bluuebunny/crossref_metadata_2025 huggingface dataset:
Antiferromagnet-mediated spin–orbit torque induced magnetization switching in perpendicularly magnetized L1-MnGa
Authors: Zhao Xupeng , Mao Siwei , Wang Hailong , Wei Dahai , Zhao Jianhua
Published: March 2021

Current-induced magnetization switching plays an essential role in spintronic devices exhibiting nonvolatility, high-speed processing, and low-power consumption. Here, we report on the spin–orbit torque-induced magnetization switching in perpendicularly magnetized L10-MnGa/FeMn/Pt trilayers grown by molecular-beam epitaxy. An antiferromagnetic FeMn layer is inserted between the spin current generating Pt layer and spin absorbing MnGa layer. Due to the exchange bias effect, the trilayers show field-free spin–orbit torque switching. Overall, the spin transmission efficiency decreases monotonically as the FeMn thickness increases. It is found that the spin current can be transmitted through an 8 nm-thick FeMn layer as evidenced by partial switching of the L10-MnGa. The damping-like spin–orbit torque efficiency shows a peak value at tFeMn = 1.5 nm due to the enhanced interfacial spin transparency and crystalline quality of the FeMn. These results help demonstrate the efficacy of emerging spintronic devices containing antiferromagnetic elements.
Tokamak ITG-KBM transition benchmarking with the mixed variables/pullback transformation electromagnetic gyrokinetic scheme
Authors: Cole M. D. J. , Mishchenko A. , Bottino A. , Chang C. S.
Published: March 2021

Electromagnetic gyrokinetic simulation of high temperature plasma is required to predict confinement in magnetic fusion devices and has posed challenges for existing codes. In this paper, we demonstrate successful global gyrokinetic simulation of the ion temperature gradient-driven mode-kinetic ballooning mode transition in a toroidal fusion plasma test case using the mixed variables/pullback transformation (MV/PT) scheme with the particle-in-cell codes XGC and ORB5, and compare to results from a conventional continuum code from the literature. The MV/PT scheme combines explicit time integration with mitigation of the well-known electromagnetic gyrokinetic “cancelation problem.” We calculate eigenmodes in the electrostatic and parallel vector potentials, and find good agreement in growth rate, real frequency, and the normalized plasma pressure of mode transition.
Energy natural orbitals
Authors: Takatsuka Kazuo , Arasaki Yasuki
Published: March 2021

We propose and numerically demonstrate that highly correlated electronic wavefunctions such as those of configuration interaction, the cluster expansion, and so on, and electron wavepackets superposed thereof can be analyzed in terms of one-electron functions, which we call energy natural orbitals (ENOs). As the name suggests, ENOs are members of the broad family of natural orbitals defined by Löwdin, in that they are eigenfunctions of the energy density operator. One of the major characteristics is that the (orbital) energies of all the ENOs are summed up exactly equal to the total electronic energy of a wavefunction under study. Another outstanding feature is that the population of each ENO varies as the chemical reaction proceeds, keeping the total population constant though. The study of ENOs has been driven by the need for new methods to analyze extremely complicated nonadiabatic electron wavepackets such as those embedded in highly quasi-degenerate excited-state manifolds. Yet, ENOs can be applied to scrutinize many other chemical reactions, ranging from the ordinary concerted reactions, nonadiabatic reactions, and Woodward–Hoffman forbidden reactions, to excited-state reactions. We here present the properties of ENOs and a couple of case studies of numerical realization, one of which is about the mechanism of nonadiabatic electron transfer.
Helicity-dependent all-optical switching based on the self-trapped triplet excitons
Authors: Zhang Longlong , Hao Yuying
Published: March 2021

Triplet excitons in organic materials are nonradiative and tightly bound as self-trapped ones due to the strong electron-lattice coupling. They exhibit a finite radius and long lifetime and so can be regarded as the isolated quantum dots. In this work, we theoretically demonstrate that the spin polarization of self-trapped triplet excitons can be coherently controlled by the short circularly polarized laser pulses, acting as a helicity-dependent all-optical switching effect. Such a switching can be achieved within dozens of femtoseconds and conducted in a reproducible manner. The pulse parameter dependence on the switching ratio is further investigated. Our calculation provides a theoretical foundation for exploring the ultrafast all-optical recording and information processing technique based on the organic materials.
The spatially homogeneous Boltzmann equation for massless particles in an FLRW background
Authors: Lee Ho
Published: March 2021

We study the spatially homogeneous relativistic Boltzmann equation for massless particles in an FLRW background with scattering kernels in a certain range of soft and hard potentials. We obtain the future global existence of small solutions in a weighted L1 ∩ L∞ space.
The importance of specifically adsorbed ions for electrokinetic phenomena: Bridging the gap between experiments and MD simulations
Authors: Döpke Max F. , Hartkamp Remco
Published: March 2021

