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A series of Ce3+ and Tb3+ singly‐ and co‐doped NaBa4(AlB4O9)2Cl3 (NBAC) phosphors have been synthesized via high‐temperature solid state route. The crystal structure, morphology, photoluminescent properties, thermal properties and energy transfer process between Ce3+ and Tb3+ were systematically investigated. The structure refinements indicated that the phosphors based on NBAC crystallized in P42nm polar space group in monoclinic phase. The emission color could be tuned from blue (0.1595, 0.0955) to green (0.2689, 0.4334) via changing the ratio of Ce3+/Tb3+. The energy transfer mechanism of Ce3+/Tb3+ was verified to be dipole–quadrupole interaction via the examination of decay times of Ce3+ based on Dexter's theory. The good thermal stability showed the intensities of Ce3+ at 150°C were about 66.9% and 64.88% in NBAC:0.09Ce3+ and NBAC:0.09Ce3+, 0.07Tb3+ of that at room temperature, and the emission intensities of Tb3+ remained 102.41% in NBAC:0.11Tb3+ and 95.22% in NBAC:0.09Ce3+, 0.07Tb3+ due to the nephelauxetic shielding effect and the highly asymmetric rigid framework structure of NBAC. The maximum external quantum efficiency (EQE) of Ce3+ in NBAC:0.09Ce3+, yTb3+ phosphors could reach 43.38% at y = 0.13. Overall, all the results obtained suggested that NBAC:Ce3+, Tb3+ could be a promising option for n‐UV pumped phosphors. [ABSTRACT FROM AUTHOR]

The appearance of a cyan cavity is unavoidable in the 480–520 nm wavebands when combining n-UV LED chips (380–420 nm) with trichromatic phosphors to obtain white-light-emitting devices. Here, a concentration perturbation effect is proposed to improve the properties of phosphors via trace substitution of Mn2+, Mg2+ or Zn2+ cations for Ba2+ and Y3+ in Ba0.97Y2Si3O10:Eu. Based on local structure distortion or electron cloud interaction, the emission band corresponding to Eu2+ is broadened with a full width at half maximum (FWHM) more than 125 nm due to redistribution of Eu2+ and the emission color can be tuned to the cyan region. The coexistence of the above two effects on the photoluminescence can be further evidenced by the shifts of emission energy for the two sites in these systems. The quenching temperature for all the samples is observed over 473 K and even higher than that for the non-substituted Ba0.97Y2Si3O10:0.03Eu and it is discussed combined with Pauling's principles, average Uiso and the distortion degree of polyhedra, which could provide some references for improvement of thermal stability. Moreover, the valence mismatch between Mn2+/Mg2+/Zn2+ and Y3+ ions leads to the coexistence of Eu2+–Eu3+, which thus realizes color selective manipulation and even white light emission in Ba0.98−nMg0.02Y2Si3O10:nEu. Our results demonstrate that the concentration perturbation effect-assisted synthesis strategy has potential in improving the properties of phosphors for WLEDs, and it can also be extended to adjusting the coordination environment of activators whose properties are sensitive to local lattice variations and electronic surroundings. [ABSTRACT FROM AUTHOR]

In this study, Bi2WO6 nanosheets were synthesized via molten salt (M-Bi2WO6) and hydrothermal method (H-Bi2WO6), respectively. Powder X-ray diffraction and scanning electron microscopy measurements demonstrated that the as-prepared Bi2WO6 samples preferred orientated alone {001} plane in both hydrothermal and molten salt system, enabling the formation of Bi2WO6 nanosheets. The results of UV-vis diffuse reflection spectrum showed that the M-Bi2WO6 nanosheets exhibited an obvious red shift in visible light absorption band in comparison with H-Bi2WO6 nanosheets, and the band gap of M-Bi2WO6 and H-Bi2WO6 nanosheets was 2.49 and 2.62 eV, respectively. As a result, the M-Bi2WO6 nanosheets reached as high as 97.13% of photodegradation efficiency of Rhodamine B under 180 min of sunlight irradiation, which was two times higher than that of the H-Bi2WO6 nanosheets (86.88%). Meanwhile, the photodegradation rate over M-Bi2WO6 (97.30%) for TC degradation was about two times higher than that of H-Bi2WO6 (78.58%). The much-enhanced photocatalytic performance of M-Bi2WO6 nanosheets was attributed to the better crystallinity, higher light-harvesting capability and superior sorption capacity. Basing on the detailed experimental study and analysis, this work could be a practical guidance for the fabrication of Bi2WO6-based microstructures with enhanced photocatalytic efficiency. [ABSTRACT FROM AUTHOR]

