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1.
锂离子电池正极材料二巯基噻二唑的研究进展 总被引:3,自引:0,他引:3
二巯基噻二唑(DMcT)作为锂离子电池正极材料,具有容量高、寿命长、制备简便等优点,但它在室温下的反应速度较慢.介绍DMcT在锂离子电池中的充放电机理及利用聚苯胺、聚吡咯、聚3,4-乙撑二氧噻吩、聚邻甲基苯胺、聚N-甲基化苯胺、聚3-烷基酯-4-甲基吡咯、聚3-丁基酯-4-甲基吡咯、聚二巯基噻二唑、金属离子以及金属纳米粉等电催化剂对DMcT进行改性的研究进展,以及电催化剂对DMcT电化学性能的影响.通过这些改性,DMcT的放电容量、正极电流、循环寿命都得到了改善. 相似文献
2.
Multi-function multi-phase static overcurrent relays, using digital technology available today, provide basic time, (51) (51G) (51N) and instantaneous (50) (50G) (50N) three phase and ground overcurrent protection, and may offer some or all of the following additional functions: undervoltage (27); overvoltage (59); reverse phase sequence (47); negative phase sequence voltage (47N); directional overcurrent (67) (67N); frequency (81O/U); reverse interlocking trip coil monitoring; and battery monitoring. This article describes two applications that use some of the additional functions in such a relay: reverse interlocking, also using the directional overcurrent (67) function; and ground fault detection for systems utilizing high resistance grounding. The first application was installed on a 4160 volt power system which was supplied by two 5000 kVA transformers 相似文献
3.
《Electrical Insulation Magazine, IEEE》2010,26(1):50-53
Books reviewed: Physics of Solar Cells, 2nd Edition (Wurfel, P.; 2009), Essentials of RF and Microwave Grounding (Holtzman, E.; 2006), Polymer Tribology (Sinha, S. K. and Briscoe,B. J.; 2009), PVC Degradation and Stabilization (Wypych, G.; 2008), Advanced Batteries (Huggins, R. A.; 2009), The Lineman's and Cableman's Field Manual, 2nd Edition (Shoemaker, T. M. and Mack, J. E.; 2009), Lead Your Boss (Baldoni, J.; 2009), Industrial Power Systems (Khan, S.; 2008) 相似文献
4.
LiNi0.78Co0.2Pr0.02O2的制备及性能研究 总被引:2,自引:2,他引:0
采用溶胶-凝胶法制备了锂离子电池正极材料LiNi0.8Co0.2O2及LiNi0.78Co0.2Pr0.02O2。用XRD、充放电测试、交流阻抗和DSC等研究了Pr的掺入对LiNi0.8Co0.2O2结构、电化学性能及热稳定性能的影响。结果表明:Pr的掺入可以提高Li-Ni0.8Co0.2O2层状结构的规整性,减少材料中阳离子的混排。LiNi0.78Co0.2Pr0.02O2的电化学性能优于LiNi0.8Co0.2O2:虽然首次充电容量稍有降低,但首次充放电效率达到89%,20次循环后的容量保持率为91%。LiNi0.78Co0.2Pr0.02O2循环性能提高的原因是Pr的掺入抑制了循环过程中电荷转移阻抗的增加。LiNi0.8Co0.2O2和LiNi0.78Co0.2Pr0.02O2与电解液反应放出的热量分别为51.95 J/g和18.23 J/g,LiNi0.78Co0.2Pr0.02O2显示出更好的热稳定性能。 相似文献
5.
