6.0×10-10mg,被测样品中均含有不同程度的农药残存.本方法检测灵敏度高,重现性好,样品预处理净化效果好,可用于中草药中啶虫眯残留量的检测.     

毛细管气相色谱法测定桔梗中六六六异构体的含量

运用毛细管气相色谱法测定了桔梗中甲体六六六(α-BHC)、乙体六六六(β-BHC)、丙体六六六(γ-BHC)、丁体六六六(δ-BHC) 4种异构体的残留量.样品以丙酮提取,在氯化钠存在下,以二氯甲烷进行液-液分配,提取液以浓硫酸净化,采用SE-30弹性石英毛细管柱分离样品,ECD检测六六六残留量.检出限为1.6×10-14～3.8×10-13 g/mL,回收率为85.24%～99.86%,峰面积相对标准偏差为0.61%～2.2%.     

离子液体为流动相添加剂高效液相色谱法同时测定莲子心中莲心碱、异莲心碱和甲基莲心碱

采用离子液体作为反相高效液相色谱流动相添加剂,建立了同时测定莲子心中莲心碱、异莲心碱和甲基莲心碱含量的方法.色谱柱为SPHERIGEL ODS C18(250 mm×4.6 mm I.D.,5μm),流动相为添加30mmol/L[HMIM][BF_4]、pH为3.0的甲醇/水(70/30,v/v),流动相流速为1.0mL/min,检测波长为280nm.在浓度范围为2-200μg/mL范围内,莲心碱、异莲心碱和甲基莲心碱的线性相关系数分别为0.999 8,0.999 7和0.999 8;对莲心碱、异莲心碱和甲基莲心碱的LOD分别为0.14 mg/L、0.17 mg/L和0.19 mg/L,LOQ分别为0.29 mg/L、0.35mg/L和0.41mg/L.     

气相色谱法测定鸡精中2种氯丙醇的方法研究

建立一种快速测定鸡精中3-氯-1,2-丙二醇(3-MCPD)和1,3-二氯-2-丙醇(1,3-DCP)质量浓度的衍生化毛细管柱气相色谱法.采用基质固相分散萃取法(MSPD),以硅藻土(ExtrelutTM 20)为吸附剂,鸡精样品用正己烷淋洗净化后用乙醚提取,用七氟丁酰眯唑(HFBI)衍生,经毛细管气相色谱柱DB-5 (30 m×0.32 mm×0.25 μm)分离,电子捕获检测器测定,外标法定量.3-MCPD和1,3-DCP均在0.010～0.250 mg/L质量浓度范围内线性关系良好,线性相关系数分别为0.999 1和0.999 3；加标水平为0.05,0.10和0.20 mg/kg时,3-MCPD的回收率在95.7％～102.2％之间,1,3-DCP的回收率在94.5％～99.3％之间,相对标准偏差均小于5.0％.3-MCPD和1,3-DCP的定量限均为0.01 mg/kg.该法操作简单、快捷,灵敏度高,试验结果准确可靠,适用于鸡精样品中2种氯丙醇的同时测定.     

高温高盐水中月桂酰胺丙基羟磺基甜菜碱在砂岩表面吸附规律研究

月桂酰胺丙基羟磺基甜菜碱表面活性剂在高盐含量水中具有较好的起泡性能,但在砂岩表面的吸附量尚不明确。本文利用Shim-pack VP-ODS 4.6 mm×250 mm色谱柱、紫外检测器,优化了流动相组成、流速、柱温等色谱条件,建立了高盐水中月桂酰胺丙基羟磺基甜菜碱的高效液相色谱检测方法。吸附性评价表明：温度为110℃、NaCl质量浓度为25×10⁴ mg/L的水中,质量分数小于1%的月桂酰胺丙基羟磺基甜菜碱在80～100目石英砂表面吸附量小于2 mg/g;在温度为110℃、水中NaCl质量浓度为(20～25)×10⁴ mg/L条件下,质量分数为0.4%月桂酰胺丙基羟磺基甜菜碱在80～100目石英砂表面吸附量随溶液中NaCl含量的增加而增加;在110℃、水中NaCl质量浓度为22.5×10⁴ mg/L、CaCl₂质量浓度为(0～3)×10⁴ mg/L条件下,质量分数为0.4%的月桂酰胺丙基羟磺基甜菜碱在80～100目石英砂表面吸附量随溶液中CaCl₂含量的增...     

双季铵盐表面活性剂的合成及表面活性研究

用脂肪酸制备了乙撑双(二甲基)季铵盐基双脂肪酸甲酯(B)及乙撑双(二甲基)季铵盐基双脂肪酸钠盐(C),用红外光谱对其结构进行了表征.经测定,分别用十二酸和十四酸制备的B1和B2其临界胶束浓度(cmc)分别为1.4×10-4和2.2×10-4 mol/L,其表面张力(γcmc)分别为30.5和37.8 mN/m;C1和C2的cmc分别为7.8×10-5和3.0×10-4 mol/L,γcmc分别为28.9和36.9 mN/m.结果表明,与普通表面活性剂相比,双子表面活性剂B1和B2的cmc要低1～2个数量级,γcmc也低了2～9个mN/m;C1、C2的cmc仅为普通表面活性剂的1/60～1/230,而γcmc相差不大.     

毛细管气相色谱法测定盐酸倍他洛尔中的残留溶剂

采用毛细管气相色谱法对盐酸倍他洛尔原料药中丙酮、异丙醇及甲苯残留量进行测定.色谱柱为HP-1石英毛细管柱(0.53 mm×30 m,1.5 μm),柱温采用程序升温,载气为氮气,流速为2.0 mL/min,在该条件下,丙酮、异丙醇在10～90 mg/L,甲苯在1.78～16.02 mg/L的质量浓度范围内峰面积与质量浓度成线性关系,相关系数分别为0.999 7,0.999 7,0.999 6.加样回收率、精密度、溶液稳定性的试验结果均可满足三者残留量分析的要求.     

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