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The early fault characteristics of rolling bearings in coal mining equipment are weak, and they are easily affected by factors such as load and working conditions. The characteristics can be submerged by noise, making bearing fault diagnosis difficult. Most existing research uses a single algorithm to process bearing fault signals, and the accuracy of fault characteristic extraction and fault diagnosis needs to be further improved. A fault diagnosis method for coal mining equipment bearings is proposed, which combines local characteristic-scale decomposition (LCD) and singular value decomposition (SVD). The LCD method is used to decompose the vibration signal of coal mining equipment bearings into several intrinsic scale components (ISC), achieving preliminary signal denoising. The method calculates the Shannon entropy of each ISC, selects the ISC with the smallest Shannon entropy for SVD. The method constructs the singular value difference spectrum of the SVD signal. The method reconstructs the signal for the maximum abrupt component to achieve signal enhancement and denoising. The method performs Hilbert envelope demodulation on the reconstructed signal to obtain the characteristic frequency of bearing faults, and then determine the bearing faults. The on-site measured data is used to validate the bearing fault diagnosis method of coal mining equipment based on LCD-SVD. The results show that this method can accurately extract the characteristic frequency of bearing faults, thereby achieving early fault diagnosis of coal mining equipment bearings.

With the gradual expansion of mining scale in open-pit coal mines, slope safety problems are increasingly diversified and complicated. In order to reduce the potential loss caused by slope sliding and reduce the major threat to the safety of life and property of residents in the mining area, this study selected two mining areas in Xinjiang as cases and focused on the relationship between phase noise and deformation. The study predicts the specific time point of slope sliding by analyzing the dynamic history correlation tangent angle between the two. Firstly, the time series data of the micro-variation monitoring radar are used to obtain the small deformation of the study area by differential InSAR (D-InSAR), and the phase noise is extracted from the radar echo in the sequence data. Then, the volume of the deformation body is calculated by analyzing the small deformation at each time point, and the standard deviation of the phase noise is calculated accordingly. Finally, the sliding time of the deformation body is predicted by combining the tangent angle of the ratio of the volume of the deformation body to the standard deviation of the phase noise. The results show that the maximum deformation rates of the deformation bodies in the studied mining areas reach 10.1 mm/h and 6.65 mm/h, respectively, and the maximum deformation volumes are 2,619,521.74 mm3 and 2,503,794.206 mm3, respectively. The predicted landslide time is earlier than the actual landslide time, which verifies the effectiveness of the proposed method. This prediction method can effectively identify the upcoming sliding events and the characteristics of the slope, provide more accurate and reliable prediction results for the slope monitoring staff, and significantly improve the efficiency of slope monitoring and early warning. [ABSTRACT FROM AUTHOR]

The Hendy Test is widely used for assessing whether isotopic equilibrium was reached in speleothems by examining the δ18O and δ13C correlation along a single growth layer. However, stalagmite micro-layers are typically only a few micrometers thick and taper off from the center towards the sides, making it challenging to sample within the same growth layer in practice. To address this, we selected three caves in the monsoon region of China (Shihua Cave in the north, Heshang Cave in the central, and Baojinggong Cave in the south) to verify whether the modern cave calcite has reached equilibrium fractionation with drip water. We examined the spatial variations in the δ18O and δ13C values of farmed calcite on glass plates, which are analogous to a single growth layer. The δ18O and δ13C correlations of farmed calcite from different cave sites are consistently strong, suggesting that kinetic fractionation effects are prevalent, especially at the drip sites with lower drip rates due to longer CO2 degassing. The δ18O–δ13C covariations can also occur along speleothem growth axes on short time scales, while isotopic variations over longer time scales are still in response to climate change. We propose that the Hendy Test criteria might not be prerequisites to isotopic equilibrium, and a Replication Test provides a more reliable indication of the integrity of isotopic proxies in paleoclimate research. [ABSTRACT FROM AUTHOR]

A spring tunnel is an ancient water installation used to artificially increase the water yield of a spring through a subterranean tunnel. We have developed a database of 216 spring tunnels documented in the central region of the Southern Levant (present‐day Israel), constructed between Iron Age II and the modern era. The study focuses on the evolution of this water installation over a period of 2500 years, examining these constructions from technological, typological, spatial, and cultural perspectives. Within the larger database, 132 spring tunnels have been mapped, from which we present 36 examples selected to outline the typology and chronology of this type of water installation. The findings of the study indicate a diachronic correlation between the distribution of settlement in the mountain region and the number and geographical distribution of spring tunnels. Ethnic and religious changes, and the complexity of the mountain region's population, are also reflected in the use of these water installations. The comprehensive water structure database presented in this article, from a peripheral, yet strategically located region in relation both to the Far East and to West Mediterranean Empires, is used for initial consideration of local initiatives versus the knowledge‐transfer process. [ABSTRACT FROM AUTHOR]

INTRODUCTION: The "prion‐like" features of Alzheimer's disease (AD) tauopathy and its relationship with amyloid‐β (Aβ) have never been experimentally studied in primates phylogenetically close to humans. METHODS: We injected 17 macaques in the entorhinal cortex with nanograms of seeding‐competent tau aggregates purified from AD brains or control extracts from aged‐matched healthy brains, with or without intracerebroventricular co‐injections of oligomeric‐Aβ. RESULTS: Pathological tau injection increased cerebrospinal fluid (CSF) p‐tau181 concentration after 18 months. Tau pathology spreads from the entorhinal cortex to the hippocampal trisynaptic loop and the cingulate cortex, resuming the experimental progression of Braak stage I to IV. Many AD‐related molecular networks were impacted by tau seeds injections regardless of Aβ injections in proteomic analyses. However, we found mature neurofibrillary tangles, increased CSF total‐tau concentration, and pre‐ and postsynaptic degeneration only in Aβ co‐injected macaques. DISCUSSION: Oligomeric‐Aβ mediates the maturation of tau pathology and its neuronal toxicity in macaques but not its initial spreading. Highlights: This study supports the "prion‐like" properties of misfolded tau extracted from AD brains.This study empirically validates the Braak staging in an anthropomorphic brain.This study highlights the role of oligomeric Aβ in driving the maturation and toxicity of tau pathology.This work establishes a novel animal model of early sporadic AD that is closer to the human pathology. [ABSTRACT FROM AUTHOR]

Oxygen isotope records from Chinese caves characterize changes in both the Asian monsoon and global climate. Here, using our new speleothem data, we extend the Chinese record to cover the full uranium/thorium dating range, that is, the past 640,00o years. The record's length and temporal precision allow us to test the idea that insolation changes caused by the Earth's precession drove the terminations of each of the last seven ice ages as well as the millennia-long intervals of reduced monsoon rainfall associated with each of the terminations. On the basis of our record's timing, the terminations are separated by four or five precession cycles, supporting the idea that the '100,000-year' ice age cycle is an average of discrete numbers of precession cycles. Furthermore, the suborbital component of monsoon rainfall variability exhibits power in both the precession and obliquity bands, and is nearly in anti-phase with summer boreal insolation. These observations indicate that insolation, in part, sets the pace of the occurrence of millennial-scale events, including those associated with terminations and 'unfinished terminations'., The seasonal cycle of solar heating over Asia gives rise to the Asian monsoon (AM), a vast system of overturning atmospheric circulation that transports heat and moisture during boreal summer [...]