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1.
本文用Deford和Hume极谱法测定了25℃、离子强度μ=4.0M条件下Cd~(2+)-Cl~-和Cd~(2+)-SO_4~(2-)络合物的稳定常数。然后以Cd~(2+)作指示离子,用Ringbom和Eriksson间接极谱法测定了同样条件下Ni~(2+)-Cl~-和Ni~(2+)-SO_4~(2-)络合物的组成和稳定常数。  相似文献   

2.
AceK是具有激酶与磷酸酶活性的双功能酶。本文研究了金属离子Mg~(2+)、Fe~(2+)、Ni~(2+)、Zn~(2+)对AceK激酶活性及磷酸酶活性的影响。实验表明Mg~(2+)是AceK激酶与磷酸酶激活剂,对激酶最佳激活浓度为2mmol·L~(-1),磷酸酶为5mmol·L~(-1)。但Fe~(2+)、Ni~(2+)、Zn~(2+)单独存在时,对AceK激酶、磷酸酶活性均没有明显作用,反而能较强地抑制Mg~(2+)激活的AceK酶活性,对激酶抑制作用由强到弱为Zn~(2+)、Ni~(2+)、Fe~(2+),对磷酸酶抑制作用由强到弱为Ni~(2+)、Fe~(2+)、Zn~(2+)。研究内容和结果为进一步研究AceK催化机制和结构功能打下了一定的基础。  相似文献   

3.
报道新显色剂2—(4,5—二甲基—2—噻唑偶氮)—5—二甲氨基酚(简称DMTAM)的合成方法和结构鉴定结果。对其溶解性,在可见光区的吸收性以及与常见金属离子的显色性能进行了试验。结果表明:DMTAM易溶于多种有机溶剂且能被各类表面活性剂增溶,DMTAM具有良好的金属生色性,与Cu~(2+)、CO~(2+)、Ni~(2+)、pd~(2+)、Zn~(2+)、Bi~(3+)等形成灵敏稳定的配合物,可用作金属指示剂和光度分析显色剂。  相似文献   

4.
用离子浮选法以C_(5-9)异羟肟酸为捕收剂,在一定条件下分别得到Cu~(2+),Ni~(2+),zn~(2+)与C_(5-9)异羟肟酸形成的螯合物沉淀浮渣。用红外光谱法对其浮渣结构进行分析,结果表明:Cu~(2+),Ni~(2+),Zn~(2+)与异羟肟酸的配位方式基本相同,即:  相似文献   

5.
本文研究了由磁控溅射Ni~(2+)、Zn~(2+)、A1~(3+)离子所形成的铁氧体表面磁层,以及它对热压铁氧体磁性能的影响。  相似文献   

6.
光度法测定微量铅、锌常用双硫腙法,此法虽灵敏但试剂不稳定,重现性差。近年有人研究了高灵敏显色剂2—(5—溴—2吡啶偶氮)—5—二乙氨基酚(简称5-Br-PADAP)与铅、锌的显色反应,作者等亦曾对 Zn~(2+)—5-Br-PADAP—CTAB 显色体系作了较系统的研究。在此基础上,本文对 Pb~(2+)—5-Br-PADAP  相似文献   

7.
本文利用X射线单晶衍射方法测定了不同阴离子条件下六元瓜环(Q[6])与La(NO3)3自组装配合物的晶体结构。结果表明,在HNO3溶液中,Q[6]与La~(3+)离子形成1∶2配合物1,La~(3+)离子与两个Q[6]羰基氧原子配位,配合物1阳离子通过游离NO_3~-阴离子与配位水分子间的氢键作用形成超分子链;而在HCl溶液中,Q[6]与La~(3+)离子也形成1∶2配合物2,但组装模式与配合物1不同,La~(3+)离子与三个Q[6]羰基氧原子配位,Q[6]空腔同时包结1个NO_3~-阴离子和1个水分子,形成分子胶囊结构,配合物2阳离子通过配位水分子间的氢键作用形成超分子链。  相似文献   

8.
采用凝胶法合成了碱土金属—粘液酸配合物的晶体.样品经过元素分析、红外光谱研究,确定了该类配合物的组成.结果表明,粘液酸的两个羧基和四个羟基均能参与配位键的形成,而中心离子 Ca~(2+)、Sr~(2+)、Ba~(2+)与配体粘液酸的配位状况存在着一定差异。  相似文献   

9.
:在 p H3 .50酸性介质中 ,Cu( )和 Fe( )在非离子表面活性剂 Tween-80存在下与 5-Br-PADAP生成有色配合物 .有色配合物最大吸收波长都位于 570 nm处 ;表观摩尔吸光系数分别为 7.96× 1 0 4 L· mol-1· cm-1和 6.3 0× 1 0 4 L· mol-1· cm-1;Cu( )在 0~ 1 3μg/2 5ml,Fe( )在 0~ 1 8μg/2 5ml范围内符合比耳定律 .用拟定的方法测定了铝片和水样中的 Cu( )和 Fe( ) ,结果令人满意  相似文献   

10.
5-(4-磺基-1-萘偶氨)-8-羟基喹啉(SNAZO)在乳化剂-OP的存在下与镍(Ⅱ)形成稳定的红色配合物,其镍(Ⅱ)与试剂的组成比为1:4。。配合物在520~540nm的范围内有最大吸收,其表观摩尔吸光系数ε=9.05×10~4l·mol~(-1)·cm~(1),Sandell灵敏度S=6.49×10~(-4)μg/cm~2,Ni(Ⅱ)的浓度在0~0.8μg/ml范围内遵守朗伯-比尔定律。经验试,研究了SNAZO与Ni~(2+)的显色反应性能,并建立了测定微量镍的吸光光度新方法。  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
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.  相似文献   

14.
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.  相似文献   

15.
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。  相似文献   

16.
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.  相似文献   

17.
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-  相似文献   

18.
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-  相似文献   

19.
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  相似文献   

20.
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  相似文献   

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