Large Potential Research Articles

Vertically Aligned Ultrathin CoNi-LDH@NiS@MXCF Core-Shell Heterostructure for Flexible Supercapacitor Electrodes and Oxygen Evolution Reaction.

A multilayer core-shell heterostructure with CoNi-LDH as the core and NiS nanosheets as the shell is deposited on MXene-coated carbon nanofibers by electrospinning and electrochemical deposition. This unique structure not only combines highly conductive and hydrophilic one-dimensional carbon nanofibers but also exposes abundant two-dimensional reactive sites and multiple ion diffusion channels to maximize material utilization, enhance electron transfer kinetics, accelerate Faraday reaction, high capacitance and strong stability. The CNNS@MXCF electrode exhibits outstanding electrochemical characteristics, including a capacity of 1441.8 F g-1 at a current density of 1 A g-1 and excellent cycling stability. The CNNS@MXCF//VN@MXCF device shows a high energy density of 84.4 Wh kg-1 at 0.8 kW kg-1 power density, with nearly 92% capacitance retention after 10,000 cycles (30 A g-1). In addition, the oxygen evolution reaction (OER) shows a small overpotential of 128 mV, confirming the versatility and large potential of the materials and strategy.

Citizen Observations Shed New Light on Geographic Variation in Colour Polymorphism of a Widespread Reptile

ABSTRACTAimColour polymorphism within ectothermic species and populations is shaped by multiple selection pressures that can vary geographically. Here, we tested different hypotheses to better understand this variation in colour polymorphism. The thermal melanism hypothesis predicts that darker colouration is beneficial in colder regions, due to enhanced heat absorption, while the predation pressure hypothesis predicts that melanistic individuals are exposed to a higher predation risk because they are more visible to predators. Additionally, temperature, land cover and predation pressure could interact to influence colour morph frequencies due to trade‐offs regarding thermoregulation and predation risk.LocationEurasia.TaxonEuropean adder (Vipera berus).MethodsWe compiled a dataset of > 7000 citizen observations across the entire distribution of the European adder, scoring adder colouration to test the above‐mentioned hypotheses concerning geographic variation in colour polymorphism, using Bayesian generalised nonlinear regression models.ResultsWe found support for the thermal melanism hypothesis, with the frequency of melanism increasing in colder regions. Moreover, in colder areas, the proportion of melanistic snakes increased with avian predator density, whereas this pattern was weaker in warmer areas, potentially because melanistic snakes spend less time basking and therefore experience reduced predation rates compared to brown and grey snakes. Finally, we found the proportion of melanistic individuals to decline at higher elevations (> 1000 m), potentially due to increased access to basking opportunities or because higher elevations facilitate easier detection of melanistic snakes by predators.Main ConclusionsCombined, our results emphasise the large potential of citizen observations to obtain novel insights concerning biogeographic patterns of morphological divergence in colouration. Our findings increase the understanding of the underlying mechanisms affecting colour polymorphism in ectothermic animals, providing valuable information to predict how species might respond to global change.

Primordial gravitational wave backgrounds from phase transitions with next generation ground based detectors

Abstract Third generation ground-based gravitational wave (GW) detectors, such as Einstein Telescope and Cosmic Explorer, will operate in the (few-104) Hz frequency band, with a boost in sensitivity providing an unprecedented reach into primordial cosmology. 
Working concurrently with pulsar timing arrays in the nHz band, and LISA in the mHz band, these 3G detectors will be powerful probes of beyond the standard model particle physics on scales T ∼106 GeV and above. Here we focus on their ability to probe phase transitions (PTs) in the early universe. We first overview the landscape of detectors across frequencies, discuss the relevance of astrophysical foregrounds, and provide convenient and up-to-date power-law integrated sensitivity curves for these detectors. We then present the constraints expected from GW observations on both first order PTs, and on topological defects that may be formed when a symmetry is broken irrespective of the order of the phase transition (strings and domain walls). These constraints can then be applied to specific models leading to first order PTs and/or topological defects. In particular we discuss the implications for axion models, which solve the strong CP problem by introducing a spontaneously broken Peccei-Quinn (PQ) symmetry. For post-inflationary breaking, the PQ scale must lie in the 108-1011 GeV range, and so the signal from a first order PQ PT falls within reach of ground based 3G detectors. A scan in parameter space of signal-to-noise ratio in a representative model reveals their large potential to probe the nature of the PQ transition. Additionally, in heavy axion type models domain walls form, which can lead to a detectable GW background. We discuss their spectrum and summarise the expected constraints on these models from 3G detectors, together with SKA and LISA.

