Mechanical Analysis Research Articles

Solidification of Loess Using a Composite Geopolymer Based on Slag Powder and Fly Ash: Influencing Factors and Mechanism Analysis

Solidification of Loess Using a Composite Geopolymer Based on Slag Powder and Fly Ash: Influencing Factors and Mechanism Analysis

How antitrust enforcement affects corporate ESG performance? Evidence from merger review cases in China

Chinese unique treatment of unreported merger cases (which should be reported according to antitrust law) in the context of merger review provides a distinctive and robust control group for the Difference-in-Differences (DID) research method. We employ the DID method to investigate the impact of China’s merger review antitrust enforcement on Environment, Social and Governance (ESG) performance. We find that the implementation of merger review antitrust enforcement suppresses corporate ESG performance, especially with significant effects observed on the Environment (E) and Governance (G) components. Mechanism analysis indicates that antitrust enforcement poses an impact on corporate profits by reducing market concentration and safeguarding fair market competition. This leads to the emergence of corporate financial performance protection behaviors, resulting in a decrease in corporate ESG performance. Heterogeneous analysis finds that the use of structural remedy in the enforcement process and stronger antitrust enforcement will further intensify the inhibitory effect of antitrust enforcement against business concentration on ESG.

The structural, elastic, optoelectronic properties and hydrogen storage capability of lead-free hydrides XZrH3 (X: Mg/Ca/Sr/Ba) for hydrogen storage application: A DFT study

Perovskite hydrides are promising materials for hydrogen capacity application to achieve the US DOE on-board criteria. We have investigated novel perovskite hydrides XZrH3 (X: Mg/Ca/Sr/Ba) for H2 storage and transportation applications. In this study we investigates the physical properties of XZrH3 light materials for solid-state hydrogen storage application by incorporating the DFT framework with the CASTEP code. We have theoretically examined the structural, mechanical, electronic, optical, and hydrogen storage properties of these materials. The selected compounds were fully relaxed and optimized in the cubic phase space group Pm-3 m. Structural phase stability was confirmed through thermodynamic, and mechanical analyses. Mechanical properties, evaluated based on Poisson’s ratio, the Puagh’s ratio, and Cauchy pressure, indicate the ductile behavior with a preference for ionic bonding. The electronic structure analysis reveals the metallic behavior of these materials. Optical calculations were also performed to provide additional insights into the physical properties of H2 compounds. The gravimetric hydrogen storage capacities were calculated as 2.55, 2.25, 1.66, and 1.31 wt% for MgZrH3, CaZrH3, SrZrH3, And BaZrH3 hydrides respectively. The identified properties of XZrH3 suggest that these materials could significantly enhance hydrogen storage systems, with potential integration into existing energy technologies, offering a pathway toward more efficient and sustainable hydrogen-based solutions.

Return-to-hometown entrepreneurship and employment of low-income households: Evidence from national returned entrepreneurial enterprise data of China

Employment is widely regarded as the most effective approach for eradicating poverty among low-income groups and preventing them from returning to poverty. Using national returned entrepreneurial enterprise data of China, this study empirically analyzes how “return-to-hometown entrepreneurship (RHE)” achieves antipoverty through a mediation effect model that incorporates moderating effects. Our findings reveal that: (1) RHE considerably enhances employment in low-income households. In particular, annual income and enterprise investment scale have a substantial positive impact on boosting the employment of low-income households. (2) Development- and value-oriented enterprises boost employment of low-income households more than survival-oriented enterprises. (3) The mechanism analysis indicates that entrepreneurship training plays a positive moderating role between the income of enterprises and the number of employed low-income households. Tax relief, loan guarantees, and industrial support policies have played multimediating roles in achieving antipoverty by RHE. These findings indicate that an effective interface between poverty alleviation and rural revitalization requires the government to attract additional high-quality RHE enterprises and actively fulfill its important institutional role in entrepreneurial training and various return-to-hometown entrepreneurial support policies.

Can Transportation Networks Contribute to the Sustainable Development of Urban Agglomeration Spatial Structures?

