bluuebunny/crossref_metadata_2025_split huggingface dataset:
X-ray sources for in situ wavelength calibration of x-ray imaging crystal spectrometers
Authors: Shah K. , Delgado-Aparicio L. , Kraus B. F. , Ono M. , Gao L. , Umbach B. , Perkins L. , Pablant N. , Hill K. W. , Bitter M. , Teall S. , Drake R. , Schmidt G. 
Published: September 2024

X-ray sources for a range of wavelengths are being considered for in situ calibration of X-ray Imaging Crystal Spectrometers (XICSs) and for monitoring line shifts due to changes in the crystal temperature, which can vary during experimental operation over a day [A. Ince-Cushman et al., Rev. Sci. Instrum. 79, 10E302 (2008), L. Delgado-Aparicio et al., Plasma Phys. Control. Fusion 55, 125011 (2013)]. Such crystal temperature dependent shifts, if not accounted for, could be erroneously interpreted as Doppler shifts leading to errors in plasma flow-velocity measurements. The x-ray sources encompass characteristic x-ray lines falling within the wavelength range of 0.9–4.0 Å, relevant for the XICSs on present and future fusion devices. Several technological challenges associated with the development of x-ray sources for in situ calibration are identified and are being addressed in the design of multiple x-ray tubes, which will be installed inside the spectrometer housing of the XICS for the JT-60SA tokamak. These x-ray sources will be especially useful for in situ calibration between plasma discharges. In this paper, laboratory experiments are described that were conducted with a Cu x-ray source, a heated quartz (102) crystal, and a pixelated Pilatus detector to measure the temperature dependent shifts of the Cu Kα1 and Kα2 lines at 1.5405 and 1.5443 Å, respectively, and to evaluate the 2d-lattice constant for the Bragg reflecting crystal planes as a function of temperature, which, in the case of in situ wavelength calibration, would have to be used for numerical analysis of the x-ray spectra from the plasma.
Observations of Fast Radio Variations in Microquasars by FAST
Authors: Wang 王 Wei 伟 
Published: September 2024

Abstract
Microquasars are the compact objects generally including accreting black holes which produce relativistic jets. The physical mechanisms of jet launching, collimation, and acceleration are poorly understood. Microquasars show strong variability in multi-wavelength observations. In x-rays, the sources show the fast variation features down to millisecond time scales, with the prominent quasiperiodic oscillations (QPOs) around 0.1 Hz–tens of Hz in light curves, however, physical origin of QPOs is still uncertain. FAST as the largest radio telescope provides the opportunity to study fast variability of both radio flux and polarization in microquasars. In the FAST observations from 2020–2022, we reported the first evidence of radio subsecond quasi-periodic oscillations of GRS 1915+105, providing the direct link between QPOs and the dynamics of relativistic jets. These QPOs with the centroid frequency around 5 Hz are transient, accompanied with strong evolution of the spectral index. Combined with multiwavelength observations, we discuss the possible physical models to produce radio QPOs in BH systems: the helical motion of jet knots or precession of the jet base. In near future, high time resolution radio monitoring of microquasars based on FAST is expected to discover more new phenomena in black hole systems, which will be important for understanding the physics in strong gravity.
Measuring the center and the dimension of our Galaxy using globular clusters
Authors: Fabjan Dunja 
Published: September 2024

Abstract
Historical measurements, such as the measurement of the size of our Galaxy and distance to its center, are based on relatively simple assumptions that allow high-school students and undergraduate college students to explore and replicate the basic analysis of astronomical data. Here, I present a practical data analysis exercise that was developed to select Slovenian participants to the International Olympiad on Astronomy and Astrophysics (IOAA). The exercise guides students to discover the globular cluster distribution within our Galaxy, use basic knowledge of spherical astronomy and coordinate transformation, explore the night sky and develop basic skills for the analysis of astronomical data.
Induction heating boosts water splitting on iron–coated nickel foam
Authors: Li Tinghua , Kang Shuai , Li Shoubo , Yang Wendi , Lei Wenbo , Lu Wenqiang , Li Zhiqiang , Zhu Donglai , Zhang Xia , Lei Ping 
Published: September 2024