Molecular Dynamics (MD) simulations are uniquely suitable for providing molecular-level insights into the Electric Double Layer (EDL) that forms when a charged surface is in contact with an aqueous solution. However, simulations are only as accurate in predicting EDL properties as permitted by the atomic interaction models. Experimental ζ-potential values and surface charges could provide a potentially suitable reference to validate and tune the interaction models, if not for the fact that they themselves are a product of imperfect models used to interpret the raw measurement data. Here, we present an approach to tune an interaction model by comparing Electro-Osmotic Flow (EOF) MD simulations against experimental Streaming Current (SC) measurements while minimizing potential modeling errors arising from both approaches. The point that is least susceptible to interpretation and modeling errors is argued to be at the concentration for which zero flow velocity is observed in EOF simulations and a net zero electric current is measured in SC experiments. At this concentration, the ζ-potential is also zero. We were able to match the experimental concentration at which ζ = 0 in MD simulations for a CaCl2 solution at pH 7.5 in contact with fused silica by tuning the ion-surface Lennard-Jones cross interactions. These interactions were found to greatly affect the ion distribution within the EDL and particularly the formation of inner-sphere surface-complexes, which, in turn, affects the electrokinetic flow. With the ion distribution determined explicitly, a series of properties can be calculated unambiguously, such as the capacitance needed for surface complexation models.
Guiding light via slippery liquid-infused porous surfaces
Authors: Asawa Kaustubh , Kumar Santosh , Huang Yuping , Choi Chang-Hwan
Published: March 2021

Slippery liquid-infused porous surfaces (SLIPSs) have been explored for many applications, taking advantage of their highly non-wetting property. In this work, we explore the SLIPS as a cladding material for waveguiding. SLIPSs are prepared by infusing perfluoropolyether oil to hydrophobized nanoporous surfaces of silicon. Power loss and transmission efficiency of an HeNe laser (1.82 mW and 632.8 nm) with varying incident angles were measured through microchannels consisting of the SLIPSs as cladding layers (noil = 1.30) and water (nwater = 1.33) as a core, compared to other cladding types including a planar silicon surface and the nanoporous surfaces in hydrophilic (Wenzel state) and hydrophobic (Cassie–Baxter state) conditions with no oil infused. Agreeing with Snell's law, a total internal reflection occurs at the incident angle as high as 14° for the SLIPSs. The waveguide loss at 14° is only 1.8 dB/cm for the SLIPSs, while those for planar silicon, hydrophilic nanoporous, and hydrophobic nanoporous surfaces are 5.9, 7.4, and 4.9 dB/cm, respectively. The power transmission efficiency of the SLIPSs is independent of the porosity because the surfaces are fully covered with the oil layer, whereas those of hydrophilic and hydrophobic nanoporous surfaces, whose pores are filled with water and air, respectively, depend on the porosity. The significantly lower power loss and the insensitivity to the surface porosity are advantages of the SLIPSs over the other surfaces and can benefit in waveguiding applications such as optofluidics.
Local well-posedness to the three-dimensional barotropic compressible magnetohydrodynamic equations with vacuum
Authors: Xu Qingmei , Zhong Xin
Published: March 2021

This paper considers the local well-posedness of strong solutions to the three-dimensional barotropic compressible magnetohydrodynamic equations with the initial density containing vacuum. We first derive the local existence and uniqueness of strong solutions. Then, we show the continuous dependence of strong solutions on the initial data under an additional compatibility condition.
Strong interlayer excitons in PtSe2/ZrS2 van der Waals heterobilayer
Authors: Xiang Longjun , Zhang Qingyun , Ke Youqi
Published: March 2021

Capturing interlayer excitons with large binding energy plays a pivotal role in exploring the quantum Bose gas and developing excitonic devices at high temperature. In this work, we combine first-principles Kohn–Sham density functional theory and many-body perturbation theory to investigate the electronic and excited-state properties of two-dimensional van der Waals heterobilayer PtSe2/ZrS2, with the consideration of spin–orbit coupling. We find that the PtSe2/ZrS2 heterobilayer possesses a strong interlayer interaction and exhibits a type-II band alignment. We obtain the optical absorption spectrum by solving the Bethe–Salpeter equation with the inclusion of electron-hole interaction and observe emerged absorption peaks in the low-energy region compared to their constituent monolayers. According to the layer-resolved band structure and the interband transition weights in reciprocal space, we further confirm that these excitons are spatially separated into different constituent layers, featuring the landscape of interlayer excitons. Importantly, the binding energy for the lowest-energy interlayer exciton is estimated as large as 350 (meV), establishing PtSe2/ZrS2 as a promising candidate toward the realization of room temperature coherent phenomena and for the development of signal processing devices based on excitons.
In-plane characterization of PZT thin films for the creation of a general impedance model
Authors: Van de Veire T. , George J. P. , Rijckaert H. , Neyts K. , Lauwaert J. , Beunis F. , Beeckman J.
Published: March 2021

The in-plane dielectric and ferroelectric properties of preferentially oriented lead zirconate titanate (PZT) thin films are characterized using interdigitated transducers (IDTs). By combining finite element method simulations and capacitance measurements, values of the dielectric constant of films with thicknesses between 150 nm and 800 nm are obtained. A modified Sawyer–Tower circuit is used to investigate the polarization loops measured in-plane using IDT electrodes. A well-defined hysteresis loop is obtained demonstrating the switching of the polarization of the ferroelectric domains. Leakage current measurements reveal high resistivity and are an indication of the high quality of the PZT film. The obtained characteristics are used to determine the total impedance of the IDT-PZT structure. Here, the structure is represented by an equivalent ladder circuit using the inductance and resistance of the IDT electrodes and the capacitance and conductance of the PZT film. The obtained total impedance matches low frequency measurements.
Object recognition for remarkably small field-of-view with speckles
Authors: Hu Qixin , Xu Siyan , Chen Xue-wen , Wang Xinggang , Wang Ken Xingze
Published: March 2021

