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Ultralow dispersion gradient refractive index (GRIN) microlens arrays (MLAs) covering the visible to mid-infrared wavelength range are imprinted in GeS 2 -Ga 2 S 3 -CsI chalcohalide glass by an efficient and economical microthermal poling process. The effect of poling voltage on GRIN microstructure, structural rearrangement, optical properties of the poled glasses, and imaging of the imprinted MLAs have been investigated. Optical focal length of the GRIN MLAs decreases from 353 to 63 μm with increasing the poling voltage from 200 to 1000 V, which is in accordance with imprinting-induced phase difference increase from 0.57 λ to 1.19 λ. Optimal chromatic aberration (between 520 and 850 nm) as low as 5% is achieved in the GRIN MLAs. Formation mechanism of GRIN MLAs is mainly associated with an enhanced transverse migration of Cs+ ions within mesh square area, which is provided by an improved anode of microthermal poling setup. Thus, an efficient and inexpensive process developed can produce broadband and ultralow dispersion GRIN MLAs for imaging, display, and photovoltaic applications. [ABSTRACT FROM AUTHOR]

This work presents the influence of glass matrix SiO 2 –B 2 O 3 –NaF on the formation of near-infrared (NIR)-shielding functional units in energy-saving glass windows. The structural analyses by XRD, XPS, and Raman confirmed that the NIR-shielding performance is insensitive to SiO 2 or B 2 O 3 glass network formers but is significantly impacted by the concentration of NaF. This is because the presence of a reasonable amount of NaF provides the much-needed sodium for the formation of NIR-shielding functional units Na 5 W 14 O 44 but too much NaF (>22 mol.%) can inhibit the formation of Na 5 W 14 O 44 by transforming the W– O –W chain in the interconnected [WO 6 ] and [WO 4 ] polyhedrons into W–O- bonds. By adjusting NaF to the optimal level (16 mol.%) and adding only a small amount of H 2 WO 4 (1.9 mol.%) as the tungsten source in the raw materials, excellent optical properties and thermal insulation performance have been achieved in the produced bulk glass, with a high transmission of 65.8% at 550 nm in the visible light region and a low transmission of 6.6% at 1550 nm in the NIR region. This performance is much better than soda lime glass and ITO glass and is comparable to cesium tungsten bronze-based membrane coated glass. This study paves a way for glass composition design to achieve high NIR-shielding performance with the minimum amount of tungsten source, leading to cost-effective glass fabrication and enhanced mechanical strength of energy-saving glass windows. [ABSTRACT FROM AUTHOR]

NIR-shielding window materials were fabricated by direct embedding of Ta 0.3 W 0.7 O 2.85 nanocrystals in bulk borosilicate glass-ceramics during a facile melt-quenching process. Optical and thermal performance of the prepared windows can be adjusted by varying the concentration of H 2 WO 4 and Ta 2 O 5 in the starting materials. The optimized window fabricated from raw materials containing 4.5 mol% H 2 WO 4 and 0.3 mol% Ta 2 O 5 exhibited high visible light transmittance 74.4% and strong NIR-shielding ability ΔT = 68.9%. Its thermal insulation performance is much better than soda lime glass or ITO glass, and its visible light transmission is higher than cesium-tungsten-bronze-based film coated glass. The distribution of Ta 0.3 W 0.7 O 2.85 functional nanocrystals in the glass matrix was confirmed by sample characterization using XRD, Raman, XPS, HRTEM and EDS. The NIR-shielding property has been attributed to local surface plasmon resonance due to oxygen vacancies in the Ta 0.3 W 0.7 O 2.85 nanocrystals. This study sheds a light on fabricating energy-saving windows with a tunable NIR-shielding performance. [ABSTRACT FROM AUTHOR]

