bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Three Eradication Treatment Protocols for Pseudomonas
Aeruginosa in Children and Adolescents with Cystic Fibrosis
Authors: Schütz Katharina , Grewendorf Simon , Kontsendorn Julia , Fuge Jan , Happle Christine , Rudolf Isa , Dopfer Christian , Sedlacek Ludwig , Hansen Gesine , Junge Sibylle , Dittrich Anna-Maria
Published: February 2023

Background Pseudomonas aeruginosa (Pa) continues to affect disease
progression in cystic fibrosis (CF). However, the best eradication regimen
remains unclear. This work compares three different antibiotic eradication
regimens in pediatric CF: an administration according to a standard-operating
procedure (SOP) order vs. administration outside of this order (ooSOP).

Methods This observational study includes all CF patients<18 years
who received one of three Pa eradication treatments in the past eight years at
our center: 1) inhaled high-dose tobramycin (Hi-TOBI), 2) inhaled
colistin+oral ciprofloxacin (COL/Cip), 3) inhaled low-dose
tobramycin+4 intravenous 14-day Pa active antibiotic treatments
(lo-Tobra/IV). We compared eradication rates of the three treatment
regimens performed according to the SOP-based order vs. ooSOP. Logistic
regression analysis was performed to identify risk factors for eradication
failure.

Results Performed according to SOP order, Hi-TOBI showed the greatest
efficacy, followed by lo-Tobra/IV and finally COL/Cip, while
ooSOP lo-Tobra/IV was most successful, followed by COL/Cip and
Hi-TOBI. Previous Pa-infections and Pa-therapies along with age at CF diagnosis
were risk factors for eradication failure.

Conclusion Antibiotic treatment in SOP-based pre-defined order leads to
significantly better eradication rates than individual modifications of the
order of administration. A short course of inhalational high-dose Tobramycin is
most successful at the first attempt. Prolonged antibiotic therapy seems to
improve eradication after failed initial attempts.
Erythrosine B Catalyzed Synthesis of trans-Dihydro-4H-furo[3,2-c]chromen-4-ones through Photocatalytic Dehydrogenative sp
3 C–O Bond Formation
Authors: Bagdi Avik Kumar , Das Sourav , Paul Suvam , Choudhuri Tathagata , Sikdar Papiya
Published: February 2023

A simple and efficient visible-light-induced methodology has been developed for the selective synthesis of dihydro-4H-furo[3,2-c]chromen-4-one derivatives via dehydrogenative coupling reaction. The methodology is highly useful for the synthesis of varieties of dihydro-4H-furo[3,2-c]chromen-4-ones from readily accessible reactants under oxygen atmosphere. Importantly, the additive-free approach has been also demonstrated for this transformation. The results of the mechanistic investigation showed that this dehydrogenative reaction proceeded through a radical pathway. Additionally, the synthesized dihydro-4H-furo[3,2-c]chromen-4-one has been transformed into different 4H-furo[3,2-c]chromen-4-ones through simple protocols.
Pendant droplets throw light a curve
Authors: Patrick Chris
Published: February 2023

Changing the shape of uncured ultraviolet resin droplets allows simple generation and control of non-diffracting, self-accelerating beams.
Asymptotic profiles and singular limits for the viscoelastic damped wave equation with memory of type I
Authors: Chen Wenhui , Liu Yan
Published: February 2023

In this paper, we are interested in the Cauchy problem for the viscoelastic damped wave equation with memory of type I. By applying the WKB analysis and the Fourier analysis, we explain the memory’s influence on dissipative structures and asymptotic profiles of solutions to the model with additionally weighted L1 initial data. Furthermore, concerning standard energy and the solution itself, we establish the singular limit between the dissipative Moore–Gibson–Thompson equation with memory and the viscoelastic damped wave equation with memory, where a crucial compatibility condition of the initial datum is found.
Biased quartz crystal microbalance method for studies of chemical vapor deposition surface chemistry induced by plasma electrons
Authors: Niiranen Pentti , Nadhom Hama , Zanáška Michal , Boyd Robert , Sortica Mauricio , Primetzhofer Daniel , Lundin Daniel , Pedersen Henrik
Published: February 2023

A recently presented chemical vapor deposition (CVD) method involves using plasma electrons as reducing agents for deposition of metals. The plasma electrons are attracted to the substrate surface by a positive substrate bias. Here, we present how a standard quartz crystal microbalance (QCM) system can be modified to allow applying a DC bias to the QCM sensor to attract plasma electrons to it and thereby also enable in situ growth monitoring during the electron-assisted CVD method. We show initial results from mass gain evolution over time during deposition of iron films using the biased QCM and how the biased QCM can be used for process development and provide insight into the surface chemistry by time-resolving the CVD method. Post-deposition analyses of the QCM crystals by cross-section electron microscopy and high-resolution x-ray photoelectron spectroscopy show that the QCM crystals are coated by an iron-containing film and thus function as substrates in the CVD process. A comparison of the areal mass density given by the QCM crystal and the areal mass density from elastic recoil detection analysis and Rutherford backscattering spectrometry was done to verify the function of the QCM setup. Time-resolved CVD experiments show that this biased QCM method holds great promise as one of the tools for understanding the surface chemistry of the newly developed CVD method.
The atmospheric X-ray imaging spectrometer (AXIS) instrument: Quantifying energetic particle precipitation through bremsstrahlung X-ray imaging
Authors: Berland G. D. , Marshall R. A. , Martin C. , Buescher J. , Kohnert R. A. , Boyajian S. , Cully C. M. , McCarthy M. P. , Xu W.
Published: February 2023

