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Zhang X.,Tianjin University | Ze L.,Tianjin University | Yang Z.,Tianjin Key Laboratory of Film Electronic and Communication Devices | Wu R.,Tianjin University | And 2 more authors.
Journal of Computational and Theoretical Nanoscience | Year: 2017

In this paper, a new concept of calibration hold-up time was defined. On the basis of the concept, a novel method was proposed to predict retention times in temperature programmed (isothermal) under constant flow and constant pressure mode each other, and the method also researched in simultaneous pressure and temperature programmed. The prediction results show that average relative errors are 1.33% (0.64%) in temperature programmed (isothermal) under constant pressure mode by using isothermal dates in constant flow mode, and the other way around, average relative errors are 0.62% (-0.62%). For simultaneous pressure and temperature programmed, retention times were predicted by using isothermal dates in constant flow and constant pressure mode, average relative errors are -0.24% and -0.16%; and retention times were predicted by using isothermal dates directly, average relative errors are -0.62%. © 2017 American Scientific Publishers.


Ren G.,Tianjin University of Technology | Zhou C.,Tianjin Key Laboratory of Film Electronic and Communication Devices
Applied Mechanics and Materials | Year: 2012

Propose an application of multi-objective genetic algorithm (GA) for pattern synthesis of circular arrays with equally spaced isotropic elements. Aim at reduce the side-lobe level and deep the null of array antenna patterns, adopt improved real-coded genetic algorithm, which modify the crossover operator and mutation operator compare with standard GA, both the crossover and mutation probability adjustable in accordance with the generation numbers, in the final, the approach for antenna pattern synthesis can suppress interferences by deep the nulls at directions of interfering sources and placing main beam in direction of desired signal by controlling amplitude weights. Numerical results show effectiveness of the procedure proposed. © (2012) Trans Tech Publications, Switzerland.


Mingju G.,Tianjin University of Technology | Shexiang M.,Tianjin University of Technology | Xin M.,Tianjin University of Technology | Shuanggen Z.,Tianjin Key Laboratory of Film Electronic and Communication Devices | And 2 more authors.
Proceedings - 4th International Conference on Emerging Intelligent Data and Web Technologies, EIDWT 2013 | Year: 2013

This article discussed a packet error rate of Automatic Identification System messages measurement system. Packet Error Rate is the only verdict conditions of the receive-performance of shipboard AIS, but so far there is no relative equipment. In this paper a measurement scheme is proposed, and there is an arbitrary waveform generator used for generating standard measurement signals and a personal computer used to receive VDM messages via serial port and calculate the packet error rate. Experiments show that this scheme can meet the functional requirement and has some practice value. © 2013 IEEE.


Ma M.,Tianjin University of Technology | Ma M.,Tianjin Key Laboratory of Film Electronic and Communication Devices | Chang M.,Tianjin University of Technology | Chang M.,Tianjin Key Laboratory of Film Electronic and Communication Devices | And 2 more authors.
Journal Wuhan University of Technology, Materials Science Edition | Year: 2012

Highly boron-doped diamond films were deposited on porous titanium substrates by hot filament chemical vapor deposition technique. The morphology variation of highly boron-doped diamond films grown on porous titanium substrates was investigated, and the effects of carbon concentration on nucleation density and diamond growth were also studied. The continuous change of surface morphology and structure of diamond film were characterized by scanning electron microscopy. The structures of diamond film and interlayer were analyzed by X-ray diffraction. The quality of boron-doped diamond film was confirmed by visible Raman spectroscopy. The experimental results reveal that surface morphology and quality of boron-doped diamond films are various due to the change of carbon concentration. The thickness of intermediate layer decreases with the carbon concentration increasing. © Wuhan University of Technology and Springer Verlag Berlin Heidelberg 2012.


Ma X.,Tianjin University of Technology | Li K.,Tianjin Key Laboratory of Film Electronic and Communication Devices | Wang X.,Tianjin Key Laboratory of Film Electronic and Communication Devices
Optical Fiber Technology | Year: 2015

In this paper, a novel compensation scheme for receiver (Rx) in-phase/quadrature (IQ) mismatch is proposed in coherent optical orthogonal frequency division multiplexing (CO-OFDM) system in the presence of laser phase noise. In this scheme, laser phase noise and channel distortion were combined as a new channel transfer factor, the IQ mismatch factor and initial channel transfer factor can be estimated independently based on the relationship of IQ mismatch factors. And the channel transfer factor can be updated on a symbol-by-symbol basis which retrieves an estimation of the phase noise value by extracting and averaging the phase drift of all OFDM sub-channels. Numerical results indicate that when the phase and amplitude mismatch are 10° and 2. dB respectively, a 1.6. dB optical signal-to noise ratio is improved at laser linewidth of 60. kHz. Furthermore, the complexity of the proposed method is analyzed in terms of the number of required complex multiplications per bit. © 2015.


