bluuebunny/crossref_metadata_2025 huggingface dataset:
Effective tuning of spin mixing conductance at the Py/Cu–Nd interface
Authors: Chen Qian , Cao Lulu , Li Jinji , Fu Qiang , Zhu Yonghui , Guo Qingjie , Liu Ruobai , Li Tian , Zhang Wen , Du Jun , Zheng Jianguo , Huang Zhaocong , Wong Ping Kwan Johnny , Fang Bin , Zeng Zhongming , Zhai Ya
Published: June 2022

Spin mixing conductance (SMC) at the ferromagnetic/non-magnetic material (FM/NM) interface governs the transport efficiency of the spin current. A high level of SMC is crucial for efficient spin injection and spin manipulation. Here, we report a reliable way to enhance the SMC at the FM/NM interface by rare-earth doping in the NM layer. As evidenced by the decreased saturation magnetization in permalloy (Py)/Cu–Nd structures, an induced magnetism in Nd is proposed, which is likely to be antiferromagnetically coupled to Py at the interface. By changing the doping content of Nd, the Py/Cu–Nd interface can be well designed, which gives rise to an effective tuning of the SMC from 0.37 × 1015 to 16.26 × 1015 cm−2. Such a tuning effect of SMC is suppressed by inserting a Cu spacer, demonstrating the key role of the antiferromagnetically coupled interface to the improved SMC. Our results highlight the significance of rare-earth materials in spin transport, expanding the design capability of energy-efficient spintronic devices.
A comparison of Newtonian and non-Newtonian pulsatile blood rheology in carotid bifurcation through fluid–solid interaction hemodynamic assessment based on experimental data
Authors: Samaee Milad , Nooraeen Ahmad , Tafazzoli-Shadpour Mohammad , Taghizadeh Hadi
Published: June 2022

Endothelial cells play a crucial role in the arterial homeostasis. In addition to physiological risk factors, abnormal levels of hemodynamic parameters induced by the pulsatile flow contribute to atherosclerotic plaque formation and development. In this study, we used an experimental setup to study the hemodynamics of Newtonian and non-Newtonian blood flow on a deformable model of human carotid bifurcation. The flow/pressure pulses of the experimental model were fed into a fluid–structure interaction numerical model, and respective hemodynamic parameters were obtained and compared between the two flow regimes. Results revealed noticeable differences among the two flow regimes when the pulsatile nature of blood flow and pressure were considered, with more distinct differences near junction sites. Velocity profiles of the non-Newtonian model were more flattened with higher back flow during the diastole. The shear stress waves as well as shear-dependent parameters, such as oscillatory shear index, relative residence time, and vorticity, as well as wall stress and strain, also indicated significant differences among the two models. Regardless of flow regime, results showed a good agreement with clinical outcomes in human carotid bifurcation, especially the carotid sinus. Near the bifurcation, marked fluctuations of shear stress are evident. Around the junction site, wall pulsation experienced variations up to five times of the normal pulse span. The quantified hemodynamic parameters obtained from proposed accurate model of carotid bifurcation may help to achieve technological solutions to adjust the out of biological ranges of these parameters, and avoid atheroma formation or treat the diseased artery.
Crystal nucleation and growth processes in Cu-rich glass-forming Cu–Zr alloys
Authors: Lu A. K. A. , Louzguine-Luzgin D. V.
Published: June 2022

The glass formation ability of an alloy depends on two competing processes: glass-transition, on one hand, and crystal nucleation and growth, on the other hand. While these phenomena have been widely studied before in nearly equiatomic Cu–Zr alloys, studies are lacking for solute/solvent-rich ones. In the present work, molecular dynamics simulations show that the addition of a small amount of Zr (1–10 at. %) to Cu drastically increases the incubation time and slows down crystal growth, thus, leading to an improved glass forming ability. The crystal nucleation and growth processes of a competing face-centered cubic (FCC) Cu crystalline phase are analyzed in detail. In particular, the values of the critical cooling rate, incubation period for crystallization, and growth rate of FCC Cu crystals in these Cu-rich alloys are obtained. The growth of a supersaturated FCC Cu solid solution is found to be polymorphic at the interface (except for alloys with 9 and 10 at. % Zr) though a Zr concentration gradient is observed within growing crystals at high enough Zr content. The crystal growth rate before crystal impingement is nearly constant in all alloys, though it decreases exponentially with the Zr content. Crystallization kinetics are also analyzed within the existing theories and compared with the experimental values available in the literature.
Ear and hearing health in Niue: a qualitative study on the worldviews, knowledge, beliefs and use of health care
Authors: Holt Elizabeth A-L , Nosa Vili , McCool Judith , Thorne Peter R.
Published: June 2022

