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Transparent Tb 3+ -doped glass ceramics containing BaF 2 nanocrystals were prepared by melt-quenching method with subsequent heat treatment. The XRD and EDS results showed the precipitated crystalline phase in the glass matrix was BaF 2 . Under 376 nm light, Tb 3+ doped oxyfluoride glass ceramics containing BaF 2 nanocrystals showed more intense green emission than the as-made glass, and the emission intensity increased with increasing heat treatment temperature and time. The lifetimes of 541 nm emission of Tb 3+ doped oxyfluoride glass ceramics were longer than that of as-made glass, which are in the range from 3.00 ms to 3.55 ms. Under X-ray excitation, the green emission was enhanced in the glass ceramics compared to the as-made glass. The results indicate Tb 3+ doped oxyfluoride glass ceramics containing BaF 2 nanocrystals could be a material candidate for X-ray glass scintillator for slow event detection. [ABSTRACT FROM AUTHOR]

Clay-based composite materials have been widely used for environmental remediation due to their excellent physicochemical properties, however, there are few studies on clay-based composite materials as ozone catalyst carriers. In this study, Ce-loaded sepiolite (Ce/SEP) catalyst was synthesized using an impregnation-calcination method. Ce/SEP catalysts had a higher efficiency for heterogeneous catalytic ozonation than sepiolite alone. Among different mass ratios of Ce element to sepiolite (5 % Ce/SEP, 7 % Ce/SEP, 10 % Ce/SEP, and 15 % Ce/SEP), 10 % Ce/SEP showed the best catalytic performance with the mineralization efficiency of p-nitrophenol (PNP) as 71 % that was 1.15, 1.08, and 1.18 times higher than that of 5 % Ce/SEP, 7 % Ce/SEP, and 15 % Ce/SEP, and increased by 30 % compared to that of the ozonation alone. Larger surface area and abundance of strong acid sites of Ce/SEP favored adsorption of ozone molecules on the catalyst surface. High content of oxygen vacancies in the catalyst promoted Ce3+/Ce4+ cycling and subsequently a superior catalytic activity of the Ce/SEP catalyst. In addition, free radical quenching experiments as well as electron spin resonance analysis indicated that hydroxyl radical (∙OH) was the main contributor to the mineralization of PNP in this system. This study provides a novel strategy for the heterogeneous catalytic ozonation of refractory organic pollutants in water. [Display omitted] • Ce-loaded sepiolite catalysts (Ce/SEP) were synthesized by impregnation-calcination method. • The best catalytic performance of 10 % Ce/SEP increased the TOC removal rate by 30 % compared to ozonation alone. • Surface hydroxyl groups, acidic sites and lattice oxygen of Ce/SEP synergistically catalyzed the ozonation. • OH is the main active substance for mineralization of p-nitrophenol. [ABSTRACT FROM AUTHOR]

Threat generalisation is an adaptive process that is essential for individual survival. In contrast, over‐generalisation is a pathological process that underlies the development of anxiety disorders. Intolerance of uncertainty (IU) is an individual characteristic known to influence threat generalisation by altering the responses to threat in uncertain situations. However, how it affects contextual threat generalisation remains unclear. Here, we used a novel paradigm to investigate whether contextual threat generalisation varied between individuals depending on their IU level (high or low) and the predictability of a situation (predictable or unpredictable). We analysed shock expectancy in 82 participants (age: 18–27 years) during threat acquisition and generalisation. Results showed that compared with the low IU group, the high IU group exhibited increased contextual threat generalisation to threat‐related cues in unpredictable situation. These findings suggest that IU could be a marker for anxiety disorder susceptibility, as well as a target for anxiety treatment. [ABSTRACT FROM AUTHOR]

Cubic-to-hexagonal phase evolution, narrow crystalline size distribution and enhancement of luminescence are simultaneously achieved by modifying the ratio of SiO2/B2O3 content in the Eu3+-doped oxyfluoride borosilicate glass ceramics containing NaGdF4 nanocrystals. The mechanisms of phase evolution of NaGdF4 nanocrystals are discussed on the basis of IR spectra, viscosity, XRD and TEM data. The results indicate that the stresses developed during the thermal treatment process play an important role in the phase evolution, which provides an experimental evidence of pressure-induced disorder-to-order phase evolution during the crystallization process for the first time. It is also found that the excitation and emission spectra as well as the luminescence lifetimes of the Eu3+ ions in the oxyfluoride glass ceramic are sensitive to the crystal lattice of NaGdF4. [ABSTRACT FROM AUTHOR]

