bluuebunny/crossref_metadata_2025 huggingface dataset:
Animal welfare testing for shooting and darting free-ranging wildlife: a review and recommendations
Authors: Hampton Jordan O. , Arnemo Jon M. , Barnsley Richard , Cattet Marc , Daoust Pierre-Yves , DeNicola Anthony J. , Eccles Grant , Fletcher Don , Hinds Lyn A. , Hunt Rob , Portas Timothy , Stokke Sigbjørn , Warburton Bruce , Wimpenny Claire
Published: April 2021

Several important techniques for managing wildlife rely on ballistics (the behaviour of projectiles), including killing techniques (shooting) as well as capture and marking methods (darting). Because all ballistic techniques have the capacity to harm animals, animal welfare is an important consideration. Standardised testing approaches that have allowed refinement for other physical killing and capture methods (e.g. traps for mammals) have not been applied broadly to ballistic methods. At the same time, new technology is becoming available for shooting (e.g. subsonic and lead-free ammunition) and darting (e.g. dye-marker darts). We present several case studies demonstrating (a) how basic ballistic testing can be performed for novel firearms and/or projectiles, (b) the benefits of identifying methods producing undesirable results before operational use, and (c) the welfare risks associated with bypassing testing of a technique before broad-scale application. Following the approach that has been used internationally to test kill-traps, we suggest the following four-step testing process: (1) range and field testing to confirm accuracy and precision, the delivery of appropriate kinetic energy levels and projectile behaviour, (2) post-mortem assessment of ballistic injury in cadavers, (3) small-scale live animal pilot studies with predetermined threshold pass/fail levels, and (4) broad-scale use with reporting of the frequency of adverse animal welfare outcomes. We present this as a practical approach for maintaining and improving animal welfare standards when considering the use of ballistic technology for wildlife management.
Cocos nucifera (coconut).
Authors: Rojas-Sandoval Julissa , Acevedo-Rodríguez Pedro
Published: April 2021

C. nucifera is believed to have originated in the Indo-Malayan to Western Pacific region (Parrotta, 1993) and is now of pan-tropical distribution, mainly the result of cultivation for its nuts and by natural dispersal by the oceans. It can be cultivated up to an elevation of 1200 m near the equator or 900 m at higher latitudes (Moistero, 1978), with annual rainfall of 700-5000 mm but growth and fruit production are reduced at the extremes (Parrotta, 1993). Commercial production of coconuts is mainly concentrated in low coastal lands. It prefers deep, fertile and adequately drained soils at pH 5.5-6.5, with either a high water-table or continually replenished surface soil moisture (Francis and Liogier, 1991; PCARRD, 1993). Generally, C. nucifera is propagated from seeds (the nuts), which take 8-10 weeks to germinate and 30 weeks to reach planting-out size. It is intolerant of shade, self-pruning, highly resistant to wind damage and may tolerate some salinity (Parrotta, 1993). Besides its nuts, C. nucifera trees are of enormous general utility. The timber is used for poles, construction, furniture, boxes, fixtures, particle board, paper pulp, charcoal, and occasionally veneers. The wood is difficult to saw, requiring tungsten carbide teeth. Coconut milk may be drunk or used as a medium for tissue culture; the copra (dried endosperm) is used for extraction of oils for use in foods, cosmetics, and medicines; the cori (mesocarp fibres) is used to construct mats, ropes, carpets, brushes, brooms, and bags, packaging, and potting media; the shell is used to make bowels, cups, spoons, ladles, smoking pipes, ashtrays, vases, boxes, and toys. The leaves are used in thatching, and the terminal bud may be eaten as a vegetable. The roots have medicinal properties, and provide a sweet sucrose-rich liquid known as toddy (Westphal and Jansen, 1989).
Influence of magnetic fields on the stability and the phase transition of quark matter in the Nambu–Jona–Lasinio model
Authors: Su Shou-Zheng , Wen Xin-Jian
Published: April 2021

In the presence of the external magnetic fields, we investigate the stability of quark matter as well as the phase transition in the framework of two flavor Nambu–Jona–Lasinio model. The investigation focuses on the magnetic effects with the fixed coupling constant and the running coupling constant G(B, T) depending on both magnetic field and temperature. The dynamical quark mass can be increased by strong magnetic fields and be reduced by the running coupling constant G(B, T). The baryon number density is also increased by strong magnetic fields but is weakly influenced by the running coupling constant G(B, T). Importantly, the stability can be enhanced by the magnetic fields of a proper strength. While it will be reduced by the much weaker or much stronger magnetic fields. The magnetic-field-dependence in the running coupling constant has slight effect on the stability. Finally, the phase transition and the location of critical end point for both coupling cases are numerically shown.
Motion-induced inertial effects and topological phase transitions in skyrmion transport
Authors: Teixeira A W , Castillo-Sepúlveda S , Rizzi L G , Nunez A S , Troncoso R E , Altbir D , Fonseca J M , Carvalho-Santos V L
Published: April 2021

