4 research outputs found

    Density-dependent NN-interaction from subleading chiral 3N-forces: short-range terms and relativistic corrections

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    We derive from the subleading contributions to the chiral three-nucleon force (short-range terms and relativistic corrections, published in Phys. Rev. C84, 054001 (2011)) a density-dependent two-nucleon interaction VmedV_\text{med} in isospin-symmetric nuclear matter. The momentum and kfk_f-dependent potentials associated with the isospin operators (11 and τ1 ⁣ ⁣τ2 \vec\tau_1\!\cdot\!\vec\tau_2) and five independent spin-structures are expressed in terms of loop functions, which are either given in closed analytical form or require at most one numerical integration. Our results for VmedV_\text{med} are most helpful to implement subleading chiral 3N-forces into nuclear many-body calculations.Comment: 16 pages, 5 figure

    Corrosion Failure Cause Analysis of Buried Pipelines in Oil and Gas Stations

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    Objective: To explore the failure cause of buried pipelines in an oil and gas station. Method: The chemical elements and metallographic structure of the failed pipes were analyzed to evaluate whether the pipe body meets the requirements of relevant standards; the morphology and composition of the corrosion products were analyzed to discover the cause of corrosion. Result: The metal surface was rough and full of pitting pits with severe localized corrosion, and no crack of the metallic matrix was found. The corrosion products mainly contain Fe3O4 and a small amount of FeCO3, wherein Fe3O4 is the secondary corrosion product formed in the air, and FeCO3 is the corrosion product of CO2 in an oil and gas environment. The surface of the corroded product is loose in structure and easy to peel off, leading to further corrosion of the metallic matrix. Conclusion: The pipeline corrosion failure was caused by CO2-induced corrosion failure in the medium

    GL9 from Oryza glumaepatula controls grain size and chalkiness in rice

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    Grain size is a key factor influencing grain yield and appearance quality in rice. We identified twelve quantitative trait loci (QTL) for grain length (GL), nine for grain width (GW), and nine for 1000-kernel weight (TKW) using GLU-SSSLs, which are single-segment substitution lines with Oryza glumaepatula as donor parent and Huajingxian 74 (HJX74) as recipient parent. Among the QTL, qGL1-2, qGL1-4, qGL9-2, qGW2-2, qGW9-1 and qTKW9-2 contributed to high grain yield. GL9 was identified as a candidate gene for qGL9-2 by map-based cloning and sequencing, and is a novel allele of GS9. The kernel of NIL-gl9 was slenderer and longer than that of HJX74, and the TKW and grain yield per plant of NIL-gl9 were higher than those of HJX74. The proportion of grain chalkiness of NIL-gl9 was much lower than that of HJX74. Thus, gl9 increased grain yield and appearance quality simultaneously. Three pyramid lines, NIL-gs3/gl9, NIL-GW7/gl9 and NIL-gw8/gl9, were developed and the kernel of each was longer than that of the corresponding recipient parent lines. The gl9 allele may be beneficial for breeding rice varieties with high grain yield and good appearance quality