Explore the vast range of titles available.

Traditional metal alloys require energy-intensive processes to manage atomic complexity for improved strength and toughness, with stringent control over impurities and processing conditions. High-/medium-entropy alloys (HEAs/MEAs) offer a sustainable alternative by introducing atomic complexity with fewer constraints, enabling unique phase transitions. Here, a Cu–Au–Ag MEA is fabricated using vacuum suspension melting followed by heat treatment. The alloy exhibits three distinct levels of heterogeneous structures: micron-scale phase separation, nano-ordered L1 2 phase, and chemical short-range order (CSRO). It demonstrates tensile and compressive strengths of 550 MPa and 1700 MPa for the micropillar sample, respectively, with 25% tensile elongation and over 50% compressive strain. The large-scale sample achieves a tensile strength and elongation of about 500 MPa and 40%, respectively. Compared to traditional gold, silver, and copper alloys, both the strength and plasticity are enhanced. The microstructural characteristics and corresponding mechanical properties are found to match the experimental structure through high-temperature ternary alloy phase diagrams and simulations. This work introduces a alloy design approach that leverages atomic affinity manipulation to regulate multilayer heterogeneous structures, which offers an efficient pathway for designing MEAs suitable for demanding high-performance electronic packaging applications. A Cu-Au-Ag medium-entropy alloy with Damascus-style hierarchical layers provides balanced strength–ductility combination, enabling greener and more mechanically reliable metallic materials for advanced electronic packaging.

Fluid lubricated bearings have been widely adopted as support components for high-end equipment in metrology, semiconductor devices, aviation, strategic defense, ultraprecision manufacturing, medical treatment, and power generation. In all these applications, the equipment must deliver extreme working performances such as ultraprecise movement, ultrahigh rotation speed, ultraheavy bearing loads, ultrahigh environmental temperatures, strong radiation resistance, and high vacuum operation, which have challenged the design and optimization of reliable fluid lubricated bearings. Breakthrough of any related bottlenecks will promote the development course of high-end equipment. To promote the advancement of high-end equipment, this paper reviews the design and optimization of fluid lubricated bearings operated at typical extreme working performances, targeting the realization of extreme working performances, current challenges and solutions, underlying deficiencies, and promising developmental directions. This paper can guide the selection of suitable fluid lubricated bearings and optimize their structures to meet their required working performances. Design and optimization of fluid lubricated bearings operated with extreme working performances are comprehensively reviewed. Techniques related to ultra-high precision aerostatic bearings, ultra-high speed aerodynamic bearings, ultra-heavy load hydrostatic bearings and ultra-high temperature hydrodynamic bearings are all involved. Mutual problems existed in the bearing field including the characterization of the microscopic flow field, the coupling modeling of multi-physics and the management of thermal effect are discussed. Recent developments related to the adaptation of advanced materials in the bearing field, like the magnetorheological fluids, the supercritical carbon dioxide and the liquid metal, are included. Current challenges, current solutions, underlying deficiencies and promising developing directions regarding to the design and optimization of fluid lubricated bearings are systematically pointed out.

Proton-coupled electron transfer (PCET) is key to the activation of the blue light using flavin (BLUF) domain photoreceptors. Here, to elucidate the photocycle of the central FMN-Gln-Tyr motif in the BLUF domain of OaPAC, we eliminated the intrinsic interfering W90 in the mutant design. We integrated the stretched exponential function into the target analysis to account for the dynamic heterogeneity arising from the active-site solvation relaxation and the flexible H-bonding network as shown in the molecular dynamics simulation results, facilitating a simplified expression of the kinetics model. We find that, in both the functional wild-type (WT) and the nonfunctional Q48E and Q48A, forward PCET happens in the range of 105 ps to 344 ps, with a kinetic isotope effect (KIE) measured to be ∼1.8 to 2.4, suggesting that the nature of the forward PCET is concerted. Remarkably, only WT proceeds with an ultrafast reverse PCET process (31 ps, KIE = 4.0), characterized by an inverted kinetics of the intermediate FMNH·. Our results reveal that the reverse PCET is driven by proton transfer via an intervening imidic Gln.

