bluuebunny/crossref_metadata_2025 huggingface dataset:
Germline SAMD9L truncation variants trigger global translational repression
Authors: Allenspach Eric J. , Soveg Frank , Finn Laura S. , So Lomon , Gorman Jacquelyn A. , Rosen Aaron B.I. , Skoda-Smith Suzanne , Wheeler Marsha M. , Barrow Kaitlyn A. , Rich Lucille M. , Debley Jason S. , Bamshad Michael J. , Nickerson Deborah A. , Savan Ram , Torgerson Troy R. , Rawlings David J.
Published: March 2021

SAMD9L is an interferon-induced tumor suppressor implicated in a spectrum of multisystem disorders, including risk for myeloid malignancies and immune deficiency. We identified a heterozygous de novo frameshift variant in SAMD9L in an infant with B cell aplasia and clinical autoinflammatory features who died from respiratory failure with chronic rhinovirus infection. Autopsy demonstrated absent bone marrow and peripheral B cells as well as selective loss of Langerhans and Purkinje cells. The frameshift variant led to expression of a truncated protein with interferon treatment. This protein exhibited a gain-of-function phenotype, resulting in interference in global protein synthesis via inhibition of translational elongation. Using a mutational scan, we identified a region within SAMD9L where stop-gain variants trigger a similar translational arrest. SAMD9L variants that globally suppress translation had no effect or increased mRNA transcription. The complex-reported phenotype likely reflects lineage-dominant sensitivities to this translation block. Taken together, our findings indicate that interferon-triggered SAMD9L gain-of-function variants globally suppress translation.
Breathe—Your immune system is counting on it
Authors: McCarty Nael A.
Published: March 2021

Always, but especially in these times of COVID pandemic, we know the dangers of breathing into our lungs a deadly pathogen. Fortunately, healthy lungs are equipped with an innate immune system that works to clear those pathogens. A study in this issue (2021. J. Exp. Med.https://doi.org/10.1084/jem.20201831) shows, for the first time, that breathing-induced changes in the pH of the airway surface contribute to bacterial killing, pointing to new therapeutic strategies for maintaining pulmonary health.
An (e, 2e
+ ion) study of electron-impact ionization and fragmentation of carbon dioxide clusters
Authors: Wang Xing , Yang Hongjing , Hossen Khokon , Dorn Alexander , Ren Xueguang
Published: March 2021

We report an experimental study of the electron-impact ionization (E
0 = 65 eV) and fragmentation of carbon dioxide clusters for the formation of

C
O

2

+

and

(

C
O

2

)

2

+

using a reaction microscope. All three charged particles, two outgoing electrons and one cation, are detected in coincidence such that the momentum vectors and, consequently, the kinetic energies for these final-state particles are determined. The reaction mechanisms correlated to ionic species are analyzed using the measured binding energy spectra over a broad range of ionization energy (8–32 eV). We observe that the

(

C
O

2

)

2

+

cations with small momenta are formed mainly from the direct ionization of the outermost 1π

g
orbital in the carbon dioxide dimer (CO2)2. While the (1π

u
)−1, (3σ

u
)−1 and (4σ

g
)−1 states in

(

C
O

2

)

2

+

are unstable and most likely dissociate into

C
O

2

+

and neutral species. The

(

C
O

2

)

2

+

cations with high momenta are attributed to the ionization of small carbon dioxide clusters (CO2)
n
(n ⩾ 3) and subsequent dissociation processes. Compared to the appearance energy studies of carbon dioxide clusters where only the outermost 1π

g
orbital ionization was observed for formation of

(

C
O

2

)

2

+

, several additional channels are identified in this work.
Nature of the magnetic moment of cobalt in ordered FeCo alloy
Authors: Gerasimov Arsenii , Nordström Lars , Khmelevskyi Sergii , Mazurenko Vladimir V , Kvashnin Yaroslav O
Published: March 2021

The magnets are typically classified into Stoner and Heisenberg type, depending on the itinerant or localized nature of the constituent magnetic moments. In this work, we investigate theoretically the behaviour of the magnetic moments of iron and cobalt in their B2-ordered alloy. The results based on local spin density approximation for the density functional theory (DFT) suggest that the Co magnetic moment strongly depends on the directions of the surrounding magnetic moments, which usually indicates the Stoner-type mechanism of magnetism. This is consistent with the disordered local moment picture of the paramagnetic state, where the magnetic moment of cobalt gets substantially suppressed. We argue that this is due to the lack of strong on-site electron correlations, which we take into account by employing a combination of DFT and dynamical mean-field theory (DMFT). Within LDA + DMFT, we find a substantial quasiparticle mass renormalization and a non Fermi-liquid behaviour of Fe–3d orbitals. The resulting spectral functions are in very good agreement with measured spin-resolved photoemission spectra. Our results suggest that local correlations play an essential role in stabilizing a robust local moment on Co in the absence of magnetic order at high temperatures.
Probing extreme states of matter using ultra-intense x-ray radiation
Authors: McMahon M I
Published: March 2021

