bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent advances in electron manipulation of nanomaterials for photoelectrochemical biosensors
Authors: Li Zijun , Lu Jiarui , Wei Wanting , Tao Min , Wang Zhaoyin , Dai Zhihui
Published: October 2022

This feature article discusses the recent advances and strategies of building photoelectrochemical (PEC) biosensors from the perspective of regulating the electron transfer of nanomaterials.
Beyond darunavir: recent development of next generation HIV-1 protease inhibitors to combat drug resistance
Authors: Ghosh Arun K. , Weber Irene T. , Mitsuya Hiroaki
Published: October 2022

We describe design and syntheses of a new generation of exceptionally highly potent non-peptidic HIV-1 protease inhibitors.
A novel thermally activated delayed fluorescence macrocycle
Authors: Zhou He-Ye , Zhang Da-Wei , Han Xiao-Ni , Han Ying , Chen Chuan-Feng
Published: October 2022

A novel luminescent macrocycle was conveniently synthesized, which exhibited flexible conformations and excellent thermally activated delayed fluorescence properties.
Novel triple mutant of an extremophilic glycosyl hydrolase enables the rapid synthesis of thioglycosides
Authors: Pillet Lauriane , Lim David , Almulhim Nourah , Benítez-Mateos Ana I. , Paradisi Francesca
Published: October 2022

A novel triple mutant of an extremophilic glycosyl hydrolase allowed the stereoselective, efficient, and sustainable synthesis of still elusive thioglycosides.
Role of hydrogen bonding in bulk aqueous phase decomposition, complexation, and covalent hydration of pyruvic acid
Authors: Barquilla Michael Dave P. , Mayes Maricris L.
Published: October 2022

The behavior of hydrogen bonding changes between the gas and aqueous phase, altering the mechanisms of various pyruvic acid processes and consequently affecting the aerosol formation in different environments.
Application of machine learning and statistical modeling to identify sources of air pollutant levels in Kitchener, Ontario, Canada
Authors: Mohammed Wisam , Adamescu Adrian , Neil Lucas , Shantz Nicole , Townend Tom , Lysy Martin , Al-Abadleh Hind A.
Published: October 2022

Machine learning is used in air quality research to identify complex relations between pollutant levels, emission sources, and meteorological variables.
D-CryptO: deep learning-based analysis of colon organoid morphology from brightfield images
Authors: Abdul Lyan , Xu Jocelyn , Sotra Alexander , Chaudary Abbas , Gao Jerry , Rajasekar Shravanthi , Anvari Nicky , Mahyar Hamidreza , Zhang Boyang
Published: October 2022

D-CryptO is a deep learning-based tool that can be used to analyze colon organoid structural maturity directly from brightfield images. D-CryptO can be applied in many cases such as analyzing organoids following chemotherapeutic drug treatment.
Structural and theoretical study of copper(ii) complex incorporating chalcone and 2,2′-bipyridine mixed ligands: a probable candidate for optical material
Authors: Gaur Ruchi , Kallem Parashuram
Published: October 2022

We report the synthesis, structural and photophysical data for a Cu(ii) complex, [Cu(L·bpy)(NO3)], with mixed chalcone and 2,2′-bipyridine ligands. Calculations are used to consider prospective applications in optoelectronic devices.
An assembly-inducing PDC enabling the efficient nuclear delivery of nucleic acid for cancer stem-like cell suppression
Authors: Wang Dongyuan , Tian Yuan , Zhang Yu , Sun Xiaona , Wu Yuxuan , Liu Ruping , Zeng Fang , Du Jingjing , Hu Kuan
Published: October 2022

Nucleic acid therapy is attracting great attention in diverse clinical translations because of its therapeutic advantages.
Scalable two-tier protruding micro-/nano-optoelectrode arrays with hybrid optical-electrical modalities by hierarchical modular design
Authors: Mejia Elieser , Song Junyeob , Zhao Yuming , Qian Yizhou , Xiao Chuan , Lezec Henri J. , Agrawal Amit , Zhou Wei
Published: October 2022

Modular integration of plasmonic nanoantennas with 3D micropillar electrode arrays offer hybrid optical-electrical functionality, crucial for advancing in situ spatiotemporal characterization of correlated bioelectrical and biochemical processes.
Synthesis of crystallizable poly(behenyl methacrylate)-based block and statistical copolymers and their performance as wax crystal modifiers
Authors: Dorsman Isabella R. , Chan Derek H. H. , Cunningham Victoria J. , Brown Steven L. , Williams Clive N. , Varlas Spyridon , Armes Steven P.
Published: October 2022

Behenyl methacrylate-based diblock and statistical copolymers are evaluated as additives for the crystal habit modification of a model wax (n-octacosane) inn-dodecane. The statistical copolymers more strongly influence the wax crystal morphology.
Quasiliving carbocationic polymerization of isobutylene using FeCl3 as an efficient and water-tolerant Lewis acid: synthesis of well-defined telechelic polyisobutylenes
Authors: Bohdan Mikalai , Shiman Dmitriy I. , Nikishau Pavel A. , Vasilenko Irina V. , Kostjuk Sergei V.
Published: October 2022

A cost-efficient approach for the preparation of well-defined low molecular weight difunctional polyisobutulenes possessing an exo-olefin or hydroxyl group was developed in this study.
Assembling ionic liquids in MOF “Monomer” based membranes to trigger CO2/CH4 separation
Authors: Cui Xiaolei , Kang Zixi , Fan Weidong , Pang Jia , Feng Yang , Zhang Caiyan , Yu Liting , Liu Shuo , Tang Xiuxian , Fan Lili , Wang Rongming , Sun Daofeng
Published: October 2022

