bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fabrication of high-performance carbon nanotube/copper composite fibers by interface thiol-modification
Authors: Guo Lei , Li Huifang , Liu Dandan , Zhou Yurong , Dong Lizhong , Zhu Siqi , Wu Yulong , Yong Zhenzhong , Kang Lixing , Jin Hehua , Li Qingwen 
Published: April 2022

Abstract
Carbon nanotube (CNT)/copper (Cu) composite fibers are placed great expectations as the next generation of light-weight, conductive wires. However, the electrical and mechanical performances still need to be enhanced. Herein, we demonstrate a strategy that is electrodeposition Cu on thiolated CNT fibers to solve the grand challenge which is enhancing the performance of CNT/Cu composite fibers. Thiol groups are introduced to the surface of the CNT fibers through a controllable O2 plasma carboxylation process and amide reaction. Compared with CNT/Cu composite fibers, there are 82.7% and 29.6% improvements in electrical conductivity and tensile strength of interface thiol-modification composite fibers. The enhancement mechanism is also explored that thiolated CNT fibers could make strong interactions between Cu and CNT, enhancing the electrical and mechanical performance of CNT/Cu composites. This work proposes a convenient, heat-treatment-free strategy for high-performance CNT/Cu composite fibers, which can be manufactured for large-scale production and applied to next-generation conductive wires.
End-to-end deep learning for interior tomography with low-dose x-ray CT
Authors: Han Yoseob , Wu Dufan , Kim Kyungsang , Li Quanzheng 
Published: April 2022

Abstract

Objective. There are several x-ray computed tomography (CT) scanning strategies used to reduce radiation dose, such as (1) sparse-view CT, (2) low-dose CT and (3) region-of-interest (ROI) CT (called interior tomography). To further reduce the dose, sparse-view and/or low-dose CT settings can be applied together with interior tomography. Interior tomography has various advantages in terms of reducing the number of detectors and decreasing the x-ray radiation dose. However, a large patient or a small field-of-view (FOV) detector can cause truncated projections, and then the reconstructed images suffer from severe cupping artifacts. In addition, although low-dose CT can reduce the radiation exposure dose, analytic reconstruction algorithms produce image noise. Recently, many researchers have utilized image-domain deep learning (DL) approaches to remove each artifact and demonstrated impressive performances, and the theory of deep convolutional framelets supports the reason for the performance improvement. Approach. In this paper, we found that it is difficult to solve coupled artifacts using an image-domain convolutional neural network (CNN) based on deep convolutional framelets. Significance. To address the coupled problem, we decouple it into two sub-problems: (i) image-domain noise reduction inside the truncated projection to solve low-dose CT problem and (ii) extrapolation of the projection outside the truncated projection to solve the ROI CT problem. The decoupled sub-problems are solved directly with a novel proposed end-to-end learning method using dual-domain CNNs. Main results. We demonstrate that the proposed method outperforms the conventional image-domain DL methods, and a projection-domain CNN shows better performance than the image-domain CNNs commonly used by many researchers.
Photoinduced transient states of antiferromagnetic orderings in La1/3Sr2/3FeO3 and SrFeO3−δ
thin films observed through time-resolved resonant soft x-ray scattering
Authors: Yamamoto Kohei , Tsuyama Tomoyuki , Ito Suguru , Takubo Kou , Matsuda Iwao , Pontius Niko , Schüßler-Langeheine Christian , Minohara Makoto , Kumigashira Hiroshi , Yamasaki Yuichi , Nakao Hironori , Murakami Youichi , Katase Takayoshi , Kamiya Toshio , Wadati Hiroki 
Published: April 2022

