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White light-emitting diodes (WLEDs) represent a revolutionary type of energy-saving and environmentally friendly light source, which has been extensively employed in a multitude of lighting and display applications. Nevertheless, traditional organic packaging is unable to fulfill the requirements of highly reliable high-power WLEDs, including hemertic property, heat resistance, and excellent luminous properties. Herein, an all-inorganic hermetic packaging based on laser-localized welding and phosphor-in-glass film sintered on a sapphire lens (PiGF-SL) has been developed for high-power WLEDs. The PiGF-SL with a Kovar frame was welded to a three-dimensional direct-plated ceramic (3D-DPC). The high-strength and crack-free welded joint with a shear strength of 258.83 MPa and packaging cavity with excellent gas tightness (leakage rate 8.6 × 10−10 Pa m3/s) were simultaneously obtained, resulting in the high-power WLED capable of maintaining its excellent optical properties for an extended period in harsh environments. Furthermore, the optical performance of welded WLEDs was optimized by adjusting the PiGF-SL film thickness and red CaAlSiN3:Eu2+ (CASN) phosphor content. The welded WLED emits a cool white light by improving the PiGF thickness to 91 μm and exhibits high color quality with red CASN phosphor content of 8 wt%, which simultaneously presents outstanding color rendering index (CRI) of 91, luminous efficacy (LE) of 44.8 lm/W, and correlated color temperature (CCT) of 4322 K. Following a 200-h aging process, the laser-welded PiGF-SL-based WLED exhibited a slightly reduced efficiency loss and a stable color quality in comparison to reflow-soldered and epoxy-bonded WLEDs. Our work provides valuable guidance and solutions for the highly reliable and board-level packaging of WLEDs. [ABSTRACT FROM AUTHOR]

To address the problems of low luminous efficacy and poor thermal stability of reflective phosphor-in-glass (PiG) converter, a thermally robust and highly reflective PiG-boron nitride (BN)-aluminum nitride (AlN) converter was designed for enabling ultrahigh efficiency laser-driven white lighting. Benefiting from the ingenious sandwich design with the thermally conductive AlN substrate and highly reflective BN-glass interface, a La 3 Si 6 N 11 :Ce3+ (LSN) PiG-BN-AlN converter achieves white light emission with a high luminous efficacy of 214.2 lm/W under the 3.15 W blue laser excitation, which is the best recorded value for the reflective PiG-based converters thus far, and the surface temperature of LSN PiG is low to 126 °C. Furthermore, the LSN PiG-BN-AlN converter incorporates CaAlSiN3:Eu2+ (CASN) red phosphor to enable high-quality white light emission with high luminous flux and good color quality. The results reveal that the designed PiG-BN-AlN converter provides a promising strategy for achieving ultrahigh efficiency laser-driven white lighting. [ABSTRACT FROM AUTHOR]

Laser diodes (LDs) combined with color converters have been considered as new-generation high-brightness white light source. Whereas, the luminescence of phosphor materials is easily influenced by accumulated heat originating from laser-driven conversion. In order to alleviate the thermal effect under focused laser of high-power, we proposed a high-luminescence laser-driven color converter of heat-conducting La 3 Si 6 N 11 :Ce3+ (LSN:Ce) phosphor-in-glass (PiG). The LSN:Ce nitride phosphor exhibits excellent opto-thermal property. The LSN:Ce-PiG-AlN converter was fabricated by sintering the LSN:Ce-PiG layer (∼50 μm) upon a AlN ceramic substrate. Due to excellent luminescence of LSN:Ce and high thermal conductivity of AlN, the LSN:Ce-PiG-AlN converter achieves a luminous flux (LF) of 376.1 lm, a luminous efficiency (LE) of 158 lm/W, and a correlated color temperature (CCT) of 4462 K under 2.39 W laser excitation. In addition, the temperature of PiG film surface still stays low level (<150 °C) when driven by 4.82 W laser irradiation. The proposed LSN:Ce-PiG-AlN converter is a high-performance and promising phosphor converter for high-luminescence white laser lighting. [ABSTRACT FROM AUTHOR]

