Observation of perovskite topological valley exciton-polaritons at room temperature.

Topological exciton-polaritons are a burgeoning class of topological photonic systems distinguished by their hybrid nature as part-light, part-matter quasiparticles. Their further control over novel valley degree of freedom (DOF) has offered considerable potential for developing active topological optical devices towards information processing. Here, employing a two-dimensional (2D) valley-Hall perovskite lattice, we report the experimental observation of valley-polarized topological exciton-polaritons and their valley-dependent propagations at room temperature.

Higher-order topological polariton corner state lasing.

Unlike conventional laser, the topological laser is able to emit coherent light robustly against disorders and defects because of its nontrivial band topology. As a promising platform for low-power consumption, exciton polariton topological lasers require no population inversion, a unique property that can be attributed to the part-light-part-matter bosonic nature and strong nonlinearity of exciton polaritons. Recently, the discovery of higher-order topology has shifted the paradigm of topological physics to topological states at boundaries of boundaries, such as corners.

Controllable vortex lasing arrays in a geometrically frustrated exciton-polariton lattice at room temperature.

Quantized vortices appearing in topological excitations of quantum phase transition play a pivotal role in strongly correlated physics involving the underlying confluence of superfluids, Bose-Einstein condensates and superconductors. Exciton polaritons as bosonic quasiparticles have enabled studies of non-equilibrium quantum gases and superfluidity. Exciton-polariton condensates in artificial lattices intuitively emulate energy-band structures and quantum many-body effects of condensed matter, underpinning constructing vortex lattices and controlling quantum fluidic circuits.

Surface-Adsorbed Carboxylate Ligands on Layered Double Hydroxides/Metal-Organic Frameworks Promote the Electrocatalytic Oxygen Evolution Reaction.

Metal-organic frameworks (MOFs) with carboxylate ligands as co-catalysts are very efficient for the oxygen evolution reaction (OER). However, the role of local adsorbed carboxylate ligands around the in-situ-transformed metal (oxy)hydroxides during OER is often overlooked. We reveal the extraordinary role and mechanism of surface-adsorbed carboxylate ligands on bi/trimetallic layered double hydroxides (LDHs)/MOFs for OER electrocatalytic activity enhancement.

Nonlinear Parametric Scattering of Exciton Polaritons in Perovskite Microcavities.

Comparing with pure photons, higher nonlinearity in polariton systems has been exploited in various proof-of-principle demonstrations of efficient optical devices based on the parametric scattering effect. However, most of them demand cryogenic temperatures limited by the small exciton binding energy of traditional semiconductors or exhibit weak nonlinearity resulting from Frenkel excitons. Lead halide perovskites, possessing both a large binding energy and a strong polariton interaction, emerge as ideal platforms to explore nonlinear polariton physics toward room temperature operation.

Spontaneously coherent orbital coupling of counterrotating exciton polaritons in annular perovskite microcavities.

Exciton-polariton condensation is regarded as a spontaneous macroscopic quantum phenomenon with phase ordering and collective coherence. By engineering artificial annular potential landscapes in halide perovskite semiconductor microcavities, we experimentally and theoretically demonstrate the room-temperature spontaneous formation of a coherent superposition of exciton-polariton orbital states with symmetric petal-shaped patterns in real space, resulting from symmetry breaking due to the anisotropic effective potential of the birefringent perovskite crystals. The lobe numbers of such petal-shaped polariton condensates can be precisely controlled by tuning the annular potential geometry.

Hierarchical porous Ni, Fe-codoped Co-hydroxide arrays derived from metal-organic-frameworks for enhanced oxygen evolution.

The multi metal organic frameworks (BTC-CoNiFeZn) were used as the precursors of in situ structure reconstruction in alkaline solution, and we synthesized hierarchical porous Ni,Fe-codoped Co-hydroxide nanowire array (Ni0.8Fe0.2/Co-H NAs/NF) catalyst for the oxygen evolution reaction (OER).

Transient circular dichroism and exciton spin dynamics in all-inorganic halide perovskites.

All-inorganic metal halides perovskites (CsPbX, X = Br or Cl) show strong excitonic and spin-orbital coupling effects, underpinning spin-selective excitonic transitions and therefore exhibiting great promise for spintronics and quantum-optics applications. Here we report spin-dependent optical nonlinearities in CsPbX single crystals by using ultrafast pump-probe spectroscopy. Many-body interactions between spin-polarized excitons act like a pseudo-magnetic field and thus lift the degeneracy of spin states resulting in a photoinduced circular dichroism.

Structural evolution from a fence-like to pillared-layer metal-organic framework for the stable oxygen evolution reaction.

A stable pillared-layer metal-organic framework (MOF) was obtained through post-synthesis modification from an unstable fence-like MOF for the first time. By virtue of high exposure of active sites on the layers, the evolved MOF with Fe doping exhibits an ultralow overpotential of 238 mV at 10 mA cm-2 during the oxygen evolution reaction (OER). Moreover, it shows a superior electrocatalytic stability with almost no attenuation for more than 168 h.

Evaluation of menopausal status among breast cancer patients with chemotherapy-induced amenorrhea.

Objective: In patients with chemotherapy-induced amenorrhea (CIA), the menopausal status is ambiguous and difficult to evaluate. This study aimed to establish a discriminative model to predict and classify the menopausal status of breast cancer patients with CIA.

Methods: This is a single center hospital-based study from 2013 to 2016.

Efficient Hydrogen Evolution on Cu Nanodots-Decorated NiS Nanotubes by Optimizing Atomic Hydrogen Adsorption and Desorption.

Low-cost transition-metal dichalcogenides (MS) have attracted great interest as alternative catalysts for hydrogen evolution. However, a significant challenge is the formation of sulfur-hydrogen bonds on MS (S-H), which will severely suppress hydrogen evolution reaction (HER). Here we report Cu nanodots (NDs)-decorated NiS nanotubes (NTs) supported on carbon fibers (CFs) (Cu NDs/NiS NTs-CFs) as efficient electrocatalysts for HER in alkaline media.