This paper discusses secondary unit substations transformers (USTs) ranging from 300 up through 2500 kVA with 34.5-kV maximum primary voltages and with secondary voltages 600 V and below. Pad-mounted (compartmentalized) transformers are not considered in this paper. The first part of this paper discusses USTs belonging to two general categories, liquid type and dry type (nonliquid type). Liquid types include a discussion of the presently available insulating fluids: mineral oil, high-temperature hydrocarbon fluid, silicone fluids, and the new vegetable-based fluids. Dry types include a discussion of vacuum pressure impregnated polyester, vacuum pressure encapsulated silicone, partial cast, and full cast insulation systems. The National Electric Code (1999) requirements as they affect both liquid- and dry-type USTs for both outdoor and indoor locations are considered. The paper discusses the relative advantages of each UST within each category with respect to the following: (1) first cost; (2) operating costs (losses); (3) overload capability; (4) fan cooling; (5) space factor; (6) environmental factors; (7) sound levels; and (8) maintenance 相似文献
6.
4,4’-双(4-氨基苯氧基)-3,3’,5,5’-四甲基联苯及其聚酰亚胺的合成与性能研究 总被引:1,自引:0,他引:1
4,4'-二羟基-3,3',5,5'-四甲基联苯(TMBP)、4-氯硝基苯(4CNB)和碳酸钾在N,N-二甲基甲酰胺(DMF)和甲苯的混合溶剂体系中回流反应,合成得到了4,4'-双(4-硝基苯氧基)-3,3',5,5'-四甲基联苯(BNTMBP);随后,在Pd/C-水合肼的还原体系中,被进一步还原,得到了4,4'-双(4-氨基苯氧基)-3,3',5,5'-四甲基联苯(BATMBP).利用差示扫描量热计(DSC)、傅立叶转换红外光谱仪(FT-IR)等仪器,对其进行了表征.另外,将所得到的4,4'-双(4-氨基苯氧基)-3,3',5,5'-四甲基联苯(BATMBP)与均苯四甲酸二酐(PMDA)在强极性非质子有机溶剂中进行聚合反应,得到了粘稠状的聚酰胺酸(BATMBP/PMDA-PAA)溶液,涂膜、热亚胺化,获得了相应的聚酰亚胺(BATMBP/PMDA-PI)薄膜,并对其性能进行了研究. 相似文献
7.
《Electrical Insulation Magazine, IEEE》2007,23(2):47-51
The following books are reviewed in this issue: Electric Motors and Drives, Third Edition (Hughes, A.; 2006); Light Alloys - From Traditional Alloys to Nanocrystals, Fourth Edition (Polmear, I.; 2006); Principles of Electrical Measurements (Tumanski, S.; 2006); Heat Transfer and Fluid Flow in Minichannels and Microchannels (Kanklikar, S.G.; 2006); Creativity for Engineers (Dhillon, B.S.; 2006); Understanding Lightning and Lightning Protection (Horvath, T.; 2006); Industrial Power Engineering and Applications Handbook (Agrawal, K.C.; 2001); and The Wisdom Network (Benton, S. and Giovagnoli, M.; 2006). 相似文献
8.
相依变异是水文过程变异的一种重要表征形式,可以用自回归、滑动平均和自回归滑动平均模型进行描述,但如何有效地确定模型阶数是前提和关键。相关系数准则是针对自回归模型提出的定阶准则,该准则基于相依成分与原序列间的相关系数指标,计算其均方误差以反映模型的拟合优劣,并构造信息熵函数以衡量模型不确定性及复杂程度。本文基于相关系数定阶准则,尝试探讨该准则对于滑动平均和自回归滑动平均模型的适用性。以三阶以内的滑动平均模型和自回归滑动平均模型为例,统计试验表明:相关系数准则所判定阶数相较于其它两种常用的准则更为准确。最后选取实测水文序列对其进行验证,结果表明该定阶准则同样适用于滑动平均和自回归滑动平均模型。 相似文献
9.
挠性覆铜板用环氧胶粘剂的咪唑固化促进剂的优选研究 总被引:1,自引:0,他引:1
分别采用2-乙基-4-甲基咪唑(2E4MZ)、1-氰乙基-2-乙基-4-甲基咪唑(2E4MZ-CN)、2-十一烷基咪唑(C11Z)、1-氰乙基-2-十一烷基咪唑(C11Z-CN)和2-十七烷基咪唑(C17Z)为促进剂,以环氧树脂(EP)/二氨基二苯砜(DDS)/丁腈橡胶(CTBN)为基本体系,制备了挠性覆铜板(FCCL)用胶粘剂。研究了各树脂体系的固化反应性和动态力学性能,并对比研究了FCCL的基本性能,确定该体系最佳促进剂为2E4MZ-CN。 相似文献
10.
