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1.
研究了在不同稀释剂中N—癸酰吗啡林(DMPHL)与磷酸三丁酯(TBP)协同萃取铀(VI)的性能.在不同稀释剂中考察了硝酸浓度、萃取剂浓度、盐析剂效应及温度对萃取平衡的影响.此协萃体系对铀(VI)的萃取性能在不同稀释剂中由弱到强的顺序为:氯仿、四氯化碳、环己烷、煤油、苯,并且求出了萃取反应的各个热力学函数变化值.  相似文献   

2.
研究了二—(2—乙基己基)磷酸(HDEHP)与三正辛基氧化膦(TOPO)从硫酸盐介质中对钴(Ⅱ)的协同萃取.测得协萃络合物的组成为CoA_2·3HA·TOPO,协萃平衡常数 K_3=10~(0.55).协萃机理可视为CoA_2·3HA与TOPO的加合,对熵效应的测定结果支持这一观点。  相似文献   

3.
1—苯基—3—甲基—4—苯甲酰基吡唑酮(HPMBP)是稀土元素的优良萃取剂,利用诸如三正辛基氧化膦(TOPO)、磷酸三丁酯(TBP)等中性磷型萃取剂的协萃效应可显著提高萃取率。如:HPMBP—TOPO苯溶液萃取铕和钪、HPMBP—TBP苯萃取体系(PH5.5~6.5)萃取荧光法测定铕和铽、HPMBP—TBP或TOPO环已烷—氯仿体系萃取铕等。鉴于同是中性磷型萃取剂的三苯基氧化膦(TPPO)的协萃效应的有关研究尚未见报导,本文对铕、铽—HPMBP—TPPO苯协萃体系的萃取条件、协萃常  相似文献   

4.
TBP从盐酸溶液中萃取Sn~(4+)时,其稀释剂的影响不仅与稀释剂的性质有关,而且与盐酸浓度,萃取剂浓度,初始水相中锡的浓度等有关。只有[HCl]<6mol/L,[TBP]<40%,[Sn~(4+)]_(in)<1.5g/L时,才能排除这些因素的影响,因为这时各种稀释剂对Sn~(4+)的分配比D_(Sn~(4+))随这些因素的变化趋势相一致。在TBP-SnCl_4-HCl体系中,对于非极性类稀释剂,若按D_(Sn~(4+))的大小来排列,则烷烃类(环己烷、正己烷、正庚烷)>芳烃类(苯)>卤代烃类(四氯化碳),且可用稀释剂的极化率与摩尔体积等因素来解释;对于极性类有接受电子基团的稀释剂,则硝基苯>1,2-二氯乙烷>氯苯>氯仿,可用稀释剂的偶极矩、介电常数、溶解度参数或粘度等物性参数来解释其规律。  相似文献   

5.
低浓度含铬废水萃取分离的研究   总被引:1,自引:0,他引:1  
采用磷酸三丁脂(TBP)为萃取剂,煤油为稀释剂,研究了萃取时间、TBP初始浓度、废水中H+浓度以及盐析剂(NaCl)对萃取过程的影响。结果表明,TBP对Cr(VI)萃取速率较快,15min后基本达萃取平衡;TBP初始浓度及废水中H+浓度在较低范围内对萃取效果影响较大;加入盐析剂可促进反应平衡,提高萃取效果。  相似文献   

6.
以磷酸三丁酯(TBP)为络合剂,以正辛醇、环己烷、氯仿、四氯化碳、石油醚为稀释剂。测定了络合萃取剂(TBP)对间苯二酚溶液的相平衡分配系数(D).讨论了TBP的含量、稀释剂、盐和体系pH值对萃取相平衡分配系数(D)的影响.确定了络合物的组成.  相似文献   

7.
本文在298±1K下,用恒界面池法研究了2-乙基已基膦酸单(2-乙基己基)酯(HEH[EHP],HA)-正庚烷-lmol·dm~(-3) (Na,H)NO_3体系萃取Fe(Ⅲ)的动力学。用电位法检测水相中Fe(Ⅲ)浓度随时间的变化。实验表明,苹取速控步骤发生在两相交界处,并考察了水相酸度,苹取剂浓度及介质浓度对初始正向萃取速率的影响。  相似文献   

8.
本文采用两相滴定法测定了2-乙基已基膦酸2-乙基已基酯(简称HEH(EH)P)的某些基本常效.研究了用HEH(EH)P在煤油溶剂中萃取碱土金属Ca,Sr等的平衡.在有机相中,金属-萃取剂的萃合物组成分别是CaA_2·2HA和SrA_2·2HA它们的表观萃取常数分别为lgK_(1·2)~ca=-4.14,lgK_(1·2)~(sr)=-4.30.  相似文献   

9.
考察了水相酸度、萃取剂浓度、温度和水相介质浓度对HEH[EHP]煤油从硫酸介质中萃取Mn(Ⅱ)、Fe(Ⅲ)、Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)、Zn(Ⅱ)等元素的影响;确定了萃取反应式、萃合物组成和萃取平衡常数;计算出萃取反应的△H°、△G°及△S°;对HEH[EHP]萃取金属的顺序和Co(Ⅱ)、Ni(Ⅱ)的萃取分离中的某些问题作了简单讨论。  相似文献   

10.
得到了NdCl_3(0.75~O.10M)—HCI(0.40~0.06M)—HEH[HEP](1.0M)—200~#磺化煤油体系的分配平衡状态图,分配比随水相氯化钕的初始浓度和初始酸度的变化规律,用氨水先将HEH[HEP]皂化40%,再与氯化钕水溶液平衡,使HEH[HEP](1.0M)—200~#磺化煤油的萃取容量提高2—3倍。  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.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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