bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analyzing facial action units in children to differentiate genuine and fake pain during inferior alveolar nerve block: a cross-sectional study
Authors: Alkhouli Muaaz , Al-Nerabieah Zuhair , Dashash Mayssoon 
Published: September 2023

AbstractThis study aimed to investigate the association between facial action units and pain levels in Syrian children, focusing on both genuine and fake pain expressions. A total of 300 Syrian children aged 6–9 years participated in the study. Pain levels were assessed using the validated Face, Legs, Activity, Cry, Consolability scale, and facial expressions were analyzed using the Facial Action Coding System. The children were asked to mimic their feelings after receiving a dental injection to elicit fake pain expressions. Statistical analysis, including multinomial logistic regression and chi-square tests, was conducted to determine the Action Units (AUs) associated with each pain level and to compare the differences between real and fake pain expressions. The results revealed significant associations between specific AUs and pain levels. For real pain expressions, the most activated AUs across different pain levels with positive coefficient values of correlation (P-value < 0.01) were analyzed. In contrast, for fake pain expressions, AU12 and AU38 were consistently observed to be the most activated. These findings suggest that certain AUs are uniquely associated with fake pain expressions, distinct from those observed in real pain expressions. Furthermore, there were no significant differences between boys and girls in terms of their genuine and fake pain expressions, indicating a similar pattern of AU activation (P-value > 0.05). It was concluded that AUs 4, 6, 41, and 46 were associated with mild pain, and AUs 4, 6, 41, 46, and 11 were associated with moderate pain cases. In severe pain, AUs 4, 6, 7, 9, 11, and 43 were associated. In fake pain feelings, AU43, AU38, and AU12 were the most activated with no difference between boys and girls.
Study on the forming characteristics of polytetrafluoroethylene/copper jet with different preparation processes
Authors: Yi Jianya , Hao Ruijie , Tang XueZhi , Guan Siman , Wang Zhijun , Yin Jianping 
Published: September 2023

AbstractIn this paper, PTFE/Cu composite material for liner is taken as the research object, and the preparation process and jet forming characteristics of PTFE/Cu composite liner are studied. The liners were prepared by extrusion molding, molded sintering and hot-pressing sintering. Due to different preparation processes, different microstructures of the liner can occur, including defects such as pores and microcracks, resulting in different strength and density of the liner, leading to differences in the forming characteristics of the jet. Therefore, the forming process of the jet was simulated by the finite element numerical simulation software. It was found that there was obvious radial expansion effect in the head of the jet, but with the increase of density, the radial expansion effect was weakened, and the jet velocity decreased gradually. The strength and densification of the shaped charge liner prepared by different processes were different. The densification of the molded sintering liner was generally better than that of the other two kinds of shaped charge liners. As a result, the velocity of the jet formed by the molded sintering liner is always the highest, with a numerical simulation velocity of 6642 m/s and an experimental velocity of 6534.7 m/s. The second is the jet of the hot-pressing sintering liner and the lowest velocity is the jet of the extrusion molding cover, with a numerical simulation velocity of 6482 m/s, while the experimental velocity is only 6397.9 m/s. The jet velocity measured by the pulse X-ray experiment was compared with the velocity of the numerical simulation, and the error was within 2.96%, which verifies the accuracy of the numerical simulation.
High-latitude vegetation changes will determine future plant volatile impacts on atmospheric organic aerosols
Authors: Tang Jing , Zhou Putian , Miller Paul A. , Schurgers Guy , Gustafson Adrian , Makkonen Risto , Fu Yongshuo H. , Rinnan Riikka 
Published: September 2023

AbstractStrong, ongoing high-latitude warming is causing changes to vegetation composition and plant productivity, modifying plant emissions of biogenic volatile organic compounds (BVOCs). In the sparsely populated high latitudes with clean background air, climate feedback resulting from BVOCs as precursors of atmospheric aerosols could be more important than elsewhere on the globe. Here, we quantitatively assess changes in vegetation composition, BVOC emissions, and secondary organic aerosol (SOA) formation under different climate scenarios. We show that warming-induced vegetation changes largely determine the spatial patterns of future BVOC impacts on SOA. The northward advances of boreal needle-leaved woody species result in increased SOA optical depth by up to 41%, causing cooling feedback. However, areas with temperate broad-leaved trees replacing boreal needle-leaved trees likely experience a large decline in monoterpene emissions and SOA formation, causing warming feedback. We highlight the necessity of considering warming-induced vegetation shifts when assessing land radiative feedback on climate following the BVOC-SOA pathway.
Revealing inverted chirality of hidden domain wall states in multiband systems without topological transition
Authors: Jeong Seung-Gyo , Han Sang-Hoon , Kim Tae-Hwan , Cheon Sangmo 
Published: September 2023

AbstractChirality, a fundamental concept from biological molecules to advanced materials, is prevalent in nature. Yet, its intricate behavior in specific topological systems remains poorly understood. Here, we investigate the emergence of hidden chiral domain wall states using a double-chain Su-Schrieffer-Heeger model with interchain coupling specifically designed to break chiral symmetry. Our phase diagram reveals single-gap and double-gap phases based on electronic structure, where transitions occur without topological phase changes. In the single-gap phase, we reproduce chiral domain wall states, akin to chiral solitons in the double-chain model, where chirality is encoded in the spectrum and topological charge pumping. In the double-gap phase, we identify hidden chiral domain wall states exhibiting opposite chirality to the domain wall states in the single-gap phase, where the opposite chirality is confirmed through spectrum inversion and charge pumping as the corresponding domain wall slowly moves. By engineering gap structures, we demonstrate control over hidden chiral domain states. Our findings open avenues to investigate novel topological systems with broken chiral symmetry and potential applications in diverse systems.
A swin transformer based bird nest detection approach with unmanned aerial vehicle images for power distribution and pole towers
Authors: Meng Yue , Song Yu , Chen Yuquan , Zhang Xin , Wu Mei , Du Biao 
Published: September 2023

AbstractThe authors propose a novel object detection algorithm for identifying bird nests in medium voltage power line aerial images, which is crucial for ensuring the safe operation of the power grid. The algorithm utilises an improved Swin Transformer as the main feature extraction network of Fast R‐CNN, further enhanced with a channel attention and modified binary self‐attention mechanism to improve the feature representation ability. The proposed algorithm is evaluated on a newly constructed image dataset of medium voltage transmission lines containing bird nests, which are annotated and classified. Experimental results show that the proposed algorithm achieves satisfied accuracy and robustness in recognising bird nests compared to traditional algorithms.
Feature selection algorithm for substation main equipment defect text mining based on natural language processing
Authors: Mai Xiaoqing , Zhang Tianhu , Hu Changwu , Zhang Yan 
Published: September 2023

AbstractThe dimension of relevant text feature space and feature weight of substation main equipment defect information is high, so it is difficult to accurately select mining features. The Natural Language Processing (NLP) medium and short‐term neural network model is used to realise the defect information text feature word segmentation in the log. After extracting the text features of defect information of main substation equipment with high categories to form the feature space; the TF‐IDF algorithm is designed to calculate the importance weight of text keywords, judge the criticality of defect information text feature vocabulary, accurately locate defect information text features, and realise defect information text feature mining. Experiments show that the algorithm has high precision for specific word segmentation of massive substation main equipment log information.
PDE‐constrained model predictive control of open‐channel systems
Authors: Xie Yongfang , Zeng Ningjun , Zhang Shaohui , Cen Lihui , Chen Xiaofang 
Published: September 2023

