Hasil untuk "Materials Science"

Theodore L. Brown

H. Bönnemann, R. Richards

The CMS collaboration, V. Chekhovsky, A. Hayrapetyan et al.

Abstract A search for nonresonant new physics phenomena in high-mass dilepton events produced in association with b-tagged jets is performed using proton-proton collision data collected in 2016–2018 by the CMS experiment at the CERN LHC, at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 138 fb −1. The analysis considers two effective field theory models with dimension-six operators; involving four-fermion contact interactions between two leptons (ℓℓ, electrons or muons) and b or s quarks (bbℓℓ and bsℓℓ). Two lepton flavor combinations (ee and μμ) are required and events are classified as having 0, 1, or ≥2 b-tagged jets in the final state. No significant excess is observed over the standard model backgrounds. Upper limits are set on the production cross section of the new physics signals. These translate into lower limits on the energy scale Λ of 6.9 to 9.0 TeV in the bbℓℓ model, depending on model parameters, and on the ratio of energy scale and effective coupling, Λ/g *, of 2.0 to 2.6 TeV in the bsℓℓ model. Lepton flavor universality is also tested by comparing the dielectron (ee) and dimuon (μμ) mass spectra for different b-tagged jet multiplicities. No significant deviation from the standard model expectation of unity is observed.

Stephen M. Budy, Scott T. Iacono

Abstract The development of conductive polymer composites is critical for advancing low-cost, flexible electrochemical sensors. In this study, carbon black-polyvinylidene fluoride (CB-PVDF) composites were fabricated using various processing methods, extrusion, injection molding, spin coating, and solution casting, to investigate the relationship between morphology, crystallinity, and electrochemical performance in sensor applications. Structural integrity of the PVDF matrix was confirmed via NMR spectroscopy, with FTIR and Raman analyses revealing the presence of multiple crystalline phases and minor spectral shifts due to carbon black addition. Thermal analysis via TGA and DSC showed high thermal stability across all composites, with degradation temperatures remaining above 430 °C and crystallinity varying by processing method. Scanning electron microscopy (SEM) revealed significant differences in carbon black dispersion, with solution-processed films demonstrating more uniform distribution compared to thermally processed samples. Electrochemical sensor analysis using cyclic voltammetry (CV) indicated that sanded extruded CB-PVDF fibers exhibited the highest electroactive surface area (23.8 m2/g) and the most consistent redox activity across a range of solvents, outperforming injection molded and solution cast films. These results highlight the critical role of processing in tailoring composite properties and identify sanded extruded CB-PVDF fibers as a promising platform for high-performance electrochemical sensor applications.

Melissa Ariza Gonzalez, Supawitch Hoijang, Dang B. Tran et al.

Recent advancements in nanotechnology and materials science have enabled the development of magnetic photocatalysts with improved efficiency, stability, and reusability, offering a promising approach for wastewater treatment. The integration of magnetic nanoparticles (MNPs) into photocatalytic processes has gained significant attention as a sustainable method for addressing emerging pollutants—such as antibiotics and pharmaceutical compounds—which pose environmental and public health risks, including the proliferation of antibiotic resistance. Surface modification techniques, specifically applied to MNPs, are employed to enhance their photocatalytic performance by improving surface reactivity, reducing nanoparticle agglomeration, and increasing photocatalytic activity under both visible and ultraviolet (UV) light irradiation. These modifications also facilitate the selective adsorption and degradation of target contaminants. Importantly, the modified nanoparticles retain their magnetic properties, allowing for facile separation and reuse in multiple treatment cycles via external magnetic fields. This review provides a comprehensive overview of recent developments in surface-modified MNPs for wastewater treatment, with a focus on their physicochemical properties, surface modification strategies, and effectiveness in the removal of antibiotics from aqueous environments. Furthermore, the review discusses advantages over conventional treatment methods, current limitations, and future research directions, emphasizing the potential of this technology for sustainable and efficient water purification.

Qing Liao, Ke Hu, Haihua Zhang et al.

Sunho Jeong, Young-Geun Ha, Jooho Moon et al.

P. May

Xingyi Gan, Guang Yao, Cunbo Li et al.

