Potassium-ion batteries (KIBs) are emerging as one of the most promising candidates for large-scale energy storage owing to the natural abundance of the materials required for their fabrication and the fact that their intercalation mechanism is identical to that of lithium-ion batteries. However, the larger ionic radius of K + is likely to induce larger volume expansion and sluggish kinetics, resulting in low specific capacity and unsatisfactory cycle stability. A new Ni/ Mn-based layered oxide, P2-type K 0.44 Ni 0.22 Mn 0.78 O 2 , is designed and synthesized. A cathode designed using this material delivers a high specific capacity of 125.5 mAh g −1 at 10 mA g −1 , good cycle stability with capacity retention of 67% over 500 cycles and fast kinetic properties. In situ X-ray diffraction recorded for the initial two cycles reveals single solid-solution processes under P2-type framework with small volume change of 1.5%. Moreover, a cathode electrolyte interphase layer is observed on the surface of the electrode after cycling with possible components of K 2 CO 3 , RCO 2 K, KOR, KF, etc. A full cell using K 0.44 Ni 0.22 Mn 0.78 O 2 as the cathode and soft carbon as the anode also exhibits exceptional performance, with capacity retention of 90% over 500 cycles as well as superior rate performance. These findings suggest P2-K 0.44 Ni 0.22 Mn 0.78 O 2 is a promising candidate as a high-performance cathode for KIBs.

Aqueous‐ion batteries have received much attention owing to the merits of high safety, low cost, and environmental friendliness. Among potential cathode candidates, transition metal sulfides drew little attention since they suffer from low capacity, low working potential, and fast capacity fading. Here, advantage is taken of the chemical instability of VS2 in aqueous electrolyte to in situ fabricate a heterostructural VS2/VOx material. Benefiting from the internal electric field at heterointerfaces, high conductivity of vanadium sulfide and high chemical stability of vanadium oxides, heterostructural VS2/VOx delivers an enhanced working potential by 0.25 V, superior rate capability with specific capacity of 156 mA h g−1 at 10 A g−1, and long‐term stability over 3000 cycles as Zn2+ storage electrode. In addition, heterostructural VS2/VOx is employed as the cathode for aqueous NH4+ ion storage with high reversible capacity over 150 mA h g−1 and long lifespan over 1000 cycles, surpassing the state‐of‐the‐art materials. VS2/VOx is proved to demonstrate a (de)intercalation process for Zn2+ storage, while a conversion reaction accompanied by insertion is responsible for nonmetal NH4+. The strong insight obtained in this study sheds light on a new methodology of exploring the potential of transition metal sulfides‐based cathode materials for aqueous ion batteries.

Network embeddings, which learn lowdimensional representations for each vertex in a large-scale network, have received considerable attention in recent years. For a wide range of applications, vertices in a network are typically accompanied by rich textual information such as user profiles, paper abstracts, etc. We propose to incorporate semantic features into network embeddings by matching important words between text sequences for all pairs of vertices. We introduce a word-by-word alignment framework that measures the compatibility of embeddings between word pairs, and then adaptively accumulates these alignment features with a simple yet effective aggregation function. In experiments, we evaluate the proposed framework on three real-world benchmarks for downstream tasks, including link prediction and multi-label vertex classification. Results demonstrate that our model outperforms state-of-the-art network embedding methods by a large margin.

Layered transition metal oxides are ideal Na + /K + host materials due to their high theoretical capacities and appropriate working potentials, and the pursuit of cost-effective and environmentally friendly alternatives with high energy density and structural stability has remained a hot topic. Herein, we design and synthesize a low-cost and zero-strain cathode material, P3-type K 0.4 Fe 0.1 Mn 0.8 Ti 0.1 O 2 , which demonstrates superior properties for both potassium and sodium storage. The cathode delivers a reversible potassium storage capacity of 117 mA h g −1 at 20 mA g −1 and a fast rate capability of 71 mA h g −1 at 1000 mA g −1 . In situ Xray diffraction reveals a solid−solution transition with a negligible volume change of 0.5% upon K + insertion/deinsertion that ensures long cycling stability over 300 cycles. When the material is employed for sodium storage, a spontaneous ion-exchange process with Na + -containing electrolytes occurs. Thanks to the positive effects of the remaining K + ions that protect the layered structure from collapse as well as expand the interlayer structure, and the resulting K 0.12 Na 0.28 Fe 0.1 Mn 0.8 Ti 0.1 O 2 demonstrates a high sodium storage capacity of 160 mA h g −1 and superior cycling stability with capacity retention of 81% after 300 cycles as well as fast kinetics.

We have observed a glitch in the Crab pulsar (PSR B0531+21) in the 0.5–10 keV X-ray band with the X-Ray Pulsar Navigation-I (XPNAV-1) satellite. This glitch occurred around 2017 November 8. Observations at radio frequency by the Jodrell Bank observatory and the Lovell telescope have confirmed it to be the largest ever observed. We report the results of X-ray observation of this glitch. The measured rotation frequency increase of the Crab is Δν 0 = (14.3 ± 2.0) × 10−6 Hz, corresponding to a fractional increase of Δν 0/ν 0 = (0.48 ± 0.09) × 10−6. Two transient components in the rotation frequency change are detected: one is the short transient term of Δν n1 = 6.6 × 10−6 Hz with a timescale of 38.6 days and the other is the very short one of Δν n2 = −1.35 × 10−6 Hz with a timescale of 2.4 days. The step change in the rotation frequency derivative is determined to be Hz s−1. We also examine the relationship between the persistent offset and Δν 0, giving . No significant X-ray flux changes are observed pre- and post-glitch.