Slow Propagation Velocities in Schrödinger Operators with Large Periodic Potential

Slow Propagation Velocities in Schrödinger Operators with Large Periodic Potential

Biopolymer‐Based Gel Electrolytes for Advanced Zinc Ion Batteries: Progress and Perspectives

AbstractIn recent years, aqueous zinc ion batteries (ZIBs) with ultra‐high safety and environmental friendliness have emerged as a promising candidates for energy storage and energy conversion devices. However, the severe side reactions and dendrites issues discourage the practical application of ZIBs. Recently, biopolymer‐based gel electrolytes have disclosed large potential in tackling these challenges of ZIBs, with numerous advancements reported. Their advantages lie in suppressing side reactions including hydrogen evolution and Zn metal anode corrosion, as well as inhibiting the growth of Zn dendrites. This review comprehensively examines the classification, structures and properties of biopolymer‐based gel electrolytes, with a focus on hydrogel electrolytes derived from various natural macromolecular biopolymers, along with a brief discussion on non‐hydrogel electrolytes using ionic liquids or organic solutions as solvents. Subsequently, the preparation of biopolymer‐based gel electrolytes with physical and chemical methods are summarized. Furthermore, the practical applications of biopolymer‐based gel electrolytes in ZIBs with diverse cathodes materials are introduced. Finally, it highlights the environmental benefits and excellent electrochemical performance of biopolymer‐based gel electrolytes, outlining their prospects for the next generation of ZIBs and proposing future perspectives.

The role of AI, big data and predictive analytics in mitigating unemployment insurance fraud

The fraudulent claims for Unemployment Insurance (UI) have also risen massively in the United States especially during the onset of COVID-19 pandemic with billions of dollars that were lost. These approaches applied formerly in fraud detection and prevention have been challenged by new and advanced fraud systems. For this reason, AI, Big Data and Predictive Analytics are now crucial for improving fraud mitigation in UI programs. The aim of this research is to understand how far AI, Big Data and Predictive Analytics have been utilized, for how effective they are and the barriers they pose in tackling unemployment insurance fraud in the United States. An online quantitative self-administered questionnaire was administered where 200 participants from the unemployment insurance agencies of the U.S, covering fraud investigators, IT personnel, data analysts and policymakers, were included in the study. Data were analyzed to establish the correlation between technology adoption to application of anti-fraud measures using descriptive statistics, chi-square test and regression analysis. The survey shows that about 42.5% of agencies actively use AI and 34% of them use Big Data very often. However, difficulties like high costs, integration troubles and limited availability of specialized staff are still issues that make adoption a problem. The results of using AI and Big Data were moderate and optimistic but rather elevated, as seen through regression analysis; on the other hand, predictive analytics demonstrated large potential when applied successfully. The study’s results indicate that AI, Big Data and Predictive Analytics present enormous potential for mitigating UI fraud, although broad integration will not be possible without overcoming essential infrastructural and resource limitations.

Investigation of Cr2SiC Ceramic MAX Phase Coated Metallic Bipolar Plates in Ex-situ Conditions for Proton Exchange Membrane Fuel Cells

