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CoCrCuFeNi high-entropy alloy (HEA) has distinctive properties such as good ductility and corrosion resistance, whereas its low strength severely limits its engineering applications for structural components. To solve this issue, herein, laminated CoCrCuFeNi HEA was synthesized using a combined powder metallurgy and spark plasma sintering technique. Effects of ball milling durations on powder morphologies, microstructural evolution, mechanical properties and fracture behaviors of the sintered CoCrCuFeNi HEA were investigated. Results show that the average flake diameter of CoCrCuFeNi powders firstly increases (from ~ 60.44 μm to ~ 160.29 μm) but then sharply decreases (~37.59 μm) with the further increase of ball milling duration up to six hours. Microstructure of sintered CoCrCuFeNi HEA exhibits a flake feature with the bimodal structure (i.e., with both fine- and coarse-grained regions). Cu-rich spherical nanoparticles with an average size of ~ 30 nm are uniformly spread in the CoCrCuFeNi matrix. After two-hour ball milling, the yield strength of the sintered HEA is 706.9 MPa and its uniform elongation is 22.2%, which are much higher than those of the original CoCrCuFeNi HEA (i.e., with a yield strength of 569.3 MPa and a uniform elongation of 3.9%). The enhanced mechanical properties are mainly attributed to the formation of bimodal grains, dislocation strengthening and second phase strengthening due to Cr2O3 and Cu-rich spherical nanoparticles. [ABSTRACT FROM AUTHOR]

Deformation processing is a key strategy to improve the strength‐ductility of metal matrixcomposites. Herein, TiC/TC4 composites are spark plasma sintered usingreinforcement precursors of reduced graphene oxide to reinforce TC4 matrix. Inorder to investigate the hot deformation behaviors and mechanisms of TiC/TC4 composites, the composites are hot compressed over temperature range of 870–1070 °C and strain range of 0.001–10 s−1. The results indicate that the optimal processing window of hot deformation ismainly within the temperature range of 890–970 °C and the strain rate range of 0.01–0.1 s−1. The flow instability of TiC/TC4 composites occurs in the temperature range of 890–930 and 1000–1060 °C at the strain rate range from 0.1 to 10 s−1. The thermal deformation mechanism of TiC/TC4 composites in the processingwindow region involves continuous dynamic recrystallization and discontinuous dynamic recrystallization. TiC can effectively hinder thedislocation motion, leading to the generation of high‐density dislocationsaround TiC. Consequently, this promotes sub‐grains formation and rotation,facilitating CDRX. Meanwhile, TiC particle induces high‐angle grain boundarymigration and provides more nucleation sites for recrystallized grains. These findings enhance understanding the role of hot deformation behaviors of Ti compositesand provide insights into their deformation processing. [ABSTRACT FROM AUTHOR]

Induced shock waves significantly influence cavitation evolution and load characteristics, offering a feasible means to control cavitation. However, the complex coupling mechanism between shock waves and cavitation remains to be fully elucidated. This study uses numerical simulations to investigate the effects of shock wave characteristics on cavitation dynamics and load characteristics under free field, near-rigid wall, and near-elastic–plastic wall conditions. Results show that the increased shock wave intensity accelerates cavitation collapses, increases collapse loads, and enhances the peak velocities of collapsing water jets, exacerbating damage to elastic–plastic structures. Reflection waves from rigid walls enhance the nonlinear characteristics of the cavitation collapses, leading to different collapse modes. Elastic–plastic thin walls, with limited reflection capability, exert a weaker influence on the dynamics of primary cavitation collapses but significantly alter the evolution of secondary collapses and their load intensities. The study provides a fitting formula for the relationship between burst distance, peak jet velocity, and corresponding time, which predicts the parameters of water jets from cavitation collapses within a specific range. These findings deepen the understanding of the interactions between cavitation and induced shock waves, significantly aiding in controlling and utilizing cavitation effects. [ABSTRACT FROM AUTHOR]

In this work, low‐cost TiC/Ti composites with high strength‐ductility and superior abrasive resistance are fabricated using hydrogenation‐dehydrogenation powder and graphene nanoplates as raw materials via spark plasma sintering (SPS) and hot rolling (HR) processes. Effects of in situ TiC contents on the microstructure, mechanical properties and wear behavior of the TiC/Ti composites are investigated. The results indicate that the microstructure after HR is equiaxial α‐Ti grain with random orientation. The TiC/Ti composite exhibits higher strength compared to pure Ti matrix after HR. The ultimate tensile strength of the 1.82 vol% TiC/Ti composite is 1059 MPa, which represents a 49.3% increase compared to pure Ti. The coefficient of friction of the TiC/Ti composite decreases from 0.51 to 0.43 with an increase in TiC contents. The improvement of strength is attributed to refinement strengthening, dislocation strengthening and TiC load transfer. In addition, the increase of TiC contents will reduce the friction coefficient of the composites, thereby improving the wear resistance of the composites. The article proposes a cost‐effective method with good prospects for industrial applications to improve the mechanical properties and wear‐resistant properties of the titanium alloys. [ABSTRACT FROM AUTHOR]

