Enhanced upconversion luminescence of UCNPs@CsPbI nanocomposites via constructing multiple energy transfer channels.

The application of upconversion nanomaterials relies heavily on the ability to produce bright upconversion luminescence (UCL) or high upconversion quantum yields (UCQYs) at low power density excitation. Herein, we synthesized silica-coated NaYF:Yb@NaGdF:Tm@NaYF:Tb upconversion nanoparticles (UCNPs) and CsPbI perovskites quantum dots (PeQDs) nanocomposites by the slow hydrolysis of (3-aminopropyl)triethoxysilane. The energy transfer (ET) of Gd→Tb accelerates the five-photon upconversion process of Yb-Tm and the design of the core@shell@shell layer effectively mitigates the energy jumps between Gd ions.

High-efficiency upconversion luminescence in UCNPs/CsPbBr nanocomposites enhanced by silver nanoparticles.

Upconversion nanocomposites with multiple light-emitting centers have attracted great attention as functional materials, but their low efficiency limits their further applications. Herein, a novel, to the best of our knowledge, system for nanocomposites consisting of upconversion nanoparticles (UCNPs) and perovskite quantum dots (PeQDs) assembled with Ag nanoparticles (NPs) is proposed. Upconversion luminescence (UCL) operation from PeQDs is triggered by near-infrared (NIR) sensitization through Förster resonance energy transfer (FRET) and photon reabsorption (PR).

Regional horizontal ecological compensation and ecosystem service value based on water resources pattern and insurance gain.

Ecological compensation plays an important role in maintaining ecosystem services and promoting regional green development. We built a regional horizontal ecological compensation model based on water resources pattern and insurance gain, and which was used to solve the problems of single compensation method and low compensation efficiency. Taking the Beijing-Tianjin-Hebei region as an example, we analyzed water footprint and water ecological carrying capacity from 2000 to 2019.

Site-selective occupation, optical spectrum regulation and photoluminescence property investigation of Eu-activated blue light-excited yellow-orange emitting phosphors.

We report yellow-orange emitting phosphors SrCaMg(PO):0.05Eu (SCMPO:Eu, = 0.5-2.

Pressure-induced distinct excitonic properties of 2D perovskites with isomeric organic molecules for spacer cations.

Spacer organic cations in two-dimensional (2D) perovskites play vital roles in inducing structural distortion of the inorganic components and dominating unique excitonic properties. However, there is still little understanding of spacer organic cations with identical chemical formulas, and different configurations have an impact on the excitonic dynamics. Herein, we investigate and compare the evolution of the structural and photoluminescence (PL) properties of [CH(CH)NH]PbI ((PA)PbI) and [(CH)CH(CH)NH]PbI ((PNA)PbI) with isomeric organic molecules for spacer cations by combining steady-state absorption, PL, Raman and time-resolved PL spectra under high pressures.

Multi-color UCNPs/CsPb(BrI) for upconversion luminescence and dual-modal anticounterfeiting.

Advanced hybrid materials have attracted extensive attention in optoelectronics and photonics application due to their unique and excellent properties. Here, the multicolor upconversion luminescence properties of the hybrid materials composed of CsPbX(X = Br/I) perovskite quantum dots and upconversion nanoparticles (UCNPs, core-shell NaYF:25%Yb,0.5%Tm@NaYF) is reported, achieving the upconversion luminescence with stable and bright of CsPbX perovskite quantum dots under 980 nm excitation.

Synthesis, structure, and luminescence properties of Europium/Cerium/Terbium doped strontium-anorthite-type green phosphor for solid state lighting.

Novel phosphor exploration and luminescence property regulation are two important strategies in pursing high performance phosphors for white light emitting diodes, and have attracted great attention from the researchers. Herein, novel green phosphors SrGaSiO:Eu and SrGaSiO:Ce,Tb had been obtained by high-temperature solid-state reactions and their luminescence properties had been investigated in detail. Powder X-ray diffraction and Rietveld structure refinement results verified the phase purity and gave the crystal structure of the prepared samples.

Revealing photoluminescence mechanisms of single CsPbBr/CsPbBr core/shell perovskite nanocrystals.

CsPbBr nanocrystals (NCs) encapsulated by CsPbBr has attracted extensive attention due to good stability and high photoluminescence (PL) emission efficiency. However, the origin of photoluminescence (PL) emission from CsPbBr/CsPbBr composite materials has been controversial. In this work, we prepare CsPbBr/CsPbBr core/shell nanoparticles and firstly study the mechanism of its photoluminescence (PL) at the single-particle level.

STED microscopy reveals in-situ photoluminescence properties of single nanostructures in densely perovskite thin films.

