jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Zhengyi Zhang | Hua Fang
Source: Journal of the Chinese Chemical Society (article, 2024-06-29)
Field: Chemistry — Spectroscopy

Effects of amino‐ and dimethylamine‐groups on the fluorescent properties of novel flavone‐based derivatives with <scp>ESIPT</scp> behavior: A <scp>TD</scp>‐<scp>DFT</scp> study Abstract In this work, the effects of different functional groups on the excited‐state intramolecular proton transfer behavior and fluorescent features of 3‐hydroxy‐2‐(naphthalen‐2‐yl)‐4H‐chromen‐4‐one (HFN) are explored in detail. Three new compounds (HFN‐1, HFN‐2, and HFN‐3) are designed based on the HFN by introducing the electron‐donating groups (–NH 2 , –N(CH 3 ) 2 ). The mainly geometrical parameters of optimized configuration showed that the intramolecular hydrogen bonds of the studied compounds are enhanced in the excited (S 1 ) state, confirming by the ground (S 0 ) and excited states infrared spectra, electron densities and reduced density gradient isosurfaces. The S 0 → S 1 transitions of HFN derivatives are dominated by ππ* charge transfer transition. The introduction of electron‐donating group (–NH 2 , –N(CH 3 ) 2 ) weakens the intramolecular hydrogen bond, increases the excited‐state intramolecular proton transfer barrier and red‐shifts the absorption/fluorescence peak. The coexistence of –NH 2 and –N(CH 3 ) 2 make the absorption and fluorescence wavelengths of HFN‐1/HFN‐2 red‐shift/blue‐shift. Chemistry ; Dimethylamine ; Fluorescence ; Organic chemistry Molecular Sensors and Ion Detection ; Photochromic and Fluorescence Chemistry ; Synthesis of Organic Compounds
Authors: Donghyo Hahm | Valerio Pinchetti | Clément Livache | Namyoung Ahn | Jungchul Noh | Xueyang Li | Jun Du | Kaifeng Wu | Victor I. Klimov
Source: arXiv (Cornell University) (preprint, 2024-01-16)
Field: Materials Science — Materials Chemistry

Liquid-State Semiconductor Lasers Based on Type-(I+II) Colloidal Quantum Dots Present-day liquid-state lasers are based on organic dyes. Here we demonstrate an alternative class of liquid lasers that employ solutions of colloidal quantum dots (QDs). Previous efforts to realize such devices have been hampered by fast nonradiative Auger recombination of multi-carrier states needed for optical gain. We overcome this challenge using type-(I+II) QDs that feature a trion-like optical-gain state with strongly suppressed Auger recombination. When combined with a Littrow optical cavity, static (non-circulated) solutions of these QDs exhibit stable lasing tunable from 634 nm to 594 nm. These results point towards the feasibility of technologically viable dye-like QD lasers that feature wide spectral tunability and, importantly, allow for stable operation without the need for a bulky circulation system, a standard attribute of traditional dye lasers. Lasing threshold ; Laser ; Trion ; Optoelectronics ; Materials science ; Auger effect ; Quantum dot laser ; Quantum dot ; Dye laser ; Semiconductor ; Semiconductor laser theory ; Auger ; Optics ; Physics ; Atomic physics Quantum Dots Synthesis And Properties ; Semiconductor Lasers and Optical Devices ; Strong Light-Matter Interactions
Authors: Baihua Ren | Jun Song
Source: arXiv (Cornell University) (preprint, 2024-03-02)
Field: Materials Science — Polymers and Plastics