MOF composite membranes are prepared using the interfacial assembly method and functional modification of ILs to enhance the CO2/CH4 sieving performance.
Hexagon path planning algorithm
Authors: Arnaoot Hany Mohamed Elsayed Ibrahim Mohamed
Published: October 2022

The paper presents a novel 2D geometrical path plan algorithm that reduces calculation load and time by filtering obstacles before path planning starts by the newly introduced hexagon filter and also while path search is in progress. Unlike other methods that use only obstacle filtering before path planning starts. The suggested algorithm was able to solve a randomly created maze that contains 400 obstacles with 800 nodes, which was considered before, as next to impossible to solve. This is because computational time is proportional to n2log(n) where n is the number of obstacles, node suggested algorithm reduced the computational time to about 1 in 2500 times compared to the best of (ESOVG, DVG or ECoVG). In addition, the suggested algorithm can be used in the case of a fixed start point and different target points (e.g. a swarm of robots leaving from the same start point with different targets).
Torque ripple investigation in coaxial magnetic gears
Authors: Tzouganakis Panteleimon , Gakos Vasilios , Kalligeros Christos , Papalexis Christos , Tsolakis Antonios , Spitas Vasilios
Published: October 2022

Magnetic gears offer significant advantages such as low noise and vibration level, lower maintenance and higher reliability compared to mechanical gears and are suitable for many applications in the industry. The coaxial magnetic gear has been extensively discussed in the literature, since it achieves higher torque densities amongst other magnetic gear configurations. The magnetic field is generated by permanent magnets mounted on the two rotors and a modulator between them. The modulator consists of ferromagnetic segments that are typically encased in a resin in order to increase its stiffness without compromising the generated magnetic field. However, due to the development of radial forces, oscillations of the ferromagnetic segments occur, which lead to torque ripples that affect the operation of the coaxial magnetic gear drive in applications where accuracy is required. This work introduces a computationally lightweight analytical 2D model in order to determine the applied radial force on the ferromagnetic segments at each angle of rotation of the two rotors and henceforth calculate the displacement of these segments using FEA. In this way it is possible to assess the variation of the torque (ripple) versus the angle of rotation of the input or output shaft. A parametric investigation examining the influence of the ferromagnetic segment thickness on the resulting torque ripple of a specific drive was carried out illustrating the benefits of the analytical models developed herein.
Impact of temperature and pressure on phase separation in the basal plane of Y0.77Pr0.23Ba2Cu3O7–δ single crystals
Authors: Solovjov A. L. , Khadzhai G. Ya. , Vovk R. V. , Mazepulin A. V. , Chroneos A.
Published: October 2022

Here, we study the impact of high hydrostatic pressure (up to 11 kbar) on the conductivity in the basal ab plane of Y0.77Pr0.23Ba2Cu3O7–δ single crystals. Conversely to YBa2Cu3O7–δ single crystals, it was found that high pressure leads to phase separation in the basal plane of Y0.77Pr0.23Ba2Cu3O7–δ single crystals. The mechanisms of the influence of praseodymium and high hydrostatic pressure on the two-step resistive transition to the superconducting state are discussed.
The anisotropy of conductive characteristics of Y1−yPryBa2Cu3O7−δ single crystals
Authors: Khadzhai G. Ya. , Solovjov A. L. , Vovk R. V.
Published: October 2022

The anisotropy of the conduction mechanisms of Y1−yPryBa2Cu3O7−δ single crystals has been studied in a wide range of praseodymium concentrations in the region of the transition from metallic to semiconductor conductivity with account fluctuation conductivity in the 3D Aslamazov–Larkin model. The correspondence of the obtained experimental results with the predictions of various theoretical models is analyzed. The anisotropy of Tc increases with increasing y, and the anisotropy of Tc increases most sharply when approaching the nonsuperconducting composition. As the concentration of praseodymium increases, the anisotropy of the ideal resistance passes through a maximum at y ≈ 0.19. It is shown that the temperature dependence of the anisotropy of the resistance in the semiconductor state exhibits a maximum associated with jumps of variable length along the c axis. At the same time, the temperature dependence of the fluctuating conductivity anisotropy passes through a maximum due to the significant anisotropy of the coherence length.
A new model of a molecular rotor in the oscillating electric field
Authors: Gabovich A. M. , Voitenko A. I.
Published: October 2022

In the framework of classical electrostatics, the rotation of an adsorbed polar molecule near a plane interface between two homogeneous insulators under the influence of an external electric field E is considered. The molecule is treated as a permanent point dipole, which polarizes the interface and interacts with the induced image charges. It has been shown that a molecular rotor can emerge for an arbitrary (not normal or parallel to the interface) orientation of the field E.
Phase V–T diagrams of solid freons. Part II: halomethanes
Authors: Konstantinov V. A. , Karachevtseva A. V. , Revyakin V. P. , Sagan V. V.
Published: October 2022

