bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic confinement of effectively unmagnetized plasma particles
Authors: Ordonez C. A.
Published: December 2020

A purely magnetic applied field may provide plasma confinement under conditions where the bulk of the plasma is effectively free of the applied magnetic field. The applied magnetic field surrounds the bulk of the plasma, and plasma particles that are incident on the applied magnetic field can be reflected back into the effectively unmagnetized region of plasma. The concept belongs to a class of magnetic plasma confinement approaches studied long ago, for which some experimental results indicated that classical (collision-based) cross-magnetic-field transport may occur. However, multiple magnetic coils are required to be immersed within the confined plasma, and rapid plasma loss may occur if material structures are present, which pass through the plasma (e.g., to hold the immersed coils in place). In the work reported, the concept is studied in combination with magnetic plasma expulsion [R. E. Phillips and C. A. Ordonez, Phys. Plasmas 25, 012508 (2018)], which would be employed to keep plasma away from material structures that pass through the plasma. A planar model is used for the study. A classical trajectory Monte Carlo simulation is carried out on particles that are independently incident on the applied magnetic field. With monoenergetic incident particles, the results indicate that the applied magnetic field can reflect all independently incident particles in certain regions of parameter space. Prospects for achieving three-dimensional magnetic confinement of an effectively unmagnetized plasma with a Maxwellian velocity distribution are discussed.
Enhancement of spin–orbit torque and modulation of Dzyaloshinskii–Moriya interaction in Pt100-xCrx/Co/AlOx trilayer
Authors: Quan Jiazhi , Zhao Xiaotian , Liu Wei , Liu Long , Song Yuhang , Li Yang , Ma Jun , Li Shuqiao , Zhao Xinguo , Zhang Zhidong
Published: December 2020

Alloying a heavy metal (HM) layer is a useful approach to enhance the current-spin converting efficiency ξSH while keeping a relatively low resistance for spin–orbit torque (SOT) based devices. In this work, we report the enhancement of ξSH and nonlinear modification of the Dzyaloshinskii–Moriya interaction (DMI) by alloying Pt with Cr in a Pt100-xCrx/Co/AlOx trilayer. The maximum of ξSH is found at the composition of Pt75Cr25. At the compositions of Pt75Cr25 and Pt50Cr50, the DMI constant |D| is strongly shifted in the opposite sign, implying ferromagnetic coupling and antiferromagnetic coupling existing in the heavy metal layer can both influence the DMI. Finally, the current-driven switching behavior is observed by the magneto-optical effect. This work shows that adjusting the composition of the magnetic alloyed HM layer is an efficient approach to obtain an optimized SOT performance.
Propagation of weakly stretched premixed spherical spray flames in localized homogeneous and heterogeneous reactants
Authors: Li Qiang , Zhang Huangwei , Shu Chang
Published: December 2020

Propagation of weakly stretched spherical flames in partially pre-vaporized fuel sprays is theoretically investigated in this work. A general theory is developed to describe flame propagation speed, flame temperature, droplet evaporation onset, and completion locations. The influences of liquid fuel and gas mixture properties on spherical spray flame propagation are studied. The results indicate that the spray flame propagation speed is enhanced with increased droplet mass loading and/or evaporation heat exchange coefficient (or evaporation rate). Opposite trends are found when the latent heat is high due to strong evaporation heat absorption. Fuel vapor and temperature gradients are observed in the post-flame evaporation zone of heterogeneous flames. The evaporation completion front location considerably changes with flame radius. For larger droplet loading and a smaller evaporation rate, the fuel droplet tends to complete evaporation behind the flame front. Flame bifurcation occurs with high droplet mass loading under large latent heat, leading to multiplicity of flame propagation speed, droplet evaporation onset, and completion fronts. The flame enhancement or weakening effects by the fuel droplet sprays are revealed by the enhanced or suppressed heat and mass diffusion process in the pre-flame zone. Besides, for heterogeneous flames, heat and mass diffusion in the post-flame zone also exists. The mass diffusion for both homogeneous and heterogeneous flames is enhanced with a decreased Lewis number. The magnitude of the Markstein length is considerably reduced with increased droplet loading. Moreover, post-flame droplet burning behind the heterogeneous flame influences the flame propagation speed and Markstein length when the liquid fuel loading is relatively low.
Synthesis of fluorocarbon nanofilms on titanium using high-power KrF laser radiation
Authors: Sergeev P.B. , Kirichenko A.N. , Kravchuk K.S. , Morozov N.V. , Khmelnitskii R.A.
Published: December 2020

Fluorocarbon (C : F) nanofilms up to 60 nm thick are synthesised on a titanium surface. The films are obtained by annealing thin layers of fluorocarbon oil (FO) (with an area of 0.6 cm2) in air with pulsed (80-ns) KrF laser radiation having a fluence of more than 4 J cm−2. The strength of C : F nanocoatings turns out to be comparable with that of titanium and exceeds several hundred times the corresponding characteristics of Teflon F-4. The high transparency of FO indicates a possibility of using it as a cover liquid when modifying titanium surface using beams of various technological lasers.
Destruction of absorbing metal films during laser printing with gel microdroplets
Authors: Zhigarkov V.S. , Minaev N.V. , Yusupov V.I.
Published: December 2020