LiNi0.75Co0.2Al0.05-xMgxO2的合成及性能研究 总被引:1,自引:1,他引:0
采用溶胶-凝胶法制备了锂离子电池正极材料LiNi0.75Co02Ab0.05-xMgxO2(x=0,0.01,0.025),通过充放电实验、慢扫描循环伏安法和交流阻抗技术进行了电化学性能测试.结果表明:对LiNi1-xCoxO2实施共掺杂Mg2 、Al3 ,可改善其层状结构稳定性和充放电循环特性.将所得LiNi075Co0.2Al0.025Mg0.025O2作为锂离子二次电池正极材料,电池首次放电比容量达170 mAh/g,经100次循环充放电后仍能保持初始容量的78.3%. 相似文献
11.
以市售YF30铁氧体预烧料为基料,采用陶瓷法制备了La-Co掺杂的M型锶铁氧体Sr1-xLaxFe12-xCoxO19(x=0~0.21)。通过X射线衍射和MATEST-2010H永磁(稀土)磁性材料自动测量仪研究La-Co掺杂量对材料结构与磁性能的影响。结果表明,在1210℃烧结时,Sr1-xLaxFe12-xCoxO19(x=0~0.21)均为单一的磁铅石相结构,适量La-Co掺杂明显改善了M型锶铁氧体的内禀磁性能;在1195℃烧结时,Sr1-xLaxFe12-xCoxO19锶铁氧体在x=0.15处获得最佳磁性能:Br=410mT,Hcj=358.0kA/m,(BH)max=32.2kJ/m3。 相似文献
12.
以化学共沉淀法制备出的球形Ni0.5Co0.3Mn0.2CO3前驱体,合成了振实密度高达2.60 g/cm3的球形正极材料LiNi0.5Co0.3Mn0.2O2.研究表明,LiNi0.5Co0.3Mn0.2O2为10 μm左右的球形粉体,为纯相的α-NaFeO2层状结构.在2.7~4.3V,0.2 C倍率进行充放电,LiNi0.5Co0.3Mn0.2O2的首次放电比容量170.2 mAh/g,50次循环后容量保持率为94.3%;在2.7~4.6 V,在0.2 C倍率下放电,首次放电比容量为191.8 mAh/g,循环50次后容量保持率为90.5%.LiNi0.5Co0.3Mn0.2O2的首次循环伏安测试结果和交流阻抗测试结果进一步表明材料具有良好的电化学性能. 相似文献
13.
流变相法制备的Li_(1+x)MnO_(1.92)F_(0.08)的性能 总被引:1,自引:0,他引:1
采用流变相法制备了Li1+xMnO1.92F0.08(x=0、0.05、0.10和0.20).在800 ℃、氮气保护下煅烧8 h制备的产物中,LiMnO1.92F0.08和Li1.05MnO1.92F0.08有完整的正交层状结构,Li1.10MnO1.92F0.08和Li1.20MnO1.92F0.08有Li2MnO3和Li2Mn2O4杂质.以0.2 C放电,Li1.05MnO1.92F0.08的最大放电比容量为157.85 mAh/g,第30次循环的比容量为157.15 mAh/g. 相似文献
14.
