Highest Emission Intensity Research Articles

A smart insulation material achieving self-reporting and autonomous repairing against electrical and mechanical damages based on targeted controllable microcapsules

Under the long-term action of electrical and mechanical stresses, irreversible micro-damages, such as electrical trees and cracks tend to occur inside solid insulation materials, leading to insulation failures, which have no effective countermeasures. This study develops a multi-responsive, target-controlled microcapsule to endow the epoxy resin with dual functions of self-reporting and autonomous repair against internal damage even under strong electric fields without human intervention. A turn-on mechanism for self-reporting signals is designed, to be applicable to electrical tree damage inside an epoxy matrix. In situ UV emissions generated by the partial discharge during electrical treeing are employed to automatically cure the microcapsule core material released into the damaged channel. This triggers aggregation-induced emission (AIE) signals and simultaneously repairs the damaged matrix. The polyurethane hybrid shell filled with magnetic particles endows the microcapsules with magnetic response characteristics. Under the control of a directional magnetic field, the microcapsule is concentrated around the vulnerable areas, obtaining high fluorescence emission intensity under low doping content without affecting the matrix performance. This method enables the autonomous inspection and maintenance of electric equipment and electronic devices under live working and provides new insight into the bionic intelligence of electrical and electronic insulation materials.

Design of an ultrafast plasmonic nanolaser for high-intensity broadband emission operating at room temperature.

We propose a plasmonic nanolaser based on a metal-insulator-semiconductor-insulator-metal (MISIM) structure, which effectively confines light on a subwavelength scale (∼λ/14). As the pump power increases, the proposed plasmonic nanolaser exhibits broadband output characteristics of 20 nm, and the maximum output power can reach 20 µW. Furthermore, the carrier lifetime at the upper energy level in our proposed structure is measured to be about 400 fs using a double pump-probe excitation. The ultrafast characteristic is attributed to the inherent Purcell effect of plasmonic systems. Our work paves the way toward deep-subwavelength mode confinement and ultrafast femtosecond plasmonic lasers in spaser-based interconnected, eigenmode engineering of plasmonic nanolasers, nano-LEDs, and spontaneous emission control.

Simple Encoded Circularly Polarized Protein Lighting

AbstractLighting systems with circularly polarized luminescence (CPL) are an emerging field with high hopes in, for example, neural cell circuits and encoding applications. The major challenges that forfeits their real‐world application are i) the design of chiroptical materials (CMs) with high CPL brightness (BCPL; today's record is Eu‐based compounds with average 287 M−1cm−1, while 90% of other CMs show <150 M−1cm−1 in solution) and ii) how to keep CPL response in films/coatings of technological relevance. Since natural evolution is driven by chiral selectivity at the supramolecular level, fluorescent proteins (FPs) are ideal candidates to provide large BCPL spanning visible and near‐infrared regions. This hypothesis is confirmed for all the known FP classes, demonstrating high emission intensities (photoluminescence quantum yields (ϕ) up to 76%) and record average BCPL of |200| M−1cm−1 (solution). What is more, the CPL response is also kept in polymer coatings. It is rationalized that structural factors (chromophore rigidity, surrounding amino acids, supramolecular packaging, and exciton coupling) hold a significant influence, regardless of the ϕ values. Finally, proof‐of‐concept CPL‐encoded signals in monochromatic/white hybrid light‐emitting diodes with FP‐polymer filters show exceptional stabilities. Overall, this work stands out FPs toward a new CM family, in general, and biogenic CPL‐encoded lighting systems, in particular.

Development of a FRET aptasensor based on MoS2-doped Zn-MOF as luminophore for selective detection of cadmium in aqueous solutions.

