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Soil – the largest terrestrial pool of actively-cycling carbon – has the potential to sequester vast amounts of carbon globally. Chemical- and physical-associations of organic matter with mineral surfaces are known to play a critical role in this storage and preservation. However, the maximum capacity of soils to store carbon globally, and the role of mineralogy in driving this limit and its spatial variation, is still unknown. Here we present a comprehensive analysis of mineral-associated carbon and auxiliary variables from sites that span diverse biomes and soil types. We find that soil mineralogical properties dictate the maximum capacity of soils to stabilize organic matter associated with minerals, and that this mineral-associated organic matter accounts for the majority of carbon and nitrogen in soil organic matter. Explicit representations of mineral-organic associations are still lacking in Earth system models, and our findings are essential for informing and parameterizing model formulations at global scales. Our results suggest that most soils contain substantially less carbon than their mineral-associated carbon capacity (i.e., they are below carbon saturation), and that this is particularly evident in deeper soils and in poorly-managed and degraded lands. We calculate the mineralogical limit of low- and high-activity mineral soils to stabilize carbon, and use these empirically-derived limits to estimate the global potential for soil minerals to stabilize carbon. This estimate, and the underlying spatial distribution, provides crucial insights and motivation for targeted soil management and conservation efforts. Increasing soil carbon storage through restoration is a promising avenue for mitigating global emissions with lasting co-benefits. [ABSTRACT FROM AUTHOR]

Introduction: The issue of tobacco control remains a significant concern for public health worldwide. In recent years, remarkable progress has been made toward adopting smoke-free measures in indoor public places. Although China has yet to introduce a national regulation, specifically for smoke-free public places, more than a dozen cities have successively approved and implemented comprehensive smoke-free regulations. Different cities in China have diverse attitudes and behaviors toward smoke-free policies; however, the reasons for these policy differences and the influencing factors have not received sufficient attention and research., Methods: On the basis of the multiple streams framework, this study selects 36 key Chinese cities as research samples and uses a directed dyad-year event history analysis method to analyze the factors influencing the implementation of comprehensive smoke-free policies in cities., Results: Results show that the adoption of such policies is positively influenced by scientific evidence, focal events, media coverage, institutional foundations, economic comparisons, and the influence of health departments and of tobacco control groups. By contrast, policy adoption is negatively affected by the differences in administrative levels, central policy signals, and the influence of the tobacco industry., Discussion: This study contributes to understanding the internal logic behind local governments' adoption of comprehensive smoke-free policies, offering insights for further advocacy at the city and national levels in China and providing experiences that can promote the global tobacco control movement., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Feng, Qin, Jin and Li.)

The electrode materials of potassium ion storage system have attracted considerable attention given the promising prospect of a potassium ion system in large-scale electrochemical energy storage applications. Despite the excellent anode performance of metal oxides in Li + and Na + batteries, the study on their K + storage performance is still rarely reported. In this study, we report a safe and low-cost strategy to prepare FeO x /N-doped carbons by using NaHCO 3 and Fe nanopowder. Benefiting from the oxidation of Fe to Fe 3 O 4 , an interesting "one stone, two birds" role of the Fe powder can be identified in the heating process. As a reduction agent, the Fe powder can consume the excess oxygen in the bio-massed carbon framework, facilitating the formation of short-range-ordered domains in the biomass-derived carbon materials (FeO x @GBHCs). Moreover, the close combination of oxidization products (Fe 3 O 4 particles) and carbon matrix leads to numerous FeO x clusters grafted on the surface of the carbon framework via the strong C-O-Fe binding. Therefore, the resultant FeO x /porous carbon exhibits a high reversible capacity of 410 mA h g -1 and an excellent cycling capability. The assembled FeO x @GBHCs//AC potassium-ion hybrid supercapacitor delivers a high energy density of 133 W h kg -1 at a power density of 700 W kg -1 , demonstrating a potential prospect of metal oxides in boosting the potassium ion storage performance.

