Cotransport of fullerene nanoparticles and clay colloids in porous media: The relation between aggregation and transport.

In the study, cotransport of fullerene nanoparticles (nC) and mobile clay colloids (illite (ILL), kaolinite (KL), montmorillonite (ML)) in aquifer porous media and its relation to the aggregative interaction between these two types of particles was investigated. Minimal interaction occurred between nC and ILL, resulting in unaffected transport. Strong heteroaggregation between ML and nC resulted in not only significant retention of both particles during their cotransport but also the retention of nC in the media pre-injected with ML.

Effect of Pouring Techniques and Funnel Structures on Crucible Metallurgy: Physical and Numerical Simulations.

In the planar flow casting process of amorphous strips, the flow behavior of molten metal and the inclusion content in the crucible are crucial to the morphology and magnetic properties of the material. This study conducts a comparative analysis of the effects of non-immersed and immersed funnels, as well as various funnel structures, on the fluid flow and inclusion removal efficiency in the crucible by integrating numerical and physical models. The findings reveal that for the same pouring flow rate, the diameter of the liquid column in non-immersed pouring conditions is smaller than that of the funnel outlet, leading to a faster injection flow velocity.

Continuous Casting Slab Mold: Key Role of Nozzle Immersion Depth.

Based on a physical water model with a scaling factor of 0.5 and a coupled flow-heat transfer-solidification numerical model, this study investigates the influence of the submerged entry nozzle (SEN) depth on the mold surface behavior, slag entrapment, internal flow field, temperature distribution, and initial solidification behavior in slab casting. The results indicate that when the SEN depth is too shallow (80 mm), the slag layer on the narrow face is thin, leading to slag entrapment.

Assessing bioavailability risks of heavy metals in polymetallic mining regions: a comprehensive analysis of soils with varied land uses.

To accurately assess the bioavailability risk of heavy metals (HMs) in a representative polymetallic mining region, we undertook an exhaustive analysis of Cu, Pb, Ni, Co, Cd, Zn, Mn, and Cr in soils from diverse land-use types, encompassing agricultural, forest, residential, and mining areas. We employed speciation analysis methods and a modified risk assessment approach to ascertain potential ecological threats posed by the HMs. Our findings reveal that both the total potential ecological risk and the modified bioavailability risks are most pronounced in the soil of the mining area.

Research on the Relative Placement Angle of the Induction Heater and the Channel in a Four-Channel Induction-Heating Tundish.

In order to optimize the application effect of induction heating (IH) tundishes, a four-channel IH tundish is taken as the research object. Based on numerical simulation methods, the influence of different relative placement angles of induction heaters and channels on the electromagnetic field, flow field and temperature field of the tundish is investigated. We focus on comparing the magnetic flux density (B) and electromagnetic force (EMF) distribution of the channel.

Screening and optimization of interpolation methods for mapping soil-borne polychlorinated biphenyls.

There is yet no scientific consensus, and for now, on how to choose the optimal interpolation method and its parameters for mapping soil-borne organic pollutants. Take the polychlorinated biphenyls (PCBs) for instance, we present the comparison of some classic interpolation methods using a high-resolution soil monitoring database. The results showed that empirical Bayesian kriging (EBK) has the highest accuracy for predicting the total PCB concentration, while root mean squared error (RMSE) in inverse distance weighting (IDW) is among the highest in these interpolation methods.

Source-based health risk assessment of heavy metal contamination in soil: a case study from a polymetallic mining region in Southeastern Hubei, Central China.

To conduct a precise health risk assessment of heavy metals (HMs) in soil, it is imperative to ascertain the primary sources of potential health risks. In this study, we conducted comprehensive measurements of HMs, specifically focusing on the accumulation of Cu, Cd, Sb, Zn, and Pb in local soil, which may pose threats to environmental quality. To achieve our objective, we employed a method that combines positive matrix factorization with a health risk assessment model to quantify the health risks associated with specific sources.

Effective adsorption of bisphenol A from aqueous solution using phosphoric acid-assisted hydrochar.

Sycamore leaf biochar (PSAC) was prepared by a two-step phosphoric acid-assisted hydrothermal carbonization combined with a short-time activation method. The characterization results showed that the introduction of phosphoric acid molecules and thermal activation resulted in a substantial increase in the specific surface area (994.21 m/g) and microporous capacity (0.

Insight into the effect mechanism of sedimentary record of polycyclic aromatic hydrocarbon: Isotopic evidence for lake organic matter deposition and regional development model.

