Twin-solute, twin-dislocation and twin-twin interactions in magnesium

Magnesium alloys have received considerable research interest due to their lightweight, high specific strength and excellent castability. However, their plastic deformation is more complicated compared to cubic materials, primarily because their low-symmetry hexagonal closepacked (hcp) crystal structure. Deformation twinning is a crucial plastic deformation mechanism in magnesium, and twins can affect the evolution of microstructure by interacting with other lattice defects, thereby affecting the mechanical properties. This paper provides a review of the interactions between deformation twins and lattice defects, such as solute atoms, dislocations and twins, in magnesium and its alloys. This review starts with interactions between twin boundaries and substitutional solutes like yttrium, zinc, silver, as well as interstitial solutes like hydrogen and oxygen. This is followed by twin-dislocation interactions, which mainly involve those between {10[]2} tension or {10[]1} compression twins and 〈 a 〉 , 〈 c 〉 or 〈 c +-a 〉 type dislocations. The following section examines twin-twin interactions, which occur either among the six variants of the same {10[]2} or {10[]1} twin, or between different types of twins. The resulting structures, including twin-twin junctions or boundaries, tension-tension double twin, and compression-tension double twin, are discussed in detail. Lastly, this review highlights the remaining research issues concerning the interactions between twins and lattice defects in magnesium, and provides suggestions for future work in this area

Symmetric or asymmetric glide resistance to twinning disconnection?

Successive gliding of twinning disconnections (TDs) creates three-dimensional twins in parent crystal and accommodates shear deformation. It is generally recognized that TD is subject to the same Peierls stress as it glides forward or backward because of its dislocation character and the twofold rotation symmetry of the twin plane. Based on atomistic simulations, we demonstrate that the glide of TDs may be subject to a symmetric or asymmetric resistance corresponding to step character, symmetric resistance for A/A type steps but asymmetric resistance for A/B type steps, where A and B represent crystallographic planes in twin and matrix. Furthermore, we experimentally demonstrate that the asymmetric resistance results in asymmetric propagation and growth of twins in Mg alloys

NeRFTAP: Enhancing Transferability of Adversarial Patches on Face Recognition using Neural Radiance Fields

Face recognition (FR) technology plays a crucial role in various applications, but its vulnerability to adversarial attacks poses significant security concerns. Existing research primarily focuses on transferability to different FR models, overlooking the direct transferability to victim's face images, which is a practical threat in real-world scenarios. In this study, we propose a novel adversarial attack method that considers both the transferability to the FR model and the victim's face image, called NeRFTAP. Leveraging NeRF-based 3D-GAN, we generate new view face images for the source and target subjects to enhance transferability of adversarial patches. We introduce a style consistency loss to ensure the visual similarity between the adversarial UV map and the target UV map under a 0-1 mask, enhancing the effectiveness and naturalness of the generated adversarial face images. Extensive experiments and evaluations on various FR models demonstrate the superiority of our approach over existing attack techniques. Our work provides valuable insights for enhancing the robustness of FR systems in practical adversarial settings

Atomistic simulations of twin facets associated with three-dimensional { []011 } twins in magnesium

Twinning is a deformation mechanism that creates three-dimensional (3D) twin domains through the migration of twin facets. This occurs via the nucleation and glide of twinning disconnections (TDs), which can pile up to create twin facets. A comprehensive under- standing of twin facets associated with 3D twins, including their atomic structures and energies, is crucial for understanding deformation twinning. In this study, we propose a molecular statics/dynamics (MS/MD) approach to determine characteristic twin facets enclosing 3D non-equilibrium/equilibrium { [] 011 } twin domains, which has been much less studied than the counterpart { [] 012 } twin domains. The stability of different TD pile-up arrangement with varying line senses informs the morphology of 3D non-equilibrium twins, which are bounded by { 10 [] 0 } T ||{ [] 013 } M , { 10 [] 1 } T ||{0002} M and { 10 [] 3 } T ||{ 10 [] 3 } M coherent facets associated with pile-up of edge TDs, and discrete non-edge TDs aligned along CTBs with their line senses parallel to \u3c 4 [] 13 \u3e , \u3c 1 [] 01 \u3e , \u3c 5 [] [] 6 \u3e \u3c 2 [][] 3 \u3e or \u3c 10 [] 2 \u3e axes. Formation of semi-coherent facets of equilibrium twins is accompanied by rearrangement of TDs around misfit dislocations. 3D equilibrium { []011 } twins may comprise { 10 [] 1 } T ||{0002} M , { 14 [] 7 } T ||{ 3 [] 19 } M , { [] 6 [] 7 } T ||{ 5 [] 17 } M , { [] 4 [] 3 } T ||{ 3 [] 13 } M , { 01 [] 0 } T ||{ 01 [] 1 } M and { 0 [] 21 } T ||{ 0 [] 21 } M semi-coherent facets in \u3c 1 [] 10 \u3e , \u3c 4 [] 13 \u3e , \u3c 1 [] 01 \u3e , \u3c 5 [] [] 6 \u3e , \u3c 2 [] [] 3 \u3e and \u3c 10 [] 2 \u3e axes, respectively

