bluuebunny/crossref_metadata_2025 huggingface dataset:
Small-scale movement and migration cues of Australian bass (
Authors: Brown Culum , Byrnes Evan E.
Published: March 2022

Urban river catchments are often severely affected by human activities but may still retain significant biodiversity. Surprisingly little is known about the behaviour of urban fishes, even those popular with anglers. Key environmental variables that trigger fish behaviour, such as river flow, are highly affected by instream structures including weirs and changes in the natural flow regime. Here, we used acoustic telemetry to examine the movements of Australian bass in a river located in suburban Sydney, Australia. We found that fish tended to be nocturnally active, however, small-scale movements were highly idiosyncratic and less associated with river flow than other factors. Larger-scale movements associated with spawning migrations were strongly correlated with winter floods. Half of the tagged fish migrated to the confluence of the river with Sydney Harbour to breed. Their return migration was hampered by a weir, but the provision of a new fish way facilitated successful return to freshwater at high tide. Despite occupying a highly affected, urban catchment fish behaviour showed similarity to those occupying more natural drainages. Our results highlight the importance of maintaining natural river flows in urban catchments and sustaining fish movement and migration capabilities through the installation of appropriate fish passage devices.
Co-condensation of proteins with single- and double-stranded DNA
Authors: Renger Roman , Morin Jose A. , Lemaitre Regis , Ruer-Gruss Martine , Jülicher Frank , Hermann Andreas , Grill Stephan W.
Published: March 2022

Significance

Biomolecular condensates are intracellular organelles that are not bounded by membranes and often show liquid-like, dynamic material properties. They typically contain various types of proteins and nucleic acids. How the interaction of proteins and nucleic acids finally results in dynamic condensates is not fully understood. Here we use optical tweezers and fluorescence microscopy to study how the prototypical prion-like protein Fused-in-Sarcoma (FUS) condenses with individual molecules of single- and double-stranded DNA. We find that FUS adsorbs on DNA in a monolayer and hence generates an effectively sticky FUS–DNA polymer that collapses and finally forms a dynamic, reversible FUS–DNA co-condensate. We speculate that protein monolayer-based protein–nucleic acid co-condensation is a general mechanism for forming intracellular membraneless organelles.
Purging of deleterious burden in the endangered Iberian lynx
Authors: Kleinman-Ruiz Daniel , Lucena-Perez Maria , Villanueva Beatriz , Fernández Jesús , Saveljev Alexander P. , Ratkiewicz Mirosław , Schmidt Krzysztof , Galtier Nicolas , García-Dorado Aurora , Godoy José A.
Published: March 2022

Significance

The dynamics of deleterious variation under contrasting demographic scenarios remain poorly understood in spite of their relevance in evolutionary and conservation terms. Here we apply a genomic approach to study differences in the burden of deleterious alleles between the endangered Iberian lynx (Lynx pardinus) and the widespread Eurasian lynx (Lynx lynx). Our analysis unveils a significantly lower deleterious burden in the former species that should be ascribed to genetic purging, that is, to the increased opportunities of selection against recessive homozygotes due to the inbreeding caused by its smaller population size, as illustrated by our analytical predictions. This research provides theoretical and empirical evidence on the evolutionary relevance of genetic purging under certain demographic conditions.
Dual-field-of-view high-spectral-resolution lidar: Simultaneous profiling of aerosol and water cloud to study aerosol–cloud interaction
Authors: Wang Nanchao , Zhang Kai , Shen Xue , Wang Yuan , Li Jing , Li Chengcai , Mao Jietai , Malinka Aleksey , Zhao Chuanfeng , Russell Lynn M. , Guo Jianping , Gross Silke , Liu Chong , Yang Jing , Chen Feitong , Wu Lingyun , Chen Sijie , Ke Ju , Xiao Da , Zhou Yudi , Fang Jing , Liu Dong
Published: March 2022

Significance

Aerosol–cloud interaction affects the cooling of Earth’s climate, mostly by activation of aerosols as cloud condensation nuclei that can increase the amount of sunlight reflected back to space. But the controlling physical processes remain uncertain in current climate models. We present a lidar-based technique as a unique remote-sensing tool without thermodynamic assumptions for simultaneously profiling diurnal aerosol and water cloud properties with high resolution. Direct lateral observations of cloud properties show that the vertical structure of low-level water clouds can be far from being perfectly adiabatic. Furthermore, our analysis reveals that, instead of an increase of liquid water path (LWP) as proposed by most general circulation models, elevated aerosol loading can cause a net decrease in LWP.
Suppression of toxicity of the mutant huntingtin protein by its interacting compound, desonide
Authors: Song Haikun , Wang Cen , Zhu Chenggang , Wang Ziying , Yang Huiya , Wu Peng , Cui Xiaotian , Botas Juan , Dang Yongjun , Ding Yu , Fei Yiyan , Lu Boxun
Published: March 2022