Extreme states of matter, that is, matter at extremes of density (pressure) and temperature, can be created in the laboratory either statically or dynamically. In the former, the pressure–temperature state can be maintained for relatively long periods of time, but the sample volume is necessarily extremely small. When the extreme states are generated dynamically, the sample volumes can be larger, but the pressure–temperature conditions are maintained for only short periods of time (ps to μs). In either case, structural information can be obtained from the extreme states by the use of x-ray scattering techniques, but the x-ray beam must be extremely intense in order to obtain sufficient signal from the extremely-small or short-lived sample. In this article I describe the use of x-ray diffraction at synchrotrons and XFELs to investigate how crystal structures evolve as a function of density and temperature. After a brief historical introduction, I describe the developments made at the Synchrotron Radiation Source in the 1990s which enabled the almost routine determination of crystal structure at high pressures, while also revealing that the structural behaviour of materials was much more complex than previously believed. I will then describe how these techniques are used at the current generation of synchrotron and XFEL sources, and then discuss how they might develop further in the future at the next generation of x-ray lightsources.
Relaxation dynamics of Pd–Ni–P metallic glass: decoupling of anelastic and viscous processes
Authors: Soriano Daniel , Zhou Hongbo , Hilke Sven , Pineda Eloi , Ruta Beatrice , Wilde Gerhard
Published: March 2021

The stress relaxation dynamics of metallic glass Pd40Ni40P20 was studied in both supercooled liquid and glassy states. Time-temperature superposition was found in the metastable liquid, implying an invariant shape of the distribution of times involved in the relaxation. Once in the glass state, the distribution of relaxation times broadens as temperature and fictive temperature decrease, eventually leading to a decoupling of the relaxation in two processes. While the slow one keeps a viscous behavior, the fast one shows an anelastic nature and a time scale similar to that of the collective atomic motion measured by x-ray photon correlation spectroscopy (XPCS). These results suggest that the atomic dynamics of metallic glasses, as determined by XPCS at low temperatures in the glass state, can be related to the rearrangements of particles responsible of the macroscopically reversible anelastic behavior.
Influence of the simultaneous calibration of multiple ring dosimeters on the individual absorbed dose
Authors: Calatayud-Jordán J , Candela-Juan C , Palma J D , Pujades-Claumarchirant M C , Soriano Á , Gracia-Ochoa M , Vilar-Palop J , Vijande J
Published: March 2021

Ring dosimeters for personal dosimetry are calibrated in accredited laboratories following ISO 4037-3 guidelines. The simultaneous irradiation of multiple dosimeters would save time, but has to be carefully studied, since the scattering conditions could change and influence the absorbed dose in nearby dosimeters. Monte Carlo simulations using PENELOPE-2014 were performed to explore the need to increase the uncertainty of

H

p

0

.07

in the simultaneous irradiation of three and five DXT-RAD 707H-2 (Thermo Scientific) ring dosimeters with beam qualities: N-30, N-80 and N-300. Results show that the absorbed dose in each dosimeter is compatible with each of the others and with the reference simulation (a single dosimeter), with a coverage probability of 95% (k = 2). Comparison with experimental data yielded consistent results with the same coverage probability. Therefore, five ring dosimeters can be simultaneously irradiated with beam qualities ranging, at least, between N-30 and N-300 with a negligible impact on the uncertainty of

H

p

0

.07

.
Development of compact electronic noses: a review
Authors: Cheng Lu , Meng Qing-Hao , Lilienthal Achim J , Qi Pei-Feng
Published: March 2021

An electronic nose (e-nose) is a measuring instrument that mimics human olfaction and outputs ‘fingerprint’ information of mixed gases or odors. Generally speaking, an e-nose is mainly composed of two parts: a gas sensing system (gas sensor arrays, gas transmission paths) and an information processing system (microprocessor and related hardware, pattern recognition algorithms). It has been more than 30 years since the e-nose concept was introduced in the 1980s. Since then, e-noses have evolved from being large in size, expensive, and power-hungry instruments to portable, low cost devices with low power consumption. This paper reviews the development of compact e-nose design and calculation over the last few decades, and discusses possible future trends. Regarding the compact e-nose design, which is related to its size and weight, this paper mainly summarizes the development of sensor array design, hardware circuit design, gas path (i.e. the path through which the mixed gases to be measured flow inside the e-nose system) and sampling design, as well as portable design. For the compact e-nose calculation, which is directly related to its rapidity of detection, this review focuses on the development of on-chip calculation and wireless computing. The future trends of compact e-noses include the integration with the internet of things, wearable e-noses, and mobile e-nose systems.
Scalable nanophotonic neural probes for multicolor and on-demand light delivery in brain tissue
Authors: Lanzio V , Lorenzon M , Dhuey S , Pirri C F , Lamberti A , Cabrini S
Published: March 2021

