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111.
112.
We further study the projective synchronization of a new hyperchaotic system. Different from the most existing methods, intermittent control is applied to chaotic synchronization in the present paper. We formulate the intermittent control system that governs the dynamics of the projective synchronization error, then derive the sufficient conditions for the exponential stability of intermittent control system by using Lyapunov stability theory, and finally establish the periodically intermittent controller according to the stability criterion by which the projective synchronization is expected to be achieved. The analytical results are also demonstrated by several numerical simulations. 相似文献
113.
ZnO nanorod arrays with tunable size and field emission properties on an ITO substrate achieved by an electrodeposition method
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In the present work,vertically aligned ZnO nanorod arrays with tunable size are successfully synthesized on nonseeded ITO glass substrates by a simple electrodeposition method.The effect of growth conditions on the phase,morphology,and orientation of the products are studied in detail by X-ray diffraction(XRD),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).It is observed that the as-prepared nanostructures exhibit a preferred orientation along c axis,and the size and density of the ZnO nanorod can be controlled by changing the concentration of ZnCl2.Field emission properties of the as-synthesized samples with different diameters are also studied,and the results show that the nanorod arrays with a smaller diameter and appropriate rod density exhibit better emission properties.The ZnO nanorod arrays show a potential application in field emitters. 相似文献
114.
电沉积法制备铂纳米粒子过程中卤素阴离子对粒子形貌及电催化性质的影响 总被引:2,自引:0,他引:2
在电化学沉积铂纳米粒子的过程中, 通过添加卤素阴离子, 可以显著地改变纳米粒子的形貌. 通过添加氯离子、溴离子和碘离子, 可以在导电基底上分别获得球形、片状及立方结构的铂纳米粒子. 对卤素阴离子影响电沉积铂纳米粒子形貌的原因进行了探讨. 研究了铂纳米粒子的电催化活性, 发现通过添加卤素阴离子制备得到的铂纳米粒子对于甲醇的电化学催化氧化表现出较低的电化学催化活性. 通过电化学氧化法全部或部分除去铂表面吸附的卤素阴离子后, 纳米粒子对甲醇的电化学催化氧化活性显著提高. 相似文献
115.
研究羟基亚乙基二膦酸(HEDPA)镀铜液中三乙醇胺(TEA)对铜还原和氧化过程的影响. 用Hull Cell测试阴极电流密度分布, 通过电位扫描、循环伏安和交流阻抗研究铜沉积的电化学行为, 通过镀液的吸光度测试和固体配合物的红外光谱分析推断配位化合物的形式. 结果表明: TEA的加入能够扩大HEDPA镀铜体系的阴极允许电流密度, 对铜电沉积有阻化作用, 促进铜阳极溶解, 并可抑制氢气的析出|随着溶液中TEA浓度增加, 在玻碳电极上发生的铜还原过程由电化学控制逐渐转变为扩散控制, 可获得结晶细小、表面平整的致密铜镀层. TEA的加入, 主要是在HEDPA镀铜体系中形成CuTEA(OH)2配位化合物, 并吸附在电极表面而影响电化学反应. 相似文献
116.
传统上,RuO2/TiO2复合电极制备是通过在TiO2/Ti基体上多次涂覆含Ru前驱体溶液和随后热分解(TD)来实现的. 为克服上述方法中Ru用量大和利用率低之不足, 本工作主要基于循环伏安法(CV)在TiO2纳米管阵列(TNA)上电沉积RuO2制备RuO2CV/TNA复合电极. SEM、GIXRD和CV结果表明, 电沉积的RuO2为无定型结构, 所制备电极中的Ru用量约为传统的RuO2TD/TNA电极中Ru用量的1/30. 尽管两电极催化CO2还原产物的法拉第效率接近, 但是RuO2CV/TNA电极比RuO2TD/TNA电极展示了更高的还原电流, 较正的初始还原电位和更好的稳定性. 与磷酸盐缓冲溶液中电还原CO2相比,RuO2CV/TNA电极在0.1 mol•L-1 KHCO3中电还原CO2除生成更高法拉第效率的甲酸根和甲烷外,还检测到CO的生成. 相似文献
117.
首次通过高效电化学沉积法在FTO导电玻璃上成功合成三元复合材料CeO2@Ag@CdSe纳米管阵列.在该体系中,银纳米粒子能够在表面等离子体效应下增强光吸收性能,而且能够提供一个内部通道促进光生载流子的转移与分离.CeO2@Ag@CdSe纳米棒阵列在偏压为-0.2 V(vs.Ag/AgCl)时,能够产生较高的光生电流3.92 mA·cm-2,该光生电流密度比双组分系统CeO2@CdSe(0.802 mA·cm-2)高4.9倍.该三元材料在360 nm单色光下的光电转换效率高达72%,且该光电极在连续测试16 min后仍能保持其光稳定性能. 相似文献
118.
《Ultrasonics sonochemistry》2014,21(6):2010-2019
This paper concerns a preliminary study for a new copper recovery process from ionic solvent. The aim of this work is to study the reduction of copper in Deep Eutectic Solvent (choline chloride–ethylene glycol) and to compare the influence of temperature and the ultrasound effects on kinetic parameters. Solutions were prepared by dissolution of chloride copper salt CuCl2 (to obtain Copper in oxidation degree II) or CuCl (to obtain Copper in oxidation degree I) and by leaching metallic copper directly in DES. The spectrophotometry UV–visible analysis of the leached solution showed that the copper soluble form obtained is at oxidation degree I (Copper I). Both cyclic voltammetry and linear voltammetry were performed in the three solutions at three temperatures (25, 50 and 80 °C) and under ultrasonic conditions (F = 20 kHz, PT = 5.8 W) to calculate the mass transfer diffusion coefficient kD and the standard rate coefficient k°. These parameters are used to determine that copper reduction is carried out via a mixed kinetic-diffusion control process. Temperature and ultrasound have the same effect on mass transfer for reduction of CuII/CuI. On the other hand, temperature is more beneficial than ultrasound for mass transfer of CuI/Cu. Standard rate constant improvement due to temperature increase is of the same order as that obtained with ultrasound. But, by combining higher temperature and ultrasound (F = 20 kHz, PT = 5.6 W at 50 °C), reduction limiting current is increased by a factor of 10 compared to initial conditions (T = 25 °C, silent), because ultrasonic stirring is more efficient in lower viscosity fluid. These values can be considered as key-parameters in the design of copper recovery in global processes using ultrasound. 相似文献
119.
120.
Dynamics and intermittent stochastic stabilization of a rumor spreading model with guidance mechanism in heterogeneous network
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Xiaojing Zhong 《中国物理 B》2022,31(4):40205-040205
We propose a novel rumor propagation model with guidance mechanism in heterogeneous complex networks. Firstly, the sharp threshold of rumor propagation, global stability of the information-equilibrium and information-prevailing-equilibrium under R0 <1 and R0> 1 is carried out by Lyapunov method and LaSalle's invariant principle. Next, we design an aperiodically intermittent stochastic stabilization method to suppress the rumor propagation. By using the Itô formula and exponential martingale inequality, the expression of the minimum control intensity is calculated. This method can effectively stabilize the rumor propagation by choosing a suitable perturb intensity and a perturb time ratio, while minimizing the control cost. Finally, numerical examples are given to illustrate the analysis and method of the paper. 相似文献