Understanding the extent of contamination, sources and various carcinogenic and non-carcinogenic risks associated with different heavy metals in soil-crop systems is crucial for the prevention of heavy metal pollution. A survey was undertaken to determine heavy metal concentrations and degree of pollution in soil-crop systems (rice, wheat, and corn) using various indices such as pollution factor (CF), geo-accumulation index (I_geo), enrichment coefficients and transfer coefficient, and to determine the source of heavy metals pollution in the Wanjiang Economic Zone, Anhui Province, China. A total of 308 pairs of soil-crop samples were collected in this study, comprising 245 pairs of soil-rice samples, 53 pairs of soil-wheat samples, and 10 pairs of soil-corn samples. The concentrations of cadmium (Cd) and nickel (Ni) in the soil of the study area exceeded the national limitation of heavy metals in the soil of China (GB 15618-2018, Soil Environmental Quality: Risk Control Standard for Soil Contamination of Agricultural Land. Ministry of Environmental Protection of China. Beijing. China). The concentrations of copper (Cu), zinc (Zn) and lead (Pb) were also above the national limits to a lesser extent. All eight heavy metals (Cd, Cu, Ni, Pb Zn, arsenic (As), chromium (Cr), and mercury (Hg)) exceeded the background values in the study area. The enrichment coefficients of rice, wheat and maize to Cd, Cu and Zn were higher than those to other elements. On the basis of I_geo, it can be indicated that the rhizosphere soil of rice was slightly polluted by Cd and Hg, while the concentrations of the other heavy metals were below the safety limits. The CF and pollution load index (PLI) indicated that the soil in the study area was heavily contaminated with heavy metals. A principal component analysis identified different sources of soil heavy metal pollution, that is, Cu, Pb, Zn and Cd from industrial sources, Cr and Ni from natural sources, and As and Hg from agricultural sources. The carcinogenic risk of heavy metals was related to the intake of crops. Residents in the study area ingest rice, wheat, and corn on a daily basis. On the basis this study, it is suggested that local governments should pay attention to the carcinogenic risk of heavy metals in rice.

Heavy metals in freshwater lake sediments often exist in various chemical forms. However, the investigation and evaluation of heavy-metal elements in the sediments of the study area have not been reported, and there is a lack of objective understanding of the concentration level of heavy-metal elements. Therefore, this study is the first to report the concentrations, sources, and potential ecological risks of heavy metals in the sediments of Chengdong Lake and Chengxi Lake in Huoqiu County, Anhui Province, China. The spatial distribution, pollution characteristics, potential pollution sources, and ecological risks of heavy metals in the sediments of Chengxi Lake and Chengdong Lake of Huoqiu City in the middle section of Huaihe River in Anhui Province, China have not been reported. In this study, the sediment samples of the two Lakes were collected systematically, and the concentrations of heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) were determined. The potential sources of heavy-metal elements in sediments were quantitatively analyzed according to the principal component analysis–absolute principal component fraction–multiple linear regression (PCA–APCS–MLR) receptor model. Descriptive statistics data showed that the enrichment degree of heavy metals in Chengxi Lake was higher than that in Chengdong Lake. The geo-accumulation index (I_geo) and pollution load index (PLI) indicated that there was moderate pollution for Cu, As, Hg, Ni, and Zn. The calculation results of the potential ecological risk index (E_r) of the two lakes indicated that Cd (E_r,max = 92.22, n = 60) and Hg (E_r,max = 64.39, n = 60) showed a certain potential ecological risk in a small amount of sediment, while other heavy metals were classified as low risk. The mean sediment quality guideline quotient indicated that there was a moderate degree of potential adverse biological toxicity in lake sediments. Spatially, the seriously polluted contamination zones were the central position of Chengxi Lake and the northeast end of Chengdong Lake. The PCA–APCS–MLR receptor model revealed that Cr, Ni, Cu, and Zn were mainly from natural sources while Cd, As, Hg, and Pb elements were mainly from industrial sources and pesticide sources.

Under the effect of strong earthquakes, collisions or excessive inter-story displacements may occur between adjacent building structures to the extent that the building structure is damaged. The traditional seismic measures for these structures can no longer meet the needs in practical engineering. In this paper, we propose the application of parallel and serial TID-based control systems in adjacent buildings as an example of a single-story adjacent building, and use it to form a new adjacent building seismic reduction structure. In this paper, the dynamic characteristics and design parameter optimization of the vibration control system are investigated by means of the Monte Carlo pattern search method and H₂ norm theory. The results show that the introduction of serial and parallel TID in adjacent building structures can effectively improve the seismic resistance of adjacent buildings. The problem of vibration amplification caused by resonance is obviously improved, which is especially evident in the adjacent building structure vibration control system based on parallel TID. The vibration control system of adjacent building structures based on parallel TID is more robust. When optimizing the right building, the damping requirement of the TID decreases for the vibration control system based on parallel TID as the adjacent building mass ratio increases, while the damping requirement of the TID increases for the vibration control system based on serial TID. In both vibration control systems, the difference in the optimal inertial mass ratio is small. In practice, a moderate increase in the difference between adjacent building masses can have a positive effect on the vibration control performance of the systems. The main contribution of this paper is to fill the research gap in parallel and serial TID applications for adjacent building vibration reduction.