The Atmospheric X-ray Imaging Spectrometer (AXIS) described in this work is a compact, wide field-of-view, hard x-ray imager. The AXIS instrument will fly onboard the Atmospheric Effects of Precipitation through Energetic X-rays (AEPEX) 6U CubeSat mission and will measure bremsstrahlung x-ray photons in the 50–240 keV range with cadmium–zinc–telluride (CZT) detectors using coded aperture optics. AXIS will measure photons generated by energetic particle precipitation for the purpose of determining the spatial scales of precipitation and estimating electron precipitation characteristics. This paper describes the design and testing of the AXIS instrument, including a summary of simulations performed that motivate the shielding, optics, and mechanical design. Testing and characterization is reported that validates the instrument design and shows that the instrument design meets or exceeds the measurement requirements necessary for AEPEX mission success.
Phenomenon of photo-regulation on gold/diamond Schottky barriers and its detector applications
Authors: Zhang Xiaohui , Liu Kang , Liu Benjian , Dai Bing , Zhang Yumin , Zhu Jiaqi
Published: February 2023

A thickness asymmetric electrode structure on an oxygen-terminated type IIa diamond was designed and prepared (one electrode was semitransparent to ultraviolet light and the other blocked the transmission of ultraviolet light). This structure exhibited an apparent photo-induced rectification property under irradiation by a deuterium lamp. This is attributed to the mechanism by which the light penetrating the electrode reduces the metal–diamond contact barrier. Furthermore, we developed a light-modulated Schottky barrier diamond photodetector based on this mechanism. Solar-blind light can lower the Schottky barrier height in situ in the presence of light, which significantly enhances the photocurrent. However, the Schottky barrier is not reduced by light regulation when there is no light; therefore, the low dark current of the detector is still guaranteed. Compared with the non-photo-regulated Schottky barrier detector, the photo-regulated Schottky barrier detector exhibits a 128% increase in responsivity at 220 nm under a 1.6 V/μm bias. For such an obvious difference in detection performance, this mechanism has rarely been a focus of studies on diamond detectors. In addition to diamond detectors, light-modulated barrier technology can also be applied to other fields related to the diamond surface potential, such as color center control and Schottky diodes; it can also be used to control or evaluate device performance.
Double diffusive instability with a constriction
Authors: Legare Sierra , Grace Andrew , Stastna Marek
Published: February 2023

Confined geometries have an effect on hydrodynamic instabilities, and this provides opportunities for controlling the rate of mixing in flows of engineering relevance. In multi-component fluids, differential diffusion allows for novel types of hydrodynamic instability that have finite amplitude manifestations even in millimeter-scale channels. We present numerical simulations that demonstrate that localized channel constrictions can serve to partially “catch” the manifestations of double diffusive instabilities. The fluid collects just above the narrowest point of the constriction and eventually undergoes a secondary instability. We study this secondary instability, focusing on its chaotic nature and on the way in which flow into the region below the constriction is controlled by the constriction amplitude and shape.
Low leakage current in isolated AlGaN/GaN heterostructure on Si substrate by N ion implantation performed at an elevated temperature
Authors: Wang Zheming , Yu Guohao , Yuan Xu , Deng Xuguang , Zhang Li , Dai Shige , Yang Guang , Zhang Liguo , Ji Rongkun , Kan Xiang , Zhang Xuan , Fu Houqiang , Zeng Zhongming , Wong Roy K.-Y. , Cai Yong , Zhang Baoshun
Published: February 2023

Electrical characterizations of AlGaN/GaN heterojunctions isolated by N implantation at elevated temperatures were investigated. Three-terminal measurements were carried out to characterize leakage paths, and crystal lattice damage due to implantation was monitored by high-resolution x-ray diffraction. Compared with room temperature implantation, the current leakage was reduced by ∼103 times by the implantation at 300 °C. The low leakage was attributed to low acceptor-like energy levels due to low crystal lattice damage by the “dynamic annealing” effect at high-temperature implantation. The post-annealing process increased the current leakage by two orders of magnitude. This indicates that the implantation isolation process should be conducted after higher temperature processes (>450 °C) in the fabrication of GaN devices. These results can provide valuable information for the fabrication, reliability, and mass production of various GaN-based photonics and electronics.
Feedback-controlled solute transport through chemo-responsive polymer membranes
Authors: Milster Sebastian , Kim Won Kyu , Dzubiella Joachim
Published: February 2023

