Study on coal pulverization characteristics and gas desorption mechanism based on impact crushing experiment.

The coal's particle size distribution properties after pulverization and the gas desorption behavior driven by pulverization are of profound meaning to the study of coal and gas outburst mechanism. In this paper, based on the impact crushing experiment, the tectonic coal and primary coal are crushed under different impact energy conditions. After screening the broken coal, the particle size distribution law is analyzed, and the characterization function suitable for the particle size distribution of coal particles after crushing is determined. The relationship between crushing work and new surface area and fractal dimension of coal body is discussed. The consequences indicated that the mass proportion of tectonic coal below 0.074 mm particle size is much huger than that of raw coal. G-S, R-R, and fractal distribution model describe the best particle size distribution of the two coals in the scope of 0.074∼4 mm. The new surface area added increases with the crushing work, and the tectonic coal is 1.34-1.96 times that of the raw coal. The fractal dimension diminishes first and then increases with the crushing work ratio. In addition, the gas desorption amount of coal particles with different particle sizes after coal pulverization was measured, and a dynamic model suitable for coal pulverization-driven gas desorption was established, and the experimental results were verified. The research results of this paper can provide experimental and theoretical basis for the analysis of energy dissipation in coal and gas outburst.

A Ni-O-Ag photothermal catalyst enables 103-m2 artificial photosynthesis with >17% solar-to-chemical energy conversion efficiency.

The scalable artificial photosynthesis composed of photovoltaic electrolysis and photothermal catalysis is limited by inefficient photothermal CO2 hydrogenation under weak sunlight irradiation. Herein, NiO nanosheets supported with Ag single atoms [two-dimensional (2D) Ni1Ag0.02O1] are synthesized for photothermal CO2 hydrogenation to achieve 1065 mmol g-1 hour-1 of CO production rate under 1-sun irradiation. This performance is attributed to the coupling effect of Ag-O-Ni sites to enhance the hydrogenation of CO2 and weaken the CO adsorption, resulting in 1434 mmol g-1 hour-1 of CO yield at 300°C. Furthermore, we integrate the 2D Ni1Ag0.02O1-supported photothermal reverse water-gas shift reaction with commercial photovoltaic electrolytic water splitting to construct a 103-m2 scale artificial photosynthesis system (CO2 + H2O → CO + H2 + O2), which achieves more than 22 m3/day of green syngas with an adjustable H2/CO ratio (0.4-3) and a photochemical energy conversion efficiency of >17%. This research charts a promising course for designing practical, natural sunlight-driven artificial photosynthesis systems.

Characterization of Coal Particle Methane Desorption and Optimization of Desorption Model Based on Desorption Damage.

In view of the current situation where most studies on gas desorption characteristics are limited to the atmospheric pressure desorption environment, we have independently developed a coal methane desorption instrument to test the nonatmospheric pressure desorption characteristics for coal particle gas beneath the condition of desorption damage. The instrument can arbitrarily adjust the gas pressure in the range of measurement while controlling the instantaneous release of excess gas to keep the desorption environment pressure constant. We measured the methane desorption amount of coal samples with different desorption times within 3 h and calculated the desorption velocity. The results show that the final desorption amount and desorption velocity of gas scale up with the increase of times, and the final desorption amount of coal sample W-01 increases the most, which is 18.5%. With the passage of time, the diffusion coefficient decreases gradually, and the number of desorption times is directly proportional to the diffusion coefficient. Its relative deviation of diffusion coefficient between different desorption times of the same coal sample can reach up to 40%, and the desorption time in the range of 5 to 30 min is the area with high relative deviation. A quantitative index Ki of a double-parameter damage model based on desorption conditions and adsorption pressure is proposed, and the damage extent of each sample is evaluated. The damage quantitative index of coal sample W-01 is the highest, which is 0.87. The methane desorption model of coal under the condition of desorption damage is constructed, and more than 30 groups of experiments are verified.

Influence of magma intrusion on coal geochemical characteristics: a case study of Tiefa Daxing coal mine.