Abstract Chronic ophthalmic diseases are multivariate, time-varying, and degenerative. Smart contact lenses have emerged as a scalable platform for noninvasive ocular signal detection and disease diagnosis. However, real-time monitoring and decoupling of multiple ocular parameters, particularly when the eyes are closed, remain challenging in clinical medicine. In this work, we propose a stretchable bimodal contact lens (BCL) amalgamating self-decoupled electromagnetic capacitive intraocular pressure (CIOP) and magnetic eye movement (MEM) monitoring components. The sandwich-integrated BCL can be intimately attached to the eyeball, enabling closed-eye, wireless, and precise signal acquisition without interference. During the eye open and closed, the serpentine-geometry CIOP unit was validated on a rabbit model, achieving supered resolution (1 mmHg) and sensitivity (≥0.22 MHz mmHg−1) for reversible hypo- to hyper-IOP fluctuations. Ex vivo and in vivo MEM monitoring, based on composition-optimized magnetic interlayer film, demonstrated exceptional accuracy (≥97.25%) with eyes open and closed, surpassing existing methods. The collected CIOP and MEM data could be wirelessly aggregated and transmitted to portable devices via integrated acquisition modules within frame glasses for real-time eye healthcare. Emerging noninvasive and bimodal modalities reconcile the trade-off between minimal discomfort, eye status, and reliable measurement, spurring the widespread adoption of the integrated monitoring system for continuous ocular health monitoring.

Pengran Liu, Dan Zhang, Yufei Chen et al.

Objective: The high rates of missed diagnosis and misdiagnosis limit the diagnosis of femoral neck fracture (FNF), which requires a new method to assist doctors to get more accurate diagnosis of FNF. This study aims to estimate the ability of AI in the detection of FNF and further compare its performance with human level. And the performance of AI-aided human level is also explored to confirm the value of AI as an assistant for clinical doctors to detect the FNF. Materials and methods: 4477 hip X-rays (consisted of 2884 FNF X-rays and 1593 normal hip X-rays) from eight Chinese top tree hospitals (Union Hospital, Tongji Medical College, Huazhong University of Science and Technology (Wuhan Union Hospital), Wuhan Pu'ai Hospital, Tianyou Hospital, Wuhan University of Science and Technology, Hanyang Hospital, Wuhan University of Science and Technology, Northern Jiangsu People's Hospital, Xiangya Changde Hospital, People's Hospital of Tibet Autonomous Region and the Second Affiliated Hospital of Soochow University) were collected to establish a large multi-center clinical sample database. Then the X-rays were labeled, and the database was divided into training dataset (4029 X-rays) and testing dataset (448 X-rays). A Faster RCNN model with three different backbones (VGG16, VGG16-nottop and Resnet 50) was set up and trained with the training dataset, then the diagnostic performance of the Faster RCNN was assessed by the testing dataset and further compared with five doctors, in the form of accuracy, sensitivity, specificity, missed diagnosis rate, misdiagnosis rate, positive predictive value (PPV), negative predictive value (NPV), and time consumption. The result of the backbone with best performance was further set as reference for the doctor to diagnose the testing dataset again to confirm the value of AI as an assistant to detect the FNF. Results: Faster RCNN with Resnet 50 performed best compared with the other two backbones (VGG16 performed lowest, VGG16-nottop performed at medium level) in accuracy (0.82 vs 0.58 and 0.76), sensitivity (0.93 vs 0.83 and 0.94), specificity (0.62 vs 0.12 and 0.43), missed diagnosis rate (0.07 vs 0.17 and 0.06), misdiagnosis rate (0.38 vs 0.88 and 0.57), PPV (0.82 vs 0.63 and 0.75), NPV (0.82 vs 0.28 and 0.81) and time consumption (0.02h vs 0.04 h and 0.03h). And compared with human level, the Faster RCNN with Resnet 50 expressed better ability in terms of accuracy, sensitivity, missed diagnosis rate, NPV and time consumption, and worse ability in specificity and misdiagnosis rate. As for the PPV, there was not significant difference. Under the assistance of Faster RCNN with Resnet 50, the human level was enhanced in all aspects. Conclusion: As a new application of intelligent medicine, AI can be qualified in the detection of FNF, and can also be an excellent assistant for clinical doctors to improve the diagnosis of FNF.

Srinivasa Kartik Nemani, Nicola Gilli, Steven Goldy et al.

Abstract MXenes are a family of two‐dimensional (2D) transition metal carbides, nitrides, and carbonitrides with potential applications in ceramics and composites due to their nanometer‐thick morphology, hydrophilic surfaces, and negative zeta potentials. In this study, we investigated titanium carbide MXene (Ti3C2Tx) as an additive in ultra‐high‐temperature ceramics (UHTCs), specifically zirconium diboride (ZrB2). Homogeneous green bodies of Ti3C2Tx and ZrB2 were synthesized via electrostatic self‐assembly in aqueous media without surfactants and subsequently densified using field‐assisted (spark plasma) sintering. The incorporation of 0.5 wt.% MXene enhanced the relative density of ZrB2 from ≈89% (pure ZrB2) to ≈96% under identical sintering conditions. MXene addition significantly reduced the oxygen content from ≈5 at.% in pure ZrB₂ to ≈2–3 at.% at 2.5 wt.% MXene loading. The presence of MXene also facilitates the formation of a core–shell microstructure, where (Zr,Ti)B2 shells encapsulate ZrB₂ cores, with arrays of dislocations observed at the core–shell interface. Mechanical characterizations show substantial improvements, including a 36% increase in hardness, a ≈12% enhancement in Young's modulus, and a ≈15% increase in flexural strength at 2.5 wt.% MXene loading. These findings demonstrate the potential of MXenes as effective sintering aids and reinforcement agents in UHTCs, offering promising pathways for advancing materials designed for extreme environments.