In order to deal with the problems of resource waste and environmental pollution caused by solid waste, iron tailings (mainly SiO₂, Al₂O₃ and Fe₂O₃) were used as the main raw material to create a type of lightweight and high-strength ceramsite. Iron tailings, dolomite (industrial grade, purity 98%) and a small amount of clay were combined in a N₂ atmosphere at 1150 °C. X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and a themogravimetric analysis (TGA) were performed and the specific surface area was analyzed to determine the strength and adsorption of the ceramsite. The results of the XRF showed that SiO₂, CaO and Al₂O₃ were the main components of the ceramsite, with MgO and Fe₂O₃ also included. The results of the XRD and SEM-EDS showed that the ceramsite contained several kinds of minerals and was mainly composed of akermanite, gehlenite and diopside, and that the morphology of the internal structure of the ceramsite was mainly massive and contained a small number of particles. The ceramsite could be used in engineering practice to improve the mechanical properties of materials and meet the requirements of actual engineering for the strength of materials. The results of the specific surface area analysis showed that the inner structure of the ceramsite was compact and that there were no large voids. The voids were mainly medium and large, with a high stability and strong adsorption ability. The TGA results showed that the quality of the ceramsite samples will continue to increase within a certain range. According to the XRD experimental results and experimental conditions, it was speculated that in the part of the ore phase containing Al, Mg or Ca in the ceramsite, the elements underwent relatively complex chemical reactions with each other, resulting in the formation of an ore phase with a higher molecular weight. This research provides the basis of characterization and analysis for the preparation of high-adsorption ceramsite from iron tailings and promotes the high-value utilization of iron tailings for waste pollution control.

The structural fracture of the coal seam with its low permeability is the dominant reason for the "difficult gas out" of the broken soft coal seam. The brittleness of the roof and floor rock stratum of the broken soft coal seam has a significant effect on the fracture extension pressure of the surrounding rock after casing perforation and hydraulic fracturing of the horizontal well for coalbed methane (CBM). In this paper, 15 rock samples were scientifically collected from the roof and floor of the main mining coal seam of the Early Permian coal-bearing series in the Xinxie-1 well of the Huainan Coalfield in Anhui Province, China. On the basis of mineral composition analysis of these samples, the influence of mineral composition on the mechanics properties of the rock at the roof and floor of the coal seam was investigated. The correlation analysis and gray correlation analysis were adopted to construct an evaluation method for the brittleness of the rock at the roof and floor of the coal seam based on the mineral content. The results indicated that the most significant compositions of the minerals in the rock at the roof and floor of the broken soft coal seam were quartz and clay minerals. The most significant types of rock cementation are quartz agglomeration and rhodochrosite cementation. Pore destruction as a result of cementation was much greater than that of compaction. In comparison to clay minerals, the variation in the content of brittle minerals such as quartz, plagioclase, and siderite in the rock showed more sensitivity to the mechanics properties of the rock. The more sensitive minerals for compressive strength (CS), shear strength (SS), modulus of elasticity (E), softening coefficient (K), and Poisson's ratio (μ) are quartz, those for tensile strength (TS) are plagioclase and siderite, and those for Poisson's ratio are clay minerals. Based on the established mineral content weighting analysis method, it was calculated that the brittleness index (BI) of the rocks at the roof of the 13-1, 11-2, 9-2, and 4-2 coal seams was larger, which was advantageous for the formation of longer fracturing crack networks. This is theoretical guidance for the optimization of horizontal well fracturing design in the deep coal beds of the Huainan Coalfield.

Currently, the application of electromagnetic dampers in structural vibration control and energy harvesting has become increasingly widespread. The optimization research of electromagnetic dampers in building design has also received more attention. Previous studies on vibration control of building structures with electromagnetic dampers have been conducted under fixed foundations, neglecting the effect of soil-structure interaction on building structures with electromagnetic dampers. The main contribution of this paper is to fill the research gap in the study of building structural vibration control with electromagnetic dampers considering soil-structure interaction. An effective design and parameter optimization method for building structures with both soil-structure interaction and electromagnetic energy harvesting is explored. The soil-structure interaction is taken into account, and the building model with electromagnetic dampers is improved to form a coupled vibration reduction system with both structural vibration control and energy harvesting functions. The dynamic equations of the system with both structural vibration control and energy harvesting are derived and then optimized using the $H_2$ norm criterion and Monte Carlo-mode search method. A single-layer building structure is used as an example to study the influence of soil-structure interaction on building structures equipped with electromagnetic dampers under strong earthquake action. The dynamic response and energy harvesting of building structures under earthquake action considering soil-structure interaction are analyzed and evaluated. The results show that the influence of soil-structure interaction on building structures equipped with electromagnetic dampers needs to be considered. As the soil density decreases, the dynamic response of the building structure under earthquake action becomes larger using the electromagnetic damper system. Compared to the use of fixed foundations, the energy harvesting effect of building structures with electromagnetic dampers is weakened when considering soil-structure interactions.Definition: