碱水解-分光光度法快速检测有机磷农药的研究

建立快速检测蔬菜中3种有机磷农药的碱水解-分光光度法,优化了实验条件,并对建立的方法进行了评价.结果表明,3种农药标准曲线的线性范围分别为：乙酰甲胺磷0.570-20 mg/kg,氧化乐果0.285-20 mg/kg,乐果0.344-20 mg/kg; 线性相关系数分别为：乙酰甲胺磷0.9953,氧化乐果0.9922,乐果0.9961; 检出限分别为：乙酰甲胺磷0.359 mg/kg,氧化乐果0.420 mg/kg,乐果0.386 mg/kg.以样品测定结果计算方法的精密度,其相对标准偏差分别为：乙酰甲胺磷3.5%,氧化乐果3.46%,乐果4.62%.采用加标回收率评价方法的准确度,加标回收率为74.0%-95.0%.     

气相色谱-串联质谱(GC-MS/MS)法测定茶叶中20种农药残留

本文建立了气相色谱-串联质谱(GC-MS/MS)同时测定茶叶中多种药物残留的方法。样品加入正己烷作为提取液,经石墨化炭固相萃取小柱净化,待测物在气相色谱-串联质谱(GC-MS/MS)上测定,以保留时间和特征离子对定性,外标法定量。分析物质在50-500μg/L线性关系良好,定量离子对的相关系数大于0.99。分析物在添加水平为0.01-0.10 mg/kg时,回收率范围在70.0%-110.0%,相对标准偏差为5.0%-11.0%,符合残留分析要求。分析物质的定量下限(S/N10)为0.01 mg/kg。该方法快速、灵敏、准确,各项技术指标均满足国内外农药残留监测限量标准要求,能够很好的应用于茶叶中痕量农药的残留测定。     

气相色谱-质谱联用法测定内墙涂料中的游离甲醛

本文建立了内墙涂料中游离甲醛的气相色谱-质谱联用测定方法。优化了甲醛与2,4-二硝基苯肼的衍生条件。研究数据显示,该方法简便快捷、准确可靠。加标回收率在87.5%-94.6%之间;相对偏差小于5%,检出限为0.5 mg/kg。     

6%抗坏血酸水剂在烟草及土壤中残留分析方法

建立了6%抗坏血酸水剂在烟草及土壤中的残留分析方法,该方法的最小检出量为2.0×10^-8g.按0.1、1.0、10.0 mg/kg进行添加回收试验,结果表明：烟草植株的平均回收率为94.0%-95.1%,相对标准偏差为5.0%-9.0%;土壤样本的回收率为90.0%-98.4%,相对标准偏差为2.3%-7.4%,该方法的灵敏度、准确度、精密度均符合农药残留检测的要求。     

高效液相色谱-串联质谱(HPLC-MS/MS)法测定茶叶中高关注的25种农药残留

本文建立了茶叶中25种常用农药多残留同时检测的液相色谱-串联质谱(HPLC-MS/MS)检测方法。样品以乙腈作为提取剂,经石墨化炭固相萃取小柱净化,采用phenomenex C18色谱柱(50 mm×2.1 mm,2.6μm,100 A)分离,以乙腈-0.1%甲酸水溶液为流动相梯度洗脱,以电喷雾电离(ESI)、多反应监测(MRM)模式检测,外标法定量。25种农药在5-200μg/L范围内,线性相关系数均大于0.99,线性良好。分析目标物添加水平为0.01-0.10 mg/kg时,回收率范围为70%-116%,RSD范围为4.3%-10.8%,符合残留分析的要求。25种农药的定量下限(S/N10)为0.01 mg/kg。该方法的提取效果好、净化较彻底,灵敏度满足国内外限量标准的要求,适合茶叶中常用农药残留的同时测定。     

芦荟酒中锰元素的测定

采用火焰原子吸收光谱法测定芦荟酒中的锰元素。该方法的加标回收率在95.1%-101.8%，平均加标回收率为98.9%；相对标准偏差为0.020-0.054%；检出限量为0.02mg/L。     

离子色谱法快速测定原料乳中硫氰酸盐含量的研究

建立了以离子色谱快速检测原料乳中硫氰酸盐的方法.该方法采用三氯乙酸-乙腈法对样品进行前处理并离心,上清液经C18固相萃取小柱净化后,利用阴离子色谱柱分离、检测.试验结果表明：该方法的线性范围在0-100 mg/L,相关系数为0.999 5,检出限为0.1 mg/L,加标回收率为90.5%-95.4%,相对标准偏差（RSD）为4.7%-6.6%.本方法快速、准确、灵敏度高,精密度好,适用于原料乳中硫氰酸盐含量的测定.     

LC-MS/MS检测棉花中阿维菌素残留量的研究

本文建立了液相色谱串联质谱法测定棉花中的阿维菌素残留量的测试方法.通过对提取溶剂、流动相、离子源温度等优化，确定了最佳前处理条件和仪器分析条件.分析物阿维菌素在20.0-200.0 g/L的浓度范围内呈现出良好的线性关系，检出限为：0.01 mg/kg,在50.0 g/L,100.0 g/L,200.0 g/L的加标水平下，平均回收率为：75.1%-80.2%.试验结果表明，该方法检出限低，操作简单，测定结果可靠.本研究可为棉花中农药残留风险监测提供一定的技术参考.     

两种柴油污染方式对水稻生产的影响

两种不同的柴油污染方式对水稻生长影响的试验表明,柴油拌入土壤的两个处理(400 mg/kg和600 mg/kg),其营养生长和籽粒产量与对照处理相比均未出现显著差异;而柴油污染灌溉水的两个处理(200mg/kg和400mg/kg)均较严重地影响了水稻分蘖的发生和发展,最后导致籽粒产量下降了7.39%-15.01%.     

超声提取-分散固相萃取-气相色谱法测定绿茶中有机磷类农药残留

应用超声辅助提取和分散固相萃取前处理方法结合气相色谱（配火焰光度检测器）建立了绿茶中13种有机磷类农药残留的快速分析方法.5 g茶叶样品用20 m L乙腈（含1%乙酸）超声辅助提取后,以石墨化炭黑与伯仲胺混合型固相分散净化,高速离心后氮吹浓缩复溶,过滤膜,用气相色谱-火焰光度检测器进行检测.在0.02-0.10 mg/kg的添加水平,13种有机磷农药的平均回收率是84.78%-116.72%,相对标准偏差是0.12%-9.32%,检出限是0.000 8-0.01 mg/kg.本方法简便快速,准确性好,成本低,该方法已用于市面上销售的绿茶产品中有机磷类农药残留测定,结果均低于国家标准GB 2763—2012的最大残留量要求.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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