bluuebunny/crossref_metadata_2025 huggingface dataset:
State regulation of supply chains through the introduction of goods marking
Authors: Sharova Irina , Slepenkova Elena , Sobolev Dmitry , Melnikov Michail , Rykalina Olga
Published: July 2021

Among the most acute problems of the modern economy is not only reducing the cost and improving the efficiency of supply chains, but also their protection from the influence of the shadow economy. In this case, the greatest threat is the illicit trafficking of industrial products. Authors analyze state regulation of supply chains in Russia and abroad, consider the prospects for the development of digital marking and traceability of goods as a method of state regulation of supply chains. The article emphasizes that the existing marking system contains a number of shortcomings. The authors propose mechanisms to improve state regulation of supply chains in modern conditions.
Analysis and forecasting of performance indicators of air transport facilities
Authors: Kochkina Elena , Radkovskaya Elena , Denezhkina Kseniya
Published: July 2021

Aviation is one of the most significant growth drivers not only for the transportation infrastructure, but also for country’s economy as it contributes to both industrial and social progress of society. The paper focuses on Sheremetyevo International Airport, one of the largest Russian airports and analyzes it in terms of short-term and long-term perspectives. Using real statistical data, the article presents the models for forecasting essential performance indicators of airports, namely, passenger traffic and revenue. By comparing quality characteristics, most suitable models were selected and checked for adequacy. Forecasts of the probable changes in the values of the performance indicators were made under the assumption of maintaining the previously formed development trend.
Gradient discretization of two-phase poro-mechanical models with discontinuous pressures at matrix fracture interfaces
Authors: Bonaldi Francesco , Brenner Konstantin , Droniou Jérôme , Masson Roland , Pasteau Antoine , Trenty Laurent
Published: July 2021

We consider a two-phase Darcy flow in a fractured and deformable porous medium for which the fractures are described as a network of planar surfaces leading to so-called hybrid-dimensional models. The fractures are assumed open and filled by the fluids and small deformations with a linear elastic constitutive law are considered in the matrix. As opposed to [F. Bonaldi, K. Brenner, J. Droniou and R. Masson, Comput. Math. with Appl. 98 (2021)], the phase pressures are not assumed continuous at matrix fracture interfaces, which raises new challenges in the convergence analysis related to the additional interfacial equations and unknowns for the flow. As shown in [K. Brenner, J. Hennicker, R. Masson and P. Samier, J. Comput. Phys. 357 (2018)], [J. Aghili, K. Brenner, J. Hennicker, R. Masson and L. Trenty, GEM – Int. J. Geomath. 10, (2019)], unlike single-phase flow, discontinuous pressure models for two-phase flows provide a better accuracy than continuous pressure models even for highly permeable fractures. This is due to the fact that fractures fully filled by one phase can act as barriers for the other phase, resulting in a pressure discontinuity at the matrix fracture interface. The model is discretized using the gradient discretization method [J. Droniou, R. Eymard, T. Gallouët, C. Guichard, and R. Herbin, Springer, Mathematics & Applications, 82 (2018)], which covers a large class of conforming and non conforming schemes. This framework allows for a generic convergence analysis of the coupled model using a combination of discrete functional tools. In this work, the gradient discretization of [F. Bonaldi, K. Brenner, J. Droniou and R. Masson, Comput. Math. with Appl. 98 (2021)] is extended to the discontinuous pressure model and the convergence to a weak solution is proved. Numerical solutions provided by the continuous and discontinuous pressure models are compared on gas injection and suction test cases using a Two-Point Flux Approximation (TPFA) finite volume scheme for the flows and ℙ2 finite elements for the mechanics.
Die Dämonisierung der Manuellen Therapie
Authors: Cook Chad E.
Published: July 2021

„Dämonisierung“ nennt der amerikanische Physiotherapeut und Professor Dr. Chad E. Cook die in den letzten Jahren lauter werdende Kritik an der Manuellen Therapie. Acht dieser „Dämonisierungen“ greift er auf und bewertet diese sorgfältig anhand der aktuellen Literatur. Seine Ziele mit dem Artikel sind: Diskussionen anstoßen, falsche Annahmen abbauen und Patienten eine evidenzbasierte Therapie ermöglichen.
High-performance ion source generated by ultraviolet laser irradiation of Cu crystals
Authors: Zheng Xiaolong , Zhang Xiaomei , Ahrens Sven , Shen Baifei
Published: July 2021

Ultraviolet laser driven radiation pressure acceleration of Cu crystals is investigated by using particle-in-cell simulations. When an ultrathin Cu crystal is irradiated by a circularly polarized pulse with wavelength λ = 72 nm, waist radius w0=4λ, and normalized magnitude a0=20 (energy of 85 mJ), a plasma with a lattice structure is generated first. Then, an acceleration field of 14.2 TV/cm can be induced by the radiation pressure of the ultraviolet pulse in the target, which is about one order of magnitude larger than that of optical lasers for the same a0, and the lattice structure exerts effect on the acceleration only in the vicinity of the optimal target thickness. As a result, a quasi-monoenergetic Cu ion beam of energy of 5 GeV (75 MeV/nucleon), a charge of 0.12 nC, and the emittance of 7×10−9 m rad can be produced, which implies that using ultraviolet lasers instead of optical lasers should turn down the size and emittance of ion sources by orders lower than that of optical lasers. Therefore, a high-performance ion source is produced, which may have potential applications in medical therapy and ion radiography.
Mach number dependence of ion-scale kinetic instability at collisionless perpendicular shock: Condition for Weibel-dominated shock
Authors: Nishigai Takuro , Amano Takanobu
Published: July 2021

