Investigation of the first quasi-rectangular metro tunnel constructed by the 0−θ method

Quasi-rectangular shield tunneling is a cutting-edge trenchless method for constructing metro tunnels with double tubes, owing to its advantages in saving underground space and reducing ground disturbance. However, the conventional quasi-rectangular shield tunneling method is not applicable when constructing a tunnel without a center pillar,...

Controllable Fabrication and Rectification of Bipolar Nanofluid Diodes in Funnel-Shaped Si₃N₄ Nanopores

Solid-state nanopores attract widespread interest, owning to outstanding robustness, extensive material availability, as well as capability for flexible manufacturing. Bioinspired solid-state nanopores further emerge as potential nanofluidic diodes for mimicking the rectification progress of unidirectional ionic transport in biological K<sup>...

Analysis of Metallization Effects of Pressure-Assisted Cu Nanoparticle Sintering on DBC by Experiment and Nanoscale Simulation

Substrate metallization is a crucial factor affecting the mechanical properties of sintered nanoparticles in microelectronics applications, as it is essential for ensuring good adhesion between the substrate and the sintered material. In this study, we investigated the influence of metallization on pressure-assisted nanocopper sintering and...

Electron-Irradiation-Induced Degradation of Transfer Characteristics in Super-Junction VDMOSFET

High electric-field stress is an effective solution to the recovery of irradiated devices. In this paper, the dependence of the recovery level on the magnitude of gate voltage and duration is investigated. Compared with the scheme of high gate-bias voltage with a short stress time, the transfer characteristics are significantly recovered by...

Operational risk allocation in urban rail transit public–private partnership projects

Operation risk (OR) has affected sustainable development of urban rail transit (URT) public–private partnership (PPP) projects in China. Balanced distribution of operational risks among stakeholders (the public, government, and private companies) involved in URT PPP projects can maximize overall profit. Quantitative analysis of operational...

High-Voltage and High-Current IGBT Press-pack Module for Power Grid

On the basis of the development and application requirements of flexible DC transmission techniques, a 1 kA/10 kV half-bridge IGBT press-pack module is studied. The module is composed of three subunits in series, and each subunit consists of IGBT chips in parallel. In order to solve the problem of chips failure caused by non-uniform rigid...

Effects of shell thickness on the thermal stability of Cu-Ag core-shell nanoparticles: A molecular dynamics study

Cu-Ag core-shell (CS) nanoparticle (NP) is considered as a cost-effective alternative material to nano silver sintering material in die attachment application. To further reduce the cost, the thickness of the Ag shell can be adjusted. Whereas the shell thickness will also affect the thermal stability of the Cu-Ag CSNPs. In this study, molecular...

High-temperature nanoindentation characterization of sintered nano-copper particles used in high power electronics packaging

Nano-copper sintering is one of new die-attachment and interconnection solutions to realize the wide bandgap semiconductor power electronics packaging with benefits on high temperature, low inductance, low thermal resistance and low cost. Aiming to assess the high-temperature reliability of sintered nano-copper die-attachment and...

New innovations in pavement materials and engineering: A review on pavement engineering research 2021

Sustainable and resilient pavement infrastructure is critical for current economic and environmental challenges. In the past 10 years, the pavement infrastructure strongly supports the rapid development of the global social economy. New theories, new methods, new technologies and new materials related to pavement engineering are emerging....

Degradation behaviors and in-vivo biocompatibility of a rare earth- and aluminum-free magnesium-based stent

Biodegradable stents can provide scaffolding and anti-restenosis benefits in the short term and then gradually disappear over time to free the vessel, among which the Mg-based biodegradable metal stents have been prosperously developed. In the present study, a Mg-8.5Li (wt.%) alloy (RE- and Al-free) with high ductility (&gt; 40%) was...