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To investigate how the micro-mechanism of multi-component gas injection affects the process of retrieving methane, a combination of density functional theory and molecular dynamics simulation method has been conducted under different gas injection ratios of CO 2 and N 2. The results of DFT demonstrate that the adsorption energy of the gas molecules over bituminous coal fragment are in order of CO 2 > CH 4 > N 2. Independent gradient model analyses show that the Van der Waals interactions are the dominant force contributing to these three adsorption behaviors. To gain further insight into the influence of functional groups on CH 4 adsorption, the radial distribution function analyses have been performed. It was found that oxygen-containing functional groups have a substantial impact on the adsorption of CH 4 on coal molecules. Among these, CH 4 preferentially adsorb around the hydroxyl group of coal molecule. Moreover, density profiles of the three gas molecules within nanopores demonstrate that CO 2 molecules cause CH 4 molecules to desorb by molecular swapping. In contrast, N 2 slows down CH 4 adsorption spontaneity by lowering CH 4 partial pressure. Furthermore, it should be noted that increasing the proportion of CO 2 in the gas mixture system can significantly improve the displacement efficiency of CH 4. Conversely, the diffusion coefficient becomes small. The microscopic mechanism revealed in the present work helps us gain a better understanding of gas displacement processes, which provides new insights for optimizing gas injection compositions for field applications. • The microscopic mechanism of CO 2 /N 2 displacement of CH 4 in coal micropores was proposed. • Oxygen-containing functional groups in coal play a key role in the adsorption and displacement processes of CH 4. • A method was proposed to consider the CO 2 /N 2 injection ratio. [ABSTRACT FROM AUTHOR]

In this study, a novel bimetallic complexation–curing nucleation–anaerobic calcination method was developed to synthesize a nano-CuFe 2 O 4 @coconut shell biochar (CuFe 2 O 4 @CSBC) catalyst to activate peroxymonosulfate for degradation of tetrabromobisphenol A (TBBPA). The reaction processes of the TBBPA on CuFe 2 O 4 @CSBC have been investigated using in situ characterization and metal leaching. The effects of initial reaction conditions and degradation mechanism were investigated. Greater than 99% degradation of TBBPA at 10 mg L−1 was achieved in 30 min under the condition of pH 11, a total organic carbon removal rate of up to 70.67% was achieved and the degradation efficiency was 90% after 5 cycles of CuFe 2 O 4 @CSBC use. The degradation was in a second-order reaction at a constant of 0.797 M−1 min−1 (R2 = 0.993). The degradation was attributed to the main active species (SO 4 ·−≈·OH < 1O 2), and the surface active site of CuFe 2 O 4 @CSBC was the key role. The degradation process involved three main degradation pathways. Path A: ·OH attacked the C–Br bonds (TBBPA→TriBBPA→DBBPA→MBBPA→BPA); Path B: Hydroxylation and decarboxylation; Path C: Dehydrocoupling of TBBPA. What's more, the practical application of the system was very positive, achieved >77% degradation in sewage and industrial wastewater. [Display omitted] • CuFe 2 O 4 @CSBC was prepared by an innovative method and achieved an excellent effect • TBBPA and TOC removal rates of up to 100% and 70.67%, respectively, were achieved • Cu + acted directly on PMS or transferred electrons to Fe3+ to form Fe2+-activated PMS • SO 4 ·−, ·OH, 1O 2 , and electron transfer were involved in TBBPA degradation • CuFe 2 O 4 @CSBC/PMS had good practical application performance [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol (PVA) is a biodegradable material that can be degraded under natural conditions. In this study, a sustained-release agent (SRA) was prepared from calcium compounds and PVA (PVA-Ca) to effectively degrade long-chain fatty acids in food waste (FW) and improve the performance of anaerobic digestion (AD). The most appropriate materials and conditions for synthesizing Ca-SRA were chosen according to the characteristics of the sample and changes in the electrical conductivity of a solution of the SRA. The calcium release kinetics were analyzed by curve fitting. Moreover, analytical methods were used to analyze the formation mechanism of PVA-Ca. Finally, the effect of PVA-Ca on the performance of AD was investigated. The results showed that the most suitable materials for preparing the Ca-SRA were Ca(OH) 2 powder and PVA1799. The most suitable synthesis conditions were freezing for 24 h at −20 °C and thawing for 24 h with one freeze–thaw cycle. PVA-Ca achieved rapid release during the first 48 h, which corresponded to first-order kinetics (k = 0.0354 h−1). The release of Ca2+ corresponded to changes in pH and the concentration of volatile fatty acids during hydrolysis and acidification of FW. After PVA-Ca was added, the duration of the system lag phase was significantly shortened to 10 days, the methane yield per unit load was increased from 238.2 to 489.3 mL g−1 volatile solids(VS), and the kinetic constant of AD of FW was 0.083 day−1. Adding PVA-Ca could increase the methane yield by 98.82%. Moreover, the value of T 90 was reduced to a maximum of about 16 days. PVA-Ca was successfully employed in the AD of FW for the first time. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Tube-like nanostructure, especially carbon nanotube, usually has distinguished properties, making itself useful substrate for producing hybrid and composite materials with various applications. In this study, we proposed a space-confined self-oriented reaction in a single-ended reactor for the directional-induced decomposition of plate-like Zn-Fe double metal cyanide nanostructure. Two novel different kinds of magnetic self-supported carbon-based nanocomposites, FeC nanoparticle@ZnCN 2 nanotube composite and austenite/Fe nanoparticle@carbon nanotube composite, were respectively synthesized. These nanotubes subjected to the plate-like precursor were short and non-intertwined, unlike most carbon nanotubes reported before. It was found that reactor geometry plays key roles in the self-oriented growth of these carbon-based nanoarrays and fine tubular reactors with different reducing aspect ratio (AR) values result in different nanocomposite products. [ABSTRACT FROM AUTHOR]

