Textured Asymmetric Membrane Electrode Assemblies of Piezoelectric Phosphorene and Ti_(3)C_(2)T_(x)MXene Heterostructures for Enhanced Electrochemical Stability and Kinetics in LIBs

Black phosphorus with a superior theoretical capacity(2596 mAh g^(-1))and high conductivity is regarded as one of the powerful candidates for lithium-ion battery(LIB)anode materials,whereas the severe volume expansion and sluggish kinetics still impede its applications in LIBs.By contrast,the exfoliated two-dimensional phosphorene owns negligible volume variation,and its intrinsic piezoelectricity is considered to be beneficial to the Li-ion transfer kinetics,while its positive influence has not been discussed yet.Herein,a phosphorene/MXene heterostructure-textured nanopiezocomposite is proposed with even phosphorene distribution and enhanced piezo-electrochemical coupling as an applicable free-standing asymmetric membrane electrode beyond the skin effect for enhanced Li-ion storage.The experimental and simulation analysis reveals that the embedded phosphorene nanosheets not only provide abundant active sites for Li-ions,but also endow the nanocomposite with favorable piezoelectricity,thus promoting the Li-ion transfer kinetics by generating the piezoelectric field serving as an extra accelerator.By waltzing with the MXene framework,the optimized electrode exhibits enhanced kinetics and stability,achieving stable cycling performances for 1,000 cycles at 2 A g^(-1),and delivering a high reversible capacity of 524 m Ah g^(-1)at-20℃,indicating the positive influence of the structural merits of self-assembled nanopiezocomposites on promoting stability and kinetics.

A Classification of Completely Positive Maps

This paper concerns classifying completely positive maps between certain C*-algebras. Several invariants for classifying completely positive maps are constructed. It is proved that one of them is isomorphic to the Ext-group of C*-algebra extensions in special circumstances. Furthermore, this invariant induces a functor from C*-algebras to abelian groups which is split-exact.

Sustained release of hydrogen sulfide from anisotropic ferrofluid hydrogel for the repair of spinal cord injury

Spinal cord injury(SCI)results in massive neuronal death,axonal disruption,and cascading inflammatory response,which causes further damage to impaired neurons.The survived neurons with damaged function fail to form effective neuronal circuits.It is mainly caused by the neuroinflammatory microenvironment at injury sites and regenerated axons without guidance.To address this challenge,a ferrofluid hydrogel(FFH)was prepared with Ferric tetrasulfide(Fe3S4),carboxymethyl chitosan,and gold.Its internal structural particles can be oriented in a magnetic field to acquire anisotropy.Moreover,Fe3S4 can release hydrogen sulfide(H2S)with anti-inflammatory effects under acidic conditions.Regarding in vitro experiments,0.01g/ml Fe3S4 FFH significantly reduced the inflammatory factors produced by LPS-induced BV2 cells.Oriented and longer axons of the induced neural stem cells loaded on anisotropic FFH were observed.In vivo experiments showed that FFH reduced the activated microglia/macrophage and the expression of pro-inflammatory factors in SCI rats through the NF-κB pathway.Moreover,it significantly promoted directional axonal regrowth and functional recovery after SCI.Given the critical role of inhibition of neuroinflammation and directional axonal growth,anisotropic Fe3S4 FFH is a promising alternative for the treatment of SCI.

Distance Between Unitary Orbits of Self-Adjoint Elements in C^(*)-Algebras of Tracial Rank One

The note studies certain distance between unitary orbits.A result about Riesz interpolation property is proved in the first place.Weyl(1912) shows that dist(U(x),U(y))= δ(x,y) for self-adjoint elements in matrixes.The author generalizes the result to C*-algebras of tracial rank one.It is proved that dist(U(x),U(y)) = D_(c)(x,y) in unital AT-algebras and in unital simple C*-algebras of tracial rank one,where x,y are self-adjoint elements and D_(C)(x,y) is a notion generalized from δ(x,y).