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1.
用椭圆法和电化学方法研究了苯胺在含不同碱金属阳离子的H2SO4溶液中的聚合反应,分析了不同聚合条件下的循环伏安曲线和光学参量Δ、Ψ及光学参量变化速率Vop对扫描电压E的关系曲线。结果表明在慢扫描下无论是否含碱金属阳离子,循环伏安曲线的形貌并无明显差异,在0.4-0.5V区域内均出现了第二阳极峰;第一阳性峰峰值的高低说明碱金属阳离子的存在能够影响聚苯胺膜的生长速率;聚苯胺膜电极在不同电解液中的循环伏安行为表明已形成的聚苯胺膜的电化学活性不受碱金属阳离子的影响,碱金属的嵌入是一个不可逆的过程。  相似文献   

2.
聚苯胺的合成及性能   总被引:6,自引:2,他引:6  
分别采用脉冲极化法和恒电流法聚苯胶膜的峰值电流合成聚苯胺,用循环伏安曲线对它的电化学性质进行表征,研究了温度对聚苯胺膜的峰值电流的影响.研究结果表明:脉冲极化法合成的聚苯胺膜在循环伏安曲线上的峰值电流比恒电流法合成的高,电化学活性强.扫描电镜照片表明这2种方法合成的膜结构不同,脉冲极化法合成的聚苯胺膜在介质条件分别为0.5 mol/L H2SO4和1 mol/L HNO3水溶液中合成的膜结构均为纤维状,且在HNO3介质条件下膜纤维形状更好,纤维长度更长;恒电流法合成的聚苯胺呈颗粒状.温度越高,聚苯胺膜的峰值电流越大,电化学活性越强,聚苯胺在对应电位时的电化学储能能力越强.  相似文献   

3.
运用溶液聚合法和沉淀法制备出氧化锌-聚丙烯酰胺复合水凝胶。对复合水凝胶进行X射线衍射分析,红外光谱分析,从而确定复合水凝胶中的成分为氧化锌和聚丙烯酰胺;通过研究复合水凝胶修饰玻碳电极的电化学行为,发现修饰电极对于氯化亚铁电解液具有较好的循环伏安响应;测试不同浓度氯化亚铁的循环伏安曲线,发现随着溶液浓度的增加,修饰电极对于氯化亚铁电解液的电化学响应加强;测试不同扫描速率下的循环伏安曲线,发现随着扫描速率的增加,还原峰电流与氧化峰电流都在增大,而且氧化峰与还原峰之间电位差增大;修饰电极对于其他不同的电解液进行测试,获得不同的循环伏安曲线。  相似文献   

4.
采用循环伏安法,研究了不同浓度硫酸对苯胺在铂电极上电化学聚合的影响,初步探讨了聚合机理.结果表明:用循环伏安法合成聚苯胺(PAN)时,控制电位在-0.260~0.860 V(vs SCE)之间,扫描速率为100mV·s-1.苯胺浓度为0.20 mol.L-1,随着硫酸浓度升高,苯胺的聚合反应速率加快,PAN的电化学活性增强;循环伏安曲线对称性比较好,硫酸和苯胺组成的电解液具有优良的氧化还原可逆性.  相似文献   

5.
聚苯胺修饰铂电极的研究   总被引:1,自引:0,他引:1  
采用恒电位法和循环伏安法,研究酸性水溶液中苯胺在铂电极上电化学聚合的过程及其影响因素,初步探讨了聚合机理。结果表明,用恒电位法合成聚苯胺(PAn)时,电位应控制在0.70~0.85V之间,且苯胺的聚夸反应是通过阳离子自由基中间体进行的;用循环伏安法制备PAn膜时,扫描上限一般不超过0.90V。在此基础上研究了影响PAn电化学行为的因素及电化学反应机理。  相似文献   