Polymer membranes are typically assumed to be inert and nonresponsive to the flux and density of the permeating particles in transport processes. Here, we theoretically study the consequences of membrane responsiveness and feedback on the steady-state force–flux relations and membrane permeability using a nonlinear-feedback solution–diffusion model of transport through a slab-like membrane. Therein, the solute concentration inside the membrane depends on the bulk concentration, c0, the driving force, f, and the polymer volume fraction, ϕ. In our model, the solute accumulation in the membrane causes a sigmoidal volume phase transition of the polymer, changing its permeability, which, in return, affects the membrane’s solute uptake. This feedback leads to nonlinear force–flux relations, j(f), which we quantify in terms of the system’s differential permeability, PsysΔ∝dj/df. We find that the membrane feedback can increase or decrease the solute flux by orders of magnitude, triggered by a small change in the driving force and largely tunable by attractive vs repulsive solute–membrane interactions. Moreover, controlling the inputs, c0 and f, can lead to the steady-state bistability of ϕ and hysteresis in the force–flux relations. This work advocates that the fine-tuning of the membrane’s chemo-responsiveness will enhance the nonlinear transport control features, providing great potential for future (self-)regulating membrane devices.
A numerical assessment of shock–droplet interaction modeling including cavitation
Authors: Forehand R. W. , Nguyen K. C. , Anderson C. J. , Shannon R. , Grace S. M. , Kinzel M. P.
Published: February 2023

A computational study of the wave phenomenon and probable cavitation that occurs when a droplet interacts with a shock is presented. A volume-of-fluid method with and without a cavitation model activated is employed. The model with no cavitation is used to clarify the droplet's internal wave field. The model is benchmarked using experimental data of a 22 mm water column impacted by a shock wave at Mach 2.4. Good agreement between the computational results for a two-dimensional (2D) circular droplet and the experimental results is demonstrated. A simplified 2D, square droplet is also considered in order to highlight the effects of interface curvature on the internal waves. Comparison of the results for the square and circular drops shows that the circular geometry diffuses the initial pressure wave while focusing the reflected wave. The three-dimensional (3D) spherical droplet was then analyzed. The internal wave behavior is similar to the 2D circular drop with enhanced diffusion and focusing. Two cavitation models were then used to explore the probability that cavitation occurs for a nominal sized raindrop interacting with shock waves, Mach 1.5–5. Two cavitation models, full Rayleigh–Plesset (FRP) and Schnerr-Sauer both predicted vapor formation at the same location with the FRP always predicting slightly higher amounts of vapor. The current setting for number of nuclei ensures that the simulation is not swamped by vapor formation but is unrealistically small. Therefore, while the work demonstrates that cavitation will occur, the full nature of the cavitation along with the impulsive pressure waves it should create is not currently captured.
Classical density functional theory for interfacial properties of hydrogen, helium, deuterium, neon, and their mixtures
Authors: Hammer Morten , Bauer Gernot , Stierle Rolf , Gross Joachim , Wilhelmsen Øivind
Published: February 2023

We present a classical density functional theory (DFT) for fluid mixtures that is based on a third-order thermodynamic perturbation theory of Feynman-Hibbs-corrected Mie potentials. The DFT is developed to study the interfacial properties of hydrogen, helium, neon, deuterium, and their mixtures, i.e., fluids that are strongly influenced by quantum effects at low temperatures. White Bear fundamental measure theory is used for the hard-sphere contribution of the Helmholtz energy functional, and a weighted density approximation is used for the dispersion contribution. For mixtures, a contribution is included to account for non-additivity in the Lorentz–Berthelot combination rule. Predictions of the radial distribution function from DFT are in excellent agreement with results from molecular simulations, both for pure components and mixtures. Above the normal boiling point and 5% below the critical temperature, the DFT yields surface tensions of neon, hydrogen, and deuterium with average deviations from experiments of 7.5%, 4.4%, and 1.8%, respectively. The surface tensions of hydrogen/deuterium, para-hydrogen/helium, deuterium/helium, and hydrogen/neon mixtures are reproduced with a mean absolute error of 5.4%, 8.1%, 1.3%, and 7.5%, respectively. The surface tensions are predicted with an excellent accuracy at temperatures above 20 K. The poor accuracy below 20 K is due to the inability of Feynman–Hibbs-corrected Mie potentials to represent the real fluid behavior at these conditions, motivating the development of new intermolecular potentials. This DFT can be leveraged in the future to study confined fluids and assess the performance of porous materials for hydrogen storage and transport.
Research on a matching detection method for magnetic anomaly of underwater targets
Authors: Liu Yifei , Zhang Ning , Shi Zhangsong , Gu Hongcan
Published: February 2023

In the field of aviation anti-submarine warfare, magnetic detection systems often result in a large number of false alarms due to the inability to effectively distinguish between a local geomagnetic anomaly in the background field and a target magnetic anomaly. To address this problem, this paper proposes a matching detection method for the magnetic anomaly of underwater targets. This method is based on the measured data of the magnetic anomaly in the sea area, and the geomagnetic reference map of the area is generated by interpolation of the Kriging method; then, the background field signal extracted from the geomagnetic reference map and the real-time signal acquired by detection are matched by the similarity metric algorithm; finally, the target detection is realized by using the feature fusion-isolation forest algorithm. Compared with the conventional detection methods, such as time–frequency analysis, the detection rate is improved by nearly 15% and the false alarm rate is reduced by about 40%, indicating that matching detection can effectively filter out the magnetic anomaly in the background field, reduce the false alarm, and improve the detection rate in the real geomagnetic environment, which has certain application value.
A relativistic relationship between parity-violating nuclear spin-rotation tensors and parity-violating NMR shielding tensors
Authors: Aucar I. Agustín , Colombo Jofré Mariano T. , Aucar Gustavo A.
Published: February 2023

