Search

This study aimed to increase the ammonium nitrogen adsorption capacity of lignite using ultrafine grinding, aiming to reduce eutrophication in water bodies. Ammonium sulfate (NH4)2SO4 was employed as a stand-in for ammonium nitrogen in water solutions. The lignite sample for adsorption was processed with varying milling times. Adsorption efficacy was assessed primarily through isothermal adsorption tests and other techniques. Additionally, the study delved into the adsorption mechanisms. The results demonstrate that lignite ground for 50 min follows monolayer adsorption, characterized by minimal pore size and reduced diffusion rates, thereby extending the time to reach equilibrium and maximizing adsorption. BET and SEM analyses show that coal powder is effectively ground by zirconia balls in a vertical stirring mill, diminishing its particle size and forming new micropores. Concurrently, larger native pores are transformed into mesopores and micropores, providing numerous sites for NH4+ adsorption. XPS and FTIR analyses indicate an increase in exposed carbonaceous surfaces and oxygen-containing functional groups in ultrafine lignite. Ammonium ions replace hydrogen in carboxyl groups to form COONH4, and hydrogen bonds may form between NH4+ and C-O groups. Additionally, the electrostatic attraction between NH4+ and the coal surface further enhances adsorption. It can be concluded that the physical grinding process increases the specific surface area and creates more active adsorption sites, which in turn, boosts NH4+ adsorption capacity. The maximum equilibrium adsorption capacity is as high as 550 mg/g. This study suggests that ultrafine lignite is a promising material for treating ammonia-nitrogen wastewater. [ABSTRACT FROM AUTHOR]

In order to solve problems of slow tunneling and tension of mine excavation replacement in test mine using traditional extraction technology, a scheme of using deep hole directional drilling with long directional drilling instead of conventional drilling to carry out coal seam gas extraction was proposed. Directional drilling has a large effective area on coal seam, which can change distribution of original coal stress in a large range, thus breaking dynamic balance of gas adsorption and desorption in coal seam and transforming a large number of adsorbed gas into free state; Under the action of pressure gradient formed by drilling negative pressure and coal ground stress and gas pressure, free gas flow continuously to drilling space, make the surrounding coal gas emission effectively, cause shrink deformation of coal, permeability coefficient increases significantly, ground stress and gas pressure gradient are reduced, so as to make the long drilling directional extraction influence range expanded, realize the effective gas extraction from coal seam in a large area. The test results show that using deep hole directional drilling with long directional drilling can get a well formed hole and has obvious effect in gas extraction. Total drilling footage of the test hole is 2 213 m,the maximum drilling depth reaches 523 m, and the average daily extraction pure quantity is 3 528 m3. The average volume fraction of gas extraction is up to 88.3%, and the highest value is 98.0%. The average single-hole gas extraction pure quantity is 1.23 m3/min, and the maximum value exceed 2 m3/min. Compared with conventional drilling extraction, the pure quantity of single-hole gas extraction of directional drilling is increased by more than 16 times, the volume fraction of single-hole gas extraction is increased by 2-4 times, and monthly average footage of roadway is increased by more than1 times.

There is no uniform standard for determining the drainage effective radius of CO2 phase transition fracturing in view of the fact, we analyze the traditional measurement for drainage effective radius, clarify definition of drainage radius. The time-source method is established based on SF6 tracer method and test data, and it was tested in coal mine. The research shows there is time effect between drainage influence radius and drainage effective radius, and the drainage time is the key factor to distinguish them; the time-source method divides the drainage time into drainage effective time and drainage compensation time. The drainage effective radius under a certain time is obtained through SF6 tracer method and analysis of the field data. It can reflect the drainage situation of boreholes more accurately; the test-in-place experimented at main haulage roadway in No.3 coal seam of Daping Coal Mine. The result shows that the drainage effective radius after CO2 phase transition fracturing is 12 m when the drainage time is 120 d and drainage effective radius is 16 m when the drainage time is 148 d.

This study focused on 6-year-old 'Pawnee' pecan trees to elucidate the differential responses of physicochemical properties of orchard soil and pecan fruit quality when combining chemical and organic fertilizers. The aim was to unveil the mechanisms that underlie the effects of different fertilization treatments on soil fertility, soil enzyme activities, and pecan fruit quality. Four treatments were established: sole chemical fertilizer (CF; N:P2O5:K2O is 15:15:15), chemical fertilizer combined with cake fertilizer (CF+CC), chemical fertilizer combined with manure fertilizer (CF+M), and chemical fertilizer combined with cake and manure fertilizer (CF+CC+M). Measurements were taken to assess the soil nutrient content, soil enzyme activities, and fruit growth quality in some orchards under different fertilization treatments. The results revealed that the combined application could increase yield and enhance pecan quality. Among these, the CF+M+CC treatment demonstrated the most favorable outcomes, with the pecan kernel oil and unsaturated fatty acid contents reaching 72.33% and 97.54%, respectively. The combined fertilization treatments had no significant impacts on soil trace elements such as Mg, Cu, and Mn; however, it significantly increased the Available Phosphorus (AP), Total Nitrogen (TN), Soil Organic Matter (SOM) and S-ACP (soil acid phosphatase) activities. In summary, the combined application of chemical and organic fertilizers can significantly increase the soil nutrient content and enzyme activities in pecan orchards, to promote the enhancement of fruit quality and economic aspects. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease characterized by synovial inflammation, cartilage damage and bone erosion. In the progression of RA, the inflammatory mediators including ROS, NO, TNF-α, and IL-6 play important roles in the aggravation of inflammation. Hence, reducing the generation and release of inflammatory mediators is of great importance. However, the high dose and frequent administration of clinical anti-inflammatory drugs such as glucocorticoids (GCs) usually lead to severe side effects. The development of nanotechnology provides a promising strategy to overcome these issues. Here, polyphenol-based nanoparticles with inherent anti-oxidative and anti-inflammatory activities were developed and used as a kind of nanocarrier to deliver dexamethasone (Dex). The in vitro experiments confirmed that the nanoparticles and drugs could act synergistically for suppressing inflammatory mediators in the LPS/INF-γ-induced inflammatory cell model. After intravenous administration, the Dex-loaded nanoparticles with good biosafety showed effective accumulation in inflamed joints and improved therapeutic efficacy by inducing anesis of synovial inflammation and cartilage destruction over free Dex in a collagen-induced arthritis (CIA) mouse model. The results demonstrated that polyphenol-based nanoparticles with therapeutic functions may serve as an innovative platform to synergize with chemotherapeutic agents for enhanced treatment of inflammatory diseases. [ABSTRACT FROM AUTHOR]

Simulated shallow seawater corrosion tests were conducted to explore the corrosion resistance of alumina fiberre-inforced aluminum matrix composites. The micromorphology, elemental composition, phase structure, and microhardness of ZL301 aluminum alloy-based and pure aluminum-based composites reinforced with different contents of copper-coated alumina fibers were studied using scanning electron microscope (SEM), energy-dispersive spectroscope (EDS), X-ray diffractometer (XRD), and Vickers hardness meter, respectively. The surface morphology and corrosion products of the ZL301 aluminum alloy-based composite containing 5% of copper-coated alumina fibers after being immersed in 5% NaCl solution for different time were characterized. The results showed that the corrosion resistance of pure aluminum surpassed that of ZL301 aluminum alloy. The addition of copper-coated alumina fibers weakened the corrosion resistance of the aluminum-based materials, and the corrosion resistance of the composites were gradually decreased with the increasing of fiber content. The corrosion process of copper-coated alumina fiber-reinforced ZL301 aluminum alloy matrix composite can be divided into three stages: a) adsorption of corrosive ions; b) formation of localized corrosion pits leading to the destruction of the surface oxide film; and c) corrosion of the matrix. [ABSTRACT FROM AUTHOR]

Torreya grandis Fort. ex Lindl. cv. "Merrillii" is an important woody oil crop, and the development of plantations relies on the cultivation of high-quality saplings. For this study, 6-year-old grafted T. grandis saplings, which will soon be planted on the mountain, were selected to investigate the regulatory effects of nitrogen (N), phosphorus (P), and potassium (K) on their growth and morphology. To determine the optimal dosage and ratio of N–P–K fertilizer for sapling cultivation, we employed a three-factor four-level L16 (43) orthogonal experiment design. The experiment included a total of 17 treatments—a control group where no fertilizer was applied and 16 treatments with varying levels of NPK supply. We conducted a one-season experiment under a prescribed fertilizer regime and measured root collar diameters and sapling heights, the root, shoot, leaf biomass, total biomass, and the nutritional status of plant organs (root, shoot, leaf). From these measurements, we calculated the root–shoot ratio (RS) and seedling quality index (QI). The application of N–P–K fertilizer exhibited significant benefits for T. grandis sapling cultivation, promoted their growth and biomass accumulation and altered the nutrient allocation patterns in organs. Ultimately, we determined the ideal N–P–K ratio for T. grandis growth to be 1:0.46:0.75, with a fertilizer application of 1.38 g·sapling−1 of N, 0.64 g·sapling−1 of P (P2O5), and 1.04 g·sapling−1 of K (K2O). [ABSTRACT FROM AUTHOR]