Deciphering the temporal patterns of polycyclic aromatic hydrocarbons (PAHs) in sediment cores, and the effect mechanism of sedimentary organic matter (OM) and regional development model on PAHs are crucial for pollution control and environmental management. Herein, sediment core was collected from Chenhu international wetland in Wuhan, central China. Meanwhile, historical trend and source of PAHs and sedimentary OM were presented, respectively.

Effective immobilization of bisphenol A utilizing activated biochar incorporated into soil: combined with batch adsorption and fixed-bed column studies.

This study presented the mixture of biochar and soil for removal of bisphenol A (BPA) to assess environmental remediation ability. Using phoenix tree leaves as biomass and phosphoric acid as activator, after one-step hydrothermal and short-term activation, the eventual solid product was phosphoric acid hydrothermal activated carbon (HPC). The characterizations showed that HPC had the high specific surface (994.

Occurrence and distribution of PPCPs in water from two largest urban lakes of China: First perspective from DGT in-situ measurement.

Pharmaceutical and personal care products (PPCPs) are an important group of emerging contaminants that may threaten organisms at trace concentrations. However, research on the occurrence of PPCPs in urban lakes in China is still scarce. In this study, 15 PPCPs in the Tangxun Lake and the Donghu Lake were collected using the diffusive gradients in thin-films (DGT) technique and analyzed by high performance liquid chromatography tandem-mass spectrometry (HPLC-MS/MS).

Investigation of organochlorine pesticides in the Wang Lake Wetland, China: Implications for environmental processes and risks.

Wang Lake Wetland is an important habitat for many fish and migratory birds. To explore the effect of periodic hydrological changes on the transfer and ecological risk of OCPs in the multimedia system of the wetland, eight sampling sites were selected for collecting soil (SS), sediment (SD) and water, to acquire dissolved phase (DP) and suspended particulate matter (SPM) samples during low- and high-flow periods. The results indicated that OCPs are pervasive in the various media of Wang Lake Wetland, and there was a significant temporal variability in concentration of ∑OCPs in the SPM samples.

New insight into the geochemical mechanism and behavior of heavy metals in soil and dust fall of a typical copper smelter.

The desorption mechanism of heavy metals (HMs) in soil around the mining region are complex and affected by multiple pollution sources, including sewage discharge and atmospheric deposition. Meanwhile, pollution sources would change soil physical and chemical properties (mineralogy and organic matter), thus affecting the bioavailability of HMs. This study aimed to investigate the pollution source of HMs (Cd, Co, Cu, Cr, Mn, Ni, Pb, and Zn) in soil near mining, and further evaluate influence mechanism of dust fall on HMs pollution in soil by desorption dynamics processes and pH-dependence leaching test.

Study of the Soft Magnetic Properties of FeSiAl Magnetic Powder Cores by Compounding with Different Content of Epoxy Resin.

FeSiAl is a commonly used soft magnetic material because of its high resistivity, low core loss, and low cost. In order to systematically study the effect of epoxy resin (EP) on the insulated coating and pressing effect of FeSiAl magnetic powders, six groups of composite powders and their corresponding soft magnetic powder cores (SMPCs) were prepared by changing the content of EP, and the soft magnetic properties of the powders and SMPCs were characterized. The results showed that FeSiAl powders exhibited good sphericity and morphology.

Modification of Inclusions by Rare Earth Elements in a High-Strength Oil Casing Steel for Improved Sulfur Resistance.

Steel casing pipes used in the construction of deep oil wells usually require both high strength and corrosion-resistant behavior. Due to the exploration of deep HS-bearing oil reservoirs, sulfide stress cracking (SSC) is becoming an increasingly serious concern for casing steel. The nonmetallic inclusions in the steel are among the key reasons for its service failure.

Characteristics and DGT Based Bioavailability of Cadmium in the Soil-Crop Systems from the East Edge of the Dongting Lake, China.

Contamination of heavy metals (including the cadmium, Cd) in agricultural soils has become an increased issue, posing a threat to the crop safety and human health. In order to evaluate the contamination characteristics and bioavailability of Cd in the soil−crop systems from the East edge of the Dongting Lake, four kinds of agricultural products for typical crops (rice, peanut, sweet potato, and corn) and corresponding rhizosphere soils were collected and analyzed for the Cd concentrations. The technique of diffusive gradients in thin-films (DGT) was applied to evaluate the Cd bioavailability in the rhizosphere soils.