Abstract
Alkaline water electrolysis at high temperatures can rival acidic proton–exchange membranes. However, they suffer from increased energy consumption, reduced lifespan of materials and heightened safety risks. Magnetic hyperthermia is a method of localizing intense heating in the presence of an external high–frequency alternating magnetic field (AMF). In this study, we developed a custom electromagnetic induction device capable of generating a small magnetic field of about 2 µT. High–permeability nickel foam is used as electrodes. Results show that the iron coated nickel foam decreases the overpotential of the hydrogen evolution reaction (HER) and oxygen evolution reaction by ∼150 mV and 60 mV, respectively, at 20 mAcm−2 when subjected to magnetic heating in a high–frequency AMF. The overall water splitting current of Ni foam/Fe increases 540% under intermittent induction. The enhanced stability of Ni foam/Fe is attributed to the high binding energy of metal–O on the surface. The density function theory calculations further indicates that the lattice expansion of the metal electrode under induction heating optimizes the adsorption and desorption of H*, thereby enhancing the HER performance.
Machine learning assisted crystallographic reconstruction from atom probe tomographic images
Authors: Pu Jie-Ming , Chen Shuai , Zhang Tong-Yi 
Published: September 2024

Abstract
Atom probe tomography (APT) is a powerful technique for three-dimensional (3D) atomic-scale imaging, enabling the accurate analysis on the compositional distribution at the nanoscale. How to accurately reconstruct crystallographic information from APT data, however, is still a great challenge due to the intrinsic nature of the APT technique. In this paper, we propose a novel approach that consists of the modified forward simulation process and the backward machine learning process to recover the tested crystal from APT data. The high-throughput forward simulations on Al single crystals of different orientations generate 10 000 original 3D images and data augmentation is implemented on the original images, resulting in 100 000 3D images. The big data allows the development of deep learning models and three deep learning algorithms of Convolutional Neural Network (CNN), Vision Transformer (ViT), and Variational Autoencoder (VAE) are used in the backward process. After training, the ViT model performs superior than the CNN and VAE models, which can recover the crystalline orientation outstandingly, as evaluated by the coefficient of determination

R
2

and the Mean Percent Error (MPE), viz.,

R
2

= 0.93 and MPE = 0.43%,

R
2

= 0.97 and MPE = 0.35%, and

R
2

= 0.93 and MPE = 0.77% for the rotation angles

ϕ

,

ψ

and

θ

, respectively, on the test dataset. The present work clearly demonstrates the capability of deep learning models in the recovery of the tested crystals from APT data, thereby paving the way for the further development of large artificial intelligent models of APT.
Industrial robot calibration optimization method based on R-optimal criterion and improved IOOPS algorithm
Authors: Jia Huakun , Zeng Hanbo , Zhang Jiyan , Gao Rongke , Lu Yang , Yu Liandong 
Published: September 2024

Abstract
In this paper, a novel kinematic parameter calibration method based on the R-optimal criterion and the improved iterative one-by-one pose search (IOOPS) algorithm is proposed to improve the end-effector positioning accuracy of industrial robots. First, a novel industrial robot error calibration model based on the product of exponential model and generalized error model is established, and the ideal pose transformation matrix from the robot base coordinate system to the laser tracker measurement coordinate system is obtained using the least-squares method, thereby obtaining the initial parameter vector of the robot calibration system. Second, various joint angle values at different positions within the robot’s workspace and the corresponding end-effector coordinate data, namely calibration sampling point data, are collected. Subsequently, the improved IOOPS algorithm combined with the observability index

O

R

proposed by the R-optimal criterion is used to select the optimized calibration sampling points. Finally, the optimized sampling point data are combined with the Levenberg–Marquardt algorithm to optimize the parameters and obtain the optimal kinematic parameters. The experimental results show that the average end-effector error of the robot decreases from 0.5822 to 0.2492 mm after calibration using this method, demonstrating the effectiveness of the optimized sampling points in the calibration process achieved through the improved algorithm and the new observability index.
A novel autonomous exploration algorithm via LiDAR/IMU SLAM and hierarchical subsystem for mobile robot in unknown indoor environments
Authors: Gao Zhilin , Xie Fei , Huang Yihan , Zhao Jing , Luo Haisen , Yan Xinchen , Zhao Fei , Lv Pin 
Published: September 2024

