bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of solvent releases from microfluidic devices made of cycloolefin polymer by temperature-desorption mass spectrometry
Authors: Takahashi Seiichiro , Mune Yutaka , Yamamuro Akihiko , Aiba Akira , Hatakeyama Kenji , Kamei Ken-ichiro 
Published: April 2023

Abstract
Microfluidic devices have been used in various biological experiments. The working temperature of the devices spans a wide range (approximately 23 °C–95 °C). Among thermoplastic materials, cyclo olefin polymers (COPs) are promising materials for microfluidic devices. This is because COP can overcome the well-known disadvantages of polydimethylsiloxane, a commonly used material, and have the advantage of better observability than polystyrene and polymethyl methacrylate. However, most COP-based devices are fabricated using solvents and adhesives during the bonding process. These solvents, which are known to affect biological experiments, may remain in the device and be released during the experiments. It is necessary to investigate whether solvents are actually released and, if so, how they are released. Here we introduce thermal desorption spectroscopy as a simple and quantitative method to observe solvent release from solvent-bonded and vacuum ultraviolet (VUV)-bonded products. Solvents are released from the solvent-bonded product at 31.5 °C, suggesting that it may have negative effects on various biological experiments. On the other hand, the VUV-bonded product releases solvents (cyclohexane and toluene), which are used during olefin polymerization in the synthesis process of COP, at temperatures above 84 °C. Therefore, the experiments conduct below 84 °C (e.g. in situ hybridization, reverse transcription (RT) and loop-mediated isothermal amplification) were not affected. In addition, the amount of solvent released above 84 °C is small (1/548–1/913 of the solvent-bound product), so it is expected that the extent of the effect on experiments conducted above 84 °C (RT and polymerase chain reaction) is small, if there is any. We conclude that solvent-bound devices can have undesirable effects in many biological applications, not just cell culture. We believe that evaluating solvent release from devices is important for the development of new devices in the future.
Numerical modeling of positive streamer propagation in alternative natural ester and traditional naphthenic oil under sub-microsecond pulsed voltages
Authors: Wang Zheming , Xu Hongyun , Zhou You , Wang Yaogang , Jia Bowen , Zhou Wenqiang , Zhao Yikun , Bi Jiangang , Lu Wu , Liu Yongsheng 
Published: April 2023

Abstract
In this paper, a two-dimensional axisymmetric numerical model of streamer discharge in alternative natural ester liquid and conventional naphthenic oil under a positive sub-microsecond impulse voltage is proposed. The model is based on the charge drift-diffusion approximation in a divergent electric field. Simulation shows that streamer propagation in naphthenic oil is divided into two stages: stage I with a small streamer velocity of 0–0.91 km s−1 and stage II with a rapidly rising streamer velocity up to 213 km s−1. In natural ester, the streamer velocity gradually slows down from 4.84 km s−1 to 2.11 km s−1. The electric field at the head of the streamer in natural ester ranges from 2.4 × 108 V m−1 to 2.5 × 108 V m−1 during propagation, which is visibly lower but more consistent than that in naphthenic oil (3.5 × 108 V m−1 to 8.4 × 108 V m−1). It is revealed that the different streamer features within the two types of oil are caused by the different competition between the Laplacian electric field and space charge effect at the streamer head. For streamer propagation in naphthenic oil, stage I is dominated by the Laplacian electric field whereas stage II is dominated by the space charge effect. In natural ester, the whole streamer propagation is dominated by the Laplacian electric field. Further, it is indicated that the streamer head consists of two specific discharging regions, i.e. the front region of the streamer head which guides new space charge accumulation and the back region of streamer head which guides density reduction of accumulated space charge. The expansion of the streamer tunnel is caused by the alternating space charges in these two regions. The work in this paper provides a theoretical reference for the practical application of alternative transformer liquids.
Analysis of electromechanical couplings and nonlinear carrier transport in flexoelectric semiconductors
Authors: Zhang Gongxi , Shen Shengping 
Published: April 2023

