As one of the most serious shock dynamic disasters in coal mining, rock burst only occurs under the certain geodynamic environment. Geodynamic is the necessary requirement for the occurrence of rock ...burst, and the disturbance of mining engineering is the sufficient requirement. In terms of the fault structure, the method of geodynamic zoning is used to classify fault structure forms of rock burst in mines, and a model of geological structure is established to reveal the connection between fault structure and mine engineering. Besides, the influence of fault structure on rock burst is analyzed, and the controlling mechanism of the fault structure on the tectonic evolution of the mine area and the occurrence of rock burst is revealed. This research provides a treatment plan for the prediction and prevention of rock burst and guides the safe production in the coal mining engineering.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
This study focused on the non-covalent interaction between soybean protein isolate (SPI) and β-carotene (BC). The conformational changes of SPI with β-carotene in varying proportions (BC/SPI: 2%, 4%, ...6%, 8%, and 10%) were investigated by multi-spectroscopy and molecular docking. Results showed that the quenching mode is static quenching and binding affinity increased with temperature. The stoichiometry was 1:1, indicating there was only one binding site in SPI. The binding was based on entropy and primarily driven by hydrophobic interactions and its binding constant was in the order of 10
4
L⋅mol
–1
. The addition of the β-carotene affected the secondary structure of SPI resulting in an increase in α-Helix and a decrease in random coil and β-turn content, indicating protein aggregated and hydrophobic interactions occurred. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) verified that no new larger molecular weight substance was formed and no covalent interaction existed. Molecular docking corroborated that electrostatic and hydrophobic interactions were both involved in the formation of complexes, where hydrophobic interaction was the dominant one. Moreover, β-carotene improved 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, foaming capacity, and emulsifying stability of SPI. These findings provide useful information about the interaction mechanism of SPI and β-carotene, which contributes to the further development and application of SPI products rich in β-carotene in the food industry.
In recent years, the Sanjiang Plain has experienced drastic human activities, which have dramatically changed its ecological environment. Soil microorganisms can sensitively respond to changes in ...soil quality as well as ecosystem function. In this study, we investigated the changes in soil microbial community diversity and composition of three typical land use types (forest, wetland and cropland) in the Sanjiang Plain using phospholipid fatty acid analysis (PLFA) technology, and 114 different PLFA compounds were identified. The results showed that the soil physicochemical properties changed significantly (
< 0.05) among the different land use types; the microbial diversity and abundance in cropland soil were lower than those of the other two land use types. Soil pH, soil water content, total organic carbon and available nitrogen were the main soil physico-chemical properties driving the composition of the soil microbial community. Our results indicate that the soil microbial community response to the three different habitats is complex, and provide ideas for the mechanism by which land use changes in the Sanjiang Plain affect the structure of soil microbial communities, as well as a theoretical basis for the future management and sustainable use of the Sanjiang plain, in the northeast of China.
The conformational changes and functional properties of SPI induced by quercetin was investigated via fourier transform infrared (FTIR) spectroscopy, fluorescence spectroscopy, circular dichroism ...(CD) spectroscopy and molecular docking. A decrease in the fluorescence intensity and a blue shift in the maximum wavelength were observed due to the binding process with fluorescent residues. The analysis of Stern-Volmer equation showed that the fluorescence quenching induced by quercetin took the form of static quenching, and the binding stoichiometry between SPI and quercetin was 1:1. The values of ΔH and ΔS were both positive illustrating that hydrophobic interaction was the primary binding force between quercetin and SPI. Results of FTIR and CD indicated that the binding with quercetin changed the secondary structure of SPI, resulting in a partially unfolded and more flexible structure. SDS-PAGE confirmed there was no covalent interaction between the two constituents. Molecular docking demonstrated that there were stable configurations and high matching degrees in both 11S and 7S proteins with quercetin via hydrogen bonds and hydrophobic interactions. Meanwhile, modification by quercetin enhanced the foaming and emulsifying capacities of SPI. These findings might provide theory reference for elucidation the mechanism of polyphenols-proteins interaction and development of related food additive products in future.
Lithium-sulfur (Li-S) batteries are next-generation energy storage systems with high energy density, and the rate performance is a very important consideration for practical applications. Recent ...approaches such as introducing catalytic materials to facilitate polysulfide conversion have been explored, yet the results remain unsatisfactory. Here, we present an optimized Li-S electrode featured by a large amount of highly dispersed Co
S
nanoparticles (∼10 nm in size) throughout a hierarchical carbon nanostructure hybridized from ZIF-67 and carbon nanotube (CNT) sponge. This enables homogeneous distribution and close contact between infiltrated sulfur and Co
S
nanoparticles within the ZIF-67-derived N-doped carbon nanocubes, leading to effective chemical interaction with polysulfides, maximum catalytic effect and enhanced lithium ion diffusion, while the built-in three-dimensional CNT network ensures high electrical conductivity of the electrode. As a consequence, the Li-S battery exhibits both extraordinary rate performance by maintaining a capacity of ∼850 mAh g
at very high charge/discharge rate (5 C) and long-term cycling stability with 85% retention after 1000 cycles at 5 C (an average capacity fading rate of only 0.0137% per cycle).
