Composition Distribution Research Articles

The Microstructure and Wear Properties of Ni-coated and Agglomerated-Sintered WC-10Ni/316 Composite by Laser Melting Deposition

WC-10Ni particle-reinforced stainless steel matrix composites have potential applications in aerospace, energy engineering, automotive manufacturing, and marine engineering equipment. However, there is currently insufficient research on the integrated manufacturing and comparative analysis of Ni-coated (WC-10Ni)1.5/316 and agglomerated-sintered (WC-10Ni)1.5/316 composites using Laser Melting Deposition (LMD) technology. In this work, the fabrication and examination of the LMDed specimens are conducted to determine the influence of the forming process of particle reinforcement on the microstructure and wear properties of WC-10Ni/316 composites. The microstructure, phase composition, composition distribution, microhardness, and wear resistance of the two composites were comparatively analyzed using confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), microhardness tester, X-ray diffraction(XRD), energy-dispersive spectroscopy (EDS), and a reciprocating wear tester. The results indicate that the microstructure of Ni-coated (WC-10Ni)1.5/316 composite specimen contains a higher quantity of undecomposed Ni-coated WC-10Ni particles, with a lower proportion of precipitates, and dendrites predominantly exhibit an elongated dendrite morphology. In contrast, the agglomerated-sintered (WC-10Ni)1.5/316 composite specimen features a greater content of decomposed agglomerated-sintered WC-10Ni particles, a higher content of precipitates, and dendrites mainly present as slender dendrites. Both composites consist of phases such as γ-(Fe, Ni, Cr), WC, W2C, Fe6W6C, M6C, and Cr23C6. The undecomposed WC-10Ni particles and tungsten precipitates significantly enhance the microhardness and wear resistance of the specimen. Specifically, the Ni-coated (WC-10Ni)1.5/316 composite specimen displays a microhardness of 350.2±3.3 HV1.0, with a wear rate of 1.5797±0.0455mg/(N·km). Meanwhile, the Agglomerated-sintered (WC-10Ni)1.5/316 composite specimen reveals an average microhardness of 410.9±6.1 HV1.0 and a wear rate of 0.8057±0.0352mg/(N·km).

Visualization of Anion Vacancy Defect Annihilation in CZTSe Solar Cells by Hydrogen-Assisted Selenization with In Operando X-ray Nanoprobe Studies.

The traditional sulfur selenization process in Cu2ZnSn(S,Se)4 (CZTSSe) solar cell fabrication often results in the creation of localized anion vacancies (VS and VSe). These vacancies are considered harmful defects as they can trap carriers generated by light, leading to reduced solar cell efficiency. Moreover, concrete evidence has been lacking on the extent of the impact caused by these anion vacancies. Our research introduces a novel approach: the hydrogen-assisted selenization (HAS) process, specifically designed to minimize localized anion vacancies in Cu2ZnSnSe4 (CZTSe) solar cells. Our investigation, utilizing current-voltage (I-V) and admittance spectroscopy measurements, provides clear insights. We observed notable improvements in carrier collection efficiency and a discernible reduction in defect states. Furthermore, there was a significant decrease in the activation energy required within the solar cell device, dropping from 184 to 145 meV. To delve deeper into the structural and compositional aspects, we employed synchrotron-based X-ray nanoprobes. Through nanoscale X-ray fluorescence and hard X-ray beam-induced current measurements, we can directly observe and document the relationship between the local compositional distribution and photocurrent activity in operando. These comprehensive results furnish strong evidence that mitigating anion vacancies in the CZTSe layer can substantially improve the power conversion efficiency of the CZTSe solar cells. This advancement not only sheds light on the critical role of anion vacancies in solar cell performance but also underscores the effectiveness of the HAS process in enhancing overall device efficiency.