We investigate ion-scale kinetic plasma instabilities at the collisionless shock using linear theory and nonlinear particle-in-cell (PIC) simulations. We focus on the Alfvén ion cyclotron (AIC), mirror, and Weibel instabilities, which are all driven unstable by the effective temperature anisotropy induced by the shock-reflected ions within the transition layer of a strictly perpendicular shock. We conduct linear dispersion analysis with a homogeneous plasma model to mimic the shock transition layer by adopting a ring distribution with finite thermal spread to represent the velocity distribution of the reflected ions. We find that, for wave propagation parallel to the ambient magnetic field, the AIC instability at lower Alfvén Mach numbers tends to transition to the Weibel instability at higher Alfvén Mach numbers. The instability property is, however, also strongly affected by the sound Mach number. We conclude that the instability at a strong shock with Alfvén and sound Mach numbers both in excess of ∼20–40 may be considered as Weibel-like in the sense that the reflected ions behave essentially unmagnetized. Two-dimensional PIC simulations confirm the linear theory and find that, with typical parameters of young supernova remnant shocks, the ring distribution model produces magnetic fluctuations of the order of the background magnetic field, which is smaller than those observed in previous PIC simulations for Weibel-dominated shocks. This indicates that the assumption of the gyrotropic reflected ion distribution may not be adequate to quantitatively predict nonlinear behaviors of the dynamics in high Mach number shocks.
Key parameters for surface plasma wave excitation in the ultra-high intensity regime
Authors: Marini S. , Kleij P. S. , Amiranoff F. , Grech M. , Riconda C. , Raynaud M.
Published: July 2021

Ultra-short high-power lasers can deliver extreme light intensities (≥1020 W/cm2 and ≤30 fs) and drive large amplitude Surface Plasma Wave (SPW) at over-dense plasma surface. The resulting current of energetic electron has great interest for applications, potentially scaling with the laser amplitude, provided that the laser–plasma transfer to the accelerated particles mediated by SPW is still efficient at ultra-high intensity. By means of particle-in-cell simulations, we identify the best condition for SPW excitation and show a strong correlation between the optimum surface plasma wave excitation angle and the laser's angle of incidence that optimize the electron acceleration along the plasma surface. We also discuss how plasma density and plasma surface shape can be adjusted in order to push to higher laser intensity the limit of surface plasma wave excitation. Our results open the way to new experiments on forthcoming multi-petawatt laser systems.
Magnetic domains in a uniaxial magnet Dy3Al2
Authors: Zu Lin , Lyu Boyao , Tang Jin , Gao Jianhua , Liu Fengguang , Du Yinchang , Wu Peng , Wu Yaodong , Chen Yutao , Jiang Jialiang , Wei Wensen , Du Haifeng , Zhao Weisheng
Published: July 2021

The rare-earth intermetallic Dy3Al2 is a low-temperature permanent magnet with temperature-induced spin reorientation transition. In this work, we report the observation of magnetic domains in lamellae of Dy3Al2 using Liquid-Nitrogen cryo-Lorentz transmission electronic microscopy (cryo-LTEM) above TSR (70 K). We studied the magnetic field dependence of domain evolution from stripe domains at zero magnetic field to the saturation state. When the easy axis lies within the lamella plane, stripe domains gradually narrow and disappear as the applied field increases. The saturation field decreases with the increasing temperature. In the presence of misalignment between the easy axis and external field, stripe domains evolve into type-II magnetic bubbles (as small as 50–60 nm). The spin configuration was further verified by utilizing differential phase contrast scanning transmission microscopy and micromagnetic simulations.
Construction and selection of a directivity wave function improving ill-condition problems in equivalent source method based near-field acoustic holography
Authors: Shi Ziyu , Xiang Yu , Lu Jing , Wang Yujiang , Zhang Yang
Published: July 2021

Sound-field reconstruction via the equivalent source method presents an ill-conditioned problem. This paper proposes a method in which traditional monopole equivalent source spherical wave functions are replaced with strong directional wave functions such that an ill-conditioned problem can be improved upon when building the integral equations of a near-field acoustic holography model. Using directional wave functions as an integral kernel function can cause the transfer matrix to be main-diagonally dominant. The accuracy of the proposed method for sound-field reconstruction is verified using numerical simulations, and reconstruction stability in the presence of measurement noise is considered. Furthermore, a method for selecting directional wave functions that are appropriate for various model parameters is introduced. The results show that the proposed method can greatly reduce the condition number of the transfer matrix and improve reconstruction stability.
HJ-aggregates of donor–acceptor–donor oligomers and polymers
Authors: Chang Xin , Balooch Qarai Mohammad , Spano Frank C.
Published: July 2021