Effect of particle oxidation, size and material on deformation, bonding and deposition during cold spray: a peridynamic investigation Cold spray (CS) has emerged as an important additive manufacturing technology over the past decade. This study investigates the effect of oxide layers on the CS process, focusing on the deformation behavior of copper (Cu) and iron (Fe) particles upon collision with a matching substrate. Using a peridynamics-based approach, we examine the effects of oxide thickness, particle size, and particle/substrate material on material deformation and oxide fracture processes. Our results show that thicker oxide films restrict particle deformation, delay oxide discontinuities and material jetting, and increase the critical velocity required for metal to metal contact. Larger particles, despite uniform deformation across sizes, require lower velocities to initiate jetting and oxide separation because of their higher kinetic energy, leading to metallurgical bonding at lower velocities. Soft to soft impacts induce oxide film cracking at lower velocities, resulting in larger interface areas and more oxide-free contact zones, thereby reducing the critical velocity. Furthermore, the volume of residual oxide has a power-law relationship with the particle size, indicating that the oxide-cleaning ability of the particles affects the critical velocity. This study highlights the importance of oxide deformation and fracture during CS processes and provides valuable insights into the breakage and removal of oxides and subsequent metallic bond formation. These findings offer beneficial new knowledge for the rational design and optimization of CS processes. Gas dynamic cold spray ; Materials science ; Particle (ecology) ; Particle size ; Thermal spraying ; Composite material ; Coating ; Geology ; Chemical engineering ; Engineering Flame retardant materials and properties
Authors: Ahmad Ibrahim, Muhammad Ashraf | Mansor, Fayeed Naufal | Mohd Ramli, Mohamad Ridzuan | Hamdan, Muhammad Danish Iman
Source: UiTM Institutional Repositories (Universiti Teknologi MARA) (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Thermo charged: the heat-powered holder / Fayeed Naufal Mansor ... [et. al] This abstract introduces a novel product concept—a mug holder designed to harness thermal energy from hot beverages for charging electronic devices such as smartphones. The device integrates thermoelectric generators (TEGs) and a thermal storage unit to efficiently convert heat energy into electrical power. Key design considerations include material selection for optimal heat retention and conductivity, alongside safety features to mitigate potential hazards associated with handling hot liquids. The proposed device aims to provide practical utility in both home and office environments, offering a sustainable and convenient solution for maintaining beverage temperature while simultaneously powering essential electronics. Further development focuses on enhancing energy conversion efficiency, compactness, and user-friendly design to meet diverse consumer needs and preferences. Key (lock) ; Thermal energy ; Energy (signal processing) ; Product (mathematics) ; Electric potential energy ; Efficient energy use ; Unit operation ; Thermal ; Heat energy ; Energy consumption Advanced Thermoelectric Materials and Devices ; Thermal Radiation and Cooling Technologies ; Solar-Powered Water Purification Methods
Authors: Yi Hou | Chenfeng Duan | Xiaoqiang Li | Shengguan Qu
Source: Materials (article, 2024-06-05)
Field: Materials Science — Materials Chemistry

Study of Quenching and Partitioning (Q&amp;P) and Ultrasonic Surface Rolling (USR) Process on Microstructure and Mechanical Property of a High-Strength Martensitic Steel Steel with a combination of strength and plasticity is prevalently demanded for lightweight design and emission reductions in manufacturing. In this study, a high-strength Cr-Ni-Mo martensitic steel treated by quenching and partitioning (Q&P) and ultrasonic surface rolling (USR) processes was studied for both strength and plasticity enhancement. Specimens were austenitized at 850 °C and then quenched to 240 °C via cooling by water, oil, and normalization in quenching. This was followed by partitioning, in which two groups of specimens were heated to 370 °C and 350 °C for 45 min, respectively. At last, all the specimens were quenched to room temperature with the same methods of quenching. The highest tensile strength increased from 681.73 MPa to 1389.76 MPa when compared to as-received (AR) steel after the Q&P process. The USR process with a static force of 800 N further improved the tensile strength of specimens with high tensile strength after the Q&P process, which improved from 1389.76 MPa to 1586.62 MPa and the product's strength and elongation (PSE) increased from 15.76 GPa% to 15.9 GPa%, while the total elongation showed a mitigatory decrease from 11.34% to 10.02%. Tensile fractures were also studied and verified using a combination of strength and plasticity after a combined process of Q&P and USR. Microstructure ; Materials science ; Martensite ; Quenching (fluorescence) ; Ultrasonic sensor ; Metallurgy ; Composite material ; Property (philosophy) ; Optics ; Acoustics Metal Alloys Wear and Properties ; Microstructure and Mechanical Properties of Steels ; Surface Treatment and Residual Stress
Authors: Tim Steska | Stephan Wagner | Thorsten Reemtsma | Dana Kühnel
Source: Chemical Research in Toxicology (article, 2024-01-08)
Field: Materials Science — Materials Chemistry

