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991.
1引言小波分析是近年来迅速发展起来的一门新兴学科,小波分析最显著的特征是频域和时域具有良好局部化特性,可以观察函数的任意细节,被誉为数学的显微镜.它不仅理论深刻,且理论与应用的发展交织在一起,它成功地应用于信噪分离、图像编码、图像的边缘检测、数据压缩、计算机视觉中的多分辨率分析等领域. 相似文献
992.
The controllable achievement of C—C and C—P bond formations is developed via visible-light-promoted bromoalkyne dimerization or its further transformation with ... 相似文献
993.
Shiqi You Mengyao Ruan Cuifen Lu Li Liu Yue Weng Guichun Yang Shengchun Wang Hesham Alhumade Aiwen Lei Meng Gao 《Chemical science》2022,13(8):2310
A paired electrolysis enabled cascade annulation that enables the efficient synthesis of highly functionalized quinoline-substituted bioactive molecules from readily available starting materials is reported. Using this methodology, two goals, namely, the direct synthesis of quinolines and the introduction of quinoline moieties to bioactive molecules, can be simultaneously achieved in one simple operation. The use of electroreduction for the activation of isatin, together with the further anodic oxidation of KI to catalytically result in a cascade annulation, highlight the unique possibilities associated with electrochemical activation methods. This transformation can tolerate a wide range of functional groups and can also be used as a functionalization tactic in pharmaceutical research as well as other areas.A paired electrolysis enabled cascade annulation that enables the efficient synthesis of highly functionalized quinoline-substituted bioactive molecules from readily available starting materials is reported. 相似文献
994.
不同碳源对LiFePO4/C复合正极材料性能的影响 总被引:6,自引:1,他引:6
采用固相反应法在惰性气氛下合成了橄榄石型LiFePO4/C复合正极材料. 采用XRD, SEM和激光粒度分布(LSD)以及电化学测试等手段对目标材料进行了结构表征和性能测试. 考察了葡萄糖、乙炔黑以及石墨等不同碳源对目标材料性能的影响. 结果表明, 以葡萄糖作为碳源的正极材料具有优良的电化学性能, 首次放电比容量达142.5 mAh/g, 循环30次后, 容量衰减只有2.5%. 分析了不同碳源对目标材料性能影响的原因. 相似文献
995.
A kind of ruthenium oxide with smaller particles and higher porosity was prepared by a sol-gel process with RuCl3·xH2O and NaHCO3 solution. Several details concerning this new material, including crystal structure,particle size as functions of the temperature, and electrochemical properties were also reported. The optimal annealing temperature was 210 ℃ and the powder annealed at this temperature had a rate capacitance of 541 F/g. In addition, the rate capacitance of the composite electrode reached 802 F/g after 10% carbon black was added, much higher than any previously reported value. High energy density supercapacitors were built with the newly discovered electrode material. Energy densities as high as 67 J/g were obtained based on the RuO2 ·xH2O alone. By introducing the highly porous carbon black into the electrode, energy densities great than 100 J/g could be achieved. The power density of the capacitor was enhanced significantly. 相似文献
996.
Adsorption of fluoride from water by amorphous alumina supported on carbon nanotubes 总被引:25,自引:0,他引:25
Yan-Hui Li Shuguang Wang Anyuan Cao Dan Zhao Xianfeng Zhang Cailu Xu Zhaokun Luan Dianbo Ruan Ji Liang Dehai Wu Bingqing Wei 《Chemical physics letters》2001,350(5-6):412-416
A new candidate for fluoride adsorption from water, amorphous Al2O3 supported on carbon nanotubes (Al2O3/CNTs), is reported in this Letter. The adsorption isotherms show that the best fluoride adsorption of Al2O3/CNTs occurs at a pH range of 5.0–9.0. The adsorption capacity for Al2O3/CNTs is about 13.5 times higher than that of AC-300 carbon, 4 times higher than that of γ-Al2O3 at equilibrium fluoride concentration of 12 mg/l. The broad range of the pH values and high adsorption capacity of Al2O3/CNTs make it very suitable for potential applications in fluoride removal from water. 相似文献
997.
Li-juan Ruan 《Frontiers of Physics in China》2010,5(2):205-214
The results from data taken during the last several years at the Relativistic Heavy-Ion Collider (RHIC) will be reviewed in
the paper. Several selected topics that further our understanding of constituent quark scaling, jet quenching and color screening
effect of heavy quarkonia in the hot dense medium will be presented. Detector upgrades will further probe the properties of
Quark Gluon Plasma. Future measurements with upgraded detectors will be presented. The discovery perspectives from future
measurements will also be discussed. 相似文献
998.
Hui Fang Pi Zhi Hong Zhong Han Li Ruan Peng Zhang Yong Hui Zhang Ji Zhou Wu 《中国化学快报》2008,19(7):835-836
A new hopane triterpenoid, hopane 22, 29-diol-29-formate (1), has been isolated from the whole herbs of Saxiglossum angustissimum (Cries.) Ching and its structure has been successfully determined on the basis of spectroscopic evidences. 相似文献
999.
提出了第三代同步辐射光源中的低温超导电流扭摆器和室温水冷电流扭摆器的物理设计方案。文中还讨论了电流扭摆器内腔中的磁场的分布特性,测量方法和电流扭摆器的制造技术的可行性。 相似文献
1000.