Introduction Hearing is a primary sense that facilitates the development of spoken language, social connection and an appreciation of sounds within the natural world. Hearing loss has multiple adverse effects across the life course. Understanding the worldviews of ear and hearing health in Pacific peoples is crucial to inform responsive and appropriate hearing health and primary healthcare services. Aim To understand the worldviews, knowledge and beliefs held by the Niuean community in Niue towards ear and hearing health, and the use of healthcare methods to contribute to service development. Methods Twenty semi-structured interviews were conducted with Niuean community members. Interviews were audio-recorded, transcribed verbatim, and analysed using thematic analysis methods. Results Niuean people value hearing health as an important way to communicate and connect with each other. They are proactive health seekers, have good knowledge about ear disease and hearing health and use mainstream medicines alongside spiritual practices and traditional remedies to maintain good ear and hearing health. The hospital system is responsive and accessible to the community’s needs, contrasting with Pacific people’s access to hearing health services in New Zealand. Discussion There is a high level of awareness of the importance of hearing health amongst the Niuean community and good accessibility and utilisation of healthcare services. There is potential to implement locally focused ear and hearing health strategies in Niue and conduct hearing health research among the New Zealand-based Niuean community to improve primary healthcare services delivery.
Age and growth of Pacific cownose ray,
Authors: Pabón-Aldana Karen A. , Melo-Barrera Felipe N. , Pérez-Palafox Xchel A. , Navia Andrés F. , Cruz-Escalona Víctor H. , Mejía-Falla Paola A.
Published: June 2022

Context Rhinoptera steindachneri is the third-most abundant batoid species in the artisanal gillnet fishery of the Gulf of California, but there are limited age and growth data available for management. Aims The aim was to estimate age and growth of this species from vertebral centra of 276 individuals. Methods Two adjusted data sets were constructed on the basis of the birth and capture months and defining adequately the birth band. Individual growth was described through a multi-model approach and inference by using von Bertalanffy, Gompertz, and Logistic models (two and three parameters), and a two-phase growth model (four and five parameters). Key results The model with the best fit to the size-at-age data was the two-phase model for both sexes (females: Dw∞ = 91.21 cm; k = 0.25 year−1, Dw0 = 46.2 cm; males: Dw∞ = 79.1 cm; k = 0.42 year−1, Dw0 = 45.5 cm). Maximum ages ranged from 9.92 to 10.75 years (female) and from 6.92 to 7.67 years (males). Maturity age was estimated in 3.92 years (females) and 3.72 years (males). Conclusions Rhinoptera steindachneri is a batoid species with intermediate growth and a shorter lifespan than for confamilial species and even than species with similar reproductive traits. Implications The need to carry out age validation studies for this species is highlighted.
Multilevel atlas comparisons reveal divergent evolution of the primate brain
Authors: Garin Clément M. , Garin Marie , Silenzi Leonardo , Jaffe Rye , Constantinidis Christos
Published: June 2022

Whether the size of the prefrontal cortex (PFC) in humans is disproportionate when compared to other species is a persistent debate in evolutionary neuroscience. This question has left the study of over/under-expansion in other structures relatively unexplored. We therefore sought to address this gap by adapting anatomical areas from the digital atlases of 18 mammalian species, to create a common interspecies classification. Our approach used data-driven analysis based on phylogenetic generalized least squares to evaluate anatomical expansion covering the whole brain. Our main finding suggests a divergence in primate evolution, orienting the stereotypical mammalian cerebral proportion toward a frontal and parietal lobe expansion in catarrhini (primate parvorder comprising old world monkeys, apes, and humans). Cerebral lobe volumes slopes plotted for catarrhini species were ranked as parietal∼frontal > temporal > occipital, contrasting with the ranking of other mammalian species (occipital > temporal > frontal∼parietal). Frontal and parietal slopes were statistically different in catarrhini when compared to other species through bootstrap analysis. Within the catarrhini’s frontal lobe, the prefrontal cortex was the principal driver of frontal expansion. Across all species, expansion of the frontal lobe appeared to be systematically linked to the parietal lobe. Our findings suggest that the human frontal and parietal lobes are not disproportionately enlarged when compared to other catarrhini. Nevertheless, humans remain unique in carrying the most relatively enlarged frontal and parietal lobes in an infraorder exhibiting a disproportionate expansion of these areas.
Meeting a threat of the Anthropocene: Taste avoidance of metal ions byDrosophila
Authors: Xiao Shuke , Baik Lisa S. , Shang Xueying , Carlson John R.
Published: June 2022

The Anthropocene Epoch poses a critical challenge for organisms: they must cope with new threats at a rapid rate. These threats include toxic chemical compounds released into the environment by human activities. Here, we examine elevated concentrations of heavy metal ions as an example of anthropogenic stressors. We find that the fruit flyDrosophilaavoids nine metal ions when present at elevated concentrations that the flies experienced rarely, if ever, until the Anthropocene. We characterize the avoidance of feeding and egg laying on metal ions, and we identify receptors, neurons, and taste organs that contribute to this avoidance. Different subsets of taste receptors, including members of both Ir (Ionotropic receptor) and Gr (Gustatory receptor) families contribute to the avoidance of different metal ions. We find that metal ions activate certain bitter-sensing neurons and inhibit sugar-sensing neurons. Some behavioral responses are mediated largely through neurons of the pharynx. Feeding avoidance remains stable over 10 generations of exposure to copper and zinc ions. Some responses to metal ions are conserved across diverse dipteran species, including the mosquitoAedes albopictus. Our results suggest mechanisms that may be essential to insects as they face challenges from environmental changes in the Anthropocene.
Experimental research in automatic subtitling
Authors: Karakanta Alina
Published: June 2022