Neural probes are in vivo brain-invasive devices that record and manipulate neural circuits using electricity, light, or drugs. The capability to shine distinct wavelengths and control their respective output locations for activation or deactivation of specific groups of neurons is desirable but remains unachieved. Here, we discuss our probe’s capability to deliver two independently controllable wavelengths (450 and 655 nm) in the location(s) of interest using nanophotonic directional couplers and ring resonators. These nanophotonics are scalable to dozens of outputs without significantly increasing the device’s lateral dimensions. Furthermore, they are entirely passive and thus do not require electrical input that results in heat generation. Besides, we integrate a high number of electrodes for a simultaneous neural activity readout. Thus, we overcome the challenges associated with multicolor illumination for neural devices by exploiting the capability of miniaturizable, passive probes to deliver two different frequencies in several areas of interest. These devices open the path towards investigating the in vivo electrical signal propagation under the individual or simultaneous activation or inhibition of distinct brain regions.
Composite Si–Ni nanoparticles produced by plasma spraying physical vapor deposition for negative electrode in Li-ion batteries
Authors: Ohta R , Gerile N , Kaga M , Kambara M
Published: March 2021

Si–Ni composite nanoparticles have been produced by a single and continuous plasma spray physical vapor deposition (PS-PVD) from Si and Ni powder feedstocks and their electrochemical performances as anode in lithium-ion batteries (LiB) are investigated. Si nanoparticles with 20–40 nm on which Ni is directly attached with Si/NiSi2 epitaxial interface are formed spontaneously through co-condensation of high temperature elemental gas mixtures during PS-PVD. When only a little amount of Ni is added to Si, the effect of the epitaxial Ni attachment on the Si nanoparticles becomes evident; the cycle capacity is appreciably improved to reach a 1.6 times higher capacity than that of the Si only cell after 50 cycles, due to reduced charge-transfer resistance and nanosized Si particle. In contrast, excessive Ni addition to Si feedstock leads to formation of various silicides as a result of the accelerated silicidation during PS-PVD, which results in a significant decrease in the cycle capacity due to reduction of the active Si phase amount despite reduced charge-transfer resistance.
Exploration of the form factors of turbulence kinetic energy transfer for shear exfoliation of graphene
Authors: Liu Kangwei , Chiang Sum-Wai , Liang Bin , Liang Caiwu , Sui Yiming , Dai Wanyu , Wang Min , Hu Shengyu , Kang Feiyu , Yang Cheng
Published: March 2021

Mass production of defect-free and large-lateral-size 2D materials via cost-effective methods is very important. Recently, shear exfoliation has shown great promise for large-scale production due to its simple operation, environmental-benignity and wide adaptability. However, a long-standing challenge is that with the production of more nanosheets, a ceiling yield and shattered products are encountered, which significantly limits their wider application. The method and efficiency of energy transfer in fluid is undoubtedly the key point in determining exfoliation efficiency, yet its in-depth mechanism has not yet been described. Thus, a thorough investigation of turbulence energy transfer is critically necessary. Herein, we identify two main factors that critically determine the exfoliation yield and provide a statistical analysis of the relationship between these factors and the exfoliation yield. In the initial shearing process, the coexistence of the 2D nanosheets and raw particles is the dominant factor; as time passes, the dimensional change of raw materials gradually has a greater influence on the energy transfer. These factors together lead to attenuated efficiency and a power function relationship between yield and exfoliation time. This investigation gives a statistical explanation of shear exfoliation technology for 2D material preparation and provides valuable insights for mechanical exfoliating high-quality 2D materials.
Influence of the gas pressure in a Torr regime capacitively coupled plasma deposition reactor
Authors: Kim Ho Jun
Published: March 2021

The adjustment of the gas pressure has been shown to improve the deposition rate and uniformity of a plasma process. This led us to investigate the effect of the gas pressure in a 300 mm wafer reactor. We numerically simulated SiH4/He capacitively coupled plasma discharges for the deposition of a hydrogenated amorphous silicon film. The results indicated that an increase in the gas pressure leads to uniform dissipation of the power coupled to the plasma and deposition profiles. By toggling the sidewall condition from grounded to dielectric while varying the gas pressure, we observed a modification of the plasma distributions and deposition profiles. Based thereupon, we concluded that the combination of high pressure with narrow electrode spacing can guarantee more efficient and uniform deposition. Additionally, this result was experimentally validated using the plasma deposition of hydrogenated amorphous carbon from the mixture C3H6/Ar/He. Even though the mixture differed from that we adopted in the simulation, the combination of high pressure with narrow electrode spacing still induced uniform deposition.
PISCES-RF: a liquid-cooled high-power steady-state helicon plasma device
Authors: Thakur Saikat Chakraborty , Simmonds Michael J , Caneses Juan F , Chang Fengjen , Hollmann Eric M , Doerner Russell P , Goulding Richard , Lumsdaine Arnold , Rapp Juergen , Tynan George R
Published: March 2021