When the skyrmion dynamics beyond the particle-like description is considered, this topological structure can deform due to a self-induced field. In this work, we perform Monte Carlo simulations to characterize the skyrmion deformation during its steady movement. In the low-velocity regime, the deformation in the skyrmion shape is quantified by an effective inertial mass, which is related to the dissipative force. When skyrmions move faster, the large self-induced deformation triggers topological transitions. These transitions are characterized by the proliferation of skyrmions and a different total topological charge, which is obtained as a function of the skyrmion velocity. Our findings provide an alternative way to describe the dynamics of a skyrmion that accounts for the deformations of its structure. Furthermore, such motion-induced topological phase transitions make it possible to control the number of ferromagnetic skyrmions through velocity effects.
Electric field controlled type-I and type-II conversion of BP/SnS van der Waals heterostructure
Authors: Chen Jia-Le , Wang Xin-Xin , Shi Li-Jie
Published: April 2021

Type-I heterostructure, in which electrons and holes are confined in same region, is widely used in light emitting diodes and semiconductor lasers. Type-II heterostructure is widely used in photovoltaic devices because of its excellent spatial separation property of electrons and holes. Can we integrate photovoltaic, photoelectric properties with luminescent property in one device? Here we report a van der Waals heterostructure formed by black phosphorus (BP) and SnS monolayers. It is expected to realize these functions in one device. By first-principles methods, the structural stability, electronic properties and optical properties are investigated. It was found that the BP/SnS bilayer is type-II heterostructure with an indirect bandgap of 0.56 eV. The p-like character of the band edge in BP/SnS vdW heterostructure makes it to be an excellent optoelectronic material. The type-II stability of the system can be improved by applying a negative electric field. However, when the positive electric field is bigger than 0.1 V Å−1, the system begins to transform from type-II to type I. Therefore, by adding a gate voltage the bandgap and band alignment of this system can be controlled. The photovoltaic and photoelectric properties can be integrated in one device based on this heterostructure.
Surface and interface analysis of a low-dimensional Au–Si surface alloy on Au(110) by means of XPS and XPD
Authors: Schmitz Marie , Kesper Lukas , Schulte Malte G H , Roese Peter , Berges Ulf , Westphal Carsten
Published: April 2021

The chemical and structural characteristics of a low-dimensional Au–Si surface alloy are presented in this work. Alloy formation was obtained by deposition of a sub-monolayer Si on Au(110). This preliminary phase to Si nano-ribbons is being investigated, as the transition from clean Au(110) to a silicon nano-ribbon coated surface is not yet understood. A multiple technique study has been carried out for detailed atomic structure determination and chemical investigation. Particular attention is paid to the clarification of the structural arrangement at the surface and at the interface. Using low-energy electron diffraction, the periodicity of the structure on long-range order could be examined. By means of high-precision photoemission measurements using synchrotron radiation, the electronic and atomic structure of the alloy can be presented. The investigation by photoelectron spectroscopy (XPS) using soft x-rays for a high surface sensitivity showed different chemical environments in the high-resolution spectra. The x-ray photoelectron diffraction (XPD) measurements, which are sensitive to the local atomic order, gave an approach to the structural configuration of the alloy. A new structural arrangement was found simulating both Au and Si XPD patterns. The results are compared to former proposed structure models. A deconvolution of the Si 2p XPD pattern revealed the origin of two chemically shifted XPS components.
Study of stability and rotation of a chain of saturated, freely-rotating magnetic islands in tokamaks
Authors: Casolari A , Ficker O , Grover O , Jaulmes F , Kripner L , Macusova E , Markovic T , Peterka M , Yanovskiy V ,   the COMPASS team
Published: April 2021

The non-linear dynamics of a chain of stationary, saturated magnetic islands is studied by solving a four-field system of equations that include non-ideal effects, lowest order finite Larmor radius corrections and neoclassical terms. The magnetic island rotation velocity is calculated self-consistently with the fields profiles. The solutions for the island rotation velocity and for the ion polarization current are determined as a function of the characteristic parameters of the system and the results are discussed. The results of the calculations show that island rotation velocity and the ion polarization current depend in a non-trivial way on the parameters characterizing the system, and some clear patterns emerge only in particular cases. An analysis of magnetic island rotation velocity is performed on experiments in COMPASS tokamak. Measured island rotation velocity is compared with the calculated ion and electron flow velocities, for different hypotheses on the toroidal rotation of the plasma. The comparison shows that the island rotation velocity is consistent with the ion flow velocity, under the hypothesis of slow toroidal rotation and low collisionality. Theoretical calculation of the island rotation velocity according to the model here developed suggests that the islands rotate weakly in the ion direction, in the hypothesis of slow toroidal rotation and high collisionality. The impossibility of directly measuring the plasma rotation velocity makes it difficult to distinguish between these different regimes.
Thermo-mechanical response of the twisted and coiled polymer actuator (TCPA): a finite element analysis (FEA)
Authors: Hunt Robert , Olsen Zakai , Kim Kwang
Published: April 2021