Recent developments in neural machine translation, and especially speech translation, are gradually but firmly entering the field of audiovisual translation (AVT). Automation in subtitling is extending from a machine translation (MT) component to fully automatic subtitling, which comprises MT, auto-spotting and automatic segmentation. The rise of this new paradigm renders MT-oriented experimental designs inadequate for the evaluation and investigation of automatic subtitling, since they fail to encompass the multimodal nature and technical requirements of subtitling. This paper highlights the methodological gaps to be addressed by multidisciplinary efforts in order to overcome these inadequacies and obtain metrics and methods that lead to rigorous experimental research in automatic subtitling. It presents a review of previous experimental designs in MT for subtitling, identifies their limitations for conducting research under the new paradigm and proposes a set of recommendations towards achieving replicability and reproducibility in experimental research at the crossroads between AVT and MT.
Altered regional 3D shear wave velocity patterns in youth competitive alpine skiers suffering from patellar tendon complaints – a prospective case–control study
Authors: Götschi Tobias , Franchi Martino V. , Schulz Nicole , Fröhlich Stefan , Frey Walter O. , Snedeker Jess G. , Spörri Jörg
Published: June 2022

Patellar tendon (PT) complaints are frequent throughout the population, with increased occurrence in athletes and, particularly, in youth competitive alpine skiers. Timely detection and treatment might improve prospects of recovery. Diagnostic modalities in clinical use to date rely on pain symptoms, manual palpation, and potentially, magnetic resonance imaging (MRI); however, MRI‐based imaging yields limited sensitivity. Quantitatively measuring the morphological and mechanical properties of PTs by means of B‐mode ultrasound and shear wave elastography (SWE), instead, may allow improved diagnosis or even early detection. We performed B‐mode scans and three‐dimensional ultrasound shear wave velocity (SWV) mapping and MRI of the PT in 106 youth skiers. A prospective one‐year survey on health problems combined with clinical assessments served to categorize symptomatic and asymptomatic youth skiers. Skiers suffering from distal or proximal tendon complaints showed lower SWV in the respective tendon region than asymptomatic skiers (p = 0.035 and p = 0.019, respectively). Youth skiers with distal tendon complaints additionally exhibited decreased SWV in the proximal region compared to asymptomatic counterparts (p = 0.020). Cross‐validated analysis of retrospective prediction indicated sensitivity and specificity in detecting tendon complaints in the range of 0.606–0.621 and 0.536–0.650, respectively. MRI detected distal tendon complaints with a sensitivity of 0.410 (12/29) but failed to detect any proximal cases. This study agrees with the most recent literature in that SWE holds promise as a valuable adjunct modality for the diagnosis of PT complaints or even the detection of subclinical prestages. However, to evaluate its prospective predictive value, long‐term studies are warranted.

Highlights

Patellar tendon complaints are a frequent complaint in athletes, particularly in youth competitive alpine skiers, but timely quantitative detection of related tendon properties remains challenging.

Quantitative B‐mode US and three‐dimensional ultrasound shear wave elastography assessments and magnetic resonance imaging were performed in youth competitive alpine skiers.

Three‐dimensional shear wave elastography was able to discern symptomatic from asymptomatic patellar tendons both in the distal and proximal tendon regions, whereas magnetic resonance imaging failed to detect any proximal cases.
Context-dependent effects of IL-2 rewire immunity into distinct cellular circuits
Authors: Whyte Carly E. , Singh Kailash , Burton Oliver T. , Aloulou Meryem , Kouser Lubna , Veiga Rafael Valente , Dashwood Amy , Okkenhaug Hanneke , Benadda Samira , Moudra Alena , Bricard Orian , Lienart Stephanie , Bielefeld Pascal , Roca Carlos P. , Naranjo-Galindo Francisco José , Lombard-Vadnais Félix , Junius Steffie , Bending David , Ono Masahiro , Hochepied Tino , Halim Timotheus Y.F. , Schlenner Susan , Lesage Sylvie , Dooley James , Liston Adrian
Published: June 2022

Interleukin 2 (IL-2) is a key homeostatic cytokine, with therapeutic applications in both immunogenic and tolerogenic immune modulation. Clinical use has been hampered by pleiotropic functionality and widespread receptor expression, with unexpected adverse events. Here, we developed a novel mouse strain to divert IL-2 production, allowing identification of contextual outcomes. Network analysis identified priority access for Tregs and a competitive fitness cost of IL-2 production among both Tregs and conventional CD4 T cells. CD8 T and NK cells, by contrast, exhibited a preference for autocrine IL-2 production. IL-2 sourced from dendritic cells amplified Tregs, whereas IL-2 produced by B cells induced two context-dependent circuits: dramatic expansion of CD8+ Tregs and ILC2 cells, the latter driving a downstream, IL-5–mediated, eosinophilic circuit. The source-specific effects demonstrate the contextual influence of IL-2 function and potentially explain adverse effects observed during clinical trials. Targeted IL-2 production therefore has the potential to amplify or quench particular circuits in the IL-2 network, based on clinical desirability.
Measurement of the angular correlation between the two gamma rays emitted in the radioactive decays of a 60Co source with two NaI(Tl) scintillators
Authors: Amato E C , Anelli A , Barbieri M , Cataldi D , Cellamare V , Cerasole D , Conserva F , De Gaetano S , Depalo D , Digennaro A , Fiorente E , Gargano F , Gatti D , Loizzo P , Loparco F , Mele O , Nicassio N , Perfetto G , Pillera R , Pirlo R , Schygulla E , Troiano D
Published: June 2022