ZHAO Yingmei, ZHAO Yuqing, ZHOU Xingyu et al.

Two metal-organic frameworks （MOFs）， Ce-UiO-66， and Zr-UiO-66， are synthesized using cerium ammonium nitrate （Ce（NH4）2（NO3）6） and zirconium tetrachloride （ZrCl4） as metal salts， and 1，4-benzenedicarboxylic acid （H2BDC） as the organic linker. The crystal structure and morphology of the MOFs are characterized by powder X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The MOFs-modified functional separators are prepared by loading Ce-UiO-66 and Zr-UiO-66 onto one side of commercial Celgard PP separators via vacuum filtration. The electrochemical performance of lithium-sulfur batteries is assembled and tested. The results show that the Ce-UiO-66 modified separator batteries demonstrates optimal electrochemical performance. At a rate of 0.2 C， the initial discharge capacity reaches 1047 mAh·g-1， with a capacity retention rate of 77.5% after 200 cycles and Coulombic efficiency approaching 100%. Under various current rates， the Ce-UiO-66 modified cells deliver discharge capacities of 1281， 945， 768.1， 673.2， 604.7 mAh·g-1 at 0.1， 0.2， 0.5， 1， 2 C， respectively. When returning to 0.1 C， the capacity recovers to 951.6 mAh·g-1 with a capacity retention rate of 74.3%. The above results demonstrate that the redox-active Ce₆-oxo clusters in Ce-UiO-66 can effectively catalyze the conversion reactions of lithium polysulfides （LiPSs） and enhance the redox kinetics. Furthermore， Ce-UiO-66 possesses abundant defects and unsaturated coordination sites， which can effectively anchor LiPSs， mitigate the shuttle effect， and further enhance the electrochemical performance of batteries.

Kanyarat Saenthornsin, Andrew J. Hunt, Oue-artorn Limtragool et al.

Abstract Sustainable, sulfonated mesoporous SBA-16 catalysts were synthesized from sugarcane bagasse ash (SCBA), an abundant agro-industrial waste from bio-energy production. SBA-16 modification with 3-mercaptopropyltrimethoxysilane (MPTMS) and subsequent oxidation to incorporate sulfonic acid groups, significantly enhanced the textural properties, achieving a surface area of 207 m2/g, while trace impurities from SCBA may enhance Lewis acidity. Such features improved catalytic efficiency and sustainability. A green assessment of catalyst synthesis from SCBA using the DOZN™ Green Chemistry Evaluator revealed that the SCBA-based methods are more sustainable than conventional TEOS-based methods. This study represents the first application of sulfonated SBA-16 for Biginelli reactions, yielding 99% for the reaction between benzaldehyde, methyl acetoacetate, and urea (at 105 °C, 7 h, 10 wt% catalyst, in ethanol). Catalysts demonstrated exceptional durability, with negligible loss of activity (~ 98%) over five consecutive cycles, highlighting its suitability for this application. SBA-16 catalysts exhibited broad substrate compatibility, particularly with electron-withdrawing groups across various aldehydes and β-diketones. The Biginelli reactions aligned with green chemistry principles, achieving favorable values for process mass intensity (PMI: 11.86–33.32 g/g), E-factor (10.86–32.32 g/g), solvent intensity (SI: 9.69–14.50 g/g), and water intensity (WI: 3.28–9.36 g/g). The Green Motion sustainability assessment tool score was 75/100. Sulfonated SBA-16 catalysts offer a sustainable alternative to commercial silica, with superior performance, reduced catalyst loading, and minimized environmental impact, underscoring its potential for use in industrial applications.

Hao Zhong, Wubin Shan, Lei Liang et al.

Ionic conductive hydrogel has recently garnered significant research attention due to its potential applications in the field of wearable and flexible electronics. Nonetheless, the integration of multifunctional and synergistic advantages, including reliable electronic properties, high swelling capacity, exceptional mechanical characteristics, and self-adhesive properties, presents an ongoing challenge. In this study, we have developed an ionic conductive hydrogel through the co-polymerization of 4-Acryloylmorpholine (ACMO) and sodium acrylate using UV curing technology. The hydrogel exhibits excellent mechanical properties, high conductivity, superior swelling capacity, and remarkable self-adhesive attributes. The hydrogel serves as a highly sensitive strain sensor, enabling precise monitoring of both substantial and subtle human motions. Furthermore, the hydrogel demonstrates the capability to adhere to human skin, functioning as a human-machine interface for the detection of physiological signals, including electromyogram (EMG) signals, with low interfacial impedance. This work is anticipated to yield a new class of stretchable and conductive materials with diverse potential applications, ranging from flexible sensors and wearable bio-electronics to contributions in the field of artificial intelligence.

