• Title/Summary/Keyword: Chern numbers

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SECOND CHERN NUMBERS OF VECTOR BUNDLES AND HIGHER ADELES

  • Osipov, Denis V.
    • Bulletin of the Korean Mathematical Society
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    • v.54 no.5
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    • pp.1699-1718
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    • 2017
  • We give a construction of the second Chern number of a vector bundle over a smooth projective surface by means of adelic transition matrices for the vector bundle. The construction does not use an algebraic K-theory and depends on the canonical ${\mathbb{Z}}-torsor$ of a locally linearly compact k-vector space. Analogs of certain auxiliary results for the case of an arithmetic surface are also discussed.

SIX DIMENSIONAL ALMOST COMPLEX TORUS MANIFOLDS WITH EULER NUMBER SIX

  • Donghoon Jang;Jiyun Park
    • Bulletin of the Korean Mathematical Society
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    • v.61 no.2
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    • pp.557-584
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    • 2024
  • An almost complex torus manifold is a 2n-dimensional compact connected almost complex manifold equipped with an effective action of a real n-dimensional torus Tn ≃ (S1)n that has fixed points. For an almost complex torus manifold, there is a labeled directed graph which contains information on weights at the fixed points and isotropy spheres. Let M be a 6-dimensional almost complex torus manifold with Euler number 6. We show that two types of graphs occur for M, and for each type of graph we construct such a manifold M, proving the existence. Using the graphs, we determine the Chern numbers and the Hirzebruch χy-genus of M.

Effects of Fowl Dropping, Saw Dust and Rice Hull on Soil Microflora in vitro (실내배양에서 생계분, 톱밥 및 왕겨 첨가가 토양미생물상에 미치는 효과)

  • Yang, Chang-Sool;Kong, Hye-Suk
    • Korean Journal of Soil Science and Fertilizer
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    • v.29 no.1
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    • pp.53-59
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    • 1996
  • This study was conducted to evaluate the effects of fowl dzopping. saw dust and rice hall on the soil microflora in vitro. The experiment was designed in seven treatments with the various organic materials and they were only soil (control). soil + fowl dropping (S+F), soil+fowl dropping+rice hull (S+F+R) soil+fowl dropping*saw dust (S+F+S). soil+chemical fertilizer (S+C.F), fowl dropping+rice hull (F+R) and fowl dropping+saw dust (F+S). All the samples of treatment were incubated in $28{\pm}2^{\circ}C$ condition and tested the activity of soil microflora for 84 days The activity of fungi, total bacteria, gram-negative bacteria and actinomycetes showed the highest values at, twenty-first day and the spore-forming bacteria was at forty-second day after incubation. The number of fungi and gram-negative bacteria showed the highest values in the treatment of F+S, the spore-forming bacteria and the actinomycetes were in the S+F+S. and the number of total bacteria was in the F+C.F., but in the treatment of F+R. all the microorganism except fungi showed the lowest values in their numbers. The composition ratio of dead bacteria was higher in the treatments of S+F+R and F+R than in those of others as 70% and 40% respectively. Actinomycetes isolated from the treatments of S+F and S+F+S were identified as Streptomyces sp.. Nocardia sp., Micromonospora sp. Actinomadura sp. and Saccharomonospora sp.

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