The nuclear-spin-dependent parity-violation contributions to the nuclear magnetic resonance shielding and nuclear spin-rotation tensors (σPV and MPV, respectively) are known to be formally related to one another in the non-relativistic regime. In this work, the polarization propagator formalism and the linear response within the elimination of small components model are used to show a new and more general relationship between them, which is valid within the relativistic framework. The full set of the zeroth- and first-order relativistic contributions to σPV and MPV are also given here for the first time, and these results are compared with previous findings. According to four-component relativistic calculations, the electronic spin–orbit effects are the most significant ones for the isotropic values of σPV and MPV in the H2X2 series of molecules (with X = O, S, Se, Te, and Po). When only scalar relativistic effects are taken into account, the non-relativistic relationship between σPV and MPV does hold. However, when the spin–orbit effects are taken into consideration, this old non-relativistic relationship breaks down, and therefore, the new one must be considered.
Ultra-short pulse magnetic fields on effective magnetic hyperthermia for cancer therapy
Authors: Kuwahata Akihiro , Adachi Yuui , Yabukami Shin
Published: February 2023

Alternating magnetic fields can deliver magnetic energy deeper inside the body for magnetic hyperthermia cancer therapy by using magnetic nanoparticles (MNPs). In this study, we proposed a highly effective heat generation method for the MNPs by the application of an ultra-short pulse wave. We numerically evaluated the heating power with a variety of parameters, such as pulse width, field amplitude, and frequency. The hysteresis curve and magnetization dynamics clearly indicate larger energy dissipation. Hysteresis loss and the input energy increase with increasing field strength and duty ratio and there is a large efficiency power condition. To evaluate the effective heat generation and practical temperature increment, a larger imaginary part of magnetic susceptibility (χ″ > 30) and specific loss power (SLP > 105 W/kg) are required. In addition, larger intrinsic loss power (100 nHm2/kg) is achieved. The results indicate that the contribution of magnetic harmonics signals on the ultra-short pulse wave significantly enhances the heat generation of MNPs for cancer therapy.
Pesticide extraction from soil into runoff under a rainfall simulator
Authors: Silburn D. Mark
Published: February 2023

Context Runoff estimation is an important aspect of pesticide environmental behaviour and is the major loss pathway to the environment. Aims To improve understanding of pesticide runoff. Methods Data from three rainfall simulator studies was used. Twelve pesticides were studied ranged from tightly sorbed (DDE, soil sorption coefficient (KD) ~15 000 L kg−1) to weakly sorbed (dimethoate, KD < 30). Key results Event runoff pesticide concentrations were closely related to soil concentrations (0–25 mm depth). The ratio of runoff to soil concentration (the runoff extraction ratio, ERO), was similar for pesticides with a wide range of sorption and across the three soils: runoff concentration (μg L−1) = 28 × soil concentration (mg kg−1). ERO decreased with time after spraying, presumably due to lower concentrations in the top few mm of soil. Conclusions This model provides improved or similar estimates of pesticide runoff than previous models. Similar ERO values between sites was probably due to similar hydrology (high rainfall intensity, surface sealing, moist subsoils) and erosion, and because the same masses of soil and water are involved in mixing. Reduction in runoff concentrations by leaching was not influential, because infiltration was small and soil sorption too high. Implications Conditions studied apply during summer storms on most cotton and grain land on clay soils in the northern grain and cotton lands in eastern Australia. The model should be applicable under these conditions.
Learning hydrodynamic equations for active matter from particle simulations and experiments
Authors: Supekar Rohit , Song Boya , Hastewell Alasdair , Choi Gary P. T. , Mietke Alexander , Dunkel Jörn
Published: February 2023

Recent advances in high-resolution imaging techniques and particle-based simulation methods have enabled the precise microscopic characterization of collective dynamics in various biological and engineered active matter systems. In parallel, data-driven algorithms for learning interpretable continuum models have shown promising potential for the recovery of underlying partial differential equations (PDEs) from continuum simulation data. By contrast, learning macroscopic hydrodynamic equations for active matter directly from experiments or particle simulations remains a major challenge, especially when continuum models are not known a priori or analytic coarse graining fails, as often is the case for nondilute and heterogeneous systems. Here, we present a framework that leverages spectral basis representations and sparse regression algorithms to discover PDE models from microscopic simulation and experimental data, while incorporating the relevant physical symmetries. We illustrate the practical potential through a range of applications, from a chiral active particle model mimicking nonidentical swimming cells to recent microroller experiments and schooling fish. In all these cases, our scheme learns hydrodynamic equations that reproduce the self-organized collective dynamics observed in the simulations and experiments. This inference framework makes it possible to measure a large number of hydrodynamic parameters in parallel and directly from video data.
Self-renewing macrophages in dorsal root ganglia contribute to promote nerve regeneration
Authors: Feng Rui , Muraleedharan Saraswathy Vishnu , Mokalled Mayssa H. , Cavalli Valeria
Published: February 2023

