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Abstract High-intensity coal mining has induced a series of ecological and environmental problems issues, including surface subsidence, the development of ground cracks, and the deterioration of vegetation. The disruption of water circulation systems induced by mining, such as perched groundwater, groundwater of aeration zone, and phreatic water, is the root cause of vegetation withering. The aeration zone serves as a crucial nexus in the process of water cycling and exerts a significant influence on soil fertility. To explore the characteristics of soil moisture transport in subsidence areas under the mining disturbance, on-site monitoring of the size and morphology characteristics of subsidence areas and ground cracks was conducted in typical mining areas in Inner Mongolia, China. Subsequently, a typical soil moisture transport model was constructed in subsidence areas, the soil moisture transport patterns under the influence of different types of subsidence and cracks were analyzed, and the influence law of soil damage on soil moisture transport in the aerated zone was clarified. The results indicate that (1) Based on the occurrence and distribution characteristics of subsidence cracks, the subsidence area can be divided into tension zone, compression zone, and neutral zone; the ground cracks are divided into permanent tension cracks and dynamic cracks. (2) The drought stress effect of soil in the subsidence area is significant. Under the influence of soil structure variation, the water-holding capacity of the soil in the subsidence area decreases, and the soil moisture dissipation is strong. The soil moisture transport rate in the aeration zone of the subsidence area is ranked as follows: tension zone > neutral zone > compression zone. (3) Ground cracks can exacerbate the soil moisture transport rate in the aeration zone. After 15 d of crack appearance, the soil moisture transport reaches a relatively stable state, and the soil moisture transport rate in the surface layer of the crack is the fastest, and the loss of soil moisture is the most significant. The crack effect is not significant beyond 100 cm from the crack. This study provides a theoretical and data support for soil and vegetation remediation in mining subsidence areas.

To enhance the mining area's overall use of mine water in the arid area of Western China and mitigate the current water scarcity problem, this paper introduces an intelligent optimization algorithm and neural network for mine water quality evaluation and proposes a principal component analysis (PCA)–particle swarm optimization (PSO)–back propagation (BP) mine water quality evaluation model. Firstly, the model uses PCA to identify the primary factors affecting mine water quality, then enhances the optimal weights and thresholds of the BP neural network based on the PSO algorithm, and the PCA–PSO–BP evaluation model with nine input layers, nine hidden layers, and one output layer is created. In addition, using the Shicaocun Mine as an example, the results demonstrate that the PCA–PSO–BP model has accurate mine water quality evaluation results, and the prediction accuracy reached 86.8255%. This exemplifies the PSO method's superiority to the BP neural network improvement. This study not only offers a novel theoretical framework for assessing and forecasting water quality in mining regions, but it also sets the stage for the possible broad use of state-of-the-art neural networks and optimization algorithms in the coal mining industry. HIGHLIGHTS Intelligent algorithms and neural networks are introduced into mine water quality evaluation.; Established a PCA–PSO–BP model for mine water quality evaluation.; Realized the accurate evaluation and reasonable prediction against the background of big data.; Provide reference for the in-depth research of optimization algorithms and neural networks in the field of water quality evaluation.;

Abstract Implant-associated infections due to the formation of bacterial biofilms pose a serious threat in medical healthcare, which needs effective therapeutic methods. Here, we propose a multifunctional nanoreactor by spatiotemporal ultrasound-driven tandem catalysis to amplify the efficacy of sonodynamic and chemodynamic therapy. By combining piezoelectric barium titanate with polydopamine and copper, the ultrasound-activated piezo-hot carriers transfer easily to copper by polydopamine. It boosts reactive oxygen species production by piezoelectrics, and facilitates the interconversion between Cu2+ and Cu+ to promote hydroxyl radical generation via Cu+ -catalyzed chemodynamic reactions. Finally, the elevated reactive oxygen species cause bacterial membrane structure loosening and DNA damage. Transcriptomics and metabolomics analysis reveal that intracellular copper overload restricts the tricarboxylic acid cycle, promoting bacterial cuproptosis-like death. Therefore, the polyetherketoneketone scaffold engineered with the designed nanoreactor shows excellent antibacterial performance with ultrasound stimulation and promotes angiogenesis and osteogenesis on-demand in vivo.

In this work, the frequency dependence of ferroelectric and electrocaloric properties in barium titanate-based ceramics was studied based on Maxwell relations. It is found that the maximum and remnant polarization will decrease while the coercive field increases a lot with rising frequency from 0.1 to 10[Formula: see text]Hz, indicating that polarization rotation and domain switching become difficult at high frequencies. The electrocaloric properties show the different frequency dependence at different phase structures. Isothermal entropy change ([Formula: see text]) and adiabatic temperature change ([Formula: see text]) are similar around/above Curie temperature ([Formula: see text], showing tiny frequency dependence. However, [Formula: see text] and [Formula: see text] display the obvious frequency dependence below [Formula: see text], especially in the orthorhombic–tetragonal phase-transition region with a stable ferroelectric phase, and this frequency dependence becomes more obvious under a low-electric field. It is also found that increasing the frequency can weaken the electric field dependence of electrocaloric strength. This work gives a general profile of frequency dependence for electrocaloric properties in ferroelectric ceramics.

Collet–Sicard syndrome is a rare neurological disorder caused by injury to the cranial nerve pairs IX, X, X, and XII. The author reports on a previously fit 27-year-old man who presented with dysphagia, choking on drinking water, hoarseness, weakness when turning the neck and shrugging the shoulders, and unexplained weight loss. Enhanced magnetic resonance imaging indicated a space-occupying lesion at the right jugular foramen. After surgical resection, the pathologic findings suggested a paraganglioma of the right jugular foramen and confirmed the diagnosis of Collet–Sicard syndrome. After postoperative treatment with a combination of acupuncture and modern medicine, the patient’s symptoms significantly improved. This article analyzes previous literature regarding Collet–Sicard syndrome etiology and reports the case of a patient with a rare etiology, whose prognosis improved significantly after treatment with a combination of acupuncture and modern medicine.

High-quality Piper laetispicum (Piper laetispicum C. DC) is the key to the development of foods, natural medicines, and cosmetics. Its crude fat, ash, piperine, protein, and aroma compounds were determined in this experiment. Principal component (PCA) and hierarchical cluster analyses (HCA) were used to evaluate the aroma compounds at different developmental stages. The main aroma compounds identified using steam distillation combined with GC-MS were sabinene (34.83–76.14%), α-copaene (5.11–19.51%), linalool (2.42–15.70%), trans-caryophyllene (2.37–6.57%), α-pinene (1.51–4.31%), and germacrene D (1.30–4.10%). The aroma metabolites at different developmental stages were analysed using non-targeted metabolomes, and linalool was found to be the most abundant. Based on the experimental results, there were more nutrient compounds in young Piper laetispicum than in the last three developmental stages. The aromatic metabolites contributed the most to PC1. There were also more different metabolites of aroma between the young and expanding stages. Therefore, regarding quality, young fruits have great potential.

Nowadays, computing advertising has been an intelligent Internet application which provides personalized advertising service to customers. But how to suggest suitable advertising contents to users relies on effective mining of user preference characteristics. Conventionally, machine learning-based methods were most intuitive solutions to predict unknown user features. Nevertheless, such kind of approaches highly relied on massive labelled samples, and also cost much time in algorithm training. In realistic engineering application, running efficiency acts as the top priority. To deal with this issue, this paper proposes a novel personalized recommendation model for computing advertising based on user acceptance evaluation. Firstly, the functional requirements in personalized recommendation of computing advertising is analyzed, and the perceived behavior of the algorithm ethical risks generated in computing advertising is analyzed based on collaborative filtering. Then, based on the user experience risks generated in recommendation process, a user acceptance value for personalized recommendation is calculated. We also conduct some experiments on real-world data to make empirical assessment for the proposal. It can be concluded that recommendation effect of the proposal is better than that of machine learning algorithm and ant colony algorithm.

Coal mine safety management is the foundation and decisive factor of coal mining. The manual detection model is the main way for traditional coal mine safety management, which has problems such as inefficient identification of safety risks in coal mines, poor control accuracy and slow response measures and so on. Therefore, to make up for the shortcomings in the traditional coal mine safety management model, this paper introduces digital twin technology into coal mine safety management to achieve intelligent and efficient management of coal mine safety accidents. Firstly, we introduce the digital twin technology, select the five-dimensional model as the modeling basis, based on the existing twin model architecture, analyze the types of coal mine accidents and disasters, select the most destructive gas accidents as the research object, construct a twin safety management model for coal mine gas accidents using the digital twin five-dimensional model. Secondly, analyses of the actual operation mechanism of the digital twin model, and the advantages of the twin model in achieving prior prevention, rapid response and accurate control of gas incidents are pointed out. Finally, the house of quality of the gas accident digital twin model is established through the quality functional deployment tool, and key technical requirements for the construction of the twin model are given to accelerate the application of the gas accident twin model in the field.This study innovatively introduces digital twin technology into the field of coal mine safety management, proposes the application scenarios of emerging technologies such as digital twins in the coal mine field, and provides the possibility of multi-scene application of smart mine construction and technologies such as digital twins.

Backfill mining technology is the practice of returning waste materials underground for both disposal and geotechnical stability, however, a challenge with current technologies is that they commonly require cement-based binders which have a relatively high environmental impact. Finding alternatives to cement-based binders can improve environmental performance and this paper proposes microbial grouted backfill (MGB) as a potential solution. In this paper, the effects of the cementation solution concentration (CSC), volume ratio of bacterial solution to cementation solution (VRBC), particle sizes of the aggregates, and the number of grouting batches on the mechanical properties of MGB are studied. The experimental results show that MGB strength increased, up to a peak value, as CSC was increased, before decreasing as CSC was increased further. The results also show that MGB strength increased, up to a peak value, as VRBC decreased, before decreasing as the VRBC was decreased further. The peak strength was achieved at a CSC of 2 mol/L and a VRBC of 1:9. The strength of the MGB also increased as the number of grouting batches increased. Graded MGB samples showed the highest UCS, 25.12 MPa, at particle sizes of 0.2 to 0.8 mm, while full (non-graded) MGB samples displayed mean UCS values ranging from 1.56 MPa when the maximum particle size was 0.2 mm, up to 13 MPa when the maximum particle size was 1.2 mm. MGB samples are consolidated by the calcium carbonate that is precipitated during microbial metabolism, and the strength of MGB increases linearly as calcium carbonate content increases. The calcium carbonate minerals produced in MGB materials are primarily calcite, with secondary amounts of vaterite.

Broken gangue has been extensively used in rockfill dams, subgrade, embankment, foundation cushion and other engineering construction. The deformation characteristics of broken gangue under the bearing compression play a decisive role in the firmness, stability and safety of these structures (buildings), and the meso-fabric change of broken gangue under the bearing compression significantly affects its macro deformation. In this study, the transparent characterization and quantitative analysis of 3D fabric of broken gangue under the bearing compression were performed through CT scanning test, image processing and 3D reconstruction technology, and the influence mechanism of internal fabric of broken gangue on its macro deformation was revealed. The results show that: In the loading stage of 0–2 MPa, the sharp corners, thin edges on the blocks and the bar-shaped and blade-shaped blocks with poor regularity are broken first under the bearing compression; in the loading stage of 2–8 MPa, a large number of larger particles in the sample are crushed in the mode of fragmentation; in the loading stage of 8–10 MPa, the breakage degree of samples is relieved. The axial displacement of the block inside the sample occurs, as well as the lateral displacement of the block converging to the central axis of the sample. In the rapid deformation stage, the macro deformation of the broken gangue is mainly caused by the rearrangement and adjustment of the block structure and the breakage of the block; in the slow deformation stage, it is mainly caused by the breakage of the block; in the stable deformation stage, it is mainly caused by the optimization and adjustment of the bearing skeleton in the sample.

In this article, antisynchronization problem of multiweighted coupled complex-valued delayed memristive neural networks (MWCCVDMNNs) with and without coupling delays are investigated. First, via devising a suitable controller and constructing an appropriate Lyapunov functional, a criterion for ensuring antisynchronization of MWCCVDMNNs is derived. Second, we research the generalized pinning antisynchronization of MWCCVDMNNs by creating a generalized pinning controller to guarantee that the considered networks can accomplish antisynchronization. Similarly, several sufficient conditions guaranteeing the antisynchronization and generalized pinning antisynchronization of MWCCVDMNNs with coupling delays are also presented. Third, two numerical examples are provided to verify the correctness of the obtained antisynchronization results.

Mine water is rich in various chlorides, which will inevitably affect the performance of the cemented paste backfill (CPB). In this study, the TAM Air isothermal calorimeter was used, the effects of typical chlorides (NaCl, CaCl2 and MgCl2) in mine water on the hydration heat and hydration heat flow in the solidification stage of fresh CPB were studied, and the effects of chlorides on the setting time of fresh CPB were analyzed. The hydration products of CPB samples containing different chlorides were tested by the X-ray diffractometer and thermal gravimetric analyzer. The results show that NaCl and CaCl2 can promote the early hydration reaction of CPB; and the promoting effect of CaCl2 is more significant; while MgCl2 consumes OH- in the solution and reduce the pH of the solution, thus inhibiting the early hydration reaction of CPB. With the increase of chloride concentration, the promoting effect of NaCl on the early hydration of the CPB first increases and then decreases, the promoting effect of CaCl2 increases constantly, and the inhibitory effect of MgCl2 also increases continuously. Besides, CaCl2 can significantly shorten the hydration time of CPB in the induction stage and acceleration stage, and the higher the CaCl2 concentration, the higher the cumulative hydration heat and the hydration heat release rate of CPB in the same hydration stage. This study comprehensively evaluates the influence of typical chlorides in mine water on the early hydration process and setting time of the fresh CPB, providing a reference for the clean utilization of mine water, fly ash, gangue and other solid wastes.