Influence of Silver Fiber Morphology on the Dose–Response Relationship and Enrichment in <i>Daphnia magna</i> Studied by Elemental Imaging with LA-ICP-TOF-MS This study aims to enhance the understanding of the environmental risks associated with nanomaterials, particularly nanofibers. Previous research suggested that silver fibers exhibit higher toxicity (EC<sub>50/48h</sub> 1.6-8.5 μg/L) compared to spherical silver particles (EC<sub>50/48h</sub> 43 μg/L). To investigate the hypothesis that toxicity is influenced by the morphology and size of nanomaterials, various silver nanofibers with different dimensions (length and diameter) were selected. The study assessed their toxicity toward <i>Daphnia magna</i> using the 48 h immobilization assay. The EC<sub>50</sub> values for the different fibers ranged from 122 to 614 μg/L. Subsequently, the study quantified the uptake and distribution of two representative nanofibers in <i>D. magna</i> neonates by employing digestion and imaging mass spectrometry in the form of laser-ablation-ICP-MS. A novel sample preparation method was utilized, allowing the analysis of whole, intact daphnids, which facilitated the localization of silver material and prevented artifacts. The results revealed that, despite the similar ecotoxicity of the silver fibers, the amount of silver associated with the neonates differed by a factor of 2-3. However, both types of nanofibers were primarily found in the gut of the organisms. In conclusion, the findings of this study do not support the expectation that the morphology or size of silver materials affect their toxicity to <i>D. magna</i>. Daphnia magna ; Nanofiber ; Ecotoxicity ; EC50 ; Toxicity ; Chemistry ; Nanomaterials ; Morphology (biology) ; Nuclear chemistry ; Environmental chemistry ; Ecotoxicology ; Materials science ; Nanotechnology ; Biology ; Zoology ; Biochemistry ; In vitro ; Organic chemistry Nanoparticles: synthesis and applications ; Healthcare and Environmental Waste Management ; Heavy metals in environment
Authors: Zhaoyu Han | Steven A. Kivelson
Source: arXiv (Cornell University) (preprint, 2024-05-27)
Field: Chemistry — Spectroscopy

Emergent Gauge Fields in Band Insulators By explicit microscopic construction involving a mapping to a quantum vertex model subject to the `ice rule,' we show that an electronically `trivial' band insulator with suitable vibrational (phonon) degrees of freedom can host a ``resonating valence-bond'' state - a quantum phase with emergent gauge fields. This novel type of band insulator is identifiable by the existence of emergent gapless `photon' modes and deconfined excitations, the latter of which carry non-quantized mobile charges. We suggest that such phases may exist in the quantum regimes of various nearly ferroelectric materials. Gauge (firearms) ; Physics ; Theoretical physics ; Quantum electrodynamics ; Materials science Aerogels and thermal insulation
Authors: Iliana N. Apostolova | A. Apostolov | Julia M. Wesselinowa
Source: Materials (article, 2024-09-12)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Theoretical Study of the Multiferroic Properties of Pure and Ion-Doped Pb5M3F19, M = Fe, Cr, Al In a first theoretical investigation of the multiferroic properties of Pb5Fe3F19 (PFF) and Pb5Cr3F19 (PCF), we analyze their magnetic, ferroelectric, and dielectric characteristics as functions of temperature, magnetic field, and ion doping concentration using a microscopic model and Green's function theory. The temperature-dependent polarization in PFF and PCF shows a distinctive kink at the magnetic Neel temperature TN, which vanishes when an external magnetic field is applied, indicating the multiferroic behavior of these two compounds. Ion doping effectively tunes the properties of PFF and PCF. In PFF, Cr ion doping leads to a decrease in the Neel temperature TN, while Cr and Al ion doping lowers the ferroelectric Curie temperature TC. In the case of PCF, we observe the enhancement of TC by Fe ion doping and the reduction by Al ion doping. The last result coincides well quantitatively with the experimental data. Additionally, the magnetodielectric coefficient of PFF is enhanced with the increasing magnetic field. Multiferroics ; Materials science ; Doping ; Ion ; Condensed matter physics ; Ferroelectricity ; Physics ; Optoelectronics ; Dielectric ; Quantum mechanics Multiferroics and related materials ; Ferroelectric and Piezoelectric Materials ; Magnetic and transport properties of perovskites and related materials
Authors: Qing Chen | Jialong Cui | Lishuang Feng | Dengke Zhang
Source: arXiv (Cornell University) (preprint, 2024-12-13)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Thermal atoms facilitate intensity clipping between vectorial dual-beam\n generated by a single metasurface chip Manipulating vector beams is pivotal in fields such as particle manipulation, image processing, and quantum communication. Flexibly adjusting the intensity distribution of these beams is crucial for effectively realizing these applications. This study introduces a vectorial dual-beam system utilizing thermal atoms as the medium for modulating the intensity profile of vector beams. A single metasurface is employed to generate both the control and signal vector beams, each with unique vectorial characteristics. The shaping of the signal beam profile is facilitated by the interaction with thermal atoms, which can be controlled by adjusting the control vector beam. This spatially selective absorption is a result of the thermal atoms' response to the varying polarizations within the vector beams. In this experiment, two distinct metasurface chips are fabricated to generate vector beams with doughnut-shaped and Gaussian-shaped intensity profiles. By adjusting the incident power and polarization state of the control light, the doughnut-shaped signal beams can be converted into a rotational dual-lobed pattern or the dimensions of the Gaussian-distributed signal beams can be modified. This study introduces a novel vector beam shaping technique by integrating metasurfaces with thermal atoms, offering significant promise for future applications requiring miniaturization, dynamic operation, and versatile control capabilities. Clipping (morphology) ; Intensity (physics) ; Dual (grammatical number) ; Beam (structure) ; Optics ; Thermal ; Chip ; Materials science ; Optoelectronics ; Physics ; Telecommunications ; Computer science ; Art Metamaterials and Metasurfaces Applications ; Photonic Crystals and Applications ; Photonic and Optical Devices
Authors: Katharina Brechtelsbauer | Johannes Mögerle | Hans Peter Büchler
Source: arXiv (Cornell University) (preprint, 2024-10-29)
Field: Chemistry — Spectroscopy

