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Live fuel moisture content (LFMC) is a crucial variable affecting the ignition potential of shrublands. Different remote sensing-based models (either empirical or physical) have been adopted to estimate LFMC in shrublands but with mixed success potentially owing to differences in vegetation cover (closed vs. open shrublands). This study aimed to evaluate and discuss LFMC estimation in open and closed shrublands using different remote sensing approaches. For each case, three broadly used radiative transfer models (RTMs) (PROSAILH, PROGeoSail, and PROACRM), and two empirical models were selected and compared. The empirical models were calibrated by a stepwise regression approach using a spectral index (SI) and its normalized form (SImax-min). Results showed that both RTMs and empirical models performed well in retrieving LFMC of closed shrublands (RTMs: R2 = 0.60–0.66, RMSE = 14.96–18.51%, bias = −5.99–4.36%, and empirical models: R2 = 0.69–0.72, RMSE = 10.67–11.30%, bias = 0.18–0.35%). However, all RTMs failed to retrieve LFMC for open shrublands (R2 = 0.01–0.09, RMSE = 45.21–48.66%, bias = 9.76–14.75%) potentially due to the high heterogeneity of vegetation in this vegetation type. In contrast, the SImax-min-based model outperformed the RTMs for the open shrublands LFMC estimation (R2 = 0.44, RMSE = 32.32%, bias = −0.34%) but saturated at high LFMC values (> 120%). In conclusion, PROACRM and the empirical model using SImax-min as an explanatory variable are recommended to model closed and open shrublands LFMC, respectively. This study gives insights into developing effective models for improving shrubland LFMC estimation by considering various fractions of covers of shrublands that were not previously considered.

With the decrease in the phosphate rock grade, the minor element ratios (MER) [(Fe2O3 wt% + Al2O3 wt% + MgO wt%)/P2O5 wt%] of wet-process phosphoric acid (WPA) exhibits a linear upward trend. This can lead to a huge challenge for the high-quality production of feed calcium phosphate salt (FCPS). In the present study, we proposed a novel and economical strategy to precipitate Al3+ and Mg2+ via the formation of aluminofluoride complexes (NaMgAlF6·H2O) with the anhydrous sodium sulfate (Na2SO4) and hydrofluoric acid (HF) as precipitation agents. Because of the low solubility of the complexes in WPA, the removal efficiencies of Al3+ and Mg2+ ions could reach 99.5% and 64.8%, respectively. The maximum mass loss of P2O5 was less than 0.5%. The precipitates could be separated and converted into the HF and Na2SO4 for reuse, thus further decreasing the cost of WPA purification.

The working state of the gas drainage pipe network is the key to the safe drainage of underground mine gas. In order to quickly and accurately determine whether the pipe network is working normally...

In general, the formation of martensite in the metastable austenite grains in steels during nanoindentation investigations is believed to be induced by strain as the plastic deformation of austenit...

The present work quantifies the contribution of constituting phases to the strain hardening in a medium-Mn steel during Luders deformation. The strain hardening of the ferrite matrix (∼ 46.1 MPa) i...

In this work, we investigated the structural properties of ferroelectric PbZr0.2Ti0.8O3 (PZT) and ferrimagnetic/ferroelectric [CoFe2O4(CFO)/PZT] bilayers grown on (001)SrTiO3 (STO) substrat...

A new microstructural design is proposed to develop a strong and ductile quenching and partitioning (Q&P) steel with low yield ratio. This steel has a heterogeneous dual phase microstructure which ...

The conventional alloy design of medium Mn steel is to optimize the transformation-induced plasticity (TRIP) effect. Here we show that a dual-phase heterogeneous structure is sufficient to develop a medium Mn steel with high yield strength (∼1.2 GPa) and large uniform elongation (∼14.5%). The ultra-high strength is contributed by high back-stress while the large ductility is induced by strain-gradient plasticity and back-stress hardening, both of which are inherent to dual-phase heterogeneous structure. TRIP effect is suppressed during plastic deformation. Therefore, medium Mn steel can be strong and ductile by engineering dual-phase heterogeneous structure without resorting to TRIP effect.IMPACT STATEMENTWe demonstrate that medium Mn steel can be strong and ductile by engineering dual-phase heterogeneous structure without resorting to the conventional transformation-induced plasticity (TRIP) effect.

The present work employs nano-indentation technique to investigate the C partitioning in a medium Mn steel subjected to quenching and tempering process. It is found that the C partitioning between martensite and austenite is inhomogeneous. Particularly, the large lenticular martensite has negligible C partitioning into the austenitic matrix as it maintains an ultra-high nanohardness comparable to the one without tempering. Strategies to suppress the formation of large martensite are discussed.