Phosphors-in-glass films (PiGFs) with thermally conductive substrates are considered to be an efficient color inorganic color conversion material for laser lighting. However, due to the contradiction between the light extraction and heat dissipation, achieving high brightness and excellent color quality simultaneously is still a big challenge. Herein, a unique architecture of bicolor PiGF with highly reflective interface design was proposed for high-quality laser lighting. The TiO 2 -glass films with different thicknesses were prepared on highly heat-conducting AlN substrates to obtain the TiO 2 –AlN (TA) substrates with various reflectance. In addition, mixed green/red, stacked green-red, and stacked red-green phosphor glass films were printed and sintered on the TA substrates to prepared three bicolor PiGF converters of M-PiTA, G-R-PiTA, and R-G-PiTA. At the TiO 2 -glass film thickness of 100 μm, the M-PiTA enables a luminous flux of 2053 lm@24.8 W/mm2, which is 1.9 times that of traditional M-PiGF-AlN converter (1077 lm@17.6 W/mm2). The M-PiTA converter realizes a high-quality white light with a CRI of 82.7 and a chromaticity coordinate of (0.3378, 0.3297). Furthermore, the M-PiTA converter enables higher luminance and light quality compared with the stacked G-R-PiTA and R-G-PiTA converters. With the laser power of 4.2 W, the working temperature of M-PiTA converter is only 59.2 °C, while that of R-G-PiTA and G-R-PiTA converters rises to 499 °C and 301 °C. The results demonstrate that the bicolor PiTA converters have broad prospects in the application of laser lighting. [ABSTRACT FROM AUTHOR]

This work proposed an impact momentum flexibility (IMF) to precisely and concisely characterize the soft impact behavior of twill weave laminate based on multi-scale finite element analysis. A multi-scale finite element model taking into consideration the microstructure and properties of constituents is established for twill weave laminate. The equivalent properties of fiber tows and twill weave laminate are predicted by micro-scale model and meso-scale model, respectively. Then the soft impact behavior of the laminate is investigated by macro-scale model. The multi-scale model is validated on different scales by comparing the experimental and simulated results of quasi-static compression and soft impact. On this basis, the deformation and failure of the laminate under soft impact are analyzed. The soft impact response is categorized according to the damage morphology and impact velocity. Moreover, the IMF is proposed to depict the ability to resist soft impact deformation of the laminate, and can be further adopted to rank the soft impact property of different materials. • Established the multi-scale finite element model for the twill weave laminate. • Obtained and categorized the soft impact response of the twill weave laminate. • Proposed the impact momentum flexibility (IMF). • Characterized the soft impact behavior precisely and concisely using IMF. [ABSTRACT FROM AUTHOR]

Natural gas (NG) is a clean and low-carbon fuel and the NG engine is one of the main measures used by the public transportation industry to achieve carbon peak targets. However, NG engines have problems, such as ignition difficulty and low thermal efficiency. The use of diesel to ignite NG is an effective solution to these problems; however, this solution will increase CO 2 emissions compared with NG engines. In this study, the potential of reducing CO 2 emissions from a diesel-pilot-ignited (DPI) NG engine by optimizing the injection parameters (injection pressure and injection timing) under different loads is studied through experiments. Furthermore, the formation mechanism of CO 2 in combination with chemical kinetics is analyzed. The results show that combustion in the DPI mode presents an obvious two-stage heat release and its CO 2 emission is 17.15% lower than that of pure diesel combustion (PDC). Under high-load conditions, as the diesel injection pressure increase, the THC and NO X emissions emissions decrease by 67.53% and 84.32%. As the diesel injection timing (DIT) advances, the NO X emissions increase from 1.84 to 22.96 g/kW·h respectively. According to the analysis of the chemical kinetic mechanism, the formation of CO2 in DPI mode is primarily through the reaction of CO + O 2 = CO 2 + O, whereas in conventional diesel combustion (CDC) mode, CO 2 is formed through the reaction of CO + OH = CO 2 + H. Within the range of −18 to −5°CA ATDC DIT, increasing the diesel injection pressure (DIP) or advancing the DIT can improve the thermal efficiency of DPI NG engines and reduce CO 2 emissions. [Display omitted] • Advancing injection timing, the BTE increases and the CO 2 decreases in DPI mode. • The CO 2 emission in DPI mode is much lower than that in pure diesel mode. • With optimized injection parameters, the performance in DPI mode have been improved. • The reaction path of CO.→CO 2 in DPI mode is different from that in the diesel mode. [ABSTRACT FROM AUTHOR]