An emission-tunable, Eu2+-activated, Ba2Ca(PO4)2:Eu2+ phosphor was synthesized by a conventional solid-state reaction. X-ray powder diffraction (XRD) and FT-IR spectroscopic analysis confirmed the phase formation. Electron paramagnetic resonance (EPR) analysis indicated there are three different crystallographic Ba2+ sites, namely, Ba(1), Ba(2) and Ba(3), occupied by the Eu2+ ions. The excitation and emission spectra, concentration dependence of the emission intensity and decay curves of the phosphor were investigated. The results showed that with increasing Eu2+ concentration, the emission peak wavelength redshifted from 457 to 500 nm, and the color hue can be tuned from a greenish blue to a yellowish green. A white LED was fabricated using a near ultraviolet (n-UV) 410 nm chip pumped with a blend of phosphors consisting of greenish blue-emitting Ba1.97Ca(PO4)2:0.03Eu2+ and red-emitting Ca3.97(PO4)2O:0.07Eu2+. When the applied current was 350 mA, the white LED had Commission International de l'Eclairage color coordinates of (0.3249, 0.3421) at a white light (correlated color temperature = 6020 K) and an excellent color rendering index of 93. [ABSTRACT FROM AUTHOR]

Abstract: A series of phosphors with nominal compositions of Sr1.7M0.3SiO4−x F x :0.01Eu2+, 0.08Mn2+ (x=0, 0.01, 0.05, 0.1, 0.2) were synthesized through solid-state reaction technique. Their luminescent properties were studied. Three emission bands with peaks at 455, 550 and 670nm are observed in the phosphors under 380nm light excitation. When doped with fluorine, the crystal phases of the phosphors were changed slightly, while the luminescent intensities were remarkably enhanced and colorimetric parameters (chromaticity coordinates, color rendering index and color temperature) were improved. The colorimetric parameters and thermal quenching properties of Sr1.7Mg0.3SiO4−x F x :0.01Eu2+, 0.08Mn2+ phosphors with the comparison with those of commercial 467nm stimulated YAG:Ce3+ phosphors were systematically investigated. These results indicate that the phosphor with optimized composition could be a promising phosphor as a white light-emitting phosphor for near-ultraviolet light-emitting diodes. [Copyright &y& Elsevier]

Abstract: Eu2+, Mn2+ doped Sr1.7Mg0.3SiO4 phosphors were prepared by high temperature solid-state reaction method. Their luminescence properties were studied. The emission spectra of Eu2+ singly doped Sr1.7Mg0.3SiO4 consist of a blue band (455nm) and a green band (550nm). The relative intensities of two emissions varied with Eu2+ concentration. Eu2+ and Mn2+ co-doped Sr1.7Mg0.3SiO4 phosphors emit three color lights and present whitish color. The blue (455nm) and green (550nm) emissions are attributed to the transitions of Eu2+, while the red (670nm) emission is originated from the transition of Mn2+ ion. The results indicate the energy transfer from Eu2+ to Mn2+. The mechanism of the energy transfer is resonance-type energy transfer due to the spectral overlap between the emission of Eu2+and the absorption of Mn2+. [Copyright &y& Elsevier]

Abstract: Eu3+-doped Sr2Si1−x Ge x O4 (x=0–1) phosphors have been prepared by the high temperature solid-state reaction method. The luminescent properties of these phosphors were investigated. Red fluorescence of Eu3+ is enhanced gradually in the samples with increasing substitution of Si by Ge upon the excitation of 393nm light. The intensity is increased by 50% with full substitution of Si by Ge. These results are originated from the structural changes and the phonon energy reduction in the samples due to the substitution of Si by Ge. The CIE chromaticity coordinates of the phosphors vary slightly around (0.62, 0.37) and all are in the red color region. The results indicate that these phosphors could be promising red phosphors for white light emitting diodes. [Copyright &y& Elsevier]

Due to the high organic compounds and high salinity of fishmeal wastewater (FW), it was firstly used as a novel medium to produce microbial lipid in this paper. Fermentation of FW without any additives adding showed that the broth was appropriate for the growth of strain Lipomyces starkeyi HL; however, production of 5.34 g l−1 of biomass containing 20.8% of lipid was not satisfied. In order to enhance the accumulation of lipid and cell growth, FW was supplemented with various concentrations of glucose; meanwhile, the influence of initial pH was investigated. Biomass and lipid yield on FW were markedly affected by glucose concentration and initial pH. The addition of 20 g l−1 glucose at initial pH 4.0 got the best results: 17.6 g l−1 of biomass, 2.7 g l−1 of lipid yield, 91.2% of protein removal and 43.4% of the chemical oxygen demand removal. The variation of fatty acid composition upon time course in the cellular lipid on FW or a mixture of glucose and FW was further studied. [ABSTRACT FROM PUBLISHER]