Sensory neurons located in dorsal root ganglia (DRG) convey sensory information from peripheral tissue to the brain. After peripheral nerve injury, sensory neurons switch to a regenerative state to enable axon regeneration and functional recovery. This process is not cell autonomous and requires glial and immune cells. Macrophages in the DRG (DRGMacs) accumulate in response to nerve injury, but their origin and function remain unclear. Here, we mapped the fate and response of DRGMacs to nerve injury using macrophage depletion, fate-mapping, and single-cell transcriptomics. We identified three subtypes of DRGMacs after nerve injury in addition to a small population of circulating bone-marrow–derived precursors. Self-renewing macrophages, which proliferate from local resident macrophages, represent the largest population of DRGMacs. The other two subtypes include microglia-like cells and macrophage-like satellite glial cells (SGCs) (Imoonglia). We show that self-renewing DRGMacs contribute to promote axon regeneration. Using single-cell transcriptomics data and CellChat to simulate intercellular communication, we reveal that macrophages express the neuroprotective and glioprotective ligand prosaposin and communicate with SGCs via the prosaposin receptor GPR37L1. These data highlight that DRGMacs have the capacity to self-renew, similarly to microglia in the Central nervous system (CNS) and contribute to promote axon regeneration. These data also reveal the heterogeneity of DRGMacs and their potential neuro- and glioprotective roles, which may inform future therapeutic approaches to treat nerve injury.
Tensile and wear properties of as-cast and extruded AZ91-xCNT and AZ91-1B4C-1SiC-xCNT composites
Authors: Goodarzi M. , Emamy M. , Malekan M.
Published: February 2023

Tensile and wear properties of as-cast and extruded AZ91-xCNTs and AZ91-1%B4C-1%SiC-xCNT (x:0.25,0.5,1wt.%) composites were studied. Compared to as-cast AZ91 matrix alloy, hot extruded AZ91-0.25%CNT showed a significant enhancement in UTS (385 MPa) and elongation (16%), with no substantial improvement in wear properties however, the AZ91-xCNT composites containing micron-sized 1%B4C and 1%SiC particles met the lower tensile properties. Interesting wear behaviour was obtained after adding 1wt.%B4C and 1wt.%SiC to AZ91-xCNT where improvement in wear results was considerable. Development in wear properties of the AZ91-1%B4C-1%SiC-xCNT composites can be attributed to the enhanced hardness and reduced coefficient of friction. Wear analyses of two composites exhibited various wear mechanisms, but the abrasion mechanism dominated after CNT addition and hot extrusion at 20 N load.
Loading-direction dependence of interaction types between different twin variants in AZ31 alloy
Authors: Xi Guoqiang , Luo Yu , Zhang Jing , Chen Jianhao , Chen Hao
Published: February 2023

In this research, Loading-direction dependence of interaction types between different [Formula: see text] twin variants in AZ31 alloy was investigated. The microstructure, twin evolution, and the deformation mechanisms of samples were characterised by quasi-in-situ electron backscatter diffraction. The result showed that during rolling direction (RD)-pre-compression and re-compression, the grains with co-zone twin–twin interaction (Type I) are in the majority, while during RD-pre-compression and transverse direction (TD)-re-compression, the grains with non-cozone twin–twin interaction (Type II) are dominant. Furthermore, the effect of different types of twin–twin interaction on subsequent microstructure evolution is clarified. Our experimental results may provide insights for tailoring different types of twin–twin interaction.
Deflection in higher dimensional spacetime and asymptotically non-flat spacetimes
Authors: He Jinhong , Wang Qianchuan , Hu Qiyue , Feng Li , Jia Junji
Published: February 2023

Using a perturbative technique, in this work we study the deflection of null and timelike signals in the extended Einstein–Maxwell spacetime, the Born–Infeld gravity and the charged Ellis–Bronnikov (CEB) spacetime in the weak field limit. The deflection angles are found to take a (quasi-)series form of the impact parameter, and automatically takes into account the finite distance effect of the source and observer. The method is also applied to find the deflections in CEB spacetime with arbitrary dimension. It’s shown that to the leading non-trivial order, the deflection in some n-dimensional spacetimes is of the order

. We then extended the method to spacetimes that are asymptotically non-flat and studied the deflection in a nonlinear electrodynamical scalar theory. The deflection angle in such asymptotically non-flat spacetimes at the trivial order is found to be not π anymore. In all these cases, the perturbative deflection angles are shown to agree with numerical results extremely well. The effects of some nontrivial spacetime parameters as well as the signal velocity on the deflection angles are analyzed.
Oxygen vacancy related hole fast trapping in high mobility cubic-Ge/ZrO2 interface
Authors: Liu Zhu-You , Cai Xuefen , Zhang Cai-Xin , Cao Ru-Yue , Liu Yue-Yang , Deng Hui-Xiong
Published: February 2023

Ge has the potential to replace Si as the future field-effect transistors channel material due to its superior hole mobility, and cubic zirconia with high dielectric constant and small lattice mismatch can be selected as its oxide layer. At present, the mechanism of charge trapping caused by defects in the Ge oxide layer interface and bulk of such device has not been accurately analyzed. In our work, we have constructed the cubic Ge/ZrO2 interface, and studied the electronic structure and hole trapping characteristics of the interface structure by first-principles hybrid-functional calculations with Marcus theory. According to research oxygen vacancies with the different distances (abbr. d
O-int) away from the Ge substrate, we confirm that the oxygen vacancy can act as a fast trap center to capture the hole of the valence band maximum (VBM) from Ge, resulting in the ultrafast or fast transient charge trapping in the high-k gate dielectric. We found that, when a given range of applied electric field, the hole trap is ultrafast with capture time of 10−6–10−5

