bluuebunny/crossref_metadata_2025_split huggingface dataset:
Frequency noise suppression of the high-power pumping laser in the SERF atomic magnetometer
Authors: Wang Guiqi , Duan Lihong , Ma Ning , Liu Qingbo , Hu Zeyi 
Published: October 2024

Abstract
A high-sensitivity spin exchange relaxation free (SERF) atomic magnetometer based on a noise-suppressed master oscillator power amplifier (MOPA) system is demonstrated. The spectrum and frequency noise of the laser are measured and it is proved that the frequency noise in the MOPA system is affected by the amplified spontaneous emission (ASE) stimulated from the power amplifier. The frequency noise of the MOPA system is decreased by filtering out the ASE background in the spectrum through a bandpass filter. The sensitivity of the SERF atomic magnetometer is improved by using the frequency noise-suppressed MOPA system as a pumping laser. This method can also be applied to other precision measurement fields based on MOPA systems that have high requirements for frequency noise of lasers.
A new frequency domain denoising method for coal mine transient electromagnetic measuring data
Authors: Huang Maolin , Tang Yu , Zhang Jiaqi , Yu Jingcun , Su Benyu , Li Z 
Published: October 2024

Abstract
Due to limitation of space in mine tunnel, only a 2 m × 2 m rectangle coil can be employed to collect the electromagnetic signals for the mine transient electromagnetic analysis. Hence, a small emission magnetic moment and weak detection signal strength will increase the electromagnetic analysis difficulty. Moreover, the transient electromagnetic response signal in mines exhibits exponential decay over time, with late-stage amplitudes being notably small, which makes these signals susceptible to noise interference. As a result, it is necessary to study effective noise removal methods to enhance the signal-to-noise ratio of the late-stage electromagnetic data. Addressing this challenge task, this study proposes a new method for frequency domain denoising of transient electromagnetic data. This new method utilizes the Fourier Transform to convert the original transient electromagnetic data from the time domain to the frequency domain, and then, the noise is identified and removed through the frequency characters. Lastly, the processed frequency domain information is transformed to the time domain by the Fourier Inverse Transform to restore the time domain signals. The effect of this frequency domain denoising method is demonstrated through numerical simulations and underground coal mine field data to show significant noise reduction performance on the abnormality detection in the underground coal mine.
DeepLPos: a comprehensive hybrid deep learning model for lying position recognition using a tactile sensor array system
Authors: Song Yao , Guo Shijie , Liang Bowen 
Published: October 2024

Abstract
Unpredictable limb movements or turning motions can significantly disrupt the accurate extraction of physiological signals, such as respiratory and heart rates. In clinical environments, reliable detection of lying positions is crucial for continuous patient monitoring, particularly during sleep. In this paper, a smart sleeping position recognition system is proposed, which employs a tactile pressure sensor array based on the unique structure of ‘the electrostatic double-layer capacitors’. The sensor array, comprising 64 rows and 32 columns (2048 nodes), captures four types of healthy lying positions using an 8-bit AD module. Despite challenges arising from limited experimental samples for accurate training, we propose DeepLPos, a hybrid deep learning approach combining generative adversarial networks and the you only look once network. To tackle the differentiation challenge between supine and prone positions, we introduce an SPD Conv attention module to enhance the resolution of detailed descriptions in pressure images. The model is further pruned to optimize both structure and parameters, enabling efficient real-time detection. Evaluated on the SLP dataset, the proposed system achieves an accuracy of 97.5% with a real-time processing speed of 0.069 s per frame, demonstrating its potential for practical, high-precision measurement and monitoring applications in healthcare.
Algebraic calming for the 2D Kuramoto-Sivashinsky equations
Authors: Enlow Matthew , Larios Adam , Wu Jiahong 
Published: October 2024

Abstract
We propose an approximate model for the 2D Kuramoto–Sivashinsky equations (KSE) of flame fronts and crystal growth. We prove that this new ‘calmed’ version of the KSE is globally well-posed, and moreover, its solutions converge to solutions of the KSE on the time interval of existence and uniqueness of the KSE at an algebraic rate. In addition, we provide simulations of the calmed KSE, illuminating its dynamics. These simulations also indicate that our analytical predictions of the convergence rates are sharp. We also discuss analogies with the 3D Navier–Stokes equations of fluid dynamics.
Laser-initiated electron and heat transport in gold-skutterudite CoSb3  bilayers resolved by pulsed x-ray scattering
Authors: Plech Anton , Gaal Peter , Schmidt Daniel , Levantino Matteo , Daniel Marcus , Stankov Svetoslav , Buth Gernot , Albrecht Manfred 
Published: October 2024