Abstract
In recent years, a linearization method has been extensively employed to investigate the electromechanical fields and carrier distribution in flexoelectric semiconductors, where the assumption of a small perturbation of carrier concentration is adopted. However, this method fails to accurately describe the realistic physical process in which a considerable variation of carrier concentration takes place. Based on fully coupled nonlinear equations, this paper presents a finite element approach to study the electromechanical couplings and nonlinear carrier transport in flexoelectric semiconductors. This method is applied to calculate the electrostatic potential in a bent piezoelectric semiconductive nanowire (NW) going beyond simple considerations and to simulate the nonlinear current–voltage (I–V) characteristics of a mechanically loaded flexoelectric p–n junction. The results indicate that the inherently nonlinear drift of carriers gives rise to the asymmetric distribution of the electric potential relative to the NW axis in the upper body. Flexoelectricity brings about a remarkable enhancement in output voltage and is responsible for the linear variation of electric potential along the length direction of the NW unless close to two ends. Furthermore, the barrier height and I–V relations of a flexoelectric p–n junction can be effectively tuned by mechanical forces due to the flexoelectric effect, the effect of which relies on the size of the p–n junction configuration. This work is a good starting point to comprehend the coupling of flexoelectricity and nonlinear carrier transport in static and dynamic cases, and offers an effective approach to numerically deal with the issues involved in flexoelectronics and piezoelectronics at the nanoscale.
Unpolarized transverse-momentum-dependent sea quark asymmetries of light nuclei in nonperturbative QCD
Authors: Nematollahi H 
Published: April 2023

Abstract
We investigate the transverse-momentum dependence of sea quark asymmetries in helium and deuteron nuclei. Accordingly, we calculate the nuclear sea quark distributions, in the first step, based on the modified chiral quark exchange formalism at the low Q
2 scale (Q
2 = 0.35 GeV2) in the nonperturbative region of quantum chromodynamics. In this formalism, the sea quark distributions are not symmetric because of chiral symmetry breaking. In the next step, we compute the transverse-momentum dependence of sea quark distributions using the covariant parton model, in which the unpolarized transverse-momentum-dependent (TMD) quark distribution functions are related to corresponding integrated ones. Finally, we obtain TMD quark–antiquark asymmetry of the strange sea for 3
He and deuteron, and also

(

d

¯

−

u

¯

)

asymmetry for 3
He. To study the European Muon Collaboration (EMC) effect in the 3
He nucleus, we determine the ratio of the TMD strange sea asymmetries of 3
He and deuteron.
Dynamics of active particles with translational and rotational inertia
Authors: Sprenger Alexander R , Caprini Lorenzo , Löwen Hartmut , Wittmann René 
Published: April 2023

Abstract
Inertial effects affecting both the translational and rotational dynamics are inherent to a broad range of active systems at the macroscopic scale. Thus, there is a pivotal need for proper models in the framework of active matter to correctly reproduce experimental results, hopefully achieving theoretical insights. For this purpose, we propose an inertial version of the active Ornstein–Uhlenbeck particle (AOUP) model accounting for particle mass (translational inertia) as well as its moment of inertia (rotational inertia) and derive the full expression for its steady-state properties. The inertial AOUP dynamics introduced in this paper is designed to capture the basic features of the well-established inertial active Brownian particle model, i.e. the persistence time of the active motion and the long-time diffusion coefficient. For a small or moderate rotational inertia, these two models predict similar dynamics at all timescales and, in general, our inertial AOUP model consistently yields the same trend upon changing the moment of inertia for various dynamical correlation functions.
A stable and effective calibration method for defocused cameras using synthetic speckle patterns
Authors: Wu Jun , Zhang Meimiao , Wang Haoshuang , Shan Tengfei , Zhang Xiaoyu , Guo Runxia 
Published: April 2023

