Purely organic fluorescent materials that concurrently exhibit high efficiency, narrowband emission, and circularly polarized luminescence (CPL) remain an unaddressed issue despite their promising ...applications in wide color gamut‐ and 3D‐display. Herein, the CPL optical property and multiple resonance (MR) effect induced thermally activated delayed fluorescence (MR‐TADF) emission are integrated with high color purity and luminous efficiency together. Two pairs of highly efficient green CP‐MR‐TADF enantiomers, namely, (R/S)‐OBN‐2CN‐BN and (R/S)‐OBN‐4CN‐BN, are developed. The enantiomer‐based organic light‐emitting diodes (OLEDs) exhibit pure green emission with narrow full‐width at half‐maximums (FWHMs) of 30 and 33 nm, high maximum external quantum efficiencies (EQEs) of 29.4% and 24.5%, and clear circularly polarized electroluminescence (CPEL) signals with electroluminescence dissymmetry factors (gEL) of +1.43 × 10−3/−1.27 × 10−3 and +4.60 × 10−4/−4.76 × 10−4, respectively. This is the first example of a highly efficient OLED that exhibits CPEL signal, narrowband emission, and TADF concurrently.
Two pairs of circularly polarized multiple resonance thermally activated delayed fluorescence (CP‐MR‐TADF) enantiomers are developed by combining the merits of circularly polarized luminescence (CPL) and MR‐TADF. This is the first example of a highly efficient organic light‐emitting diode (OLED) that exhibits circularly polarized electroluminescence signal, narrowband emission, and TADF concurrently.
•Nine compositionally-complex fluorite oxides (CCFOs) are made and investigated.•CCFOs exhibit reduced thermal conductivity and increased cubic phase stability.•Lower thermal conductivity is achieved ...in medium-entropy non-equimolar CCFOs.•High modulus and hardness retain in CCFOs with reduced thermal conductivity.•Non-equimolar CCFOs exhibit amorphous-like T-dependent thermal conductivity.
Using fluorite oxides as an example, this study broadens high-entropy ceramics (HECs) to compositionally-complex ceramics (CCCs) or multi-principal cation ceramics (MPCCs) to include medium-entropy and/or non-equimolar compositions. Nine compositions of compositionally-complex fluorite oxides (CCFOs) with the general formula of (Hf1/3Zr1/3Ce1/3)1-x(Y1/2X1/2)xO2-δ (X = Yb, Ca, and Gd; x = 0.4, 0.148, and 0.058) are fabricated. The phase stability, mechanical properties, and thermal conductivities are measured. Compared with yttria-stabilized zirconia, these CCFOs exhibit increased cubic phase stability and reduced thermal conductivity, while retaining high Young’s modulus (∼210 GPa) and nanohardness (∼18 GPa). Moreover, the temperature-dependent thermal conductivity in the non-equimolar CCFOs shows an amorphous-like behavior. In comparison with their equimolar high-entropy counterparts, the medium-entropy non-equimolar CCFOs exhibit even lower thermal conductivity (k) while maintaining high modulus (E), thereby achieving higher E/k ratios. These results suggest a new direction to achieve thermally-insulative yet stiff CCCs (MPCCs) via exploring non-equimolar and/or medium-entropy compositions.
•18 compositionally-complex (medium- and high-entropy) pyrochlore oxides fabricated.•Mixing of cations at A- and/or B-sites leads to reduced thermal conductivity.•Thermal conductivity correlates well ...with a modified size disorder parameter.•A new descriptor proposed for designing low-k medium- and high-entropy ceramics.•Medium-entropy ceramics can outperform their high-entropy counterparts.
High-entropy ceramics generally exhibit reduced thermal conductivity, but little is known about what controls this suppression and which descriptor can predict it. Herein, 22 single-phase pyrochlores were examined. Up to 35% reductions in thermal conductivity were achieved in medium- and high-entropy compositions with retained moduli, thereby attaining insulative yet stiff properties for thermal barrier coating applications. Notably, the measured thermal conductivity correlates well with a modified size disorder parameter δSize*, thereby suggesting the importance of severe lattice distortion. Thus, this δSize* is suggested as a useful descriptor for designing thermally-insulative compositionally-complex ceramics, where medium-entropy ceramics can outperform their high-entropy counterparts.
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•The processing conditions of a novel technology, PAW, were optimized.•Combining batches and short-term storage of PAW did not impact inactivation.•Salmonella Typhimurium MHM112 may serve as suitable ...surrogate for optimized PAW.•Inactivation by PAW was similar for cells grown in broth versus agar.