Twisted and coiled polymer actuators (TCPAs) are a recently discovered thermally driven artificial muscle, fabricated from a polymer fiber coiled into a helix. They produce axial contraction or torsion when heated above glass transition temperature and relaxes to their previous state when cooled back to their initial temperature. Studies have shown the actuator to produce enormous tensile strain (49%), power densities (27.12 kW kg−1), and specific work (2.48 kJ kg−1) [Haines (2014 Science
343 868–72)]. The remarkable capabilities of TCPAs have raised interest in the applications of smart materials, soft robotics, and artificial muscles. Recently, Yang et al investigated the physical phenomena of TCPA’s actuation through a top-down multiscale model, validated through experimental works [Yang and Li (2016 J. Mech. Phys. Solids
92 237–59)]. This paper extends Yang’s approach to a finite element analysis simulation for predicting the thermo-mechanical response of a TCPA, validated by experimental comparison. Currently, there are little to no studies done in the numerical simulation of TCPAs, which is an essential tool in all fields of engineering. A numerical simulation is imperative for increasing the model’s adaptability in real-life physical systems, where analytical solutions become too complex, and for predictive simulations for designing prototype robotic actuators. The equations developed by Yang et al are implement into a three-dimensional COMSOL Multiphysics model. The results of the numerical simulation displacement response show great accuracy when compared to the experimental data tested by a dynamic mechanical analyzer.
Anomalous isotope effect in BCS superconductors with two boson modes
Authors: Sun Gan , Lou Pan-Xiao , Lai Sheng-Qiang , Wang Da , Wang Qiang-Hua
Published: April 2021

The isotope effect in the superconducting transition temperature is anomalous if the isotope coefficient α < 0 or α > 1/2. In this work, we show that such anomalous behaviors can naturally arise within the Bardeen–Cooper–Schrieffer framework if both phonon and non-phonon modes coexist. Different from the case of the standard Eliashberg theory (with only phonon) in which α ⩽ 1/2, the isotope coefficient can now take arbitrary values in the simultaneous presence of phonon and the other non-phonon mode. In particular, most strikingly, a pair-breaking phonon can give rise to large isotope coefficient α > 1/2 if the unconventional superconductivity is mediated by the lower frequency non-phonon boson mode. Based on our studies, implications on several families of superconductors are discussed.
The Perfect Hyperfluid of Metric-Affine Gravity: the foundation
Authors: Iosifidis Damianos
Published: April 2021

We set the foundation and formulate the Perfect (Ideal) Hyperfluid. The latter represents the natural generalization of the usual perfect fluid structure where now the microscopic characteristics of matter (spin, shear, dilation) are also taken into account, sourcing a non-Riemannian arena (i.e spacetime torsion and non-metricity) for Metric-Affine Gravity. We derive the energy tensors of this Hyperfluid structure and subsequently present the conservation laws obeyed by them. Finally, we consider a Cosmological application of this Perfect Hyperfluid and classify some possible forms of this fluid structure.
Photoluminescence of green nanophosphors Sr2MgSi2O7 doped with Tb3+ under 374-nm excitation*
Authors: Mu Bo-Shi , Zhang Yi , Bian Qing-Feng , Li Cheng-Ren , Li Zhi-Chao , Chu Yun-Ting , Zhao Feng , Sun Jing-Chang
Published: April 2021

A series of Sr2MgSi2O7:Tb3+ nanophosphors is prepared using a high-temperature solid-state reaction. The x-ray diffraction patterns show that the crystal structure of the sample is not significantly affected by Tb3+ ions. However, the images of the scanning electron microscope illustrate that the average size of nanoparticles becomes larger with the increase of Tb3+ concentration. Unlike earlier investigations on down-conversion emission of Tb3+ ion excited by deep ultraviolet light, in this work, the photoluminescence characteristics of Sr2MgSi2O7 nanophosphors doped with different Tb3+ concentrations are analyzed under 374-nm excitations. The intense green emission at 545 nm is observed at an optimal doping concentration of 1.6 mol%. The main reason for the concentration quenching is due to the electric dipole–electric dipole interaction among Tb3+ ions.
Band alignment in SiC-based one-dimensional van derWaals homojunctions*
Authors: Tan Xing-Yi , Ding Lin-Jie , Ren Da-Hua
Published: April 2021

The density functional theory method is utilized to verify the electronic structures of SiC nanotubes (SiCNTs) and SiC nanoribbons (SiCNRs) one-dimensional (1D) van der Waals homojunctions (vdWh) under an applied axial strain and an external electric field. According to the calculated results, the SiCNTs/SiCNRs 1D vdWhs are direct semiconductors with a type-II band alignment and robust electronic structures with different diameters or widths. Furthermore, the SiCNTs/SiCNRs 1D vdWhs are direct semiconductors with a type-I band alignment, respectively, in a range of [–0.3, –0.1] V/Å and [0.1, 0.3] V/Å and change into metal when the electric field intensity is equal to or higher than 0.4 V/Å. Interestingly, the SiCNTs/SiCNRs 1D vdWhs have robust electronic structures under axial strain. These findings demonstrate theoretically that the SiCNTs/SiCNRs 1D vdWhs can be employed in nanoelectronics devices.
Atomistic simulations of the lubricative mechanism of a nano-alkane lubricating film between two layers of Cu–Zn alloy*
Authors: Li Jing , Zhu Peng , Sheng Yuan-Yuan , Liu Lin , Luo Yong
Published: April 2021

We describe simulations of lubrication by a hexadecane molecular lubricating film during the shearing process of a Cu-Zn alloy performed using the atomistic method. The results indicate that with increasing Zn contents, the interface slip between the alloy wall and the lubricating film first decreases and then increases, according to variations of the radius distribution function (RDF), while the interface slip reaches its lowest value of 0.12 during the shearing of CuZn30 alloy. We also discuss the relationship between interface roughness and the lubricating film. During film lubrication, the interface’s roughness effectively inhibits interfacial slip. For the convex contact model, the presence of the hexadecane lubricating film reduces the interfacial contact pressure from 11.9 GPa to 8.7 GPa and the friction coefficient from 0.81 to 0.52.
Pure spin-current diode based on interacting quantum dot tunneling junction*
Authors: Zhang Zhengzhong , Yu Min , Bo Rui , Wang Chao , Liu Hao
Published: April 2021