The degree of destruction and evaporation of metal films (Au and Ti, thickness ∼50 nm) with a gel layer during laser transfer of small volumes of a gel substrate is estimated depending on the laser fluence value. The dynamics of these processes for dry films and films with a gel layer at fluences close to threshold values is investigated using a probe beam of a He – Ne laser. It is shown that the presence of a gel leads to an increase in the ablation threshold, but the time during which the process of structural changes in the film material is completed does not change significantly. The results obtained can be used to improve the laser bioprinting technology.
Radiofrequency synthesiser with an intrinsic instability of 5 × 10−15 at the averaging time of 1 s based on a femtosecond erbium-doped fibre laser
Authors: Kireev A.N. , Shelkovnikov A.S. , Tausenev A.V. , Tyurikov D.A. , Gubin M.A.
Published: December 2020

A radio-optical synthesiser intended for operation in a radio-frequency master oscillator with an optical He – Ne/CH4 frequency standard (λ = 3.39 μm) is developed on the basis of a femtosecond erbium-doped fibre laser. The synthesiser generates equidistant harmonics in the frequency range of 1 – 10 GHz with stability determined by the optical frequency standard. A stable supercontinuum spectrum is formed in the range around 1.06 μm, which provides stable 24-hour operation of the synthesiser and is important for practical applications in off-laboratory conditions. A direct comparison of the output frequencies of two synthesisers shows that the up-grade of the fibre laser and detection system of femtosecond pulses results in the synthesiser intrinsic instability of 5 × 10−15 at the averaging time of 1 s. Such a value is by an order of magnitude less than that obtained in our earlier works.
Biosecurity risk associated with bilge water from small vessels: an evaluation of systems and operator behaviours
Authors: Fletcher Lauren M. , Atalah Javier , Hopkins Grant A.
Published: December 2020

Vessel movements are considered the main anthropogenic pathway for secondary spread of marine non-indigenous species. Recent studies have highlighted the potential for viable organisms to be transported within bilge water of small vessels. In this study, a survey was conducted to (1) describe the bilge water operational profiles of a range of domestic vessels operating in New Zealand and (2) identify factors driving the level of biosecurity risk. The proportion of vessels with pre-discharge treatments was low (13.7%), confirming the potential for organisms to be viable at discharge. Significant differences in risk scores among vessel types were shown; risk scores were highest for yachts, followed by launches, trailer boats and commercial vessels. Yachts were characterised by a high frequency of use, visits to multiple regions and a high likelihood of bilge water on board when leaving port (i.e. high-risk source regions). Almost all yachts operated automatic bilge systems, suggesting that discharge occurs primarily when the volume is sufficient to trigger the pump mechanism and that associated bilge water could be carried significant distances. Validation of vessel risk profiles through targeted sampling is recommended, along with research to identify potential practical and cost-effective mitigation measures such as public awareness campaigns.
Seasonal plasticity in the adult somatosensory cortex
Authors: Ray Saikat , Li Miao , Koch Stefan Paul , Mueller Susanne , Boehm-Sturm Philipp , Wang Hong , Brecht Michael , Naumann Robert Konrad
Published: December 2020

Significance

To survive, animals need to adapt to changes of their ecosystem by changing their behaviors or even morphing the organs responsible for generating these behaviors. Small mammals have a high metabolic rate, and to balance energy deficits during winter they can decrease their brain and body size, a phenomenon termed Dehnel’s effect. We find specific seasonal changes in the brain of the smallest terrestrial mammal, the Etruscan shrew. Their cortex shrinks in the winter, with layer-width and neuron number reduction in the energetically expensive somatosensory cortical layer 4. Imaging of neural activity revealed reduced suppressive responses to whisker touch during winter, indicating that such cortical adaptation may have synergistic functional and behavioral effects in addition to direct metabolic benefits.
Individual variations lead to universal and cross-species patterns of social behavior
Authors: Choi Sang Hyun , Rao Vikyath D. , Gernat Tim , Hamilton Adam R. , Robinson Gene E. , Goldenfeld Nigel
Published: December 2020

Significance

To probe the collective nature of social organisms, we measured the duration of food transfer (trophallaxis) and face-to-face events experienced by thousands of barcoded honeybees in a colony, over their entire lifetimes. The interaction time distribution is heavy-tailed, as previously reported for human face-to-face interactions. We develop a detailed theory for the universality of these findings and show that they reflect individual variations in the population. Using a measure of inequality from economics, we quantify these individual differences in both honeybees and humans. We show that bees have individual differences but exhibit less individuality than humans. This work demonstrates how individual variations can lead to universal patterns of behavior across different species and specific mechanisms for social interactions.
Micellar TIA1 with folded RNA binding domains as a model for reversible stress granule formation
Authors: Fritzsching Keith J. , Yang Yizhuo , Pogue Emily M. , Rayman Joseph B. , Kandel Eric R. , McDermott Ann E.
Published: December 2020

