High quality factor and sensitivity are critical to wireless sensors targeting small perturbation detection. Although introducing parity-time symmetric dynamics promises enhanced performance, the symmetric scheme often yields limited sensing behaviors. In particular, its implementation is hindered by the inherent difficulties in decoupling capacitance- and coupling strength–induced responses, the requirements of delicately matching and/or tuning both gain and loss, and the need of strong coupling strength. Here, we report a concept of critical point (CP)–based wireless sensors that do not rely on balanced gain-loss configurations, delivering ultrahigh quality factor with an extended interrogation distance. Owing to a sharp and deep reflection dip, the CP-based scheme can resolve the change in coupling coefficient down to 1.92 × 10−4 and features frequency-independent responses. Furthermore, the CP-based scheme allows for identification of tiny asymmetric capacitive perturbations as small as 2.5 × 10−5 without requiring active tuning of the other parameters under weak coupling. Critical-point wireless sensors with unbalanced gain and loss enable reliable and sensitive detection under weak coupling.
Although the term ‘intellectual tradition’ is frequently used, it is rarely clearly defined, leaving a vast and largely unknown space for multidimensional inquiry. This article explores how to find tacit intellectual traditions by drawing upon cross-cultural philosophical resources and proposing possible methodological directions for educational research. The main argument is that intellectual traditions can be tacit at both epistemological and ontological levels. Three Western theorists—Edward Shils, Michael Polanyi, and Michael Oakeshott—critically reflect on anti-traditionalism and objectivism since the Enlightenment. They contend that intellectual traditions, including the tradition of science, as tacit knowledge, play an important role in human knowing and action. Chinese philosophy also attaches great importance to the tacit dimensions of intellectual tradition particularly at the ontological level, as exemplified by the core concept of ‘Dao’. As a foundational assumption underlying the worldview in ancient China, Dao generated different ways of knowing in Confucianism, Daoism, and Zen Buddhism. Even today, it continues to shape how Chinese people interpret and transmit traditions. The philosophical comparison between East and West reveals the complexities inherent in intellectual traditions, which bring new opportunities for educational research. Incorporating diverse tacit intellectual traditions can help researchers better understand cross-cultural educational issues in teaching, learning, and research. For this purpose, we propose ethnoepistemology, ontography, and hermeneutics as potential methodological tools.
Heterogeneous reaction of sulfur dioxide (SO2) on mineral dust is known to be an important pathway for SO2 removal mainly resulting in sulfate formation in the atmosphere, and its kinetic and mechanism can be significantly influenced by the presence of trace gases, such as, O3, NO2 and H2O2. However, little is known about the role of carbonyl compounds, such as formaldehyde (HCHO), that plays in this reaction. In this study, we investigated the heterogeneous reaction of SO2 on mineral dust, in this case, α-Al2O3 and SiO2 particles, in the presence of HCHO at different RHs using a flow reactor coupled with transmission-Fourier transform infrared (T-FTIR). Infrared spectra show that hydroxymethanesulfonate (HMS) can be formed through the interaction of HCHO with adsorbed SO2 on mineral dust even under dry conditions. HCHO plays a double-edged role in the heterogeneous reactions of SO2 at different RHs. The presence of HCHO inhibits the adsorption of SO2 on particles under dry conditions by competing with surface active sites, while it facilitates the amount of SO2 uptake by particles (N) at high RH by providing addition pathway for SO2 conversion. This enhancement also significantly shortens the discrepancy in different heterogeneous reactivity of particles towards SO2. The N value for α-Al2O3 particles is 5.2 times larger than SiO2 particles for particles exposed to SO2 alone, but this increase factor drops to 1.6 in the presence of HCHO at 80% RH. These findings deepen the understanding of SO2 heterogeneous chemistry in the atmosphere and how it is affected by the coexistence of other trace gases.
A novel, rapid, and efficient technique for removing phoxim residues from grapes was developed using microbubbles plasma-activated water (mbPAW). The mbPAW system was generated by utilizing a non-thermal plasma jet as the working gas of the Venturi tube. The phoxim residues in the grapes were quantified using high-performance liquid chromatography. Results indicated that the mbPAW treatment significantly enhanced the removal efficiency of the phoxim residues in grapes (92.82 %) compared with plasma-activated water (PAW) treatment (73.60 %) and microbubble generator without the plasma (mbW) treatment (13.56 %). The improved decontamination efficacy of mbPAW was attributed to its stronger oxidation capability and acidic environment, particularly the increased concentration of hydroxyl radicals, which facilitated phoxim removal from the grapes. Notably, LC-Q-TOF analysis revealed identical degradation products of phoxim (diethyl (Z)-(((cyano (phenyl)methylene)amino)oxy)phosphonate and (Z)-N-hydroxybenzimidoyl cyanide) in both the systems, confirming consistent degradation pathways. Crucially, post-treatment quality assessments revealed no statistically significant differences in grape physicochemical properties, including color, firmness, sugar content, vitamin C concentration, and superoxide dismutase activity. This study establishes mbPAW as a green, residue-free strategy for pesticide decontamination in horticultural products, offering high removal efficiency with minimal adverse impacts on produce quality.