Significance

Classical drug discovery identifies inhibitors that block the activities of pathogenic proteins. This typically relies on a measurable biochemical readout and accessible binding sites whose occupancy influences the activity of the target protein. These requirements make many pathogenic proteins “undruggable.” Here, we report a strategy to target these undruggable proteins: screening for compounds that directly bind to the undruggable target and rescue disease-relevant phenotypes. These compounds may suppress the target’s pathogenic functions via direct binding to it. We applied this strategy to the mutant HTT protein, which is an undruggable protein that causes Huntington’s disease (HD). We revealed desonide, an FDAapproved drug, as a possible lead compound for HD drug discovery.
Reciprocal regulation of IL-33 receptor–mediated inflammatory response and pulmonary fibrosis by TRAF6 and USP38
Authors: Yi Xue-Mei , Li Mi , Chen Yun-Da , Shu Hong-Bing , Li Shu
Published: March 2022

Significance

IL-33R mediates local inflammatory responses and plays crucial roles in the pathogenesis of immune diseases. In this study, we identified USP38, which negatively regulates IL-33-triggered signaling by mediating K27-linked deubiquitination of IL-33R at K511 and its autophagic degradation. USP38 deficiency aggravates IL-33–induced lung inflammatory response and bleomycin-induced pulmonary fibrosis. We further show that the E3 ubiquitin ligase TRAF6 catalyzes K27-linked polyubiquitination of IL-33R at K511, and that deficiency of TRAF6 inhibits IL-33–mediated signaling. Our findings reveal an important mechanism regarding how IL-33R is precisely regulated to ensure its inactivation in rest cells and proper activation following IL-33 stimulation.
50 years of British accent bias
Authors: Sharma Devyani , Levon Erez , Ye Yang
Published: March 2022

Do accent biases observed half a century ago (Giles 1970) and 15 years ago (Coupland and Bishop 2007) still hold in Britain today? We provide an updated picture of national attitudes to accent labels by replicating and extending previous studies. Mean ratings and relative rankings of 38 accents for prestige and pleasantness by a large representative sample of the British population (N = 821) attest to a remarkably stable, long-standing hierarchy of accent status. We find little evidence of demotion of conservative prestige varieties or reranking of accents, although we do observe a slight improvement in lower rankings. We focus in detail on age and life stage, finding that most of the age patterns observed in earlier studies were in fact instances of age-grading (lifespan effects), not real-time change in attitude. The midlife phase of life corresponds to conservative shifts in the perception of global, migrant-heritage, and stigmatised varieties. Our findings add change in speech evaluation to the growing body of research on lifespan change in speech production. Finally, although effects of ethnicity, social class, regional self- and other-bias, and age remain firmly in place, earlier gender differences in respondent behaviour have more or less disappeared.
The historical logic of the mode of capital accumulation in Mozambique
Authors: Castel-Branco Carlos Nuno
Published: March 2022

This article critically analyses the political economy dynamics and trajectory of the mode of capital accumulation in post-independence Mozambique, focusing on the capitalist restructuring that followed the adoption of the Washington Consensus from the late 1980s. The article highlights the main structural characteristics, dynamics and tensions in the economy, the relationships and conflicts that explain why they reproduce and expand, what makes them change and the nature of the crises that emerge. The historical logic of the mode of capital accumulation is explored focusing on the historically built and class-structured conditions of capital accumulation, highlighting linkagency, which is the dynamic relationship between agents and linkages. The historically specific traits of the mode of accumulation in Mozambique are derived from the structures of accumulation and class struggle conditions, both domestic and international. The argument is that the recent trajectory of the Mozambican economy was not inevitable, and that it can be logically understood and derived from the existing historical conditions of accumulation. Understanding this historical logic enables us to articulate socially transformative actions which are drawn from the objective and concrete analysis of the mode of accumulation and its contradictions, countering idealistic perspectives in political economy.
An integrated approach for numerically predicting the failure of resistance spot welds
Authors: Wang Hui , Kasuya Tadashi , Kondo Takaaki , Inoue Junya
Published: March 2022

In this study, a numerical approach was proposed to predict the failure of resistance spot welds, into which theoretical and empirical models as well as finite element (FE) model are integrated. In this approach, the hardness of spot welds was first evaluated and the estimated hardness was then used to determine the local mechanical properties. The weld geometry and boundary conditions were faithfully followed when generating the FE model. A Gurson-type damage model and a cohesive zone model were simultaneously considered for the two main failure modes, i.e. pull-out failure and interface failure. The predictions were validated by experimental observations. The successful estimation of critical nugget size, as an exemplary application, demonstrated the utility and reliability of this approach.
Effect of low heat-input double-pulse gas metal arc welding on weld formation and microstructure of 6061 aluminium alloy
Authors: Yu Xiaoyan , Xue Jiaxiang , Shen Qingkai , Zheng Zehong , Ou Ning
Published: March 2022

Double-pulse gas metal arc welding (DP-GMAW) is a common low-melting-point metal welding method. In this study, a low heat-input double-pulse gas metal arc welding (LHDP-GMAW) was proposed based on DP-GMAW. The welding process stability, weld bead shape, microstructure, and microhardness of 6061 aluminium alloy welding were analyzed for DP-GMAW and LHDP-GMAW with different low-frequency (3, 5 and 7 Hz). Compared with DP-GMAW, the stirring effect of alternating strong and weak pulses on the molten pool of LHDP-GMAW is enhanced and the heat input is reduced. Therefore, the LHDP-GMAW can produce more obvious fish-scale ripples, lower penetration, smaller and more uniform grains, and higher microhardness. This study provides a new solution for improving the welding quality of low-melting-point metal.
Engineering of a synthetic antibody fragment for structural and functional studies of K+ channels
Authors: Rohaim Ahmed , Slezak Tomasz , Koh Young Hoon , Blachowicz Lydia , Kossiakoff Anthony A. , Roux Benoît
Published: March 2022