The effect of filler distribution on electromagnetic properties of nanocarbon/magnetic particles/polymer composites

The type of multi-component fillers and their spatial distribution in conductive polymer-based composites greatly influenced their electrical properties, electromagnetic shielding efficiency (SE), and absorption capability, which require a deep understanding of how these properties improve with changes in the phase composition, content, and distribution of these fillers in the composite. In this study, three-phase polymer composite materials (CMs) with random (epoxy-based) and segregated (polyethylene-based) distribution of nanocarbon (graphite nanoplatelets GNP and carbon nanotubes CNTs) and magnetic (Fe and Co3O4) fillers have been developed. It was found that permittivity εr′ in the frequency range (40–60 GHz) increases sufficiently with the nanocarbon content and their values are slightly higher for random GNP-filled CMs (εr′=10–15 for 3–5 wt. % GNP) compared to CNT-filled CMs and much higher compared to segregated CMs (εr′=4–7 for 3–5 wt. % of nanocarbon). Dielectric loss tangent tanδ is increased with the nanocarbon content (especially for Fe-filled CMs) and sufficiently higher in segregated CMs compared to similar random composites. These enhanced tanδ values correlate with higher electromagnetic shielding efficiency due to absorption of segregated nanocarbon/magnetic/polyethylene CMs, for example, SEAd ≈ 18–23 dB/mm for 5 wt. %GNP. The most preferable for microwave absorption are random and segregated CMs with 2–3 wt. % GNP/30 wt. % magnetic filler: RLmin = −(27–35) dB, effective absorption bandwidth (EAB) Δf10dB=11.5–12.5GHz at a sample thickness of 0.5–0.7 mm. In CNT-based segregated CMs, |RLmin| and EAB values are lower compared with GNP-based CMs. The ability to manipulate these characteristics is important for obtaining good shielding and absorptive properties in the microwave range of electromagnetic radiation.

Mouse Models Enable the Functional Investigation of Tertiary Lymphoid Structures in Cancer.

Tertiary lymphoid structures (TLSs) are organized lymphoid aggregates that form within nonlymphoid tissue, including tumors, in response to persistent inflammatory stimulation. In cancer patients, TLSs are generally associated with positive clinical outcomes. However, the cellular composition and spatial distribution of TLSs can vary depending on the underlying disease state, complicating interpretations of their prognostic significance. Murine models are indispensable for providing a deeper insight into the mechanisms involved in TLS formation and function. Studies using these models can complement current clinical efforts to characterize TLSs via genetic sequencing and histopathology of human samples. Several features of TLSs resemble that of secondary lymphoid organs (SLOs). Consequently, vascular system components and structural support elements are important for TLS formation and maintenance. Furthermore, TLSs in different tissue environments can exhibit distinct characteristics, necessitating careful consideration when selecting mouse models for study. Herein, we discuss critical aspects to consider when modeling TLSs and describe recent findings of TLS studies in the mouse lung and intestinal gut environments as examples to highlight the importance of considering tissue-specific regulatory mechanisms for TLSs. In this chapter, we also summarize the mechanistic insights derived from murine models on the formation and function of TLSs, which may translate to the future therapeutic modulation of TLS in disease.

Solvent-Dependent Sequence-Controlled Copolymerization of Lactones: Tailoring Material Properties from Robust Plastics to Tough Elastomers.

Copolymerization stands as a versatile and potent method for tailoring polymer properties by adjusting structural unit composition and sequence distribution. However, achieving sequence-controlled copolymerization in a one-step and one-pot process remains challenging. This study introduces a solvent-dependent sequence-controlled copolymerization strategy to produce block and statistical copolyesters from 4-phenyl-2-oxabicyclo[2.1.1]hexan-3-one (4Ph-BL) and ε-caprolactone (ε-CL). The distinct kinetics of the two monomers enable the facile synthesis of diblock and triblock copolyesters, PCL-b-P(4Ph-BL) and P(4Ph-BL)-b-PCL-b-P(4Ph-BL), in non-coordinating solvents, such as dichloromethane and toluene. Conversely, coordinating solvents like tetrahydrofuran, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, 1,4-dioxane, and 1,2-dimethoxyethane facilitate frequent transesterifications, yielding statistical copolyesters P[CL-stat-(4Ph-BL)] with varying ratios of heterosequences. Density functional theory (DFT) calculations confirmed that coordinating solvents stabilize the transition state for transesterification, thereby validating their role in triggering this process. By varying the microstructures and compositions, the resultant copolyesters display tunable thermal and mechanical properties, evolving from robust plastics with an ultimate tensile strength of up to 46.3 ± 3.1 MPa to tough elastomers with >99.3% elastic recovery. All the copolyesters exhibit remarkable thermal stability (Td,5% = 376 °C) and maintain desirable chemical circularity (>92%), supporting a closed-loop life cycle for sustainable material economy.