Ma X.,Tianjin University of Technology | Ma X.,Tianjin Key Laboratory of Film Electronic and Communication Devices | Xu Y.,Tianjin University of Technology | Xu Y.,Tianjin Key Laboratory of Film Electronic and Communication Devices | And 4 more authors.
Optics Communications | Year: 2015

A novel high precision adaptive equalization method is introduced and applied to dynamic equalization for quadrature phase shift keying (QPSK) coherent optical communication system in this paper. A frequency-domain constant modulus algorithm (CMA) method is used to equalize the received signal roughly. Then, some non-ideal output signals will be picked out through the error measurement, and they will be equalized accurately further in a fixed time-domain CMA equalizer. This high precision equalization method can decrease the equalization error, then it can reduce the bit error ratio (BER) of coherent communication system. Simulation results show that there is a 6% decrease for computation complexity by proposed scheme when compared with time-domain CMA. Furthermore, compared with time-domain CMA and frequency-domain CMA, about 2 dB and 2.2 dB in OSNR improvement can be obtained by proposed scheme at the BER value of 1e-3, respectively. © 2015, Elsevier B.V. All rights reserved.


Ma X.,Tianjin University of Technology | Ma X.,Tianjin Key Laboratory of Film Electronic and Communication Devices | Wang X.,Tianjin University of Technology | Wang X.,Tianjin Key Laboratory of Film Electronic and Communication Devices | And 4 more authors.
Optics Communications | Year: 2015

We analyze the residual chromatic dispersion (CD) monitoring of non-return-to-zero on-off keying (NRZ-OOK) signals using delay-tap asynchronous sampling. By evaluating the distance ratio of delay-tap plots and using a 0.5-bit optical delay interferometer (ODI), signed residual CD can be monitored accurately via numerical simulations. This CD monitoring method is independent of optical signal-to-noise ratio (OSNR) and polarization-mode dispersion (PMD). The measuring range was around ±900 ps/nm for 10-Gbit/s NRZ-OOK link and ±60 ps/nm for 40 G link, the monitoring error is smaller than 2 ps/nm. © 2014 Elsevier B.V.


Li H.,Tianjin University of Technology | Li H.,Tianjin Key Laboratory of Film Electronic and Communication Devices | Jing H.,Tianjin University of Technology | Jing H.,Tianjin University | And 9 more authors.
Materials and Design | Year: 2016

For high conversion efficiency thermoelectric generators, the preparation of fine and stable junctions between thermoelectric (TE) materials and electrodes is one of the core issues. In this paper, TE material AgSbTe2.01 applied in medium temperature (200-400°C) was successfully connected to copper electrode by low-temperature joining technique with nanosilver paste. 316 stainless steel was sputtered on the surface of TE material as the diffusion barrier layer. To investigate the interfacial evolution behavior, joints suffered from a bulk of harsh aging treatments under 200°C to 400°C in air environment. The results proved that 316 stainless steel could effectively block the diffusion between thermoelectric elements and element Ag in the solder at 200°C to 400°C. The formation of FeTe2 at AgSbTe2.01/316 stainless steel interface realized a fine metallurgical interconnection which was benefit for the improvement of joint strength. However, the mismatch of crystal structure between FeTe2 and AgSbTe2.01 might lead to defects under harsh environment. It was also concluded that the failure at Ag/Cu interface caused by the formation of CuO would be the main reason for the failure of the whole junction. © 2015 Elsevier Ltd.


Li H.,Tianjin University of Technology | Li H.,Tianjin Key Laboratory of Film Electronic and Communication Devices | Jing H.,Tianjin University of Technology | Jing H.,Tianjin University | And 9 more authors.
Journal of Alloys and Compounds | Year: 2016

Lead free solder Sn96.5Ag3·0Cu0.5 (SAC305) and nano-silver paste were used to connect graded thermoelectric (TE) arms, respectively. A series of harsh aging tests were carried out on joints of both p-type and n-type graded TE arms. The results showed that nano-silver paste printed by low-temperature joining technique was much more suitable for the stable connection of TE materials working in medium temperature range. 316 stainless steel and nickel were proved effectively as diffusion barrier layers in p-type junctions. While for n-type TE junctions, when aging at 300 °C, (Fe, Cr, Te) ternary alloy could be detected at Bi2Te2.7Se0.3/316 stainless steel interface. The formation of ternary compound realized fine metallurgical interconnection which was benefit for the improvement of joint strength. The average joint strength for p-type and n-type junctions in graded TE arms were above 20 MPa and 30 MPa, respectively. © 2015 Elsevier B.V.


Wu P.,Tianjin Key Laboratory Of Film Electronic and Communication Devices | Ren G.-J.,Tianjin Key Laboratory Of Film Electronic and Communication Devices | Yao J.-Q.,Institute of Laser and Opto electronics
Optoelectronics and Advanced Materials, Rapid Communications | Year: 2014

The production of filter combined terahertz with photonic crystal fiber is rare. Fill the nematic liquid crystal in the photonic crystal fiber air hole, photonic crystal optical fiber transmission mechanism was tuned by changing the nature of the liquid crystal. Liquid crystal refractive index change with temperature, so that the defect mode frequency will move. Based on this mechanism, threshold switching or filter can be designed. For the terahertz sensing characteristics in this article, mode field area and sensitivity become small as the wavelength increases. © 2014, National Institute of Optoelectronics. All right reserved.

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