The advancements in global urbanisation have significantly elevated the configuration of transportation networks for the sustainable development of urban agglomeration spatial structures (UASS). Using a comprehensive panel dataset covering 140 counties and districts in the Chengdu-Chongqing Economic Circle from 2014 to 2023, this study empirically examines the impact of transportation networks on the sustainability of UASS. It elucidates the underlying mechanisms using spatial Durbin, spatial spillover and multiple mediation effect models. The findings reveal that transportation networks considerably enhance the sustainability of UASS and generate substantial positive spatial spillover effects. The decay boundary of the spatial spillover effects exhibits a transition from positive to negative, eventually approaching ineffectiveness. The heterogeneity analysis indicates significant variations in terms of transportation network expansion and regional functional division on the sustainability of UASS across regions with various levels of economic development. This outcome suggests that regional development policies should carefully consider regional economic development disparities. The mechanism analysis further reveals that transportation networks enable the sustainability of UASS by accelerating regional hierarchical systems and regional connectivity.

COSMO-RS prediction, experimental investigation, and mechanism analysis: A new approach to separating the n-hexane–tert-butanol azeotropic system via liquid-liquid extraction with ionic liquids

n-Hexane and tert-Butanol (TBA) are frequently utilized to refine the conditions for Grignard, Wittig, and Friedel-Crafts alkylation reactions. During the synthesis of loratadine, the formation of azeotropic mixtures n-hexane and TBA, which are challenging to separate through conventional distillation, is inevitable. This study utilizes the COSMO-RS model to identify suitable ionic liquids (ILs) for the separation of the n-hexane–TBA azeotropic system. Based on solvent capacity and selectivity, 1-ethyl-3-methylimidazolium trifluoroacetate ([EMIM][TFA]), 1-butyl-3-methylimidazolium trifluoroacetate ([BMIM][TFA]), and 1-hexyl-3-methylimidazolium trifluoroacetate ([HMIM][TFA]) were selected as extractants. The liquid–liquid equilibrium (LLE) data for the n-hexane–TBA – ILs ternary system were measured at 303.15 K and atmospheric pressure. Distribution coefficients and selectivity were calculated to evaluate the performance of the extractants, with the NRTL model used to correlate the experimental LLE data. The consistency of the NRTL model parameters was corroborated through topological analysis associated with the Gibbs tangent principle. Quantum chemical calculations, including interaction energy, ESP analysis, IGMH analysis, and QTAIM topological analysis, were performed to explore the separation mechanism at the molecular level. The results indicated that the interaction energies between the ILs and TBA were higher than those between the ILs and n-hexane, indicating a stronger attraction of ILs to TBA. Consequently, the ILs effectively separated TBA from the n-hexane–TBA azeotropic system, with extraction capacities ranked as [EMIM][TFA] > [BMIM][TFA] > [HMIM][TFA]. The quantum chemical calculations successfully explained the experimental results, aligning with COSMO-RS model predictions and confirming their reliability. IGMH and QTAIM topological analyses systematically explored the types and strengths of interactions, revealing that hydrogen bonds are predominant between the ILs and TBA, with additional contributions from van der Waals forces. Furthermore, the hydrogen bond strengths between TBA and the anions and cations of the ILs are classified as strong and moderate, respectively. This work provides valuable insights into the separation of azeotropic systems using ILs, elucidating the underlying mechanisms behind this process.

Promotion effect of nitrogen doping on the low-temperature NH3-SCR of NO over activated carbon: Characterization and mechanism analysis

Heteroatom nitrogen doping in carbon catalysts is recognized an effective strategy for tailoring the properties of carbon catalysts for various flue gas de-NOx applications. However, accurately discerning the active structures after nitrogen doping and elucidating the promotion effect on low-temperature selective catalytic reduction activity remains a formidable challenge under different nitrogen doping preparation conditions. In this study, a series of nitrogen-doped activated carbon catalysts was synthesized through the L16(45) orthogonal array design method, and the degree of influence of various preparation conditions on de-NOx catalytic activities was also assessed. The optimal preparation conditions determined by range analysis were employed to synthesize NOAC-17, achieving the NO conversion of 95% and N2 selectivity of 99% at 300 °C, respectively. Subsequently, various characterization results proved that nitrogen doping induced the formation of abundant basic groups. The imine, amide, amine, and N-6 groups altered the acid-base of the activated carbon surface and increased the adsorption of acidic NOx. The N-5 and N-Q groups enhanced electronic interaction in the carbon matrix and accelerated electron mobility in the catalytic reaction process. Moreover, the N-6 group played multiple roles beyond the aforementioned effect due to its special structure. It also enhanced the accumulation of oxygen vacancies, which were closely associated with further oxidation of adsorbed NO. The lone electron pair in the N-6 group within the activated carbon framework can alter the polarity of the catalyst, thereby exerting a positive influence on the adsorption and activation of NH3. The nitrogen-doped catalyst identified through range analysis of the orthogonal experiment primarily facilitated the NH3-SCR reaction via the E-R mechanism with supplementary contribution from L-H mechanism at low temperatures. The nitrogen doping conditions obtained for the activated carbon catalyst provide valuable insights for the strategic enhancement of its catalytic performance in low-temperature NH3-SCR reactions.