A vibronic exciton model is developed to account for the spectral signatures of HJ-aggregates of oligomers and polymers containing donor–acceptor–donor (DAD) repeat units. In (DAD)N π-stacks, J-aggregate-promoting intrachain interactions compete with H-aggregate-promoting interchain interactions. The latter includes Coulombic coupling, which arises from “side-by-side” fragment transition dipole moments as well as intermolecular charge transfer (ICT), which is enhanced in geometries with substantial overlap between donors on one chain and acceptors on a neighboring chain. J-behavior is dominant in single (DAD)N chains with enhanced intrachain order as evidenced by an increased red-shift in the low-energy absorption band along with a heightened A1/A2 peak ratio, where A1 and A2 are the oscillator strengths of the first two vibronic peaks in the progression sourced by the symmetric quinoidal–aromatic vibration. By contrast, the positive H-promoting interchain Coulomb interactions operative in aggregates cause the vibronic ratio to attenuate, similar to what has been established in H-aggregates of homopolymers such as P3HT. An attenuated A1/A2 ratio can also be caused by H-promoting ICT which occurs when the electron and hole transfer integrals are out-of-phase. In this case, the A1 peak is red-shifted, in contrast to conventional Kasha H-aggregates. With slight modifications, the ratio formula derived previously for P3HT aggregates is shown to apply to (DAD)N aggregates as well, allowing one to determine the effective free-exciton interchain coupling from the A1/A2 ratio. Applications are made to polymers based on 2T-DPP-2T and 2T-BT-2T repeat units, where the importance of the admixture of the excited acceptor state in the lowest energy band is emphasized.
A two-terminal spin valve device controlled by spin–orbit torques with enhanced giant magnetoresistance
Authors: Avci Can Onur , Lambert Charles-Henri , Sala Giacomo , Gambardella Pietro
Published: July 2021

We report on the combination of current-induced spin–orbit torques and giant magnetoresistance in a single device to achieve all-electrical write and readout of the magnetization. The device consists of perpendicularly magnetized TbCo and Co layers separated by a Pt or Cu spacer. Current injection through such layers exerts spin–orbit torques and switches the magnetization of the Co layer, while the TbCo magnetization remains fixed. Subsequent current injection of lower amplitude senses the relative orientation of the magnetization of the Co and TbCo layers, which results in two distinct resistance levels for parallel and antiparallel alignment due to the current-in-plane giant magnetoresistance effect. We further show that the giant magnetoresistance of devices including a single TbCo/spacer/Co trilayer can be improved from 0.02% to 6% by using a Cu spacer instead of Pt. This type of devices offers an alternative route to a two-terminal spintronic memory that can be fabricated with a moderate effort.
Multi-target tracking and activity classification with millimeter-wave radar
Authors: Rajab Khalid Z. , Wu Bang , Alizadeh Peter , Alomainy Akram
Published: July 2021

The millimeterwave radar has made possible high resolution tracking, activity classification, and vital signs detection, at higher precisions than is possible with most other wireless approaches. However, detecting multiple moving targets is a challenge, as dynamic scene with a lot of motion leads to clutter and noise, which interfere with the responses of targets of interest. We present a digital beamforming approach using the MIMO radar, with a range resolution of 6.4 cm and a Doppler resolution of 0.18 m/s, which reduces interference between closely neighboring targets. Thus, measurements of individual target micro-Doppler signatures are possible, even in the presence of multiple other moving targets, and the signatures are, thereby, used to train a Deep Neural Network (DNN) for activity classification. The DNN has been applied to recognize six exercise-based classes, correctly predicting with over 95% classification accuracy for all classes, but that is extendable to fall detection and other activities.
Development of generalized bubble growth model for cavitation and flash boiling
Authors: Zanje Sachin , Iyer Kannan , Murallidharan Janani Srree , Punekar Hemant , Gupta Vinay Kumar
Published: July 2021

Cavitation occurs in a wide range of applications, such as in marine propellers, diesel injectors, supercavitating projectiles, etc. Currently, the available cavitation models rely on expressions derived from inertial bubble growth models and fine-tuned using a few experiments. Revisiting the literature on bubble growth models indicates that there is scope for improvement in the bubble growth expressions presently employed. The previous studies in this subject have assumed that the vapor in the bubble remains saturated. Detailed numerical studies using one-dimensional saturated vapor model reveals over-prediction of the bubble radius when compared with a wide range of experimental data. To overcome this, a coupled mass, momentum, and energy model, termed full model, is then developed and the analysis suggests that this model gives good agreement over the entire experimental data. Parametric studies carried out to generate non-dimensional bubble growth rate expressions indicate that the growth rate climbs linearly on a log –log plot during initial stages of bubble growth which is function Jakob number Ja and finally settles into an asymptotic non-linear curve which is independent of Ja. The bubble growth rate expressions when integrated to obtain bubble radius as function of time is able to predict the experimental data with mean relative error of 1.2% and root mean square relative error of 8% for Ja varying from 13.53 to 2745.
Subgrid scale modeling considerations for large eddy simulation of supercritical turbulent mixing and combustion
Authors: Unnikrishnan Umesh , Huo Hongfa , Wang Xingjian , Yang Vigor
Published: July 2021