Object recognition conventionally requires a sufficiently large field of view that could fully encompass an object. However, we have discovered that, under coherent illumination, one can use a much smaller field of view for object recognition without loss of accuracy. This is because part of the speckle pattern related to an object contains some of its global information. Our approach can be applied to covert imaging and non-line-of-sight object recognition and image reconstruction.
Illumination-induced modulation of conductivity and Gunn oscillation properties in epitaxial GaAs
Authors: Hsu Hua-Wei , Sih Vanessa
Published: March 2021

We illuminate a gallium arsenide (GaAs) Gunn device and study the light-induced changes of Gunn oscillation properties. We observe that illumination leads to the modulation of the Gunn threshold voltage, the Gunn oscillation magnitude, and the coherency of Gunn oscillation, with the nature of the modulation being closely related to the position of illumination on the device. These effects are attributed to the generation of optically excited carriers, which results in the modulation of conductivity and the electric field profile along the device. The finite element method is used to simulate the change of the field profile of the Gunn device caused by illumination. We also report an unexpected phenomenon of Gunn oscillation property manipulation with an optical chopper. In addition, wavelength-dependent, power-dependent, and pulsed illumination measurements are performed to help with further understanding the observations.
How symmetry-breaking can amplify the magnetosensitivity of dipolarly coupled n-radical systems
Authors: Keens Robert H. , Sampson Chris , Kattnig Daniel R.
Published: March 2021

In systems of more than two reactive radicals, the radical recombination probability can be magnetosensitive due to the mere effect of the inter-radical electron–electron dipolar coupling. Here, we demonstrate that this principle, previously established for three-radical systems, generalizes to n-radical systems. We focus on radical systems in the plane and explore the effects of symmetry, in particular its absence, on the associated magnetic field effects of the recombination yield. We show, by considering regular configurations and slightly distorted geometries, that the breaking of geometric symmetry can lead to an enhancement of the magnetosensitivity of these structures. Furthermore, we demonstrate the presence of effects at low-field that are abolished in the highly symmetric case. This could be important to the understanding of the behavior of radicals in biological environments in the presence of weak magnetic fields comparable to the Earth’s, as well as the construction of high-precision quantum sensing devices.
Deep potential generation scheme and simulation protocol for the Li10GeP2S12-type superionic conductors
Authors: Huang Jianxing , Zhang Linfeng , Wang Han , Zhao Jinbao , Cheng Jun , E Weinan
Published: March 2021

Solid-state electrolyte materials with superior lithium ionic conductivities are vital to the next-generation Li-ion batteries. Molecular dynamics could provide atomic scale information to understand the diffusion process of Li-ion in these superionic conductor materials. Here, we implement the deep potential generator to set up an efficient protocol to automatically generate interatomic potentials for Li10GeP2S12-type solid-state electrolyte materials (Li10GeP2S12, Li10SiP2S12, and Li10SnP2S12). The reliability and accuracy of the fast interatomic potentials are validated. With the potentials, we extend the simulation of the diffusion process to a wide temperature range (300 K–1000 K) and systems with large size (∼1000 atoms). Important technical aspects such as the statistical error and size effect are carefully investigated, and benchmark tests including the effect of density functional, thermal expansion, and configurational disorder are performed. The computed data that consider these factors agree well with the experimental results, and we find that the three structures show different behaviors with respect to configurational disorder. Our work paves the way for further research on computation screening of solid-state electrolyte materials.
Piezoelectric and electronic properties of hydrogenated penta-BCN: A computational study
Authors: Thanasarnsurapong Thanasee , Dabsamut Klichchupong , Maluangnont Tosapol , T-Thienprasert Jiraroj , Jungthawan Sirichok , Boonchun Adisak
Published: March 2021

The pentagonal boron carbon nitride (penta-BCN) monolayer has been recently proposed as a new member of the pentagon-based two-dimensional nanosheets [Zhao et al., J. Phys. Chem. Lett. 11(9), 3501 (2020)]. By using density functional theory with the generalized gradient approximation, we have carried out detailed investigations of a hydrogenated penta-BCN sheet, where the pristine penta sheet is decorated with H atoms to the composition BCNH2. The hydrogenated penta-BCN (H-BCN) structure is mechanically, thermally, and dynamically stable. It has a wide and indirect bandgap of 4.46 eV, contrasting with the direct gap of 1.70 eV in pristine BCN. H-BCN is environmentally stable at 1 bar of H2 down to 10−10 bar; beyond this point, pristine BCN becomes more stable. Compared with penta-BCN, the components of the elastic modulus tensor C11 and C12 of hydrogenated penta-BCN are reduced, while C12 and C66 are increased. The strain tensors of piezoelectricity in H-BCN are d21=0.462,d22=0.213, and d16=1.03pm/V, which are lower than those of pristine penta-BCN. The hydrogenated BCN structure displays a higher spontaneous polarization Ps than penta-BCN (4.64 × 10−10 vs 3.38 × 10−10 C/m, respectively). The smaller in-plane Young's moduli Ea and Eb for H-BCN indicated that that they are softer than those for penta-BCN. Strain engineering can help tune electronic properties. In agreement with this claim, we found that the indirect gap of H-BCN was tunable from 4.46 to 3.26 eV under an applied tensile strain of 0%–16%, the range where the structure is dynamically stable throughout. Meanwhile, H-BCN is dynamically unstable under an applied compressive strain.
Formation of hot ice caused by carbon nanobrushes. II. Dependency on the radius of nanotubes
Authors: Matsumoto Masakazu , Yagasaki Takuma , Tanaka Hideki
Published: March 2021

