Abstract
Na-ion cathode materials operating at high voltage with a stable cycling behavior are needed to develop future high-energy Na-ion cells. However, the irreversible oxygen redox reaction at ...the high-voltage region in sodium layered cathode materials generates structural instability and poor capacity retention upon cycling. Here, we report a doping strategy by incorporating light-weight boron into the cathode active material lattice to decrease the irreversible oxygen oxidation at high voltages (i.e., >4.0 V vs. Na
+
/Na). The presence of covalent B–O bonds and the negative charges of the oxygen atoms ensures a robust ligand framework for the NaLi
1/9
Ni
2/9
Fe
2/9
Mn
4/9
O
2
cathode material while mitigating the excessive oxidation of oxygen for charge compensation and avoiding irreversible structural changes during cell operation. The B-doped cathode material promotes reversible transition metal redox reaction enabling a room-temperature capacity of 160.5 mAh g
−1
at 25 mA g
−1
and capacity retention of 82.8% after 200 cycles at 250 mA g
−1
. A 71.28 mAh single-coated lab-scale Na-ion pouch cell comprising a pre-sodiated hard carbon-based anode and B-doped cathode material is also reported as proof of concept.
Recycling of spent lithium-ion batteries has recently become a critical issue based on environmental concerns and a desire to reutilize resources. Among the existing recycling strategies, direct ...regeneration is largely encouraged from an economic and environmental perspective. However, current procedures used to separate the active cathode materials from the aluminum foil have some limitations for direct regeneration because they either destroy the structure of the cathode or use too many toxic and expensive reagents. Hence, we conducted comprehensive research on the microstructural evolution of the LiNi
1−
x
−
y
Co
x
Mn
y
O
2
degraded electrode and then proposed a targeted method to recycle the spent cathode materials based on the increased residual lithium compounds. This separation process involves no other reagents but water, and toxic organic solvents, complicated processes, and waste treatments are unnecessary compared with the existing pretreatment strategies. Moreover, the separated cathodes are suitable for direct regeneration. Satisfactory capacity recovery of the cathode was achieved
via
simple sintering. Such a recycling process enables a sustainable closed-loop for the spent cathodes and provides new inspiration for the design of LIB recycling.
Based on the increased residual lithium compounds of the degraded cathode, a green water-based strategy is designed for achieving closed-loop recycling of spent lithium-ion batteries.
•Microplastic-induced changes affect soil function and soil microbial communities.•The effects of microplastics on soil or soil organisms depend on particle types, concentration and exposure ...time.•Consumption of microplastics can cause mechanical damage, chemical responses and disrupt gut microbial communities.•Microplastics have potential effects on plant growth and may accumulate and transport in plants.•Some bacteria biodegrade microplastics could be used for soil bioremediation.
Microplastics are emerging contaminants and their presence in water and soil ecosystems has recently drawn considerable attention because they pose a great threat to entire ecosystems. Recent researches have focused on the detection, occurrence, characterization, and toxicology of microplastics in marine and freshwater ecosystems; however, our understanding of the ecological effects of microplastics in soil ecosystems is still limited compared with that in aquatic ecosystems. Here, we have compiled literature, studying the sources, migration of microplastics in soil, negative impacts on soil health and function, trophic transfer in food chains, and the corresponding adverse effects on soil organisms in order to address the potential ecological and human health risks caused by microplastics in soil. This review aims to address gaps in knowledge, shed light on the ecological effects of microplastics in soil, and propose future studies on microplastic pollution and the resultant soil ecotoxicity. Furthermore, this review is focused on limiting microplastics in soil and establishing management and remediation measures to mitigate the risks posed by microplastic pollution.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
The thermal stability of organic solar cells is critical for practical applications of this emerging technology. Thus, effective approaches and strategies need to be found to alleviate their inherent ...thermal instability. Here, we show a polymer acceptor-doping general strategy and report a thermally stable bulk heterojunction photovoltaic system, which exhibits an improved power conversion efficiency of 15.10%. Supported by statistical analyses of device degradation data, and morphological characteristics and physical mechanisms study, this polymer-doping blend shows a longer lifetime, nearly keeping its efficiency (t = 800 h) under accelerated aging tests at 150
C. Further analysis of the degradation behaviors indicates a bright future of this system in outer space applications. Notably, the use of polymer acceptor as a dual function additive in the other four photovoltaic systems was also confirmed, demonstrating the good generality of this polymer-doping strategy.
