Realizing highly efficient deep-blue organic light-emitting diodes towards Rec.2020 chromaticity by restricting the vibration of the molecular framework.

Deep-blue organic light-emitting diodes (OLEDs) with narrow emission spectra and high efficiency, meeting the Rec.2020 standard, hold significant promise in the realm of 4K/8K ultrahigh-definition displays. However, the development of light-emitting materials exhibiting both narrowband emission and high efficiency, particularly in the realm of deep-blue thermally activated delayed fluorescence (TADF), confronts substantial challenges.

Unveiling the Sources and Transfer of Mercury in Forest Bird Food Chains Using Techniques of Vivo-Nest Video Recording and Stable Isotopes.

Knowledge gaps in mercury (Hg) biomagnification in forest birds, especially in the most species-rich tropical and subtropical forests, limit our understanding of the ecological risks of Hg deposition to forest birds. This study aimed to quantify Hg bioaccumulation and transfer in the food chains of forest birds in a subtropical montane forest using a bird diet recorded by video and stable Hg isotope signals of biological and environmental samples. Results show that inorganic mercury (IHg) does not biomagnify along food chains, whereas methylmercury (MeHg) has trophic magnification factors of 7.

A spiroacridine-based thermally activated delayed fluorescence emitter for high-efficiency and narrow-band deep-blue OLEDs.

A novel deep-blue thermally activated delayed fluorescence molecule of SAC-BOC was reported. The SAC-BOC-based device exhibits a narrow full width at half maximum of 57 nm, an impressive maximum external quantum efficiency (EQE) of 15.3% and CIE coordinates of (0.

Acquiring Charge-Transfer-Featured Single-Molecule Ultralong Organic Room Temperature Phosphorescence via Through-Space Electronic Coupling.

Although long-lived triplet charge-transfer ( CT) state with high energy level has gained significant attention, the development of organic small molecules capable of achieving such states remains a major challenge. Herein, by using the through-space electronic coupling effect, we have developed a compound, namely NIC-DMAC, which has a long-lived CT state at the single-molecule level with a lifetime of 210 ms and a high energy level of up to 2.50 eV.

Ambient Phosphor with High Efficiency and Long Lifetime in Poly(Methyl Methacrylate) Through Charge-Transfer-Mediated Triplet Exciton Formation for Photolithography Applications.

Currently, purely organic compounds showing ambient phosphorescence with high efficiency (Φ ) and ultra-long lifetime (τ ) are quite rare and often need to be achieved in hydrophilic poly(vinyl alcohol)-based hosts. This severely limits their applications. Here, we provide a solution to this issue by constructing an ortho-linked donor-acceptor (D-A) dyad whose D moiety has not only a long-lived T state to achieve a long τ , but also a T state that is close to the S state of the dyad to trigger effective spin-orbit charge transfer intersystem crossing (SOCT-ISC).

A Reusable Fluorescent Molecular Self-Assembly Cage for Simultaneous Detection and Recycling of Silver(I) Ion.

Although molecular self-assembled porous materials capable of ratiometric fluorescence probing and recycling of metal ions are both economically and environmentally attractive, very few current efforts have been devoted. Herein, we demonstrated a three-dimensional pure organic cage, namely 4-cage, which can serve as a fluorescent probe for simultaneous ratiometric detection and recycling of Ag ion. Taking advantage of the promising emission behavior of its rigidified tetraphenylethylene scaffolds and the chelating ability of its dynamically reversible imine moieties, on one hand, upon the addition of Ag , 4-cage undergoes coordination to form a stable but poorly soluble fluorescent complex, Ag @4-cage, accompanied by a fluorescence color change from bluish-green to yellowish-green.

Isomeric Effect of a π Bridge in an IDT-Based Nonfused Electron Photovoltaic Acceptor.

A pair of isomers, IDT-BOF containing S⋅⋅⋅O/F⋅⋅⋅H noncovalently configurational locks and IDT-BFO containing F⋅⋅⋅H/O⋅⋅⋅H noncovalently configurational locks, with an acceptor-π-donor-π-acceptor (A-π-D-π-A) structure have been designed and synthesized by choosing 4,9-dihydro-s-indaceno[1,2-b : 5,6-b']dithiophene (IDT) as the D unit, an F/n-hexyloxy substituted phenyl ring as π bridge, and 3-(dicyanomethylidene)indan-1-one as the A unit. Owing to the S⋅⋅⋅O/F⋅⋅⋅H or F⋅⋅⋅H/O⋅⋅⋅H noncovalently configurational locks, both IDT-BOF and IDT-BFO have a completely planar structure. IDT-BOF exhibits a similar LUMO to IDT-BFO, but higher HOMO energy levels, leading to a smaller optical bandgap and red-shifted absorption.

