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This paper proposes a spawned targets tracking algorithm—STT-δ-GLMB—by extending the δ-GLMB algorithm. In the course of the research, we found that for the original δ-GLMB algorithm, performance of the spawned target tracking is seriously insufficient in the environment of the low signal-to-noise ratio. For this problem, the biggest difficulty is spawned target birth detection, and we need to model spawned target. Therefore, this paper uses the characteristics, position and velocity of the spawned target, and multiple frames of measurements to detect the spawned target. By referring to parent target state arguments, we model spawned target based on δ-GLMB. Simulation results show that under low detection rate and strong clutters, the proposed algorithm can accurately estimate spawned targets, and the performance is significantly better than the original δ-GLMB algorithm.

Dimethyl phthalate(DMP), a biotoxic organic compound, has been listed as one of the priority control pollutants by China's Environmental Monitoring Center and the USA Environmental Protection Agency. Soil microorganism can accurately and quickly respond to the changes of soil environment and soil contamination. Therefore, it is necessary to study the response of soil microorganisms to DMP. This study investigated the impact of dimethyl phthalate(DMP) on the microbial community structure, diversity and signal regulation pathway in soils through metagenome sequencing. DMP were used to treat uncontaminated soil, and the final concentration of DMP was 0, 5, 10, 20, 40 mg·kg-1. Then, the samples were incubated for 20 days in dark and sequenced by metagenome. The results showed that the growth of degradation of aromatic compound was promoted and the growth of the remainder strain was inhibited by DMP contamination. Inhibitory effect was positively correlated with DMP concentration. DMP decreased microbial community diversity in soils. The total abundance of ABC transporters, two-component system(TCS) and phosphotransferase system(PTS) genes were increased by DMP contamination. The gene abundance of relative enzymes also was enhanced along with the increasing DMP concentration. Therefore, DMP contamination changed microbial community structure, and disturbed ecological balance and soil health in soils. The ecotoxicological effect of DMP on soil is of scientific significance and practical value to optimize the service function of environmental ecosystem and improve the environmental quality.

Plant growth-promoting rhizobacteria(PGPR)can secrete the growth hormone and promote soil nutrient cycling, thus, is an important germplasm resource of bio -fertilizer. In this study, the PGPR was isolated from the rice rhizosphere. According to 16S rDNA sequences, 10 strains were identifed, including 4 organic phosphorus bacteria (Bacillus pumilus LZP02, Bacillus aryabhattai LZP08, Staphylococcus epidermidis LZP10, Bacillus ginsengisoli LZP05), 3 inorganic phosphorus bacteria(Bacillus megaterium LZP03, Bacillus oryzaecorticis LZP04, Bacillus ginsengisoli LZP07)and 3 potassium bacteria(Bacillus aryabhattai LZP01, Bacillus subtilis LZP06, Bacillus licheniformis LZP09). The results from nutrient conversion analysis showed that Bacillus aryabhattai LZP01 and Bacillus subtilis LZP06 performed better on the potassium releasing ability. Bacillus pumilus LZP02 and Bacillus huizhouensis LZP05 performed better on the function of organic phosphorus. Bacillus megaterium LZP03 and Bacillus ginsengisoli LZP07 performed better on the function of inorganic phosphorus. Further, the hormone secretion capacity was measured for these 6 strains. The results showed that all 6 strains could produce auxin and gibberellin, and had the ability to synthesize iron carrier. Moreover, the results showed that Bacillus megaterium LZP03, Bacillus huizhouensis LZP05 and Bacillus subtilis LZP06 had stronger ability to promote the nutrient conversion and hormone secretion. Systematically, we believe that these three strains have great potential application on microbial fertilizer.