All-inorganic perovskite nanomaterials have attracted much attention recently due to their prominent optical performance and potential application for optoelectronic devices. The carriers dynamics of all-inorganic perovskites has been the research focus because the understanding of carriers dynamics process is of critical importance for improving the fluorescence conversion efficiency. While photophysical properties of excited carrier are usually measured at the macroscopic scale, it is necessary to probe the in-situ dynamics process at the nanometer scale and gain deep insights into the photophysical mechanisms and their localized dependence on the thin-film nanostructures.

Luminescence property improvement and controllable color regulation of a novel Bi doped CaTaO green phosphor through charge compensation engineering and energy transfer.

In pursuit of warm WLEDs, exploration of novel phosphors and regulation of the existing phosphors are the two approaches usually used in the luminescent material field. In this work, we prepared green CaTaO:Bi phosphors firstly and investigated their properties in detail. The as-prepared CaTaO:Bi exhibits intense green emission in the 450-580 nm range under UV excitation, which matches well with the UV chip and can efficiently avoid the re-absorption problem.

The structures and luminescence properties of SrGdNa(PO)F:Ce,Tb green phosphors with zero-thermal quenching of Tb for WLEDs.

In this paper, novel green-emitting Sr4Gd3Na3(PO4)6F2:Ce3+,Tb3+ phosphors with zero-thermal quenching of Tb3+ have been prepared and investigated. X-ray diffraction together with Rietveld structure refinement was employed to give an insight into the structures of the samples. The luminescence spectra at 300 K and 80 K confirmed that the Ce3+ ions in Sr4Gd3Na3(PO4)6F2:Ce3+ were distributed randomly on the cation sites and gave intense emission.

Transcriptome sequencing, molecular markers, and transcription factor discovery of Platanus acerifolia in the presence of Corythucha ciliata.

The London Planetree (Platanus acerifolia) are present throughout the world. The tree is considered a greening plant and is commonly planted in streets, parks, and courtyards. The Sycamore lace bug (Corythucha ciliata) is a serious pest of this tree.

Efficient green phosphor realized by Ce→Tb energy transfer in LiSc(PO) for ultraviolet white light-emitting diodes.

A series of Ce3+/Tb3+ doped Li3Sc2(PO4)3 phosphors has been obtained using high temperature solid state reactions. Density functional theory (DFT) calculations using the CASTEP module have given an insight into the bandgap and electronic structures of the hosts. The phase formation and the crystal structure of the prepared samples were verified using X-ray diffraction and Rietveld structure refinement analysis.

Synthesis and Study of Optical Characteristics of TiO/CdS Hybrid Sphere Structures.

The optical properties of alternating ultrathin TiO nanosheets and CdS nanoparticle hybrid spherical structures designed by the layer-by-layer (LBL) assembly technique are investigated. From the photoluminescence (PL) spectral measurements on the hybrid spherical structures, a spectrum-shifted fluorescence emission occurs in this novel hybrid material. The time-resolved PL measurements exhibit a remarkably increased PL lifetime of 3.

Potential color tunable SrLaNa(PO)F:Eu/Tb/Mn phosphor induced by Eu → Tb and Tb → Mn energy transfer for WLEDs.

Color tunable SrLaNa(PO)F:Eu,Tb and SrLaNa(PO)F:Tb,Mn phosphors were prepared by a high temperature solid state reaction. The crystal structure, luminescence properties, and energy transfer mechanism of the samples were investigated in detail. The Eu doped phosphors can be efficiently excited in the range from 250 to 410 nm, which matches well with the commercial n-UV LED chips.

Temperature and Wavelength Dependence of Energy Transfer Process Between Quantized States and Surface States in CdSe Quantum Dots.

Temperature and wavelength dependence of energy transfer (ET) process between quantized states and surface trap states of CdSe quantum dots was investigated, respectively. The experimental results demonstrate that the photoluminescence (PL) intensity of the quantized states decreases with respect to the trap state emission, especially at lower temperatures. The observed ET process between quantized states and trap states which is influenced by the thermal population behavior.

Overexpression of Histone Deacetylase and Amyloid Precursor Protein in Hepatocellular Carcinoma.

Epigenetic modifications are involved in the pathogenesis of cancer, and histone deacetylase inhibitors are considered potential therapeutic agents. Histone tails undergo acetylation at lysine residues, which is associated with transcriptional activation. However, previous studies indicated that as histone deacetylase inhibitors, both (-)-epigallocatechin-3-gallate and valproic acid presented the effects of downregulation of amyloid precursor protein expression, which resulted in the induction of apoptosis.

Broadband Yellowish-Green Emitting Ba4Gd3Na3(PO4)6F2:Eu(2+) Phosphor: Structure Refinement, Energy Transfer, and Thermal Stability.