μ

s

when d
O-int is within the range of 2–7

A

∘

, and there is a 2–3 order of magnitude increases in capture time as d
O-int exceeds 7

A

∘

with the maximum capture cross section reducing substantially. Here, our work provides a clear and reasonable description of the distance-dependent hole trapping process at the Ge/high-k dielectrics metal-oxide-semiconductor (MOS) devices and provides significant support for solving the reliability problem of microelectronic devices.
Compact thin-film lithium niobate modulators using slotted coplanar waveguide electrode suitable for high-volume fabrication
Authors: Li Heng , Tang Yongqian , Chen Quanan , Dai Xiangyang , Li Xiaohan , Lu Mingzhi , Lu Qiaoyin , Guo Weihua
Published: February 2023

Lithium niobate (LN) is a good candidate for fabricating modulators due to its superior material characteristics. However, the application of traditional LN modulators is limited due to their large footprint and low modulation efficiency resulting from weak optical confinement. In recent years, with the development of the thin-film lithium niobate (TFLN) platform and LN etching technology, the size of the optical mode of the TFLN modulator is 20 times smaller than that of the traditional LN modulator. Furthermore, TFLN modulators have demonstrated a wide bandwidth, low half-wave voltage and small footprint in recent reports. The length of the TFLN modulators can be further reduced by employing a folded design and therefore applicable to compact transceiver package, such as being packaged in the quad small form factor pluggable double density transceiver. In this paper, we report on a folded TFLN modulator fabricated from a 4 inch LN wafer, which is suitable for large-volume fabrication. A fiber-to-fiber insertion loss of 2.5 dB and a voltage–length product of 1.85 V cm have been achieved. The measured electro-optic response curve has a 2.3 dB roll-off at 40 GHz, and the simulated 3 dB bandwidth reaches 65 GHz. Compared to traditional coplanar waveguide traveling wave electrodes, the slotted coplanar waveguide traveling wave electrode (slotted CPW-TWE) design adopted in this work allows adjusting the high-speed characteristics and modulation efficiency with more flexibility. This is the first time a slotted CPW-TWE design has been applied in a folded TFLN modulator.
Les Houches 2021—physics at TeV colliders: report on the standard model precision wishlist
Authors: Huss Alexander , Huston Joey , Jones Stephen , Pellen Mathieu
Published: February 2023

Les Houches activities in 2021 were truncated due to the lack of an in-person component. However, given the rapid progress in the field and the restart of the LHC, we wanted to continue the bi-yearly tradition of updating the standard model precision wishlist. In this work we therefore review recent progress (since Les Houches 2019) in fixed-order computations for LHC applications. In addition, necessary ingredients for such calculations such as parton distribution functions, amplitudes, and subtraction methods are discussed. Finally, we indicate processes and missing higher-order corrections that are required to reach the theoretical accuracy that matches the anticipated experimental precision.
The structure and multifunctionality of high-boron transition metal borides
*
Authors: Zhao Bo , Wang Lu , Tao Qiang , Zhu Pinwen
Published: February 2023

High boron content transition metal (TM) borides (HB-TMBs) have recently been regarded as the promising candidate for superhard multifunctional materials. High hardness stems from the covalent bond skeleton formed by high content of boron (B) atoms to resist deformation. High valence electron density of TM and special electronic structure from p-d hybridization of B and TM are the sources of multifunction. However, the reason of hardness variation in different HB-TMBs is still a puzzle because hardness is a complex property mainly associated with structures, chemical bonds, and mechanical anisotropy. Rich types of hybridization in B atoms (sp, sp2, sp3
) generate abundant structures in HB-TMBs. Studying the intrinsic interaction of structures and hardness or multifunction is significant to search new functional superhard materials. In this review, the stable structure, hardness, and multifunctionality of HB-TMBs are summarized. It is concluded that the structures of HB-TMBs are mainly composed by sandwiched stacking of B and TM layers. The hardness of HB-TMBs shows a increasing tendency with the decreasing atom radius. The polyhedron in strong B skeleton provides hardness support for HB-TMBs, among which C2/m is the most possible structure to meet the superhard standard. The shear modulus (G
0) generates a positive effect for hardness of HB-TMBs, but the effect from bulk modulus (G
0) is complex. Importantly, materials with a value of B
0/G
0 less than 1.1 are more possible to achieve the superhard standard. As for the electronic properties, almost all TMB3 and TMB4 structures exhibit metallic properties, and their density of states near the Fermi level are derived from the d electrons of TM. The excellent electrical property of HB-TMBs with higher B ratio such as ZrB12 comes from the channels between B–B π-bond and TM-d orbitals. Some HB-TMBs also indicate superconductivity from special structures, most of them have stronger hybridization of d electrons from TM atoms than p electrons from B atoms near the Fermi level. This work is meaningful to further understand and uncover new functional superhard materials in HB-TMBs.
Decay processes of long-lived phonons in 6H-SiC
Authors: Pshenay-Severin D A , Adamov R B , Vinnichenko M Ya , Moldavskaya M D , Shalygin V A
Published: February 2023