Phase V–T diagrams of solid halomethanes R12 (CF2Cl2), R20 (CHCl3), R22 (CHF2Cl), R23 (CHF3), and R30 (CH2Cl2) were constructed using both literature and our experimental data obtained during the study of isochoric thermal conductivity. The carbon tetrachloride V–T phase diagram was presented earlier. The jumps in molar volume during melting and the boundaries of the existence of phases have been determined. At pressures up to several kbar halomethanes R12, R20, R23, and R30 exist in only one crystal modification, whereas R22 shows a shift type phase transition near 59 K, and the high-temperature phase of CCl4 is dynamically orientationaly disordered. Experimental values of thermal pressures (dP/dT)V and dPm/dT on melting line were measured, and they are compared with those calculated by the Clapeyron-Clausius formula.
ICARUS-Q: Integrated control and readout unit for scalable quantum processors
Authors: Park Kun Hee , Yap Yung Szen , Tan Yuanzheng Paul , Hufnagel Christoph , Nguyen Long Hoang , Lau Karn Hwa , Bore Patrick , Efthymiou Stavros , Carrazza Stefano , Budoyo Rangga P. , Dumke Rainer
Published: October 2022

We present a control and measurement setup for superconducting qubits based on the Xilinx 16-channel radio-frequency system-on-chip (RFSoC) device. The proposed setup consists of four parts: multiple RFSoC boards, a setup to synchronize every digital to analog converter (DAC) and analog to digital converter (ADC) channel across multiple boards, a low-noise direct current supply for tuning the qubit frequency, and cloud access for remotely performing experiments. We also designed the setup to be free of physical mixers. The RFSoC boards directly generate microwave pulses using sixteen DAC channels up to the third Nyquist zone, which are directly sampled by its eight ADC channels between the fifth and the ninth zones.
A first-principles investigation of point defect structure and energetics in ThO2
Authors: Singh Maniesha , Kumagai Tomohisa , El-Azab Anter
Published: October 2022

The structure and energetics of charged point defects in thorium dioxide (ThO2) have been investigated using the density functional theory (DFT) and phonon simulations. DFT simulations were performed under both zero-pressure and constant volume conditions. Termed as the free volume change of the point defects, the change in volume of the supercell has been computed in the zero-pressure case. Supercell expansion was observed with the increase of the (nominal) charge state of anion (O) interstitials and cation (Th) vacancies from neutral to its maximum. On the contrary, contraction of the supercell has been observed with anion vacancies and cation interstitials as the defect charge increases. The supercell volume change with respect to the charge state has been correlated with the resulting defect energetics. It has been observed that, as the defect charge increased, the internal energy and entropy of defect formation of the cation vacancies and anion interstitials were found to increase, while that of the cation interstitials and anion vacancies decreased. The temperature dependence of internal energy and entropy has also been examined. It was found that, as the temperature increases, the internal energies of the formation of cation vacancies and anion interstitials decrease, while those of the cation interstitials and anion vacancies increase. An opposite observation is seen for the entropies of formation defects when above room temperatures.
The National Spherical Torus Experiment-Upgrade poloidal high-k scattering system pitch angle design modifications
Authors: Liu X. , Domier C. W. , Dannenberg J. , Zhu Y. , Sirigiri J. R. , Ren Y. , Stratton B. , Luhmann N. C.
Published: October 2022

A 693 GHz, eight-channel, poloidal high-k (k refers to wavenumber) collective scattering system is under development for the National Spherical Torus Experiment-Upgrade device. It will replace the previous 280 GHz, five-channel, tangential scattering system to study high-k electron density fluctuations, thereby providing a measurement of the kθ-spectrum of both electron temperature gradient and ion temperature gradient modes. A tool is under development to calculate the wavenumber that exists in the presence of strong magnetic pitch angles. We use this tool to motivate a new receiver optical design for significantly improved performance, details of which are presented herein.
Fresnel zone plate point spread function approximation for zeroth order mitigation in millimetric field of view x-ray imaging
Authors: Do A. , Kozioziemski B. J.
Published: October 2022

High spatial and temporal resolution x-ray radiography images are required at the National Ignition Facility (NIF) for high-energy density experiments. One technique that is in development to achieve the required resolution uses Fresnel zone plate (FZP) optics to image an object that is backlit by an x-ray source. The multiple FZP diffraction orders do not focus on the same plane, which increases the background and reduces the contrast. Understanding the point spread function of the different diffraction orders will allow the prediction of the expected background using simulations. We find that the two-dimensional point spread function of the FZP can be approximated by the addition of a sharp Gaussian with a disk. This allowed for the estimation of the background in NIF experimental images of Rayleigh–Taylor spikes and their interpretation. An alternative design of FZP is discussed to allow the inclusion of a zeroth order blocker to reduce the background.
Spatial calibration and synthetic diagnostic of a multi-energy hard x-ray camera at WEST tokamak
Authors: Barbui T. , Chellaï O. , Delgado-Aparicio L. F. , Peysson Y. , Stratton B. , Dumont R. , Hill K. W. , Pablant N. A.
Published: October 2022

WEST (tungsten environment in steady-state tokamak) is starting operation for the first time with a water-cooled full tungsten divertor, enabling long pulse operation. Heating is provided by radiofrequency systems, including lower hybrid current drive (LHCD). In this context, a compact multi-energy hard x-ray camera has been installed for energy and space-resolved measurements of the electron temperature, the fast electron tail density produced by LHCD and runaway electrons, and the beam–target emission of tungsten at the target due to fast electron losses interacting with the divertor plates. The diagnostic is a pinhole camera based on a 2D pixel array detector (Pilatus 3 CdTe CMOS Hybrid-Pixel detector produced by DECTRIS). The novelty of this diagnostic technique is the detector’s capability of adjusting the threshold energy at pixel level. This innovation provides great flexibility in the energy configuration, allowing simultaneous space and energy-resolved x-ray measurements. This contribution details two important steps in the preparation of the diagnostic operation. First, the in-vessel spatial calibration that was carried out with a radioactive source. Second, the synthetic diagnostic is obtained by the suite of codes ALOHA/C3PO/LUKE/R5-X2, which simulates LH wave propagation and absorption, as well as the fast electron bremsstrahlung production.
Characterization of a 1D-imaging high-energy x-ray backlighter driven by the National Ignition Facility Advanced Radiographic Capability laser
Authors: Hill M. P. , Williams G. J. , Kalantar D. H. , Bachmann B. , Martinez D. A. , Stan C. V. , Murphy A. , Arend M. J. , Mercado G. A. , Wong H. C. , Dunn Z. , Santos C. D. , Lockard T. E. , Gumbrell E. T. , Rudd R. E. , McNaney J. M. , Le Galloudec K. K. , Remington B. A. , Park H.-S.
Published: October 2022