This paper presents a systematic investigation of large eddy simulation (LES) and subgrid scale (SGS) modeling with application to transcritical and supercritical turbulent mixing and combustion. There remains uncertainty about the validity of extending the LES formalism developed for low-pressure, ideal-gas flows to simulations of high-pressure real-fluid flows. To address this concern, we reexamine the LES theoretical framework and the underlying assumptions in the context of real-fluid mixing and combustion. Two-dimensional direct numerical simulations of nonreacting and reacting mixing layers of gaseous methane and liquid oxygen in the thermodynamically transcritical and supercritical fluid regimes are performed. The computed results are used to evaluate the exact terms in the LES governing equations and associated SGS models. Order of magnitude analysis of the exact filtered and subgrid terms in the LES equations and a priori analysis of the simplifications are performed at different filter widths. It is shown that several of these approximations do not hold for supercritical turbulent mixing. Subgrid scale terms, which are neglected in the LES framework for ideal-gas flows, become significant in magnitude compared to the other leading terms in the governing equations. In particular, the subgrid term arising from the filtering of the real-fluid equation of state is shown to be important.
Gaseous pre-lattice assisted supercontinuum enhancement of femtosecond laser filamentation
Authors: Guo Yajun , Wang Jianji , Song Xiaowei , Lin Jingquan
Published: July 2021

White-light supercontinuum from a femtosecond laser filamentation is essential for many applications due to its broadening spectrum and remote sensing ability. We propose to enhance the supercontinuum intensity by presetting the gaseous lattice in the path of femtosecond laser filamentation. Our results show that the introduction of a gaseous lattice can increase the spectral intensity in both visible and infrared wings, up to about ten times over the no lattice case in a gas medium. We find that the gaseous lattice dramatically affects the time-domain evolutions of the optical intensity and the electron density during the nonlinear propagation of the pulse, thereby resulting in spectral intensity enhancement. The results provide a new way to enhance the supercontinuum generation in the ultra-intense nonlinear process by using a gaseous pre-lattice with a special spatial refractive index profile.
Friction drag reduction based on a proportional-derivative control scheme
Authors: Wong Chi Wai , Cheng Xiaoqi , Fan Dewei , Li Wenfeng , Zhou Yu
Published: July 2021

Dielectric barrier discharge plasma actuators (DBD-PAs) are deployed experimentally for the first time in a feed-forward proportional-derivative (PD) control system, where the fluctuating wall-pressure Pw is demonstrated to be an effective feed-forward signal, to manipulate a turbulent boundary layer for drag reduction. A floating-element force balance with an area of 50 mm (streamwise length) × 200 mm (spanwise length) is deployed to capture the spatially averaged drag variation behind the DBD-PAs. The DBD-PAs generate streamwise vortices, whose occurrence synchronizes with the output signal of the controller with a predominant frequency of 40 Hz under the optimally tuned PD control. The control system proves to be effective, achieving a spatially averaged drag reduction by 16%, and efficient, cutting down its energy consumption by 30% at a negligibly small expense of drag reduction compared with the open-loop control. It has been found that the optimally tuned PD control aptly increases the voltage applied to the DBD-PAs upon detecting large Pw fluctuations or coherent structures, accounting for the savings in input power, Pinput. The experimental data have been carefully analyzed, which cast light upon the underlying physical mechanism behind the drag reduction. The reason behind the efficient control is also clearly elaborated.
Breakdown, discharge modes, and gaseous recovery of atmospheric air with repetitive 10 ns pulses
Authors: Li Yutai , Li Handong , Liu Zhigang , Fu Yangyang , Luo Haiyun , Zou Xiaobing , Wang Xinxin
Published: July 2021

The breakdown and recovery characteristics of the highly repetitive (≤100 kHz) and short nanosecond (∼10 ns) pulsed discharge were investigated. It was found that if one pulse of 40 kV is applied, the air gap between two conical electrodes for a reliable breakdown is only 1 mm; however, if 1000 same pulses are repetitively applied, the longest gap that can be broken down dramatically increases with the increase in the repetitive rate and it reaches 90 mm at 100 kHz. During the preceding pulses that do not cause the breakdown of the gap, long streamers develop from both conical electrodes and nearly bridge the gap, which provides the residual and decaying plasma channels for the rapid breakdown of 90-mm gap in the following pulses, which was experimentally proved to be unique in the extremely non-uniform electric field. The voltage recovery was determined with the two-pulse method and found that the physical processes of the voltage recovery after the short nanosecond pulsed breakdown are similar to that after the microsecond pulsed breakdown, but the time needed for a full recovery in the gas density, in between 50 and 100 μs, is shorter by three orders than that after the microsecond pulsed breakdown. The faster recovery in the gas density may be understood from the small energy of 36 mJ in one nanosecond pulse, which does not induce a high perturbation in the gas density. The evolution in the discharge mode in a 15-mm gap, from corona to diffuse and finally to multichannel spark, with the applied voltage and the repetitive rate was observed. The formation of the multichannel spark is due to the limited energy per pulse that is not enough to heat the primary channel to high conductivity for the collapse of the gap voltage.
Mid-wave infrared transmittance filters in suspended GaAs subwavelength gratings
Authors: Barrow Michael , Phillips Jamie
Published: July 2021

