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In this paper, an energy-conserving finite element method is developed and intensively analyzed for a class of nonlinear fourth-order wave equations in a general sense for the first time, where the two-level, Crank-Nicolson type of temporal discretization scheme is designed to cooperate with the Lagrange finite element approximation in space in order to achieve the conservation of discrete energy at each time step. The energy conservation is crucial in engineering field to preserve the total energy as constant for dynamic vibration problems of beams and thin plates that can be modeled by the presented wave equations. In addition, the optimal spatial convergence properties in both L 2 - and H 1 -norm and the second-order temporal approximation rate are obtained for finite element solutions of u (deflection), Δ u (bending moment) and/or u t (deflection speed) at the same time. Numerical experiments are carried out to validate all attained theoretical results. [ABSTRACT FROM AUTHOR]

The Yellow River Basin (YRB) is an important region for both ecological and economic growth in China, and a healthy and stable ecological environment is fundamental to achieving high-quality development. Investigating the spatio-temporal changs of vegetation carbon sinks in the YRB is necessary to improve understanding of the regional carbon cycle. This study analyzed the YRB using the Google Earth Engine (GEE) platform. The basin was divided into sections based on ecological function regionalization schemes. We applied Theil-Sen median trend analysis and Spearman correlation analysis, along with the lasso regression model, to examine the NPP's temporal and spatial patterns and its driving factors in these regions. The objective was to examine the NPP' s temporal and spatial patterns and its driving factors in these regions, identifying commonalities within regions and differences between regions, while analyzing in a targeted manner the lack of vegetation carbon sequestration in ecological areas. This study highlighted the importance of ecological engineering in ecological civilization and carbon neutrality, providing scientific theoretical support and a decision-making basis for the realization of carbon neutrality. The research results indicate significant upward trends (p <0.001) in both the average annual NPP (AANPP) growth rate (57.98%) and the total annual NPP (TANPP) growth rate (41.9%) in the YRB from 2001 to 2020. The multi-year average NPP (MYANPP) exhibit a spatial distribution with high values in the south and low values in the north. The spatial distribution of NPP exhibits notable spatial aggregation and heterogeneity, where regions demonstrating improvement trends constitute 93.01% of the area, and approximately 79.73% of this region displays low volatility. A high-value area is concentrated in the Agroecological Zone of the Fenwei Basin (I-11), the Loess Plateau Agriculture and Grassland Ecological Zone (I-12), and the Qinba Mountains Deciduous and Evergreen Broad-leaved Forest Ecological Zone (I-15), with significant spatial differences. Temperature, precipitation, and forests are the foremost elements affecting NPP in the YRB, exhibiting positive correlations. Conversely, farmland displays negative correlations. Overall, NPP shows an increasing trend in all ecological function areas, and the NPP of the YRB shows a trend of improvement as a whole, as the ecological environment of the YRB has improved significantly. • Significant differences in NPP were observed among ecological functional zones. • The vegetation condition of the Yellow River Basin has been improved continuously. • Population, temperature, precipitation, forest were the main driving factor of NPP. • The average annual NPP and the total annual NPP increased significantly. [ABSTRACT FROM AUTHOR]

[Display omitted] • We propose a novel decoupled Image and Frequency-domain Spatial-Spectral Framework. • The proposed module extracts multi-scale features from dual domains. • A module can transfer the advantages of convolution to the transformer. • The proposed neural network can achieve better performance. Hyperspectral image classification (HSIC) is a rapidly developing field that utilizes deep learning methods. However, the reliance on convolutional neural networks (CNNs) for spectral–spatial feature extraction presents certain limitations. Specifically, the use of the fixed-position convolutional kernels in CNNs hinders their ability to capture fully the spectral information around the spatial central pixel, thereby overlooking critical differences between features. To address this issue, a decoupled image- and frequency-domain spectral–spatial framework for HSIC was developed in this study. This method incorporates image- and frequency-domain-based multiscale learnable convolutional attention to refine the differentiating features of the different feature distributions. Additionally, a novel frequency-domain information enhancement module was designed to extract the structural shape and texture details under the semantic constraints of the frequency phase, complementing the image domain to improve the extracted feature maps. Furthermore, a simple and efficient hierarchical feature representation module was introduced to extract both local and global information effectively from the fused features. The experimental results obtained using three open datasets and a practical hyperspectral image of the Gaofen-5 satellite demonstrate that the proposed method outperforms other state-of-the-art HSIC methods. [ABSTRACT FROM AUTHOR]

As the invasion of alien species intensifies, the native salt marsh vegetation, especially the ecosystem of Suaeda salsa (S. salsa), in Chinese coastal wetlands has been severely disrupted, significantly impeding its functionality within coastal wetland ecosystems. Chlorophyll content (C ab) is an important parameter for monitoring the growth and health status of vegetation. However, the remote sensing mechanism of C ab for different phenotypes of green and red vegetation influenced by betacyanin under different water and salt conditions is not clear. Therefore, to further clarify the remote sensing mechanism of S. salsa and improve the generality of C ab prediction for different phenotypes under different water and salt conditions, we designed a growth experiment under different groundwater levels and salt concentrations. This experiment was used to simulate the growth of S. salsa in different habitats in nature and investigate the relationship between their physicochemical parameters, spectra, and environmental stress. We propose using the specific absorption coefficient of betacyanin (Beta) to adjust PROSAIL-D to better fit the spectral characteristics of S. salsa. The relationship between Beta and C ab was utilized to further optimize the simulation accuracy of the PROSAIL-D model in different environments. Feature extraction algorithms, including differential enhancement of two-dimensional correlation spectroscopy (FD-2DCOS) and three-band models, were introduced to construct multiple spectral features for establishing a C ab prediction model for S. salsa. The research results showed that: (1) S. salsa had the best response of C ab and spectra to salinity under a higher groundwater level and showed a gradual reddening trend. (2) The spectral curves simulated by the adjusted PROSAIL-D model were more consistent with the spectral characteristics of S. salsa under different water-salt environments, and the simulation effect could be further optimized by using the relationship between Beta and C ab. (3) The FD-2DCOS analysis method we proposed could highlight the useful spectral information related to C ab better than the original 2DCOS algorithm. The final eight spectral features of (1/R 701 –1/R 540)R 540 , Mean(D 590 – 600), Mean(D 660 – 670), Mean(D 677 – 685), FDVI_NRG, FDVI_NIR, Skewness (D 677 – 750) and Position(D 677 – 750) had the best response to C ab of S. salsa , and had the least influence on LAI and soil background. (4) The particle swarm optimization random forest regression (PSO-RFR) model based on eight spectral features and adding 70% measured spectral data performed the best in predicting the actual C ab of S. salsa , with an RMSE of 2.326 μg·cm−2. Although further optimization and calibration of the adjusted PROSAIL-D model and C ab prediction model of S. salsa are needed in the future, this study extended its application to S. salsa , a special local salt marsh vegetation, and promoted the development of C ab monitoring of salt marsh vegetation in coastal wetlands. • C ab of Suaeda salsa responds best to salinity stress under high groundwater table. • The adjusted PROSAIL-D model is more suitable for the simulation of Suaeda salsa. • Pay attention to the ratio of betacyanin and C ab when using PROSAIL-D simulation. • The proposed FD-2DCOS can better highlight the information of C ab in the spectrum. • The constructed PSO-RFR model can better predict the C ab of Suaeda salsa. [ABSTRACT FROM AUTHOR]

In this paper, an energy-stable finite element method with the Crank–Nicolson type of temporal discretization scheme is developed and analyzed for a class of nonlinear fourth-order parabolic equations (including the Swift–Hohenberg (SH) equation and the extended Fisher–Kolmogorov (EFK) equation). In addition to the energy stability properties, the optimal spatial convergence properties in both L ∞ (L 2) - and L ∞ (H 1) -norm and the second-order temporal approximation rate are also obtained for numerical solutions approximating to the real solution and its Laplacian for the developed energy-stable finite element method in both semi- and fully discrete schemes. Numerical experiments are carried out to validate all attained theoretical results. • Energy-stable FEM is developed for a class of nonlinear fourth-order parabolic equations. • The model is more general than Swift–Hohenberg/extended Fisher–Kolmogorov equation. • Semi-discrete and Crank–Nicolson/fully discrete schemes are developed and analyzed. • The discrete energy is proved to be stable all the time for both schemes. • Optimal convergences in both L ∞ (H 1) - and L ∞ (L 2) -norm are obtained for both schemes. • Numerical results of 7 numerical experiments agree with all theoretical results. [ABSTRACT FROM AUTHOR]

As solid waste posing a great threat to the environmental system, the disposal of arsenic-alkali slag has become the top priority in the development of the antimony industry. In this paper, a novel technological scheme combining the advantages of chemical precipitation and fractional crystallization is proposed for the safe disposal and resource utilization of arsenic-alkali slag. The scheme is mainly composed of three parts, namely, leaching of arsenic-alkali slag, selective removal of arsenic in the arsenic-alkali solution, and evaporation crystallization of alkali solution. In the leaching part, the optimum leaching parameters are determined by orthogonal tests. In the arsenic and alkali separation part, based on thermodynamic analysis, the selective removal of arsenic from arsenic-alkali solution is realized by forming ammonium magnesium arsenate (MgNH 4 AsO 4) precipitation. In the evaporation crystallization part, the crystalline product with sodium carbonate (Na 2 CO 3) content of 89.87% is obtained by the evaporation crystallization experiment. The whole process does not produce secondary pollution and realizes the reuse of wastewater. The final products are leaching residue, arsenic slag, and sodium carbonate with an arsenic content of 0.83%, 24.93%, and 0.18%, respectively. [ABSTRACT FROM AUTHOR]