Abstract
Well-focused and sharp target images are essential in traditional calibration, but they generally cause difficulty and inconvenience in image acquisition in practical applications. To address this problem, a stable and effective calibration method for defocused cameras is proposed in this study. Firstly, two speckle patterns are created, one of which has control points to estimate the initial value while the other, used for point pair match registration, is without control points. They are subsequently displayed on a fixed monitor and captured at each camera pose. Secondly, the initial guess for the control points is estimated using the proposed method. The retrieval of query points can then be done with high accuracy using the digital image correlation algorithm. Finally, all the calibration parameters, including lens distortion, are calculated using the plane calibration algorithm. The experiment in this study demonstrates the practicality and effectiveness of the proposed method. The accuracy and precision were quantitatively evaluated by the mean reprojection error, which was 0.057 pixels.
Automatic identifying OSAHS patients and simple snorers based on Gaussian mixture models
Authors: Sun Xiaoran , Ding Li , Song Yujun , Peng Jianxin , Song Lijuan , Zhang Xiaowen 
Published: April 2023

Abstract

Objective. Snoring is a typical symptom of Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS). In this study, an effective OSAHS patient detection system based on snoring sounds is presented.Approach. The Gaussian mixture model (GMM) is proposed to explore the acoustic characteristics of snoring sounds throughout the whole night to classify simple snores and OSAHS patients respectively. A series of acoustic features of snoring sounds of are selected based on the Fisher ratio and learned by GMM. Leave-one-subject-out cross validation experiment based on 30 subjects is conducted to validation the proposed model. There are 6 simple snorers (4 male and 2 female) and 24 OSAHS patients (15 male and 9 female) investigated in this work. Results indicates that snoring sounds of simple snorers and OSAHS patients have different distribution characteristics. Main results. The proposed model achieves average accuracy and precision with values of 90.0% and 95.7% using selected features with a dimension of 100 respectively. The average prediction time of the proposed model is 0.134 ± 0.005 s. Significance. The promising results demonstrate the effectiveness and low computational cost of diagnosing OSAHS patients using snoring sounds at home.
Impact of the turbulence wavenumber spectrum and probing beam geometry on Doppler reflectometry perpendicular velocity measurements
Authors: Frank A , Höfler K , Happel T , Görler T , Lechte C , Stroth U 
Published: April 2023

Abstract
The perpendicular propagation velocity of turbulent density fluctuations is an important parameter in fusion plasmas, since sheared plasma flows are crucial for reducing turbulence, and thus an essential input parameter for turbulent transport simulations. In the recent past various fusion devices have observed poloidal asymmetry in this velocity using Doppler reflectometry (DR) and correlation reflectometry. In this work, the phase screen model is used to analytically explain and quantify the combined effect of finite wavenumber resolution due to plasma curvature and probing beam geometry in a realistic turbulence wavenumber spectrum, leading to a reduced dominantly back-scattered wavenumber and a further underestimation of the perpendicular propagation velocity determined by DR. The full-wave code IPF-FD3D, which simulates microwave propagation and scattering, is used as a synthetic DR to study the effects of this diagnostic effect in a circular geometry using various isotropic synthetic turbulence wavenumber spectra. Angular scans from the midplane and variations in the position of the probing antenna are shown to estimate the impact of the diagnostic effect on the poloidal asymmetries.
Experimental study on seismic behavior of concrete walls with external magnetorheological dampers
Authors: Zhao Jun , Luo Jing , Zhang Xiangcheng , Ruan Xiaohui , Sun Yuping 
Published: April 2023