A robust "on-off" fluorescent aptasensor was developed using nanohybrids of molybdenum sulfide (MoS2) quantum dot (QD)-doped zinc metal-organic frameworks (Zn-MOF) for selective and sensitive detection of cadmium ions (Cd2+) in water. This nanohybrid (MoS2@Zn-MOF), synthesized via "bottle around the ship" methodology, exhibited a high-intensity fluorescence emission centered at 430nm (λEm) (blue) on excitation at 320nm (λEx). Further, the conjugation of this fluorophore to phosphate-modified cadmium aptamer (Cd-2-2) was achieved through carbodiimide reaction. The hybridization of prepared sensing probe (MoS2@Zn-MOF/Cd-2-2 aptamer) was done with dabcyl-conjugated complementary DNA (cDNA), acting as energy donor-acceptor pair in the fluorescence resonance energy transfer (FRET) system. This hybridizationcauses the fluorescence quenching of the nanohybrid. In the presence of Cd2+, the aptamer from the fabricated nano-biosensing probe binds to these ions, resulting in release of dabcyl-cDNA oligomer. This release of dabcyl-cDNA oligomer from the sensing probes restores the fluorescence of the nanohybrid. Under optimized conditions (sensing probe/dabcyl-cDNA ratio 1/7, pH 7.4, and temp 28°C), the sensing probe showed a fast response time of 1min. The fluorescence intensity of the nanohybrid can be utilizedto determine the concentration of Cd2+. The proposed aptasensor achieved highly sensitive detection of Cd2+ with a limit of detection (LOD) of 0.24ppb over the range of 1 × 10-9 to 1 × 10-4M along with minimal effects of interferences (e.g., Hg2+, Pb2+, and Zn2+) and good reproducibility. The designed aptasensor based on MoS2@Zn-MOF nanofluorophore offers a highly sensitive and selective approach for rapid screening of metal ions in aqueous environments.

Plasma-deposited reactive species assisted synthesis of colloidal zinc-oxide nanostructures

A surface-wave microwave discharge is applied to deposit reactive oxygen and nitrogen species (RONS) into the liquid subsequently used as a medium for laser ablation of a Zn metallic target. It is shown that during laser ablation in plasma-treated liquids the H2O2 concentration decreases, while in deionized water (DIW) significant H2O2 is produced. Meanwhile, the pH—initially adjusted by applying reductive metals—increases in the acidic liquids and decreases in the alkaline ones. During months of storage the pH of colloids stabilize around pH 6, which insures the long-term stability of RONS. It is demonstrated that in DIW metallic Zn NPs are created, which gradually oxidize during storage, while in the plasma-treated liquids ZnO NPs are produced with the mean size of 18 nm. In the alkaline plasma-treated liquid the NPs form large aggregates, which slows the dissolution of NPs. In the acidic and neutral solutions besides NPs nanosheets are also formed, which during storage evolve into nanosheet networks as a result of the dissolution of NPs. The band gap of the colloidal ZnO is found to decrease with the formation of aggregates and nanosheet networks. The ZnO NPs ablated in plasma-treated liquids exhibit a high-intensity visible emission covering the green-to-red spectral region. The photoluminescence spectra is dominated by the orange-red emission—previously not detected in the case of laser-ablated ZnO NPs and attributed to the interstitial Zn and oxygen sites—and the yellow emission, which can be attributed to the OH groups on the surface. It is shown that during months of storage, due to the dissolution of NPs and formation of nanosheets, the intensity of the visible emission decreases and shifts to the blue-green spectral region.

Tele-connecting regional carbon inequality in China to global consumers

Global trade may lead to unequal distribution of CO2 emissions and economic benefits among countries. While regional carbon inequality within a country driven by specific foreign consumers is rarely discussed. Taking China as an example, this study constructed a nested MRIO table to trace the CO2 emissions & value-added flows between each province of China (30 in total) and 18 other countries/regions, and measured the provincial carbon inequality based on emission terms of trade (ETT), emission-value (EV), carbon-Gini coefficient indicators triggered by these global consumers. Here we show that most provinces are net emission exporters and almost half of China's provinces suffered both environmental and economic losses in international trade. What is worse, it triggered severe regional imbalance of emissions and economic gains within China. The less developed western provinces with high emission intensity are always at a disadvantage in international trade, but some eastern provinces are on the favorable side. The consumption of the EU caused the most severe carbon inequality among provinces. These findings provide further information to relieve trade-induced carbon inequality at a refined scale and give inspiration to build more equitable trading mechanisms globally.