在2.0 mol/L HClO_4溶液中通过恒电流阶跃方法制备了电化学改性石墨电极(MGE)。发现其在硫酸溶液中对V(Ⅳ)/V(Ⅴ)和Ti(Ⅲ)/Ti(Ⅳ)氧化还原反应具有良好的催化可逆性,并提出了受电位影响的电极表面含氧官能团电对与金属离子电对间的氧化还原协同作用机理。将V(Ⅳ)/V(Ⅴ)和Ti(Ⅲ)/Ti(Ⅳ)分别作为正、负极活性物质构建成氧化还原液流电池并评价其充放电性能。在10 mA/cm~2下恒流充放电,相应的电压效率为94.2%,能量效率达到91%,展示了基于MGE构建的钒/钛液流电池潜在的应用价值。 相似文献
15.
Using immune genetic algorithm based hybrid techniques for short-term unit commitment problem 总被引:2,自引:0,他引:2
G.-C. Liao 《Electrical Engineering (Archiv fur Elektrotechnik)》2005,87(5):267-279
This paper presents a hybrid chaos search (CS), immune algorithm (IA)/genetic algorithm (GA), and fuzzy system (FS) method (CIGAFS) for solving short-term thermal generating unit commitment (UC) problems. The UC problem involves determining the start-up and shut-down schedules for generating units to meet the forecasted demand at the minimum cost. The commitment schedule must satisfy other constraints such as the generating limits per unit, reserve, and individual units. First, we combined the IA and GA, then we added the CS and the FS approach. This hybrid system was then used to solve the UC problems. Numerical simulations were carried out using three cases: 10, 20, and 30 thermal unit power systems over a 24 h period. The produced schedule was compared with several other methods, such as dynamic programming (DP), Lagrangian relaxation (LR), standard genetic algorithm (SGA), traditional simulated annealing (TSA), and traditional Tabu search (TTS). A comparison with an immune genetic algorithm (IGA) combined with the CS and FS was carried out. The results show that the CS and FS all make substantial contributions to the IGA. The result demonstrated the accuracy of the proposed CIGAFS approach. 相似文献
16.
The growth and electrical properties of Pb(Yb 1/2 Nb 1/2 )O 3 -PbTiO 3 (PYbN-PT) epitaxial films were investigated. PYbN-PT epitaxial films with SrRuO 3 bottom electrodes were grown by pulsed laser deposition. Optimization of the growth conditions for the PYbN-PT epitaxial films was carried out on (100) SrRuO 3 /(100) LaAlO 3 substrates using the (50/50) composition target. It was found that formation of pyrochlore phase could be caused not only by low growth temperatures or lead deficiency, but also by poor surface condition of the SrRuO 3 bottom electrodes. (001) PYbN-PT epitaxial films with good crystalline quality were obtained for a range of deposition rates (60-100 nm/min) and temperatures (620-680 °C) after vacuum annealing the SrRuO 3 bottom electrodes. The ferroelectric and piezoelectric properties of 1 w m-thick PYbN-PT epitaxial films with (50/50) and (60/40) compositions and with (001) and (111) orientations were investigated using (100) LaAlO 3 , (100) SrTiO 3 , and (111) SrTiO 3 substrates with SrRuO 3 bottom electrodes. The highest remanent polarization (29 w C/cm 2 ) and effective piezoelectric coefficient e 31.f ( m 14 C/m 2 ) were observed in the (001) PYbN-PT (50/50) film. The transition temperature of the (001) PYbN-PT (50/50) film was about 380 °C. Because of the degradation of the target during the deposition, a 3 w m-thick film was prepared by three depositions (1 w m each layer). The 3 w m-thick film exhibited a higher e 31.f coefficient of m 19 C/m 2. 相似文献
17.
