hand side of NLS equation behave as subcritical for large time. We transform the equation by integrating by parts with respect to time, thereby obtaining a new formulation with higher-order nonlinearities that exhibit improved decay properties for large time in the supercritical regime. We assume that the initial data u0 admit small analytic extensions in a suitable sector of the complex plane. Under these assumptions, we find the large-time asymptotics of the global solution. (c) 2026 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
In this study, based on the synergistic strategy of sustained release reduction and in-situ surface nanostructuring, oxidation-resistant and rapid sintering of submicron copper (Cu) paste in an air atmosphere was achieved. First, the critical temperature points at which Cu undergoes severe oxidation were identified. Based on this, the reductant system, composed of ascorbic acid and polyethylene glycol (PEG30 0), was specially designed to match the oxidation threshold of Cu. Notably, due to the sustained release effect of the reductant system, reduction activity was sustained throughout the entire sintering process. During sintering, both CuO and Cu2O were ultimately reduced to ultrafine Cu nanoparticles. Simultaneously, in-situ surface nanostructuring occurred on submicron Cu particles, enabling oxidation-resistant and rapid sintering in air. At a sintering temperature of 250 degrees C for 5 min, the resulting joints exhibited a shear strength of 38.1 MPa, meeting the requirements for power device packaging. This work provides a novel strategy for oxidation-resistant Cu sintering and its industrial application. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )
We consider the initial-value problem in the d-dimensional Euclidean space Rd (d ≥ 3) for the compressible Navier-Stokes-Korteweg equations under the zero sound speed case (namely, P′(ρ*)=0, where P=P(ρ) stands for the pressure). The system is well-known as the Diffuse Interface model describing the motion of a vaper-liquid mixture in a compressible viscous fluid. The purposes of this paper are to obtain the global-in-time solution around the constant equilibrium states (ρ*, 0) (ρ* > 0) satisfying the estimate on the analyticity as established by Foias-Temam (1989), and investigate the Lp−L1 type time-decay estimates in scaling critical settings based on Fourier-Herz spaces. In addition, we also derive the first order asymptotic formula with higher derivatives for solutions as the application of the analyticity.
The influence of sputtering pressure on the structural and electrical properties of In–Ga–Zn–O (IGZO) thin films deposited by high-power pulsed magnetron sputtering (HPPMS) was systematically investigated. By controlling the deposition pressure between 0.65 and 3.0 Pa, the plasma characteristics during HPPMS deposition were significantly modified. Optical emission spectroscopy revealed that lower pressures increased the relative contribution of emissions from ionized species, suggesting enhanced plasma activity during film growth. Despite substrate temperatures remaining below 70 °C throughout deposition, X-ray diffraction analysis showed the emergence of structurally ordered and partially crystallized IGZO phases within an optimized pressure region around 1.5 Pa. X-ray photoelectron spectroscopy further demonstrated that the optimized growth condition promoted metal-oxygen bonding while reducing the higher-binding-energy O 1s component associated with oxygen-deficient bonding environments. Following post-deposition annealing, IGZO thin-film transistors fabricated from films deposited at 1.5 Pa exhibited the smallest subthreshold swing among all investigated conditions. These improvements are associated with enhanced structural ordering and reduced defect density resulting from pressure-controlled film growth. The present results demonstrate that sputtering pressure plays a critical role in governing the structural evolution of IGZO thin films during HPPMS deposition and provide further insight into pressure-controlled growth behavior under low-temperature deposition conditions.
The crystallographic orientation of β-Sn plays a critical role in determining the reliability of solder joints owing to its highly anisotropic properties. In this study, a scalable orientation-control strategy was developed by depositing CoSn3 thin films onto Cu wires using DC magnetron sputtering. Following solder-joint fabrication, the influence of the deposited CoSn3 layer on β-Sn orientation selection and electromigration behavior was systematically investigated. EBSD analysis revealed that majority of the solder joints fabricated using CoSn3-deposited Cu wires exhibited β-Sn grains with their [001] direction (c-axis) oriented nearly perpendicular to the sample Z-axis, whereas conventional Cu/solder/Cu joints showed nearly random orientations. Electromigration tests were conducted at current densities ranging from 1 × 104 to 3 × 104 A cm−2 and ambient temperatures of 25–60 °C. Pronounced orientation-dependent growth of intermetallic compounds (IMC) was observed in joints with small angles between the β-Sn c-axis and the current direction, while IMC growth was strongly suppressed when the c-axis was nearly perpendicular to the electron flow direction. The CoSn3 seed layer effectively controlled the orientation of β-Sn grains, thereby suppressing Cu diffusion and the subsequent excessive growth of IMCs. These findings demonstrate that sputter deposited CoSn3 thin films provide an effective and scalable route for controlling β-Sn orientation and offer valuable insights into the microstructural evolution of orientation-controlled solder joints under electromigration.