6.
聚苯胺与聚乙烯醇的原位复合膜及电色性   总被引:3,自引:0,他引:3  
采用恒电位原位聚合法制备了聚苯胺/聚乙烯醇复合膜(PVA-PAN).研究了单体浓度和掺杂酸的种类对复合膜性能的影响.通过循环伏安法、光谱电化学法等对复合膜的电学性能和光学性能进行了研究.与无基体的纯聚苯胺膜相比,复合膜与ITO(铟锡氧化玻璃)电极表面具有更好的粘结性能和均匀性、更好的电活性以及更快的响应.当施加电位在-0.50 V到-0.14 V之间时,复合膜呈现无色透明状态,当施加电位在+0.40-+0.90 V之间时,复合膜呈现紫色状态,可见光的吸收峰峰位产生明显的紫移.经过1 422次电位循环扫描之后,复合膜的循环伏安曲线中的峰电流强度以及可见光的吸光度分别能保持83%左右和60%左右,显示出适宜的循环寿命.  相似文献   

7.
Zn^2+对电化学合成聚苯胺膜的影响   总被引:3,自引:0,他引:3  
应用循环伏安法和扫描电子显微镜(SEM)研究了ZnSO4对电化学合成聚苯胺(PAN)的影响.结果表明,在含0.1mol/L苯胺的1.0mol/L硫酸溶液中加入0.1~1.0mol/L的ZnSO4,能提高PAN膜的电沉积速度;Zn^2 还能使电聚合的PAN膜在1.0mol/LH2SO4溶液中的电化学降解速度降低,并导致PAN膜的表面呈现多孔状的形貌.  相似文献   

8.
通过阳极电化学氧化法, 制备不同氧化程度的掺硼金刚石膜(BDD)电极, 并对其进行表征。分别采用循环伏安法和 Mott-Schottky 曲线, 研究不同氧化程度的 BDD 电极的电化学性质和电荷转移速率。扫描电子显微镜和拉曼光谱分析表明, 氧化后的 BDD 电极形貌和晶型结构几乎未发生变化, 但 EDX 能谱分析发现BDD 表面氧含量明显增加。循环伏安法和 Mott-Schottky 曲线阳极电流法研究发现, 电荷转移速率随氧化程度的增大而逐渐增大。接触角实验进一步证实, 随着 BDD 电极氧化程度的增加, 接触角减小, 电极表面亲水性逐渐增大, 因此以阳极电流方式表示的电荷转移速率增大。然而, Mott-Schottky 曲线以氧化还原电位差方式表示的电荷转移速率随氧化程度的增大, 先增大, 后减小, 这是由于在不同的氧化时间下, 表面基团的种类及其各成分在总含氧量中所占比例不同, 因此产生的电荷转移速率也不相同。  相似文献   

9.
电化学合成聚苯胺涂层防护性能的研究   总被引:1,自引:0,他引:1  
采用循环伏安法在Q235钢表面电化学合成了聚苯胺涂层,通过极化曲线评价了扫描方式、电位区间、扫描速率、循环次数等电聚合参数对聚苯胺涂层在Q235钢耐腐蚀性能方面的影响,结果表明:合成条件对聚苯胺涂层的防护性能影响显著.在0.1 mol/L苯胺+0.3 mol/L草酸溶液中,循环电位区间–0.5~1.6 V,扫速10 m V/s,连续扫描5个循环,可获得最佳防护性能.该涂层在3.5%Na Cl溶液中对Q235钢具有较好的保护作用.扫描电镜观察表明:聚苯胺膜具有颗粒状纤维状结构.  相似文献   

10.
脉冲电流聚合苯胺   总被引:2,自引:0,他引:2  
采用脉冲电流和恒电流分别合成聚苯胺,通过循环伏安曲线和电镜扫描照片对它的电化学性质进行表征,脉冲电流合成聚苯胺的峰值电流比恒电流的高,其电化学活性更强.两种方法合成的膜结构不同,脉冲电流合成的聚苯胺是纳米纤维结构,恒电流合成的聚苯胺是颗粒结构.并且在硫酸、硝酸不同介质条件下的聚苯胺的扫描电镜图相似,均为纤维结构.  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.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
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   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  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.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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