Solvent‐Dependent Sequence‐Controlled Copolymerization of Lactones: Tailoring Material Properties from Robust Plastics to Tough Elastomers

Copolymerization stands as a versatile and potent method for tailoring polymer properties by adjusting structural unit composition and sequence distribution. However, achieving sequence‐controlled copolymerization in a one‐step and one‐pot process remains challenging. This study introduces a solvent‐dependent sequence‐controlled copolymerization strategy to produce block and statistical copolyesters from 4‐phenyl‐2‐oxabicyclo[2.1.1]hexan‐3‐one (4Ph‐BL) and ε‐caprolactone (ε‐CL). The distinct kinetics of the two monomers enable the facile synthesis of diblock and triblock copolyesters, PCL‐b‐P(4Ph‐BL) and P(4Ph‐BL)‐b‐PCL‐b‐P(4Ph‐BL), in non‐coordinating solvents, such as dichloromethane and toluene. Conversely, coordinating solvents like tetrahydrofuran, 2‐methyltetrahydrofuran, 2,5‐dimethyltetrahydrofuran, 1,4‐dioxane, and 1,2‐dimethoxyethane facilitate frequent transesterifications, yielding statistical copolyesters P[CL‐stat‐(4Ph‐BL)] with varying ratios of heterosequences. Density functional theory (DFT) calculations confirmed that coordinating solvents stabilize the transition state for transesterification, thereby validating their role in triggering this process. By varying the microstructures and compositions, the resultant copolyesters display tunable thermal and mechanical properties, evolving from robust plastics with an ultimate tensile strength of up to 46.3 ± 3.1 MPa to tough elastomers with >99.3% elastic recovery. All the copolyesters exhibit remarkable thermal stability (Td,5% = 376 °C) and maintain desirable chemical circularity (>92%), supporting a closed‐loop life cycle for sustainable material economy.

The Effect of Season and The Implications For Sustainable Fisheries on The Catch Results of Yellowfin Tuna In Indonesia

This study assessed the purse seine, handline and pole and line catches at PPS (Samudera Fishing Port Kendari) specifically targeting skipjack and yellowfin tuna in the Banda Sea. Although there has been a rise in tuna output over the past two years, the examination of fish size in September until November revealed substantial fluctuation. Additionally, the implementation of the moratorium policy had a detrimental effect. Ensuring the sustainability of fisheries in the Banda Sea, particularly for large pelagic fish like skipjack and yellowfin tuna, necessitates the implementation of adaptive management and selective fishing practices, with a particular focus on enforcing mesh size regulations. The aims of this study were to examine the patterns of tuna fisheries landing at PPS, specifically focusing on the sorts of catches made using purse seine, handline, and pole and line fishing methods. Additionally, the study aimed to assess the length frequency distribution of Thunnus albacares caught using purse seine, handline, and pole and line fishing gear. The methodology offers a thorough framework for eval_uating the sustainability of Thunnus albacares fisheries in PPS Kendari. Policymakers can develop effective management plans for long-term resource sustainability by assessing catch composition, productivity, and size distribution across various fishing gears. The analysis of this study conducted in September - November 2023 revealed that the fish catches varied in size, ranging from 13 cmFL to 124 cmFL.

Direct Recycling of LixNi0.5Mn0.3Co0.2O2 from Production Scrap and End‐Of‐Life Batteries, Using Solid‐State Relithiation

AbstractDirect recycling of Li‐ion battery cathodes offers a sustainable and potentially cost‐effective alternative to conventional methods, often involving complex chemical processes and significant material losses. This study focuses on the relithiation of cathode materials from quality control reject (QCR) and end‐of‐life (EoL) Li‐ion cells to restore their physical structure, morphology, and electrochemical performance. Two NMC532/graphite pouch cells from the same manufacturer were studied. QCR cells, stored under ambient conditions, experienced corrosion and degradation before recycling, while EoL cells were cycled to the end of life. The cells were disassembled, and the cathode materials were delaminated using NaOH solution, then relithiated with LiOH at 700 °C for 15 hours in the air. Extensive characterization analyzed elemental composition, structural properties, thermal stability, and particle size distribution. Results indicated that relithiation successfully restored lithium content and improved the structural ordering and morphology of the cathode materials. The electrochemical performance of the relithiated cathodes exhibited good stability over 100 charge‐discharge cycles. The relithiated QCR samples achieved a capacity of 155.57 mAh g−1, while EoL samples reached 152.53 mAh g−1, comparable to pristine materials. This study highlights relithiation's potential to extend the lifecycle of Li‐ion cathodes, contributing to a more sustainable circular economy for battery materials.

