Hydroxymethyl hydroperoxide (HMHP, HOCH2OOH) is one of the most abundant organic peroxides (POs) in the atmosphere. Owing to its extremely high solubility, HMHP readily partitions into cloudwater and aerosol liquid water, where it hydrolyzes to hydrogen peroxide (H2O2) and formaldehyde (HCHO). However, previous studies were conducted in dilute solutions and did not adequately account for the high-salinity characteristic of deliquesced aerosol particles. Here, we systematically investigate the combined effects of pH (0–6), temperature (277–313 K), ionic strength (0–10 M), and ion identity (NH4+, Na+, SO42–, and Cl–) on the hydrolysis kinetics of HMHP. For the first time, a parametrization formula describing the dependence of the hydrolysis rate constant on ionic strength is established, demonstrating that ionic strength exerts only a limited influence on HMHP hydrolysis. However, it is found that in highly concentrated ammonium salt solutions, HMHP undergoes a previously unrecognized NH3-driven reaction pathway. This new pathway competes with hydrolysis, accelerating the apparent transformation rate of HMHP by more than an order of magnitude while significantly reducing the yield of H2O2 and HCHO. Our findings highlight that future atmospheric chemical models should fully account for the NH3-driven pathway in aqueous-phase reactions of POs, thereby enabling a more accurate assessment of the role of POs in atmospheric oxidant cycling and secondary particulate matter formation.
Formic acid and acetic acid are the most abundant gas-phase organic acids in the atmosphere, yet their concentrations are substantially underestimated by both global and regional atmospheric models across diverse environments. In this study, we report unexpectedly high yields of formic acid and acetic acid during the multi-generational photooxidation of toluene, a canonical anthropogenic volatile organic compound. Their yields exhibit a strong dependence on hydroxyl radical (•OH) exposure ([•OH] × residence time), increasing from 25 % and 24 % under low exposure (< 0.2 equivalent days) to 74 % and 40 % under elevated exposure (1–3 equivalent days) for formic and acetic acid, respectively. The formation of these organic acids is not significantly affected by NOx concentrations. A modified box model based on MCM v3.3.1 underestimates the peak concentrations of both acids by approximately a factor of five, indicating substantial gaps in current mechanistic understanding. Although both secondary aerosol formation and organic acid production increase with aging to a certain degree of oxidation, their distinct temporal evolutions suggest that particle photodegradation is not the dominant pathway. The contrasting •OH exposure dependence between organic acids and primary carbonyl compounds further implies that these acids are predominantly multi-generational oxidation products. These findings demonstrate that multi-generational oxidation of aromatic compounds is an important and previously underappreciated source of atmospheric organic acids. The omission of organic acid formation from aromatic oxidation in current chemical mechanisms likely contributes to their widespread underestimation in models, highlighting the need for detailed laboratory studies and updated chemical mechanisms.
Transistor-integrated flexible pressure sensors have received considerable interest in emerging fields such as humanoid robotics, prosthetics, and implantable electronics. However, existing designs for these integrated sensors often exhibit a trade-off between pressure response and operating voltage, thus significantly limiting their practical applications. In this letter, we report a unique device design of integrated pressure sensors based on deformable microstructured electrodes capacitively coupled with floating-gate carbon nanotube transistors. The microstructured electrodes can dramatically enhance the pressure-introduced electrostatic control of the transistor, enabling a substantial improvement in the transduced pressure response at low operating voltages. With this unique design, we achieve a high pressure response of $10^5$ and an ultrahigh sensitivity up to $10^4 \text kPa^\text - 1$ at a low operating voltage below 3 V, which holds great promise for the development of advanced functionalized flexible electronics.
