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61.
Preparation and electrochemical characterization of activated carbons by chemical-physical activation 总被引:2,自引:0,他引:2
A process was proposed based on the combination of chemical and physical activation for the production of activated carbons
used as the electrode material for electric double layer capacitor (EDLC). By material characterization and electrochemical
methods, the influences of the activitation process on the specific surface area, pore structure and electrochemical properties
of the activated carbons were investigated. The results show that specific surface area, the mesopore volume, and the specific
capacitance increase with the increase of the mass ratio of KOH to char (m(KOH)/m(char)) and the activation time, respectively. When m(KOH)/m(char) is 4.0, the specific surface area and the mesopore volume reach the maximum values, i.e. 1 960 m2/g and 0.308 4 cm3/g, and the specific capacitance is 120.7 F/g synchronously. Compared with the chemical activation, the activated carbons
prepared by chemical-physical activation show a larger mesopore volume, a higher ratio of mesopore and a larger specific capacitance.
Foundation item: Project(2007BAE12B01) supported by the National Key Technology Research and Development Program of China 相似文献
62.
ZHANG Chuan-xiang DUAN Yu-ling XING Bao-lin ZHAN Liang QIAO Wen-ming LING Li-cheng 《中国矿业大学学报(英文版)》2009,19(3):295-299
Nitrogen-containing carbons were prepared by modification of activated carbons. The modified carbons were used as electrode materials with improved electrochemical performance. Precursor anthracite was activated by KOH (KOH: anthracite= 1:1), modified by melamine or urea and then treated at 1173 K to obtain the modified carbons. The porous structure, the chemical composition and the electrochemical characteristics of the carbons were investigated by nitrogen sorption, XPS and electrochemical methods respectively. Electrochemical experiments were performed in an organic electrolytic solution of 1 M (C2H5)4NBF4/PC.The samples modified by the different methods showed differences in chemical composition that introduced varying degrees of electrochemical performance enhancement. The presence of nitrogen enhanced the electron donor properties and the surface wettability of the activated carbons: this ensured a sufficient utilization of the exposed surface for charge storage. 相似文献
63.
Bifurcation analysis for an SMIB power system with series capacitor compensation associated with sub-synchronous resonance 总被引:1,自引:0,他引:1
In this paper,an introduction to the bifurcation theory and its applicability to the study of sub-synchronous resonance (SSR) phenomenon in power system are presented. The continuation and bifurcation analysis software AUTO97 is adopted to investigate SSR for a single-machine-infinite-bus power system with series capacitor compensation. The investigation results show that SSR is the result of unstable limit cycle after bifurcation. When the system exhibits SSR, some complex periodical orbit bifurcations, such as torus bifurcation and periodical fold bifurcation, may happen with the variation of limit cycle. Furthermore, the initial operation condition may greatly influence the ultimate state of the system. The time-domain simulation is carried out to verify the effectiveness of the results obtained from the bifurcation analysis. 相似文献
64.
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66.
地铁再生制动储能装置参数设计 总被引:1,自引:0,他引:1
为了利用地铁列车制动过程产生的再生能量,维持牵引网电压的稳定,设计一种基于列车制动的超级电容型储能装置。根据北京地铁5号线的电动列车实际参数,通过对列车制动动力学和制动特性的对比和分析,更准确地计算出列车制动过程反馈到牵引网的再生能量;分析了储能装置的物理模型,根据限制条件确定了储能装置的主要参数和阵列配置;验证分析表明,该储能装置能满足地铁制动过程中各物理量的要求。 相似文献
67.
After analyzing the working condition of the conventional diesel forklift, an energy recovery system in hybrid forklift is considered and its simulation model is built. Then, the control strategy for the proposed energy recovery system is discussed, which is validated and evaluated by simulation. The simulation results show that the proposed control strategy can achieve balance of the power and keep the state of charge (SOC) of ultra capacitor in a reasonable range, and the fuel consumption can be reduced by about 20.8% compared with the conventional diesel forklift. Finally, the feasibility of the simulation results is experimentally verified based on the lifting energy recovery system. 相似文献
68.
逆变弧焊电源中变压器的偏磁与防护 总被引:1,自引:0,他引:1
分析了全桥式逆变孤焊电源中变压器产生偏磁的原因及危害;阐述了在变压器一次侧串联电容或设置自动纠偏电路等防止偏磁的原理和方法。 相似文献
69.
分析了EAL-120/6型电子束焊机高压电源存在的安全隐患,提出了消除隐患的两种措施:一是不改动油箱电路,从操作规程上加以解决;二是给高压电容加装并联放电电阻支路.给出一种改进实例.经试验证明,第二种消除隐患措施更为有效,停机10 s后,高压电缆间无"火花"出现. 相似文献
70.