bluuebunny/crossref_metadata_2025 huggingface dataset:
Awareness to Orthodontics among a Sample of Final Year Dental Students
Authors: Kadhom Zainab Mousa , Hassan Alaa Faleh Albo , Kadhum Hossam Ibrahim , Nahidh Mohammed , Marrapodi Maria Maddalena , Russo Diana , Cicciù Marco , Minervini Giuseppe
Published: September 2024

Objective Because of esthetic demand, awareness about orthodontic treatment has increased nowadays, especially among young people and adolescents, in addition to the fact that knowledge of orthodontics and various details of it is more significant among dental students according to what they learned in their curricula and their examination and observation of many cases of malocclusion. The objective of the present study was to evaluate the awareness of the final year of undergraduate dental students toward orthodontics.

Materials and Methods About 532 (320 females and 212 males) students in the fifth year of six Iraqi universities were invited to participate in this questionnaire distributed via the Google classroom. This questionnaire included 20 questions about orthodontics. Pearson's chi-square test evaluated the gender and universities differences.

Results In general, the awareness responses were very high in most of the questions answered except in three questions in which the percentage of positive answers varies from 49 to 76%. Also, there were no significant gender differences in 17 question answers, and only 3 showed significant gender differences. Females expressed a high level of awareness than males.

Conclusion The high and close level of awareness expressed by students' responses in this study revealed the integrated education in orthodontic sciences in Iraqi dental colleges in different universities, except in some questions that deal with topics about the acceleration of tooth movement and the relation between vitamin D3 and teeth movement.
A Survey of Preoperative, Perioperative, and Postoperative Management Practices for Testicular Torsion in Pediatric Patients among European Surgeons
Authors: Beher Amit , Moreno-Alfonso Julio César , Garnier Hanna , Darici Dogus , Salö Martin Jonathan , Aubert Ophelia
Published: September 2024

Introduction Management of testicular torsion varies between specialties resulting in lack of standardization. The aim of this survey was to assess pre-, peri-, and postoperative differences.

Methods An online questionnaire was distributed in 2023 to general and pediatric surgeons, pediatric urologists, and urologists by the Trainees of European Pediatric Surgery.

Main Results Among 88 respondents (92% tertiary referral hospital), 38% always or usually perform sonography in case of suspected torsion respectively. In addition, 15% always attempt manual detorsion and 44% depending on the clinical presentation. Most surgeons (93%) favor a scrotal approach. Interestingly, pediatric surgeons choose a transscrotal while other specialties opt for a midline incision (p = 0.002). The majority (57%) employ a three-point fixation, while 42% opt for a two-point fixation. In case of necrotic testis, 61% puncture the testis with 52% opting for surgical removal, while 33% perform orchiectomy and 6% leave it in situ. Regarding necrotic or borderline-appearing testis, 54% take a biopsy. Furthermore, 82% perform prophylactic orchidopexy of the contralateral side during the same session. Postoperative antibiotics are always administered by 12%, while 52% do so sometimes. Most perform sonographic (58%) or clinical (57%) follow-up 3 months postoperatively. Notably, pediatric surgeons and urologists perform follow-up more frequently themselves, while general surgeons/urologists recommend follow-up by pediatricians (p = 0.002). In addition, 76% of responders affirm adhering to European Association of Urology guidelines. Unawareness of guidelines and institutional practices are reasons most commonly cited for nonadherence.

Conclusion Our study reveals significant disparities in the pre-, peri-, and postoperative management of testicular torsion underscoring the need for establishing standardized practices.
Ferroelectric tunnel junctions based on a HfO2/dielectric composite barrier
Authors: Wu Zhijun , Duan Tianpeng , Tian Zhihong , Jiang Yongheng , Zhou Yichun , Jiang Jie , Yang Qiong
Published: September 2024

