Optical Upconversion in Mononuclear Lanthanide Co-Crystal Assemblies.

In this work, we developed two kinds of co-crystal assemblies systems, consisting of discrete mononuclear Yb and Er and mononuclear Yb and Pr, which can achieve Er and Pr upconversion luminescence, respectively, by Yb sensitization under 980 nm excitation. The structure and composition of two co-crystal assemblies were determined by single crystal X-ray diffraction. By investigation of the series of two assemblies, respectively, it is found that the strongest upconversion luminescence is both obtained when the molar ratio of Yb and Ln (Ln=Er or Pr) is 1 : 1.

Ultrahigh-Q Polarization-Independent Terahertz Metamaterial Absorber Using Pattern-Free Graphene for Sensing Applications.

In contrast to noble metals, graphene exhibits significantly lower loss, especially useful for optical sensing applications that require ultrahigh Q factors, and offer wide range tunability via an adjustable Fermi level. However, precise graphene patterning is difficult, especially for large areas, severely limiting its applications. Here, a tunable terahertz metamaterial absorber (TMMA) with ultrahigh Q factors consisting of a continuous, pattern-free graphene is demonstrated.

Concave Version Printing of High-Performance Polymer THz Filters.

The development of high and tunable narrowband filters that can efficiently manipulate THz beams is critical for various THz applications, such as imaging and sensing. However, for filters made of metals and dielectrics, issues such as high losses, limited tunability, and lengthy process flows exist. Here, a scalable concave version reprinting technique to mass produce high-performance microstructured polymer filters is presented.

Effect of biochar with various pore characteristics on heavy metal passivation and microbiota development during pig manure composting.

Understanding the porosity of biochar (BC) that promotes the heavy metal (HM) passivation during composting can contribute to the sustainable management of pig manure (PM). The current work aimed to explore the influence of BC with varying pore sizes on the physicochemical properties and morphological changes of HMs (including Zn, Cu, Cr, As, and Hg), and microbiota development during PM composting. The various pore sizes of BC were generated by pyrolyzing pine wood at 400 (T1), 500 (T2), 600 (T3) and 700 (T4) °C, respectively.

Er-Sensitized Upconversion/Down-Shifting Luminescence in Metal-Organic Frameworks.

Photoluminescent metal-organic frameworks (MOFs) are used as optical materials with excellent properties, of which the lanthanide-doped MOFs are able to emit in a broad region from visible to near-infrared due to their unique 4f-orbital electronic structure. Herein, Er and Y ions are selected as the metal centers of the MOFs and Er is used as a sensitizer to absorb 980 nm excitation light. At the same time, Er ions also act as activators that emit upconverting visible light and down-shifting near-infrared light.

Polarization- and angle-insensitive broadband long wavelength infrared absorber based on coplanar four-sized resonators.

In many potential applications, there is a high demand for long wavelength infrared (LWIR) absorbers characterized by a compact configuration, broad operational bandwidth, high absorption efficiency, and polarization- and angle-insensitive characteristics. In this study, we design and demonstrate a high-performance broadband LWIR absorber based on coplanar four-sized resonators, consisting of arrays of titanium (Ti) disks with different diameters supported by a continuous zinc selenide (ZnSe) layer and by a Ti film acting as a back-reflector. Particle swarm optimization (PSO) is employed to optimize the complicated geometry parameters, and the final optimized device exhibits near-unity absorption (∼96.

THz transmissive all-dielectric guided-mode resonance filter with high Q and tunability using suspended gratings.

Most currently available THz narrowband filters employ metal that introduces loss, or work in reflection mode, which limits their scope of application. Here, a transmissive all-dielectric guided-mode resonance filter in the THz region is presented. It contains a suspended grating layer and a waveguide layer, separated by an air layer.

Upconversion Luminescence in Mononuclear Yb/Sm Co-crystal Assemblies at Room Temperature.

Metal-based upconversion luminescence transforming high-energy photons into low-energy photons is an attractive anti-Stokes shift process for fundamental research and promising applications. In this work, we developed the upconversion luminescence in co-crystal assemblies consisting of discrete mononuclear Yb and Sm complexes. The characteristic visible emissions of Sm were observed under the excitation of absorption band of Yb at 980 nm.

Research on the Differences in Phenotypic Traits and Nutritional Composition of Acer Truncatum Bunge Seeds from Various Regions.

