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The objective of this study was to optimize the extraction process of flavonoids from Abrus precatorius Linn, and explored its antioxidant activity. Ethanol volume fraction, solid-liquid ratio, ultrasonic energy and ultrasonic extracting time as variables, the yield of flavonoids as evaluation index, single factor tests and Box-Behnken method were used to optimize the extraction process. The scavenging ability on DPPH, ABTS+ free radicals, and the reducing power of flavonoids from Abrus precatorius Linn were also detected to estimate the antioxidant activities. Results showed that, when solid-liquid ratio reached 1:50, the optimum extraction process (0.696%, highest yield) could be achieved under condition of ethanol volume fraction 82%, ultrasonic energy 507 J and ultrasonic extracting time 42 min. Half effective concentration being EC50 0.028 and 0.009 mg/mL respectively. Abrus precatorius Linn flavonoids were able to scavenge DPPH and ABTS+ free radicals effectively, and its ability risen as mass concentration increases, meaning it is superior to Trolox. When flavonoid concentration was set at 5 mg/mL, the reducing power on iron ion reached 2.42 mmol/L, which was weaker than Trolox. To sum up, ultrasonic extraction technology can be effectively employed to the extraction of Abrus precatorius Linn flavonoids, resulting in better antioxidant activity. [ABSTRACT FROM AUTHOR]

In this study, the crystal structure analysis by particle swarm optimization (CALYPSO) was used to search the structure of negative LiBn− (n = 2–12) clusters, and the corresponding ground-state structures and low energy isomers were determined. Based on the predicted ground state structures, the doped Li atom has little modification on Bn− skeleton, which can be seen from the charge analysis that it is caused by the transfer of electron from dopant to Bn− part. The photoelectron spectroscopy (PES) simulations were conducted using time-dependent density functional theory (TD-DFT). By analyzing the stability, we find LiB8− cluster with high symmetry C7V with ideal stability, and it has a classic umbrella structure. Deep analysis of the bonding characteristics of the LiB8− cluster shows that the B–B covalent bonds in the B8− part and the electrostatic interaction between the B8− wheel and the Li atom stabilize the LiB8− cluster. [ABSTRACT FROM AUTHOR]

Temperature measurement based on thermally dependent emissions from intra-configurational 4f–4f transitions of rare earth ions has been developed as an efficient method for non-contact thermometry, but it remains challenging for high resolution temperature measurement due to the inherent limitation of the energy gap (200–2000 cm−1) between the thermally coupled energy levels (TCELs). In this work, a group of oxide phosphors, Y2O3:xEr3+, yLi+, prepared by a low-temperature combustion method (LCM) were developed for dual-mode optical thermometry by leveraging the temperature-responsive upconversion (UC) emission from Er3+ ions. We discover that the introduction of the dopant (Li+ ion) into Y2O3: Er3+ synthesized by the LCM can significantly regulate the original crystal configuration and its surface structure. Its transition to a monocrystalline state can solve the problem of high impurity defects and possible high dislocation density that cannot be overcome by a polycrystalline state, thus remarkably increasing the emission intensity of UC (about 28 times). In addition, the dual-mode optical thermometry based on thermally coupled energy levels (TCELs) and non-thermally coupled energy levels (NTCELs) was examined with respect to the different temperature dependence of the three characteristic emission peaks of the Er3+ ions (i.e., from excited levels of 2H11/2, 4S3/2 and 4F9/2). At temperatures from 123 to 443 K, the maximum relative sensitivities (SRmax) are 6.67% K−1 and 1.13% K−1 and the maximum absolute sensitivity (SAmax) reaches 0.42% K−1and 2.48% K−1, respectively. The excellent sensitivity at low temperatures indicates that our results not only provide an effective doping strategy for improving the crystal type character and surface structure of oxide phosphors, but also provide an effective guideline for the low temperature environmental applications of functional upconversion optical thermometers. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: Co‐culturing the mangrove endophytic fungus Penicillium sclerotiorum THSH‐4 with Penicillium sclerotiorum ZJHJJ‐18 in PDB medium resulted in the production of nine new azaphilones derivatives, peniazaphilones A—I (1—9), and six known azaphilones derivatives (10—15). Their structures were elucidated by analysis of detailed spectroscopic data, single‐crystal X‐ray diffraction, ECD spectra, 13C NMR calculation and DP4+ analysis. It is noteworthy that compound 1 with an isoquinoline quinone moiety, was isolated from natural source for the first time. Besides, compound 2 is the third reported phenylhydrazone derivative from fungi. In the bioactivity assays, compounds 1, 12, 14 and 15 (IC50 = 4.71—17.64 μmol/L) exhibited potent inhibition of LPS‐induced NO release from RAW264.7 without obvious cytotoxicity within 50 μmol/L compared to the positive control indomethacin (IC50 = 35.27 μmol/L). Moreover, compounds 1 and 13 displayed moderate to strong cytotoxicity to A549 and MDA‐MB‐435, with IC50 values in the range of 6.84—14.63 μmol/L. Together compound 1 showed moderate broad‐spectrum antibacterial activity. [ABSTRACT FROM AUTHOR]

