酶联免疫测定法(ELISA)在检测牛奶中氯霉素残留的应用

运用酶联免疫法测定牛奶中的氯霉素残留.氯霉素在0.1～3 μg/L范围内呈线性,线性方程为y=-22.306 x 45.667,r=0.9932.向样品中分别添加0.45,1.35,4.05 μg/kg 3个水平的氯霉素,平均回收率分别为86.7%,89.6%和81.8%,最低检测限为0.1 μg/L,批内变异系数为5.9%～8.4%,批间变异系数为5.9%～14.2%.结果表明该方法灵敏度高,重复性好,适合牛奶中氯霉素残留筛选检测.     

新型固相萃取-离子色谱在线联用技术测定水中F-, Cl-, NO3-, SO42-

将填充有自制苯乙烯-二乙烯苯共聚物的色谱小柱以安装保护柱的方式与离子色谱进行了在线联用,该方法回收率为96%～102%,精密度为1.7%～2.9%,检出限(质量浓度)在5.0～9.0 μg/L之间.用该联用方法测定了成都东郊的地下水及地表水中F-, Cl-, NO3-, SO42- 4种阴离子的质量浓度,地下水中这4种阴离子的质量浓度分别为0.16 μg/L, 7.35 μg/L, 1.08 μg/L, 12.26 μg/L;地表水中这4种阴离子的质量浓度分别为0.2 μg/L, 3.79 μg/L, 0.72 μg/L, 6.09 μg/L.该方法实现了在线消除乙酸干扰、延长分析柱寿命等预处理操作,克服了离线状态下对水样进行预处理既繁琐又费时的缺点.     

双道原子荧光法同时测定岩石中砷和锑

介绍了一种使用双道原子荧光法同时测定大量岩石样品中砷和锑的方法,对测定条件进行了优化.As和Sb分别在0～100 μg/L和0～10μg/L范围有好的线性关系,检出限分别为0.28μg/L和0.11μg/L,RSD分别为0.78%和0.55%,回收率分别在95.2%～108%和96.7%～102.5%之间.该方法用于4种岩石样品中As和Sb的同时测定,测定值与标准值基本相符.     

微波消解-氢化物发生原子荧光光谱法测定煤中砷和硒

采用浓盐酸和氢氟酸作消解剂,以微波消解的方法处理原煤样品,氢化物发生-原子荧光光谱法测定煤中砷、硒,设定了最佳的样品处理条件和仪器测定条件.利用加标回收试验,对分析方法进行了验证.砷、硒的检出限分别为0.05 μg/L和0.06 μg/L,测定煤中砷、硒的回收率分别为97.9%～104.8%、96.6%～106.3%,RSD分别为1.26%～1.59%、1.68%～2.33%.     

流动注射在线分离富集-火焰原子吸收光谱法用于Cr(Ⅲ)和Cr(Ⅵ)的形态分析

在单阀流动注射系统中 ,分别以串联在阀体流路中的阴、阳离子交换树脂微型柱分离富集 ,两种洗脱剂逆向洗脱 ,实现了Cr(Ⅲ )和Cr(Ⅵ )的在线分离富集和火焰原子吸收光谱法同时测定 .当富集 2min时 ,分析速度为 1 8样 /h ,测定Cr(Ⅲ )和Cr(Ⅵ )的特征浓度分别为 1 0 .1 2 μg/L和 1 4.43μg/L ( 1 %吸收 ) ,线性范围分别为0～ 1 0 μg/mL和 0～ 1 5 μg/mL ,对浓度分别为 1 μg/mL的Cr(Ⅲ )和Cr(Ⅵ )测定的相对标准偏差分别为 1 .6 2 %和 3.94% .该法应用于实际水样分析 ,加标回收率在90 .9%～ 1 0 4 5 %之间 .     

便携式气相色谱顶空法现场测定水体中的苯系物

用便携式GC在现场对水体中苯系物进行定性、定量,为妥善解决环境污染事故提供技术依据.该方法操作简单,灵敏度高,重复性好、适用范围广,对水中苯系物的最低检出浓度分别为苯1.0 μg/L、甲苯1.0 μg/L、二甲苯1.0 μg/L各组分变异系数均在4.5%～5.8%,方法精密度较好.该方法可用于应急事故中水道和河网水质中苯系物进行定量.     

萃取荧光法测定电解还原法制备的对氨基苯酚中的微量杂质4,4′—二氨基二苯醚

以 pH =9～ 11的条件下 ,用乙酸乙酯萃取电解—还原法生产的对氨基苯酚 (PAP)产品中的 4 ,4′—二氨基二苯醚 (DAPE) ,并以 2mol/LHCl将DAPE反萃取到水相中 ,在激发和发射波长分别为 2 5 4和 36 0nm条件下 ,荧光强度与DAPE的量成正比 ,线性范围为 30～ 180 μg/L ,检测限为 8.0 μg/L ,样品加标回收率为 78～ 95 % .     

银鲫肌肉中甲苯咪唑及其代谢物残留检测方法的建立—HPLC法

利用高效液相色谱法(HPLC-UV),建立了银鲫肌肉中甲苯咪唑(MBZ)及其两种代谢产物氨基甲苯咪唑(MBZ-NH2)和羟基甲苯眯唑(MBZ-OH)残留的检测方法.采用氨化乙酸乙酯作为提取溶剂,减压浓缩后去脂,二氯甲烷萃取,氢氧化钠净化,乙酸乙酯二次萃取,N2吹干,定容后使用高效液相色谱分析.方法在0.1～4.0μg/mL之间呈线性相关,相对标准偏差为1.09%～5.12%,MBZ、MBZ-NH2、MBZ-OH平均加标回收率分别为72.17%～77.44%、63.51%～68.07、82.37%～86.83%,检出限分别为10 μg/kg、15 μg/kg和10 μg/kg.     

河水中酰胺醇类抗生素的分析测定

建立了河水中3种酰胺醇类抗生素氯霉素、甲砜霉素和氟甲砜霉素的分析方法.利用HLB固相萃取柱进行水样的富集、净化,超高压液相色谱-串联质谱仪多反应监测离子模式进行定性、定量分析.工作曲线的线性范围为1～1 000 μg/L,3种目标物的方法检测限为1 ng/L(S/N=10,1 000倍浓缩);加标浓度分别为5.0、20.0和100 ng/L时的回收率为52.1%～77.5%,相对标准偏差1.9%～8.5%(n＝4).方法初步应用于福建省九龙江下游河水样品的分析.     

35%甲戊·扑草净乳油的UPLC-MS/MS检测

采用超高效液相色谱-串联质谱仪,对同时检测二甲戊灵和扑草净含量的方法进行了研究,以0. 1%甲酸水溶液和甲醇为流动相,在电喷雾正离子模式下,多反应监测(MRM)模式进行检测。结果表明,二甲戊灵和扑草净均在0. 0001～0. 05 mg/L范围内,具有较好的线性关系,相关系数为0. 9999;加标回收率分别为85. 61%～89. 62%和89. 73%～92. 85%,相对标准偏差分别为0. 45%和0. 27%,最低检测浓度分别为0. 106μg/L和0. 0930μg/L。该方法高效、准确,为二甲戊灵和扑草净的微量检测提供参考。     

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