Creat membership Creat membership
Sign in

Forgot password?

  • Forgot password?
    Sign Up
  • Confirm
    Sign In
home > search

Now showing items 1 - 16 of 16

  • Instability Mechanism of Du Yun Pass Tunnel Entrance Weathered Stacking Area Analysis

    Liu, Lin   Rong, Yao   Zhang, Cheng Ke   Mao, Meng Yun   Zhang, Lu Lin  

    Download Collect
  • High-Temperature Characteristics of GaInNAs/GaAsSingle-Quantum-Well Lasers Grown by Plasma-Assisted Molecular BeamEpitaxy

    Pan Zhong   Li Lian He   Du Yun   LinYao Wang   Wu Rong Han  

    GaInNAs/GaAs single-quantum-well (SQW) lasers have been grown bysolid-source molecular beam epitaxy. N is introduced by a home-madedc-active plasma source. Incorporation of N into InGaAs decreases thebandgap significantly. The highest N concentration of 2.6%in a GaInNAs/GaAsQW is obtained, corresponding to the photoluminescence (PL) peakwavelength of 1.57 µm at 10 K. The PL peak intensity decreases rapidlyand the PL full width at half maximum increases with the increasing Nconcentrations. Rapid thermal annealing at 850°C couldsignificantly improve the crystal quality of the QWs. An optimumannealing time of 5s at 850°C was obtained. TheGaInNAs/GaAs SQW laser emitting at 1.2 µm exhibits a highcharacteristic temperature of 115 K in the temperature range of20°C-75°C.
    Download Collect
  • Water Bodies’ Mapping from Sentinel-2 Imagery with Modified Normalized Difference Water Index at 10-m Spatial Resolution Produced by Sharpening the SWIR Band

    Du Yun   Zhang Yihang   Ling Feng   Wang Qunming   Li Wenbo   Li Xiaodong  

    Download Collect


    Download Collect
  • Chen Yun\"s Strategy for China\"s Development. A Non-Maoist Nicholas R. Lardy; Kenneth Lieberthal; Mao Tong; Du Anxia;The Chinese Economic Stephan Feuchtwang; Athar Hussain

    Review by: Samuel P. S. Ho  

    Download Collect
  • Erratum for “Direct Inversion Algorithm for Pipe Resistance Coefficient Calibration of Water Distribution Systems” by Kun Du, Rong-yi Ding, Zhi-hao Wang, Zhi-gang Song, Bing-feng Xu, Ming Zhou, Yun Bai, and Jin Zhang

    Du, Kun   Ding, Rong-yi   Wang, Zhi-hao   Song, Zhi-gang   Xu, Bing-feng   Zhou, Ming   Bai, Yun   Zhang, Jin  

    Download Collect
  • Chen Yun\"s strategy for China\"s development: A non-maoist alternative: Nicholas R. Lardy and Kenneth Lieberthal, eds., Translated by Mao Tong and Du Anxia. The China Book Project. Armonk, N. Y.: M. E. Sharpe, 1983. xliii + 211 pp., no index. $25.00

    Jan S Prybyla  

    Download Collect
  • Superresolution land cover mapping using spatial regularization.

    Ling Feng   Li XiaoDong   Xiao Fei   Du Yun  

    Superresolution mapping (SRM) is a method of predicting the spatial locations of land cover classes within mixed pixels in remotely sensed images. This paper proposes a novel SRM framework that is operated from the perspective of spatial regularization. Within the proposed framework, SRM aims to generate final superresolution land cover maps that conform to inputted fraction images, with spatial regularization intended for exploiting a priori knowledge about the land cover maps. Two SRM models are constructed by using maximal spatial dependence as the spatial regularization term and the L1 or L2 norm as the data fidelity term. The proposed models are evaluated by using synthetic Landsat, real IKONOS, and real Airborne Visible/Infrared Imaging Spectrometer images and compared with hard classification technologies, as well as pixel-swapping, Hopfield neural network, and Markov random field SRM models. We perform linear spectral mixture analysis (LSMA) and multiple endmember spectral mixture analysis (MESMA) to estimate fraction images. Results show that the accuracy of inputted fraction images plays an important role in the final superresolution land cover maps and that using MESMA fraction images results in higher accuracy than using LSMA fraction images. Moreover, the L-curve criterion is suitable for choosing the optimal regularization parameter in both SRM models. Compared with hard classification technologies and other SRM models, the proposed model derives the highest Kappa coefficients and lowest class area proportion errors when MESMA fraction images are used as input.
    Download Collect
  • Construction of lake bathymetry from MODIS satellite data and GIS from 2003 to 2011

    Yan Yi   Xiao Fei   Du Yun  

    In recent years, sedimentation conditions in Dongting Lake have varied greatly because of signifi cant changes in runoff and sediment load in the Changjiang (Yangtze) River following the construction of Three Gorges Dam. The topography of the lake bottom has changed rapidly because of the intense exchange of water and sediment between the lake and the Changjiang River. However, time series information on lake-bottom topographic change is lacking. In this study, we introduced a method that combines remote sensing data and in situ water level data to extract a record of Dongting Lake bottom topography from 2003 to 2011. Multi-temporal lake land/water boundaries were extracted from MODIS images using the linear spectral mixture model method. The elevation of water/land boundary points were calculated using water level data and spatial interpolation techniques. Digital elevation models of Dongting Lake bottom topography in different periods were then constructed with the multiple heighted waterlines. The mean root-mean-square error of the linear spectral mixture model was 0.036, and the mean predicted error for elevation interpolation was -0.19 m. Compared with fi eld measurement data and sediment load data, the method has proven to be most applicable. The results show that the topography of the bottom of Dongting Lake has exhibited uneven erosion and deposition in terms of time and space over the last nine years. Moreover, lake-bottom topography has undergone a slight erosion trend within this period, with 58.2% and 41.8% of the lake-bottom area being eroded and deposited, respectively.
    Download Collect
  • Application of dynamic recurrent neural networks in non-linear system identification - art. no. 635754

