107 research outputs found

    Allowable Deformation Prediction for Surrounding Rock of Underground Caverns Based on Support Vector Machine

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    This paper presents a novel allowable deformation prediction model of surrounding rock based on support vector machine (SVM). The engineering rock mass classification is subdivided based on the national standards Standard for Engineering Classification of Rock Masses in order to get more accurate physicalmechanical parameters. Using the developed parameters, 100 sets of multi-factors and multi-levels orthogonal experiments are designed, which are simulated with two-dimensional numerical models established based on ABAQUS. 100 groups of learning samples and 9 samples of random inspection are obtained. The prediction model has been established from the study of learning samples based on LibSVM. Using this model, 9 samples of random inspection and 9 engineering examples are predicted and the prediction accuracy is good compared with their actual values. It is indicated that this model can meet the initial support design requirements of underground caverns well. The novel model has the advantages of convenience, rapidity, and reliability

    UAV hyperspectral analysis of secondary salinization in arid oasis cotton fields: effects of FOD feature selection and SOA-RF

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    Secondary salinization is a crucial constraint on agricultural progress in arid regions. The specific mulching irrigation technique not only exacerbates secondary salinization but also complicates field-scale soil salinity monitoring. UAV hyperspectral remote sensing offers a monitoring method that is high-precision, high-efficiency, and short-cycle. In this study, UAV hyperspectral images were used to derive one-dimensional, textural, and three-dimensional feature variables using Competitive adaptive reweighted sampling (CARS), Gray-Level Co-occurrence Matrix (GLCM), Boruta Feature Selection (Boruta), and Brightness-Color-Index (BCI) with Fractional-order differentiation (FOD) processing. Additionally, three modeling strategies were developed (Strategy 1 involves constructing the model solely with the 20 single-band variable inputs screened by the CARS algorithm. In Strategy 2, 25 texture features augment Strategy 1, resulting in 45 feature variables for model construction. Strategy 3, building upon Strategy 2, incorporates six triple-band indices, totaling 51 variables used in the model’s construction) and integrated with the Seagull Optimization Algorithm for Random Forest (SOA-RF) models to predict soil electrical conductivity (EC) and delineate spatial distribution. The results demonstrated that fractional order differentiation highlights spectral features in noisy spectra, and different orders of differentiation reveal different hidden information. The correlation between soil EC and spectra varies with the order. 1.9th order differentiation is proved to be the best order for constructing one-dimensional indices; although the addition of texture features slightly improves the accuracy of the model, the integration of the three-waveband indices significantly improves the accuracy of the estimation, with an R2 of 0.9476. In contrast to the conventional RF model, the SOA-RF algorithm optimizes its parameters thereby significantly improving the accuracy and model stability. The optimal soil salinity prediction model proposed in this study can accurately, non-invasively and rapidly identify excessive salt accumulation in drip irrigation under membrane. It is of great significance to improve the growing conditions of cotton, increase the cotton yield, and promote the sustainable development of Xinjiang’s agricultural economy, and also provides a reference for the prevention and control of regional soil salinization

    Experimental evaluation of UAV spraying for peach trees of different shapes: effects of operational parameters on droplet distribution