Temperature evolution of the high-resolution far-infrared transmission spectra of 6H-SiC single crystal slab is experimentally examined in a temperature range of 5–320 K. Temperature dependences of the phonon lifetimes for long-lived phonons, namely the IR active folded transverse acoustic (FTA) phonon doublet, are determined. These dependences are interpreted in the framework of a theoretical model developed using first principle anharmonic lattice dynamics. It is shown that three-phonon anharmonic processes dominate in the FTA phonon decay at temperatures above 160 K resulting in a rapid decrease of the phonon lifetimes with increasing temperature. Contribution of four-phonon anharmonic processes is negligibly small at temperatures below 320 K.
Demodulated synchrosqueezing S-transform and its application to machine-fault diagnosis
Authors: Liu Wei , Liu Yang , Li Shuangxi , Zhai Zhixing
Published: February 2023

The time–frequency analysis (TFA) technique has been viewed as a useful tool for processing non-stationary signals in the field of industrial machinery. Rub-impacts of a rotor system will cause vibration of the rotor and stator, thus any vibration signal with rub-impacts will be accompanied by high-frequency oscillation characteristics. In this paper, a novel TFA algorithm, termed a demodulated synchrosqueezing S-transform (DSSST), is proposed to extract the strong time-varying features in rub-impact vibration signals. The DSSST method is based on a modified S-transform, and introduces a pre-processing technique, a demodulation algorithm, to partially demodulate the oscillated modes for rub-impact identification. Meanwhile, a synchrosqueezing transform is utilized to further sharpen the time–frequency representation. Assisted by the proposed method, the rub-impact phenomenon and its impact frequency are clearly recognized through experimental and real validations.
Comparing the images formed by uses of lens surfaces
Authors: Isik Hakan
Published: February 2023

In this study, university students’ experiences with conventional and novel applications for the surfaces of biconvex and biconcave lenses were examined. This work used practical tools to depict refraction and reflection processes that occur on lens surfaces. In the main activity, the surfaces of each lens were used by the students to examine a single image created by refracted light rays and then two images created by reflected light rays. When the students compared the properties of virtual and real images, they discovered that viewing both real and virtual images at the same time is more beneficial and simulating than viewing each image type separately.
Enhancement of nonvolatile memory characteristics caused by GaN/AlN resonant tunneling diodes
Authors: Nagase Masanori , Takahashi Tokio , Shimizu Mitsuaki
Published: February 2023

This paper reports an enhancement of the nonvolatile memory characteristics of GaN/AlN resonant tunneling diodes (RTDs) by reducing the crystal defects in the quantum well structure. Pit-shaped crystal defects are strongly suppressed when pure N2, instead of a N2/H2 mixture, is used as a carrier gas and trimethylindium is introduced as a surfactant for metalorganic vapor phase epitaxy of the quantum well structure. In addition, the density of dislocations is lowered by controlling the growth conditions and structure of the buffer layer between a GaN/AlN RTD and a sapphire (0001) substrate. The leakage current through the quantum well structure is lowered, and an extremely high ON/OFF of >1300, which is 20 times higher than the values obtained in previous studies, is induced. Theoretical calculations based on Poisson’s equation and the Tsu–Esaki formula indicate that a high ON/OFF ratio of >103 can be enhanced by increasing the density of electrons accumulating in the quantum well to a level on the order of 1018 cm–3. Furthermore, nonvolatile memory operations were performed by inputting the sequential pulse voltages with a speed of nanosecond time scale which is faster than speeds of electron releases from the crystal defects. These results strongly indicate that the nonvolatile memory characteristics of GaN/AlN RTDs are due to intersubband transitions and electron accumulation in the quantum well and are not attributed to electron trapping by the crystal defects.
Numerical study on flux-jump occurrence in a cup-shaped MgB2 bulk for magnetic shielding applications
Authors: Fracasso M , Gömöry F , Solovyov M , Gerbaldo R , Ghigo G , Laviano F , Sparacio S , Torsello D , Gozzelino L
Published: February 2023

MgB2 is one of the most promising materials for superconducting bulk applications. However, thermomagnetic instabilities can arise in the material because of its low heat capacity and thermal conductivity as well as its high critical current density. Being able to predict these phenomena, can guide and optimize MgB2-based devices for magnetic flux shielding or trapping applications. In this work, the flux-jump occurrence in an MgB2 cup-shaped shield is numerically studied using the finite element method by means of the commercial software COMSOL 6.0 Multiphysics®. To this aim, we developed a 2D axial-symmetric model coupling the heat diffusion equation and the magnetic equations based on a magnetic vector-potential (

A
⃗

) formulation. The comparison of the computed shielding curves with the experimental ones evidenced a good agreement between the two sets of data at different temperatures and positions along the shield’s axis. The as-validated model was then exploited to investigate possible optimization routes via the improvement of both the thermal conductivity of the material and the thermal exchange between the device and the cooling stage.
Near-isotropic enhancement of the 20 K critical current of REBa2Cu3O7 coated conductors from columnar defects
Authors: Strickland Nicholas M , Wimbush Stuart C , Soman Arya Ambadiyil , Long Nicholas J , Rupich Martin W , Knibbe Ruth , Li Ming , Notthoff Christian , Kluth Patrick
Published: February 2023

