In this paper,a fast-speed and real-time online rail inspection method based on half-cycle orthogonal power demodulation algorithm is proposed.For this method,the power characters of de-tection signal which represent ...In this paper,a fast-speed and real-time online rail inspection method based on half-cycle orthogonal power demodulation algorithm is proposed.For this method,the power characters of de-tection signal which represent the degree of rail track can be calculated using only half-cycle detec-tion signal because of the symmetry characteristic of detected sine signal and reference signal.The theoretical analysis,simulation results and experiment results show that the demodulation preci-sion of proposed method is almost equal to fast Fourier transform(FFT)demodulation method and orthogonal demodulation method,but has high demodulation efficiency and less FPGA resources cost.A high-speed experiment system based on three coils structured sensor is built for rail inspec-tion experiment at a moving speed of 200 km/h.The experiment results show that proposed meth-od is more effective for rail inspection and the time resolution of proposed method is double of clas-sic method that based on FFT and orthogonal.展开更多
Incorporation of guest ions into porous frameworks changed magnetism of the host materials significantly. However, in most cases, the guest ions were monovalent due to lack of reliable method to insert divalent and tr...Incorporation of guest ions into porous frameworks changed magnetism of the host materials significantly. However, in most cases, the guest ions were monovalent due to lack of reliable method to insert divalent and trivalent guest ions. In this work, we demonstrated that divalent and trivalent metal ions could be inserted into frameworks of a coordinate polymer, Cu3[Fe(CN)6]2, through electrochemical intercalation. The magnetism of the host frameworks was changed among paramagnetic, superparamagnetic, and ferromagnetic as demonstrated by physical property measurement system (PPMS). Furthermore, the magnetization of the frameworks under low temperatures correlated to the guest ions significantly. The ionic radius and net charge of the guest ions influenced the intercalation amount of the guest ions, therefore affected the valence change of Fe3+ ions in the host frameworks, finally leading to variation of the magnetism of the host materials.展开更多
基金supported by the National Natural Science Found-ation of China(No.61771041).
文摘In this paper,a fast-speed and real-time online rail inspection method based on half-cycle orthogonal power demodulation algorithm is proposed.For this method,the power characters of de-tection signal which represent the degree of rail track can be calculated using only half-cycle detec-tion signal because of the symmetry characteristic of detected sine signal and reference signal.The theoretical analysis,simulation results and experiment results show that the demodulation preci-sion of proposed method is almost equal to fast Fourier transform(FFT)demodulation method and orthogonal demodulation method,but has high demodulation efficiency and less FPGA resources cost.A high-speed experiment system based on three coils structured sensor is built for rail inspec-tion experiment at a moving speed of 200 km/h.The experiment results show that proposed meth-od is more effective for rail inspection and the time resolution of proposed method is double of clas-sic method that based on FFT and orthogonal.
基金supported by the National Natural Science Foundation of China (Nos. 21473059, U1830130, 61504043, 61774061)
文摘Incorporation of guest ions into porous frameworks changed magnetism of the host materials significantly. However, in most cases, the guest ions were monovalent due to lack of reliable method to insert divalent and trivalent guest ions. In this work, we demonstrated that divalent and trivalent metal ions could be inserted into frameworks of a coordinate polymer, Cu3[Fe(CN)6]2, through electrochemical intercalation. The magnetism of the host frameworks was changed among paramagnetic, superparamagnetic, and ferromagnetic as demonstrated by physical property measurement system (PPMS). Furthermore, the magnetization of the frameworks under low temperatures correlated to the guest ions significantly. The ionic radius and net charge of the guest ions influenced the intercalation amount of the guest ions, therefore affected the valence change of Fe3+ ions in the host frameworks, finally leading to variation of the magnetism of the host materials.