Radio-frequency (RF) driven helicon plasma sources can produce relatively high-density plasmas (n > 1019 m−3) at relatively moderate powers (<2 kW) in argon. However, to produce similar high-density plasmas for fusion relevant gases such as hydrogen (H), deuterium (D) and helium (He), much higher RF powers are needed. For very high RF powers, thermal issues of the RF-transparent dielectric window, used in the RF source design, limit the plasma operation timescales. To mitigate this constraint, we have designed, built and tested a novel helicon plasma source assembly with a fully liquid-cooled RF-transparent window which allows steady state operations at high power (up to 20 kW) and successfully produces high-density plasma with both argon and H. Deionized (DI) water, flowing between two concentric dielectric RF windows, is used as the coolant. We show that a full azimuthal blanket of DI water does not prevent high-density plasma production. From calorimetry on the DI water, we measure the net heat removed by the coolant at steady state conditions. Using infra-red imaging, we calculate the constant plasma heat deposition and measure the final steady state temperature distribution patterns on the inner surface of the ceramic layer. The heat deposition pattern follows the helical shape of the antenna. We also show the consistency between the heat absorbed by the DI water, as measured by calorimetry, and the total heat due to the combined effect of the plasma heating and the absorbed RF. These results are being used to answer critical engineering questions for the 200 kW RF device materials plasma exposure experiment being designed at the Oak Ridge National Laboratory as a next generation plasma material interaction device.
The shape memory properties of multi-layer graphene reinforced poly(L-lactide-co-ϵ-caprolactone) by an atomistic investigation
Authors: Zhang Xue-Jiao , Yang Qing-Sheng , Shang Jun-Jun , Liu Xia , Leng Jin-song
Published: March 2021

In this paper, an atomistic investigation was performed to reveal the dependence of the graphene content on the shape memory effect of the multilayer graphene reinforced poly (L-lactide-co-ε-caprolactone). Uniaxial compression deformation was carried out to show the shape memory effect of the graphene composites. The temperature response of the composites was obtained during shape recovery. It is observed that the composites with higher graphene content exhibit larger recovery ratio and are more sensitive to temperature during a gradual warming recovery. The graphene composites show good reusable properties and the shape of composites is able to fully recover by constant temperature recovery tests. Especially, the graphene of the composite was subjected to a separate heating test to check the role of the graphene in shape recovery of the composite, where electro-induced indirect heating was qualitatively simulated. It is shown that the recovery first appeared in composites with the most content of graphene. The polymer will have a temperature hysteresis compared with graphene in composites. The shape recovery trajectory of graphene and the evolution of the interaction between graphene and polymers during the process of shape memory were clearly presented to reveal the mechanism how graphene promotes the performance of shape memory. This research can provide a guidance for obtaining composite materials with ideal shape memory effect.
Electronic transport properties and hydrostatic pressure effect of FeSe0.67Te0.33 single crystals free of phase separation
Authors: Xing Xiangzhuo , Sun Yue , Yi Xiaolei , Li Meng , Feng Jiajia , Meng Yan , Zhang Yufeng , Li Wenchong , Zhou Nan , He Xiude , Ge Jun-Yi , Zhou Wei , Tamegai Tsuyoshi , Shi Zhixiang
Published: March 2021

FeSe1−x
Te
x
superconductors manifest some intriguing electronic properties depending on the value of x. In FeSe single crystal, the nematic phase and Dirac band structure have been observed, while topological surface superconductivity (SC) with the Majorana bound state was found in the crystal of x∼ 0.55. Therefore, the electronic properties of single crystals with 0 < x ⩽ 0.5 are crucial for probing the evolution of those intriguing properties as well as their relations. However, this study is still left blank due to the lack of single crystals because of phase separation. Here, we report the synthesis, magnetization, electronic transport properties, and hydrostatic pressure effect of FeSe0.67Te0.33 single crystals free of phase separation. A structural (nematic) transition is visible at T
s = 39 K, below which the resistivity exhibits a Fermi-liquid behavior. Analysis of the upper critical fields suggests that spin-paramagnetic effect should be taken into account for both H || c axis and H || ab plane. A crossover from the low-H quadratic to the high-H quasi-linear behavior is observed in the magnetoresistance, signifying the possible existence of Dirac-cone state. Besides, the strong temperature dependence of Hall coefficient, violation of (modified) Kohler’s rule, and two-band model analysis indicate the multiband effects in FeSe0.67Te0.33 single crystals. Hydrostatic pressure measurements reveal that T
s is quickly suppressed with pressure while T
c is monotonically increased up to 2.31 GPa, indicating the competition between nematicity and SC. No signature of magnetic order that has been detected in FeSe1−x
S
x
is observed. Our findings fill up the blank of the knowledge on the basic properties of FeSe1−x
Te
x
system with low-Te concentrations.
Astrophysics with heavy-ion beams
Authors: Senger P
Published: March 2021

The ‘Facility for Antiproton and Ion Research’ (FAIR), an international accelerator centre, is under construction in Darmstadt, Germany. FAIR will provide high-intensity primary beams of protons and heavy-ions, and intense secondary beams of antiprotons and of rare short-lived isotopes. These beams, together with a variety of modern experimental setups, will allow to perform a unique research program on nuclear astrophysics, including the exploration of the nucleosynthesis in the universe, and the exploration of QCD matter at high baryon densities, in order to shed light on the properties of neutron stars, and the dynamics of neutron star mergers. The Compressed Baryonic Matter (CBM) experiment at FAIR will investigate collisions between heavy nuclei, and measure various diagnostic probes, which are sensitive to the high-density equation-of-state (EOS), and to the microscopic degrees-of-freedom of high-density matter. The CBM physics program will be discussed.
Modified MIT Bag Models—part II: QCD phase diagram and hot quark stars
Authors: Lopes Luiz L , Biesdorf Carline , Marquez K D , Menezes Débora P
Published: March 2021

