Spinodal decomposition in Cu-Ni-Sn alloys produces ordered phases that impart high strength, yet discontinuous precipitation (DP) along grain boundaries during late-stage aging reduces both strength and ductility. Overcoming this inherent strength-ductility trade-off remains a key challenge for advanced engineering applications. To address this issue, a Cu-9Ni-6Sn-0.1Mn alloy was designed under the guidance of density functional theory calculations. High-density shear bands and nanotwins were introduced by cold-drawing, followed by aging treatment to tailor the characteristics of precipitates. The regulated high-density nanoscale DO22 and L12 ordered phases exhibit coherent interfaces and an extremely low lattice mismatch, generating intense elastic strain fields that strongly impede dislocation motion and thus significantly enhance the strength. Notably, micro-shear bands act as heterogeneous nucleation sites for fine semi-coherent DP particles, promoting their uniform dispersion within grains. The synergistic effect of high-density ordered phases, nanotwins, Lomer-Cottrell locks, and intersecting stacking fault networks endows the alloy with outstanding mechanical properties, with an ultimate tensile strength of 1176 MPa and a ductility of 4.6%. This study proposes a strategy for enhancing the overall performance of Cu-Ni-Sn alloys and establishes a foundational framework for controlling their microstructure and mechanical properties. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.
The composite segmented slip ring (CSSR) serves as a critical component for power and signal transmission. It is capable of alternately triggering and interrupting electrical signals, which is used to control the start/stop of associated mechanical operations. As an instantaneous switch, the CSSR faces the critical challenge of avoiding signal control blind spots at key actuation nodes. This study focuses on the tribological and electrical performance of two typical tribo-pairs (QBe2.0/ZrO2 and QBe2.0/QBe2.0) associated with the CSSR. Tribological test results demonstrate that the QBe2.0/QBe2.0 tribo-pair exhibits higher friction coefficient and more severe wear. Arc ablation and material transfer blur the insulation/conduction boundary of the CSSR, which is identified as the direct cause of signal distortion. This research clarifies the relationship between current-carrying tribological behavior and electrical signal transmission failure of the CSSR, providing a theoretical and experimental basis for optimizing the service performance and reliability of CSSR in mission-critical applications.
Tracked vehicles are widely used on soft, cohesive terrain, but inadequate longitudinal force can compromise mobility. This study investigated curved grousers using a coupled DEM–MBD framework, a 33 full-factorial performance study, and independent soil-bin tests. The DEM–MBD response was the temporal mean of the positive longitudinal track–soil interaction-force samples over a common, event-defined interval of 1.6–3.0 s. The soil-bin response was the arithmetic mean of three run-level peak net tractive force after subtraction of the unloaded rig resistance. Because these quantities differ in statistical definition and physical location, the soil-bin comparison was used to assess only the relative trends and ranking of the grouser configurations and operating conditions, rather than direct numerical equality. A physics-guided analytical model was formulated, and a backpropagation neural network combined with a genetic algorithm was used for parameter optimization within the sampled design domain. The smallest-radius configuration (R = 12 mm) produced the largest numerical response and a 9.25% increase relative to the R = 24 mm numerical baseline; it also ranked highest in the soil-bin comparisons. The results indicate that a smaller curvature radius redirects soil reaction more effectively in the travel direction and that its benefit becomes more pronounced as normal load increases. These findings provide a bounded basis for curved-grouser design in wet, cohesive soils.
Potassium (K) is an essential macronutrient that supports plant growth, development, and stress tolerance. However, low soil K is widespread and can sharply reduce crop yields worldwide. To cope with the K shortage, plants rely on coordinated responses, and plant hormones play a central role in organizing these adjustments. This article describes how major hormones (including auxin, ethylene, jasmonic acid, gibberellin, and abscisic acid) change in synthesis and signaling when plants experience K deprivation. We focus on how hormone-driven pathways, often functioning through complex crosstalk and shared signaling hubs (such as ROS and calcium signals), regulate K⁺ uptake systems, such as the High-Affinity K⁺ transporter 5 (HAK5), through gene regulatory cascades, including hormone-responsive transcription factors, kinases, and other secondary messengers. We also explain how these signals reshape root growth patterns to increase soil exploration and improve K acquisition. By synthesizing findings across various species, we highlight that while core mechanisms are often conserved in the model plant Arabidopsis, hormonal responses exhibit significant dynamic diversity across major crops like rice and maize. By bringing together evidence on hormone interactions and nutrient sensing, this paper clarifies the key physiological and molecular processes that enable plants to tolerate K starvation and highlights opportunities to breed crops with improved potassium use efficiency.
Space-based gravitational-wave detection missions typically deploy three spacecraft in a widely spaced triangular formation in deep-space heliocentric or high Earth orbits. Maintaining high-precision coherence across this distributed, large-scale, and multi-degree-of-freedom system is critical to long-term, stable, and precise detector operations. High-accuracy orbit determination is foundational to mission success. Although a variety of tracking and measurement techniques exist, achievable orbit-determination accuracy is constrained by tracking coverage, systematic measurement errors, formation geometry, orbit-control capability, and the geometry of ground-based tracking networks. This paper presents a systematic overview of orbit-determination requirements for different mission architectures, analyses the performance and technical characteristics of ground-based and space-based tracking methods applicable to spacecraft in heliocentric and geocentric orbits, and discusses current challenges and future directions in high-precision orbit determination technologies to enable reliable, precise operation of space-based gravitational-wave detectors.