The ferroelectric tunnel junction (FTJ), which possesses a simple structure, low power consumption, high operation speed, and nondestructive reading, has attracted great attention for the application of next-generation nonvolatile memory. The complementary metal–oxide–semiconductor-compatible hafnium oxide (HfO2) ferroelectric thin film found in the recent decade is promising for the scalability and industrialization of FTJs. However, the electric performance, such as the tunneling electroresistance (TER) effect, of the current HfO2-based FTJs is not very satisfactory. In this work, we propose a type of high-performance HfO2-based FTJ by utilizing a ferroelectric/dielectric composite barrier strategy. Using density functional theory calculations, we study the electronic and transport properties of the designed Ni/HfO2/MgS/Ni (001) FTJ and demonstrate that the introduction of an ultra-thin non-polar MgS layer facilitates the ferroelectric control of effective potential barrier thickness and leads to a significant TER effect. The OFF/ON resistance ratio of the designed FTJ is found to exceed 4 × 103 based on the transmission calculation. Such an enhanced performance is driven by the resonant tunneling effect of the ON state, which significantly increases transmission across the FTJ when the ferroelectric polarization of HfO2 is pointing to the non-polar layer due to the aroused electron accumulation at the HfO2/MgS interface. Our results provide significant insight for the understanding and development of the FTJs based on the HfO2 ferroelectric/non-polar composite barrier.
Ambulatory ECG noise reduction algorithm for conditional diffusion model based on multi-kernel convolutional transformer
Authors: Wang Huiquan , Zhang Juya , Dong Xinming , Wang Tong , Ma Xin , Wang Jinhai
Published: September 2024

Ambulatory electrocardiogram (ECG) testing plays a crucial role in the early detection, diagnosis, treatment evaluation, and prevention of cardiovascular diseases. Clear ECG signals are essential for the subsequent analysis of these conditions. However, ECG signals obtained during exercise are susceptible to various noise interferences, including electrode motion artifact, baseline wander, and muscle artifact. These interferences can blur the characteristic ECG waveforms, potentially leading to misjudgment by physicians. To suppress noise in ECG signals more effectively, this paper proposes a novel deep learning-based noise reduction method. This method enhances the diffusion model network by introducing conditional noise, designing a multi-kernel convolutional transformer network structure based on noise prediction, and integrating the diffusion model inverse process to achieve noise reduction. Experiments were conducted on the QT database and MIT-BIH Noise Stress Test Database and compared with the algorithms in other papers to verify the effectiveness of the present method. The results indicate that the proposed method achieves optimal noise reduction performance across both statistical and distance-based evaluation metrics as well as waveform visualization, surpassing eight other state-of-the-art methods. The network proposed in this paper demonstrates stable performance in addressing electrode motion artifact, baseline wander, muscle artifact, and the mixed complex noise of these three types, and it is anticipated to be applied in future noise reduction analysis of clinical dynamic ECG signals.
Thermodynamic potential construction and biaxial stress analysis of K0.4Na0.6NbO3 single crystals
Authors: Liu Mingxuan , Hu Chengpeng , Meng Xiangda , Sun Xuejie , Zhang Yao , Xing Bohan , Qiu Ming , Dong Yining , Jin Song , Tian Hao
Published: September 2024

The macroscopic properties of piezoelectric materials can be profoundly influenced by stress. In this research, thermodynamic potential parameters of K0.4Na0.6NbO3 (KNN) single crystals have been experimentally quantified to assess the effects of stress. Leveraging the Landau thermodynamic potential theory, it has been identified that the application of biaxial tensile stress causes a significant elevation in both the piezoelectric property and phase transition temperature in KNN crystals. This transition remarkably extends their working range and improves the material's applicated potential. The coherence between these computational outcomes and experimental data—from the strategic growth of KNN single crystals with internal stress—underscores the reliability of our findings (dielectric constant from 213 to 1274, TO-T from 180 to 234 °C). Additionally, theoretical calculation predicts a potential enhancement in the piezoelectric capabilities of KNN single crystals. This study provides valuable insights for the growth of high-quality piezoelectric crystals and further promotes the application of lead-free piezoelectric materials.
Nanomembrane blazed grating coupler for vertical fiber-chip interface
Authors: Liu Xingyu , Guo Rongxiang , Zhang Shujiao , Zhang Zunyue , Wang Jiaqi , Liu Tiegen , Cheng Zhenzhou
Published: September 2024

Mid-infrared (mid-IR) silicon photonics holds promising applications for the Internet of Things, LiDAR, and optical communications. Perfectly vertical grating couplers are superior mid-IR light coupling techniques, featuring ease of packaging, positioning flexibility, and mass production scalability. However, high-efficiency mid-IR perfectly vertical grating couplers still need to be developed due to the difficulties of efficiently engineering grating directionality and diffracted light at long wavelengths. In this paper, we present a mid-IR nanomembrane blazed grating coupler with segmented structure engineering based on a standard multi-project wafer service. The method is based on exploring the improvement of the grating directionality and modal overlap by combining grating units with different structures and thicknesses. Experimental results showcase a maximum coupling efficiency of −4.4 dB with a 3-dB bandwidth of ∼70 nm at 2100 nm wavelengths. This study contributes to the strategy of designing exceptional grating couplers with multiple functional units, paving the way for developing mid-IR photonic integrated circuits based on silicon photonics foundries.
Signatures of exciton–exciton annihilation in 2DES spectra including up to six-wave mixing processes
Authors: Bubilaitis Vytautas , Abramavicius Darius
Published: September 2024