A magnetic field-controlled spin-current diode is theoretically proposed, which consists of a junction with an interacting quantum dot sandwiched between a pair of nonmagnetic electrodes. By applying a spin bias V
S across the junction, a pure spin current can be obtained in a certain gate voltage regime,regardless of whether the Coulomb repulsion energy exists. More interestingly, if we applied an external magnetic field on the quantum dot, we observed a clear asymmetry in the spectrum of spin current I
S as a function of spin bias, while the charge current always decays to zero in the Coulomb blockade regime. Such asymmetry in the current profile suggests a spin diode-like behavior with respect to the spin bias, while the net charge through the device is almost zero. Different from the traditional charge current diode, this design can change the polarity direction and rectifying ability by adjusting the external magnetic field, which is very convenient. This device scheme can be compatible with current technologies and has potential applications in spintronics or quantum processing.
Minimum structure of high-harmonic spectra from aligned O2 and N2 molecules*
Authors: Yan Bo , Wang Yi-Chen , Gao Qing-Hua , Cheng Fang-Jing , Jing Qiu-Shuang , Liang Hong-Jing , Ma Ri
Published: April 2021

We experimentally investigated the high-order harmonic generation (HHG) from aligned O2 and N2 molecules in a linearly polarized laser field, and presented the dependence of the harmonic spectrum on the driving laser intensity and molecular alignment angle. The minimum position of HHG of O2 varies with changing the laser intensity, which is caused by multi-orbital interference. However, the location of the observed minimum structure in N2 harmonic spectrum remained unchanged upon changing the laser intensity. The mechanism of the spectral minimum for N2 case is regarded as a Cooper-like minimum in HHG associated with the molecular electronic structure. This work indicates that harmonic spectroscopy can effectively uncover information about molecular structure and electron dynamics.
NBFTP: a dedicated data transfer system for remote astronomical observation at Dome A*
Authors: Huang Si-Yuan , Yu Ce , Sun Chao , Hu Yi , Shang Zhaohui , Ma Bin , Che Ming , Lu Xiao-Xiao
Published: April 2021

Dome A, Antarctica, has been thought to be one of the best astronomical sites on the Earth for decades. Since it was first visited by astronomers in 2008, dozens of facilities for astronomical observation and site testing were deployed. Due to its special geographical location, the data and message exchange between Dome A and the domestic control center could only depend on Iridium. Because the link bandwidth of Iridium is extremely limited, the network traffic cost is quite expensive and the network is rather unstable, the commonly used data transfer tools, such as rsync and scp, are not suitable in this case. In this paper, we design and implement a data transfer tool called NBFTP (narrow bandwidth file transfer protocol) for the astronomical observation of Dome A. NBFTP uses a uniform interface to arrange all types of data and matches specific transmission schemes for different data types according to rules. Break-point resuming and extensibility functions are also implemented. Our experimental results show that NBFTP consumes 60% less network traffic than rsync when detecting the data pending to be transferred. When transferring small files of 1KB, the network traffic consumption of NBFTP is 40% less than rsync. However, as the file size increases, the network traffic consumption of NBFTP tends to approach rsync, but it is still smaller than rsync.
Reflections and standing waves on the Tianlai cylinder array
Authors: Li Ji-Xia , Wu Feng-Quan , Sun Shi-Jie , Yu Zi-Jie , Zuo Shi-Fan , Liu Ying-Feng , Wang You-Gang , Zhang Cong , Ansari Reza , Timbie Peter , Chen Xuelei
Published: April 2021

In 21 cm intensity mapping, the spectral smoothness of the foreground is exploited to separate it from the much weaker 21 cm signal. However, the non-smooth frequency response of the instrument complicates this process. Reflections and standing waves generate modulations on the frequency response. Here we report the analysis of the standing waves in the bandpass of the signal channels of the Tianlai Cylinder Array. By Fourier transforming the bandpass into the delay time domain, we find various standing waves generated on the telescope. A standing wave with time delay at ∼142 ns is most clearly identified which is produced in the 15-meter feed cable. We also identify a strong peak at a shorter delay of τ < 50 ns, which may be a mix of the standing wave between the reflector and feed, and the standing wave on the 4 m intermediate frequency (IF) cable. We also show that a smoother frequency response could be partially recovered by removing the reflection-inducted modulations. However, the standing wave on the antenna is direction-dependent, which poses a more difficult challenge for high precision calibration.
Temporal variation of solar flare index during solar cycles 21 − 24
Authors: Roy Soumya , Prasad Amrita , Panja Subhash Chandra , Patra Sankar Narayan
Published: April 2021

