Optimizing Model Learning Performance on a Challenging Heck Reaction Yield Data Set.

The development of machine learning (ML) in organic synthesis is limited due to the lack of available data sets. The ML-compatible literature data set for Heck reaction yields, named HeckLit, has been established. With 10,002 cases, the data set spans multiple reaction subclasses and covers a larger chemical space compared to high-throughput experimentation data sets, including nearly 3.

MetaSSL: A General Heterogeneous Loss for Semi-Supervised Medical Image Segmentation.

Semi-Supervised Learning (SSL) is important for reducing the annotation cost for medical image segmentation models. State-of-the-art SSL methods such as Mean Teacher, FixMatch and Cross Pseudo Supervision (CPS) are mainly based on consistency regularization or pseudo-label supervision between a reference prediction and a supervised prediction. Despite the effectiveness, they have overlooked the potential noise in the labeled data, and mainly focus on strategies to generate the reference prediction, while ignoring the heterogeneous values of different unlabeled pixels.

Optimal Methylammounium Chloride Additive for High-Performance Perovskite Solar Cells.

Organic-inorganic lead halide perovskite solar cells (PSCs) have presented promising improvements within recent years due to the superior photophysical properties of perovskites. The efficiency of PSCs is closely related to the quality of the of the perovskite film. Additive engineering is an effective strategy to regulate the crystallization of perovskite film.

Natural and polyanionic heparin polysaccharide functionalized upconversion nanoparticles for highly sensitive and selective ratiometric detection of pesticide.

Pesticide contamination is a global concern, threatening human health and food safety. Herein, we developed heparin (HEP) functionalized upconversion nanoparticles (UCNPs)-based ratiometric nanosensor for the sensitive detection of 2,6-dichloro-4-nitroaniline (DCN) pesticide via inner filter effect. The strategy for HEP functionalization of UCNPs is based on adjusting the surface potentials of UCNPs with polyanionic HEP through the electrostatic interaction.

Broadband near-infrared luminescence in a cubic pyrophosphate AlTaPO:Cr phosphor for multi-functional applications.

Near-infrared phosphor-converted light-emitting diodes (NIR pc-LEDs) are considered as next-generation of NIR light sources for spectroscopy. However, it is still a challenge to develop an inexpensive broadband NIR phosphor with relatively long-wavelength ( > 800 nm) emission. In this work, an octahedral Al-containing pyrophosphate AlTaPO with a cubic structure was chosen as a host for Cr.

Broadband and strength-switchable circular dichroism in a GeSbTe-based metasurface.

Circular dichroism (CD) is highly required in the applications of biological detection and analytical chemistry. In this paper, we achieved a giant, broadband, and strength-switchable CD effect in a quadruple -shaped (GST) metasurface. At the amorphous state of GST (a-GST), the giant CD reaches 0.

Broadband 1.0 µm emission in Nd/Yb co-doped phosphate glasses and fibers for photonic applications.

In this work, the spectroscopic properties of 1.0 µm emission in Nd/Yb co-doped phosphate glasses were systematically investigated under 808 nm excitation. Notably, broadband 1.

Broadband near-infrared amplified spontaneous emission of Er-doped germanate glass fiber.

Er-doped glass and fiber are very attractive for near-infrared (NIR) lasers and photonic applications. In this work, the full width at half maximum (FWHM) of NIR fluorescence emission of the Er-doped germanate glass can be broadened from 72 to 99 nm when AlO was added. In addition, the spectroscopic properties, including absorption and emission spectra, Judd-Ofelt intensity parameters, absorption and emission cross sections, gain coefficient, and fluorescence lifetime, of the AlO-modified germanate glass were systematically investigated.

Dynamically Adjusting Borophene-Based Plasmon-Induced Transparency in a Polymer-Separated Hybrid System for Broadband-Tunable Sensing.

Borophene, an emerging two-dimensional (2D) material platform, is capable of supporting highly confined plasmonic modes in the visible and near-infrared wavebands. This provides a novel building block for light manipulation at the deep subwavelength scale, thus making it well-suited for designing ultracompact optical devices. Here, we theoretically explore a borophene-based plasmonic hybrid system comprising a continuous borophene monolayer (CBM) and sodium nanostrip gratings (SNGs), separated by a polymer spacer layer.