Improvement of superconducting, morphological, and flux pinning ability of YBa2Cu3O7−y matrix with oxygen and Mn2O3 impurity

Abstract In the current work, the influence of oxygen and Mn2O3 impurity levels intervals 0.00 ≤ x ≤ 0.30 on various key properties such as electrical resistivity, superconducting, flux pinning ability, stabilization of ceramic system, and morphological properties of YBa2Cu3O7-y (Y-123) superconductor were examined by electrical resistivity, critical current density, and scanning electron microscopy (SEM), electron dispersive x-ray (EDX) measurements. The EDX test results indicated that all the Y-123 ceramics produced possessed different composition distributions on the sample surface. SEM photomicrographs also confirmed the improvement in the appearance of surface morphology and crystallinity quality of the YBa2Cu3O7-y system. Moreover, the development in the interaction quality between grains, pinning ability and strength quality of 2D coupled vortices was obtained with the oxygen ambient and optimum manganese impurity addition highly dispersing throughout the intra grain and inter-grain boundary couplings due to the increase in the artificial flux pinning nucleation sites in the Y-123 system. Thus, the best sample with the highest Jc value of 98 A/cm2 showed the most resistance to the applied magnetic field and current. Similarly, the same sample exhibited the greatest superconductive offset (98.320 K) and onset (100.504 K) temperatures values based on the development of the Cu-O coordination and stability of the crystal structure. In conclusion, this comprehensive study based on the analysis of oxygen and Mn2O3 impurity addition mechanism through the YBa2Cu3O7-y ceramic matrix may open a new and applicable field for advanced engineering, heavy industry technology and large-scale applications.

Probabilistic shaping probability distribution scrambling based on a chaotic system for integrating secure transmission and adaptive key updating

A probabilistic shaping probability distribution scramble (PSPDS) scheme based on chaotic systems is proposed to fulfill both secure transmission and adaptive key updating. The chaotic Chen and logistic systems are adopted to generate a chaotic random sequence. The probabilistic shaping is achieved by constant composition distribution matching (CCDM) and probabilistic amplitude shaping architecture. The chaotic, random sequences are used to scramble the probability distribution of CCDM, improving security. The session key is embedded into a probability distribution. The legal receiver extracts the error-free session key when OSNR is higher than the requirement of the forward error correction threshold. We employ a coherent OFDM 16QAM transmission experiment on 120 km fiber, confirming our proposed scheme with a net rate of 9.95 Gbit/s. The results show that the PSPDS scheme has no encryption penalty compared with the baseline without encryption. The key updating rate has the ability to vary adaptively and reaches 224.2 Mbit/s by adjusting the block length of CCDM in our experiment. The key space reaches 10136. Even if an illegal party obtains a ciphertext signal, the plaintext and session key can hardly be inferred due to a probability distribution scramble.

Multicore@shell nanoparticle synthesis from a single multicomponent target by gas aggregation source

Synthesis of multifunctional nanomaterials is known as a critical challenge in advanced nanoscience. Multicore@shell nanostructures are generated here via a gas phase synthesis approach. To achieve this objective, we used conventional DC magnetron sputtering in conjunction with a gas aggregation chamber. We employed a customized Au-Ti target to produce metal-metal oxide multicore@shell nanoparticles (NPs) with tunable properties. The deposited NPs were characterized with regard to their chemical composition, morphology, structural status, NP size distribution and optical properties. The obtained data clearly confirms that the crystalline Au cores are encapsulated in a TiOx matrix in each individual NP. Furthermore, the chemical composition and size distribution of the NPs can be affected by the operating pressure. Our approach provides a versatile route with many different possibilities to synthesize multicore@shell NPs from a variety of composite targets for well-desired applications including environmental, optical/plasmonic, and energy.