A series of Ba4Gd3Na3(PO4)6F2:Eu(2+) phosphors with a broad emitting band have been synthesized by a traditional solid state reaction. The crystal structural and photoluminescence properties of Ba4Gd3Na3(PO4)6F2:Eu(2+) are investigated. The different crystallographic sites of Eu(2+) in Ba4Gd3Na3(PO4)6F2:Eu(2+) phosphors have been verified by means of their photoluminescence (PL) properties and decay times.

Neuroprotective effect of β-asarone against Alzheimer's disease: regulation of synaptic plasticity by increased expression of SYP and GluR1.

Aim: β-asarone, an active component of Acori graminei rhizome, has been reported to have neuroprotective effects in Alzheimer's disease. As the underlying mechanism is not known, we investigated the neuroprotective effects of β-asarone in an APP/PS1 double transgenic mouse model and in NG108 cells.

Materials And Methods: APPswe/PS1dE9 double transgenic male mice were randomly assigned to a model group, β-asarone treatment groups (21.

Topotactic Transformation Route to Monodisperse β-NaYF4:Ln(3+) Microcrystals with Luminescence Properties.

A novel nonorganic wet route for direct synthesis of uniform hexagonal β-NaYF4:Ln(3+) (Ln = Eu, Tb, Ce/Tb, Yb/Er, and Yb/Tm) microcrystals with various morphologies has been developed wherein the intermediate routine cubic-hexagonal (α → β) phase transfer process was avoided. The morphology can be effectively tuned into hexagonal disc, prism, and novel hierarchical architectures by systematically fine manipulating the Na2CO3/F(-) feeding ratio. It has been found that the routine α → β phase transfer for NaYF4 was not detected during the growth, while NaY(CO3)F2 emerged in the initial reaction stage and fast transformed into β-NaYF4 via a novel topotactic transformation behavior.

A two-step synthetic route to GdOF:Ln(3+) nanocrystals with multicolor luminescence properties.

GdOF:Ln(3+) (Ln = Eu, Tb, Eu/Tb, Ce/Tb, Yb/Er, and Yb/Tm) nanocrystals with a hexagonal prism morphology have been readily synthesized by a novel topotactic transformation route. The Gd(OH)2F precursor was first synthesized and structurally analyzed by the Rietveld refinement method. It has been found that the Gd(OH)2F precursor was formed by a novel type of ion-exchange from the brucite-like Gd2(OH)5NO3·0.

An intense NIR emission from Ca14Al10Zn6O35:Mn(4+),Yb(3+)via energy transfer for solar spectral converters.

To date, most current reports on the development and optimization of solar spectral converters have described the utilization of energy transfer among rare-earth ions. Here, we introduce non-rare-earth ion Mn(4+) to transfer energy to Yb(3+), which can exhibit strong near-infrared luminescence. It can harvest UV-blue photons and exhibits intense NIR emission of Yb(3+) around 1000 nm, perfectly matching the maximum spectral response of Si solar cells.

Enhancing photoluminescence performance of SrSi2O2N2:Eu(2+) phosphors by Re (Re = La, Gd, Y, Dy, Lu, Sc) substitution and its thermal quenching behavior investigation.

Eu(2+)-doped SrSi2O2N2 has recently been identified as a viable green phosphor that in conjunction with a blue-emitting diode can be used in solid-state white-lighting sources. In this study, we attempt to improve the photoluminescence and thermal quenching behavior by codoping Re(3+) (Re = La, Gd, Y, Dy, Lu, Sc) and Li(+) instead of Sr(2+). Trivalent cation substitution at the Sr(2+) site enhances the photoluminescence intensities and also achieves better thermal stability at high temperature.

Synthesis, structure, and photoluminescence properties of novel KBaSc2 (PO4 )3 :Ce(3+) /Eu(2+) /Tb(3+) phosphors for white-light-emitting diodes.

A series of novel KBaSc2 (PO4 )3 :Ce(3+) /Eu(2+) /Tb(3+) phosphors are prepared using a solid-state reaction. X-ray diffraction analysis and Rietveld structure refinement are used to check the phase purity and crystal structure of the prepared samples. Ce(3+) - and Eu(2+) -doped phosphors both have broad excitation and emission bands, owing to the spin- and orbital-allowed electron transition between the 4f and 5d energy levels.

Optical properties and energy transfer of a novel KSrSc2(PO4)3:Ce3+/Eu2+/Tb3+ phosphor for white light emitting diodes.

A new langbeinite-type phosphate KSrSc2(PO4)3 has been synthesized by conventional high temperature solid state reaction. Rietveld structure refinement, a field emission scanning electron microscope, photoluminescence spectra, quantum efficiency as well as lifetimes were used to characterize the samples. Structure refinement reveals that KSrSc2(PO4)3 has two kinds of Sr(2+) and Sc(3+) sites for the doped ions to occupy, forming emission centers.