Mining coal-rock interface nodal GPR rapid dynamic detection system and experimental research

Coal-rock interface recognition technology is one of the key technologies for intelligent mining in coal mines. Based on high-frequency radar wave detection technology, high-precision detection of coal-rock interfaces can be achieved with mining, but there are still safety risks for equipment caused by rib spalling and roof caving in ultra-high mining heights (≥6 m) in mines, as well as spatial restrictions on equipment passing through during sudden changes in mining height (mining height ≤2 m). Based on previous work, this paper proposes a rapid dynamic detection system and method for coal-rock interfaces in mines using nodal GPR. The main contents include: ① Explaining the principle of the nodal GPR observation system in mines, designing a coal-rock interface recognition observation system plan and radar antenna sensor installation method based on the actual environment of the mine working face; ② Studying and proposing a nodal acquisition control system and information interaction transmission design plan to achieve dynamic data acquisition, control, and storage; ③ Studying and proposing enhanced processing methods for sensor detection data and coal-rock interface recognition algorithms based on nodal acquisition methods and radar reflection echo characteristics of coal-rock interfaces, which can effectively achieve intelligent recognition and tracking of coal-rock interfaces, as well as calculation of coal seam thickness and spatial coordinates. To verify the feasibility of this method, multiple geological radar antenna sensors with a center frequency of 1.5 GHz were used for physical model verification experiments, and a comparative analysis of nodal data acquisition and continuous data acquisition results was conducted. The experimental results show that both nodal and continuous acquisition methods can effectively identify coal-rock interfaces. Compared with continuous acquisition methods, the nodal detection method proposed in this paper can achieve rapid and dynamic repetitive data acquisition, with a single acquisition time controlled within 10 seconds, an average error of 1.07 cm for coal seam thickness detection results, a maximum error of 1.47 cm, and an average error percentage of 7.64%. This method provides technical support for dynamic high-precision detection of coal-rock interfaces in intelligent mining in mines

Phononic real Chern insulator with protected corner modes in graphynes

Higher-order topological insulators have attracted great research interest recently. Different from conventional topological insulators, higher-order topological insulators do not necessarily require spin-orbit coupling, which makes it possible to realize them in spinless systems. Here, we study phonons in 2D graphyne family materials. By using first-principle calculations and topology/symmetry analysis, we find that phonons in both graphdiyne and $\gamma$-graphyne exhibit a second-order topology, which belongs to the specific case known as real Chern insulator. We identify the nontrivial phononic band gaps, which are characterized by nontrivial real Chern numbers enabled by the spacetime inversion symmetry. The protected phonon corner modes are verified by the calculation on a finite-size nanodisk. Our study extends the scope of higher-order topology to phonons in real materials. The spatially localized phonon modes could be useful for novel phononic applications.Comment: 6 pages, 5figure

Clinical characteristics of tracheobronchomalacia complicated with pulmonary infection in children and the significance of electronic fiberoptic bronchoscopy in diagnosis and treatment

Objective To analyze the clinical features of children with tracheobronchomalacia （TBM） complicated with pulmonary infection，and to explore the significance of fiberoptic bronchoscopy in the diagnosis and treatment of this disease. Methods Clinical data of 236 children admitted to our hospital due to recurrent pulmonary infection were collected. Among them， 37 children were diagnosed with TBM by fiberoptic bronchoscopy. Clinical features of TBM and fiberoptic bronchoscopy results were analyzed. The differences between TBM and non-TBM children were statistically compared. Results The proportion of TBM children aged<1 year was high （30/37）. The average age of TBM children was significantly younger than that of non-TBM counterparts， and the average length of hospital stay of TBM children was significantly longer than that of non-TBM counterparts， and the differences were statistically significant （both P < 0.05）. The main manifestations of TBM and non-TBM children were cough， wheezing and recurrent respiratory tract infection， and there were no statistical differences in the male-to-female ratio （all P > 0.05）. Fiberoptic bronchoscopy found mild and moderate TBM at a single site in TBM children， and favorable outcomes were obtained. Conclusion TBM is one of the important factors of recurrent pulmonary infection and wheezing in young children. It is challenging to identify the symptoms of TBM. Bronchoscopy is beneficial to timely diagnosis and treatment

Radiation Enhances the Epithelial– Mesenchymal Transition of A549 Cells via miR3591-5p/USP33/PPM1A

