The impact of an abandoned mercury mine on the environment in the Xiushan region, Chongqing, southwestern China

Mercury contamination is a serious problem in the Hg mining area of Xiushan County, Chongqing, southwestern China. The concentrations of total mercury (THg) and methylmercury (MeHg) in paddy soil, surface water, and rice (grain) samples were determined to investigate the regional distribution of Hg contamination. Simultaneously, gaseous elemental Hg (GEM) in ambient air near the sampling sites was measured. The total Hg concentrations in surface water were highly elevated, ranging from 13 to 2390 ng/L, and the total MeHg concentrations varied between 0.17 and 1.1 ng/L. The dissolved Hg and MeHg concentrations in surface water ranged from 4.7 to 470 ng/L and 0.14–0.35 ng/L, respectively. High THg and MeHg concentrations were also obtained in paddy soils from mining areas, ranging from 0.45 to 68 μg/g and 0.13–4.8 ng/g, respectively. Similar to the high concentrations in water and soil, the THg concentration in rice (grain) ranged from 4.7 to 550 ng/g and MeHg from 2.9 to 26 ng/g. Elevated Hg concentrations in rice, as a staple food of local residents, confirmed that rice consumption could be a vital pathway for MeHg exposure to native people. Humic acid and fulvic acid had significant correlations with soil MeHg, implying that they have important roles that influence MeHg production in soil. The spatial distribution characteristics of Hg and MeHg pollution in the local environment indicated their origins from historic Hg mining sites in the Xiushan area.acceptedVersio

The impact of an abandoned mercury mine on the environment in the Xiushan region, Chongqing, southwestern China

Mercury contamination is a serious problem in the Hg mining area of Xiushan County, Chongqing, southwestern China. The concentrations of total mercury (THg) and methylmercury (MeHg) in paddy soil, surface water, and rice (grain) samples were determined to investigate the regional distribution of Hg contamination. Simultaneously, gaseous elemental Hg (GEM) in ambient air near the sampling sites was measured. The total Hg concentrations in surface water were highly elevated, ranging from 13 to 2390 ng/L, and the total MeHg concentrations varied between 0.17 and 1.1 ng/L. The dissolved Hg and MeHg concentrations in surface water ranged from 4.7 to 470 ng/L and 0.14–0.35 ng/L, respectively. High THg and MeHg concentrations were also obtained in paddy soils from mining areas, ranging from 0.45 to 68 μg/g and 0.13–4.8 ng/g, respectively. Similar to the high concentrations in water and soil, the THg concentration in rice (grain) ranged from 4.7 to 550 ng/g and MeHg from 2.9 to 26 ng/g. Elevated Hg concentrations in rice, as a staple food of local residents, confirmed that rice consumption could be a vital pathway for MeHg exposure to native people. Humic acid and fulvic acid had significant correlations with soil MeHg, implying that they have important roles that influence MeHg production in soil. The spatial distribution characteristics of Hg and MeHg pollution in the local environment indicated their origins from historic Hg mining sites in the Xiushan area.acceptedVersio

Aggregation-Induced Emission (AIE), Life and Health

Light has profoundly impacted modern medicine and healthcare, with numerous luminescent agents and imaging techniques currently being used to assess health and treat diseases. As an emerging concept in luminescence, aggregation-induced emission (AIE) has shown great potential in biological applications due to its advantages in terms of brightness, biocompatibility, photostability, and positive correlation with concentration. This review provides a comprehensive summary of AIE luminogens applied in imaging of biological structure and dynamic physiological processes, disease diagnosis and treatment, and detection and monitoring of specific analytes, followed by representative works. Discussions on critical issues and perspectives on future directions are also included. This review aims to stimulate the interest of researchers from different fields, including chemistry, biology, materials science, medicine, etc., thus promoting the development of AIE in the fields of life and health

Fabrication of Organic Solvent Nanofiltration Membrane through Interfacial Polymerization Using N-Phenylthioure as Monomer for Dimethyl Sulfoxide Recovery