Significance

Structural characterization of fl mouse TIA1 (43 kDa monomer) with solid-state NMR reveals structured functional domains and a disordered low-complexity domain. These data are consistent with a micellar form of apo fl TIA, unexpected based on much previous literature. We expect that these models of TIA1 and the NMR approaches will help us understand many similar proteins and their roles in the cellular stress response.
Fluctuating optimum and temporally variable selection on breeding date in birds and mammals
Authors: de Villemereuil Pierre , Charmantier Anne , Arlt Debora , Bize Pierre , Brekke Patricia , Brouwer Lyanne , Cockburn Andrew , Côté Steeve D. , Dobson F. Stephen , Evans Simon R. , Festa-Bianchet Marco , Gamelon Marlène , Hamel Sandra , Hegelbach Johann , Jerstad Kurt , Kempenaers Bart , Kruuk Loeske E. B. , Kumpula Jouko , Kvalnes Thomas , McAdam Andrew G. , McFarlane S. Eryn , Morrissey Michael B. , Pärt Tomas , Pemberton Josephine M. , Qvarnström Anna , Røstad Ole Wiggo , Schroeder Julia , Senar Juan Carlos , Sheldon Ben C. , van de Pol Martijn , Visser Marcel E. , Wheelwright Nathaniel T. , Tufto Jarle , Chevin Luis-Miguel
Published: December 2020

Significance

Many ecological and evolutionary processes strongly depend on the way natural selection varies over time. However, a gap remains when trying to connect theoretical predictions to empirical work on this question: Most theory assumes that adaptation involves tracking a moving optimum phenotype through time, but this is seldom estimated empirically. Here, we have assembled a large database of wild bird and mammal populations, to estimate patterns of fluctuations in the optimum breeding date and its influence on the variability of natural selection. We find that optimum fluctuations are prevalent. However, their influence on temporal variance in natural selection is partly buffered by tracking of the optimum phenotype through individual phenotypic plasticity.
Inverse correlation between fatty acid transport protein 4 and vision in Leber congenital amaurosis associated with RPE65 mutation
Authors: Li Songhua , Gordon William C. , Bazan Nicolas G. , Jin Minghao
Published: December 2020

Significance

Mutations in the retinal pigment epithelium (RPE)65 are associated with Leber congenital amaurosis (LCA), for which there is no effective therapy alleviating progressive retinal degeneration in affected patients. Here, we show that fatty acid transport protein 4 (FATP4)-deficiency markedly increases synthesis of 11-
cis
- and 9-
cis
-retinals, improving solubility, stability, and trafficking of cone opsins in the R91W knockin (KI) mouse model of LCA. Numbers of S-cones in 6-mo-old KI;Fatp4-/- mouse retinas were 13.5-fold greater than those in age-matched KI mice. Survival and function of S- and M-cones are negatively correlated with expression levels of FATP4 in the RPE of KI, KI;Fatp4+/-, and KI;Fatp4-/- mice. These findings establish FATP4 as a promising therapeutic target to preserve vision in patients with RPE65 mutations.
Local elected officials’ receptivity to refugee resettlement in the United States
Authors: Shaffer Robert , Pinson Lauren E. , Chu Jonathan A. , Simmons Beth A.
Published: December 2020

Significance

The recent global surge in forcibly displaced persons has produced grave humanitarian consequences. This surge has prompted close scrutiny of public sentiment toward refugees in recipient countries. But less attention has been paid to local governments, despite the outsized influence they wield over refugee resettlement and well-being. We provide an experimental study of US local elected officials’ attitudes toward refugees seeking to settle in their communities. We find that local elected officials support a broad range of refugee groups, though they are most supportive of refugees whom they believe will contribute to the local economy and fit with community values. Our results offer guidance to advocates seeking to improve resettlement outcomes and a rejoinder to national-level suspicion toward refugee resettlement.
Visual motion assists in social cognition
Authors: Guterstam Arvid , Graziano Michael S. A.
Published: December 2020

Significance

Recent evidence suggests that our brains may generate subtle, fictitious motion signals streaming from other people to the objects of their attention. However, the functional significance of this internally-generated motion signal remains unclear. Here, we tested whether subthreshold motion processing plays a causal role in judging others’ attention. Participants viewed a display including faces, objects, and a subthreshold motion hidden in the background. Judgments of the attentional state of the faces were significantly altered by the motion signal. Control experiments indicated the effect was specific to judging attention. These findings suggest that a crucial aspect of social cognition, monitoring others’ attention, draws on useful but highly physically inaccurate models of social agents in the world, rooted in low-level perceptual mechanisms.
The null and force-free electromagnetic field
Authors: Menon Govind
Published: December 2020

This paper describes the electrodynamics of a null and force-free field in completely geometric terms. As was previously established in Menon (2020 Class. Quantum Grav.
37 245006), solutions to force-free electrodynamics are governed by the existence of certain special types of foliations of spacetime. Here the nature of the foliations in a coordinate-free formalism in the null case is prescribed. All of the general results are illustrated by constructing a new null, force-free electrodynamic field in a Friedmann–Lemaitre–Robertson–Walker spacetime.
Optical isolation of spectral lines emitted by sputtered tungsten in a weakly magnetized plasma
Authors: Ertmer S , Marchuk O , Sackers M , Dickheuer S , Brezinsek S , Mertens Ph , Kreter A
Published: December 2020