When LAMOST meets Gaia DR3. Exploring the metallicity of open clusters

Open clusters (OCs) are excellent probes as their age and abundance can be tightly constrained, allowing us to explore the distribution of metallicity and composition across the disk of the Milky Way. By conducting a comprehensive analysis of the metallicity of OCs, we can obtain valuable information about the history of their chemical enrichment. Moreover, by observing stars in different regions of the Milky Way, we can identify significant spatial structures in their chemical composition and abundance. This enables us to understand stellar birth radii through chemical tagging. Nevertheless, it remains challenging to infer the original positions of OCs using current data alone. The aim of this study is to investigate the distribution of metallicity in the solar neighborhood using a large dataset from Gaia DR3 combined with LAMOST spectra. With accurate ages and metallicity measurements, we can determine birth radii for the stars and attempt to understand their migration pattern. We chose a total of 1131 OCs within 3 Kpc of the Sun from the Gaia DR3 and LAMOST DR8 low-resolution spectral database (R=1800). We used an artificial neural network to correct the LAMOST data by incorporating high-resolution spectral data from GALAH DR3 (R=28000). The average metallicity of the OCs was determined based on the reliable Fe/H values for their members. We then examined the distribution of metallicity across different regions within the Galaxy and inferred birth radii of the OCs from their age and metallicity. The correction method presented here can partially eliminate the systematic offset for LAMOST data. We discuss the metallicity trend as a function of Galactocentric distance and the guiding radii. We also compare these observational results with those from chemo-dynamic simulations. Values derived from observational metallicity data are slightly lower than predicted values when the uncertainties are not considered. However, the metallicity gradients are consistent with previous calculations. Finally, we investigated the birthplace of OCs and find hints that the majority of OCs near the Sun have migrated from the outer Galactic disk.

미호강 유역 구석기시대 주먹도끼류의 출토 맥락 - 청주지역 내 유적을 중심으로

The excavated contexts on the handaxes of paleolithic from Cheongju City in the Miho River basin were identified through a geoarchaeological approach. The handaxes are mostly concentrated on the slopes and slope ends of hilly mountains within 50m above sea level adjacent to floodplains. They are also found on some floodplain flats and in the mountains. These features are subject to slope and fluvial deposits. At the sites, fluvial deposits formed at MIS 3 and MIS 5. The slope deposits were deposited repeatedly, some rapidly. The slopes are related with MIS 2~MIS 4, and the ends of slope with MIS 2~MIS 5. Some Paleolithic artifacts are recovered from fluvial deposits, but most are found within the slope deposits. The handaxes are excavated from five layers. First. The dark brown clay layer with a developed upper soil wedge: the end of MIS 3. Second, the layer under the dark brown clay layer with grain size roughening and a reddish tint: the second half of MIS 3. Third, the layer within the fluvial deposits under the dark brown clay layer: the second half of MIS 3. Fourth, the reddish-brown clay layer with a developed lower soil wedge and the layers under it: the first half of MIS 3~MIS 5, Lastly, the layers in the flowing water deposition under the reddish-brown clay layer: the first half of MIS 3 or earlier. Thus, the handaxes are related with the MIS 5 to MIS 3. The artifact composition and spatial distribution varied between sites as the influence of slope deposits. In addition, Differences in micro-environments and temporal gaps, including differences in the energy of slope deposition between sites, had different effects on sites formation and post-depositional processes.

Machine learning assisted crystallographic reconstruction from atom probe tomographic images

Atom probe tomography (APT) is a powerful technique for three-dimensional (3D) atomic-scale imaging, enabling the accurate analysis on the compositional distribution at the nanoscale. How to accurately reconstruct crystallographic information from APT data, however, is still a great challenge due to the intrinsic nature of the APT technique. In this paper, we propose a novel approach that consists of the modified forward simulation process and the backward machine learning process to recover the tested crystal from APT data. The high-throughput forward simulations on Al single crystals of different orientations generate 10 000 original 3D images and data augmentation is implemented on the original images, resulting in 100 000 3D images. The big data allows the development of deep learning models and three deep learning algorithms of Convolutional Neural Network (CNN), Vision Transformer (ViT), and Variational Autoencoder (VAE) are used in the backward process. After training, the ViT model performs superior than the CNN and VAE models, which can recover the crystalline orientation outstandingly, as evaluated by the coefficient of determinationR2and the Mean Percent Error (MPE), viz.,R2= 0.93 and MPE = 0.43%,R2= 0.97 and MPE = 0.35%, andR2= 0.93 and MPE = 0.77% for the rotation anglesϕ,ψandθ, respectively, on the test dataset. The present work clearly demonstrates the capability of deep learning models in the recovery of the tested crystals from APT data, thereby paving the way for the further development of large artificial intelligent models of APT.

