We propose a method to estimate the natural frequencies of the multi-walled carbon nanotubes （MWCNTs） embedded in an elastic medium. Each of the nested tubes is treated as an individual bar interacting with the adja...We propose a method to estimate the natural frequencies of the multi-walled carbon nanotubes （MWCNTs） embedded in an elastic medium. Each of the nested tubes is treated as an individual bar interacting with the adjacent nanotubes through the inter-tube Van der Waals forces. The effect of the elastic medium is introduced through an elastic model. The mathematical model is finally reduced to an eigen value problem and the eigen value problem is solved to arrive at the inter-tube resonances of the MWCNTs. Variation of the natural frequencies with different parameters are studied. The estimated results from the present method are compared with the literature and results are observed to be in close agreement.展开更多
The electrochemical performance of CoO-filled multi-walled carbon nanotubes(MWCNTs) is described. MWCNTs were purified, opened and filled with cobalt salt in one-step by wet-chemistry route. Followed by calcinations i...The electrochemical performance of CoO-filled multi-walled carbon nanotubes(MWCNTs) is described. MWCNTs were purified, opened and filled with cobalt salt in one-step by wet-chemistry route. Followed by calcinations in Ar atmosphere, the salt filled in the MWCNTs decomposed to CoO subsequently. Structural characterization of the composite material by X-ray diffraction and transmission electron microscopy showed that MWCNTs were filled by discrete nano-size CoO. Compared to the MWCNTs purified by HNO3, the CoO-filled MWCNTs exhibited higher capacity and better cyclability during galvanastatic charge-discharge cycling and cyclic voltammetry (CV) tests.展开更多
The development of global information technology makes human life intelligent,and the large-scale use of various electronic devices increases the electromagnetic radiation in the surrounding environment.This has creat...The development of global information technology makes human life intelligent,and the large-scale use of various electronic devices increases the electromagnetic radiation in the surrounding environment.This has created a requirement for the development of high-performance electromagnetic wave absorbers to eliminate electromagnetic pollution.However,the preparation of electromagnetic wave absorbers with excellent electromagnetic loss capability remains a great challenge.Here,we present a method to prepare Co/ZnO/C@MWCNTs(CZC@M)composites by pyrolysis of ZnCo-MOF@MWCNTs(MOF@M).Specifically,MWCNTs are uniformly distributed on the CZC surface to form multiple heterogeneous interfaces,which will lead to an increase in polarizability.In addition,changing the amounts of MWCNTs in the composite can modulate its dielectric constant and impedance matching properties.Impressively,at only 10%sample content,the minimum reflection loss of-41.75 d B and the maximum effective absorption bandwidth of 4.72 GHz are obtained at thicknesses of 2.4 mm and 2.2 mm,respectively.Overall,the results reported in this work provide a new design strategy for the synthesis of high-performance electromagnetic wave absorbers with potential applications in the elimination of electromagnetic pollution.展开更多
文摘We propose a method to estimate the natural frequencies of the multi-walled carbon nanotubes （MWCNTs） embedded in an elastic medium. Each of the nested tubes is treated as an individual bar interacting with the adjacent nanotubes through the inter-tube Van der Waals forces. The effect of the elastic medium is introduced through an elastic model. The mathematical model is finally reduced to an eigen value problem and the eigen value problem is solved to arrive at the inter-tube resonances of the MWCNTs. Variation of the natural frequencies with different parameters are studied. The estimated results from the present method are compared with the literature and results are observed to be in close agreement.
文摘The electrochemical performance of CoO-filled multi-walled carbon nanotubes(MWCNTs) is described. MWCNTs were purified, opened and filled with cobalt salt in one-step by wet-chemistry route. Followed by calcinations in Ar atmosphere, the salt filled in the MWCNTs decomposed to CoO subsequently. Structural characterization of the composite material by X-ray diffraction and transmission electron microscopy showed that MWCNTs were filled by discrete nano-size CoO. Compared to the MWCNTs purified by HNO3, the CoO-filled MWCNTs exhibited higher capacity and better cyclability during galvanastatic charge-discharge cycling and cyclic voltammetry (CV) tests.
基金the Natural Science Foundation of Shandong Province(No.ZR2019YQ24)Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites)。
文摘The development of global information technology makes human life intelligent,and the large-scale use of various electronic devices increases the electromagnetic radiation in the surrounding environment.This has created a requirement for the development of high-performance electromagnetic wave absorbers to eliminate electromagnetic pollution.However,the preparation of electromagnetic wave absorbers with excellent electromagnetic loss capability remains a great challenge.Here,we present a method to prepare Co/ZnO/C@MWCNTs(CZC@M)composites by pyrolysis of ZnCo-MOF@MWCNTs(MOF@M).Specifically,MWCNTs are uniformly distributed on the CZC surface to form multiple heterogeneous interfaces,which will lead to an increase in polarizability.In addition,changing the amounts of MWCNTs in the composite can modulate its dielectric constant and impedance matching properties.Impressively,at only 10%sample content,the minimum reflection loss of-41.75 d B and the maximum effective absorption bandwidth of 4.72 GHz are obtained at thicknesses of 2.4 mm and 2.2 mm,respectively.Overall,the results reported in this work provide a new design strategy for the synthesis of high-performance electromagnetic wave absorbers with potential applications in the elimination of electromagnetic pollution.