Date palm (Phoenix dactylifera L.) pollen-based microgel and its promising medical and environmental applications

Pollen, a natural bi-layered porous microcapsule, plays a crucial role in plant reproduction by protecting the plant's genetic material. Due to its unique properties, it has garnered attention for medical and environmental applications. Recent studies have focused on transforming the pollen's rigid structure to soft, gel-like matter, enabling the creation of pollen-based products such as paper and sponge. The main factor in the gelation process involves pectin-to-pectate conversion within the pollen's inner layer. Previously, claimed that this transformation is restricted to eudicot plants, and some others, such as monocot plant pollens do not exhibit this gelation phenomenon. In this study, we successfully produced microgel from date palm (Phoenix dactylifera L.) pollen (DPP), challenging this assertion. A significant portion of these monocot plant pollens exceeds the requirement of date production, presenting an opportunity for large-scale production without environmental concerns. Here, we have prepared pollen-based microgel, paper, and sponge and conducted a comprehensive analysis using various techniques such as optical and fluorescence microscopy, scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), elemental CHN analysis, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric differential thermal analysis (TGA/DTA), rheological measurements, mechanical analysis, pH-sensitivity tests, swelling analysis, and oil absorption capacity. By discerning the specific physicochemical properties of these materials, we propose potential medical and environmental applications for further investigation.

Genetic variation analysis of Guanling cattle based on whole-genome resequencing.

The objective of this study was to unravel the genetic traits of Guanling cattle, pinpoint genes advantageous for muscle growth, and lay a foundation for the preservation of genetic diversity and further analysis of regulation mechanism of important economic traits in local cattle breed. In this study, we sequenced the whole genome of 3 Guanling cattle in Guizhou province using the Illumina HiSeq cBo sequencing platform. And, high- multiplex polymerase chain reaction technology was employed to detect high-quality single nucleotide polymorphism (SNP) sites of other 55 Guanling cattle. Our study identified 166,411 non-synonymous SNPs (nsSNPs) and 42,423 insertions and deletions (indels). Through SNP annotation, gene function enrichment analysis, and comparing with Simmental, Angus, and Limousin cattle, we identified six genes (LEPR, AKAP9, SIX4, SPIDR, PRG4, FASN) which are potentially influential on meat quality traits, playing crucial roles in muscle growth, fat metabolism, and bodily support. We also examined polymorphisms at seven SNP sites in Guanling cattle and found that all seven were in Hardy-Weinberg equilibrium. These findings suggested that these gene sites are stable and widespread in the Guanling cattle population. Our research lays the groundwork for future genetic enhancement and variety identification of Guanling cattle.

Efficient catalytic oxidation of xylose to formic acid with the oxygen vacancies of CeO2 promoted the vanadium catalysts anchored on biochar

The catalytic oxidation of carbohydrates for the preparation of formic acid (FA) is an prominent route for high-value utilisation of biomass. Reforming xylose, a biomass derivative, into FA with high efficiency is essential for the advancement of non-homogeneous V-type catalysts. Here, we present the self-assembly of V and Ce onto a cellulose pulp for the synthesis of oxygen vacancy (Ov)-rich non-homogeneous-bimetallic catalysts (5Ce-VOx/BC-600). Under the optimised conditions, 71.46 % FA was obtained, which far exceeded the catalytic performance of the single-metal catalyst. Furthermore, the 5Ce-VOx/BC-600 catalyst showed excellent stability and reusability. Kinetic studies revealed that glyceric and glycolic acids served as the pivotal intermediates, undergoing subsequent deacidification and oxidation processes to yield FA and CO2. The analysis of the catalytic mechanism indicated that the incorporation of Ce enhanced the quantity of acidic sites and the concentration of Ov in the 5Ce-VOx/BC-600 catalyst, which promoted substrate adsorption and O2 activation. Meanwhile, the catalyst showed high lattice oxygen (OL) mobility and assisted the redox cycle of V5+/V4+ to oxidise xylose to FA. Significantly, the synergistic effect of Ce, V species and Ov enhances the OL mobility of the catalysts, thus promoting the efficient oxidation of xylose. The catalytic system was further extended to the oxidation of other biomass derivatives to FA, demonstrating excellent catalytic performance.