Boosting Near‐Infrared Emission in Spinel‐Type Phosphor via Oxygen Vacancy Engineering for Versatile Application

AbstractFe3+‐doped MgGa2O4 (MGO: Fe3+) spinel‐type near‐infrared (NIR) phosphor with non‐toxicity, outstanding thermal stability, and tunable emission has recently gained great concern owing to its wide applications. Nevertheless, the existence of detrimental O defects in the MgGa2O4 host and the forbidden d‐d transitions of Fe3+ lead to unsatisfactory luminescence efficiency, limiting the commercial application. In this study, a vacancy repairing engineering has been innovatively developed via F− substitution in MGO: Fe3+ (MGOF: Fe3+) for significantly enhancing NIR emission and maintaining outstanding thermal stability. Specifically, F− substitution with a similar radius effectively repairs the intrinsic O vacancy defects of MGO, thereby prohibiting the detrimental electron‐capturing effect. Meanwhile, F− incorporation can make the lattice of MGO distort and break the forbidden transition of Fe3+. Significantly, the obtained MGOF: Fe3+ presents a 16‐fold higher emission intensity than that of MGO: Fe3+. More important, the MGOF: Fe3+ can remain at 91.17% (363 K) and 85.10% (423 K). Finally, the NIR emission of MGOF: Fe3+ can be used for night vision, non‐destructive biological tissue detection, and food analysis. The proposed vacancy repairing strategy can certainly stimulate some new thoughts and concepts in designing high‐performance phosphors for wider applications.

Mild Alkaline-Enhanced depolymerization of Long-Flame coal for the synthesis of Coal-Derived fluorescent carbon dots with application as probes

The intricate composition and structural of low-rank coal have hindered its broad utilization in the field of material science. The study utilized an alkaline hydrothermal method to enhance the depolymerization of long-flame coal and achieve the purification of fluorescent carbon dots for the first time, which were then being employed for the trace detection of Cu2+ or Fe3+ ions. The carbon extraction efficiency reached 58 %, with the carbon dots averaging size of 1.36 ± 0.42 nm, the sp2 hybridized structure of the carbon dots indicated successfully purification under alkaline conditions. After reduction with sodium borohydride, defects in the core region of the carbon dots were repaired, and the C = O functional groups were transformed into O–H groups, leading to an increase in fluorescence intensity. At a concentration of 0.25 g/L of carbon dots, demonstrated high emission intensity at both long and low emission wavelengths, which can be used as LED luminescent material. Furthermore, the application of these carbon dots in detecting heavy metal ions (Cu2+, Fe3+) in aqueous solutions was explored, showing as low as detection limit of ∼ 0.04 μM. This study achieved higher depolymerization of coal and purification of fluorescent carbon dots for use in probe-based detection, providing fresh perspectives on the high-value utilization of low-rank coal.

Resonance photoemission in pure and Tb doped CePO4 luminescent nanowires

The resonance photoemission spectroscopy (RPES) studies on pure and Terbium doped CePO4 nanowires (NWs) are reported here with the supporting characterizations using structural, optical and morphological properties. The NWs with varying Terbium (Tb) doping concentrations were synthesized using chemical synthesis route. Photoluminescence (PL) showed high PL emission intensity in the visible wavelength range indicating strong green luminescence due to efficient Ce3+ to Tb3+ energy transfer. The PL intensity increased up to a doping concentration of 15 wt% Tb3+, beyond which it decreased due to concentration quenching or cross-relaxation effect. Based on PL studies, pure, 5 wt% (the lowest doping amount) and 15 wt% (that shows the highest PL) doped samples were chosen for RPES studies. To understand the comparative contribution of Ce3+ and Ce4+ in the valence band, RPES measurements performed around the Ce 4d →4 f resonance threshold indicated strong presence of Ce 4 f states in pure CePO4 NWs, which reduced upon 5 wt% Tb doping in CePO4 NWs. At 15 wt% Tb3+ doping, the sample did not show resonance of Ce 4 f feature, which may be because Tb3+ ions have replaced Ce3+ ions in the CePO4 lattice. The results are crucial to understand the relative participation of Ce3+ and Ce4+ oxidation states in the valence band, which is an important factor in defining the optical properties of the material that determine the PL intensity.