Combined ICP-OES and XPS analysis to evaluate the [AlO] concentration in quartz: limiting the formation temperature of quartz.

A proposed quartz thermometer is based on the concentration of [AlO] tetrahedra determined by combining inductively coupled plasma optical emission spectrometry (ICP-OES) with X-ray photoelectron spectroscopy (XPS) data. The concentration of [AlO] tetrahedra in the quartz lattice (/ppm) and the formation temperatures of quartz (/°C) from agate, gold deposits, and granodiorite are calculated by = (ppm) × and (°C) = 3.6 × (ppm) × + 33.

The mercury flow through a terrestrial songbird food chain in subtropical pine forest: Elucidated by Bayesian isotope mixing model and stable mercury isotopes.

In order to comprehend the transfer of inorganic mercury (IHg) and methylmercury (MeHg) within food chains in terrestrial pine forests, we collected samples of Great Tit nestlings, common invertebrates, plants, and soil in a subtropical pine forest and used Bayesian isotope mixing model analysis, Hg daily intake, and stable Hg isotopes to elucidate the flow of MeHg and IHg in these food chains. Results indicate that caterpillars and cockroaches are the predominant prey items for nestlings, accounting for a combined contribution of 81.5%.

A red ambient afterglow material with lifetime of 0.5 s and efficiency over 12.

γCbPhAP, a D-A dyad with γ-carboline as the D unit and 3-phenylacenaphtho[1,2-]pyrazine-8,9-dicarbonitrile as the A moiety and phosphorescence core, was designed and synthesized. The doping system of 1 wt% γCbPhAP in PMMA shows red ambient phosphorescence-dominated afterglow with long lifetime of 0.5 s and decent efficiency over 12%.

A Low-Cost Test Method for Accurate Detection of Different Excited-State Species with a Lifetime Span over 5 Orders of Magnitude in One Time Window.

Accurate quantification on the quantum yields (φ) of both the prompt fluorescence (PF) and the delayed fluorescence (DF) species is quite essential for the clarification of molecular design rationales for thermally activated delayed fluorescence (TADF) luminogens. Currently, most φ and φ data of TADF fluorophores were acquired through time-correlated single-photon counting (TCSPC) lifetime measurement systems. However, because of their equal-time-channel working manner, so far all the commercially available TCSPC systems cannot render accurate measurement on φ of TADF materials due to the lack of enough valid data points in the faster decay region of the corresponding photoluminescence (PL) decay curves.

Ultra-fast triplet-triplet-annihilation-mediated high-lying reverse intersystem crossing triggered by participation of nπ*-featured excited states.

The harvesting of 'hot' triplet excitons through high-lying reverse intersystem crossing mechanism has emerged as a hot research issue in the field of organic light-emitting diodes. However, if high-lying reverse intersystem crossing materials lack the capability to convert 'cold' T excitons into singlet ones, the actual maximum exciton utilization efficiency would generally deviate from 100%. Herein, through comparative studies on two naphthalimide-based compounds CzNI and TPANI, we revealed that the 'cold' T excitons in high-lying reverse intersystem crossing materials can be utilized effectively through the triplet-triplet annihilation-mediated high-lying reverse intersystem crossing process if they possess certain triplet-triplet upconversion capability.

A water-soluble sensor for distinguishing DO from HO by dual-channel absorption/fluorescence ratiometry.

By taking advantage of the slight difference in the acidity of DO and HO, we report a novel DO optical sensor, namely Cy, with integrated great water-solubility, absorption/fluorescence dual-channel ratiometric response and even RGB visual sensing application. This work puts forward a facile method for distinguishing DO from HO with high sensitivity and high accuracy.

Mercury Uptake, Accumulation, and Translocation in Roots of Subtropical Forest: Implications of Global Mercury Budget.

Plant roots are responsible for transporting large quantities of nutrients in forest ecosystems and yet are frequently overlooked in global assessments of Hg cycling budgets. In this study, we systematically determined the distribution of total Hg mass and its stable isotopic signatures in a subtropical evergreen forest to elucidate sources of Hg in plant root tissues and the associated translocation mechanisms. Hg stored in roots and its isotopic signatures show significant correlations to those found in surrounding soil at various soil depths.

