Dendrite growth of alkali metal anodes limited their lifetime for charge/discharge cycling. Here, we report near-perfect anodes of lithium, sodium, and potassium metals achieved by electrochemical ...polishing, which removes microscopic defects and creates ultra-smooth ultra-thin solid-electrolyte interphase layers at metal surfaces for providing a homogeneous environment. Precise characterizations by AFM force probing with corroborative in-depth XPS profile analysis reveal that the ultra-smooth ultra-thin solid-electrolyte interphase can be designed to have alternating inorganic-rich and organic-rich/mixed multi-layered structure, which offers mechanical property of coupled rigidity and elasticity. The polished metal anodes exhibit significantly enhanced cycling stability, specifically the lithium anodes can cycle for over 200 times at a real current density of 2 mA cm
with 100% depth of discharge. Our work illustrates that an ultra-smooth ultra-thin solid-electrolyte interphase may be robust enough to suppress dendrite growth and thus serve as an initial layer for further improved protection of alkali metal anodes.
Steel production is a difficult-to-mitigate sector that challenges climate mitigation commitments. Efforts for future decarbonization can benefit from understanding its progress to date. Here we ...report on greenhouse gas emissions from global steel production over the past century (1900-2015) by combining material flow analysis and life cycle assessment. We find that ~45 Gt steel was produced in this period leading to emissions of ~147 Gt CO
-eq. Significant improvement in process efficiency (~67%) was achieved, but was offset by a 44-fold increase in annual steel production, resulting in a 17-fold net increase in annual emissions. Despite some regional technical improvements, the industry's decarbonization progress at the global scale has largely stagnated since 1995 mainly due to expanded production in emerging countries with high carbon intensity. Our analysis of future scenarios indicates that the expected demand expansion in these countries may jeopardize steel industry's prospects for following 1.5 °C emission reduction pathways. To achieve the Paris climate goals, there is an urgent need for rapid implementation of joint supply- and demand-side mitigation measures around the world in consideration of regional conditions.
The production, consumption, and waste of plastics have been rapidly growing worldwide in the last decades. A variety of data are needed to characterize plastics stocks and flows across space, time, ...and life cycle to derive insights for developing strategies to address various sustainability challenges from plastics and plastics waste. Here we review data sources on plastics stocks and flows to identify data gaps and research needs. We categorize the reviewed data sources by life cycle stages of plastics including material production, semi‐manufacturing, manufacturing, additives, consumption, in‐use stock, end‐of‐life, waste treatment, and trade. We identify four data gaps in these existing data for characterizing plastics stocks and flows, including inconsistent classification, missing data, conflicting data, and inexplicit data for plastics products and waste. These data gaps represent critical research needs including common platform for data sharing, standard methods for data reconciliation and estimation, consistent data collection and reporting, and new approaches for data collection and curation. This review establishes the state‐of‐the‐art of plastics stock and flow data and develops a roadmap for a high‐quality, comprehensive characterization of plastics stocks and flows to develop management strategies to address the sustainability challenges of plastics production, consumption, waste, and pollution.
A hybrid organic–inorganic compound, (pyrrolidinium)MnBr3
, distinguished from rare earth (RE)‐doped inorganic perovskites, is discovered as a new member of the ferroelectrics family, having ...excellent luminescent properties and relatively large spontaneous polarization of 6 μC cm−2, as well as a weak ferromagnetism at about 2.4 K. With a quantum yield of >28% and emission lifetime >0.1 ms, such multiferroic photoluminescence is a suitable candidate for future applications in luminescence materials, photovoltaics, and magneto‐optoelectronic devices.
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While electric vehicles (EVs) have been promoted for green consumption, improper or inadequate management of end-of-life (EOL) EV batteries, as the current practice, compromises the ...benefits of EV adoption. This study aims to contribute to both theoretical research of material flow analysis and timely management of EOL EV batteries at various geographic scales (i.e., national, state, and county).