Design of alkali metal oxide adsorbent for direct air capture: Identification of physicochemical adsorption and analysis of regeneration mechanism

Direct air capture (DAC) represents an advanced negative carbon emission technology, with the key being high-performance CO2 adsorbents. First, this work carefully identifies CO2 physisorption and chemisorption by CaO/HcATP (CaO loaded on acid-modified attapulgite) as DAC adsorbent. The chemisorption of amorphous "CaO" plays a crucial role in both the adsorption capacity and rate, with contributions of 66.8 % and 50.85 %, respectively. The adsorption capacity of CaO/HcATP is only 212.4 ± 25.7 µmol/g via the simple CO2 physisorption and improved by 426.7 µmol/g owning to the chemisorption of amorphous CaO. Second, the concentration of silanol groups on CaO/HcATP plays a pivotal role in the adsorption process. The concentration of silanol groups decreases to 3.85 OH/nm2 after undergoing 30 cycles of adsorption-desorption. Then it increases to 9.54 OH/nm2 by adsorbing the moisture in the air, resulting in a recovered adsorption capacity of 90.7 %. Furthermore, the pseudo-first-order adsorption kinetics model effectively predicted the experimental results. Finally, the dual loop of CO2 capture and regeneration is summarized using the CaO/HcATP as DAC adsorbent. The amorphous "CaO" interacts with the surface silanol of HcATP, synergistically capturing CO2 in the form of "CaO···CO2", which reduces desorption energy consumption. The wetting property of HcATP contributes to the regeneration of CaO/HcATP. This work contributes to establishing fundamental principles for designing cost-effective DAC adsorbents.

Light harvesting S-scheme g-C3N4/TiO2/M photocatalysts for efficient removal of hazardous moxifloxacin

The development of advanced photocatalysts with enhanced efficiency for environmental remediation is critical for addressing persistent organic pollutants like Moxifloxacin. In this study, we present a novel S-scheme heterojunction g-C3N4/TiO2/M photocatalyst designed to optimize light harvesting and charge separation for the effective degradation of Moxifloxacin. The innovative S-scheme configuration enables superior charge transfer dynamics by retaining potent photogenerated electrons in the conduction band of TiO2 and holes in the valence band of g-C3N4, significantly improving photocatalytic performance compared to conventional Type-II systems. Heterogeneous photocatalysis, particularly using TiO2-based materials, offers a promising approach. Here, we synthesized TiO2 hybridized with metal-doped g-C3N4 (GCNTM) via a simple hydrothermal method. The fabricated nanocomposites were characterized using SEM, XRD, FTIR, and UV–Vis (DRS). These GCNTM nanocomposites were employed for the degradation of hazardous Moxifloxacin (MXF) under visible light. Detailed analysis of the photocatalytic mechanism reveals that the synergistic interaction between g-C3N4, TiO2, and the co-catalyst M not only broadens the light absorption spectrum but also enhances the separation and lifespan of charge carriers. Among the synthesized materials, GCNTLa demonstrated the highest degradation efficiency, achieving 96 % removal of MXF. This enhanced activity is attributed to the effective suppression of charge recombination, leading to the generation of reactive species responsible for MXF degradation. Additionally, GCNTM showed remarkable stability and reusability, with only a 6 % reduction in efficiency after five cycles, confirming its high reusability and mechanical stability. Our S-scheme photocatalyst demonstrates a marked increase in the degradation rate of Moxifloxacin under visible light irradiation, highlighting its potential for practical environmental applications.