Effect of Mg on Plasticity and Microstructure of Al-Mg-Ga-Sn-In Soluble Aluminum Alloy.

Soluble aluminum alloy materials used in underground operational tools are synthesized via a high-temperature smelting process. The microstructure and composition distribution of the alloy were analyzed using X-ray diffraction, metallographic microscopy, and scanning electron microscopy with energy-dispersive X-ray and electron backscatter diffraction techniques. The mechanical properties were evaluated using a universal testing machine and hardness tester, while solubility assessments were conducted in a constant-temperature water bath. This study focuses on the plasticity and dissolution characteristics of Al-Mg-Ga-Sn-In alloys with varying Mg contents. The tensile strength (σb) of the alloy was 181.99 MPa, with an elongation (δ) of 27.49% and cross-sectional shrinkage (φ) of 11.67% at a magnesium content of 3.0 wt.%. Additionally, in the compressive test, the compressive yield strength (σsc) was recorded at 188.32 MPa, while the compression rate (δ) was 27.06% and the section expansion rate (φ) was 138.66%. Furthermore, the alloy demonstrated the ability to dissolve spontaneously in water at 90 °C, exhibiting an average dissolution rate of 1.0 g·h-1cm-2 and a maximum dissolution rate of 3.25 g·h-1cm-2 after 12.0 h. Consequently, this alloy composition not only satisfies the requirements for rapid solubility but also exhibits favorable plasticity, providing a novel reference for the selection of soluble aluminum alloy materials.

Temperature-enhanced effects of iron on Southern Ocean phytoplankton

Abstract. Iron (Fe) is a key limiting nutrient for Southern Ocean phytoplankton. Input of Fe into the Southern Ocean is projected to change due to global warming, yet the combined effects of a concurrent increase in temperature with dissolved Fe (dFe) addition on phytoplankton growth and community composition have not been extensively studied. To improve our understanding of how Antarctic phytoplankton communities respond to Fe and enhanced temperature, we performed four full factorial onboard bioassays under trace-metal-clean conditions with phytoplankton communities from different regions of the Weddell Sea and the Amundsen Sea in the Southern Ocean. Treatments consisted of 2 nM Fe addition with 2 °C warming (TF), Fe addition at in situ temperature (F) +2 °C warming with no Fe addition (T) and a control at in situ temperature with no Fe addition (control, C). Temperature had a limited effect by itself but boosted the positive response of the phytoplankton to Fe addition. Photosynthetic efficiency, phytoplankton abundances and chlorophyll a concentrations typically increased (significantly) with Fe addition (F and/or TF treatment), and the phytoplankton community generally shifted from haptophytes to diatoms upon Fe addition. The < 20 µm phytoplankton fraction displayed population-specific growth responses, resulting in a pronounced shift in community composition and size distribution (mainly towards larger-sized phytoplankton) for the F and TF treatments. Such a distinct enhanced impact of dFe supply with warming on Antarctic phytoplankton size, growth and composition will likely affect trophic transfer efficiency and ecosystem structure, with potential significance for the biological carbon pump.

Precipitation–Flotation Process for Molybdenum and Uranium Separation from Wastewater

The mining of molybdenum and uranium ores inevitably results in the generation of large volumes of wastewater containing low concentrations of metals, which poses significant threats to the environment. This study presents a novel precipitation–flotation process for the simultaneous separation of molybdenum and uranium from wastewater. A systematic investigation was conducted on the impacts of the type of precipitant, flotation reagent type, and flotation parameters on the experimental results. Ferric salt served better as a precipitant than aluminum salt and humic acid did, and sodium dodecyl sulfate (SDS) was more suitable than sodium dodecyl benzene sulfonate for acting as a surfactant and foaming agent. Under specific conditions, including a pH of 6.6, an Fe3+ dosage of 0.6 mmol·L−1, an SDS dosage of 40 mg·L−1, an air flow rate of 25 mL·min−1, and a flotation time of 10 min, the removal efficiencies of molybdenum and uranium reached 96.6% and 93.6%, respectively. After flotation, the molybdenum concentration, uranium concentration, chemical oxygen demand, and turbidity of the treated water all meet the emission standards. Furthermore, the metal removal mechanisms, including the particle size distribution, functional group structure, surface element composition, microstructure, and element distribution, were elucidated on the basis of characterization of the precipitation–flotation products.