Engineered antibody fragments (Fabs) have made major impacts on structural biology research, particularly to aid structural determination of membrane proteins. Nonetheless, Fabs generated by traditional monoclonal technology suffer from challenges of routine production and storage. Starting from the known IgG paratopes of an antibody that binds to the “turret loop” of the KcsA K+ channel, we engineered a synthetic Fab (sFab) based upon the highly stable Herceptin Fab scaffold, which can be recombinantly expressed in Escherichia coli and purified with single-step affinity chromatography. This synthetic Fab was used as a crystallization chaperone to obtain crystals of the KcsA channel that diffracted to a resolution comparable to that from the parent Fab. Furthermore, we show that the turret loop can be grafted into the unrelated voltage-gated Kv1.2–Kv2.1 channel and still strongly bind the engineered sFab, in support of the loop grafting strategy. Macroscopic electrophysiology recordings show that the sFab affects the activation and conductance of the chimeric voltage-gated channel. These results suggest that straightforward engineering of antibodies using recombinant formats can facilitate the rapid and scalable production of Fabs as structural biology tools and functional probes. The impact of this approach is expanded significantly based on the potential portability of the turret loop to a myriad of other K+ channels.
Moment of inertia: tricky ways
Authors: Aghamohammadi Amir
Published: March 2022

We use dimensional analysis as well as the parallel axis theorem to obtain the moment of inertia for some homogeneous two-dimensional objects. These objects should possess some sort of symmetry: they should have shapes that can be decomposed into smaller copies of themselves. In the second part of the article, it is seen that as the moment of inertia of a composed object is the summation of the moment of inertia of its decomposed parts, this may give us a shortcut to obtaining the moment of inertia of some objects.
Combination regulation of terahertz OAM vortex beams on multi-bit metasurface
Authors: Li Jiu-Sheng , Pan Wei-Mang
Published: March 2022

High efficiency terahertz orbital angular momentum (OAM) vortex beam manipulation is of crucial importance for ultra large capacity wireless communication in terahertz frequencies region. We present a silicon-based multi-bit encoded metasurface structure based on convolution and addition theorem to generate flexible regulation of OAM multiple combinations such as vortex beam and beam splitting combination, vortex beam splitting, deflected beam and vortex beam combination. The proposed metasurfaces is composed of periodic array of silicon pillar with quadrangular ridge on top of a metal plate substrate. The advantage of this scheme in producing vortex beam is its simple structure, flexible design and controls to arbitrary presented directions easily. This work provides a new approach to realize powerful and flexible adjustment of terahertz wave.
Steerable chromatic dispersive metalenses in dual bands
Authors: Fu Boyan , Li Tianyue , Zou Xiujuan , Ren Jianzheng , Yuan Quan , Wang Shuming , Cao Xun , Wang Zhenlin , Zhu Shining
Published: March 2022

As a promising flat optical element, metasurfaces possess the powerful ability to manipulate chromatic dispersion, resulting in achromatic imaging, ultracompact spectrometers, and wavelength-dependent multifunctional nano-devices. However, conventional chromatic metalenses are incapable of arbitrarily tailoring dispersion within different bandwidths. Here, with a supercell composed of two nanostructures, we can arbitrarily control the chromatic dispersion of the metalens by using the phase differential equation and genetic optimization. We design three metalenses to verify the simultaneous tailoring of different chromatic dispersions in dual bands, which exhibits stronger chromatic dispersion manipulation capability compared with a single-structure-cell-based metalens. Our approach paves a new way for dispersion engineering of metalenses with potential applications in spectral imaging and material analysis.
Toward a qualitative connection between the nuclear modification factors of hadrons and their quark component
Authors: Sa Ben-Hao , Zhou Dai-Mei , Yan Yu-Liang , Liu Wen-Di , Hu Shou-Yang , Li Xiao-Mei , Zheng Liang , Chen Gang , Cai Xu
Published: March 2022

In this work, we propose a method qualitatively connecting the hadron nuclear modification factor to its quark component nuclear modification factor. A parton and hadron cascade model, PACIAE, based on PYTHIA6 is then employed calculating the hadron (in final hadronic state) and its quark component (in final partonic state) nuclear modification factors in the 0%–5% most central Pb + Pb collisions at

s

N
N

= 2.76 TeV. It turns out that the hadron nuclear modification factor is usually smaller than its quark component factor. On the other hand, the flavor (mass) ordering of the nuclear modification factor is investigated for a hadron in the final hadronic state and a quark in the final partonic state. It is found that the nuclear modification factor is more likely to be identified with the quarks and mesons but not with the baryons.
Inducing chiral superconductivity on honeycomb lattice systems
Authors: Alsharari Abdulrhman M , Ulloa Sergio E
Published: March 2022