Abstract
Electron and lattice heat transport have been investigated in bilayer thin films of gold and CoSb3  after photo-excitation of the nanometric top gold layer through picosecond x-ray scattering in a pump-probe setup. The kinetics of heat transfer are detected by thermal lattice expansion and compared to simulations based on the two-temperature model of coupling of electron and phonon degrees of freedom. The unexpected observation of a larger portion of the deposited heat being detected in the underlying CoSb3  layer before the topmost gold layer is heated supports the picture of transport of the photo-excited electrons from gold to the underlying layer to be converted into lattice heat. The change of partition of heat between the gold and CoSb3  layer with laser fluence and wavelength (either exciting intraband transitions or additionally interband transitions) is rooted in the amplitude of electron temperature. Higher electron temperatures result in a longer equilibration time with the lattice and thus a larger proportion of ballistic electron transport across the interface.
Vacuum entanglement probes for ultra-cold atom systems
Authors: Gooding Cisco , Sachs Allison , Mann Robert B , Weinfurtner Silke 
Published: October 2024

Abstract
This study explores the transfer of nonclassical correlations from an ultra-cold atom system to a pair of pulsed laser beams. Through nondestructive local probe measurements, we introduce an alternative to destructive techniques for mapping Bose–Einstein Condensate (BEC) entanglement. Operating at ultra-low temperatures, BEC density fluctuations emulate a relativistic vacuum field. We show that lasers can serve as Unruh–DeWitt detectors for vacuum BEC phonons. A quantum vacuum holds intrinsic entanglement, transferable to distant probes briefly interacting with it—a phenomenon termed ‘entanglement harvesting’. Our study accomplishes two primary objectives: first, establishing a mathematical connection between a pair of pulsed laser probes interacting with an effective relativistic field and the entanglement harvesting protocol; and second, to closely examine the potential and persisting obstacles for realising this protocol in an ultra-cold atom experiment.
Transmission enhancement mechanism of PT symmetric photonic crystal coupled with grooved sub-wavelength grating
Authors: Chen Ying , Shi Moqing , Zhao Meng , Cui Dongyan , Wang Qinghui , Zhao Guoting , Li Weiqiang 
Published: October 2024

Abstract
In order to enhance the sensing characteristics of the sensor, based on the periodic sub-wavelength grating(SWG), a groove structure is introduced to make the Fano resonance waveform sharper. At the same time, based on the Parity-Time(PT) symmetry principle, by making the periodic photonic crystal meet the PT symmetry condition, the structure can absorb the energy of the emitted light on the original basis, produce the transmission enhancement effect, and make the transmission peak of the structure exceed 1. The sensing is realized by using the property that the different refractive indices of the detected medium corresponds to different transmission. When the incident light is 1550 nm, the sensitivity and FOM (Figure of Merit) value of the proposed structure reach 5.702 × 105RIU−1and 1.9 × 107 respectively, which greatly improves the performance of the sensor.
A space-time meshfree method for heat transfer analysis in porous material
Authors: Lin Yuanjian , Wang Fuzhang 
Published: October 2024

Abstract
Porous material batteries are a new type of battery technology that uses porous materials as electrode materials, with advantages such as long lifespan. In the present study, we manily propose a space-time meshfree method for heat transfer problems in porous material energy storage battery. The thermal behavior is demonstrated based on a numerical solution of the energy conservation equation. A simple space-time meshless collocation scheme, which is based on a new type space-time radial basis function, is presented to get the approximate solution of the energy conservation equation. The energy conservation equation was transferred into a system of linear algebraic equations. By introducing prescribed boundary conditions, the heat transfer analysis in porous material energy storage battery can be shown with numerical results. Numerical discussions show that the proposed meshless collocation method is appropriate to simulate thermal behavior in porous material energy storage battery, while the traditional finite element method failed to provide the reasonable results for the tested examples in this paper.
Switchable phase modulation and multifunctional metasurface with vanadium dioxide layer
Authors: Su Mingzhu , Wang Xufeng , Mu Kaijun , Fan Chunzhen 
Published: October 2024