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    Small-scale plant protection Unmanned Aerial Vehicles (UAVs) are finding a wide range of applications in modern agriculture management (including aerial spraying) due to their high efficiency and flexibility, low labour/water requirement and no damage to crops and soils, which substantially increase agricultural productivity and sustainability. UAV operational parameters, however, have remarkable effects on droplet distribution in UAV spraying, which significantly affect pesticide utilization rate and treatment effectiveness. Therefore, this work aimed to evaluate the effects of UAV operational parameters on droplet distribution for orchard trees. In particular, peach, an important orchard tree worldwide, is investigated in this study, and two typical tree shapes were considered including Y-shape and Central Leader (CL)-shape. Specifically, UAV spraying experiments were performed in Shandong Institute of Pomology, Shandong Province, China, and gas powered helicopter 3WQF120-12 was chosen as the spraying platform. The UAV operational parameters under consideration include flight route (intra-row, inter-row), flight velocity (four levels: 2, 3, 4, 5 m/s), number of spray times (1 vs 2) and nozzle flow rate. Droplet coverage rate at different positions and layers, obtained by water sensitive papers, was chosen as the metric to evaluate spraying performance. Experimental results show that: (1) the spraying uniformity is different between Y-shape and CL-shape peach tree, where Y-shape exhibits uniformity for positions at inner or outer layers. CL-shape results in a higher droplet coverage at top layer while with uniformity at lower three layers; (2) for Y-shape peach, intra-row route obtained a higher droplet coverage rate; while for CL-shape peach inter-row not only saved spraying volume but also results in a higher droplet coverage rate; (3) for both tree shapes, the increase in flight velocity (2--5 m/s) significantly decreased the droplet coverage rate; (4) for Y-shape peach with doubling the number of spraying times decreased the spraying performance for unit area. (5) for CL-shape peach with intra-row route, increasing the nozzle flow rate from 1.8 to 2.2 L⋅min−1L\cdot min^{-1} can significantly improve the droplet coverage rate at top and bottom two layers. It is envisioned that this study can provide some fundamental guidance of the operation of small UAVs for the aerial spraying of peach trees and similar orchards

    Assessing Heavy Metal Pollution of the Largest Nature Reserve in Tianjin City, China

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    Embargo until June 10, 2023Beidagang Wetland (BW) Nature Reserve is centrally situated in Tianjin City, experiencing an extreme industrial development. This study uses index characteristic analysis systems for assessing the individual and combined heavy metal pollution loading in the water during the spring and autumn seasons. By combining the pollution level of single pollutant, a more comprehensive evaluation of water quality in BW was achieved. Water quality was worst during autumn due to high level of Cd and Pb, which indicate the type of anthropogenic activities have a serious effect on heavy metal pollution in BW. In addition, high exchangeable amounts of Cd (> 40%) were found in the sediments of BW, indicating Cd pollution has emerged. There is a need for appropriate abatement actions curbing heavy metal loading and improving water quality of the BW Nature Reserve, thereby ensuring a sustainable management of its ecosystem services.acceptedVersio

    Gateroad protection mechanism and surrounding rock control for gob-side entry with slender pillar in deep and inclined extra-thick coal seams

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    The depth of coal mining in the central and eastern China is increasing, the ground pressure is high, the roadway deformation and burst risk is great. Gob-side entry with slender gate pillar (GESGP) is constantly adopted to improve surrounding rock environment. In order to grasp ground pressure behavior of the gob-side entry and develop targeted surrounding rock control measures, field observation and numerical simulation have been carried out against a case of GESGP of 3 m pillar in a ultra thick coal seam of a 800 m cover depth. The results show that: ① Fragmentation and deformation of surrounding rock on the coal pillar side are larger than the other side. Fragmentation and deformation of pillar at the gob side is larger than the other; Although the buried depth is great, the gob is settled and a large amount of overburden load is sustained by it, so the stress is sufficiently transferred to the deep rocks; ② The deformation of the gob-side entry is asymmetrical, the roof sags more on the pillar side than the other, pillar rib top and solid coal side rid middle are greater with deformation occurring mostly at shallow part; ⑱ Gob is the “escape” passage for entry deformation which is good for slow release of deformation energy and reduction of burst; ④ The range of the pressure relief area is expanded from triangle before excavation to parallelogram after excavation, also the location of the stress concentration area is shifted to the upper right of the entry; â‘€ Interface of the first/second shear failure planes on the pillar and the high stress zone on the upper right of the entry are the key targeted control zones. The surrounding rock control system was put forward that coal pillar reinforcement based on multiple plastic zone development cycles and precise destress of high stress zone. The research can provide research foundation and scientific basis for the adjacent panels and other similar deep and inclined extra-thick coal seams