    Du Yun   Wu Xueli   Sun Huiqin   Zhang Suying   Tian Qiang  

    An adaptive identification method of simple dynamic recurrent neural network (SRNN) for nonlinear dynamic systems is presented in this paper. This method based on the theory that by using the inner-states feed-back of dynamic network to describe the nonlinear kinetic characteristics of system can reflect the dynamic characteristics more directly, deduces the recursive prediction error (RPE) learning algorithm of SRNN, and improves the algorithm by studying topological structure on recursion layer without the weight values. The simulation results indicate that this kind of neural network can be used in real-time control, due to its less weight values, simpler learning algorithm, higher identification speed, and higher precision of model. It solves the problems of intricate in training algorithm and slow rate in convergence caused by the complicate topological structure in usual dynamic recurrent neural network.
    Download Collect


    Download Collect
  • Replicon-based Japanese encephalitis virus vaccines elicit immune response in mice.

    Huang Ying   Liu Shan   Yang Peng   Wang Chao   Du Yun   Yu WeiYuan   Sun ZhiWei  

    In this study, a replicon vaccine vector system for Japanese encephalitis virus (JEV) was established. The system included a trans-complementing cell line, a series of JEV DNA-based subgenomic replicons, and several encapsidated JEV propagation-deficient pseudoinfectious particles (PIPs). The DNA-based JEV replicon vectors, which deleted the structural coding region, could be able to self-replicate and express the reporter gene. A stable BHK packaging cell line named BHK-CME, which constitutively expressed the capsid protein C, the precursor membrane and envelope proteins (C-prM-E) of JEV, was generated. BHK-CME cells were used to trans-complement the JEV replicons and proved to package the JEV replicons into single-round infectious PIPs efficiently. The PIPs were produced in titers of up to 1.6*10 5 IU/ml. To investigate the efficacy of JEV replicon-based vaccines, four groups of female BALB/c mice were inoculated three times at 3-week intervals with the JEV PIPs and others. The JEV-specific antibody titers reached to 1:6400 and the neutralizing antibody titers reached 1:256 after three rounds of immunization with JEV PIPs. And the antisera collected from immunized mice were shown to be protective partially against lethal infection when passively transferred to susceptible weanling mice. These results demonstrated the value of the JEV replicon vector system for the development of new vaccine candidates.
    Download Collect
  • Remote-sensing and modeling of the potential suitable sites for restoration in Dajiuhu sub-alpine wetland

    Xiao Fei   Du Yun   Ling Feng   Wang Xuelei  

    In view of the data limitations for mountain wetland, we validated the application of high spatial resolution satellite imagery and DEM for mountain wetland conservation and restoration in this paper. Dajiuhu wetland, a rare sub-alpine wetland which is threatened by degradation and currently poorly understood, was select as the study area. Although there are scarce of basis data in Dajiuhu wetland, spatial patterns of the wetland vegetation could be obtained from the remote sensing interpretation, and the classification could achieve the plant formation level via integrating the high spatial resolution images with field survey. Total classification accuracy is about 83%. Despite of the widespread manmade drainage systems and the great changes on topography, hydrology, vegetations and land-cover, the potential suitable sites for wetland restoration could be modeled and located by the spatial analyzing to the result of satellite imagery classification and a high resolution (10m) DEM. Total area of the simulated potential lakes is 107.03hm(2), which is comparable with the original perennial lakes before 1950s. The research could provide basic data for the restoration of the Dajiuhu mountain wetland, and would be a useful tool to locate the potential suitable sites for wetland restoration.
    Download Collect
  • An investigation on fiber coupled polymer waveguide for electro-optic modulator

    Yang Xiaohong   Du Yun   Yin Aimin   Shi Zhiwen   Wu Ronghan   Li Zhao   Zhou Jiayun   Zhao Yuxia   Shen Yuquan  

    A novel crosslinkable polyurethane is used as the core layer of the electro-optic (E-O) modulator. The refractive index and dispersion of this material have been detected by analyzing the F-P oscillation in transmission spectra. Calculated results from the effective index method are given to design the Mach-Zehnder and straight 5-layer ridge waveguide device (including the metal electrodes). With light at 1.31 mum being fiber coupled into waveguide, the mode properties of these devices have been demonstrated in a micron control system. The guided mode is accordant with the theoretical analysis
    Download Collect
  • Instability Mechanism of Du Yun Pass Tunnel Entrance Weathered Stacking Area Analysis

    Liu, Lin; Rong, Yao; Zhang, Cheng Ke; Mao, Meng Yun; Zhang, Lu Lin  

    Download Collect
  • Output characteristics of square and circular resonator microlasers connected with two output waveguides

    HUANG YongZhen   Lü XiaoMeng   LIN JianDong   DU Yun  

    Square and circular resonator microlasers connected with two output waveguides are investigated for correlation of output powers from the two output ports.The square resonator microlasers with two output waveguides connected at the midpoint of one side and one vertex are fabricated and tested by measuring the output power versus injection current and the laser spectra of the two ports.The laser spectra indicated that the output power correlation between the two output ports is very weak because of different lasing modes in different ports of the square microlaser.Circular resonator microlaser with two output waveguides can realize single mode operation and has good output correlation from the two ports.So the output power from one port of the circular microlasers can be monitored by that of another port.
    Download Collect


If you have any feedback, Please follow the official account to submit feedback.

Turn on your phone and scan

Submit Feedback