Superconductivity in graphene-based systems has recently attracted much attention, as either intrinsic behavior or induced by proximity to a superconductor may lead to interesting topological phases and symmetries of the pairing function. A prominent system considers the pairing to have chiral symmetry. The question arises as to the effect of possible spin–orbit coupling on the resulting superconducting quasiparticle (QP) spectrum. Utilizing a Bogolyubov–de Gennes (BdG) Hamiltonian, we explore the interplay of different interaction terms in the system, and their role in generating complex Berry curvatures in the QP spectrum, as well as non-trivial topological behavior. We demonstrate that the topology of the BdG Hamiltonian in these systems may result in the appearance of edge states along the zigzag edges of nanoribbons in the appropriate regime. For suitable chemical potential and superconducting pairing strength, we find the appearance of robust midgap states at zigzag edges, well protected by large excitation gaps and momentum transfer.
A method for improving the performance of centering rod surveying based on two-position correction
Authors: Dai Minpeng , Pan Xiong , Yang Yanqiang , Li Zhicheng , Zhu Yi
Published: March 2022

To address the problem of a decrease in the measurement accuracy of centering rod surveying as a result of accelerometer bias and scale factor error, a performance improving method for pitch measurement is proposed. The error model of centering rod surveying is built so that the relationship between pitch measurement error and the accelerometer’s bias and scale factor error are clear. Numerical simulations are conducted and the error variation is revealed. A two-position correction method is developed and 12 verification experiments are carried out. After correction, the measurement error is reduced from a few centimeters to submillimeter scale. The experimental results illustrate that the accuracy of the pitch measurement is improved effectively, which meets the requirements for use. Three repeated experiments are carried out; the calculated uncertainties are 0.053%, 0.035% and 0.027% separately, which indicates the feasibility and effectiveness of the proposed method in practical applications. This method can provide some guidance for improving the performance of centering rod surveying.
Improving the dimensional accuracy of 3D x-ray microscopy data
Authors: Villarraga-Gómez Herminso , Kotwal Naomi , Parwani Rachna , Weiß Daniel , Krenkel Martin , Kimmig Wolfgang , Graf Vom Hagen Christoph
Published: March 2022

X-ray microscopy instruments have the unique ability to achieve nondestructive imaging with higher spatial resolutions than traditional x-ray computed tomography (CT) systems. This unique ability is of interest to industrial quality control entities, as they deal with small features in precision manufactured parts (with tolerances in the order of±25 µm or better). Since many of today’s technology and manufacturing companies demand increasingly higher levels of precision, accuracy, and reliability for dimensional measurements on feature sizes that are much smaller than 5 mm, it would be ideal to further expand the imaging capabilities of x-ray microscopy to the field of precision metrology. To address such demand, this paper describes the development of a measurement workflow, through a package consisting of hardware and software, to improve the accuracy of dimensional data obtained with 3D x-ray microscopes (XRMs)—also known as sub-micrometer CT systems. The measurement workflow, called Metrology Extension (MTX), was designed to adjust and configure the XRM instrument work-zone to perform dimensional measurement tasks. The main adjustments of an XRM instrument through the MTX workflow, which must be implemented before scanning parts of interest for dimensional evaluation, include applying a distortion map correction on the image projections produced by the x-ray detector and a voxel scale correction. The main purpose of this article is to present, evaluate, and analyze the experimental results of various measurement tests to verify the metrological performance of several XRM systems operating with the MTX workflow. The main results show that these systems can produce repeatable and reproducible measurements, with repeatability standard deviations of the order of 0.1 μm and reproducibility standard deviations of less than 0.5 μm. In addition, coordinate-based 3D XRM measurements produce dimensional accuracies comparable to those offered by high-precision tactile coordinate measurement machines (with deviations within the range of ±0.95 µm). Therefore, once the MTX workflow is executed, XRM instruments can be used to measure small volumes, in the order of (5 mm)3or less, with improved dimensional accuracy.
Interface transport barriers in magnetized plasmas
Authors: Norscini Claudia , Cartier-Michaud Thomas , Dif-Pradalier Guilhem , Garbet Xavier , Ghendrih Philippe , Grandgirard Virginie , Sarazin Yanick
Published: March 2022

We address the formation of Interface Transport Barriers using a generic turbulent transport model, reduced to 2D, and used to investigate interchange turbulence in magnetized plasmas. The generation of a transport barrier at the edge-scrape off layer (SOL) plasma interface is governed by a zonation regime in the edge region with closed-field lines. The barrier is triggered by a gap in the turbulent spectrum between zero, the zonal flow wave vector, and the wave vector of the spectrum maximum. This gap is controlled by the energy injection wave vector of the interchange instability and the Rhine scale that bounds the inverse cascade. Increasing the magnitude of the turbulence drive at a given gap reinforces the transport barrier. In the interface transport barrier regime, edge relaxation bursts of turbulence regenerate the zonal flows that are eroded by damping processes such as collisions. The duration of the quiescent phase between the quasi-periodic relaxation events is then governed by the ion collision frequency. Such an interface transport barrier can play the role of a seed barrier prior to a full bifurcation to improved confinement.
Determining the fuel ion ratio for D(T) and T(D) plasmas at JET using neutron time-of-flight spectrometry
Authors: Eriksson B , Conroy S , Ericsson G , Eriksson J , Hjalmarsson A , Ghani Z , Carvalho I S , Jepu I , Delabie E , Maslov M , Lennholm M , Rimini F , King D
Published: March 2022

The fusion fuel ion ratio,

n

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/

n

D

, is an important plasma parameter that needs to be tuned to maximize the power of a tokamak type fusion reactor. It is recognized as a parameter required for optimizing several ITER operating scenarios, and will likely be continuously monitored in future high-performance fusion devices such as DEMO. Tritium was recently introduced in the Joint European Torus (JET) plasma for the first time since the 1997 DTE1 and 2003 TTE campaigns, enabling the possibility to investigate fuel ion ratios. We present a method for measuring

n

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n

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using neutron time-of-flight (TOF) spectrometry. By fitting the measured neutron spectral features, the relative reaction rate intensities between different ion species can be inferred, from which the fuel ion ratio can be extracted for a corresponding modeled reactivity. Unlike previous measurements of

n

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/

n

D

using neutron spectrometry, we utilize the neutron energy continuum produced in the three-body TT reaction to determine the fuel ion ratio for plasmas with large concentrations of tritium. Furthermore, the use of neutron TOF spectrometry has never previously been demonstrated for evaluating

n

T

/

n

D

. The method is applied to TOF spectra acquired with TOFOR (JET name KM11) and shown to be consistent with the optical JET diagnostic KT5P which uses optical spectroscopy of a modified Penning gauge plasma to measure tritium and deuterium concentrations in the divertor exhaust gas.
Photon yield of superradiant inverse Compton scattering from microbunched electrons
Authors: Schaap B H , de Vos T D C , Smorenburg P W , Luiten O J
Published: March 2022

Compact x-ray sources offering high-brightness radiation for advanced imaging applications are highly desired. We investigate, analytically and numerically, the photon yield of superradiant inverse Compton scattering from microbunched electrons in the linear Thomson regime, using a classical electrodynamics approach. We show that for low electron beam energy, which is generic to inverse Compton sources, the single electron radiation distribution does not match well to collective amplification pattern induced by a density modulated electron beam. Consequently, for head-on scattering from a visible laser, the superradiant yield is limited by the transverse size of typical electron bunches driving Compton sources. However, by simultaneously increasing the electron beam energy and introducing an oblique scattering geometry, the superradiant yield can be increased by orders of magnitude.
Divergence gating towards far-field isolated attosecond pulses
Authors: Zhang Yi , Zhong Conglin , Zhu Shaoping , He Xiantu , Qiao Bin
Published: March 2022

Divergence gating, a novel method to generate far-field isolated attosecond pulses (IAPs) through controlling divergences of different pulses, is proposed and realized by relativistic chirped laser–plasma interactions. Utilizing various wavefronts for different cycles of incident chirped lasers, reflected harmonics with minimum divergences are obtained only at the peak cycle when plasma targets are adjusted to proper distances from foci of lasers. Therefore, the corresponding attosecond pulse is isolated in far field due to much slower decay during propagation than others. Confirmed by three-dimensional numerical simulations, millijoule-level sub-50 as IAPs with intensity approaching 1016 W cm−2 (1017–1018 W sr−1) are obtained by our scheme, where low-order harmonics can be preserved.
Axion-like particle searches with MeerKAT and SKA
Authors: Ayad Ahmed , Beck Geoff
Published: March 2022

In the past few years, the search for axion-like particles (ALPs) has grown significantly due to their potential to account for the total abundance of the cold dark matter (CDM) in the universe. The coupling between ALPs and photons allows the spontaneous decay of ALPs into pairs of photons. For ALPs condensed in CDM halos around galaxies, the stimulated decay of ALPs is also possible. In this work, we examine the detectability of the radio emissions produced from this process with forthcoming radio telescopes such as the Square Kilometer Array (SKA) and MeerKAT. Our results, using recent more realistic sensitivity estimates, show that previous non-observation upper-limits projected for the SKA were highly optimistic, with the limits from dwarf galaxy observations being weakened by an order of magnitude at least. Notably, our results also depend far more strongly on ALP mass than previously, due to the inclusion of frequency dependent degradation effects. We show that the strongest potential environment to probe ALPs is nearby radio galaxies (due to the strong photon enhancement factor). In addition, with the use of a visibility taper, ALPs in the mass range of 4.96 × 10-7 − 1.04 × 10-4 eV would have non-observation upper limits on the ALP-photon gaγ
in the range of 1.83 × 10-12 − 7.69 × 10-10 GeV-1 with SKA. MeerKAT can only produce limits similar to the CAST experiment within 50 hours of observation. Finally, we demonstrate that magnetic conversion of CDM ALPs to photons, in galactic magnetic fields, is highly sub-dominant, even to spontaneous decay.
Lattice simulation of multi-stream inflation
Authors: Cai Tingqi , Jiang Jie , Wang Yi
Published: March 2022

We present the first lattice simulation to investigate the nature of multi-stream inflation. The simulation confirms the physical picture of multi-stream inflation, and with new findings in parameter space and field behaviors. Our simulation shows that gradient energy plays a significant role in multi-stream inflation. For a double field potential with a shifted Gaussian barrier, bifurcation probability is controlled by the shift distance with an error function relation. The bubbles created by bifurcation tend to be more spherical as bifurcation probability decreases. Also, the bifurcation is more likely to introduce oscillations of field values inside the bubbles than outside.
Stability and luminescence properties of CsPbBr3/CdSe/Al core-shell quantum dots
Authors: Yao Heng , Lu Anjiang , Bai Zhongchen , Jiang Jinguo , Qin Shuijie
Published: March 2022

To improve the stability and luminescence properties of CsPbBr3 QDs, we proposed a new core-shell structure for CsPbBr3/CdSe/Al quantum dots (QDs). By using a simple method of ion layer adsorption and a reaction method, CdSe and Al were respectively packaged on the surface of CsPbBr3 QDs to form the core-shell CsPbBr3/CdSe/Al QDs. After one week in a natural environment, the photoluminescence quantum yields of CsPbBr3/CdSe/Al QDs were greater than 80%, and the PL intensity remained at 71% of the original intensity. Furthermore, the CsPbBr3/CdSe/Al QDs were used as green emitters for white light-emitting diodes (LEDs), with the LEDs spectrum covering 129% of the national television system committee (NTSC) standard color gamut. The core-shell structure of QDs can effectively improve the stability of CsPbBr3 QDs, which has promising prospects in optoelectronic devices.
Combination of spark discharge and nanoparticle-enhanced laser-induced plasma spectroscopy
Authors: Li Qing-Xue , Zhang Dan , Jiang Yuan-Fei , Li Su-Yu , Chen An-Min , Jin Ming-Xing
Published: March 2022

A combination of spark discharge and nanoparticle-enhanced laser-induced plasma spectroscopy is investigated. Depositing Au nanoparticles at the surface of a brass target can enhance the coupling of the target and the laser. More atoms in the brass sample are excited. As a secondary excitation source, spark discharge reheats the generated plasma, which further amplifies the enhancement results of nanoparticles. The spectral intensity with the spark discharge increases more obviously with nanoparticle concentration increasing than without the spark discharge. Also, plasma temperature and electron density are calculated by the Boltzmann plot and Stark broadening. The changes in the plasma temperature and electron density are consistent with the spectral emission changes.
Passively stabilized single-photon interferometer
Authors: Liu Hai-Long , Wang Min-Jie , Bao Jia-Xin , Liu Chao , Li Ya , Li Shu-Jing , Wang Hai
Published: March 2022

A single-photon interferometer is a fundamental element in quantum information science. In most previously reported works, single-photon interferometers use an active feedback locking system to stabilize the relative phase between two arms of the interferometer. Here, we use a pair of beam displacers to construct a passively stable single-photon interferometer. The relative phase stabilization between the two arms is achieved by stabilizing the temperature of the beam displacers. A purely polarized single-photon-level pulse is directed into the interferometer input port. By analyzing and measuring the polarization states of the single-photon pulse at the output port, the achieved polarization fidelity of the interferometer is about 99.1±0.1%. Our passively stabilized single-photon interferometer provides a key element for generating high-fidelity entanglement between a photon and atomic memory.
Porous AlN films grown on C-face SiC by hydride vapor phase epitaxy
Authors: Chen Jiafan , Huang Jun , Li Didi , Xu Ke
Published: March 2022

We report the growth of porous AlN films on C-face SiC substrates by hydride vapor phase epitaxy (HVPE). The influences of growth condition on surface morphology, residual strain and crystalline quality of AlN films have been investigated. With the increase of the V/III ratio, the growth mode of AlN grown on C-face 6H-SiC substrates changes from step-flow to pit-hole morphology. Atomic force microscopy (AFM), scanning electron microscopy (SEM) and Raman analysis show that cracks appear due to tensile stress in the films with the lowest V/III ratio and the highest V/III ratio with a thickness of about 3 μm. In contrast, under the medium V/III ratio growth condition, the porous film can be obtained. Even when the thickness of the porous AlN film is further increased to 8 μm, the film remains porous and crack-free, and the crystal quality is improved.
Substitutions of vertex configuration of Ammann–Beenker tiling in framework of Ammann lines
Authors: Ye Jia-Rong , Huang Wei-Shen , Fu Xiu-Jun
Published: March 2022

The Ammann–Beenker tiling is a typical model for two-dimensional octagonal quasicrystals. The geometric properties of local configurations are the key to understanding its formation mechanism. We study the configuration correlations in the framework of Ammann lines, giving an in-depth inspection of this eightfold symmetric structure. When both the vertex type and the orientation are taken into account, strict confinements of neighboring vertices are found. These correlations reveal the structural properties of the quasilattice and also provide substitution rules of vertex along an Ammann line.
Inertial focusing and rotating characteristics of elliptical and rectangular particle pairs in channel flow
Authors: Lin Pei-Feng , Hu Xiao , Lin Jian-Zhong
Published: March 2022

The lattice Boltzmann method is used to study the inertial focusing and rotating characteristics of two-dimensional elliptical particles and rectangular particles in channel flow. The results show that both elliptical particles and rectangular particles initially located on one side and two sides of channel centerline migrate first towards the equilibrium position. Then, the single-line particle train with an increasing spacing and the staggered particle train with stable spacing are formed. The axial spacing of the staggered particle pair increases with aspect ratio and Reynolds number increasing. The staggered elliptical or rectangular particle pairs form perpendicular orientation angles, which will be more obvious at larger aspect ratio and lower Reynolds number. The single-line particle trains with different shapes seldom form the perpendicular orientation angle.
Scanning the optical characteristics of lead-free cesium titanium bromide double perovskite nanocrystals
Authors: Yu Chenxi , Gao Long , Li Wentong , Wang Qian , Wang Meng , Zhang Jiaqi
Published: March 2022