Mineralogical and Geochemical Characteristics of Banded Agates from Placer Deposits: Implications for Agate Genesis.

The phase composition and geochemical characteristics in banded agates with different structural sequences have been investigated in detail. The results reveal that the agate bands have a combination of a pseudo-granular silica → fibrous chalcedony → crystalline quartz (type I) sequence and a newly discovered pseudo-granular silica → crystalline quartz (type II) sequence. The banded agates mainly consist of α-quartz, moganite, and a minor amount of amorphous silica, goethite, hematite, kaolinite, illite, and carbonates.

Visualizing Lysosomal Positioning with a Fluorescent Probe Reveals a New Synergistic Anticancer Effect.

The observation and discovery of lysosome dynamic alterations will greatly contribute to the in-depth understanding of lysosome biology and the development of new cancer therapeutics. To visualize lysosomal dynamics, here we have developed a lysosome-targetable fluorescent probe of showing integrated high selectivity, high photostability, and low cytotoxicity. With the aid of the excellent spatial and temporal imaging capability of , three different types of motion of lysosomes were defined, and perinuclear accumulation of lysosomes in response to the pro-inflammatory cytokine stimulus was observed in various cells.

Canopy-Level Flux and Vertical Gradients of Hg Stable Isotopes in Remote Evergreen Broadleaf Forest Show Year-Around Net Hg Deposition.

Vegetation uptake represents the dominant route of Hg input to terrestrial ecosystems. However, this plant-directed sink is poorly constrained due to the challenges in measuring the net Hg exchange on the ecosystem scale over a long period. Particularly important is the contribution in the subtropics/tropics, where the bulk (∼70%) of the Hg deposition is considered to occur.

Cooperative roles of Sn(IV) and Cu(II) for efficient transformation of biomass-derived acetol towards lactic acid production.

Acetol as one of the major constituent derived from biomass pyrolysis has shown high potential as feedstock to produce chemicals but remains challenging due to the unsatisfied productivity. We here developed a novel technology (Sn(IV)-Cu(II) system), achieving acetol transformation towards lactic acid (LaA) production with an unprecedented yield (91.8 C-mol%), the highest value among the state-of-the-art strategies.

Increase of litterfall mercury input and sequestration during decomposition with a montane elevation in Southwest China.

Litterfall mercury (Hg) input has been regarded as the dominant Hg source in montane forest floor. To depict combining effects of vegetation, climate and topography on accumulation of Hg in montane forests, we comprehensively quantified litterfall Hg deposition and decomposition in a serial of subtropical forests along an elevation gradient on both leeward and windward slopes of Mt. Ailao, Southwest China.

Vivianite and Its Oxidation Products in Mammoth Ivory and Their Implications to the Burial Process.

The phase composition and distribution characteristics have been obtained from two mammoth ivory samples with typical blue and yellowish-brown outer layers. The results reveal that hydroxyapatite, newberyite, organic matter, and quartz exist in all structures of mammoth ivory. Vivianite and santabarbaraite mainly contribute to the blue and yellowish-brown oxide layers of mammoth ivory, respectively.

Quantification of Atmospheric Mercury Deposition to and Legacy Re-emission from a Subtropical Forest Floor by Mercury Isotopes.

Air-soil exchange of elemental mercury vapor (Hg) is an important component in the budget of the global mercury cycle. However, its mechanistic detail is poorly understood. In this study, stable Hg isotopes in air, soil, and pore gases are characterized in a subtropical evergreen forest to understand the mechanical features of the air-soil Hg exchange.

Tetraphenylethylene-conjugated polycation covered iron oxide nanoparticles for magnetic resonance/optical dual-mode imaging.

Magnetic resonance (MR)/optical dual-mode imaging with high sensitivity and high tissue resolution have attracted many attentions in biomedical applications. To avert aggregation-caused quenching of conventional fluorescence chromophores, an aggregation-induced emission molecule tetraphenylethylene (TPE)-conjugated amphiphilic polyethylenimine (PEI) covered superparamagnetic iron oxide (Alkyl-PEI-LAC-TPE/SPIO nanocomposites) was prepared as an MR/optical dual-mode probe. Alkyl-PEI-LAC-TPE/SPIO nanocomposites exhibited good fluorescence property and presented higher relaxivity (352 Fe mMs) than a commercial contrast agent Feridex (120 Fe mMs) at 1.