Study on the Electrochemical Behaviors of Zinc-Bismuth Alloy Electrode in Alkaline Electrolyte

锌是一种重要的金属能源材料，由于其具有储量丰富、电极平衡电位负、比能量高、可逆性好、成本低、无环境污染等优点，已被广泛用作碱性一次和二次电池的负极材料。随着全球对能源和环境问题的高度关注，锌作为能源材料的重要地位日益突显。由于锌电极在浓的碱性溶液中存在着自腐蚀、自钝化、形变和枝晶等问题，使二次锌电池的性能变差，如自放电严重，循环容量迅速降低，严重缩短了电池的寿命，甚至存在安全隐患，从而使锌系列二次电池的大规模开发和应用受到极大的限制。目前有关电极的合金化、电解液中Carbopol树脂的添加量以及工作电极与对电极的距离等电池体系因素对锌电极在强碱性溶液中的电化学行为的影响仍缺乏系统和深入的研究。...Zinc is one of the most important energy materials, and it is widely used as an anode in alkaline primary and secondary battery due to its various advantages including rich resource, negative equilibrium potential, high specific energy, good reversible, low cost, no environmental pollution, etc. With the increasing attention to the energy and environment problems, the importance of zinc as energy ...学位：理学硕士院系专业：化学化工学院化学系_物理化学(含化学物理)学号：2052006115197

Effect of Ferric Citrate on Microstructure and Corrosion Resistance of Micro-arc Oxidation Black Film on Mg-alloy AZ40M

利用二次微弧氧化法在AZ40M镁合金表面成功制备了黑色的氧化膜层,通过SEM、EDS和XRD表征了膜层的微观形貌和成分组成。结果表明,柠檬酸铁添; 加剂浓度可显著影响镁合金表面氧化膜的形貌、组成和厚度,添加剂浓度越高,膜层中的铁氧化物含量也越高,而对膜层厚度的影响则没有呈现出明显规律。同时,; 测试了0.1 mol/L; NaCl溶液中的电化学阻抗谱和动电位极化曲线,结果显示镁合金表面黑色膜层具有较好的耐蚀性,且膜层越厚,铁含量越少,膜层的耐蚀性越好。Black oxide films on Mg-alloy AZ40M were prepared by means of a two-step; micro-arc oxidation process in electrolytes of 15 g/L Na_3PO_4+ 3 g/L; NaF+5.6 g/L KOH and 20 g/L Na_3PO_4+5 g/L NaF with different additions; of ferric citrate respectively. The microstructure and composition of; the films were characterized by scanning electron microscope (SEM),; energy dispersive spectrometer (EDS) and X-Ray diffractometer (XRD). The; electrochemical corrosion property of the films was assessed by using; electrochemical impedance spectroscopy (EIS) and potentiodynamic; polarization curves in 0.1 mol/L NaCl solution. Results showed that the; concentration of ferric citrate strongly affects the surface morphology,; composition and thickness of the formed oxide films. The oxide films; have good corrosion resistance. The thicker oxide film with less iron; content presents better corrosion resistance.国家自然科学基