Ageing response and microstructural evolution of biodegradable Zn-1.5Cu-1.5Ag alloy

In this study, the age-hardening response and microstructural evolution of an as-extruded biodegradable Zn-1.5Cu-1.5Ag (wt.%) alloy during ageing at 25 ℃, 100 ℃, 150 ℃ and 200 ℃ are studied. The age-hardening response is generally weak, and the largest hardness increment is observed after ageing at 150 ℃ for 24 h. Discontinuous precipitation (DP) and continuous precipitation (CP) occur competitively during ageing at 150 ℃ or 200 ℃, while only DP is observed during ageing at 25 ℃ or 100 ℃. All the precipitates formed through DP and CP are identified as ε-(Ag, Cu)Zn4 that has a hexagonal structure. Analysis of possible strengthening mechanisms shows that grain boundary strengthening and precipitation hardening contribute to the major part of yield strength in the as-extruded condition. Ageing treatments generate a limited increment in yield strength due to the small difference between the hardness of ε-(Ag, Cu)Zn4 and the Zn matrix and the reduced solid solution strengthening effect. Artificial ageing at 150 ℃ for 48 h effectively improves the stability of the mechanical properties of the as-extruded Zn-1.5Cu-1.5Ag alloy. This process fully depletes the excessive solutes in the supersaturated Zn matrix, ensuring that the alloy maintains consistent mechanical properties when stored at room temperature.

Catalytic Role of the Digital Economy in Fostering Corporate Green Technology Innovation: A Mechanism for Sustainability Transformation in China

The digital economy is a novel catalyst for economic growth and sustainable development, representing an emerging trend in economic development. This study investigates the impact of the digital economy on green technology innovation within Chinese listed companies between 2009 and 2022. The empirical studies indicate the digital economy significantly promotes green technology innovation in corporations, especially in non-state-owned, large-sized, and mid-western companies. The analysis of the influence mechanism reveals that the digital economy has a substantial impact on the advancement of green technology innovation. This is achieved through alleviating financing constraints, promoting human capital agglomeration, and improving resource allocation efficiency. This research provides decision-making references for promoting green development and resolving the paradox of imbalanced and insufficient growth among companies with various ownership structures, total asset sizes, and regions.

Experimental and Numerical Analyses of Shear Failure Mechanisms of Rock Bolt Surrounded by Bedded Rock

Experimental and Numerical Analyses of Shear Failure Mechanisms of Rock Bolt Surrounded by Bedded Rock

Mitophagy and its regulatory mechanisms in the biological effects of nanomaterials.

Mitophagy is a selective cellular process critical for the removal of damaged mitochondria. It is essential in regulating mitochondrial number, ensuring mitochondrial functionality, and maintaining cellular equilibrium, ultimately influencing cell destiny. Numerous pathologies, such as neurodegenerative diseases, cardiovascular disorders, cancers, and various other conditions, are associated with mitochondrial dysfunctions. Thus, a detailed exploration of the regulatory mechanisms of mitophagy is pivotal for enhancing our understanding and for the discovery of novel preventive and therapeutic options for these diseases. Nanomaterials have become integral in biomedicine and various other sectors, offering advanced solutions for medical uses including biological imaging, drug delivery, and disease diagnostics and therapy. Mitophagy is vital in managing the cellular effects elicited by nanomaterials. This review provides a comprehensive analysis of the molecular mechanisms underpinning mitophagy, underscoring its significant influence on the biological responses of cells to nanomaterials. Nanoparticles can initiate mitophagy via various pathways, among which the PINK1-Parkin pathway is critical for cellular defense against nanomaterial-induced damage by promoting mitophagy. The role of mitophagy in biological effects was induced by nanomaterials, which are associated with alterations in Ca2+ levels, the production of reactive oxygen species, endoplasmic reticulum stress, and lysosomal damage.

Drought-mediated oxidative stress and its scavenging differ between citrus hybrids with medium and late fruit maturation

Drought stress is a major environmental factor limiting citrus productivity. Still, differences in drought sensitivity between citrus hybrids of different maturation periods have so far not been reported. Here, we selected a medium-maturing (Fertile orange: FO (Citrus reticulata cv. Fertile orange) and a late-maturing citrus hybrid (Newhall Navel orange: NO (Citrus sinensis Osbeck cv. Newhall) and determined the physiological and biochemical traits of leaves, roots, wood and bark. Our results showed that drought significantly decreased net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) of citrus leaves. Oxidative stress upon drought was indicated by enhanced foliar malondialdehyde (MDA) and hydrogen peroxide contents, as well as a stimulation of the anti-oxidative system. This stimulation included the contents of dehydroascorbic acid (DHA), glutathione (GSH) and oxidized glutathione (GSSG) in leaves, roots, wood and bark, as well as activities of antioxidative enzymes of glutathione reductase (GR), dehydroascorbate reductase (DHAR), superoxide dismutase (SOD) and peroxidase (POD). The late maturing NO hybrid not only showed better general physiological performance as indicated by increased Pn in leaves, but also higher biochemical ROS scavenging and osmotic capacity as indicated by increased ascorbic acids (ASA), DHA, and proline contents, as well as activities of enzymes of SOD, POD, ASA/DHA and GSH/GSSG ratios in the investigated tissues compared to the FO hybrid under drought and control conditions. Analysis of molecular mechanisms of signaling, regulatory and functional genes expression are suggested for future studies to elucidate the complex interplay of molecular, biochemical and physiological responses of citrus hybrids to drought.