Acer truncatum Bunge (ATB) is an excellent edible woody oil tree species since it bears a huge amount of fruit and has strong adaptability to be widely cultivated. Selecting an optimal cultivation region for ATB is crucial to improving China's woody oil industrialization. Chemical analysis, correlation analysis, and affiliation function values were used in the present research to systematically analyze the phenotypic traits, organic compound content, and seed oil chemical composition of the seeds of ATB from nine regions.

Fluorescent deactivation behaviors based on ESIPT and TICT of novel double target fluorescent probe and its sensing mechanism for Al/Mg: A TD-DFT study.

Based on density functional theory (DFT) and time-dependent DFT (TD-DFT) methods with integral equation formula polarized continuum model (IEFPCM), the fluorescent behavior and recognizing mechanism of probe N'-((1-hydroxynaphthalen-2-yl)methylene)isoquinoline-3-carbohydrazide (NHMI) for Al/Mg ion were investigated in more detail. Excited state intramolecular proton transfer (ESIPT) process in probe NHMI occurs in the stepwise pattern. The proton H of enol structure (E1) firstly moves from O to N to form single proton-transfer (SPT2) structure, and then the proton H of SPT2 transfers from N to N to form the stable double proton-transfer (DPT) structure.

Cooperative Sensitization Upconversion in Solution Dispersions of Co-Crystal Assemblies of Mononuclear Yb and Eu Complexes.

Lanthanide upconversion luminescence in nanoparticles has prompted continuous breakthroughs in information storage, temperature sensing, and biomedical applications, among others. Achieving upconversion luminescence at the molecular scale is still a critical challenge in modern chemistry. In this work, we explored the upconversion luminescence of solution dispersions of co-crystals composed of discrete mononuclear Yb(DBM) Bpy and Eu(DBM) Bpy complexes (DBM: dibenzoylmethane, Bpy: 2,2'-bipyridine).

Computational Insights into Sensing Mechanism for Al in a New Acylhydrazone Fluorescent Probe Based on Excited-State Intramolecular Proton Transfer (ESIPT) and Twisted Intramolecular Charge Transfer (TICT).

The work explored the fluorescent properties of probe '-(2, 4-dihydroxy-benzylidene)pyridine-3-carbohydrazide (HL) and its sensing mechanism for the Al ion in detail. HL has two competing deactivation processes: ESIPT and TICT. Upon light-excitation, only one proton can transfer, and the SPT1 structure is generated.

Upconversion Luminescence through Cooperative and Energy-Transfer Mechanisms in Yb -Metal-Organic Frameworks.

Lanthanide-doped metal-organic frameworks (Ln-MOFs) have versatile luminescence properties, however it is challenging to achieve lanthanide-based upconversion luminescence in these materials. Here, 1,3,5-benzenetricarboxylic acid (BTC) and trivalent Yb ions were used to generate crystalline Yb-BTC MOF 1D-microrods with upconversion luminescence under near infrared excitation via cooperative luminescence. Subsequently, the Yb-BTC MOFs were doped with a variety of different lanthanides to evaluate the potential for Yb -based upconversion and energy transfer.

A visualized and scientometric analysis of research trends of weight loss in overweight/obese children and adolescents (1958-2021).

Background: Weight loss is an appropriate approach to reduce the health risks associated with overweight/obese children and adolescents, and the optimal method of weight loss requires further research. This study systematically explores scientific co-operation, disciplinary interaction, hotspots and trends in the field of weight loss in overweight/obese children and adolescents (WLOCA), and provides references for further research.

Methods: Citespace 5.

Aerobic exercises and cognitive function in post-stroke patients: A systematic review with meta-analysis.

Objective: To study the effect of aerobic exercise on cognitive function of post-stroke patients, especially to identify specific interventions that the most likely to maximize cognitive benefits of stroke patients.

Methods: According to the PRISMA principle, the databases of Web of Science, EMBASE, PubMed and Cochrane library were searched to collect randomized controlled trial data of aerobic exercise on cognitive function intervention of post-stroke patients. The Cochrane bias risk evaluation instrument was used to assess the methodological quality of included studies.

Greenhouse gas reduction and nitrogen conservation during manure composting by combining biochar with wood vinegar.