Abstract: Charge compensation was the effective methods to enhance the luminescence properties of phosphors. In this paper, novel single‐phased orange light emitting Sr2Mg3P4O15:Eu3+ phosphors were prepared by solid state method. The phase purity and luminous characteristics were examined in detail. Meanwhile, three kinds of charge compensation methods (co‐doping the alkali metal R+ (R+ = Li, Na, and K), substituting Si4+ for P5+ and self‐compensation) were employed to solve the charge imbalance problem between Sr2+ and Eu3+. The results showed that emission intensity of Eu3+ was improved by 1.43 (Li+), 1.58 (Na+), 1.53 (K+), 1.61 (Si4+), and 1.30 (self) times than that of Sr1.6Mg3P4O15:0.40Eu3+, respectively, and there was no change in the emitting color simultaneously. Furthermore, as the temperature reached at 423 K, the emission intensity increased from 41.67% of Sr1.6Mg3P4O15:0.40Eu3+ to 55.69% (Li+), 61.62% (Na+), 58.98% (K+), 71.15% (Si4+), and 80.59% (self) of that at room temperature. The reasons of those phenomena were the reduction in ion vacancies caused by charge imbalance through the charge compensation process. The specific mechanisms were elaborated in detail. Overall, this research validated that the charge compensation strategies could be severed as the key method to improve the luminescence properties, especially the thermal stability of phosphor. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the therapeutic effects of Euterpe oleracea Mart. (EO) on alcoholic liver diseases (ALD). A total of 30 Wistar rats were randomly divided into three groups (10 rats per group), including alcohol group (alcohol intake), EO group (alcohol + EO puree intake) and control group (distilled water intake). The activity of superoxide dismutase (SOD) and alkaline phosphatase (ALP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and the levels of cholesterol (CHO), triglyceride (TG), malondialdehyde (MDA) and glutathione (GSH) in the serum as well as the liver tissue levels of interleukin 8 (IL-8), tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β) were measured. Histopathological changes in liver tissues were observed by hematoxylin and eosin staining. Reverse-transcription quantitative PCR analysis was performed for detecting the expression of nuclear factor (NF)-κB and CD68. The results indicated that EO intake significantly decreased ALT, AST, ALP, TG and CHO as well as the hepatic index in alcohol-treated rats. In addition, EO treatment relieved alcohol-induced oxidative stress by decreasing the levels of MDA and TG, and increasing the activity of SOD and GSH levels. In addition, the expression of TNF-α, TGF-β, IL-8, NF-κB and CD-68 in the liver were decreased by EO treatment. Furthermore, EO intake alleviated the histopathological liver damage, including severe steatosis and abundant infiltrated inflammatory cells. In conclusion, EO alleviated alcohol-induced liver injury in rats by alleviating oxidative stress and inflammatory response. [ABSTRACT FROM AUTHOR]

The bluish-green KBaY(BO):Eu phosphors were prepared by high-temperature solid state reaction method. The photoluminescence properties, concentration quenching and energy transfer as well as the luminescence decays were investigated. The emission spectrum showed a single intensive band centered at 500 nm, which correspond to the 4 f 5 d → 4 f transition of Eu. The optimal concentration for the luminescence of Eu in KBaY(BO):Eu was determined to be 0.03 mol. The critical energy transfer distance was calculated as 21.34 Å. The corresponding concentration quenching mechanism was verified to be a dipole-dipole interaction. And the blue-shift behavior of KBaY(BO):Eu with increasing temperature was analyzed by the configurational coordinate diagram. The results indicate that the KBaY(BO):Eu phosphors have potential applications as an ultraviolet-convertible phosphor due to its effective excitation in the ultraviolet rang. [ABSTRACT FROM AUTHOR]

