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Your search keyword '"Ma, J.-Z."' showing total 8 results
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8 results on '"Ma, J.-Z."'

6. Scattering Characteristic Extraction Method for Manmade Target Based on Target Null Theory

Author

Lu, D. W., Ma, J. Z., Pang, B., Guan, Y. F., Feng, D. J., Lu, D. W., Ma, J. Z., Pang, B., Guan, Y. F., and Feng, D. J.

Abstract

Scattering characteristic extraction is an essential part of manmade target recognition. However, if two scattering points are in adjacent pixels, scattering characteristic extraction may fail to acquire accurate polarimetric scattering matrices (PSMs) of the weak scattering points due to the contamination caused by the strong scattering points. Target null theory provides a way to solve this problem. By selecting the transmitting and receiving polarization states of radar antennas simultaneously, the echo power of a strong scattering point becomes zero and the contamination effect is avoided. In this paper, a method based on target null theory for scattering characteristic extraction is proposed. First, we optimize the transmitting and receiving polarization states of the radar antenna to suppress the intensities of the strong scattering points to highlight the positions of the weak scattering points in certain polarimetric channels. Second, to suppress the contamination effects of strong scattering points in other polarimetric channels, we establish perturbation correction equations to erase the error generated by the point spread function (PSF) among adjacent scattering points in the radar image. Finally, the solved polarimetric scattering matrices of corresponding positions are implemented for target retrieval. The electromagnetic simulation results demonstrate the effectiveness of the proposed method.

Published
2023

7. Giant Chern number of a Weyl nodal surface without upper limit

Author

Ma, J.-Z., primary, Zhang, S.-N., additional, Song, J. P., additional, Wu, Q.-S., additional, Ekahana, S. A., additional, Naamneh, M., additional, Radovic, M., additional, Strocov, V. N., additional, Gao, S.-Y., additional, Qian, T., additional, Ding, H., additional, He, K., additional, Manna, K., additional, Felser, C., additional, Plumb, N. C., additional, Yazyev, O. V., additional, Xiong, Y.-M., additional, and Shi, M., additional

Published
2022
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8. NUTRIENT RESPONSES OF CAREX SCHMIDTII TO CONSECUTIVE DROUGHT AND RE-FLOODING EPISODES IN SEMI-ARID WETLANDS: IMPLICATIONS FOR TUSSOCK RESTORATION.

Author

ZHANG, D. J., XIA, J. B., SUN, J. K., MA, J. Z., ZHAO, D. D., DUAN, D. X., WANG, X. H., and TONG, S. Z.

Subjects
DROUGHTS, WETLANDS, WETLAND plants, PLANT nutrients, DROUGHT management, WETLAND restoration, STOICHIOMETRY
Abstract

The regulation mechanism of wetland plants in response to consecutive drought (D) and re-flooding (RT) events can be identified via nutrient responses. Nutrient responses of Carex schmidtii were tested using a simulation experiment with five treatments: D, wetting (W) and RT resulted in C. schmidtii being re-flooded after 30, 40 and 60 days of drought. D and RT treatments partly affected nutrient stoichiometry of C. schmidtii. Plant nutrient stoichiometry experienced a shift of adaption from drought to flooding and making part or full recoveries after RT with reference to D and W treatments. Plant P concentration had a negative relationship with N:K ratio. D and RT effects on plant trade-offs and scaling exponents of C. schmidtii were profound; the scaling exponent of P~N increased with initial re-flooding time, while that of K~N decreased. Although nutrient trade-offs in D gradually differed from W and RT over time, the nutrient trade-offs of RT recovered with reference to W. The D and RT were recorded to contribute to nutrient flexibility of C. schmidtii; however, strong internal stability of stoichiometric relationships effectively relieved changes in plant nutrient stoichiometry. The findings aid our understanding of nutrient responses of C. schmidtii to D and RT. [ABSTRACT FROM AUTHOR]

Published
2022
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