Cardioprotective effect of Shenxiong glucose injection on acute myocardial infarction in rats via reduction in myocardial intracellular calcium ion overload

Purpose: To explore the cardioprotective effects and potential mechanisms of Shenxiong Glucose Injection (SGI) in rat acute myocardial infarction (AMI).Methods: AMI model was created by ligating left anterior descending coronary artery. After 7 days’ consecutive intravenous administration of SGI, serum samples were used to conduct biochemical analysis while hearts were excised and processed for infraction size, enzyme activity, histopathology and qPCR studies. Intracellular Ca2+ {(Ca2+)i} overload in H9c2 cells was measured by laser scanning confocal microscope (LSCM).Results: In AMI rats, pretreatment with SGI significantly ameliorated myocardial histopathologic damage. It exerted cardioprotective effect by decreasing myocardial infarct size, electrocardiogram (ECG) ST segment elevation, and CK, cTnI, BNP levels in serum. In addition, SGI significantly decreased calmodulin (CaM) and calmodulin-dependent protein kinase II (CaMK II) mRNA expression, but increased Ca2+-Mg2+-ATPase and Na+-K+-ATPase activities in myocardium. In doxorubicin (DOX)- induced H9c2 cells injury model, SGI reversed (Ca2+)i overload to protect cells.Conclusion: The results demonstrate SGI exerts cardioprotective effect by decreasing myocardial infarct size, restoring ST segment and reversing (Ca2+)i overload. It suggests that SGI may be a new clinical candidate to treat myocardial infarction.Keywords: Shenxiong glucose injection, Tanshinol, Ligustrazine, Myocardial infarction, Intracellular Ca2+ overload, Calmodulin, Calmodulin-dependent protein kinase I

Visible-light-driven coproduction of diesel precursors and hydrogen from lignocellulose-derived methylfurans

Photocatalytic hydrogen production from biomass is a promising alternative to water splitting thanks to the oxidation half-reaction being more facile and its ability to simultaneously produce solar fuels and value-added chemicals. Here, we demonstrate the coproduction of H2 and diesel fuel precursors from lignocellulose-derived methylfurans via acceptorless dehydrogenative C 12C coupling, using a Ru-doped ZnIn2S4 catalyst and driven by visible light. With this chemistry, up to 1.04\u2009g\u2009gcatalyst 121\u2009h 121 of diesel fuel precursors (~41% of which are precursors of branched-chain alkanes) are produced with selectivity higher than 96%, together with 6.0\u2009mmol\u2009gcatalyst 121\u2009h 121 of H2. Subsequent hydrodeoxygenation reactions yield the desired diesel fuels comprising straight- and branched-chain alkanes. We suggest that Ru dopants, substituted in the position of indium ions in the ZnIn2S4 matrix, improve charge separation efficiency, thereby accelerating C 12H activation for the coproduction of H2 and diesel fuel precursors

Evolution and coupling of “seepage field and chemical field” under regional grouting disturbance