Abstract
The relationship between the magnetic interaction and photoinduced dynamics in antiferromagnetic perovskites is investigated in this study. In La1/3Sr2/3FeO3 thin films, commensurate spin ordering is accompanied by charge disproportionation, whereas SrFeO3−δ
thin films show incommensurate helical antiferromagnetic spin ordering due to increased ferromagnetic coupling compared to La1/3Sr2/3FeO3. To understand the photoinduced spin dynamics in these materials, we investigate the spin ordering through time-resolved resonant soft x-ray scattering. In La1/3Sr2/3FeO3, ultrafast quenching of the magnetic ordering within 130 fs through a nonthermal process is observed, triggered by charge transfer between the Fe atoms. We compare this to the photoinduced dynamics of the helical magnetic ordering of SrFeO3−δ
. We find that the change in the magnetic coupling through optically induced charge transfer can offer an even more efficient channel for spin-order manipulation.
Evolution of surface morphology and helium bubble in tungsten under 40 keV helium ions implantation followed by deuterium plasma exposure
Authors: Xia Tongjun , Wang Zizhao , Jiang Zhenyu , Shi Yongzhi , Wu Jianwei , Ren Xinyu , Zhu Kaigui 
Published: April 2022

Abstract
Surface morphology and internal microstructure of tungsten (W) pre-implanted by 40 keV mass-separated helium (He) ions with different fluences at room temperature were investigated in this work. The morphology changes of the samples were analyzed almost in situ, by repetitively examined the specified irradiation area which is marked by focused ion beam technology. As the samples were implanted by He ion with a fluence of 6 × 1020 He m−2, no He blisters or other microstructures could be found on the surface. When the fluence reaches 6 × 1021 He m−2, a large number of He blisters with the size of ∼1 μm were observed on the W specimens. For the results of the subsequent deuterium plasma exposure, instead of deuterium-induced blistering, no changes on the W surface which pre-irradiated by He ion irradiation at low fluence (6 × 1020 He m−2). Surprisingly, for He ions pre-implanted W with high fluence (6 × 1021 He m−2), almost all the He blisters were cracked and their lids even peeled off. It could be attributed to the lateral stress caused by subsequent D exposure. Moreover, the size of He bubbles was also increased under subsequent deuterium exposure, suggesting that He atoms can attract D atoms. No deuterium blisters were found on these samples which were pre-implanted with high and low fluences, suggesting that He ion pre implantation can effectively inhibit the surface blistering caused by deuterium exposure.
Image lossless encoding and encryption method of SPECK based on 1D chaotic map
Authors: Xiao Yantong , Tong Xiaojun , Zhang Miao , Wang Zhu 
Published: April 2022

Abstract
In order to satisfy the requirements of high quality and security during image transmission and storage, this paper proposes an image lossless compression encryption algorithm based on 1D chaotic map and Set Partitioned Embedded block encoder (SPECK). Initially, this paper proposes a new 1D chaotic map, and applies the chaotic sequences generated by it to each stage of the compression encryption algorithm. In addition, according to the feature that the degree of energy concentration in the wavelet coefficient matrix gradually decreases from low frequency to high frequency, this paper proposes a wavelet coefficient encryption algorithm, which can balance security and compression performance. Furthermore, multiple encryption points are introduced in the SPECK encoding process, and a secure SPECK encoding algorithm is proposed. Finally, theoretical analysis and simulation results show that the proposed algorithm is close to the theoretical value in terms of information entropy, correlation coefficient, mean square error of reconstructed image and other related indicators. Therefore, the algorithm has high security and lossless compression performance.
Pt/SeO2 optical receivers designed for terahertz and 5G/6G technologies
Authors: Alfhaid Latifah Hamad Khalid , Qasrawi A F 
Published: April 2022

Abstract
Selenium oxide thin films are highly transparent optical layers proper for optoelectronic technology. However, SeO2 films are rarely studied and observed suffering from clustery surface morphology, low light absorbability and low dielectric constant. For this reason herein, in an attempt to enhance its properties, platinum nanosheets (10–50 nm) are used as plasmonic substrates to grow transparent selenium oxide thin films. The films are deposited onto glass and Pt substrates using thermal evaporation technique under a vacuum pressure of 10−5 mbar. Both films of the glass/SeO2 and Pt/SeO2 are characterized by the techniques of x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, optical spectrophotometry and impedance spectroscopy. While no significant effect of Pt nanosheets on the amorphous nature of structure of SeO2 is observed, remarkable enhancements in the light absorbability by 50 times and in dielectric constant by three times are achieved. In addition, Pt nanosheets form plasmonic interfaces resulting in improving the plasmon frequency, drift mobility and free carrier density of the films. Pt/SeO2 films showed plasmon frequency larger than 6.0 GHz and free carrier density of 1018 cm−3. Moreover, analysis of the terahertz cutoff frequency and impedance spectra have shown that the Pt/SeO2 interfaces can also be employed as terahertz receivers and as low pass filters suitable for 5G/6G technologies.
Homodyne detection in quantum optics: deterministic extractors and quantum random number generators on ‘vacuum fluctuations’
Authors: Molotkov S N 
Published: April 2022