Essential for compact and lightweight proton exchange membrane fuel cell (PEMFC) stacks, metallic bipolar plates (MBPs) suffer from durability and conductivity issues due to surface corrosion and passivation. This study conducts ex-situ characterization of Cr2SiC ceramic MAX phase coatings on stainless steel (SS) 316 L substrates to evaluate their suitability for MBP application. The investigation encompasses coating structure, surface morphology, corrosion resistance, surface wettability, in-plane electrical conductivity, and interfacial contact resistance. X-ray diffraction and X-ray photoelectron spectroscopy confirm the presence of Cr2SiC coatings on SS316L, while energy-dispersive X-ray spectroscopy verifies uniform coverage and elemental weight percentage. Corrosion resistance is evaluated using potentiostatic and potentiodynamic polarization tests, showing excellent resistance with low corrosion current density (Icorr) at both 25 °C (3.29E-03 μA/cm2) and 80 °C (4.32E-02 μA/cm2), meeting US Department of Energy (DOE) technical targets. Potentiodynamic polarization reveals large corrosion potential and small Icorr values at both temperatures, outperforming uncoated samples. Electrochemical impedance spectroscopy post-accelerated corrosion tests show high charge transfer resistance at 25 °C (3.68E+05 Ω cm2) and 80 °C (3.02E+05 Ω cm2), indicating stability in acidic environments. Surface wettability analysis indicates low water affinity with a large contact angle (75°) and low surface free energy (28.92 mJ/m2) for the coated samples as compared to the uncoated samples. Electrical conductivity meets DOE targets with an in-plane conductivity of 4.59E+05 S/m and interfacial contact resistance of 8.04 mΩcm2 after 5-h accelerated corrosion tests at 80 °C. These results suggest that Cr2SiC coated SS316L exhibits excellent corrosion resistance, surface wettability, and electrical characteristics, making them viable for PEMFC applications.

Giant miniature endplate potentials at vertebrate neuromuscular junctions: A review.

An unusually large amplitude spontaneous miniature endplate potentials (gMEPPs) occur naturally at low frequency at the vertebrate neuromuscular junction. Unlike the normal miniature endplate potentials (nMEPPs), these gMEPPs have long duration and long time to peak. More strikingly, gMEPPs seem to be independent of extracellular and intracellular Ca+2. and have a greater temperature sensitivity than nMEPPs. They are potentiated by tetrodotoxin but inhibited by acetylcholine (ACh) receptor blockers indicating ACh is the neurotransmitter responsible for gMEPPs. The frequency of gMEPPs is greatly increased in muscles weakened by various drugs, toxins or disease conditions suggesting that gMEPPs may be a part of possible neurotrophic mechanism to preserve effective neuromuscular transmission when the normal function is compromised.

Enhancing Real-Time Vision Systems: Integrating Dynamic Vision Sensors with Vision Transformers to Increase Computational Efficiency

Abstract. Optimizing and understanding vision systems' computational accuracy is crucial as they become increasingly integrated into daily life. Dynamic Vision Sensors (DVS) and Vision Transformers (ViTs) lead computer vision technology with efficient object recognition and image processing. However, DVS data's high computational complexity poses a problem for its real-time implementations. Merging these technologies can enhance vision system performance in dynamic environments and optimize real-time DVS processing. In our work, we use a ViT architecture to classify the DVS 128 dataset and compare our results with existing works using SNNs. We analyze how our method affects accuracy and loss, experimenting with different DVS-to-ViT input patch sizes. Our results show that the large patch size of 32x32 pixels has better accuracy and smaller loss than the 4x4 pixel patches as epochs increase. Our method also achieved a high 98.4% accuracy and low 0.22 loss within five epochs, significantly outperforming previous works averaging 93.13% accuracy over more epochs. These results highlight ViTs' large potential for real-time DVS data classification in applications that require high accuracy, like autonomous vehicles and surveillance systems.

Frazil ice changes winter biogeochemical processes in the Lena River

The ice-covered period of large Arctic rivers is shortening. To what extent will this affect biogeochemical processing of nutrients? Here we reveal, with silicon isotopes (δ30Si), a key winter pathway for nutrients under river ice. During colder winter phases in the Lena River catchment, conditions are met for frazil ice accumulation, which creates microzones. These are conducive to a lengthened reaction time for biogeochemical processes under ice. The heavier δ30Si values (3.5 ± 0.5 ‰) in river water reflect that 39 ± 11% of the Lena River discharge went through these microzones. Freezing-driven amorphous silica precipitation concomitant to increased ammonium concentration and changes in dissolved organic carbon aromaticity in Lena River water support microbially mediated processing of nutrients in the microzones. Upon warming, suppressing loci for winter intra-river nitrogen processing is likely to modify the balance between N2O production and consumption, a greenhouse gas with a large global warming potential.