This study investigates the effects of external magnetic fields on the synthesis of silver nanoparticles and the modulation of their properties. Silver nanoparticles were synthesized via liquid‐phase chemical reduction. Their composition, micromorphology, and surface properties were characterized using scanning electron microscopy (SEM), differential scanning calorimetry, infrared (IR) spectroscopy, and X‐ray photoelectron spectroscopy (XPS). The results show that external magnetic fields significantly influence the morphology, size, distribution, and optical and electrical properties of the silver nanoparticles. Specifically, applying a magnetic field during the reduction of silver ions to monomeric silver using formaldehyde as the reducing agent promotes anisotropic growth. This research proposes a novel magnetic field–assisted method to control silver nanoparticle synthesis. In addition, it establishes a theoretical and experimental basis for their applications, particularly in sensors, catalysts, and electronic devices. For example, in sensor applications, the ability to precisely control the properties of silver nanoparticles using magnetic fields can enhance both sensitivity and selectivity, enabling more accurate detection of target substances. Theoretically, this work deepens the understanding of magnetic field effects on nanoparticle growth dynamics. These insights can help optimize nanoparticle properties for advanced applications, such as electronic packaging and energy storage devices.

Blue light using flavin (BLUF) photoreceptors respond to light via one of nature’s smallest photo-switching domains. Upon photo-activation, the flavin cofactor in the BLUF domain exhibits multi-phasic dynamics, quenched by a proton-coupled electron transfer reaction involving the conserved Tyr and Gln. The dynamic behavior varies drastically across different species, the origin of which remains controversial. Here, we incorporate site-specific fluorinated Trp into three BLUF proteins, i.e ., AppA, Oa PAC and Sy PixD, and characterize the percentages for the W out , W in NH in and W in NH out conformations using 19 F nuclear magnetic resonance spectroscopy. Using femtosecond spectroscopy, we identify that one key W in NH in conformation can introduce a branching one-step proton transfer in AppA and a two-step proton transfer in Oa PAC and Sy PixD. Correlating the flavin quenching dynamics with the active-site structural heterogeneity, we conclude that the quenching rate is determined by the percentage of W in NH in , which encodes a Tyr-Gln configuration that is not conducive to proton transfer. Here the authors combine 19 F NMR and femtosecond transient absorption to characterise the structural origin of the multiphasic quenching dynamics in various species of BLUF domains, highlighting the importance of the heterogeneous active-site H-bond network.

This paper proposes a high torque density dual-stator flux-reversal-machine with multiple poles Halbach excitation (MPHE-DSFRM), which uses two pole pairs’ numbers (PPNs) of PM excitation on one outer stator tooth, and one PPN of PM excitation on one inner stator tooth. The introduction of different PPNs of PM excitation on the outer and the inner stators can optimize magnetic circuit and airgap flux density. A Halbach array is formed by inserting three pieces of circumferentially magnetized PMs into four pieces of radially magnetized permanent magnets (PMs) on the outer stator, which aims to further enhance torque density, and reduce torque ripple. Based on the flux modulation effect, the analytical modeling of the proposed MPHE-DSFRM is established, together with the evolution process, and the working principle is presented. Then, the key design parameters of MPHE-DSFRM are optimized to achieve high torque density and low torque ripple for high torque quality. Three representative DSFRMs and a conventional FRM are designed and analyzed, and they share the same design key parameters, including PM usage, outer radius of the outer stator, and active airgap length. The electromagnetic performances, including airgap flux density, back electromotive force (back-EMF), and torque characteristics, are analyzed and compared by finite element analysis (FEA). The calculated results show that the proposed MPHE-DSFRM can provide high torque density and high PM utilization.

The fragility of Au80Sn20 eutectic solder is the major bottleneck of its application, which origins from the coarse primary ζ′-phase and the intrinsic brittleness of irregularly eutectic structure. To tackle this problem, various solidification processes have been adopted in this work, and the influence of those processes on phase composition and eutectic microstructure is studied. The results show that simply increasing the cooling rate does not prevent the formation of detrimental ζ′-Au 5 Sn phases, although the resulting eutectic morphology changes from dendritic to isometric. Applying magnetic field into rapid solidification can effectively remove the primary ζ′-Au 5 Sn phases, which is attributed to the fission of primary crystal nucleus during the fast eutectic nucleation course. The alloys through magnetic-field-induced rapid cooling exhibit a superior room-temperature compressive property, and the fracture stress and strain reach up to 1456.7 MPa and 64% respectively. Our finding on the effect of cooling rate and magnetic field on solidification not only sheds light on future research direction but also provides practical guidance to the engineers in solder industry.

