异硫氰酸苯酯柱前衍生法测定奶粉中的牛磺酸

采用异硫氰酸苯酯为衍生剂,反相液相色谱法测定牛磺酸的含量。使用VP-ODS柱,以醋酸钠缓冲液-乙腈体系为流动相,流速为1.0mL/min,在254nm波长处紫外检测。牛磺酸在5~100μg/mL范围与峰面积呈良好线性关系,相关系数r=0.9993,平均回收率为99.2,RSD=1.32%(n=6)。该方法结果准确,重现性好。     

柱前衍生高效液相色谱法测定红牛维生素功能饮料中牛磺酸含量

用邻苯二甲醛(OPA)柱前衍生高效液相色谱法,运用C18色谱柱为固定相,甲醇 0.05mol/L NaAc溶液(45 55)为流动相,检测波长330nm,测定红牛维生素功能饮料的牛磺酸.结果衍生化反应迅速,分离效果好,在10～50μg/ml的浓度范围内,牛磺酸色谱峰面积与浓度之间的线性相关系数为0.9999,加标回收率为97.48%～101.0%,RSD为2.5%.     

应用高效液相色谱法测定铜镍选矿废水中的黄原酸盐

为了有效分离和测定铜镍选矿废水中的黄原酸盐,以内蒙古某铜镍选矿废水为水样,采用高效液相色谱法,即在分析该水样水质的基础上,在水样中加入适量的捕收剂,生成黄原酸铜络合物和黄原酸镍络合物,再用硫酸铜柱前衍生法和硫酸镍柱前衍生法对水样进行预处理,然后利用高效液相色谱仪测定预处理后水样中的黄原酸盐含量.实验结果表明:采用该方法,检测两种选矿废水的四组加标样,其中乙基黄原酸盐的回收率可达95.1%～97.3%,丁基黄原酸盐的回收率可达96.1%～97.0%,各组样品7次测定结果的RSD值均在1.78%～4.55%之间;较好地分离和测定了该铜镍选矿废水中乙基黄原酸盐和丁基黄原酸盐.该方法为同类型选矿废水中黄原酸盐的分离和测定提供一定参考.     

柱前衍生—高效液相色谱法测定酱油中游离氨基酸

建立一种测定酱油17种游离氨基酸的方法。酱油经离线衍生后,采用常用C18色谱柱,进行反相高效液相色谱分析。方法检出限为0.5μmol/L,样品加标回收率为92%～102%。该方法不需专用氨基酸分析色谱柱,灵敏度高、重现性好、检出限低、回收率高。     

培氟沙星的气相色谱法测定及其应用

采用三氟化硼-甲醇为衍生化试剂,以HP-FFAP毛细管柱为分离柱,建立了培氟沙星的气相色谱分析法.培氟沙星在质量浓度1.0 mg/L～250.0 mg/L内,药物与内标物峰面积比和药物浓度呈良好的线性关系,检出限为10 μg/L.该方法前处理步骤简单,处理后杂质干扰少,灵敏度高,适用性强,用于药物制剂和体液中培氟沙星含量的测定,平均回收率为93.75%～102.73%,日间RSD均小于2.85%(n=5).     

柱后碘衍生—高效液相色谱法测定脂必妥片中黄曲霉毒素B1的含量

为建立测定脂必妥片中黄曲霉毒素B1含量的高效液相分析法,样品经80%甲醇溶液超声提取后,通过免疫亲合柱净化、柱后碘衍生化,以荧光检测器检测,采用Waters Sunfire C18色谱柱(4.6 mm×250 mm,5μm);甲醇—乙腈—水(40∶18∶42)为流动相;流速,0.8 m L/min;柱温,25℃;衍生溶液为0.05%的碘溶液,衍生化泵流速,0.3 m L/min,衍生化温度70℃;激发波长λex=360 nm,发射波长λem=450 nm.结果显示,黄曲霉毒素B1在0.0008~0.0040 ng(r=0.9999)范围内呈良好的线性关系;回收率为97.13%(RSD=0.73%),检出限为0.5μg/kg.本方法简便,结果准确可靠,适于测定脂必妥片中黄曲霉毒素B1的含量.     

IC-ICP-MS测定大气颗粒物中的碘物种

建立了离子色谱(IC)与电感耦合等离子体质谱(ICP-MS)线下联用测定大气颗粒物中碘物种的方法,采用IC对样品进行分离,ICP-MS对进行检测.采用Dionex ICS-1000,配以AS18分析柱和AG18型保护柱,以40 mmol/L的KOH作为淋洗液测定大气颗粒物(Aero-sols)中的碘物种(Iodine Species),该方法的检出限为0.1μg/L,精密度(RSD)在4.2%～5.4%,加标回收率在80%～101%范围,方法适用于碘物种的测定.     

烟草中游离糖类的BSTFA衍生化与气相色谱-质谱联用分析方法研究

研究了衍生化试剂BSTFA对烟草中糖类的衍生化反应,并用GC-MS进行分析.烟草中的糖类用水超声提取,用C18SPE柱预分离,衍生化后用GC-MS分析测定.结果表明,该方法的检出限范围是4.7~7.6 ng,加标回收率为96%~106%,相对标准偏差(RSD)为4.63%~6.06%.实验证明该方法具有较高的准确度、快速和简便的特点.     

HPLC定量检测体外培养巨噬细胞液中PGF2α方法的建立

采用香豆素类物质BDMC为衍生剂进行柱前衍生,以C8反相柱(4.6mm×150mm)为固定相,乙腈-甲醇-水(35∶10∶55)为流动相,流速为1.5mL/min,柱温为22℃,检测波长为Ex/Em=354nm/440nm,建立定量检测体外培养巨噬细胞液中PGF2α的HPLC方法.PGF2α峰呈尖峰,分离度良好;在25~500μg/L范围内成线性(R2=0.995 0);其精密度RSD为4.34%(n=5);重复性RSD为7.88%(n=6),稳定性RSD为4.43%(n=5);平均加样回收率为87.20%±7.63%(n=3).结论:该方法稳定、可靠、重复性好,可用于体外培养巨噬细胞液中PGF2α的定量检测.     

婴幼儿配方乳粉中唾液酸含量的测定

建立婴幼儿配方乳粉中唾液酸含量测定的液相色谱方法。用酸水解法释放婴幼儿配方乳粉中存在的唾液酸,在80℃下与邻苯二胺衍生50 min;采用SB-AQ C18柱(150 mm×4.6 mm,5μm)对衍生产物进行分离,流动相为乙腈-1%四氢呋喃水溶液(含0.2%的磷酸)进行梯度洗脱,荧光检测器检测(激发波长231 nm,发射波长465 nm)。结果表明,唾液酸在1.0~60.0μg/mL范围内线性关系良好,相关系数为R2=0.999 8,回收率在95.0%~105.2%之间,变异系数在0.6%~1.9%之间,检测限为10.0 mg/100g。该方法简便、快速、可靠,可用于市售婴幼儿配方乳粉中唾液酸含量的测定。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

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.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

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

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.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the