In this work, to systematically investigate the evolution characteristics of electrical properties in polymorphic piezoceramics, the Ba(Ti0.92Zr0.08)O3 ceramics are selected as a paradigm that possesses all the general phase structures above room temperature. It is found that the evolution of electrical properties with temperature change can be divided into three stages based on phase structure transforming: high ferroelectric and stable strain properties at R and R-O, high ferroelectric and enhanced strain/converse piezoelectric properties at O, O-T, and T phase, and the rapidly decreased ferroelectric and strain properties in T-C and C phase. However, the ferroelectric and strain properties all increase with rising electric field and their evolution can be divided into two parts based on phase structures. The high property and slow increase rate are present at R, R-O, O, and O-T, while the poor property but a high increase rate is present around T-C. Similar results can be found in the evolution of electrostrictive property. Finally, the highest d33* of ~1240 pm/V and Q33 of ~0.053 m4/C2 are obtained at O-T due to the high ferroelectricity but easy domain switching. This work affords important guidance for the property optimization of polymorphic piezoceramics.

Background: Several quantitative systematic reviews of Kanglaite (KLT), an herb preparation used to treat cancer and malignant pleural effusion, have been published in recent years. However, the clinical evidence reported in these studies has not been pursued further and the methodological quality of these meta-analyses remains unknown. Therefore, an overview was designed to map the evidence landscape based on the published meta-analyses on KLT in cancer treatment.Methods: Two bibliographic databases (PubMed and Embase) were searched from inception to 25 November 2021. Two independent reviewers were involved in study selection, data abstraction, and methodological quality assessment using AMSTAR 2. The principal features of publications and the clinical outcomes of efficacy and safety were synthesized narratively, and results of methodological quality were reported as frequencies and percentages with the corresponding 95% confidence intervals. The evidence map was used to visualize the overall quality. Excel 2016 and Stata 17/SE were used for data analysis.Results: Thirteen meta-analyses published in English were included for in-depth analysis. Among them, the year of publication ranged from 2008 to 2021, and the number of included patients ranged from 488 to 2,964. Regarding the cancer type, seven articles focused on non-small cell lung cancer, two on malignant pleural effusion, and four reviews on digestive system malignancies, such as hepatocellular carcinoma and pancreatic cancer. Almost all included meta-analyses reported that KLT as adjunctive therapy could improve various efficacy outcomes (such as disease response rates, quality of life, immune indicators) and reduce the rate of occurrence of adverse reactions, such as nausea and vomiting, leukopenia, and anemia. In terms of their methodological quality, three meta-analyses were of low quality, whereas 10 studies were critically low in quality. The methodological flaws main involved items 2 (“predesigned protocol and registration informatio’’), 3 (“rationale of study design for inclusion”), 4 (“comprehensive search strategy’’), 5 (“literature selection in duplicate’’), 7 (“list of excluded studies with reasons’’), 8 (“adequate information on included studies’’), 10 (“funding support for included primary studies’’), and 12 (“evaluation of the potential impact of risk of bias’’) based on the AMSTAR 2 tool.Conclusion: Current evidence reveals that KLT is effective and safe as an adjunctive treatment for non-small cell lung cancer, malignant pleural effusion, and digestive system malignancies (such as hepatocellular carcinoma). However, the results assessed in this overview should be further verified using well-designed and clearly reported clinical trials and meta-analyses of KLT.

The application of water resources protection mining has alleviated greatly the deterioration of ecological environment in the ecologically fragile mining areas of Western China. To quantitatively evaluate the improvement effect of this technology on the ecological environment of the mining area, the evaluation index system of ecological environment in the mining area was proposed based on the water-preserved mining techniques of water resources protection mining. The entropy weight method and the Decision-making Trial and Evaluation Laboratory were selected as the subjective and objective weight method, and the cloud model theory was used as the modeling basis, then a quantitative evaluation model of ecological environment of water-preserved mining was constructed. Besides, the Halagou coal mine in Shendong Group was taken as an example, and the ecological environment of this mining area was quantitatively assessed to verify the rationality of the proposed evaluation model. The results show that the ecological environment level of the Halagou mining area is between Excellent and Good (generally at a good level), which is consistent with the actual ecological environment situation of the Halagou mining area. Thus, the rationality of the proposed evaluation model is verified. Through the evaluation cloud map, the evaluation results are biased towards the evaluation level of Good, indicating that there is still room for improvement in the ecological environment of the Halagou coal mine. Combined with the analysis results, suggestions for the sustainable improvement of the ecological environment of the mining area are given: Halagou coal mine should focus on the restoration of subsidence area and the control of mine water inflow.