AbstractA PDE‐constrained model predictive control (MPC) algorithm for open‐channel systems based on the Saint‐Vevant(S‐V) equations is investigated in this paper. The S‐V equations, which precisely model the dynamics of open‐channel systems, are quasi‐linear hyperbolic partial differential equations (PDEs) without analytical solutions. Directly applying the S‐V equations to an MPC controller design becomes sophisticated. In this work, the calculus of variation is used to obtain the adjoint equations and the adjoint analysis method is utilized to deduce the gradients of the MPC optimization problem. Particularly, the physical constraints involving both the state and control variables are also considered. A gradient‐based optimization algorithm in combination with the numerical computation of Preissmann implicit scheme is proposed to solve the constrained MPC optimization problem. The control performances of the developed PDE‐constrained MPC algorithm with respect to the controlled water levels and gate openings are compared with those of the MPC controller designed for the linearized model. All the simulation tests are carried out on an aqueduct reach in Yehe Irrigation District in Hebei Province, China. The results show that the proposed PDE‐constrained MPC algorithm is a promising method in dealing with the constraints in terms of hyperbolic PDEs, control variables and state variables simultaneously.
A dual P‐layer 4H‐SiC p‐i‐n photodetector for the detection from extreme ultraviolet to ultraviolet‐A
Authors: Zhang Ruijun , Liu Jia , Liu Geng , Yao Liang , Liu Ying , Hong Rongdun , Zhang Feng 
Published: September 2023

AbstractA dual P‐layer 4H‐SiC p‐i‐n ultraviolet photodetector is proposed and studied. The modeling results of the photoelectric characteristics demonstrate the dual P‐layer structure could effectively reduce the recombination of the photogenerated carriers and separate more electron‐hole pairs near the surface of the device. And, the photodetector exhibits a significantly high response and detectivity, especially in the wavelength range of extreme ultraviolet to ultraviolet‐C. A high spectral response peak of 0.2 A/W corresponding to a quantum efficiency of 95.3% is achieved. Furthermore, an avalanche breakdown voltage as low as 182 V is observed. The dual P‐layer structure significantly presents an innovative approach for the advancement of future ultraviolet photodetectors applied in the detection at illumination wavelengths ranging from extreme ultraviolet to ultraviolet‐A.
Research on cogging torque reduction method for permanent magnet synchronous motor accounting for the magnetic pole edge effect
Authors: Yan Dong , Yan Yan , Cheng Yiqiu , Guo Liyan , Shi Tingna 
Published: September 2023

AbstractDue to the existence of the magnetic pole edge effect, the actual cogging torque of the existing segmented step skew motor does not reach the theoretical minimum. Thus, a method for suppressing cogging torque of permanent magnet synchronous motor considering the magnetic pole edge effect is proposed. The magnetic pole edge effect is creatively converted into the amplitude and phase offset of the cogging torque generated by each pole segment. On this basis, an optimization problem is constructed in which the fundamental component of cogging torque is zero and the total harmonics is minimum. The optimal magnetic pole length and skew angle parameters of each segment are obtained by solving the optimization problem quantitatively. The results can provide theoretical guidance for motor design, which can minimize the cogging torque of step skew structures. The effectiveness of the proposed method in weakening the cogging torque of the step skew motor is demonstrated by theoretical calculation, 3D finite element analysis, and experimental results.
The effect of Jupiter on the CAI storage problem
Authors: Jongejan S. , Dominik C. , Dullemond C.P. 
Published: September 2023