Stable crystalline structures of confined water can be different from bulk ice. In Paper I [T. Yagasaki et al., J. Chem. Phys. 151, 064702 (2019)] of this study, it was shown, using molecular dynamics (MD) simulations, that a zeolite-like ice structure forms in nanobrushes consisting of (6,6) carbon nanotubes (CNTs) when the CNTs are located in a triangle arrangement. The melting temperature of the zeolite-like ice structure is much higher than the melting temperature of ice Ih when the distance between the surfaces of CNTs is ∼0.94 nm, which is the best spacing for the bilayer structure of water. In this paper, we perform MD simulations of nanobrushes of CNTs that are different from (6,6) CNTs in radius. Several new porous ice structures form spontaneously in the MD simulations. A stable porous ice forms when the radius of its cavities matches the radius of the CNTs well. All cylindrical porous ice structures found in this study can be decomposed into a small number of structural blocks. We provide a new protocol to classify cylindrical porous ice crystals on the basis of this decomposition.
Sturdy nanoribbons are a cross between a soap bubble and a bulletproof vest
Authors: Miller Johanna L.
Published: March 2021

A new strategy for molecular design takes self-assembled materials where they’ve never gone before.
The three physicists
Authors: DeWitt Chris , Edelstein José , Tekin Bayram
Published: March 2021

Since 1951, the Prize of the Three Physicists has been awarded by the École Normale Supérieure in honor of Henri Abraham, Eugène Bloch, and Georges Bruhat—successive directors of the university’s physics laboratory. These are their stories.
A root aphid Aploneura lentisci is affected by Epichloë endophyte strain and impacts perennial ryegrass growth in the field
Authors: Popay Alison J. , Hume David. E. , Mace Wade J. , Faville Marty J. , Finch Sarah C. , Cave Vanessa
Published: March 2021

The aphid Aploneura lentisci is widespread in Australia and New Zealand, living all year round on roots of its secondary grass hosts. The fungal endophyte (Epichloë festucae var. lolii), strain AR37 in Lolium perenne is known to greatly reduce populations and was a likely reason for the superior growth and persistence of this association previously observed in the field. Aphid populations were quantified in a field trial near Ballarat, comparing yields of perennial ryegrass infected with eight different endophyte strains and an endophyte-free (Nil) control in a common ryegrass background (Grasslands Samson (G. Samson)). AR37 and another endophyte strain, AR5, had significantly fewer aphids than all other endophytes. These differences were significantly related to yield increases taken before and after sampling that persisted until the end of the trial. In a pot trial comparing commercially available ryegrass-endophyte combinations with equivalent Nil controls, aphid numbers were lower on G. Samson AR37 and Banquet II with AR5 (Endo®5) than on all other cultivar-endophyte combinations. Compared with Nil controls, the common toxic strain in G. Samson, and two strains in Trojan also reduced aphid numbers. The AR5 endophyte produces the alkaloid ergovaline but high concentrations of this in roots of potted plants could not account for differences in root aphid numbers. Root concentrations of epoxyjanthitrems, the only known alkaloids produced by AR37, were low and unlikely to be the cause of resistance to A. lentisci.
Targeting tumor-derived NLRP3 reduces melanoma progression by limiting MDSCs expansion
Authors: Tengesdal Isak W. , Menon Dinoop R. , Osborne Douglas G. , Neff Charles P. , Powers Nicholas E. , Gamboni Fabia , Mauro Adolfo G. , D’Alessandro Angelo , Stefanoni Davide , Henen Morkos A. , Mills Taylor S. , De Graaf Dennis M. , Azam Tania , Vogeli Beat , Palmer Brent E. , Pietras Eric M. , DeGregori James , Tan Aik-Choon , Joosten Leo A. B. , Fujita Mayumi , Dinarello Charles A. , Marchetti Carlo
Published: March 2021

Significance

The nucleotide-binding domain, leucine-rich containing family, pyrin domain-containing-3 (NLRP3) inflammasome, an intracellular complex that regulates maturation and release of interleukin (IL)-1β, is active in biopsies of metastatic melanoma. Here, we demonstrate that NLRP3 activation in melanoma cells drives tumor progression in mice. Subsequent to NLRP3 activation in melanoma cells, IL-1β induces melanoma-associated inflammation, resulting in immunosuppression. Oral administration of a single NLRP3 inhibitor (OLT1177) reduces melanoma growth and melanoma-associated myeloid-derived suppressor cell expansion. Inhibition of the NLRP3 signaling in combination with anti–PD-1 revealed augmented efficacy compared to monotherapy. These data propose that NLRP3 is a therapeutic target for human melanoma.
Genome wide association study of HTLV-1–associated myelopathy/tropical spastic paraparesis in the Japanese population
Authors: Penova Marina , Kawaguchi Shuji , Yasunaga Jun-ichirou , Kawaguchi Takahisa , Sato Tomoo , Takahashi Meiko , Shimizu Masakazu , Saito Mineki , Tsukasaki Kunihiro , Nakagawa Masanori , Takenouchi Norihiro , Hara Hideo , Matsuura Eiji , Nozuma Satoshi , Takashima Hiroshi , Izumo Shuji , Watanabe Toshiki , Uchimaru Kaoru , Iwanaga Masako , Utsunomiya Atae , Tabara Yasuharu , Paul Richard , Yamano Yoshihisa , Matsuoka Masao , Matsuda Fumihiko
Published: March 2021

