137 research outputs found

    SeisT: A foundational deep learning model for earthquake monitoring tasks

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    Seismograms, the fundamental seismic records, have revolutionized earthquake research and monitoring. Recent advancements in deep learning have further enhanced seismic signal processing, leading to even more precise and effective earthquake monitoring capabilities. This paper introduces a foundational deep learning model, the Seismogram Transformer (SeisT), designed for a variety of earthquake monitoring tasks. SeisT combines multiple modules tailored to different tasks and exhibits impressive out-of-distribution generalization performance, outperforming or matching state-of-the-art models in tasks like earthquake detection, seismic phase picking, first-motion polarity classification, magnitude estimation, back-azimuth estimation, and epicentral distance estimation. The performance scores on the tasks are 0.96, 0.96, 0.68, 0.95, 0.86, 0.55, and 0.81, respectively. The most significant improvements, in comparison to existing models, are observed in phase-P picking, phase-S picking, and magnitude estimation, with gains of 1.7%, 9.5%, and 8.0%, respectively. Our study, through rigorous experiments and evaluations, suggests that SeisT has the potential to contribute to the advancement of seismic signal processing and earthquake research

    Are Farmers Willing to Pay for Centralized Mode Provision of Rural Domestic Sewage Treatment? A Large-Scale Assessment in North China

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    peer reviewedEvaluation of farmers’ willingness to participate (WTPP) and willingness to pay (WTP) for the centralized mode provision (CMP) of rural domestic sewage treatment (RDST) is imperative to improve the rural environment as well as to alleviate government financial pressures. This study adopted the contingent valuation method as well as face-to-face interview questionnaires to assess rural residents’ provision mode preferences, WTPP, and WTP for the CMP of RDST in China. Based on 761 samples collected from Shandong, Jilin, and Gansu provinces of China, we applied econometric models to estimate farmers’ WTPP and WTP for the CMP of RDST and explore the potential influencing factors, respectively. Results show that 1) 81.87% of the farmers would be willing to contribute to CMP of RDST; 2) farmers’ perceptions of the necessity of RDST, pollution of rural domestic sewage, and government propaganda significantly and positively affect their WTP; and 3) the expected WTP for CMP of RDST with the total respondents and the respondents with positive WTPP were estimated to be 7.59 USD/year and 10.10 USD/year (for a total of 20 years), accounting for 16.28 and 21.65% of construction costs, respectively. Based on these outcomes, it could be further estimated that the aggregate value was between 179.05 million USD/year and 238.26 million USD/year which implied that the farmers’ WTP may be a potentially non-negligible funding source for the CMP of RDST. The enhancement of environmental awareness of farmers and strengthening of propaganda should be the next priority of the Chinese government. Priority should also be assigned to villages closer to towns when the government formulates relevant strategies and policies. The results of this study provide references for policy formulation related to broadening the funding sources in RDST and exploring farmer payment mechanisms and implications for other developing countries

    Mine earthquake mechanism of extremely thick strata based on focalmemchanism analysis