Deep Learning Assisted Plasmonic Dark-Field Microscopy for Super-Resolution Label-Free Imaging.

Dark-field microscopy (DFM) is a widely used imaging tool, due to its high-contrast capability in imaging label-free specimens. Traditional DFM requires optical alignment to block the oblique illumination, and the resolution is diffraction-limited to the wavelength scale. In this work, we present deep-learning assisted plasmonic dark-field microscopy (DAPD), which is a single-frame super-resolution method using plasmonic dark-field (PDF) microscopy and deep-learning assisted image reconstruction. Specifically, we fabricated a designed PDF substrate with surface plasmon polaritons (SPPs) illuminating specimens on the substrate. Dark field images formed by scattered light from the specimen are further processed by a pretrained convolutional neural network (CNN) using a simulation dataset based on the designed substrate and parameters of the detection optics. We demonstrated a resolution enhancement of 2.8 times on various label-free objects with a large potential for future improvement. We highlight our technique as a compact alternative to traditional DFM with a significantly enhanced spatial resolution.

Structure, relationships and diversity in the community of aphids and aphidophagous species in alfalfa.

There is a need for comprehensive research on the species structure and the population dynamics of the most common aphidophagous species. A critical factor of the effectiveness of aphid biocontrol is the ratio of beneficial polyphagous (generalist) to oligo- or monophagous (specialist) species within the various trophic groups. Aphids' population density and environmental conditions influence the development and potential feeding of useful insects. The present study aimed to determine the community structure, relationships and diversity between aphids and their aphidophagous species in alfalfa fields using the following methods: sweeping with an entomological net, the quadratic method, coloured sticky board method, route survey method and visual observations. Research on the structure of the aphid-aphidophagous community revealed that aphidophagous species belong to three groups: (1) polyphagous predatory bugs from the families Anthocoridae and Nabidae, (2) oligophagous and polyphagous predators from the families Coccinellidae, Syrphidae and Chrysopidae; and (3) monophagous and oligophagous parasitoids, primarily from the families Aphidiidae and Ichneumonidae. From mid-May to June, there was a sufficiently large potential for aphidophagous species (Coccinellidae, Syrphidae, Chrysopidae, Anthocoridae and Nabidae) to control aphids, while in September, predatory ladybirds from the Coccinellidae family were the main biological control agents. Coccinellidae (Coleoptera) exhibited the highest values of diversity, dominance and richness indices among insect groups in the aphid-aphidophagous community. The existence of diverse aphidophagous species in alfalfa fields suggests that these predators can complement each other, leading to effective biological control of aphids. The synergy among different predator species holds promise for enhancing the overall efficacy of integrated pest management strategies.

Investigation of thermochemical energy storage materials for building heating applications: Desorption behaviors of MgSO4·7H2O–silica gel composite

MgSO4-silica gel composites have a large potential for application in large-scale long-term energy storage systems, but the theoretical research on materials is not yet sufficiently thorough, and the reaction mechanism is still unclear, especially the lack of relevant experimental investigation and validation. Therefore, in order to better understand the nature and behavior of the desorption process, the reaction mechanism of monomer MgSO4·7H2O and MgSO4·7H2O-silica gel composites were investigated in this paper. The experimental results presented the desorption process of both the pure salt and the composites can be divided into six stages, and at 150 °C, the two can desorb 40.42 %–44.14 %, accounting for 79 %–86 % of the total desorption, so it is more appropriate to take 150 °C as the temperature of desorption in the energy storage system. The desorption mechanisms of pure salt and composite materials can be described by the same model in the same temperature range, and the desorption curve types and reaction mechanism models corresponding to different desorption temperatures were obtained, which were S-shape-A2 (110 °C and 120 °C), accelerated-R2 (130 °C), and decelerated-F1 (140 °C and 150 °C), respectively, which revealed the kinetics and control mechanisms of desorption process. The control mechanism, which was an important guideline for optimizing the heat and mass transfer process inside the salt particles. Compared with the pure salt, the activation energy and pre-exponential factor of the composites were lower, 48.55 kJ/mol (58.05 kJ/mol for the pure salt) and 3.31 × 104 s−1 (1.88 × 105 s−1 for the pure salt), respectively, indicating the number of active sites in the composites was higher and the reaction rate was faster; The lower the activation energy, the smaller the effect of temperature on the reaction rate constant. It can be seen the composite material is more advantageous in the process of practical application. After 60 cycles, the decay rate of adsorption/desorption performance of SM20 was only 5 %-8 %, indicating that the composite material had good cycling stability and can be used as a candidate material for large-scale long-term seasonal energy storage.