Normal-incidence irradiation by 100 MeV Ag ions is used to improve flux pinning in previously optimised commercial REBCO tapes from the American Superconductor Corporation. We observe distinct critical-current anisotropy enhancements below and above 40 K. Above 40 K a strong c-axis peak appears in the angular dependence of the critical current, as is usually expected upon the introduction of columnar defects. The critical current is enhanced significantly but only for a limited range of field angles. Close to the parallel-field direction there is no enhancement or even a reduction in critical current. Below 40 K, on the other hand, the enhancement is much broader with respect to field angle, creating an almost isotropic response at 20 K, 3 T. The absence of a prominent c-axis peak does not indicate a lack of pinning, since the absolute value of the critical current still increases by a factor of 2.8 compared to an unirradiated sample. Instead, we postulate that pre-existing point-like pinning centres act to mediate an interaction between the existing planar and newly-introduced columnar pins, broadening both contributions. The point-like pins become less effective with increasing temperature as the coherence length increases, leading to a reduction in this interaction and a separation of the individual peaks relating to planar and columnar pins. At 20 K, we achieve an enhancement in the angular-minimum critical current by a factor of 2.7, in a material that had already been process-optimised for low-temperature pinning.
Synthesis and modification of the structural, optical, and thermal properties of PVA–PEO by LDH nanoplates
Authors: Hosni N M , El-Sayed S , El Sayed Adel M , Saber S
Published: February 2023

Nanocomposites with thermal stability and tunable optical properties became essential for developed optoelectronic and electrochemical devices. This work represents an attempt to synthesize PVA–PEO polymeric blend and modifies its structural, optical, and thermal properties. This was performed by incorporating different ratios of double-layered hydroxide (Zn/Fe-LDH) nanoplates (NP) which were prepared by the co-precipitation process. XRD results revealed that the incorporation of LDH, 43 nm in size and rhombohedral phase, influenced the degree of crystallinity (X
C) of the blend. FE-SEM analysis showed the uniform distribution of LDH NP in the polymer matrix until 7.0 wt% content, beyond this ratio some voids were formed in the blend surface and particle agglomeration took place. FTIR spectroscopy illustrated the good miscibility of the polymers forming the blend, the interaction, and complexation between LDH NP and the blend functional groups. UV–vis-NIR spectroscopy analysis was performed to study the transmittance of the nanocomposites, extinction coefficient, refractive index, and optical conductivity. Besides, the direct and indirect band gaps of the films were found to decrease with increasing LDH NP content until a certain limit, after which they increased again. TGA&DSC analysis revealed the thermal stability of the films until 240 °C, and the DSC curves indicated three endothermic peaks. The obtained results confirmed that LDH NP incorporation is an interesting approach for tuning the optical and thermal properties to widen the technological applications based on PVA–PEO blend.
Localized wave solutions for (2+1)-dimensional third-order Fokou-Kofane-Mohamadou-Yomba equation
Authors: Fokou M , Kofane T C , Mohamadou A , Yomba E
Published: February 2023

Analytical and numerical investigations of localized wave solutions for a nonlinear evolution of shallow water waves with surface tension, which is described by the (2+1)-dimensional third-order Fokou-Kofane-Mohamadou-Yomba (FKMY) equation are performed. Furthermore, we show, mainly by Maple software and the Hirota bilinear method, that appropriated ansatzes can be used to generate new large families of traveling localized structures such as lump, soliton, periodic soliton, quasi-periodic soliton, and quasi-periodic breather solutions. Interactions between those soliton solutions and their dependence on the system physical parameters have been carefully analysed. We show that the soliton solutions of the 2D third-order FKMY display a very rich spectrum of dynamical behaviour when its parameters are varied. The present results could be applicable in explaining the basic features of localized disturbances in many fields of science where the 2D third-order FKMY equation appears.
Impact of the capture time on power saturation of quantum-well diode lasers
Authors: Boni A , Wenzel H , Crump P
Published: February 2023

Injected electrons and holes are captured into quantum wells with a non-vanishing time. Simulation results are presented, showing that this results in a non-equilibrium of free and bound carriers in a diode laser. Analysis of an exemplary diode laser structure is used to show that if the capture time is too large, the carrier densities in regions adjacent to the quantum well rise strongly beyond their values at threshold at very high output power. This results in an increase of the free carrier absorption and the non-stimulated recombination, causing a reduction of the slope efficiency and a downwards-bending of the power-current characteristics (power saturation), consistent with experimental results. For the layer structure studied, the additional losses due to accumulation of holes in the n-doped region is predicted to be the dominant effect.
Shaft inflation in Randall-Sundrum model
Authors: Loc Ngo Phuc Duc
Published: February 2023

Shaft inflation is a model in which the inflaton potential approaches a plateau far from
the origin, while it mimics chaotic inflation near the origin. Meanwhile, the Randall-Sundrum type
II model (RSII) is an interesting extra-dimensional model to study cosmological phenomenology. In
this paper, we study shaft inflation in the RSII model. We find that the predictions are in
excellent agreement with observation. The fundamental five-dimensional Planck scale is found to be 
M
5 ≃ 1016 GeV, which is consistent with the lower bound M
5 ≳ 109 GeV obtained
from experimental Newtonian gravitational bound. This is an important result that can be used to explore further the implications of extra dimension in other contexts.