Significance

Human T cell leukemia virus type 1 (HTLV-1) proviral load is associated with the risk of developing HTLV-1–associated myelopathy/tropical spastic paraparesis (HAM/TSP) and several small-scale candidate gene approaches have also identified associations of particular
HLA
alleles with HAM/TSP risk. However, no large-scale genome-wide association (GWA) studies have been performed to date. By a large-scale GWA study and comprehensive genotyping of classical
HLA
genes, we found that
HLA-DRB1
alleles carrying leucine at the antigen presentation groove domain (DRB1-GB-7-Leu) increased the susceptibility to HAM/TSP. Individuals who were homozygous for DRB1-GB-7-Leu had a ninefold increased odds of developing HAM/TSP. This effect of DRB1-GB-7-Leu was independent of proviral load. These findings identify DRB1-GB-7-Leu as a genetic risk marker of HAM/TSP development.
Stunted upward mobility in a learning environment reduces the academic benefits of growth mindsets
Authors: Jia Lile , Lim Chun Hui , Ismail Ismaharif , Tan Yia Chin
Published: March 2021

Significance

Recent debates about the failure of the education system in uplifting the disadvantaged have focused on the implications for social justice and stability. Learners’ psychology is understudied. How may a low-mobility learning environment, which signals a reduced potential for disadvantaged learners to achieve success, impact individuals’ recruitment of adaptive psychological processes? In both naturally existing and experimentally constructed contexts, we observe that low-mobility environments, as compared to high-mobility ones, are associated with reduced potency of the otherwise highly beneficial growth mindsets—the beliefs that one’s abilities and talents can be developed. Our study shows that stunted upward mobility in a learning environment incurs costs to individuals’ active learning and development.
Human arrival and landscape dynamics in the northern Bahamas
Authors: Fall Patricia L. , van Hengstum Peter J. , Lavold-Foote Lisa , Donnelly Jeffrey P. , Albury Nancy A. , Tamalavage Anne E.
Published: March 2021

Significance

The oral history for Amerindian migration through The Bahamas was lost after Columbus’s arrival in 1492 CE and Lucayan enslavement in the early sixteenth century. The Lucayans encountered unique prehuman reptile-dominated terrestrial food webs (i.e., tortoise and crocodile), with palm and hardwood forests that were resilient to regional oceanographic cooling and hurricane perturbations. New evidence indicates that Lucayans arrived in the northern Bahamas by about 830 CE after expanding rapidly throughout The Bahamas in less than 100 y. Following subsequent burning, reptiles were extirpated, and pyrogenic pine forests took over Great Abaco Island. Compounded perturbations, including forecasts of future hurricane intensification, may continue to alter Bahamian ecosystems, particularly pine forests, which are less resilient than precontact tropical hardwood ecosystems.
Genome-wide shifts in climate-related variation underpin responses to selective breeding in a widespread conifer
Authors: MacLachlan Ian R. , McDonald Tegan K. , Lind Brandon M. , Rieseberg Loren H. , Yeaman Sam , Aitken Sally N.
Published: March 2021

Significance

Temperate trees originating from warmer localities usually grow faster and acclimate to winter later than trees of the same species from colder localities. However, when trees are selected for faster growth, are climatically adaptive genes and traits affected? Our research demonstrates a simple, sensitive, broadly applicable, and elusive approach to integrating complex polygenic variation into applied environmental management. We show that selective breeding increases allele frequencies of many trait-associated genes, and that alleles that increase most display strong genetic linkage and potential trade-offs among traits. Increasing tree growth while maintaining adaptation is essential to reforestation in a changing climate, but this may be challenging because trait-associated genetic variation that underpins climate adaptation is responsive to selection for tree growth.
Progenitor cell diversity in the developing mouse neocortex
Authors: Ruan Xiangbin , Kang Bowei , Qi Cai , Lin Wenhe , Wang Jingshu , Zhang Xiaochang
Published: March 2021

Significance

How projection neuron types are temporally and sequentially generated in the mammalian neocortex remains unclear. We performed single-cell RNA sequencing analysis of embryonic day (E) 10.5 through E18.5 mouse neocortical cells and identified progenitor cell types across development. Our results uncovered molecular signatures for neuroepithelial cells and temporal gene expression in radial glial progenitors. Importantly,
Eomes
-positive cells display temporal expression of previously characterized neuronal identity genes. These results delineate neocortical progenitor cell diversity and the timing of neuron type specification.
Dual oxidase enables insect gut symbiosis by mediating respiratory network formation
Authors: Jang Seonghan , Mergaert Peter , Ohbayashi Tsubasa , Ishigami Kota , Shigenobu Shuji , Itoh Hideomi , Kikuchi Yoshitomo
Published: March 2021

Significance

The insect respiratory system consists of tubular tracheae that transport oxygen to the organs. We show that, in the insect pest
Riptortus pedestris
, the establishment of an essential symbiosis in the gut with the aerobic bacterial species
Burkholderia insecticola
triggers the development of an extensive tracheal network enveloping the gut. Genetically blocking the trachea formation prevents this gut symbiosis. We further discovered that the reactive oxygen species-generating enzyme Duox is crucial for the formation and stabilization of tracheae by forming protein cross-links in the tracheal matrix. Reactive oxygen species generated by Duox can be scavenged with antioxidants such as N-acetylcysteine, and feeding insects with this compound prevents tracheal formation and symbiosis, suggesting that antioxidants can be used as novel insecticides.
Bilingual reference production
Authors: Torregrossa Jacopo , Bongartz Christiane , Tsimpli Ianthi Maria
Published: March 2021