Abstract
Metasurface, comprising subwavelength unit cells, offers a flexible modulation of the optical phase. However, traditional metasurfaces are typically engineered to function solely in one mode, limiting their efficiency and adaptability. In this study, we proposed a switchable metasurface consisting of gold bars deposited on polyimide and vanadium dioxide (VO2) layer. Upon the phase transition of VO2, this switchable metasurface exhibits functionality in both transmissive and reflective modes. Specifically, it efficiently converts left circularly polarized (LCP) light into right circularly polarized (RCP) light. For the dielectric (metallic) phases of VO2, the design behaves as metalens with a focal length of 1000 (906) μm at working frequency of 1.2 THz, respectively. Furthermore, the vortex phase can be effectively manipulated with topological number from 1 to 4 through the analysis of the electric field distribution. A directional emission from 12.9° to 42.2° is obtained in the reflective mode and Airy beam paths way can also be well regulated at 1.49 THz. The phase modulation is further achieved by varying the inter-mediums and its thickness. Finally, the sensing ability is explored with different covered solution. Consequently, this multifunctional and adaptable metasurface offers valuable insights for the development of reflectors, modulators, lenses and sensors.
Unveiling half-metallic, thermoelectric and optoelectronic behavior of the new Heusler alloy RbCrZ (Z = Si, Ge): a DFT perspective
Authors: Gurunani Bharti , Gupta Dinesh C 
Published: October 2024

Abstract
Utilizing the density functional theory (DFT) method, this study aims to predict with precision the structural, elastic, electronic, magnetic, thermoelectric, thermal, and optical properties of two recently discovered half-Heusler alloys, namely RbCrSi and RbCrGe. The exchange and correlation potential are accounted for using the generalized gradient approximation of Perdew–Burke–Ernzerhof (GGA-PBE) and the Tran–Blaha-modified Becke–Johnson exchange potential (TB-mBJ). Through structural analysis, it is observed that both RbCrSi and RbCrGe alloys exhibit energetic stability in a type-3 structure with a ferromagnetic (FM) state. Both alloys exhibit half-metallic properties and integer magnetic moments of 3 μB, following the Slater-Pauli rule. Additionally, elastic calculations confirm their mechanical stability and anisotropic ductile behavior. The quasi-harmonic Debye model (QHDM) is employed for calculating thermodynamic properties, while the BoltzTraP code, based on semi-classical Boltzmann theory (SCBT), is utilized for evaluating thermoelectric properties. Findings reveal that RbCrZ alloys (with Z = Si, Ge) exhibit high figure of merit (ZT) values nearing unity at highest temperature. Consequently, the newfound half-Heusler alloys RbCrSi and RbCrGe hold significant promise for applications in thermoelectricity and spintronic devices. This comprehensive analysis underscores the potential of these alloys in the realm of renewable energy applications.
Aluminum doped zinc oxide as UV laser-based nanothermometer
Authors: Azmi Atiqah Nabieha , Wan Ahmad Kamil Wan Maryam , Halim Mohd Mahadi , Wan Ismail Wan Zakiah 
Published: October 2024

Abstract
This work explores thermal laser-based nano-sensing capabilities utilising random lasing emission obtained from zinc oxide (ZnO) nanorods prepared by chemical bath deposition. The ZnO nanorods were doped with Aluminum (Al) at a concentration of 10 mM by using a simple dip method for several dip durations of 20 s, 30 s, 40 s, 60 s, 80 s, and 100 s, respectively. Random lasing emission was observed in all samples and was tested on its thermal sensitivity from the increased heat of the nanorod structure. The highest thermal sensitivity of 0.001 °C−1 was obtained from Al-doped ZnO nanorods that were dipped for 60 s. The lasing threshold was 22.92 mJ cm−2 and the lasing spectral width was 1.16 nm.
High-throughput screening of the potential alloying elements for high-strength Mg alloys based on solid-solution strengthening
Authors: Zhou Fei , Huang Jingtao , Liao Mingqing , Xu Chao 
Published: October 2024

Abstract
49 types of alloy atomic dopants and their effects on the doping stability and micro-mechanical behaviour of magnesium matrix were investigated using density functional theory and high throughput first-principles calculations. Geometry optimization was performed for each doping system, and the ability of atom doping into the magnesium matrix was assessed based on the doping energy and atomic radius. Results show that the transition metal elements have negative or near negative doping energy, especially for the elements with a radius that similar to Mg. The micro-mechanical properties of the doping system were evaluated by computing the fracture energy and theoretical tensile stress. Through a screening on the doping stability and strengthening effect of 49 types of alloy atoms, a set of elements (Re, Os, Ir, Tc and W, etc) are screened out that could strengthen the magnesium matrix with a good doping stability. The high throughput screen results serve as a theoretical guide for the selection of appropriate alloy elements for designing the high-strength magnesium alloys in the regime of solid solution strengthening effects.
Enhanced optoelectronic characteristics of La-doped ZnO and its compatibility with Cs-doped MAPbI3 perovskite absorber material
Authors: Tabriz Ayesha , Shahzad Nadia , Pervaiz Hina , Shahzad Muhammad Imran , Nadeem Saad , Mehmood Sana , Ali Ghulam , Iqbal Naseem , Pugliese Diego 
Published: October 2024