• Aging of FeS nanoparticles seriously affects arsenic removal but slight on copper. • Controllable FeS are the targeted sulfurizing agents in different acidity wastewater. • BP-GA model are developed to precisely predict copper and arsenic removal with R of 0.9923. • Temperature and FeS aging time are necessary to gain high separation accuracy. • The model provides an essential reference in selecting sulfurizing reagent types. Iron sulfide (FeS) is a promising material for separating copper and arsenic from strongly acidic wastewater due to its S2− slow-release effect. However, uncertainties arise because of the constant changes in wastewater composition, affecting the selection of operating parameters and FeS types. In this study, the aging method was first used to prepare various controllable FeS nanoparticles to weaken the arsenic removal ability without affecting the copper removal. Orthogonal experiments were conducted, and the results identified the Cu/As ratio, H 2 SO 4 concentration, and FeS dosage as the three main factors influencing the separation efficiency. The backpropagation artificial neural network (BP-ANN) model was established to determine the relationship between the influencing factors and the separation efficiency. The correlation coefficient (R) of overall model was 0.9923 after optimizing using genetic algorithm (GA). The BP-GA model was also solved using GA under specific constraints, predicting the best solution for the separation process in real-time. The predicted results show that the high temperature and long aging time of FeS were necessary to gain high separation efficiency, and the maximum separation factor can reached 1,400. This study provides a suitable sulfurizing material and a set of methods and models with robust flexibility that can successfully predict the separation efficiency of copper and arsenic from highly acidic environments. [Display omitted] [ABSTRACT FROM AUTHOR]

• The solar potential in different residential blocks is simulated. • The influences of block morphological parameters on solar potential are varified. • Four parameters that impact on the block solar potential more than 70% are verified. • The facade PV capacity in high-rise and hybrid residential blocks is more than 66%. • The average PV installation rate of roof, south and west facade is 96%, 32% and 39%. Block-scale application of photovoltaic technology in city is becoming a viable solution for renewable energy utilization. Rapid urbanization process has made urban buildings have huge development potential for solar energy in China, especially in residential areas that occupy large parts of the city. However, the residential blocks in China show differences in the morphological layout and parameters, which means they have diverse potential for solar energy development. This paper studies the effect of quantified morphological parameters on solar potential for residential blocks in Wuhan, China. The distribution characteristics of solar potential in different block environments are discussed. Various strategies are evaluated in terms of the installation position and height of PV modules. The results showed that floor area ratio, building density, average building height and building interval have significant impact on solar potential for residential block, and their correlation can reach 75%, 71%, 78% and 72% respectively. The average PV installation ratio of roof, south facade and west facade can reach 96%, 32% and 39% respectively. The results of this paper not only provide a reference to the block-scale application of PV technology in urban environment, but also stimulate the implementation of photovoltaic policies on various residential blocks in China. [ABSTRACT FROM AUTHOR]

• A porous hollow molecularly imprinted microsphere was synthesized by O/W/O composite emulsion polymerization. • The obtained microspheres were superparamagnetic and thermo-responsive. • The HMMIM adsorption capacity toward BSA was 89.9 mg/g and a good separation efficacy toward BSA was observed in bovine whole blood. Molecular imprinting technology is highly successful for low-molecular-weight molecules, but is still confronted with many challenges for proteins. This study introduces a strategy to synthesize hollow magnetic molecularly imprinted microspheres (HMMIMs) under Fe 3 O 4 magnetic nanoparticles matrix, by oil-in-water-in-oil composite emulsion polymerization with alkylphenol ethoxylates and Span-80 as emulsifiers. The synthesis conditions after optimization were 1.0 mmol thermo-sensitive functional monomer N-isopropylacrylamide, 1.0 mmol cross-linker N, N-methylene bisacrylamide, 2.0 wt% vinyl-modified silk fibroin, and 50 mg Fe 3 O 4 @COOH nanoparticles. The morphology structure and the forming process of the acquired HMMIMs were well characterized by POM, SEM, TEM and FT-IR. The HMMIMs were synthesized successfully with a porous structure and large specific surface area. The particle size of the obtained HMMIMs was at 10–20 µm. The obtained microspheres were superparamagnetic and thermo-responsive. The HMMIM adsorption capacity at 25 °C toward bovine serum albumin (BSA) was 89.9 mg/g and the BSA separation factor in BSA/BHb mixtures was 2.12. A good separation efficacy toward BSA was also observed in bovine whole blood. The prepared HMMIM possessed heterogeneous active sites, the BSA adsorption process on HMMIM was chemisorption controlled. [ABSTRACT FROM AUTHOR]

• A new type of 2D-on-3D MOF heterostructure (Cu-MOF@In-MOF) was constructed via anisotropic growth. • This "dimensionality-hybrid" nanostructure simultaneously handle the composition and dimensionality of the heterostructure. • The well-defined Cu-MOF@In-MOF exhibited superb photocatalytic activity and stability for Cr (VI) reduction. • Z-scheme heterojunction of Cu-MOF@In-MOF promoted the separation of hole-electron pairs and boosted electron transfer rate. A novel two-dimensional (2D)–on-3D metal–organic framework (MOF) "dimensionality-hybrid" heterostructure was established by the anisotropic growth method and exploited as the robust photocatalyst to efficiently remove Cr(VI) ions in the polluted water system under visible irradiation. The 2D Cu-MOF nanosheet was in situ grown around the 3D In-MOF nanorods, thus forming the MOF-on-MOF Z-scheme heterojunction (denoted as Cu-MOF@In-MOF). Benefiting to the large specific surface area (718.1 m2 g−1) and promoted the photoabsorption property within visible-light region, the attained Cu-MOF@In-MOF heterojunction exhibited the remarkably enhanced separation ability of photocarriers and electron transfer. Comparing with the sole MOFs (Cu-MOF and In-MOF) the 2D/3D Cu-MOF@In-MOF Z-scheme heterojunction demonstrated high photocatalytic reduction efficiency toward Cr(VI) (98%) within 1 h under visible-light irradiation (50 mg/L, pH 5.4), markedly higher than those of the sole MOFs and most of reported photocatalysts (50 mg/L, pH 5.4). Moreover, the photocatalysis mechanism of the Cr(VI) reduction by Cu-MOF@In-MOF was provided based on the analysis of energy band structure trapping experiments and electron spin resonance results. The presented MOF-on-MOF photocatalyst shows the synergistic effect of various components for efficiently photocatalytic removal of harmful pollutants in water, thus giving the great potential applications in environmental governance field. [ABSTRACT FROM AUTHOR]

Solar energy has been rapidly utilized in urban environments owing to its significant potential to fulfill the energy demand. The precise forecasting of solar energy, including solar radiation and photovoltaic power forecasting, is crucial for effective energy utilization in cities. Currently, artificial intelligence algorithms, including machine learning (ML) and deep learning (DL) algorithms, have been widely utilized in the research of solar energy forecasting and have shown excellent performance. The different research scales lead to variations in the influencing factors and forecasting approaches used in solar energy prediction. Therefore, this paper provides a comprehensive review of solar radiation and photovoltaic power forecasting research using ML and DL algorithms from a multi-scale perspective, including the meso-scale, micro-scale, and building-scale forecasting in urban environments. The aim is to summarize the state-of-the-art progress and evaluate the solar forecasting effectiveness in diverse research scenarios. The characteristic analyses of ML- and DL-based solar forecasting approaches, prediction models, forecasting horizons, inputs and outputs were conducted for different research scales. This paper discusses the existing issues and future research directions for multiscale solar energy forecasting in cities. The analyses can help researchers and engineers in identifying suitable prediction algorithms and approaches. Consequently, this exploration can contribute to the efficient utilization of solar radiation and photovoltaic power generation in multi-scale urban environments. [Display omitted] • Machine learning and deep learning-based solar radiation and photovoltaic power forecasting research in urban environment are classified from a multi-scale perspective. • The characteristics and key points of solar radiation and photovoltaic power forecasting at the meso-scale, micro-scale, and building-scale in cities are analyzed. • Solar radiation and photovoltaic power forecasting approaches, prediction models, input and output values, and forecasting horizons are discussed. • Future research directions of solar radiation and photovoltaic power forecasting in urban environment are presented. [ABSTRACT FROM AUTHOR]