We investigate reference production in bilingual children. Based on Kibrik (2011), we analyze the production of referring expressions in discourse in terms of activation of a
referent. We propose a novel approach, which calculates activation by taking into account different activation-lending factors
and their respective weight. This allows us to compare the activation encoded by referring expressions across languages and
groups of speakers, and to run correlational analyses with the speakers’ cognitive profiles. In particular, the study
addresses the correlation between activation and lexical processing among bilinguals, based on the distribution of referring
expressions in narratives by 20 German-Greek bilingual children, compared to their monolingual peers. We found that bilingual
pronouns correspond to a lower activation than monolingual ones. Speed of lexical retrieval is a predictor of the bilingual
performance. Our model of analysis accounts for how reference production varies across individuals and which cognitive
mechanisms underlie this variation.
Efficiency in shaping grammars
Authors: Yang Xiaolong , Wu Yicheng
Published: March 2021

Hawkins (1994,1999,2004,2014a) proposes a performance-grammar correspondence hypothesis, claiming that grammars can be shaped by processing systems with reference to the degree of preference in communication. Given that Hawkins’s proposal mainly highlights the role of efficiency in language comprehension, this paper demonstrates that parsing principles can also be employed to account for language production. Based on an analysis of the production mechanism behind multiple occurrences of the Chinese reflexiveziji‘self’ in a single clause, it shows that the notion of intersubjectivity can sometimes play a significant role in sentence planning, in the sense that the Chinese reflexive assists speakers to produce an utterance in line with the principle of efficiency, which will in turn help hearers compute the intended meaning by identifying potential referents.
Organizing Forensic Mental Health Care Delivery: Putting the Trinitarian Model of Therapeutic Security to the Test
Authors: De Pau Marjolein , Nicaise Pablo , Bourmorck Delphine , Vanderplasschen Wouter , Vander Laenen Freya
Published: March 2021

The Trinitarian model of therapeutic security is used to organize forensic mental health care in Ireland, England and Scotland. However, it remains unclear whether this model captures all significant factors for the organization of forensic mental health care delivery. In this case study, the Trinitarian model is applied to and tested on Belgian forensic mental health services. Relational security as a discriminative factor is debated and an extension of this institution-oriented model to the policy- and service users’ level is recommended. Finally, we propose to disentangle the concepts of therapeutic security, risk and care in forensic mental health.
Cardiac MyBP-C phosphorylation regulates the Frank–Starling relationship in murine hearts
Authors: Hanft Laurin M. , Fitzsimons Daniel P. , Hacker Timothy A. , Moss Richard L. , McDonald Kerry S.
Published: March 2021

The Frank–Starling relationship establishes that elevated end-diastolic volume progressively increases ventricular pressure and stroke volume in healthy hearts. The relationship is modulated by a number of physiological inputs and is often depressed in human heart failure. Emerging evidence suggests that cardiac myosin-binding protein-C (cMyBP-C) contributes to the Frank–Starling relationship. We measured contractile properties at multiple levels of structural organization to determine the role of cMyBP-C and its phosphorylation in regulating (1) the sarcomere length dependence of power in cardiac myofilaments and (2) the Frank–Starling relationship in vivo. We compared transgenic mice expressing wild-type cMyBP-C on the null background, which have ∼50% phosphorylated cMyBP-C (Controls), to transgenic mice lacking cMyBP-C (KO) and to mice expressing cMyBP-C that have serine-273, -282, and -302 mutated to aspartate (cMyBP-C t3SD) or alanine (cMyBP-C t3SA) on the null background to mimic either constitutive PKA phosphorylation or nonphosphorylated cMyBP-C, respectively. We observed a continuum of length dependence of power output in myocyte preparations. Sarcomere length dependence of power progressively increased with a rank ordering of cMyBP-C KO = cMyBP-C t3SA < Control < cMyBP-C t3SD. Length dependence of myofilament power translated, at least in part, to hearts, whereby Frank–Starling relationships were steepest in cMyBP-C t3SD mice. The results support the hypothesis that cMyBP-C and its phosphorylation state tune sarcomere length dependence of myofibrillar power, and these regulatory processes translate across spatial levels of myocardial organization to control beat-to-beat ventricular performance.
Fast inactivation of Nav current in rat adrenal chromaffin cells involves two independent inactivation pathways
Authors: Martinez-Espinosa Pedro L. , Neely Alan , Ding Jiuping , Lingle Christopher J.
Published: March 2021

