共查询到20条相似文献,搜索用时 578 毫秒
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化学微型实验,顾名思义:“实验药品微量化,实验仪器微型化”。根据微型实验的特点和要求,可以将一些普通的化学实验改造为微型实验,运用微型化的仪器进行化学实验。一方面,降低了实验成本,减少了环境的污染,体现了绿色经济的理念。另一方面,提高了学习者学习化学实验的兴趣,促进了新的教学模式的发展,体现了科学创新的理念。 相似文献
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典型有机化学实验的绿色化研究 总被引:4,自引:0,他引:4
将绿色合成新技术应用于有机化学实验教学,通过对烯烃溴化实验、己二酸合成实验、肉桂酸合成实验的绿色化改进,减少或消除了实验产生的污染,提高了反应产率,缩短了实验时间,实现了实验流程的绿色化。因此,逐步推广绿色有机化学实验,是化学实验教学改革的重点,也是解决环境污染的重要手段。 相似文献
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对《化学卷发液原料巯基乙酸铵的制备》进行了三方面的改进。第一,物料的用量和配比;第二,碳酸钠用量的量化和加料方式的改进;第三,实验的第四步和第五步合并,简化了实验操作。改进后的实验降低了学生实验成本,缩短了实验时间,减轻了环境污染。改进后的学生实验现象明显,实验效果良好。 相似文献
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基础化学实验开放式教学模式的研究与探索 总被引:1,自引:0,他引:1
本文对基础化学实验课程的教学模式做了研究与改革探索,在实验课程教学中实施了开放式教学法即:实验时间开放、实验项目开放、实验仪器药品开放,经过多年的教学实践证明,开放式实验教学方式,可以极大地促进学生实验课程教学的积极性和主动性,可以激发学生的实验兴趣,培养和锻炼学生的创新能力与综合能力,极大地提高了实验课程的教学质量。 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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Yu. G. Morozov O. V. Belousova M. V. Kuznetsov 《International Journal of Self-Propagating High-Temperature Synthesis》2011,20(3):208-210
We suggest two approaches to collecting the electromotive force (E
c) generated by SHS reactions such as the use of mechanical systems with a movable voltage-collecting electrode and the so-called
battery assembly. The use of the battery system comprising of two reactive systems generating voltage of opposite polarity
afforded to increase E
c up to 2.3 V. 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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建立全钒液流电池六参数开路电压计算模型,揭示开路电压由电池总电势和VO2+/VO2+电极电势决定,并与电解液中钒离子透膜扩散行为密切相关。模型计算得到开路电压存在两个电压平台和一个转折点,与实验结果较为一致。利用该模型计算了电池开路时电解液中4种钒离子浓度随时间的变化关系,指出电池电解液不均衡性是由不同价态钒离子在膜相的Donnan平衡和透膜扩散系数不同产生的。该模型可为优化电池操作提供理论指导,并可为电池长期运行时电解液管理提供工程指导。 相似文献
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在水样中加入总离子强度调节缓冲溶液,由离子选择电极法测定标准溶液剂水样的电动势,由标准溶液的标准曲线求得水样的氟离子含量。 相似文献
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磷酸铁锂动力电池性能研究 总被引:1,自引:0,他引:1
采用导电性能优异的纳米碳管替代部分导电碳用以制作磷酸铁锂正极片,磷酸铁锂电池的充放电性能得到极大改善,电池内阻由未掺纳米碳管的7.5±0.5Ω降为1.7±0.3Ω,电池1 C电流下充放循环700次,容量未见衰减,维持在10 Ah。-20℃下放电容量为25℃时容量的57.35%。与1C下的放电容量相比,5 C下的放电容量未见减小。电池的优异电化学性能主要归功于整个电池电导性能的改进。 相似文献
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Cai Zhijiang 《Journal of Polymer Research》2006,13(3):207-211
This study is intended to develop a polyindole-based polymer battery system which has a high electromotive force together
with a high cycle property and is capable of fast charging and discharging. The battery includes poly(5-nitroindole) as the
anode active material and polyaniline as the cathode active material. Sulfuric acid (40%) was used as the electrolytic solution
with about 1.3-V electromotive force. The battery achieves about 79–65 mA h/g at charge and discharge current densities of
10–103 A/m2. As the theoretical capacity of poly(5-nitroindole) is 84 mA h/g, its capacity occurrence rate is 94% at a charge and discharge
current density of 10 A/m2 with a very high reaction rate. In addition, the discharge capacity at a charge and discharge current density of 103 A/m2 maintains 82% of the capacity relative to that at 10 A/m2. This indicates that this battery has excellent fast charge and discharge properties. The cycle life of the battery, which
is measured at a current density of 103 A/m2 with a discharge depth of 60% at 25°C, is about 32,000. This shows the battery system has an excellent cycle property. Moreover,
the discarded battery will do little harm to the environment because it is free of heavy metals. In summary, this polyindole-based
polymer battery system would be promising in future applications such as a hybrid electric vehicle with the development of
the battery system. 相似文献
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The electrode kinetics of dissolution of a smooth Pb electrode and a battery plate in 5 M H2SO4 have been measured using a new automated measurement system. The Pb dissolution reaction and H2 evolution reaction can be separated using equivalent circuit and a least squares fitting procedure of theory to experiment. 相似文献