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    In the Ordos mining area of North China, the Jurassic coal seam is commonly overlain by extremely thick cretaceous sandstone strata. Based on the seismic displacement field and relative moment tensor inversion method, this paper investigates the mine earthquake mechanism and roof fracture characteristics of coal seams under extremely thick strata. In this study, by using seismic source groups as units and microseismic stations as objects, the source mechanism of mine earthquakes is inverted by constructing an inversion matrix, which greatly improves the inversion efficiency and accuracy. The focal mechanism of large-energy mine earthquakes located in solid coal section and goaf section under extremely thick strata is calculated. The characteristics of roof fracture evolution and the influence of vibration wave radiation are quantitatively analyzed. The results show that the extremely thick strata of Cretaceous goaf start to break when the panel below retreats along goaf. During this period, the surface subsidence increases rapidly, and the significant mine earthquakes with energy above 100 kJ begin to occur, and the mine earthquake distribution is more concentrative than that in the solid coal stage. Most of the large-energy mine earthquakes are located behind the goaf, which is closely related to the breakage and slide of the thick roof. Roof tension rupture accounts for more than 85% of the mine earthquakes. During mining along goaf, the seismic sources tend to expand upward, and more shear slip ruptures are presented compared with that in the solid coal mining stage. The strike of the fracture surface has a similar direction or an angle of “X” with the advancing direction. However, compared with that in the solid coal stage, the angle of “X” during mining along goaf increases from 30° to 45°. For the source rupture surface, the dip angle of between 0°−30° accounts for about 50% of the total. The failure type of roof is dominated by horizontal separation tension and roof rotation compression. The generated P waves mostly propagate to the goaf below, which causes a minor influence on the mining face. Only a small part of the P waves propagate to the surrounding working face, which may pose a great impact on the working face. The prevention and control strategy on the extremely-thick-strata type mine earthquakes can be conducted by weakening the integrity of thick strata and making thick strata break in tiers, aiming to reduce the rockburst risks to the working face induced by the breakage of the whole thick strata

    A low power circuit design of BLE baseband transmission data processing module

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    With the quickly development of the Internet of Things technology, Bluetooth (BLE) protocol has been increasingly adopted in consumer communication applications, industry communication utilization, and even positioning requirement, due to its advantages such as low power consumption, low cost, and low complexity. Especially the outstanding low power capability compared with other short-range communication protocol, many power limited AIoT (Artificial Intelligence IoT) devices select BLE as basic component. So, the low power, high performance, and small area BLE module become the key point of successful of whole AIoT system. In BLE system, the baseband data processing is the foundation. A good hardware circuit design of BLE baseband can improve BLE module performance and decrease power simultaneously. This paper analyzes the baseband data processing function of BLE in detail, and designs the baseband transmission data processing RTL circuit IP using Verilog HDL Hardware description language based on BLE protocol. The IP includes CRC verification module, whitening module and coding mapping function module. The RTL design is simulated and evaluated in workstation server with Synopsys VCS tool. The simulation results show that this design can achieve the Low-power BLE Bluetooth baseband function

    Cryo-EM structures of lipopolysaccharide transporter LptB2FGC in lipopolysaccharide or AMP-PNP-bound states reveal its transport mechanism

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    Lipopolysaccharides (LPS) of Gram-negative bacteria are critical for the defence against cytotoxic substances and must be transported from the inner membrane (IM) to the outer membrane (OM) through a bridge formed by seven membrane proteins (LptBFGCADE). The IM component LptB2FG powers the process through a yet unclarified mechanism. Here we report three high-resolution cryo-EM structures of LptB2FG alone and complexed with LptC (LptB2FGC), trapped in either the LPS- or AMP-PNP-bound state. The structures reveal conformational changes between these states and substrate binding with or without LptC. We identify two functional transmembrane arginine-containing loops interacting with the bound AMP-PNP and elucidate allosteric communications between the domains. AMP-PNP binding induces an inward rotation and shift of the transmembrane helices of LptFG and LptC to tighten the cavity, with the closure of two lateral gates, to eventually expel LPS into the bridge. Functional assays reveal the functionality of the LptF and LptG periplasmic domains. Our findings shed light on the LPS transport mechanism

    Separation of the Climatic and Land Cover Impacts on the Flow Regime Changes in Two Watersheds of Northeastern Tibetan Plateau

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    Assessment of the effects of climate change and land use/cover change (LUCC) on the flow regimes in watershed regions is a fundamental research need in terms of the sustainable water resources management and ecosocial developments. In this study, a statistical and modeling integrated method utilizing the Soil and Water Assessment Tool (SWAT) has been adopted in two watersheds of northeastern Tibetan Plateau to separate the individual impacts of climate and LUCC on the flow regime metrics. The integrated effects of both LUCC and climate change have led to an increase in the annual streamflow in the Yingluoxia catchment (YLC) region and a decline in the Minxian catchment (MXC) region by 3.2% and 4.3% of their total streamflow, respectively. Climate change has shown an increase in streamflow in YLC and a decline in MXC region, occupying 107.3% and 93.75% of the total streamflow changes, respectively, a reflection of climatic latitude effect on streamflow. It is thus construed that the climatic factors contribute to more significant influence than LUCC on the magnitude, variability, duration, and component of the flow regimes, implying that the climate certainly dominates the flow regime changes in northeastern Tibetan Plateau