• A self-healing hydrogel with sequential delivery property was developed for wound healing. • The self-healing ability of hydrogel was due to dynamic imine and acylhydrazone bonds. • The encapsulated CHA was released rapidly, and the bFGF was sustainably released. • The hydrogel could inhibit infection promptly and accelerate wound healing continuously. • This hydrogel is a highly promising dressing material for wound healing. The conventional injectable hydrogels as wound dressing materials frequently encounter bacterial infection and lack self-healing ability. Besides, the hydrogels injected into the irregular wound sites are easily damaged by external forces, which further hinder wound healing. To make up for these deficiencies, we developed a novel hydrogel with the unique properties including dynamic covalent based self-healing, antibacterial and sequential drug release. This injectable and self-healing hydrogel was constructed via the dynamic reaction of aminated gelatin (NGel), adipic acid dihydrazide (ADH) and oxidized dextran (ODex). After injection or damage, the broken hydrogel pieces performed excellent self-healing capability to generate an integral hydrogel owing to dynamic imine and acylhydrazone bonds. Meanwhile, bFGF@PLGA microspheres and chlorhexidine acetate (CHA) were embedded into the hydrogels. This bFGF@PLGA/CHA/hydrogel presented a good biodegradability, and it could retain the morphological stability after swelling. Moreover, bFGF@PLGA/CHA/hydrogels achieved the sequential release of CHA and bFGF during the drug release assay. When topically applied onto the wound skin of rats, the hydrogels can effectively prevent infection at the early stages due to the rapid release of CHA, then further accelerate cell proliferation and wound healing through the sustained release of bFGF. These results indicate that the proposed self-healing hydrogel with sequential release properties is a highly promising dressing material for wound healing. [ABSTRACT FROM AUTHOR]

Soil moisture (SM) controls the exchange of water and heat energy between the land surface and the atmosphere through evaporation and plant transpiration, and timely and accurate estimates of soil moisture are crucial for many studies. Although remote sensing provides many algorithms to obtain bare-soil moisture on large scales (e.g., Soil Moisture and Ocean Salinity (SMOS) and Soil Moisture Active and Passive (SMAP) products), these algorithms are restricted to studies with low ground resolution. In the present study, we propose and evaluate three normalized shortwave-infrared (SWIR) difference bare soil moisture indices [NSDSI1 = (B SWIR1 -B SWIR2)/B SWIR1 , NSDSI2 = (B SWIR1 − B SWIR2)/B SWIR2 , NSDSI3 = (B SWIR1 − B SWIR2)/(B SWIR1 + B SWIR2), where, SWIR1 = 1550–1750 nm, SWIR2 = 2100–2300 nm] to estimate the bare-soil moisture content and, based on the water absorption difference between shortwave-infrared bands, use them to map bare-soil moisture with high ground resolution Sentinel-2 MSI images. The three proposed bare-soil moisture indices are obtained by using the different water absorption in shortwave-infrared bands. Four traditional hyperspectral-based bare-soil moisture indices (such as the water index SOIL, or WISOIL, the normalized soil moisture index, or NSMI, etc.) were used as benchmark. The results show that (i) the differences in water absorption between shortwave-infrared bands is linear in soil moisture content; (ii) the combined use of two shortwave-infrared bands from four soils provides more accurate bare-soil moisture estimates than do single shortwave-infrared (SWIR) bands, and (iii) our proposed bare-soil moisture indices can be applied on broadband remote-sensing images (such as Landsat, Sentinel-2 MSI). The bare-soil moisture estimates obtained by using the proposed bare-soil moisture indices may help to obtain bare-soil moisture maps with high ground resolution. [ABSTRACT FROM AUTHOR]

Porphyrins and their derivatives have attracted great attention due to their unique properties and diverse functionalities which contribute to their wide applications such as catalysis, solar cells, biomedicine and environmental science. It is interesting to note that porphyrin-containing polymers have recently aroused great interest due to the simultaneous presence of both porphyrinic and polymeric characteristics, especially for porphyrin-containing polymers linked by covalent bonds giving well-defined macromolecular architectures, unique self-assembly morphologies and promising applications. Herein, we summarize the different synthetic strategies and self-assembly protocols adopted in recent years to explore various applications of porphyrin-based functional polymers followed by a brief discussion on the challenges and outlooks for future research. With the discovery of advanced polymerization techniques such as living/controlled radical polymerization and click chemistry, the synthesis of porphyrin-containing functional polymers with well-defined architectures has been greatly developed. Porphyrin molecules tend to form the aggregates based on the self-assembly driving force of π-π stacking. Much attention has been paid to the self-assembly behavior of porphyrin-containing functional polymers, and various nanostructures have been constructed including nano-sized or micron-sized spheres, vesicles, belts, wires, rings, tubes, and rods. Porphyrin-containing functional polymers, with special photochemical and photophysical properties, present significant applications in photovoltaics, catalysis, biological and biomedicine fields. Particularly, the porphyrin-based photosensitizers for photodynamic therapy, porphyrin-conjugated polymers for solar cell devices, porphyrin-based polymeric nanocomposites in catalysis and chemical adsorption and separation have been widely studied. We hope this review on porphyrin-based functional polymers will be beneficial to researchers and newcomers in related fields. [ABSTRACT FROM AUTHOR]

• The crystal structures of Mn(II)/Co(II) complexes of enrofloxacin (EFX) are reported. • Both complexes could maintain the coordinated status in aqueous solution. • Both complexes show comparable antibacterial activity to EFX. • They exhibit slight higher antibacterial activity than EFX towards E. coli & S. typhi. Enrofloxacin (EFX) is a third-generation fluoroquinolone drug especially used for animals world wide, which shows broad-spectrum and significant antibacterial activities. In this study, EFX was selected as the ligand to synthesize two transition metal complexes, EFX-Mn and EFX-Co, in which the bio-active metal ions, manganese(II) and cobalt(II), was set to be the active metal center. Their crystal structures were reported and characterized by X-ray single crystal diffraction analysis. Both the crystal structures of EFX-Mn and EFX-Co belong to the same monoclinic crystal system with P2 1 /c space group. Viewed from the crystal structure of EFX-Mn or EFX-Co, the central Mn(II)/Co(II) adapted a six-coordinated octahedral configuration, respectively by two EFX ligands and two H 2 O co-ligands. The characteristic UV-Vis absorption peaks of both complexes were examined in tris-saline buffer solution in a time-dependent mode in 24 h, which suggested that the coordination status of EFX-Mn and EFX-Co in the solid state still maintained under near-physiological condition. In vitro antibacterial activity tests demonstrated that EFX-Mn and EFX-Co showed similar and significant growth inhibitory effects towards five typical pathogenic bacteria, compared with EFX itself. While for two gram-negative bacterial strains, E. coli and S. typhi , EFX-Mn and EFX-Co showed higher bactericidal effects than EFX, the bactericidal concentration of which was only a half as low as that of EFX. The manganese(II) and cobalt(II) complexes of enrofloxacin were reported and their crystal structures were characterized. It indicated that the coordination of enrofloxacin with Mn(II) and Co(II) maintained the antibacterial activity in vitro , and showed superiority towards E. coli & S. typhi , making both complexes promising metal-based veterinary drugs. [Display omitted] [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) play a crucial role in regulating various physiological processes, including cell differentiation, proliferation, and apoptosis. However, their specific functions in response to heat stress are not fully understood. This study aimed to investigate the regulatory effects of miR-199a-3p on the proliferation of heat stress-treated spermatogonial stem cells (SSCs). SSCs were isolated from mouse testes and cultured in vitro to identify marker molecules. Lentiviruses carrying miR-199a-3p-over, miR-199a-3p-inhibit, and ID4 -over constructs were generated for stable transfection. Luciferase assay was employed to confirm the targeting relationship between miR-199a-3p and ID4. An in vitro SSCs heat stress model was established, and the miR-199a-3p-inhibit and ID4 -over groups were included. Cellular proliferation was assessed using CCK-8, EdU, and cell cycle analysis methods after heat stress. Expression levels of miR-199a-3p and ID4 were evaluated by western blotting and qRT-PCR. The results demonstrated that miR-199a-3p-over inhibited SSCs proliferation, while ID4 -over promoted an increase in SSCs number. Luciferase assay confirmed the regulatory effect of miR-199a-3p on ID4 expression. Moreover, after heat stress treatment, miR-199a-3p-inhibit and ID4 -over enhanced SSCs proliferation compared to the control group. These findings suggest that miR-199a-3p modulates SSCs proliferation by targeting ID4 , especially under heat stress conditions. • Compared with the control group, heat stress inhibited the self-renewal of spermatogonial stem cells. • When subjected to heat stress, miR-199a-3p affects the proliferation of spermatogonial stem cells. • Spermatogonial stem cells are essential for male fertility. [ABSTRACT FROM AUTHOR]

