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Background: Viruses are the most abundant biological entities on the planet and drive biogeochemical cycling on a global scale. Our understanding of biogeography of soil viruses and their ecological functions lags significantly behind that of Bacteria and Fungi. Here, a viromic approach was used to investigate the distribution and ecological functions of viruses from 19 soils across China.Results: More than 60% of viral genome fragments could not be classified, representing potential new viruses. Among the 27 viral families identified, 15 families belonged to dsDNA viruses and 12 families belonged to ssDNA viruses. Soil samples clustered more significantly by geographical location than type of soil (agricultural and natural). Three clusters of viral communities were identified from North, Southeast and Southwest regions; these clusters differentiated using taxonomic as well as functional composition and were mainly driven by latitude. Phylogenetic analyses of the phoH gene showed a remarkable diversity and two new viral clades. Notably, five proteins involved in phosphorus (P) metabolism-related nucleotide synthesis functions, including dUTPase, MazG, PhoH, Thy1, and RNR, were mainly identified in agricultural soils. Conclusions: The present work revealed that soil viral communities and their functions were distributed across China according to geographical location, with latitude as the dominant driving factor. In addition, P metabolism genes encoded by these viruses probably drive the synthesis of nucleotides for their own genomes inside bacterial hosts, thereby affecting P cycling in the soil ecosystems.

The DPCC(deformation processed Cu-based in-situ composite) behaved better combined performance. In this paper, Cu-10Fe-1.5Ag and Cu-10Fe-1.5Ag-0.1Zr in-situ composites were prepared using different forming processes and annealing techniques. The microstructure evolution was explored by SEM during the plastic deformation. It was found that Fe fibers were produced during drawing process and changed from trees dendrite to fiber structure in the form of flake. The effect of Zr on thermal stability of composite was analyzed also. It was shown that the adding of Zr element was helpful to increase the thermal stability of Cu-Fe composite by multi elements compound.