Voltage-dependent sodium (Nav) current in adrenal chromaffin cells (CCs) is rapidly inactivating and tetrodotoxin (TTX)–sensitive. The fractional availability of CC Nav current has been implicated in regulation of action potential (AP) frequency and the occurrence of slow-wave burst firing. Here, through recordings of Nav current in rat CCs, primarily in adrenal medullary slices, we describe unique inactivation properties of CC Nav inactivation that help define AP firing rates in CCs. The key feature of CC Nav current is that recovery from inactivation, even following brief (5 ms) inactivation steps, exhibits two exponential components of similar amplitude. Various paired pulse protocols show that entry into the fast and slower recovery processes result from largely independent competing inactivation pathways, each of which occurs with similar onset times at depolarizing potentials. Over voltages from −120 to −80 mV, faster recovery varies from ∼3 to 30 ms, while slower recovery varies from ∼50 to 400 ms. With strong depolarization (above −10 mV), the relative entry into slow or fast recovery pathways is similar and independent of voltage. Trains of short depolarizations favor recovery from fast recovery pathways and result in cumulative increases in the slow recovery fraction. Dual-pathway fast inactivation, by promoting use-dependent accumulation in slow recovery pathways, dynamically regulates Nav availability. Consistent with this finding, repetitive AP clamp waveforms at 1–10 Hz frequencies reduce Nav availability 80–90%, depending on holding potential. These results indicate that there are two distinct pathways of fast inactivation, one leading to conventional fast recovery and the other to slower recovery, which together are well-suited to mediate use-dependent changes in Nav availability.
Design and manufacture of a micro-tensile testing machine for in situ optical observation and DIC analysis: application to 3D-printed and compression-molded ABS
Authors: Nazari-Onlaghi Sina , Sadeghi Alireza , Karimpour Morad
Published: March 2021

In this paper, a novel micro-tensile testing apparatus is designed and built to characterize the micromechanical behavior of materials. Furthermore, a special geometry for micro specimens is introduced that could facilitate problems related to the handling, gripping, and aligning such specimens. The device can be integrated with an optical microscope to observe the microstructural evolution taking place during deformation. Using the developed system, the micromechanical response of additively-printed and compression-molded ABS was determined. 3D-printed specimens demonstrated higher mechanical properties over the compression-molded specimens. Digital image correlation (DIC) technique was also applied to the optical images taken during deformation to measure the strain field in a micron-sized area of interest. DIC results revealed a more intense strain localization for the 3D-printed specimen compared to the monolithic sample. Comparing stress–strain curves and DIC results indicate that the apparatus and technique were quite successful in the in situ characterization of mechanical response.
Verification of a calibration method for 3D screw thread metrology
Authors: Przyklenk A , Schädel S , Stein M
Published: March 2021

The novel approach for holistic screw thread calibrations developed by the Physikalisch-Technische Bundesanstalt was published in 2019. A significant achievement has been made in order to meet increasing demands in manufacturing processes and quality assurance, particularly when workpieces with complex geometries are under inspection. This article deals with the verification of the previously presented three-dimensional calibration procedure for screw threads. Screw thread pitch diameters, the lead and flank angles are compared to those determined by the standardized method based on line-like, rather two-dimensional measurements and evaluation. In order to provide a reliable basis for the verification, one thread gauge was calibrated under laboratory conditions for precision metrology. Additionally, calibrations were conducted by three alternating operators on three different coordinate measuring machines to investigate the influence by user and machine. The resulting normalized errors

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of screw thread determinants under test and reference values are significantly smaller than 0.5 which indicates a high level of agreement.
Vortex particles in axially symmetric fields and applications of the quantum Busch theorem
Authors: Karlovets Dmitry
Published: March 2021

The possibilities to accelerate vortex electrons with orbital angular momentum (OAM) to relativistic energies and to produce vortex ions, protons, and other charged particles crucially depend on whether the OAM is conserved during the acceleration and on how phase space of the wave packet evolves. We show that both the OAM and a mean emittance of the packet, the latter obeying the Schrödinger uncertainty relation, are conserved in axially symmetric fields of electric and magnetic lenses, typical for accelerators and electron microscopes, as well as in Penning traps. Moreover, a linear approximation of weakly inhomogeneous fields works much better for single packets than for classical beams. We analyze quantum dynamics of the packet’s rms radius ⟨ρ
2⟩, relate this dynamics to a generalized form of the van Cittert–Zernike theorem, applicable at arbitrary distances from a source and for non-Gaussian packets, and adapt the Courant–Snyder formalism to describe the evolution of the packet’s phase space. The vortex beams can therefore be accelerated, focused, steered, trapped, and even stored in azimuthally symmetric fields and traps, somewhat analogously to the classical angular-momentum-dominated beams. We also give a quantum version of the Busch theorem, which states how one can produce vortex electrons with a magnetized cathode during either field- or photoemission, as well as vortex ions and protons by using a magnetized stripping foil employed to change a charge state of ions. Spatial coherence of the packets plays a crucial role in these applications and we provide the necessary estimates for particles of different masses.
A radar-infrared compatible broadband absorbing surface: Design and analysis*
Authors: Yu Qing-Tao , Zeng Yuan-Song , Ma Guo-Jia
Published: March 2021

A radar-infrared compatible stealth surface is designed and analyzed. Without modifying the radar absorbing material (RAM), the design can theoretically achieve radar-infrared compatibility and broadband radar absorption through surface patterns and structures. A transmission-line-based model (TLM) is developed to analyze the radar absorbing performance of the surface. Optimization of the structure geometries is conducted aiming to maximize the –10 dB absorption bandwidth in 2–18 GHz. Surface with optimized structure geometries exhibits a superior absorption bandwidth, more than twice the bandwidth of the original 1.5 mm RAM slab, while maintaining a relatively low infrared emissivity.
Effect of hydrogen content on dielectric strength of the silicon nitride film deposited by ICP-CVD*
Authors: Zhang Yudong , Tang Jiale , Hu Yongjie , Yuan Jie , Guan Lulu , Li Xingyu , Cui Hushan , Ding Guanghui , Shi Xinying , Xu Kaidong , Zhuang Shiwei
Published: March 2021

