共查询到17条相似文献,搜索用时 125 毫秒
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从锌电极的制备方法和参比电极的使用与维护两方面对原电池电动势测定实验进行了一些改进,提高了实验测量值的精确度,同时也减少了对环境污染。 相似文献
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电池电动势的测定及使用实验是大学<物理化学实验>有关电化学知识的一个重要实验.考虑到电解质溶液的温度及浓度对电池电动势的影响,增加相关的实验内容,即改变电解质溶液的温度和浓度取得相关数据.这样便于学生对不同温度和电解质溶液浓度的条件下得到实验结果进行对比,有利于学生加深和理解有关电化学方面的理论知识,增强感性认识. 相似文献
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在温度700℃,组成0≤Xsn≤0.28的范围内,对固体Cu—Sn合金的α、β相的电池电动势测量研究表明,在固态高温相区,采用一固体电解质构成电池后,通过电动势测量,来获取热力学函数仍是一可靠方法。从锡活度的测定,体系的相对偏摩尔过剩自由能被确定。体系同理想混合行为的偏差可归结为在本质上是合金组份之间的互相作用,主要表现为在合金组成时的变形贡献和电子相互作用两个方面。 相似文献
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电化学是研究化学现象和电现象之间的相互关系以及化学能与电能相互转化规律的学科,是物理化学的重要组成部分,也是物理化学考研科目的必考内容。可逆电池电动势的计算及应用是电化学中非常重要的内容。本文结合物理化学考研真题对可逆电池电动势的计算及应用内容的考研考点进行了总结和深入分析,以期为物理化学的教学提供参考,使学生能更好的理解和掌握此考点。 相似文献
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常规电动势法测定热力学函数存在电动势的温度系数不稳定,仍至无法估计或修正等问题。使用改进型盐桥,在20~50°C温度范围内,对比测定了两支参比电极(氯化银和甘汞电极)组成的原电池的电动势。结果表明,其温度系数为正(2.22×10~(-4)V℃~(-1)),反应的热力学函数变化值Δ_rG_m(298 K)、Δ_rS_m(298 K)和Δ_rH_m(298K)分别为-52.87 k J·mol~(-1)、-67.14 J·K~(-1)·mol~(-1)、-69.98 k J·mol~(-1)。与热力学函数理论值相比,其相对误差分别为3.7%、-2.4%和-2.5%。满足基础物理化学实验教学要求。 相似文献
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本文给出了Co-Mn-Ni-O非晶薄膜样品在200-330K温度范围内的温差电动势率和直流电导率与温度的关系。实验结果表明,温差电动势率在所测温区内为正,且随温度的升高而增大。电导率呈现T~(-1/4)变化规律。这些结果可以用Fermi能级附近的定域态内的变程跳跃电导来解释。 相似文献
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V. F. Proskudin 《Combustion, Explosion, and Shock Waves》2002,38(5):571-576
A method that allows continuous measurement of the electromotive force due to combustion in condensed conducting systems during the whole burning period is proposed and experimentally tested. The method is based on the use of electrodes made of the system's solid combustion products (slag). Key words: condensed systems, solid-:flame burning, electromotive force due to combustion and its components, continuous measurement, oscillographic testing. 相似文献
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Haruyoshi Otobe Mitsuo Akabori Kazuo Minato 《Journal of the American Ceramic Society》2008,91(6):1981-1985
The oxygen potentials of AmO2− x were measured in the x range of 0.01–0.5 and the temperature range of 1000–1333 K by the electromotive force method. The oxygen potentials at 1333 K were −19.83 kJ/mol for x =0.019 and −319.1 kJ/mol for x =0.485, which were higher than those of CeO2− x by approximately 200 kJ/mol for the corresponding x values. From the dependence of the oxygen potentials on x and temperature, a tentative phase diagram of Am–O system was proposed, which suggested the presence of the intermediate phases of Am7 O12 and Am9 O16 in the Am–O system. 相似文献
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V. F. Proskudin 《Combustion, Explosion, and Shock Waves》2006,42(4):430-435
By an example of condensed 3Zr + 2WO3 and Al + Ni systems, it is demonstrated that the electromotive force of solid-flame combustion measured by probing in loose
systems is significantly higher than that in the same systems in a pressed state. An explanation for this phenomenon is offered,
based on the difference in electrical conductivity in different zones of the combustion wave in loose and pressed condensed
systems.
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Translated from Fizika Goreniya i Vzryva, Vol. 42, No. 4, pp. 71–77, July–August, 2006. 相似文献
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全液压内循环二板式注塑机性能特点及锁模精度研究 总被引:1,自引:0,他引:1
全面深入地分析了新型全液压内循环二板式注塑机的性能特点,并对合模机构的锁模性能进行研究.新型二板式注塑机采用内循环式的舍模油缸,省去液压油外部循环过程并简化液压系统结构,节能、节材效果显著.移模和锁模动作分别采用不同油缸,解决了力与速度的关系,锁模特性优异,成型性能稳定性高.机器配备伺服电机驱动定量泵的动力系统,节能降耗,噪音低.合模机构锁模力的测试结果表明:2000 kN试验机台的锁模力符合设计要求;新型内循环二板式注塑机比同规格的肘杆三板机具有更优异的锁模性能,在最大锁模力情况时,前者比后者的锁模力重复精度高出0.33‰,为注射成型精密化提供保证. 相似文献
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分析热电阻温度测量系统的误差来源 ,介绍用Pt60 0热电阻和用 80C196KC单片机组成的高精度温差测量系统的原理和误差修正的方法及其在现场的运行情况 相似文献
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Danilo Marimpietri Irma Airoldi Angelo Corso Faini Fabio Malavasi Fabio Morandi 《International journal of molecular sciences》2021,22(8)
The long-underestimated role of extracellular vesicles in cancer is now reconsidered worldwide by basic and clinical scientists, who recently highlighted novel and crucial activities of these moieties. Extracellular vesicles are now considered as king transporters of specific cargoes, including molecular components of parent cells, thus mediating a wide variety of cellular activities both in normal and neoplastic tissues. Here, we discuss the multifunctional activities and underlying mechanisms of extracellular vesicles in neuroblastoma, the most frequent common extra-cranial tumor in childhood. The ability of extracellular vesicles to cross-talk with different cells in the tumor microenvironment and to modulate an anti-tumor immune response, tumorigenesis, tumor growth, metastasis and drug resistance will be pinpointed in detail. The results obtained on the role of extracellular vesicles may represent a panel of suggestions potentially useful in practice, due to their involvement in the response to chemotherapy, and, moreover, their ability to predict resistance to standard therapies—all issues of clinical relevance. 相似文献