(E,E)-2,5-Bis(5-chloro-2-methoxyphenyl)-3,4-diazahexa-2,4-diene

The title compound, C18H18Cl2N2O2, was synthesized by the reaction of 1-(5-chloro-2-methoxy­phen­yl)ethanone with hydrazine hydrate. The mol­ecule lies on a crystallographic twofold axis passing through the mid-point of the N—N bond with one half-mol­ecule in the asymmetric unit. The dihedral angle between the two aromatic rings is 44.33 (4)°. In the crystal, inter­molecular C—H⋯O inter­actions link the mol­ecules into columns along the c axi

Enhanced stratosphere-troposphere and tropics-Arctic couplings in the 2023/24 winter

The stratosphere-troposphere and the tropics-Arctic couplings were intermittently enhanced in the 2023/24 winter. Here we used ERA5 reanalysis data and found that due to the amplification of planetary wavenumber 1 and 2 pulses, three displacement-type sudden stratospheric warming events occurred in one winter under the background conditions of warming equatorial middle and east Pacific, active equatorial convections, and easterly stratospheric equatorial winds. During the sudden stratospheric warming events, the stratospheric disturbances propagated downward to the surface, followed by continental cold surges. The residual meridional circulation was strengthened across the tropics and Arctic, anomalously more water vapor was transported into the stratosphere in tropics, while ozone content diminished in the lower stratosphere and grew in the upper stratosphere over the tropics. Meanwhile, water vapor and ozone over the Arctic exhibited a dipping pattern from the upper to the lower stratosphere

A retrospective study evaluating the correlation between the severity of intervertebral disc injury and the anteroposterior type of thoracolumbar vertebral fractures

OBJECTIVE: To evaluate the correlation between the severity of intervertebral disc injury and the anteroposterior type of thoracolumbar vertebral fractures. METHODS: Fifty-six cases of thoracolumbar vertebral fractures treated in our trauma center from October 2012 to October 2013 were included in this study. The fractures were classified by the anteroposterior classification, whereas the severity of intervertebral disc injury was evaluated using magnetic resonance imaging. The Spearman correlation coefficient was used to analyze the correlation between the severity of intervertebral disc injury and the anteroposterior type of thoracolumbar fractures, whereas a χ2 test was adopted to measure the variability between different fracture types and upper and lower adjacent disc injuries. RESULTS: The Spearman correlation coefficients between fracture types and the severity of the upper and lower adjacent disc injuries were 0.739 (P

Coherence-enhanced thermodynamic performance in a periodically-driven inelastic heat engine

Quantum thermodynamics with microscopic inelastic scattering processes has been intensively investigated in recent years. Here, we apply quantum master equation combined with full counting statistics approach to investigate the role of quantum coherence on the periodically-driven inelastic heat engine. We demonstrate that the inelastic quantum heat engine exhibits dramatic advantage of thermodynamic performance compared to their elastic counterpart. Moreover, it is found that inelastic currents, {output work}, and the efficiency can be enhanced by quantum coherence. In particular, the geometric effect proves crucial in achieving maximal values of generated output work and energy conversion efficiency. The Berry curvature boosted by quantum coherence unveils the underlying mechanism of periodically-driven inelastic heat engine. Our findings may provide some insights for further understanding and optimizing periodically-driven heat engines via quantum coherence resource and inelastic scattering processes.Comment: 13 pages, 7 figure

Arena: Multi-leader Synchronous Byzantine Fault Tolerance

Byzantine fault-tolerant state machine replication (BFT-SMR) replicates a state machine across a set of replicas, and processes requests as a single machine even in the presence of Byzantine faults. Recently, synchronous BFT-SMRs have received tremendous attention due to their simple design and high fault-tolerance threshold. In this paper, we propose Arena, the first multi-leader synchronous BFT-SMR. Thanks to the synchrony assumption, Arena gains the performance benefit from multi-leader with a much simpler design (compared to other partially synchronous multi-leader designs). Furthermore, it is more robust: ``no progress\u27\u27 of a leader will not trigger a view-change. Our experimental results show that Arena achieves a peak throughput of up to 7.7$\times$ higher than the state-of-the-art

Aurora: Leaderless State-Machine Replication with High Throughput

State-machine replication (SMR) allows a state machine to be replicated across a set of replicas and handle clients\u27 requests as a single machine. Most existing SMR protocols are leader-based, i.e., requiring a leader to order requests and coordinate the protocol. This design places a disproportionately high load on the leader, inevitably impairing the scalability. If the leader fails, a complex and bug-prone fail-over protocol is needed to switch to a new leader. An adversary can also exploit the fail-over protocol to slow down the protocol. In this paper, we propose a crash-fault tolerant SMR named Aurora, with the following properties: • Leaderless: it does not require a leader, hence completely get rid of the fail-over protocol. • Scalable: it can scale to a large number of replicas. • Robust: it behaves well even under a poor network connection. We provide a full-fledged implementation of Aurora and systematically evaluate its performance. Our benchmark results show that Aurora achieves a peak throughput of around two million TPS, up to 8.7$\times$ higher than the state-of-the-art leaderless SMR