• Droplet impact dynamics of R113, water, ethanol and acetone were compared. • Initial droplet diameter minimally affects the morphology and spreading factor. • Low droplet viscosity and surface tension produced large spreading capability. • Large droplet impact velocity and viscosity promoted splashing. • General maximum spreading factor correlation was proposed based on experiments. Droplet impact on a solid surface is a common phenomenon observed in industries. Fundamental investigations of droplet impact are helpful in enhancing spray cooling capability and advance spray–wall impingement model. In this work, the effects of droplet diameter, impact velocity, viscosity, and surface tension on droplet impact dynamics were systematically investigated with four liquids, that is, R113, deionized water, ethanol, and acetone. Results illustrated that the initial droplet diameter minimally affects morphology and dynamic spreading factor, whereas large viscosity and surface tension hindered droplet spreading, thereby yielding a small maximum spreading factor and velocity. Low droplet viscosity and surface tension contribute to enhancing spray cooling capability by producing improved atomization, large spreading velocity, and extended contact area. The existing maximum spreading factor correlations failed to predict experimental results accurately. On the basis of experimental data in this work, general maximum spreading factor and splashing threshold correlations are proposed. All the proposed correlations agreed well with the present experimental results and literature data. The maximum spreading factor correlation indicated that large droplet impact velocity, small viscosity, and surface tension will produce a large maximum spreading capability. [ABSTRACT FROM AUTHOR]

• The flotation separation of fluorite from calcite and celestite was realized. • The optimum conditions for flotation separation were found. • The selective depression mechanism of the mixed depressant Al 2 (SO 4) 3 -AWG was discussed. To cope with the increase of sulfate gangue minerals in fluorite ores, flotation separation of fluorite from calcite and celestite using Al 2 (SO 4) 3 and acidified water glass (AWG) as mixture depressants was studied in this paper. The flotation separation performance and underlying mechanism were studied by flotation experiments, zeta potential measurements, microcalorimetric analysis, adsorption measurements, and X-ray photoelectron spectroscopy (XPS). The flotation results show that under optimum conditions, the inhibition effect of AWG on celestite is more remarkable with the assistance of Al 2 (SO 4) 3 , but has no obvious effect on the flotation of fluorite. Zeta potential measurements show that both positively charged Al species and negatively charged Si species are adsorbed on the surface of the minerals. Microcalorimetric analysis confirms that the interaction between Al 2 (SO 4) 3 and celestite is more intense than that of calcite and fluorite, while AWG is more likely to be adsorbed on the calcite surface. Adsorption measurements reVeal that there is competitive adsorption between the depressant and collector and that the adsorption of the depressant AWG prevents the collector NaOL from adsorbing on the surface of the minerals. The XPS results show that Al species and Si species are chemically adsorbed on the surface of the minerals and change the chemical surroundings of the elements on the mineral surface. Moreover, compared with fluorite, Al species can more clearly enhance the adsorption of Si species on the celestite surface. [ABSTRACT FROM AUTHOR]

The dissolved components of calcium-bearing gangue minerals will adsorb onto the celestite surface, which increases the difficulty of the flotation separation of celestite from fluorite and calcite. Single mineral and artificial mineral flotation experiments show that EDTA exhibits an excellent selective inhibition effect towards celestite and calcium-bearing minerals. Surface dissolution experiments reveal that EDTA can strongly inhibit the dissolution of calcium ions on the fluorite surface, thus reducing the influence of dissolved calcium ions on celestite flotation. Zeta potential experiments and adsorption experiments demonstrate that the amount of depressant EDTA adsorbed on the fluorite surface is greater than that on the celestite surface, which is contrary to the adsorption amount of collector sodium dodecyl sulfate (SDS) on the fluorite and celestite surfaces. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses further reveal that, through chelating with calcium ions, EDTA can change the chemical surroundings of elements on the fluorite surface, while the chelation is not evident on the celestite surface. Based on the experimental and analytical results above, a possible model for the flotation separation process is created. Unlabelled Image • EDTA can selective inhibit the flotation of celestite and calcium bearing minerals. • EDTA can strongly inhibit the dissolution of calcium ions on the fluorite surface. • The adsorption of EDTA on the fluorite surface is greater than that of celestite. • EDTA can be adsorbed by chelating with calcium ions on the fluorite surface. [ABSTRACT FROM AUTHOR]

Abstract A newly designed glass-ceramic system consisting of 15Bi 2 O 3 -15Nb 2 O 5 -40SiO 2 -30Al 2 O 3 was successfully prepared, which was followed by its controlled crystallization at different heating temperatures. The effects of crystallization temperature on the microstructure, phase evolution and the energy storage behaviors of the novel material were systematically investigated. A maximum theoretical energy storage density of up to 15.3 J/cm3 was found in the samples heated at 800 °C. The polarization-electric (PE) hysteresis loops of this material exhibited very good linear character and high energy efficiency. In addition, an approximate value of 25 ns for discharged period T has been obtained, which demonstrated that most of the energy stored in dielectric was released over a very short time. The maximum powder density exceeds a high value of 90 MW/cc in a 390 kV/cm electric field. Therefore, the new developed Bi 2 O 3 -Nb 2 O 5 -SiO 2 -Al 2 O 3 glass-ceramic can be used as an alternative, promising high-performance electrostatic capacitor material. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Construction of redox-responsive porphyrin-based amphiphilic copolymer nanoparticles. • High content disulfide units and porphyrin units contribute the alternating structure. • Appropriate and stable size enhances the cellular uptake efficiency of nanoparticles. • Redox-triggered rapid porphyrin release and enhancing 1O 2 generation in cancer cells. Abstract Stimulus-sensitive nanoparticles (NPs) have been established to widely adapt to remarkable abnormalities under the tumor microenvironment, which can observably enhance the therapeutic efficiency, improve the specific targeting ability and reduce the side effects. Photodynamic therapy (PDT) as a promising non-invasive and selective treatment for cancers through photodynamic reaction can profit from stimulus-sensitive NPs. Herein, a harmonious amphiphilic polymer (PEG- b -PTPPDS- b -PEG) with an extremely sensitive redox response is constructed via click chemistry between N 3 -TPPC6-N 3 , PEG-N 3 and alkynyl-containing disulfide ester for PDT. This polymer can be self-assembled into micelles with excellent stability, ultra-fast sensitivity of redox-triggered porphyrin release, and significant photodynamic anticancer performance. The redox-triggered dissociation of micelles and the release of porphyrin are much faster than common porphyrin-containing polymer. The bio-distribution and phototoxicity of micelles against A549 cells are measured and evaluated in vitro by flow cytometry, confocal scanning laser microscopy (CLSM) and MTT assay, respectively. The results reveal that PEG- b -PTPPDS- b -PEG micelles can effectively enhance the cellular uptake and cellular internalization of porphyrin and have an extremely low dark toxicity with efficient PDT towards A549 cells. This intracellular responsive nanoparticle provides a potential strategy for anticancer therapeutic application. [ABSTRACT FROM AUTHOR]

Abstract Compared with ferroelectric ceramics, antiferroelectric ceramics, ferroelectric thin film and polymer-based composites, ferroelectric glass-ceramics have the advantages of high energy storage density, fast discharge speed and high power density. The effects of phase structures on dielectric properties, electric breakdown strength, energy-storage and charge-discharge performances have been systematically investigated in Na 2 O-BaO-PbO-Nb 2 O 5 -SiO 2 -Al 2 O 3 glass-ceramics. The content of SiO 2 and Nb 2 O 5 affected the dielectric energy storage performances of the glass-ceramics by changing their ferroelectric phase proportions and crystallinity. By XRD analysis and Rietveld refinements, it was found the dielectric constant of the glass-ceramics was positively correlated with the relative proportions of M 2 NaNb 5 O 15 (M = Ba or Pb) and NaNbO 3 phases. The electric breakdown strength was negatively correlated with crystallinity and grain boundary activation energy. The maximum energy storage density 17.9 J cm−3 was obtained in these glass-ceramics. When the content of Nb 2 O 5 was 30 mol%, under the charge electric field 300 kV cm−1 in overdamped discharge circuit, the instantaneous power density of glass-ceramics capacitors reached 75 MW cm−3. The discharge time for all glass-ceramics capacitors was less than 50 ns. [ABSTRACT FROM AUTHOR]

Abstract In this study, novel heat-treated shell-core-structured (SCS) NiCr-23Mo powder is employed to realize the deposition of a bulk-like metallic coating with excellent mechanical performance by plasma spraying. The SCS NiCr-23Mo powder was fabricated by cladding spherical Ni20Cr particles with refractory Mo as an alloying element. This ensures the generation of ultra-high temperature Ni16Cr23Mo droplets during the in-flight process of plasma spraying. The interface bonding between the Ni16Cr23Mo single splats and steel substrate, as well as the microstructure of the Ni16Cr23Mo coating were characterized. Mechanical behavior of the coating was examined by erosion test. Results showed that the Ni16Cr23Mo coating exhibited a dense microstructure with significantly improved adhesive strength. Moreover, effective bonding was formed at 78% of interfaces between the Ni16Cr23Mo splat and steel substrate, which was much higher than the 36% of the conventional NiCr splat. Erosion test revealed that the Ni16Cr23Mo coating presented excellent erosion resistance, being comparable to that of the Ni-based bulk alloy. Moreover, the Ni16Cr23Mo coating presents ductile mechanical behavior during erosion test rather than the brittle behavior of the conventional Ni-based alloy coating. Thus, a mechanically bulk-like coating with excellent interface bonding and excellent erosion resistance can be achieved by plasma spraying of the novel SCS NiCr-23Mo powder. Graphical abstract Unlabelled Image Highlights • A bulk-like NiCrMo coating was obtained by plasma spraying of novel shell-core-structured (SCS) NiCr-23Mo powders. • Effective bonding was formed at 78% of interface between Ni16Cr23Mo splat and steel substrate. • The mechanical behavior of the Ni16Cr23Mo coating becomes ductile rather than brittle based on erosion test results. • The Ni16Cr23Mo coating exhibited excellent erosion resistance comparable to that of the Ni-based alloy bulk. [ABSTRACT FROM AUTHOR]