The present investigation attempts to quantify the temporal variation of Solar Flare Index (SFI) with other activity indices during solar cycles 21 – 24 by using different techniques such as linear regression, correlation, cross-correlation with phase lag-lead, etc. Different Solar Activity Indices (SAI) considered in this present study are Sunspot Number (SSN), 10.7 cm Solar Radio Flux (F10.7), Coronal Index (CI) and MgII Core-to-Wing Ratio (MgII). The maximum cycle amplitude of SFI and considered SAI has a decreasing trend from solar cycle 22, and cycle 24 is the weakest solar cycle among all other cycles. The SFI with SSN, F10.7, CI and MgII shows hysteresis during all cycles except for solar cycle 22 where both paths for ascending and descending phases are intercepting each other, thereby representing a phase reversal. A positive hysteresis circulation exists between SFI and considered SAI during solar cycles 22 and 23, whereas a negative circulation exists in cycles 21 and 24. SFI has a high positive correlation with coefficient values of 0.92, 0.94, 0.84 and 0.81 for SSN, F10.7, CI and MgII respectively. According to cross-correlation analysis, SFI has a phase lag with considered SAI during an odd-number solar cycle (solar cycles 21 and 23) but no phase lag/lead during an even-numbered solar cycle (solar cycles 22 and 24). However, the entire smoothed monthly average SFI data indicate an in-phase relationship with SSN, F10.7 and MgII, and a one-month phase lag with CI. The presence of those above characteristics strongly confirms the outcomes of different research work with various solar indices and the highest correlation exists between SFI and SSN as well as F10.7 which establishes that SFI may be considered as one of the prime activity indices to interpret the characteristics of the Sun’s active region as well as for more accurate short-range or long-range forecasting of solar events.
Timing analysis of the black hole candidate EXO 1846–031 with Insight-HXMT monitoring
Authors: Liu He-Xin , Huang Yue , Xiao Guang-Cheng , Bu Qing-Cui , Qu Jin-Lu , Zhang Shu , Zhang Shuang-Nan , Jia Shu-Mei , Lu Fang-Jun , Ma Xiang , Tao Lian , Zhang Wei , Chen Li , Song Li-Ming , Li Ti-Pei , Xu Yu-Peng , Cao Xue-Lei , Chen Yong , Liu Cong-Zhan , Cai Ce , Chang Zhi , Chen Gang , Chen Tian-Xiang , Chen Yi-Bao , Chen Yu-Peng , Cui Wei , Cui Wei-Wei , Deng Jing-Kang , Dong Yong-Wei , Du Yuan-Yuan , Fu Min-Xue , Gao Guan-Hua , Gao He , Gao Min , Ge Ming-Yu , Gu Yu-Dong , Guan Ju , Guo Cheng-Cheng , Han Da-Wei , Huo Jia , Jiang Lu-Hua , Jiang Wei-Chun , Jin Jing , Jin Yong-Jie , Kong Ling-Da , Li Bing , Li Cheng-Kui , Li Gang , Li Mao-Shun , Li Wei , Li Xian , Li Xiao-Bo , Li Xu-Fang , Li Yang-Guo , Li Zheng-Wei , Liang Xiao-Hua , Liao Jing-Yuan , Liu Bai-Sheng , Liu Guo-Qing , Liu Hong-Wei , Liu Xiao-Jing , Liu Yi-Nong , Lu Bo , Lu Xue-Feng , Luo Qi , Luo Tao , Meng Bin , Nang Yi , Nie Jian-Yin , Ou Ge , Sai Na , Shang Ren-Cheng , Song Xin-Ying , Sun Liang , Tan Ying , Tuo You-Li , Wang Chen , Wang Guo-Feng , Wang Juan , Wang Ling-Jun , Wang Weng-Shuai , Wang Yu-Sa , Wen Xiang-Yang , Wu Bai-Yang , Wu Bo-Bing , Wu Mei , Xiao Shuo , Xiong Shao-Lin , Xu He , Yang Jia-Wei , Yang Sheng , Yang Yan-Ji , Yang Yi-Jung , Yi Qi-Bin , Yin Qian-Qing , You Yuan , Zhang Ai-Mei , Zhang Cheng-Mo , Zhang Fan , Zhang Hong-Mei , Zhang Juan , Zhang Tong , Zhang Wan-Chang , Zhang Wen-Zhao , Zhang Yi , Zhang Yi-Fei , Zhang Yong-Jie , Zhang Yuan-Hang , Zhang Yue , Zhang Zhao , Zhang Zhi , Zhang Zi-Liang , Zhao Hai-Sheng , Zhao Xiao-Fan , Zheng Shi-Jie , Zheng Yao-Guang , Zhou Deng-Ke , Zhou Jian-Feng , Zhu Yu-Xuan , Zhuang Ren-Lin , Zhu Yue
Published: April 2021

We present the observational results from a detailed timing analysis of the black hole candidate EXO 1846–031 during its outburst in 2019 with the observations of Insight-HXMT, NICER and MAXI. This outburst can be classified roughly into four different states. Type-C quasi-periodic oscillations (QPOs) observed by NICER (about 0.1–6 Hz) and Insight-HXMT (about 0.7–8 Hz) are also reported in this work. Meanwhile, we study various physical quantities related to QPO frequency. The QPO rms–frequency relationship in the energy band 1–10 keV indicates that there is a turning pointing in frequency around 2 Hz, which is similar to that of GRS 1915+105. A possible hypothesis for the relationship above may be related to the inclination of the source, which may require a high inclination to explain it. The relationships between QPO frequency and QPO rms, hardness, total fractional rms and count rate have also been found in other transient sources, which can indicate that the origin of type–C QPOs is non-thermal.
GRB 130310A: very high peak energy and thermal emission
Authors: Qin Song-Mei , Jiang Lu-Yao , Wang Xiang-Gao
Published: April 2021