The high-Q resonances observed in subwavelength gratings support many applications, including optical phase arrays, refractive index sensing, enhancement of nonlinear effects, and spectral filtering. Integrating these functions with active devices opens new possibilities for microscale optical systems. GaAs high-contrast gratings (HCGs) simplify the integration of resonant structures with active III–V semiconductor devices. These structures are particularly useful in the mid-wave infrared (5–7 μm), overcoming several limitations of the material systems presented in previous works. By selectively removing an underlying AlGaAs layer, a high index contrast is introduced between suspended GaAs gratings and air without using an exotic low-index substrate. Furthermore, epitaxial growth enables precise device thickness. In this work, we demonstrate GaAs/air HCG transmittance filters for operation in the mid-wave infrared. A numerical study investigates the dependence of filter performance on substrate proximity. We fabricate experimental filters using an HBr-based plasma etch and a selective wet etch. Optical characterization demonstrates quality factors >50 and transmittance peak efficiency >50%. The observed filter performance is comparable to other mid-wave infrared subwavelength grating filters. This work concludes with discussion of experimental nonidealities, emphasizing the considerable influence of grating size and optical measurement conditions. The suspended GaAs HCG filters show potential for direct integration with active devices such as photodetectors and lasers.
Current-induced magnetization switching at charge-transferred interface between topological insulator (Bi,Sb)2Te3 and van der Waals ferromagnet Fe3GeTe2
Authors: Fujimura Reika , Yoshimi Ryutaro , Mogi Masataka , Tsukazaki Atsushi , Kawamura Minoru , Takahashi Kei S. , Kawasaki Masashi , Tokura Yoshinori
Published: July 2021

Ferromagnetic two-dimensional van der Waals materials attract enormous interest as a platform to explore spin-related quantum phenomena, especially in conjunction with other quantum materials. Topological insulator is one such candidate to form the junction, because the spin-polarized nature of the surface or interface Dirac states enables the highly efficient spin-charge conversion. Here, we report the current-driven magnetization switching in the bilayer film of a van der Waals ferromagnetic semimetal Fe3GeTe2 (FGT) and a topological insulator (Bi1−xSbx)2Te3 (BST). We observed the current-induced magnetization switching via the Edelstein effect in a wide temperature range, whose threshold current density is as small as that reported for the heterostructure of FGT with a Pt layer. By analyzing the transport properties in heterostructures with different Fermi level (EF) positions in the BST layer, we found that the EF position of the charge-transferred interface Dirac states causes the significant variation of the threshold current density with a Bi/Sb ratio. The present result may promise spintronic phenomena in heterostructures of 2D van der Waals ferromagnets with topological insulators/semimetals.
Demonstration of infrared nBn photodetectors based on the AlInAsSb digital alloy materials system
Authors: Chen Dekang , Wang Renjie , Andrew McArthur J. , Xue Xingjun , Jones Andrew H. , Bank Seth R. , Campbell Joe C.
Published: July 2021

We report an nBn photodetector based on the AlInAsSb digital alloy materials system, which has the advantage of a near-zero valence band offset. These photodetectors have achieved 28% external quantum efficiency, dark current densities of 2.6 × 10−3 A/cm2 at 300 K and 1.8 × 10−9 A/cm2 at 100 K with −0.5 V bias, and detectivity of 1.7 × 1010 Jones at room temperature under 2 μm wavelength illumination.
Adsorbate modification of electronic nonadiabaticity: H atom scattering from p(2 × 2) O on Pt(111)
Authors: Lecroart Loïc , Hertl Nils , Dorenkamp Yvonne , Jiang Hongyan , Kitsopoulos Theofanis N. , Kandratsenka Alexander , Bünermann Oliver , Wodtke Alec M.
Published: July 2021

We report inelastic differential scattering experiments for energetic H and D atoms colliding at a Pt(111) surface with and without adsorbed O atoms. Dramatically, more energy loss is seen for scattering from the Pt(111) surface compared to p(2 × 2) O on Pt(111), indicating that O adsorption reduces the probability of electron–hole pair (EHP) excitation. We produced a new full-dimensional potential energy surface for H interaction with O/Pt that reproduces density functional theory energies accurately. We then attempted to model the EHP excitation in H/D scattering with molecular dynamics simulations employing the electronic density information from the Pt(111) to calculate electronic friction at the level of the local density friction approximation (LDFA). This approach, which assumes that O atoms simply block the Pt atom from the approaching H atom, fails to reproduce experiment due to the fact that the effective collision cross section of the O atom is only 10% of the area of the surface unit cell. An empirical adiabatic sphere model that reduces electronic nonadiabaticity within an O–Pt bonding length scale of 2.8 Å reproduces experiment well, suggesting that the electronic structure changes induced by chemisorption of O atoms nearly remove the H atom’s ability to excite EHPs in the Pt. Alternatives to LDFA friction are needed to account for this adsorbate effect.
Electrical explosion across gas–liquid interface: Aerosol breakdown, shock waves, and cavity dynamics
Authors: Han Ruoyu , Li Chen , Ouyang Jiting , Wu Jiawei , Wang Yanan , Wang Xinxin
Published: July 2021