Enhancement-mode (E-mode) p-channel field-effect transistors (p-FETs) remain challenging for GaN complementary logic (CL) technology due to their unstable threshold voltage (Vth), low current density, and large on-resistance (RON) at 6 V CL-compatible operation. In this work, we demonstrate a high-performance E-mode GaN p-FET with a p-NiO/p-GaN heterojunction gate. Notably, the suppressed Vth shift and improved channel conductivity were simultaneously achieved in the E-mode channel. The improvement is primarily due to the type-II band alignment at the p-NiO/p-GaN interface. This structure reduces band overlap, resulting in a low interface trap density (DT) of 3.29–5.71 × 1010 cm−2 eV−1 as measured by the sub-bandgap photo-assisted capacitance–voltage method. The fabricated device with LG/LGS/LGD = 1.5/3/3 μm exhibits a Vth of −0.6 V with a minimal hysteresis of 0.02 V and maximum shift of 0.04 V under stress, a ID of 5.5 mA/mm, a RON of 0.47 k Ω mm, and a transconductance (gm) of 1.8 mS/mm for 6 V CL-compatible operation.
Sound source localization (SSL) under unknown or variable sound sources conditions remains a challenging task. Existing methods suffer from limitations such as grid resolution constraints, fixed output dimensionality and insufficient exploitation of mutual assitance between temporal and spatial information. In this paper, we propose an Envelope Separation Aided Multi-Task Learning model for blind source counting and localization, which adaptively generates attractors to estimate source numbers and jointly optimizes envelope separation and direction estimation through a multi-task learning model using permutation invariant training (PIT). Experimental results demonstrated that the proposed model achieved better performance, by leveraging temporal domain envelope separation to aid spatial localization, outperforming baseline approaches.
The evolution of Fe(II)-oxidizing microorganisms has been closely linked to the evolution of Earth's iron biogeochemical cycle and redox history. However, its impact on the coupled biogeochemical cycling of iron and phosphorus, particularly the distribution of iron-bound phosphate (PFe) in water columns, remains largely unexplored. This study elucidates the distinct Fe(II) oxidation mechanisms of the anoxygenic Rhodobacter ferrooxidans SW2 and the oxygenic Synechococcus sp. PCC 7002, along with the properties, transformation processes, and phosphate interactions of their biogenic iron (oxyhydr)oxides. SW2-mediated Fe(II) oxidation via iron oxidase drove sequential transformation from ferrihydrite to green rust and then to goethite. The resulting cell-mineral aggregates had a large hydrodynamic diameter (Dh, up to 26 μm), a high Fe/C ratio (∼2.5), and a rapid sedimentation rate (up to 57.7 m/day), efficiently transporting PFe to deep-sea sediments. In contrast, PCC 7002 indirectly oxidized Fe(II) via oxygen production, forming poorly crystalline iron (oxyhydr)oxides stabilized by extracellular polymeric substances. The resultant small aggregates (Dh = ∼6.9 μm), with a slower sedimentation rate (∼3.9 m/day), exhibited high phosphorus retention and were susceptible to dissimilatory iron reduction, facilitating PFe recycling in surface waters. These findings suggest that biogenic iron (oxyhydr)oxides from anoxygenic iron oxidizers act as carriers, transporting phosphorus to deep sediments, whereas those from oxygenic cyanobacteria function as phosphorus traps in surface waters. This study provides new insights into how the evolution of Fe(II)-oxidizing microorganisms reshapes PFe cycling and distribution in water columns, emphasizing the need to integrate microbiological and geochemical perspectives in understanding Earth's biogeochemical cycles.
Earth’s core has long been speculated to be the largest reservoir of hydrogen (H) on the planet. However, current estimates of its H content involve substantial uncertainties, due to the challenge of quantifying H under extreme conditions. Here, we perform superliquidus metal-silicate partitioning experiments on H using laser-heated diamond anvil cells, and combine it with atom probe tomography. The direct observation of H at silicon- and oxygen-rich nanostructures in the iron alloy indicates coupled sequestration of silicon, oxygen and hydrogen into Earth’s core during its formation. With the observed molar Si/H ratio close to unity, Earth’s core is estimated to contain 0.07-0.36 wt.% H, equivalent to 9-45 oceans of water. Such an amount would require the Earth to obtain the majority of its water from the main stages of terrestrial accretion, instead of through comets during late addition.