A series of Eu2+ and Tb3+ singly-doped and co-doped Sr3Y2(Si3O9)2 (SYSO) phosphors have been synthesized via a conventional high-temperature solid-state reaction. The crystal structures, photoluminescence properties, fluorescence lifetimes, thermal properties and energy transfer of SYSO:Eu2+,Tb3+ were systematically investigated in detail. Rietveld structure refinement of the obtained phosphors indicated that the SYSO host crystallized in a monoclinic system with the space group C2/c (15) and there are three kinds of cation sites for the doped ions to occupy forming emission centers. The photoluminescence (PL) emission bands of SYSO:xEu2+ show a red-shift tendency with increasing Eu2+ content which should be attributed to more Eu2+ ions entering into Sr2/Y2 and Sr3/Y3 sites from the Sr1/Y1 site. For the co-doped SYSO:Eu2+,Tb3+ samples, tunable colors from cyan to green can be realized by varying the doping concentration of the Tb3+ ions. The intense green emission was realized in the SYSO:Eu2+,Tb3+ phosphors on the basis of the highly efficient energy transfer from Eu2+ to Tb3+ with an efficiency of over 89%. As a result, the emission intensity of SYSO:0.01Eu2+,0.21Tb3+ is about 2.5 times higher than that of SYSO:0.21Tb3+ under 340 nm UV excitation. The energy transfer mechanism from Eu2+ to Tb3+ in the SYSO host was ascribed to the quadrupole–quadrupole interactions. These results indicated that the SYSO:Eu2+,Tb3+ phosphors can act as single-phase green emitting phosphors for possible applications in ultraviolet light-based white light-emitting diodes (w-LEDs). [ABSTRACT FROM AUTHOR]

[Display omitted] • The SMCs were fabricated using flaky FeSiCr modified by ZnO nanoflowers. • Stress of flake was design and analyzed by Helmholtz coils and torque model. • Nonlinear regression method was used to evaluate the loss separation. • The P cv of SMCs modified by ZnO nanoflowers is 421.29 kW/m3 at 50 mT, 100 kHz. The power loss and permeability of soft magnetic composite (SMC) might be improved by surface modification and magnetic field orientation of flake particles. The oriented ZnO-modified flaky FeSiCr SMCs were produced under the magnetic field. The orienting mechanism of flake powder under a magnetic field produced by Helmholtz coils was investigated using torque model analysis. After surface modification, the permeability and power loss of ZnO-modified flaky FeSiCr SMCs could reach 63 and 421.29 kW/m3(at 50 mT, 100 kHz), respectively. The three-dimensional loss separation results demonstrate that spin rotation mechanism, defects, and dislocations of ZnO modification from theory and experiment may be responsible for the enhanced soft magnetic characteristics. [ABSTRACT FROM AUTHOR]

In order to solve the problem that bolts in traditional packaged direct methanol fuel cells (DMFCs) take up a large area and reduce the specific energy (energy per unit weight) and power density (power per unit area), a new button-type micro direct methanol fuel cell (B-μDMFC) is designed, assembled, and packaged. The cell with four different structures was tested before and after packaging. The results indicate that the button cell with three-dimensional graphene and springs has the best performance. The equivalent circuit and methanol diffusion model was applied to explain the experimental results. The peak volumetric specific power density of the cell is 11.85 mW cm−3. This is much higher than traditional packaged DMFC, because the novel B-μDMFC eliminates bolts in the structure and improves the effective area ratio of the cell. [ABSTRACT FROM AUTHOR]

So far, developed microwave absorbers exhibit significant changes in absorption with temperature, which hinder their operation within a wide temperature range. In this paper, a microwave absorber based on SiBCN ceramics was prepared. Due to the excellent high‐temperature stability of SiBCN ceramics, its permittivity changes less with temperature, avoiding the issue of performance deterioration or even failure that traditional refractory absorbers face at high temperatures. The experiment proves the absorption bandwidth for –15 dB of the SiBCN metamaterials absorber (SMA) is 12 GHz at 800°C, with a maximum absorptivity of 99.99%. According to the computed data, the resonance loss contributes 81.9 to 94.5% of the microwave absorption of SMA. This work demonstrates significant potential for applications in radar stealth under harsh conditions. [ABSTRACT FROM AUTHOR]