Abstract
Autonomous exploration in unknown environments is an essential capability for mobile robots. The complexity of autonomous exploration, however, means that existing algorithms struggle to balance efficiency and comprehensiveness, causing low mapping accuracy and redundant path planning. To perform accurate and efficient exploration tasks, we have proposed a novel autonomous exploration algorithm via LiDAR/IMU (Inertial Measurement Unit) Simultaneous Localization and Mapping (SLAM) and hierarchical subsystem for mobile robot in unknown environments. Firstly, to enhance mapping accuracy for mobile robot exploration, LiDAR/IMU SLAM is improved with the assistance of backward propagation and iterated Kalman filter, and Bidirectional Rapidly–Exploring Random Trees* (BI–RRT*) is applied for efficient frontier point detection. Secondly, we optimize local path planning by leveraging information theory through perceptual quality evaluation, which is then integrated with global path planning utilizing an enhanced Travelling Salesman Problem solver and a sparse grid map to amplify exploration efficiency. Thirdly, an enhanced hierarchical autonomous exploration method for mobile robots is proposed, which incorporates local path planning for seamless navigation around highly promising exploration spots, coupled with global path planning to effectively interconnect various sub–regions. Finally, simulations and field tests have demonstrated that the proposed method explores an unknown indoor environment with a 30.8% reduction in exploration time and a 29.9% reduction in exploration path in comparison with Dynamic Stage Viewpoint Planner. The map constructed in this paper has more accurate details and exploration paths have been shortened to ensure effective exploration.
Chaos-driven detection of methylene blue in wastewater using fractional calculus and laser systems
Authors: Martínez-Ayala Lizeth , Bornacelli Jhovani , Ojeda-Misses Manuel Alejandro , Arano-Martinez Jose Alberto , Torres-Torres Carlos , Martines-Arano Hilario 
Published: September 2024

Abstract
Methylene blue (MB) concentrations in residual water were detected using fractional calculus, the Rössler chaotic attractor and laser systems. A Nd:YVO4 nanosecond pulsed laser at 532 nm, with pulse energies ranging from 2 µJ to 7 µJ, was applied to irradiate different water samples containing MB concentrations from 20 µl to 100 µl. Fractional calculus was employed with the purpose of modeling the temperature distribution in the samples, with the Caputo fractional derivative describing photothermal effects induced by laser irradiation. Different MB concentrations were detected by using the Rössler chaotic attractor, it monitored variation on concentrations, associating attractor shapes with MB concentrations. Lower concentrations showed a weaker attractor response, whereas higher concentrations manifest stronger attractor shapes in magnitude. Raman spectroscopy confirmed the detection of MB in residual water from the Requena dam, located in Tepeji del Río de Ocampo, Hidalgo, Mexico. The application of fractional calculus improved the prediction of heat distribution in the samples, by incorporating numerical simulation. The results suggest that this approach is suitable for real-time monitoring, as it associates MB concentrations with distinct chaotic attractor shapes. This technique shows promise for the detection of other contaminants as well. Future research should focus on refining this method and expanding its application to develop innovative monitoring solutions.
In situ Raman investigation to electrochemical synthesis of ammonia on Pd nanocrystals
Authors: Bai Xiaoxia , Luo Jingying , Wu Keming , Sun Congcong , Pang Haili , Zhang Hui , Khosla Ajit 
Published: September 2024