Electrochemical Behavior of Zinc-Bismuth Alloy Electrodes in Gelled Electrolytes

锌电极的自腐蚀速率,持续放电下的阳极溶解速率和电极钝化的难易程度是碱性电池性能的重要电化学参数.本文应用线性极化、恒流放电等电化学实验方法研究了电解液中添加CArbOPOl树脂以及电极中添加bI对锌电极电化学行为的影响.并应用金相显微镜和环境扫描电子显微镜(ESEM)对锌电极和锌铋合金电极浸蚀及放电后的形貌进行了表征.结果表明:电解液中添加适量的CArbOPOl树脂可明显提高电极的极化电阻,显著降低电极的自腐蚀速率;阳极的溶解电位出现不同程度的正移,阳极过电位显著增大且大电流密度放电时较明显促进电极钝化.锌电极中添加一定量的bI对改善电极表面氧化物膜的沉积形貌和电极表面固液界面的传质条件,减小电极的自腐蚀速率,抑制电极自腐蚀等方面具有显著作用.The self-corrosion rate, anodic dissolution rate, and passivating tendency of a zinc anode are important parameters that affect the performance of alkaline batteries.Effects of the addition of Carbopol resin to the electrolyte and the addition of passivation Bi passivation to the electrodes on the electrochemical behavior of Zn electrodes were investigated by linear polarization and chronopotentiometry.Surface morphologies of Zn electrodes and Zn-Bi alloy electrodes after etched and constant current dissolution were examined using a metallographic microscope and environmental scanning electron microscope (ESEM).Results showed that the addition of Carbopol resin significantly enhanced the polarization resistance, decreased the self-corrosion current, led to a positive shift in anodic dissolution potential, remarkably increased the anodic overpotential and promoted the passivation of alloy electrodes.The addition of Bi markedly improved the oxide film morphology and mass transfer between solid-liquid interfaces, decreased the self-corrosion rate of Zn electrodes and inhibited the self-corrosion process in Zn electrodes.国家自然科学基金(50731004);国家科技支撑计划(2007BAB27B04-N43CTT)资助项目---

连续陶瓷纤维的制备、结构、性能和应用:研究现状及发展方向

连续陶瓷纤维是纤维增强陶瓷基复合材料的增强体,对提高陶瓷基复合材料的强度和韧性起关键作用,高损伤容限和高强度陶瓷纤维是阻止裂纹扩展实现陶瓷基复合材料强韧化的保障。本文对碳化硅、氮化硅、氮化硼、氧化铝和氧化锆等几种陶瓷纤维的制备方法、结构、性能和应用等方面进行了全面的综述,指出了今后的发展方向,期望为未来陶瓷纤维的研究、开发及应用提供参考。国家高技术研究发展计划(863)(2003AA305630);;国家自然科学基金(51472144);;山东省科技重大专项(2015ZDZX11003);;山东省青年学者未来计划(2016WLJH27

Electrochemical Behavior of Zinc-Bismuth Alloy Electrodes in Gelled Electrolytes

The self-corrosion rate, anodic dissolution rate, and passivating tendency of a zinc anode are important parameters that affect the performance of alkaline batteries. Effects of the addition of Carbopol resin to the electrolyte and the addition of passivation Bi passivation to the electrodes on the electrochemical behavior of Zn electrodes were investigated by linear polarization and chronopotentiometry. Surface morphologies of Zn electrodes and Zn-Bi alloy electrodes after etched and constant current dissolution were examined using a metallographic microscope and environmental scanning electron microscope (ESEM). Results showed that the addition of Carbopol resin significantly enhanced the polarization resistance, decreased the self-corrosion current, led to a positive shift in anodic dissolution potential, remarkably increased the anodic overpotential and promoted the passivation of alloy electrodes. The addition of Bi markedly improved the oxide film morphology and mass transfer between solid-liquid interfaces, decreased the self-corrosion rate of Zn electrodes and inhibited the self-corrosion process in Zn electrodes.National Natural Science Foundation of China [50731004]; National Sci-Tech Supporting Program of China [2007BAB27B04-N43CTT

低温和限食对黑线仓鼠贮食行为的影响

贮食行为是动物在应对环境变化为度过食物短缺期，或为交配、繁殖后代而储备食物的生存策略。为探究季节性环境因子变化和食物资源对黑线仓鼠（Cricetulus barabensis）贮食行为的影响，本文测定了温度光周期、动物性别、限食对该物种贮食量、摄食量、体重等指标的影响。结果显示，雄性黑线仓鼠的体重、摄食量及贮食量均显著高于雌性；在类似于晚秋的低温等光照（10 ℃±2 ℃，L∶D=12∶12）条件下驯化1周，会诱导雄性个体体重降低，但摄食量不变，雌性个体则增加摄食量维持体重不变，雌雄的贮食量均不变；每日在白天时段限食可以降低雌性动物体重，但对其贮食量、摄食量无显著影响。结论，黑线仓鼠雌雄两性在低温和食物短缺条件下的能量对策不同。雌性由于体型较小，身体内不能贮存足量脂肪用于能量供应，在类似于晚秋的低温环境下只能通过增加摄食量以满足体温维持的能量需要，但由于受到身体消化吸收能力的生理限制，无法满足维持严寒条件下恒温的能量需求，因此体型较小的雌性个体会采取蛰眠的策略；雄性则由于相对较大的体型，身体贮存较多的可动员能量，且比雌性贮存更多的食物，这可能是其冬季能维持恒温，不蛰眠的原因