The electrical explosion of a conductor driven by a pulsed current can be used to simulate the effects of explosions in the laboratory, including the resulting shock waves and bubble dynamics. A fine metallic wire can also be used to initiate pulsed discharge in different media. This study shows images of an exploding wire across an air–water interface for the first time in the literature. The transient process was analyzed using high-speed backlit photography as well as waveforms of the spectrum and discharge. Streamer-like discharge developed from a triple-junction point within the current pause to induce a restrike in metallic aerosol, verifying that gas discharge was prevalent in the system. An upward dense plasma jet accompanied by a crown-like water spike was then observed and led to violent plasma–water interactions (mushroom cloud-like cluster) that were examined through a hydrodynamic simulation. The Stark broadening of the Hα line at 656.28 nm suggested that the electron density of the reaction zone could be 1018 cm−3 or higher. The resolved spatial–temporal images revealed that the plasma evolution process (in μs) was much faster than hydrodynamic processes, including damage to the interface and perturbations of the bubbles (in ms). Water, thus, remained in a “rigid” state during the pulsed discharge, and the explosion of the wire in it was not an adiabatic process at a timescale of 102 μs. Recombination and heat loss through the electrode governed the evolution of the post-discharge plasma, and the microscopic images revealed nano-lamellate nucleation on the surface of the electrode.
Giant spontaneous resistivity jumps in La0.825Ce0.175Fe12B6
Authors: Diop L. V. B. , Isnard O.
Published: July 2021

We report the observation of spontaneous and very sharp resistivity jumps at low temperatures in the antiferromagnetic itinerant-electron system La0.825Ce0.175Fe12B6. This intermetallic compound undergoes multiple magnetic transformations, antiferromagnetic–ferromagnetic (AFM–FM) and ferromagnetic–paramagnetic (FM–PM), triggered by changes in both the temperature and the applied magnetic field. The magnetoresistance isotherms display irreversible abrupt steps at T ≤ 4 K, whereas the field dependence of the resistivity becomes smooth above 4 K. Meanwhile, the evolution with time of the electrical resistivity exhibits a huge spontaneous jump after an incubation time when both the applied magnetic field and temperature are constant. A giant negative magnetoresistance (MR = −71%) is discovered associated with the magnetic-field-induced first-order AFM-FM transition.
Wake structure and evolution of flow over a finned circular cylinder
Authors: Zhu Hongjun , Liu Wenli
Published: July 2021

This paper reports the results of a numerical investigation into the flow over a circular cylinder evenly attached with rectangular ribs around its circumference and the associated near-wall vortex structure as well as the evolution of wake flow. The effect of the number of ribs (n) ranging from 1 to 12 is examined in a low Reynolds number range of 60–180. Five kinds of near-wall vortices are identified with the presence of rectangular ribs, including quasi-stagnation vortices, subordinate vortices, inter-rib vortices, inter-rib quasi-stagnation vortices, and dynamic inter-rib vortices. These near-wall vortices and their evolution are sensitive to Re as well as n. With the introduction of ribs, each boundary layer experiences multiple separations that increase from 2 to 4 as n increases from 1 to 12. The intermittent emergency of the last separation is attributed to the switching of the final separation between two adjacent ribs. Furthermore, the duration of the last separation depends on Re and the evolution of dynamic inter-rib vortices. The hydrodynamic coefficients and vortex shedding frequency are closely related to the vortex formation length (Lf*) and wake width (W*). The different variation of Lf* and W* with Re is possibly associated with the appearance and number of subordinate vortices. In addition, the fluctuation of W* is mainly attributed to the switching of boundary layer separation point. The wake flow experience two evolutions as the vortices are convected downstream: the transition from one-row primary vortex street to the two-layered vortices, and the transition from two-layered vortices to the secondary vortex street. The latter is only observed in the wake of a finned cylinder with 3–5 ribs at Re = 180, while the two-layered vortices are decayed in the far wake in other cases.
The structurally conserved TELR region on shelterin protein TPP1 is essential for telomerase processivity but not recruitment
Authors: Sandhu Ranjodh , Sharma Madhav , Wei Derek , Xu Lifeng
Published: July 2021

Significance

Telomerase directs the synthesis of new telomeric repeats at chromosome ends, enabling cells to overcome the end replication problem and to continue to divide. The shelterin protein TPP1 interacts with telomerase, promoting both telomerase recruitment and processivity (the addition of multiple telomeric repeats after a single substrate binding event). Here, we identify separation-of-function mutants of TPP1 that eliminate telomerase processivity but leave the telomerase recruitment function intact. When introduced into human cells in a homozygous manner, these mutations can induce critical telomere shortening and cellular senescence. Our observations therefore demonstrate that TPP1 stimulation of telomerase processivity is a key regulatory step in vivo for telomerase-mediated extension of telomeres and continued cell proliferation.
Non-Foster acoustic radiation from an active piezoelectric transducer
Authors: Rasmussen Curtis , Alù Andrea
Published: July 2021

Significance

Many of the exciting wave phenomena found in acoustic metamaterials arise as a result of the collective response of subwavelength resonators. To widen the frequency range of these phenomena, it is necessary to understand the source of these bandwidth limitations and explore techniques that can overcome them. Here, we quantify the general tradeoff between size and bandwidth of passive acoustic resonators and show how this constraint can be overcome by actively loading them. As an example, we demonstrate a large bandwidth enhancement of a sonar transducer by connecting it to a specialized active non-Foster circuit. This important finding can have long-lasting impact in acoustic metamaterials for exotic sound interactions, paving the way to enhanced compact resonant acoustic devices.
A [3Fe-4S] cluster and tRNA-dependent aminoacyltransferase BlsK in the biosynthesis of Blasticidin S
Authors: Wang Xiankun , Zhao Yuchun , Gao Yaojie , Luo Xiangkun , Du Aiqin , Deng Zixin , Zabriskie T. Mark , He Xinyi , Jiang Ming
Published: July 2021