Abstract
Nitrate and nitrite are widely present in industrial wastewater and domestic sewage, so electrocatalytic reduction of both nitrate and nitrite to ammonia synthesis is considered to be a sustainable development approach. Pd nanostructures have attracted much attention because of their high activity in catalyzing the nitrate electrochemical reduction reaction. Here we prepare Pd nanocube and octahedron for the electrochemical reduction of nitrate and nitrite. It is found that Pd octahedron shows slightly higher activity toward nitrate reduction than Pd nanocube, while for nitrite reduction, Pd octahedron shows much higher activity than Pd nanocube. The ammonia yield rate is more potential–dependent. In situ Raman characterization further confirms the existence of adsorbed ammonia on the surface of nanocube and octahedron, indicating similar reduction pathways on (111)–facet octahedron and (100)–facet nanocube.
Commissioning of the tracer-encapsulated solid pellet (TESPEL) injection system for Wendelstein 7-X and first results for OP1.2b
Authors: Bussiahn R , Tamura N , McCarthy K J , Buttenschön B , Brandt C , Dinklage A , Langenberg A ,   the W7-X Team
Published: September 2024

Abstract
A new tracer-encapsulated solid pellet (TESPEL) injection system was successfully commissioned for the stellarator fusion experiment Wendelstein 7-X (W7-X) during its OP1.2b operational campaign. TESPELs are polystyrene encapsulated solid pellets loaded with tracer impurities that have been employed in other stellarator devices for impurity transport studies. During the OP1.2b campaign approximately 140 pellet injections were performed with a successful delivery rate of 89%, thus this system has proven to be very reliable. Here, the experimental set-up and methodology are described first. In addition, it is outlined how, through the analysis of TESPEL time-of-flight signals and of the temporal evolution of line emissions originating from shell and tracer species as well as comparisons with ablation models, the radial localization of the deposited tracer is determined. This contribution also provides a general overview of the TESPEL injector performance during OP1.2b, discusses the global effects of TESPEL injections on W7-X plasmas and reports on first results in terms of a summary of TESPEL injections, plasma response to TESPELs, the post-deposition evolution of tracer spectral emission lines and soft x-ray emissions.
Experimental determination of the sulfur K-shell fundamental parameters employing the holistic approach
Authors: Hönicke Philipp 
Published: September 2024

Abstract
Sulfur and its compounds are both very abundant in the environment and very important for technological applications such as batteries. X-ray spectroscopic characterizations of sulfur compounds for a quantitative determination of the present amount of sulfur often requires a good knowledge on the atomic fundamental parameters involved. These quantitatively describe the processes of photoionization and x-ray fluorescence emission, making them crucial for x-ray spectroscopy-based quantifications. By employing the recently demonstrated holistic approach, the atomic fundamental parameters of the sulfur K-shell were experimentally determined using the radiometrically calibrated instrumentation of the Physikalisch-Technische Bundesanstalt. The transition probabilities of the main K-shell fluorescence lines, the K-shell fluorescence yield, the K-shell Auger yield, the subshell photoionization cross section and fluorescence production cross section were determined by means of photon energy dependent x-ray fluorescence and transmission measurements on a thin InS coated silicon nitride membrane. The results are also downloadable from Zenodo as plain text.
Electrically switchable behavior in coupled EIT-like meta-molecule and Fabry-Pérot cavity
Authors: Yang Lei , Gao Lei , Jiang Rui , He Wenzhe , Wang Jun , Wu Qian , Sun Yong , Wu Quanying , Chen Yongqiang 
Published: September 2024

Abstract
In this paper, we propose a microstrip Fabry–Pérot (FP) cavity embedded with an active electromagnetically-induced-transparency-like (EIT-like) meta-molecule to investigate the electrically switchable behavior. The phenomenon of EIT is achieved by coupling a ‘bright’ comb-line resonator with a ‘dark’ split-ring resonator. The FP cavity is fabricated by etching two narrow slots on a microstrip line. With two different resonance mechanisms working together, the proposed composite EIT-cavity design is shown to exhibit the enhanced EIT-like transmission characteristics, accompanied by two sharp Fano-type line-shapes. By incorporating PIN diodes into the composite EIT-cavity structure, we can dramatically modulate the transmission spectrum via external DC voltage. In particular, we show the multi-band unity modulations through biasing the proposed active samples. Moreover, the slow light on-to-off switching processes are also obtained with modifying the state of PIN diode from dielectric to conductive. Our results may open important opportunities for fabricating dynamic functional photonic devices in the future.
Disconnection of edge coherent modes between the outer midplane and divertor target in EAST H-mode plasma
Authors: Zhou Z.Q. , Zhang T. , Long F.F. , Zhou Z. , Geng K.N. , Ye K.X. , Zhong F.B. , Shi Q.Q. , Li G.S. , Huang J. , Yu L. , Yang S.Q. , Wen F. , Ma J.Y. , Meng L.Y. , Liu H.Q. , Zhao H.L. , Ye Y. , Wang L. , Gao X. ,   the EAST Team
Published: September 2024