Magma intrusion has an important influence on the physical and mechanical properties of coal and rock. In the area of magma intrusion, disasters such as gas outburst are prone to occur. Revealing its invasion law will be conducive to disaster management and energy development. For this purpose, changes in industrial analysis components of coal, mineral composition, major oxides, trace elements, and rare earth elements of coal under the thermal metamorphism of magma intrusion were analyzed. It is found that the moisture and volatile matter contents of the thermally affected coals in the mining face are generally lower than that of normal coals, while moisture and volatile matter contents are reduced towards to the magma intrusion contact. For example, the moisture and volatile matter of coal sample M01 decreased by 64.6% and 38.6% respectively compared with coal sample M05. During magma intrusion, some minerals remain on the surface of the coal body, resulting in changes in the mineral composition of the coal body. The decrease in carbon atom net spacing, the increase in crystallite aggregation and ductility, and aromaticity in thermally affected coals have a positive impact on the improvement of coal metamorphism. Due to the influences of magmatic intrusion, the variation rules of major oxides in coal are different, and the closer to the magmatic intrusion zone, the easier the major oxides are to be depleted. However, magma intrusion will not lead to the loss of all major oxides in thermally affected coals, such as content of CaO is 54.8%, which is higher than that of coal not affected by magmatic hydrothermal fluid. Most of the trace elements in the thermally affected coals of the No. 9 coal seam are depleted. The contents of rare earth elements are low on the whole coalbasis, with an average of 29.48 µg/g, and the distribution pattern towards to magmatic intrusion shows a wide and gentle "V" curve with left high and right low, showing the characteristics of enrichment of light rare earth elements.

T cell-mediated skin-brain axis: Bridging the gap between psoriasis and psychiatric comorbidities.

Psoriasis, a chronic inflammatory skin condition, is often accompanied by psychiatric comorbidities such as anxiety, depression, suicidal ideation, and other mental disorders. Psychological disorders may also play a role in the development and progression of psoriasis. The intricate interplay between the skin diseases and the psychiatric comorbidities is mediated by the 'skin-brain axis'. Understanding the mechanisms underlying psoriasis and psychiatric comorbidities can help improve the efficacy of treatment by breaking the vicious cycle of diseases. T cells and related cytokines play a key role in the pathogenesis of psoriasis and psychiatric diseases, and are crucial components of the 'skin-brain axis'. Apart from damaging the blood-brain barrier (BBB) directly, T cells and secreted cytokines could interact with the hypothalamic-pituitary-adrenal axis (HPA axis) and the sympathetic nervous system (SNS) to exacerbate skin diseases or mental disorders. However, few reviews have systematically summarized the roles and mechanisms of T cells in the interaction between psoriasis and psychiatric comorbidities. In this review, we discussed several key T cells and their roles in the 'skin-brain axis', with a focus on the mechanisms underlying the interplay between psoriasis and mental commodities, to provide data that might help develop effective strategies for the treatment of both psoriasis and psychiatric comorbidities.

Effect of Desorption Damage on the Kinetic Characteristics of Coal Particle Gas Desorption.

There is a positive feedback mechanism of desorption, pulverization, and redesorption in the process of coal and gas outburst. The coal pore structure changes to some extent in the process of coal pulverization and has a related impact on the dynamic parameters of coal particle gas desorption. To understand the impact of desorption damage on the dynamic characteristics of coal particle gas desorption, in this paper, a self-developed coal particle gas desorption test device is used to measure the amount of methane desorption of different coal samples repeatedly desorbed under the same adsorption equilibrium pressure. The results show that the methane desorption kinetic curves of the four coal samples based on desorption damage basically have the same trend. Nie's diffusion model can better describe the methane desorption characteristics of coal particles. After desorption, the methane desorption amount, initial desorption velocity, diffusion ability, and ultimate amount of methane desorption of the coal samples are greater than those before desorption. The desorption damage affects the relevant dynamic parameters of the coal particle gas diffusion model, and its impact on the outburst coal is greater than that on raw coal. In addition, the pore size distribution and change characteristics of the coal samples before and after desorption are analyzed quantitatively via a low-temperature liquid nitrogen adsorption test and fractal dimension-related theory. It was found that the pore volume peak area of the coal samples affected by desorption damage within each pore size range was significantly larger than that before desorption. Among them, micropores have the most significant impact on the desorption damage of coal samples, and the peak area of the pore volume of protruding coal is greater than that of raw coal, indicating that the internal pores of coal after desorption damage are more developed than those of raw coal.

Geochemical Changes in the Late Ordovician to Early Silurian Interval in the Northern Margin of the Upper Yangtze Platform, Southern China: Implications for Hydrothermal Influences and Paleocean Redox Circumstances.

A comprehensive chemostratigraphic study, including evaluation of rare earth elements and trace elements, was conducted to explain the paleoenvironments of the northern margin of the Upper Yangtze Platform. Trace elements, like Ba, U, V, Cu, and Zn, tended to be more abundant in these formations than in the upper continental crust. The authigenic abundances of Al-normalized U and V, as well as the Th/U and V/Sc ratios, were used as indicators of the redox circumstances. In the Nanjiang area, the redox circumstances of the bottom water during the Ordovician-Silurian transition changed from oxic in the Late Katian to slightly anoxic in the Hirnantian and then gradually became anoxic in the Early Rhuddanian. In the Chengkou area, the redox circumstances of the bottom water during the Ordovician-Silurian transition abruptly changed from oxic in the Late Katian to strongly anoxic in the Hirnantian and continued to become more anoxic until the Rhuddanian. The total organic carbon concentrations were well correlated with the redox circumstances of the bottom water. We conclude that the transient hydrothermal activity was not widely distributed during the Late Ordovician-Early Silurian transition, and it might also have been only a local event in the Upper Yangtze Platform. The enrichment in organic matter was mostly sourced from the photic zone and was governed by the redox circumstances of the bottom water.

