bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uncovering the physical properties, structural characteristics, and electronic application of superlattice-like Ti/Sb phase-change thin films
Authors: Huang Yufeng , Wu Weihua , Xu Shengqing , Zhu Xiaoqin , Shen Bo , Zhai Jiwei , Yue Zhenxing , Song Sannian , Song Zhitang 
Published: February 2022

Abstract
Superlattice-like (SLL) Ti/Sb thin films were proposed and investigated from the viewpoint of physical properties, structural characteristics, and electronic application. Magnetron sputtering was employed to deposit the SLL Ti/Sb thin films with different thickness ratios. In-situ resistance–temperature measurement indicates that the crystallization temperature, crystallization-activation energy, and data-retention capacity increase significantly and the resistance drift index reduces with an increment in thickness ratio of the Ti to Sb layer, meaning higher amorphous thermal stability and reliability of SLL Ti/Sb thin films. X-ray diffraction and Raman spectra reveal that the inserted Ti layer can inhibit grain growth and refine the grain size, causing remarkable improvement of thermal stability and crystalline resistance. Analyses of x-ray reflectivity and atomic force microscopy demonstrate that the thickness fluctuation of SLL Ti/Sb thin films becomes smaller and the surface topography becomes smoother, respectively. The Avrami exponent of the SLL (Ti3Sb7)5 thin film reflects the growth-dominated crystallization mechanism, implying a rapid phase transition speed. Phase-change memory cells based on the SLL (Ti3Sb7)5 thin film can realize a reversible SET/RESET operation under an electrical pulse with a width of 100 ns. The RESET power consumption was estimated to be much lower than that of traditional Ge2Sb2Te5 material. The above results strongly prove that the suitable SLL structure of Ti/Sb thin films have tremendous potential in the area of high-temperature and low-power electronic storage.
Emergence of Floquet edge states in the coupled Su–Schrieffer–Heeger model
Authors: Borja Carla , Gutiérrez Esther , López Alexander 
Published: February 2022

Abstract
The emergence of non equilibrium topological phases in low dimensional systems offers an interesting route for material properties engineering. We analyze the dynamical modulation of two coupled one-dimensional chains, described by the Su–Schrieffer–Heeger model. We find that the interplay of driving interactions and interchain coupling leads to the emergence of non-equilibrium edge states with nontrivial topological properties. Using an effective Hamiltonian approach, we quantify the emergent topological phases via the winding number and show that oscillations in the mean pseudospin polarization arise as a consequence of the periodic modulation. The patterns of these pseudospin oscillations are different for the static trivial and topological phases offering a dynamical means to distinguish both physical configurations. The system also exhibits non integer values of the winding number, which have been recently reported experimentally in connection to spin textures.
From spherical to periodic symmetry: the analog of orbital angular momentum for semiconductor crystals
Authors: Combescot Monique , Shiau Shiue-Yuan 
Published: February 2022

Abstract
The angular momentum formalism provides a powerful way to classify atomic states. Yet, requiring a spherical symmetry from the very first line, this formalism cannot be used for periodic systems, even though cubic semiconductor states are commonly classified according to atomic notations. Although never noted, it is possible to define the analog of the orbital angular momentum, by only using the potential felt by the electrons. The spin–orbit interaction for crystals then takes the

L
^

⋅

S
^

form, with

L
^

reducing to

L
^

=

r
^

×

p
^

for spherical symmetry. This provides the long-missed support for using the eigenvalues of

L
^

and

J
^

=

L
^

+

S
^

, as quantum indices to label cubic semiconductor states. Importantly, these quantum indices also control the phase factor that relates valence electron to hole operators, in the same way as particle to antiparticle, in spite of the fact that the hole is definitely not the valence-electron antiparticle. Being associated with a broader definition, the

(

L
^

,

J
^

)

analogs of the

(

L

^

,

J

^

)

angular momenta, must be distinguished by names: we suggest ‘spatial momentum’ for

L
^

that acts in the real space, and ‘hybrid momentum’ for

J
^

that also acts on spin, the potential symmetry being specified as ‘cubic spatial momentum’. This would cast

