Based on the quasi-steady-state approximation, the dynamic equation of char combustion in the oxidation zone of underground coal gasification (UCG) was derived. The parameters of the dynamic equation were determined a...
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Based on the quasi-steady-state approximation, the dynamic equation of char combustion in the oxidation zone of underground coal gasification (UCG) was derived. The parameters of the dynamic equation were determined at 900℃ using a thermo-gravimetric (TG) analyzer connected to a flue gas analyzer and this equation. The equation was simplified for specific coals, including high ash content, low ash content, and low ash fusibility ones. The results show that 1) the apparent reaction rate constant increases with an increase in volatile matter value as dry ash-free basis,2) the effective coefficient of diffusion decreases with an increase in ash as dry basis, and 3) the mass transfer coefficient is independent of coal quality on the whole. The apparent reaction rate constant, mass-transfer coefficient and effective coefficient of diffusion of six char samples range from 7.51×104 m/s to 8.98×104 m/s, 3.05×106 m/s to 3.23×106 m/s and 5.36×106 m2/s to 8.23×106 m2/s at 900℃, respectively.
The interplay between novel topological states and superconductivity has garnered substantial interest due to its potential for topological quantum *** Josephson effect serves as a useful probe for edge superconductiv...
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The interplay between novel topological states and superconductivity has garnered substantial interest due to its potential for topological quantum *** Josephson effect serves as a useful probe for edge superconductivity in these hybrid topological *** Josephson junctions based on topological materials,supercurrents exhibit unique quantum interference patterns,including the conventional Fraunhofer oscillations,theΦ_(0)-periodic oscillation,and the 2Φ_(0)-periodic oscillation in response to the external magnetic field(Φ_(0)=h/2e is the flux quantum,h the Planck constant,and e the electron charge).These interference patterns stem from varied Andreev reflection mechanisms and the associated current density *** review seeks to comprehensively examine the theoretical and experimental advancements in understanding the quantum interference patterns of edge supercurrents in Josephson junctions based on quantum spin Hall,quantum Hall,and quantum anomalous Hall systems.
To improve the resilience of railway stations,a typical station was selected as the research object,and an isolation design was ***-four groups of near-fault pulse-like ground motions were *** seismic resilience of th...
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To improve the resilience of railway stations,a typical station was selected as the research object,and an isolation design was ***-four groups of near-fault pulse-like ground motions were *** seismic resilience of the no-isolation railway stations(NIRS)and the isolation railway stations(IRS)were compared to provide a numerical result of the improvement in *** results show that in the station isolation design,the station's functional requirements and structural characteristics should be considered and the appropriate placement of isolation bearings is under the waiting *** the action of a rare earthquake,the repair cost,repair time,rate of harm and death of the IRS were decreased by 8.04 million,18.30 days,6.93×10^(-3)and 1.21×10^(-3),respectively,when compared to the *** IRS received a seismic resilience grade of three-stars and the NIRS only one-star,indicating that rational isolation design improves the seismic resilience of ***,for the design of stations close to earthquake faults,it is suggested to utilize appropriate isolation techniques to improve their seismic resilience.
The hydrodynamics and their evolution on the Upper Yangtze Block during the Ordovician-Silurian transition period remain unclear. The present study is an assessment of how regional and global events may have influence...
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The hydrodynamics and their evolution on the Upper Yangtze Block during the Ordovician-Silurian transition period remain unclear. The present study is an assessment of how regional and global events may have influenced the hydrodynamic evolution based on a planar lamination investigation of the shales from the Upper Yangtze Block. Analyses of large thin sections and argon-ion polished thin sections using field emission-scanning electron microscopy(FE-SEM) showed that there are four types of planar lamination, namely, silty graded planar lamination(SGPL), silt-clay graded planar lamination(SCGPL), silt-clay interlaminated planar lamination(SCIPL), and paper-like planar lamination(PPL). SGPL is formed by turbidity current with a flow speed less than 15 cm/s. SCGPL is formed by turbidity currents with a flow speed less than 15 cm/s for normal grading type and 15-25 cm/s for alternating grading type. SCIPL has a continuum of sparsely spaced type, closely spaced type, and alternating type, which is formed by bottom current with an increasing flow speed from 15 to 25 cm/s to above 25 cm/s. PPL can be divided into normal grading and composite grading types. The former is formed by vertical settling, while the latter is formed by bottom current with a flow speed of 5-15 cm/s. Vertically, types of planar lamination varied from SGPL to PPL and then SCIPL manifesting the waxing and waning of flow speed with a positive excursion at graptolite biozone Metabolograptus extraordinarius(WF4) and a negative excursion at graptolite biozone Persculptograptus persculptus(LM1). The sudden decrease in flow speed across Linxiang and graptolite biozone Paraorthograptus pacificus(WF3) and the subsequent progressive increase from graptolite biozone Akidograptus ascensus(LM2)to graptolite biozone Demirastrites triangulatus(LM6) and to graptolite biozone Stimulograptus sedgwickii(LM8) during deposition of the Ordovician-Silurian transition succession on the Upper Yangtze Block were linked to th
Why do humans punish free riders at their own expense? This behavior represents an evolutionary puzzle in human societies. This study explores the role of exit strategies in fostering altruistic punishment within evol...