The design of electrodes with simultaneously high compaction density, developed porosity, and structural stability has always been a challenge so as to meet the demand of high volumetric performance lithium ion storage devices. In this paper, we demonstrate a new compositing method for hollow carbon "room" loading of Fe 3 O 4 nanoparticles (HCR@Fe 3 O 4 ) with the assistance of Na 2 CO 3 salt crystal templates. The as-obtained HCR@Fe 3 O 4 composites have a massive compaction density (1.79 g cm -3 ), abundant multimodal pores (1.26 cm 3 g -1 ), and a large content of Fe 3 O 4 (64.2 wt%), which leads to excellent volumetric capacitive performance. More importantly, the unique compositing model not only provides a fast transmission channel for Li + but also alleviates the mechanical strain efficiently through the cavity between the Fe 3 O 4 nanoparticles and the carbon wall. When evaluated as an anode of lithium ion batteries, the resultant HCR@Fe 3 O 4 electrode exhibits a remarkable volumetric capacity of 2044 mA h cm -3 at 0.2 A g -1 and a stable cycle life of 828 mA h cm -3 after 1000 cycles at 5 A g -1 . The assembled HCR@Fe 3 O 4 //AC lithium ion hybrid capacitor device exhibits a high energy density of 173 W h L -1 at a power density of 190 W L -1 , demonstrating its high-level integrated volumetric density/power density.

Bioinspired mineralization is a powerful method for designing and preparing nanomaterials. In this work, we developed a bioinspired mineralization approach under freezing conditions and fabricated methyl cellulose (MC)/NaHCO 3 flake precursors with a sophisticated hierarchical structure. Based on this, amazing wing-like porous carbon sheets (WPCSs) assembled by numerous interconnected hollow carbon bubbles were obtained after carbonization and removal of inorganic crystals, which are seldom obtained by other artificial methods. Benefiting from their open framework, large surface area, and enlarged interlayer spacing of graphitized nanocrystallites, the obtained WPCSs exhibited an obvious boost in potassium storage performance. As an anode of potassium-ion batteries, they showed high reversible capacities of 347 mAh g -1 at 50 mA g -1 and 122 mAh g -1 at 20 A g -1 and relatively stable cyclability for 3000 cycles. The assembled WPCS//WPCS potassium-ion hybrid supercapacitor delivered a high energy density of 108 Wh kg -1 at a power density of 280 W kg -1 . Given the cost effectiveness and green process, the modified bioinspired mineralization under freezing conditions would provide a facile and green way for exploring porous carbons with controlled structures and rich multifunction.

Quantifying soil organic carbon (SOC) decomposition under warming is critical to predict carbon-climate feedbacks. According to the substrate regulating principle, SOC decomposition would decrease as labile SOC declines under field warming, but observations of SOC decomposition under warming do not always support this prediction. This discrepancy could result from varying changes in SOC components and soil microbial communities under warming. This study aimed to determine the decomposition of SOC components with different turnover times after subjected to long-term field warming and/or root exclusion to limit C input, and to test whether SOC decomposition is driven by substrate lability under warming. Taking advantage of a 12-year field warming experiment in a prairie, we assessed the decomposition of SOC components by incubating soils from control and warmed plots, with and without root exclusion for 3 years. We assayed SOC decomposition from these incubations by combining inverse modeling and microbial functional genes during decomposition with a metagenomic technique (GeoChip). The decomposition of SOC components with turnover times of years and decades, which contributed to 95% of total cumulative CO 2 respiration, was greater in soils from warmed plots. But the decomposition of labile SOC was similar in warmed plots compared to the control. The diversity of C-degradation microbial genes generally declined with time during the incubation in all treatments, suggesting shifts of microbial functional groups as substrate composition was changing. Compared to the control, soils from warmed plots showed significant increase in the signal intensities of microbial genes involved in degrading complex organic compounds, implying enhanced potential abilities of microbial catabolism. These are likely responsible for accelerated decomposition of SOC components with slow turnover rates. Overall, the shifted microbial community induced by long-term warming accelerates the decomposition of SOC components with slow turnover rates and thus amplify the positive feedback to climate change., (© 2017 John Wiley & Sons Ltd.)