In Huaibei coalfield, the technology of ground directional drilling and high-pressure grouting is widely used to control the karst water disaster of coal measures floor. After grouting, the filling and drainage path of the seepage field changes, and the grouting high pressure and the slurry water will change the distribution characteristics of the groundwater seepage field and chemical field of the injected target aquifer in a certain period of time. Taking Taoyuan Coal Mine in Huaibei Coalfield as the research object, the evolution model of seepage field and chemical field (referred to as “double field”) of the target layer under regional grouting disturbance is built by using the software of Feflow, the coupling mechanism of “double field” is discussed, and the Cl− which is less affected by the environment is selected as the simulation factor, and the analysis of the factors affecting solute transport under the “double field” coupling effect is carried out. On this basis, the mathematical model of solute diffusion under regional grouting disturbance is constructed. The results show that in the seepage field model after identification and verification, 71.9% of the points where the error between the simulated water level and the measured water level is less than 3m, and the simulation effect is good; Among the identified and verified chemical field models, the simulation effect of solute transport in mining area II4 is good, and the simulation value in mining area II1 is about 14.4 mg/L lower, with an error of about 6.6% of the actual value, less than 10%. The overall simulation effect is good. The Cl− in mining area II4 and II2 with relatively high permeability coefficient is easy to migrate and diffuse, while the rock in mining area II1 with low permeability coefficient is dense and has poor permeability. During the 50 years of model operation, it basically exists in the state of “stagnant water”. Based on the evolution characteristics of local seepage field in II4 mining area under grouting disturbance, it is considered that solute transport is mainly controlled by permeability coefficient, dispersion, hydraulic gradient, seepage velocity, grouting time, slurry specific gravity and other parameters. It is found that the concentration of Cl− reaches a peak within 18−22 years after the completion of grouting, and then begins to decrease, and reaching the equilibrium state before regional grouting approximately 40 years later. Based on the data obtained from multiple parameter setting operations, a mathematical model of solute diffusion under the “double field” coupling is established. The data with error rate less than 10% accounts for 81.4%, which indicates that the established mathematical model of solute diffusion is basically reliable. This study can provide scientific basis for the study of the water environment evolution of the injected target aquifer under the regional grouting disturbance and the prediction and early warning of coal mine water disasters, and has important theoretical and practical significance

The LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) in the Southern Galactic Cap I. The Spectroscopic Redshift Catalog

We present a spectroscopic redshift catalog from the LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) in the Southern Galactic Cap (SGC), which is designed to observe all sources (Galactic and extra-galactic) by using repeating observations with a limiting magnitude of $r=18.1~mag$ in two $20~deg^2$ fields. The project is mainly focusing on the completeness of LAMOST ExtraGAlactic Surveys (LEGAS) in the SGC, the deficiencies of source selection methods and the basic performance parameters of LAMOST telescope. In both fields, more than 95% of galaxies have been observed. A post-processing has been applied to LAMOST 1D spectrum to remove the majority of remaining sky background residuals. More than 10,000 spectra have been visually inspected to measure the redshift by using combinations of different emission/absorption features with uncertainty of $\sigma_{z}/(1+z)<0.001$. In total, there are 1528 redshifts (623 absorption and 905 emission line galaxies) in Field A and 1570 redshifts (569 absorption and 1001 emission line galaxies) in Field B have been measured. The results show that it is possible to derive redshift from low SNR galaxies with our post-processing and visual inspection. Our analysis also indicates that up to 1/4 of the input targets for a typical extra-galactic spectroscopic survey might be unreliable. The multi-wavelength data analysis shows that the majority of mid-infrared-detected absorption (91.3%) and emission line galaxies (93.3%) can be well separated by an empirical criterion of $W2-W3=2.4$. Meanwhile, a fainter sequence paralleled to the main population of galaxies has been witnessed both in $M_r$/$W2-W3$ and $M_*$/$W2-W3$ diagrams, which could be the population of luminous dwarf galaxies but contaminated by the edge-on/highly inclined galaxies ($\sim30\%$).Comment: 19 pages, 14 figures, 2 MRT, accepted by ApJ

Unraveling the evolutionary dynamics of the TPS gene family in land plants

Terpenes and terpenoids are key natural compounds for plant defense, development, and composition of plant oil. The synthesis and accumulation of a myriad of volatile terpenoid compounds in these plants may dramatically alter the quality and flavor of the oils, which provide great commercial utilization value for oil-producing plants. Terpene synthases (TPSs) are important enzymes responsible for terpenic diversity. Investigating the differentiation of the TPS gene family could provide valuable theoretical support for the genetic improvement of oil-producing plants. While the origin and function of TPS genes have been extensively studied, the exact origin of the initial gene fusion event - it occurred in plants or microbes - remains uncertain. Furthermore, a comprehensive exploration of the TPS gene differentiation is still pending. Here, phylogenetic analysis revealed that the fusion of the TPS gene likely occurred in the ancestor of land plants, following the acquisition of individual C- and N- terminal domains. Potential mutual transfer of TPS genes was observed among microbes and plants. Gene synteny analysis disclosed a differential divergence pattern between TPS-c and TPS-e/f subfamilies involved in primary metabolism and those (TPS-a/b/d/g/h subfamilies) crucial for secondary metabolites. Biosynthetic gene clusters (BGCs) analysis suggested a correlation between lineage divergence and potential natural selection in structuring terpene diversities. This study provides fresh perspectives on the origin and evolution of the TPS gene family