Abstract
The present study investigates the structural, electrical and optical characteristics of pristine and lanthanum (La)-doped zinc oxide (ZnO) electron transport layers fabricated by the sol–gel method and their compatibility with Cs0.10MA0.90Pb(I0.9Br0.10)3 absorber layer for perovskite solar cells. All the electron transport layers were deposited under the same deposition conditions, with the only difference in La percentage in the precursor solutions, ranging from 0 to 6%. X-ray diffraction analysis demonstrated the presence of crystalline ZnO thin films and the absence of any impurity phases after La-doping. The calculated crystallite size, determined using Scherrer’s equation, increased from 11.13 to 21.76 nm after the introduction of dopant. The doping with 4% La led to the decrease in the optical band gap from 3.32 eV of pristine ZnO to 3.23 eV. Scanning electron microscopy analysis revealed better morphology of perovskite / 4% La:ZnO specimen, which facilitated the absorbance and reduced the charge carrier recombination. It also exhibited superior resilience towards moisture and humidity which will eventually contribute to the development of more stable and efficient planar perovskite solar cells.
Comprehensive study on the optoelectronic properties of ZnSnP2 compound by DFT and simulation for the application in a photodetector
Authors: Pappu Md Alamin Hossain , Mondal Bipanko Kumar , Shiddique Sheikh Noman , Hossain Jaker 
Published: October 2024

Abstract
This article presents the density function theory (DFT) calculation of ZnSnP2 (ZTP) and its application as a photodetector. A DFT calculation has been performed to determine ZTP’s optical and electronic characteristics. The direct bandgap of ZnSnP2 is found to be 1.0 eV which agrees well with the previously reported bandgap (0.95 eV). The total density of states (TDOS) of ZTP is determined to be 1.40 states/eV which is attributed to the 3p orbital of P, with minor impacts from the 3d orbital of Zn and the 5p orbital of Sn to TDOS. The real and imaginary dielectric functions and refractive indices ZTP have been determined to be 16.44 and 17.60, 4.07 and 2.92, respectively. The absorption coefficient and reflectivity of ZTP obtained from this investigation are 2.6 × 105 cm−1 and 57.5%, respectively. After calculating the electrionic and optical properties, ZTP-based n-CdS/p-ZnSnP2/p+-AlSb photodetector (PD) with CdS and AlSb as the window and back surface field (BSF) layers, respectively, has been computationally analyzed and optimized using solar cell capacitance simulator (SCAPS-1D). In a single heterojunction, the photocurrent, voltage, responsivity, and detectivity values have been obtained at 44.52 mA cm−2, 0.66 V, 0.73 A W−1, and 6.81 × 1013 Jones, respectively. Insertion of a thin AlSb BSF layer improves the photocurrent, voltage, responsivity, and detectivity to 48.75 mA cm−2, 0.78 V, 0.86 A W−1, and 8.22 × 1014 Jones, respectively. The outcomes are highly promising for the fabrication of a high performance ZTP-based PD in the future.
Ensemble Learning for Stellar Classification and Radius Estimation from Multimodal Data
Authors: Deng Zhi-Jie , Yu Sheng-Yuan , Luo A-Li , Kong Xiao , Li Xiang-Ru 
Published: October 2024