Understanding the broadband near-infrared luminescence in a highly distorted garnet CaHfGeO:Cr phosphor.

Broadband near-infrared (NIR) spectroscopy generated from a phosphor-converted light-emitting diode (pc-LED) has multifunctional applications, including food-quality analysis, bio-medical and night-vision, stimulating the demand for developing various NIR phosphors with desired properties. Herein, we selected a highly distorted garnet CaHfGeO as the host and explored the near-infrared luminescence of Cr. As expected, this material achieved a long-wavelength NIR emission and excellent absorption efficiency based on the effect of Jahn-Teller distortion.

An efficient and thermally stable near-infrared phosphor derived from the LnScInGaO:Cr (Ln = La, Gd, Y, and Lu) garnet family.

A broadband near-infrared (NIR) light source based on a phosphor-converted light-emitting diode (pc-LED) has attracted increasing interest to be used in non-destructive examination, security-monitoring and medical diagnosis fields, which stimulates the exploration of NIR phosphors with high performance. Herein, a series of Cr-activated garnet LnScInGaO:Cr (Ln = La, Gd, Y, and Lu) phosphors were reported, allowing an emission peak ranging from 726 to 822 nm. Among them, YScInGaO:Cr with an optimized Cr-doping concentration of 6 mol% exhibits a high internal quantum efficiency (IQE = 83.

Enhanced 2-µm and upconversion luminescence properties regulated by network structure in Ho/Yb co-doped germanate laser glasses.

Rare-earth (RE) ions doped laser glass has attracted the interest of many researchers because of its numerous potential applications in planar waveguides and fiber lasers. In this work, the 2-µm and upconversion luminescence properties of Ho are simultaneously enhanced through the design of components used to regulate the network structure of the germanate glass. Furthermore, the thermal, structural, and spectroscopic properties of the Ho/Yb co-doped germanate laser glass are systematically investigated.

Producing Tunable Broadband Near-Infrared Emission through Co-Substitution in (GaMg)(GaGe)O:Cr.

Broadband near-infrared (NIR) phosphors are in high demand for creating "smart" NIR phosphor-converted light-emitting diode (pc-LED) sources. In this work, a series of Cr-substituted NIR-emitting materials with highly efficient, broad, tunable emission spectra are achieved by modifying the simple oxide GaO using [Mg-Ge] and [Ga-Ga] co-unit substitution. The results show that the emission peak can be shifted from 726 to 830 nm while maintaining a constant excitation peak in the blue light region, enabling extensive application.

Enhanced circular dichroism in GeSbTe-loaded metasurface.

Circular dichroism (CD) is originally obtained from three-dimensional spiral structures by simultaneously exciting electric and magnetic resonances. To simplify construction, multilayer stacked asymmetric structures and the symmetric structures relying on oblique incidence are proposed for enhancing CD. Herein, we achieved the enhancement of dual-waveband CD by adding a GeSbTe (GST) layer on the top of a Z-shape gold array in a normally incident system.

Achieving a tunable and ultra-broadband near-infrared emission in the GaZnGeO:Cr phosphor.

Near-infrared (NIR) spectroscopy (700-1100 nm) based on a phosphor-converted light-emitting diode (pc-LED) has multi-functional applications in bio-imaging, night-vision, and food quality analysis, simulating the development of efficient and ultra-broadband NIR phosphors. Herein, a series of tunable and ultra-broadband NIR phosphor GaZnGeO:Cr was successfully produced by a [Zn-Ge] unit co-substituting a [Ga-Ga] unit in GaO:Cr. With the increasing amount of [Zn-Ge] incorporation, the emission peak can be tuned from 726 to 808 nm, and the maximum FWHM can be extended from 126 to 190 nm.

Multifunctional metasurfaces for switchable polarization selectivity and absorption.

A multifunctional metasurface capable of dynamic control for polarization selectivity and absorption is proposed by controlling the phase of GeSbTe (GST) in the near-infrared region. At amorphous state of GST (a-GST), the proposed GST strip array realized polarization selectivity in transmission-reflection integrated modes. The high-efficiency asymmetric transmission (AT = 0.

Active metasurface in the near-infrared region by gating ultrathin TiN films.