Theoretically, this study tests two battery lifespan scenarios (i.e., constantly at 3–8 years and dynamically increasing over time), three discard probability functions (i.e., uniform, truncated normal, and Weibull), and three EV sale projections (i.e., low, moderate, and high). Results show that the short-term EOL volume (by 2025) can be particularly sensitive to the lifespan parameter. The long-term estimates involve most uncertainties related to the EV market penetration. Various discard probability functions generally derive similar results.
In practical terms, the results suggest that necessary infrastructure for proper EOL EV battery management is needed sooner than the public may have perceived. This study urges for regional planning that incorporates both temporal and spatial considerations. To illustrate an example of regional solutions, this study adopts empirical data in California to simulate and spatially match EOL EV battery clusters and the renewable energy facilities that can potentially reuse EV batteries as energy storage. Meanwhile, the spatial mis-match between the supply and demand, as can be the case in other regions, calls for region-wide coordination in terms of both infrastructure development and transportation planning.
Proinflammatory cytokine such as interleukin (IL)‐1β causes inflammation of articular cartilage. In this current study, we explored the chondroprotective effects of long noncoding RNA (lncRNA) ...MALAT‐1 on cell proliferation, apoptosis, and matrix metabolism in IL‐1β‐induced inflammation in articular chondrocytes. Articular chondrocytes from knee joints of normal rats were isolated and cultured, followed by identification through observation of toluidine blue and COL II immunocytochemical stainings. The proliferation of chondrocytes at passage 2 was detected by the 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide (MTT) assay. The inflammatory chondrocytes induced by 10 ng/mL IL‐1β were observed and identified by toluidine blue and COL II immunocytochemical stainings. pcDNA 3.1 and pcDNA‐MALAT‐1 were transfected in the chondrocytes. Ultrastructure of chondrocytes was observed by using a transmission electron microscope. The MTT assay was carried out to evaluate chondrocyte viability. Hoechst 33258 staining and flow cytometry were adopted to assess chondrocyte apoptosis. The chondrocytes at passage 2 with the biological characteristics of chondrocytes were used for subsequent experiments. In IL‐1β‐treated chondrocytes, the growth rate of chondrocytes slowed down, the cells became narrow and long, the vacuoles were seen in the cells, and the morphology of the chondrocytes was irregular. The toluidine blue staining and the immunohistochemical staining of COL II became weaker. In response to IL‐1β induction, articular chondrocytes showed reduced MALAT‐1 expression; moreover, obvious cartilage injury was observed with decreased chondrocyte viability and Col II expression and elevated chondrocyte apoptosis, MMP‐13 expression, and p‐JNK expression. With the treatment of pcDNA‐MALAT‐1, the cartilage injury was alleviated with increased chondrocyte viability and type II collagen (Col II) expression and reduced chondrocyte apoptosis, MMP‐13 expression and p‐JNK expression. Taken together these results, lncRNA MALAT‐1 blocked the activation of the JNK signaling pathway; thereby, IL‐1β‐induced inflammation in articular chondrocytes was reduced with enhanced chondrocyte proliferation and suppressed chondrocyte apoptosis and extracellular matrix degradation.
Newly defined categories of WEEE have increased the types of China’s regulated WEEE from 5 to 14. Identification of the amounts and valuable-resource components of the “new” WEEE generated is ...critical to solving the e-waste problem, for both governmental policy decisions and recycling enterprise expansions. This study first estimates and predicts China’s new WEEE generation for the period of 2010–2030 using material flow analysis and the lifespan model of the Weibull distribution, then determines the amounts of valuable resources (e.g., base materials, precious metals, and rare-earth minerals) encased annually in WEEE, and their dynamic transfer from in-use stock to waste. Main findings include the following: (i) China will generate 15.5 and 28.4 million tons WEEE in 2020 and 2030, respectively, and has already overtaken the U.S. to become the world’s leading producer of e-waste; (ii) among all the types of WEEE, air conditioners, desktop personal computers, refrigerators, and washing machines contribute over 70% of total WEEE by weight. The two categories of EEEelectronic devices and electrical applianceseach contribute about half of total WEEE by weight; (iii) more and more valuable resources have been transferred from in-use products to WEEE, significantly enhancing the recycling potential of WEEE from an economic perspective; and (iv) WEEE recycling potential has been evolving from ∼16 (10–22) billion US$ in 2010, to an anticipated ∼42 (26–58) billion US$ in 2020 and ∼73.4 (44.5–103.4) billion US$ by 2030. All the obtained results can improve the knowledge base for closing the loop of WEEE recycling, and contribute to governmental policy making and the recycling industry’s business development.