Green synthesis of polyoxometalate Cu3Mo2O9 nanoparticles for efficient degradation of organic dyes under visible light irradiation and their photoluminescence

Well-constructed photocatalysts with efficient catalytic activity have attracted much attention due to their efficient visible-light absorption and superior charge separation capability. Visible-light responsive Cu3Mo2O9 nanoparticles are synthesized utilising a simple and environmentally friendly green combustion process with Butea monosperma leaf extract as a reducing agent. X-ray diffraction pattern confirms the formation of orthorhombic crystal structure of Cu3Mo2O9 NPs corresponding to space group Pnma (62). Furthermore, the synthesized NPs were characterized using FTIR, UV-DRS, PL, SEM and TEM studies. It was found that the direct energy band gap was 2.29 eV. Through photodegradation in the presence of visible light, the dye-sorbed photocatalyst exhibited excellent results. The sorbents have also been examined for recycling, and it has been observed that they maintain their effectiveness even after multiple successive runs. These substances therefore appear to have potential as efficient industrial dye wastewater remediators. Moreover, the high intensity emission in the green zone is amply confirmed by the photoluminescence emission spectra and CIE coordinates. The Latent fingerprints (LFP) are visible with the application of the powder dusting process. The synthesized CMO nanoparticles exhibit ridge patterns that are well-resolved and useful for identifying unique LFP.

Carbon reduction and corporate sustainability: Evidence from low-carbon city pilot policy

The enhancement of corporate environmental, social, and governance (ESG) performance represents a crucial aspect of the broader green transformation agenda. Using a DID design, this paper examines the impact of China's low-carbon city pilot (LCCP) policy on the corporate ESG performance. Our findings demonstrate that the construction of LCCP exerts a positive influence on corporate ESG performance in pilot regions, particularly in industries and areas with high carbon emission intensity. Channel analyses reveal that LCCP policy heightens the environmental concerns of local governments and the public. Furthermore, LCCP policy has a crowding out effect with firms located in the surrounding cities. This paper responds to the calls for the determinants of ESG and enriches the understanding of policy impacts on corporate sustainability practices.

The confrontation and symbiosis of green and development: Coupling coordination analysis between carbon emissions and spatial development in urban agglomerations of China

Chinese cities face challenges of uneven development, high carbon emission intensity, and low efficiency in urbanization processes. Achieving harmonization and equilibrium between urban development and carbon emissions is crucial for sustainable development. This paper analyzes the development trajectory from 2013 to 2021 of four urban agglomerations in China: Northeast China (NEC), Beijing-Tianjin-Hebei (BTH), Yangtze River Delta (YRD), and Pearl River Delta (PRD). It identifies and calculates the urban spatial development patterns and carbon emissions, comparing the spatial-temporal variations in carbon emissions under different urban development patterns. The study also explores the coupling coordination relationship between these two aspects at various stages. The findings suggest that urban spatial development and carbon emissions are often uncoordinated in shrinking cities. In terms of coordination within urban agglomerations, BTH and NEC show suboptimal development, characterized by overall lag and polarization; YRD exhibits the best development, being consistently stable and balanced; PRD is generally improving, though with some cities lagging. Planning departments should revise urban and environmental policies to optimize spatial structures and infrastructure, aligning with regional development and promoting synergy in urban agglomerations. This research provides theoretical and empirical support for China to formulate relevant policies aimed at green, coordinated, and sustainable urban development.