The narrow‐band emitting phosphors have been extensively investigated in recent years, with the expectation that a wide color gamut of phosphor‐converted backlighting device could be fabricated. Due to the weak electric–phonon interaction and low structural relaxation caused by the high rigid crystal structure and symmetric coordination environment, Sr2MgAl22O36:Mn2+ (SMAO:Mn2+) shows a narrow full‐width at half‐maximum of 26 nm, a high color purity of 81.5%, and a low thermal quenching (82% at 473 K of the initial intensity at 298 K). Using K2SiF6:Mn4+ as the red phosphor, SMAO:Mn2+ as the green one, and GaN‐based chip as the blue component, the white light‐emitting diode exhibits a National Television Standard Committee value of 127%. All the results demonstrate that the SMAO:Mn2+ phosphor has a promising application in the field of advanced wide‐color‐gamut backlight display, and the establishment of the relationships between the narrow‐band emission and crystal structure can also be applied to design other novel narrow‐band phosphors for backlighting technologies. A novel narrow‐band green‐emitting phosphor Sr2MgAl22O36:Mn2+ with peak position at 518 nm, full‐width at half‐maximum of 26 nm, and a low thermal quenching at high temperature (82% of room temperature intensity at 498 K) under the excitation of blue light‐emitting diode chip is discovered. These good luminesce properties are benefited from the high rigid crystal structure and symmetric coordination environment. [ABSTRACT FROM AUTHOR]

Although human pluripotent stem cell (PSC)‐derived brain organoids have enabled researchers to gain insight into human brain development and disease, these organoids contain solely ectodermal cells and are not vascularized as occurs during brain development. Here it is created less complex and more homogenous large neural constructs starting from PSC‐derived neuroprogenitor cells (NPC), by fusing small NPC spheroids into so‐called concentroids. Such concentroids consisted of a pro‐angiogenic core, containing neuronal and outer radial glia cells, surrounded by an astroglia‐dense outer layer. Incorporating PSC‐derived endothelial cells (EC) around and/or in the concentroids promoted vascularization, accompanied by differential outgrowth and differentiation of neuronal and astroglia cells, as well as the development of ectodermal‐derived pericyte‐like mural cells co‐localizing with EC networks. Single nucleus transcriptomic analysis revealed an enhanced neural cell subtype maturation and diversity in EC‐containing concentroids, which better resemble the fetal human brain compared to classical organoids or NPC‐only concentroids. This PSC‐derived "vascularized" concentroid brain model will facilitate the study of neurovascular/blood‐brain barrier development, neural cell migration, and the development of effective in vitro vascularization strategies of brain mimics. [ABSTRACT FROM AUTHOR]

Boron carbide (B4C) has excellent high-temperature oxidation resistance, high hardness, low relative density, high melting point and excellent abrasive resistance, which is widely used in fields such as refractories, wear-resistant materials and lightweight protective materials. The research progress and application of B4C materials in China and overseas in recent years were summarized. The influences of sintering processes (pressureless sintering, hot-pressing sintering, hot isostatic pressing sintering, spark plasma sintering and microwave sintering) and sintering additives (simple substances, oxides and carbides) on the B4C densification were analyzed. The development of B4C materials was prospected. [ABSTRACT FROM AUTHOR]

Surface traveling waves (STWs) contribute greatly to non-specular scattering, but their scattering and attenuation characteristics in an absorbing coating are unclear. Thus, the scattering peak angular location and the electromagnetic (EM) loss of the STWs are calculated. The results show that the thickness of an absorbing coating should be appropriate to achieve a large EM loss in wide frequency bandwidth, and the magnetic loss is dominant in the attenuation constant. Moreover, radar cross section (RCS) features of the STW and the effect of EM parameters' imaginary part on the RCS reduction of the STW at 6 GHz were investigated. The simulated results show that the wedge model can effectively excite the STW. Meanwhile, the permeability μ″ of the coating material has a more significant influence on the RCS reduction of the STW than the permittivity ɛ″. Furthermore, the simulated results were verified by the experimental results with an error of less than 20%. [ABSTRACT FROM AUTHOR]

