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Abstract: Morphology, orientation and diffraction patterns of δ-Ni2Si precipitates in a Cu–Ni–Si alloy are investigated by TEM and HREM. Many disk-shaped nanosized δ-Ni2Si precipitates are uniformly distributed in Cu–1.5wt%Ni–0.34wt%Si alloy in an over-aging condition. The δ-Ni2Si precipitates preserve an orthogonal structure with a =0.708±0.005nm, b =0.504±0.005nm, and c =0.364±0.005nm. The orientation relationships of six variants of δ-Ni2Si precipitates with Cu-matrix can be determined as (100)p||{001}Cu, [100]p||〈110〉Cu and [010]p||〈110〉Cu. Two typical diffraction pattern models under [001]Cu and [111]Cu zone axis are simulated according to diffraction effects of multiple variants, secondary diffraction and the size of particles, which coincide with the experimental results perfectly. [Copyright &y& Elsevier]

Abstract: A method based on Euler space was adopted in magnesium alloy for rigorous twinning analyses, in which twinning processes were considered consecutive rotation (φ′1, Ф′, φ′2,φ″1, Ф″, φ″2……). This method was successful in rigorous twinning identification and Schmid factor calculation in the current work. It was found that all the dominating twin variants formed with largest SF while secondary twinning systems may be activated in a more complex way under the influence of stress location caused by deformation. [Copyright &y& Elsevier]

Abstract: Hot-rolling experiments with a reduction from 10% to 60% in single pass were conducted on AZ31B twin-roll cast sheets. Optical microscope (OM), electron backscattered diffraction (EBSD) tests and transmission electron microscope (TEM) were used to investigate twinning and DRV/DRX behaviors at different stage in the hot-rolling process. Two types of twinning occurred in the initial stage of hot-rolling process. DRV and discontinuous recrystallization dominated at moderate strain while continuous DRX took place homogeneously throughout original grains at the largest strains. [Copyright &y& Elsevier]

Abstract: Water stress is known to alter cytosine methylation, which generally represses transcription. However, little is known about the role of methylation alteration in maize under osmotic stress. Here, methylation-sensitive amplified polymorphism (MSAP) was used to screen PEG- or NaCl-induced methylation alteration in maize seedlings. The sequences of 25 differentially amplified fragments relevant to stress were successfully obtained. Two stress-specific fragments from leaves, LP166 and LPS911, shown to be homologous to retrotransposon Gag–Pol protein genes, suggested that osmotic stress-induced methylation of retrotransposons. Three MSAP fragments, representing drought-induced or salt-induced methylation in leaves, were homologous to a maize aluminum-induced transporter. Besides these, heat shock protein HSP82, Poly [ADP-ribose] polymerase 2, Lipoxygenase, casein kinase (CK2), and dehydration-responsive element-binding (DREB) factor were also homologs of MSAP sequences from salt-treated roots. One MSAP fragment amplified from salt-treated roots, designated RS39, was homologous to the first intron of maize protein phosphatase 2C (zmPP2C), whereas – LS103, absent from salt-treated leaves, was homologous to maize glutathione S-transferases (zmGST). Expression analysis showed that salt-induced intron methylation of root zmPP2C significantly downregulated its expression, while salt-induced demethylation of leaf zmGST weakly upregulated its expression. The results suggested that salinity-induced methylation downregulated zmPP2C expression, a negative regulator of the stress response, while salinity-induced demethylation upregulated zmGST expression, a positive effecter of the stress response. Altered methylation, in response to stress, might also be involved in stress acclimation. [Copyright &y& Elsevier]

Normal recrystallization and abnormal recrystallization induced by Ni in pure tungsten (W) sheet were studied by EBSD. It was demonstrated that (001)[1 1 ¯ 0] and (111)[1 1 ¯ 0] textures in the deformed W sheet remain after normal recrystallization, but with lower densities. In addition, (001)[0 1 ¯ 0] and (111)[ 1 ¯ 1 ¯ 2] textures arise after recrystallization, which can be explained on the subgrain coarsening recrystallization mechanism. During the abnormal recrystallization of W sheets, grain boundary phase change occurred first between Ni and W, which leads to the formation of liquid-like films on grain boundaries. The occurrence of grain boundary phase change depends mainly on the grain boundary misorientation angle. Grain boundaries with liquid-like film will migrate under the driving force of eliminating deformation storage energy, which gives rise to abnormal recrystallization in W sheets. After abnormal recrystallization, (001)[1 1 ¯ 0] and (111)[1 1 ¯ 0] textures disappeared, leaving only weak texture near (001)[0 1 ¯ 0]. [ABSTRACT FROM AUTHOR]