Achieving high strength and ductility for Ti alloys and their composites has been a key objective and also a great challenge for their engineering applications. Herein, we designed TiC/(TC18 + TC4) composites with bionic and heterogeneously lamella structures, achieving an exceptional combination of high strength and ductility. This is attributed to the formation of alternative layers of TC18-coarse grains and TC4-fine grains with TiC precipitated at their interfaces. Plastic incompatibility of these three-phases produces significant hetero-deformation-induced hardening, induced by mutual interactions of heterogeneous grains and TiC precipitates, as well as activation of extensive < c + a > slip groups. An optimal yield strength of ∼ 1168 MPa and a uniform elongation of ∼ 6% have been achieved, which are much higher than those of the TC4 matrix (i.e. ∼919 MPa and ∼2%). This study provides a new strategy for composite designs to overcome the trade-off dilemma for strength-ductility. [ABSTRACT FROM AUTHOR]

Long non-coding RNAs (lncRNAs) could modulate expression of immune checkpoints (ICPs) by cooperating with immunity genes in tumor immunization. However, precise functions in immunity and potential for predicting ICP inhibitors (ICI) response have been described for only a few lncRNAs. Here we present an integrated framework that leverages network-based analyses and Bayesian network inference to identify the regulated relationships including lncRNA, ICP and immunity genes as ICP-related LncRNAs mediated Core Regulatory Circuitry Triplets (ICP-LncCRCTs) that can make robust predictions. Hub ICP-related lncRNAs such as MIR155HG and ADAMTS9-AS2 were highlighted to play central roles in immune regulation. Specific ICP-related lncRNAs could distinguish cancer subtypes. Moreover, the ICP-related lncRNAs are likely to significantly correlated with immune cell infiltration, MHC, CYT. Some ICP-LncCRCTs such as CXCL10-MIR155HG-ICOS could better predict one-, three- and five-year prognosis compared to single molecule in melanoma. We also validated that some ICP-LncCRCTs could effectively predict ICI-response using three kinds of machine learning algorithms follow five independent datasets. Specially, combining ICP-LncCRCTs with the tumor mutation burden (TMB) improves the prediction of ICI-treated melanoma patients. Altogether, this study will improve our grasp of lncRNA functions and accelerating discovery of lncRNA-based biomarkers in ICI treatment. An integrated framework to identify immune checkpoint-related lncRNA core regulatory circuitry triplets has the potential to improve our understanding of lncRNA functions and accelerate the discovery of lncRNA-based biomarkers for immune checkpoint inhibitor treatment. [ABSTRACT FROM AUTHOR]

Long non-coding RNAs (lncRNAs) could modulate expression of immune checkpoints (ICPs) in tumor-immune. However, precise functions in immunity and potential for predicting ICP inhibitors (ICI) response have been described for only a few lncRNAs. Here, a multiple-step pipeline was developed to identify cancer- and immune-context ICP and lncRNA cooperative regulation pairs (ICPaLncCRPs) across cancers. Immune-related ICPs and lncRNAs were extracted follow immune cell lines and immunologic constant of rejection groups. ICPaLncCRP networks were constructed, which likely to modulate tumor-immune by specific patterns. Common and specific hub ICPaLncs such as MIR155HG, TRG-AS1 and PCED1B-AS1 maybe play central roles in prognosis and circulating. Moreover, these hub ICPaLncs were significantly correlated with immune cell infiltration based on bulk and single-cell RNA sequencing data. Some ICPaLncCRPs such as IDO1-MIR155HG could predict three- and five-year prognosis of melanoma in two independent datasets. We also validated that some ICPaLncCRPs could effectively predict ICI-response follow six independent datasets. Collectively, this study will enhance our understanding of lncRNA functions and accelerate discovery of lncRNA-based biomarkers in ICI treatment. [ABSTRACT FROM AUTHOR]

Although substantial advances have been made regarding synthetic chiral assemblies, obtaining the two‐dimensional (2D) system with a sophisticated supramolecular chirality remains challenging. Herein, we report the switchable supramolecular chiral 2D materials via donor‐acceptor interaction between a pyrene amphiphile and 7,7,8,8‐tetracyanoquinodimethane (TCNQ). The resulting supramolecular chiral sheets spontaneously disassemble when TCNQ is irreversibly photo‐reduced to its anion. Subsequent additions of TCNQ drive the disassembled molecules to repeatedly form optically active sheet structures, demonstrating that the assembled materials exist transiently only while TCNQ is supplied. The chiral sheets emit intense circularly polarized light with a large luminescence dissymmetric factor (glum). [ABSTRACT FROM AUTHOR]