    The relationship between coffee-related factors and cortical and hippocampal structure: a triangulation of evidence approach and Mendelian randomization research

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    ObjectiveExisting studies have reported sustained changes in the cortical structure of rats due to coffee-related factors, which are speculated to occur in the human body. However, there is a lack of research on this topic. Additionally, previous observational studies have found the impact of diseases on cortical structure and the potential therapeutic effects of coffee on these diseases. Our aim was to study the causal effects of coffee-related factors on the human brain using SNPs (single nucleotide polymorphisms). We will connect these discovered causal effects to the impact of diseases on the brain. Through triangulating evidence, we will reveal the potential active areas of coffee in preventing diseases.MethodsWe utilized GWAS data from multiple cohorts and their databases, selecting instrumental variables for genetic prediction of coffee intake and plasma levels of caffeine and its direct metabolites. We applied these instrumental variables to individual data on cortical thickness and surface area, as well as hippocampal volume, from the ENIGMA and CHARGE consortium for Mendelian randomization analysis (MR). Triangular evidence was obtained by integrating existing evidence through a specified retrieval strategy, calculating the overlap between coffee's effects on brain regions and disease-related brain regions to identify potential regions of action.ResultsThe MR analysis yielded 93 positive results for 9 exposures, among which theobromine, a metabolite in the caffeine pathway, was found to be associated with increased hippocampal volume. For cortical structure, theobromine in the caffeine pathway was associated with a decrease in total surface area, while theobromine and caffeine in the pathway were associated with an increase in total thickness. The overlap rate of triangular evidence showed no difference in both overall and subgroup analyses, indicating a high overlap between the effects of coffee on brain regions and disease.ConclusionsFrom predicted outcomes from causal effects, coffee intake-related factors may have lasting effects on cortical structure. Additionally, theobromine and theophylline have the greatest impact on certain brain gyri, rather than caffeine. Triangulation evidence indicates that disease and coffee intake-related factors act on the same cortical regions, suggesting the presence of potential shared or antagonistic pathways

    C1q complement/tumor necrosis factor-associated proteins in cardiovascular disease and covid-19

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    With continually improving treatment strategies and patient care, the overall mortality of cardiovascular disease (CVD) has been significantly reduced. However, this success is a double-edged sword, as many patients who survive cardiovascular complications will progress towards a chronic disorder over time. A family of adiponectin paralogs designated as C1q complement/tumor necrosis factor (TNF)-associated proteins (CTRPs) has been found to play a role in the development of CVD. CTRPs, which are comprised of 15 members, CTRP1 to CTRP15, are secreted from different organs/tissues and exhibit diverse functions, have attracted increasing attention because of their roles in maintaining inner homeostasis by regulating metabolism, inflammation, and immune surveillance. In particular, studies indicate that CTRPs participate in the progression of CVD, influencing its prognosis. This review aims to improve understanding of the role of CTRPs in the cardiovascular system by analyzing current knowledge. In particular, we examine the association of CTRPs with endothelial cell dysfunction, inflammation, and diabetes, which are the basis for development of CVD. Additionally, the recently emerged novel coronavirus (COVID-19), officially known as severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), has been found to trigger severe cardiovascular injury in some patients, and evidence indicates that the mortality of COVID-19 is much higher in patients with CVD than without CVD. Understanding the relationship of CTRPs and the SARS-CoV-2-related damage to the cardiovascular system, as well as the potential mechanisms, will achieve a profound insight into a therapeutic strategy to effectively control CVD and reduce the mortality rate

    C1q/TNF-Related Protein 3 Prevents Diabetic Retinopathy via AMPK-Dependent Stabilization of Blood–Retinal Barrier Tight Junctions