To recover dimethyl sulfoxide, an organic solvent nanofiltration membrane is prepared via the interfacial polymerization method. N-Phenylthiourea (NP)is applied as a water-soluble monomer, reacted with trimesoyl chloride (TMC) on the polyetherimide substrate crosslinked by ethylenediamine. The results of attenuated total reflectance-fourier transform infrared spectroscopy and X-ray electron spectroscopy confirm that N-Phenylthiourea reacts with TMC. The membrane morphology is investigated through atomic force microscopy and scanning electronic microscopy, respectively. The resultant optimized TFC membranes NF-1NP exhibited stable permeance of about 4.3 L m−2 h−1 bar-1 and rejection of 97% for crystal violet (407.98 g mol−1) during a 36 h continuous separation operation. It was also found that the NF-1NP membrane has the highest rejection rate in dimethyl sulfoxide (DMSO), and the rejection rates in methanol, acetone, tetrahydrofuran, ethyl acetate and dimethylacetamide(DMAc) are 51%, 84%, 94%, 96% and 92% respectively. The maximum flux in the methanol system is 11 L m−2 h−1 bar−1, while that in acetone, tetrahydrofuran, ethyl acetate and DMAc is 4.3 L m−2 h−1 bar−1, 6.3 L m−2 h−1 bar−1, 3.2 L m−2 h−1 bar−1, 4.9 L m−2 h−1 bar−1 and 2.1 L m−2 h−1 bar−1, respectively. It was also found that the membrane prepared by N-Phenylthiourea containing aromatic groups has lower mobility and stronger solvent resistance than that of by thiosemicarbazide.</jats:p

TwoArchRH: Enhanced Two-Archive Algorithm for Many-Objective Optimization

Multi-objective optimization is a cornerstone of modern engineering and management, tackling challenges in complex system design, resource allocation, and financial portfolio optimization. Effective multi-objective optimization algorithms must strike a balance between convergence and diversity, a process that inherently reflects the symmetry in objectives and their trade-offs. However, real-world complexities introduce significant hurdles: the exponential increase in Pareto optimal solutions diminishes the effectiveness of dominance-based selection, while escalating problem complexity heightens the tension between convergence and diversity. To address these issues, we propose a two-archive evolutionary algorithm that integrates reference vectors and a novel hypervolume contribution strategy. This approach employs two complementary archives&mdash;convergence and diversity&mdash;for parallel optimization. Within the diversity archive, candidate solutions are first filtered using angular relationships to maintain uniform distribution. A novel hypervolume contribution evaluation strategy (HVindex) then determines whether updating solutions can improve the overall quality of the neighborhood population. For the convergence archive, we first select all the non-dominated solutions through non-dominated sorting. These solutions are further refined using reference vectors, and the final archive is completed by adding some opposite characteristic solutions based on distance measurements. The experimental results demonstrate that the proposed algorithm outperforms existing methods in multi-objective optimization

Hydrocarbon-conversion reaction and new paraffin-kinetic model during straight-run gas oil (SRGO) hydrotreating

A series of related experiments were carried out based on prepared hydrocracking catalyst, Catalyst-HC. Ni &amp; W and USY molecular sieve were selected as the hydrogenation active component and the cracking component of Catalyst-HC, respectively. Meanwhile, a kinetic model for paraffin conversion was constructed based on paraffin conversion law. Results obtained through this work indicate that the impact of H2-pressure is relatively complex. As the H2-pressure changes, the degree of hydrocracking reaction may be influenced by both hydrogen supply capacity and hydrogen proton concentration. Obtained conversion priority for three types of hydrocarbons on USY molecular sieve is as follows, aromatic ≫ cycloalkane > paraffin. Aromatic content in SRGO can affect its paraffin-retention in Hydro-D. Compared with the hydrotreating of SRGO with low aromatic content, when SRGO with relatively higher aromatic content is hydrotreated, its paraffin-retention is higher and its paraffin loss is also relatively smaller. Base on constructed model, the calculated values of SRGO-BJ conversion rate and paraffin-retention in Hydro-D are within ±10 % and ±5 % error lines, respectively. Thus, model schematic diagram is reasonable and can provide modeling reference for relevant model research

First results of high density H-mode operation in metal-wall EAST tokamak

In metal-wall EAST superconducting tokamak, H-mode operation with plasma density close to the Greenwald density limit nGW has been achieved with radio frequency and NBI heating for the first time. Both gas puffing from horizontal plane and HFS pellet fueling were used for density ramp-up during the experiment. The confinement of H-mode gradually deteriorates with plasma density increasing. And the H-L transition can be observed after heating power dropping or pellet injection. In the density range of (0.6–1)×nGW, the divertor detachment occurs and causes an obvious confinement degradation. The maximum accessible density ne, max in H-mode phase deviates from the Greenwald scaling. It has been observed that the fraction ne, max/nGW is almost independent of the total heating power, but a high heating power is helpful to extend the duration of high density H-mode. And ne,max/nGW has an increase relation with the safety factor q95 varied by changing plasma current. Besides, it is also found that the discharges with low plasma current have a higher ne, max/nGW than those with high plasma current. All these findings will provide a good reference to the high density plasma operation for future metal-wall fusion devices