Abstract
A reinforcing method for developing a kind of shear wall with both excellent self-centering capacity and high energy dissipation was presented, in which carbon fiber reinforced polymer (CFRP) bars or steel strands were longitudinally placed to provide a restoring effect, while magnetorheological (MR) dampers were externally coupled with wall panels to provide extra energy dissipation. To verify the feasibility of this method, three slender concrete walls were tested under reversed cyclic lateral loading while subjected to constant axial compression with an axial load ratio of 0.26, of which one was reinforced with CFRP bars, the second one was reinforced with CFRP bars and two external MR dampers, and the third one was reinforced with steel strands and two external MR dampers. The results indicated that the test walls possessed remarkable load-resisting capacities even when the lateral drift was as large as 1.8% as well as a lateral deformation recovery rate of 74%–89% after unloading. Owing to external MR dampers, the initial stiffness and ductility were increased by 28.3% and 29.8%, respectively. In addition, a specific quantitative analysis showed that the dampers could increase the cumulative energy dissipation of shear walls by 16.6%, of which the contribution provided by MR damper was 64.8%, confirming the effectiveness of MR dampers in improving energy dissipation while preserving the self-centering capacity.
Observational entropy, coarse-grained states, and the Petz recovery map: information-theoretic properties and bounds
Authors: Buscemi Francesco , Schindler Joseph , Šafránek Dominik 
Published: April 2023

Abstract
Observational entropy provides a general notion of quantum entropy that appropriately interpolates between Boltzmann’s and Gibbs’ entropies, and has recently been argued to provide a useful measure of out-of-equilibrium thermodynamic entropy. Here we study the mathematical properties of observational entropy from an information-theoretic viewpoint, making use of recently strengthened forms of the monotonicity property of quantum relative entropy. We present new bounds on observational entropy applying in general, as well as bounds and identities related to sequential and post-processed measurements. A central role in this work is played by what we call the ‘coarse-grained’ state, which emerges from the measurement’s statistics by Bayesian retrodiction, without presuming any knowledge about the ‘true’ underlying state being measured. The degree of distinguishability between such a coarse-grained state and the true (but generally unobservable) one is shown to provide upper and lower bounds on the difference between observational and von Neumann entropies.
Treatment of symmetry in the tight-binding method for crystals with several atoms per unit cell
Authors: Melnikov N B , Reser B I 
Published: April 2023

Abstract
Consistent treatment of symmetry in the tight-binding method, developed by Egorov et al [Phys. Stat. Sol.
26, 391 (1968)] for crystals with two atoms per unit cell, is generalized to crystals with several atoms per unit cell. A method is presented for expressing the matrix components of the tight-binding Hamiltonian in terms of independent parameters using group-theoretical techniques. The method is demonstrated by obtaining an analytical form for the low-dimensional effective Hamiltonian describing the electronic structure of the 2H-TaSe2 conduction band with quasi 2D hexagonal crystal structure.
A high-efficiency C-band coaxial transit time oscillator with a dual-cavity extractor under low-magnetic fields
Authors: Zhu Danni , Cui Yancheng , Meng Jin , Wang Haitao , Deng Bingfang , Yuan Yuzhang 
Published: April 2023

Abstract
A high-efficiency C-band coaxial transit time oscillator with a dual-cavity extractor under low-magnetic fields is designed and studied through small-signal theory and particle-in-cell simulation. Small-signal theory analysis indicates that a dual-cavity extractor is superior to a single-cavity extractor in terms of the beam-coupling coefficient, the resonant frequency, and the external quality factor, which are good for high efficiency. Typical simulation results of the proposed device show that an output power of 1.73 GW and a frequency of 6.37 GHz can be obtained with a diode voltage of 455 kV and current of 9.75 kA. The corresponding power efficiency reaches 39%, and the guiding magnetic field is 0.8 T. Further simulation demonstrates that the power efficiency exceeds 34% in a rather large range of diode voltage from 385 kV to 470 kV and can reach higher than 35% with a low guiding magnetic field of 0.4 T. Then this coaxial transit time oscillator is compared with the typical relativistic backward wave oscillators from the magnetic field, efficiency and power saturation time.
Modeling and experimental investigation of indentation creep behavior of hypoeutectic Sn-Bi and Sn-Bi- Sb2O3 alloys using genetic programming approach
Authors: Abdelaziz Shereen M , Lebda H I , El-Rehim A F Abd , Habashy D M 
Published: April 2023