J

^

as a ‘spherical hybrid momentum’, a bit awkward for the concept is novel.
Short-time consistent domain adaptation for rolling bearing fault diagnosis under varying working conditions
Authors: Zhang Qiyang , Zhao Zhibin , Zhang Xingwu , Liu Yilong , Yu Xiaolei , Chen Xuefeng 
Published: February 2022

Abstract
Although traditional deep learning improves the accuracy of intelligent fault diagnosis, it suffers from a problem, which is that a change in working conditions may reduce the diagnostic accuracy. The reason for this phenomenon is that a change of working conditions influences the probability distributions. To solve this problem, domain adaptation is adopted to perform intelligent fault diagnosis. However, the design of regularization methods, such as maximum mean discrepancy (MMD), neglects the phenomenon of fault extension. Considering the property of fault extension, the paper sums up a concept named short-time consistency which means that ‘during stable operation, a failure does not expand over a short time period.’ Moreover, short-time consistent regularization is proposed to ensure that the output of the model meets the requirement for short-time consistency, and closed-set regularization is proposed to further solve the problem of ‘types of label drop’ when short-time consistent regularization is used. When the problem occurs, the number of predicted label types in the target domain is smaller than that in the source domain in the closed-set domain adaptation. Two types of regularization, namely entropy-based regularization and regularization based on the

L
2

norm, are easily adopted in the final loss function. The proposed method is verified by experiments.
The irradiance instrument subsystem (IRIS) on the airborne-lunar spectral irradiance (air-LUSI) instrument
Authors: Grantham Steven E , Turpie Kevin R , Stone Thomas C , Gadsden S Andrew , Larason Thomas C , Zarobila Clarence J , Maxwell Stephen E , Woodward John T , Brown Steven W 
Published: February 2022

Abstract
The objective of the airborne lunar spectral irradiance (air-LUSI) project is to make low uncertainty, SI-traceable measurements of the LUSI in the visible to near-infrared region from an aircraft above most of the optically absorbing components of the atmosphere. The measurements are made from a NASA ER-2 aircraft, which can fly at altitudes of approximately 20 km above sea level. Air-LUSI measurements, corrected for residual atmospheric attenuation, are designed to provide a matrix of low uncertainty top-of-the-atmosphere lunar irradiances at known lunar phase and libration angles to be compared and combined with other lunar irradiance data sets to constrain the uncertainties in models of lunar irradiance and reflectance. The measurements are also expected to provide insight into the differences between models and satellite sensor measurements of lunar irradiance. This paper describes the development and characterization of the air-LUSI subsystem for acquiring lunar measurements, called the irradiance instrument subsystem, prior to flight.
1D NiO–3D Fe2O3 mixed dimensional heterostructure for fast response flexible broadband photodetector
Authors: Reddy B Kumaar Swamy , Veeralingam Sushmitha , Borse Pramod H , Badhulika Sushmee 
Published: February 2022

Abstract
Conventional heterojunction photodetectors rely on planar junction architecture which suffer from low interfacial contact area, inferior light absorption characteristics and complex fabrication schemes. Heterojunctions based on mixed dimensional nanostructures such as 0D-1D, 1D-2D, 1D-3D etc have recently garnered exceptional research interest owing to their atomically sharp interfaces, tunable junction properties such as enhanced light absorption cross-section. In this work, a flexible broadband UV–vis photodetector employing mixed dimensional heterostructure of 1D NiO nanofibers and 3D Fe2O3 nanoparticles is fabricated. NiO nanofibers were synthesized via economical and scalable electro-spinning technique and made composite with Fe2O3 nanoclusters for hetero-structure fabrication. The optical absorption spectra of NiO nanofibers and Fe2O3 nanoparticles exhibit peak absorption in UV and visible spectra, respectively. The as-fabricated photodetector displays quick response times of 0.09 s and 0.18 s and responsivities of 5.7 mA W−1 (0.03 mW cm−2) and 5.2 mA W−1 (0.01 mW cm−2) for UV and visible spectra, respectively. The fabricated NiO–Fe2O3 device also exhibits excellent detectivity in the order of 1012 jones. The superior performance of the device is ascribed to the type-II heterojunction between NiO–Fe2O3 nanostructures, which results in the localized built-in potential at their interface, that aids in the effective carrier separation and transportation. Further, the flexible photodetector displays excellent robustness when bent over ∼1000 cycles thereby proving its potential towards developing reliable, diverse functional opto-electronic devices.
On the nonlinear dynamics of a cardiac electrical conduction system model: theoretical and experimental study
Authors: Kuate Guy Chance Gildas , Fotsin Hilaire Bertrand 
Published: February 2022