Objective Abnormalities in the gray matter structure of cerebral small vessel disease (CSVD) have been observed throughout the brain. However, whether cortico‐cortical connections exist between regions of gray matter atrophy in patients with CSVD has not been fully elucidated. This question was tested by comparing the gray matter covariance networks in CSVD patients with and without cognitive impairment (CI). Methods We performed multivariate modeling of the gray matter volume measurements of 61 patients with CI (CSVD‐CI), 85 patients without CI (CSVD‐NC), and 108 healthy controls using source‐based morphological analysis (SBM) to obtain gray matter structural covariance networks at the population level. Then, correlations between structural covariance networks and cognitive functions were analyzed in CSVD patients. Finally, a support vector machine (SVM) classifier was used with the gray matter covariance network as a classification feature to identify CI among the CSVD population. Results The results of the analysis of all the subjects showed that compared with healthy controls, the expression of the thalamic covariance network, cerebellum covariance network, and calcarine cortex covariance network was reduced in patients with CSVD. Moreover, CSVD‐CI patients showed a significant reduction in the expression of the thalamic covariance network, encompassing the thalamus and the parahippocampal gyrus, relative to CSVD‐NC patients, which persisted after excluding CSVD patients with thalamic lacunes. In patients with CSVD, cognitive functions were positively correlated with measures of the thalamic covariance network. More than 80% of CSVD patients with CI were correctly identified by the SVM classifier. Interpretation Our findings provide new evidence to explain the distribution state of gray matter reduction in CSVD patients, and the thalamic covariance network is the core region for early gray matter reduction during the development of CSVD disease, which is related to cognitive deficits. Reduced expression of thalamic covariance networks may provide a neuroimaging biomarker for the early identification of cognitive impairment in CSVD patients.

We report the synthesis of single-crystal iron germanium nanowires via chemical vapor deposition without the assistance of any catalysts. The assembly of single-crystal FeGe 2 nanowires with tetragonal C16 crystal structure shows anisotropic magnetic behavior along the radial direction or the growth axial direction, with both antiferromagnetic and ferromagnetic orders. Single FeGe 2 nanowire devices were fabricated using e-beam lithography. Electronic transport measurement in these devices show two resistivity anomalies near 250 K and 200 K which are likely signatures of the two spin density wave states in FeGe 2 .

Lack of understanding of the response of hepatocellular carcinoma (HCC) to anticancer drugs causes the high mortality of HCC patients. Bleomycin (BLM) that induces DNA damage is clinically used for cancer therapy, while the mechanism underlying BLM-induced DNA damage response (DDR) in HCC cells remains ambiguous. Given that 14-3-3 proteins are broadly involved in regulation of diverse biological processes (BPs)/pathways, we investigate how a 14-3-3 isoform coordinates particular BPs/pathways in BLM-induced DDR in HCC. Using dual-tagging quantitative proteomic approach, we dissected the 14-3-3ε interactome formed during BLM-induced DDR, which revealed that 14-3-3ε via its associations with multiple pathway-specific proteins coordinates multiple pathways including chromosome remodeling, DNA/RNA binding/processing, DNA repair, protein ubiquitination/degradation, cell cycle arrest, signal transduction and apoptosis. Further, \"zoom-in\" investigation of the 14-3-3ε interacting network indicated that the BLM-induced interaction between 14-3-3ε and a MAP kinase TAK1 plays a critical role in determining cell propensity of apoptosis. Functional characterization of this interaction further revealed that BLM triggers site-specific phosphorylations in the kinase domain of TAK1. These BLM-induced changes of phosphorylations directly correlate to the strength of the TAK1 binding to 14-3-3ε, which govern the phosphorylation-dependent TAK1 activation. The enhanced 14-3-3ε-TAK1 association then inhibits the anti-apoptotic activity of TAK1, which ultimately promotes BLM-induced apoptosis in HCC cells. In a data-dependent manner, we then derived a mechanistic model where 14-3-3ε plays the pivotal role in integrating diverse biological pathways for cellular DDR to BLM in HCC. Our data demonstrated on a systems view that 14-3-3ε coordinates multiple biological pathways involved in BLM-induced DDR in HCC cells. Specifically, 14-3-3ε associates with TAK1 in a phosphorylation-dependent manner to determine the cell fate of BLM-treated HCC cells. Not only individual proteins but also those critical links in the network could be the potential targets for BLM-mediated therapeutic intervention of HCC.