The inductively coupled plasma chemical vapor deposition (ICP-CVD) deposited silicon nitride (SiN
x
) thin film was evaluated for its application as the electrical insulating film for a capacitor device. In order to achieve highest possible dielectric strength of SiN
x
, the process parameters of ICP-CVD were carefully tuned to control hydrogen in SiN
x
films by means of tuning N2/SiH4 ratio and radio frequency (RF) power. Besides electrical measurements, the hydrogen content in the films was measured by dynamic secondary ion mass spectrometry (D-SIMS). Fourier transform infrared spectroscopy (FTIR) and micro Raman spectroscopy were used to characterize the SiN
x
films by measuring Si–H and N–H bonds’ intensities. It was found that the more Si–H bonds lead to the higher dielectric strength.
Comparative study of photoionization of atomic hydrogen by solving the one- and three-dimensional time-dependent Schrödinger equations*
Authors: Wang Shun , Khan Shahab Ullah , Tian Xiao-Qing , Sun Hui-Bin , Jiang Wei-Chao
Published: March 2021

We develop a numerical scheme for solving the one-dimensional (1D) time-dependent Schrödinger equation (TDSE), and use it to study the strong-field photoionization of the atomic hydrogen. The photoelectron energy spectra obtained for pulses ranging from XUV to near infrared are compared in detail to the spectra calculated with our well-developed code for accurately solving the three-dimensional (3D) TDSE. For XUV pulses, our discussions cover intensities at which the ionization is in the perturbative and nonperturbative regimes. For pulses of 400 nm or longer wavelengths, we distinguish the multiphoton and tunneling regimes. Similarities and discrepancies between the 1D and 3D calculations in each regime are discussed. The observed discrepancies mainly originate from the differences in the transition matrix elements and the energy level structures created in the 1D and 3D calculations.
Design and optimization of a nano-antenna hybrid structure for solar energy harvesting application
Authors: Rabienejhad Mohammad Javad , Davoudi-Darareh Mahdi , Mazaheri Azardokht
Published: March 2021

A novel hybrid structure with high responsivity and efficiency is proposed based on an L-shaped frame nano-antenna (LSFNA) array for solar energy harvesting application. So, two types of LSFNAs are designed and optimized to enhance the harvesting characteristics of traditional simple electric dipole nano-antenna (SEDNA). The LSFNA geometrical dimensions are optimized to have the best values for the required input impedance at three resonance wavelengths ofλres= 10 μm, 15 μm, and 20 μm. Then the LSFNAs with three different sizes are modeled like a planar spiral-shaped array (PSSA). Also, a fractal bowtie nano-antenna is connected with the PSSA in the array gap. This proposed hybrid structure consists of two main elements: (I) Three different sizes of the LSFNAs with two different material types are designed based on the thin-film metal–insulator–metal diodes that are a proper method for infrared energy harvesting. (II) The PSSA gap is designed based on the electron field emission proposed by the Fowler–Nordheim theory for the array rectification. Finally, the proposed device is analyzed. The results show that the PSSA not only has an averaged 3-time enhancement in the harvesting characteristics (such as return loss, harvesting efficiency, etc.) than the previously proposed structures but also is a multi-resonance wide-band device. Furthermore, the proposed antenna takes up less space in the electronic circuit and has an easy implementation process.
Shortcut-based quantum gates on superconducting qubits in circuit QED*
Authors: Zhao Zheng-Yin , Yan Run-Ying , Feng Zhi-Bo
Published: March 2021

Construction of optimal gate operations is significant for quantum computation. Here an efficient scheme is proposed for performing shortcut-based quantum gates on superconducting qubits in circuit quantum electrodynamics (QED). Two four-level artificial atoms of Cooper-pair box circuits, having sufficient level anharmonicity, are placed in a common quantized field of circuit QED and are driven by individual classical microwaves. Without the effect of cross resonance, one-qubit NOT gate and phase gate in a decoupled atom can be implemented using the invariant-based shortcuts to adiabaticity. With the assistance of cavity bus, a one-step SWAP gate can be obtained within a composite qubit-photon-qubit system by inversely engineering the classical drivings. We further consider the gate realizations by adjusting the microwave fields. With the accessible decoherence rates, the shortcut-based gates have high fidelities. The present strategy could offer a promising route towards fast and robust quantum computation with superconducting circuits experimentally.
Phase-field study of spinodal decomposition under effect of grain boundary*
Authors: Deng Ying-Yuan , Guo Can , Wang Jin-Cheng , Liu Qian , Zhao Yu-Ping , Yang Qing
Published: March 2021

Grain boundary directed spinodal decomposition has a substantial effect on the microstructure evolution and properties of polycrystalline alloys. The morphological selection mechanism of spinodal decomposition at grain boundaries is a major challenge to reveal, and remains elusive so far. In this work, the effect of grain boundaries on spinodal decomposition is investigated by using the phase-field model. The simulation results indicate that the spinodal morphology at the grain boundary is anisotropic bicontinuous microstructures different from the isotropic continuous microstructures of spinodal decomposition in the bulk phase. Moreover, at grain boundaries with higher energy, the decomposed phases are alternating α/β layers that are parallel to the grain boundary. On the contrary, alternating α/β layers are perpendicular to the grain boundary.