Abstract
The heart has a leading and vital role in the human body, scientific researches dealing with this theme are sources of growing interest. In recent years, several mathematical models of the heart electrical conduction system have appeared in the scientific literature. In the present paper, the nonlinear dynamics of a heart’s electrical conduction system model is investigated. The model consists of three coupled nonlinear oscillators with time delay coupling as earlier proposed by Gois et al [S R F S M Gois and M A Savi, 2009 ‘An analysis of heart rhythm dynamics using a three-coupled oscillator model,’ Chaos, Solitons Fractals, 41, 2553-2565]. Our study here is both theoretical and experimental; theoretical study includes fixed points analysis, bifurcations analysis where the effect of some parameters on the system dynamics is investigated, coexisting bifurcations and hysteresis phenomenon are found for some range of the system parameters, Lyapunov exponents and basin of attraction calculation. The experimental study includes sizing an analog implementation of the mathematical model using OrCAD/Pspice software, as well as the practical realisation of the model. Experimental and practical results are then presented in order to confirm theoretical predictions.
Comparison of Mainardi, cos-Mainardi and cosh-Mainardi beams with and without optical vortex in FT and FrFT systems
Authors: Habibi Forouzan , Moradi Mohammad 
Published: February 2022

Abstract
In this paper, we investigated the propagation of the Mainardi, cos-Mainardi and cosh-Mainardi beams under the Fractional Fourier transforms (FrFT) and Fourier transforms (FT). The results show that with the change of b, q, p, and z, which are the hyperbolic parameter, the fractional order of Mittag-Leffler function, the fractional Fourier transform order, and the distance propagation, respectively, the properties of the Mainardi beam with and without optical vortex can be controlled. The results show that with changing b and q parameters, the beam size, number, width and direction of the beam changes. These results can be useful in signal processing and beam manipulation. Mainardi beam similar to AiB holds promise for wide applications because of its unique features of being diffraction-free, self-accelerating, and self-healing.
Jupiter Observing Velocity Experiment (JOVE): Introduction to Wind Rider Solar Electric Propulsion Demonstrator and Science Objectives
Authors: Freeze Brent , Greason Jeff , Nader Ronnie , Febres Jaime Jaramillo , Chaves-Jiminez Adolfo , Lamontagne Michel , Thomas Stephanie , Cassibry Jason , Fuller John , Davis Eric , Conway Darrel 
Published: February 2022

Abstract
The Jupiter Observing Velocity Experiment (JOVE) is a solar-powered technology demonstration of rapid flight to outer solar system targets, performing a flyby of Jupiter 30 days after launch. This is achieved using a magnetic drag device to accelerate with the solar wind plasma. This “Wind Rider” propulsion system can potentially also decelerate against the Jovian magnetosphere dawn eddy, to enable Jupiter orbital insertion in future missions. The 16U cubesat bus contains scientific instruments to record the plasma parameters from the vicinity of the spacecraft, with principal measurements coming from a SPAN-I ion velocity sensor. This paper includes a description of the propulsive mechanisms and supporting subsystems and trajectory simulation results derived from solar wind measurements over the past two solar cycles. The objectives of the JOVE technology demonstrator design include: (1) verify Wind Rider stability and control; (2) characterize loss mechanisms in the solar wind, such as resistive losses in the plasma, as well as the magnetic field transient interaction time; (3) operate onboard instruments to measure the velocity and direction of the solar wind (SPAN-Ai) and speed of the spacecraft relative to the Earth (radio Doppler shift), to enable precision navigation on future science missions; and (4) characterize the Lift-to-Drag ratio of the plasma magnetic field. (The lift force enables lateral course control and maneuvering within the solar wind.) Applying existing scientific data from Voyagers and other deep space probes into new engineering models was important for enabling new insights about Wind Rider propulsion. It enables more science to be performed in a shorter amount of time, across the Jovian system.
Research on Autofocus Recognition of the LAMOST Fiber View Camera System Under Front and Back Illumination
Authors: Zhou Zengxiang , Liang Jiadong , Duan Shipeng , Cai Zeyu , Hu Hongzhuan , Wang Jianping , Liu Zhigang , Cui Xiangqun , Zhang Yong , Zhang Haotong 
Published: February 2022