5羟甲基糠醛制备及其应用研究进展

5-羟甲基糠醛(HMF)被认为是最重要的生物质基平台分子之一,广泛应用于制备精细化学品、关键医药中间体、功能聚酯、溶剂和液体燃料等多功能化合物。目前,HMF的制备是生物质领域研究的热点,大量的研究使得制备HMF的原料和方法得到不断扩展。简单介绍了HMF的主要制备方法及其反应机理,系统综述了制备HMF的催化体系,包括催化过程中所使用的催化剂(无机酸、离子液体、金属氯化物、固体酸及其他催化剂)种类及制备HMF的溶剂体系。归纳了HMF重要衍生物的制备路径及应用,总结了目前研究中所存在的问题,并展望了未来的研究方向

中国新归化大戟科植物——头序巴豆

本文报道了大戟科(Euphorbiaceae)巴豆属的植物头序巴豆(Croton capitatus)在中国的首次入侵纪录,及该种的形态特征、地理分布、生物学特征、入侵危害和防治措施,澄清了关于密毛巴豆(Croton lindheimeri)在中国归化的错误,以期为外来入侵植物的鉴定及防控提供借鉴

基于UPLC-Q-TOF-MS技术的玫瑰石斛生物碱研究

玫瑰石斛(Dendrobium crepidatum)是兰科石斛属多年生附生草本植物,具有较高保健和药用价值。本研究利用超高效液相色谱-四级杆飞行时间质谱(UPLC-Q-TOF-MS)技术,研究了玫瑰石斛茎中生物碱成分和相对含量。从玫瑰石斛茎中共鉴定出15种成分:相对含量大于50μg/g的成分有两种,玫瑰石斛胺174.844μg/g,玫瑰石斛啶碱92.862μg/g;含量介于5～50μg/g间的成分有玫瑰石斛碱B、玫瑰石斛碱D、玫瑰石斛碱、玫瑰石斛碱C、玫瑰啶碱B;含量低于5μg/g的成分有玫瑰石斛素、N-异戊烯基石斛碱、石斛碱、N-异戊烯基石斛星碱、杓唇石斛素、玫瑰石斛碱E、玫瑰酚A、石斛酮碱。该研究首次在玫瑰石斛中发现4种倍半萜类生物碱。玫瑰石斛生物碱以八氢中氮茚类生物碱为主

镍基合金表面五重孪晶形成的分子动力学模拟

五重孪晶结构能够改善合金的表面性能,而关于合金五重孪晶化表面的研究较少报道。基于分子动力学模拟和纳米压痕方法,采用嵌入原子势函数(EAM)和等温等压系综(NPT),使用半径为14 nm的圆柱压头以40 m/s的压痕速度沿着[112]晶向对单晶镍基合金持续压痕,采用共领域分析法对合金在应力诱导作用下的变形行为进行了分析。结果表明,非共格孪晶界形成于四个不同{111}滑移面交叉中心附近。交叉中心处白色高能原子发射不全位错,堆垛层错产生。随着不全位错持续发射,孪晶得以形核、生长,孪晶界相继形成,最终五重孪晶形成于合金表面。合金表面中五重孪晶的形成并非源于晶界连续不断发射不全位错,而是与压痕过程中合金表面能量增加以及非共格孪晶界息息相关