Yi Peng, Hongyan Tian, Mingjia Yao et al.

Abstract The recently synthesized monolayer MoSi2N4 (Science 2020, 369, 367) exhibits exceptional environmental stability, a moderate band gap, and excellent mechanical properties, presenting exciting opportunities for the exploration of two-dimensional (2D) MX2Z4 materials. However, the low carrier mobility of α-phase MoSi2N4 significantly limits its potential applications in field-effect transistor (FET) devices. In this study, we systematically investigate the structural stability, elastic properties, and carrier mobility of a novel family of β-phase MX2N4 (M = Mo, W; X = Si, Ge) monolayers through first-principles calculations. Our findings reveal that these β-phase MX2N4 monolayers demonstrate remarkable dynamic, thermal, and mechanical stability. Specifically, we identify the MoSi2N4, MoGe2N4, WSi2N4, and WGe2N4 monolayers as semiconductors with band gaps of 2.70 eV, 1.57 eV, 3.12 eV, and 1.93 eV, respectively, as calculated using the HSE06 functional. Moreover, the MX2N4 monolayers exhibit significant elastic anisotropy, characterized by high ideal tensile strengths and a critical tensile strain exceeding 25%. Notably, the WGe2N4 monolayer displays exceptional anisotropic in-plane charge transport, achieving mobility levels of up to 104 cm2V− 1S− 1, surpassing those of the α-phase MX2N4 monolayers. These novel ternary monolayer structures have the potential to broaden the 2D MX2Z4 material family and emerge as promising candidates for applications in field-effect transistors.

Zhengxiong Su, Jun Ding, M. Song et al.

Zhengxiong Su, Jun Ding, Miao Song, Li Jiang, Tan Shi, Zhiming Li, Sheng Wang, Fei Gao, Di Yun, Chenyang Lu, En Ma a Department of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an, 710049, China b Center for Alloy Innovation and Design (CAID), State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China c Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109, United States d School of Materials Science and Engineering, Dalian University of Technology, Dalian, 116024, China e School of Materials Science and Engineering, Central South University, Changsha, 410083, China

Y. Zhou, Tadanori Kurosawa, Wei Ma et al.

K. Hutter

Lucas Caretta, Y. Shao, Jia Yu et al.

Electric fields typically break symmetry when applied as a stimulus to materials. Here, by forming a superlattice of BiFeO_3 and TbScO_3, it is shown that an electric field can repeatedly stabilize mixed-phase polar and antipolar BiFeO_3. Competition between ground states at phase boundaries can lead to significant changes in properties under stimuli, particularly when these ground states have different crystal symmetries. A key challenge is to stabilize and control the coexistence of symmetry-distinct phases. Using BiFeO_3 layers confined between layers of dielectric TbScO_3 as a model system, we stabilize the mixed-phase coexistence of centrosymmetric and non-centrosymmetric BiFeO_3 phases at room temperature with antipolar, insulating and polar semiconducting behaviour, respectively. Application of orthogonal in-plane electric (polar) fields results in reversible non-volatile interconversion between the two phases, hence removing and introducing centrosymmetry. Counterintuitively, we find that an electric field ‘erases’ polarization, resulting from the anisotropy in octahedral tilts introduced by the interweaving TbScO_3 layers. Consequently, this interconversion between centrosymmetric and non-centrosymmetric phases generates changes in the non-linear optical response of over three orders of magnitude, resistivity of over five orders of magnitude and control of microscopic polar order. Our work establishes a platform for cross-functional devices that take advantage of changes in optical, electrical and ferroic responses, and demonstrates octahedral tilts as an important order parameter in materials interface design.

Yong Hu, C. Niemeyer

In the past 35 years, DNA nanotechnology has grown to a highly innovative and vibrant field of research at the interface of chemistry, materials science, biotechnology, and nanotechnology. Herein, a short summary of the state of research in various subdisciplines of DNA nanotechnology, ranging from pure “structural DNA nanotechnology” over protein–DNA assemblies, nanoparticle‐based DNA materials, and DNA polymers to DNA surface technology is given. The survey shows that these subdisciplines are growing ever closer together and suggests that this integration is essential in order to initiate the next phase of development. With the increasing implementation of machine‐based approaches in microfluidics, robotics, and data‐driven science, DNA‐material systems will emerge that could be suitable for applications in sensor technology, photonics, as interfaces between technical systems and living organisms, or for biomimetic fabrication processes.