Two-dimensional electronic spectroscopy (2DES) is a powerful spectroscopic tool that allows us to study the dynamics of excited states. Exciton–exciton annihilation is at least a fifth order process, which corresponds to intrachromophoric internal conversion from the double-excited high-energy chromophoric state into the single-excited state of the same chromophore. At high excitation intensities, this effect becomes apparent in standard 2DES and can be inspected via high order nK1⃗−nK2⃗+K3⃗ nonlinear processes. We calculate 2DES based on K1⃗−K2⃗+K3⃗ and 2K1⃗−2K2⃗+K3⃗ wave mixing processes to reveal exciton–exciton annihilation (EEA) induced exciton symmetry breaking, which occurs at high excitation intensities. We present the general theory that captures all these processes for bosonic and paulionic quasiparticles in a unified way and demonstrate that the NEEs can be easily utilized for highly nonlinear two-dimensional spectra calculations by employing phase cycling for separating various phase matching conditions. The approach predicts various excitonic third- to fifth-order features; however, due to high excitation intensities, contributions of different order processes become comparable and overlap, i.e., the signals no longer can be associated with well-defined order-to-the-field contributions. In addition, EEA leads to breaking of the exciton symmetries, thus enabling population of dark excitons. Such effects are due to the local nature of the EEA process.
N
2
+
Meinel band quenching coefficients for vibrational levels 0 and 1
Authors: Espy Patrick J. , Pendleton William R.
Published: September 2024

Experimental rate coefficients for the quenching of vibrational levels 0 and 1 of the N2+A2Πu state by N2 are presented. The experiments were performed using near-infrared observations of the N2+ Meinel bands excited by electron impact at several pressures of the N2 target/quenching gas. The total removal rate coefficients were derived from a Stern–Volmer analysis of the Meinel band intensities as a function of N2 density and yielded rate coefficients of (2.5 ± 0.5 × 10−10) and (5.6 ± 0.6 × 10−10) cm3⋅molecule−1⋅s−1 for vibrational levels 0 and 1, respectively. It is shown that rate coefficients increase with increasing vibrational level and decreasing energy gap. Our results impact modeling studies of the disturbed atmosphere and ionosphere as the reduced quenching rate coefficients for the preferentially excited A-state vibrational levels <2 lower the quenching altitude in the atmosphere by one scale height, or about 6 km.
Benchmarking the exponential ansatz for the Holstein model
Authors: Yang Junjie , Cui Zhi-Hao , Mahajan Ankit , Zhai Huanchen , Reichman David R. , Chan Garnet Kin-Lic
Published: September 2024

Polarons are quasiparticles formed as a result of lattice distortions induced by charge carriers. The single-electron Holstein model captures the fundamentals of single polaron physics. We examine the power of the exponential ansatz for the polaron ground-state wavefunction in its coupled cluster, canonical transformation, and (canonically transformed) perturbative variants across the parameter space of the Holstein model. Our benchmark serves to guide future developments of polaron wavefunctions beyond the single-electron Holstein model.
Analysis of noise and its characteristics in avalanche photodiode
Authors: Jia XiaoFei , Wei Qun , Zhu Yan , Zhang WenPeng
Published: September 2024

Avalanche photodiodes (APDs) produce noise during operation, which affects the device performance. However, the previous research on its noise is mainly theoretical analysis and is only reflected as optical noise. Therefore, according to the characteristics of APD material and the mechanism of noise generation, the main noise of the device is analyzed in this paper. First, the test method of noise in APDs is established, including testing of dark noise, optical noise, and multiplication noise in high frequency bands. The main noises in APDs are 1/f noise, thermal noise, shot noise, generation recombination noise, and multiplication shot noise, and shot noise is suppressed by Fermi–Dirac distribution and Coulomb action. Second, the reliability of APDs is evaluated by measuring and analyzing the noise parameters of the device through thermal aging experiments. It is concluded that the defects introduced by thermal aging can be reflected by the change in noise, which is consistent with the results in the literature. This method can comprehensively obtain the noise in APDs, which is helpful to improve the working efficiency, life, and reliability of the device.
People who share encounters with racism are silenced online by humans and machines, but a guideline-reframing intervention holds promise
Authors: Lee Cinoo , Gligorić Kristina , Kalluri Pratyusha Ria , Harrington Maggie , Durmus Esin , Sanchez Kiara L. , San Nay , Tse Danny , Zhao Xuan , Hamedani MarYam G. , Markus Hazel Rose , Jurafsky Dan , Eberhardt Jennifer L.
Published: September 2024