We implemented a didactic experiment to study the angular correlation between the two gamma rays emitted in typical 60Co radioactive decays. We used two NaI(Tl) scintillators, already available in our laboratory, and a low-activity 60Co source. The detectors were mounted on two rails, with the source at their center. The first rail was fixed, while the second could be rotated around the source. We performed several measurements by changing the angle between the two scintillators in the range from 90° to 180°. Dedicated background runs were also performed, removing the source from the experimental setup. We found that the signal rate increases with the angular separation between the two scintillators, with small discrepancies from the theoretical expectations.
Defect-control electron transport behavior of gallium nitride/silicon nonplanar-structure heterojunction
Authors: Zhang Yan , Jiang Hang-Hui , Luo Yuan-Hang , Xiao Meng-Zhen , Wen Chao , Xing Ya-Kun , Li Xin-Jian
Published: June 2022

Compared with a traditional heterojunction, a nonplanar-structure heterojunction can reduce the problems caused by a lattice mismatch through a three-dimensional stress release mechanism, which will be helpful for promoting the performance and stability of related devices. In this paper, we report our study on the electron transport behavior of a gallium nitride (GaN)/silicon (Si) heterojunction with nonplanar-structure interface, which was prepared through growing GaN on a hierarchical structure, Si nanoporous pillar array (Si-NPA). To clarify the electron transport mechanism and promote the device performance, annealing treatment in ammonia atmosphere was carried out to as-prepared GaN/Si-NPA. The formation of the heterojunction was verified by the typical rectification behavior observed in both as-prepared and annealed samples. After annealing treatment, a lower turn-on voltage, a smaller reverse saturation current density, a larger forward current density and a higher reverse breakdown voltage were obtained, which indicate the promotion of the heterojunction performance. By comparatively studying the spectrum evolution of photoluminescence before and after annealing treatment, the underlying mechanism is clarified as the variation of the type and density of point defects such as gallium vacancy (V
Ga), oxygen substitutional impurity (ON), and their complex defect V
Ga−ON in GaN. The results illustrate an effective defect-control strategy for optimizing the performance of GaN/Si heterojunction optoelectronic devices.
Wavefunction-based quantum-chemical ab initio calculations for core electron binding energies of small open shell molecules
Authors: Staemmler Volker
Published: June 2022

Core electron binding energies (CEBEs), i.e. ionization energies of 1s core orbitals, are calculated by means of wavefunction-based quantum-chemicalab initiomethods for a series of small open-shell molecules containing first-row atoms. The calculations are performed in three steps: (a) Koopmans’ theorem, where the orbitals of the electronic ground state are used unchanged also for the ions, (b) Hartree–Fock or self consistent field (SCF) approximation in which the orbitals are allowed to relax after 1s ionization (ΔSCF), (c) dynamic correlation effects on top of SCF. For open-shell molecules 1s ionization leads to ions in several spin states, mostly to a pair of a triplet and a singlet state. In several cases one or both of these ionic states are only poorly described by a single-reference SCF wavefunction, therefore a multi-reference complete active space self consistent field (CAS-SCF) wavefunction is used instead. The correlation effects are evaluated by means of our multi-reference coupled electron pair approximation program. The accuracy of the calculated CEBEs is in the order of 0.1–0.4 eV. This is in agreement with experimental results for NO and O2. But there exist only very few gas phase data for CEBEs of open-shell molecules.
Biological/metal oxide composite transport layers cast from green solvents for boosting light harvesting response of organic photovoltaic cells indoors
Authors: Dagar Janardan , Brown Thomas M
Published: June 2022

Organic solar cells with biological/metal–oxide electron transport layers (ETLs), consisting of a ZnO compact layer covered by a thin DNA layer, both of which deposited with green solvents (water or water/alcohols mixtures) are presented for application under low intensity indoor lighting. Under white LED lamp (200, 400 lx), photovoltaic cells with P3HT:PC70BM polymer semiconductor blends delivered an average maximum power density (MPD) of 8.7 μW cm−2, corresponding to a power conversion efficiency, PCE, of = 8.56% (PCE of best cell was 8.74%). The ZnO/DNA bilayer boosted efficiency by 68% and 13% in relative terms compared to cells made with DNA-only and ZnO-only ETLs at 400 lx. Photovoltaic cells with ZnO/DNA composite ETLs based on PTB7:PC70BM blends, that absorb a broader range of the indoor lighting spectrum, delivered MPDs of 16.2 μW cm−2 with an estimated average PCE of 14.3% (best cell efficiency of 15.8%) at 400 lx. The best efficiencies for cells fabricated on flexible plastic substrates were 11.9% at 400 lx. This is the first report in which polymer photovoltaics incorporating biological materials have shown to increment performance at these low light levels and work very efficiently under indoor artificial light illumination. The finding can be useful for the production of more bio-compatible photovoltaics as well as bio-sensing devices based on organic semiconductors.
Vectorial probing of electric and magnetic transitions in variable optical environments and vice-versa
Authors: Chacon Reinaldo , Leray Aymeric , Kim Jeongmo , Lahlil Khalid , Bouhelier Alexandre , Kim Jong-Wook , Gacoin Thierry , Colas des Francs Gérard
Published: June 2022

