Science and Technology on Near surface Detection Laboratory

Wuxi, China

Science and Technology on Near surface Detection Laboratory

Wuxi, China
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Guo C.,Science and Technology on Near Surface Detection Laboratory | Junchao S.,Science and Technology on Near Surface Detection Laboratory
ICALIP 2016 - 2016 International Conference on Audio, Language and Image Processing - Proceedings | Year: 2016

Design of high performance power supply for acoustic shock acquisition system is discussed from the perspective of engineering practice of acoustic shock acquisition system. In this connection, design of multi-output power is proposed based on switching regulator. Moreover, by analyzing key components, the problem of high ripple with switching regulator is successfully solved, while power supply efficiency is further improved. The small-sized SMD package is adopted to improve the power density of switching regulator, making it more suitable for limited installation space of acoustic shock acquisition system. In practical applications, the proposal reaches expected design indexes. © 2016 IEEE.


Kai D.,Science and Technology on Near Surface Detection Laboratory | Hao L.,Science and Technology on Near Surface Detection Laboratory | Yichao Z.,Science and Technology on Near Surface Detection Laboratory | Shuang Q.,Science and Technology on Near Surface Detection Laboratory
ICALIP 2016 - 2016 International Conference on Audio, Language and Image Processing - Proceedings | Year: 2016

When intelligent fuse is detecting target acoustic signal, affected by external interference and other factors, the signal may bring on trend term. Existence of trend term may cause direct influence on the accuracy of target acoustic signal, so that it should be removed. In allusion to the problems in existing trend term removal methods, such as trend term type should be assumed in advance, and the calculation process is quite complicated, a smoothness priors approach based method is proposed to remove trend term of target acoustic signal. 3 categories of target acoustic signals were processed in the research. According to the results, the approach is effective in removing trend term of time domain waveform and power spectrum of target acoustic signal. Moreover, the method is simple and efficient, and is applicable to the trend term removal preprocessing of target sound signal. © 2016 IEEE.


Zhang B.,Shanghai JiaoTong University | Zhang B.,Science and Technology on Near Surface Detection Laboratory | Hu S.,Science and Technology on Near Surface Detection Laboratory | Chen J.,Shanghai JiaoTong University
Bandaoti Guangdian/Semiconductor Optoelectronics | Year: 2017

Presented is an ant-based routing algorithm demanding on energy(ARADE), to improve the two situations of short lifetime and slow convergence speed of ant colony algorithm caused by unbalanced energy distribution. The inversed pheromone table which stores routing information simplifies the data structure of routing request packet. The residual energy of the node, energy consumption of the path and the number of hops are normalized to a parameter as a performance evaluation value, which can balance the residual energy of the entire network node. What's more, the maximum pheromone value during the iteration will be used in the self-iteration to make the pheromone value get a positive feedback. As a result, the convergence speed of the algorithm can be accelerated. The simulation of the experiment is performed on NS-2 platform. With the increase of the transmission rate of the data packet, its lifetime, average energy consumption and end-to-end delay will be better than AODV. © 2017, Editorial Office of Semiconductor Optoelectronics. All right reserved.


Shen G.,Nanjing University of Information Science and Technology | Mei B.,Nanjing University of Information Science and Technology | Wu H.,Nanjing University of Information Science and Technology | Wei H.,Nanjing University of Aeronautics and Astronautics | And 2 more authors.
Journal of Physical Chemistry C | Year: 2017