Abstract Global environmental concerns on the toxicity of lead‐based piezoelectrics impel the great mass fervor on investigations of lead‐free alternatives. Barium titanate (BaTiO3, BT) ceramics, the first discovered perovskite ferroelectrics, were widely employed to fabricate dielectric capacitors from 1950s. Since a piezoelectric breakthrough was achieved via chemical modification, intensive researches have been performed embracing lead‐free BT‐based piezoelectrics and their extensional functionalities. In this review, we encompass the state‐of‐the‐art progress on chemical modification tuning phase structure toward advanced electrical properties in BT‐based ceramics. Generally, modulated regularity of cations substitution on phase transition is summarized and clarified. Then, we highlight the common methodologies of phase structure (phase boundary, relaxor phase, room‐temperature phase transition, etc.) design for optimizing piezoelectricity, electrostrictive strain, electrocaloric, dielectric energy storage or permittivity performances, and cover the noticeable developments and relevant physical mechanisms. Finally, perspectives and challenges on future research issues are featured. This review proposes to exert the significant guidance and service for material design of BT‐based and other lead‐free perovskite materials with superior functionalities.

Abstract Background No consensus has been reached on capillary blood reference intervals for platelet parameters in full-term neonates. We aimed to establish neonatal capillary blood reference intervals for platelet parameters and evaluate influences of sex, gestational age and postnatal age on platelet parameters. Methods This study was a prospective investigation and implemented in 594 healthy full-term neonates from 12 to 84 h of age, using SYSMEX XN-9000 haematology automatic analyser by means of capillary blood. Reference intervals for platelet parameters were defined by an interval of 2.5th − 97.5th percentiles. Results Capillary reference interval for platelet count was (152–464) × 109/L. No significance was found between sex-divided reference intervals for platelet parameters. The values of platelet count changed minimally across gestational age (37–41 weeks) and postnatal age (12–84 h). Reference intervals for other platelet parameters were affected by these factors to a different extent. Conclusions We established capillary blood reference intervals for platelet parameters in the first days after birth of full-term neonates in China.

The inflammatory response is the key pathophysiological character of acute lung injury (ALI). Berberine (BBR), a natural quaternary ammonium alkaloid, plays a functional role in anti-inflammation both in vitro and in vivo. However, the underlying mechanism between BBR and ALI has not been expounded. Here, we found that BBR improved the permeability of pulmonary and repressed the inflammatory factors in the lipopolysaccharides (LPSs)-induced ALI model. We demonstrated that BBR could suppress the expression of phosphorylated nuclear factor-kappa B (NF-κB) and further restrain the downstream gene nucleotide-binding domain and leucine-rich repeat protein-3 (Nlrp3). Moreover, we also revealed that BBR could directly interact with Nlrp3 protein. After knocked down of Nlrp3 by using siRNA, the protective role of BBR was abrogated in vitro. The expression of IL-1β and IL-18 was downregulated by BBR via the two signaling pathways. Notably, in Nlrp3 deficient mice, the protective effect of BBR was abolished. These findings demonstrate that BBR has a depressant effect on inflammatory response caused by LPS via regulating NF-κB/Nlrp3 signaling pathway, providing a potential therapeutic strategy in ALI.

Background. The study was to analyze the clinical manifestation variety and management choices of symptomatic Meckel’s diverticulum in children. Methods. From July 2008 to October 2018, 28 cases of Meckel’s diverticulum with a variety of complications were admitted to our hospital. The clinical data included age, gender, symptoms and signs, investigations, intraoperative and pathological findings, and outcome. Results. The ratio of males to females was 2.5 : 1. The diagnoses were made by 99mTc-pertechnetate scan (in 5 cases) and by exploratory laparotomy (in 2 cases). The initial diagnosis in the other cases includes intussusception (in 4 cases), acute appendicitis (in 5 cases), intestinal obstruction (unknown origin), peritonitis, and even shock in 12 cases. Laparoscopic surgery was performed in 8 cases; 18 cases underwent open surgery. Excision of partial bowel segment with diverticulum and primary anastomosis was done in 22 cases and wedge resection of diverticulum in 4 cases. Two other cases received nonoperative therapy and went to other hospitals to receive surgical management. Ectopic gastric mucosa in the diverticulum was found in 9 cases, including 6 cases with lower gastrointestinal bleeding. Conclusion. The clinical characteristics of Meckel’s diverticulum varied. Children with hematochezia, peritonitis, and intestinal obstruction without history of prior abdominal operation should be suspected with this disease until proven otherwise. Hematochezia is often associated with ectopic gastric mucosa in the diverticulum. Laparoscopic surgery should be one of the choices for the diagnosis and treatment of Meckel’s diverticulum with complications.