The flotation separation of spodumene from feldspar was investigated using a new type of mixed anionic/cationic collector, sodium oleate/tributyl tetradecyl phosphonium chloride (NaOL/TTPC). Microflotation experiments, fluorescence spectroscopy measurements, microcalorimetric analysis, and Fourier transform infrared analysis were performed. Microflotation experiments show that the highest flotation separation performance can be achieved at the NaOL:TTPC molar ratio of 5:1 at the pH of 4.0. Fluorescence spectroscopy measurements show that the critical micelle concentration (CMC) of the mixed collector NaOL/TTPC is smaller than either of its components alone. Microcalorimetric results indicate that the difference in adsorption reaction heat between spodumene and feldspar is larger for the mixed collector than either single collector, confirming the former’s separation advantage. Fourier transform infrared analyses show that in the mixed collector, both NaOL and TTPC adsorb on the spodumene surface through chemical interaction and electrostatic attraction, respectively; while only trace amounts of them are adsorbed on the feldspar surface. [ABSTRACT FROM AUTHOR]

BaO-K 2 O-Nb 2 O 5 -SiO 2 (BKNS) glass ceramics were prepared by microwave crystallization of transparent glass matrices and the effects of microwave treatment temperature on their dielectric performances, phase structure, microstructure and breakdown strength (BDS) were investigated systematically. X-ray diffraction results suggested that microwave treatment had no significant influence on the type of precipitated phases. The microstructure of the glass ceramics was remarkably optimized via microwave treatment. The dielectric constant and breakdown strength of microwave-treated samples were significantly improved as compared with conventional-heated samples at the same temperature. The maximum theoretical energy storage density of microwave-treatment samples at 750 °C reached 12.7 J/cm 3 , which was larger than that of the conventional-heated samples (8.6 J/cm 3 ). [ABSTRACT FROM AUTHOR]

In vegetation-abundant ecosystems, accurate fractional cover estimation of multiple targets, including non-photosynthetic vegetation (NPV), photosynthetic vegetation (PV) and bare soil (BS) is an important indicator of carbon storage and climate change, and a contributing factor to soil and water conservation, wildfire, and drought. Satellite remote sensing began with sensors limited to the visible and near infrared (VNIR, 380 nm to 1000 nm), and advancing to sensors spanning the whole solar domain (350 nm to 2500 nm) over the last five decades. However, NPV is still difficult to distinguish from BS in satellite images covering large spatial areas, since their spectral reflectances are always mixed and have subtly different spectral features. Many spectral indices have been proposed to identify NPV, however, most include a short-wave infrared band which is lacking on many current and historical spaceborne sensors. To fully utilize current and historical airborne/satellite images with only VNIR bands, a novel spectral index – the VNIR spectral shape index (SSI) – is proposed in this paper. Using spectra of PV, NPV, and BS acquired from world-recognized spectral libraries, the SSI was devised using only blue, green, red, and NIR bands. When applied to Sentinel-2 MSI images, the SSI was effective in estimating/mapping the fractional cover of PV, NPV, and BS using the triangular space method. The resulting fractional cover was evaluated in three 3 km × 2 km study areas including one grassland, one woodland, and one cropland. The spectral reflectance collected by spectroradiometer in field work and digital image collect by digital camera mounted on unmanned aerial vehicle (UAV) support that the triangular space method is able to estimate the fractional cover of photosynthetic and non-photosynthetic vegetation simultaneously, and that endmember selection relying solely on satellite images is reasonable. Comparing the abundance of each target in UAV images to corresponding MSI pixels, the SSI index and triangular space method proved effective for fractional cover estimation in varied vegetated ecosystems. For fractional cover evaluation in grassland, woodland, and cropland, the R2 reaching to 0.59, 0.62, and 0.70, respectively. These results demonstrate that the SSI is feasible for multiple sensors, enabling potential large temporal and/or spatial scale applications. • Spectral index, SSI, is devised to separate soil and non-photosynthetic vegetation. • SSI employs blue, green, red, and NIR bands to catch spectral shape difference. • Four bands in SSI are equipped on most satellite/airborne sensors since 1980s. • SSI-NDVI combination can estimate fraction of land cover using triangle method. [ABSTRACT FROM AUTHOR]

Anisotropic surface properties of minerals play an important role in a variety of fields. With a focus on the two most intensively investigated silicate minerals (i.e., phyllosilicate minerals and pegmatite aluminosilicate minerals), this review highlights the research on their anisotropic surface properties based on their crystal structures. Four surface features comprise the anisotropic surface chemistry of minerals: broken bonds, energy, wettability, and charge. Analysis of surface broken bond and energy anisotropy helps to explain the cleavage and growth properties of mineral crystals, and understanding surface wettability and charge anisotropy is critical to the analysis of minerals' solution behavior, such as their flotation performance and rheological properties. In a specific reaction, the anisotropic surface properties of minerals are reflected in the adsorption strengths of reagents on different mineral surfaces. Combined with the knowledge of mineral crushing and grinding, a thorough understanding of the anisotropic surface chemistry properties and the anisotropic adsorption behavior of minerals will lead to the development of effective relational models comprising their crystal structure, surface chemistry properties, and targeted reagent adsorption. Overall, such a comprehensive approach is expected to firmly establish the connection between selective cleavage of mineral crystals for desired surfaces and designing novel reagents selectively adsorbed on the mineral surfaces. As tools to characterize the anisotropic surface chemistry properties of minerals, DLVO theory, atomic force microscopy (AFM), and molecular dynamics (MD) simulations are also reviewed. [ABSTRACT FROM AUTHOR]

A series of strontium potassium niobate (KSN-based) glass-ceramics with different nucleating agents have been prepared by conventional controlled crystallization method. The effects of different nucleating agents on crystallization kinetics behavior, dielectric properties and energy storage performances of glass-ceramics have been investigated. It was found that nucleating agents can improve the reaction rate constant (k) of crystallization, which made the KSN-based glasses crystallize at low temperature. Due to the increase of crystallinity, the dielectric constant rose and the breakdown strength decreased. The maximum theoretical energy storage density of 13.5 J/cm 3 was obtained when 3 mol.% CaF 2 were added as nucleating agents. [ABSTRACT FROM AUTHOR]

In-flight particle temperature is a vital factor controlling the formation of the interface bonding and therefore the overall properties of thermally sprayed coatings. In our previous study, a novel shell-core-structured powder approach was proposed which was designed by cladding low melting point alloy NiCr powders with refractory Mo shell to significantly raise the in-flight particle temperature during plasma spraying to improve the interface bonding within the plasma-sprayed coating. Previous results revealed that the significantly improved interface bonding was obtained for the plasma sprayed NiCr-Mo coating. Therefore, in this study, in order to clarify the effect of Mo-cladding on the temperature evolution of the Ni-based alloy particle, the heating history of the Mo-clad-NiCr particle injected into plasma jet during in-flight process are numerically simulated and further experimentally measured. Effect of particle surface vaporization on the heating characteristic of particle was examined. As a result, both the numerical and experimental results show that through such novel particle design, the elemental vaporization of NiCr core is effectively suppressed and the Ni-based alloy particle is definitely heated up to an ultra-high temperature, 2920 K, which is comparable to that of molten Mo particles and is about 500 K higher than that of conventional NiCr particle. Consequently, an almost fully-dense NiCrMo coating with excellent interface bonding can be obtained by plasma spraying of this ultra-high temperature Mo-clad-NiCr particle. [ABSTRACT FROM AUTHOR]

In this paper, a complete scheme aimed at improving the flotation performance of spodumene and comprehensively recycling mica and feldspar from lithium tailings in an economical and environmentally friendly way is put forward. The flotation performance of spodumene and feldspar with four size ranges (0–19, 19–38, 38–45 and 45–75 μm) are investigated in single mineral micro-flotation tests. The results show that the maximum spodumene recovery is obtained with coarse particles of 38–45 μm, while for feldspar, the best flotation performance is found with fine particles of 0–19 μm. In condition tests, the optimum dose of mixed collector SX is found to be 1600 g/t. The optimum doses of the regulators Na 2 CO 3 , NaOH and CaCl 2 are selected as 800, 800 and 300 g/t, respectively, by orthogonal tests. Based on the single mineral micro-flotation and condition experiment results, three flowsheets are designed to produce qualified spodumene products in batch flotation tests. After comparison, the flowsheet-C is recommended, which improves the grade and recovery of Li 2 O in spodumene concentrates to 6.02% and 87.34%, respectively. This paper also puts forward an environmentally friendly flotation flowsheet aimed at recycling feldspar in spodumene tailings, through which K 2 O + Na 2 O has a grade and recovery of 11.33% and 61.33%, respectively, in the feldspar concentrates. By adopting the flowsheets presented in the paper, nearly 70% of raw lithium pegmatite ore is translated into qualified mica, spodumene and feldspar products to realize a comprehensive utilization of the resource. The brief economic analysis further confirms that the new scheme has greater economic potential than the commonly used one. [ABSTRACT FROM AUTHOR]