The special GRB 130310A was observed by Fermi Gamma-Ray Burst Monitor and Large Area Telescope, with T
90∼ 2.4 s. With a combination of a Band function and a blackbody (BB) function, the time-resolved spectral analysis of GRB 130310A confirmed that there is a sub-dominate thermal component in the early period (e.g., slice T
0 + [4.03 – 4.14] s) spectrum with BB temperature (kT) being ∼7∼5 keV, which can be interpreted as photosphere emission. The precursor of GRB 130310A can be fitted well with a BB component with kT ∼ 45 keV, which is higher than that of the main burst. It suggests that the radiation of GRB 130310A is in transition from thermal to non-thermal. Such a transition is an indication of the change in jet composition from a fireball to a Poynting-flux-dominated jet. A very high peak energy is obtained in the first time bin, with the peak energy Ep
of the Band component for Band+BB and Band model being ∼8.5∼5.2 MeV and ∼11.1∼7.4 MeV, respectively. Afterwards, the Ep
drops to ∼ 1 MeV. The Ep
evolution patterns with respect to the pulses in the GRB 130310A light curves show a hard-to-soft evolution. The interpretation of the high peak energy Ep
within the photosphere and internal shock model is difficult. It also suggests that at least for some bursts, the Band component must invoke a non-thermal origin in the optically thin region of a GRB outflow. Assuming the redshift is z ∼ 0.1 ∼ 8, the radius of the jet base r
0 ∼ 109 cm to allow (1 + σ
15) > 1 in line with the calculation results of the magnetization parameter at ∼1015 cm (σ
15). However, the value of (1 + σ
15) is ≃ 1 in the zone z around 3 for r
0 ∼ 109 cm, suggesting the non-excluded possibility that the origin is from ICMART with a low value. The photosphere-internal shock seems capable of interpreting the high peak energy, which requires electron Lorentz factor γe
∼ 60 and εe
∼ 0.06.
PtSe2 phototransistors with negative photoconductivity
Authors: Di Bartolomeo A , Urban F , Faella E , Grillo A , Pelella A , Giubileo F , Askari M B , McEvoy N , Gity F , Hurley P K
Published: April 2021

Platinum diselenide (PtSe2) is one of the most studied materials of the emerging group-10 transition-metal dichalcogenides. We investigate the electrical conduction and the photoconduction of PtSe2 ultrathin films exploited as the channel of back-gated field-effect transistors. The channel resistance decreases with the rising temperature and shows that the films have semiconducting behaviour. The gate modulation confirms a p-type conductivity with field-effect mobility up to 30 cm2/(Vs). Under exposure to the radiation from a super-continuous white light source, a reduction of the PtSe2 electrical conductivity (negative photoconductivity) is observed in low vacuum, while a positive photoconductivity emerges only under high-power illumination conditions. Although, the positive photoconductivity arises from conventional photoconductive effect, the negative photoconductivity can be explained as the combination of the photogating effect caused by charge accumulation in the SiO2 dielectric and the photo-induced desorption of adsorbates.
Time-Frequency Bandpass Filter with Nonstationary Signal Decomposition Application
Authors: Yu Xiaoluo , Yang Yang , He Qingbo , Peng Zhike
Published: April 2021

In various applications such as speech processing, underwater sound, radar application and mechanical fault diagnosis, there are large number of nonstationary signals. In order to achieve nonstationary signal decomposition, the instantaneous frequency ridge is extracted through interactive mode, and a time-frequency bandpass filter (TFBPF) method is proposed. This method is the modified version of Intrinsic Chirp Component Decomposition (ICCD) and has the physical essence of time-frequency domain bandpass filter. The superiority and application potential of TFBPF in complex engineering signal decomposition are demonstrated through two numerical examples. In the first one, we prove that TFBPF can decompose the weak signal component directly through analyzing the vibration signal of hydraulic turbine; While in the second one, we prove that TFBPF can effectively overcome the drawbacks of ICCD through analyzing the vibration signal during the speed-up process of a complex equipment. TFBPF is still very effective even for complex signal decomposition in a strong noise environment.
Design and Implementation of Wireless Identification and Sensing Platform in Structure Monitoring
Authors: Qiu Xunchao , Yuan Jianqing , Hou Lijun , Gao Wei , Xi Wangyuan , Yan Wei
Published: April 2021

In the process of structure monitoring, active wireless sensor devices are often used. In order to replace the energy limitation bottleneck of the power supply unit, the Wireless Identification and Sensing Platform (WISP) with real-time data transmission function is adopted to realize the collection of structural vibration acceleration data. Firstly, the various functional modules of the WISP with three-axis acceleration are introduced. Then, through software programming of the low-power MSPF430F2132 microprocessor on it, the drive and control of the external three-axis acceleration sensor ADXL330 is realized. Finally, it was tested through comparative experiments. The research results show that the acceleration data monitored by the WISP is accurate, effective and reliable. Compared with the active wireless Narada unit, the similarity is more than 83%. Compared with the OpenSEES system, the accuracy of the structure frequency monitored by the WISP is 99.07%. Therefore, it is feasible and reliable to use the WISPs to perform multi-point deployment control in structural dynamic monitoring.
Anomaly Detection in Text Data Sets using Character-Level Representation
Authors: Mohaghegh Mahsa , Abdurakhmanov Amantay
Published: April 2021