Color-tunable and white-emitting Pr3+ and Tb3+ co-doped La 2 Ti 2 O 7 phosphors were prepared via a molten salt method. The as-synthesized samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflection spectra (DRS), photoluminescence spectra (PL), fluorescence decay curves and temperature-dependent photoluminescence spectra in detail. The La 2 Ti 2 O 7 :Pr3+, Tb3+ phosphors are uniform square-like nanobelt and the band gap of La 2 Ti 2 O 7 host is calculated to be 3.83 eV by DRS. Under 296 nm wavelength UV excitation, the La 2 Ti 2 O 7 :Pr3+ compounds show strong red emission with peaking at 612 nm. Four typical emission lines of Tb3+ ions are observed from the region of 480–650 nm in La 2 Ti 2 O 7 :Tb3+ phosphors, and the strongest green emission peak is located at 545 nm. What's more, the emission color of La 2 Ti 2 O 7 :0.001Pr3+, 0.010 Tb3+ can be tuned from white (0.3274, 0.3379) to pink (0.4777, 0.2890) upon the excitation from 290 to 348 nm and the emission color of La 2 Ti 2 O 7 :0.001Pr3+, x Tb3+ can be also tuned from white to green by changing the concentration of Tb3+. The La 2 Ti 2 O 7 :Pr3+, Tb3+ phosphors have the poor temperature dependence, resulting from the value of Δ R (the displacement between parabolas of the intervalence charge transfer states and ground states) for Tb3+ and Pr3+ both are larger. The results indicate that La 2 Ti 2 O 7 :Pr3+, Tb3+ phosphors could be a promising tunable and white light emission phosphor. Image 1 • The La 2 Ti 2 O 7 : Pr3+/Tb3+ nanostrips were successfully prepared by molten salt method. • Multi-color luminescence evolution was achieved. • A new single-phased white light emission was realized through Pr3+/Tb3+-codoping. [ABSTRACT FROM AUTHOR]

Abstract Exploring the process of structure evolution and mechanism of controllable luminescence in the solid solution phosphors is meaningful but still challenging. Herein, new solid solution phosphors of Ca 9 Al 1- x Y x (PO 4) 7 :Eu2+ were selected as examples to address the challenging via the construction of bi-directional relationships between structure evolution and photoluminescence property. In Ca 9 Al 1- x Y x (PO 4) 7 , the structure evolution caused the redistribution of Eu2+ in the multiple cationic sites, accompanied by the changes of emission color from blue (0.1828, 0.1192) to cyan (0.1723, 0.3305), which were investigated by Gaussian fitting, decay time, and bond energy theory. Conversely, the Gaussian fitting peaks displayed different blue or red shifts in the process of structure evolution, which could reversely reflect the specific changes of bond lengths in each cationic site and were helpful for exhaustive understanding the process of structure evolution in Ca 9 Al 1- x Y x (PO 4) 7. Besides, the thermal stability behaviors of Ca 8.95 Al 1- x Y x (PO 4) 7 :0.05Eu2+ exhibited that the decline rate of low energy bands were faster than that of high energy bands due to the thermally active phonon-assisted effect. The constructed bi-directional relationships pave a feasible way to investigate the variations of structure evolution and emission properties, which will be helpful for the design of new kinds of phosphors. Graphical abstract Image 1 Highlights • Bi-directional relationships between structure evolution and luminescence were built. • The structure evolution caused the redistribution of Eu2+ in various cationic sites. • The delicate information of structure was analyzed by the shifts of emission peaks. • The changes of thermal stabilities were detected and analyzed. [ABSTRACT FROM AUTHOR]

Abstract Novel single-phased and emission-tunable layered Bi 4 Ti 3 O 12 :Pr3+ nanosheets have been successfully synthesized via molten salt method. The as-prepared samples were characterized by X-ray diffraction and scanning electron microscopy to investigate their crystalline phases and morphologies. Furthermore, we explored the photoluminescence properties of the Bi 4 Ti 3 O 12 :Pr3+ phosphors, while the cross-relaxation processes between 1D 2 , 3P 0 emitting states and the Pr3+–Ti4+ intervalence charge transfer state, color tuning and thermally stability were discussed in detail. Besides, the emission hue of Bi 4 Ti 3 O 12 :Pr3+ could be adjusted from white-light (0.3059, 0.2731) to yellow (0.5167, 0.4792) by tuning the excitation wavelength, in which the ratio of 3P 0 →3H 4 and 1D 2 →3H 4 was changed. In addition, the increases in temperatures led to the cooperative effects of thermal-quenching behavior and the cross-relaxation processes, thus resulting in the significant decrease of 3P 0 →3H 4 emission in comparison to the 1D 2 →3H 4 emission. The results suggested that the Bi 4 Ti 3 O 12 :Pr3+ is an effective color-tuning phosphor. Graphical abstract Image 1 Highlights • The regular sheet-like Bi 4 Ti 3 O 12 :Pr3+ phosphors were successfully prepared by molten salt method. • The phosphors show color tuning emissions form near white to yellow. • The thermal stability of the 1D 2 emission is obviously better than that of 3P 0. [ABSTRACT FROM AUTHOR]

