怎样正确使用Nernst方程

对Nernst方程使用时出现的问题进行了剖析,阐明了正确运用Nernst方程的方法.     

Application of corncob-based activated carbon as electrode material for electric double-layer capacitors

To investigate the influence of expansion pretreatment for materials on carbon structure, activated carbons (ACs) were prepared from corncob with/without expansion pretreatment by KOH activation, the structure properties of which were determined based on N 2 adsorption isotherm at 77 K. The results show that the expansion pretreatment for corncobs is beneficial to the preparation of ACs with high surface area. The specific surface area of the AC derived from corncob with expansion pretreatment (AC-1) is 32.5% larger than that without expansion pretreatment (AC-2). Furthermore, to probe the potential application of corncob-based ACs in electric double-layer capacitor (EDLC), the prepared ACs were used as electrode materials to assemble EDLC, and its electrochemical performance was investi- gated. The results indicate that the specific capacitance of AC-1 is 276 F/g at 50 mA/g, which increases by 27% com- pared with that of AC-2 (217 F/g). As electrode materials, AC-1 presents a better electrochemical performance than AC-2, including a higher voltage maintenance ratio and a lower leakage current.     

离子选择性电极测定牙膏中的总氟含量

使用氟离子选择性电极测定含单氟磷酸钠型牙膏中总氟含量的分析测定方法,探讨了TI-SAB溶液作为金属离子掩蔽剂和OH-离子的pH调节剂对氟离子选择电极测定牙膏氟含量的影响.研究结果表明加入少量HCl酸化试液,控制TISAB的用量在2～3 mL,调节溶液的pH值为7时,测定氟的回收率为98.95%～102.42%,RSD<2.0%.该分析方法的准确度、重现性、线形关系、稳定性均能达到科研和生产的要求,操作简便,此方法能作为单氟磷酸钠型牙膏中氟离子含量测定的有效方法.     

基于RBF神经网络的ZGMn13堆焊焊条的设计

提出了一种基于RBF神经网络的CaO—CaF2-SiO2渣系ZGMn13堆焊焊条配方优化设计方法．利用实验采集的数据对网络进行训练,以加工硬化后的硬度为优化目标,得到最优的焊条配方．实验结果表明：优化后熔敷金属的动载加工硬化性能和静载加工硬化性能良好。     

有限混合非线性结构方程模型的参数估计

针对数据不同质现象的广泛存在,将非线性结构方程模型推广到有限混合非线性结构方程模型,用EM算法进行估计,E步引入Gibbs抽样及MH算法,M则采用条件极大的方法。最后,对收敛条件及误差进行估计。     

蘑菇组织膜—二茂铁修饰的L-酪氨酸传感器

本文采用二茂铁作为电子传递介体,利用蘑菇组织含有丰富的酪氨酸酶,将蘑菇组织肉浆固定在二茂铁(PVC膜)修饰石墨电极上,用电流法测定L-酪氨酸浓度.研究了电极的制备和最佳实验条件,其线性响应范围为2.0×10-4～4.5×10-3 mol.L-1,响应时间小于5 min,电极寿命至少30?d,可用于实际样品分析.,A new approach for assembling amperometric mushroom pulp tissue-based membrane electrode for determination of L-tyrosine analysis is proposed. Ferrocene is used as a mediator of electron transfer between tyrosinase in mushroom tissue and a graphite electrode. The optimal operation conditions are studied. The linear response range of the biosensor is 2.0×10-4to 4.5×10-3mol.L-1 with response time of less than 5 min and lifetime of at least 30 d. The biosensor can be applied to practical sample analysis.     

环境温度对RE(NiCoMnAl)_5贮氢合金电化学性能的影响

对LaxCe0 .9-x(PrNd) 0 .1 (Ni3 .5 5 Co0 .75 Mn0 .4Al0 .3)合金 (x =0 .4～ 0 .9)在不同温度下( 2 98K～ 333K)的电化学性能进行了系统的研究 .结果表明 ,随着温度由 2 98K升高到 333K ,合金的活化性能得到改善 ;合金的最大放电容量增大 ,并在 313K时达到最大值 (平均提高了 2 2 .9mAh/g) ,而当温度提高到 3 33K时 ,各合金的最大放电容量又大幅度下降 (平均降低了 83 .9mAh/g) ;随着温度的升高 ,合金的高倍率放电性能得到改善 ,但合金的循环稳定性明显降低 (在 1C充放电电流下经2 2 0次充放电循环后的容量保持率平均降低了 4 0 %以上 ) .     

不同Pan含量的Pan/Ben纳米复合材料的合成与表征

钠型膨润土 (Na/Ben)与盐酸苯胺进行离子交换后洗不同次数 ,可制得不同苯胺含量的苯胺膨润土(An/Ben) ;将其氧化可制得不同聚苯胺含量的聚苯胺膨润土 (Pan/Ben) ,并用XRD、循环伏安、交流阻抗技术进行检测     

自由能与电极电势初探

本讨论了自由能与不同类型的电对的电极电势的关系。     

岩石及粉尘中游离二氧化硅的测定

采用焦磷酸分离岩石及粉尘中的游离二氧化硅,再用氢氟酸-饱和氯化钾将分离出来的游离二氧化硅溶解,使硅形成K2SiF6沉淀.然后水解,应用氟离子选择性电极间接测定游离二氧化硅的含量,方法简便、准确、快速.