牧草中矿质元素测定前处理的比较研究

牧草中矿质元素的测定前处理的方法有干灰化法，混酸消化法，本文提出用４ＮＨＣＩ煮沸提取，并将此法与前两法的测定结果进行比较．统计检验结果得出，酸煮沸提取法与干灰化法、混酸消化法比较，大多数结果非常一致，除铬外，其余不存在显著性差异．     

动物体内毒性元素汞、砷、铅的样品预处理方法及测试研究

汞、砷、铅为无机毒性元素。本文作者采用微波高压消化法对动物体组织进行消化处理，用等离子发射光谱仪对消化试样进行分析。该方法具有较好的回收率、灵敏度及极好的准确性，从而建立了一个快速、准确、简便的测定汞、砷、铅的方法。     

灰渣的湿法消化法及其利用

采用高压消化罐法消化样品，采用正交试验设计实验方案，用ICP-AES测定了煤燃烧后底灰中的镁、锰、镍、钾、钙、铝、铁、铜、镓、钛、汞、钒、锗、铈14种元素的含量，方法回收率在89.0％～108．7％之间，相对标准偏差均小于1．97％．方法简单、快速、准确性好，实现了多元素同时测定，测量结果表明，煤燃烧后的底灰与原煤相比微量金属元素普遍得到了富集．     

火焰原子吸收法测定蒜渣中的微量元素

用硝酸－高氯酸（4：1）混酸对烘干后的蒜渣进行消化处理，用原子吸收光谱法测定处理溶液中的Ca、Fe、Mg、Zn、Cu、Co、Mn、Ni、Pb、Cd等10种微量元素，结果表明，蒜渣中对人体有益的元素如Ca、Fe、Mg、Zn含量丰富，具有很大的使用价值。     

茯苓中锰、镁、铅元素的形态分析

对中草药茯苓中微量元素Mn、Mg、Pb的形态进行了研究.用0.45μm滤膜将茯苓水煎液分成可溶态和悬浮态,将其中可溶态用LSA-10树脂柱分成有机态和无机态,对茯苓煎渣则用HCl和CCl4进行浸渍和提取,然后用混合酸消化法和悬浮液直接进样法分别测定各微量元素的总量,再用原子吸收分光光度法测定了3种元素各形态的含量.结果表明,悬浮液直接进样法优于混合酸消化法,Mn、Mg、Pb 3种元素主要以可溶态存在,Mg以有机态为主,Mn、Pb以无机态为主.     

微波消解-火焰原子吸收法测定岩白菜素中铁锌

用微波消化技术对岩白菜素试样进行预处理．针对样品特性，选择了较佳的微波消化条件与操作参数，建立了用微波消化-火焰原子吸收法测定岩白菜素中铁锌含量的方法．减少了样品处理过程中的损失，回收率为97．5％-102％；RSD为1．5％-5．1％（n=10）．     

应用IOP—AES同时测定5种花草茶的微量元素

花草茶是用植物的根、茎、叶、花或皮等部位单独或综合干燥后，加以煎煮或冲泡而产生的芳香味道的草本饮料。采用高压密封消化罐对五种花草茶进行处理，将化学计量学中的正交试验设计应用于ICP—AES法同时测定5种花草茶中的Se，Sr，Cu，Mn，Fe，Pb六种微量元素。该方法操作简单、快速、灵敏度高，准确性好，多种元素同时测定，回收率在97．5％～101．9％之间，相对偏差小于2．15％。实验结果发现5种花草茶中均不含Pb元素，且Se，Sr，Cu，Fe，Mn对人身体有益的微量元素含量较高，提示了5种花草茶的具有较高的营养价值。     

凯氏定氮法测定蛋白质含量的改进

对凯氏定氮法测定蛋白质含量进行改进。消化过程用碱液吸收瓶，防止SO2排入大气中造成的环境污染；蒸馏过程用例扣的漏斗防止例吸。测定结果表明，硫酸铵中氮的平均回收率由96．95％提高到99．70％，相对标准偏差由4．5％下降到0．6％；海带多糖中粗蛋白含量测定的相对标准偏差由4．3％下降到0．6％。改进的方法提高了测定的准确性。     

石墨炉原子吸收法测定动物组织中痕量铬的研究

本文报导了在酸性介质中，用石墨炉原子吸收法测定动物组织中痕量铬的最佳实验条件。系统的论述了消化剂的选择，消化时间控制，进样酸度以及共存元素对测定结果的影响。实验结果表明，采用ＨＮＯ３－ＨＣｌＯ４进行动物组织样品消化效果优于ＨＮＯ３－ＨＣｌ－Ｈ２Ｏ２。本文给出了动物组织的最佳消化条件及分析方法。     

不同产地枸杞子质量的综合评价

主成分分析是一种将多个变量化为少数几个综合新变量的多元统计分析方法．应用该方法对不同产地枸杞子质量进行了综合评价．根据综合得分给出了不同产地枸杞子质量的科学排名,客观地反映了不同产地枸杞子微量元素各方面的特征．     

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