影响分光光度法测定IAA含量因素的研究

测定了叶绿素、高岭土、活性炭、不同加热时间、蛋白质、不同pH等条件对分光光度法测定IAA含量的影响。结果表明 ,叶绿素对IAA含量的测定有影响 ,而且随浓度的增大 ,其影响也增大 ;活性炭对IAA含量的测定有极显著的影响 ,在吸附色素的同时也吸附了IAA ;高岭土对IAA含量的测定没有影响。煮沸时间对测定结果有影响 ,短时间 (5min)煮沸对测定结果影响不大。样品中蛋白质的含量对测定结果有极显著的影响。体积分数为 0 10的三氯乙酸对测定结果影响不显著     

不同溶剂和抽提方法测定脂肪含量的比较

采用不同方法测定了鱼粉、豆饼、鱼油、豆油的脂肪含量.结果表明,不同测定方法测定的值显著不同,测定鱼粉和豆饼时,以氯仿-甲醇为溶剂抽提测得的脂肪含量高.测定鱼油和豆油时,氯仿-甲醇冷抽提测定的值较高.     

微机线性滴定法测定弱酸、混合弱酸及弱碱盐的浓度

将微机引入线性滴定后,可使传统滴定方法无法测定的,离解常数低至10~(-10) 数量级的酸碱,得以准确、快速、简便地测定出来。本文在前文的基础上,探讨并改进了测定条件,扩大了该法的应用范围,测定了极弱酸、混合弱酸及弱碱盐的浓度,结果令人满意。     

应用氯化6,7-二羟基-2,4-二苯基苯并吡喃比色测定微量钨的初步探讨

钨与氯化６,７－二羟基－２,４－二苯基苯并吡喃在酸性介质中,生成橙红色化合物,其吸收■位于５００Ｎｙ,可用于钨的比色测定。我们探讨了最适宜的测定条件,拟定了应用该试剂比色测定微量钨的新方法,测定灵敏度为０．０７微克钨／毫升．大量Ｃｒ３＋、ＣＯ２＋、Ｎｉ２＋、ＶＩＶ和ＥＤＴＡ不干扰测定,但Ｍ０ＶＩ干扰测定．经初步应用于含钨钢样中钨的测定,得到较为满意的结果。     

电感耦合等离子发射光谱-质谱法测定土壤中镓的方法研究

电感耦合等离子发射光谱-质谱法测定土壤中镓的方法研究,主要探讨了土壤样品中镓测定的前处理条件及测定条件,通过不同浸提时间、不同提取液浓度条件的研究得出了比较理想的定量分析条件,采用该方法测定土壤中镓,操作简便,检出限、准确度、精密度均能达到要求。     

利用高精度时频信号测定重力位

与传统测量方法相比,利用高精度时频信号测定重力位更加快捷,可实现陆地与岛屿之间的重力位差测定．进入21世纪以来,随着原子钟的精度不断提高,使得高精度时频信号测定重力位成为可能,相对论方法测定重力位逐渐成为全球研究热点,并取得了重要进展与成果．这里介绍了高精度时频信号测定重力位的基本原理,包括光纤电缆信号传递、激光时间传递、卫星双向时频传递、GNSS共视时频传递、GNSS载波相位时频传递、卫星频率信号传递和VLBI时频信号传递等测定重力位的方法和技术,并讨论了时频信号传递测定重力位的发展趋势．未来原子钟精度达到10^-18量级时,有望在厘米级精度测定重力位和海拔高．     

邻苯三酚自氧化法测定超氧化物歧化酶活性的研究

目前超氧化物歧化酶(SOD)活性测定结果混乱,为提高测定结果的可比性,对邻苯三酚自氧化法测定SOD活性的方法进行了研究,就该活力测定体系中缓冲溶液的介质组成、浓度、pH及所含的EDTA量等因素对测定结果的影响进行了探讨,根据实验结果,提出了新的改良方法.     

土壤水分测定方法简介

本文简述了现今国内外土壤水分研究现状,总结了常用的测定土壤水分的方法及其原理,比较分析了各种测定方法的优缺点。详细阐述了TDR,FDR和探地雷达在土壤水分测定中的应用,为土壤水分测定精度、操作性、实用性的研究提供一定的参考。     

矿井下测定煤层瓦斯含量的方法分析

煤层瓦斯含量直接测定新技术解决了取芯和损失量推算的技术难题,形成了井下煤层瓦斯含量直接快速测定方法与装置,实现了煤层瓦斯含量的直接、准确快速测定,是煤层瓦斯含量测定的发展趋势。     

冷原子荧光法间接测定中药材中无机硫

采用冷原子荧光法间接测定中药材(黄芪和使君子)中的无机硫,建立了测定中药材中无机硫的方法,确定了定量分析的条件.测定线性范围为11.12ng/ml～55.60ng/ml,回归系数r=0.99978.该方法所需试剂较少、样品处理简单、测定灵敏度较高,结果可靠.     

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