原子吸收分光光度法测定无限极儿童口服液中微量元素Zn的含量

目的 测定无限极儿童口服液中微量元素Zn的含量.方法 光源用锌空心阴极灯,波长为213.8 nm,灯电流为2.5 mA,狭缝1.2 m,空气流量5.0 L/min,乙炔流量1.0 L/min.结果 Zn在1～7 mg/L质量浓度范围内线性关系良好(r=0.999 6),平均加样回收率为99.45%(RSD=2.16%,n=5).结论 该方法简便、快速、准确、灵敏度高、精密度好.     

HPLC快速测定发酵液中L–色氨酸

建立一种测定发酵液中L–色氨酸的高效液相色谱(HPLC)方法.以Agilent C18(5μm,150.mm×4.6.mm)为分离柱,V(0.03%的KH2PO4溶液)﹕V(甲醇)=90﹕10为流动相,流量为1 mL/min,在278.nm处检测L–色氨酸.该方法简便、快速、准确,在0.000～1.000.g/L范围内线性关系良好(R2=0.999 9),平均回收率为98.93%,精密度(RSD)为0.247%,可有效应用于发酵液中L–色氨酸含量的测定.     

液相色谱法同时测定芩连片中芍药苷、黄芩苷、盐酸巴马汀和盐酸小檗碱的含量

研究并建立了液相色谱法同时测定芩连片中芍药苷、黄芩苷、盐酸巴马汀和盐酸小檗碱含量的新方法.实验条件为Agilent ZorbaxSB—C_(18)柱(250 mm×4.6 mm,5μm),乙腈-0.05%磷酸溶液.梯度洗脱.检测波长为0～8.5 min 230 nm,8.5～23 min 280 nm和23～30 min 346nm.流速1.0 mL/min.芍药苷、黄芩苷、盐酸巴马汀和盐酸小檗碱线性范围分别为3.87～38.72 mg/L、4.18～41.80 mg/L、1.62～16.20 mg/L、2.10～21.00mg/L.应用该法测定芩连片中芍药苷、黄芩苷、盐酸巴马汀和盐酸小檗碱含量.加样回收率分别为100.9%(RSD=2.7%),101.5%(RSD=0.7%),97.9%(RSD=2.0%)和102.2% (RSD=1.6%).     

ICP-AES同时测定土壤中的环境有效态铅和锰

建立了电感耦合等离子发射光谱(ICP-AES)同时测定土壤中可利用的环境有效态铅(Pb)和锰(Mn)的方法.采用王水-高氯酸体系消解土壤样品,考察了ICP-AES实验条件对检测结果的影响,以220.353、257.610nm波长分别测定Pb和Mn的含量,选择延迟时间30s,射频功率1.3kW,雾化器流量0.8L/min,泵流速1.5mL/min,轴向观测位,作为ICP-AES测定土壤样品的条件.结果表明,建立的方法简便可靠,可测定土壤中Pb和Mn的有效态含量,可用于评价土壤中Pb、Mn的污染程度.     

旱柳树叶中水杨苷、邻苯二酚和颤杨苷的含量分析

建立HPLC法同时测定不同时间旱柳树叶中水杨苷、邻苯二酚和颤杨苷的含量的分析方法,在流动相为甲醇-缓冲液(乙酸钠0.02 mol/L-冰乙酸2%)梯度洗脱(0→18 min,5∶95;18→45 min,36∶64),体积流量1.0m L/min,检测波长:0→3 min(356 nm),3→18 min(270 nm),18→27 min(356 nm),27 min以后270 nm条件下测定,平均加样回收率分别为100.5%,100.4%和100.2%。     

气相色谱法测定白酒中甲醇含量条件优化

以白酒为原料,对甲醇测定条件进行优化,建立甲醇分析条件.实验结果表明:最佳色谱条件为即载气流速1.00 m L/min,柱温6℃/min,气化温度300℃,氢气流量28 m L/min,检测器温度300℃.线性方程为y=66.209x+1.712 5,r=0.999 6,最小检出限为0.41mg/L,日内精密度2.07%,日间精密度2.40%,样品加标回收率为83.88%~94.53%.该方法适用于白酒中甲醇含量的测定,测得10个白酒样品中甲醇的含量4.18~66.97 mg/L之间.     

正己烷液液萃取-超高压液相色谱法测定邻苯二甲酸酯

采用正己烷液液萃取-超高压液相色谱法(紫外检测器)测定邻苯二甲酸二丁酯和邻苯二甲酸二(2-乙基己基)酯的含量,确定的色谱条件为:流动相为甲醇/水,梯度洗脱:0～1min=85/15(Ⅴ/Ⅴ),1～4min=95/5(Ⅴ/Ⅴ),4～7min=85/15(V/V);流速=0.300ml/min;柱温35.0℃;检测波长220nm;进样量5μl。方法的检出限分别为0.3μg/L和0.4μg/L,相对标准偏差分别为1.59%～3.86%和1.99%～3.86%,加标回收率分别为95.0%～99.7%和98.0%～106.5%,满足环境监测的要求,可以用于饮用水中邻苯二甲酸酯的测定。     

液相色谱法同时测定栀子金花丸中栀子苷和盐酸小檗碱的含量

研究并建立液相色谱法同时测定栀子金花丸中栀子苷和盐酸小檗碱含量的新方法.实验条件为Thermo Hypersil-C18柱(250 mm×4.6 mm,5μm),乙腈-水(含10 mmol/L SDS)梯度洗脱,流速1.0 mL/min,栀子苷和盐酸小檗碱的检测波长分别为240 nm和346 nm,柱温40℃.栀子苷和盐酸小檗碱线性范围分别为4.0~59.5 mg/L(r=0.999 0)和4.0~60.6 mg/L(r=0.999 9),平均加样回收率分别为99.8%(RSD=1.9%)和100.5%(RSD=0.8%).     

Si纳米线的Au催化固-液-固生长与结构表征

为:Au膜层厚度为5～10 nm,温度为1 100 ℃,N2气流量为1.5 L/min.     

基于毛细管气相色谱法的花色蛤中扑草净残留量测定

建立了花色蛤中扑草净含量的毛细管气相色谱测定方法.采用SPL进样口,毛细管色谱柱rtx-5(弱极性,30m×0.25 mm×0.25μm),火焰光度检测器(FPD)进行检测.进样口温度,250℃,分流比5∶1,载气流速,1.47 m L/min;线速率控制方式:线速率,37 cm/s,柱室温度,100℃保持1 min,以30℃/min升至220℃,保持10 min;检测器温度,250℃,氢气气流量,40 m L/min,空气流量,60 m L/min.实验结果表明:方法简单、快速、重现性好,平均回收率大于85%,RSD小于6.0%,线性范围为0.05~1μg/m L,检出限(定性限)为0.001 mg/kg.     

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.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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.     

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