jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Lena Theresa Leusch | Thomas J. J. Müller
Source: European Journal of Organic Chemistry (article, 2026-01-30)
Field: Materials Science — Materials Chemistry

T‐Shaped 8‐Aryl(ethynyl)‐Substituted Psoralens With Tunable Charge‐Transfer Absorption Two series of novel T‐shaped 8‐substituted psoralen derivatives bearing (hetero)aryl and arylethynyl substituents were synthesized via Suzuki and Sonogashira coupling starting from 8‐methoxypsoralen (8‐MOP). Predominantly, electron‐donating substituents such as anisyl and phenothiazine were introduced at the 8‐position of the psoralen for increasing the electron density in comparison to 8‐MOP. Photophysical properties were studied by absorption and emission spectroscopy in solution and in the solid state. Increasing the donor strength of the substituent causes a bathochromic shift of both absorption and emission maxima. The absorption behavior can be correlated with Hammett substituent parameters of remote substituents at the p ‐aryl moieties that are directly or by ethynyl spacing positioned at the 8‐position of psoralen. In most cases, fluorescence in the solid state is more pronounced than in solution. One derivative also displays significant aggregation‐induced emission. For two amino‐substituted psoralen derivatives, positive emission solvatochromism was observed and associated with a considerable change of dipole moment upon photonic excitation according to Lippert–Mataga analysis. Furthermore, the p K a value of the T‐shaped dimethylaminophenyl psoralen derivative was determined from absorption spectra. In addition, emission quenching is caused by protonation on the nitrogen atom. TD‐DFT (time‐dependent density functional theory) calculations are in good agreement with experimental data and rationalize the electronic structure. Solvatochromism ; Bathochromic shift ; Substituent ; Absorption (acoustics) ; Oscillator strength ; Fluorescence ; Density functional theory ; Absorption spectroscopy ; Time-dependent density functional theory Luminescence and Fluorescent Materials ; Molecular Sensors and Ion Detection ; Photochromic and Fluorescence Chemistry
Authors: Boning Li | Patrick Hautle | Duhan Zhang | Liangping Zhu | Ashley Beers | Zeyu Wang | Paola Cappellaro | Tom Wenckebach | Yifan Quan
Source: arXiv (Cornell University) (article, 2026-03-29)
Field: Chemistry — Spectroscopy

Enhancing Spin Coherence of Optically-Addressed Molecular Qubit by Nuclear Spin Hyperpolarization Optically addressable molecular triplet spins provide a chemically tunable platform for quantum application, but their coherence is often limited by interactions with surrounding spin baths. Here we demonstrate controlled suppression of nuclear-bath-induced decoherence in photoexcited triplet spins of pentacene co-crystallized in high-purity naphthalene single crystals. By hyperpolarizing the proton spin bath through triplet dynamic nuclear polarization (triplet-DNP), magnetic noise generated by the nuclear spins is suppressed, leading to an extension of the electron spin transverse coherence time. Experimentally, we observe a 25\% enhancement of the spin-echo decay time with $60\%$ polarization of the proton spin bath. The measured scaling of the spin-echo decay time ($T_2$) with nuclear polarization quantitatively follows the predicted dependence derived from the polarization-controlled nuclear second moment. Both the enhancement and the absolute value of the coherence time are quantitatively reproduced by cluster correlation expansion (CCE) simulations. These results establish nuclear spin hyperpolarization as a general and actively tunable approach to engineering coherence in molecular qubits. This work provides a broadly applicable design framework for high-coherence molecular and solid-state spin systems. Spins ; Hyperpolarization (physics) ; Coherence (philosophical gambling strategy) ; Qubit ; Quantum decoherence ; Polarization (electrochemistry) ; Coherence time ; Spin polarization Advanced NMR Techniques and Applications ; Magnetism in coordination complexes ; Nonlinear Optical Materials Research
Authors: Antônio Maqs da Silva Júnior | F. Bechstedt | Marcelo Marques | L. K. Teles
Source: ChemRxiv (article, 2026-02-03)
Field: Chemistry — Physical and Theoretical Chemistry

