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81.
锂离子电池用Li4Ti5O12-碳复合材料的制备与电化学性能 总被引:6,自引:0,他引:6
Li4Ti5O12-C composite was prepared by sol-gel method using ethyl alcohol as solvent, lithium acetate and tetrabutyl titanate as raw materials, and graphite as carbon source. Li4Ti5O12-C composites were characterized by thermogravimertric(TG) analysis and differential thermal analysis(DTA), X-ray diffraction(XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and electrochemical tests. Results show that Li4Ti5O12-C composite with 5% carbon containing can be obtained by annealing the precursor at 600 ℃ for 6 h in N2 atomsphere. The composites can deliver a specific capacity of 167.1 mAh·g-1, 99.0% and 105.1% of the capacity can be retained after discharged for 80 times at 0.1C and 2.0C, respectively. Compared with pure Li4Ti5O12, Li4Ti5O12-C composite shares larger discharge capacity, better cyclability and rate performance. 相似文献
82.
LiNi0.5Mn1.5O4 was prepared by rheological method using CH3COOLi, Ni(CH3COO)2 and Mn(CH3COO)2 as raw materials. XRD and SEM results show that LiNi0.5Mn1.5O4 synthesized at 850 ℃ has cubic spinel structure with clearly defined shape and particle size of 0.2~0.4 μm. Electrochemical tests show that the LiNi0.5Mn1.5O4 presents a plateau near 4.7 V and delivers the maximum discharge capacity of 140.5 mAh·g-1. After 100 cycles, the capacity loss per cycle was only 0.015% discharged at 0.2C and the capacity retention was more than 76.3% discharged at 2.0C at room temperature and the capacity loss per cycle was only 0.32% discharged at 0.2C at 55 ℃. 相似文献
83.
Yue Dou Li Guo-Yin Ma Xin-Ru Fu Wen-Ping Zou Ying-Pei Qin Ling Zhang Ming-Dao 《Crystallography Reports》2021,66(7):1262-1267
Crystallography Reports - Two isostructural Co/Ni(II)-based coordination polymers, namely, {[Co1/2(bpba)(H2O)]?2H2O}n (1) and {[Ni1/2(bpba)(H2O)]?2H2O}n (2), where Hbpba = 3,5-bis... 相似文献
84.
85.
Xun-Ru Yin Wen-Ping Ma Wei-Yan Liu 《International Journal of Theoretical Physics》2013,52(11):3915-3921
A three-party quantum key agreement protocol with two-qubit entangled states is proposed. In this paper, the three parties are entirely peer entities and each party has a equal contribution to the establishment of the shared secret key. Moreover, any subset of the three participants except the universal set can not determine the shared key alone. Finally, the security analysis shows that the present protocol can resist against both the outsider attack and the insider attack. 相似文献
86.
对于一个稳定的动力系统而言,系统变量的概率密度具有较为稳定的分布型,而当系统的动力学结构发生变化后可能会导致系统变量的分布型发生不同程度的变化.鉴于此,本文从识别系统变量的概率密度分布的微小变化角度出发,将描述时间序列概率分布特征的偏度系数和峰度系数应用于时间序列的突变检测中.数值试验结果表明,偏度系数和峰度系数对突变信号具有很好的识别能力,进而揭示了一条检测突变的新途径.进一步的研究表明,新方法的检测结果对于子序列长度的选择具有较小的依赖性. 相似文献
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88.
Peng WP Johnson GE Fortmeyer IC Wang P Hadjar O Cooks RG Laskin J 《Physical chemistry chemical physics : PCCP》2011,13(1):267-275
Soft landing (SL) of mass-selected ions is used to transfer catalytically-active metal complexes complete with organic ligands from the gas phase onto an inert surface. This is part of an effort to prepare materials with defined active sites and thus achieve molecular design of surfaces in a highly controlled way. Solution-phase electrochemical studies have shown that V(IV)O(salen) reacts in the presence of acid to form V(V)O(salen)(+) and the deoxygenated V(III)(salen)(+) complex-a key intermediate in the four electron reduction of O(2) by vanadium-salen. In this work, the V(V)O(salen)(+) and [Ni(II)(salen) + H](+) complexes were generated by electrospray ionization and mass-selected before being deposited onto an inert fluorinated self-assembled monolayer (FSAM) surface on gold. A time dependence study after ion deposition showed loss of O from V(V)O(salen)(+) forming V(III)(salen)(+) over a four-day period, indicating a slow interfacial reduction process. Similar results were obtained when other protonated molecules were co-deposited with V(V)O(salen)(+) on the FSAM surface. In all these experiments oxidation of the V(III)(salen)(+) product occurred upon exposure to oxygen or to air. The cyclic regeneration of V(V)O(salen)(+) upon exposure to molecular oxygen and its subsequent reduction to V(III)(salen)(+) in vacuum completes the catalytic cycle of O(2) reduction by the immobilized vanadium-salen species. Moreover, our results represent the first evidence of formation of reactive organometallic complexes on substrates in the absence of solvent. Remarkably, deoxygenation of the oxo-vanadium complex, previously observed only in highly acidic non-aqueous solvents, occurs on the surface in the UHV environment using an acid which is deposited into the inert monolayer. This acid can be a protonated metal complex, e.g. [Ni(II)(salen) + H](+), or an organic acid such as protonated diaminododecane. 相似文献
89.
Xiaoyu Zhou Zhiqiang Zhu Caiqiao Xiong Rui Chen Wenjun Xu Haoxue Qiao Wen-Ping Peng Zongxiu Nie Yi Chen 《Journal of the American Society for Mass Spectrometry》2010,21(9):1588-1595
In this article, the Poincare-Lighthill-Kuo (PLK) method is used to derive an analytical expression on the stability boundary
and the ion trajectory. A multipole superposition model mainly including octopole component is adopted to represent the inhomogeneities
of the field. In this method, both the motional displacement and secular frequency of ions have been expanded to asymptotic
series by the scale of nonlinear term ε, which represents a weak octopole field. By solving the zero and first-order approximate
equations, it is found that a frequency shift exists between the ideal and nonlinear conditions. The motional frequency of
ions in nonlinear ion trap depends on not only Mathieu parameters, a and q, but also the percentage of the nonlinear field and the initial amplitude of ions. In the same trap, ions have the same mass-to-charge
ratio (m/z) but they have different initial amplitudes or velocities. Consequently, they will be ejected at different time through after
a mass-selective instability scan. The influences on the mass resolution in quadrupole ion trap, which is coupled with positive
or negative octopole fields, have been discussed respectively. 相似文献
90.
利用胆汁酸在氧化型辅酶I(NAD+)共存下被3α-类固醇脱氢酶(3α-HSD)催化脱氢,同时NAD+被还原为还原型辅酶I(NADH)可增强三联吡啶钌(Ru(bpy)32+)的电化学发光(ECL)信号,实现电化学发光法间接检测胆汁酸。检测池中含2.5mmol/LRu(bpy)23+,833U/L3α-HSD,70nmol/LNAD+,50mmol/L磷酸盐缓冲液(pH8.0)。ECL强度与胆汁酸的浓度在1.0~100fmol/L范围内呈良好的线性关系,线性方程y=0.7707x+12.04(r=0.9975);检出限为0.02fmol/L;平均回收率为97.5%。本方法与临床采用的酶循环放大法有较好的相关性。 相似文献