Plastic deformation of samples compressed to Mbar pressures at high strain rates at the National Ignition Facility (NIF) forms the basis of ongoing material strength experiments in conditions relevant to meteor impacts, geophysics, armor development, and inertial confinement fusion. Hard x-ray radiography is the primary means of measuring the evolution of these samples, typically employing a slit-collimated high-Z microdot driven by the NIF laser to generate >40 keV x rays [E. Gumbrell et al., Rev. Sci. Instrum. 89, 10G118 (2018) and C. M. Huntington et al., Rev. Sci. Instrum. 89, 10G121 (2018)]. Alternatively, a dysprosium “micro-flag” target driven by the Advanced Radiographic Capability laser (∼2 kJ, 10 ps) can deliver significantly higher spatiotemporal resolution [M. P. Hill et al., Rev. Sci. Instrum. 92, 033535 (2021)], especially in high-opacity samples. Initial experiments revealed problematic brightness and spectral gradients from this source, but by radiographing a set of diamond-turned, 105 µm-thick Pb test objects and supported by simulations using the 3D Monte Carlo code GEANT4, these geometry-dependent gradients across the field of view are quantified and mitigation strategies are assessed. In addition to significantly enhancing the modulation transfer function compared to the existing system, image stacking from multiple layers of image plate is shown to almost double the signal to noise ratio that will reduce uncertainties in future dynamic strength experiments.
Enhancement of the anomalous Nernst effect in epitaxial Fe4N films grown on SrTiO3(001) substrates with oxygen deficient layers
Authors: Ito Keita , Wang Jian , Shimada Yusuke , Sharma Himanshu , Mizuguchi Masaki , Takanashi Koki
Published: October 2022

Anomalous Nernst effect of epitaxial Fe4N films on MgO(001), MgAl2O4(MAO)(001), and SrTiO3(STO)(001) substrates grown by molecular beam epitaxy was investigated. Moderately large anomalous Nernst coefficients (SANE) of 1.4 and 1.7 μV/K were obtained in the Fe4N films on the MgO(001) and MAO(001) substrates, respectively, and large anomalous Hall angles (∼0.06) and transverse thermoelectric conductivities [∼1.3 A/(m K)] were derived from the experimental results. On the other hand, a large effective SANE of 2.8 μV/K was obtained in the Fe4N film on the STO(001) substrate. The origin of the enhanced effective SANE is the negatively large Seebeck coefficient (SSE) in an oxygen deficient STO layer near the surface of the STO substrate. This indicates that it is possible to enhance the effective SANE of ferromagnetic materials by utilizing adjacent materials with large |SSE| such as the oxygen deficient STO layer.
Boson peak: Damped phonon in solids
Authors: Guo Q. , Zhang H. P. , Lu Z. , Bai H. Y. , Wen P. , Wang W. H.
Published: October 2022

The boson peak has long been considered an exclusive fingerprint of structural glasses, attributed to the disordered structure nature of glass. However, numerous studies also revealed the existence of boson peaks in many crystalline materials. The paradox is an unsolved knot in condensed matter physics. Here, we systematically explore the boson peaks in various disordered materials via a low-temperature specific heat perspective. A linear relationship between the boson peak temperature and the transverse sound velocity is well established, which indicates the phonon nature of the boson peak. Further analysis reveals that the boson peak is a ubiquitous hallmark of all solids that originates from the transverse mode damping, and glasses with disordered structures could enhance the phonon damping and result in the distinct boson peak phenomenon. The results have benefits for a better understanding of the structural origins of boson peaks.
Spin Hall magnetoresistance of CoFe2O4/Pt heterostructures with interface non-collinear magnetic configurations
Authors: Guo J. Q. , Meng K. K. , Zhang T. Z. , Liu J. J. , Chen J. K. , Wu Y. , Xu X. G. , Jiang Y.
Published: October 2022

We have investigated the spin Hall magnetoresistance (SMR) in CoFe2O4/Pt heterostructures deposited on (001) MgO and (001) MgAl2O4 substrates, respectively. It is found that the interface non-collinear magnetic configurations should exist in both of the two films in the whole temperature range from 5 to 300 K but mainly dominate the spin transport properties at low temperature. Furthermore, the spin transport has featured epitaxial-strain-modified characteristics induced by different substrates, which has been investigated by magnetic curves, SMR, anisotropic magnetoresistance, and Hall effect measurements.
Weak and strong coupling regimes in a topological photonic crystal bowtie cavity
Authors: Medina-Vázquez José A. , Murillo-Ramírez José G. , González-Ramírez Evelyn Y. , Olive-Méndez Sion F.
Published: October 2022

