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.     

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 .     

氢化物发生原子荧光法测定土壤中铅镉砷3种有害重金属

应用氢化物发生-原子荧光法对土壤中铅镉砷含量进行测定。研究了分析测定条件;测定铅、镉、砷的线性范围分别为:0～40μg/L,0～5μg/L,0～40μg/L;相关系数分别为:0.9999,0.9999,0.9994。应用于样品测定,测定结果的相对偏差小于2.6%;加标回收率为96.8%～104%。     

HPLC法测定5年及6年生黄芪中黄酮类成分的含量

通过冷浸、回流提取、超声提取法分别对山西浑源 5 a和6 a生黄芪中水溶物、槲皮素,5-O-甲基维斯阿米醇苷和芒柄花素进行了提取分离,并进行了含量比较.采用Zorbax SB-C18色谱柱,以甲醇-0.4%H3PO4(V:V=50:50)为流动相,流速为1.0 mL/min,在254 nm处同时测定了槲皮素,5-O-甲基维斯阿米醇 苷和芒柄花素的含量.结果表明:槲皮素,5-O-甲基维斯阿米醇苷和芒柄花素的线性范围分别为:0.028 0 μg～0.350 0 μg,0.400 0 μg～30.000 0 μg,0.080 0 μg～ 0.600 0μg.回收率分别为:91.25%,111.02%,95.15%.RSD分别为:1.59%,4.28%,1.84%.该方法简便,准确,重复性好,可用于黄芪药材的质量评价.     

镉-溴化钾-邻菲罗啉共振光散射法测定痕量镉的研究

在pH 9.0的KH2PO4-NaOH缓冲液中,Cd2+与溴化钾、邻菲罗啉反应生成多元配合物导致体系共振光散射强度增大,在λ = 470.3 nm处共振光散射增大程度与镉的浓度有良好的线性关系.方法线性范围为:0.04～2.68 μg/mL,检出限为1.28×10-2 μg /mL,相对标准偏差为0.98%和1.68%,样品加标回收率为91.8%～104.7%.     

荧光光度法测定中药芦荟大黄素

利用荧光光度法研究确定了测定芦荟大黄素的适用条件 .在λex/em =470 /5 4 0nm ,pH =7.0的实验条件下 ,测定的线性范围为 1 .0～ 8.1 μg .mL- 1 ,检测限为 0 .0 3 1 μg .mL- 1 ,方法精密度为 2 .1 8% ,并成功地测定了样品决明子、血清和尿样中芦荟大黄素的含量 .     

草鱼实验性镉中毒的肝、肾病理学研究

用200尾(10.8±1.2)g的草鱼作实验性镉中毒实验.实验分为4组,每组50条.实验各组水中镉含量分别为1/10 LC50组80 μg.L-1,1/50LC50组16μg·L-1,1/100LC50组8μg·L-1,对照组为＜1μg·L-1,实验期120d.研究内容为草鱼镉中毒时肝、肾生化指标与病理变化.结果表明①草鱼镉中毒的24h-LC50为800μg·kg-1;②各组草鱼的死亡率分别是64%,24%,20%,4%;③实验各组草鱼肝胰脏、肾脏镉含量(湿质量)较对照组极显著升高(P＜0.01);④实验各组草鱼血浆中谷草转氨酶、碱性磷酸酶、胆固醇、甘油三酯、葡萄糖均较对照组明显地升高,而总蛋白则下降明显(P＜0.05);⑤实验各组草鱼血清中钙、磷、镁含量显著减少(P＜0.05);⑥病理学变化主要为肝胰脏和肾脏严重受损,发生颗粒变性、水泡变性和脂肪变性与溶解坏死.透射电镜下,肝细胞、肾小管上皮细胞内线粒体肿胀、嵴断裂、溶解;肾小球基底膜节段性增厚.     

痕量镉快速检测方法的研究

研究了达旦吐温80与镉的显色反应,并简化了该试剂分光光度法测定微量镉的操作过程.探讨了干扰离子的掩蔽方法.在碱性溶液中达旦黄与镉易形成橙黄色的配合物.研究表明,该反应的λmax=472 nm,ε= 1.38×105 L/(mol*cm).镉的质量浓度在0～0.3 μg/mL内符合比尔定律.样品加标回收率为99.87%～100.5%.该方法实验条件简单,选择性好,灵敏度高.用本法测定废水中微量镉的含量,结果满意.     

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 % .     

磷锑钼蓝共振瑞利散射法测定蛋白质

在稀H2SO4介质中, 蛋白质与磷锑钼蓝结合而使共振瑞利散射(RRS)增强并产生一个新的RRS光谱. 以磷锑钼蓝(PSbMo heteropoly blue, PSbMo)-牛血清白蛋白(bovine serum albumin, BSA)为例, 考察了其相应的光谱特征、影响因素和适宜的反应条件. 结果表明:当BSA的浓度在0～6.0 μg/mL范围内与RRS强度成正比. 方法对于测定蛋白质具有高的灵敏度, 对BSA、人血清白蛋白(human serum albumin, HSA)、α-糜蛋白酶的检测限(3σ)分别为0.021 μg/mL, 0.023 μg/mL和0.030 μg/mL. 实验了共存物质的干扰影响, 方法有较好的选择性, 用于合成样品的分析, 结果满意.     

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