In this study, an arid grassland was selected, and the chlorophyll content of the leaf and canopy level was estimated based on Landsat-8 Operational Land Imager OLI data using the PROSAIL radiative transfer RT model. Two vegetation indices green chlorophyll index, CIgreen, and greenness index, G were selected to estimate the leaf and canopy chlorophyll content LCC and CCC. By analysing the effect of soil background on the two indices, the LCC was divided into low and moderate-to-high levels. A different combination of the two indices was adopted at each level to improve the chlorophyll content estimation accuracy. The results suggested that the chlorophyll content estimated using the proposed method yielded a higher accuracy with coefficient of determination, R2 = 0.84, root-mean-square error, RMSE = 9.67 μg cm−2 for LCC and R2 = 0.85, RMSE = 0.43 g m−2 for CCC than that using CIgreen alone with R2 = 0.62, RMSE = 20.04 μg cm−2 for LCC and R2 = 0.85, RMSE = 0.71 g m−2 for CCC. The results also confirmed the validity of this approach to estimate the chlorophyll content in arid areas.

Soil moisture retrieval is often confounded by the influence of vegetation and surface roughness on the backscattered radar signal in vegetated areas. In this study, a semi-empirical methodology is proposed to retrieve soil moisture in prairie areas. The effect of vegetation is eliminated by the ratio vegetation method and water cloud model WCM, respectively. The conditions of vegetation are characterized by leaf area index LAI, vegetation water content VWC, normalized difference vegetation index NDVI, and enhanced vegetation index EVI, respectively. To remove the dependence on surface roughness, the dielectric constant is explicitly expressed as the function of co-polarization backscattering coefficients and sensor parameters based on the Dubois model. The ground measurements and satellite data collected from the Ruoergai and Wutumeiren prairies of China allow for validating the feasibility and effectiveness of the proposed methodology. From the perspective of soil moisture retrieval accuracy, the ratio vegetation method performs better than WCM. In the Ruoergai prairie, the best soil moisture retrieval result is obtained when EVI is used, with correlation coefficient r and root mean square error RMSE of 0.87 and 3.50 vol.%, respectively. While in the Wutumeiren prairie, the lowest retrieval error is obtained when LAI is used, with r and RMSE values of 0.79 and 5.73 vol.%, respectively. These results demonstrate that the Dubois model has a potential for enhancing soil moisture retrieval in prairie areas using synthetic aperture radar SAR and optical data.

The effect of ausforming temperature and strain on the bainitic transformation kinetics was investigated in a low carbon boron steel. A new mechanism, which is based on the competition between the increase in nucleation rate and the decrease in average volume of bainite sheaf after deformation, is proposed. The increase in nucleation rate is due to the decrease in boron concentration at the grain boundaries after small deformation and the formation of sub-grain boundaries at the grain interior after large deformation. The decrease in average volume of bainite sheaf is ascribed to the frequent impingement of bainite sub-units after deformation. The increase in nucleation rate after deformation results in the decrease in incubation time, which is confirmed from the experiment. The increase in nucleation rate overcomes the decrease in average volume of bainite sheaf, resulting in the increase in transformation velocity and volume fraction after small deformation. On the contrary, the decrease in the average ...

Systematic nanohardness measurements on martensite, lower bainite, upper bainite, granular bainite and ferrite were carried out using nanoindentation technique. The variation of nanohardness among these ferritic phases is ascribed to the different capacity of strengthening factors in confining the geometrically necessary dislocation within indentation plastic zone. The large scatter of nanohardness distribution in lath martensite may be due to the uneven block boundary strengthening, inhomogeneous dislocation forest strengthening and the different extent of auto-tempering.

Weights-of-evidence modeling has been extensively applied in mineral exploration and has also been used to examine the relationship between point patterns and map patterns. Generally, the evidence to be integrated is binary, whereas the real world consists of continuous and multi-class data, and the reclassification of these data into a binary form can result in the loss or distortion of information. However, extended weights-of-evidence modeling can be used to reduce the loss of useful information. This paper integrates multi-source geological spatial data (geological, geophysical, geochemical, and remote sensing data) for decision-making processes, aided by GIS spatial analysis techniques. Mineral-potential mapping for Cu-Pb-Zn deposits is proposed using extended weights-of-evidence modeling and generalized weights-of-evidence modeling in East Kunlun region of Qinghai Province, China. The study area was classified into three target zones of high potential, moderate potential, and low potential, based on...