Topological photonics has attracted remarkable attention in recent years due to its ability to generate robust topological states, especially suitable for the study of cavity quantum electrodynamics. In this work, we present a theoretical study of a topological photonic crystal based on the 2D Su–Schrieffer–Heeger model, with corner states induced by a rotational operation on the axis parallel to the interface of two different topologies of a photonic crystal, forming a bowtie cavity. The studied topological photonic crystal presents inversion symmetry due to the rotation operation allowing the simultaneous existence of two non-degenerated corner states: one located in the weak coupling regime and the other in the strong coupling regime. Therefore, we present the emergence of distinctive effects from both regimes, such as the Purcell effect and Rabi splitting. We also address the study of the origin and evolution of the corner states resulting from the bulk-edge-corner correspondence. The topological bowtie cavity studied in this work combines the virtues of topological systems and the extreme confinement offered by cavities with bowtie architecture, which enriches the study of corner states in sophisticated topological structures.
Reactive co-sputtering of ternary Au–Ta–O films with tunable electrical resistivity
Authors: Shin S. J. , Bayu Aji L. B. , Engwall A. M. , Bae J. H. , Baker A. A. , Moody J. D. , Kucheyev S. O.
Published: October 2022

Heavy-metal-based films with high electrical resistivity are needed for hohlraums for magnetically assisted inertial confinement fusion. Here, we study ternary Au–Ta–O films deposited by reactive direct-current magnetron co-sputtering from elemental Au and Ta targets in an oxygen containing atmosphere. By varying the O content, the electrical resistivity of films can be tuned in a wide range of ∼100–40 000 μΩ cm. With increasing O content, a drastic increase in resistivity occurs at ∼45 at. % of O, separating regimes with two different dominant conduction mechanisms attributed to metallic conduction through the Au–Ta alloy matrix (for ≲45 at. % of O) and tunneling across insulating Ta2O5 layers separating conducting islands (for ≳45 at. % of O). Post-deposition annealing at 300 °C leads to the segregation of Au into ∼50-nm islands, sharply decreasing the resistivity for films with ≳45 at. % of O but not for the metal-like films with lower O content.
A dual-broadband dual-function polarization converter based on reflective metasurface
Authors: Zhou Xiaofeng , Wu Jiong , Yang Helin , Li Shangru , Yang Yuejie , Chen Jiao
Published: October 2022

In this paper, we introduce a dual-broadband dual-function polarization conversion metasurface, which can convert a linearly polarized (LP) incident electromagnetic wave into a cross-polarized LP wave and a circularly polarized wave, effectively, in different bands. The numerical simulations and experiments show that the metasurface can be used as a high-efficiency cross-polarization converter from 5.50 to 12.4 GHz, where the polarization conversion ratio is greater than 0.9 with a fractional bandwidth of 77.1%. Simultaneously, it can convert the LP incident wave into a right-handed circularly polarized wave from 13.50 to 19.75 GHz, where the axis ratio is lower than 3 dB and the fractional bandwidth is 37.4%. A honeycomb is used as a support layer instead of air gaps, which improves the efficiency of cross-polarization conversion and broadens the bandwidth of linear to circular conversion. To reveal the conversion mechanism of the proposed polarization converter, the surface current is analyzed. Finally, we fabricated and tested it, and the experimental results are in line with the simulation results.
Large out-of-plane piezoelectricity of VIA group functionalized MXenes thin films for MEMS
Authors: Zhang He-Na , Yang Chunhua , Li Yun-Qin , Zhu Shi-Yu , Wang Xin-Yu , He Qi-Wen , Tang Dai-Song , Wang Xiao-Chun
Published: October 2022

The integration of piezoelectric and micro-electro-mechanical system (MEMS) technologies is promoting the rapid development of the MEMS industry. However, due to the lack of excellent in-plane and out-of-plane piezoelectric coefficients, good ambient temperature stability, and high mechanical durability, the reported two-dimensional piezoelectric thin films are facing severe challenges in the development of MEMS. Therefore, based on density functional theory calculations, we simulated the VIA group (the sixth main family in the periodic table of elements) functional MXenes, namely, Sc2CXY (Sc2COS, Sc2COSe, Sc2CSO, and Sc2CSeO). The results show that this kind of material has good dynamic, thermal, and mechanical stability. Importantly, the structure exhibits good in-plane and out-of-plane piezoelectric effects due to the inversion asymmetry, bandgap adjustability, flexibility, and different electronegativity. Among them, the piezoelectric strain value of d33 is one to three orders of magnitude higher than that of d22 or d31, which makes these materials can become a strong candidate for advanced equipment such as nano-wearable electronics, robot bionic skin, and piezoelectric products for MEMS.
Titanium dioxide surface energy levels tuning by self-assembled monolayers
Authors: Zhu T. , Olthof S. , Pauporté Th.
Published: October 2022

Tailoring the work function of functional layers in an optoelectronic device is an important means for performance improvement, as it results in changes in charge extraction or recombination. One way to proceed is to adsorb molecules with varying dipole moment strengths and signs. In this communication, the surface of anatase TiO2 is modified using different self-assembled monolayers (4-chlorobenzoic acid, 4-nitrobenzoic acid, 4-methoxybenzoic acid, and β-alanine) and the energetics at the interface is determined using a series of photoelectron spectroscopy techniques, namely, ultraviolet photoelectron spectroscopy, x-ray photoelectron spectroscopy, and inverse photoemission spectroscopy. The observed changes in work function are correlated with the dipole moments of the respective acids, calculated by density functional theory. Finally, the relevance of this interfacial engineering for controlling the charge extraction from an optoelectronic device is illustrated.
Generalized weighted permutation entropy
Authors: Stosic Darko , Stosic Dusan , Stosic Tatijana , Stosic Borko
Published: October 2022