In the present work we use the modified versions of the MIT bag model, on which both a vector field and a self-interacting term are introduced, to obtain hot quark matter and to investigate the QCD phase diagram. We first analyze two-flavored quark matter constrained to both the freeze-out and the liquid-gas phase transition at the hadronic phase. Later, three-flavored quark matter subject to β equilibrium and charge neutrality is used to compute quark star macroscopic properties, which are confronted with recent observational massive and canonical star radius results. Finally, a comparison with QCD phase diagrams obtained from the Nambu-Jona-Lasinio model is performed.
Ricci flow in general relativity: dynamics of gluon fields on an arbitrary curved background from unified spinor fields
Authors: Bellini Mauricio
Published: March 2021

We describe the gluon field dynamics from Unified Spinor Fields, taking into account the quantum self-interactions which come from a Ricci flow in a varied Einstein-Hilbert action. A new action to describe the Yang-Mills fields is introduced and it is obtained the nonlinear equation of motion on a curved background Riemann manifold, with self-interactions included, for the gluon field components.
Neutrino mass bounds from confronting an effective model with BOSS Lyman-α data
Authors: Garny Mathias , Konstandin Thomas , Sagunski Laura , Viel Matteo
Published: March 2021

We present an effective model for the one-dimensional
Lyman-α flux power spectrum far above the baryonic Jeans
scale. The main new ingredient is constituted by a set of two
parameters that encode the impact of small, highly non-linear scales
on the one-dimensional power spectrum on large scales, where it is
measured by BOSS. We show that, by marginalizing over the model
parameters that capture the impact of the intergalactic medium, the
flux power spectrum from both simulations and observations can be
described with high precision. The model displays a degeneracy
between the neutrino masses and the (unknown, in our formalism)
normalization of the flux power spectrum. This degeneracy can be
lifted by calibrating one of the model parameters with simulation
data, and using input from Planck CMB data. We demonstrate that this
approach can be used to extract bounds on the sum of neutrino masses
with comparably low numerical effort, while allowing for a
conservative treatment of uncertainties from the dynamics of the
intergalactic medium. An explorative analysis yields an upper bound
of 0.16eV at 95% C.L. when applied to BOSS data at
3 ≤ z ≤ 4.2. We also forecast that if the systematic and
statistical errors will be reduced by a factor two the upper bound
will become 0.1eV at 95% C.L, and 0.056eV when assuming a
1% error.
On the energy of the protons producing the very high-energy astrophysical neutrinos
Authors: Roulet Esteban , Vissani Francesco
Published: March 2021

We study the distribution of the energy of the protons that can produce an astrophysical neutrino with a given observed energy, in the TeV–PeV range, both through pp or pγ interactions. Due to the increasing multiplicity of the pion production at high center of mass energies, the resulting average proton energies can be much larger than the often used approximate value Ep
≃ 20Eν
. Also the threshold of the pγ process can lead to a pronounced increase in the values of 〈Ep
〉/Eν
for decreasing neutrino energies. The results depend sensitively on the assumed proton spectrum, since steeper spectra give less weight to the lower energy neutrino tail resulting from the decays of the abundant low-energy pions. In the pγ scenarios they also depend sensitively on the spectrum of the target photons. The results are in particular relevant to relate possible characteristics of the neutrino spectrum to those of the corresponding cosmic rays that generated them. We also discuss the associated production of gamma rays at the sources.
NBN-doped nanographene embedded with five- and seven-membered rings on Au(111) surface*
Authors: Yang Huan , Cao Yun , Gao Yixuan , Fu Yubin , Huang Li , Liu Junzhi , Feng Xinliang , Du Shixuan , Gao Hong-Jun
Published: March 2021

Nanographenes (NGs) can be embedded with predesigned dopants or nonhexagonal rings to tailor the electronic properties and provide ideal platforms to study the unique physical and chemical properties. Here, we report the on-surface synthesis of NBN-doped NG embedded with five- and seven-membered rings (NBN-575-NG) on Au(111) from a oligophenylene precursor preinstalled with a NBN unit and a heptagonal ring. Scanning tunneling microscopy and non-contact atomic force microscopy images elucidate the intramolecular cyclodehydrogenation and the existence of the five- and seven-membered rings. Scanning tunneling spectroscopy spectra reveal that the NBN-575-NG is a semiconductor, which agrees with the density functional theory calculation results on a freestanding NBN-575-NG with the same structure. This work provides a feasible approach for the on-surface synthesis of novel NGs containing non-hexagonal rings.
Simulations of monolayer SiC transistors with metallic 1T-phase MoS2 contact for high performance application*
Authors: Xie Hai-Qing , Wu Dan , Deng Xiao-Qing , Fan Zhi-Qiang , Zhou Wu-Xing , Xiang Chang-Qing , Liu Yue-Yang
Published: March 2021

We preform a first-principles study of performance of 5 nm double-gated (DG) Schottky-barrier field effect transistors (SBFETs) based on two-dimensional SiC with monolayer or bilayer metallic 1T-phase MoS2 contacts. Because of the wide bandgap of SiC, the corresponding DG SBFETs can weaken the short channel effect. The calculated transfer characteristics also meet the standard of the high performance transistor summarized by international technology road-map for semiconductors. Moreover, the bilayer metallic 1T-phase MoS2 contacts in three stacking structures all can further raise the ON-state currents of DG SiC SBFETs in varying degrees. The above results are helpful and instructive for design of short channel transistors in the future.
Fabrication and characterization of all-Nb lumped-element Josephson parametric amplifiers*
Authors: Xue Hang , Lin Zhirong , Jiang Wenbing , Niu Zhengqi , Liu Kuang , Peng Wei , Wang Zhen
Published: March 2021