Optical isolation of the clockwise or the counter-clockwise circular polarization of spectral lines was applied to emission of sputtered tungsten atoms. As a result one measures the weak magnetic field at plasma-surface interface resulting in splitting of spectral lines (W I at 4008.751 Å and 4982.593 Å) being negligibly small with respect to the Doppler broadening. One relies only on the phase rotation of a reflected circular polarized light propagating at the normal incidence to the mirror-like surface. The spectral shift of the signal from sputtered W atoms on the detector using high-resolution spectrometer provides the value of the magnetic field at a known dispersion, i.e. no further modeling or additional assumption on the distribution of atoms is required. The isolation of spectral line components is equivalent to isolation of the effect of the magnetic field from the measured line shape. It is complete for Zeeman triplet lines and partial for other lines. The results are found to be in a very good agreement of 3% with calculations and the Zeeman resolved laser absorption spectroscopy (10%) on metastable levels of Ar I atoms.
Evolution and ion kinetics of a XUV-induced nanoplasma in ammonia clusters
Authors: Michiels R , LaForge A C , Bohlen M , Callegari C , Clark A , von Conta A , Coreno M , Di Fraia M , Drabbels M , Finetti P , Huppert M , Oliver V , Plekan O , Prince K C , Stranges S , Wörner H J , Stienkemeier F
Published: December 2020

High-intensity extreme ultraviolet (XUV) pulses from a free-electron laser can be used to create a nanoplasma in clusters. In reference Michiels et al (2020 Phys. Chem. Chem. Phys.
22 7828–34) we investigated the formation of excited states in an XUV-induced nanoplasma in ammonia clusters. In the present article we expand our previous study with a detailed analysis of the nanoplasma evolution and ion kinetics. We use a time-delayed UV laser as probe to ionize excited states of H and

H

2

+

in the XUV-induced plasma. Employing covariance mapping techniques, we show that the correlated emission of protons plays an important role in the plasma dynamics. The time-dependent kinetic energy of the ions created by the probe laser is measured, revealing the charge neutralization of the cluster happens on a sub-picosecond timescale. Furthermore, we observe ro-vibrationally excited molecular hydrogen ions

H

2

+
*

being ejected from the clusters. We rationalize our data through a qualitative model of a finite-size non-thermal plasma.
Theoretical evaluation of multivalent cation diffusion in the 1T-δ-MnO2 electrode via potential energy surface
Authors: Zhou Bo , Zhou Zhaoyu , Li Bo , Qu Zilin , Song Qi , Zhang Chunmei , Jiang Zhenyi , Ding Yi
Published: December 2020

Polymorphs of MnO2 have been studied extensively for their potential application in rechargeable batteries which provide attractive structures as the host for the cation insertion. In this study, the simplest form of δ-MnO2 has been taken as the representative of layered MnO2 and the ion diffusion performance is carefully examined. The potential energy surfaces of Li+, Na+, K+, NH4
+, Mg2+, Zn2+, Ca2+ and Al3+ ion diffusing in the 1T-δ-MnO2 are firstly obtained within the density functional theory framework, which give a comprehensive and detailed view of the diffusing process. We not only assess the 1T-δ-MnO2 as candidate electrode material quantitatively but also elucidate the influence of the cooperative Jahn–Teller effect which governs multivalent diffusion in the intuitive and clear view. Our findings are well matched with the reported results and lead to practical and implementable guidelines to find MnO2-based fast-diffusion multivalent ion conductors.
Bremsstrahlung emission and plasma characterization driven by moderately relativistic laser–plasma interactions
Authors: Singh Sushil , Armstrong Chris D , Kang Ning , Ren Lei , Liu Huiya , Hua Neng , Rusby Dean R , Klimo Ondřej , Versaci Roberto , Zhang Yan , Sun Mingying , Zhu Baoqiang , Lei Anle , Ouyang Xiaoping , Lancia Livia , Laso Garcia Alejandro , Wagner Andreas , Cowan Thomas , Zhu Jianqiang , Schlegel Theodor , Weber Stefan , McKenna Paul , Neely David , Tikhonchuk Vladimir , Kumar Deepak
Published: December 2020

Relativistic electrons generated by the interaction of petawatt-class short laser pulses with solid targets can be used to generate bright x-rays via bremsstrahlung. The efficiency of laser energy transfer into these electrons depends on multiple parameters including the focused intensity and pre-plasma level. This paper reports experimental results from the interaction of a high intensity petawatt-class glass laser pulses with solid targets at a maximum intensity of 1019 W cm−2. In-situ measurements of specularly reflected light are used to provide an upper bound of laser absorption and to characterize focused laser intensity, the pre-plasma level and the generation mechanism of second harmonic light. The measured spectrum of electrons and bremsstrahlung radiation provide information about the efficiency of laser energy transfer.
Extreme-value statistics of stochastic transport processes
Authors: Guillet Alexandre , Roldán Edgar , Jülicher Frank
Published: December 2020

We derive exact expressions for the finite-time statistics of extrema (maximum and minimum) of the spatial displacement and the fluctuating entropy flow of biased random walks. Our approach captures key features of extreme events in molecular motor motion along linear filaments. For one-dimensional biased random walks, we derive exact results which tighten bounds for entropy production extrema obtained with martingale theory and reveal a symmetry between the distribution of the maxima and minima of entropy production. Furthermore, we show that the relaxation spectrum of the full generating function, and hence of any moment, of the finite-time extrema distributions can be written in terms of the Marčenko–Pastur distribution of random-matrix theory. Using this result, we obtain efficient estimates for the extreme-value statistics of stochastic transport processes from the eigenvalue distributions of suitable Wishart and Laguerre random matrices. We confirm our results with numerical simulations of stochastic models of molecular motors.
Eliminating the Unruh effect of relativistic Dirac fields by partial measurements
Authors: Khan N A , Amin Syed Tahir , Jan Munsif
Published: December 2020

The retrieval of lost entanglement for relatively accelerated fermionic observers of a tripartite system by a partial measurement technique has been investigated. From the prospective of the negativities of one-tangles and the π-tangle, we show that the degraded entanglement in noninertial frames with single-mode approximation is completely retrieved by an optimal strength of the partial measurement or the partial measurement reversal. In addition, we find that the optimal one-tangle with respect to inertial and noninertial observers turns out to be the same for an optimal strength of partial measurements at q
0 = 0 when two accelerated observers move with infinite acceleration.
Monolithic epitaxy and optoelectronic properties of single-crystalline γ-In2Se3 thin films on mica*
Authors: Yin Xibo , Shen Yifan , Xu Chaofan , He Jing , Li Junye , Ji Haining , Wang Jianwei , Li Handong , Zhu Xiaohong , Niu Xiaobin , Wang Zhiming
Published: December 2020

The growth of γ-In2Se3 thin films on mica by molecular beam epitaxy is studied. Single-crystalline γ-In2Se3 is achieved at a relatively low growth temperature. An ultrathin β-In2Se3 buffer layer is observed to nucleate and grow through a process of self-organization at initial deposition, which facilitates subsequent monolithic epitaxy of single-crystalline γ-In2Se3 at low temperature. Strong room-temperature photoluminescence and moderate optoelectronic response are observed in the achieved γ-In2Se3 thin films.
Tunable valley filter efficiency by spin–orbit coupling in silicene nanoconstrictions*
Authors: Shi Yi-Jian , Wang Yuan-Chun , Wang Peng-Jun
Published: December 2020

Valley filter is a promising device for producing valley polarized current in graphene-like two-dimensional honeycomb lattice materials. The relatively large spin–orbit coupling in silicene contributes to remarkable quantum spin Hall effect, which leads to distinctive valley-dependent transport properties compared with intrinsic graphene. In this paper, quantized conductance and valley polarization in silicene nanoconstrictions are theoretically investigated in quantum spin-Hall insulator phase. Nearly perfect valley filter effect is found by aligning the gate voltage in the central constriction region. However, the valley polarization plateaus are shifted with the increase of spin–orbit coupling strength, accompanied by smooth variation of polarization reversal. Our findings provide new strategies to control the valley polarization in valleytronic devices.
Low thermal expansion and broad band photoluminescence of Zr0.1Al1.9Mo2.9V0.1O12
*
Authors: Wang Jun-Ping , Chen Qing-Dong , Chen Li-Gang , Ji Yan-Jun , Liu You-Wen , Liang Er-Jun
Published: December 2020

A new material of Zr0.1Al1.9Mo2.9V0.1O12 is synthesized by the traditional solid state synthesis method. The phase transition, coefficient of thermal expansion, and luminescence properties of Zr0.1Al1.9Mo2.9V0.1O12 are explored with Raman spectrometer, dilatometer, and x-ray diffraction (XRD) diffractometer. The results show that the Zr0.1Al1.9Mo2.9V0.1O12 possesses the strong broad-band luminescence characteristics almost in the whole visible region. The sample is crystallized in a monoclinic structure group of P21/a (No. 14) crystallized at room temperature (RT). The crystal is changed from monoclinic to orthorhombic structure when the temperature increases to 463 K. The material has very low thermal expansion performance in a wide temperature range. Its excellent low thermal expansion and strong pale green light properties in a wide temperature range suggest its potential applications in light-emitting diode (LED) and other optoelectronic devices.
In-situ fabrication of ZnO nanoparticles sensors based on gas-sensing electrode for ppb-level H2S detection at room temperature*
Authors: Xuan Jing-Yue , Zhao Guo-Dong , Shi Xiao-Bo , Geng Wei , Li Heng-Zheng , Sun Mei-Ling , Jia Fu-Chao , Tan Shu-Gang , Yin Guang-Chao , Liu Bo
Published: December 2020

The zinc oxide (ZnO) nanoparticles (NPs) sensors were prepared in-situ on the gas-sensing electrodes by a one-step simple sol-gel method for the detection of hydrogen sulfide (H2S) gas. The sphere-like ZnO NPs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), energy dispersive x-ray analysis (EDX), and their H2S sensing performance were measured at room temperature. Testing results indicate that the ZnO NPs exhibit excellent response to H2S gas at room temperature. The response value of the optimal sample to 750 ppb H2S is 73.3%, the detection limit reaches to 30 ppb, and the response value is 7.5%. Furthermore, the effects of the calcining time and thickness of the film on the gas-sensing performance were investigated. Both calcining time and film thickness show a negative correlation with the H2S sensing performance. The corresponding reaction mechanism of H2S detection was also discussed.
Nonlocal advantage of quantum coherence in a dephasing channel with memory*
Authors: Hu Ming-Liang , Zhang Yu-Han , Fan Heng
Published: December 2020