Abstract
Quantum random number generators with a continuous variable are considered based on a primary randomness of the outcomes of homodyne measurements of a coherent state. A deterministic method of extraction of truly random 0 and 1 from the primary sequence of measurements of the quadrature of the field in homodyne detection is considered. The method, in the case of independence of successive measurement outcomes, in the asymptotic limit of long sequences, allows us to extract with a polynomial complexity all the true randomness contained in the primary sequence. The method does not require knowledge of the probability distribution function of the primary random sequence, and also does not require additional randomness in the extraction of random 0 and 1. The approach with deterministic randomness extractors, unlike other methods, contains fewer assumptions and conditions that need to be satisfied in the experimental implementation of such generators, and is significantly more effective and simple in experimental implementation. The fundamental limitations dictated by nature for achieving statistical independence of successive measurement outcomes are also considered. The statistical independence of the measurement outcomes is the equivalent of true randomness, in the sense that is possible in the case of the independence of the measurement outcomes, provably, with deterministic extractor, to extract a ‘truly random sequence of 0 and 1’. It is shown that in the asymptotic limit it is possible to extract all the true randomness contained in the outcomes of physical measurements.
Variable viscosity effects on the flow of MHD hybrid nanofluid containing dust particles over a needle with Hall current—a Xue model exploration
Authors: Ramzan Muhammad , Alotaibi Hammad 
Published: April 2022

Abstract
This study scrutinizes the flow of engine oil-based suspended carbon nanotubes magneto-hydrodynamics (MHD) hybrid nanofluid with dust particles over a thin moving needle following the Xue model. The analysis also incorporates the effects of variable viscosity with Hall current. For heat transfer analysis, the effects of the Cattaneo–Christov theory and heat generation/absorption with thermal slip are integrated into the temperature equation. The Tiwari–Das nanofluid model is used to develop the envisioned mathematical model. Using similarity transformation, the governing equations for the flow are translated into ordinary differential equations. The bvp4c method based on Runge–Kutta is used, along with a shooting approach. Graphs are used to examine and depict the consequences of significant parameters on involved profiles. The results revealed that the temperature of the fluid and boundary layer thickness is diminished as the solid volume fraction is raised. Also, with an enhancement in the variable viscosity parameter, the velocity distribution becomes more pronounced. The results are substantiated by assessing them with an available study.
Coherent control of spin tunneling in a driven spin–orbit coupled bosonic triple well
Authors: Luo Yuxin , Yi Jia , Li Wenjuan , Xie Xin , Luo Yunrong , Hai Wenhua 
Published: April 2022

Abstract
We investigate the coherent control of spin tunneling for a spin–orbit (SO) coupled boson trapped in a driven triple well. In the high-frequency limit, the quasienergies of the system are obtained analytically and the fine energy band structures are shown. By regulating the driving parameters, we reveal that the directed spin-flipping or spin-conserving tunneling of an SO-coupled boson occurs along different pathways and in different directions. The analytical results are demonstrated by numerical simulations and good agreements are found. Further, an interesting scheme of quantum spin tunneling switch with or without spin-flipping is presented. The results may have potential applications in the design of spintronic devices.
Optical bistability in a negative refractive index media using the electron tunneling effect
Authors: Sahandi Rima , Darkhosh Ahad 
Published: April 2022