To overcome the tradeoff between strength and ductility of materials and obtain titanium matrix composites with excellent mechanical properties, in this study, the in situ-synthesized TiC particles and Ti-Al-V-Mo-Cr (Ti1400) alloy-reinforced Ti6Al4V (TC4) matrix composites ((Ti1400 + TiC)/TC4) were fabricated by low-energy ball milling and spark plasma sintering. The inhomogeneous distribution of TiC particles and Ti1400 alloy, as well as the compositional and structural transition zone, were characterized. The TiC/TC4 composite displayed a significantly higher yield strength and tensile strength compared to the TC4 alloy. However, the total elongation of the TiC/TC4 composite was only 57% of that in the TC4 alloy. In contrast, the (Ti1400 + TiC)/TC4 composites exhibited noticeably higher total elongation than the TiC/TC4 composite. Furthermore, the tensile strength of the composite increased with the increase in Ti1400 alloy content. The increase in strength can be attributed to solid solution strengthening and fine grain strengthening. The compositional and structural transition zone, formed by element diffusion, provided a better interface combination between the reinforcements and TC4 matrix. In the transition zone and Ti1400 region, a large number of α/β interfaces can effectively alleviate the stress concentration, and the increase in the β phase can bear more plastic deformation, which is conducive to improving the elongation of the composite. As a result, the (Ti1400 + TiC)/TC4 composites exhibited simultaneous improvements in strength and ductility. [ABSTRACT FROM AUTHOR]

When ceramic particles are incoherent with copper matrices, or when large coherent strains exist due to the differences between their crystal structure and lattice parameters in traditional dispersion-strengthened copper alloys, the strengthening effect of dispersoids at high temperatures is reduced. In the present work, a Cu-0.48Al-3.5Yb2O3 alloy was fabricated by mechanical alloying and spark plasma sintering. The investigation results prove that completely coherent inert ceramic particle YbAlO3 without coherent strains is introduced into the copper matrix. The microstructural evolution and thermal stability of the alloy after annealing at high temperatures are investigated and discussed, and it is found that the alloys exposed at 600~800 °C for 3 h exhibit excellent thermal stability and exceptional structural stability. The exceptional resistance to grain growth in the alloy can be attributed to the Zener pinning effect provided by the fine dispersion of YbAlO3 particles. High-density geometrically necessary dislocation (GND) is retained in the alloy even after annealing at 800 °C for 3 h, as is the presence of parallel GND rows because they do not easily react with opposite rows to annihilate the dislocation. At the same time, dispersed YbAlO3 acts as a strong obstacle to moving the GND. The present work proves that the structural stability of copper can be significantly improved by introducing completely coherent dispersed particles. [ABSTRACT FROM AUTHOR]

Ball milling process has become one of the effective methods for dispersing graphene nanoplates (GNPs) uniformly into matrix; however, there are often serious issues of structural integrity and interfacial reactions of GNPs with matrix. Herein, GNPs/Ti‐6Al‐4V (GNPs/TC4) composites are synthesized using high energy ball milling (HEBM) and spark plasma sintering. Effects of ball milling on microstructural evolution and interfacial reactions of GNPs/TC4 composite powders during HEBM are investigated. As ball milling time increase, particles size of TC4 is first increased (e.g., ≈104.15 μm, 5 h), but then decreased to ≈1.5 μm (15 h), which is much smaller than that of original TC4 powders (≈86.8 μm). TiC phases are in situ formed on the surfaces of TC4 particles when ball milling time is 10Thinsp;h. GNPs/TC4 composites exhibit 36–103% increase in compressive yield strength and 57–78% increase in hardness than those of TC4 alloy, whereas the ductility is reduced from 28% to 7% with an increase of ball milling time (from 2 to 15 h). A good balance between high strength (1.9 GPa) and ductility (17%) of GNPs/TC4 composites is achieved when the ball milling time is 10 h, attributing to the synergistic effects of grain refinement strengthening, solid solution strengthening, and load transfer strengthening from GNPs and in situ formed TiC. [ABSTRACT FROM AUTHOR]