We investigate nonlocal advantage of quantum coherence (NAQC) in a correlated dephasing channel modeled by the multimode bosonic reservoir. We obtain analytically the dephasing and memory factors of this channel for the reservoir having a Lorentzian spectral density, and analyze how they affect the NAQC defined by the l
1 norm and relative entropy. It is shown that the memory effects of this channel on NAQC are state-dependent, and they suppress noticeably the rapid decay of NAQC for the family of input Bell-like states with one excitation. For the given transmission time of each qubit, we also obtain the regions of the dephasing and memory factors during which there is NAQC in the output states.
Influence of irradiation-induced point defects on the dissolution and diffusion properties of hydrogen in α-Al2O3: a first-principles study
Authors: Pan Xin-Dong , Xu Yu-Ping , Lu Tao , Zhou Hai-Shan , Li Xiao-Chun , Gao Fei , Luo Guang-Nan
Published: December 2020

Alpha-alumina (α-Al2O3) is considered to be an ideal candidate material for the tritium permeation barrier (TPB) with excellent tritium resistance properties. However, in a fusion reactor, the irradiation-induced defects could sum up on fabrication-induced defects so to reduce drastically the barrier performance. The underlying mechanism is still not settled. In this paper, the first-principles density functional theory (DFT) approach is used to explore the influence of irradiation-induced point defects on the dissolution and diffusion properties of hydrogen (H) in α-Al2O3.

H

+

−

V

A
l

−
3

and

H

+

−

V

O

0

defects have much lower formation energies at E
G/2 in both Al-rich and O-rich growth environments that H atoms are easily captured by vacancy-type irradiation-induced point defects. As a result, higher H retention can be expected, which is consistent with the experimental results. Moreover, by calculating several different diffusion pathways of H-defect complexes and the corresponding diffusion coefficient, it can be inferred that H atoms and vacancy-type point defects can hardly diffuse as a bound entity. Therefore, isolated vacancy-type irradiation-induced point defects can trap multiple H atoms to form H-defect complexes and impede the diffusion process of H, which can enhance the efficiency of protection against H permeation through α-Al2O3 TPB. However, the minimum diffusion barrier for O
i
H− migration to the first nearest neighbor O interstitial site is 0.44 eV, which is so low that O
i
H− can migrate quickly at room temperature. This fast diffusion pathway for H could be the underlying mechanism for the low efficiency in preventing H permeation through irradiated α-Al2O3. Our results provide a sound theoretical explanation for recent experimental results of H permeation in α-Al2O3 under irradiation environment.
A Brief Discussion about Application of Artificial Intelligence in Computer Network Technology in the Era of Big Data
Authors: Luo Dongmei , Zhou Corresponding author: Xiaodong
Published: December 2020

With the rapid development of science and technology, the era of big data has come in full swing. A critical problem meriting reflection at present is how to take full advantage of this era in order to continuously improve the technological application level. As one of emerging technologies in modern society, artificial intelligence (AI) has achieved favorable effects when applied to different fields, e.g. AI computer network technology (CNT). The era of big data and AI were briefly expounded, the development of AI and its extensions in the era of big data were analyzed, and its application in CNT and development prospect were deeply explored, expecting to contribute to further application and development of AI in the era of big data.
The Game of Communication: An Analysis of The Emoji Landscape in Social Media
Authors: Hon Nicholas Yeung Ming
Published: December 2020

The empowerment of social media makes us into the era of diversification of transmission. The spread of the mass media content production and social organization monopoly pattern is broken. The Internet emerges as one the most unique landscape within the framework of public discourse. As a communication tool, emojis gradually become a refuge for various ideologies. It can be said that the popularity of emojis on social media is the result of a power game between various forms of ideologies. On the one hand, the emoji landscape formed in social media can be seen as the awakening of the subject consciousness of the public and the objectified product of network quality, but on the other hand, people have to watch out for the dissolution of social solemnness brought by the excessive entertainment of emojis, and the public has since become one-dimensional creature.
Review of the Application of Big Data and Artificial Intelligence in Geology
Authors: Chen Lirong , Wang Liang , Miao Jinli , Gao Huan , Zhang Yue , Yao Yao , Bai Ming , Mei Lisi , He Jing
Published: December 2020

Big data and artificial intelligence (AI) have provided new methods and opportunities for many applications in geology. Nevertheless, big data and AI-based geoscience applications are still in their infancy, and the methods and objectives are still scattered, lacking a unified theoretical and application framework. This study reviews the application of big data and AI in geology and analyzes and summarizes the current status, development trends and existing problems of ongoing studies from the perspectives of geology. This study can provide a reference for the future research and development of the application of big data and AI in the field of geology.
Packing Design and Application Based on VR Technology
Authors: Lu Peipei , Zhang Xinyue
Published: December 2020

