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  1. Article ; Online: Construction of macromolecular structure in KunNing coal and analysis of Macro-Micro oxidation characteristics

    Dongjie Hu / Zongxiang Li / Yu Liu / Lin Li

    Arabian Journal of Chemistry, Vol 17, Iss 1, Pp 105499- (2024)

    1481  

    Abstract: To explore the macro–micro coal oxidation characteristics for the purpose of preventing coal spontaneous combustion and achieving efficient coal conversion and utilization, the enclosed coal oxidation characteristics of KunNing coal sample (KN) under 25– ... ...

    Abstract To explore the macro–micro coal oxidation characteristics for the purpose of preventing coal spontaneous combustion and achieving efficient coal conversion and utilization, the enclosed coal oxidation characteristics of KunNing coal sample (KN) under 25–70 °C were investigated. KN coal molecular models were constructed based on analysis and testing results of X-ray Photoelectron Spectroscopy (XPS), Carbon-13 Nuclear Magnetic Resonance Spectroscopy (13C NMR), Fourier Transform Infrared Spectroscopy (FTIR) and other techniques. The pyrolysis processes of coal-oxygen reaction systems with different oxygen contents were simulated using ReaxFF force field. The results show that the oxygen consumption rate, CO release rate, CO2 release rate and oxidation heat release intensity of coal increase exponentially with rising temperature. The ratio of aromatic bridge carbon to peripheral carbon in KN coal molecular structure is 0.08, and the molecular formula is C149H76O15N2S2. In the later stage of the experimental and molecular dynamics simulation processes, the CO content decreased while the growth rate of CO2 increased. Different indicator gases exhibit varied responses to oxygen content. The C-atom labeling and traceback results for the four indicator gas molecules demonstrate that CO2 mainly comes from aldehyde, hydroxyl, carboxyl and methoxy groups in coal molecules, CO is primarily generated from esters, phenols, carbonyls, C2H2 is predominantly derived from ring-opening and cracking of cycloalkanes, and the source of C2H4 is related to cycloalkanes and alcohols.
    Keywords Enclosed coal oxidation test ; Oxidation heat release intensity ; Reaction kinetics ; Indicator gas molecule traceback ; Active groups ; Chemistry ; QD1-999
    Subject code 660
    Language English
    Publishing date 2024-01-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Dynamic distribution and prevention of spontaneous combustion of coal in gob-side entry retaining goaf.

    Dongjie Hu / Zongxiang Li

    PLoS ONE, Vol 17, Iss 5, p e

    2022  Volume 0267631

    Abstract: The 11101 working face of Qipanjing Mine was taken as the research object to explore the dynamic change law of the spontaneous combustion of the remaining coal in the gob-side entry retaining goaf area. A sealed oxygen consumption experiment was ... ...

    Abstract The 11101 working face of Qipanjing Mine was taken as the research object to explore the dynamic change law of the spontaneous combustion of the remaining coal in the gob-side entry retaining goaf area. A sealed oxygen consumption experiment was conducted to determine the (critical) oxygen volume fraction in the suffocation zone and continuous oxygen consumption rate of coal samples. The parameters of the working face were measured on site, and the air volume fraction in the goaf was monitored using a beam tube. Considering upward ventilation and the effect of gravity, a UDF control program for the falling medium in the gob-side entry retaining goaf was written. Based on the experimental results, a control program for the continuous oxygen consumption rate of the remnant coal was compiled, the dynamic distribution of the flow field in the gob-side entry retaining goaf was simulated with different advancing positions and air leakage at the working face, and a prediction model for the spontaneous combustion danger area was established. Finally, fire prevention measures via grouting in the return air lane side and nitrogen injection in the retaining lane side were put forward. The results showed that with the variation in the advancing position of the working face or in the air leakage of the air intake lane, the range of the natural hazardous area of the gob-side entry retaining goaf presents a distribution with a power function SF = xn+b (0 < n < 1). The theoretically proposed fire-fighting measures can effectively reduce the risk of spontaneous combustion of coal.
    Keywords Medicine ; R ; Science ; Q
    Subject code 690
    Language English
    Publishing date 2022-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Effects of stratified mining on the low-temperature oxidation and physicochemical properties of lower coal layers

    Dongjie Hu / Zongxiang Li / Yu Liu / Cong Ding / Chuntong Miao / Haiwen Wang

    Arabian Journal of Chemistry, Vol 17, Iss 2, Pp 105476- (2024)

    2024  

    Abstract: To investigate the impact of stratified mining on the spontaneous combustion characteristics of lower coal in thick coal seams, an analysis was conducted on the macro pore structure, temperature rise, oxygen consumption characteristics, chemical ... ...

