应用ICP-AES技术测定水中的有机碳含量

文章探讨了应用ICP-AES技术测定水中有机碳含量的方法。与国外同类方法相比，该法具有前期处理简单方便、测定时间短、灵敏度高、精密度良好的特点，适合各种天然水体中有机碳含量的测定。     

火焰原子发射光谱法测定水中钾钠影响因素的探讨

文章对采用火焰原子发射光谱法测定水中钾钠存在的诸多影响因素和干扰问题进行了试验与探讨，得出了较准确的测定条件和数据。     

火焰光度法同时测定常见水果中的钾钠含量

通过硝酸消化法制备了8种常见水果的待测试液,用火焰光度法同时测定了其中钾钠的含量.根据正常人体对钾钠的需求,以及钾钠缺乏及过量的症状和危害,进行对比分析发现,可以通过经常食用水果来维持人体内钾钠离子的生理平衡,特别对高血压患者以及想通过改善膳食增进健康的人们具有一定的指导作用.     

微量铝的富集分离方法研究

本文提供了一种新的快速富集分离测定水中微量铝的方法，该法简便、快速、灵敏度高，检测限为２．０×１０－９ｇ／Ｌ．用于天然水中微量铝的测定取得满意结果。     

GDX富集法测定天然水中的痕量铜

本文以ＧＤＸ－４０３为吸附剂，研究了对Ｃｕ（Ⅱ）的直接吸着、洗脱；并将吸附柱与火焰原子吸收光度计进样口相连，应用于天然水中铜含量的测定．该法简便实用，树脂易再生，最大富集约１０倍左右，提高灵敏度２５～３０倍     

差示脉冲溶出伏安法测定天然水中痕量锌

<正> 1 引言 锌是人体必须的微量元素之一,人体缺锌会导致机体免疫能力降低,代谢过程中消耗的锌是由饮食来补偿的。天然水中不同程度存在锌,其含量已受到人们越来越多的关注。许多商品矿泉水已把含锌量作为其品质的一项指标。由于天然水中锌含量很低,一般测量锌常用的原子吸收法,比色法,普通极谱法等均不宜使用。本实验用差示脉冲溶出伏安法测定天然水中痕量锌效果良好。     

用比色法测定天然水中镁离子之含量

测定天然水中镁离子之方法,向以重量法为主,1952年A.S.T.M.书仍将重量法作为最标准的方法。重量法虽能获得准确结果,但手续过繁,费时过多,实用上颇不方便。1927年,Kolthoff发表论文,主张用钛黄测定镁离子含量。1942年Ludwig及Johnson发表论文,对于用钛黄(titan yellow)作试剂测定镁离子之光电比色法作详     

原子吸收光度法测定天然水中的微量元素

以负载了PAN的微晶萘为吸附剂，以乙醇为洗脱剂，富集天然水中的铜、钴和铬，再用原子吸收光谱法(AAS)测定．对富集条件进行了试验，方法回收率为95％～105％．     

水中磷酸盐的测定—■钼黄水相及有机有萃取比色法

水中磷酸盐的测定,已有不少报导。一般对于水中高含量磷酸盐的测定多采用喹钼拧酮重量法或容量法,而对于水溶性磷酸盐的测定多采用钼兰比色法。前者虽然准确可靠,但操作麻烦费时,并且只适用于磷含量较高的样品的分析,后者操作简便,快速,但只适用于磷含量较低的样品的分析。目前水中磷酸盐的测定,亦常采用钒钼黄水相比色法,此法具有快速,操作简便等优点,但亦只适用于磷酸盐含量稍高的样品的分析。而事实上,水中磷     

悬浮液进样—火焰原子吸收光谱法测定中草药中的钾钠

将悬浮液进样-火焰原子吸收光谱法应用于中草药中钾钠的测定,建立了中草药中钾钠的快速分析新方法,将样品粉碎、磨细悬浮于琼脂胶体中,直接喷入空气-乙炔火焰,以空白溶液为参比,用氚灯作背景扣除,用标准曲线法测定了山药、枸杞、泽泻、沸手四种中草药中的钾钠。     

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