Coal dust accumulation poses a serious risk to personnel safety. Currently, Microbially Induced Carbonate Precipitation (MICP) technology is widely employed for controlling coal dust. This study aimed to isolate a urease-producing strain, Bacillus subtilis, from a coal mining area and investigate the optimal environmental conditions affecting urease activity. The optimal conditions were found to be a urea concentration of 0.648 M, NaCl concentration of 11.899 g·L−1, and a pH value of 7.602, under these conditions, the urease activity was strongest. As evidenced by the dust suppression effect test which reduced the mass loss of coal dust samples after using biological dust suppression materials under optimal growth conditions to 0.3%. Microscope scans showed that the optimized microbial dust suppression material produced mineral particles of larger size (approximately 40 µm in diameter), with precipitation primarily in the form of calcite. The x-ray diffraction analysis showed that the optimized dust suppression material produced mineralized products with large crystal size (43.2 nm) and high crystallinity (90.3%). Additionally, molecular dynamics analysis was conducted on the Z-axis relative concentration curves of coal molecules, solution molecules, and phospholipids before and after the addition of bacteria, the analysis showed that bacteria could enhance the wettability of water to coal dust at the molecular level. Overall, the experimental data suggested that this bacteria have significant potential for suppressing coal dust. [Display omitted] • Proved that bacteria screened from coal are more adaptable to the environment. • Response surface optimization was used to illustrate the importance of medium environmental conditions for strain growth. • Verify that bacteria increase the wettability of water to coal dust at the molecular level. • A series of performance experiments show that the strain can effectively inhibit coal dust. [ABSTRACT FROM AUTHOR]

This study examines the differential effects of airport service quality on behavioral intention in the Guangdong-Hong Kong-Macao Greater Bay Area. The relationships among airport service quality, flight offer, perceived airfare, passengers' satisfaction, alternatives' attractiveness, switching cost, and behavioral intention were investigated based on the push-pull-mooring theory. Partial least squares–structural equation was used to analyze the data collected from the overlapping market of multi-airports. The findings reinforce the linkage between service quality and behavioral intentions through the mediation of satisfaction in the airport industry. Also, the results highlight the role of mandatory process, facility, and environment on passengers' satisfaction. The effects of such two dimensions of airport service quality showed significant differences across various airports' types. This integrative approach can also help authorities design and implement more effective engagement strategies, which could be used to reduce the leakage of passengers and foster the sustainable development of the multi-airports. [ABSTRACT FROM AUTHOR]

[Display omitted] • LVB experienced extensive conversion of forest and grass to agricultural land. • SWAT model presents good applicability in seasonal runoff modeling in LVB. • annual runoff generally increased with seasonal differences due to LULC changes. • hydrological drought aggravated over central western and eastern LVB with increased frequency and lengthened duration. Understanding the hydrological impacts of land use and land cover (LULC) changes is significant for sustainable water resources management and planning. The Lake Victoria basin (LVB) has experienced extensive forest and grass degradation and agricultural land expansion under rapid socio-economic development and population growth in recent decades. However, the hydrological impacts of LULC changes for the whole LVB is still poorly documented. This study first investigated the LULC changing effects of LVB, focusing on its impacts on the annual and seasonal runoff and the hydrological drought based on a distributed hydrological modeling of the Soil and Water Assessment Tool (SWAT). SWAT model showed comparatively good applicability in seasonal runoff simulation of LVB, with the percent bias (PBIAS) kept within ± 20 % and the coefficient of determination (R2) over 0.6 at ten hydrological stations available over the calibration and validation phases. Generally, the annual runoff obtained a monthly increase of 1.5 mm under collective LULC changes. Moreover, the LULC effects presented considerable seasonal dependence. A largest runoff increase of approximately 4 mm was detected in short rainy season attributed to the combined surface runoff and groundwater increase. Insignificant runoff increase was observed in long rainy and dry seasons under the complementary effects of surface runoff increase and groundwater decrease. Additionally, the hydrological drought was generally aggravated with increased drought frequency and lengthened duration, particularly for the central western and eastern regions with massive conversion of forest to agricultural land. The findings provide importance implication for rational water resources management and drought disaster response for the LVB. [ABSTRACT FROM AUTHOR]