Context. Meteorites preserve an imprint of conditions in the early Solar System. By studying the distribution of calcium-aluminium-rich inclusions (CAIs) that are embedded within meteorites, we can learn about the dynamical history of the protoplanetary disk from which our Solar System formed. A long-standing problem concerning CAIs is the CAI storage problem. CAIs are thought to have formed at high temperatures near the Sun, but they are primarily found in carbonaceous chondrites, which formed much further out, beyond the orbit of Jupiter. Additionally, radial drift of CAI particles should have removed them from the solar protoplanetary disk several million years before the parent bodies of meteorites in which they are encountered would have accreted.
Aims. We revisit a previously suggested solution to the CAI storage problem by Desch, Kalyaan, and Alexander which proposed that CAIs were mixed radially outward through the disk and subsequently got trapped in a pressure maximum created by Jupiter’s growing core opening a planet gap. Our aim is to investigate whether their solution still works when we take into account the infall phase during which the disk builds up from the collapse of a molecular cloud core.
Methods. We build a 1D numerical code in Python using the DISKLAB package to simulate the evolution of the solar protoplanetary disk, starting with a collapsing molecular cloud. CAIs are created in the model by thermal processing of solar nebula composition dust, and subsequently transported through the disk by turbulent diffusion, radial drift and advection by the gas.
Results. We find that outward transport of CAIs during the infall phase is very efficient, possibly mixing them all the way into the far outer disk. Subsequent inward radial drift collects CAIs in the pressure maximum beyond Jupiter’s orbit while draining the inner disk, roughly reproducing parts of the result by Desch et al. By introducing CAI formation so early, abundances out to 100 AU remain significant, possibly not consistent with some meteoritic data. It is possible to create a disk that does not expand as far out and also does not push CAIs as far out by using a very slowly rotating cloud.
A new measurement of the expansion history of the Universe at z = 1.26 with cosmic chronometers in VANDELS
Authors: Tomasetti E. , Moresco M. , Borghi N. , Jiao K. , Cimatti A. , Pozzetti L. , Carnall A. C. , McLure R. J. , Pentericci L. 
Published: September 2023

Aims. We aim to derive a new constraint on the expansion history of the Universe by applying the cosmic chronometers method in the VANDELS survey, studying the age evolution of high-redshift galaxies with a full-spectral-fitting approach.
Methods. We selected a sample of 39 massive (log(M⋆/M⊙) > 10.8) and passive (log(sSFR/yr−1) < −11) galaxies from the fourth data release of the VANDELS survey at 1 < z < 1.5. To minimise the potential contamination by star-forming outliers, we selected our sample by combining different selection criteria, considering both photometric and spectroscopic information. The analysis of the observed spectral features provides direct evidence of an age evolution with redshift and of mass-downsizing, with more massive galaxies presenting stronger age-related features. To estimate the physical properties of the sample, we performed full spectral fitting with the code BAGPIPES, jointly analysing spectra and photometry of our sources without any cosmological assumption regarding the age of the population.
Results. The derived physical properties of the selected galaxies are characteristic of a passive population, with short star formation timescales (⟨τ⟩ = 0.28 ± 0.02 Gyr), low dust extinction (⟨AV, dust⟩ = 0.43 ± 0.02 mag), and sub-solar metallicities (⟨Z/Z⊙⟩ = 0.44 ± 0.01) compatible with other measurements of similar galaxies in this redshift range. The stellar ages, even if no cosmological constraint is assumed in the fit, show a decreasing trend compatible with a standard cosmological model, proving the robustness of the method in measuring the ageing of the population. Moreover, they show a distinctive mass-downsizing pattern, with more massive galaxies (⟨log(M⋆/M⊙)⟩ = 11.4) being older than less massive ones (⟨log(M⋆/M⊙)⟩ = 11.15) by ∼0.8 Gyr. We thoroughly tested the dependence of our results on the assumed SFH, finding a maximum 2% fluctuation on median results using models with significantly different functional forms. The derived ages are combined to build a median age–redshift relation, which we used to perform our cosmological analysis.
Conclusions. By fitting the median age–redshift relation with a flat ΛCDM model, assuming a Gaussian prior on ΩM, 0 = 0.3 ± 0.02 from late-Universe cosmological probes, we obtain a new estimate of the Hubble constant H0 = 67−15+14 km s−1 Mpc−1. In the end, we derive a new estimate of the Hubble parameter by applying the cosmic chronometers method to this sample, deriving a value of H(z = 1.26) = 135 ± 65 km s−1 Mpc−1 considering both statistical and systematic errors. While the error budget in this analysis is dominated by the scarcity of the sample, this work demonstrates the potential strength of the cosmic chronometers approach up to z > 1, especially in view of the next incoming large spectroscopic surveys such as Euclid.
Testing external photoevaporation in the σ-Orionis cluster with spectroscopy and disk mass measurements
Authors: Maucó K. , Manara C. F. , Ansdell M. , Bettoni G. , Claes R. , Alcala J. , Miotello A. , Facchini S. , Haworth T. J. , Lodato G. , Williams J. P. 
Published: September 2023