Josephson parametric amplifiers (JPAs) with nearly quantum-limited noise performance have become indispensable devices for the measurements of superconducting quantum information. We have developed an all-Nb lumped-element flux-driven JPA operating in the three-wave mixing mode. Our Nb-based JPA comprises Nb/Al-AlO
x
/Nb Josephson junctions, a parallel-plate capacitor with SiO2 dielectric sandwiched between two Nb layers, a bottom coplanar waveguides layer, and a top Nb wiring layer. We experimentally demonstrate a 20 dB gain over a 190 MHz bandwidth, a mean 1 dB compression of –123 dBm, and near quantum-limited noise performance. This fabrication process can be further used to design impedance transformed parametric amplifiers for multiple-qubit readout.
Strain-modulated ultrafast magneto-optic dynamics of graphene nanoflakes decorated with transition-metal atoms*
Authors: Zhang Yiming , Liu Jing , Li Chun , Jin Wei , Lefkidis Georgios , Hübner Wolfgang
Published: March 2021

We perform first-principles calculations and coherent laser-matter interaction analyses to investigate the laser-induced ultrafast spin flip on graphene nanoflakes (GNFs) with transition metal elements attached on the boundary [TM&GNFs (TM = Fe, Co, Ni)]. It is shown that the spin-flip process on TM&GNFs is highly influenced by the involved element species and the position attached to the nanoflakes. Furthermore, taking Ni&GNF as an example, the first-principles tensile test predicts that the variation of the C–Ni bond length plays an important role in the spin density distribution, especially for the low-lying magnetic states, and can therefore dominate the spin-flip processes. The fastest spin-flip scenario is achieved within 80 fs in a Ni&GNF structure under 10% tensile strain along the C–Ni bond. The local deformation modulation of spin flip provides the precursory guidance for further study of ultrafast magnetization control in GNFs, which could lead to potential applications in future integrated straintronic devices.
Detection of multi-spin interaction of a quenched XY chain by the average work and the relative entropy*
Authors: Zhang Xiu-Xing , Li Fang-Jv , Wang Kai , Xue Jing , Huo Guang-Wen , Fang Ai-Ping , Li Hong-Rong
Published: March 2021

We investigate the nonequilibrium thermodynamics of a quenched XY spin chain with multi-spin interaction in a transverse field. The analytical expressions of both the average work and the relative entropy are obtained under different quenching parameters. The influences of the system parameters on the nonequilibrium thermodynamics are investigated. We find that at finite temperature the critical phenomenon induced by the multi-spin interaction and the external field can be revealed by the properties of the system nonequilibrium thermodynamics. In addition, our results indicate that the average work and the relative entropy can be used to detect both the existence and strength of the multi-spin interaction in the nonequlibrium system.
Measurement of miscut angles in the determination of Si lattice parameters
Authors: Sasso C P , Mana G , Massa E
Published: March 2021

The measurement of the angle between an interferometer’s front mirror and the diffracting planes is a critical aspect of the measurement of Si lattice parameters by combined x-ray and optical interferometry. In addition to being measured offline by x-ray diffraction, it was checked online by moving the analyser crystal transversely and observing the phase shift of the interference fringe. We describe the measurement procedure and give the miscut angle of the 28Si crystal, whose lattice parameter was an essential input datum for the determination of the Avogadro constant in the past and which is now used in the definition of the kilogram, based on counting atoms. These data will benefit others that might wish to repeat the measurement of the lattice parameters of this unique crystal.
A Novel Design of Blowfish Algorithm for Image Security
Authors: Hashim Ashwaq T. , Jassem Ammar H. , Ali Suhad A.
Published: March 2021

In order to improve the security and efficiency of image encryption systems comprehensively an image encryption based on enhanced design of Blowfish scheme is proposed. The proposed system is employed block based image encryption technique combined with chaotic map properties. Firstly the digital image is scrambled and decomposed into several key based blocks randomly to decorrelated the relationship between original and processed image then each block is passed through an enhanced blowfish algorithm. The enhancement in design is to gain advantage of the strong facility, which is maintained by blowfish algorithm by overcoming its flaws, which leads to a significant improvement in security/performance. As a result the proposed system offers good performance for image encryption. The proposed algorithm is 320-bit Blowfish-like block cipher, where cascaded looking composition of F-functions is used instead of rounds. The key is accepted a variable length up to 400 bytes. The pragmatic aim of the proposed system is to decrease memory requirements and execution time while keeping the cipher simple and highly adaptable to future demands. To ensure improved encryption algorithm, the implementation of both techniques has been carried out for experimental purposes which is showed that the original image has a flat histogram after encrypted, a decreasing correlation between adjacent pixels in all color components and increasing entropy for the cases studied. The proposed algorithm has a sufficiently large key space and a very high sensitivity to the key. A comparative study with previous Blowfish algorithm shows the superiority of the modified algorithm.
Circuit simulation of two-degree-of-freedom unilateral impact dynamics system with gap
Authors: Chang Fengliang , Wang Zheng , Tao Yiming
Published: March 2021