The dissolution of manganese (Mn) (hydr)oxides induced by low-molecular-weight organic compounds (LMWOCs) critically influences Mn and carbon cycling, yet limited high-resolution characterization hinders mechanistic understanding. Here, we investigated the dissolution kinetics of Mn(III/IV) (hydr)oxides mediated by citric acid, pyruvic acid, oxalic acid, and hydroquinone, as well as the controlling factors (LMWOC type and concentration, pH, and coexisting ions), by real-time and in-situ electrochemical quartz crystal microbalance (EQCM), complemented by grazing-incidence wide-angle X-ray scattering (GIWAXS) and kinetic modeling. Hydroquinone and citric acid promoted significant dissolution at pH 5 and 6, with hydroquinone dominating initially but slowing later; at pH 7, hydroquinone remained highly effective, far surpassing citric acid. In contrast, pyruvic acid and oxalic acid at pH 5, 6, and 7 showed negligible dissolution. Citric acid– and hydroquinone–mediated dissolution exhibited characteristic S-shaped kinetics with induction, acceleration, and deceleration stages, indicating an autocatalytic pathway, whereas pyruvic acid and oxalic acid showed no such pattern. Analysis of controlling factors showed that citric acid–mediated dissolution increased with increasing citric acid concentration and decreasing pH. Coexisting ions, including NO3−, Cl−, SO42− (5–50 mM), and Mg2+, Ca2+, Zn2+ (0.5–4 mM), inhibited the dissolution. Notably, HPO42− and P2O74− (0.1–1 mM) and Mn2+ (0.5–4 mM) exhibited concentration-dependent dual effects on dissolution, arising from competing promotive and inhibitory processes. GIWAXS analysis revealed that citric acid–mediated dissolution of Mn(III/IV) (hydr)oxides was facet-dependent, whereas exogenous Mn2+ promoted non-selective citric acid–mediated dissolution. This study provides insights into complex interfacial geochemical processes on redox-active minerals.
We studied the horizontally oriented ice crystals (HOIC) with the combinational observations of a zenith-pointing and a slant-pointing (with a zenith angle of 15 degrees) polarization lidar in Beijing in 2022. The HOICs account for approximately 7.3 % of total ice-containing clouds. These results have the potential to enhance the parameterization scheme in climate models for this unique form of ice crystals.
Geological carbon cycle (GCC) directly impacts the global carbon cycle and climate change, where CO2 adsorption is one most critical factor, governs the GCC's efficiency and security. However, the fundamental mechanisms of CO2 adsorption and its effects on interfacial properties remain inadequately understood due to the inherent complexities of mineral compositions, pore structures, and wettability heterogeneities. To address these challenges, this review systematically explores the theoretical foundations of CO2 adsorption, providing a mechanistic elucidation of CO2 adsorption and its effects on interfacial properties. It integrates insights from mathematical modeling, molecular simulations, and experimental methodologies to elucidate the mechanisms of CO2 sorption and its competitive behavior with other fluid components such as CH4 and H2O in geological formations. We critically assess CO2 adsorption behaviors at diverse interfaces, including solid-fluid interfaces (organic, inorganic, and composite models) and fluid-fluid interfaces (e.g., CO2-water), and discuss influencing factors, such as pore shape/size, temperature, pressure, moisture, wettability, and external electric fields. Furthermore, the review specifically evaluates the key physicochemical mechanisms underlying CO2-interface interactions and its implications for interfacial properties, including wettability alteration, interfacial tension changes and adsorption-induced deformation. Meanwhile, we provide a comprehensive understanding of adsorption scenarios within the GCC. Finally, we outline current research challenges and identify prospects to advance the fundamental understanding of how CO2 adsorption influences mineral interfacial properties and the GCC processes, thereby contributing to global climate governance and carbon neutrality efforts.Keywords: CO2 adsorption; Interfacial properties; Gas–solid interactions; Minerals; Geological carbon cycle
This paper presents a longitudinal narrative ethnography tracing the embodied experiences of Hippo, a young woman navigating clinical depression and a shifting relationship with physical activity over 6 years. Set against prevailing discourses that promote exercise-as-cure for mental illness, the paper does not seek to test efficacy, but to explore what movement does, emotionally, socially, and existentially, for someone living with chronic distress. Rather than offering generalisable claims or neat resolutions, this study privileges temporality, subjectivity, and storied complexity. Hippo’s journey unfolds not as a linear transformation, but through slow, recursive encounters with walking, swimming, running, and moments of stillness. Her initial curiosity about movement was sparked not by medical advice but by reading a running narrative. Over time, she experiments with exercise as a form of survival, not salvation. The story was co-constructed through diaries, unstructured interviews, conversational dialogue, fieldnotes, and collaborative storytelling. Grounded in storytelling and phenomenological sensibility, the paper argues that physical activity can foster a mode of ‘being-with’ depression rather than simply offering a route out. Hippo’s story highlights traits of slowness, coexistence, ambivalence, and embodied re-sensation, challenging dominant health narratives that assume movement leads to measurable recovery. In advocating for narrative as a method and as knowledge, this work contributes to growing calls for research that centres the lived, affective, and complex realities of those whose stories do not fit mainstream frameworks. It invites readers to understand movement not just as medicine, but as a mode of being with difficulty and of becoming.
