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CuSn8Ni alloy powders were deposited on the low carbon steel plate by laser cladding technology to prepare a CuSn8Ni/ST37-2G steel bimetallic bearing material. Microstructure, microhardness, and interfacial elemental diffusion of the CuSn8Ni laser clad coating were investigated. The optimum process parameters for laser cladding the CuSn8Ni alloy were obtained. The results showed that when the laser power was 1300 W, scanning speed was 8 mm/s and the powder feed speed was 0.5 rpm, the CuSn8Ni laser clad layer had an excellent metallurgical bond with the matrix and had no apparent defects. The laser clad layer had a dendritic microstructure. It mainly consisted of Sn-containing a-Cu solid solution and interdendritic (a+d) eutectoid. Cu and Fe elements had significant element diffusion behaviours, and the diffusion distance was about 1 to 2 µm. The average hardness of the coating was 128.6 HV, twice that of the traditional Cu-Pb bearing material. [ABSTRACT FROM AUTHOR]

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1134/S0022476624050287 [ABSTRACT FROM AUTHOR]

The concentrations and stoichiometry of soil carbon (C), nitrogen (N), and phosphorus (P) have critical implications for nutrient cycling and ecosystem function. While their high sensitivity to atmospheric N deposition is well known, it remains unclear for the soil depth-dependence of such responses to N deposition. Here, we examined the responses of soil C : N : P stoichiometry at three soil depths in the upper humus horizon (0–5, 5–10, and 10–20 cm) of Haplic Chernozem (Loamic) across a gradient of urea addition rates (0, 2, 10, 20, and 50 g N m–2 year–1) after five years treatments in a hay-harvest meadow steppe of northern China. We found that the effects of increasing N addition rates on the concentrations and stoichiometry of soil C, N and P did not depend on soil depth, though those parameters varied greatly across different soil layers. Across all soil depths, the concentrations of soil C and N increased with increasing N addition rates, but soil P concentration was not affected by N addition. The higher sensitivity of soil N than soil C to N enrichment resulted in decreasing soil C : N ratio across the N addition gradient, especially for the surface soil layer. Soil N : P ratio showed a positive response to the increases of N addition rates. The unbalanced responses of soil C, N, and P concentrations to N enrichment, as indicated by the decreases of soil C : N ratio and the increases of soil N : P ratio across the N addition gradient, highlighted the role of N enrichment in decoupling soil nutrient cycling in the temperate steppe. [ABSTRACT FROM AUTHOR]

We perform a global QCD analysis of high energy scattering data within the JAM Monte Carlo framework, including a coupling to a dark photon that augments the Standard Model (SM) electroweak coupling via kinetic mixing with the hypercharge B boson. We first set limits on the dark photon mass and mixing parameter assuming that the SM is the true theory of Nature, taking into account also the effect on g – 2 of the muon. If instead we entertain the possibility that the dark photon may play a role in deep-inelastic scattering (DIS), we find that the best fit is preferred over the SM at 6.5σ, even after accounting for missing higher order uncertainties. The improvement in χ2 with the dark photon is stable against all the tests we have applied, with the improvements in the theoretical predictions spread across a wide range of x and Q2. The largest improvement corresponds to the fixed target and HERA DIS data, while the best fit yields a value of g – 2 which significantly reduces the disagreement with the latest experimental determination. [ABSTRACT FROM AUTHOR]