首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
采用光电化学技术和实时交流阻抗测量等现场方法研究铅阳极膜的阴极还原过程,发现PbO电位区阳极氧化形成的阳极膜在阴极还原时有两种PbO的还原,即o-PbO和t-PbO二种氧化物的还原,还原过程中的电极阻抗变化情况表明PbO层是均匀还原的,且是t-PbO先还原,o-PbO后还原.还分析了铅阳极膜在阴极还原过程中所表现出来的阴极光响应.  相似文献   

2.
过实验探讨了铅(Pb)在阳极极化过程中形成的阳极PbO_2膜的电催化性能,结果表明:在硫酸溶液中的恒电位极化得到铅的阳极Pb0_2膜,比未形成阳极膜的铅电极(Pb)对于Mn ̄(2+)氧化成的反应具有电催化性能,能使反应速率加快。  相似文献   

3.
采用阴极线性电位扫描法、实时交流阻抗测量及光电子能谱等研究Pb/PbO/PbSO4电极在硫酸溶液中的阴极还原过程.结果表明,PbO还原峰的峰电位随氧化时间的增加而负移,PbO在还原时分为两个阶段即o-PbO和t-PbO的还原,PbO还原发生在PbO与基底Pb的界面.  相似文献   

4.
添加剂对粘结镍电极性能的影响   总被引:1,自引:0,他引:1  
用球形Ni(OH)2做为镍电极的活性物质,讨论了电极中加入各种添加剂(如Co、Zn、Ba和Cs等)对涂膏式镍电极活性物质Ni(OH)2利用率、快速放电能力、放电电位、电极膨胀率和氧析出电位等性能的影响。电极中添加CoC,Ni(OH)2利用率大大增加,电极快速放电能力增强,电极反应加逆性变好。电极中添加CoO和一定量的ZnO或Ba(OH)2能够抑制过充电时γ-NiOOH的生成,降低电极膨胀率。  相似文献   

5.
用电沉积法制备Mo-W-Ni-Pb-Ca多元活性阴极,研究了在0.5mol/L H2SO4中的析氢反应,结果表明,多元阴极具有较高的电催化活性,其析氢过电位比软钢阴极降低305mV,i0提高三个数量级,且有较好的稳定性,并用光电子能谱研究了表面组成和结构。证实表面有:Ni,NiO,MoO2,MoO^2-4,WO3,PbO2,PbO,Ca^++等物质。  相似文献   

6.
次亚磷酸根在Pt电极上的电氧化研究   总被引:1,自引:1,他引:0  
用循环伏安法研究H2PO2^-在铂电极上的电氧化行为,并讨论了电氧化的机理。结果表明,在0.5mol/LH2SO4介质中,H2PO^-2抑制氢和氧在Pt电极上的吸附,并通过两种径在0.4-1.2V的电位范围发生氧化:H2PO^-2直接氧化形成H2PO3^-3和H2PO^2通过前置化学步骤形成吸附中间物H3PO3然后进一步电氧化形成H3PO4。所述机理可以较好地解释电位扫描速度、介质温度及次亚磷酸根  相似文献   

7.
用电化学沉积法制备了As-Mo杂多阴离子修电极,在0.3mol/L H2SO4溶液中及0.70V~0.00V电位范围内,该电极具有三对可逆氧化还原表面波,它们分别对应于As-Mo杂多阴离子中Mo的三个2电子氧化还原过程,这三对表面波分别对NO2^-IO3^-及AsMo12O^340离子具有电催化活性,文中给出了其催化机理及浓度响应范围。  相似文献   

8.
 制备了NiOOH的涂膏式电极和粉末微电极,并对两种电极进行了循环伏安测试.测试结果表明,粉末微电极出现了还原峰和氧化峰,而涂膏式电极只出现了还原峰,表明粉末微电极的电极可逆性优于涂膏式电极;对于粉末微电极,其氧化峰及还原峰的峰电位、峰电流最终均趋于稳定,说明所制备NiOOH较为稳定;而其ΔE值最小仅为0.131 V,小于涂膏式电极所测值,说明粉末微电极用于循环伏安测试效果更好,所制备NiOOH样品晶格结构较为稳定,具有较好的电极可逆性.对造成涂膏式电极和粉末微电极测试结果差异的原因进行了分析探讨.  相似文献   

9.
初步探讨了Pb-Pb3(PO4)2化学修饰电极的响应机理,提出了该修饰电极在溶液中的界面模型,说明了该修饰电极电位的产生  相似文献   

10.
进行了β-PbO2/SnO2/Ti电极的研制及其性能的研究,与以前做的β-PbO2/Ti进行比较,显示了β-PbO2/SnO2/Ti修饰电极导电性能好并节省电能等方面的优越性。  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.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号