A novel heuristic approach is proposed here for time series data analysis, dubbed Generalized weighted permutation entropy, which amalgamates and generalizes beyond their original scope two well established data analysis methods: Permutation entropy and Weighted permutation entropy. The method introduces a scaling parameter to discern the disorder and complexity of ordinal patterns with small and large fluctuations. Using this scaling parameter, the complexity-entropy causality plane is generalized to the complexity-entropy-scale causality box. Simulations conducted on synthetic series generated by stochastic, chaotic, and random processes, as well as real world data, are shown to produce unique signatures in this three dimensional representation.
The trilayer exciton emission in WSe2/WS2/MoS2 van der Waals heterostructures
Authors: Xin Ming , Lan Wenze , Bai Qinghu , Huang Xin , Watanabe Kenji , Taniguchi Takashi , Wang Gang , Gu Changzhi , Liu Baoli
Published: October 2022

In this Letter, we present the experimental observation of trilayer exciton emission in the WSe2/WS2/MoS2 heterostructures by photoluminescence spectroscopy at a low temperature of ∼10 K. It is found that the trilayer exciton has a lower exciton binding energy than that in the WSe2/MoS2 heterobilayer due to the insertion of monolayer WS2, which is manifested by the blueshift of this trilayer exciton peak relative to the bilayer exciton. Through the measurements of the exciton peak position as a function of excitation power, the trilayer excitons exhibited the density-dependent repulsive interaction among them, and the reduction of binding energy ∼8 meV is deduced. Moreover, the trilayer exciton has a longer lifetime than the bilayer exciton, resulting from the reduction of electron–hole wavefunction overlap.
Velocity distributions in a gas-gun microparticle accelerator
Authors: Barrios Siria , Lance Pedro , Abate Anabella A. , Prieto German , García Nicolás A. , Piqueras Cristian M. , Vega Daniel A. , Satti Angel , Gómez Leopoldo R.
Published: October 2022

Here, we build and characterize a single-stage gas-gun microparticle accelerator, where a pressurized gas expands and launches particles on a target. The microparticles in the range of 60–250 μm are accelerated by the expansion of pressurized nitrogen. By using a high-speed camera, we study how the velocity distribution of accelerated particles is modified by particle size, pressure in the gas reservoir, valve’s opening time, and diaphragm’s thickness and composition. We employ this microparticle accelerator to study the impact of glass particles with diameters of (69 ± 6) μm accelerated at moderate velocities ∼ (10–25) m/s, using films of poly-dimethylsiloxane as targets.
Plasma instability in graphene field-effect transistors with a shifted gate
Authors: Crabb J. , Roman X. Cantos , Jornet J. M. , Aizin G. R.
Published: October 2022

We present detailed numerical analysis of the Dyakonov–Shur (DS) plasma instability in a DC biased graphene field-effect transistor (FET) with the gate shifted with respect to the middle of the transistor conducting channel. We show that the geometric asymmetry is sufficient to trigger the DS instability in the two-dimensional electron gas in the transistor channel. We demonstrate sustained plasma oscillations in the instability end point and analyze the properties of these oscillations for different positions of the gate and at different values of other physical and geometric FET parameters. The obtained results show the possibility of designing a tunable on-chip source of terahertz electromagnetic radiation based on the graphene FET with shifted gate.
Unravelling the role of oxygen vacancies on the current transport mechanisms in all-perovskite nickelate/titanate heterojunctions for nonvolatile memory applications
Authors: Zhang Yong , Gao Shunhua , Ma Chunrui , Lu Lu , Han Chuan Yu , Liu Ming
Published: October 2022

The micrometer-sized nickelate–titanate heterojunctions with LaNiO3 (LNO) electrode have been fabricated to investigate the dominant current transport mechanisms under positive and negative bias. The LNO/SmNiO3 (SNO)/Nb:SrTiO3 (NSTO) heterojunction exhibits a highly rectifying feature with a very low leakage in a broad temperature region (from 200 to 425 K), which is attributed to the formation of a Schottky-like barrier at the SNO/NSTO interface. In addition, it is found that the trap defects (i.e., oxygen vacancies) play an essential role in determining the current density (J)–voltage (V) characteristics irrespective of the voltage polarity. The leakage current at low electric fields (<0.25 MV/cm) is dominated by temperature-enhanced trap assisted tunneling process, which is caused by the interface oxygen vacancy induced states. Further analysis suggests that, at high fields (>1.2 MV/cm), the leakage is ascribed to the bulk-limited field enhanced thermal ionization of trapped carriers in the SNO film (i.e., Poole–Frenkel emission). Specially, the oxygen vacancy redistribution near the SNO/NSTO heterointerface driven by a high temperature (425 K) or high electrical field (>3.8 MV/cm) stress is emphasized to account for the transition from the Schottky contact limited to bulk-limited conduction mechanism (i.e., space charge limited conduction). This work will benefit the further analysis of the resistive switching phenomena in nickelate-based devices, showing a potential for nonvolatile memory applications.
High mobility p-channel tin monoxide thin-film transistors with hysteresis-free like behavior
Authors: Kim Taikyu , Lee Hochang , Kim Se Eun , Kim Jeong-Kyu , Jeong Jae Kyeong
Published: October 2022