We model the newly synthesized magic-angle-twisted bilayer graphene superconductor with two p_{x,y}-like Wannier orbitals on the superstructure honeycomb lattice, where the hopping integrals are ...constructed via the Slater-Koster formulism by symmetry analysis. The characteristics exhibited in this simple model are well consistent with both the rigorous calculations and experiment observations. A van Hove singularity and Fermi-surface (FS) nesting are found in the doping levels relevant to the correlated insulator and unconventional superconductivity revealed experimentally, based on which we identify the two phases as weak-coupling FS instabilities. Then, with repulsive Hubbard interactions turned on, we performed random-phase-approximation based calculations to identify the electron instabilities. As a result, we find chiral d+id topological superconductivity bordering the correlated insulating state near half-filling, identified as noncoplanar chiral spin-density wave ordered state, featuring the quantum anomalous Hall effect. The phase diagram obtained in our approach is qualitatively consistent with experiments.
Rapid urbanization generates substantial demand, use, and demolition waste of construction materials. However, the existing top‐down or bottom‐up frameworks combining material flow analysis (MFA) and ...geographic information system (GIS) tend to underestimate both input and output of construction material flows due to insufficient descriptions of key processes in building construction and demolition. To address this limitation, this study identifies four important and complementary processes—construction, demolition, replacement, and maintenance, and integrates them into an improved framework to capture all material flows. We take Xiamen, a rapidly urbanizing city, as a case study to verify this framework. The results show that ∼40% of material inputs and ∼65% of outputs are underestimated by previous frameworks because they fail to capture material inputs in building maintenance and outputs in construction. These findings indicate a better estimation of such key flows in the modeling framework helps to accurately characterize building material metabolism. Based on systematic counting of material stocks and flows, the improved framework can help design effective policies for urban resource management by explicitly recognizing the spatiotemporal patterns and processes of material metabolism.
•Global plastic waste trade networks (GPWTNs) from 1988 to 2017 are established.•The spatiotemporal evolution of the GPWTNs is analyzed.•The direct and indirect impacts of China’s import ban on the ...GPWTNs are evaluated.•Practical implications are given according to analysis of the GPWTNs.
Millions of tonnes (teragrams) of plastic waste are traded around the world every year, which plays an important role in partially substituting virgin plastics as a source of raw materials in plastic product manufacturing. In this paper, global plastic waste trade networks (GPWTNs) from 1988 to 2017 are established using the UN-Comtrade database. The spatiotemporal evolution of the GPWTNs is analyzed. Attention is given to the country ranks, inter- and intra-continental trade flows, and geo-visual communities in the GPWTNs. We also evaluate the direct and indirect impacts of China’s plastic waste import ban on the GPWTNs. The results show that the GPWTNs have small-world and scale-free properties and a core-periphery structure. The geography of the plastic waste trade is structured by Asia as the dominant importer and North America and Europe as the largest sources of plastic waste. China is the unrivaled colossus in the global plastic waste trade. After China’s import ban, the plastic waste trade flows have been largely redirected to Southeast Asian countries. Compared with import countries, export countries are more important for the robustness of GPWTNs. Clearly, developed countries will not announce bans on plastic waste exports; these countries have strong motivation to continue to shift plastic waste to poorer countries. However, the import bans from developing countries will compel developed countries to build new disposal facilities and deal with their plastic waste domestically.
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