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41.
采用3种不同pH值的去离子水,NH4NO3和H2C2O4溶液对富锂层状正极材料Li[Li0.2Mn0.54Ni0.13Co0.13]O2进行表面化学侵蚀改性,旨在改善其整体电化学性能。ICP结果表明pH值对材料中Li的析出具有显著影响。X射线衍射(XRD)表明表面化学侵蚀对材料的结构有影响。拉曼光谱(Raman spectroscopy)表明材料表面结构发生了变化。H2C2O4溶液侵蚀过的样品的首次效率有了极大提高,但同时中值电压和循环性能显著恶化。NH4NO3溶液侵蚀过的样品的首次效率从63%提高到了85%,1C倍率下的放电比容量从149 mAh·g-1提高到194 mAh·g-1,同时保持了温和的中值电压变化曲线。通过高分辨透射电镜(HRTEM),X射线光电子能谱(XPS)和电化学阻抗谱(EIS)对改性机理进行了研究。 相似文献
42.
We propose a secure quantum protocol for comparing the equality of information with the help of a semi-honest third party (Trent). Our protocol utilizes the triplet W states, and the single-particle measurement. The technique for preparing W state is mature, which ensures the utility of our protocol. The security of our protocol with respect to both outsider attack and participant attack is discussed. Any information about the private information, the comparison result will not be leaked out, even the third party cannot know these information. 相似文献
43.
44.
W. L. J. Hasi X. Y. Guo X. Li X. Z. Geng Z. W. Lu D. Y. Lin W. M. He R. Q. Fan 《Applied physics. B, Lasers and optics》2010,100(3):577-580
A new method based “Split-combined” principle is proposed to improve the load capacity of stimulated Brillouin scattering
(SBS) phase-conjugating mirror (PCM). The incident light is split into two beams by polarizer, which will respectively produce
SBS in the same experimental conditions, and then the generated two beams of Stokes light are combined together so as to improve
the system’s load capacity. The method is verified in Continuum Nd: YAG seed-injected laser system and use FC-72 as the SBS
medium. The results show that this method not only has a simple structure and high efficiency characteristics, but also improves
the system’s power-load capacity and acquires a better quality linearly-polarized beam, which is expected to provide a new
program for the application of SBS phase-conjugating mirror in a high-power system. 相似文献
45.
Naphthalimide derivatives, N-ethyl-4-acetylamino-l ,8-naphthalimide (EAAN) and polymer with N-propyl-4-acetylamino-l,8-naphthalimide (PAAN) side-chain (P-PAAN) were successfully synthesized. Electroluminescent devices of ITO/PVK(120nm)/EAAN(50nm)/Al(150nm) (Ⅰ) and ITO/PVK P-PAAN( 10:1) (50nm)/Al(150nm) (Ⅱ) constructed with EAAN and P-PAAN as the emitting layer were investigated, whereas the single-layer devices of ITO/EAAN or P-PAAN(50nm)/Al(l50nm) (Ⅲ) were not observed to have any e-mission light. The emission results revealed that the exciton recombination formed by positive and negative charge carriers injected from electrodes of devices Ⅰ and Ⅱ was much more balanced than that of devices Ⅲ, which implied that naphthalimide derivatives are a new type of electron-transporting materials with high performance. The electron-transporting properties of naphthalimide derivatives were also elucidated by investigation of the electroluminescent behaviors from both devices of ITO/PPV (80nm)/Al and ITO/P 相似文献
46.
采用基于密度泛函理论的计算方法,研究了苯胺低聚物及盐酸、对甲苯磺酸掺杂苯胺低聚物的几何结构和电子结构.结果表明,质子酸掺杂使苯胺低聚物分子链上醌环中C-C单、双键交替的性质被削弱,同时链间C=N键长明显增大.掺杂位上链间C-N-C键角增大,相邻环间的扭转角减小,分子链的共面性有所改善.与盐酸掺杂对比,对甲苯磺酸掺杂更利于电子从环内向链间转移,理论上可更好地改善聚苯胺材料的导电性能. 相似文献
47.
Yan-Bing He Guo-Wei Ling Zhi-Yuan Tang Quan-Sheng Song Quan-Hong Yang Wu Chen Wei Lv Yan-Jun Su Qiang Xu 《Journal of Solid State Electrochemistry》2010,14(5):751-756
The carbon-coated LiFePO4 materials were synthesized, and their structure and morphology were characterized by X-ray diffraction and transmission electron
microscopy. The safety and heating mechanism of the 066094-type liquid state soft pack high power batteries with carbon-coated
LiFePO4/graphite electrodes under abusive conditions, such as overcharge, overdischarge, and short current were extensively investigated.
It was found that the increase in the temperature of the LiFePO4/graphite high power batteries during overcharge was attributed to the reaction of the electrolyte decomposition and the Joule
heat. The batteries were heated rapidly by the irreversible heat generated from the current passing through the electrodes
during short current. The temperature rise of the batteries which were overdischarged to 0 V was mainly due to the Joule heat.
The overdischarge at 1 C/0 V almost did not influence the cycling performance of the batteries. The batteries did not fire,
smoke, and explode under the above-mentioned abusive conditions. Therefore, the 066094-type liquid state soft film pack high
power batteries with carbon-coated LiFePO4/graphite electrodes showed excellent safety performance. 相似文献
48.
Imino sugars, sometimes called azasugars, are an important class of natural and unnatural compounds that have activity to selectively inhibit glycohydrolases responsible for the cleavage of glycosidic bonds.[1,2] In azasugars, the ring oxygen is replaced by nitrogen, which can be protonated under physiological pH, thus mimicking the glycopyranosyl cation. Because of the potential chemotherapeutic applications of such compounds, lots of chemists have continuing interests in the synthesis of imino sugars, such as deoxynojirimycin (DNJ, 1,5-dideoxy-1,5-imino-D-glucitol) and miglitol derivatives. 相似文献
49.
沸石载体结构对甲烷无氧芳构化性能的影响 总被引:7,自引:1,他引:6
考察了担载MoO3的沸石催化剂上甲烷的无氧芳构化性能,并与沸石结构相关联.结果表明,孔径与苯分子动态直径相当的ZSM-5、ZSM-8、ZSM-11和β沸石等是甲烷无氧芳构化催化剂的良好载体,其中3%MoO3/HZSM-11具有最高的甲烷芳构化活性和稳定性,973K下的转化率和苯选择性分别为8.0%和90.9%;6%MoO3/HZSM-8与7%MoO3/H-β芳构化性能相当.以HMCM-41和HSAPO-34为载体时芳构化活性很低,以HMOR、HX和HY为载体时仅有少量乙烯生成,而以HSAPO-5和HSAPO-11为载体时未检测到烃类生成. 相似文献
50.