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    Background The impairment of the inner blood–retinal barrier (iBRB) increases the pathological development of diabetic retinopathy (DR), a severe complication in diabetic patients. Identifying approaches to preserving iBRB integrity and function is a significant challenge in DR. C1q/tumor necrosis factor-related protein-3 (CTRP3) is a newly discovered adipokine and a vital biomarker, predicting DR severity. We sought to determine whether and how CTRP3 affects the pathological development of non-proliferative diabetic retinopathy (NPDR). Methods To clarify the pathophysiologic progress of the blood–retinal barrier in NPDR and explore its potential mechanism, a mouse Type 2 diabetic model of diabetic retinopathy was used. The capillary leakage was assessed by confocal microscope with fluorescent-labeled protein in vivo. Furthermore, the effect of CTRP3 on the inner blood–retinal barrier (iBRB) and its molecular mechanism was clarified. Results The results demonstrated that CTRP3 protects iBRB integrity and resists the vascular permeability induced by DR. Mechanistically, the administration of CTRP3 activates the AMPK signaling pathway and enhances the expression of Occludin and Claudin-5 (tight junction protein) in vivo and in vitro. Meanwhile, CTRP3 improves the injury of human retinal endothelial cells (HRMECs) induced by high glucose/high lipids (HG/HL), and its protective effects are AMPK-dependent. Conclusions In summary, we report, for the first time, that CTRP3 prevents diabetes-induced retinal vascular permeability via stabilizing the tight junctions of the iBRB and through the AMPK-dependent Occludin/Claudin-5 signaling pathway, thus critically affecting the development of NPDR

    Nicotine aggravates vascular adiponectin resistance via ubiquitin-mediated adiponectin receptor degradation in diabetic Apolipoprotein E knockout mouse

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    There is limited and discordant evidence on the role of nicotine in diabetic vascular disease. Exacerbated endothelial cell dysregulation in smokers with diabetes is associated with the disrupted adipose function. Adipokines possess vascular protective, anti-inflammatory, and anti-diabetic properties. However, whether and how nicotine primes and aggravates diabetic vascular disorders remain uncertain. In this study, we evaluated the alteration of adiponectin (APN) level in high-fat diet (HFD) mice with nicotine (NIC) administration. The vascular pathophysiological response was evaluated with vascular ring assay. Confocal and co-immunoprecipitation analysis were applied to identify the signal interaction and transduction. These results indicated that the circulating APN level in nicotine-administrated diabetic Apolipoprotein E-deficient (ApoE−/−) mice was elevated in advance of 2 weeks of diabetic ApoE−/− mice. NIC and NIC addition in HFD groups (NIC + HFD) reduced the vascular relaxation and signaling response to APN at 6 weeks. Mechanistically, APN receptor 1 (AdipoR1) level was decreased in NIC and further significantly reduced in NIC + HFD group at 6 weeks, while elevated suppressor of cytokine signaling 3 (SOCS3) expression was induced by NIC and further augmented in NIC + HFD group. Additionally, nicotine provoked SOCS3, degraded AdipoR1, and attenuated APN-activated ERK1/2 in the presence of high glucose and high lipid (HG/HL) in human umbilical vein endothelial cells (HUVECs). MG132 (proteasome inhibitor) administration manifested that AdipoR1 was ubiquitinated, while inhibited SOCS3 rescued the reduced AdipoR1. In summary, this study demonstrated for the first time that nicotine primed vascular APN resistance via SOCS3-mediated degradation of ubiquitinated AdipoR1, accelerating diabetic endothelial dysfunction. This discovery provides a potential therapeutic target for preventing nicotine-accelerated diabetic vascular dysfunction

    Mean Interplanetary Magnetic Field Measurement Using the ARGO-YBJ Experiment

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    The sun blocks cosmic ray particles from outside the solar system, forming a detectable shadow in the sky map of cosmic rays detected by the ARGO-YBJ experiment in Tibet. Because the cosmic ray particles are positive charged, the magnetic field between the sun and the earth deflects them from straight trajectories and results in a shift of the shadow from the true location of the sun. Here we show that the shift measures the intensity of the field which is transported by the solar wind from the sun to the earth.Comment: 6 papges,3 figure
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