Investigating the relationships between luminescent properties and the energy positions of rare earth ions is helpful for the design of phosphors. Herein, (Ca 1- x Sr x ) 8 Mg 3 Al 2 Si 7 O 28 :Ce 3+ /Eu 2+ were synthesized by solid state reaction. The variations of energy positions of lowest 5d levels of Ce 3+ and Eu 2+ with the changes of centroid shift, crystal field splitting and stokes shifts were qualitatively calculated based on the empirical formulas. Substitution of Ca 2+ by Sr 2+ ions made the emission peaks of Eu 2+ in (Ca 1- x Sr x ) 8 Mg 3 Al 2 Si 7 O 28 shift from 527 to 469 nm and the full width at half-maximum of Ce 3+ in (Ca 1- x Sr x ) 8 Mg 3 Al 2 Si 7 O 28 widen from 55 to 66 nm. On the basis of calculated results, the variations of emission peaks of Eu 2+ were mainly ascribed to the elevating of lowest 5d levels caused by the weakened centroid shift and crystal field splitting, especially the declined energy of crystal field splitting (from 2.28 to 2.01 eV). The effects of decreased rigidity and increased disorder of lattice caused by Sr 2+ substituting Ca 2+ had a greater impact than that of the centroid shift and crystal field splitting on the luminescence properties of Ce 3+ in (Ca 1- x Sr x ) 8 Mg 3 Al 2 Si 7 O 28 . Serious thermal quenching behaviors occurred in the series phosphors due to the thermal ionization processes, which were proofed by the constructed host-referred binding energy and vacuum-referred binding energy diagrams according to the experimental and calculated results of (Ca 1- x Sr x ) 8 Mg 3 Al 2 Si 7 O 28 :Ce 3+ /Eu 2+ . [ABSTRACT FROM AUTHOR]

A series of monodisperse cruciate multilayer H 3 Sr 6 (PO 4 ) 5 ·2H 2 O:Eu 2+ microarchitectures assembled by crossed nanorods have been successfully synthesized via a facile surfactant-assisted hydrothermal route. XRD and FT-IR confirmed the existence of crystalline water in the phosphor. The FE-SEM images revealed that the phase and morphology of resulting samples were strongly depended on the optimization of the reaction conditions, especially the pH value and the molar ratio of citric acid (CA)/Cations. Furthermore, the possible growth mechanism of H 3 Sr 6 (PO 4 ) 5 ·2H 2 O:Eu 2+ microarchitectures was proposed in detail. Under near-ultraviolet excitation of 365 nm, the as-obtained H 3 Sr 6 (PO 4 ) 5 ·2H 2 O:0.05Eu 2+ sample exhibited intense wide characteristic blue emission of Eu 2+ , which could be decomposed by Gaussian fitting into two peaks corresponding to different Eu 2+ luminous centers. The present results demonstrated that the morphology-tunable H 3 Sr 6 (PO 4 ) 5 ·2H 2 O:Eu 2+ microarchitecture could be used as a potential candidate for future optoelectronic device applications. [ABSTRACT FROM AUTHOR]

The electromagnetic wave (EMW) absorbing materials are widely applied to attenuate the useless and harmful EMW generated from wireless communication and 5G networks, which could protect the human health and electronic device safety. In this study, La-doped SiBCN ceramics with broadband EMW absorption capability were prepared via generating abundance of heterointerfaces, as graphene were in-situ grown by La 2 O 3 catalyzing. The graphene in-situ formed in the ceramics can be attributed to the La atom decreasing the potential energy of the free carbon ring nucleation from −760.9 Ha to −8984.3 Ha. Consequently, the electrical conductivity of the SiBCN ceramics improved from 12.360 S/m to 18.025 S/m, the minimum reflection loss (RL min) obtained was −26.48 dB at 7.2 GHz and the effective absorption bandwidth (EAB) was 6.32 GHz (11.68–18.00 GHz) at a thickness of 1.7 mm. At 700 °C, the RL min and EAB values reached −43.18 dB and 4.2 GHz, respectively. The enhanced EMW absorbing capability can be attributed to the rationally tailor the heterointerfaces to improve the polarization loss and conduction loss of the SiBCN ceramics. The interfaces between graphene and amorphous phases generate built-in electric fields and space chare regions to strengthen the interface polarization, while the electrons migrating rapidly in the graphene and other crystals improved the electrical conductivity. The positive effect of heterointerfaces regulation of graphene in-situ growth improved the dielectric loss capacity of the SiBCN ceramics; therefore, this study provides a feasible method to enhance the EMW absorption capability of polymer-derived ceramics. [ABSTRACT FROM AUTHOR]

