Gas Overrun Risk Assessment in Coal Mining Face Based on Fuzzy Bayesian Network

A risk assessment technology based on a fuzzy Bayesian network is proposed to improve the degree of gas control management in the coal mining face and avoid gas overrun. Five characteristics of the coal mining working face, i.e., geological structure, ventilation conditions, gas extraction, mining activities, and coal mine management affecting the coal mining working face, were examined for 17 risk variables and a gas overrun assessment model was created. A priori information and sample data indicate that there is a 3% chance of gas overflow. The reverse reasoning test found that the main reasons for gas overrun were unreported gas anomalies, ventilation modes, gas content in coal seams, goaf extraction volume, and coal mining rate in coal mining face. The research results show that the approach can assess the risk of gas overflow in coal mining face

Discussion on Calculation Method of Soft Soil Foundation Settlement in Guangdong-Hong Kong-Macao Greater Bay Area

The modulus of compressibility of muddy soil in Dawan District is low, and the equivalent value of modulus of compressibility within the calculated depth range of foundation settlement is generally less than 2.5MPa, which exceeds the value range of empirical coefficient calculation basis for settlement calculation in the specification, and has the characteristics of large settlement. This time, according to the measured data of a coastal foundation settlement in Dawan District, the maximum settlement is fitted with the hyperbolic method, and the theoretical value of the total settlement is calculated according to the Code for Design of Building Foundation (GB50007-2011). Based on this analysis, the fitting curve equation of the empirical coefficient of settlement calculation when the equivalent value of the compression modulus is 2.5~4.15MPa is given, and the recommended value of the empirical coefficient of settlement calculation when the equivalent value of the compression modulus is 1.5~2.5MPa is calculated, so as to improve the calculation deviation of the original formula

Strong ion pairing at the origin of modified Li-cation solvation and improved performances of dual-salt electrolytes

Organic phosphates have been widely used as fire-retardant additives/co-solvents to improve the Li-ion electrolyte safety. However, these solvents show poor compatibility with low potential electrodes and cannot work efficiently as sole solvent at low salt concentration. The utilization of high concentration electrolytes was shown to improve the interfacial properties by altering the solvation structure but the drawbacks are low ionic conductivity, high viscosity, and elevated costs. Herein, a dual-salt phosphate-based electrolyte consisting of medium concentration lithium nitrate (LiNO3) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salts in triethyl phosphate (TEP) is analyzed and found to address the above issues. Benefiting from the strong affinity between NO3− and Li+, the use of LiNO3 is found to perturb the solvation structure, with mixed anion (NO3− and TFSI−) pairing with Li+. The detailed environment of Li+ in dual-salt phosphate-based electrolyte is probed through nuclear magnetic resonance and Raman analysis, corroborated by theoretical calculations. The dual-salt formulation is found to lead to the formation of a LiF–Li3N-LiNxOy-rich solid-electrolyte interphase on Li metal surface. The results and analyses not only allow the assembly of LiNi0·5Co0·2Mn0·3O2||Li cells with significantly improved cycling and low-temperature performances but also shine a light on taming strong polarity phosphate electrolytes with fine solvation interplay

Aft2, a Novel Transcription Regulator, Is Required for Iron Metabolism, Oxidative Stress, Surface Adhesion and Hyphal Development in <i>Candida albicans</i>