Significance

Transfer RNA (tRNA) transfer appropriately activated amino acids to the end of the growing peptide chain, playing significant roles in primary metabolism. Importantly, tRNA have also been shown to function outside of translation. In this report, we present the characterization of a new class of aminoacyl-tRNA (aa-tRNA)–dependent enzyme, BlsK, from
Streptomyces griseochromogenes
. BlsK catalyzes an aa-tRNA–dependent leucyl transfer reaction in blasticidin S biosynthesis. BlsK contains a [3Fe-4S] cluster that is necessary for its function and unprecedented in previously identified tRNA-dependent transferases. Because BlsK does not show similarity to any known functional protein, it may represent a type of aa-tRNA–dependent enzyme. As such, this work has broad implications for both tRNA-dependent and iron–sulfur–containing enzymes.
Tradeoffs for a viral mutant with enhanced replication speed
Authors: Lanahan Matthew R. , Maples Robert W. , Pfeiffer Julie K.
Published: July 2021

Significance

Viruses have characteristic replication speeds within a given cell type. Many factors can slow the rate of viral replication, including attenuating mutations and host antiviral responses. However, it has been unclear whether it would be possible to “speed up” a virus that already replicates efficiently in a specific cell type. Here, we selected for a mutant coxsackievirus with enhanced replication speed by sequentially harvesting the very earliest progeny in multiple rounds of selection. A single mutation conferred the fast-replication phenotype. While this mutant virus has enhanced replication in cultured cells due to faster genome uncoating, it was attenuated in mice. These results highlight selective pressures that shape viral populations in different environments.
Contact with Child Protective Services is pervasive but unequally distributed by race and ethnicity in large US counties
Authors: Edwards Frank , Wakefield Sara , Healy Kieran , Wildeman Christopher
Published: July 2021

This article provides county-level estimates of the cumulative prevalence of four levels of Child Protective Services (CPS) contact using administrative data from the 20 most populous counties in the United States. Rates of CPS investigation are extremely high in almost every county. Racial and ethnic inequality in case outcomes is large in some counties. The total median investigation rate was 34.5%; the risk for Black, Hispanic, and White children exceeded 10% in all counties. Risks of having a CPS investigation were highest for Black children (32.9 to 62.8%). Black children also experienced high rates of later-stage CPS contact, with rates often above 20% for confirmed maltreatment, 10% for foster care placement, and 2% for termination of parental rights (TPR). The only other children who experienced such extreme rates of later-stage CPS interventions were American Indian/Alaska Native children in Middlesex, MA; Hispanic children in Bexar, TX; and all children except Asian/Pacific Islander children in Maricopa, AZ. The latter has uniquely high rates of late-stage CPS interventions. In some jurisdictions, such as New York, NY, (0.2%) and Cook, IL (0.2%), very few children experienced TPR. These results show that early CPS interventions are ubiquitous in large counties but with marked variation in how CPS systems respond to these investigations.
Quantitative perspectives in Cognitive Linguistics
Authors: Janda Laura A.
Published: July 2021

As a usage-based approach to the study of language, cognitive linguistics is theoretically well poised to apply
quantitative methods to the analysis of corpus and experimental data. In this article, I review the historical circumstances that
led to the quantitative turn in cognitive linguistics and give an overview of statistical models used by cognitive linguists,
including chi-square test, Fisher test, Binomial test, t-test, ANOVA, correlation, regression, classification and regression
trees, naïve discriminative learning, cluster analysis, multi-dimensional scaling, and correspondence analysis. I stress the
essential role of introspection in the design and interpretation of linguistic studies, and assess the pros and cons of the
quantitative turn. I also make a case for open access science and appropriate archiving of linguistic data.
Construction in conversation
Authors: Hsieh Chen-Yu Chester , I-Wen Su Lily
Published: July 2021

Although the Construction Grammar (CxG) model has yielded fruitful findings, the role that pragmatics plays in
language has not yet been fully considered in this theoretical framework. The recent development of spoken corpora, however,
enables construction grammarians to develop a new approach called Interactional Construction Grammar, which incorporates
interactional factors into CxG analysis to account for patterns that involve interpersonal functions and global contexts. Adopting
this approach, the present study attempts to examine the use of a complement-taking mental predicate xiangshuo in
Taiwan Mandarin conversation and analyze the co-occurrence patterns of this cognitive verb with different subjects. We identify
three sequential patterns in which xiangshuo most frequently occurs, including account-giving,
contrast-projecting and involvement-constructing, and argue that only by taking into account the sequential context and
interactional function can the distribution patterns of subjects and particles that recurrently collocate with
xiangshuo be explained.
Challenges and solutions in test adaption
Authors: Enns Charlotte , Kolbe Vera , Becker Claudia
Published: July 2021