Abstract: Charge compensation was the effective methods to enhance the luminescence properties of phosphors. In this paper, novel single‐phased orange light emitting Sr2Mg3P4O15:Eu3+ phosphors were prepared by solid state method. The phase purity and luminous characteristics were examined in detail. Meanwhile, three kinds of charge compensation methods (co‐doping the alkali metal R+ (R+ = Li, Na, and K), substituting Si4+ for P5+ and self‐compensation) were employed to solve the charge imbalance problem between Sr2+ and Eu3+. The results showed that emission intensity of Eu3+ was improved by 1.43 (Li+), 1.58 (Na+), 1.53 (K+), 1.61 (Si4+), and 1.30 (self) times than that of Sr1.6Mg3P4O15:0.40Eu3+, respectively, and there was no change in the emitting color simultaneously. Furthermore, as the temperature reached at 423 K, the emission intensity increased from 41.67% of Sr1.6Mg3P4O15:0.40Eu3+ to 55.69% (Li+), 61.62% (Na+), 58.98% (K+), 71.15% (Si4+), and 80.59% (self) of that at room temperature. The reasons of those phenomena were the reduction in ion vacancies caused by charge imbalance through the charge compensation process. The specific mechanisms were elaborated in detail. Overall, this research validated that the charge compensation strategies could be severed as the key method to improve the luminescence properties, especially the thermal stability of phosphor. [ABSTRACT FROM AUTHOR]

By substituting Ca 2+ or Sr 2+ for Ba 2+ and Yb 3+ or La 3+ for Y 3+ , in whole or in part, the single-phased Ba 0.97- x M x Y 2 Si 3 O 10 :0.03Eu 2+ and Ba 0.97 Y 2- y RE y Si 3 O 10 :0.03Eu 2+ phosphors (M = Sr 2+ or Ca 2+ , RE = La 3+ or Yb 3+ ) were synthesized successfully via high temperature solid-state reaction method. The introduction of different cations caused higher covalence and rigidity of the as-prepared samples and enhanced the interaction between electrons around Eu 2+ ions, leading to the variation of emission color from bluish violet to light blue or greenish blue upon optimum excitation wavelength. In addition, the effect of cation substituting level on thermal stability of BaY 2 Si 3 O 10 :0.03Eu 2+ was investigated in details. The emission intensities of Ba 0.97- x Y 2 Si 3 O 10 :0.03Eu 2+ , x Sr 2+ , Ba 0.97- x Y 2 Si 3 O 10 :0.03Eu 2+ , x Ca 2+ , Ba 0.97 Y 2- y Si 3 O 10 :0.03Eu 2+ , y Yb 3+ and Ba 0.97 Y 2- y Si 3 O 10 :0.03Eu 2+ , y La 3+ varied in the range of 68.09%–78.64%, 78.44%–81.00%, 67.38%–79.90% and 60.25%–79.84% at 423 K compared to the initial intensity at room temperature, respectively. Meanwhile, the crystal filed split effect (CFSE) and nephelauxetic effect (NE) mechanisms were also proposed to better explain the red shifts and the changes of thermal quenching behavior of above samples. This work shed some light on the design of phosphors with controllable emission colors and higher thermal stability for the applications in phosphor-converted devices. [ABSTRACT FROM AUTHOR]

