Insights into the Structure Stability of Prussian Blue for Aqueous Zinc Ion Batteries

The reversible storage of Zn^(2+)ions in Prussian blue analogues with typical aqueous solution was challenged by fast degradation and poor coulombic efficiency,while the mechanism is yet to be uncovered.This study correlates the performance of the nickel hexacyanoferrate to the dynamics of H_(2)O in the electrolyte and the associated phase stability of the electrode.It demonstrates severe Ni dissolution in conventional diluted aqueous electrolyte(1 M ZnSO^(4)or 1 M Zn(TFSI)^(2)),leading to structure collapse with the formation of an electrochemical inert phase.This is regarded as the descriptor for the fast decay of nickel hexacyanoferrate in diluted aqueous electrolyte.However,a well-preserved open framework for zinc storage was obtained in concentrated aqueous electrolyte(1 M Zn(TFSI)_(2)+21 M LiTFSI)—the H_(2)O activity is highly suppressed by extensive coordination—thus,reversible capacity of 60.2 m Ah g^(-1)over 1600 cycles could be delivered.

Excitatory somatostatin interneurons in the dentate gyrus drive a widespread seizure network in cortical dysplasia

Seizures due to cortical dysplasia are notorious for their poor prognosis even with medications and surgery,likely due to the widespread seizure network.Previous studies have primarily focused on the disruption of dysplastic lesions,rather than remote regions such as the hippocampus.Here,we first quantified the epileptogenicity of the hippocampus in patients with late-stage cortical dysplasia.We further investigated the cellular substrates leading to the epileptic hippocampus,using multiscale tools including calcium imaging,optogenetics,immunohistochemistry and electrophysiology.For the first time,we revealed the role of hippocampal somatostatin-positive interneurons in cortical dysplasia-related seizures.Somatostatin-positive were recruited during cortical dysplasia-related seizures.Interestingly,optogenetic studies suggested that somatostatin-positive interneurons paradoxically facilitated seizure generalization.By contrast,parvalbumin-positive interneurons retained an inhibitory role as in controls.Electrophysiological recordings and immunohistochemical studies revealed glutamate-mediated excitatory transmission from somatostatin-positive interneurons in the dentate gyrus.Taken together,our study reveals a novel role of excitatory somatostatin-positive neurons in the seizure network and brings new insights into the cellular basis of cortical dysplasia.

Distributed Vibration Sensor With Laser Phase-Noise Immunity by Phase-Extraction φ-OTDR

We have demonstrated a distributed vibration sensor based on phase-sensitive optical time-domain reflectometer (φ-OTDR) system exhibiting immunity to the laser phase noise. Two laser sources with different linewidth and phase noise levels are used in the φ-OTDR system, respectively. Based on the phase noise power spectrum density of both lasers, the laser phase is almost unchanged during an extremely short period of time, hence, the impact of phase noise can be suppressed effectively through phase difference between the Rayleigh scattered light from two adjacent sections of the fiber which define the gauge length. Based on the phase difference method, the external vibration can be located accurately at 41.01 km by the(φ-OTDR system incorporating these two lasers. Meanwhile, the average signal-to-noise ratio (SNR) of the retrieved vibration signal by using Laser I is found to be -37.7 dB, which is comparable to that of -37.5 dB by using Laser II although the linewidth and the phase noise level of the two lasers are distinct. The obtained results indicate that the phase difference method can enhance the performance of(φ-OTDR system with laser phase-noise immunity for distributed vibration sensing, showing potential application in oil-gas pipeline monitoring, perimeter security, and other fields.