Search

Surface harmless storage of concentrated full tailings (CFTs) involves the technology of adding a curing agent to the tailings slurry discharged from the thickener to realize the modification of the tailings and centralized storage of the tailings on the surface to realize the harmless treatment of the tailings. High water content of tailings is still the key technical problem that restricts the harmless storage of piles at present. Regarding the above problems, we implemented the consolidation test and numerical simulation of seepage-stress coupling consolidation of CFT, clarified the consolidation characteristics and parameters of CFT under different curing ages, and conducted a comparative analysis of pore water pressure in the whole cross-section of piles with different drainage schemes based on the results of the test. In addition, we also clarified the drainage effect of interlayer drainage on reducing the excess pore water pressure of piles and compared the simulation results of the pore water pressure of piles under different permeability coefficients. The results show that as the permeability coefficient of the concentrated tailings material decreases, the pore pressure accumulation inside piles under the same drainage scheme is more serious, and the length of time for consolidation and stabilization becomes longer. Therefore, it is recommended that the excess porous water pressure be relieved by means of increased drainage facilities under a small permeability coefficient.

As a regulator of ecological environment, Baiyangdian Wetland is in a pivotal position in constructing the blue-green space (BGS) of Xiong’an New Area in China. This study aims to reveal the spatiotemporal changes of the BGS in Baiyangdian Wetland from 2016 to 2021. It uses Google Earth Engine (GEE) to calculate NDVI and NDWI based on Sentinel-2 Satellite remote sensing data and extracts the blue-green space by a classification model driven by NDVI and NDWI. Moreover, the land-use transfer matrix and landscape pattern indices are applied for evaluating the BGS changes in the wetland. According to the results, vegetation in the wetland shows no obvious spatial transfer. From 2016 to 2020, the BGS proportion in the wetland showed a stable increase, with the blue space getting larger by 10.8%. The indicators of the Number of Patches (NP), Patch Density (PD), Largest Patch Index (LPI), Contagion, and Landscape Shape Index (LSI) of the wetland decreased, suggesting a better ecological environment since the establishment of Xiong’an New Area in 2017. Based on the results, the author makes the following conclusion: the construction of BGS in Baiyangdian Wetland results in a well-organized ecological environment. The study provides a reference for building Xiong’an New Area and monitoring BGS changes in other regions.

This article introduces a technology of integrated presplitting blasting, which can be applied to a new nonpillar coal mining method (i.e., Gob-side Entry Retaining by Roof Cutting (GERRC)) under the condition of thick and hard roofs. First, the new nonpillar coal mining method emerging in China is explained. Then, the concept of integrated presplitting blasting was put forward, and the mechanism of the technology was explained by the method of numerical simulation. Through a mining case with a thick hard limestone roof, the relevant design of nonpillar mining and the design parameters of integrated presplitting blasting are explained in detail. After field practice verification, from the construction process and test results, as well as combined with underground pressure observation and analysis, it shows that technology and design are reasonable. This research supplements the mining technology system of coal mining engineering and the proposed technologies and methods have strong applicability, especially for related coal mines nonpillar mining and safe and efficient mining.

With the adjustment of human diet and lifestyle changes, the prevalence of obesity is increasing year by year. Obesity is closely related to the excessive accumulation of white adipose tissue (WAT), which can synthesize and secrete a variety of adipokines. Apelin is a biologically active peptide in the adipokines family. Past studies have shown that apelin plays an important regulatory role in the pathogenesis and pathophysiology of diseases such as the cardiovascular system, respiratory system, digestive system, nervous system, and endocrine system. Apelin is also closely related to diabetes and obesity. Therefore, we anticipate that apelin-13 has an effect on lipometabolism and intend to explore the effect of apelin-13 on lipometabolism at the cellular and animal levels. In in vitro experiments, amidation-modified apelin-13 can significantly reduce the lipid content; TG content; and the expression of PPARγ, perilipin mRNA, and protein in adipocytes. Animal experiments also show that amidation modification apelin-13 can improve the abnormal biochemical indicators of diet-induced obesity (DOI) rats and can reduce the average diameter of adipocytes in adipose tissue, the concentration of glycerol, and the expression of PPARγ and perilipin mRNA and protein. Our results show that apelin-13 can affect the metabolism of adipose tissue, inhibit adipogenic differentiation of adipocytes, promote lipolysis, and thereby improve obesity. The mechanism may be regulating the expression of PPARγ to inhibit adipogenic differentiation and regulating the expression of perilipin to promote lipolysis. This study helps us understand the role of apelin-13 in adipose tissue and provide a basis for the elucidation of the regulation mechanism of lipometabolism and the development of antiobesity drugs.

The thermogravimetric method was applied to study the combustion characteristics of waste plastics and semicoke mixture at different heating rates with temperature ranging from room temperature to 1173 K. Also, the kinetic parameters of combustion process were also estimated by fitting the experimental data to the calculated data. The results showed that the mixed combustion process of waste plastics and semicoke could be divided into volatile combustion stage and fixed carbon combustion stage. The addition of waste plastics could increase the comprehensive combustion characteristic index (S) and flammability index (C). It showed synergistic effect in the mixed combustion process. When the additive amount of waste plastics was 60%, the S value and C value reached peak point at the heating rate of 20 K/min. The heating rate had a promotion effect on combustion rate. The mixed combustion process of waste plastics and semicoke could be well simulated by the n-order rate model of double parallel reactions. The activation energies E in the first stage of combustion of the mixture were higher than that in the second stage, and the preexponential factor k was opposite. Meanwhile, a marked kinetic compensation effect was presented between the activation energy and the preexponential factor.