Aluminosilicate minerals (e.g., spodumene, albite) have complex crystal structures and similar surface chemistries, but they have poor selectivity compared to traditional fatty acid collectors, making flotation separation difficult. Previous research has mainly considered the mineral crystal structure as a whole. In contrast, the surface characteristics at the atomic level and the effects of different crystal interfaces on the flotation behavior have rarely been investigated. This study focuses on investigating the surface anisotropy quantitatively, including the chemical bond characteristics, surface energies, and broken bond densities, using density functional theory and classical theoretical calculations. In addition, the anisotropy of the surface wettability and adsorption characteristics were examined using contact angle, zeta potential, and Fourier-transform infrared measurements. Finally, these surface anisotropies with different flotation behaviors were investigated and interpreted using molecular dynamics simulations, scanning electron microscopy, and X-ray photoelectron spectroscopy. This systematic research offers new ideas concerning the selective grinding and stage flotation of aluminosilicate minerals based on the crystal characteristics. [ABSTRACT FROM AUTHOR]

The effects of Pb 2+ ions on ilmenite flotation and adsorption of benzohydroxamic acid (BHA) as a collector were investigated using microflotation tests, zeta potential measurements, adsorption analysis, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The microflotation results indicate that the addition of Pb 2+ significantly improves the recovery of ilmenite using BHA as a collector. A maximum recovery of 88.46% is obtained at pH 8.12 in the presence of Pb 2+ ; a maximum recovery of 45% is obtained at the same pH using BHA alone. At pHs below 8.0, lead nitrate are mainly present in the solution as Pb 2+ and PbOH + , while at pHs above 8.0, the predominant components are Pb(OH) 2(s) and Pb(OH) 3− . The adsorption of these lead species influences the zeta potential of ilmenite and the number of activated sites on the ilmenite surface. FTIR and XPS analyses reveal that lead species and BHA react with the metal sites on the ilmenite surface. The lead species in solution are either adsorbed onto the ilmenite surface, which increases the surface activity of ilmenite, or react with BHA in solution to form complexes of lead and BHA. [ABSTRACT FROM AUTHOR]

The analysis of flotation and adsorption of mixed collectors on oxide and silicate minerals is of great importance for both industrial applications and theoretical research. Over the past years, significant progress has been achieved in understanding the adsorption of single collectors in micelles as well as at interfaces. By contrast, the self-assembly of mixed collectors at liquid/air and solid/liquid interfaces remains a developing area as a result of the complexity of the mixed systems involved and the limited availability of suitable analytical techniques. In this work, we systematically review the processes involved in the adsorption of mixed collectors onto micelles and at interface by examining four specific points, namely, theoretical background, factors that affect adsorption, analytical techniques, and self-assembly of mixed surfactants at the mineral/liquid interface. In the first part, the theoretical background of collector mixtures is introduced, together with several core solution theories, which are classified according to their application in the analysis of physicochemical properties of mixed collector systems. In the second part, we discuss the factors that can influence adsorption, including factors related to the structure of collectors and environmental conditions. We summarize their influence on the adsorption of mixed systems, with the objective to provide guidance on the progress achieved in this field to date. Advances in measurement techniques can greatly promote our understanding of adsorption processes. In the third part, therefore, modern techniques such as optical reflectometry, neutron scattering, neutron reflectometry, thermogravimetric analysis, fluorescence spectroscopy, ultrafiltration, atomic force microscopy, analytical ultracentrifugation, X-ray photoelectron spectroscopy, Vibrational Sum Frequency Generation Spectroscopy and molecular dynamics simulations are introduced in virtue of their application. Finally, focusing on oxide and silicate minerals, we review and summarize the flotation and adsorption of three most widely used mixed surfactant systems (anionic–cationic, anionic–nonionic, and cationic–nonionic) at the liquid/mineral interface in order to fully understand the self-assembly progress. In the end, the paper gives a brief future outlook of the possible development in the mixed surfactants. [ABSTRACT FROM AUTHOR]

Surface heat flux is an important parameter in various industrial applications. It is often estimated based on measured temperature by solving inverse heat conduction problems (IHCPs). In the present work, a filter solution to solve 1D single-layer IHCPs is applied to calculate the surface heat flux for 2D multi-layer mediums. An optimal comparison criterion is implemented for 2D IHCPs to optimize the key regularization parameters. Afterward, the 2D filter solution is used for heat flux estimation with thin-film thermocouple (TFTC) and fine thermocouple (FTC) measurements during cryogen spray cooling. The accuracy of the estimated heat fluxes is tested with the measured temperature response to cryogen spray cooling. A small error (maximum value of 1.0740 °C) is observed between the temperature simulated based on estimated heat fluxes and the measured temperature. The maximum heat flux obtained by the 2D filter solution is 13.6% higher than that obtained by 1D method for TFTC measurement. This finding indicates that lateral heat transfer cannot be disregarded, especially when the heat conductivity coefficient of the material is large. [ABSTRACT FROM AUTHOR]

The flotation behavior of ilmenite and titanaugite using anionic collector sodium oleate (NaOL), cationic collector dodecylamine acetate (DAA) and the mixed anionic/cationic collector (NaOL-DAA) was investigated through micro-flotation experiments, zeta potential measurements, Fourier transform infrared (FTIR) analyses, and the artificially mixed minerals flotation experiments. The results of the microflotation experiments indicate that DAA exhibits good flotation performance to both ilmenite and titanaugite at a pH > 6.0. The flotation separation of ilmenite from titanaugite can be performed using the mixed NaOL-DAA in a wide pH range of 5.0–7.0. In this pH range, the recovery of ilmenite remains constant at approximately 90%, while the recovery of titanaugite remains < 25%. The best separation result can be achieved with NaOL-DAA molar ratios of 10:1. The results of the zeta potential experiments and the FTIR analyses indicate that the adsorption of the mixed collector, NaOL-DAA, on the ilmenite surface is larger than on the titanaugite surface and that the NaOL-DAA complex might be mainly adsorbed on the ilmenite surface by chemical adsorption, apart from electrostatic adsorption. The synthetic mineral mixture micro-flotation results demonstrate that, compared to NaOL, NaOL-DAA not only increases the recovery and grade of the TiO 2 by 7.02% and 6.71%, respectively, but also decreases the reagent consumption by half. [ABSTRACT FROM AUTHOR]

• Our method focuses on fractional cover (fc) and chlorophyll content (CC). • Confounding effect of fc and CC is well analyzed in VNAI-NDVI-space. • Polar coordinate method (PCM) is based on VNAI-NDVI-space under linear assumption. • PCM surpasses NDVI threshold in differentiating crop maturity. Crop leaf chlorophyll content (CC) and fractional cover (fc) are critical parameters for assessing crop growth and dynamic vegetation changes at regional and global scales. As CC and fc are the key factors dominating crop canopy reflectance, the confounding effects of CC and fc on canopy vegetation spectra and spectral indices (SIs) limit their remote sensing estimation. We combined the Normalized Difference Vegetation Index (NDVI) and Visible and near-infrared (NIR) Angle Index (VNAI) to understand the vegetation canopy SI differences caused by CC and fc (abbreviated as VNAI-NDVI-space). The VNAI-NDVI-space is approximately fan-shaped with high-CC and low-CC edges; the pixels inside the fan-shaped space represent crops with various CC and fc. We proposed a Polar Coordinate method (PCM) for assessing CC and fc. The performance of the VNAI-NDVI-space in assessing CC and fc was tested using a field-based spectrometer and an unmanned aerial vehicle (UAV)-based imaging spectrometer measurement for three soybean fields and six growth stages. Analysis of this imaging led to three conclusions: (i) The VNAI-NDVI-space can be used to analyze the confounding effects of CC and fc on crop canopy SIs; (ii) The VNAI-NDVI-space can track critical crop growth features; the VNAI-NDVI-space is not saturated at medium-to-high vegetation cover; (iii) the (a) confounding effect of CC on fc estimation; and (b) the confounding effect of fc on CC estimation was mitigated by the proposed VNAI-NDVI-space and PCM. The proposed PCM was successfully used to estimate CC and fc from the simulated dataset (CC: r = 0.97, RMSE = 4.10 μg/cm2; fc : r = 0.99, RMSE = 0.10), the field measurements (CC: r = 0.82, RMSE = 5.61 Dualex-units; fc : r = 0.78, RMSE = 0.08), and the UAV measurements (CC: field-PJ, r = 0.87, RMSE = 5.99 Dualex-units, field-PB, r = 0.66, RMSE = 7.29 Dualex-units; fc : r = 0.46, RMSE = 0.11). Thus, VNAI-NDVI-space and PCM are promising for assessing crop CC and fc. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new normalized differential soil organic carbon spectral index was proposed. • Some measured environmental auxiliary data can be replaced by spectral indices. • NDVI, LST, SI, and CI contribute the most to the prediction of SOC. • The PSO-RFR model can better predict the SOC of coastal wetlands. To study the dynamic changes of soil organic carbon (SOC) content in coastal wetlands over the past 23 years, we use the third core area of the Dafeng Elk Nature Reserve in Jiangsu Province, China as the study area. A normalized difference soil spectral index (NDSOC), which is directly related to SOC, was constructed by using the spectral reflectance of Landsat images, and six auxiliary environmental variables related to SOC were extracted: surface temperature, surface moisture, soil salinity, the normalized difference vegetation index (NDVI), surface brightness, and soil texture information. The coastal wetland soil surface SOC inversion model was constructed by multiple linear regression, support vector machine, and particle swarm optimization-based random forest regression (PSO-RFR). By using the best inversion model, we obtain the dynamic distribution of soil surface SOC in the third core area of the Dafeng Elk Reserve for the past 23 years. The results indicate (1) that the NDSOC index constructed based on the short-wave infrared (SWIR) bands 1 and 2 of the Landsat images has a strong indication of SOC. Among the extracted auxiliary environmental variables, the NDVI, soil clay content, surface temperature, and soil salinity contribute more strongly to the SOC content of coastal wetlands, which averaged 27.9 %, 24.4 %, 22.1 %, and 18 %, respectively. (2) The PSO-RFR algorithm provided the best simulation of the surface SOC content of coastal wetlands: the model determination coefficient R 2 is 0.731, the average fitting root mean square error RMSE is 0.917 g/kg, and the fitting uncertainty standard deviation was 0.362 g/kg. (3) From 2000 to 2022, the organic carbon storage and organic carbon density in the third core area of the Dafeng Elk Reserve gradually increased, the highest value was reached in 2016, they were 4.017 (104 t) and 1.718 kg/cm2, respectively. [ABSTRACT FROM AUTHOR]