Pb tolerant mechanisms, plant physiological response and Pb sub-cellular localization in the root cells of Iris halophila were studied in sand culture and the Pb mine tailings. Results showed that the activities of superoxide dismutase (SOD) and peroxidase (POD) in the underground parts and the activity of catalase (CAT) in the aboveground and underground parts increased as Pb level was enhanced. Glutathione (GSH) and ascorbic acid (AsA) contents increased by Pb treatments. Pb deposits were found in the middle cell walls or along the inner side of epibiotic protoplasm of some cells which accumulated a large quantity of Pb and died. The dry weights (DWs) of aboveground parts under all Pb tailings treatments decreased insignificantly, while the DW of the underground parts growing in the pure Pb tailings decreased significantly. Pb, Cu, Cd, and Zn contents increased significantly as the levels of Pb tailings were enhanced and Pb contents in the aboveground and underground parts reached 64.75 and 751.75 μg/g DW, respectively, at pure Pb tailings treatment. The results indicated that I. halophila is a promising plant in the phytoremediation of Pb contaminated environment. Some antioxidant enzymes, antioxidants and compartmentalization of Pb were played major roles in Pb tolerance of I. halophila. [ABSTRACT FROM AUTHOR]

Tunable waterbomb origami has attracted significant attention for its superior capability in structural reconfiguration, which is utilized to tailor the mechanical properties of metamaterials. Recent researches mainly focus on the kinematic analysis of waterbomb origami folding process to convert the planar crease pattern to a three-dimensional folded configuration. Nevertheless, the inverse problem, i.e., the design of crease patterns based on an arbitrary waterbomb origami configuration, is rarely studied. In the paper, an innovative "seven-crease" waterbomb pattern is proposed by modification of the classic "six-crease" waterbomb crease pattern. The new pattern design avoids the risk of self-penetration during folding process. Recursive algorithm and design constraints of the "seven-crease" waterbomb crease patterns are derived based on the kinematic relationship. The folding feasibility of the proposed crease pattern is validated against the finite element simulations of two sample models, which match well with the theoretical results. • Seven-crease origami is proposed to tail shells with single-curvature configuration. • Geometric constraint is established to avoid self-penetration of adjacent unit cells. • Recursive algorithm is developed for crease pattern design based on target prototype. • Rigid foldability of seven-crease origami is verified by finite element analysis. [ABSTRACT FROM AUTHOR]

Abstract: A three-dimensional (3-D) cellular automaton model for dendritic growth in multi-component alloys is developed. The velocity of advance of the solid/liquid (S/L) interface is calculated using the solute conservation relationship at the S/L interface. The effect of interactions between the alloying elements on the diffusion coefficient of solutes in the solid and liquid phases are considered. The model is first validated by comparing with the theoretical predictions for binary and ternary alloys, and then applied to simulate the solidification process of Al–Cu–Mg alloys by a coupling of thermodynamic and kinetic calculations. The numerical results obtained show both the free dendrite growth process as well as the directional solidification process. The calculated secondary dendrite arm spacing in the directionally solidified Al–Cu–Mg alloy is in good agreement with the experimental results. The effect of interactions between the various alloying elements on dendritic growth is discussed. [Copyright &y& Elsevier]