With the rapid urbanization in Shanghai, China, suitable fill materials have been reported to be in great shortage in recent years. A prospective solution to these issues is to convert the huge amount of existing dredged marine soils to construction materials via solidification. However, there have been no studies on the shear behavior of solidified dredged materials from Shanghai region so far, while it has been reported by various researchers that the available data obtained from certain types of clay cannot be confidently and readily applied to other types of soils. To address this challenging issue, in this article, samples of Shanghai marine dredged soils were retrieved from the world’s largest reclamation project in Shanghai Lin-gang New City. A series of laboratory tests have been conducted to investigate the shear behavior of Shanghai dredged marine soils solidified using a new composite curing agent made of cement and lignin. The test results and the effect of this cement–lignin agent on the shear behavior of Shanghai marine soils, including the stress–strain behavior, shear strength properties, and failure characteristics are presented and discussed, which can provide valuable reference for the use of dredged soils as construction materials in the Shanghai region. [ABSTRACT FROM AUTHOR]

Eu3+‐activated red‐emitting inorganic phosphors have been favored highly for their classical 5D0→7FJ (J = 0, 1, 2, 3, 4) emissions. However, the fatal drawbacks of poor luminous efficacy and weak 5D0→7F4 transition persist, resulting in the ongoing challenge of achieving far‐red emission. This research reports series of highly efficient far‐red phosphors LnTeBO5 (Ln = La3+, Y3+, Gd3+):Eu3+ with anomalously strong 5D0→7F4 transition, resulting from the distorted square antiprism [Ln/EuO8]. Both the luminous efficacy and thermal stability can be greatly enhanced via the simple composition variation. [Ln/EuO8] square antiprism‐triggered 5D0→7F2,4 transitions are elucidated in depth, acquiring ultra‐high luminous efficacy (IQE = 95%, EQE = 40%, and AE = 42%) and near‐zero thermal quenching (99%@150°C and 98%@200°C). Subsequently, the versatile utilizations in indoor lighting, plant growth lighting, and security ink are illustrated. This finding establishes a deep understanding for constructing high‐quality far‐red phosphors via the Eu3+‐centered structural units of square antiprism. [ABSTRACT FROM AUTHOR]