Lightweight nitrogen-doped ordered mesoporous carbon (NOMC) with high specific surface area and pore volume have been prepared through self-assembly and subsequent heat treatment route. The spherical NOMC particles are decorated with CoFe2O4 nanoparticles via coprecipitation method to enhance their microwave absorption property. The electromagnetic parameters of the NOMC and CoFe2O4/NOMC composites are measured and the microwave reflection loss properties are evaluated in the frequency range of 0.5-18 GHz. The results show that both the real part and imaginary part of permittivity of NOMC totally decline and the real part of permeability increases with the introduction of ferrite. However, the negative values of the imaginary part of the complex permeability appear for the CoFe2O4/NOMC composites, which may be caused by enhanced eddy current effect due to the introduction of ferrite. The reflection loss results exhibit that the CoFe2O4/NOMC composites have excellent microwave absorption performances. The absorption bandwidth less than -10 dB reaches 5.0 GHz (11.9-16.9 GHz) for 40-F/NOMC composite (40 wt % ferrite) with 1.5 mm of thickness and the minimum reflection loss value is up to -38.3 dB at 3.9 GHz for 30-F/NOMC composite with 4.0 mm of thickness. The excellent absorption properties derive from the synergistic effect between dielectric loss of NOMC and magnetic loss of ferrite and better impendence matching at air and ferrite/NOMC composite interface. Thus, the lightweight ferrite/NOMC composites exhibit their great potential as microwave absorbing materials. © 2017 American Chemical Society.


Yang M.,Nanjing Southeast University | Yin X.,Nanjing Southeast University | Chen Z.N.,National University of Singapore | Rong Y.,Science and Technology on Near Surface Detection Laboratory | Qian H.,Science and Technology on Near Surface Detection Laboratory
IEEE Antennas and Wireless Propagation Letters | Year: 2016

A planar bow-tie antenna loaded with open stubs is proposed to realize image rejection and gain enhancement for superheterodyne applications. The loading open stubs are two open-circuit double-sided parallel-strip lines symmetrically connected to the feedline of a planar bow-tie antenna, which functions as a bandstop filter in frequency band lower than the operating frequency to reject image interference and simultaneously as a reflector across the operating frequency band to enhance the antenna gain. Simulated results show that the realized gain of the proposed antenna in the main radiation direction is suppressed by 25 dB at the image frequency and is enhanced by about 3 dB at the operating frequency compared to that of an unloaded antenna. Good agreements between the simulated and the measured results have been observed. © 2015 IEEE.


Qi H.,Nanjing Southeast University | Yin X.,Nanjing Southeast University | Liu L.,Nanjing University of Posts and Telecommunications | Rong Y.,Science and Technology on Near Surface Detection Laboratory | Qian H.,Science and Technology on Near Surface Detection Laboratory
IEEE Antennas and Wireless Propagation Letters | Year: 2016

This letter introduces an effective solution for improving isolation between closely spaced patch antennas. A satisfactory isolation is realized by three interdigital lines that excite an orthogonal polarization mode on the adjacent patch. A two-patch array is simulated and fabricated to verify the decoupling effectiveness of the proposed structure. The investigations of the electric field and current distributions reveal the working mechanism of the proposed structure. The experimental results show that the achieved isolation is better than 20 dB, and the maximum isolation enhancement is 24.7 dB, with a compact edge-to-edge separation of just 0.07λ0. Moreover, the proposed structure can also be applied for the decoupling of a multielement patch array. © 2002-2011 IEEE.


Shen G.,Nanjing University of Information Science and Technology | Xu Y.,Science and Technology on Near Surface Detection Laboratory | Liu B.,Nanjing University of Information Science and Technology
Desalination and Water Treatment | Year: 2016

Carbon materials are effective for removal of both toxic inorganic and organic substances. In this study, a novel magnetic mesoporous carbon aerogel which combined high specific surface area, adsorption capacity and magnetic property of Fe3C was prepared by citrate sol-gel method. The as-prepared samples were characterized by powder X-ray diffraction, TEM, scanning electron microscope, and BET methods. Results show that the aerogel has the specific surface and average pore size of 290 m2/g and 2.7 nm, respectively. Magnetic Fe3C nanoparticles were dispersed uniformly in carbon matrix and exhibit excellent response to an external magnetic field. As a result, the adsorbent can be easily separated from solution using an external magnetic field. Batch experimental results on As(V) removal showed that the adsorption kinetics and isotherm data were fitted well by a pseudo-second-order model and a Freundlich model, respectively. The monolayer adsorption capacity (qm) of the adsorbent was calculated to be 56.2 mg/g at pH 7.0. The excellent uptake capability of the magnetic mesoporous materials make it be potentially attractive materials for removal of hazardous substances from water. © 2016 Balaban Desalination Publications. All rights reserved.