Achieving sound field reproduction (SFR) with high sound quality and accurate spatial localization in automotive cabins is particularly challenging due to complex acoustics and constrained loudspeaker layouts. This paper proposes a learning-based method to address this challenge, integrating a spatial domain physics-informed constraint based on plane-wave decomposition (PWD) with a multi-position control strategy. Results from both objective evaluations and in-situ subjective listening tests consistently validated the superiority of the proposed approach over several baseline methods. Moreover, we show that the correlation of spatial power maps (SPMs) derived from PWD provides a reliable objective metric that closely reflects perceived spatial localization in the cabin environment.
The effects and mechanisms of carbon (C)- and nitrogen (N)-deficient nutrient conditions (prevalent in natural environment) on bacterial mobile performance in porous media are unclear. This study systematically investigated the transport/retention performance of Gram-negative Escherichia coli and Gram-positive Bacillus subtilis experiencing different nutrient conditions (i.e. nutrient-sufficient, C-deficient, or N-deficient conditions) in column, parallel plate flow chamber (PPFC) and microfluidic chamber systems. We found that compared to those in nutrient-sufficient condition, bacteria (regardless of their type) exposure to C-deficient nutrient condition exhibited 7–14% reduced mobility in porous media, whereas those experienced N-deficient condition had 7–20% enhanced transport in both simulated electrolyte solutions and real groundwater samples. The underlying mechanisms driving to different mobile performance of bacteria exposure to different nutrient conditions were correlated with the composition of proteins (one major component of extracellular polymeric substances (EPS)). Compared to nutrient-sufficient condition, C-deficient condition increased EPS hydrophobicity via enhancing hydrophobic amino acids contents and altering secondary structure within proteins thus decreased bacterial transport, while N-deficient condition decreased EPS hydrophobicity through decreasing the abundance of hydrophobic amino acids within proteins and increased cell mobility. The results showed that via changing cell surface hydrophobicity, exposure bacteria to different nutrient conditions could induce different mobile performance of bacteria.
With seven temperate Earth-sized planets revolving around an ultracool red dwarf, the nearby TRAPPIST-1 system offers a unique opportunity to verify models of exoplanet composition, differentiation, and interior structure. In particular, the low bulk densities of the TRAPPIST-1 planets, compared to terrestrial planets in our Solar system, require either substantial amount of volatiles to be present or a core-free scenario where the metallic core is fully oxidized. Here, we test the validity of the core-free scenario given thermodynamic constraints. In particular, we update a metal–silicate partitioning model within the equilibrium differentiation framework. We show that during core–mantle differentiation, oxygen becomes more siderophile (iron-loving) with increasing pressure, implying larger planet radii. For the seven TRAPPIST-1 planets, however, we find that they are not sufficiently massive to oxidize all the iron in the core, if they differentiate from an Earth-like composition. Oxygen partitioning in rocky worlds thermodynamically precludes coreless planets up to 4 M⊕. The observed density deficit in the TRAPPIST-1 planets, and more generally in M dwarf systems if confirmed by future observations, may be explained by system-dependent element budgets during planet formation, which are intrinsically linked to their stellar metallicity.
The rapid development of multimodal epidermal sensing requires scalable, energy-efficient data processing architectures capable of processing large volumes of raw data. Conventional systems suffer from high energy consumption and transmission latency due to the physical separation of sensors and processors. Here, we present an ultrathin flexible edge computing circuit based on carbon nanotube thin-film transistors (CNT-TFTs) and machine learning (ML)-assisted design. By incorporating substrate engineering, ML-derived device modeling, and industry-compatible design methodologies, we establish a complete toolchain from device to system. The ML model achieves 91.2% prediction accuracy, enabling simulation-guided optimization of logic gates. A CNT-based standard cell library enables the construction of flexible circuits with 361 transistors and 160 logic gates. Monolithic integration with an 8-channel tilt sensor achieves 62.5% data compression while maintaining functionality after undergoing 360° deformation. This work establishes an ML-assisted CNT circuit design framework for fully integrated flexible edge computing, enabling scalable wearable applications.