Ischemic heart disease (IHD) is one of the leading causes of death worldwide. C-type lectin domain family 3 member B (CLEC3B) is a C-type lectin superfamily member and is reported to promote tissue remodeling. The serum levels of CLEC3B are downregulated in patients with cardiovascular disease. However, the molecular mechanisms of CLEC3B in IHD is not well-characterized. Therefore, we overexpressed CLEC3B and silenced CLEC3B in H9c2 rat cardiomyocytes for the first time. We then constructed a model of IHD in vitro through culturing H9c2 cardiomyocytes in serum-free medium under oxygen-deficit conditions. Then, Cell Counting Kit-8 (CCK-8), flow cytometry, qRT-PCR, and western blot assays were performed to investigate cell viability, apoptosis, and expression levels of CLEC3B, phosphatidylinositol 3-kinase (PI3K), phosphorylated PI3K (p-PI3K), protein kinase B (Akt), phosphorylated Akt (p-Akt), and cleaved-caspase 3. We observed that the mRNA expression of CLEC3B was decreased in hypoxic H9c2 cardiomyocytes (P

Two types of coupled different dimensional delayed reaction-diffusion neural network (CDDDRDNN) models without and with parametric uncertainties are analyzed in this paper. On the one hand, passivity and synchronization of the raised network model with certain parameters are studied through exploiting some inequality techniques and Lyapunov stability theory, and some adequate conditions are established. On the other hand, the problems of robust passivity and robust synchronization of CDDDRDNNs with parameter uncertainties are solved. Finally, two numerical examples are given to testify the effectiveness of the derived passivity and synchronization conditions.

Synchronization and robust synchronization of fractional-order coupled neural networks (FCNNs) are considered in this paper. Different with the most published works on synchronization based on a special solution of an isolate node of the networks, we remove this restriction and introduce a more widely accepted definition of synchronization. Meanwhile, because of parametric uncertainties of network models, robust synchronization for FCNNs is investigated. In addition, by utilizing pinning control strategies, several sufficient conditions are derived to make sure that the considered networks can realize pinning synchronization and robust pinning synchronization. Finally, the correctness of the obtained results is substantiated by two given numerical examples.

In order to analyze the impact of compound breakage of key strata on overlying strata movement and strata pressure behavior during the fully mechanized caving mining in shallow and extremely thick seams, this paper took the 1322 fully mechanized caving face in Jindi Coal Mine in Xing County as the engineering background. Under the special mining and geological condition mentioned above, UDEC numerical simulation software was applied to research the engineering problems, and results of numerical simulation were verified through the in-site measurement. The research results showed that during the fully mechanized caving mining in shallow and extremely thick seams, the inferior key strata affected by mining movement behaved in the mode of sliding instability and could not form the stable structure of the voussoir beam after breaking and caving. In addition, the main key strata behaved in the mode of rotary instability, and the caving rocks behind the goaf were gradually compacted because of the periodic instability of the main key strata. With the continuous advance of the working face, the abutment pressure of the working face was affected by the compound breakage and periodic instability of both the inferior key strata and the main key strata, and the peaks of the abutment pressure presented small-big-small-big periodical change characteristics. Meanwhile, the risk of rib spalling ahead of the working face presented different levels of acute or slowing trends. The actual measurement results of ground pressure in the working face showed that, in the working process, the first weighting interval of the inferior key strata was about 51 m and its average periodic weighting interval was about 12.6 m, both of which were basically consistent with the results of numerical simulation. The research has great significance in providing theoretical guidance and practical experience for predicting and controlling the ground pressure under the similar mining and geological conditions.

In the eastern mining area of Ningxia, China, multi-layered sandstone aquifers are widely distributed in the underground. However, the water abundance of these aquifers is not clear, which brings great challenges to the prevention and control of mine water disaster. In this paper, five mining areas in eastern Ningxia were taken as the study area, and the distribution characteristics of aquifer and the mine water filling source were analyzed through the analysis of geological data and numerical simulation. Finally, the lithology influencing index (LII) was constructed, and the water abundance of the aquifer was evaluated. The results show that the sandstone aquifer III in the lower part of the Jurassic Zhiluo formation is the main water-source aquifer of the #2 coal seam in the study area, while the middle aquifer II and the upper aquifer I are indirect water-source aquifers; the areas with extremely strong and strong water abundance are Maiduoshan, Hongliu, the south of Shicaocun, southeast and southwest of Meihuajing, and the central and southern areas of Shuangma mining areas; when the depth of water drainage boreholes in the roof reaches the development height of the water-conducting fracture zone, the pre-drainage measures can effectively control the mining inrush water of the working face and ensure the safety production. This research is of great significance to the prevention and control of mine water disaster.