<div><p>Morphological transition and iron metabolism are closely relevant to <i>Candida albicans</i> pathogenicity and virulence. In our previous study, we demonstrated that <i>C. albicans</i> Aft2 plays an important role in ferric reductase activity and virulence. Here, we further explored the roles of <i>C. albicans</i> Aft2 in numerous cellular processes. We found that <i>C. albicans</i> Aft2 exhibited an important role in iron metabolism through bi-directional regulation effects on iron-regulon expression. Deletion of <i>AFT2</i> reduced cellular iron accumulation under iron-deficient conditions. Furthermore, both reactive oxygen species (ROS) generation and superoxide dismutase (SOD) activity were remarkably increased in the <i>aft2Δ/Δ</i> mutant, which were thought to be responsible for the defective responses to oxidative stress. However, we found that over-expression of <i>C. albicans AFT2</i> under the regulation of the strong <i>PGK1</i> promoter could not effectively rescue <i>Saccharomyces cerevisiae aft1Δ</i> mutant defects in some cellular processes, such as cell-wall assembly, ion homeostasis and alkaline resistance, suggesting a possibility that <i>C. albicans</i> Aft2 weakened its functional role of regulating some cellular metabolism during the evolutionary process. Interestingly, deletion of <i>AFT2</i> in <i>C. albicans</i> increased cell surface hydrophobicity, cell flocculation and the ability of adhesion to polystyrene surfaces. In addition, our results also revealed that <i>C. albicans</i> Aft2 played a dual role in regulating hypha-specific genes under solid and liquid hyphal inducing conditions. Deletion of <i>AFT2</i> caused an impaired invasive growth in solid medium, but an increased filamentous aggregation and growth in liquid conditions. Moreover, iron deficiency and environmental cues induced nuclear import of Aft2, providing additional evidence for the roles of Aft2 in transcriptional regulation.</p></div

A dicarbonate solvent electrolyte for high performance 5 V-Class Lithium-based batteries

Rechargeable lithium batteries using 5 V positive electrode materials can deliver considerably higher energy density as compared to state-of-the-art lithium-ion batteries. However, their development remains plagued by the lack of electrolytes with concurrent anodic stability and Li metal compatibility. Here we report a new electrolyte based on dimethyl 2,5-dioxahexanedioate solvent for 5 V-class batteries. Benefiting from the particular chemical structure, weak interaction with lithium cation and resultant peculiar solvation structure, the resulting electrolyte not only enables stable, dendrite-free lithium plating-stripping, but also displays anodic stability up to 5.2 V (vs. Li/Li+), in additive or co-solvent-free formulation, and at low salt concentration of 1 M. Consequently, the Li | |LiNi0.5Mn1.5O4 cells using the 1 M LiPF6 in 2,5-dioxahexanedioate based electrolyte retain >97% of the initial capacity after 250 cycles, outperforming the conventional carbonate-based electrolyte formulations, making this, and potentially other dicarbonate solvents promising for future Lithium-based battery practical explorations

Aft2 is required for the oxidative stress response.

<p>(A) Overnight cultures of each strain were resuspended in YPD medium with OD₆₀₀ of 0.1. 5 ul of cells in 10-fold serial dilutions were spotted onto solid YPD or YPD +1 mM Fe³⁺ medium that was supplemented with the indicated concentrations of H₂O₂. The plates were incubated at 30°C for 2 days and photographed. (B, C) Reactive oxygen species (ROS) and superoxide dismutase enzymes (SOD) activity were measured as described in Materials and methods.</p

Strains and plasmids used in this study.

<p>Strains and plasmids used in this study.</p

Environmental stimuli induce <i>C.albicans</i> Aft2 nuclear accumulation.

<p>Overnight cultures of the strain transformed with Aft2-GFP fusion plasmid were regrown to mid-exponential phase in YPD, YPD+100 µM BPS, YPD+10% serum and Spider medium, respectively. Cells were fixed with 3.7% formaldehyde, and then stained with 1 µg/ml 4',6-diamidino-2-phenylindole (DAPI) for 10 min. The subcellular localization of Aft2 was determined by confocal laser scanning microscopy. DIC, Differential interference contrast.</p

Influence of <i>AFT2</i> on surface properties in <i>C.albicans</i>.

<p>(A) The strains indicated were cultivated in RPMI 1640 medium to mid-exponential phase at 37°C. All tubes were vigorously vortexed, and cells were allowed to settle for 10 min before the flocculation observation. (B) Cell surface hydrophobicity was determined by the hydrocarbon/water partition method with xylene and hexadecane. Data indicate mean values ± standard deviations from three independent experiments performed in triplicates. (C) After 2 h, 4 h and 12 h incubation, the ability of adhesion to polystyrene was assessed through the quantification of total biomass by crystal violet staining. (D) The SEM assay was performed after 12 h incubation in a 24-well cell culture plate.</p