In situ preparation of water-stable SiO2@mSiO2/CsPbBr3 and its application in WLED

Recently, all-inorganic perovskites as photoluminescent materials have attracted significant attention in the field of light-emitting diodes. However, their instability towards UV light, high temperature, and water has impeded widespread commercial applications. We propose a facile strategy for synthesizing CSSM-CPB by encapsulating perovskite CsPbBr3 (CPB) into the channels of core-shell silica microspheres (CSSM). Subsequently, the channels of CSSM-CPB were sealed with octadecyltrichlorosilane (ODS). Consequently, the stability of CSSM-CPB to UV light, high temperature, and water significantly improved. Notably, CSSM-CPB retains a high fluorescence emission intensity even after immersion in water for 30 days. Furthermore, the photoluminescence quantum yield of CSSM-CPB reaches 68%, compared to just 30% for discrete CPB. A CSSM-CPB-WLED was also developed, exhibiting a color temperature (Tc) of 5869 K, Commission Internationale de l′Éclairage (CIE) color coordinates of (0.34, 0.34), a luminous efficiency of 86.31 lm W−1, and a color gamut overlap with the NTSC space of approximately 121.1%. These results indicate a significant enhancement over CPB-WLED, suggesting that the stability of CPB can be improved through silica encapsulation and hydrophobic material sealing. This approach has potential for commercial application in display devices requiring high stability.

Abstract 4147: Chitosan luminescent rare-earth doped nanoparticles as cancer cell tracking for imaging tumors and their immune response

Abstract Background: Cancer is a group of diseases characterized by the unregulated growth of cells, which can be hard to diagnose due to the high false negatives or positives derived from technical and human mistakes.The detection of solid tumors during resection surgery is also a common issue, so contrast agents are used for both cancer diagnosis and tumor visualization during surgery, facilitating the tumor resection procedure. Nevertheless, they cause long-term problems because they accumulate in specific tissues, low penetration, and rapid clearance from the circulation. It is necessary to study new contrast agents that improve tumor detection to address these issues.Here, we synthesized two different kinds of luminescent nanoparticles (LNPs) conjugated with chitosan (Ch) and functionalized with folic acid (FA) for breast cancer detection. We compared in vitro its physicochemical characteristics and effects on the proliferation of cancer cells. Evaluated its impact on the immune system in vivo and implemented a differential imaging process to resemble a refined 3D visualization of cluster cells using Light Sheet Microscopy. Results: Luminescent nanoparticles (LNPs) synthesized by sol-gel method and functionalized with FA using EDC-NHS coupling revealed high-intensity yellow emission at 540 nm wavelength with a quantum yield of ~ 36%. In vitro viability assay at different times with 293T epithelial cells, MDA-MB-231, and T-47D cancer cells demonstrated biocompatibility and high improvement of cellular uptake by LNP functionalized with FA for cancer cells versus normal cells. Light-sheet microscopy analysis of cell-LNP interactions to visualize tagged MDA-MB-231 clusters with LNP/Ch-FA showed positive interactions due to higher stability and adherence. Biodistribution and effects on the immune system by LNP/Ch-FA nanoparticles inoculated in mice were evaluated by flow cytometer analysis. LNP/Ch-FA were well tolerated in vivo. No adverse effects were observed macroscopically. Peripheral blood analysis from animals injected with LNP/Ch-FA after 2 or 6 days of the treatment showed that a single injection of the different NPs did not have any effects on the amount of circulating neutrophils or monocytes in peripheral blood when assessed 2 or 6 days after the injection. With T cells, the core NP induced a significant decrease in circulating T cells (-31%, p=0.045) that seemed specific to the CD4+ T cells (-33%, p=0.0479). However, conjugation of the NP to chitosan prevented this effect. Conclusions: Our work presented significant evidence that could allow a better understanding of LNPs conjugated with Ch and functionalized with FA for possible upcoming clinical applications that could work singly or in synergy with the present detection techniques to boost accuracy and precision for cancer detection without compromise the inmunosystem. Citation Format: Rodrigo Osorio-Arciniega, Eduardo Lucero-Meza, Bonifacio Can-Uc, Israel Rocha-Mendoza, Pierrick G.J. Fournier, Gustavo A Hirata, Patricia Juarez. Chitosan luminescent rare-earth doped nanoparticles as cancer cell tracking for imaging tumors and their immune response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4147.

Trimethylamine from Subtropical Forests Rival Total Farmland Emissions in China.

