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991.
Co(OH)2 nanoparticles were synthesized using only CoSO4·7H2O and NaOH as reactants without other auxiliary reagents via a simple, low-cost and practical ball-milling technique and investigated as the active electrode materials for supercapacitors. The structure and morphology of the resulting Co(OH)2 samples were examined by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and transmission electron microscopy (TEM). The observations revealed the formation of brucite-like phase of β-Co(OH)2, which had an irregular sphere-like shape with an average size of 50-100 nm. When investigated as electrode materials for supercapacitors, the β-Co(OH)2 exhibited good energy-storage performances in terms of high specific capacitance of 599 F g−1 and excellent capacity retention, suggesting its potential application in the electrode material for supercapacitors. 相似文献
992.
Bifunctional magnetic-optical Fe3O4/ZnO nanocomposites with different molar ratio were successfully synthesized by a facile two-step strategy. Compared with the other methods, it was found to be mild, inexpensive, green, convenient and efficient. Fe3O4 nanocrystal was used as seed for the deposit and growth of ZnO nanoparticle. A series of the characterizations manifested that the combination of Fe3O4 with ZnO nanoparticles was successful. Photocatalytic activity studies confirmed that as-prepared nanocomposites had excellent photodegradating behavior to Methyl Orange (MO) compared to the pure ZnO nanoparticles. The results showed that the degradation percentage of MO was about 93.6% for 1 h when the amount of catalyst was 0.51 g L−1 and initial concentration of MO was 6 × 10−5 mol L−1 in the pH 7 solution. Moreover, the kinetics of photocatalytic degradation reaction could be expressed by the first-order reaction kinetic model. Furthermore, the Fe3O4/ZnO nanocomposites could be also served as convenient recyclable photocatalysts because of their magnetic properties. 相似文献
993.
994.
995.
将微穿孔板吸声结构应用到外加旁支管路的管道声源特性测量方法中,分析和仿真了单层及双层微穿孔板及其后腔结构采用不同参数(板厚、微孔直径、穿孔率、后腔深度等)时改变管道负载声阻抗的作用和影响.研究结果表明:改变板厚、微孔直径、穿孔率、管道横截面积比等参数,可以有效地改变负载声阻;改变后腔深度及微穿孔板与主体管道之间距离,可... 相似文献
996.
Ying Li Gaoyang Zhao Jian Su Erfeng Shen Yang Ren 《Applied Physics A: Materials Science & Processing》2011,104(4):1069-1073
Top electrode (TE) material on the resistive switching behavior of (TE)/CuO/SnO2:F/Si substrate has been studied. We investigated the switching properties of CuO films deposited by sol-gel process. Two
kinds of top electrode (TE) material on the resistive switching behaviors have been studied. The nonpolar and bipolar resistive
switching phenomenon was observed in CuO thin films with different top electrodes. The filamentary mechanism was used to explain
the two kinds of resistive switching behaviors. For the Pt/CuO/ATO device, it showed the nonpolar resistive switching where
conducting path is formed and disappear due to the oxygen vacancy. For the Cu/CuO/ATO device, the resistance reduction is
due to the existing Cu to form conduction Cu-rich pathways. An opposite bias takes the existing Cu back to the Cu electrode
to its high-resistance state. CuO thin films are also observed by XRD, AFM and XPS. 相似文献
997.
In this work we study single balance law ut+∇⋅Φ(u)=f(u) with bounded initial value, and find that there may exist maximal and minimal solutions, if f(u) is not Lipschitz continuous at u=0. We also show that comparison principle is valid for such solutions, and the solutions may blow up or not under certain conditions. It is determined by the strength of source supply, as well as the competition between the source and flux. 相似文献
998.
Yuning Yang Qingzhi Yang Su Zhang 《Journal of Optimization Theory and Applications》2014,163(1):130-147
In this paper, we propose two new multiple-sets split feasibility problem models and new solution methods. The first model is more separable than the original one, which enables us to apply a modified alternating direction method with parallel steps to solve it. Then, to overcome the difficulty of computing projections onto the constraint sets, a special version of this modified method with the strategy of projection onto half-space is given. The second model consists in finding a least Euclidean norm solution of the multiple-sets split feasibility problem, for which we provide another modified alternating direction method. Numerical results presented at the last show the efficiency of our methods. 相似文献
999.
Let $p$ be the smallest prime divisor of the order of a finite group $G$ . We examine the structure of $G$ under the hypothesis that $p$ -subgroups of $G$ of certain orders are complemented in $G$ . In particular, we extend some recent results. 相似文献
1000.
Recent research shows that the class of rotation symmetric Boolean functions is potentially rich in functions of cryptographic significance. In this paper, based on the knowledge of compositions of an integer, we present two new kinds of construction of rotation symmetric Boolean functions having optimal algebraic immunity on either odd variables or even variables. Our new functions are of much better nonlinearity than all the existing theoretical constructions of rotation symmetric Boolean functions with optimal algebraic immunity. Further, the algebraic degree of our rotation symmetric Boolean functions are also high enough. 相似文献