Behavior of Mold Electromagnetic Stirring for Round Bloom Castings and Its Eccentric Stirring Problem.

In this paper, a mold electromagnetic stirring (M-EMS) model was established to investigate the behavior of M-EMS for round bloom castings under different conditions, and an electromagnetic-flow-heat transfer-solidification coupling model was established to explore the problem of eccentric stirring for various formats of round blooms. The results show that the magnetic flux density decreased with the increase in the current frequency, but the electromagnetic torque increases first and then decreases with it, and the same structure of M-EMS for round blooms has the same optimal current frequency at any current intensity. The electromagnetic torque and electromagnetic force both increase as a quadratic function of the current intensity, and the electromagnetic torque, which drives the steel flow, can directly characterize the real M-EMS performance.

The characteristics of polycyclic aromatic hydrocarbons and heavy metals in water and sediment of dajiuhu subalpine wetland, shennongjia, central China, 2018-2020: Insights for sources, sediment-water exchange, and ecological risk.

Polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) are persistent environmental issues. Secondary emissions are produced as a result of climate change and human activity. To observe spatio-temporal variations of PAHs and HMs and to discuss the sources as well as the source or sink of PAHs for sediment and peat, twelve surface sediment and surface water sites were chosen along the direction of the flow to down hole in the Dajiuhu area, simultaneously, surface peat and water samples were collected in peatland.

Fe-Based Amorphous Magnetic Powder Cores with Low Core Loss Fabricated by Novel Gas-Water Combined Atomization Powders.

FeSiBCCr amorphous powders were produced by a novel gas-water combined atomization process, and the corresponding MPCs (magnetic powder cores) were subsequently fabricated by phosphating treatment (0.4~1.6 wt.

Pollution Characteristics and Human Health Risk Assessment of Heavy Metals in Street Dust from a Typical Industrial Zone in Wuhan City, Central China.

This study aimed to assess the pollution levels, sources, and human health risks of heavy metals in street dust from a typical industrial district in Wuhan City, Central China. In total, 47 street dust samples were collected from the major traffic arteries and streets around Wuhan Iron and Steel (Group) Company (WISC) in Qingshan District, Wuhan. The concentrations of heavy metals (Cr, Mn, Ni, Zn, Fe, Cu, and Cd) in street dust were determined by atomic absorption spectroscopy.

Impact of short-term control measures on air quality: A case study during the 7th Military World Games in central China.

The 7th Military World Games held in Wuhan (WH) in Oct 2019 provided an opportunity to clarify the impact of short-term control measures on air quality. Fine particulate matters (PM) were collected in WH, Huangshi (HS), and Huanggang (HG) during the control (Oct 13-28, 2019) and non-control periods (Oct 29- Nov 5, 2019). The results showed that air quality was good during the control period, with the concentrations of PM and gaseous pollutants being below the Grade Ⅱ of China Ambient Air Quality Standard.

Variation of pollution sources and health effects on air pollution before and during COVID-19 pandemic in Linfen, Fenwei Plain.

Stringent pollution control measures are generally applied to improve air quality, especially in the Spring Festival in China. Meanwhile, human activities are reduced significantly due to nationwide lockdown measures to curtail the COVID-19 spreading in 2020. Herein, to better understand the influence of control measures and meteorology on air pollution, this study compared the variation of pollution source and their health risk during the 2019 and 2020 Spring Festival in Linfen, China.

Bioavailability and regional transport of PM during heavy haze episode in typical coal city site of Fenwei Plain, China.

Despite the decrease in anthropogenic emissions, haze episodes were still frequent in the Fenwei Plain, which was identified as one of the three key areas for air pollution control. Herein, PM samples were collected to investigate the influence of festival effect during the Chinese Spring Festival from February 2rd to 13th, 2019, in Linfen on the Fenwei Plain. The characteristics of element pollution, enrichment factor, source apportionment, regional transport of PM, and health risk assessment were discussed.

Effect of Flow Field Optimization of an Asymmetric Multi-Strand Tundish on the Quality Consistency of Cracking Con-Rod Steel.

Cracking con-rod is an advanced high-precision connecting structure based on brittle expansion, breaking and reconnection of steel, to solve the problem of assembly circle missing. High carbon micro-alloyed steel C70S6, as a dominant material for the production of cracking con-rod, has extremely strict requirements on non-metallic inclusions in steel and microstructure stability. Continuous casting tundish plays an important role in removing large-sized inclusions and stabilizing casting quality.