Improving the adaptability of packing box and packing materials is the main target of packaging. Introduction of VR technology to packaging design could reach the virtual reality modeling language, so it is convenient for the calculation of inner space of packaging to enhance the comfort of packaging. Or the outer size of packaging could be calculated according to the interaction of inner space and outer space for the convenience of appearance design to enhance artistry. The main method is as follow. Firstly, build up model with 3Dax software; secondly, the structure, node and outer packaging size of virtual space through VRML; thirdly, a link is generated through system to have a 3D printing of the filling modeling of inner space. The picture of outer packaging and commodity information are set with the combination of inner data of the packaging; and then the virtual appearance of packaging would be generated through VR technology light and rendering, so as to gain the final result of the packaging design. It could be confirmed according to the experimental analysis data, the packaging compactness would be 37% increased and the compression resistance ratio is also 29% increased through the 3D VR packaging design. It is proved that the packaging effectively improve the seismic performance of products. The application of the virtual outer packaging design of product also sufficiently proves the important use value of the method.
Development of Higher Vocational Artificial Intelligence Course based on Enterprise Real Project
Authors: Zhou Yuehong , Wang Liqi , Ma Rui
Published: December 2020

In the era of intelligence, the development of artificial intelligence technology has greatly promoted the demand of relevant professional courses. This paper mainly analyses the framework and implementation process of the enterprise real project “garbage sorting robot system” which is the project carrier of artificial intelligence course. On this basis, according to the knowledge system of artificial intelligence technology, the relevant teaching knowledge points and teaching methods of artificial intelligence course are designed.
Mechanical equipment fault detection applying data mining technology
Authors: Liu Yiqun , Wang Xiaogang , Gong Xiaoyuan , Mu Hua
Published: December 2020

Mechanical equipment fault detection in manufacturing enterprises has always been an important link in the manufacturing process. Along with the computer technology, artificial intelligence technology and various sensors are widely used in manufacturing industry, The amount of data produced by manufacturing machinery and equipment at all stages of the production process is also increasing rapidly, It is particularly important to analyze the data generated by these devices for fault detection and even prediction, Data mining technology provides advanced analysis methods for this purpose. This paper first introduces the basic concepts of Data Mining, Data Mining process and the key technology of Data Mining, and then focuses on the application of Data Mining in machinery fault detection, finally through the analysis of Data Mining in the field of top class meeting KDD2019, explored the could be applied to machinery fault detection of new technology, forecast the Data Mining technology in the fault detection of possible development trend.
Cybersecurity Analysis of Intelligent IIOT Robots
Authors: Yuehong Zhang
Published: December 2020

This paper studies the possible threats to the damaged robots. By analyzing the security problems of intelligent robots, the purpose is to strengthen the safety of robots and prevent the possible serious damage to enterprises, consumers and their surrounding environment after the vulnerabilities are maliciously exploited by attackers. (Abstract)
Research on Fintech Methods Based on Artificial Intelligence
Authors: Hu Zhongjian
Published: December 2020

The financial industry is one of the earliest and most comprehensive industries that integrate with artificial intelligence. The application of a series of artificial intelligence technologies such as data mining, accurate profiling, machine learning, neural networks, will provide financial products, service channels, service methods, risk management, Credit financing and investment decision-making have brought about a new round of changes. Firstly, the rapid development of artificial intelligence has a profound impact on the high-end finance of the deep service value chain; Secondly, the integrated development of artificial intelligence and finance is irreversible, risks and opportunities coexist, and the financial industry must accelerate the pace of adjustment and development; Finally, the financial supervision department further clarifies the supervision responsibility, applies artificial intelligence technology to supervision methods and means, and improves the degree of supervision automation and intelligence.
The New Type of Reducts in Intuitionistic Fuzzy β-covering Approximation Spaces
Authors: Chang Zaibin , Wei Junchao , Dai Xuezhen
Published: December 2020

A type of reducts in intuitionistic fuzzy (IF) β-coverings has been presented based on the union operation. But for some problems, there is no reducts in IF β-coverings according to this definition. That is to say, this notion has its boundedness. Therefore, we present the new type of reducts in IF β-coverings in this paper, and we call it type-2 reduct. Moreover, the type-2 reducts in IF β-covering approximation spaces are investigated while adding and removing some objects of the universe. Firstly, the notion of the type-2 reduct in an IF β-covering approximation space is presented. Then, some properties of type-2 reducts of IF β-coverings are investigated while adding and removing some objects.
A dynamic instrumentation tool for obtaining software logs
Authors: Zhou Hongchen , Li Jing
Published: December 2020

Compared with the software analysis based on source code, log based software analysis technology has gradually emerged in recent years, but it is not easy to obtain the log of software. To automatically obtain enough information on the software log, this paper proposes a dynamic instrumentation tool, it can dynamically instrument a software implemented in Java language, and get the log finally. This tool does not require users to be familiar with the software, and the instrumentation process will not cause an intrusive impact on the source code. It is a general-purpose automatic dynamic instrumentation tool.
STL_Siam: Real-time Visual Tracking based on reinforcement guided network
Authors: Shijia Huang , Luping Wang
Published: December 2020