Abstract
This study employs genetic programming (GP) to model the impact of aging temperature and the addition of nano-sized Sb2O3 particles on the mechanical properties of hypoeutectic Sn-5 wt% Bi alloy. Vickers hardness measurements were used to investigate the indentation creep behavior of the alloy under different testing conditions, comparing Sn-5 wt% Bi (alloy A) and Sn-5 wt% Bi-0.5 wt% Sb2O3 (alloy B). Microstructure development was studied using a scanning electron microscope (SEM). A MATLAB code was employed to optimize the GP parameters during the training process. Two GP models were developed to describe the indentation creep behavior of alloys A and B, respectively, as a function of dwell time, aging temperature, and applied load, using experimental data with errors of 0.0844 and 0.086 and a correlation coefficient greater than 0.9. The equations generated by the GP approach demonstrate excellent agreement with the experimental findings, and the GP model predicts the data with high accuracy.
Weighted variation after projection method for low-lying nonyrast states*
Authors: Lian Zhan-Jiang , Lu Xiao , Li Xue-Wei , Gao Zao-Chun , Chen Yong-Shou 
Published: April 2023

Abstract
We propose a simple algorithm to further improve the previous variation after projection (VAP) wave functions for low-lying nonyrast states. We attach a weight factor to each calculated energy; then, the sum of these weighted energies is minimized. It turns out that a low-lying nonyrast VAP wave function can be further optimized when the weight factor for the corresponding energy is far larger than the other ones. Based on the improved WVAP wave functions, the energy-variance extrapolation method is applied to estimate the exact shell model energies. The calculated results for nuclei in the

and

model spaces clearly show that the extrapolated energies for all the calculated states are very close to the exact shell model ones within

keV.
Research progress on vanadium oxides for potassium-ion batteries
Authors: Wu Yuhan , Chen Guangbo , Wu Xiaonan , Li Lin , Yue Jinyu , Guan Yinyan , Hou Juan , Shi Fanian , Liang Jiyan 
Published: April 2023

Abstract
Potassium-ion batteries (PIBs) have been considered as promising candidates in the post-lithium-ion battery era. Till now, a large number of materials have been used as electrode materials for PIBs, among which vanadium oxides exhibit great potentiality. Vanadium oxides can provide multiple electron transfers during electrochemical reactions because vanadium possesses a variety of oxidation states. Meanwhile, their relatively low cost and superior material, structural, and physicochemical properties endow them with strong competitiveness. Although some inspiring research results have been achieved, many issues and challenges remain to be further addressed. Herein, we systematically summarize the research progress of vanadium oxides for PIBs. Then, feasible improvement strategies for the material properties and electrochemical performance are introduced. Finally, the existing challenges and perspectives are discussed with a view to promoting the development of vanadium oxides and accelerating their practical applications.
Proprioceptive wake classification by a body with a passive tail
Authors: Rodwell Colin , Pollard Beau , Tallapragada Phanindra 
Published: April 2023

Abstract
The remarkable ability of some marine animals to identify flow structures and parameters using complex non-visual sensors, such as lateral lines of fish and the whiskers of seals, has been an area of investigation for researchers looking to apply this ability to artificial robotic swimmers, which could lead to improvements in autonomous navigation and efficiency. Several species of fish in particular have been known to school effectively, even when blind. Beyond specialized sensors like the lateral lines, it is now known that some fish use purely proprioceptive sensing, using the kinematics of their fins or tails to sense their surroundings. In this paper we show that the kinematics of a body with a passive tail encode information about the ambient flow, which can be deciphered through machine learning. We demonstrate this with experimental data of the angular velocity of a hydrofoil with a passive tail that lies in the wake generated by an upstream oscillating body. Using convolutional neural networks, we show that with the kinematic data from the downstream body with a tail, the wakes can be better classified than in the case of a body without a tail. This superior sensing ability exists for a body with a tail, even if only the kinematics of the main body are used as input for the machine learning. This shows that beyond generating ‘additional inputs’, passive tails modulate the response of the main body in manner that is useful for hydrodynamic sensing. These findings have clear application for improving the sensing abilities of bioinspired swimming robots.