Are members of marginalized communities silenced on social media when they share personal experiences of racism? Here, we investigate the role of algorithms, humans, and platform guidelines in suppressing disclosures of racial discrimination. In a field study of actual posts from a neighborhood-based social media platform, we find that when users talk about their experiences as targets of racism, their posts are disproportionately flagged for removal as toxic by five widely used moderation algorithms from major online platforms, including the most recent large language models. We show that human users disproportionately flag these disclosures for removal as well. Next, in a follow-up experiment, we demonstrate that merely witnessing such suppression negatively influences how Black Americans view the community and their place in it. Finally, to address these challenges to equity and inclusion in online spaces, we introduce a mitigation strategy: a guideline-reframing intervention that is effective at reducing silencing behavior across the political spectrum.
Childhood PM
2.5
exposure and upward mobility in the United States
Authors: Lee Sophie-An Kingsbury , Merlo Luca , Dominici Francesca
Published: September 2024

Although it is well documented that exposure to fine particulate matter (PM
2.5
) increases the risk of several adverse health outcomes, less is known about its relationship with economic opportunity. Previous studies have relied on regression modeling, which implied strict assumptions regarding confounding adjustments and did not explore geographical heterogeneity. We obtained data for 63,165 US census tracts (86% of all census tracts in the United States) on absolute upward mobility (AUM) defined as the mean income rank in adulthood of children born to families in the 25th percentile of the national income distribution. We applied and compared several state-of-the-art confounding adjustment methods to estimate the overall and county-specific associations of childhood exposure to PM
2.5
and AUM controlling for many census tract–level confounders. We estimate that census tracts with a 1 μg/m
3
higher PM
2.5
concentrations in 1982 are associated with a statistically significant 1.146% (95% CI: 0.834, 1.458) lower AUM in 2015, on average. We also showed evidence that this relationship varies spatially between counties, exhibiting a more pronounced negative relationship in the Midwest and the South.
On the construction of translation cultures*
Authors: Prunč Erich , Blum Hanna , Schögler Rafael Y.
Published: September 2024

The paper by Erich Prunč introduces and develops the concept of translationskultur, a concept
that captures cultural and social aspects of translation. Expanding beyond the narrow traditional views of equivalence and text
oriented approaches that were dominant in translation studies when Prunč developed the concept, Prunč presents translation as a
critical practice not only in mediating between languages but also as an essential act of transcultural communication.

The concept of translationskultur is theorized as a self-referential, self-regulating subsystem
of culture, characterized by a set of socially established norms and behaviors shared by individuals involved in translation.
Prunč emphasizes the complexity of translation cultures, which arise from the delicate compromises among all stakeholders engaged
in or affected by the translation process, including translators, authors, and recipients. Translation cultures are shaped by
power dynamics within the field, and factors like societal status and resource allocation contribute to the establishment of
hierarchies relevant for translation practices.

By introducing this concept, Prunč moreover aims to encourage a conscientious reflection on the roles and
responsibilities of translators and interpreters, their loyalties towards themselves, and advocates for more confident and
self-critical agents acting towards ideals of a prototypical democratic translation culture. The paper concludes with the vision
of translators and interpreters who are aware of their significant role in shaping discourses and who exercise their power with a
sense of professional pride and ethical diligence.
Real-time particle visualization in an electric-cooled cloud chamber using machine learning
Authors: Fujiwara Takeshi , Kimura Hiromi , Shimodan Chihiro , Futagi Sawako
Published: September 2024

This paper presents the development and implementation of an electric-cooled cloud chamber designed to visualize alpha and beta particle tracks. Traditional cloud chambers rely on dry ice for cooling, which can be cumbersome and impractical for extended use. Our approach employs a Peltier device coupled with a commercial CPU cooler, providing a stable, large field of view, and long-lasting cooling environment. Additionally, we have integrated a real-time visualization system utilizing OpenCV and machine learning with TensorFlow. This system accurately identifies and labels particle tracks, enhancing the educational experience. The cloud chamber operates seamlessly with consumer laptops, such as the MacBook Air with an M1 chip, making it accessible and convenient for educational purposes. Initial qualitative results demonstrate the system’s effectiveness. Future work will focus on refining detection accuracy and exploring additional applications. This advancement not only improves the usability of cloud chambers but also offers new possibilities for interactive scientific education.
Phonons in stringlet-land and the boson peak
Authors: Jiang Cunyuan , Baggioli Matteo
Published: September 2024