We use europium doped single crystalline NaYF4 nanorods for probing the electric and magnetic contributions to the local density of optical states (LDOS). Reciprocically, we determine intrinsic properties of the emitters (oscillator strength, quantum yield) by comparing their measured and simulated optical responses in front of a mirror. We first experimentally determine the specifications of the nanoprobe (orientation and oscillator strength of the electric and magnetic dipoles moments) and show significant orientation sensitivity of the branching ratios associated with electric and magnetic transitions. In a second part, we measure the modification of the LDOS in front of a gold mirror in a Drexhage’s experiment. We discuss the role of the electric and magnetic LDOS on the basis of numerical simulations, taking into account the orientation of the dipolar emitters. We demonstrate that they behave like degenerated dipoles sensitive to polarized partial LDOS.
Modeling of the electron beam induced current signal in nanowires with an axial p-n junction
Authors: Lahreche Abderrezak , Babichev Andrey V , Beggah Yamina , Tchernycheva Maria
Published: June 2022

A tridimensional mathematical model to calculate the electron beam induced current (EBIC) of an axial p-n nanowire junction is proposed. The effect of the electron beam and junction parameters on the distribution of charge carriers and on the collected EBIC current is reported. We demonstrate that the diffusion of charge carriers within the wire is strongly influenced by the electrical state of its lateral surface which is characterized by a parameter called surface recombination velocity (v
r). When the surface recombination is weak (i.e. low v
r value), the diffusion of charge carriers occurs in one dimension (1D) along the wire axis, and, in this case, the use of bulk EBIC models to extract the diffusion length (L) of charge carriers is justified. However, when the surface effects are strong (i.e. high v
r values), the diffusion happens in three dimensions (3D). In this case, the EBIC profiles depend on v
r value and two distinct cases can be defined. If the L is larger than the nanowire radius (r
a), the EBIC profiles show a strong dependency with this parameter. This gives evidence that the recombination of generated carriers on the surface through v
r is the dominant process. In this situation, a decrease of two orders of magnitude in the EBIC profiles computed with a high and a low v
r value is observed in neutral regions of the junction. For the case of L smaller than r
a the dependency of the EBIC profiles on the v
r is weak, and the prevalent recombination mechanism is the bulk recombination process.
Finite element modeling and validation of a soft array of spatially coupled dielectric elastomer transducers
Authors: Croce Sipontina , Neu Julian , Moretti Giacomo , Hubertus Jonas , Schultes Günter , Rizzello Gianluca
Published: June 2022

Dielectric elastomer (DE) transducers are suitable candidates for the development of compliant mechatronic devices, such as wearable smart skins and soft robots. If many independently-controllable DEs are closely arranged in an array-like configuration, sharing a common elastomer membrane, novel types of cooperative and soft actuator/sensor systems can be obtained. The common elastic substrate, however, introduces strong electro-mechanical coupling effects among neighboring DEs, which highly influence the overall membrane system actuation and sensing characteristics. To effectively design soft cooperative systems based on DEs, these effects need to be systematically understood and modeled first. As a first step towards the development of soft cooperative DE systems, in this paper we present a finite element simulation approach for a 1-by-3 silicone array of DE units. After defining the system constitutive equations and the numerical assumptions, an extensive experimental campaign is conducted to calibrate and validate the model. The simulation results accurately predict the changes in force (actuation behavior) and capacitance (sensing behavior) of the different elements of the array, when their neighbors are subjected to different electro-mechanical loads. Quantitatively, the model reproduces the force and capacitance responses with an average fit higher than 93% and 92%, respectively. Finally, the validated model is used to perform parameter studies, aimed at highlighting how the array performance depends on a relevant set of design parameters, i.e. DE-DE spacing, DE-outer structure spacing, membrane pre-stretch, array scale, and electrode shape. The obtained results will provide important guidelines for the future design of cooperative actuator/sensor systems based on DE transducers.
Sending-or-not-sending twin field quantum key distribution with imperfect vacuum sources
Authors: Hu Xiao-Long , Jiang Cong , Yu Zong-Wen , Wang Xiang-Bin
Published: June 2022

The sending-or-not-sending (SNS) protocol of the twin-field (TF) quantum key distribution (QKD) can tolerant large misalignment error and its key rate can exceed the linear bound of repeaterless QKD. The original SNS protocol and all variants of TF-QKD require perfect vacuum sources, but in the real world experiments there is no practical perfect vacuum source. Instead, experimenters use extremely weak sources to substitute vacuum sources, which may break the security of the protocol. Here we propose an SNS protocol with imperfect vacuum sources and give the non-asymptotic decoy-state analysis of this protocol. Our numerical simulation shows that when the imperfect vacuum sources are close to perfect vacuum sources, our protocol can obtain similar key rate as that with perfect vacuum sources. This is the first result that closes the potential security loophole due to imperfect vacuum of TF-QKD.
A competitive advantage through fast dead matter elimination in confined cellular aggregates
Authors: Pollack Yoav G , Bittihn Philip , Golestanian Ramin
Published: June 2022