通过固定床实验系统的烟气脱除零价汞实验,研究了活性炭纤维协同滤袋用聚酰亚胺、芳纶1313、聚苯硫醚、玻璃纤维、芳砜纶以及聚四氟乙烯等常用纤维,对烟气中零价汞的脱除效果。研究了改性前不同性能掺炭纤维,以及用质量分数分别为5%、10%、15%的溴化钾、碘化钾溶液改性后的活性炭纤维(activatedcarbonfiber,ACF)和聚苯硫醚(polyphenylenesulfide,PPS)形成的掺炭纤维,对模拟燃煤烟气中零价汞(Hg0)的吸附性能。结果表明:在汞蒸气入口浓度为30μg/m^3,吸附温度为160℃时,不同性能掺炭纤维脱Hg0率在39%71%范围之间变化,区别较大。经过溴化钾和碘化钾改性后的ACF+PPS掺炭纤维对Hg0的吸附效率分别能达到80%、90%以上,未改性ACF+PPS掺炭纤维的吸附效率最高也只有70%左右;相同质量分数时,碘化钾溶液改性后的ACF+PPS掺炭纤维对Hg0的吸附效果要优于溴化钾溶液改性后的ACF+PPS掺炭纤维,并且碘化钾溶液浓度越大,改性后的ACF+PPS掺炭纤维对Hg0的吸附效果越好,当用质量分数为15%的碘化钾溶液改性后的ACF+PPS掺炭纤维吸附Hg0一定时间后,对Hg0的脱除率可以达到98%以上,因此,经过改性后的掺炭纤维能保持较高的烟气脱Hg0率。 相似文献
18.
以Pt(NH3)4Cl2和Pt(NH3)2(NO2)2为前驱体、采用浸渍法制备了质子交换膜燃料电池用Pt/C催化剂。HRSEM和XRD分析表明,Pt/C-Pt(NH3)2(NO2)2的晶粒细小均匀,Pt/C-Pt(NH3)4Cl2的晶粒则发生团聚。循环伏安和旋转圆盘电极实验表明,Pt/C-Pt(NH3)4Cl2与Pt/C-Pt(NH3)2(NO2)2的晶面分布存在明显的差异,Pt/C-Pt(NH3)2(NO2)2具有更高的氧催化活性,Pt(NH3)2(NO2)2是更适合的前驱体材料。 相似文献
19.
Ho Nyung Lee Dmitri Zakharov Stephan Senz Alain Pignolet Dietrich Hesse 《Integrated ferroelectrics》2013,141(1-4):73-80
Abstract We have successfully grown non-c-axis-oriented epitaxial ferroelectric SrBi2Ta2O9 (SBT) films with (116) and (103) orientations on Si(100) substrates using epitaxial (110)- and (111)-oriented SrRuO3 (SRO) bottom electrodes, respectively. The SRO orientations have been induced by coating the Si(100) substrates with epitaxial YSZ(100) and MgO(111)/ YSZ(100) buffer layers, respectively. All films were sequentially grown by pulsed laser deposition. Specific in-plane orientations of the epitaxial SBT films were found, which are in turn determined by specific in-plane orientations of the epitaxial SRO bottom electrodes. These include a diagonal rectangle-on-cube epitaxy of SRO(110) on YSZ(100) and a triangle-on-triangle epitaxy of SRO(111) on MgO(111). 相似文献
20.
4,4'-双(4-氨基苯氧基)联苯的合成及其聚酰亚胺薄膜的表面性能研究 总被引:2,自引:1,他引:1
4,4'-二羟基基联苯(44DHBP)、4-氯硝基苯(4CNB)和碳酸钾在N,N-二甲基甲酰胺(DMF)和甲苯的混合溶剂体系中回流反应,合成4,4'-双(4-硝基苯氧基)联苯(44B4NPOBP);随后,在Pd/C-水合肼的还原体系中,被进一步还原成4,4'-双(4-氨基苯氧基)联苯(44B4APOBP)。利用差示扫描量热计(DSC)、傅立叶转换红外光谱仪(FT-IR)等仪器,对其进行了表征。另外,将4,4'-双(4-氨基苯氧基)联苯(44B4APOBP)与均苯四甲酸二酐(PMDA)在强极性非质子有机溶剂中进行聚合反应,得到粘稠状的聚酰胺酸(44B4APOBP/PMDA-PAA)溶液,经涂膜、热亚胺化后,制成相应的聚酰亚胺(44B4APOBP/PMDA-PI)薄膜,并对其表面性能进行了研究。 相似文献