This paper proposes a character-level representation of unsupervised text data sets for anomaly detection problems. An empirical examination of the character-level text representation was conducted to demonstrate the ability to separate outlying and normal records using an ensemble of multiple classic numerical anomaly classifiers. Experimental results obtained on two different data sets confirmed the applicability of the developed unsupervised model to detect outlying instances in various real-world scenarios, providing the opportunity to quickly assess a large amount of textual data in terms of information consistency and conformity without knowledge of the data content itself.
Big Data Technology of Precision Poverty Alleviation Tracking Audit System under the Internet
Authors: Wang Wei
Published: April 2021

As our country’s poverty alleviation has entered a decisive moment, it has become an urgent task to count the poor. Based on the Internet perspective, this article combs the basic theories and related overviews of the precision poverty alleviation policy, and on this basis, carries out the follow-up audit evaluation system construction; In order to improve the audit effect, this paper uses big data technology, case analysis method, literature analysis method and other methods to collect data from databases such as CNKI, Wanfang database, SSCI, etc., build a tracking audit system model, and pass The literature survey method reads and analyzes a large number of related literature. The study found that through the introduction of big data calculations, the tracking audit effect has been improved, the accuracy has increased by 30%, and the classification and tracking of the poor have been greatly improved. The index is above 0.8, an increase of about 40%. This shows that under the follow-up audit of precision poverty alleviation, big data technology can play an important role and greatly improve poverty alleviation work.
Single-scale Residual Dense Dehazing Network
Authors: Wang Nian , Li Aihua , Cui Zhigao , Su Yanzhao , Lan Yunwei
Published: April 2021

Recently, image dehazing algorithm has been widely used in the preprocessing of target tracking and pattern recognition. A large number of end-to-end convolutional networks have achieved good results in dehazing by image translation. In this paper, we use Residual Dense structure, which has been prove effective in high resolution reconstruction, to build feature extract block, and stack these block to form a single-scale dehazing network. In order to further enhance the performance, we convey the feature of shallow layer to deep layer by channel concatenation. The results show that our network has achieved good results in both the synthetic haze removal and the real haze removal.
Application of Big Data Processing Technology in Human Resource Management Information System
Authors: Zeng Jiayi
Published: April 2021

As an important part of the high-level management model, human resource management has attracted much attention in all fields. Human resource management faces a large number of data problems, and it is urgent to discover valuable knowledge and provide decision-making support for enterprises to develop talent training strategies. The purpose of this article is to analyze the application of big data processing technology in human resource management information system. This paper proposes a literature research method, a case research method and a comparative research method to conduct a comprehensive analysis of the human resource management information system of a company. In addition, this paper takes the human resource data of a company as an example, through a large amount of data preprocessing work, design a human resource data mining system based on association rules is implemented, which realizes the application of incremental association rule mining algorithm to human resource data mining, realizes visualization, and finally mines valuable information. The experimental results of this paper show that the number of users of the client and server in the human resource management information system is less than 100, and the performance of the system can fully meet the needs of actual work in actual use.
Sustainable Development of Leisure Tourism Agriculture in Guangzhou Based on Data Hierarchical Modeling
Authors: Wang Ning , Zhou Jinyu , Liu Liming
Published: April 2021

Hierarchical modeling breaks down the problem of multiple input and multiple output modeling into a series of single input multiple output data modeling problems. This method can improve the efficiency and accuracy of multi-input multi-output system modeling. The model is suitable for describing a system with a complex structure and can contain more input variables, which is conducive to making full use of the existing system information. The problem of data modeling is to get this kind of mapping relationship. Usually a set of basic functions is selected for linear combination, an expression of F with a parameter is given, and then the coefficient of the parameter is determined by least square method or other methods. Urban agriculture was proposed in the process of industrialization and urbanization, with the rapid development of the urban economy, the increasingly severe environmental problems, and the deepening of the idea of sustainable development. Urban agriculture tourism is developed based on urban agriculture by developing various functions of urban agriculture. It makes the development of urban tourism more plentiful and novel, and further expands the space for agricultural development. Therefore, to find the efficient way, this paper proposes the pattern of the sustainable development of leisure tourism agriculture in Guangzhou based on data hierarchical modeling. Numerical analysis and the sample overview are provided to test he performance of the proposed methodology.
Implementation of Simulation Control Automation Tool Based on Android Accessibility Service
Authors: Xie Nan , Ni Yiran , Liu Xiaoxiao , Cao Yu , Chen Weimin
Published: April 2021

With the development of Internet plus era and the increasing popularity of mobile phone in China, people still use the traditional finger touch mode. However, in the face of some application scenarios with high repetition frequency, an automatic control method can be built to reduce repetitive operation of users. This paper introduces how to solve the problem of automatic control process for Android operating system, and provides a complete solution for the design and construction of automation tools. Starting from the wake-up of the device, the system automatically unlocks, and then uses intent to transfer parameters to start the target application and specify the activity. After entering the specified application interface, the tool will scan the XML information of the interface layout drawn by the system, and accurately capture the view control through the regular matching of attribute values and other information of the control. Finally, the control object can be operated by simulating events, so as to achieve the same effect as the user operation. In addition, the automatic control tool obtains the control information accurately through OCR identification, and realizes the multithreading cycle operation through the delay start function, which improves the operation efficiency of the tool automation degree and the user operation efficiency of the smart phone.
Virtual Tourism Simulation System Based on VR Technology
Authors: Hou Tingfei
Published: April 2021