Competition of different species or cell types for limited space is relevant in a variety of biological processes such as biofilm development, tissue morphogenesis and tumor growth. Predicting the outcome for non-adversarial competition of such growing active matter is non-trivial, as it depends on how processes like growth, proliferation and the degradation of cellular matter are regulated in confinement; regulation that happens even in the absence of competition to achieve the dynamic steady state known as homeostasis. Here, we show that passive by-products of the processes maintaining homeostasis can significantly alter fitness. Even for purely pressure-regulated growth and exclusively mechanical interactions, this enables cell types with lower homeostatic pressure to outcompete those with higher homeostatic pressure. We reveal that interfaces play a critical role for this specific kind of competition: there, growing matter with a higher proportion of active cells can better exploit local growth opportunities that continuously arise as the active processes keep the system out of mechanical equilibrium. We elucidate this effect in a theoretical toy model and test it in an agent-based computational model that includes finite-time mechanical persistence of dead cells and thereby decouples the density of growing cells from the homeostatic pressure. Our results suggest that self-organization of cellular aggregates into active and passive matter can be decisive for competition outcomes and that optimizing the proportion of growing (active) cells can be as important to survival as sensitivity to mechanical cues.
3d-Electron-doping induced multiferroicity and half-metallicity in PbTiO3
Authors: Gilani S , Nazir S , Zulfiqar M , Zhao Y
Published: June 2022

Atomic interactions can be used to control and tune the physical properties of the systems, which are different from the pristine structure. Herein, we explored the ferroelectric, magnetic, and electronic properties of 3d transition metals (TM = Sc, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn)-doped PbTiO3 utilizing density functional theory calculations. The structural stability of the undoped and doped systems is checked by computing the formation enthalpies in terms of the Convex Hull analysis, affirms the experimental realization of all the motifs. It is established that the versatile multiferroic properties can be obtained by TM-doping, which are ranging from non-magnetic/magnetic semiconductor or conductor (Sc-, Zn-, and Ni-doped systems)/(V-, Mn-, Fe-, and Cu-doped systems) to half-metallic ferromagnetic (Cr- and Co-doped systems). The most striking feature of the present study is that Cr- and Co-doped systems display half-metallic behavior along with a moderate spontaneous polarization (SP) of 40.07 and 59.77 μC/cm−2, respectively. The metallicity in the spin-minority channel mainly comes from the Cr and Co 3dyz+xz orbitals with a small contribution from d

xy
. However, Zn-doped motif displays a higher SP magnitude of 70.32 μC/cm−2 than that of other doped systems. Finally, the induced magnetism in these doped structures is explained by addressing the low and high spin state configurations of TM ions. As it found that Mn- and Fe-doped structures exhibit a larger moment of 2.9 and 2.7 μ

B
and lie in a high spin states of S = 2.0 and 2.02, respectively. Hence, our calculations highly demand the experimental verification of these doped materials for their potential realization in spintronic devices.
CrAlGe: An itinerant ferromagnet with strong tunability by heat treatment
Authors: Dong Zhaokun , Wang Zhen , Zhang Te , Xiang Junsen , Zhang Shuai , Liu Lihua , Sun Peijie
Published: June 2022

We present a comprehensive investigation on CrAlGe and realize that it is an itinerant ferromagnet with strong tunability of the Curie temperature T
C and the spontaneous moment μ
0 depending on annealing heat treatment. While the value of T
C was previously reported to be 80 K with μ
0 ≈ 0.41μ
B, in this work the two quantities attain values as high as 170 K and 0.66μ
B, respectively. Heat treatment does not cause changes of the lattice parameters and symmetry, but results in a slight narrowing of the Bragg peaks. The strong tunability of the itinerant ferromagnetism indicates significantly tunable hybridization between the Cr 3d electrons and the conduction bands, in agreement with the dominant Cr–Al/Ge bonds of this compound. Further tuning along the same line towards even stronger or weaker itinerant ferromagnetism promises an interesting follow-up to clarify the localized-itinerant duality of the 3d electrons in this compound.
AA-stacked borophene-graphene bilayer as an anode material for alkali-metal ion batteries with a superhigh capacity
Authors: Liang Yi-Bo , Liu Zhao , Wang Jing , Liu Ying
Published: June 2022

As the lightest two-dimensional material, monolayer borophene exhibits great potential as electrode materials, but it suffers from stability issues in the free-standing form. Here, the striped-borophene and graphene bilayer (sB/Gr) is found to be a high-performance anode material for rechargeable alkali-metal ion batteries. The first-principles results show that all the three alkali-metal atoms, Li, Na, and K, can be strongly adsorbed on sB/Gr with ultra-low diffusion barriers than that on pristine borophene/graphene, indicating good charge-discharge rates. Remarkably, high storage capacities are proposed for LIBs (1880 mA⋅h/g), NIBs (1648 mA⋅h/g), and KIBs (470 mA⋅h/g) with relatively small lattice change rate (<2.9%) in the process of alkali-metal atoms intercalations. These intriguing features of sB/Gr make it an excellent choice for batteries.
Structural evolution-enabled BiFeO3 modulated by strontium doping with enhanced dielectric, optical and superparamagnetic properties by a modified sol-gel method
Authors: Sharon V S , Veena Gopalan E , Malini K A
Published: June 2022

