合金元素对铝阳极电化学性能的影响

通过正交试验法研究Mg,Sn和Hg元素对铝合金阳极电化学性能的影响,采用恒电流扫描法、动电位极化法和排水析氢法检测Al-Mg-Sn-Hg阳极的电化学性能和腐蚀性能,采用环境扫描电镜结合能谱分析研究A1-Mg-Sn-Hg阳极的表面形貌和显微组织.结果表明:Sn和Hg的加入使得一部分Mg与2种元素形成第二相,成为80℃、大电流密度下铝阳极活化的主要因素,并能很好地抑制析氢;另一部分Mg固溶在Al中,成为铝阳极保持活化状态的重要原因;得到了综合性能优良的Al-Mg-Sn-Hg铝合金阳极材料,它在电流密度为650 mA/cm2、80℃、4.5％的NaOH溶液中稳定电位为-1.707 V,析氢速率为0.38 mL/(cm2.min).     

温度对Al-Zn-In-Sn-Mg阳极性能影响的探讨

对Al 5Zn 0 .0 5In 0 .1Sn 1Mg合金牺牲阳极进行 5 10℃× 10h的固溶处理 ,测定了未经固溶处理和经固溶处理的阳极在 2 0℃和 6 5℃ 30 g/L的溶液中的电化学性能 ,并进行交流阻抗测试 .结果表明 :温度升高 ,铝阳极电化学性能和溶解性能变差 ;固溶处理对阳极性能改善有利 ;高温下 ,铝阳极晶粒脱落和析氢自腐蚀更剧烈导致阳极电流效率下降 .     

热轧道次变形量对铝阳极组织结构和电化学性能的影响

采用析氢测量法、计时-电位法(E-T曲线)和Tafel曲线法,研究在温度为370℃时,不同热轧道次变形量制得的铝合金阳极的电化学性能和耐腐蚀性能,所用电解液是温度为80℃、添加Na2SnO3缓蚀剂的5 mol/L NaOH溶液.通过透射电镜、扫描电镜和能谱等分析相关材料的结构.研究结果表明:随着道次变形量的增加,铝合金阳极经历了动态再结晶组织的转变过程,铝合金阳极开路电位有所正移,活性有所降低,而自腐蚀电流密度先降低后升高,耐腐蚀性能先提高后降低;在370℃时,以道次变形量为40%轧制时所得的铝合金阳极综合性能最佳.     

N80油管钢的CO_2高温高压腐蚀电化学行为与机理研究

在高温高压釜中模拟油气井腐蚀环境 ,采用电化学交流阻抗和动电位扫描极化曲线测试技术 ,研究了N80钢在温度为 10 0℃ ,CO2 分压为 1.18MPa条件下的腐蚀电化学行为和阳极与阴极反应机理 ,实时监测了腐蚀产物膜对腐蚀行为和腐蚀反应机理的影响 .研究结果表明 :N80钢的阳极反应过程服从Bockris机理 ;N80钢的阴极反应以H2 CO3的还原为主 ;反应中间产物吸附与腐蚀产物膜覆盖的竞争导致交流阻抗谱随腐蚀时间而变化 ,影响着钢的腐蚀行为 ,产物膜对钢基体具有一定的保护作用     

轧制温度和道次变形量对铝阳极Al-Mg-Sn-Bi-Ga-In性能的影响

采用析氢测量法、计时-电位法(E-T曲线)、Tafel曲线、扫描电镜和能谱分析等分析测试方法研究不同轧制工艺的Al-Mg-Sn-Bi-Ga-In铝合金阳极在80℃、在浓度为5mol/L NaOH电解液中添加缓蚀剂Na2SnO3的电化学性能和耐腐蚀性能。研究结果表明:按道次变形量40%进行轧制时,随着轧制温度的升高,开路电位负移,而活性和耐腐蚀性能先提高后降低;在370℃进行轧制时,随着道次变形量增大,开路电位正移,活性逐渐降低,而耐腐蚀性能先提高后降低;在370℃,按道次变形量40%进行轧制时,铝合金阳极的综合性能最佳。     