In a two-degree-of-freedom unilateral collision system with a gap, the two oscillators will produce nonlinear motion. A dynamic model of the two-degree-of-freedom collision system is established, and the two oscillators are analyzed separately by numerical simulation. On this basis, an electronic circuit composed of TL074CN operational amplifier, capacitance and resistance is designed, which is equivalent to the mathematical model. The electronic circuit is simulated by multisim12.0, and the result is consistent with that of numerical simulation. The equivalent electronic circuit model not only has dramatically shortened the calculation time, but also has the advantage of adjustable dynamic parameters, which makes up for the lack of numerical simulation and provides a reference tool for the simulation analysis of multi-degree-of-freedom nonlinear mechanical vibration systems.
Comment on Security and Improvement of Partial Blind Signature Scheme and Revocable Certificateless Signature Scheme
Authors: Hu Xiaoming , Chen Fangshu , Ma Chuang , Tan Wenan
Published: March 2021

Partial blind signature scheme (BLD-SS) can protect the specific content of the signed message by adding factor to blind the signed message and can also prevent the misuse of the signature by adding common information negotiated in advance. Revocable certificateless signature scheme (RCSS) can prevent the user’s privacy from leaking by adding time key in the signature process and signature verification process. BLD-SS and RCSS both have wide applications in electronic-voting, electronic-cash system and other fields. In this paper, it presents a security analysis on a partial blind signature scheme and a revocable signature scheme proposed recently. It points out that the BLD-SS does not satisfy the unforgeability. A malicious user can forge a partial blind signature on any message and any common information without known from PKG (Private Key Generation). It also shows that the RCSS does not satisfy the unforgeability. A malicious enemy can forge a signature on any message and on any user. The PKG also cannot update the time key immediately when a user’s key is leaked or his identity is expired. In order to overcome these problems, it proposes some simple improvement methods which are almost the same efficiency with the original signature scheme.
Research on Industry Question Answering System Based on Near Neighbor Vector Search
Authors: Gao Ming , Wu Heng , Hua Huangsheng , Zhang Wenfei , Chen Zhuozhuo , Wang Dehui
Published: March 2021

In the field of natural language processing, language-based question answering has been widely studied and made great achievements. As an important form of search engine, question answering system can further improve the search quality compared with traditional search engines. Traditional tree-based indexing methods are inefficient in high-dimensional space. This paper focuses on the application of k nearest neighbor search in large-scale image databases, and researches on high-dimensional indexing technology based on vector approximation method. Fast-Hessian detector is used to detect feature points and generate SURF feature description vector; Then, the initial matching point pair is obtained by fast approximate nearest neighbor search algorithm, and then the unidirectional matching results are matched bidirectionally; at the same time, it makes a detailed analysis of the situation that the events in the sentences are verbs of “abstract change”, so as to realize the automatic question and answer after the change of abstract relations between entities.
Research on Scene Fusion and Interaction Method Based on Virtual Reality Technology
Authors: Liu Jintao , Chen Yanlin
Published: March 2021

The construction of a virtual interactive model based on VR technology breaks through the single mode of traditional virtual reality helmets, through optical attitude sensing, immersive cave virtual reality, multi-person network collaboration, 9D interactive media applications, and mobile terminal interaction. The organic integration and application of technologies have improved the user’s interactive experience, and the inheritance and development of local folk culture and the continuous research on intangible cultural heritage can be a useful exploration. However, the development cost of the entire design is relatively high, and there is no unified construction standard and policy support for such projects in China, especially the lack of effective support from the network application platform, which makes it difficult to implement online, and the reproducibility is low.
Design of a multi-channel micro-capacitor acquisition system
Authors: Wu Yun , Ding Yunguang , Jia Yunfei , Liao Yucheng
Published: March 2021

Aiming at the measurement method of electrical capacitance tomography, a set of micro-capacitance acquisition system for planar array capacitance sensor is designed. Using the circuit principle design of high sensitivity and anti-interference, a dual-channel signal generator with adjustable amplitude and phase was designed to excite the capacitance sensor. The core capacitance voltage conversion circuit of the acquisition system adopts an AC excitation type conversion circuit with the ability to resist stray capacitance interference, and analyzes the error influencing factors in combination with the actual circuit components. The array control switch group is designed for multi-channel switching acquisition, and optimized in conjunction with the capacitor voltage conversion circuit. For the phase demodulation method, an orthogonal optimization method based on hardware multiplier is proposed. A micro-capacitor experiment is designed to calibrate the acquisition circuit. The experimental results show that the capacitance acquisition resolution of the micro-capacitor acquisition system within the acquisition range is 2.84fF, the linearity is 0.9998, and the acquisition error is less than 0.12fF.
Human eye-fixation prediction based on Convolutional Neural Network in RGB images
Authors: yue Miao , Wei Li , chunle Li
Published: March 2021