Effect of AP and AN on the combustion and injection performance of Al-H2O gelled propellant

Aluminum-water propellants (Al-H2O propellants), representing a novel class of solid propellants, demonstrate the merits of cost efficiency and reduced feature signal characteristics. However, the conventional formulations of Al-H2O propellants are hampered by the generation of substantial condensed residues. In our investigation, we explored the incorporation of oxidizers into the Al-H2O propellant grain, aiming to enhance combustion and injection performance. Employing a multifaceted experimental approach, we conducted thermal gravimetric analysis, laser ignition experiments, and ignition tests within a lab-scale solid rocket motor (SRM) firing to systematically examine the effects of varying content of ammonium perchlorate (AP) and ammonium nitrate (AN) on the combustion and injection performance of Al-H2O propellants. Our findings indicated that integrating AP and AN at a mass fraction of 3 % each notably curtailed ignition delay time by approximately 67 % and 90 %, respectively, and concurrently decreased burning rates by approximately 50 % and 58 %. Significantly, it has been observed that a composition incorporating a 5 % mass fraction of AP enhances the combustion efficiency of the Al-H2O propellant system by approximately 2 %. Conversely, the integration of a 5 % mass fraction of AN into the same propellant matrix results in an augmentation of the injection efficiency by an estimated 47 %. Empirical evidence validating the augmentative impacts of AP and AN on the performance of Al-H2O propellants has been substantiated through a series of motor hot firing experiments. Furthermore, the combustion behavior of Al-H2O propellants has been elucidated through an analysis of the combustion physical mechanism of Al particles. The thermal decomposition of AP yields a substantial volume of oxidizing gases, which effectively accelerates the combustion rate of the Al particles, subsequently leading to an enhancement in the overall combustion efficiency of the propellant. Conversely, the decomposition of AN results in an increased production of nitrogen gas, thereby augmenting the velocity of gas flow and, consequently, elevating the injection efficiency of the propellant. This finding holds promise for guiding the developmental trajectory of Al-H2O propellants and refining the design parameters of propulsion systems.

Environmental triggers and future risk of developing autoimmune diseases: Molecular mechanism and network toxicology analysis of bisphenol A

Environmental triggers and future risk of developing autoimmune diseases: Molecular mechanism and network toxicology analysis of bisphenol A

Performance and Hydration Mechanism of Fly Ash Coal-Based Solid Waste Backfill Material Affected by Multiple Factors

Masses of coal-based solid waste like fly ash are emitted during coal combustion, with low utilization rate. Preparing fly ash into backfill material can not only improve waste utilization efficiency, but also repair the cracks in mining areas. In this research, the performance and hydration mechanism of fly ash coal-based solid waste backfill material were investigated through slurry performance experiment, mechanical strength test and microstructure analysis. Besides, the grouting effect of the backfill material was verified by grouting experiment. The research demonstrated that the increase of fly ash to cement ratio (from 0.5 to 1.5) improved the fluidity, viscosity and bleeding rate of the slurry, but prolonged the setting time. The adjustability of backfill material was good, and the compressive strength of specimen reached its highest value of 27.1 Mpa through changing multiple factors. The grouting effect of fine-grained macadam was better than that of coarse-grained macadam. The compressive strength and Young's modulus of the backfill material specimens containing 0.5-1cm macadam were 12.2% and 17.4% higher, respectively, than those with 1-2cm macadam. The primary hydration product of backfill material was gel, which structural elements were Si, Al and Ca. As the curing age increased, the distribution of the three elements became denser, and more gel was formed, corresponding to the changes in the compressive strength of the backfill material. The research offers material source and selection basis for backfilling cracks in mining areas and enhances utilization efficiency of coal-based solid waste.