Abstract
Stellar classification and radius estimation are crucial for understanding the structure of the Universe and stellar evolution. With the advent of the era of astronomical big data, multimodal data are available and theoretically effective for stellar classification and radius estimation. A problem is how to improve the performance of this task by jointly using the multimodal data. However, existing research primarily focuses on using single-modal data. To this end, this paper proposes a model, Multi-Modal SCNet, and its ensemble model Multimodal Ensemble for Stellar Classification and Regression (MESCR) for improving stellar classification and radius estimation performance by fusing two modality data. In this problem, a typical phenomenon is that the sample numbers of some types of stars are evidently more than others. This imbalance has negative effects on model performance. Therefore, this work utilizes a weighted sampling strategy to deal with the imbalance issues in MESCR. Some evaluation experiments are conducted on a test set for MESCR and the classification accuracy is 96.1%, and the radius estimation performance Mean of Absolute Error and σ are 0.084 dex and 0.149 R
⊙, respectively. Moreover, we assessed the uncertainty of model predictions, confirming good consistency within a reasonable deviation range. Finally, we applied our model to 50,871,534 SDSS stars without spectra and published a new catalog.
Pedestal dynamics and turbulence in H-mode density ramp-up experiment on EAST
Authors: Zhong Fubin , Zhang Tao , Li Gongshun , Geng Kangning , Ye Kaixuan , Yang Shuqi , Zhou Zhen , Zhou Ziqiang , Yu Lin , Huang Jia , Wen Fei , Gao Xiang ,   the EAST Team
Published: October 2024

Abstract
Recent results of density ramp-up (<n
e>/n
GW = 0.5–0.75) experiment in type-I ELMy H-mode on experimental advanced superconducting tokamak are presented, with a focus on pedestal dynamics and turbulence behavior. With the density increase, a general trend is that the pedestal electron pressure (p
e
ped) decreases while the ELM frequency (f
ELM) increases. Especially when <n
e>/n
GW arrives at ∼ 0.68, a sudden decrease of p
e
ped and an increase of f
ELM are observed. A quasi-coherent mode (QCM) with a frequency of 200–300 kHz is observed in the pedestal region and appears in both density and magnetic fluctuations. The time evolution of p
e
ped during the inter-ELM phase is analyzed for different densities. The analysis suggests that the pedestal behavior for <n
e>/n
GW < 0.68 is mainly attributed to pedestal stability but not due to pedestal transport. It is shown that the resistivity effect on the peeling-ballooning (PB) mode (Zhang et al 2017 Phys. Plasmas
24 062108) could be used to explain the present result. But the sudden decrease of p
e
ped and increase of f
ELM at <n
e>/n
GW > 0.68 cannot be attributed to the resistivity effect. It is found that for the plasma with <n
e>/n
GW > 0.68, the QCM disappears just before ELM and the density pedestal becomes steeper. This implies that the QCM can drive outward particle transport. The steeper density pedestal leads to a narrower pedestal width. A narrower pedestal width will lead to a lower pedestal pressure since PB mode limits the pressure gradient and could explain the observed sudden decrease of p
e
ped and increase of f
ELM.
Impact of hot plasma effects on electron cyclotron current drive in tokamak plasmas
Authors: Zheng P.W. , Feng J.L. , Lu L.F. , Yin L. , Huang Q.H. , Gong X.Y. , Zhang F. , He L.H. , Zhong Y.J. 
Published: October 2024

Abstract
Focusing on the impact of hot plasma effects on electron cyclotron current drive (ECCD), this paper presents the numerical results of top launch ECCD (TL-ECCD) and outside midplane or equatorial-plane launch ECCD (EL-ECCD) in the HL-3-like tokamak plasmas. For EL-ECCD, there is little difference in the calculated results under the cold and hot plasma propagation models, and the results are not affected by the dominant current drive mechanism of EC waves. In the cases of TL-ECCD, the large initial parallel refraction makes the influence of hot plasma effects on ECCD become significant. In the range of toroidal magnetic fields B
T discussed in this paper, the difference between the calculated results under the two propagation models rapidly decreases as the value of B
T decreases, and the difference between the two is already very small in the range of 1.8 T ⩽ B
T ⩽ 2.0 T. Therefore, the influence of hot plasma effects can also be neglected for TL-ECCD, and the cold plasma propagation model can be directly adopted. For the HL-3-like tokamak equipped with a dual-frequency EC wave system at 140 GHz and 105 GHz, if the addition of a TL-ECCD is considered in the existing outside midplane and upper launch manners, through appropriate combination of 140 GHz TL-ECCD and dual-frequency outside EL-ECCD, the ECCD can be used in a larger B
T window (1.8 T ⩽ B
T ⩽ 2.25 T) and a wider radial range (0.1 ⩽ ρ ⩽ 0.8–0.9) to generate current efficiently. The normalized current drive efficiency of the TL-ECCD is nonlinear with the injected EC power, it reaches the maximum at the injected power of 6–8 MW. This is of significance for the stable operation of HL-3-like tokamak with high plasma current above 1 MA.