Abstract
In the closed-loop detection system of the LAMOST, the lens of the fiber view camera system must focus the end of the optical fiber to accurately acquire the fiber position. It is difficult to evaluate the fibers image with a very small proportion of the image with the traditional autofocus algorithm, whether it is recognition of the front illuminated by the fiber ceramic ferrules, or the light-emitting spot of the fibers in the black background, that is, the recognition of the back illumination of the fibers. In this paper, we propose an autofocus determination method for the LAMOST closed-loop control under front and back illumination conditions. Under the condition of front illumination, to greatly reduce the calculation time, the system first pre-recognizes the focusing target through the Faster R-CNN and then uses an optimized contrast algorithm to evaluate the image definition of the corrected focusing target ROI. Then, the algorithm is compared with Tenengrad gradient and Laplacian gradient calculations using the Sobel operator and Laplacian operator in OpenCV. The results show that this method takes only one-ninth of the time required by the other methods to obtain the same accuracy. Under the condition of back illumination, we use the average number and average brightness of spot pixels as the evaluation basis of image sharpness. This method can complete the evaluation of image sharpness in the process of spot recognition and provide initial data for the subsequent detection for closed-loop control. The focus accuracy of the camera is of great significance for thousand-fiber metrology, which will have an important influence on the accuracy of astronomical observations. These focusing methods not only play an important role in the closed-loop control of the LAMOST but also apply to the focusing of closed-loop detection systems of other multi-target optical fiber spectral astronomical telescopes.
Direct and 2f-wavelength modulation spectroscopy of NO and OCS using an astigmatic multipass cell coupled with a mid-IR 5.2 µm cw-QCL
Authors: Panda Biswajit , Pal Ardhendu , Pradhan Manik 
Published: February 2022

Abstract
We developed a mid-IR 2f-wavelength modulation spectroscopy (WMS) detection system combining a continuous wave external-cavity quantum cascade laser (QCL) at 5.2 μm and an astigmatic multipass cell. The high-sensitivity performance of the 2f-WMS system was validated by simultaneously probing the strongest interference-free absorption lines of Λ-doublet components of R (6.5) rotational line in 2Π1/2 magnetic electronic sub-state of nitric oxide (NO) centred at 1900.0706 cm−1 and the R (18) rotational line of carbonyl sulphide (OCS) in the (ν
1 + 2ν
2) combination band centred at 1899.9756 cm−1. We compared the results with the direct absorption spectroscopy and have shown that a detection limit of 300 ppb for NO and 3 ppm for OCS could easily be achieved by the 2f-WMS method with an optical pathlength of 76 m. Hence, we believe that in the future the present QCL based 2f-WMS detection method with high sensitivity and specificity could be deployed for real-time monitoring of NO and OCS in a harsh environment.
Exact solutions of the 2D Schrödinger equation with the inverse square root potential
Authors: Sun Guo-Hua , Chen Chang-Yuan , Dong Shi-Hai 
Published: February 2022

Abstract
The exact solutions of the 2D Schrödinger equation with the inverse square root potential

V
(
r
)
=
−
a

/

r

(a > 0) are found as the Biconfluent Heun function

H

B

(
α
,
β
,
γ
,
δ
;
z
)

. The wave functions with the variation of the potential parameter a and angular momentum quantum number m are illustrated graphically.
On the CFT describing the spin clusters in 2d Potts model
Authors: Picco Marco , Santachiara Raoul 
Published: February 2022