Plasma-activated water (PAW) is considered a novel sanitizer for the food industry due to the antimicrobial mechanisms exhibited by reactive oxygen and nitrogen species. The plasma operation parameters can affect the chemistry of PAW and can therefore influence its microbial inactivation efficacy. This study statistically optimized the operating conditions of PAW (activation time, distance from nozzle, and volume of water) using response surface methodology. Two optimized conditions of PAW were identified for the inactivation of planktonic cells of the avirulent strain of Salmonella Typhimurium MHM112 providing a minimum reduction of 6.3 log. All three operating parameters significantly affected the physicochemical characteristics (pH, ORP, EC, nitrite, and nitrate) and microbial inactivation efficacy of PAW. Mixing of small batches using the two optimized conditions to obtain larger volumes did not significantly change the microbial inactivation. However, there were significant reductions in nitrite and nitrate concentrations in PAW due to the mixing of batches while the pH and ORP values remained unaffected. The storage of large volumes of PAW for 25 min at 40–46°C, which is the commercial egg washing temperature in the United States, did not significantly impact S. Typhimurium MHM112 inactivation or the physicochemical characteristics of PAW. A validation study using a cocktail of six pathogenic strains of Salmonella revealed no significant differences in inactivation between the avirulent S. Typhimurium MHM112 and the pathogenic strains, suggesting that the avirulent S. Typhimurium MHM112 may serve as a surrogate for sanitation of S. enterica at the optimized conditions of PAW. The results obtained from this study are useful for our long-term goal of evaluating PAW efficacy in surface egg washing to inactivate Salmonella.
•A new ensemble strategy using optimizing decision directed acyclic graph.•Performance comparison between different methods.•Misclassification cost sensitivity analysis for the proposed ...method.•Discussion of selected features for predicting listing status.
Most existing research has demonstrated the success of different decomposition and ensemble strategies for solving multi-class classification problems. This study proposes a new ensemble strategy for One-vs-One (OVO) scheme that uses optimizing decision directed acyclic graph (ODDAG) whose structure is determined by maximizing the fitness on the training set instead of by predefined rules. It makes an attempt to reduce the effect of non-competent classifiers in OVO scheme like decision directed acyclic graph (DDAG) but in another way. We test the proposed method on some public data sets and compare it to some other widely used methods to select the proper candidates and related settings for a problem with practical concern from financial industry in China, i.e. the prediction of listing status of companies. The experimental result shows that our model can outperform the benchmarked methods on this real problem. In addition, the ODDAG combined with decision tree is a white box model whose internal rules can be viewed and checked by decision makers.
The fisheye camera, with its large viewing angle, can acquire more spatial information in one shot and is widely used in many fields. However, a fisheye image contains large distortion, resulting in ...that many scholars have investigated its accuracy of orthorectification, i.e., generation of digital orthophoto map (DOM). This paper presents an orthorectification method, which first determines the transformation relationship between the fisheye image points and the perspective projection points according to the equidistant projection model, i.e., determines the spherical distortion of the fisheye image; then introduces the transformation relationship and the fisheye camera distortion model into the collinearity equation to derive the fisheye image orthorectification model. To verify the proposed method, high accuracy of the fisheye camera 3D calibration field is established to obtain the interior and exterior orientation parameters (IOPs/EOPs) and distortion parameters of the fisheye lens. Three experiments are used to verify the proposed orthorectification method. The root mean square errors (RMSEs) of the three DOMs are averagely 0.003 m, 0.29 m, and 0.61 m, respectively. The experimental results demonstrate that the proposed method is correct and effective.
Most natural materials have rotational and hierarchical properties, so they can show excellent mechanical properties such as shear resistance and impact resistance. In order to further improve the ...energy absorption characteristics of vibration absorbing structures, a new type of honeycomb structure with integral rotation and group rotation is designed and characterized. The effects of the geometrical parameters of rotation Angle on the impact deformation mode, stress response curve and energy absorption characteristics of the honeycomb structure are studied through numerical simulation and experimental design. The results show that the overall honeycomb performance of 15° is better than that of 0°, the specific energy absorption is the results show that the overall honeycomb performance of 15° is better than that of 0°, the specific energy absorption is increased by 6%, the bearing capacity is increased by 320 N, and the crushing force efficiency is increased by 2%. Compared with the whole cell and the group cell, the specific absorption energy increased by 35%, 73% and 71%. The results of this paper provide a new insight into the impact performance of monolithic and grouped rotating honeycomb structures, which is helpful for the results of this paper provide a new insight into the impact performance of monolithic and grouped rotating honeycomb structures, which is helpful for the optimization of crashworthiness structural design.