Solid materials that deviate from the harmonic crystal paradigm exhibit characteristic anomalies in the specific heat and vibrational density of states (VDOS) with respect to Debye’s theory predictions. The boson peak (BP), a low-frequency excess in the VDOS over Debye law

g
(
ω
)
∝

ω
2

, is certainly the most famous among them; nevertheless, its origin is still subject of fierce debate. Recent simulation works provided strong evidence that localized one-dimensional string-like excitations (stringlets) might be the microscopic origin of the BP. In this work, we study the dynamics of acoustic phonons interacting with a bath of vibrating 1D stringlets with exponentially distributed size, as observed in simulations. We show that stringlets strongly renormalize the phonon propagator and naturally induce a BP anomaly in the VDOS, corresponding to the emergence of a dispersionless BP flat mode. Additionally, phonon-stringlet interactions produce a strong enhancement of sound attenuation and a dip in the speed of sound near the BP frequency, consistent with experimental and simulation data. The qualitative trends of the BP frequency and intensity are predicted within the model and shown to be in good agreement with previous observations. In summary, our results substantiate with a simple theoretical model the recent simulation results by Hu and Tanaka claiming the origin of the BP from stringlet dynamics.
In-motion fine alignment algorithm for AUV based on improved extended state observer and Kalman filter
Authors: Ma Cheng , Zhou Shiyin , Wang Zihao , Zhang Haosu , Xu Lingji , Miao Jianming
Published: September 2024

Achieving fast initial alignment has always been a major challenge for autonomous underwater vehicle navigation, especially in motion. During the fine alignment process, traditional algorithms often face the slow convergence of the azimuth misalignment angle. To solve this problem, this paper proposes a fast alignment algorithm based on the improved extended state observer (ESO) and Kalman filter. Specifically, since the application potential of ESO in fine alignment has not been fully explored by previous studies, this paper introduces the improved ESO through the in-depth research of traditional ESO. The obtained improved ESO is then combined with Kalman filter to constitute the proposed fast alignment algorithm. The algorithm first uses Kalman filter to estimate the two horizontal misalignment angles. Once the horizontal angles estimation of Kalman filter tends to be stable, the improved ESO is used to estimate the azimuth misalignment angle. Simulation and lake test show the proposed algorithm has excellent performance of in-motion alignment. The comparative analysis shows that the algorithm significantly improves the convergence speed of azimuth alignment angle.
Dual-channel photonic crystal fiber dual-parameter sensor exploiting surface plasmon resonance
Authors: Xu Tengfei , Pu Shengli , Huang Siyang , Ji Yu
Published: September 2024

A surface plasmon resonance (SPR) based sensor using a negative curvature circular side-polished photonic crystal fiber was proposed. The sensor’s sensitivity was analyzed using the finite element method. The impact of structural parameters was investigated. The sensor exhibits an average wavelength sensitivity (WS) of 7846 nm/RIU in the refractive index range of 1.370–1.396 and 2350 nm/RIU in the range of 1.330–1.370, with maximum WS of 46000 nm/RIU. For refractive index and magnetic field dual-parameter sensing, the simultaneously obtained magnetic field sensitivity is 0.84 nm/mT. The proposed SPR sensor demonstrates remarkable sensitivity, making it suitable for refractive index and magnetic field sensing applications.
Optimizing 20 Gbps of ground-to-satellite free-space optical communication in low earth orbit with hybrid wavelength-mode division multiplexing
Authors: Marlina Lina , Afifah Shofuro , Liaw Shien-Kuei , Lee Pei-Jun , Kishikawa Hiroki
Published: September 2024

