405905 research outputs found
Sort by
High starch and hemicellulose labile C degradation functional genes increase soil CO2 emissions follow straw return
No full textGate-Defined Single-Electron Transistors in Twisted Bilayer Graphene
No full textTwisted bilayer graphene (tBLG) near the magic angle is a unique platform where the combination of topology and strong correlations gives rise to exotic electronic phases. These phases are gate-tunable and related to the presence of flat electronic bands, isolated by single-particle band gaps. This enables gate-controlled charge confinements, essential for the operation of single-electron transistors (SETs), and allows one to explore the interplay of confinement, electron interactions, band renormalization, and the moiré superlattice, potentially revealing key paradigms of strong correlations. Here, we present gate-defined SETs in tBLG with well-tunable Coulomb blockade resonances. These SETs allow us to study magnetic field-induced quantum oscillations in the density of states of the source-drain reservoirs, providing insight into gate-tunable Fermi surfaces of tBLG. Comparison with tight-binding calculations highlights the importance of displacement-field-induced band renormalization crucial for future advanced gate-tunable quantum devices and circuits in tBLG including, e.g., quantum dots and Josephson junction arrays
A multi-physics model for dislocation driven spontaneous grain nucleation and microstructure evolution in polycrystals
No full textThe granular microstructure of metals evolves significantly during thermomechanical processing through viscoplastic deformation and recrystallization. Microstructural features such as grain boundaries, subgrains, localized deformation bands, and non-uniform dislocation distributions critically influence grain nucleation and growth during recrystallization. Traditionally, modeling this coupled evolution involves separate, specialized frameworks for mechanical deformation and microstructural kinetics, typically used in a staggered manner. Nucleation is often introduced ad hoc, with nuclei seeded at predefined sites based on criteria like critical dislocation density, stress, or strain. This is a consequence of the inherent limitations of the staggered approach, where newly formed grain boundaries or grains have to be incorporated with additional processing.In this work, we propose a unified, thermodynamically consistent field theory that enables spontaneous nucleation driven by stored dislocations at grain boundaries. The model integrates Cosserat crystal plasticity with the Henry–Mellenthin–Plapp orientation phase field approach, allowing the simulation of key microstructural defects, as well as curvature- and stored energy-driven grain boundary migration. The unified approach enables seamless identification of grain boundaries that emerge from deformation and nucleation. Nucleation is activated through a coupling function that links dislocation-related free energy contributions to the phase field. Dislocation recovery occurs both at newly formed nuclei and behind migrating grain boundaries.The model’s capabilities are demonstrated using periodic bicrystal and polycrystal simulations, where mechanisms such as strain-induced boundary migration, subgrain growth, and coalescence are captured. The proposed spontaneous nucleation mechanism offers a novel addition to the capabilities of phase field models for recrystallization simulation
Revealing cell-substrate adhesion at subcellular resolution with ultra-flat field-effect transistor arrays
No full textMachine learning-based dual-parameter inversion for estimating snowpack liquid water content and density using common offset GPR data
No full text
Detailed assessment of combustion risk and PAR efficiency in the late phase of a severe accident within the European AMHYCO project
No full textTowards ICT-Enabled Multi-agent Based Operations in Local Energy Communities: A Proof of Concept
No full text