Chemical Exchange Saturation Transfer (CEST) Signal at -1.6 ppm and Its Application for Imaging a C6 Glioma Model.

The chemical exchange saturation transfer (CEST) signal at -1.6 ppm is attributed to the choline methyl on phosphatidylcholines and results from the relayed nuclear Overhauser effect (rNOE), that is, rNOE(-1.6). The formation of rNOE(-1.6) involving the cholesterol hydroxyl is shown in liposome models. We aimed to confirm the correlation between cholesterol content and rNOE(-1.6) in cell cultures, tissues, and animals. C57BL/6 mice (N = 9) bearing the C6 glioma tumor were imaged in a 7 T MRI scanner, and their rNOE(-1.6) images were cross-validated through cholesterol staining with filipin. Cholesterol quantification was obtained using an 18.8-T NMR spectrometer from the lipid extracts of the brain tissues from another group of mice (N = 3). The cholesterol content in the cultured cells was manipulated using methyl-ß-cyclodextrin and a complex of cholesterol and methyl-ß-cyclodextrin. The rNOE(-1.6) of the cell homogenates and their cholesterol levels were measured using a 9.4-T NMR spectrometer. The rNOE(-1.6) signal is hypointense in the C6 tumors of mice, which matches the filipin staining results, suggesting that their tumor region is cholesterol deficient. The tissue extracts also indicate less cholesterol and phosphatidylcholine contents in tumors than in normal brain tissues. The amplitude of rNOE(-1.6) is positively correlated with the cholesterol concentration in the cholesterol-manipulated cell cultures. Our results indicate that the cholesterol dependence of rNOE(-1.6) occurs in cell cultures and solid tumors of C6 glioma. Furthermore, when the concentration of phosphatidylcholine is carefully considered, rNOE(-1.6) can be developed as a cholesterol-weighted imaging technique.

pH Mapping of Skeletal Muscle by Chemical Exchange Saturation Transfer (CEST) Imaging.

Magnetic resonance imaging (MRI) is extensively used in clinical and basic biomedical research. However, MRI detection of pH changes still poses a technical challenge. Chemical exchange saturation transfer (CEST) imaging is a possible solution to this problem. Using saturation transfer, alterations in the exchange rates between the solute and water protons because of small pH changes can be detected with greater sensitivity. In this study, we examined a fatigued skeletal muscle model in electrically stimulated mice. The measured CEST signal ratio was between 1.96 ppm and 2.6 ppm in the z-spectrum, and this was associated with pH values based on the ratio between the creatine (Cr) and the phosphocreatine (PCr). The CEST results demonstrated a significant contrast change at the electrical stimulation site. Moreover, the pH value was observed to decrease from 7.23 to 7.15 within 20 h after electrical stimulation. This pH decrease was verified by 31P magnetic resonance spectroscopy and behavioral tests, which showed a consistent variation over time.

Rapid identification and differentiation of Trichophyton species, based on sequence polymorphisms of the ribosomal internal transcribed spacer regions, by rolling-circle amplification.

DNA sequencing analyses have demonstrated relatively limited polymorphisms within the fungal internal transcribed spacer (ITS) regions among Trichophyton spp. We sequenced the ITS region (ITS1, 5.8S, and ITS2) for 42 dermatophytes belonging to seven species (Trichophyton rubrum, T. mentagrophytes, T. soudanense, T. tonsurans, Epidermophyton floccosum, Microsporum canis, and M. gypseum) and developed a novel padlock probe and rolling-circle amplification (RCA)-based method for identification of single nucleotide polymorphisms (SNPs) that could be exploited to differentiate between Trichophyton spp. Sequencing results demonstrated intraspecies genetic variation for T. tonsurans, T. mentagrophytes, and T. soudanense but not T. rubrum. Signature sets of SNPs between T. rubrum and T. soudanense (4-bp difference) and T. violaceum and T. soudanense (3-bp difference) were identified. The RCA assay correctly identified five Trichophyton species. Although the use of two "group-specific" probes targeting both the ITS1 and the ITS2 regions were required to identify T. soudanense, the other species were identified by single ITS1- or ITS2-targeted species-specific probes. There was good agreement between ITS sequencing and the RCA assay. Despite limited genetic variation between Trichophyton spp., the sensitive, specific RCA-based SNP detection assay showed potential as a simple, reproducible method for the rapid (2-h) identification of Trichophyton spp.