    Abstract To investigate the impact of stratified mining on the spontaneous combustion characteristics of lower coal in thick coal seams, an analysis was conducted on the macro pore structure, temperature rise, oxygen consumption characteristics, chemical structure, surface chemical properties, and functional group distribution of the upper and lower stratified coal samples (LSC, LSR) from the LinSheng Mine 1202 re-mining face. Post re-mining, the specific surface area, average pore diameter for adsorption, micropore volume, and mesopore volume of LSR showed a significant increase compared to LSC. The maximum mass loss rate for LSR was approximately three times that of LSC, and the characteristic temperature of LSR was lower. When the volumetric fraction of oxygen exceeded 12%, the oxygen consumption rate and CO generation rate of LSR surpassed those of LSC. The alkyl carbon content in LSR was 2% lower compared to LSC, while the oxygenated carbon content was higher by 4.37%. The oxygen content in LSR and the O/C ratio were higher than those in LSC. The structural order of LSR was lower by 11.3%, and the oxygen-containing functional groups were higher by 1.15%. These findings suggest that stratified mining increases the spontaneous combustion risk of lower coal layers. This study underscores the need for careful consideration of mining strategies to mitigate potential risks.
    Keywords Stratified Mining ; Spontaneous Combustion of Coal ; Macro Pore Structure ; Oxidation Characteristics ; Micro Chemical Structure ; Chemistry ; QD1-999
    Subject code 620
    Language English
    Publishing date 2024-02-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Construction of macromolecular model and analysis of oxygen absorption characteristics of Hongyang No. 2 coal mine

    Cong Ding / Zongxiang Li / Dongjie Hu / Chuntong Miao / Bing Lu / Dameng Gao

    Arabian Journal of Chemistry, Vol 16, Iss 5, Pp 104662- (2023)

    2023  

    Abstract: Understanding the molecular structure characteristics of coal from the molecular level is of great significance for realizing rational utilization and efficient transformation of coal. The molecular structure of coal samples from 1304 working face in No ... ...

    Abstract Understanding the molecular structure characteristics of coal from the molecular level is of great significance for realizing rational utilization and efficient transformation of coal. The molecular structure of coal samples from 1304 working face in No.13 coal seam of Hongyang No.2 Mine (HY) was studied by industrial analysis, elemental analysis, Nuclear magnetic resonance carbon spectroscopy (13C NMR) and Fourier transform infrared spectroscopy (FTIR). The results show that the aromatic compounds in coal samples of HY are mainly naphthalene ring structures. The aliphatic structure mainly consists of methyl, ethyl side chains and cycloalkanes. The ratio of aromatic bridge carbon to weekly carbon in molecular structure is 0.17. Oxygen atoms exist in the form of carbonyl, hydroxyl, and ether bonds, nitrogen atoms exist in the form of pyridine and pyrrole respectively, and sulfur atoms exist in the form of thiophene. Based on this, the planar structure model of coal macromolecule in HY is constructed, and its molecular formula is C129H88O29N2S, and its molecular weight is 2160. The structure optimization and annealing kinetics simulation of a single macromolecule model were carried out, and a stable three-dimensional coal model of HY was obtained. In addition, the oxygen absorption characteristics of coal samples in HY were studied by molecular dynamics and quantum chemistry. The results show that the adsorption capacity of the Wiser model is less than that of HY coal model. This is because, compared with the Wiser model, the content of oxygenated aliphatic hydrocarbons in the molecular structure of HY coal is higher, and the condensation degree of polycyclic aromatic hydrocarbons is lower. Due to the stronger physical adsorption capacity of hydroxyl, ether bond, and carbonyl on O2, HY Mine has stronger physical adsorption capacity on O2.
    Keywords Oxygen absorption characteristics ; Molecular structure model ; 13C NMR ; FTIR ; Molecular dynamics ; Chemistry ; QD1-999
    Subject code 541
    Language English
    Publishing date 2023-05-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: Spatio-temporal evolution law of gas-temperature coupling field in "110 method" goaf and prevention of spontaneous combustion.