In recent years, deep visual tracking algorithms based on Siamese has made great breakthrough in both speed and accuracy. However, due to the dependence of Siamese network on the target template, these trackers are prone to drift or even fail to track in a complex tracking environment. In this work, we navigate the Siamese network with a STLNet model and propose the STL_Siam method. The STLNet, trained offline with the dataset enhanced by ROMIX method, is introduced into the SiamGrad algorithm to infer the movement of the target during online tracking, and guides the SiamGrad network to track. In order to evaluate the reliability of the proposed algorithm, we conducted experiments on the OTB2013 and VOT2016 two benchmarks. The algorithm achieved excellent performance, and the performance of the sequences with complex obstruction interference has been slightly improved. Experiments suggests that the proposed architecture reaches 40+fps and gets 0.865 precision on OTB2013, which is higher than results of the ACT. Meanwhile, compared with the baseline algorithm ACT, the A, R, and EAO of the proposed approach is increased by 5.6%, 1%, and 0.3% respectively on VOT2016 respectively.
Exploration-Exploitation Strategies in Deep Q-Networks Applied to Route-Finding Problems
Authors: Wei Pengyuan
Published: December 2020

Reinforcement learning is a class of algorithm that allows computers to learn how to accumulate rewards effectively in the environment and ultimately get excellent results. Among them, the exploration-exploitation tradeoff is a very important concept, since a good strategy can improve learning speed and final total reward. In this work, we applied DQN algorithm with different exploration-exploitation strategies to solve traditional route-finding problems. The experimental results show that the epsilon greedy strategy with a parabolic drop in epsilon value over reward improvement is the best, while it is not satisfactory after incorporating the softmax function. We hypothesized that the simplicity of the maze we use in this work in which the agent attempts to find the shortest path leads to the inadequacy of applying softmax to further encourage exploration. Future work thus involves experimenting with mazes at different scales and complexities and observing which exploration-exploitation strategies work best in each condition.
Intrusion detection using a combination of one-dimensional convolution and GRU
Authors: Wang Xiaojuan , Xiao Bo
Published: December 2020

Intrusion detection plays an important role in ensuring network information security. Traditional machine learning technology does not work well enough with massive data and various intrusion classes, and detection accuracy turns unsatisfied with unknown intrusions. This paper proposes a new network intrusion detection model (Conv1d-GRU) that combines one-dimensional convolution and GRU for multi-class intrusion detection scenarios, and improves data imbalance by weighting the samples of each category. NSL-KDD as an improved version of the KDD CUP99 dataset is selected for our intrusion detection system. Experimental results on this dataset show that the proposed deep learning method is superior to present intrusion detection methods based on machine learning and deep learning, and has better feature representation learning and classification capabilities.
An EHW - based Anti - power Consumption Detection Hardware Trojan Implantation Method
Authors: Liu Lijun , Ding Qiao , He Tianyu
Published: December 2020

Hardware Trojan (HT) is developing towards miniaturization and concealment, but the detection of this kind of HT is still in the research state. The main reason is that the real HT has some problems such as difficult sampling and few kinds, so it is necessary to design the circuit with this kind of HT artificially. Therefore, the EHW technology is introduced to implant this kind of HT, and the original circuit is redesigned to make the power consumption change small and increase the HT function, so as to achieve the effect of concealment.
WCET Aware Cache Locking and Task Scheduling in Single Core Embedded Systems
Authors: Zhang Tingxu , Zheng Wenguang , Xiao Yingyuan
Published: December 2020

Task scheduling in embedded system needs the WCET (Worst-Case Execution Time) of the task to ensure that tasks can be completed before their deadline. The application of cache reduces the average case execution time of tasks but increases the difficulty of scheduling because WCET becomes difficult to determine. Cache locking is a technique to help determine the WCET of a task. In addition, applying suitable cache locking selection can reduce the WCET of a task, bring easier task scheduling and further reduce the total WCET of all tasks. In this paper, we propose an approach integrated dynamic cache locking and task scheduling in a single core embedded system. We choose the most valuable locking content for each task in limited cache capacity to determine the WCET, schedule the tasks so that all the tasks can be finished before the deadline and make the total WCET minimized. We have implemented this approach and compared it to no-cache task scheduling and non-preemption task scheduling model with LRU cache by using a set of tasks. The experimental results show that our approach achieves successfully task scheduling for all test data. Compared to no-cache task scheduling, our approach achieves the average improvements of 3.22%, 12.68%,18.96% and 19.12% for the 256B, 512B, 1KB and 2KB caches, respectively. Compared to the non-preemption task scheduling model, our approach achieves the average improvements of 1.32%, 7.27%, 10.2% and 9.13% for the 256B, 512B, 1KB and 2KB caches, respectively.
On normalized generating sets for generalized quasi-twisted codes over finite fields
Authors: Lv Jingjie , Li Ruihu , Zheng Youliang , Yao Yu
Published: December 2020

In this short correspondence, we firstly determine the normalized generating set for generalized quasi-twisted codes over finite fields. Then we present an algorithm to construct it. As an application, some optimal or the best-known linear codes are derived from generalized quasi-twisted codes by applying our method.
Application of DSP Technology in Radar Signal Processing
Authors: Aichun Zhu , Wenhui Sun , Kejin Wang
Published: December 2020

Aiming at the problems existing in applying DSP technology to radar signal processing, the article analyzes the current use of DSP technology from a practical view, and proposes methods and strategies for optimal control of future technologies. The results show that only under the premise of the operational control requirements of the radar signal processing system can the application advantages and reliable effects be brought into full play, thereby promoting the healthy and stable development of the industries involved.