Abstract
In this letter, we proposed a brand-new version for investigating the optical bistability (OB) and optical multistability (OM) through electron tunneling impact in a defect one-dimensional photonic crystal (1DPC). The defect layer of 1DPC is doped with double quantum dot (DQD) nanostructure which interacts with an indirect incoherent pump and a susceptible probe incident light, respectively. By the usage of the quantum mechanical density matrix method, we first examine the refractive index properties of the defect layer through electron tunneling and indirect incoherent pumping effects. Then, through the usage of the transfer matrix methods, we acquire the reflection and transmission coefficients of the defect 1DPC. At the end, we discuss the OB and OM properties of the reflected and transmitted lighting in negative refractive index situation of the DQD. We determine that during a few parametric conditions the switching from OB to OM or vice versa is feasible for reflected and transmitted light beams.
Generation of entangled states of light using discrete solitons in waveguide arrays
Authors: Martynov V O , Munyaev V O , Smirnov L A 
Published: April 2022

Abstract
We study the quantum properties of light propagating through an array of coupled nonlinear waveguides and forming a discrete soliton. We demonstrate that it is possible to use certain types of quasi-solitons to form continuous variables entanglement between the certain pair of waveguides. Moreover, there is a possibility to entangle several pairs of waveguides independently. We show that the entanglement is generated for arbitrary high intensity of the input laser field, so it does not require a special material with an extremely high nonlinearity coefficient. Also, absorption in the waveguide media does not influence the discussed process too much.
Spatial transfer of entangled states in the correlated quantum dots system
Authors: Maslova N S , Mantsevich V N , Arseyev P I , Sokolov I M 
Published: April 2022

Abstract
We propose a protocol for spatial ‘stretching’ of an initially prepared entangled state along chains of quantum dots (QDs) or quantum wires arranged in perpendicular directions. We theoretically analyze such stretching for a triplet superposition of symmetric and antisymmetric single-electron states with opposite spins formed in a diamond-like arrangement of four QDs. Under specific choice of parameters of the system, the probability amplitude to find the system in an entangled state localized at the end dots of the chains can reach unity at particular instants of time.
The myokinetic stimulation interface: activation of proprioceptive neural responses with remotely actuated magnets implanted in rodent forelimb muscle
Authors: Montero J , Thumser Z C , Masiero F , Beckler D T , Clemente F , Marasco P D , Cipriani C 
Published: April 2022

Abstract

Objective. Proprioception is the sense of one’s position, orientation, and movement in space, and it is of fundamental importance for motor control. When proprioception is impaired or absent, motor execution becomes error-prone, leading to poorly coordinated movements. The kinaesthetic illusion, which creates perceptions of limb movement in humans through non-invasively applying vibrations to muscles or tendons, provides an avenue for studying and restoring the sense of joint movement (kinaesthesia). This technique, however, leaves ambiguity between proprioceptive percepts that arise from muscles versus those that arise from skin receptors. Here we propose the concept of a stimulation system to activate kinaesthesia through the untethered application of localized vibration through implanted magnets. Approach. In this proof-of-concept study, we use two simplified one-DoF systems to show the feasibility of eliciting muscle-sensory responses in an animal model across multiple frequencies, including those that activate the kinaesthetic illusion (70–115 Hz). Furthermore, we generalized the concept by developing a five-DoF prototype system capable of generating directional, frequency-selective vibrations with desired displacement profiles. Main results. In-vivo tests with the one-DoF systems demonstrated the feasibility to elicit muscle sensory neural responses in the median nerve of an animal model. Instead, in-vitro tests with the five-DoF prototype demonstrated high accuracy in producing directional and frequency selective vibrations along different magnet axes. Significance. These results provide evidence for a new technique that interacts with the native neuro-muscular anatomy to study proprioception and eventually pave the way towards the development of advanced limb prostheses or assistive devices for the sensory impaired.
Study on the growth and redistribution of deuterium–deuterium layer driven by temperature gradient
Authors: Tao Chaoyou , Wu Kewei , Dai Fei , He Zhibing , Yang Hong , Lin Wei , Wang Kai , Zhang Hui 
Published: April 2022

