用导数分光光度法同时测定微量钴和镍

以5—Br—PADAP为显色剂,用二阶导数分光光度法对微量钴镍进行了同时测定,按“零交法”取569nm和616nm的峰——零导数峰值分别对镍钴定量,服从比耳定律的线性范围分别为0～14μg/25mL和0～22μg/25mL.样品的测定和回收实验表明,该方法准确、灵敏,符合测定要求,与原子吸收法的分析结果相吻合。     

4-硝基-4＇-偶氮苯基重氮氨基偶氮苯三氮烯合成及其与镍（Ⅱ）的显色反应

报道了新显色剂4-硝基-4＇-偶氮苯基重氮氨基偶氮苯三氮烯的合成及其与镍的显色反应。在聚乙二醇辛基苯基醚的存在下,pH=10．0的硼砂-氢氧化钠缓冲溶液中,该试剂可与镍发生显色反应,镍与其形成物质的量比为1：2型的墨绿色配合物,在588nm处有一最大正吸收,在453nm处有一最大负吸收。以453nm为参比波长,588nm为测量波长进行双波长测定,其摩尔表观吸光系数ε=2．0×10^5L／（mol·cm）,镍量在24～300μg／L范围内符合比尔定律,用拟定方法测定铝合金中微量镍,回收率达到了99．5％-101％。     

反相高效液相色谱法测定肝组织中土霉素、四环素残留量

研究和发展了高灵敏度测定四环素类抗生素残留量的HPLC方法．用Hypersil C18(5μm,300 mm×4．6 mm ID)色谱柱,以乙腈-N,N-二甲基甲酰胺-0．01 mol／L草酸溶液为流动相,流速1．0 mL／min于356 nm处检测．土霉素、四环素分别在0．01-50．00μg／mL,0．02-50．00μg／mL范围内呈良好的线性关系,检出限分别为0．01 μg／ mL,0．02μg／mL(S／N=3),添加平均回收率分别为100．43％和100．48％,相对标准偏差分别为1．22％和1．52％ (n=5)．方法简单、分离度高,检出限低,重现性好,并成功应用于动物肝组织中土霉素、四环素残留量的测定．测定结果显示,部分地区市售动物肝组织中抗生素残留还存在超标现象．     

新显色剂5-(8-喹啉侧氮)-2,3-二羟基吡啶分光光度法测定微量钴

用作者合成的新试剂5-(8-喹啉偶氮)-2,3一二羟基吡啶作显色剂,以分光光度法测定微量钴,在pH9.3的硼砂缓冲溶液中,配合物的最大吸收波长位于624nm,钴量在0～20μg/25ml范围内符合比尔定律,摩尔吸光系数为9.0×104C·mol-1·cm-1.方法简便,快速,应用于维生素B12和镍盐中钴的测定,获得满意结果.     

双波长分光光度法测定钴的研究

提出了在高氯酸介质中,以4-(4,5-二甲基噻唑偶氮)-1,3-二氨基苯(DMTADAB)为显色剂,应用双波长叠加分光光度法测定钴(Ⅱ)的新方法.结果表明,在实验条件下,钴与试剂形成稳定的12蓝绿色配合物,该配合物在600nm和435 nm处分别有正负两个吸收峰,且正负峰吸光度绝对值之和与钴浓度线性相关,钴在0～0.4μg/mL浓度范围内服从比耳定律.利用双波长叠加的方法测得其表观摩尔吸光系数为1.56×105L/(mol·cm),灵敏度较单波长测定提高约1.7倍.所拟方法已成功地应用于含钴分子筛和金川矿样中微量钴的测定.     

SPE-HPLC法测定环境水样中3种痕量抗生素的含量

建立了一种固相萃取-高效液相色谱法同时测定水体中氧氟沙星、四环素、磺胺甲噁唑浓度。样品经固相萃取小柱富集净化、超纯水-乙腈(75∶25,体积比)洗脱后,用高效液相色谱-紫外检测器测定。检测波长λ为274 nm,柱温30℃,流动相为乙腈-磷酸水溶液(50∶50,体积比),采用梯度洗脱程序,实现了3种待测组分的基线分离,线性范围为氧氟沙星0.25~2μg/mL,四环素0.4~2μg/mL,磺胺甲噁唑0.04~2μg/mL。空白加标回收率范围分别为82.32%~94.86%。氧氟沙星、四环素、磺胺甲噁唑的检出限分别为0.04、0.25、0.01μg/mL,定量限分别为0.25、0.40、0.04μg/mL。该方法具有快速简便、灵敏高效等优点,可满足实际工作的需要。     

1-(4-硝基苯基)-3-(5-氰基吡啶)三氮烯的合成及与镍的显色反应

合成了1-(4-硝基苯基)-3-(5-氰基吡啶)三氮烯(NPCPDT)试剂,研究了该试剂与镍的显色反应.在OP表面活性剂存在条件下,在pH=10.0~11.5的Na2B4O7-NaOH缓冲溶液中,该试剂与镍发生配位反应,形成2∶1型配合物.配合物在470 nm处有一最大正吸收,在540 nm处则有一最大负吸收.以470 nm为参比波长,540 nm为测量波长进行双波长测定,表观摩尔吸光系数为9.39×105L.mol-1.cm-1.Ni2 的浓度在0~12μg/25 mL范围内符合比尔定律.用拟定方法测定合金钢样品中的微量镍,得到满意的结果.     

反相高效液相色谱法测定金樱子中的芦丁和槲皮素

建立了用反相高效液相色谱法测定金樱子中芦丁和槲皮素的方法．色谱条件：色谱柱Shim-pack VP-ODS 200mm×4．6mm,流动相为甲醇：水（含0．2％磷酸）为60：40的溶液,流速为0．8mL／min,检测波长260nm．结果表明芦丁和槲皮素达到基线分离,分别在0．03-15μg／mL（r=0．9990）和0．04-20μg／mL（r=0．9994）的浓度范围内与峰面积呈良好线性关系,检测限分别为12．6和15．2ng／mL,方法可用于金樱子中芦丁和槲皮素的测定．     

纸上吸光光度法研究 Ⅲ、三波长β—亚硝基—α—萘酚法测定水中痕量钴

本文在单波长、双波长纸上吸光光度法研究基础上,进而对三波长纸上吸光光度法做了实验。钴(Ⅲ)用2—亚硝基—1—萘酚沉淀后吸滤于纸上,用721型分光光度计在450、550和700nm三波长处光度。0～5μg的钴服从比耳定律,最低检出浓度为5×10~(-8)g/ml,1μg钴的相对标准偏差为4％。     

正交设计法用于微量金的测定

本文用正交设计法和计算机程序,选择了乙基紫-醋酸丁酯萃取分离测定金的最佳条件,并用原子吸收光谱法进行测定,测得人工合成样中金的回收率为89.0％—110％,标准偏差和变动系数分别是2.5×10~(-2)μg/mL和3.2％,金的浓度在0—25μg/25mL范围内符合比尔定律。用本法测定阳极泥和电镀液中的微量金,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