Unified Charge-Transfer Diagram for Molecules Adsorbed on Graphene: A van Arkel–Ketelaar–Inspired Framework for Teaching Doping Phenomena Understanding charge transfer between molecular adsorbates and graphene is a recurring topic in courses on physical chemistry, materials science, and nanoscience.However, students are often exposed to case-specific energy level diagrams that hinder comparative reasoning and obscure the conceptual connection between molecular electronic structure and doping behavior.In this work, we introduce a unified charge transfer diagram that maps molecular adsorbates in a two-dimensional space defined by global chemical descriptors-namely, the average frontier orbital energy and the HOMO-LUMO gap. Phase diagram ; Adsorption ; Doping ; Molecule ; Diagram Advanced Physical and Chemical Molecular Interactions ; Molecular Junctions and Nanostructures ; Various Chemistry Research Topics
Authors: Sarika Thakur | Alka Sharma | Yangala Sudheer Babu | Mulaka Maruthi | Ram Shankar Upadhayaya | Sumitra Nain | Ram Gopal Nitharwal
Source: bioRxiv (Cold Spring Harbor Laboratory) (article, 2026-03-09)
Field: Chemistry — Organic Chemistry

Biological Evaluation of Novel 2-Benzimidazole Derivatives for Antibacterial Activity Abstract Infectious diseases remain a persistent global health burden, with bacterial infections predominating. The growing global burden of drug-resistant infections has led to greater emphasis on the discovery and development of novel antibacterial compounds. In an attempt to discover new potent antibacterials, the antibacterial activity of novel 2-substituted benzimidazole derivatives (NR-1 to NR-9) was evaluated in this study against three bacteria, viz. M. smegmatis, B. subtilis and E. coli in vitro using Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). Among the nine derivatives assessed, two (NR-4 and NR-5) exhibited inhibitory activity against M. smegmatis , while two (NR-5 and NR-7) were active against B. subtilis , with MICs between 62.5 and 250 μg/ml. Notably, NR-5 demonstrated antibacterial activity against both M. smegmatis and B. subtilis , with more efficacy against M. smegmatis (MIC: 62.5 μg/ml), which was considerably closer to rifampicin (MIC: 31.25 μg/ml). Cytotoxicity analysis of these derivatives in Vero cells indicated minimal toxicity for NR-4 and NR-5, and SwissADME evaluation suggested favourable physicochemical properties and drug-likeness, supporting good oral bioavailability. Moreover, the growth kinetics profiling of the NR-5 Benzimidazole derivative demonstrated that it inhibited the growth of M. smegmatis effectively, even after prolonged exposure. These findings highlighted the promise of the active benzimidazole derivative, NR-5, as a potential candidate for developing a more effective and less toxic antimycobacterial drug. Abstract Figure Mycobacterium smegmatis ; Antimycobacterial ; Benzimidazole ; Antibacterial activity ; Minimum inhibitory concentration ; Cytotoxicity ; Bacillus subtilis ; Biological activity ; In vitro Synthesis and biological activity ; Cancer therapeutics and mechanisms ; Synthesis and bioactivity of alkaloids
Authors: Kai Zhao
Source: ArXiv.org (article, 2026-03-03)
Field: Materials Science — Metals and Alloys

HERB: a unified framework for the evaluation of Hydrogen Embrittlement mechanisms driven by the Rice-Beltz concept The multiscale picture of hydrogen embrittlement (HE) mechanisms has been under controversy for a long time. Here I report a thermomechanically-consistent HERB framework driven by the Rice-Beltz concept meanwhile incorporating the hydrogen transport near the crack-tip and void growth within the plastic zone. Triggered solely by dislocation emission from the crack tip, the HERB theory unifies multiple HE mechanisms, such as HEDE, HELP, NVC and HESIV within a single framework. Specifically, a generalized model for predicting the hydrogen-informed dislocation emission is established by incorporating the Rice-Beltz model with the transition state theory. Accounting for the dynamic variation of the trapping energy of spherical inclusions, hydrogen transport is modeled in the dislocation free zone in front of the crack tip. Semi-analytical expressions of the density of geometrically necessary dislocations are obtained by incorporating the Hutchinson-Rice-Rosengren solution with the conventional theory of mechanism-based strain gradient plasticity model. By exploring the feasibility of stochastic analysis, the present theory demonstrates that the hydrogen-informed void dynamics is dominated by the dislocation density between the limits of Lifshitz-Allen-Cahn and Lifshitz-Slyozov-Wagner laws, even though individual events remain unpredictable. These insights fundamentally reshape hydrogen/dislocation interactions across multiple scales, including the core width, short-range and long-range levels. Void (composites) ; Hydrogen embrittlement ; Dislocation ; Plasticity ; Embrittlement ; Hydrogen ; Creep ; Transition state theory Hydrogen embrittlement and corrosion behaviors in metals ; Microstructure and mechanical properties ; Titanium Alloys Microstructure and Properties
Authors: Arya K | Kaifee Sayeed | Baptiste Py | Sabiar Rahaman | Francesco Ciucci | Kavita Pandey
Source: Nanoscale Advances (article, 2026-01-01)
Field: Materials Science — Materials Chemistry