PubMed | Wuhan University and Science and Technology on Near Surface Detection Laboratory
Type: Journal Article | Journal: Sensors (Basel, Switzerland) | Year: 2016

Based on the dynamic nuclear polarization (DNP) effect, an alternative design of an Overhauser geomagnetic sensor is presented that enhances the proton polarization and increases the amplitude of the free induction decay (FID) signal. The short-pulse method is adopted to rotate the enhanced proton magnetization into the plane of precession to create an FID signal. To reduce the negative effect of the powerful electromagnetic interference, the design of the anti-interference of the pick-up coil is studied. Furthermore, the radio frequency polarization method based on the capacitive-loaded coaxial cavity is proposed to improve the quality factor of the resonant circuit. In addition, a special test instrument is designed that enables the simultaneous testing of the classical proton precession and the Overhauser sensor. Overall, comparison experiments with and without the free radical of the Overhauser sensors show that the DNP effect does effectively improve the amplitude and quality of the FID signal, and the magnetic sensitivity, resolution and range reach to 10 pT/Hz 1 / 2 @1 Hz, 0.0023 nT and 20-100 T, respectively.


Sun H.-T.,National University of Defense Technology | Chang W.-G.,National University of Defense Technology | Liu Z.-H.,Science and Technology on Near Surface Detection Laboratory
2015 IEEE International Conference on Communication Problem-Solving, ICCP 2015 | Year: 2015

Throwing-mine detection is a typical problem of low RCS (radar cross section) targets detection in heavy clutter, in which the high false alarm rate is a difficult problem. Classical CFAR (Constant False Alarm Rate) detection algorithm only utilizes the image contrast characteristics, in the case of low SNR (Signal to Noise Ratio), a large number of false alarms generates. In order to further reduce false alarm rate, CFAR-IHP (Constant False Alarm Rate-Internal Hermitian Product) detection algorithm is proposed in this paper. CFAR-IHP is based on CFAR and target azimuth coherence characteristic, therefore, we first get the sub-aperture image sequence to extract target azimuth information by the sub-aperture processing algorithm for SAR image. Lastly, based on Ku-band SAR data, we use CFAR-IHP (Constant False Alarm Rate-Internal Hermitian Product) algorithm to detect the targets, experimental results show that the method further eliminate the clutter and the azimuth coherence helpfully reduces the false alarms.


Jia G.,National University of Defense Technology | Chang W.,National University of Defense Technology | Zhang Q.,National University of Defense Technology | Luan X.,Science and Technology on Near Surface Detection Laboratory
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing | Year: 2016

Regarding the two-dimensional (2-D) imaging processing of circular synthetic aperture radar (CSAR), the motion compensation (MOCO) in the frequency domain is not fully developed. To perform the MOCO for CSAR data in the frequency domain, a novel three-step strategy is presented in this paper. The motion error model is established first, and it is found that a difficulty of MOCO for CSAR lies in the space variance of the motion errors. Specifically, according to the proposed MOCO strategy, this first step is space-invariant MOCO, the second step is space-variant MOCO in the range-compressed angular-wavenumber domain with respect to subaperture data, and the last step is the autofocus operation in the 2-D wavenumber domain after the polar format resampling. Eventually, the complete MOCO flowchart is obtained. Simulation and experimental tests verify that the proposed motion error model is valid and the three-step MOCO strategy can remove motion errors accurately and figure out well-focused CSAR images. © 2008-2012 IEEE.

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