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This paper introduces the current situation of intelligent development of shearer at home and abroad. The shearer is currently developing towards intelligent robotics and is in the primary stage of intelligence. This paper elaborates on the development process and trends of intelligent shearer. There are six scientific research projects that have played important roles in the intelligent development of shearer, including the UK remotely operated longwall face (ROLF) program, mine operating system (MINOS), NASA long wall automation cooperation project, Australian Australian coal industry’s research program (ACARP), Australian commonwealth scientific and industrial research organization (CSIRO) project, and EU new mechanisation and automation of longwall and drivage equipment (NEMAEQ). The development trend of shearer is to use continuously developing monitoring, sensing, and remote control technologies to replace manual intervention and operation, continuously improve the production efficiency and reliability of working face equipment, and develop towards informationization, integration, unmanned, and intelligent direction. This paper introduces the key technologies of intelligent perception, intelligent control, and intelligent communication of shearer. It points out that intelligent cutting technology based on coal rock recognition, intelligent drum speed regulation technology, precise positioning technology of shearer, and planning and mining technology based on three-dimensional geological models are key technologies that urgently need to be broken through. The human-machine relationship that cannot be ignored in the intelligent development process of shearer is discussed from two aspects: dust reduction and noise reduction.

Paleozoic igneous rocks exposed in the northern Yili Block are thought to have resulted from the subduction of the North Tianshan oceanic crust. However, the exact timing of the transition of the northern margin of the Yili Block from a passive to an active continental margin remains unknown. In this paper, the petrological and geochemical features, zircon U-Pb chronology, Lu-Hf isotopes, and Sr-Nd isotopes of volcanic rocks in the Nailenggeledaban area on the northern margin of the Yili Block were studied. Zircon U-Pb dating results show that the crystallization ages of the volcanic rocks in the Nailenggeledaban area on the northern margin of the Yili Block are 491 ± 2 Ma and 500 ± 2 Ma, suggesting they were formed during the Late Cambrian. Geochemical features show that the volcanic rocks are alkaline basalts with rare earth and trace element distribution patterns similar to OIB, although they exhibit some degree of Zr and Hf depletion. The εHf(t) values of alkaline basalts in the Nailenggeledaban area at the northern Yili Block range from −3.48 to −1.00, with a TDM1 age of 1152 to 1263 Ma. The εNd(t) values range from −3.53 to −0.96, with a TDM1 age of 1471 to 2162 Ma. Combined with geochemical data, the alkaline basalt magma in the Nailenggeledaban area on the northern margin of the Yili Block may be derived from the Mesoproterozoic enriched lithospheric mantle. The composition of the mantle source area is potentially garnet lherzolite, and the magma appears to have been either unaffected or only minimally contaminated by crustal materials during the ascending process. On the basis of the research results of the Early Paleozoic tectonic evolution in the northern margin of the Yili Block, this paper proposes that the volcanic rocks in the Nailenggeledaban area, located on the northern margin of the Yili Block, were formed in a back-arc extensional environment resulting from the subduction of the North Tianshan Ocean (or Junggar Ocean) beneath the northern margin of the Yili Block during the Late Cambrian. [ABSTRACT FROM AUTHOR]

Background: With public health emergencies (PHE) worldwide increasing, the perceived risk of PHE has been one of the critical factors influencing college students' psychological distress. However, the mechanisms by which the perceived risk of PHE affects college students' psychological distress are not clear. The study's purpose was to investigate the mediation roles of deviation from a balanced time perspective (DBTP) and negative coping styles between the perceived risk of PHE and psychological distress. Methods: A convenience sampling method was used to survey 1054 Chinese college students with self-reporting. Data was collected using the Public Risk Perception Scale (PRPS), the Zimbardo Time Perspective Inventory (ZTPI), the Simplified Coping Style Questionnaire (SCSQ), the PHE Anxiety Scale, and the Chinese version of the Patient Health Questionnaire (PHQ). The associations between the perceived risk of PHE, DBTP, negative coping styles, and psychological distress were clarified using the correlation analysis. Additionally, the mediating roles of DBTP and negative coping styles between the perceived risk of PHE and psychological distress were investigated using a structural equation model. Results: The findings revealed low to moderate correlations between the variables studied. Students' perceived risk of PHE was a positive predictor of their psychological distress (β = 0.219, p < 0.01). DBTP and negative coping styles played chain mediation roles between them with the effect being 0.009 and a 95% Boot CI of [0.003, 0.023]. This chain mediation model had an excellent fit index (χ 2 /df = 4.732, CFI = 0.973, TLI = 0.930, RMSEA = 0.048, SRMR = 0.047). Conclusion: These findings showed how the perceived risk of PHE affected college students' psychological distress. Specifically, these results suggested that improving students' mental ability to switch effectively among different time perspectives depending on task features and situational considerations and reducing their negative coping styles might be effective ways to promote their mental health. [ABSTRACT FROM AUTHOR]

Dust is a major source of atmospheric aerosols. Its chemical composition is often assumed to be similar to the parent soil. However, this assumption has not been rigorously verified. Here, we generated dust aerosols from soils to determine if there is particle-size-dependent selectivity of heavy metals in the dust generation. Mn, Cd, Pb and other heavy metals were found to be highly enriched in fine-dust (PM 2.5) aerosols, which can be up to ∼ 6.5-fold. To calculate the contributions of dust to atmospheric heavy metals, regional air quality models usually use the dust chemical profiles from the U.S. Environmental Protection Agency's (EPA) SPECIATE database, which does not capture the correct size-dependent selectivity of heavy metals in dust aerosols. Our air quality modeling for China demonstrates that the calculated contribution of fine-dust aerosols to atmospheric heavy metals, as well as their cancer risks, could have significant errors without using proper dust profiles. [ABSTRACT FROM AUTHOR]