This paper develops a missile formation algorithm. The general form of time-varying formation constraints in three-dimensional space for missiles is deduced, and the formation control under time-varying position constraints is transformed into constrained optimization problem. Based on discretization of trajectory and optimization of control outputs, an approach to design optimal feedback control algorithm is presented. The three degree of freedom simulation results of the missiles obtained by constraint optimization show that the formation strategy proposed in this paper is feasible in missile formation control under complex time-varying constraint. [ABSTRACT FROM AUTHOR]

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). Post-publication, the editor discovered suspicious changes in authorship between the original submission and the revised version of this paper. In summary, the author names Yan Zhang (new First Author and Corresponding Author), Fangmin Yuan, Huipeng Zhai and Chuang Song were added to the revised paper without explanation and without exceptional approval by the journal editor, which is contrary to the journal policy on changes to authorship. The editor reached out to the authors for an explanation, but they failed to provide a satisfactory explanation to these changes. In addition, it appears that Roza Poursoleiman was claiming an affiliation with Sun-Life Company, Baku, Azerbaijan. When questioned, the author was unable to provide convincing evidence of the existence and nature of this company. Overall, the editor feels that the findings of the manuscript cannot be relied uon and that the article needs to be retracted. [ABSTRACT FROM AUTHOR]

Abstract: The effect of magnetic field on the magnetic properties of the one-dimensional spin-1 ferromagnetic Heisenberg model is studied by the double-time Green’s function method. The magnetization and susceptibility are obtained within the Callen approximation. The zero-field susceptibility is as a decreasing function of the temperature . The magnetization increases in the whole field region, but the susceptibility maximum decreases. The position of the susceptibility maximum is both solved analytically and fits well to be a power law at low fields and to be linear increasing at high fields. The height decreases as a power law with increasing. The exponents obtained in our results agree with the other theoretical results. Our results are roughly in agreement with the results obtained in the experiment of Ni(OH)(NO3)H2O. [Copyright &y& Elsevier]

The synthesis of ultrathin magnetic nanosheets is significant for the development of next-generation nanodevices but remains to be a big challenge. Herein, we present facile approaches for large-scaled production of cell-unit-thick single-crystalline iron oxide nanostructures. The ultrathin hematite (α-Fe 2 O 3 ) nanosheets with unit-cell thickness of 1.3 nm are firstly synthesized using a metal-ion-intervened hydrothermal method. Then the α-Fe 2 O 3 nanosheets are converted to magnetic maghemite ( γ -Fe 2 O 3 ) nanosheets with unit-cell thickness of 0.8 nm by a simple calcination process. The Li-ion battery studies reveal that unit-cell-thick γ-Fe 2 O 3 nanosheets exhibit great enhanced electrochemical performances with high specific capacitance approaching to its theoretical value and excellent cycling stability. [ABSTRACT FROM AUTHOR]

In recent years, the usage of new technologies in distributed generation is growing due to the electricity industry movement towards privatization and decentralized production of electric energy as well as competition among the new technologies. Microgrids are practical examples of the concept of decentralized production. Also, the employment of renewable energies is rapidly promoted due to the construction barriers of conventional power plants. Therefore, selecting and applying the appropriate technologies in planning and careful design of the type and capacity of generation and energy storage units are important. This paper proposed a robust model for day-ahead production scheduling of electrical and thermal units in a large-scale virtual power plant comprising a large number of distributed generation units and consumers accompanied by energy storage. To consider real conditions, the uncertainty of electrical demands is modeled by employing scenario-based analysis and probabilistic programming. So, five scenarios are created and modeled. In addition, two operation mode of a microgrid is considered connected and islanded modes. The objective function consists of total profit resulting from the daily operation of all units. The results confirm the applicability and effectiveness of the proposed model. Moreover, the total profit of the connected mode of the microgrid is about 20% more than the islanded mode, in all scenarios, and the cumulative profit cash flow of the connected mode is about 31% more than islanded mode. [ABSTRACT FROM AUTHOR]

Effective pretreatment of corn straw is essential to improve its anaerobic digestion (AD), NaOH-cellulase pretreatment of corn straw may be effective in enhancing its AD at the theoretical level. In this study, the effects of NaOH-cellulase treatment on corn straw degradation rate and sugar yield were investigated. Moreover, the microstructure analysis of corn straw was performed to determine the treatment mechanism. Gas production, methane content, kinetic fitting, and stability of AD of corn straw were compared before and after pretreatment to determine the efficacy of NaOH-cellulase pretreatment. The results showed the highest straw degradation rate (230% higher than that of the control group) when hydrolyzed by 6.0% of NaOH as 0.10 g·g−1 dry matter cellulase, and the biomethane content in corn straw pretreated with 6.0% of NaOH-elution-cellulase reached 70.1%. The biomethane yields of the corn straw after NaOH-elution-enzymatic hydrolysis using 4% of NaOH was 317 ± 11 mL·g−1 VS. The efficiency of AD after 4.0% of NaOH pretreatment was better than that after 6.0%-NaOH pretreatment, where the anaerobic system was more stable. In this study, NaOH-cellulase was used for the first time to pretreat corn straw, which effectively improved its AD. [Display omitted] • NaOH–cellulase can usefully increase corn straw anaerobic digestion gas production. • The optimal conditions were 6% of NaOH, 0.10 g·g−1 cellulase, and 5% of substrate. • The highest straw degradation rate was 230% more than that of the control group. • The methane production of the straw pretreated with NaOH–cellulase was 317 mL·g−1 VS. • The methane content of the straw pretreated with 6% of NaOH–cellulase reached 70.1%. [ABSTRACT FROM AUTHOR]