High-speed free-space optical (FSO) communication has emerged as a promising technology for low earth orbit (LEO) region in the last decade. In this paper, we simulate 20 Gbps simplex ground-to-satellite with various wavelengths and transmitter beam pointing error of 0.1 to 2.5 urad. The C-band wavelength is chosen, and a non-return-zero (NRZ) pulse generator with 16 channels hybrid wavelength-mode division multiplexing (WDM-MDM) technique employing Hermite-Gaussian (HG) modes is used to vary the pointing error. The effect of beam pointing error and receiver aperture diameter was discussed in this paper. A transmitter beam pointing error of 2.5 urad can work appropriately at distances of 1000 km and 1500 km, with a BER value of 1.41 × 10−6 and 3.56 × 10−5, respectively. Based on the receiver aperture diameter of 100 cm, it successfully achieves a BER value of 2.4 × 10−8 at the LEO region and a clear eye diagram.
Nonlinear waves for a variable-coefficient modified Kadomtsev–Petviashvili system in plasma physics and electrodynamics
Authors: Wei Guang-Mei , Song Yu-Xin , Xing Tian-Chi , Miao Shu
Published: September 2024

In this paper, a variable-coefficient modified Kadomtsev–Petviashvili (vcmKP) system is investigated by modeling the propagation of electromagnetic waves in an isotropic charge-free infinite ferromagnetic thin film and nonlinear waves in plasma physics and electrodynamics. Painlevé analysis is given out, and an auto-Bäcklund transformation is constructed via the truncated Painlevé expansion. Based on the auto-Bäcklund transformation, analytic solutions are given, including the solitonic, periodic and rational solutions. Using the Lie symmetry approach, infinitesimal generators and symmetry groups are presented. With the Lagrangian, the vcmKP equation is shown to be nonlinearly self-adjoint. Moreover, conservation laws for the vcmKP equation are derived by means of a general conservation theorem. Besides, the physical characteristics of the influences of the coefficient parameters on the solutions are discussed graphically. Those solutions have comprehensive implications for the propagation of solitary waves in nonuniform backgrounds.
Unveiling Structure-Enhanced Positional Embedding Module in Transformer-Based 3D Human Pose Estimation
Authors: Yi Ming , Zhao Xi
Published: September 2024

With the advancement of computational capabilities, the realm of deep learning has expanded from 2D image tasks to encompass 3D video tasks. Human action recognition stands as a typical 3D video task, which emphasizes the accurately capture of local body structures. However, existing methods encounter limitations in precisely capturing these structures, especially in joints within the same body region that exhibits diverse static and dynamic features. To address this complexity, our study innovatively introduces a Structure-Enhanced Positional Embedding Module seamlessly integrated into the PoseFormer model, resulting in the innovative HStruPE-Former model. Experimental validation on the Human3.6M dataset demonstrates a significant performance improvement achieved by the HStruPE-Former model in the task of 3D human pose estimation. Particularly in scenarios involving intricate movements and postures, the module demonstrates improved stability and accuracy. Although the improvements are modest, this technology is expected to facilitate the exploration of untapped potential of structure-enhanced postion embedding modules in diverse neural network applications, thereby promoting further exploration in neural network research. This research outcome not only enhances the performance in current 3D video tasks but also paves the way for novel research directions in the field of deep learning.
Research on the Application of Deep Learning in Human Spinal Image Segmentation
Authors: Feng Zhao , Min Qi , Hua Xu
Published: September 2024

Traditional segmentation methods can only segment grayscale images, which limits their application; The segmentation process often depends on the doctor’s experience, which can lead to subjective factors affecting the results; Therefore, the accuracy and efficiency of segmentation are difficult to achieve practical application results. The deep learning model is a structural model that mimics the neural connections within the human brain. The deep learning model can accurately extract multi-level features of key information in images from low-level to high-level, and provide feedback on data interpretation, thereby achieving accurate and efficient image segmentation results. Introducing deep learning algorithms into medical image segmentation can accurately express the key information at a deeper level in spinal images, achieving better image segmentation results.
Research on failure simulation of the feeding system considering transmission gear wear
Authors: Huiyong Deng , Haitao Sun , Kaibo Cui , Yulong Zhao , Fei Yin
Published: September 2024

The feeding process of the feeding system in the power transmission chain was a high-speed, high impact, non-stationary process, and easy to detect functional faults, aimed at the problem, based on nonlinear multi-body dynamics and Dubowsky contact modeling theory, a gear transmission modeling method including backlash was proposed. A dynamic simulation model of the feeding system injected with gear wear fault was established, and the system dynamic performance under different wear levels was analyzed. The research results show that due to the wear of the gear teeth, the contact force between the teeth increased by about 70%. When the wear of a single tooth pair increased to 0.2mm, there would be jamming faults caused by delayed chain throwing. The research results provided support for the optimization and improvement of the feeding system.
Modeling and Simulation of UAV Task Assignment and Execution in Designated Area Based on Order Strike Theory
Authors: Mingxuan Li , Yanru Cui , Yifan Zhu , Weiping Wang , Xiaobo Li , Xinfeng Wang
Published: September 2024