Abstract: Powders of Cu85Fe15 alloy were manufactured by using the high-pressure gas atomization technique. The microstructures of the powders have been investigated. It is indicated that the liquid–liquid phase transformation takes place in the atomized droplets smaller than 224μm in diameter. The size of Fe-rich spheres decreases and their number density increases with the decrease of the powder size. A model has been developed to describe the microstructure evolution in the atomized droplets during a cooling through the metastable miscibility gap. Calculations have been performed with Cu85Fe15 alloy. The experimental and simulated results have been discussed in detail. [Copyright &y& Elsevier]

The in-plane dynamic compressive behavior of a 2D twill weave carbon fiber reinforced composite was investigated using the split Hopkinson pressure bar (SHPB) apparatus. Constant strain rate loading was achieved with the adoption of pulse shapers within the experiments. A non-dimensional parameter was adopted to verify the stress equilibrium state of the specimens, which ensured the effectiveness of the experimental results. The upper limit of constant strain rate for the composite, which determines the achievable range of constant strain rate, was analytically estimated and verified by the experimental results. On this basis, the dynamic compressive behavior of the composite was investigated within the strain rate range of 193/s-846/s. The stress-strain curves were obtained under the studied strain rates, an empirical equation for the strengths under different strain rates was summarized. Based on the experimental results, a viscoelastic constitutive model was adopted to characterize the dynamic stress-strain response. Finally, the deformation process of the specimens recorded through high speed photography was discussed. Together with the microscopic observations, typical damage modes of the specimens were summarized • Constant strain rate loading for the studied composite was achieved with the usage of pulse shapers. • The effectiveness of the experimental results was ensured with the verification of stress equilibrium, through the adoption of a non-dimensional parameter. • The upper limit of constant strain rate was estimated analytically and experimentally. [ABSTRACT FROM AUTHOR]

2,3,5,4′-Tetrahydroxystilbene-2-O-β- d -glucoside (TSG) is the key bioactive ingredient extracted from Polygonum multiflorum Thumb. Pharmacological studies suggest that it exerts numerous biological effects, including anti-oxidant, anti-aging, and anti-inflammation. This study aimed at investigating the effect of TSG on diethylnitrosamine (DEN)-induced acute hepatotoxicity and DNA damage. Fifty male C57BL/6 mice were randomly divided into 5 groups (n = 10 each): control, DEN, DEN+TSG (low), DEN+TSG (high) and TSG (high) groups. DEN (100 mg/kg) was injected intraperitoneally (i.p.) alone or with TSG (30 or 60 mg/kg, i.p.) for 5 consecutive days. TSG inhibited liver injury and inflammatory cell infiltration in DEN-treated mice. It also attenuated DEN-induced accumulation of reactive oxygen species (ROS), proinflammatory cytokines, and DNA damage. Moreover, TSG promoted the expression of nuclear erythroid 2-related factor 2 (Nrf2) target antioxidant genes by enhancing Nrf2 protein phosphorylation and nuclear translocation. As major phase I detoxification enzymes, cytochrome P450 family 2 subfamily E member 1 (CYP2E1) and cytochrome P450 1 subfamily A member 1 (CYP1A1) are responsible for the metabolic activation of DEN. We found that TSG administration inhibited CYP2E1 and CYP1A1 induction in DEN-treated mice. These results indicate that TSG can alleviate DEN-induced acute hepatotoxicity by modulating the Nrf2-related antioxidant system and metabolic activation of DEN. Therefore, TSG might be a promising medication for DEN-induced liver injury treatment. Unlabelled Image [ABSTRACT FROM AUTHOR]

All-inorganic phosphor-in-glass (PiG) converter withstanding high power laser excitation has garnered attention for laser-driven white lighting, while its poor heat dissipation and low fluorescence conversion efficiency has been serious challenges in high-brightness white lighting. Herein, a thermally robust PiG film converter with a sandwich phosphor structure and microstructure interface was designed for ultrahigh-brightness laser-driven white lighting. The yellow-emitting YAG PiG film was thermocompression bonded to microstructure sapphire (MS) and planar alumina (PA) to construct the MS-PiG-PA converter. The YAG PiG film possess higher luminescence intensity than YAG phosphor and was tightly attached to sapphire and alumina without microcracks. Benefiting from the double-sided heat dissipation design and microstructure interface light field strengthening effect, the MS-PiG-PA converter emits ultrahigh luminous flux white light (5197 lm) at power density of 30 W/mm2 and displays excellent CRI and CCT stability. The MS-PiG-PA converter has a lower working temperature, higher saturation threshold and luminous efficacy. [ABSTRACT FROM AUTHOR]