Ultrathin titanium nitride (TiN) films have become a novel material flatform for constructing active metasurfaces in the near-infrared region. In this Letter, we numerically achieved the dual functions of switchable linear dichroism (LD) and tunable perfect absorption in a G-shape gold resonators/TiN film hybrid metasurface by gating ultrathin TiN films. As the carrier density of TiN decreases, the modulation depth for LD strength is about 70% at 1211 nm.

Design and simulation of a GST-based metasurface with strong and switchable circular dichroism.

Circular dichroism (CD) is required in the applications of biological detection, analytical chemistry, etc. Here, we numerically demonstrated large-range switchable CD by controlling the phase change of GeSbTe (GST) in a zigzag array. At the amorphous state of GST (a-GST), the strong and dual-waveband CD effects are realized via the selective excitations of electric, magnetic, and toroidal resonances.

Temperature-Dependent Optical Properties of Perovskite Quantum Dots with Mixed-A-Cations.

In this work, metal halide perovskite quantum dots (QDs) with Formamidinium (FA) and Cs mixed cations were fabricated using a solution-processed method at room temperature. By controlling Cs doping ratios in a precursor, the optical properties of mixed-cation perovskite QDs were systematically studied. With the increase in Cs ion doping, the photoluminescence (PL) spectra of perovskite QDs were blueshifted, which was mainly due to the smaller radius of Cs ions than those of FA.

Efficient and Thermally Stable Broad-Band Near-Infrared Emission in a KAlPO:Cr Phosphor for Nondestructive Examination.

Broad-band near-infrared (NIR) phosphors are essential to assembling portable NIR light sources for applications in spectroscopy technology. However, developing inexpensive, efficient, and thermally stable broad-band NIR phosphors remains a significant challenge. In this work, a phosphate, KAlPO, with a wide band gap and suitable electronic environment for Cr equivalent substitution was selected as the host material.

Trap-free exciton dynamics in monolayer WS oleic acid passivation.

Two-dimensional transition metal dichalcogenides have attracted a great deal of attention in the past few decades owing to their attractive optoelectronic properties. However, their widespread utility in photonic devices and components is still limited owing to their weak photoluminescence. While various treating methods are in place to improve the photoluminescence yield, the impact of these treatments on the excited state (especially exciton) dynamics in these two-dimensional materials remains ill defined.

Efficient and Tunable Luminescence in GaInO:Cr for Near-Infrared Imaging.

Broadband near-infrared (NIR) emitting materials are in great demand as next-generation smart NIR light sources. In this work, a Cr-substituted phosphor capable of efficiently converting visible to NIR light is developed through the solid solution, GaInO:Cr (0 ≤ ≤ 0.5).

Ultrafast nonequilibrium dynamic process of separate electrons and holes during exciton formation in few-layer tungsten disulfide.

Femtosecond transient absorption spectroscopy has been employed to unravel separate initial nonequilibrium dynamic processes of photo-injected electrons and holes during the formation process of the lowest excitons at the K-valley in few-layer tungsten disulfide. Charge carrier thermalization and cooling, as well as concomitant many-body effects on the exciton resonances, are distinguished. The thermalization of holes is observed to be faster than that of electrons.

Ultrafast acoustic vibrations of Au-Ag nanoparticles with varying elongated structures.

Acoustic vibrations of Au and Ag elongated nano-objects with original morphologies, from Ag-Ag homodimers to Au@Ag-Ag heterodimers and Au@Ag eccentric core-shell spheroids, have been experimentally investigated by ultrafast time-resolved optical spectroscopy. Their frequencies, obtained by the analysis of time-dependent transient absorption changes, are compared with the results obtained from finite element modeling (FEM) numerical computations, which allow assignment of the detected oscillating signals to fundamental radial and extensional modes. FEM was further used to analyze the effects of morphology and composition on the vibrational dynamics.

Thermally Robust and Color-Tunable Blue-Green-Emitting BaMgSiO:Eu,Mn Phosphor for Warm-White LEDs.

The dual emission produced from Mn when codoped with rare earth ions like Eu or Ce in inorganic compounds makes these materials attractive as efficient, color-tunable phosphors for warm-white solid-state lighting. Here, a series of efficient blue-green-emitting BaMgSiO:Eu,Mn phosphors with thermally robust, tunable luminescence are reported. Steady-state and time-resolved photoluminescence spectroscopy reveal that Eu and Mn each occupy a single crystallographic site and confirm that energy transfer occurs from Eu to Mn.