摘要:
A method for manufacturing an NO2 gas sensor for detection at room temperature comprises: manufacturing a metal electrode on a surface of a flexible substrate; manufacturing an SWCNTs/SnO2 sensitive film; and bonding the SWCNTs/SnO2 sensitive film with a portion of the surface of the flexible substrate with the metal electrode, so as to form the NO2 gas sensor for detection at room temperature. The present disclosure solves the problems of the poor adhesion between the sensitive material and the flexible substrate, and a non-uniform distribution, and achieves the purposes of secure bonding between the sensitive material and the flexible substrate, and uniform distribution.
摘要:
The present disclosure provides a method for preparing compound semiconductor sensitive film based on a displacement reaction-thermal oxidation method, the method comprising: growing a layer of Zn on a high temperature-resistant substrate; submerging the substrate on which the layer of Zn has been grown into ionic solution of soluble salt of Cu, such that Cu ions in the solution are displaced so as to separate Cu nano-particles out on a surface of the layer of Zn; and performing a thermal oxidation process on the layer of Zn to whose surface Cu nano-particles are adhered, such that the Cu nano-particles are oxidized into CuO nano-particles, so as to obtain a ZnO gas sensitive film that is doped with CuO nano-particles. The above preparing method has the following advantages: good filming quality, simplified preparation process, low cost and easy to control.
摘要:
A method for collecting a signal with a frequency lower than a Nyquist frequency includes, by a data transmitting end, selecting a suitable transformation base matrix for an input signal, deriving a sparse representation of the signal using the transformation base matrix to determine a sparsity of the signal, calculating a number M of compressive sampling operations according to the sparsity, sampling the signal with fNYQ/M using M channels, and integrating sampling values of each channel to obtain M measurement values. A reconstruction end reconstructs an original signal by solving optimization problems. Based on theory, compressive sampling can be performed on a sparse signal or a signal represented in a sparse manner with a frequency much lower than the Nyquist frequency, overcoming restrictions of the typical Nyquist sampling theorem. The method can be implemented simply and decrease pressure on data collection, storage, transmission and processing.
摘要:
A gas recognition method based on a compressive sensing theory. The method comprises: collecting compressed data in an under-sampling manner; performing a reconstruction on the collected compressed data to obtain reconstructed data; training a back-propagation neural network by using the reconstructed data and storing the trained back-propagation neural network; inputting data under test into the trained back-propagation neural network, such that the trained back-propagation neural network performs a recognition on the data under test to realize qualitative recognition of gas. The method solves the problem in transmission and storage of large amount of data and the problem of imprecise recognition in current gas detection, and achieves the object that a precise qualitative recognition is achieved by using a reduced amount of data.
摘要:
A sampler adapted to a one-dimension slow-varying signal, including: a signal preprocessing unit configured to preprocess an input signal; a slope-controllable sawtooth wave signal generating unit configured to generate a slope-controllable sawtooth wave signal and perform zero-resetting; a signal comparing unit configured to compare the preprocessed input signal from the signal preprocessing unit with the sawtooth wave signal and to output a pulse signal to the generating unit and a signal outputting unit when the preprocessed input signal is equal to the sawtooth wave signal; a counting unit configured to count a number of clock signals while the sawtooth wave signal generating unit is generating the sawtooth wave signal and to transmit the counted number to the signal outputting unit; the signal outputting unit configured to, upon receipt of the pulse signal output from the signal comparing unit, output the number counted by the counting unit at the moment.