To improve the resource recovery efficiency of mining face in thick coal seams, the correlation between deformation failure of bottom coal in the gob-side entry and coal pillar width was analyzed by theoretical analysis, numerical calculation, and similar simulation experiments. The results showed that, when the coal pillar was strong, with the decrease of pillar width, the failure depth of the bottom coal in the gob-side entry and floor heave increased. The deformation failure depth of the bottom coal in the entry was inversely related to the width of the coal pillar. The bottom coal was further fractured and dispersed under the action of tension, shear, and extrusion in the process of floor heave. Based on the floor heave induced by the narrow coal pillar, a recovery technique of the bottom coal with thick coal seams in the gob-side entry was developed. The width of the narrow pillar to be reserved was obtained by theoretical calculation and revised by numerical simulation; ultimately, the reasonable width was determined. Under the complex stress of the narrow pillar, the bottom coal in the gob-side entry was fully heaved, cracked, and separated. To realize the comprehensive mechanization and resource recovery of bottom coal, a matching mining excavator loader, transfer conveyor, and retractable belt conveyor were selected to transport the crushed bottom coal in the entry. This method has been successfully applied to the return airway of working face 8407 in the No. 5 Coal Mine of Yangquan Coal Group with remarkable economic and social benefits.

The microstructure and mineral composition of the gangue play a decisive role in the precipitation of heavy metal elements. In this study, the microstructure, mineral composition, and precipitation of heavy metal elements of coal gangue with different weathering degrees were analyzed through electron microscopy, X-ray diffraction, and static immersion leaching experiments. The following results were derived. (1) After the weathering of the coal gangue, its compactness and integrity changed significantly. The coal gangue structure transformed from relatively dense to relatively loose, and the development of large pores and fractures changed from basically no development to significant development. (2) After weathering, the contents of kaolinite and illite significantly increased, while that of feldspar significantly decreased. Coal gangue contains a small amount of Mn, Cu, Zn, Ti, Ba, Cl, and other elements. After weathering, the contents of each element were reduced. (3) Under the same conditions, a higher number of heavy metal elements precipitated from the weathered coal gangue than from the fresh coal gangue. The results of this research have significant importance in revealing the precipitation mechanism of heavy metals from coal gangue and in perfecting the theory of underground water environmental protection during solid backfilling mining.

According to the Conceptual Metaphor Theory, people understand abstract concepts depending on the activation of more concrete concepts, but not vice versa. The present research aims to investigate the role of directionality and automaticity regarding the activation of the conceptual metaphor "good is up". Experiment 1 tested the automaticity of the spatial-to-valence metaphoric congruency effect by having participants judge the valence of a positive or negative word that appeared either at the top or at the bottom of the screen. They performed the task concurrently with a 6-digit verbal rehearsal task in the working-memory-load (WML) blocks and without this task in the non-WML blocks. The spatial-to-valence metaphoric congruency effect occurred for the positive words in the non-WML blocks (i.e., positive words are judged more quickly when they appeared at the top than at the bottom of the screen), but not in the WML blocks, suggesting that this metaphoric association might not be activated automatically. Experiments 2-6 investigated the valence-to-spatial metaphoric association and its automaticity. Participants processed a positive or negative prime, which appeared at the center of the screen, and then identified a letter (p/q) that subsequently appeared at the top or bottom of the screen. The valence-to-spatial metaphoric congruency effect did not occur in the WML (6-digit verbal rehearsal) or non-WML blocks, whether response modality to the prime was key-press or vocal, or whether the prime was a word or a picture. The effect only unexpectedly occurred when the task was simultaneously performed with a 4-dot-position visuospatial rehearsal task. Nevertheless, the data collapsed across multiple experiments showed a null valence-to-spatial metaphoric congruency effect, suggesting the absence of the valence-to-spatial metaphoric association in general. The implications of the current findings for the Conceptual Metaphor Theory and its alternatives are discussed.

Based on techniques of close upper protective coal-rock layer mining, relieved gas extraction, and underground gangue washing-discharging-backfilling, this paper initiates the concept of mixed fully-mechanized coal mining, which combines a solid backfilling method and a caving method (hereinafter referred to as “backfill and caving mixed mining”). After the principle and key techniques are introduced, a physical simulation experiment and a numerical simulation are used to study the characteristics of the overlying strata’s fracture development, the main roof subsidence, the stress field and its influence area in the transition area with the length ratios of the backfilling section and the caving section, and the advancing distance of the mixed longwall face. Thus, the lengths of the caving section and the backfilling section, the parameters of the support system in the transition section, and the design process of the mixed longwall face are presented. In practice, the mixed longwall face Ji15-31010 in Ping-dingshan No. 12 Colliery proves that the designed lengths of 120 m and 100 m for the backfilling section and the caving section, respectively, are appropriate. The monitoring results of the hydraulic support working resistance show that the supports were working well in general; the maximum growth height of the overlying strata fracture is 18 m; the gas drainage efficiency is up to 80% and the average gas concentration is 0.1 g/m3; a large quantity of gangue generated in the Ji14 seam is disposed underground; coal and gas are extracted simultaneously; and significant environmental and economic benefits are realized.