Using neural networks to simulate and predict human visual attention mechanism is a hot topic in the field of computer vision. In this paper, we propose an end-to-end encoder-decoder network architecture to predict the fixation mechanism of human eyes, which consists of modules composed of multiple convolutional layers with different expansion rates to capture multi-scale features in parallel. In addition, the attention module is added on the basis of the encoder network structure, and a self-attention mechanism is introduced to capture the visual feature dependency in the channel size, and the semantic interdependence in the channel dimension is modeled to predict the visual salience more accurately. In this paper, five data sets and selected examples are used to demonstrate the effectiveness of the proposed method. Our method achieves competitive and consistent results on multiple evaluation indicators on MIT1003 and CAT2000 datasets.
Design of a new voltage reference source
Authors: Li Xiaojiang , Huang Qunfeng
Published: March 2021

Current reference is a very important module in analog circuits. The main purpose of this design is to provide a stable reference voltage for a switch magnetism-sensing circuit. Because of the inherent characteristics of the circuit, the reference voltage is set to 3.3V. In this paper, the reference voltage source is designed to have a wide input range, a stable output and a good temperature characteristic. In this paper, the simulation results of the reference voltage and the complete design layout are described, and a current reference is achieved, which is independent of process, voltage and temperature, with little area increases only. The simulation results based on a 4 μm 25 V bipolar process verify the correctness of the theoretical analysis and the feasibility of the proposed methods.
Application Analysis of Electronic Information Technology in the Internet of Things
Authors: Xia Xianyu
Published: March 2021

Under the premise of technological progress, people’s thinking is constantly changing, and people have certain demands for new technologies. At present, people particularly favor information technology, which has changed people’s lifestyles. Especially after the emergence of the Internet of Things, a novel environment has been created for people’s living habits and enterprise production, and the distance between people can be effectively shortened. It can greatly improve the efficiency of life, highlighting the convenience. In the new era, the Internet of Things and electronic information technology are combined, and the two work together to help various industries move forward. It has targeted integration in multiple aspects such as QR code, intelligent transportation and electronic ordering, so that the Internet of Things brings forward action full of the times to the society, demonstrating its unique and effective use.
Research and Implementation of Multi-modal Video Retrieval System Based on Deep Learning
Authors: Bing Qi
Published: March 2021

At present, keyword-based video retrieval is gradually difficult to adapt to the needs of the rapid development of the Internet due to its strong subjectivity and huge workload. As a result, multi-modal video retrieval based on deep learning has appeared. This retrieval method can conduct video retrieval through multiple methods such as text, image, and video, which fully meets the different retrieval needs of different users, and significantly improves the accuracy and effectiveness of video retrieval. Based on this, this article discusses in detail the design of a multi-modal video retrieval system based on deep learning, analyzes and designs each functional module of the system to provide reference for future related work.
Research on the Demand of Broadband Wireless Mobile Applications Based on User Behavior
Authors: Zhang Qizeng , Zhao Biao , She Lei
Published: March 2021

Based on the different behaviors of multi-user group, this paper gives a method of demand analysis of broadband wireless mobile application. The analysis of broadband wireless mobile application, based on user behavior samples, can adopt the method of fuzzy cluster analysis to classify the user behavior by setting different clustering level, and build the model of each type of user behavior. The function of broadband wireless mobile application is designed by using the function description template based on class diagram, and the relationship between its function and user group behavior is analyzed by mapping matrix. At last, based on the application function and user behavior correlation analysis, the user behaviors are transformed into the key indicators and requirements of the application function.
A Novel All Digital Transmitter With Three-level Quadrature Differential RF-PWM
Authors: Lei Zhu , Qiang Zhou , Zhihu Wei , Zhang Chen , Jibo Wei , Jianbin Chen , Zhiyuan Zhao
Published: March 2021

To solve spectral aliasing of digital pulse width modulation (PWM) signal during digital up-conversion, a novel all-digital transmitter architecture using three-level quadrature differential RF-PWM is presented. By using triangle wave with 90° phase shift as the reference signal of quadrature differential PWM, the pulse coding of complex modulation signal and digital up-conversion will be realized. The feasibility of the transmitter is demonstrated by deriving the output formula of 3-level quadrature differential PWM, the design requirement is also given. Simulation and experiment results with QPSK and 16QAM signals show that the proposed scheme can significantly suppress the transmitter in-band noise, eliminate even harmonics, and effectively reduce the system operating frequency.
Evolutionary game of cooperative decision-making in reverse supply chain based on cooperative effort
Authors: Lin Ni , Yuli Xiong
Published: March 2021

Aiming at a large number of end-of-life (EOF) electrical products flowing into individual recycling outlets, it will squeeze the living space of formal dismantling companies and cause secondary pollution problems. The purpose of this paper is to establish a stable cooperative relationship between them to guide EOF products flowing from individual recycling outlets into the formal dismantling process. A game model involving the participation of formal dismantling enterprises and individual recycling outlets is constructed, and the role of government punishment mechanism intervention in the formation of active cooperative relations between participants in different parameter ranges is discussed. Then, the stability of the evolutionary equilibrium point is analysed. Finally, the Matlab software is used to simulate the influence of parameter on the formation of a stable cooperative relationship, and suggestions for promoting cooperation are provided.