Although supramolecular one‐dimensional (1D) and two‐dimensional (2D) structures with various unique properties have been extensively studied, the reversible switching between tubules and sheets via lateral association remains challenging. Here, we report the unique structures of a supramolecular tubular bamboo culm in which the hollow‐tubular interior is separated, at intervals, by nodes per 1.3 nm. Interestingly, the discrete tubules are able to hierarchically assemble into a flat sheet in response to an aromatic guest. The addition of trans‐azobenzene, as a guest, enables the tubules to form a hierarchical sheet assembly via the lateral interaction. The hierarchical sheet structures are disassembled into their constituent tubules upon UV irradiation due to trans‐cis isomerization. The recovery from cis‐azobenzene to trans‐form induces repeatedly the hierarchical sheet assembly, indicative of a reversible switching behavior between tubules and sheets triggered by an external stimulus. [ABSTRACT FROM AUTHOR]

W-Cu composites, as a traditional material, have attracted tremendous research interest in fields such as electric engineering, electronic information, aerospace, weapons, etc., owing to their excellent properties. This critical review presents and discusses the current development of W-Cu composites. After introduction of the synthesis methods for W-Cu composites, including the conventional and modern preparation approaches, we focus on the description of the improvement of mechanical properties and arc-erosion properties by modification techniques. Finally, the advantages of W-Cu composites in applications such as electrical contacts, electronic packaging materials, and heat sinks, as well as military materials, are described. [ABSTRACT FROM AUTHOR]

In this paper, arc ablation behavior of tungsten-copper (WCu) alloy contacts was investigated by the measurement of weight-loss, or erosion rate, and microstructures of tungsten-copper alloy contacts were examined by using scanning electron microscopy after electrical breakdown process. Experimental results showed that the arc erosion process started at the tiny sharp edges, then the arc spreaded on the second phases, or copper phase on the surface. Because of electrons/ions bombardment, the rapid evaporation and sputtering of liquid copper droplets were serious. As a result, an even contact surface became rugged, and tungsten skeleton remained because of being less eroded. With the increase of applied breakdown voltage, the ablation of tungsten-copper alloy became more significant. The WCu alloys with a higher content of copper showed more severe erosion rate as compared with that with a higher tungsten content under the same erosion conditions. Furthermore, when the number of breakdown is less, WCu alloys with a high copper content are easier for erosion for the conditions of fewer numbers of breakdowns. Whereas, WCu alloys with a high content of tungsten are easier for ablation for the conditions with many times of arc breakdown. [ABSTRACT FROM AUTHOR]

Energy piles are an emerging energy technology for both structural and thermal purposes. To support structure load, piles are always used in groups with raft; however, the cost and complexity of field tests and numerical modelling limits the research on the bearing characteristics of energy pile group. In this paper, exponential model was applied to simulate the thermo-mechanical soil-pile interaction of energy pile group. Axial load transfer (τ-z) analysis was first performed to calculate the shear stress distribution in the soil, then matrix displacement method was introduced to determine the thermo-mechanical response of energy pile group. The validity of the analytical model was tested against field tests and numerical results. A case study was further performed to analyze the influence of thermal cycles and arrangement of thermally active piles on the bearing response of the whole pile group. Test results show that with the thermally activated pile in pile group, (1) differential settlement increases with thermal cycle numbers; (2) the axial force of thermally active pile increases during heating process and decreases during cooling process, and this trend varies for the surrounding nonthermal piles; (3) induced load on thermal pile increases with thermal cycles, but decreases for nonthermal piles. The proposed analytical model is expected to serve as a simple and convenient alternative for the preliminary analysis on the bearing characteristics of energy group pile. [ABSTRACT FROM AUTHOR]

Nanocomposite powders based on metal-coated graphene were synthesized using an in-situ co-reduction method in order to improve wettability and interfacial bonding between graphene and metal. Graphene oxide (GO) of 2~3 atomic layers was synthesized using the Hummer's method with graphite as a raw material and then dispersed into a dispersing agent solution mixed with N-Methyl pyrrolidone and deionized water to form a homogeneous GO suspension, which was finally added into electroless plating solutions for the reduction process. Copper-coated graphene (Cu@graphene) and nickel-coated graphene (Ni@graphene) were synthesized using this one-step and co-reduction method by mixing salt solutions containing metal ions and GOs into the plating solution. The Cu ions or Ni ions were adsorbed and bonded onto the edges and surfaces of graphene, which was reduced from the GOs using a strong reducing agent of ascorbic acid or sodium borohydride. Crystalline Cu particles with an average size of about 200 nm were formed on the surface of graphene, whereas amorphous or nanocrystalline Ni particles with an average size of 55 nm were formed on the surface of graphene. Distribution of these metal particles on the graphene is homogeneous and highly dispersed, which can effectively improve the sinterability of composite powders. Cohesive energy distribution between graphene and metal interface was analyzed using first-principle calculation method. Formation mechanism of metal coated graphene was identified to be that both the GO and metal ions were simultaneously reduced in the reducing agents and thus a chemical bonding of graphene/metal was formed between the metal particles and graphene. [ABSTRACT FROM AUTHOR]