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IJS, KILJ, NUK, PNG, UL, UM
Most naturally fractured gas reservoirs in China exhibit strongly heterogeneous, abnormally high-pressured and, stress-sensitive behaviors. In this work, a semianalytical solution is developed to ...study the production performance for limited-entry well in composite naturally fractured formations. The pressure-dependent porosity and permeability, anisotropy and limited-entry characteristics are taken into consideration. Furthermore, conventional Warren-Root model is amended to accommodate for permeability anisotropy. Laplace and finite Fourier cosine transforms are used to solve the diffusivity equations. The model is verified on the basis of previous literature’s results and data of a field example from Moxi gas field in Southwest China. Through the parameters sensitivity analysis, the effects of prevailing factors on production performance are investigated. Results indicate that a large inner region radius and high mobility ratio can improve gas production rate in the early stage, while they also lead to a drastic decline of production rate in the late stage. Large permeability stress-dependent coefficient and low penetrated interval both have a negative impact on production rate. With its high efficiency and simplicity, this proposed approach can serve as a convenient tool to evaluate the behavior of partially penetrated production well in abnormally high-pressured composite naturally fractured gas reservoirs.
Lithium–sulfur (Li–S) batteries are next-generation energy storage systems with high energy density, and the rate performance is a very important consideration for practical applications. Recent ...approaches such as introducing catalytic materials to facilitate polysulfide conversion have been explored, yet the results remain unsatisfactory. Here, we present an optimized Li–S electrode featured by a large amount of highly dispersed Co3S4 nanoparticles (∼10 nm in size) throughout a hierarchical carbon nanostructure hybridized from ZIF-67 and carbon nanotube (CNT) sponge. This enables homogeneous distribution and close contact between infiltrated sulfur and Co3S4 nanoparticles within the ZIF-67-derived N-doped carbon nanocubes, leading to effective chemical interaction with polysulfides, maximum catalytic effect and enhanced lithium ion diffusion, while the built-in three-dimensional CNT network ensures high electrical conductivity of the electrode. As a consequence, the Li–S battery exhibits both extraordinary rate performance by maintaining a capacity of ∼850 mAh g–1 at very high charge/discharge rate (5 C) and long-term cycling stability with 85% retention after 1000 cycles at 5 C (an average capacity fading rate of only 0.0137% per cycle).
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IJS, KILJ, NUK, PNG, UL, UM
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•Hyperthermophilic composting (HTC) accelerates the humification process of sludge.•HTC enhances the decomposition and polymerization of organic matter.•The C–O stretching of ...polysaccharide contributes to the formation of humus substances.•EEM–PARAFAC and 2DCOS provide indices for assessing the degree of humification.
The aim of this work was to study the chemical and structural changes of dissolved organic matter (DOM) at the molecular level during hyperthermophilic composting (HTC) of sewage sludge using excitation–emission matrix–parallel factor (EEM–PARAFAC) combined with two-dimensional correlation spectroscopy (2DCOS) analyses. Results showed that HTC accelerated the humification process by decreasing protein-like and increasing humus substances more quickly compared to conventional thermophilic composting. The rapid humification process of HTC was related to the structural changes of DOM, in which the C–O stretching within polysaccharides could be the main factor responsible for the formation of humus substances. Redundancy analysis enabled the relationship between spectral indices and composting parameters to be explained, demonstrating that these indices can be used for assessing the degree of humification. This work has contributed to resolving the humification mechanism of HTC and expanding the application of EEM–PARAFAC and 2DCOS.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•Hyperthermophilic composting (hTC) was used for in situ MPs removal firstly.•hTC significantly enhance biodegradation of sludge-based MPs.•The critical role of hyperthermophilic ...bacteria in MPs biodegradation was disclosed.•The underlying mechanisms of bio-oxidation MPs biodegradation during hTC was proposed.
Land spreading of sewage sludge is a major source of environmental microplastics (MPs) contamination. However, conventional sludge treatments are inefficient at removing sludge-based MPs. Herein, hyperthermophilic composting (hTC) technology is proposed and demonstrated in full-scale (200 t) for in situ biodegradation of sludge-based MPs. After 45 days of hTC treatment, 43.7% of the MPs was removed from the sewage sludge, which is the highest value ever reported for MPs biodegradation. The underlying mechanisms of MPs removal were investigated in lab-scale polystyrene-microplastics (PS-MPs) biodegradation experiments. The hTC inoculum degraded 7.3% of the PS-MPs at 70 °C in 56 days, which was about 6.6 times higher than that of the conventional thermophilic composting (cTC) inoculum at 40 °C. Analyses of the molecular weight and physicochemical properties of the PS-MPs residuals indicated that hyperthermophilic bacteria in hTC accelerated PS-MPs biodegradation through excellent bio-oxidation performance. High-throughput sequencing suggested that Thermus, Bacillus, and Geobacillus were the dominant bacteria responsible for the highly efficient biodegradation during hTC. These results reveal the critical role of hyperthermophilic bacteria in MPs biodegradation during hTC, highlighting a promising strategy for sludge-based MPs removal from the real environment.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this paper, we propose an advanced variational model for image segmentation and bias correction. In contrast to the majority of existing level set segmentation models that only consider ...illumination bias fields, we additionally consider the impact of image reflectance on segmentation accuracy. Our method is capable of effectively segmenting images with blurry edge structures affected by non-uniform illumination. In order to enhance segmentation efficiency, we directly segment the underlying structures of the images, construct spatial prior and apply adaptive regularization constraints on the structural component. Therefore, in the process of segmentation, the proposed algorithm can accurately identify object boundaries without being affected by the environment. Besides, the GL operator is applied to enhance the robustness of the model against noise. Furthermore, we use the alternating direction method of multipliers and the operator splitting algorithm for numerical solution. The experimental results obtained from various sorts of images illustrate that our model outperforms many leading-edge level set models with regard to robustness, corrected results and accuracy.
•A novel image segmentation model based on image structural prior is introduced.•An adaptive regularization constraint for adaptive restoration of image intensity.•The model is robust to images with noise and intensity inhomogeneity.•The split operator and alternating minimization algorithm are combined.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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