Temporal variability and predictability predict alpine plant community composition and distribution patterns.

One of the most reliable features of natural systems is that they change through time. Theory predicts that temporally fluctuating conditions shape community composition, species distribution patterns, and life history variation, yet features of temporal variability are rarely incorporated into studies of species-environment associations. In this study, we evaluated how two components of temporal environmental variation-variability and predictability-impact plant community composition and species distribution patterns in the alpine tundra of the Southern Rocky Mountains in Colorado (USA). Using the Sensor Network Array at the Niwot Ridge Long-Term Ecological Research site, we used in situ, high-resolution temporal measurements of soil moisture and temperature from 13 locations ("nodes") distributed throughout an alpine catchment to characterize the annual mean, variability, and predictability in these variables in each of four consecutive years. We combined these data with annual vegetation surveys at each node to evaluate whether variability over short (within-day) and seasonal (2- to 4-month) timescales could predict patterns in plant community composition, species distributions, and species abundances better than models that considered average annual conditions alone. We found that metrics for variability and predictability in soil moisture and soil temperature, at both daily and seasonal timescales, improved our ability to explain spatial variation in alpine plant community composition. Daily variability in soil moisture and temperature, along with seasonal predictability in soil moisture, was particularly important in predicting community composition and species occurrences. These results indicate that the magnitude and patterns of fluctuations in soil moisture and temperature are important predictors of community composition and plant distribution patterns in alpine plant communities. More broadly, these results highlight that components of temporal change provide important niche axes that can partition species with different growth and life history strategies along environmental gradients in heterogeneous landscapes.

Assessing personalized molecular portraits underlying endothelial-to-mesenchymal transition within pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive and rapidly fatal disease with an intricate etiology. Identifying biomarkers for early PAH lesions based on the exploration of subtle biological processes is significant for timely diagnosis and treatment. In the present study, nine distinct cell populations identified based on gene expression profiles revealed high heterogeneity in cell composition ratio, biological function, distribution preference, and communication patterns in PAH. Notably, compared to other cells, endothelial cells (ECs) showed prominent variation in multiple perspectives. Further analysis demonstrated the endothelial-to-mesenchymal transition (EndMT) in ECs and identified a subgroup exhibiting a contrasting phenotype. Based on these findings, a machine-learning integrated program consisting of nine learners was developed to create a PAH Endothelial-to-mesenchymal transition Signature (PETS). This study identified cell populations underlying EndMT and furnished a potential tool that might be valuable for PAH diagnosis and new precise therapies.

Numerical Optimization of Functionally Graded Ti-HAP Material for Tibial Bone Fixation System.

Functionally graded materials (FGMs) are heterogeneous composites characterized by outstanding properties. They are built from two or more components with a gradient distribution of chemical composition along a given direction. A promising graded material for biomedical engineering as an implant could be a FGM made of titanium (Ti) and hydroxyapatite (HAP). It would allow us to counteract the difference between the stiffness modulus of pure titanium and bone tissue. Moreover, it can be a good solution to the problem of stress shielding for bone fixation plates made of conventional titanium or steel. The presented paper aims to perform micromechanical modeling and optimization of a functionally Ti-HAP graded plate, followed by numerical analysis of a fractured tibia stabilization system under specific boundary conditions. Finite element analysis was performed using ANSYS Workbench 2021 software. The models of the FGM plate and tibial fixation system were made using the Space Claim tool. The ANSYS software allowed the optimization of the model considered and the selection of the appropriate structural parameters of the FGM Ti-HAP material. In general, the results proved that the osteosynthesis plate built of graded Ti-HAP material resulted in lower bone stress compared to titanium and steel plates. The results obtained confirmed the validity of the design and the possibility to use functionally graded Ti-HAP bone fixation plates.