Since 2023, local conflicts have intensified and local wars have occurred frequently. The term “order strike” has appeared on the battlefield many times and is one of the hot spots in the study of modern warfare. Order strike has the characteristics of small scale, fast response, low cost, etc. It is a distributed combat mode proposed by the US military on the basis of theories of “Kill Chain” and “Mosaic Warfare”, etc. This paper takes the UAV penetration and strike against large targets as research case, and builds a new type of UAV penetration and strike combat platform based on the theory of “order strike”, combined with the technologies of “ StarLink “ satellite network reconnaissance and intelligent UAV control. This combat platform can continuously monitor the designated area and effectively strike the hostile targets invading the area. Finally, we conducted a preliminary simulation and initial effectiveness evaluation of the method proposed in this paper through multi-agent simulation.
Modification of Nanyang crude oil by a functional magnetically responsive flow modifier in synergy with magnetic field
Authors: Yan Feng , Li Jionghao , Li Qifu , Wang Yunchen , Nie Chaofei , Xiao Fan , San Bohong
Published: September 2024

Nanyang crude oil is classified as high wax crude oil. It has severe wax deposition and poor low-temperature fluidity, which pose a major risk to the safety of pipeline transportation of wax-containing crude oil. A large-size polymer-coated magnetic nanosphere was created by dispersion polymerization employing methyl methacrylate, nano-iron oxide, tetraethoxysilane, and dodecyltriethoxysilane as raw materials to address the aforementioned issues.Ethylene-vinyl acetate copolymer was compounded to provide a useful magnetic response flow modifier.Using FTIR and ESEM, the polymer grafted on the iron oxide nanosphere’s surface was shown. After evaluating the functional magnetic response flow modifier’s impact on the yield stress and viscosity of a Nanyang crude oil, the effect of the magnetic field was introduced to analyze the functional magnetic response flow modifier’s synergistic effect on viscosity and yield stress. The results show that the functional magnetic response flow modifier may greatly lower yield stress and viscosity when compared to the EVA pour point depressant. Additionally, applying an alternating magnetic field could amplify the functional magnetic response flow modifier’s beneficial effects on Nanyang crude oil.
Corrosion of 316 SS in chloride molten salt for thermal energy storage: Inhibitory effects of Al powder
Authors: Li Tianjiao , Zhu Ming , Deng Peng , Chen Anqi , Yan Haitong , Yi Han
Published: September 2024

MgCl2-KCl-NaCl is regarded as one of the most prospective high-temperature thermal energy storage mediums and heat transfer fluids (HTF) for 3rd generation concentrated solar power (CSP) systems. However, high corrosion to alloys limits its application. In this paper, corrosion tests were conducted on 316 SS, in MgCl2-KCl-NaCl at 800°C with different content (0 wt.%,1 wt.%, and 10 wt.%) of Al powder addition as a corrosion inhibitor. The impact of Al powder was assessed through electrochemical methods, specifically impedance spectroscopy (EIS) and potentiodynamic polarization (PDP). Following corrosion tests, the morphologies and phase compositions of 316 SS were determined by using scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS) and X-ray diffraction (XRD). The addition of Al powder can significantly reduce the corrosion current density of 316 SS in MgCl2-KCl-NaCl at 800°C, which was 183.29 times higher than that with 10 wt.% without Al addition. Al and the degree increased with increasing content of Al. With the addition of 1 wt.% Al, the thickness of the diffusion layer is significantly reduced, which was 54.6 μm (100 h), 275.1 μm (200 h), 370.4 μm (300 h), and 500 μm (400 h), respectively. When the addition of Al reaches up to 10 wt.%, the inwards diffusion of Al caused the formation of Al enriched layer, which was identified as the FeAl phase, on the surface of 316 SS during the high-temperature corrosion processes. The thickness of the Al enriched layer was associated with the diffusion time of Al, and its depth was 40.4 μm (100 h), 45.3 μm (200 h), 103.5 μm (300 h), and 139.5 μm (400 h).
Effects of several typical plastic combustion residues on gasoline
Authors: Yu Lili , Dazhi E , Liu Shujun
Published: September 2024