Sign language assessment tools are important for professionals working with DHH children to measure sign language
development and competence. Adaptation of an existing test can be a solution when initiating assessment in a sign language
community; the adaptation process must adhere to key principles and procedures. We introduce the principles of test adaptation and
outline the challenges we faced in adapting the British Sign Language Production Test (Herman, Grove, Holmes, Morgan, Sutherland & Woll 2004) to German Sign Language and American Sign
Language. Challenges included decisions regarding the normative sample, the use of terminology, and variations in the scoring
protocols to fit with each language. The steps taken throughout the test adaptation process are described, together with a
comparison of parallels and differences. We conclude that test adaptation is an effective method of developing practical tools for
sign language assessment and contributes to a better understanding of sign language development.
Single-cell analysis of human skin identifies CD14+ type 3 dendritic cells co-producing IL1B and IL23A in psoriasis
Authors: Nakamizo Satoshi , Dutertre Charles-Antoine , Khalilnezhad Ahad , Zhang Xiao Meng , Lim Shawn , Lum Josephine , Koh Geraldine , Foong Charlene , Yong Pearly Jean Ai , Tan Kahbing Jasmine , Sato Reiko , Tomari Kaori , Yvan-Charvet Laurent , He Helen , Guttman-Yassky Emma , Malleret Benoit , Shibuya Rintaro , Iwata Masashi , Janela Baptiste , Goto Tsuyoshi , Lucinda Tan Siyun , Tang Mark B.Y. , Theng Colin , Julia Valerie , Hacini-Rachinel Feriel , Kabashima Kenji , Ginhoux Florent
Published: July 2021

Inflammatory skin diseases including atopic dermatitis (AD) and psoriasis (PSO) are underpinned by dendritic cell (DC)–mediated T cell responses. Currently, the heterogeneous human cutaneous DC population is incompletely characterized, and its contribution to these diseases remains unclear. Here, we performed index-sorted single-cell flow cytometry and RNA sequencing of lesional and nonlesional AD and PSO skin to identify macrophages and all DC subsets, including the newly described mature LAMP3+BIRC3+ DCs enriched in immunoregulatory molecules (mregDC) and CD14+ DC3. By integrating our indexed data with published skin datasets, we generated a myeloid cell universe of DC and macrophage subsets in healthy and diseased skin. Importantly, we found that CD14+ DC3s increased in PSO lesional skin and co-produced IL1B and IL23A, which are pathological in PSO. Our study comprehensively describes the molecular characteristics of macrophages and DC subsets in AD and PSO at single-cell resolution, and identifies CD14+ DC3s as potential promoters of inflammation in PSO.
Transcription factor Zhx2 restricts NK cell maturation and suppresses their antitumor immunity
Authors: Tan Siyu , Guo Xiaowei , Li Mengzhen , Wang Tixiao , Wang Zehua , Li Chunyang , Wu Zhuanchang , Li Nailin , Gao Lifen , Liang Xiaohong , Ma Chunhong
Published: July 2021

The maturation and functional competence of natural killer (NK) cells is a tightly controlled process that relies on transcription factors (TFs). Here, we identify transcriptional repressor zinc fingers and homeoboxes 2 (Zhx2) as a novel regulator that restricts NK cell maturation and function. Mice with Zhx2 conditional deletion in NK cells (Zhx2Δ/Δ) showed accumulation of matured NK cells. Loss of Zhx2 enhanced NK cell survival and NK cell response to IL-15. Transcriptomic analysis revealed Zeb2, a key TF in NK cell terminal maturation, as a direct downstream target of Zhx2. Therapeutically, transfer of Zhx2-deficient NK cells resulted in inhibition of tumor growth and metastasis in different murine models. Our findings collectively unmask a previously unrecognized role of Zhx2 as a novel negative regulator in NK cell maturation and highlight its therapeutic potential as a promising strategy to enhance NK cell–mediated tumor surveillance.
Perturbation spectra and renormalization-group techniques in double-field inflation and quantum gravity cosmology
Authors: Anselmi Damiano
Published: July 2021

We study primordial cosmology with two scalar fields that participate in
inflation at the same time, by coupling quantum gravity (i.e., the theory R+R2+C2 with the fakeon prescription/projection for C2) to a
scalar field with a quadratic potential. We show that there exists a
perturbative regime that can be described by an asymptotically de Sitter,
cosmic RG flow in two couplings. Since the two scalar degrees of freedom mix
in nontrivial ways, the adiabatic and isocurvature perturbations are not RG
invariant on superhorizon scales. It is possible to identify the correct
perturbations by using RG invariance as a guiding principle. We work out the
resulting power spectra of the tensor and scalar perturbations to the NNLL
and NLL orders, respectively. An unexpected consequence of RG invariance is
that the theory remains predictive. Indeed, the scalar mixing affects only
the subleading corrections, so the predictions of quantum gravity with
single-field inflation are confirmed to the leading order.
Applications of a Grassmannian technique to hyperbolicity, Chow equivalency, and Seshadri constants
Authors: Riedl Eric , Yang David
Published: July 2021

In this paper we further develop a Grassmannian technique used to prove results about very general hypersurfaces and present three applications. First, we provide a short proof of the Kobayashi conjecture given previously established results on the Green–Griffiths–Lang conjecture. Second, we completely resolve a conjecture of Chen, Lewis, and Sheng on the dimension of the space of Chow-equivalent points on a very general hypersurface, proving the remaining cases and providing a short, alternate proof for many of the previously known cases. Finally, we relate Seshadri constants of very general points to Seshadri constants of arbitrary points of very general hypersurfaces.