Hadal trenches are the deepest and most remote regions of the ocean. The 11-kilometer deep Challenger Deep is the least explored due to the technical challenges of sampling hadal depths. It receives ...organic matter and heavy metals from the overlying water column that accumulate differently across its V-shaped topography. Here, we collected sediments across the slope and bottom-axis of the Challenger Deep that enable insights into its in situ microbial communities. Analyses of 586 metagenome-assembled genomes retrieved from 37 metagenomes show distinct diversity and metabolic capacities between bottom-axis and slope sites. 26% of prokaryotic 16S rDNA reads in metagenomes were novel, with novelty increasing with water and sediment depths. These predominantly heterotrophic microbes can recycle macromolecules and utilize simple and complex hydrocarbons as carbon sources. Metagenome and metatranscriptome data support reduction and biotransformation of arsenate for energy gain in sediments that present a two-fold greater accumulation of arsenic compared to non-hadal sites. Complete pathways for anaerobic ammonia oxidation are predominantly identified in genomes recovered from bottom-axis sediments compared to slope sites. Our results expand knowledge of microbially-mediated elemental cycling in hadal sediments, and reveal differences in distribution of processes involved in nitrogen loss across the trench.
Long‐noncoding RNAs (lncRNAs) is involved in the development of diverse diseases, including leukemia, while the role lncRNA HOX transcript antisense RNA (HOTAIR) played in leukemia remains unclear ...and in need of further investigation. Therefore, this study was conducted to explore the effects of lncRNA HOTAIR on the immunologic rejection of leukemia cells through the Wnt/β‐catenin in mice. Mice were administrated with HOTAIR mimics as well as small interfering RNA HOTAIR to explore the regulatory role of HOTAIR. The numbers of white blood cell (WBC) and platelet (PLT) and the content of hemoglobin in peripheral blood (PB) were determined. The cytokine level in PB was measured. T‐lymphocyte proliferation activity, Ig production by B cells, natural killer (NK) cell activity, and the proportion of cluster of differentiation 4 (CD4)/CD8 T cell subsets were detected. Expression of HOTAIR, β‐catenin, cyclinD1, GSK‐3β, and c‐Myc in bone marrow was determined. It was revealed that the WBC number increased, while the PLT number along with the hemoglobin content in PB decreased with the upregulated HOTAIR. Additionally, elevated HOTAIR led to decreased levels of transforming growth factor‐β, interferon‐γ, interleukin‐10, and tumor necrosis factor‐α in PB, proliferation activity in T‐lymphocyte, and inhibited Ig production, NK cell activity, and the ratio of CD4/CD8 T cell subsets in B‐lymphocyte. Furthermore, Wnt/β‐catenin was activated by overexpressing HOTAIR. Enhanced survival and proliferation were shown with increased expression of cyclinD1, GSK‐3β, and c‐Myc in the bone marrow of mice induced by overexpressing HOTAIR. These results indicate that restored HOTAIR reduces the immunologic rejection of leukemia cells in mice by activating Wnt/β‐catenin pathway.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Pure organic room temperature phosphorescence (RTP) is highly preferable because of its long lifetime and potential applications. However, these kinds of materials are still very scarce due to the ...weak spin–orbit coupling between singlet and triplet states and easily nonradiative decay of the excited states. Achieving room temperature phosphorescence under visible light excitation is particularly challenging in aqueous solution. Herein, a micelle‐assisted assembling strategy has been developed to realize pure organic RTP in water by using donor–acceptor molecules. A visible‐light responsive long‐lived RTP in water with a lifetime more than 3 ms is obtained by the prepared nanocrystals. However, the same molecules show no RTP as rigid bulk crystals. Spectroscopic studies, single‐crystal structure analysis, X‐ray diffraction patterns, and density functional theory calculations reveal that the intermolecular interactions, heavy atom effect, and the molecular packing way play critical role to the long‐lived RTP character for the assembled nanocrystals in water and thermally activated delayed fluorescence for crystals in solid.