Cs2TiBr6 nanocrystals (NCs) are a type of promising optoelectronic materials, owing to their high photoelectric properties and non-toxicity. Here, we synthesize the colloidal Cs2TiBr6 NCs using a hot-injection approach. The temperature-dependent absorption data shows that its energy band changes about 30 meV with temperature, reflecting that its energy band structure is much stable. The excitation intensity-dependent transient absorption data confirms its linear absorption cross-sections and carrier recombination rate constants, involving monomolecular and bimolecular recombination, which are all superior to those of conventional perovskite bromide counterparts. In addition, its nonlinear absorption cross-sections are also measured based on femtosecond Z-scan. Our results suggest that Cs2TiBr6 NCs can be extensively applied in the field of optoelectronics, owing to its excellent carrier dynamics and nonlinear optical properties.
Dynamical signatures of the one-dimensional deconfined quantum critical point
Authors: Xi Ning , Yu Rong
Published: March 2022

We study the critical scaling and dynamical signatures of fractionalized excitations at two different deconfined quantum critical points (DQCPs) in an S = 1/2 spin chain using the time evolution of infinite matrix product states. The scaling of the correlation functions and the dispersion of the conserved current correlations explicitly show the emergence of enhanced continuous symmetries at these DQCPs. The dynamical structure factors in several different channels reveal the development of deconfined fractionalized excitations at the DQCPs. Furthermore, we find an effective spin–charge separation at the DQCP between the ferromagnetic (FM) and valence bond solid (VBS) phases, and identify two continua associated with different types of fractionalized excitations at the DQCP between the X-direction and Z-direction FM phases. Our findings not only provide direct evidence for the DQCP in one dimension but also shed light on exploring the DQCP in higher dimensions.
Investigation of the structural and dynamic basis of kinesin dissociation from microtubule by atomistic molecular dynamics simulations
Authors: Wang Jian-Gang , Shi Xiao-Xuan , Liu Yu-Ru , Wang Peng-Ye , Chen Hong , Xie Ping
Published: March 2022

Kinesin is a molecular motor that can step processively on microtubules via the hydrolysis of ATP molecules. An important factor characterizing the processivity of the kinesin motor is its dissociation from the microtubule. Here, using all-atom molecular dynamics simulations, we studied the dissociation process of the kinesin head in weak-microtubule-binding or ADP state from tubulin on the basis of the available high-resolution structural data for the head and tubulin. By analyzing the simulated snapshots of the structure of the head-tubulin complex we provided detailed structural and dynamic information for the dissociation process. We found that the dissociation of the head along different directions relative to the tubulin exhibits very different dynamic behaviors. Moreover, the potential forms or energy landscapes of the interaction between the head and tubulin along different directions were determined. The studies have important implications for the detailed molecular mechanism of the dissociation of the kinesin motor and thus are critical to the mechanism of its processivity.
Concurrent stimulation and sensing in bi-directional brain interfaces: a multi-site translational experience
Authors: Ansó Juan , Benjaber Moaad , Parks Brandon , Parker Samuel , Oehrn Carina Renate , Petrucci Matthew , Gilron Ro’ee , Little Simon , Wilt Robert , Bronte-Stewart Helen , Gunduz Aysegul , Borton David , Starr Philip A , Denison Timothy
Published: March 2022

Objective. To provide a design analysis and guidance framework for the implementation of concurrent stimulation and sensing during adaptive deep brain stimulation (aDBS) with particular emphasis on artifact mitigations. Approach. We defined a general architecture of feedback-enabled devices, identified key components in the signal chain which might result in unwanted artifacts and proposed methods that might ultimately enable improved aDBS therapies. We gathered data from research subjects chronically-implanted with an investigational aDBS system, Summit RC + S, to characterize and explore artifact mitigations arising from concurrent stimulation and sensing. We then used a prototype investigational implantable device, DyNeuMo, and a bench-setup that accounts for tissue–electrode properties, to confirm our observations and verify mitigations. The strategies to reduce transient stimulation artifacts and improve performance during aDBS were confirmed in a chronic implant using updated configuration settings. Main results. We derived and validated a ‘checklist’ of configuration settings to improve system performance and areas for future device improvement. Key considerations for the configuration include (a) active instead of passive recharge, (b) sense-channel blanking in the amplifier, (c) high-pass filter settings, (d) tissue–electrode impedance mismatch management, (e) time-frequency trade-offs in the classifier, (f) algorithm blanking and transition rate limits. Without proper channel configuration, the aDBS algorithm was susceptible to limit-cycles of oscillating stimulation independent of physiological state. By applying the checklist, we could optimize each block’s performance characteristics within the overall system. With system-level optimization, a ‘fast’ aDBS prototype algorithm was demonstrated to be feasible without reentrant loops, and with noise performance suitable for subcortical brain circuits. Significance. We present a framework to study sources and propose mitigations of artifacts in devices that provide chronic aDBS. This work highlights the trade-offs in performance as novel sensing devices translate to the clinic. Finding the appropriate balance of constraints is imperative for successful translation of aDBS therapies.