Abstract
We report results of crystal growth, layering of the deuterium–deuterium (D2) layers in cylindrical cryogenic targets. For the first time, we realized the global coverage of the D2 layer on the inner surface of the capsule through the crystal growth of D2 ice, and the control of the temperature field without the infrared radiation, foam lining, and magnetic field. Analysis of the image of x-ray phase contrast imaging shows that the thickness of the D2 layer is about 36.53 μm, and the inner surface roughness is 3.23 μm. The finite element method is applied to simulate the temperature field of the target, and the phase transition process of D2, revealing the mechanism of D2 covering the inner surface of the capsule. These initial experiments provide a new vision and method for exploring and achieving the pure crystal growth as well as layering of D2 without operation of radioactive tritium.
Stress analysis of key components of finger rehabilitation exoskeleton robot based on finite element method
Authors: Zhang Qiuyue , Lu Guangda , Chen Ying , Guo Tinghang , Han Yu , Qie Tongtong 
Published: April 2022

Abstract
This paper analyzes the flexion and extension of three joints of a single exoskeleton mechanical finger. According to the motion characteristics of the finger, a finger rehabilitation exoskeleton robot is designed to assist patients with hand function for rehabilitation training. The three-dimensional model was established by SolidWorks, and the initial state of the robot was set under the action of gravity. The finite element analysis method was used to analyze the stress of the key components, including calculate and analyze its stress and strain. The simulation showed that the maximum stress of key components in rehabilitation training was 2140 (Pa), which is far less than the yield strength of the material 60 (MPa), and the maximum deformation was 0.092 (mm). The simulation result revealed that our design did not lead to failure of mechanical structure, which would provide a certain reference basis for its structural optimization design.
An IPSO-SA algorithm based on feedback mechanism for smooth path planning of UAV
Authors: Xu Haiqin , Yu Xujian , Dong Jie , Li Ranfei 
Published: April 2022

Abstract
The traditional PSO algorithm has been widely used in the path planning of unmanned equipment, but its algorithm is faced with the problem of premature convergence, which is easy to fall into the local optimal solution. When the initial position is not suitable, it can’t even plan the path in complex environment. At the same time, its line trajectory does not meet the requirements of the path curvature of realistic unmanned equipment. To solve the above problems, this paper proposes a new path planning strategy for unmanned equipment, and designs a new path planning algorithm for unmanned aircraft by combining the improved particle swarm optimization (IPSO) algorithm with simulated annealing algorithm (SA). At the same time, it solves the two problems that PSO algorithm is easy to fall into local optimal solution and abandoning all possible feasible solution regions in the early stage because of an illegal path. The path planned by IPSO-SA algorithm is processed by cubic spline interpolation to solve the curvature problem of its motion path. In addition, in view of the problem that the initial point is not suitable in complex environment, this algorithm designs a feedback mechanism to correct the initial point in time. The effectiveness of the algorithm is verified by theoretical derivation and simulation experiments, that is, the algorithm only needs a small number of point sequences to plan the path of UAV in simple and complex environment, and has less search amount and space-time overhead.
Wireless communication system throughput maximization based on UAV path planning
Authors: Guo Jing , Yang Shuai , Lu Dongkun , Zhang Caixia 
Published: April 2022

Abstract
This paper studies the path planning of unmanned aerial vehicle (UAV) in wireless information and energy transmission system of wireless sensor network. UAV transmits radio frequency energy to enable ground sensors, and the ground sensors transmit information to the UAV. In order to solve the non-convex optimization problem in path planning, a new alternate optimization framework is proposed to optimize the fly trajectory of the UAV and maximize the throughput of the entire system. The proposed framework firstly utlizes the lagrangian method to obtain relaxation solution without maximum speed constraint, then implements genetic algorithm and continuous convex optimization algorithm to obtain optimal trajectory and energy allocation strategy. Numerical simulations results show that the UAV-assisted wireless information and energy transmission system can realize self-powered sensor network and data collection in special environments, and improve the throughput of the sensor network system.