Decabromodiphenyl ethane (DBDPE) is the main alternative to decabromodiphenyl ether (deca-BDE) in commercial use. However, there is increasing evidence show that DBDPE is a potential persistent organic pollutant, and it has been found ubiquitously in environmental media across China in recent years. Monitoring studies have not been able to determine the overall levels and temporal trends of DBDPE contamination in China, and have been unable to explain how emission patterns can affect their environmental distribution. Therefore, this study estimated the temporal variance of DBDPE emissions and environmental concentrations in five regions of China from 2006 to 2026 using the PROduction-To-EXposure (PROTEX) mass balance model. The results showed that Guangdong Province was the greatest DBDPE pollution hotspot in China due to emissions from plastics manufacturing and e-waste disposal; there was also severe pollution in Shandong Province, where almost all the DBDPE in China is produced. The DBDPE concentrations in indoor and outdoor environments increased substantially in all regions during 2006–2021. Furthermore, in Guangdong Province and Shandong Province, the ratio of indoor/outdoor air concentrations was greater than or close to 1, indicative of significant outdoor emission sources of DBDPE. In contrast, the ratios for the Beijing–Tianjin–Hebei region, East China, and Southwest China were below 1 due to the indoor use of electronic equipment containing DBDPE. The temporal trends of these ratios indicated that DBDPE contamination has gradually spread from high-concentration environments with strong emission sources to low-concentration environments. The outcomes of this study have important implications for the risk assessment of DBDPE use in China and can be used to establish contamination-mitigation actions.
Identifying the policy effect of government subsidies on families is beneficial to alleviate household energy poverty. This study first builds a Propensity Score Matching–Difference-in-Differences (PSM-DID) model and empirically tests the impact of government subsidies on household energy poverty in China based on China Family Panel Studies data from 2016 to 2018. The results show that household energy poverty is considered to have obvious regional differences. Moreover, the results indicate that government subsidies can reduce the probability of household energy poverty by 38.1%. However, the effect of government subsidies in alleviating household energy poverty will vary depending on the specific household situation. It is concluded that subsidies provided by the Chinese government to households can effectively alleviate household energy poverty. Finally, some policy recommendations are proposed based on the results of the empirical analysis.
The discovery of superconductivity in layered MgB2 has renewed interest in the search for high-temperature conventional superconductors, leading to the synthesis of numerous hydrogen-dominated materials with high critical temperatures (Tc) under high pressures. However, achieving a high-Tc superconductor under ambient pressure remains a challenging goal. In this study, we propose a novel approach to realize a high-temperature superconductor under ambient pressure by introducing a hexagonal H monolayer into the hexagonal close-packed magnesium lattice, resulting in a new and stable few-hydrogen metal-bonded layered magnesium hydride (Mg4)2H1. This compound exhibits superior ductility compared to multi-hydrogen, cuprate, and iron-based superconductors due to its metallic bonding. Our unconventional strategy diverges from the conventional design principles used in hydrogen-dominated covalent high-temperature superconductors. Using anisotropic Migdal–Eliashberg equations, we demonstrate that the stable (Mg4)2H1 compound is a typical phonon-mediated superconductor, characterized by strong electron–phonon coupling and an excellent Tc of 37 K under ambient conditions, comparable to that of MgB2. Our findings not only present a new pathway for exploring high-temperature superconductors but also provide valuable insights for future experimental synthesis endeavors.
Environmental theoretical calculation aims to use computer simulation to assist in solving environmental problems. Herein, we present the guiding principles of environmental theoretical calculation for non-periodic systems. A summary is given of recent progress towards the use of environmental theoretical calculation to reveal the degradation/transformation mechanisms of contaminants in reactions.