Elucidating interfacial charge-transfer dynamics of Ti <sub>3</sub> C <sub>2</sub> T <sub> <i>x</i> </sub> electrodes <i>via</i> advanced distribution of relaxation times (DRT) analysis This study employs Distribution of Relaxation Times (DRT) analysis to elucidate the electrochemical charge dynamics within Ti<sub>3</sub>C<sub>2</sub>T <sub><i>x</i></sub> MXene-based electrodes. Comprehensive electrochemical characterizations, including cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), were systematically conducted in various electrolytes (H<sub>2</sub>SO<sub>4</sub>, Na<sub>2</sub>SO<sub>4</sub>, and KOH) and on multiple substrates (fluorine-doped tin oxide, carbon paper, and nickel foam) to evaluate charge storage mechanisms. Through DRT analysis, distinct electron-ion transport dynamics and relaxation processes were effectively differentiated, providing deeper insight into electrolyte-substrate interactions. Results demonstrated that acidic electrolytes (H<sub>2</sub>SO<sub>4</sub>) significantly enhanced charge transfer kinetics, while highly porous substrates (nickel foam and carbon paper) improved capacitive behavior. The DRT analysis specifically identified dominant charge-transfer peaks and clarified kinetic limitations, revealing slower dynamics at higher potentials, particularly in Na<sub>2</sub>SO<sub>4</sub>. Overall, this study underscores the capability of DRT analysis to systematically unravel complex electrochemical phenomena, highlighting its importance for optimizing MXene-based energy storage systems. Electrode ; Electrochemistry ; Relaxation (psychology) ; Dynamics (music) ; Electrical impedance ; Dielectric spectroscopy MXene and MAX Phase Materials ; 2D Materials and Applications ; Advancements in Battery Materials
Authors: Samia Tahira | Safwara Siddiqua | Fouzia Malik | Humaira Rafique
Source: Materials Advances (article, 2026-01-01)
Field: Materials Science — Materials Chemistry

DFT-Driven Insights into the Electronic, Magnetic, and Transport Properties of 2D Nb₃C₂ MXene for High-Performance Li-Ion Batteries The Two-dimensional material ‘MXene’ has attained significant attention for its outstanding characteristics inherent to nanostructures. However, to date, Nb₃C₂ MXene, particularly in Cr-doped form, has not been theoretically explored for... Work (physics) ; Process (computing) ; Deposition (geology) ; Carbon fibers MXene and MAX Phase Materials ; 2D Materials and Applications ; Graphene research and applications
Authors: Jianping Yang | Haishu Bai | Zhiqiang He | Bo Yu | Zijie Wei | Ling Chen | Shaoshuai Shi
Source: Applied Sciences (article, 2026-02-06)
Field: Materials Science — Polymers and Plastics