• Rich defective multiligand copper-based metal–organic framework (ML-Cu 2 O@Cu-MOF) is synthesized by one-pot hydrothermal method. • ML-Cu 2 O@Cu-MOF as sensing platform shows good electrochemical activity and performance for detection of S. aureus. • Ultra-low limitation of detection of 2.0 and 1.6 CFU·mL−1 can be gained through by the EIS and DPV techniques. • The developed ML-Cu 2 O@Cu-MOF-based aptasensor demonstrate good stability, excellent reproducibility, and acceptable practicality. We have proposed a novel electrochemical aptasensing strategy for efficiently detecting staphylococcus aureus (S. aureus) based on copper-based metal–organic framework encapsulated with plenty of Cu 2 O nanocrystals (represented by ML-Cu 2 O@Cu-MOF) synthesized using the mixed ligands of diphenylethyne-3,3′,5,5′-tetracarboxylic acid, 1,3,5-benzenetricarboxylic acid, and terephthalic acid. The ML-Cu 2 O@Cu-MOF nanospheres comprised multiple Cu valence states (Cu0/Cu+/Cu2+) and Cu 2 O nanocrystals, possessed defect-rich crystal structure, high anchoring ability toward aptamer and boosted electrical conductivity. The gained ML-Cu 2 O@Cu-MOF-based biosensor exhibited lower limit of detection toward S. aureus , as low as 2.0 and 1.6 CFU mL−1 within the S. aureus concentration from 10 to 1 × 108 CFU mL−1 obtained by electrochemical impedance spectroscopy and differential pulse voltammetry techniques, respectively. Additionally, the developed aptasensor also demonstrated high superior stability, excellent reproducibility, acceptable regeneration ability, and wide practicality. The present work can give rise to an alternative aptasensing strategy for analyzing foodborne bacteria or other food containments and ensuring food safety assessment. [ABSTRACT FROM AUTHOR]

To date, the electrochemical method for efficient and accurate determination of As(III) in groundwater with interference-free is still a difficultly but significantly task. Herein, a reliable, high sensitive and excellent anti-interference electrochemical sensing As(III) with amino-functionalized graphene oxide (NH 2 -GO) decorated gold (Au) microelectrode was developed in mild media with square wave anodic stripping voltammeter (SWASV). Taking advantage of the synergy between the strong absorption capability of NH 2 -GO and the excellent electrocatalytic ability of Au microwire, the NH 2 -GO modified Au microelectrode exhibits the enhanced electrochemical performance toward As(III). No obvious interference from other commonly coexisting ions on the determination of As(III) was observed. Furthermore, the robust stability and reproducibility of the electrodes were obtained. Under the optimized conditions, the limit of detection (3σ method) toward As(III) was 0.162 ppb with a sensitivity of 130.631 μA ppb −1 cm −2 . Notably, the possible mechanism of the enhanced stripping signal was preliminarily explored by using X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES) techniques. Finally, the analytical application of the raised means on the detection of As(III) in Xingwangzhuang Village groundwater, Inner Mongolia, has been successfully verified. [ABSTRACT FROM AUTHOR]

The mixed anionic collector sodium oleate (NaOL) and cationic collector dodecyl ammonium chloride (DTAC) demonstrate high selectivity for the flotation of spodumene from feldspar, and the optimal molar ratio of NaOL and DTAC is 9:1. To detect the underlying mechanism, surface tension measurements, adsorption measurements, zeta potential measurements and Fourier transform infrared (FTIR) analyses were performed. The surface and thermodynamic parameters (CMC, γ CMC , Γ max , A min , Δ G m 0 ) obtained from surface measurements show higher surface activity and a denser molecular arrangement in mixed NaOL/DTAC than in single NaOL or DTAC. Further analysis of the interaction parameters and activity coefficients ( β m , β σ , f m , and f σ ) obtained from the theory of regular solutions shows that there is a synergistic effect both in the mixed micelle and at the water/air interface. Moreover, the maximum synergistic interaction was found at X DTAC = 0.5 in mixed NaOL/DTAC. The adsorption measurements show that more NaOL is adsorbed on the spodumene surface than on feldspar and that the cationic collector can improve the adsorption of NaOL on the spodumene surface by a small amount, but not for feldspar. The zeta potential measurement and Fourier transform infrared analyses show that in the mixed NaOL/DTAC system, the anionic collector NaOL first reacts with aluminum sites on the mineral surface. Then, the cationic collector DTAC forms an electroneutral complex with the anionic collector NaOL and co-adsorbs on the Stern layer because of the chemisorption of NaOL. Based on these analyses, an adsorption model of the mixed collector NaOL/DTAC on the mineral surface was drawn. [ABSTRACT FROM AUTHOR]

Spray cooling is widely used in industries. Understanding of the complex surface heat transfer characteristics is essential to enhance cooling efficiency. In the present study, surface heat transfer of transient spray cooling with different cryogens, nozzles, and substrates were investigated. Minimum surface temperature reached −46.1 °C, −55.9 °C, and −57.9 °C and maximum surface heat flux values were 294.9, 364.1, and 377.4 kW/m 2 for R134a, R407C, and R404A, respectively, on an epoxy resin block. Results proved that R404A has the best cooling capacity. Compared with that of the straight nozzle, q max of the expansion-chamber nozzle increased from 266.9, 364.1, and 403.9 kW/m 2 to 339.3, 442.8, and 445.1 kW/m 2 or 16.6%, 18.6%, and 16.7% for R134a, R407C, and R404A, respectively. Transient cooling could be divided into two stages, namely, fast boiling cooling and film evaporation cooling. The similarity of dynamic heat flux with different cryogens, nozzles, and substrates was observed, and the dimensionless correlation was proposed by the spray Biot number, which is defined as the ratio between the internal thermal resistance of the substrate and the surface convective heat transfer resistance. The dimensionless Reynolds number Re l and Fourier number Fo l were proposed to represent the maximum heat flux ( q max ) and the corresponding time ( t max ), respectively. By coupling the Jakob number with Re l and the droplet Weber number ( We ), dimensionless correlations of maximum heat flux and the corresponding time were proposed, through which it is indicated that We number was the key factor in spray cooling. [ABSTRACT FROM AUTHOR]

Electrochemical analytical challenge for cadmium(II) [Cd(II)] determination is to seek an efficient platform to realize the sensitive and selective detection. Herein, a sensing interface for the detection of Cd(II) was designed and constructed by the amination treated porous SnO 2 nanowire bundles-room temperature ionic liquid nanocomposite (NH 2 /SnO 2 -RTIL). Through the delicate control of experimental conditions (deposition potential and electrolyte pH), the excellent sensitive and selective electroanalysis of ultra-trace Cd(II) was achieved using square wave anodic stripping voltammetry (SWASV). The NH 2 /SnO 2 -RTIL uses its efficient capture during the Cd(II) deposition step to enhance the sensitivity of the stripping response. Under the optimal experimental conditions, the NH 2 /SnO 2 -RTIL nanocomposite offered direct detection of Cd(II) within the desirable range (0.0267 μM) in drinking water as specified by the World Health Organization (WHO), a limit of detection (3σ method) of 0.0054 μM with a sensitivity of 124.03 ± 3.75 μA μM −1 was obtained in the presence of common heavy metal ions. Finally, the analytical application of the proposed method toward the detection of Cd(II) in a real water sample collected from Wangxiaoying sewage treatment plant, Hefei City, China, has been successfully verified. [ABSTRACT FROM AUTHOR]