In this Letter, we report a demonstration of p-channel tin monoxide (SnO) thin-film transistors (TFTs) with high field-effect mobility (μFE) exceeding 10 cm2/Vs and hysteresis-free like behavior. We demonstrate that maintaining metallic states before encapsulation is a key process to enhance μFE in p-type SnO thin-films. Sustaining this meta-stability involves the following two processes during fabrication: (1) postdeposition annealing (PDA) in two steps and (2) encapsulation in the middle of each PDA. This simple process not only suppresses creation of oxidized states such as adverse Sn4+ but also facilitates the lateral growth of crystals with improved crystallinity by interfacial energy stabilization. The resultant SnO TFT reveals a record-high μFE up to 15.8 cm2/Vs with a negligible hysteresis of 0.1 V. This study suggests a practical route to grant high μFE to p-channel SnO TFTs without any dopant or complex postdeposition treatment.
Low resistance epitaxial edge contacts to buried nanometer thick conductive layers of BaSnO3
Authors: Lee Jaehyeok , Cho Hyeongmin , Kim Bongju , Jeong Myoungho , Lee Kiyoung , Char Kookrin
Published: October 2022

As the size of the semiconductor device decreases, the importance of the low resistance contacts to devices cannot be overstated. Here, we studied the contact resistance to buried nanometer thick δ-doped Ba1-xLaxSnO3 (BLSO) layers. We have used epitaxial 4% (x = 0.04) BLSO as a contact material, which has additional advantages of forming Ohmic contacts to BaSnO3 and providing thermal stability even at high temperatures. The contact resistance was measured by a modified transmission line method designed to eliminate the contribution from the resistance of the contact material. The upper bound for the contact resistance to a 12 nm thick δ-doped 1% BLSO conductive layer was measured to be 1.25 × 10−1or 2.87 × 10−7 Ω cm2. Our results show that it is possible to provide low resistance epitaxial edge contacts to an embedded nanometer-thick BLSO conductive layer using an ion-milling process. Our low resistance contact method can be easily extended to a two-dimensional electron gas at the oxide interfaces such as LaInO3/BaSnO3.
Novel converging–diverging microchannel heat sink with porous fins for combined thermo-hydraulic performance
Authors: Bagherighajari Fatemeh , Abdollahzadehsangroudi Mohammadmahdi , Esmaeilpour Mehdi , Dolati Farid , Páscoa José
Published: October 2022

The optimum design of the microchannel heat sinks needs to consider both the heat transfer and pressure drop limitations of the microchannel. In this paper, a novel configuration of the microchannel heat sink is proposed to obtain improved thermo-hydraulic performance. The proposed microchannel includes porous fins that form adjacent converging–diverging channels. Three-dimensional steady laminar simulations were conducted to access the performance of this novel microchannel and compare it with the conventional parallel ones with porous and solid fins. The results showed that by using this novel design, a 9.75% decrease in pressure drop is observed when compared to conventional solid fin parallel microchannel. Also, the mean Nusselt number of the microchannel heat sink with converging–diverging porous fins showed a maximum improvement of 16.5% compared to the parallel microchannel with solid fins. The overall thermo-hydraulic performance evaluation factor of the converging–diverging microchannel showed also a significant 20% improvement compared to conventional designs. The analysis of the flow fields showed that the converging–diverging design with porous fins leads to a local pressure difference between two adjacent neighboring channels inducing a cross-wise velocity component within the porous fins leading to enhanced thermal performance. Moreover, it was shown that only for converging–diverging angles above 0.5 °, performance enhancement was observed compared with a microchannel with solid fins showing the existence of an optimum range for converging–diverging angles. The response surface method was used to find the optimum range of fin porosity and converging–diverging angle where the performance of the microchannel heat sink is maximum.
Discontinuous shear thickening (DST) transition with spherical iron particles coated by adsorbed brush polymer
Authors: Bossis Georges , Grasselli Yan , Volkova Olga
Published: October 2022

We explore the rheology of very concentrated (0.55 < Φ < 0.67) suspensions of carbonyl iron particles coated by a small polymer. A strong discontinuous shear thickening (DST) is observed in a large range of volume fraction presenting some specific behaviors in comparison with other systems. In particular, the DST transition can appear suddenly without being preceded by shear thickening. The presence of a frictional network of particles is confirmed by a simultaneous measurement of the electric resistance of the suspension and of the rheological curve. Using the Wyart–Cates (W–C) model, we show that with increasing the volume fraction, the fraction of frictional contacts increases more quickly with the stress, contrary to the prediction of numerical simulations. The same behavior is observed in the presence of a magnetic field with a strong increase in the viscosity before the DST transition. We interpret this behavior by the interpenetration of the polymer layer under the effect of the shear stress—and of the magnetic stress—followed by the expulsion of the polymer out of the surfaces between two particles in contact. We point out that above the DST transition, we do not observe a jamming in the range of volume fraction, whereas it is predicted by the W–C model. The frictional contacts are created by a shear stress and not by a static stress, so in the absence of shear flow, the polymer can adsorb again on the surface and lubricate the frictional contacts. We thus predict an asymptotic non-zero shear rate reproducing the experimental behavior.
SrTiO3/Ti3C2Tx Schottky heterojunction as a promising high-efficiency photocatalyst for H2 evolution
Authors: Fan Wenjuan , Jin Chao , Peng Chengxiao , Ren Fengzhu , Li Guoqiang , Gu Qinfen
Published: October 2022