Fabrication and Curing Kinetics of Thermal Insulation Material Suitable for Deep-Earth Extreme Environments In the extreme high-temperature (up to 150 °C) and high-pressure (up to 140 MPa) conditions of deep in situ condition-preserved coring devices, high-strength epoxy resin was selected as the insulation layer. The non-isothermal DSC method was employed at heating rates of 2.5, 5, 10, 15, and 20 °C/min, revealing that increasing the heating rate elevates curing temperatures, expands the curing range, and enhances curing rate and heat release. The curing kinetics were modeled using n-order and autocatalytic approaches, with the latter accurately describing the behavior. Optimized integration process conditions (80 °C/4 h + 150 °C/2 h + 180 °C/3 h) yielded epoxy with compressive strength of 204.47 MPa, initial thermal decomposition temperature of 345.9 °C, thermal conductivity of 0.246 W/m·K, and Tg of 193.04 °C (storage modulus 2.41 GPa at 150 °C). As insulation, it reduces rock core heat loss by 32.38% (8.78 × 104 J) and active heating demand by 44 W, enhancing system stability for in situ temperature preservation. Curing (chemistry) ; Epoxy ; Thermal stability ; Thermal conductivity ; Fabrication ; Thermal insulation ; Kinetics ; Thermal decomposition Polymer Nanocomposites and Properties ; Aerogels and thermal insulation ; Epoxy Resin Curing Processes
Authors: Ahmed S. Etman | Mohamed Farhat. O. Hameed | S. S. A. Obayya | Ahmed E. Hammad
Source: Scientific Reports (article, 2026-01-22)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Optimization of terahertz broadband polarization insensitive metamaterial absorber using bisecting rectangles technique based on quadratic surrogates In this paper, an optimization algorithm based on bisecting hyperrectangles and constructing quadratic models is exploited to attain the optimal design of a broadband metamaterial absorber (MMA) with small thickness and high absorption in the terahertz (THz) frequency range. The full wave vectorial finite element method is employed along with the introduced algorithm to simulate and optimize the investigated design. The presented absorber comprises of a vanadium dioxide (VO2) metallic layer placed on a lossy polyimide dielectric substrate. Further, the reported design exhibits a broad bandwidth of 2.9 THz where the absorptivity exceeds 90% through a frequency range between 2.43 and 5.33 THz. In addition, the proposed design could obtain polarization insensitive absorption spectrum for the transverse electric (TE) as well as transverse magnetic (TM) polarizations. Furthermore, the absorption spectrum of the suggested absorber could realize high absorptivity (greater than 80%) for the TE and TM polarizations when the wave incident angle is varied from normal incidence to 50°. Therefore, the reported optimization algorithm is highly recommended for THZ broadband MMAs based applications. Terahertz radiation ; Molar absorptivity ; Metamaterial absorber ; Broadband ; Metamaterial ; Polarization (electrochemistry) ; Bandwidth (computing) ; Absorption (acoustics) ; Lossy compression Metamaterials and Metasurfaces Applications ; Advanced Antenna and Metasurface Technologies ; Electromagnetic Scattering and Analysis
Authors: Guanhua Lin | Yaqing Zhou | Xin Chen | Chao Chen | Weijun He | Sandrine Zanna | Antoine Seyeux | Jolanta Światowska
Source: Electrochimica Acta (article, 2026-01-20)
Field: Materials Science — Biomaterials

Dual corrosion-control mechanisms induced by calcium concentration in Mg–Ca alloys for Mg–Air batteries Corrosion ; Alloy ; Dissolution ; Electrochemistry ; Context (archaeology) ; Current density ; Anode ; Characterization (materials science) Magnesium Alloys: Properties and Applications ; Corrosion Behavior and Inhibition ; Magnesium Oxide Properties and Applications
Authors: Claire Griesbach | Tizian Scharsach | Morgan Trassin | Dennis M. Kochmann
Source: ArXiv.org (article, 2026-01-14)
Field: Materials Science — Materials Chemistry

Ferroelectric polarization mapping through pseudosymmetry-sensitive EBSD reindexing Ferroelectric materials exhibit a switchable, spontaneous polarization at the unit cell level--an attractive property utilized in many emerging technologies including, among others, high-density memory storage, low-power transistors, and high-speed fiber optic communication. Understanding the local polarization switching behavior, through domain nucleation and evolution, is critical to advancing these technologies and requires characterization of the local domain microstructure. However, in application-relevant polycrystalline materials exhibiting a distribution of grain orientations, a direct mapping of the polarization direction in three dimensions has remained inaccessible using conventional experimental approaches. Here, taking barium titanate single crystals and lead zirconium titanate polycrystals as our bulk model systems, we map the local polarization directions using a new electron backscatter diffraction indexing technique based on simulated pattern-matching. Through improved pre-processing techniques (including optimized pattern processing, a new pseudosymmetry-sensitive neighbor pattern averaging method, and DIC-based global sample-detector geometry calibration) and a new pseudosymmetry confidence index (which considers not only pattern similarity but pattern dissimilarity trends with other domain variant patterns), we successfully distinguish between the six polarization directions, despite the challengingly small unit cell aspect ratio of the selected materials. The methods developed in this work are not only applicable to ferroelectrics but any material which exhibits close crystallographic pseudosymmetries--extending the current capabilities of EBSD. Ferroelectricity ; Electron backscatter diffraction ; Polarization (electrochemistry) ; Nucleation ; Barium titanate ; Crystallite Ferroelectric and Piezoelectric Materials ; Machine Learning in Materials Science ; Multiferroics and related materials
Authors: Sebastian Gloor | David Stark | Martin Frankié | Urban Senica | Mattias Beck | Giacomo Scalari | Jérôme Faist
Source: arXiv (Cornell University) (article, 2026-02-16)
Field: Chemistry — Spectroscopy

