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The main purpose of this paper was to estimate and map the ecosystem services value of Beijing, Tianjin and Hebei region. Considering regional spatial heterogeneity, the stage of social development, resource scarcity, and differences in the biomass of ecosystem, the estimated results of non-construction land were more practical. Based on the ecosystem services value of the region, we carved out individual indicator divisions with the ecosystem services value per unit area (ESVU), ecosystem services value per capita (ESVP) and ecosystem services value/GDP (ESVG) respectively; and then analysed comprehensive regionalization with the above indicators to explore the spatial and temporal heterogeneity of ecosystem services values in the area. The results showed that the ecosystem services value in region increased from 1990 to 2000, and then decreased in 2010. The ecosystem services value of the region were dominated by regulating services value(RSV) and supporting services value(SSV), the sum of the two accounts for 80% of the whole area. The mapping of individual indicators and comprehensive regionalization showed a significant stepstructure, and the ecological service value of the region had certain temporal and spatial heterogeneity. The determined carrying capacity of the ecosystem services value was not optimistic for population growth and economic sustainable development in the area. In view of the above, the paper put forward measures to guide regional sustainable development. [ABSTRACT FROM AUTHOR]

The target detection performance decreases in airborne multiple-input multiple-output (MIMO) radar space-time adaptive processing (STAP) when the training samples contaminated by interference-targets (outliers) signals are used to estimate the covariance matrix. To address this problem, a knowledge-aided (KA) generalized inner product non-homogeneity detector (GIP NHD) is proposed for MTMO-STAP. Firstly, the clutter subspace knowledge is constructed by the system parameters of MIMO radar STAP. Secondly, the clutter basis vectors are utilized to compose the clutter covariance matrix offline. Then, the GIP NHD is integrated to realize the effective training samples selection, which eliminates the effect of the outliers in training samples on target detection. Simulation results demonstrate that in non-homogeneous clutter environment, the proposed KA-GIP NHD can eliminate the outliers more effectively and improve the target detection performance of MIMO radar STAP compared with the conventional GIP NHD, which is more valuable for practical engineering application. [ABSTRACT FROM AUTHOR]

A cascaded reduced-dimension (RD) space-time adaptive processing (STAP) method for airborne multiple-input multiple-output (MIMO) radar in the presence of jammers is proposed in this paper. The proposed MIMOSTAP method for clutter plus jamming suppression proceeds in two steps. Firstly, the jamming is suppressed by its orthogonal complementary subspace obtained in the passive radar mode, while the receive dimension is reduced. Secondly, the tri-iterative algorithm (TRIA) is utilized to suppress the clutter combining the remaining receive degree o f freedom (DOF) with the transmit DOF and the Doppler DOF, and further dimension reduction is implemented. The proposed method can effectively realize the separate jamming and clutter elimination. Moreover, the training sample number and the computational complexity are significantly decreased. Simulation results verify the validity of the proposed cascaded RD MIMO-STAP method under jamming condition. [ABSTRACT FROM AUTHOR]

Radar signal recognition is one of the key technologies of modern electronic surveillance systems. Time-frequency image provides a new way for recognizing the radar signal. In this paper, a series of image processing methods containing image enhancement, image threshold binarization and mathematical morphology is utilized to extract the shape character of smoothed pseudo wigner-ville time-frequency distribution of radar signal. And then the identification of radar signal is realized by the character. Simulation results of eight kinds of typical radar signal demonstrate that when signal noise ratio (SNR) is greater than -3 dB, the Legendre moments shape character of the time-frequency image is very stable. Moreover, the recognition rate by the character is more than 90 per cent except for the FRANK code signal when SNR > -3 dB. Test also show that the proposed method can effectively recognize radar signal with less character dimension through compared with exitsing algorithms. [ABSTRACT FROM AUTHOR]

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In order to investigate the effects of NaCl on mesophilic sulfate reduction and COD removal in anaerobic digestion processes, an up-flow anaerobic sludge bed (UASB) was operated continuously for 190 d with a constant hydraulic retention time (24h) at different COD/SO42- ratios. With an increase in NaCl concentration from 0 to 4 g L-1, the sulfate reduction and COD removal were elevated significantly, but the higher salinity had a negative impact on the bioreactor performance. The maximum sulfate reduction efficiencies were obtained to be 84.66%-90.01% at COD/SO42- ratios of 10 and 5, respectively. With NaCl concentration enhancing, COD removal was increased from 50.23% to 75.19%, followed by a dramatic drop. At a NaCl concentration of 50 g L-1 in the bioreactor, more than 60% sulfate reduction and less than 30% COD removal were achieved. Quantitative real time PCR showed that the highest abundance of SRB was obtained at a NaCl concentration of 4 g L-1, which was consistent with the results of sulfate reduction and COD removal. The result obtained suggesting that sulfate reducing bacteria (SRB) was unsusceptible to high salt than methane-producing bacteria (MPB) and could be potentially applied in the hypersaline environments. [ABSTRACT FROM AUTHOR]