The constant greenhouse gases (GHGs) and ammonia emissions during pig manure (PM) composting have made large contributions to air pollution and global temperature rise. This study aimed to evaluate the addition of biochar (B) and wood vinegar (WV) to reduce GHGs emissions and improve nitrogen retention and microbial activities during PM composting. Different treatments, carried out under a 1:2 ratio (dry weight) of PM and sawdust mixture with the addition of B (5%) and various proportions of WV, include a control treatment (CT) without the addition of B and WV and, B, B+0.

Achieving Photon Upconversion in Mononuclear Lanthanide Molecular Complexes at Room Temperature.

Photon upconversion luminescence at the molecule scale is a rarely observed phenomenon despite possessing colossal potential for basic research and reality applications. Here we show that the eight-coordinate erbium molecular complex composed of Er ion, dibenzoylmethane, and 2,2'-bipyridine exhibits upconversion emission. Under direct excitation at the absorption band of Er ion at 980 nm, the complex shows upconverted green emissions of Er ion at 525 and 545 nm at room temperature.

Upconversion/Downshifting Multimode Luminescence of Lanthanide-doped Nanocrystals for Multidimensional Information Encoding Security.

Information encoding security has always been a research hotspot in the optical field. Although many studies focused on luminescent materials and techniques for information security, the optical information encoding is limited by low information capacity and security. Herein, we present new core-shell-shell (CSS) lanthanide-doped nanocrystals which display multi-stimuli-responsive and multimode emission.

Lanthanide-doped heterostructured nanocomposites toward advanced optical anti-counterfeiting and information storage.

The continuously growing importance of information storage, transmission, and authentication impose many new demands and challenges for modern nano-photonic materials and information storage technologies, both in security and storage capacity. Recently, luminescent lanthanide-doped nanomaterials have drawn much attention in this field because of their photostability, multimodal/multicolor/narrowband emissions, and long luminescence lifetime. Here, we report a multimodal nanocomposite composed of lanthanide-doped upconverting nanoparticle and EuSe semiconductor, which was constructed by utilizing a cation exchange strategy.

Lanthanide upconversion and downshifting luminescence for biomolecules detection.

Biomolecules play critical roles in biological activities and are closely related to various disease conditions. The reliable, selective and sensitive detection of biomolecules holds much promise for specific and rapid biosensing. In recent years, luminescent lanthanide probes have been widely used for monitoring the activity of biomolecules owing to their long luminescence lifetimes and line-like emission which allow time-resolved and ratiometric analyses.

Energy Migration Control of Multimodal Emissions in an Er -Doped Nanostructure for Information Encryption and Deep-Learning Decoding.

Modulating the emission wavelengths of materials has always been a primary focus of fluorescence technology. Nanocrystals (NCs) doped with lanthanide ions with rich energy levels can produce a variety of emissions at different excitation wavelengths. However, the control of multimodal emissions of these ions has remained a challenge.

The solid-state physicochemical properties and biogas production of the anaerobic digestion of corn straw pretreated by microwave irradiation.

The effect of different temperatures used in microwave pretreatment on enhancing methane production of corn straw was comparatively studied in this paper through the analysis of the physicochemical properties of the pretreated materials and the methane yield during anaerobic digestion. Analytic methods such as scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction were performed to detect the surface chemistry of the pretreated corn straw. The results indicated that microwave pretreatment could effectively disrupt the lignocellulosic structure to release cellulose, hemicellulose, and related derivatives and make them available for the process of anaerobic digestion.

Polarization-independent guided-mode resonance filtering by all-dielectric gratings in the terahertz region.

We propose an angular-dependent polarization-insensitive filter in the terahertz (THz) region, based on the guided-mode resonance of one-dimensional zero-contrast grating architectural design. Particle swarm optimization combined with the rigorous coupled-wave analysis method is used to design the filter and investigate the influences of the planes of incidence on the characteristics of the proposed all-dielectric THz filter. With the planes of incidence set at 0°, 30°, 45°, and 60°, the polarization-independent resonances occur at 0.

Comparative Evaluation of Hydrothermal Carbonization and Low Temperature Pyrolysis of Eucommia ulmoides Oliver for the Production of Solid Biofuel.

This study evaluates the feasibility of two thermal pretreatments including hydrothermal carbonization (HTC) and low temperature pyrolysis (LTP) on the production of Eucommia ulmoides biochar. The waste wood of Eucommia ulmoides Oliver was pretreated and characterized for fuel applications. The results confirm that both LTP and HTC are promising processes for improving fuel properties.