Context. The evolution of protoplanetary disks is regulated by an interplay of several processes, either internal to the system or related to the environment. As most of the stars and planets, including our own Solar System, have formed in massive stellar clusters that contain OB-type stars, studying the effects of UV radiation on disk evolution is of paramount importance.
Aims. For this work, we tested the impact of external photoevaporation on the evolution of disks in the mid-age (~3–5 Myr) σ-Orionis cluster by conducting the first combined large-scale UV to IR spectroscopic and millimeter-continuum survey of this region.
Methods. We studied a sample of 50 targets located at increasing distances from the central, massive OB system σ-Ori. We combined new spectra obtained with VLT/X-shooter, used to measure mass accretion rates and stellar masses, with new and previously published ALMA measurements of disk dust and gas fluxes and masses.
Results. We confirm the previously found decrease in Mdust in the inner ~0.5 pc of the cluster. This is particularly evident when considering the disks around the more massive stars (≥0.4 M⊙), where those located in the inner part (<0.5 pc) of the cluster have Mdust about an order of magnitude lower than the more distant ones. About half of the sample is located in the region of the Ṁacc versus Mdisk expected by models of external photoevaporation, namely showing shorter disk lifetimes than expected for their ages. The shorter disk lifetimes is observed for all targets with a projected separation from σ-Ori < 0.5 pc, proving that the presence of a massive stellar system affects disk evolution.
Conclusions. External photoevaporation is a viable mechanism to explain the observed shorter disk lifetimes and lower Mdust in the inner ~0.5 pc of the σ-Orionis cluster, where the effects of this process are more pronounced. Follow-up observations of the low stellar mass targets are crucial to constrain disk dispersion timescales in the cluster and to confirm the dependence of the external photoevaporation process with stellar host mass. This work confirms that the effects of external photoevaporation are significant down to at least impinging radiation as low as ~104 G0.
The Electrocyclization of Heptatrienyl Anions
Authors: Orellana Arturo , Komijani Samira 
Published: September 2023

AbstractThe thermal electrocyclization of heptatrienyl anions is reviewed. We begin with a succinct background on the importance of cycloheptane rings in complex molecules and a brief survey of approaches to their synthesis. We also review the fundamental aspects of this electrocyclization manifold, relying on the Woodward–Hoffmann rules for pericyclic chemistry. Then we survey the literature, covering the burst of discovery in the late 1960s and early 1970s, and the more sporadic reports in from the 1990s to the present day.1	Introduction2	The Electrocyclization of Heptatrienyl Anions3	Discovery and Early Development (1964–1975)4	Recent Developments (1996–2023)5	Concluding Remarks
High accuracy, high dynamic range optomechanical accelerometry enabled by dual comb spectroscopy
Authors: Long D. A. , Stroud J. R. , Reschovsky B. J. , Bao Y. , Zhou F. , Bresler S. M. , LeBrun T. W. , Plusquellic D. F. , Gorman J. J. 
Published: September 2023

Cavity optomechanical sensors can offer exceptional sensitivity; however, interrogating the cavity motion with high accuracy and dynamic range has proven to be challenging. Here, we employ a dual optical frequency comb spectrometer to readout a microfabricated cavity optomechanical accelerometer, allowing for rapid simultaneous measurements of the cavity’s displacement, finesse, and coupling at accelerations up to 24 g (236 m/s2). With this approach, we have achieved a displacement sensitivity of 2 fm Hz−1/2, a measurement rate of 100 kHz, and a dynamic range of 7.6 × 105, which is the highest we are aware of for a microfabricated cavity optomechanical sensor. In addition, comparisons of our optomechanical sensor coupled directly to a commercial reference accelerometer show agreement at the 0.5% level, a value that is limited by the reference’s reported uncertainty. Furthermore, the methods described herein are not limited to accelerometry but rather can be readily applied to nearly any optomechanical sensor where the combination of high speed, dynamic range, and sensitivity is expected to be enabling.