Abstract
The edge coherent mode (ECM) is considered a highly attractive pedestal mode because it extends the duration of edge-localized modes and increases particle and impurity transport without significantly affecting energy transport. Moreover, it operates compatibly with high-performance plasma discharges. The ECM can also be detected using Langmuir probes on the divertor target plate, indicating that it extends from the pedestal region into the SOL and resulting in a connection to the divertor target plate via magnetic field lines. In this work, the distribution of ECM on divertor target plates is investigated by analyzing 215 upper single null discharges on the EAST tokamak. The coherence analysis of plasma fluctuations between the electron cyclotron emission signal in the pedestal region of the outer midplane and the ion saturation current measured by Langmuir probes in the divertor region reveals that the ECM is hardly detected by the divertor probe close to the outer strike point but can be observed at far SOL. This finding indicates the presence of an ECM quiescent region near the SOL on the divertor plate, and the extent of the quiescent region in the poloidal flux coordinate (Δ) has been statistically analyzed. A pronounced relationship between Δ and triangularity (δ) has been observed, that is Δ increasing with δ. Further analysis reveals that this relationship can be attributed to the average magnetic shear in the SOL. This result is consistent with the physical picture, which states that strong magnetic shear close to X-point significantly squeezes the cross-section of flux tubes down to scales dominated by collisions.
Quantum positive matrix-positive matrix multiplication algorithm
Authors: Yang Jinchuan , He Shiping , Bai Mingqiang , Mo Zhiwen 
Published: September 2024

Abstract
In quantum computing, matrix multiplication occurs as a subroutine in more complex algorithms. We improve the quantum linear system algorithm (Harrow et al 2009 Phys. Rev. Lett.
103 150502) to perform sparse matrix-matrix multiplication and propose a subroutine for parallel vector addition. Based on them, a quantum algorithm is exhibited for N × N positive matrix-positive matrix multiplication. For some small ratio of the maximum element to the minimum element of the positive matrices (i.e.

O

(
poly
log
⁡

N

)), this algorithm achieves exponential acceleration.
Detection of carbon monoxide using a polarization-multiplexed erbium dual-comb fiber laser
Authors: Collin Aldia P E , Chen Jiayang , K C Ballentin Jonas , W Perner Lukas , Heckl O H 
Published: September 2024

Abstract
We present a simple method to develop a compact, reliable, and robust free-running erbium single-cavity dual-comb (DC) laser via polarization multiplexing. The key features of our design include dynamic tuning in the difference in repetition rates of the laser, long-term stability, and the use of off-the-shelf components. Polarization multiplexing exploits the fast and slow axes of the fiber, while modelocking is achieved through a nonlinear amplifying loop mirror scheme using readily available components. The laser operates at a repetition rate of around 74.74 MHz with a tuning capability in the difference in repetition rates from 500 Hz to 200 kHz. This tunability makes the system more flexible for DC spectroscopy experiments. Consequently, using this laser, we demonstrated a proof-of-principle DC spectroscopy of carbon monoxide, operating without any active stabilization.
The Fourth Symphony, Musically Considered
Authors: Korstvedt Benjamin M 
Published: September 2024

Abstract
This chapter is an in-depth exploration of the music of the Fourth. It begins by considering the challenges Bruckner’s music poses for listeners and analysts. The chapter then discusses the form and content of each movement in detail, pinpointing essential elements of Bruckner’s musical vocabulary and structural devices that operate throughout the symphony. Building on ideas drawn from the work of the Swiss music theorist Ernst Kurth, the chapter emphasizes the dynamic nature of Bruckner’s musical designs. It concludes by identifying a network of “subthematic” musical connections that span the entire symphony and provide the work with a level of musical continuity and emotional affirmation that has not previously been recognized.