Epitaxial growth of 2D gallium selenide flakes for strong nonlinear optical response and visible-light photodetection

As an emerging groupⅢ–Ⅵsemiconductor two-dimensional(2D)material,gallium selenide(GaSe)has attracted much attention due to its excellent optical and electrical properties.In this work,high-quality epitaxial growth of few-layer GaSe nanoflakes with different thickness is achieved via chemical vapor deposition(CVD)method.Due to the non-centrosymmetric structure,the grown GaSe nanoflakes exhibits excellent second harmonic generation(SHG).In addition,the constructed GaSe nanoflake-based photodetector exhibits stable and fast response under visible light excitation,with a rise time of 6 ms and decay time of 10 ms.These achievements clearly demonstrate the possibility of using GaSe nanoflake in the applications of nonlinear optics and(opto)-electronics.

Toward Robust and Efficient Low-Light Image Enhancement:Progressive Attentive Retinex Architecture Search

In recent years,learning-based low-light image enhancement methods have shown excellent performance,but the heuristic design adopted by most methods requires high engineering skills for developers,causing expensive inference costs that are unfriendly to the hardware platform.To handle this issue,we propose to automatically discover an efficient architecture,called progressive attentive Retinex network(PAR-Net).We define a new attentive Retinex framework by introducing the attention mechanism to strengthen structural representation.A multi-level search space containing micro-level on the operation and macro-level on the cell is established to realize meticulous construction.To endow the searched architecture with the hardware-aware property,we develop a latency-constrained progressive search strategy that successfully improves the model capability by explicitly expressing the intrinsic relationship between different models defined in the attentive Retinex framework.Extensive quantitative and qualitative experimental results fully justify the superiority of our proposed approach against other state-of-the-art methods.A series of analytical evaluations is performed to illustrate the validity of our proposed algorithm.

Recent advances in metal organic frameworks for the catalytic degradation of organic pollutants

Metal organic frameworks(MOFs)with their large surface area and numerous active sites have attracted significant research attention.Recently,the application of MOFs for the catalytic degradation of organic pollutants has provided effective solutions to address diverse environmental problems.In this review,the latest progress in MOF-based removal and degradation of organic pollutants is summarized according to the different roles of MOFs in the removal reaction systems,such as physical adsorbents,enzyme-immobilization carriers,nanozymes,catalysts for photocatalysis,photo-Fenton and sulfate radical based advanced oxidation processes(SR-AOPs).Finally,the opportunities and challenges of developing advanced MOFs for the removal of organic pollutants are discussed and anticipated.