Recent destructive seismic events have underlined the need for increasing research efforts devoted to the development of innovative seismic‐resilient structures able to reduce seismic‐induced direct ...and indirect losses. Regarding steel Moment Resisting Frames (MRFs), the inclusion of Friction Devices (FDs) in Beam‐to‐Column Joints (BCJs) has emerged as an effective solution to dissipate the seismic input energy while ensuring a damage‐free behavior. Additionally, recent studies have demonstrated the benefits of implementing similar damage‐free solutions for Column Bases (CBs). In this context, the authors have recently experimentally investigated a Self‐Centering CB (SC‐CB) aimed at residual drift reduction. Previous experimental tests only focused on the response of isolated SC‐CBs under cyclic loads. Conversely, the present paper advances the research through an experimental campaign on a large‐scale steel structure equipped with the proposed SC‐CBs, providing valuable insights into the global structural response and improved repairability. A set of eight Pseudo‐Dynamic (PsD) tests were conducted considering different records and configurations of the structure. The experimental results highlighted the effectiveness of the SC‐CBs in minimizing the residual interstory drifts and protecting the first‐story columns from damage, thus enhancing the structure's resilience. Moreover, the consecutive PsD tests allowed investigating the effectiveness of the reparation process in restoring the seismic performance of the ‘undamaged’ structure. An advanced numerical model was developed in OpenSees and validated against the global and component‐level experimental results. Incremental Dynamic Analyses were finally performed to investigate the influence of the SC‐CBs on the structure's seismic response while accounting for the record‐to‐record variability.
Motivated by the demands of integrated and silicon photonics, there is significant interest in optical isolators in on-chip integrated systems. Recent works have therefore explored nonlinear optical ...isolators and demonstrated non-reciprocal transmission contrast when waves are injected in forward or backward directions. However, whether such nonlinear isolators can provide complete isolation under practical operating conditions remains an open question. Here, we analytically prove and numerically demonstrate a dynamic reciprocity in nonlinear optical isolators based on Kerr or Kerr-like nonlinearity. We show that, when a signal is transmitting through, such isolators are constrained by a reciprocity relation for a class of small-amplitude additional waves and, as a result, cannot provide isolation for arbitrary backward-propagating noise. This result points to an important limitation on the use of nonlinear optical isolators for signal processing and for laser protection.
We study the dynamics of a driven non-Hermitian superconducting qubit which is perturbed by quantum jumps between energy levels, a purely quantum effect with no classical correspondence. The quantum ...jumps mix the qubit states leading to decoherence. We observe that this decoherence rate is enhanced near the exceptional point, owing to the cube-root topology of the non-Hermitian eigenenergies. Together with the effect of non-Hermitian gain or loss, quantum jumps can also lead to a breakdown of adiabatic evolution under the slow-driving limit. Our study shows the critical role of quantum jumps in generalizing the applications of classical non-Hermitian systems to open quantum systems for sensing and control.
Mechanical resonators are fabricated from freely suspended single-layer MoS sub(2). Their dynamics have been studied by optical interferometry. These resonators behave as membranes with resonance ...frequencies in between 10 and 30 MHz and quality factors in between 16 and 109. We also demonstrate clear signatures of nonlinear resonance in these atomically thin resonators.
The fastest possible collective response of a quantum many-body system is related to its excitations at the highest possible energy. In condensed matter systems, the time scale for such "ultrafast" ...processes is typically set by the Fermi energy. Taking advantage of fast and precise control of interactions between ultracold atoms, we observed nonequilibrium dynamics of impurities coupled to an atomic Fermi sea. Our interferometric measurements track the nonperturbative quantum evolution of a fermionic many-body system, revealing in real time the formation dynamics of quasi-particles and the quantum interference between attractive and repulsive states throughout the full depth of the Fermi sea. Ultrafast time-domain methods applied to strongly interacting quantum gases enable the study of the dynamics of quantum matter under extreme nonequilibrium conditions.
In this review, a comprehensive summary of supramolecular transformations within discrete coordination-driven supramolecular architectures, including helices, metallacycles, metallacages,
etc.
, is ...presented. Recent investigations have demonstrated that coordination-driven self-assembled architectures provide an ideal platform to study supramolecular transformations mainly due to the relatively rigid yet dynamic nature of the coordination bonds. Various stimuli have been extensively employed to trigger the transformation processes of metallosupramolecular architectures, such as solvents, concentration, anions, guests, change in component fractions or chemical compositions, light, and post-modification reactions, which allowed for the formation of new structures with specific properties and functions. Thus, it is believed that supramolecular transformations could serve as another highly efficient approach for generating diverse metallosupramolecular architectures. Classified by the aforementioned various stimuli used to induce the interconversion processes, the emphasis in this review will be on the transformation conditions, structural changes, mechanisms, and the output of specific properties and functions upon induction of structural transformations.
In this review, a comprehensive summary of supramolecular transformations within discrete coordination-driven supramolecular architectures, including helices, metallacycles, metallacages,
etc.
, is presented.
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