Multiferroic (BFO) nanoparticles doped with strontium with the general formula Bi1–x
Sr
x
FeO3 (x = 0, 0.3, 0.5, 0.7) were synthesized using a modified sol-gel auto-combustion process. The structural, electrical, optical, and magnetic properties of the samples are discussed. The structural analysis, carried out using the x-ray powder diffraction technique, shows a structural transition from rhombohedral (R-3c) to cubic (Pm-3m) for the doping amount of strontium (Sr) equal to x = 0.3. Morphological analysis of the prepared samples were carried out using scanning electron microscopy (SEM). Frequency-dependent dielectric constant and ac conductivity were studied. The doped samples, with improved dielectric properties, can be used to fabricate different optoelectronic devices. Strong dielectric dispersion and broad relaxation were exhibited by all the samples. Cole–Cole plots were employed as an effective tool to study the dispersion parameters, namely, the optical dielectric constant, static dielectric constant, relaxation time, and spreading factor. The activation energy was calculated from the relaxation peaks and Cole–Cole plots, which were found to be compatible with each other. The bandgap of the samples was calculated using diffuse reflectance spectral (DRS) analysis. Sharp and strong photoluminescence in the IR region was observed in the samples, similar to ZnO, which was reported for the first time. Room-temperature and low-temperature magnetization studies point towards the superparamagnetic nature of the samples, with an improvement in magnetic properties with doping. The antiferromagnetic behavior of bulk bismuth ferrite transforms to superparamagnetic in nature for both pure and Sr-substituted bismuth ferrite nanoparticles due to the close dimensions of crystallite size with magnetic domains leading to the break-down of the frustrated spin cycloidal moment.
A novel algorithm to analyze the dynamics of digital chaotic maps in finite-precision domain
Authors: Fan Chunlei , Ding Qun
Published: June 2022

Chaotic maps are widely used to design pseudo-random sequence generators, chaotic ciphers, and secure communication systems. Nevertheless, the dynamic characteristics of digital chaos in finite-precision domain must be degraded in varying degrees due to the limited calculation accuracy of hardware equipment. To assess the dynamic properties of digital chaos, we design a periodic cycle location algorithm (PCLA) from a new perspective to analyze the dynamic degradation of digital chaos. The PCLA can divide the state-mapping graph of digital chaos into several connected subgraphs for the purpose of locating all fixed points and periodic limit cycles contained in a digital chaotic map. To test the versatility and availability of our proposed algorithm, the periodic distribution and security of 1-D logistic maps and 2-D Baker maps are analyzed in detail. Moreover, this algorithm is helpful to the design of anti-degradation algorithms for digital chaotic dynamics. These related studies can promote the application of chaos in engineering practice.
RETRACTED: Role of Alloying Composition on the Nanomechanical Behavior of Amorphous Nanolaminates
Authors: Jasim Saade Abdalkareem , Al-Gazally Moaed E. , Abdelbasset Walid Kamal , Pradhan Preeti , Bokov Dmitry Olegovich , Abdulkadhm Mohammed Mustafa , Kadhim Mustafa M. , Altimari Usama S. , Al-Thamir Mohaimen , Thangavelu Lakshmi , Mustafa Yasser Fakri , Jabbar Abdullah Hasan , Sajjadifar Sami
Published: June 2022

In this work, the molecular dynamics (MD) simulation was performed to evaluate the nanomechanical properties and plasticity behavior of amorphous nanolaminates. For this purpose, two types of nanolaminates with the composition layers of Cu50Zr50/Cu54Zr46/Cu60Zr40 (ABC-type) and Cu50Zr50/Cu60Zr40 (AC-type) were firstly designed and the mechanical properties were then evaluated through the nanoindentation and tensile loading. The results indicated that the ABC-type nanolaminate exhibited higher strength and resisted the relaxation of stored energy in the holding stage of the indenting process. The Von-Mises strain distribution also showed that the plastic deformation initiated from the indenter/sample connection and gradually continued into the depth of the sample, while the strained regions in the AC-type considerably extended in the width of the sample perpendicular to the indenting force. The tensile loading results demonstrated that the intersection of the interface and free surface is the potential site for the initiation of shear events in both nanolaminates; however, the AC-type showed a sharp strain accumulation in the soft layer (Cu50Zr50) with the increase in the total strain value. On the other side, the gradual changes in the chemical compositions of layers and slight compositional variations at the interfaces led to more homogeneous plastic deformation in the ABC-type nanolaminate.
Enhanced single photon emission in silicon carbide with Bull’s eye cavities
Authors: Liu Xing-Hua , Ren Fang-Fang , Ye Jiandong , Wang Shuxiao , Xu Wei-Zong , Zhou Dong , Yu Mingbin , Zhang Rong , Zheng Youdou , Lu Hai
Published: June 2022

The authors demonstrate a Bull’s eye cavity design that is composed of circular Bragg gratings and micropillar optical cavity in 4H silicon carbide (4H-SiC) for single photon emission. Numerical calculations are used to investigate and optimize the emission rate and directionality of emission. Thanks to the optical mode resonances and Bragg reflections, the radiative decay rates of a dipole embedded in the cavity center is enhanced by 12.8 times as compared to that from a bulk 4H-SiC. In particular, a convergent angular distribution of the emission in far field is simultaneously achieved, which remarkably boost the collection efficiency. The findings of this work provide an alternative architecture to manipulate light–matter interactions for achieving high-efficient SiC single photon sources towards applications in quantum information technologies.
Space continuous atom laser in one dimension
Authors: Qin Yi , Shen Xiao-Yang , Chang Wei-Xuan , Xia Lin
Published: June 2022