Exposure to phthalates poses adverse health impacts to human beings. In this study, we analyzed 7 phthalates in dust samples, which were collected with vacuum cleaner from 40 to 31 residences in Beijing in summer and winter, respectively. The major phthalates (median concentration in the summer and winter, respectively) were D i BP (55 and 40 ng/mg), D n BP (99 and 30 ng/mg) and DEHP (795 and 335 ng/mg). The concentrations were significantly influenced by season and residence time of house dust. The concentrations of phthalates in dust on plastic surfaces were highest, followed by those on wooden and fabric surfaces. The dust-air partition coefficients (K d) were calculated: the median values were 0.13, 0.02 and 5.62 m3/mg in the summer and 0.06, 0.018 and 0.76 m3/mg in the winter for D i BP, D n BP and DEHP, respectively. A comparison with K d * at equilibrium state suggested that partition between air and dust deviated from equilibrium state in both seasons. The results also revealed that dust-phthalates in the summer may completely originate from source materials via direct transfer and external physical process; while dust-phthalates in the winter may come from both air (via partition) and source material (via direct transfer and external physical process). The influence of temperature on dust-phthalate concentrations differed by season, owing to different origin of dust-phthalates in two seasons. Polar organic components in dust, which are products of reactions between O 3 and unsaturated hydrocarbons in dust, likely played an important role in fate and transport of phthalates. The presence of them resulted in the significant associations between dust-phthalate concentrations and air humidity in the summer. Moreover, the impacts of indoor PM 2.5 concentrations, traffic conditions surrounding residence, household lifestyle and number of occupants were also observed. The mechanisms behind those observations were discussed. [Display omitted] • Dust-air partition of phthalates deviated from equilibrium state. • Product-to-dust phthalates migration included direct transfer and external process. • Origin of dust-phthalates may differ by season. • Built environmental determinants on dust-phthalate concentrations were characterized. [ABSTRACT FROM AUTHOR]

• Presents a combined approach of lifting path planning and assembly sequencing. • Introduces a new BIM-based intelligent assembly scheduler for precast construction. • The scheduler generates the optimal micro-schedule from inbuilt data in BIM. • Proposes a multi-level elitist genetic algorithm to compute the optimal sequence. • A case study is conducted on a real-world 4D BIM model using a tower crane. This research addresses the problem of assembly scheduling in crane-assisted precast construction while considering issues of building layout interference and optimal crane lifting. Traditionally, assembly scheduling and lifting path planning are treated as two separate issues due to their distinct natures. The current work introduces an approach that combines them for precast construction planning to achieve a comprehensive and cost-effective solution. A BIM4D-based Intelligent Assembly Scheduler (BIAS) is designed in conjunction with the Computer-Aided Lifting Planner developed at Nanyang Technological University, Singapore. BIM4D is the Building Information Modeling (BIM) with the time dimension (i.e., scheduling information). Our scheduler takes an inbuilt timeframe for selected precast elements from BIM4D as input and outputs the micro-schedule in terms of the assembly sequence for these precast elements. This problem is solved using multi-objective optimization. Given a group of precast elements and their BIM4D timeframe, the micro-scheduling is determined based on (1) the relative importance of the elements' physical properties, (2) the interference (neighbouring relation) among the elements' positions, and (3) collision-free lifting paths of the elements. A Multi-level Elitist Genetic Algorithm (MEGA) is proposed to determine the optimal sequence taking into consideration of both assembling and lifting for the elements. A case study is performed with the BIM4D data of a residential building. The results of the case study demonstrate BIAS's efficiency and effectiveness for BIM4D based construction scheduling. [ABSTRACT FROM AUTHOR]

A transparent Tb3+ and Yb3+ codoped oxyfluoride glass-ceramic containing CaF2nanocrystals was prepared by heat treating the as-made glass. Formation of CaF2 nanocrystals in the glass-ceramic was confirmed by x-ray diffraction (XRD) and transmission electron microscopy (TEM). Ultraviolet (UV) and visible emission spectra of the as-made glass and the glass-ceramic following excitation by a 974 nm diode laser were recorded at room temperature. An intense UV emission at 381 nm was observed in the glass-ceramic. The origin of the enhancement of the emission at 381 nm was investigated using spectroscopy and Judd-Ofelt analysis. The enhancement of the emission at 381 nm could be attributed to the change of the ligand field of Tb3+ ions due to the incorporation of some Tb3+ and Yb3+ ions into the CaF2 nanocrystals in the glass-ceramic. [ABSTRACT FROM AUTHOR]

Abstract: The spectroscopic properties of Sm3+-ions in tellurite, fluorophosphate, and fluorine-modified silicate glasses are examined under the excitations at 488nm (Ar+ ion laser) and 1060nm laser. The effect of dopant ion and glass–host interaction, branching ratio of transitions and line shapes of emission lines in the visible region are discussed in view of the ionicity and covalency of hosts. The lifetimes of metastable levels are also reported and the results are explained for designing the visible and UV laser hosts. [Copyright &y& Elsevier]