This paper presents the synthesis of a waterproof geopolymer based on the modification of silicon phosphate (Si 3 (PO 4) 4) that adheres to alumina and quartz glass substrate, which can replace traditional organic polymers for packaging deep-ultraviolet light-emitting diodes. The waterproof property of geopolymer strongly depends on the Si 3 (PO 4) 4 loading amount due to its hydrolysate H+ substitutes Na+, which is vulnerable to water. FESEM and microhardness results show that aging by 85°C/85% relative humidity for 100 h, the optimal waterproof geopolymer adhesive is successfully synthesized when the mass ratio of metakaolin, water glass, and Si 3 (PO 4) 4 is equal to 0.48: 1: 0.08 respectively, and the corresponding adhesion strength of 6.41 MPa to alumina substrate is achieved after the reliability testing. The rheological properties show that the optimal waterproof geopolymer adhesive, with shear thinning behavior and good thixotropy, is suitable for processing while holding the original shape. [ABSTRACT FROM AUTHOR]

Adding an interfacial active element to alloy melt is beneficial to the formation of a well-dispersed microstructure of immiscible alloys. A simple but effective criterion − L B − A < (L A − i − L B − i ) < L A − B is proposed to choose the interfacial active element i for an A (solvent)-B (solute) immiscible alloy with L A-B , L B-A , L A- i and L B- i being the interaction energy parameters for the liquid A-B alloy in the A-rich corner, the liquid A-B alloy in the B-rich corner, the liquid A- i alloy in the A-rich corner and the liquid B- i alloys in the B-rich corner, respectively. Solidification experiments were conducted on Al-Bi and Zn-Pb alloys micro-alloyed with different elements. The proposed criterion is verified by comparing its predictions with the experimental results. [Display omitted] [ABSTRACT FROM AUTHOR]

An analytical model is developed to calculate the segregation behavior of a micro-alloying element to the liquid/liquid interface and its effect on the liquid/liquid interfacial energy during the solidification of a monotectic alloy based on the thermodynamics of alloys. Experiments are carried out with Al-Bi alloy micro-alloyed by different elements. The model is verified by the experimental results. Calculation results demonstrate that, for an A-B monotectic system, the segregation behavior of the micro-alloying element i depends on the partition coefficient K i (ratio of the mole fraction of i in the B-rich melt to that in the A-rich melt), which is closely related to the atomic interaction energy parameters L A- i for the A- i binary alloy, L B- i for the B- i binary alloy, L A-B for the A-B binary alloy. A simple but efficient criterion is proposed based on K i for choosing the interface active element i for the A-B monotectic alloy: K A < K i < K B. [Display omitted] [ABSTRACT FROM AUTHOR]

Solidification experiments were carried out for Al-Bi alloys with the addition of TiC. It is demonstrated that the average size of the Bi-rich minority phase particles (MPPs) shows a tendency of keeping constant, increasing, decreasing and then keeping constant again with the increase of the additive amount of TiC. The MPPs can be refined effectively with the addition of an appropriate amount of TiC. A model was developed to describe the kinetic behavior of the TiC particles in the melt and the microstructure evolution during the liquid-liquid (L-L) phase transformation of the Al-Bi alloys with the addition of TiC. The numerical results show that TiC particles may dissolve and coarsen during the heating period, and precipitate out during the cooling period of the melt. There may be two kinds of TiC particles: the one remained during holding temperature and the one precipitated during a cooling of the melt. Both of them can work as the inoculants for the nucleation of the minority phase droplets. What determines the refining efficiency is the resultant number density of the TiC particles in the melt cooled to the binodal line temperature. This research demonstrates that inoculation is an effective method for controlling the L-L phase transformation. The addition of the efficient inoculant may promote the formation of a monotectic alloy with a well dispersed microstructure. [ABSTRACT FROM AUTHOR]

