| 1 | Coherent change detection of fine traces based on multi-angle SAR observations显示文摘Coherent change detection(CCD) is an effective method to detect subtle scene changes that occur between temporal synthetic aperture radar(SAR) observations. Most coherence estimators are obtained from a Hermitian product based on local statistics. Increasing the number of samples in the local window can improve the estimation bias, but cause the loss of the estimated images spatial resolution. The limitations of these estimators lead to unclear contour of the disturbed region, and even the omission of fine change targets. In this paper, a CCD approach is proposed to detect fine scene changes from multi-temporal and multi-angle SAR image pairs. Multi-angle CCD estimator can improve the contrast between the change target and the background clutter by jointly accumulating singleangle alternative estimator results without further loss of image resolution. The sensitivity of detection performance to image quantity and angle interval is analyzed. Theoretical analysis and experimental results verify the performance of the proposed algorithm. | KOU Xiuli WANG Guanyong LI Jun CHEN Jie | 2023 | Journal of Systems Engineering and Electronics2023，34，1： | 0 |
| 2 | Extensive sequence divergence between the reference genomes of Taraxacum kok-saghyz and Taraxacum mongolicum显示文摘Plants belonging to the genus Taraxacum are widespread all over the world,which contain rubber-producing and non-rubberproducing species.However,the genomic basis underlying natural rubber(NR)biosynthesis still needs more investigation.Here,we presented high-quality genome assemblies of rubber-producing T.kok-saghyz TK1151 and non-rubber-producing T.mongolicum TM5.Comparative analyses uncovered a large number of genetic variations,including inversions,translocations,presence/absence variations,as well as considerable protein divergences between the two species.Two gene duplication events were found in these two Taraxacum species,including one common ancestral whole-genome triplication and one subsequent round of gene amplification.In genomes of both TK1151 and TM5,we identified the genes encoding for each step in the NR biosynthesis pathway and found that the SRPP and CPT gene families have experienced a more obvious expansion in TK1151 compared to TM5.This study will have large-ranging implications for the mechanism of NR biosynthesis and genetic improvement of NR-producing crops. | Tao Lin Xia Xu Huilong Du Xiuli Fan Qingwen Chen Chunyan Hai Zijian Zhou Xiao Su Liquan Kou Qiang Gao Lingwei Deng Jinsheng Jiang Hanli You Yihua Ma Zhukuan Cheng Guodong Wang Chengzhi Liang Guomin Zhang Hong Yu Jiayang Li | 2022 | Science China(Life Sciences)2022，65，3： | 0 |
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