Cold atom physics in space station arouses a lot of interest of scientists. We investigate the dynamical output process of the space continuous atom laser by solving nonlinear Gross–Pitaevksii equations numerically. Slow-moving continuous atom beams in two directions are observed simultaneously. The slow-moving coherent atom beams can be used as a source of atom interferometer to realize long-time measurements. We also control the output of space atom laser by adjusting the output coupling strength.
Effect of the codoping of N–H–O on the growth characteristics and defects of diamonds under high temperature and high pressure
Authors: Cai Zhenghao , Li Bowei , Chen Liangchao , Wang Zhiwen , Fang Shuai , Wang Yongkui , Ma Hongan , Jia Xiaopeng
Published: June 2022

Diamond crystals were synthesized with different doping proportions of N–H–O at 5.5 GPa–7.1 GPa and 1370 °C–1450 °C. With the increase in the N–H–O doping ratio, the crystal growth rate decreased, the temperature and pressure conditions required for diamond nucleation became increasingly stringent, and the diamond crystallization process was affected. [111] became the dominant plane of diamonds; surface morphology became block-like; and growth texture, stacking faults, and etch pits increased. The diamond crystals had a two-dimensional growth habit. Increasing the doping concentration also increased the amount of N that entered the diamond crystals as confirmed via Fourier transform infrared spectroscopy. However, crystal quality gradually deteriorated as verified by the red-shifting of Raman peak positions and the widening of the Raman full width at half maximum. With the increase in the doping ratio, the photoluminescence property of the diamond crystals also drastically changed. The intensity of the N vacancy center of the diamond crystals changed, and several Ni-related defect centers, such as the NE1 and NE3 centers, appeared. Diamond synthesis in N–H–O-bearing fluid provides important information for deepening our understanding of the growth characteristics of diamonds in complex systems and the formation mechanism of natural diamonds, which are almost always N-rich and full of various defect centers. Meanwhile, this study proved that the type of defect centers in diamond crystals could be regulated by controlling the N–H–O impurity contents of the synthesis system.
Selective formation of ultrathin PbSe on Ag(111)
Authors: Wang Jing , Bagheri Tagani Meysam , Zhang Li , Xia Yu , Wu Qilong , Li Bo , Tian Qiwei , Tian Yuan , Yin Long-Jing , Zhang Lijie , Qin Zhihui
Published: June 2022

Two-dimensional (2D) semiconductors, such as lead selenide (PbSe), locate at the key position of next-generation devices. However, the ultrathin PbSe is still rarely reported experimentally, particularly on metal substrates. Here, we report the ultrathin PbSe synthesized via sequential molecular beam epitaxy on Ag(111). The scanning tunneling microscopy is used to resolve the atomic structure and confirms the selective formation of ultrathin PbSe through the reaction between Ag5Se2 and Pb, as further evidenced by the theoretical calculation. It is also found that the increased accumulation of Pb leads to the improved quality of PbSe with larger and more uniform films. The detailed analysis demonstrates the bilayer structure of synthesized PbSe, which could be deemed to achieve the 2D limit. The differential conductance spectrum reveals a metallic feature of the PbSe film, indicating a certain interaction between PbSe and Ag(111). Moreover, the moiré pattern originated from the lattice mismatch between PbSe and Ag(111) is observed, and this moiré system provides the opportunity for studying physics under periodical modulation and for device applications. Our work illustrates a pathway to selectively synthesize ultrathin PbSe on metal surfaces and suggests a 2D experimental platform to explore PbSe-based opto-electronic and thermoelectric phenomena.
EMvelop stimulation: minimally invasive deep brain stimulation using temporally interfering electromagnetic waves
Authors: Ahsan Fatima , Chi Taiyun , Cho Raymond , Sheth Sameer A , Goodman Wayne , Aazhang Behnaam
Published: June 2022

Objective. Recently, the temporal interference stimulation (TIS) technique for focal noninvasive deep brain stimulation (DBS) was reported. However, subsequent computational modeling studies on the human brain have shown that while TIS achieves higher focality of electric fields than state-of-the-art methods, further work is needed to improve the stimulation strength. Here, we investigate the idea of EMvelop stimulation, a minimally invasive DBS setup using temporally interfering gigahertz (GHz) electromagnetic (EM) waves. At GHz frequencies, we can create antenna arrays at the scale of a few centimeters or less that can be endocranially implanted to enable longitudinal stimulation and circumvent signal attenuation due to the scalp and skull. Furthermore, owing to the small wavelength of GHz EM waves, we can optimize both amplitudes and phases of the EM waves to achieve high intensity and focal stimulation at targeted regions within the safety limit for exposure to EM waves. Approach. We develop a simulation framework investigating the propagation of GHz EM waves generated by line current antenna elements and the corresponding heat generated in the brain tissue. We propose two optimization flows to identify antenna current amplitudes and phases for either maximal intensity or maximal focality transmission of the interfering electric fields with EM waves safety constraint. Main results. A representative result of our study is that with two endocranially implanted arrays of size

4.2
 cm

×

4.7
 cm

each, we can achieve an intensity of 12 V m−1 with a focality of

3.6
 cm

at a target deep in the brain tissue. Significance. In this proof-of-principle study, we show that the idea of EMvelop stimulation merits further investigation as it can be a minimally invasive way of stimulating deep brain targets and offers benefits not shared by prior methodologies of electrical or magnetic stimulation.