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91.
Among the various Ni‐based layered oxide systems in the form of LiNi1‐y‐zCoyAlzO2 (NCA), the compostions between y = 0.1–0.15, z = 0.05 are the most successful and commercialized cathodes used in electric vehicles (EVs) and hybrid electric vehicles (HEVs). However, tremendous research effort has been dedicted to searching for better composition in NCA systems to overcome the limitations of these cathodes, particularly those that arise when they are used use at high discharge/charge rates (>5C) and in high temperature (60 °C) environments. In addition, improving the thermal stability at 4.5 V is also very important in terms of the total amount of heat generated and the onset temperature. Here, a new NCA composition in the form of LiNi0.81Co0.1Al0.09O2 (y = 0.1, z = 0.09) is reported for the first time. Compared to the LiNi0.85Co0.1Al0.05O2 cathode, LiNi0.81Co0.1Al0.09O2 exhibits an excellent rate capability of 155 mAh g?1 at 10 C with a cut‐off voltage range between 3 and 4.5 V, corresponding to 562 Wh kg?1 at 24 °C. It additionally provides significantly improved thermal stability and electrochemical performance at the high temperature of 60 °C, with a discharge capacity of 122 mAh g?1 after 200 cycles with capacity retention of 59%. 相似文献
92.
Systematic study of photoluminescence,lyoluminescence and mechanoluminescence in Ce3+‐ and Eu3+‐activated Li3PO4 phosphors
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Li3PO4 phosphor was prepared using a modified solid‐state diffusion technique. In this work, photoluminescence, lyoluminescence and mechanoluminescence studies were carried out in a Li3PO4 microcrystalline powder doped with different rare earths. In photoluminescence studies, characteristic emission of Ce and Eu was observed. The lyoluminescence glow curves of Li3PO4 microcrystals show that lyoluminescence intensity initially increases with time and then decreases exponentially. The decay time consists of two components for all masses. The dependence of decay time, especially the longer component, on mass has been investigated. Experiments on γ‐irradiated crystals have proved that the light emission originates from the recombination of released F‐centres with trapped holes (V2‐centres) at the sulfuric acid–solid interface. Incorporation of bivalent alkali in solid lithium phosphate leads to an enhancement of lyoluminescence. A possible explanation for the experimental results has been attempted. The phosphor has a mechanoluminescence single glow peak. Mechanoluminescence intensity under various loading conditions was investigated. It is observed that mechanoluminescence intensity increases with increasing impurity concentration and increasing piston impact velocity. The results may be considered as only being of academic interest in solid‐state materials. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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三尖杉酯碱和高三尖杉酯碱的生物活性及临床应用 总被引:1,自引:0,他引:1
概述了从粗榧料植物中分离的抗肿瘤生物碱三尖杉酯碱和高三尖杉酯碱和高三尖杉酯碱等的生物活性,包括其实验及临床药理、临床毒性、分子药理机制,化学研究和未来市场的研究展望。 相似文献
96.
山姜属中药草豆蔻和益智nrDNA ITS区序列的测定 总被引:5,自引:0,他引:5
中药草豆蔻、益智的原植物分别为山姜属草豆蔻(Alpinia hainanensis K.Schum.)与益智(A.oxyphyla Miq.)。本文采用PCR直接测序法,首次测定了它们的核糖体DNA ITS区序列。结果显示,两者序列长度(ITS1+ITS2)分别为403bp与404bp,序列间具有27个变异位点(包括5.8S编码区)。本研究为山姜属中药材的DNA分子鉴定提供了必要的序列资料。 相似文献
97.
Using RAPD technique, the DNA diversity of Cephalotaxus mannii Hook. f., its genetic diversity pattern,the reasons for its endangered position and conservative approaches were studied. The results show that: 1. The genetic diversity of C. mannii collected from five localities in Hainan is low, and its adaptability to environmental change is weak. 2. The differences of genetic diversity between intra and inter populations are great, and the major variation distributes within the population (DNA diversity is 85.1%). 3. The excessive lumbering, man made destruction, violent typhoon, edible value of the seeds and genetic drift were the main reasons for the low level genetic diversity of C. mannii and its endangered position. 4. The difference of the micro environment and other random factors affecting the population should also be taken into full consideration in the study and in protection of such occasionally scattered plants. 5. Enforced measures should be taken to protect the present population, enlarge the population and lower the loss rate of its gene. Mt. Limulin should be chosen as a conservative spot because of its high genetic diversity and less destruction of the forest. Meanwhile, the protection of other populations should be enforced. 6. The differences within and between the populations are great based on different primers used. The change of proportions in polymorphic loci between the populations is more than that between the primers. 相似文献
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99.
Examination of the type specimens of Amaranthus taishanensis F. Z. Li et C. K. Ni shows that it is actually conspecific with A. polygonoides L., a North American species. 相似文献
100.
A new species of Gesneriaceae, Hemiboea rubribracteata Z. Y. Li & Yan Liu, is described from Guangxi, China. The new species is similar to H. cavaleriei Lévl. in its leaf form, but differs by its robust and rigid stem, red involucre, longer calyx lobes, corolla white and glabrous outside, lower lip of corolla 3-lobed to middle.
Key words Hemiboea, Hemiboea rubribracteata Z. Y. Li & Yan Liu, Gesneriaceae, new species, Guangxi, China. 相似文献