Abstract: The near infrared spectroscopic properties of Tm3+−Yb3+ co-doped tellurite glasses were investigated using a 980nm laser diode. The 1.81μm emission corresponding to the 3F4→3H6 transition of Tm3+ and the 1.02μm emission of Yb3+ were recorded at room temperature. The effects of Tm3+ and Yb3+ ion concentrations on the emission characteristics and the lifetimes of 1.81μm and 1.02μm were also analyzed. These results indicate that the energy transfer occurred between the Yb3+ and Tm3+ ions in the co-doped tellurite glasses. The luminescence mechanism in Yb3+ and Tm3+ co-doped tellurite glass was also discussed, which is important to develop 1.8μm fiber lasers or 1.8μm and 1.465μm fiber amplifiers. [Copyright &y& Elsevier]

The Er3+–Eu3+-codoped tellurite fibre was pumped at 800 nm (CW) using a Ti–sapphire tunable laser source. The emission spectra at 592 and 613 nm, both attributed to Eu3+ transitions from 5D0→7F1 and 5D0→7F2, respectively, were recorded at room temperature. Although the upconversion fluorescence from the Er3+:4S3/2 level is well known, the observed efficient energy transfer from the Er3+:(2H11/2, 4S3/2) levels to the Eu3+:(5D1, 5D0) levels is not known in the literature. The calculated energy transfer efficiency is approximately 20%. The observed visible emissions point out that the Er3+–Eu3+-codoped tellurite fibre is a potential host material for designing a 589 nm laser for satellite communication and a compact 613 nm fibre laser for medical applications. [Copyright &y& Elsevier]

• The D-tagaturonate epimerase (UxaE), which has a C4 epimerization function, catalyzes the synthesis of d -tagatose. • Semi-rational design has optimized UxaE to a 10.8-fold increase in efficiency. • Reshaping the substrate-binding pocket can effectively enhance the 4 epimerization function of the epimerase. d -tagatose, a rare sugar with broad applications in the food and pharmaceutical industries, can be synthesized from d -fructose by epimerases, an approach with significant biosynthesis potential. However, so far there has been only one attempt to engineer tagatose 4‑epimerase through random mutagenesis. The lack of exploration has severely restricted the application of epimerases in the industrial production of d -tagatose. The previous research primarily focused on enhancing the catalytic activity of epimerases through random mutagenesis, with limited understanding of how substrate-adjacent residues affect enzyme efficiency, which was hence the subject of this study. First, using a semi-rational design approach, after three rounds of mutagenesis and screening, the mutant (S125D/S268A/Q124E) of D-tagaturonate epimerase (UxaE) from Thermotoga neapolitana was obtained, which increased d -tagatose production efficiency by 10.8-fold compared to the wild type, with a specific activity of 1505.6 U/g, representing the highest specific activity reported for a UxaE mutant to date. Molecular dynamics simulations showed that the substitution of Ser to Asp-125 enhanced substrate-enzyme interactions, while the substitution of Glu to Gln-124 reinforced the hydrogen bond network around the catalytic residue Glu-128, further reshaping the substrate-binding pocket and enhancing catalytic activity. This study for the first time explored the enhancement of the C4 epimerization function of epimerases by reshaping their substrate-binding pockets, thereby providing a feasible route for the industrial biosynthesis of d -tagatose. [Display omitted] [ABSTRACT FROM AUTHOR]

The rapidly growing field of cannabinoid research is gaining recognition for its impact in neuropsychopharmacology and mood regulation. However, prenyltransferase (NphB) (a key enzyme in cannabinoid precursor synthesis) still needs significant improvement in order to be usable in large-scale industrial applications due to low activity and limited product range. By rational design and high-throughput screening, NphB's catalytic efficiency and product diversity have been markedly enhanced, enabling direct production of a range of cannabinoids, without the need for traditional enzymatic conversions, thus broadening the production scope of cannabinoids, including cannabigerol (CBG), cannabigerolic acid (CBGA), cannabigerovarin (CBGV), and cannabigerovarinic acid (CBGVA). Notably, the W3 mutant achieved a 10.6-fold increase in CBG yield and exhibited a 10.3- and 20.8-fold enhancement in catalytic efficiency for CBGA and CBGV production, respectively. The W4 mutant also displayed an 9.3-fold increase in CBGVA activity. Molecular dynamics simulations revealed that strategic reconfiguration of the active site's hydrogen bonding network, disulfide bond formation, and enhanced hydrophobic interactions are pivotal for the improved synthetic efficiency of these NphB mutants. Our findings advance the understanding of enzyme optimization for cannabinoid synthesis and lay a foundation for the industrial-scale production of these valuable compounds. [ABSTRACT FROM AUTHOR]