Chen S.,Tongji University |
Nai W.,Tongji University |
Zhang F.,Tongji University |
Wang S.,Tongji Zhejiang College |
And 2 more authors.
Advances in OptoElectronics | Year: 2015
Wavelength-division-multiplexing passive-optical-network (WDM-PON) has been recognized as a promising solution of the "last mile" access as well as multibroadband data services access for end users, and WDM-RoF-PON, which employs radio-over-fiber (RoF) technique in WDM-PON, is even a more attractive approach for future broadband fiber and wireless access for its strong availability of centralized multiservices transmission operation and its transparency for bandwidth and signal modulation formats. As for multiservices development in WDM-RoF-PON, various system designs have been reported and verified via simulation or experiment till now, and the scheme with multiservices transmitted in each single wavelength channel is believed as the one that has the highest bandwidth efficiency; however, the corresponding mathematical verification is still hard to be found in state-of-the-art literature. In this paper, system design and data transmission performance of a quintuple services integrated WDM-RoF-PON which jointly employs carrier multiplexing and orthogonal modulation techniques, have been theoretically analyzed and verified in detail; moreover, the system design has been duplicated and verified experimentally and the theory system of such WDM-RoF-PON scheme has thus been formed. © 2015 Shuai Chen et al.
Zhou S.,Tongji University |
Zhou S.,Tongji Zhejiang College |
Wang S.-J.,Tongji University
Journal of Donghua University (English Edition) | Year: 2015
A diesel engine of conventional trucks has a low efficiency under the idling condition, leading to a high cost for heating or cooling in the cab during night. The solution to this problem will have great significance on energy conservation and emission reduction. A new auxiliary power unit of solid oxide fuel cell (SOFC-APU) with high efficiency solves this problem perfectly. Heat pump air conditioner is considered as a promising device for the application of SOFC-APU with a high cooling and heating efficiency. To make a quantitative analysis for the application of SOFC-APU, a model is built in Matlab/Simulink. The diesel engine model and SOFC-APU model are fitted based on some experimental data of SOFC-APU and diesel engine during the idling operation. An analysis of the application of SOFC-APU on different trucks in Northeast China is comprehensively made, including efficiency and emission. Copyright © 2015 Editorial Department of Journal of Donghua University, Shanghai, China. All rights reserved.
Zhu B.,University of Shanghai for Science and Technology |
Zhu B.,Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering |
Sun X.-J.,University of Shanghai for Science and Technology |
Sun X.-J.,Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering |
And 3 more authors.
Kung Cheng Je Wu Li Hsueh Pao/Journal of Engineering Thermophysics | Year: 2015
3D numerical simulation of a H-type Darrieus vertical axis wind turbine with blade-tip end plates was performed by means of a self-developed computational uid dynamics (CFD) code UCFD. The effects of geometrical parameters such as shape and size of the end plate on the aerodynamic performance of Darrieus wind turbine were investigated. Numerical results indicate that the vortex at the leading edge of rotor blade can be suppressed by adding a at plate at both ends of its blade and an improved blade-tip surface pressure distribution can be found. As a result, the efficiency and stability of such type of wind turbine can be evidently promoted. © 2015, Science Press. All right reserved.
Zhong Y.-W.,Renmin University of China |
Zhong Y.-W.,Tongji Zhejiang College |
Li T.,Renmin University of China |
Han Q.,Renmin University of China |
Han Q.,University of Hong Kong
Physical Review B - Condensed Matter and Materials Physics | Year: 2011
From the perspective of thermal fluctuations, we investigate the pseudogap phenomena in underdoped high-temperature curpate superconductors. We present a local update Monte Carlo procedure based on the Green's function method to sample the fluctuating pairing field. The Chebyshev polynomial method is applied to calculate the single-particle spectral function directly and efficiently. The evolution of Fermi arcs as a function of temperature is studied by examining the spectral function at Fermi energy as well as the loss of spectral weight. Our results signify the importance of the vortexlike phase fluctuations on the formation of Fermi arcs. © 2011 American Physical Society.
Zhang G.-X.,Tongji Zhejiang College |
Guan L.-B.,Tongji Zhejiang College
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2014
Based on the soil-nailing tensile experiments under different pressure grouting parameters, the effect of grouting parameters such as grouting amount and water-cement ratio on bearing capacity of soil nailings with different lengths is analyzed. The results show that, in the experimental range, under the same quantity of grouting, the ultimate tensile strength of soil nailings increases with the decreasing water-cement ratio. Specifically speaking, for the short soil nailings with higher grouting quantity in unit length, the higher the grouting quantity is, the lower the effect of water-cement ratio on the change rate of the ultimate tension is. On the contrary, for the long soil nailings with lower grouting quantity in unit length, the effect of water-cement ratio on the change rate of the ultimate tension is larger while the quantity of grouting is higher. Meanwhile, under the same water-cement ratio, the maximum tensile strength of soil nailings increases with the quantity of grouting increases. Here, for the short soil nailings with higher grouting quantity in unit length, the higher the water-cement ratio is, the larger the effect of grouting quantity on the change rate of the ultimate tension is. Conversely, for the long soil nailings with lower grouting quantity in unit length, the higher the water-cement ratio is, however, the lower the effect of grouting quantity on the change rate of the ultimate tension is.