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Why do humans punish free riders at their own expense? This behavior represents an evolutionary puzzle in human societies. This study explores the role of exit strategies in fostering altruistic punishment within evolutionary game theory. We extend the traditional prisoner's dilemma model by incorporating exiters, players who opt out for a small payoff while nullifying their opponent's payoff, and altruistic punishers who cooperate and punish non-cooperators. Our findings indicate that in well-mixed populations, exiters destabilize defection but do not promote altruistic punishment. In social networks, however,exiters enable altruistic punishment via cyclic dominance among altruistic punishers, defectors, and exiters. Notably, this cyclic dominance is sensitive to exit payoffs; adjustments can lead to cyclic dominance of non-punishing cooperators, defectors, and exiters, or to a bi-stable state between these two types of cyclic dominance. These results highlight the nuanced impact of exiters on altruistic punishment, emphasizing the need for careful incentivization of exit behavior. While exiters can support altruistic punishment in networked populations, their effectiveness is not a panacea and is highly sensitive to exit payoffs, indicating limits to the voluntary participation mechanism.
Rare earth-doped inorganic compounds contribute mostly to the family of persistent luminescent materials due to the versatile energy levels of rare earth *** of the key research aims is to match the trap level stemmin...
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Rare earth-doped inorganic compounds contribute mostly to the family of persistent luminescent materials due to the versatile energy levels of rare earth *** of the key research aims is to match the trap level stemming from the doped rare earth ion or intrinsic defects to the electronic structure of the host,and therefore thermoluminescence measurement becomes a radical technology in studying trap depth,which is one of the significant parameters that determine the properties of persistent luminescence and photostimulated ***,the results of trap depth obtained by different thermoluminescence methods are quite different so that they are not ***,we analyzed different thermoluminescence methods,selected and improved the traditional peak position method of Tm/500 to be E=(-0.94Inβ+30.09)*** the experimental heating rate(β) is needed additionally,but the accuracy is improved greatly in most *** convenient and accurate method will accelerate the discovery of novel rare earth-doped materials.
Tanycytes, specialized ependymal cells located in the hypothalamus, play a crucial role in the generation of new neurons that contribute to the neural circuits responsible for regulating the systemic energy balance. T...
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Tanycytes, specialized ependymal cells located in the hypothalamus, play a crucial role in the generation of new neurons that contribute to the neural circuits responsible for regulating the systemic energy balance. The precise coordination of the gene networks controlling neurogenesis in naive and mature tanycytes is essential for maintaining homeostasis in adulthood. However, our understanding of the molecular mechanisms and signaling pathways that govern the proliferation and differentiation of tanycytes into neurons remains limited. This article aims to review the recent advancements in research into the mechanisms and functions of tanycyte-derived neurogenesis. Studies employing lineage-tracing techniques have revealed that the neurogenesis specifically originating from tanycytes in the hypothalamus has a compensatory role in neuronal loss and helps maintain energy homeostasis during metabolic diseases. Intriguingly,metabolic disorders are considered early biomarkers of Alzheimer's disease. Furthermore,the neurogenic potential of tanycytes and the state of newborn neurons derived from tanycytes heavily depend on the maintenance of mild microenvironments, which may be disrupted in Alzheimer's disease due to the impaired blood–brain barrier ***, the specific alterations and regulatory mechanisms governing tanycyte-derived neurogenesis in Alzheimer's disease remain unclear. Accumulating evidence suggests that tanycyte-derived neurogenesis might be impaired in Alzheimer's disease, exacerbating neurodegeneration. Confirming this hypothesis, however, poses a challenge because of the lack of long-term tracing and nucleus-specific analyses of newborn neurons in the hypothalamus of patients with Alzheimer's disease. Further research into the molecular mechanisms underlying tanycyte-derived neurogenesis holds promise for identifying small molecules capable of restoring tanycyte proliferation in neurodegenerative diseases. This line of investigation could pro
N-participated lignin depolymerization is of great importance for the transformation of waste lignin into value-added *** vast majority of developed strategies employ organic amines as nitrogen source,and considerable...
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N-participated lignin depolymerization is of great importance for the transformation of waste lignin into value-added *** vast majority of developed strategies employ organic amines as nitrogen source,and considerablemethods rely on excessive use of strong base,which suffers severe environmental ***,benzonitrile derivatives are synthesized from oxidized ligninβ-O-4 model compounds in the presence of solid nitrogen source(NH_(4))_(2)CO_(3)under mild,base-free conditions over commercially available copper *** studies suggest the transformation undergoes a one-pot,highly coupled cascade reaction path involving oxidative C-C bond cleavage and in-situ formation of C≡N *** which,Cu(OAc)2 catalyzes the transfer of hydrogen from C_(β)(C_(β)-H)to C_(α),leading to the cleavage of C_(α)-C_(β)bonds to offer benzaldehyde derivative,this intermediate then reacts in-situ with(NH_(4))_(2)CO_(3)to afford the targeted aromatic nitrile *** iodide(TBAI),acting as a promoter,plays a key role in breaking the C_(α)-C_(β)bonds to form the intermediate benzaldehyde *** this protocol,the feasibility of the production of value-added syringonitrile from birchwood lignin has been *** transformation provides a sustainable approach to benzonitrile chemicals from renewable source of lignin.
Renewable energy-driven bicarbonate conversion to valuable chemicals presents an attractive strategy for mitigating CO_(2)emissions,as bicarbonate can be efficiently generated from the capture of atmospheric CO_(2)usi...
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Renewable energy-driven bicarbonate conversion to valuable chemicals presents an attractive strategy for mitigating CO_(2)emissions,as bicarbonate can be efficiently generated from the capture of atmospheric CO_(2)using alkaline solutions with reactive *** this work,we present a CO_(2)-mediated bicarbonate conversion to pure formate using a cation exchange membrane-based electrolyzer with a 25 cm^(2)electrode *** electrolysis achieved selectivities exceeding 75%for formate at a total current of 2.5 A,achieving formate concentrations up to 1.2 M and yields as high as 95%over extended *** techno-economic assessment confirmed the economic viability of the process,highlighting the potential for bicarbonate electrolysis as a sustainable method for producing valuable chemicals.
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