Many types of living plants release gaseous trimethylamine (TMA), making it a potentially important contributor to new particle formation (NPF) in remote areas. However, a panoramic view of the importance of forest biogenic TMA at the regional scale is lacking. Here, we pioneered nationwide mobile measurements of TMA across a transect of contiguous farmland in eastern China and a transect of subtropical forests in southern China. In contrast to the farmland route, TMA concentrations measured during the subtropical forest route correlated significantly with isoprene, suggesting potential TMA emissions from leaves. Our high time-resolved concentrations obtained from a weak photo-oxidizing atmosphere reflected freshly emitted TMA, indicating the highest emission intensity from irrigated dryland (set as the baseline of 10), followed by paddy field (7.1), subtropical evergreen forests (5.9), and subtropical broadleaf and mixed forests (4.3). Extrapolating their proportions roughly to China, subtropical forests alone, which constitute half of the total forest area, account for nearly 70% of the TMA emissions from the nation's total farmland. Our estimates, despite the uncertainties, take the first step toward large-scale assessment of forest biogenic amines, highlighting the need for observational and modeling studies to consider this hitherto overlooked source of TMA.

Enhanced upconversion emission in Nd, Yb, Er and Ho tetra-doped Y2O3 phosphor

Yb3+, Nd3+, Er3+ and Ho3+ tetra ions doped Y2O3 upconversion phosphors have been prepared by the combustion route. Crystalline phase purity and cubic phase of prepared samples have been confirmed from powder X-ray diffraction study. Absorbance of samples over spectral range 200–1100 nm has been measured by diffuse reflectance spectroscopy. All samples exhibit large band gaps. Scanning electron micrograph analysis reveals spherical morphology of particles and sizes around 200 nm. Upconversion emission has been studied under a 980 nm diode laser excitation with 166 mW laser power. The Ho3+, Nd3+ and Yb3+ co-doped Y2O3 phosphor show very high emission intensity of a green band centred at around 550 nm and another moderate intensity red band centred on 667 nm, while reverse is the case for Er3+, Nd3+ and Yb3+ co-doped Y2O3 phosphor. Er3+, Ho3+, Nd3+ and Yb3+ co-doped Y2O3 phosphor show enhanced high emission intensity in both green and red bands. These two bands are not visible in Nd3+ and Yb3+ co-doped Y2O3 phosphor but show weak upconversion emission at 549, 568 and 799 nm. Owing to the high emission intensity of green band, Ho3+, Nd3+ and Yb3+ co-doped Y2O3 phosphor may find potential applications in medical and security, while Er3+, Ho3+, Nd3+ and Yb3+ co-doped phosphor showing enhanced upconversion in green and red bands may find applications in white light generation.

Indexes for evaluation of dynamic characteristics of pressure-sensitive paint based on pressure sensitivity and frequency response

Two evaluation indexes were proposed to select the optimal PSP for unsteady pressure measurement from various PSPs with different pressure sensitivity and frequency response. An effective sensitivity coefficient calculated by pressure sensitivity and gain attenuation due to the response delay was proposed. Furthermore, an effective amount of intensity change was recommended, which takes into account the emission intensity and the effective sensitivity coefficient, because the magnitude of the intensity of a PSP is also important for unsteady-pressure measurement with high-speed sampling. A total of five types of PC-PSPs developed in previous studies were compared: two types of fast-response PC-PSPs using Pt(II) meso-tetra (pentafluorophenyl) porphine (PtTFPP) with poly(isobutyl methacrylate) (poly(IBM)) and ruthenium complex with RTV silicone, respectively, and three types of PC-PSPs using PtTFPP with poly[1-trimethylsilyl)-1-propyne] (poly(TMSP)). A comparison was made using the proposed evaluation indexes under various pressure ranges. The results shows that poly(TMSP)-based PC-PSP has a high effective sensitivity coefficient at pressures less than 20 kPa. On the other hand, poly(IBM)-based PC-PSP has the highest effective sensitivity coefficient at a pressure of 100 kPa. The effective amount of intensity change of poly(TMSP)-based PC-PSP is the highest at 2 kPa, but that of poly(IBM)-based PC-PSP is the highest at a pressure higher than 5 kPa among the evaluated PC-PSPs due to its high luminescence intensity. A PSP with high emission intensity will provide high performance in terms of fluctuation of emission intensity detected by the photodetector when the excitation intensity and the exposure time are limited due to limitations of optical equipment or high-speed sampling.