Quantum Simulation of Spin-1 XXZ-Heisenberg Models and the Haldane Phase with Dysprosium Dysprosium atoms have proven to be a promising platform for quantum simulation due to their strong magnetic moment and high tunability of interactions. In this work, we propose Dysprosium atoms for simulating the one-dimensional spin-1 XXZ-Heisenberg model, which is known to have a rich phase diagram including the famous Haldane phase. To realize the model, we make use of the strong dipolar exchange interactions that naturally occur in the ground state of Dysprosium due to its large electron angular momentum of J=8. To implement spin-1 particles, we encode the spin degree of freedom into three Zeeman sublevels, which are energetically isolated by applying a magnetic field. Using the density-matrix renormalization group, we analyze the ground-state properties of the resulting effective model. We find that a chain of fermionic Dysprosium atoms in a suitable magnetic field can form a Haldane state with the characteristic spin-1/2 edge modes. Furthermore, we discuss the use of AC Stark shifts and Raman-type schemes for bosonic Dysprosium to isolate effective spin-1 systems and to increase the tunability of model parameters. Dysprosium ; Heisenberg model ; Quantum ; Spin (aerodynamics) ; Physics ; Phase (matter) ; Mathematical physics ; Quantum mechanics ; Condensed matter physics ; Antiferromagnetism ; Thermodynamics Advanced NMR Techniques and Applications ; Quantum, superfluid, helium dynamics
Authors: Yi‐Ming Wu | Chaitanya Murthy | Steven A. Kivelson
Source: arXiv (Cornell University) (preprint, 2024-05-15)
Field: Materials Science — Materials Chemistry

Possible Sliding Regimes in Twisted Bilayer WTe$_2$ Inspired by the observation of increasingly one-dimensional (1D) behavior with decreasing temperature in small-angle twisted bilayers of WTe$_2$ (tWTe$_2$), we theoretically explore the exotic sliding regimes that could be realized in tWTe$_2$. At zero displacement field, while hole-doped tWTe$_2$ can be thought of as an array of weakly coupled conventional two-flavor 1D electron gases (1DEGs), the electron-doped regime is equivalent to coupled four-flavor 1DEGs , due to the presence of an additional "valley'' degree of freedom. In the decoupled limit, the electron-doped system can thus realize phases with a range of interesting ordering tendencies, including $4k_F$ charge-density-wave and charge-$4e$ superconductivity. Dimensional crossovers and cross-wire transport due to inter-wire couplings of various kinds are also discussed. We find that a sliding Luther-Emery liquid with small inter-wire couplings is probably most consistent with current experiments on hole-doped tWTe$_2$. Bilayer ; Materials science ; Mechanics ; Physics ; Condensed matter physics ; Chemistry ; Membrane 2D Materials and Applications ; Molecular Junctions and Nanostructures ; Fullerene Chemistry and Applications
Authors: Pavel A. Panchenko | Anastasija V. Efremenko | Anna S. Polyakova | Alexey V. Feofanov | Maria A. Ustimova | Yu. V. Fedorov | Olga A. Fedorova
Source: Chemistry - An Asian Journal (article, 2024-09-23)
Field: Chemistry — Spectroscopy