The role of Xizang in China's transition towards a carbon-neutral power system

Developing renewable energy is crucial for achieving China's carbon neutrality target by 2060. Xizang has a large renewable energy potential, especially hydropower potential, and it could become an important source of clean energy. Meanwhile, climate change has been affecting and will significantly alter hydropower resources in Xizang. This study estimates the development of Xizang's power system and its role in the national power supply under China's carbon neutrality target. In particular, it considers the changes in theoretically available hydropower potential from glacial retreat and transmission-supporting policies. The results show that considering the hydropower potential changes from glacier retreat under climate change, an additional 5.7–6.8 GW of hydropower capacity could be developed in Xizang by 2060, concentrated in Linzhi and Naqu areas. This additional hydropower capacity could increase to 15.9–17.7 GW if transmission subsidies are provided. Under such a scenario, Xizang could export renewable electricity to other provinces for up to about 3 % of the national electricity demand by 2060. The results indicate the importance of considering the impacts of climate change in power system planning and implementing transmission-supporting policies, which could facilitate Xizang to become a renewable energy base for China.

Widespread Misinterpretation of pKa Terminology for Zwitterionic Compounds and Its Consequences.

The acid dissociation constant (pKa), which quantifies the propensity for a solute to donate a proton to its solvent, is crucial for drug design and synthesis, environmental fate studies, chemical manufacturing, and many other fields. Unfortunately, the terminology used for describing acid-base phenomena is sometimes inconsistent, causing large potential for misinterpretation. In this work, we examine a systematic confusion underlying the definition of "acidic" and "basic" pKa values for zwitterionic compounds. Due to this confusion, some pKa data are misrepresented in data repositories, including the widely used and highly trusted ChEMBL database. Such datasets are frequently used to supply training data for pKa prediction models, and hence, confusion and errors in the data make the model performance worse. Herein, we discuss the intricacies of this issue. We make suggestions for describing acid-base phenomena, training pKa prediction models, and stewarding pKa datasets, given the high potential for confusion and potentially high impact in downstream applications.

Recent Advances in Smart Sensing Based on Excited‐State Intramolecular Proton‐Transfer (ESIPT)‐Inspired Emitters

The optical materials based on excited state intramolecular proton transfer (ESIPT) have garnered significant attention due to their unique photophysical properties and applications in sensors and imaging agents (probes). These materials exhibit an intrinsic four‐level photocycle scheme through the enol (E)–keto (K) phototautomerization process, resulting in a large Stokes shift, environmental sensitivity, and potential for ratiometric sensing. This review primarily focuses on elucidating the luminescence mechanism and structure‐property relationships of recent ESIPT molecules, as well as exploring the sensing applications of phosphorescent functional materials.

Perturbative QCD meets phase quenching: The pressure of cold quark matter

Nonperturbative inequalities constrain the thermodynamic pressure of quantum chromodynamics (QCD) with its phase-quenched version, a sign-problem-free theory amenable to lattice treatment. In the perturbative regime with a small QCD coupling constant αs, one of these inequalities manifests as an O(αs3) difference between the phase-quenched and QCD pressures at large baryon chemical potential. In this work, we generalize state-of-the-art algorithmic techniques used in collider physics to address large-scale multiloop computations at finite chemical potential, by direct numerical integration of Feynman diagrams in momentum space. Using this novel approach, we evaluate this O(αs3) difference and show that it is a gauge-independent and small positive number compared to the known perturbative coefficients at this order. This implies that at high baryon densities, phase-quenched lattice simulations can provide a complementary nonperturbative method for accurately determining the pressure of cold quark matter at O(αs3). Published by the American Physical Society 2024

