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51.
将无机盐NH4F加入到MnO2的前驱体溶液中,通过高效、简单的一步水热法制备了具有氧缺陷的F掺杂α-MnO2纳米棒(记为F-MnO2)。氧空位和F掺杂对提高F-MnO2的导电性、促进离子扩散、提高倍率性能起着至关重要的作用。另外,由于F掺杂,形成了F—Mn键,这可以有效地抑制放电产物中Mn3+的Jahn-Teller畸变,从而提高结构的稳定性。得益于这些协同效应,组装的Zn||F-MnO2全电池在0.5 A·g-1下,首圈放电比容量高达274 mAh·g-1,且具有较长的循环寿命和优异的倍率性能。同时,通过循环伏安(CV)和恒流充放电(GCD)曲线证明了F-MnO2的储能机制为H+和Zn2+的共嵌入/脱出过程。 相似文献
52.
ZHONG XiChun TANG PengFei GAO BeiBei MIN JiXiong LIU ZhongWu ZHENG ZhiGang ZENG DeChang YU HongYa QIU WanQi 《中国科学:物理学 力学 天文学(英文版)》2013,(6):1096-1099
The magnetic properties and magnetocaloric effects of amorphous and crystalline Gd55Co35Ni10 ribbons are investigated.A main phase with a Ho 12 Co 7-type monoclinic structure(space group P21/c) and a minor phase with a Ho4Co3-type hexagonal structure(space group P63/m) are obtained for crystalline ribbon after annealing.The amorphous ribbons order ferromagnetically and undergo a second-order transition at 192 K.For crystalline Gd55Co35Ni10 ribbons,two magnetic phase transitions occur at 158 and 214 K,respectively.The peak value of-△SM under a field change of 0-5 T is 6.5 J/kg K at 192 K for amorphous Gd55Co35Ni10 ribbons.A relatively large magnetic entropy change(~5.0 J/kg K) under a field change of 0-5 T for the crystalline Gd55Co35Ni10 ribbons is obtained in the temperature interval range of 154-214 K.The large platform of magnetic entropy change and the negligible thermal/magnetic hysteresis loss mean the crystalline Gd55Co35Ni10 compound can satisfy the requirement of the Ericsson-type refrigerator working in the temperature range from 154K to 214K. 相似文献
53.
ZHOU Xin FANG JianShu LIAO XiangPing ZHU QianQuan LIU ZhiMin TANG Bin 《中国科学:物理学 力学 天文学(英文版)》2013,(9):1664-1669
The effects of different defects on optical properties and plasmon resonances properties of Au nanoshell arrays were investigated by using the finite-difference time-domain(FDTD) theory.It is found that the optical properties of the nanoshell arrays are strongly influenced by different defects.We show that when the hollow Au nanoshell arrays are placed in air,there is a wide photonic band gap(PBG) in the infrared region,but the band gap becomes narrower as we introduced different defects.Based on the distributions of electric field component E z and the total energy distribution of the electric and the magnetic field,we show that there exhibit dipoles field distributions for the plasmon mode at the long-wavelength edge of the band gap,but composite higher order modes are excited at the short-wavelength edge of the band gap.The plasmon resonant modes also can be controlled by introducing defects. 相似文献
54.
LI HaoJun TANG GuiFeng HE Feng WU Bin HU XiaoGong CHEN YanLing 《中国科学:物理学 力学 天文学(英文版)》2013,(8):1591-1597
A new strategy to realize precise absolute positioning for a single-frequency user is presented. In the presented strategy, the receiver clock and ambiguities are removed using the satelliteand epoch-differenced (SDED) algorithm. As a further development of the SDED algorithm, a regional augmentation network is used to generate the SDED atmospheric delays at the user. The weakened mathematic property due to the epoch-differenced operation is improved by adding the generated atmospheric delays and applying the robust estimation. To test the new approach, the 24-h data at 5 Continuous Operation Reference Station (CORS) stations in Shanghai is processed. The results show a more than 96% success rate, defined as the case where three directions achieve the desired positioning accuracy of 10 cm, when the observation is longer than 20 min. The 20-min static results show that the new method can reach an accuracy of 3.42, 4.76 and 9.26 cm in the North, East and Up directions, respectively. An experiment was carried out to assess the kinematic positioning. The results show that the kinematic positioning accuracy is 4.11, 5.31 and 4.05 cm in the north-south, east-west and height directions,respectively. 相似文献
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以二能级原子作为量子位,利用求解相互作用系统约化密度矩阵非对角元的方法,分别研究热库中量子位模型和依赖强度耦合Jaynes-Cummings模型的消相干特性.当外加驱动场消除消相干时,得到两种模型下驱动场必须满足的约束方程.? 相似文献
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