Possible mechanisms behind the enhanced antimicrobial activity of gallic acid (GA) and its ester propyl gallate (PG) in the presence of UV-A light against Escherichia coli O157:H7 were investigated. ...GA by itself is a mild antimicrobial and has a pro-oxidant ability. We found that the presence of UV-A light increases the uptake of GA by the bacteria. Once GA is internalized, the interaction between GA and UV-A induces intracellular ROS formation, leading to oxidative damage. Concurrently, GA + UV-A also inhibits the activity of superoxide dismutase (SOD), magnifying the imbalance of redox status of E. coli O157:H7. In addition to ROS induced damage, UV-A light and GA also cause injury to the cell membrane of E. coli O157:H7. UV-A exposed PG caused oxidative damage to the cell and significantly higher damage to the cell membrane than GA + UV-A treatment, explaining its higher effectiveness than GA + UV-A treatment. The findings presented here may be useful in developing new antimicrobial sanitation technologies for food and pharmaceutical industries.
A synergistic interaction between gallic acid (GA) and UV-A light (UV-A+GA) to inactivate E. coli O157:H7 in spinach wash water and in biofilm was evaluated. A 30-min exposure to UV-A light in ...presence of 10mM GA had relevant biological effect in the inactivation of E. coli O157:H7 in suspension in the absence (>5 log(CFU/mL) ) and the presence of organic content (>3-log(CFU/mL) in 2000mgO2/L COD (Chemical Oxygen Demand) organic load), and resulted in ~80% decrease in the metabolic activity of E. coli O157:H7 biofilm. GA solutions could be recycled through at least 3-cycles of UV-A treatment without a significant loss in antibacterial effect. Catalase reduced the extent of E. coli O157:H7 inactivation from the UV-A+GA treatment suggesting that generation of hydrogen peroxide was partially responsible for the observed antimicrobial effect. The UV-A+GA treatment was also found to be effective in causing >3 log(CFU/mL) reductions in E. coli O157:H7 on the surface of spinach leaves. UV-A+GA treatment can serve as an effective intervention in the fresh produce sanitation.
The results of this study show that a synergistic interaction between gallic acid (GA) and UV-A (365nm) light is an effective treatment for sanitation of fresh produce and water used to wash fresh produce. It was also found to be effective against the E.coli O157:H7 biofilm. The attractive attributes of this technology include a relatively low cost; specific, light-triggered activity; non-toxic nature and scalability. Thus, this technology has potential to replace conventional chemical sanitizer-based sanitation approaches.
•GA+UV-A inactivated 3.7 log(CFU/mL) E. coli O157:H7 in solution of 2000mg/L COD.•GA can be reused in multiple cycles of continuous treatment without losing efficacy.•Catalase protected E. coli from the effect of photosensitized GA in suspension.•UV-A exposed GA inhibited the metabolic activity of E. coli O157:H7 biofilm by ~75%.•GA in suspension was absorbed by E. coli O157:H7 cells
Additive manufacturing (AM) is a novel manufacturing technology that can create highly customized products with more complex geometries than traditional techniques. Despite its significant ...advantages, including the freedom of design, mass customization, and ability to produce complex structures, AM consumes a large amount of energy and incurs high costs. In addition, AM suffers from long production cycles and low production efficiency in the large-scale manufacturing of metal structures. This study offers a review of the existing literature focused on metal AM technology. To avoid the shortcomings of AM and highlight its benefits, which are widely used for manufacturing in combination with casting. The current combination application of AM and casting is reviewed to provide solutions to the problem of manufacturing large metal components from the perspective of the use of different AM technology and quality control in casting. However, such integration is insufficient for producing large castings with complex shapes, structures, or multiple features. Therefore, a novel method for integrating AM into casting to enable the manufacture of large scale metal parts with complex shapes is introduced as a topic for possible future research. This method divides complex castings with multiple features into an AM processing part and the casting substrate. The complex features were processed by AM on the fabricated casting substrate. This study provides a review of the application of AM into casting and presents a novel idea for the integration application of AM and other processes. This promising method has significant value for future study.
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