    Song Wei / Zhenqing Fang / Zongxiang Li / Yu Liu / Dongjie Hu / Chuntong Miao / Haiwen Wang

    PLoS ONE, Vol 18, Iss 11, p e

    2023  Volume 0293829

    Abstract: To investigate the distribution characteristics of spontaneous combustion disaster (SCD) zones in the goaf of "110" mining method with U + L ventilation system and formulate corresponding fire prevention measures, enclosed coal oxidation experiments were ...

    Abstract To investigate the distribution characteristics of spontaneous combustion disaster (SCD) zones in the goaf of "110" mining method with U + L ventilation system and formulate corresponding fire prevention measures, enclosed coal oxidation experiments were carried out to measure the oxidation characteristics of Dongrong Coal Mine bituminous coal sample. A coupled 3DEC-CFD (3 dimensional Distinct Element Code) model was established. The 3D transient distribution characteristics of SCD zones in the "110" mining goaf under U+L ventilation condition were analyzed. Nitrogen injection in the tailgate was proposed for coal spontaneous combustion prevention. The results show that air leakage changed the distribution of oxygen and temperature fields in the "110" goaf, causing the region 20~60 m parallel to the retained roadway to remain in the oxidation zone for spontaneous combustion. As the working face advanced, the area change curve of SCD zones in the "110" goaf exhibited a "double inflection point" pattern. Eliminating the "retained roadway oxidation zone" can effectively reduce the spontaneous combustion risks in the "110" goaf and ensure mining safety. This study enriches the mechanisms of coal spontaneous combustion.
    Keywords Medicine ; R ; Science ; Q
    Language English
    Publishing date 2023-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Inhibition of cystathionine β-synthase promotes apoptosis and reduces cell proliferation in chronic myeloid leukemia

    Dan Wang / Huan Yang / Yun Zhang / Rong Hu / Dongjie Hu / Qunxian Wang / Yannan Liu / Mingjing Liu / Zijun Meng / Weihui Zhou / Weihong Song

    Signal Transduction and Targeted Therapy, Vol 6, Iss 1, Pp 1-

    2021  Volume 11

    Abstract: Abstract Increased endogenous hydrogen sulfide (H2S) level by cystathionine β-synthase (CBS) has been shown to closely relate tumorigenesis. H2S promotes angiogenesis, stimulates bioenergy metabolism and inhibits selective phosphatases. However, the role ...

    Abstract Abstract Increased endogenous hydrogen sulfide (H2S) level by cystathionine β-synthase (CBS) has been shown to closely relate tumorigenesis. H2S promotes angiogenesis, stimulates bioenergy metabolism and inhibits selective phosphatases. However, the role of CBS and H2S in chronic myeloid leukemia (CML) remains elusive. In this study, we found that CBS and H2S levels were increased in the bone marrow mononuclear cells of pediatric CML patients, as well as in the CML-derived K562 cells and CBS expression levels were correlated with different disease phases. Inhibition of CBS reduced the proliferation of the CML primary bone marrow mononuclear cells and induced growth inhibition, apoptosis, cell cycle arrest, and migration suppression in K562 cells and tumor xenografts. The knockdown of CBS expression by shRNA and inhibiting CBS activity by AOAA decreased the endogenous H2S levels, promoted mitochondrial-related apoptosis and inhibited the NF-κB-mediated gene expression. Our study suggests that inhibition of CBS induces cell apoptosis, as well as limits cell proliferation and migration, a potential target for the treatment of chronic myeloid leukemia.
    Keywords Medicine ; R ; Biology (General) ; QH301-705.5
    Subject code 610
    Language English
    Publishing date 2021-02-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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