To understand the problem of differences in the dust migration law of ascensional and descensional ventilation, this study numerically simulates the dust migration law under the condition of ascensional and descensional ventilation, and proposes corresponding automatic spray control schemes. The results show that under the influence of wind flow, the migration distance of dust under ascensional ventilation was longer than that under descensional ventilation at the same time, and the distance difference of dust migration between ascensional and descensional ventilation also increased with the evolution of time. Among them, the distance differences at 10 s, 25 s, 50 s and 75 s were 2 m, 7 m, 9 m and 14 m respectively. The lift of the ascensional wind hindered dust deposition, which caused the dust at 0–15 m on the downwind side of the shearer to seriously affect the breathing belt, with an average dust concentration of 1683.3 mg/m³. The thrust of the descensional wind caused the roof near the moving support to seriously affect the breathing belt, with an average dust concentration of 1435.1 mg/m³. [Display omitted] • Used the mathematical model of DPM-EDM and CFD calculation method. • The movement law of airflow-dust under the conditions of ascensional and descensional ventilation was simulated. • Analyzed the temporal and spatial distribution of dust pollutants through particle maps and cloud maps. • Two targeted automatic spray dust control schemes were proposed. [ABSTRACT FROM AUTHOR]

Gradient refractive index (GRIN) micro-optics present unique opportunities for control of the chromatic properties, new degrees of freedom for optical design as well as the potential for use in new optical system applications. GRIN microgratings were imprinted in GeS 2 -Ga 2 S 3 -MCl (M = Na, K, Cs) chalcohalide glasses by microthermal poling, and the effects of the type and concentration of alkali cations on their performance were investigated. Two effective imprinting formation regions of the GRIN microstructure based on the poling saturation voltage (U s) and glass composition are observed at fixed poling time and temperature. The U s increases from 140 to 750 and 2600 V in accordance with the activation energy (E a) of alkali ions (Na+ to K+ and Cs+) increasing from 45.15 to 58.62 and 92.58 kJ/mol for studied samples. The saturated numbers of diffraction order (N s) of the gratings in these samples are 7, 9 and 6, respectively, the highest number being provided by the K+-containing sample. This is in accordance with imprinting-induced phase differences (0.14λ, 0.19λ and 0.09λ) measured in the fabricated samples containing Na+, K+ and Cs+ ions. Furthermore, the U s of samples decreases from 1500 to 300 V with four concentrations of K+ from 10 to 30%, associated with their E a of K+ decreasing from 69.62 to 53.46 kJ/mol, while N s increases from 8 to 14, which is attributed to the increase of the phase difference in the GRIN structures. The controllable GRIN microstructures are realized by adjusting the type and concentration of alkali cations in chalcohalide glasses, which is expected to drive the design of broadband GRIN microgratings. [ABSTRACT FROM AUTHOR]

A series of MoVTeNbO x -mixed metal oxides were synthesized by high-pressure hydrothermal method. The effects of temperature and time during the preparation process on the structure and catalytic performance of MoVTeNbO x were investigated. It was demonstrated that high content of M1 phase (94.5%) MoVTeNbO x with typical needle-shape morphology and high surface abundance of V5+ (68.9%) could be fabricated by high-pressure hydrothermal method in a short time (30–60 min) without hydrogen peroxide post-treatment. The catalytic results of propane selective oxidation showed that the MoVTeNbO x sample synthesized at 200 °C for 30 min possessed the highest surface V5+ abundance and largest proportion of terminating (001) plane, displaying the highest selectivity (74.1%) for acrylic acid. Moreover, the prepared MoVTeNbO x showed excellent stability in high temperature continuous reaction. [Display omitted] • MoVTeNbO x was fabricated facilely by high-pressure hydrothermal technology. • This developed method could shorten preparation time dramatically. • High content M1 phase MoVTeNbO x could be obtained without H 2 O 2 post-treatment. • Synthesized MoVTeNbO x had high surface V5+ abundance of 68.9%. • As prepared MoVTeNbO x exhibited excellent catalytic performance. [ABSTRACT FROM AUTHOR]