Cl-和HCO3-对N80钢阳极电化学行为的协同作用

采用动电位极化曲线和动电位电化学阻抗谱对含不同浓度Cl-和HCO3-溶液体系中N80钢的阳极电化学行为进行了研究.溶液体系中不含Cl-的情况下,HCO3-的浓度超过0.03 mol.L-1时可使N80钢发生钝化.Cl-能极大提高发生钝化的HCO3-浓度临界值,同时对材料表面的钝化膜具有强烈的破坏作用.在阳极区,同等HCO3-浓度下,含Cl-的溶液体系中点蚀电位下降,维钝电位区间变窄,维钝电流密度升高.动电位电化学阻抗谱结果与动电位极化曲线基本对应.等效电路中电器元件与极化电位的关系表明,在含Cl-的溶液体系中N80钢的钝化膜粗糙度与致密性均有所下降,维钝电流密度升高主要由电荷转移电阻的降低所致.     

Ce0.8Sm0.2O1.9中间层对La0.75Sr0.25Cr0.5Mn0.5O3-δ阳极电化学性能的影响

通过固相反应法合成La0.75Sr0.25Cr0.5Mn0.5O3-δ(LSCM)以及Ce0.8Sm0.2O1.9(SDC)粉体。采用X线衍射仪(XRD)、扫描电子显微镜(SEM)、电化学阻抗谱法、循环伏安法和热膨胀法分别对试样的晶体结构、化学相容性、微观结构、电化学性能和热膨胀系数进行了研究。结果表明:LSCM阳极与SDC之间具有良好的化学相容性;含有SDC中间层的LSCM阳极显示出更小的比表面电阻和极化过电位;在800℃H2气氛下,含有SDC中间层的LSCM阳极的比表面电阻为0.76Ω.cm2,与单层LSCM阳极相比下降了72.1%,阳极极化过电位(电流密度为0.05A/cm2)下降了70.4%;SDC中间层的加入会导致热膨胀不匹配率的略微增大。     

温度对铝合金牺牲阳极活化溶解行为的影响

在20℃和65℃，对Al-Zn-In-Sn-Mg牺牲阳极进行电化学性能测试、活性离子沉积实验、极化腐蚀形貌观察和孔蚀性能的测定．分析认为：在常温下，铝阳极的活化过程主要是活性元素的“溶解-再沉积”过程；高温下以小孔腐蚀和晶间腐蚀为主要的溶解方式．     

镧含量对铝合金牺牲阳极海水综合电化学性能的影响

【目的】分析Al-Zn-In-Si系牺牲阳极添加不同含量配比的稀土元素镧(La)时,其电化学性能的作用规律,获得在海水环境下最佳牺牲阳极电化学性能的La添加量。【方法】通过模拟海洋环境,采用XRD分析、极化曲线、交流阻抗(EIS)和恒电流加速试验等方法,研究含La铝合金牺牲阳极的开路电位、工作电位、溶解形貌、电流效率以及极化等行为及其发生机理。【结果】La的加入改变了铝合金牺牲阳极溶质元素的存在形式,并随着含量的变化对其产生不同程度的影响;EIS谱表明含La铝合金牺牲阳极活化溶解过程体现了点蚀诱导期和发展期,极化曲线表明加入过量La后铝合金牺牲阳极的腐蚀电位变正,活化性能变差;恒电流测试实验表明加入La后铝合金牺牲阳极的电流效率有所升高。【结论】适量添加稀土元素La可有效改善铝合金牺牲阳极在海水中的电化学性能,其中La含量为0.2%的铝合金牺牲阳极电流效率最高。     

离子熵对应原理及其应用

一前言对于高温(如大于100℃)水溶液体系的电化学的重要性,近十余年来有了进一步的认识。例如,对于不同温度下电极性能的研究、不同温度时的电氧化还原反应的研究、高温下电位—pH图的制作和应用等等都需要不同温度下的热力学数据以及电极电位、活度系数、电离常数、电离度数据,这些数据对电化学的研究部是十分重要的。不同温度下电化学数据,例如,不同温度下的电极电位数据可以通过实验方法,即测定不同温度下的电池的电动势,然后用最小二乘法找出适合该电极的电极电位的幂级数方程。如我们常用的参比电极之一,氯化银电极,Greeley测定了下列电池在25°～275℃时的电动势。     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

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.     

An Index mechanism for multi-scale view in spatial databases

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.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

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。     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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