Exploring low-cost, high-efficiency, and stable photocatalysts is still a significant challenge. SrTiO3, one of the appealing photocatalysts, can meet most of the screening criteria except for its efficiency, which is restricted by its poor absorption of visible light and its prompt photogenerated carrier recombination. Recently, a two-dimensional transition metal carbide Ti3C2Tx (2D MXene) has been found to serve as a co-catalyst due to its excellent metallic conductivity, hydrophilic property, large specific surface area, abundance of active sites, and low reaction barrier to hydrogen production. In this work, SrTiO3 nanoparticles are rationally integrated with Ti3C2Tx nanosheets via a simple hydrothermal process. The hydrogen production rate can achieve up to 3.43 mmol g−1 h−1 in the hybridization of SrTiO3-3 wt. % Ti3C2Tx, which is almost six times that of SrTiO3 alone. This remarkable enhancement arises predominantly from the Schottky contact between SrTiO3 and Ti3C2Tx, which can effectively suppress the recombination of photogenerated carriers and accelerate their separation. In addition, such enhancement benefits from the hydrogen evolution capacity of Ti3C2Tx. This work opens an excellent prospect for constructing highly active, low-cost, and stable photocatalysts with 2D MXene and finding potential applications of 2D MXene in energy conversion fields.
Recent development in termite bait and baiting methodology: A mini review
Authors: Dhang Partho
Published: October 2022

Termite baiting has evolved as a successful method of control globally. The methods hold significance as climate change, urbanization and international trade are spreading termites across the globe. The methodology uses minimal insecticide, precise application, and kills the colony compared to the soil treatment method. The subject is well reviewed, and the intent of this mini review is to provide updated information on some of the critical aspects of this technology, such as bait efficacy and criteria for evaluating colony elimination.
Mice with R2509C-RYR1 mutation exhibit dysfunctional Ca2+ dynamics in primary skeletal myocytes
Authors: Tsuboi Yoshitaka , Oyama Kotaro , Kobirumaki-Shimozawa Fuyu , Murayama Takashi , Kurebayashi Nagomi , Tachibana Toshiaki , Manome Yoshinobu , Kikuchi Emi , Noguchi Satoru , Inoue Takayoshi , Inoue Yukiko U. , Nishino Ichizo , Mori Shuichi , Ishida Ryosuke , Kagechika Hiroyuki , Suzuki Madoka , Fukuda Norio , Yamazawa Toshiko
Published: October 2022

Type 1 ryanodine receptor (RYR1) is a Ca2+ release channel in the sarcoplasmic reticulum (SR) of the skeletal muscle and plays a critical role in excitation–contraction coupling. Mutations in RYR1 cause severe muscle diseases, such as malignant hyperthermia, a disorder of Ca2+-induced Ca2+ release (CICR) through RYR1 from the SR. We recently reported that volatile anesthetics induce malignant hyperthermia (MH)-like episodes through enhanced CICR in heterozygous R2509C-RYR1 mice. However, the characterization of Ca2+ dynamics has yet to be investigated in skeletal muscle cells from homozygous mice because these animals die in utero. In the present study, we generated primary cultured skeletal myocytes from R2509C-RYR1 mice. No differences in cellular morphology were detected between wild type (WT) and mutant myocytes. Spontaneous Ca2+ transients and cellular contractions occurred in WT and heterozygous myocytes, but not in homozygous myocytes. Electron microscopic observation revealed that the sarcomere length was shortened to ∼1.7 µm in homozygous myocytes, as compared to ∼2.2 and ∼2.3 µm in WT and heterozygous myocytes, respectively. Consistently, the resting intracellular Ca2+ concentration was higher in homozygous myocytes than in WT or heterozygous myocytes, which may be coupled with a reduced Ca2+ concentration in the SR. Finally, using infrared laser-based microheating, we found that heterozygous myocytes showed larger heat-induced Ca2+ transients than WT myocytes. Our findings suggest that the R2509C mutation in RYR1 causes dysfunctional Ca2+ dynamics in a mutant-gene dose-dependent manner in the skeletal muscles, in turn provoking MH-like episodes and embryonic lethality in heterozygous and homozygous mice, respectively.
Convergence of level sets in fractional Laplacian regularization
Authors: Iglesias José A , Mercier Gwenael
Published: October 2022

The use of the fractional Laplacian in image denoising and regularization of inverse problems has enjoyed a recent surge in popularity, since for discontinuous functions it can behave less aggressively than methods based on H
1 norms, while being linear and computable with fast spectral numerical methods. In this work, we examine denoising and linear inverse problems regularized with fractional Laplacian in the vanishing noise and regularization parameter regime. The clean data is assumed piecewise constant in the first case, and continuous and satisfying a source condition in the second. In these settings, we prove results of convergence of level set boundaries with respect to Hausdorff distance, and additionally convergence rates in the case of denoising and indicatrix clean data. The main technical tool for this purpose is a family of barriers constructed by Savin and Valdinoci for studying the fractional Allen–Cahn equation. To help put these fractional methods in context, comparisons with the total variation and classical Laplacian are provided throughout.
Controlling magnetic frustration in 1T-TaS2 via Coulomb engineered long-range interactions
Authors: Chen Guangze , Rösner Malte , Lado Jose L
Published: October 2022

Magnetic frustrations in two-dimensional materials provide a rich playground to engineer unconventional phenomena. However, despite intense efforts, a realization of tunable frustrated magnetic order in two-dimensional materials remains an open challenge. Here we propose Coulomb engineering as a versatile strategy to tailor magnetic ground states in layered materials. Using the frustrated van der Waals monolayer 1T-TaS2 as an example, we show how long-range Coulomb interactions renormalize the low energy nearly flat band structure, leading to a Heisenberg model which depends on the Coulomb interactions. Based on this, we show that superexchange couplings in the material can be precisely tailored by means of environmental dielectric screening, ultimately allowing to externally drive the material towards a tunable frustrated regime. Our results put forward Coulomb engineering as a powerful tool to manipulate magnetic properties of van der Waals materials.