A micelle‐assisted assembly strategy to realize long‐lived pure organic room temperature phosphorescence under visible light excitation in water is reported. The molecular packing plays a critical role to the room temperature phosphorescence character in the assembled nanocrystals and delayed fluorescence in the crystals.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Northwest China is one of the most arid regions in the world and has experienced intriguing climate warming and humidification. Nonetheless, future climate conditions in Northwest China still remain ...uncertain. In this study, we applied an ensemble of the 12 latest model simulations of the Coupled Model Intercomparison Project Phase 6 (CMIP6) to assess future drought conditions until 2099 in Northwest China, as inferred from the Palmer Drought Severity Index (PDSI). Future drought conditions were projected under three climate change scenarios through the combination of shared socioeconomic pathways (SSPs) and representative concentration pathways (RCPs), namely, SSP126 (SSP1 + RCP2.6, a green development pathway), SSP245 (SSP2 + RCP4.5, an intermediate development pathway), and SSP585 (SSP5 + RCP8.5, a high development pathway). For 2015-2099, drought severity showed no trend under SSP126, in contrast, for the SSP245 and SSP585 scenarios, a rapid increase during 2015-2099 was observed, especially under SSP585. We also found that the drought frequency in Northwest China under SSP585 was generally lower than that under SSP126 and SSP245, although the drought duration under SSP585 tended to be longer. These findings suggest the green development pathway in drought mitigation and adaptation strategies in Northwest China, an arid and agricultural region along the Silk Road.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Reasonable design and controllable synthesis of non-Pt catalysts with high methanol oxidation activity are regarded as a valid way to promote the large-scale commercial applications of direct ...methanol fuel cells (DMFCs). Herein, we develop a convenient and cost-effective approach to the successful fabrication of nanosized Rh grown on single-walled carbon nanohorns (Rh/SWCNH) as anode catalysts for DMFCs. The unique architectural configuration endows the as-obtained hybrids with a series of intriguing structural merits, including large specific surface areas, abundant opened holes, optimized electronic structures, homogeneous Rh dispersion, and good electrical conductivity. As a consequence, the resulting Rh/SWCNH catalysts exhibit exceptional electrocatalytic properties in terms of a large electrochemically active surface area of 102.5 m
2
·g
−1
, a high mass activity of 784.0 mA·mg
−1
, as well as reliable long-term durability towards the methanol oxidation reaction in alkaline media, thereby holding great potential as alternatives for commercial Pt/carbon black and Pd/carbon black catalysts.
Graphic abstract
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•Obtain deformation failure mechanisms of deep broken rock roadways based on a detail field investigation.•Analyze and evaluate the shortcomings of a primary support scheme using FLAC3D and onsite ...experiments.•Propose and validate an improved support method for roadways in broken rock mass and high geo-stress.
The roadway support has always been a difficult problem in the mining engineering, especially in the deep soft rock roadway, whether it can provide endurable and effective support directly affects the safety production and sustainable development of the mine. In order to solve the supporting issues, it is necessary to make the deformation failure mechanism of deep soft rock roadway clear. This paper describes a case study of the deformation failure mechanism and support technology of deep roadway with soft rock mass in No.2 mine zone of Jinchuan mine that is located in Gansu Province, China. Based on a detailed field investigation and previous research experience, the modes, influencing factors, laws and mechanisms of deformation failure in the roadway are summarized. Then the primary combined supporting scheme “double layer bolt-mesh-shotcrete and U-shaped steel” is evaluated through numerical simulation calculation and onsite experiments. To make up for the shortcomings of the primary support, an improved combined supporting scheme “double layer long bolt-mesh-shotcrete and CFST (concrete filled steel tube)” is proposed. The results of numerical simulation, field monitoring and economic analysis show that the new support can control the deformation of the roadway effectively and has a high cost performance. Finally, several suggestions for supporting in deep soft rock roadway are put forward, aiming at serve as a reference for other engineering.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
PDF
