共查询到20条相似文献，搜索用时 343 毫秒
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《邢台职业技术学院学报》2019,(3):86-91
锂离子电池被广泛用于电动汽车来代替传统能源,其性能优劣直接关系到整车的性能,而温度是影响锂离子电池性能的主要因素,如果锂电池长时间处于高温下工作,电池性能会迅速衰减,甚至会引发热失控,因此研究锂离子电池的散热方法尤为重要。首先,从锂离子电池的充电机理和熔化过程分析了温度过高对于锂电池的性能影响;总结了空气冷却、液体冷却、相变材料冷却、热管冷却等4种常见锂电池散热方法的原理、特点和应用;最后,分别从不同方面归纳了4种不同散热方法的特点。 相似文献
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《赣南师范学院学报》2017,(6):61-67
正极材料的能量密度是制约锂离子电池体系的瓶颈,锂电池的综合性能的提升很大程度上取决于正极材料的特性.当前锂离子电池正极材料主要为基于层状结构、尖晶石结构以及聚阴离子结构无机材料.本文概述了无机正极材料的性能特点以及最新研究进展. 相似文献
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周少鹏 《阅读与作文(高中版)》2017,(23)
锂电池主要材料包括正极材料、负极材料、电解液和隔膜,其中隔膜被公认为最具技术含量的环节.隔膜的成本约占锂离子电池成本的20％,毛利率可以达到50％-60％,是四大材料中盈利能力最高的产品.目前锂离子电池倍广泛运用于3C电子产品,新能源汽车、储能电站等领域. 相似文献
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曾经有人说:"世界锂电池的研究开发就像攀登珠穆朗玛峰,日本已站到了8000米的高度,美国站到了7000米,欧渊站到6000米,而中国仅仅站到5000米。果真如此吗?北大其鲁教授深谙锂离子二次电池正极材料研发的战略意义,通过不懈的努力,终于研究开发出具有我国自主知识产权的锂离子二次电池,并使其在锂电池高科技产业领域跻身世界前列。 相似文献
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2019年的诺贝尔化学奖颁给了约翰·古迪纳夫、斯坦利·惠廷厄姆和吉野彰,以表彰这三位科学家在锂离子电池领域做出的卓越贡献。“他们创造了一个可充电的世界。”瑞典皇家科学院这样评价道。我们时刻能感受到锂电池对人类的重要意义——如今的电子产品都离不开锂电池:智能手机、笔记本电脑、扫地机器人、充电宝……它们都需要锂电池;锂电池已经成为小型电子设备、电动汽车和固定式储能系统的普遍电源。 相似文献
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综述了锂离子二次电池负极材料和电介质的研究现状 ,对现行研究和应用的二次锂电池负极材料、电解质中存在的问题进行了深入分析并对材料的分类、特点和发展方向进行了研究 相似文献
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《实验室研究与探索》2020,(7):41-44
针对锂离子电池组后备电源的均衡充电特性,选取易于采集的电池工作电压作为电池组均衡控制参数,据此设计制作了锂离子电池组均衡控制电路。设定3.4、3.5、3.6 V的3个不同均衡阈值电压分别对4只3.2 V 20 Ah磷酸铁锂电池组成的电池组进行0.1 C、0.25 C和0.5 C倍率的充电均衡测试,并记录每组电池的充电电流、电压和内阻。通过分析对比发现,同倍率的充电均衡阈值电压越大,均衡能耗越低,均衡速度越快。因此,重要场合的锂离子电池组后备电源系统宜采用大电流大阈值均衡控制方法,迅速有效地将电池组充满电,确保后备电源给设备提供稳定的电能。 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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GUO Bao-feng Xiao Da-wei 《重庆大学学报(英文版)》2005,4(3):129-133
Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator＇s Garden. Translating building data to the Virtual Reality Modeling Language （VRML） is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-ofdetail switching. 相似文献