Potential of Dry Leaf Waste as A Raw Material for Charcoal Briquettes Preparation as an Alternative Fuel

This research was motivated by the large potential of dry leaf waste in the campus environment of the University of North Sumatra and the awareness of the importance of appropriate innovation in the use of dry leaf waste as an environmentally friendly alternative fuel. The aim of this research was to determine the potential of leaf waste in the campus environment as a raw material for making environmentally friendly charcoal briquettes. The research method was observation, conducted in the campus environment of the University of North Sumatra, followed by calculating the amount of leaf waste produced per day, and testing continued with the production of dry leaf briquettes. The test results of the three combustions with different mixtures of raw materials in each combustion resulted in solid dry leaf briquettes that could ignite well. This study produced briquettes with proximate and ultimate tests that met SNI No.01-6235-2000 standards with a moisture content test of 4.35%, ash content test of 5.65%, carbon content test of 78.68%, calorific value of 6115 cal/g, and a burning rate of 1.5 grams/minute. Briquettes that meet SNI standards can become an environmentally friendly alternative energy source, a source of livelihood, and will certainly have a positive impact on waste management on the campus of the University of North Sumatra.

Bio-irrigation Promotes Reactive Phosphorus Recycling in an Oxidized Sedimentary Environment

Bio-irrigation by burrowing macrofauna regulates benthic functioning via direct and indirect effects on sediment properties, microbial activities, oxygen dynamics, and organic matter and nutrient turnover. The effects of macrofauna bio-irrigation on benthic nitrogen cycling have been thoroughly investigated, whereas those on phosphorus (P) are comparatively understudied. This is surprising as such effects contribute to sediment oxidation and have a large potential to regulate P mobility and increase P retention. Dissolved oxygen (O2) and inorganic phosphorus (DIP) fluxes, pore water chemistry (DIPpw, Fe[II]pw, Mn[II]pw, pHpw, and oxidation–reduction potential (ORPpw)), and solid-phase Fe(III) pools were measured in reconstructed sediments without or with surface (the amphipod Corophium volutator) and deep (the polychaete Alitta succinea) burrowing macrofauna. Sediments and burrowing macrofauna were collected from the Goro Lagoon (Po River Delta, Italy) in April 2022. Measurements were carried out after a 2-week preincubation to allow sediment conditioning by bioturbators (e.g., burrow construction, bio-irrigation, burrow wall oxidation, steady chemical gradients within sediments and between pore and bottom waters). ORPpw analysis suggested that bio-irrigated sediments were less reduced, and Fe solid-phase analysis suggested a tendency towards an increase in the Fe(III) pool in deep bio-irrigated sediments. Both bioturbators stimulated O2 fluxes and DIP recycling (by a factor of ~ 2), and halved DIPpw, Fe(II)pw, and Mn(II)pw concentrations. The amphipod contributed to DIP fluxes via direct excretion, whereas polychaete excretion was negligible. Polychaetes contributed to DIP fluxes by ventilation of deep burrows within DIP-rich pore water. Bio-irrigation by both burrowers simultaneously promoted higher DIP recycling and sediment oxidation, ensuring the mobilization of a limiting nutrient and preventing the accumulation of reduced chemical species in the surface sediment.

Second Language Teaching in the Digital World: Why We Need Digital Technologies?

Technology and science are developing at an unprecedented pace nowadays, and digital technology in particular has largely improved the tools and ways available to investigate new pedagogical approaches. The paper demonstrates how the advent of contemporary information and communication technology has influenced second language teaching, resulting in a shift away from the conventional teacher-centered and text-bound classrooms into interactive and student-centered paradigms. Also, the large potential and unique advantages of digital technologies have been analyzed, compared with some difficulties teachers and students meet during second language learning process in traditional language classes. However, digital tools are not a panacea which also require careful design and consideration. Therefore, the paper also puts forward several practical ways to bring the largest efficacy of digital technology on second language learning.