Molecular dynamics simulations on mechanical behaviors of sintered nanocopper in power electronics packaging

Nano-metal materials have received considerable attention because of their promising performance in wide bandgap semiconductor packaging. In this study, molecular dynamics (MD) simulation was performed to simulate the nano-Cu sintering mechanism and the subsequent mechanical behaviors. Hybrid sintering, comprising nanosphere (NS) and...

High temperature viscoplastic deformation behavior of sintered nanocopper paste used in power electronics packaging: Insights from constitutive and multi-scale modelling

As a promising technology for high-power and high-temperature power electronics packaging, nanocopper (nanoCu) paste sintering has recently received increasing attention as a die-attachment. The high-temperature deformation of sintered nanoCu paste and its underlying mechanisms challenge the reliability of high-power electronics packaging. In...

Overcoming inertia for sustainable urban development: Understanding the role of stimuli in shaping residents' participation behaviors in neighborhood regeneration projects in China

Neighborhood regeneration has become essential component of environmental improvement, and promoting resident participation is a key aspect of effective environmental management. However, in China, the legacy of the former housing allocation system and specific cultural contexts have led to residents' psychological inertia towards...

Mixed-mode fatigue crack propagation simulation by means of G_eq and walker models of the structural steel S355

In this paper, a numerical simulation method of mixed-mode fatigue crack propagation was explored using the extended finite element method (XFEM) and the Virtual Crack Closure Technique (VCCT). Both 2D and 3D numerical models were selected to simulate the fatigue crack propagation of steel specimens. Two coefficients were proposed to...

Review on shallow geothermal promoting energy efficiency of existing buildings in Europe

The energy-saving renovation of existing buildings has been attracted sufficient attention to reduce fossil fuels and mitigate global warming in Europe. The shallow geothermal for building cooling and heating, as an environmentally-friendly and cost-effective alternative, has been widely explored to promote energy efficiency of existing...

Long-term deterioration of lubricant-infused nanoporous anodic aluminium oxide surface immersed in NaCl solution

This study investigated the deterioration of a lubricant-infused anodic aluminium oxide surface in a 1 M NaCl solution for ∼200 days. Direct observation by cryo-SEM and quantitative analyses by UV spectroscopy and EIS revealed that the long-term deterioration of the lubricant-infused surface was divided into two stages: the surface-adhered...

Efficient Li-Metal Plating/Stripping in Carbonate Electrolytes Using a LiNO₃-Gel Polymer Electrolyte, Monitored by Operando Neutron Depth Profiling

The development of safe and high-performance Li-metal anodes is crucial to meet the demanded increase in energy density of batteries. However, severe reactivity of Li metal with typical electrolytes and dendrite formation leads to a poor cycle life and safety concerns. Therefore, it is essential to develop electrolytes that passivate the...

Cyclic behavior of low rise concrete shear walls containing recycled coarse and fine aggregates

In this study, the cyclic behaviors of low rise concrete shear walls using recycled coarse or fine aggregates were investigated. Eight low rise Recycled Aggregates Concrete (RAC) shear wall specimens were designed and tested under a cyclic loading. The following parameters were varied: replacement percentages of recycled coarse or fine...

Experimental study on mechanical behavior of shear connectors of square concrete filled steel tube

In order to quantitatively evaluate the shear-bearing capacity of shear connectors of square concrete filled steel tube (CFST), push-out tests on 14 square CFSTs with shear connectors have been carried out. Among the 14 CFSTs, there are 13 specimens with steel plate connectors and one specimen with steel bar connectors. The following factors...

Cross section-based hollowing and structural enhancement

Recently, 3D printing has become a powerful tool for personal fabrication. However, the price of some materials is still high which limits its applications in home users. To optimize the volume of the model, while not largely affecting the strength of the objects, researchers propose algorithms to divide the model with different kinds of...

A Facile Surface Reconstruction Mechanism toward Better Electrochemical Performance of Li₄Ti₅O₁₂ in Lithium-Ion Battery

Through a facile sodium sulfide (Na₂S)-assisted hydrothermal treatment, clean and nondefective surfaces are constructed on micrometer-sized Li₄Ti₅O₁₂ particles. The remarkable improvement of surface quality shows a higher first cycle Coulombic efficiency (≈95%), a significantly enhanced cycling...