In literary sources we find Amastris a thriving second-century civitas with a much frequented port and an intellectual community (cf. Plin. Ep. 10.98; Luc. Alex. 26ff; Luc. Tox. 57ff), but what of the land that supported it? The Amastriane, as Strabo calls it (Ἀμαστρίανη", Strab. 12.3.10), had a lot of good boxwood, but beyond this much is unclear. This paper takes an epigraphic perspective to discuss observable dynamics in the Amastriane, in two steps.The first step attempts to visualize Christian Marek's hypothetical Amastrian territorium – an administratively defined Amastriane – with Google Earth Pro, using epigraphic findspot information and geographical features Marek identified for the representation. GPS coordinates of field surveys collated by Peri Johnson are added to identify potential settlement locations active in the first to third centuries CE within Marek's proposed territorium. Through the cross-referencing attempt one can observe a cluster of twelve "Amastrian" inscriptions and two settlement mounds (Ören Höyük & Çengelli) in the Eflani Plateau south of the Küre Mountains. This correlation between two sets of data seems to have gone previously unnoticed in relevant scholarship. This paper assumes that inquiry into this cluster of inscriptions and settlement mounds may lead to further insights on the dynamics of an extensive and rugged territory under the control of a civitas during the Principate.The second step interrogates this group of evidence: what can we learn from the assemblage regarding communal diversity, social relations, institutional participation, and connectivity on the periphery of the Amastriane? Of importance is an inscription that specifically refers to an Amastrian archon who was also a genearch of what appears to be a local clan, found at Meyre (approx. 70 km southeast of Amastris; Marek Kat. Amastris no. 95). Scholars have focused more on the cult that the genearch's family worshipped and naos they built, and less if any on the genos' involvement with Amastrian civic institutions. The second key inscription is for a nomikos Demetrios son of Kyrenios (Marek Kat. Amastris no. 97). He was perhaps related to a Chrestes son of Kyrenios and a self-designated Amastrian of the tribe Halicarnassus, who set up a funerary monument at Deresameail (Marek Kat. Hadrianopolis no. 29; 10 km northeast of Hadrianopolis) for his brother-in-law Sextus Vibius Epaphroditus, perhaps related to the Trajanic primipilarius Sextus Vibius Gallus from Amastrian Kytoros. While Corsten and Ruscu have suggested and commented on these relationships, there remains considerable potential to discuss how such relationships formed despite geography, territorial boundaries, institutional divisions, and other inhibiting factors.This paper wishes to suggest that Marek' expansive Amastrian territorium would have initially been a highly fragmented social and political space, but familial recruitment, manumission, intermarriage, and mobility between significant urban centers gradually created common ground for integration. Also, the clan at Meyre may have benefited from intensifying interaction between Amastris, Hadrianopolis and Pompeiopolis, leading to its increased importance and greater participation in Amastrian institutions and norms.
Seismic recordings made during the InSight mission 1 suggested that Mars's liquid core would need to be approximately 27% lighter than pure liquid iron 2,3 , implying a considerable complement of light elements. Core compositions based on seismic and bulk geophysical constraints, however, require larger quantities of the volatile elements hydrogen, carbon and sulfur than those that were cosmochemically available in the likely building blocks of Mars 4 . Here we show that multiply diffracted P waves along a stratified core–mantle boundary region of Mars in combination with first-principles computations of the thermoelastic properties of liquid iron-rich alloys 3 require the presence of a fully molten silicate layer overlying a smaller, denser liquid core. Inverting differential body wave travel time data with particular sensitivity to the core–mantle boundary region suggests a decreased core radius of 1,675 ± 30 km associated with an increased density of 6.65 ± 0.1 g cm −3 , relative to previous models 2,4–8 , while the thickness and density of the molten silicate layer are 150 ± 15 km and 4.05 ± 0.05 g cm −3 , respectively. The core properties inferred here reconcile bulk geophysical and cosmochemical requirements, consistent with a core containing 85–91 wt% iron–nickel and 9–15 wt% light elements, chiefly sulfur, carbon, oxygen and hydrogen. The chemical characteristics of a molten silicate layer above the core may be revealed by products of Martian magmatism.