Application of RET Approach for Ratiometric Response Enhancement of ICT Fluorescent Hg<sup>2+</sup> Probe based on Crown‐containing Styrylpyridinium Dye Styrylpyridinium dye bearing azadithia-15-crown-5 ether receptor group SP and 4-alkoxy-1,8-naphthalimide fluorophore were linked using copper-catalyzed azide-alkyne cycloaddition click reaction to afford dyad compound NI-SP. Chemosensor NI-SP exhibited selective ratiometric fluorescent response to the presence of Hg<sup>2+</sup> in aqueous solution due to the interplay between resonance energy transfer (RET) and intramolecular charge transfer (ICT) processes occurred upon excitation. The observed switching of the ratio of emission intensities in the blue and red channels R was higher than in the case of monochromophoric styrylpyridine derivative SP showing ratiometric response based on ICT mechanism only. Biological studies revealed that NI-SP penetrates into human lung adenocarcinoma A549 cells and accumulates in cytoplasm and lysosomes. When cells were pre-incubated with mercury (II) perchlorate, the ratio R was increased 2.6 times, which enables detection of intracellular Hg<sup>2+</sup> ions and their quantitative analysis in the 0.7-6.0 μM concentration range. Chemistry ; Fluorescence ; Photochemistry ; Fluorophore ; Crown ether ; Intramolecular force ; Sonogashira coupling ; Cycloaddition ; Ion ; Nuclear chemistry ; Stereochemistry ; Catalysis ; Organic chemistry Molecular Sensors and Ion Detection ; Luminescence and Fluorescent Materials ; Advanced biosensing and bioanalysis techniques
Authors: Romain Brette
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2024-12-20)
Field: Chemistry — Organic Chemistry

Theory of axo-axonic inhibition Abstract The axon initial segment of principal cells of the cortex and hippocampus is contacted by GABAergic interneurons called chandelier cells. The anatomy, as well as alterations in neurological diseases such as epilepsy, suggest that chandelier cells exert an important inhibitory control on action potential initiation. However, their functional role remains unclear, including whether their effect is indeed inhibitory or excitatory. One reason is that there is a relative gap in electrophysiological theory about the electrical effect of axo-axonic synapses. This contribution uses resistive coupling theory, a simplification of cable theory based on the observation that the small initial segment is resistively coupled to the large cell body acting as a current sink, to fill this gap. The main theoretical finding is that a synaptic input at the proximal axon shifts the action potential threshold by an amount equal to the product of synaptic conductance, driving force at threshold, and axial axonal resistance between the soma and either the synapse or of the middle of the initial segment, whichever is closer. The theory produces quantitative estimates useful to interpret experimental observations, and supports the idea that axo-axonic cells can potentially exert powerful inhibitory control on action potential initiation. Significance statement Chandelier cells form GABAergic synapses on the initial segment of pyramidal cells of the cortex and hippocampus. Despite their striking morphology and alterations in neurological diseases such as epilepsy, their functional role remains unclear. This study develops a quantitative theory to precisely assess the electrical impact of a synaptic input at the proximal axon. It shows that axo-axonic inhibition acts by shifting the action potential threshold proportionally to the synaptic conductance. This work underlines the role of chandelier cells in controlling action potential initiation and provides a quantitative tool to interpret experimental observations. Economic geography ; Geography Click Chemistry and Applications ; Chemical Synthesis and Analysis ; Organic Chemistry Cycloaddition Reactions
Authors: Yuki Amari | Muneto Nitta
Source: arXiv (Cornell University) (preprint, 2024-09-12)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Skyrmion crystal phase on a magnetic domain wall in chiral magnets We study a magnetic domain wall in the ferromagnetic phase in chiral magnets in two dimensions with an in-plane easy-axis anisotropy and an out-of-plane Zeeman magnetic field, and find a chiral soliton lattice (spiral) phase beside a ferromagnetic phase inside the domain line, where the former represents a domain-wall skyrmion crystal from the bulk point of view. We first determine the phase diagram on the domain wall by numerically constructing domain-wall solutions. We then analytically reproduce the phase diagram in a domain-wall theory (a chiral double sine-Gordon model) that we construct within the moduli approximation by treating the Zeeman magnetic field perturbatively. While we find good agreements between the phase diagrams of the numerical and effective theory methods, the numerical solution exhibits a decomposition of the topological charge into a bimeron which cannot be captured by the effective theory. Skyrmion ; Magnet ; Phase (matter) ; Condensed matter physics ; Magnetic domain ; Domain (mathematical analysis) ; Materials science ; Domain wall (magnetism) ; Physics ; Magnetic field ; Magnetization ; Quantum mechanics ; Mathematics Magnetic Properties of Alloys ; Hydrogen Storage and Materials ; Geomagnetism and Paleomagnetism Studies