Clinical trial: Institutional Review Board and Investigational Device Exemption numbers: NCT02649166/IRB201501021 (University of Florida), NCT04043403/IRB52548 (Stanford University), NCT03582891/IRB1824454 (University of California San Francisco). IDE #180 097.
L1-norm based time-varying brain neural network and its application to dynamic analysis for motor imagery
Authors: Li Peiyang , Li Cunbo , Bore Joyce Chelangat , Si Yajing , Li Fali , Cao Zehong , Zhang Yangsong , Wang Gang , Zhang Zhijun , Yao Dezhong , Xu Peng
Published: March 2022

Objective
. Electroencephalogram (EEG)-based motor imagery (MI) brain-computer interface offers a promising way to improve the efficiency of motor rehabilitation and motor skill learning. In recent years, the power of dynamic network analysis for MI classification has been proved. In fact, its usability mainly depends on the accurate estimation of brain connection. However, traditional dynamic network estimation strategies such as adaptive directed transfer function (ADTF) are designed in the L2-norm. Usually, they estimate a series of pseudo connections caused by outliers, which results in biased features and further limits its online application. Thus, how to accurately infer dynamic causal relationship under outlier influence is urgent. Approach
. In this work, we proposed a novel ADTF, which solves the dynamic system in the L1-norm space (L1-ADTF), so as to restrict the outlier influence. To enhance its convergence, we designed an iteration strategy with the alternating direction method of multipliers, which could be used for the solution of the dynamic state-space model restricted in the L1-norm space. Furthermore, we compared L1-ADTF to traditional ADTF and its dual extension across both simulation and real EEG experiments. Main results
. A quantitative comparison between L1-ADTF and other ADTFs in simulation studies demonstrates that fewer bias errors and more desirable dynamic state transformation patterns can be captured by the L1-ADTF. Application to real MI EEG datasets seriously noised by ocular artifacts also reveals the efficiency of the proposed L1-ADTF approach to extract the time-varying brain neural network patterns, even when more complex noises are involved. Significance
. The L1-ADTF may not only be capable of tracking time-varying brain network state drifts robustly but may also be useful in solving a wide range of dynamic systems such as trajectory tracking problems and dynamic neural networks.
Serial powering and signal integrity characterization for the TEPX detector for the Phase-2 CMS Inner Tracker
Authors: Reimers A. C.
Published: March 2022

The entire CMS silicon pixel detector will be replaced to operate at the high-luminosity LHC. In this contribution, the new tracker endcap pixel detector will be presented, focusing on a novel concept to provide both power and data connectivity to the modules through a disk-shaped PCB. As this part of the detector also features the longest serial powering chains in the CMS Phase-2 Inner Tracker, emphasis is put on serial powering results and the characterization of the signal integrity.
Octopus-inspired sucker to absorb soft tissues: stiffness gradient and acetabular protuberance improve the adsorption effect
Authors: Wang Yi , Sun Guangkai , He Yanlin , Zhou Kangpeng , Zhu Lianqing
Published: March 2022

Rigid suckers commonly used in surgical procedures often cause absorption damage, while their soft counterparts are difficult to handle due to their weak anchoring. Alternatively, the octopus sucker is both soft and has strong suction power. Further observation revealed that its structure is self-sealing and that the tissues are layered in hardness. Inspired by said structure and the characteristics of associated materials, a bionic soft sucker with stiffness gradient and acetabular roof structure was proposed, made of silicone with varying hardness including structures such as acetabular roof and circle muscles. The automatic tensile force measurement system was used to experimentally analyze the adsorption performance of the suckers to the soft curved contact surface. Both dry and wet conditions were tested, along with practical tests on organisms. The bionic sucker adsorption force was increased by 25.1% and 34.6% on the cylindrical surface, and 45.2% and 7.3% on the spherical surface for dry and wet conditions, respectively. During the experiment, the bionic suckers did not cause notable suction damage to the contact surfaces. Thus, this type of bionic sucker shows good application prospects in the field of surgery.
Analytical solution and hidden symmetry operators of asymmetric two-mode quantum Rabi model
Authors: Yan Zhanyuan , Xia Yifei , Li Jurihui , Ma Jinying , Liu Yan
Published: March 2022

The asymmetric two-mode quantum Rabi model (tmQRM) breaks

Z

2

-symmetry and also implies hidden symmetry. In this paper, the energy spectrum are analytically computed with Bogoliubov transformation and SU(1, 1) Lie algebra. The analytical results are in good agreement with those obtained by numerical calculation. We identify the condition for the bias parameter such that level crossings appear in the spectrum which are caused by the hidden symmetry. This condition is related not only to the field frequency, but also to the coupling strength between the field and qubit. The level crossing points could be determined by the pole energy and recurrence coefficients. This is tested and verified in the low energy levels. The generators of the hidden

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-symmetry, commuting with the Hamiltonian, are derived within the Bogoliubov operator approach. The present results may provide more information to the hidden symmetry in the asymmetric tmQRM.