Excellent thermostable performance is the basis for the further development of microwave absorbing materials in the field of military stealth. Herein, a high‐temperature metamaterial absorber (HMA) with high impedance patterns (multi‐octagonal‐rings), two quartz (SiO2) layers, and a metallic ground film is designed and simulated. The optimal structural parameters are obtained by optimizing the circuit parameters and the size of HMA. The interaction of electric and magnetic resonance in multioctagonal rings results in a wide absorption bandwidth and excellent absorption performance. The experimental results show that the structure has good impedance matching performance, and the effective absorption bandwidth (−10 dB) (EAB) of the structure can reach 10.6 GHz from room temperature to 700 °C under the combined effect of resonance loss and ohmic loss. [ABSTRACT FROM AUTHOR]

The novel phosphors BaZrSi 3 O 9 :Ce 3+ (BZS:Ce 3+ ) have been successfully synthesized by the conventional solid-state reaction. The phase purity and crystal structure were obtained by X-ray diffraction (XRD) measurements and Rietveld refinement. The photoluminescence spectroscopy revealed that the as-prepared phosphors exhibited a bright blue emission under the excitation by near ultraviolet light and the PL emission peaks of BZS: x Ce 3+ showed a red-shift from 432 nm to 451 nm on the Ce 3+ concentration increasing. The corresponding red-shift mechanism has been discussed. The concentration quenching behavior was observed. The luminescence decay curves and lifetime values were analyzed. This phosphor exhibited high internal quantum efficiency. Thermal quenching luminescence properties showed that the emitting intensity was remained 44.60% of that measured at room temperature when the temperature increased to 398 K. The results indicate that the BaZrSi 3 O 9 :Ce phosphor is a promising blue-emitting phosphor for the application as an ultraviolet-convertible phosphor. [ABSTRACT FROM AUTHOR]

Double-roadway tunneling could mitigate the contradiction between mining production needs and tunneling speed, which is pivotal to the sustainable development of underground mines. However, it is very difficult to control the stability of a mining roadway on an adjacent working face suffering from strong mining disturbance due to double-roadway tunneling, especially at a large mining height working face. In order to control the stability of the return air roadway (RAR) 23205 of a strong mining roadway at working face 23205 in the Zhuanlongwan Coal Mine in Inner Mongolia, we carried out field monitoring, theoretical analysis, numerical simulations, and engineering practice to identify the main factors influencing the deformations and the stress distribution law of the surrounding rock in order to propose countermeasures for strong mining roadways. The results show the factors influencing the large deformation of strong mining roadways include large mining height, repeated mining, stress concentration due to the large coal pillar, and a small thickness of the anchorage layer in the roof. The stress peak in the central coal pillar caused by the first and second mining is 23.19 MPa and 27.49 MPa, respectively, and the stress concentration coefficients are 4.538 and 5.379, respectively. Countermeasures (pressure relief via large-diameter boreholes in the large coal pillar and long anchorage for roof reinforcement) were created to control the stability of a strong mining roadway, i.e., RAR 23205. Field measurements indicated that deformations in RAR 23205 could be efficiently controlled. The maximum deformation of the surrounding rock was 50 mm, which meets the safety and efficient production requirements of the coal mine. In addition, new roadway layout optimization and control countermeasures are put forward to control the stability of mining roadways. [ABSTRACT FROM AUTHOR]

Background: Pancreatic cancer is one of the most lethal cancers worldwide. Aidi injection (ADI) is a representative antitumor medication based on Chinese herbal injection, but its antitumor mechanisms are still poorly understood. Materials and methods: In this work, the subcutaneous xenograft model of human pancreatic cancer cell line Panc-1 was established in nude mice to investigate the anticancer effect of ADI in vivo. We then determined the components of ADI using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS) and explored the possible molecular mechanisms against pancreatic cancer using network pharmacology. Results: In vivo experiments, the volume, weight, and degree of histological abnormalities of implanted tumors were significantly lower in the medium and high concentration ADI injection groups than in the control group. Network pharmacology analysis identified four active components of ADI and seven key targets, TNF, VEGFA, HSP90AA1, MAPK14, CASP3, P53 and JUN. Molecular docking also revealed high affinity between the active components and the target proteins, including Astragaloside IV to P53 and VEGFA, Ginsenoside Rb1 to CASP3 and Formononetin to JUN. Conclusion: ADI could reduce the growth rate of tumor tissue and alleviate the structural abnormalities in tumor tissue. ADI is predicted to act on VEGFA, P53, CASP3, and JUN in ADI-mediated treatment of pancreatic cancer. [ABSTRACT FROM AUTHOR]