Since the weight of overburden is sustained by both the backfill body and the unmined solid coal in coal mining with compacted backfilling (CMCB) panels, the stress and deformation characteristics of the surrounding rocks in coal mining are radically changed. The overburden movement control mechanism by coordinating with backfill body and shield in CMCB was studied systematically in this paper. Based on the analysis of deformational and structural characteristics of surrounding rock in CMCB panels, the methods of theoretical analysis, numerical simulation and engineering test are employed. The results show that the fracture of the main roof is mainly controlled by the filling ratio φ and is non-correlated to the shield supporting pressure p. However, p has a significant control effect on the deflection of roof within the shield canopy length, and adversely affects the filling ratio. With the increase of the filling ratio of the gob, the maximum sagging of the immediate and the main roofs, the peak front and the influence range of the abutment pressures are gradually reduced. Correspondingly, the stable period of internal pressure of backfill body in the gob is shortened. Engineering practice shows that the sagging of the gob roof, the distribution of the abutment pressure, the distribution of the internal pressure in the backfill body, and the ground surface sagging results obtained by the in-situ measurement are approximately corresponding to the theoretical analysis and numerical simulation results.

With the development of Internet technology, multimodal data have become the main data resource in the information age. Multimodal learning mode, as an education and teaching mode developed on multimodal data technology, provides more convenience for multimedia teaching. However, many challenges persist in its actual development and application. Currently, the multimodal learning model is susceptible to classroom noise, lack of teaching information, and other factors, which adversely affect multimodal data collection, teaching application, and achievement output. Thus, this paper optimizes the multimodal learning model in the open learning environment and takes 120 engineering students from a university in Guangxi Province as the research object. First, a sequential modal extraction method is proposed by constructing a multimodal probability generation model and then the data are modeled. Semi-supervised learning is then achieved by analyzing and combining the supervised and unsupervised learning processes. Finally, the knowledge base technology with information fusion characteristics is applied to the multimodal teaching mode. This teaching mode has been proven to improve students' learning ability and learning achievement and teachers' teaching effectiveness. [ABSTRACT FROM AUTHOR]

In fully mechanized solid backfilling mining (FMSBM), the loose gangues backfill body (LGBB) that filled into the goaf becomes the main body of bearing the overburden load. The deformation resistance of LGBB is critical for controlling overburden movement and surface subsidence. During the process of load bearing, LGBB will experience grain crushing, which has a significant effect on its deformation resistance. Gangues block will be accompanied with obvious acoustic emissions (AE) features in process of slipping, flipping and damaging. Under confined compression test, monitoring the AE parameters of LGBB can reveal the impact mechanism of grain crushing on LGBB deformation. The study is of great significance for obtaining an in-depth understanding of the mechanical properties of LGBB, and providing guidance to the engineering practice of FMSBM. In order to study the rules of acoustic emissions (AE) of graded Loose gangues backfill body (LGBB) in confined compression test, this article introduces the AE systems to conventional confined compression test to monitor AE signals resulted from the friction and fragmentation among LGBB. The test results show that in the process of LGBB compaction, AE parameters are highly correlated with the strain-stress curve. AE events of balanced-sized graded gangues are more inactive than other two graded samples in different compression stages, AE events of large-particle-dominated graded gangues are most active. In the spatial distribution, AE events are the most active on the edges and the middle part of test samples and the phenomenon of grain crushing is the most obvious in these positions. [ABSTRACT FROM AUTHOR]

Even though solid backfill mining can address some environmental issues of coal mining (like surface subsidence and gangue storage), on the other hand the long exposure of gangue to rain or other surficial water will also result in the leaching of heavy metal ions, which in turn will pose the threat of potential pollution to groundwater. In response to resolving the above-mentioned problem, this paper simulated the concentration distribution and migration principle of Cu2+ in various soils by applying COMSOL Multiphysics software, and the results show that the diffusion distance of Cu2+ in different soils are ranked as clay, silty clay, loess, and sandy soil. In addition, the concentration will decrease with the increase of depth and the Darcy velocity contours of Cu2+ distribute radially and symmetrically in the transverse direction. The velocity gradient of Darcy velocity in different soils is clay soil > Silty clay soil > loess > sandy soil. [ABSTRACT FROM AUTHOR]