Performance of Ce:YAG-MgO composite ceramics as high-power LED phosphor densified by non-reactive sintering

A novel white light converter has been successfully synthesized using a non-reactive sintering process to afford a fully densified Ce:YAG-MgO composite ceramic phosphor with high wavelength conversion efficiency under excitation at 450 nm. The composite obtained by HIP (hot isostatic pressing) treatment at 1080 ºC has no residual pores and the XRD (X-ray diffraction) analysis shows that there are no secondary phases other than Ce:YAG and MgO, moreover, the EDS (Energy-dispersive X-ray spectroscopy) analysis indicates no interdiffusion at the Ce:YAG-MgO contact interface. The thermal conductivity of 5–7.5 wt% Ce:YAG-added MgO composites is over 40 W/mK, nearly reaching the theoretical value. Due to the synergetic effect of “the difference in refractive index between MgO and Ce:YAG” and “MgO matrix with strong birefringence”, the excitation light (450 nm) is multiply scattered inside the composite medium, which provides efficient excitation even in a thin medium, resulting in the photoluminescence intensity that is 2.6 times higher than that of transparent Ce:YAG ceramics. This innovative white light converter combines a highly thermal conductive MgO matrix and Ce:YAG phosphor with high emission intensity.

Tracking coordination environment and optoelectronic structure of Eu3+ and Sm3+ sites via X-ray absorption spectroscopy and X-ray excited optical luminescence

In this work, the photophysical characteristics of the [Eu(tta)3(H2O)2] and [Sm(dbm)3(phen)] complexes, tta: 3-thenoyltrifluoroacetonate, dbm: dibenzoylmethane, and phen: phenanthroline were explored through X-ray excited optical luminescence (XEOL) in correlation with the local electronic/chemical structure evidences from the element-specific X-ray absorption fine structure (XAFS) analysis. The monochromatic hard X-ray photon at a synchrotron light source has added advantageous tunability with desirable penetration depth, avoiding optical photons scattering contrary to the optical LASER to unravel the relationship of the luminescence to the electronic structure and coordination environment of RE3+ (RE: Eu and Sm) site in compounds by tuning the photon energy of monochromatic X-ray to the L-edge of the rare earth. Accordingly, the XEOL spectra of both the rare earth complexes measured under excitations with tunable Eu3+ and Sm3+ L-edge monochromatic X-ray photon energy manifested considerably higher emission intensity from the hypersensitive 5D0→7F2 and 4G5/2→6H9/2 forced electric dipole (FED) transitions of Eu3+ and Sm3+ ions, respectively. This result suggested the non-centrosymmetric RE3+ site (lower symmetry), validating through quantitative XAFS analyses, which confirm the triclinic and monoclinic local structure for the [Eu(tta)3(H2O)2] and [Sm(dbm)3(phen)] complexes, respectively.

Real-time high-resolution modelling of grid carbon emissions intensity

Reducing greenhouse gas emissions in the energy industry is broadly acknowledged as important with numerous countries implementing targets to reduce emissions. Understanding the carbon emissions intensity of electricity grids is an important step in this process, and higher spatial and temporal granularity estimates are critical for delivering actionable insights. Existing emissions intensity models are limited in terms of their real-time availability and, in particular, their spatial granularity. Here we outline a method for estimating emissions intensity of large-scale interconnected electricity networks in real-time at substation-level resolution. This is realized by integrating nation-wide high-resolution electricity generation and demand data, regional population data, a detailed model of the electricity grid, and power flow simulation and flow tracing models. Results for Australia's National Electricity Market reveal that most capital city locations have higher emissions intensity than neighbouring regional areas, though the variation within a city can also be substantial. In general, emissions intensity is higher in areas closer to, or directly fed by emissions intensive coal and gas generators. These results have important implications for the design of energy efficiency incentives and demand response strategies, in the rollout of distributed renewable generation, and in carbon accounting.