    Farmers' preferences for sustainable farmland construction — Insights from a discrete choice experiment in China

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    peer reviewedSustainable farmland construction (SFC) is a priority development strategy used to address the integrated goals of “efficiency output, resource conservation, and environmental friendliness” in agricultural systems. Introducing farmer participation to optimize SFC institutions can improve farmland construction efficiency and address limited construction funding. This study analyzed farmer preferences for participating in SFC through a discrete choice experiment survey of farmers in the project area. This study also evaluated farmers' willingness to pay for different SFC schemes. The findings indicate that farmers prefer constructing mechanized production roads (MPR), leveling farmland and transforming the contiguous farmland (LF and CF), integrated irrigation and fertilizer facilities (IIFF), and moderate improvement in ecological protection facilities. On the basis of the heterogeneity of the farmer preferences, they can be classified as benefits-driven and ecology-driven. In addition, factors such as age, educational level, risk proneness, land transfer, and cultivated land quality can influence the classification of farmer preferences. Farmers' willingness to pay for MPR, LF and CF, ED, IIFF, and moderate improvement in ecological facilities has reached 50–80 % of construction costs, essentially bridging the investment gap under the SF standards set by the central government. Based on the aforementioned, SFC schemes should be designed to consider farmers' needs and regional development requirements. Allocating SF construction costs according to farmers' willingness to pay for various facilities, formulating diverse investment ratios, and forming a coherent government-farmer cooperation mode are recommended. This study introduces policy tools to establish a farmers' participation mechanism in farmland construction, offering valuable insights into institutional reforms in land consolidation projects across other developing countries

    A new critical exposition of the controversy between H.L.A. Hart and R.M. Dworkin

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    textabstractObjective: To adapt the Appropriateness Evaluation Protocol (AEP) to the specific settings of health care in China and to validate the Chinese version AEP (C-AEP). Methods: Forward and backward translations were carried out to the original criteria. Twenty experts participated in the consultancy to form a preliminary version of the C-AEP. To ensure applicability, tests of reliability and validity were performed on 350 admissions and 3,226 hospital days of acute myocardial infraction patients and total hip replacement patients in two tertiary hospitals by two C-AEP reviewers and two physician reviewers. Overall agreement, specific agreement, and Cohen's Kappa were calculated to compare the concordance of decisions between pairs of reviewers to test inter-rater reliability and convergent validity. The use of "overrides" and opinions of experts were recorded as measurements of content validity. Face validity was tested through collecting perspectives of nonprofessionals. Sensitivity, specificity, and predictive values were also reported. Results: There are 14 admission and 24 days of care criteria in the initial version of C-AEP. Kappa coefficients indicate substantial agreement between reviewers: with regard to inter-rater reliability, Kappa (κ) coefficients are 0.746 (95% confidence interval [CI] 0.644-0.834) and 0.743 (95% CI 0.698-0.767) of admission and hospital days, respectively; for convergent validity, the κ statistics are 0.678 (95% CI 0.567-0.778) and 0.691 (95% CI 0.644-0.717), respectively. Overrides account for less than 2% of all judgments. Content validity and face validity were confirmed by experts and nonprofessionals, respectively. According to the C-AEP reviewers, 18.3% of admissions and 28.5%of inpatient days were deemed inappropriate. Conclusions: The C-AEP is a reliable and valid screening tool in China's tertiary hospitals. The prevalence of inappropriateness is substantial in our research. To reduce inappropriate utilization, further investigation is needed to elucidate the reasons and risk factors for this inappropriateness. Copyright
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