Phosphor-converted laser lighting has become a credible candidate in next-generation high-brightness white lighting, and the configuration types of phosphor converters have a great influence on the opto-thermal performances of laser lighting. In this work, we proposed nitride phosphor-in-glass films (PIGFs) for high-brightness laser lighting and investigated the opto-thermal performances of PIGFs in transmissive (T) and reflective (R) modes. The Y-PIGFs were prepared by low-temperature sintering a mixture of yellow-emitting La 3 Si 6 N 11 :Ce3+ (LSN) phosphor and borosilicate glass, and the Y/R-PIGFs were achieved by incorporating red-emitting CaAlSiN 3 :Eu2+ (CASN) phosphor into the Y-PIGFs. The PIGFs display higher thermal stability and luminescence intensity than the raw phosphors. By tailoring the thickness of Y-PIGFs, the Y-PIGF with a film thickness of 75 μm achieves the luminous efficacy of 199.4 lm/W and 91.5 lm/W in the T mode and R mode, respectively, and the PIGF realizes the highest luminous efficacy of 207.8 lm/W by collecting backward light in the T mode. At the CASN/LSN ratio of 0.20, the Y/R-PIGF enables high-quality white light with a color rendering index (CRI) higher than 89. Furthermore, under 4.82 W laser excitation, the central temperatures of Y-PIGF in the T-mode and R-mode are only 98 °C and 67.4 °C, respectively. The results indicate that the PIGFs enable high-performance white laser lighting with distinct opto-thermal properties by adjusting configuration types. [ABSTRACT FROM AUTHOR]

• A combined process is developed for treatment and recovery of metal mixture in WPCBs. • Liquid-liquid phase separation is used for metal enrichment. • Amphoteric metals are separated by low-temperature alkaline smelting. • Noble metals gold and silver are efficiently enriched to form a high-value group. Waste printed circuit boards (WPCBs) contain a variety of valuable and hazardous materials. Recycling WPCBs is an important subject not only for environmental protection but also for sustainable development of resources. In this work, a new method combined low-temperature alkaline smelting with liquid-liquid phase separation is proposed to separate and recycle metal mixture in pyrolysis residue of WPCBs of mobile phones. During the low-temperature alkaline smelting process, amphoteric metals Al, Pb, Si, Sn, and Zn are firstly separated and recycled from the metal mixture with the separation rates of 99.5%, 81.6%, 97.8%, 88.4% and 95.7%, respectively. To separate the remaining metal mixture mainly containing elements Cu, Fe, Cr, Ni, Au and Ag, a liquid-liquid phase separation system is designed. As a result, the noble metals Au and Ag are concentrated in the copper-rich substance to form a high-value group, while the elements Ni and Cr distribute in the iron-rich substance. The iron-rich substance can be reused in the liquid-liquid phase separation process. In the super-gravity field, the recycling rates of the metals Au, Ag, Cr and Ni reach 98.1%, 99.8%, 95.6% and 75.4%, respectively. Furthermore, the iron-rich substance can be reused back to the liquid-liquid separation system. The copper-rich substance enriched by the noble metals can be efficiently recovered with low energy consumption and less pollution. This work provides an environmentally friendly and efficient route for separating and recycling the metal mixture in WPCBs. [ABSTRACT FROM AUTHOR]

Abstract Al-Bi-Sn alloy was solidified directionally in space. The sample shows a well-dispersed microstructure. A model was developed to describe the microstructure formation during solidification. Calculations demonstrate that the Stokes settlement of the Minority Phase Droplets (MPDs) and the convection of the melt are against the establishment of the steady state of solidification and macro-segregation occurs soon after the beginning of the solidification on ground. The diminished melt convection and the Stokes motions of the MPDs under microgravity conditions promote the establishment of the steady state of solidification and the formation of a well-dispersed microstructure. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]