Short period InGaAs/AlInAs THz quantum cascade laser in thin double metal cavities operating up to 188K We present a two-well terahertz (THz) quantum cascade laser designed for high temperature operation based on the InGaAs/AlInAs material system. The lighter effective mass and higher energy barriers increase the gain at high temperatures (T > 150K). When processed in copper-based double metal waveguides the devices show laser action up to a maximum operating temperature of 188K with a maximum current density of 1.4kA/cm$^2$. The low Joule heating due to reduced active region thickness and low electrical bias allows operation at 10% duty cycle up to a temperature of 170K. Duty cycle ; Terahertz radiation ; Laser ; Cascade ; Quantum cascade laser ; Joule heating ; Joule (programming language) ; Operating temperature ; Current density ; Temperature measurement Spectroscopy and Laser Applications ; Semiconductor Lasers and Optical Devices ; Semiconductor Quantum Structures and Devices
Authors: Nicola Cefis | Riccardo Rosso | P. Astori | Alessandro Airoldi | Roberto Fedele
Source: Journal of Composites Science (article, 2026-03-07)
Field: Materials Science — Materials Chemistry

Ballistic Impact Tests on Fiber Metal Laminates: Experiments and Modeling In the aviation industry the so-called ballistic impact of small accidental or human-made sources on aircraft elements during their service life encompasses several scenarios of practical interest. The experimental assessment of ballistic impact requires dedicated infrastructures (such as the light-gas gun system utilized in this study) and exhibits intrinsic difficulties, mainly concerning the proper acceleration of a projectile and the accurate measurement by a high-speed camera of its (inlet and outlet) velocity. As a first objective, this study aimed at characterizing the dynamic response of fiber metal laminates, manufactured ad hoc by the authors with two different stacking sequences currently not available in commerce. The layups included aluminum 2024 T3 and aramid fiber-reinforced prepregs, leading through specific treatments to excellent specific properties. The collision of the laminate with a 25 g, 9 mm radius steel sphere, traveling at speeds ranging from 90 to 145 m/s, caused a variety of scenarios: partial or complete penetration, with the projectile passing through and continuing its trajectory, remaining stuck in the sample (embedment) or even being bounced back (ricochet). The experimental information led to the estimation, for each typology of sample, of a conventional ballistic limit according to the Lambert-Jonas approximation, as a second objective, these data were utilized to validate an accurate heterogeneous model of the samples developed in the ABAQUS® platform, discretized by finite elements in explicit dynamics and including geometric nonlinearity and contact. We describe plasticity and damage of the metal layers by the Johnson–Cook phenomenological model, progressive failure in the fiber-reinforced plies through a 2D Hashin criterion with damage evolution, and interlaminar debonding at multiple cohesive interfaces governed by the Benzeggagh–Kenane criterion. The outlet speed of the bullet measured during the experiments was retrieved correctly by this model, and a satisfactory agreement of the finite element predictions was found with the deformation patterns and the damage mechanisms identified by post mortem visual inspection. Finally, several discussion points are raised, concerning the robustness of the numerical analyses, the reliability of the constitutive modeling and the identification of the governing parameters. Projectile ; Ballistic impact ; Ballistic limit ; Ballistics ; Aerospace ; Solid mechanics ; RADIUS ; Plasticity ; Discretization High-Velocity Impact and Material Behavior ; Mechanical Behavior of Composites ; Structural Response to Dynamic Loads