Eu3+ doped phosphors with efficient and intense 5D0‐7F4 far‐red luminescence hold significant potential in daily and agricultural illuminations. However, Eu3+ ions typically emit orange/red luminescence from 5D0‐7F1,2 transitions, and the development of high‐quality Eu3+ doped far‐red phosphors is still lacking and challenging. Herein, two potassium‐bismuth‐phosphate phosphors are developed to manipulate the coordination geometry from octahedron to distorted square antiprism, achieving intense 5D0‐7F4 far‐red emission with a high quantum efficiency of 90.5%. Specifically, formation energy calculations and transient spectral measurements reveal that Eu3+ occupies distorted square antiprism symmetric site in K6Bi13(PO4)15:Eu3+, resulting in intense 5D0‐7F4 far‐red emission. Conversely, the octahedral symmetry generates weak 5D0‐7F4 emission in K5Bi(P2O7)2:Eu3+. Moreover, K6Bi13(PO4)15:0.08Eu3+ (90%@423 K) exhibits better thermal stability compared to K5Bi(P2O7)2:0.2Eu3+ (83%@423 K). Spectral analyses and Debye temperature calculations exclude contributions from charge transfer band and structural rigidity, and elevated thermal stability is attributed to suppressed energy migration to quenching centers facilitated by smaller Eu3+ doping level in K6Bi13(PO4)15:0.08Eu3+. Finally, excellent photoelectric properties of white‐LEDs and plant growth lighting by utilizing the representative K6Bi13(PO4)15:0.08Eu3+ as red/far‐red components indicate its application potentiality. This work provides a feasible method for constructing efficient Eu3+ doped far‐red phosphors. [ABSTRACT FROM AUTHOR]

Describes an envelope curve as a 12-month rolling sum permit limit on air quality permitting in the United States. Envelope construction; Annual limit for the amount of fuel or raw material used by a stationary source; Independence of the envelope curve from the initial starting month.

Achieving single-phase full-spectrum white light (SFWL) phosphors is a central goal in the optical field because they simplify white-LEDs assembly and avoid long-term color instability. Despite many approaches are developed, current SFWL phosphors still suffer from chromaticity drift due to inconsistent thermal quenching of multiple emitting centers. Herein, an absolutely structural disorder strategy is established to develop a single-emitting center-based SFWL phosphor. Precisely controlling the flux added induces a structural translation from the absolutely ordered Y 0.75 Ta 0.25 O 1.75 :Bi 3+ to the absolutely disordered Y 0.785 Ta 0.215 O 1.715 :Bi 3+ , as directly identified by STEM-HAADF analyses. Structural disorder enables Y 0.785 Ta 0.215 O 1.715 :Bi 3+ to produce SFWL with the FWHM of 6194 cm -1 (175 nm) by employing a single activator site, a 1352 cm -1 increase compared to the cyan-emitting Y 0.75 Ta 0.25 O 1.75 :Bi 3+ despite Bi 3+ occupies two lattice positions. This single-emitting center-based SFWL, coupled with minimal thermal expansion of the unit cell and inapparent spectral overlap of excitation and emission bands, ensure zero-chromaticity shift with elevated temperature. A prototype white-LEDs using Y 0.785 Ta 0.215 O 1.715 :Bi 3+ as a single luminescent layer generates warm white light without perceptible CIE coordinates shift under various currents or after extremely long-term continuous operation. This work highlights the potential of structural disorder in designing SFWL phosphors with exceptional color stability., (© 2024 Wiley‐VCH GmbH.)

Constructing a phosphor with multifunctional applications is an imperative challenge. Especially, highly thermostable luminescence of phosphor is indispensable for stable white-light-emitting diodes (LEDs). Nevertheless, good thermal quenching resistance behavior is unfavorable for a fluorescence intensity ratio (FIR)-based optical temperature sensor. Herein, a highly thermostable Ba 3 (ZnB 5 O 10 )PO 4 (BZBP)-based phosphor is successfully achieved via replacing Ba 2+ with Dy 3+ , demonstrating simultaneously promising lighting and thermometry utilizations. Under the excitation of 350 nm, the title phosphor only loses 12% of the initial intensity when the temperature is up to 473 K, ensuring sufficient luminescence thermostability for white-LED lighting. The white-LED device fabricated using the title phosphor emits high-quality white light with a high color rendering index ( R a = 93) and low correlated color temperature (CCT = 3996 K). Meanwhile, the yellow and blue emission intensities demonstrate a downtrend difference with rising temperature. Temperature sensing properties are assessed through FIR technology. The maximal relative sensitivity reaches as high as 0.0379 K -1 at 298 K. These results reveal that the title phosphor has a great potential for indoor lighting and thermometry applications.