Background/Aims: Radiotherapy plays a critical role in lung cancer treatment. Radiation can activate transforming growth factor-β (TGF-β) signaling and induce the epithelial-mesenchymal transition (EMT), which may lead to distant metastases. MicroRNAs (miRNAs) have been suggested to affect radiotherapy in lung cancer. Methods: miRNA Next-Generation Sequencing was performed to investigate the effects of irradiation on the miRNA profile of lung cancer A549 cells. The functions of identified miRNA on the radiation induced EMT and TGF-β activation in A549 cells were then explored. Protein expression was evaluated by western blotting. Immunofluorescence staining was performed to detect the localization of Snail. Luciferase Assay was used to determine the target gene regulated by the identified miRNA. Results: Radiation time-dependently induced EMT in A549 lung cancer cells as indicated by the changes of morphology, the expression of EMT marker proteins (E-cadherin, α-SMA and Vimentin) and the nuclear localization of Snail. Moreover, miR-3591-5p was identified as the most significant increased miRNA in response to radiation, and further experiments indicated that miR-3591-5p was required for radiation induced EMT and TGF-β/ Smad2/3 activation. Ubiquitin Specific Peptidase 33 (USP33) was a downstream target of miR-3591-5p as predicted by TargetScan and validated by 3’ untranslated regions (UTRs) Luciferase Assay. USP33 could deubiquitinate PPM1A (protein phosphatase, Mg2+/Mn2 + dependent 1A), a phosphatase for Smad2/3. Ectopic expression of USP33 or PPM1A partially abolished the effects of miR-3591-5p on EMT and TGF-β/ Smad2/3 activation. Conclusion: The present study revealed the critical role of miR-3591-5p/USP33/PPM1A in radiation-induced EMT via TGF-β signaling and may suggest novel radiation sensitise strategies for lung cancer

An economic-psychological perspective on perceived land tenure security : Evidence from rural eastern China

Land tenure security perceived by farmers is generally considered an important precondition for rural development. In this paper, we first propose a holistic framework of land tenure security that integrates Van Gelder's tripartite view of tenure security with Ho's credibility thesis. Following this framework, we empirically investigate the interrelation between the cognitive and the affective components of tenure security perceptions, and analyze how these perceptions are influenced by psychological factors, such as personality traits and economic preferences. We apply the generalized structural equation modeling to a dataset collected in 2019 among 1359 rice farmers in three provinces in eastern China. We found that the cognitive component shows an inverse “U-shape” relationship with the affective component, indicating farmers are not necessarily worried about the possible future land reallocation even if they think it is very likely to take place and that the widely used indicator, i.e., estimated probability of land reallocation, is thereby not sufficient to reflect a farmer's overall perceived tenure security. We also found that individual differences in personality traits (e.g., neuroticism) can help explain observed variations in perceived tenure security. The results showing perceived land tenure security of rural farmers also comprises nonequivalent “feeling” and “thinking” components and their influencing psychological factors have important implications for future research and policy making on rural institutional development

Effect of Microcrystalline Cellulose on the Properties of PBAT/Thermoplastic Starch Biodegradable Film with Chain Extender

Poly (butylene adipate-co-terephthalate) (PBAT) is a fully biodegradable polymer with toughness and ductility. It is usually compounded with thermoplastic starch (TPS) to balance the cost for manufacturing biodegradable films such as disposable plastic bags. However, blending with TPS reduces valuable tensile strength, which limits the bearing capacity of PBAT film. In this study, microcrystalline cellulose (MCC) was employed as a reinforcement to strengthen the PBAT/TPS biodegradable film. The effect of MCC content on the mechanical, thermal, and morphological properties of the composite film were investigated. The optimal tensile strength and elongation at break reached 5.08 MPa and 230% when 4% MCC was added. The thermal stability and thermal resistance were improved with the addition of MCC; for example, Tmax increased by 1 °C and Tonset increased by 2–8 °C. Moreover, good compatibility among PBAT, TPS, and MCC can be achieved when the MCC content was below 6%. Consequently, the optimal MCC content was found to be 4%. These results could provide experimental data and method support for preparing high-performance PBAT hybrid films

Effect of personality traits on smallholders’ land renting behavior: Theory and evidence from the North China Plain

This study investigates the effect of smallholders’ personality traits on their land rental market decisions. We develop a conceptual framework and show that these internal factors could affect smallholders’ land rental market participation beyond institutional and socio-demographic factors. Our empirical analysis is based on a survey of 2119 rural households collected in the North China Plain. We find that smallholders with a higher level of openness are more active in participating in the farmland rental market. Moreover, internal locus of control plays a significant role in explaining smallholders’ land renting behavior. We further show that need for achievement mediates the link between internal locus of control and smallholder’s intention to rent land, indicating that fostering a higher level of internal locus of control—and subsequently achievement desire—could play an important role in promoting smallholders’ land-renting behavior. More generally, our results imply that taking rural smallholders’ personality traits into account in designing land rental policies may increase the effectiveness of policies aimed at promoting land rental market participation among smallholders and incubating crop farm scale enlargement in rural China