Rice is considered to be one of the dominant sources of exposure to Cd(II) for human being, thus monitoring the concentration of Cd(II) in rice is very important. The anti-interference ability for several current approaches (especially electrochemical method) is expected to be dramatically improved due to more extreme complicated conditions in real rice sample. Here, a methodology combined electrochemistry with laser-induced breakdown spectroscopy (EC-LIBS), as well as choice of negatively charged graphene oxides (GO(-)), was selected for the determination of trace Cd(II) in rice. In this method, the target Cd(II) was preconcentrated on the surface of GO(-) modified Ti plate in the form of Cd(0) by electrochemcial deposition, the succeeding elemental identification and quantification was achieved using LIBS. Electrochemcial deposition and the modification of GO(-) on electrode significantly increased the sensitivity of the Cd(II) analysis in rice utilized LIBS only (for the same mass of rice sample) by 3 orders of magnitude and a ppb-level limits of detection (LOD) was obtained. Good anti-interference ability was also achievable during the actual measurements, particularly when Cu(II) and Mn(II) co-existed. The combination of electrochemistry and LIBS techniques, as well as the presence of GO, made it very attractive for the purposes of Cd(II) sensing in standard and nonstandard conditions. [ABSTRACT FROM AUTHOR]

The alkaline leaching process of arsenic-containing solid waste discharged during nonferrous metal smelting affords typical high-salinity alkaline arsenic-containing wastewater (HSAW). In this study, for the first time, Me (Ca2+ and Mg2+)–AsO 4 3−–OH−–H 2 O and Me (Ca2+ and Mg2+)–AsO 4 3−–CO 3 2−–H 2 O systems are studied based on a thermodynamic equilibrium diagram and an arsenic removal experiment, proving that the removal of arsenic using single metal ions in the presence of CO 3 2− is infeasible because of carbonate coprecipitation. Based on this observation, a new method that uses magnesium ammonium complex salts (MACSs) for HSAW treatment is proposed. Based on the thermodynamic calculations of the Mg2+–AsO 4 3−–NH 4 +–CO 3 2−–H 2 O system and the arsenic removal experiment, carbonate and arsenate can be selectively separated by the formation of magnesium ammonium arsenate (NH 4 MgAsO 4 ·6H 2 O). In an arsenic solution containing 150-g/L Na 2 CO 3 , the arsenic removal rate and the arsenic grade of the precipitation product reach 90.16% and 27.13%, respectively, when the molar ratios of Mg2+/NH 4 +:As(V) are 1.8:1 and 2:1, respectively. The proposed method is successfully employed for treating a leaching solution of alkaline arsenic slag discharged during antimony smelting. The findings of this study will broaden the basic theory of HSAW treatment and lay a foundation for the resource treatment of arsenic-containing solid waste. [Display omitted] • The traditional arsenic removal methods were infeasible in Na 2 CO 3 solution. • A method for the selective separation of arsenic and alkali by MACSs was proposed. • Arsenic component was precipitated in the form of MgNH 4 AsO 4. • The theoretical systems of arsenic removal by MACSs were established. • Alkaline arsenic slag can be disposed cleanly and safely by the novel method. [ABSTRACT FROM AUTHOR]

• AuP-PS consist of P[5]A-capped AuNPs and "V" type polymers by host–guest interaction. • The reversible host–guest interaction enhances ROS production and catalytic activity. • The design provides a complementary therapy strategy for indepth antitumor treatment. Supramolecular chemistry as a promising tool bridges the gap between conveniently synthetic processes and multifunction through reversible noncovalent interactions. Herein, a supramolecular nanoplatform, AuP-PS , is built by flexible and reversible supramolecular interactions between pillar[5]arene-capped gold nanoparticles (AuP s) and porphyrin-containing "V" shape block copolymers (PS). The biosafety of AuP-PS was greatly improved by the formation of supramolecular complexes. Taking advantage of gradient pH changes in the tumor microenvironment (TME), AuP-PS can first disassemble into single AuP-PS nanoparticles due to the pH-sensitive DPA units of PS under pH = 6.5 and enter into the in-depth tumor sites. Whereafter, single AuP-PS nanoparticles completely dissociate, release PS and expose AuP s due to the reversible host-guest interaction at pH = 5.4, where photodynamic therapy and catalytic therapy were sufficiently activated to combat against the in-depth tumor. In vitro results indicate that the singlet oxygen yield of supramolecular AuP-PS nanoplatform was amplified 5.6 times under pH = 5.4 than that under pH = 7.4, and the nanozyme activity of AuP-PS nanoplatform was dramatically boosted 6.7 times than that of the control sample without reversible linkers under pH = 5.4. In vivo data further reveal that the supramolecular AuP-PS nanoplatform displayed superb therapeutic efficacy. Hence, this supramolecular AuP-PS nanoplatform may provide a programmed and complementary synergistic therapy strategy for in-depth and efficient treatment for solid tumors. [ABSTRACT FROM AUTHOR]

A new Li(I)-based metal–organic framework (MOF), namely {(Me 2 NH 2 ) 2 [Li(NTB)](H 2 O) 3 (DMF) 2 } n ( 1 , NTB = 4.4′,4″-nitrilotrisbenzoate; DMF = N , N -dimethylformamide), has been successfully achieved by solvothermal reaction of a C 3 -symmetric tricarboxytriphenylamine based ligand and Li(I) ion. The resulting framework features a binuclear Li(I) secondary building unit (SBU) and a rare 3.6-connected ant topology. Luminescence properties of 1 towards different metal ions and solvents have also been investigated systematically, with emission intensities significantly quenched towards Fe(III) ion and nitrobenzene (NB). The quenching mechanism has also been investigated in detail. [ABSTRACT FROM AUTHOR]

Inter-splat bonding dominates the properties and performance of thermally sprayed metallic coatings. Thus, enhancing the inter-splat bonding is a necessary approach to improve the performances of the metallic coatings. In this study, a new approach is proposed to create metallurgical bonding within plasma-sprayed metal alloy coatings by using shell-core-structured powder particle, which is designed by cladding spherical Ni20Cr powders with refractory Mo as alloying element to raise particle temperature significantly high enough to cause impact melting. NiCr-Mo coating was used as model material which was deposited on stainless steel by gas shrouded plasma spraying. NiCr-Mo splats were deposited on Inconel-738 substrate to study the bonding mechanism. Scanning electron microscope (SEM) was employed to characterize the interface bonding within the coating and between the coating and the substrate. Electron Back-Scattered Diffraction (EBSD) was used to examine the crystallographic relationship between each interface. The results show that the NiCr-Mo coating presents much dense structure with remarkably improved cohesion and adhesion strength in comparison with conventional NiCr coating. Higher bonding strength results from the formation of metallurgical bonding at the interfaces both between substrate and coating, and between lamellae. The strong self-bonding strength among lamellae is attributed to increased Ni-based alloy particle temperature higher than the melting point of Mo achieved by Mo cladding NiCr particle design, which is confirmed theoretically by numerical simulation. [ABSTRACT FROM AUTHOR]

By combining experiment with molecular simulation, the CO 2 sorption performance of a 2D honeycomb layered coordination polymer, {[Zn 2 (bpydb) 2 (H 2 O) 2 ](DMA) 3 (H 2 O)} n ( 1 ) (bpydb = 4,4′-(4,4′-bipyridine-2,6-diyl) dibenzoate) was systematically investigated. The desolvated 1 not only shows high CO 2 capacity (72.5 cm 3 /g at 273 K and 42.9 cm 3 /g at 298 K) with a moderate high zero-coverage adsorption enthalpy (29.7 kJ/mol), but also exhibits excellent CO 2 /N 2 selectivity around room temperature. To better understand the adsorption behaviors and adsorption sites for CO 2 in 1 , GCMC simulations were carried out, which indicate that the open metal sites between two adjacent layers account for the high CO 2 sorption capacity and strong CO 2 binding ability. Moreover, the thermal stability of 1 was further confirmed by the TGA and VT-PXRD, which indicate that 1 could be thermally stable up to 400 °C. [ABSTRACT FROM AUTHOR]

Here we report a system using ultrathin SnO 2 nanosheets with high reactive exposed (110) surface modified gold electrode for sensitive detection of As(III) by Square wave anodic stripping voltammetry (SWASV) with a mild acid condition (pH 5.0). Ultrathin SnO 2 nanosheets have been synthesized via a hydrothermal process successfully with the thickness of about 0.52 nm (four atomic layers thick). This oxide is used as electrode modifier, and the modified electrode exhibits good performance in stripping determination of As(III). The LOD actually measured is 5 μg L −1 and below the guideline value given by the World Health Organization (WHO). As compared with SnO 2 bulks, ultrathin SnO 2 nanosheets are found to exhibit stronger adsorption capability and better detection performance toward As(III), it may be due to the atomic thickness and extremely huge percentage of (110) facet ultrathin nanosheets materials exposed. Finally, this system is successfully applied for the analysis of a real sample collected from Inner Mongolia, China. Most importantly, we pose a potential for the use of ultrathin materials to improve the electrochemical performance of bare gold electrode in mild acid condition. [ABSTRACT FROM AUTHOR]