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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]

[Display omitted] • The mathematical model of CFD-DEM calculation method was used. • The inhale and dust exposure characteristics of driver were analyzed. • Different area airflow patterns of bronchus were analyzed. • The deposition rate of different particle diameters were analyzed. To study the dust exposure law of the operator in the anchor digging working face, the CFD-DEM method was used to numerically simulate the dust deposition pattern in the bronchus of the anchor digging driver. The results show that the highest dust concentration in the vortex region of the anchor digging working face can reach 2364.76 mg/m3, seriously endangering the health of anchor digging driver. The average dust concentration in the respiratory hemisphere of the driver is 510.57 mg/m3, and the range of inhaled dust diameter is 0–60 μm in the breathing state of moderate labour. Over time, the deposition mass in the bronchial showed a pattern of rapid and then slow increase, which was consistent with the trend of the Boltzmann model. Increasing dust particle diameter was positively correlated with bronchial deposition rate and negatively correlated with alveolar deposition rate. Among them, 0–10 μm particles were deposited throughout the bronchus and a large number of particles were deep into the alveoli, with the alveolar deposition rate as high as 56.3 %, while the alveolar deposition rate for particles of 10–20 μm decreased to 20.4 %, and for particles larger than 30 μm, the effect on the alveoli was smaller. [ABSTRACT FROM AUTHOR]

• A multicomponent acid solution consisting of SDBS,BS-12, HF and C6H8O7 was used to acidifie coal samples. • Acidification treatment can promote the formation of oxygen-containing functional groups C O and C O. • Provide an effective method for realizing high-efficiency clean mining of coal. • The micro mechanism of wettability was explained using molecular dynamics software. In order to explore the influence mechanism of different surfactants on the wettability of coal samples acidified with multi-component acid solutions, the effects of multi-component acid solutions and surfactant composite acid solutions on the functional groups and microcrystalline structures of coal samples were studied. In this paper, a multicomponent acid solution consisting of sodium dodecyl benzene sulfonate (SDBS), dodecyl dimethyl betaine (BS-12), hydrofluoric acid (HF), and citric acid (C 6 H 8 O 7) was used to acidification and contact angle experiments on coal samples. Fourier transform infrared spectroscopy (FTIR) results show that acidification can promote the formation of C O and C O, and the synergistic effect of surfactant BS-12 on multi-component acid solution is more prominent. X-ray diffraction (XRD) results show that the variation trend of aromatic lamellar diameter L a of coal samples is consistent with the aromatic layer spacing d 002. Surfactants can slow down the damage of multi-component acid solution to the microcrystalline structure of coal samples. The change of contact angle shows that the instantaneous synergistic wetting effect of BS-12 is better than that of SDBS. At the same time, molecular dynamics simulation technology was used to verify the effect of surfactants on the wettability of multi-component acid solutions. Therefore, this study provides a feasible method and theoretical guidance for improving the efficiency of coal production and utilization through chemical means. [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]

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]