Abstract
We have considered clusters of like spins in the Q-Potts model, the spin Potts clusters (S clusters). Using Monte Carlo simulations, we studied these clusters on a square lattice with periodic boundary conditions for values of Q ∈ [1, 4]. We continue the work initiated by Delfino et al (2013 J. Stat. Mech. P11011) by measuring the universal finite size corrections of the two-point connectivity. The numerical data are perfectly compatible with the conformal field theory (CFT) prediction, thus supporting the existence of a consistent CFT, still unknown, describing the connectivity Potts spin clusters. We provided in particular new insights on the energy field of such theory. For Q = 2, we found a good agreement with the prediction that the Ising spin clusters behave as the Fortuin–Kasteleyn ones at the tri-critical point of the dilute one-Potts model. We show that the structure constants are likely to be given by the imaginary Liouville structure constants, consistently with the results by Delfino et al (2013 J. Stat. Mech. P11011); Ang and Sun (2021 arXiv:2107.01788). For Q ≠ 2 instead, the structure constants we measure do not correspond to any known bootstrap solutions. The validity of our analysis is backed up by the measures of the spin Potts cluster wrapping probability for Q = 3. We evaluate the main critical exponents and the correction to the scaling. A new exact and compact expression for the torus one-point of the Q-Potts energy field is also given.
Statistical aspects of interface adhesion and detachment of hierarchically patterned structures
Authors: Esfandiary Nosaibeh , Zaiser Michael , Moretti Paolo 
Published: February 2022

Abstract
We introduce a three dimensional model for interface failure of hierarchical materials adhering to heterogeneous substrates. We find that the hierarchical structure induces scale invariant detachment patterns, which in the limit of low interface disorder prevent interface failure by crack propagation (‘detachment fronts’). In the opposite limit of high interface disorder, hierarchical patterns ensure enhanced work of failure as compared to reference non-hierarchical structures. While the study of hierarchical adhesion is motivated by examples of fibrous materials of biological interest, our results indicate that hierarchical patterns can be useful in engineering scenarios in view of tuning and optimizing adhesion properties.
A note on matrix algebra for cryptography settings and applications
Authors: Ayo-Aderele A. O. , Edeki S. O. , Udjor V. O. , Ugbenu O. 
Published: February 2022

Abstract
Cryptography is an interdisciplinary topic that adopts concepts from several disciplines. In today’s environment, cryptography makes important use of computer science and mathematics, especially discrete mathematics. This study aims to discuss the daily use of matrices in cryptography. Globally, secure text communication is critical while various cryptosystems exist to accomplish this security. Hence, with regard to the cryptosystem, the key matrix from the plane’s equation is considered by determining the orthogonal matrix that implements reflection. This method boosts encryption security by making it more arduous to locate a secret key matrix. In order to produce encryptions, the approach uses the orthogonal matrix transform characteristics. The suggested encryption method’s simplicity enables it to be adapted to other circumstances requiring secret communication transmission
Geometric progression and relative strength index applied to FX hedging
Authors: Ebong D. J. , Ogunniyi P. O. , Edeki S. O. 
Published: February 2022

Abstract
This research aims at profit maximization and loss minimization in any FX market trading. A geometric progression (geometric sequence), is said to be a non-zero number progression or sequence in which each term following the first is obtained via multiplying the prior by the common ratio, which is a predetermined non-zero value. This method seeks to open an opposite position to an existing initial position in order to hedge that initial position in the event that the market moves against our trade. There are a number of mathematical models to develop new hedging strategies for Forex trading. Due to the apparent high level of unpredictability in price movement, forecasting the future of a stock price is a challenging endeavor. The research would like to study one with geometric progression in particular. In other words, every number can be entered as multiple integer of a different number. Thus, 1, 2, 4, 8,..., 2n is a step forward. Smart traders never take more risks than their capital, however, the otherwise is viewed and considered here.
Elzaki Adomian decomposition method applied to Logistic differential model
Authors: Dosunmu D.A. , Edeki S.O. , Achudume C. , Udjor V.O. 
Published: February 2022

Abstract
This study applies Elzaki Adomian Decomposition Method (EADM) to solve the Logistic Differential Model (LDM) of different forms and coefficients. Illustrative examples are considered, and the obtained results are in good agreement compared to those already in the literature. This study, therefore, recommends the proposed method (EADM) for application in other aspects of applied mathematics for real-life problems.