With the development of tourism, the number of tourists in China has reached 6.7 billion every year. In order to alleviate the problem that the number of tourists in domestic popular scenic spots is too large to bear the burden, 3dsmax modeling software is used to realize 3D terrain and building wood construction, and unity3d platform is used to integrate to get 3D virtual scene. At the same time, the virtual tourism simulation system based on VR technology is realized by using VR hardware equipment in this paper, through the simulation of a park scene, the participants are investigated by questionnaire, and the function of the system is tested. The simulation system can meet the needs of tourism and provide a good direction for the future development of tourism.
Research on Optimization Methods of Public Grassroots Governance Based on Big Data Analysis
Authors: Cui Dandan
Published: April 2021

With the continuous progress of the society and the continuous improvement of the people’s level, the social mechanism is gradually sound, people also put forward higher requirements for public grass-roots governance. The development of science and technology, especially the emergence of artificial intelligence, provides convenient conditions for the expansion of the field of big data(BD), and BD analysis is gradually applied to various fields. At present, public grass-roots governance is faced with many difficulties due to its wide scope and complex content. Using BD for analysis provides more convenient conditions for promoting the optimization of public grass-roots governance methods. In recent years, the BD analysis and basic research deepening and expanding public governance scheme, we can conclude the traditional grassroots governance is to stay on the surface, there is no grass-roots level, the optimization study is based on analysis of large data base, only combined with digital information, through data analysis to improve work efficiency and better achieve better control effect. By studying the public grassroots governance based on BD analysis, this paper analyzes the existing problems of public grassroots governance under the background of BD, proposes solutions according to the existing problems, and continuously realizes the optimization of public grassroots governance methods.
Neural network model based on travel planning for travel time prediction
Authors: Xu Weixiang , Rong Weiyao
Published: April 2021

The development of smart cities presents new challenge to more convenient and intelligent transportation, while the advent of big data era promotes the sharing of travel data, which provides powerful data support for the development of smart travel. As an important part of smart travel, accurate travel time prediction is definitely crucial. Different from traditional passive forecasting methods which is only based on historical data, this paper proposes a Conv-LSTM network model based on travel planning data for travel time prediction from the perspective of user travel. This model can actively predict the upcoming traffic state according to the upcoming data generated by the user’s travel planning information released before travel. Specifically, we first introduce the definition of travel plan and how to calculate the future planned flow according to travel planning information. Then, the future planned data and the corresponding segment historical data are introduced into the designed Conv-LSTM model to extract spatial-temporal features and then realize the prediction of road travel time. In this study, specific travel path is taken as the research object. Extensive experimental results demonstrate that this method has high accuracy, and remarkably outperforms benchmark methods in various metrics.
Overview of Image Smoothing Algorithms
Authors: Li Pei , Wang Hongjuan , Yu Mengbei , Li Yeli
Published: April 2021

In the process of image generation and transmission, it is easy to be polluted and affected by various kinds of noise, which reduces the quality of the image. In order to avoid the adverse effects of image processing and image visual effect, we can use image smoothing technology to improve the adverse effects, so as to make the image clearer. There are a variety of image smoothing techniques, which had great smoothing effect, but there are also different defects. Based on the analysis of different noise models, this paper uses mean smoothing, median smoothing, Gaussian smoothing, bilateral filtering and other techniques to study and analyse the image processing algorithm, the implementation method and efficiency, which provides efficient theoretical value for image processing and image visual effect in various fields involved in image processing.
Study of Gender-based Playing Style Stereotype in Overwatch using Machine Learning Analysis
Authors: Zhou Ralph Jinghao , Gao Yumeng , Han Qian
Published: April 2021

Since its release in 2016, Overwatch has become a game with a high amount of daily users (over 50 million users Worldwide) and made a great amount of profit for the company that produced it — Blizzard. However, it is common that the stereotypes and biases hide under the popularity of the games. In past researches, it is shown that gender could affect the designs, abilities, and player’s view of in-game characters. In this research, a survey regarding gender stereotypes in Overwatch is conducted, and statistical and machine learning methods are applied to analyze the results. The result suggests that many of the players in the game had given biased or stereotypical actions or thoughts toward female players. Simultaneously, we propose an Ensemble Late Fusion (ELF) method that unifies the weighted predicted probabilities generated from various state-of-art classifiers to classify the player behaviors with or without gender-based stereotypes in Overwatch. The experimental results show that when using ELF, the optimal classification result reaches AUC to 0.9044, which beats several well-known traditional machine learning and deep learning classifiers. Moreover, the connection between certain biased ideas and rather a user in sexist is graphed and discussed in the paper.
Research on the Application of Computer Technology in Music Creation
Authors: Liu Chuanli , Wei Lizhi , Chen Libin
Published: April 2021

Along with the development of science and technology, computer technology is not only widely used in manufacturing, IT, construction, e-commerce and other industries, but also rapidly popularized in the creation and dissemination of music. The introduction of computer technology makes music more possible in writing, polyphony, harmony and secondary creation. In a sense, computer technology can not only enrich the means and forms of music creation, but also be an essential factor in the production and development of modern music. In view of this, this paper analyzes the advantages of computer technology in music creation, and systematically explains the specific application of this technology in music writing, harmony practice, orchestration and so on.