In order to solve the interference caused by polymer materials on gasoline accelerants in arson cases, the characteristics of residues after combustion of some typical plastics are studied. Comparing it to the combustion residue of gasoline, we discussed the interference in gasoline detection. The results show that the combustion products of these plastics mainly interfere with the alkanes and aromatic hydrocarbons in gasoline. Polyethylene, polystyrene, and polyvinyl chloride mainly produce C9-C16 branched-chain and straight-chain alkanes. Polystyrene and ABS resin generated C5 and C6 alkanes, also generated C1-benzene, C2 - benzene, and styrene. It mainly affects the identification of aromatic hydrocarbons in gasoline combustion residues. Understanding the types and characteristics of products in the combustion residues of these plastics can provide powerful evidence for fire investigators and criminal technicians in physical evidence identification.
Comparison of thermo-catalytic and photo-assisted thermo-catalytic conversion of glucose to HMF with Cr-MOFs@ZrO2
Authors: Chang Kanglu , Tao Xumei
Published: September 2024

Thermo-catalytic and photo-assisted thermo-catalytic are two effective pathways for conversion of glucose. Thermo-catalytic and photo-assisted thermo-catalytic conversion of glucose was studied with Cr-MOFs@ZrO2 as catalysts in nitrogen atmosphere at 150 °C. Cr-MOFs@ZrO2 possesses simultaneously Lewis acid sites as well as Brønsted acid sites, and also has strong Brønsted acidity, so it can exhibit good thermos-catalytic performanc. When the glucose was 3 g/L, the reaction was carried out at 150 °C for 2 h with DMF as solvent, the glucose conversion was 97.9% while the HMF yield was 38%. The yield of HMF can be increased to 51.1% by adding 500w xenon lamp irradiation on the basis of thermal catalytic reaction condition. A comparison of the two reactions revealed that light-assisted thermal catalysis was more favorable for the reaction.
Imine-based nickel/cobalt covalent organic framework with high rate and stability for supercapacitor
Authors: Wang Guanwen , Chi Chunlei , Liu Zheng , Fan Zhuangjun
Published: September 2024

Due to their regular pore structure, long-range order, and structural stability, COFs (Covalent Organic Frameworks) have gradually been employed as electrode materials for supercapacitors. However, owing to their two-dimensional stacking structure, poor conductivity, and the lack of effective redox-active sites, they usually exhibit inferior rate performance and cycling stability. Therefore, we design an imine-based Ni0.7Co0.3-COF anchored with Ni/Co redox centres at the atomic level and adjust their proportion. This approach optimizes the electronic structure and enhances the electronic conductivity and redox activity of Ni0.7Co0.3-COF. Ni0.7Co0.3-COF are grown through thin-layered cross-linking, significantly shortening both the ion and electron transport pathways. This improves the contact area between electrolyte ions and electrode materials and enhances the utilization of redox centres, thereby substantially improving the rate performance (1300 F g−1 at 50 A g−1) and cycling stability (72% retention after 5000 cycles) of Ni0.7Co0.3-COF.
High proportion of new energy power system frequency and voltage support and regulation technology based on doubly fed induction generator
Authors: Zhang Jian , Li Wenfeng , Geng Zhichen , Guo Changhao
Published: September 2024

With the increasing proportion of new energy in power systems, issues regarding system voltage, inertia, and primary frequency regulation have become increasingly severe. In response to control and grid safety issues, a high proportion of new energy power system frequency and voltage support and regulation technology based on a doubly fed induction generator (DFIG) is proposed. The voltage-magnetic link equation of DFIG is theoretically derived, and the control principles of active and reactive power of DFIG are proposed. The support and regulation characteristics of improving the voltage of new energy substations are studied. Verification is conducted through large-scale grid simulation and on-site measurements.
Comparative analysis of radiant air-conditioning systems combined with two different types of solar-powered dehumidification methods
Authors: Li Gang , Liao Yixuan , Dou Yubo , Sun Jiaqi , Nan Jia , Chen Jinlong
Published: September 2024

This paper proposes a solar liquid desiccant radiation air-conditioning system(SLDRS) and a solar desiccant wheel radiant air-conditioning system(SDWRS) that combine with a phase change energy storage radiation terminal, solar energy, and heat pump system. The models of the two systems are simulated with the transient system tool (TRNSYS) to compare the refrigeration and dehumidification effects and energy saving of the two systems. The results show that the total refrigeration capacity of the SLDRS is reduced by 20.45% compared with the solar desiccant wheel radiation air-conditioning system, the monthly average dehumidification capacity is increased by 37.09%, and the total energy consumption is reduced by 712.9 KW·h. It is evident that the cooling and dehumidifying effect and energy efficiency of the SLDRS are superior to those of the SDWRS.
Impact of the horizontal resolution of GEOS-Chem on land‒ocean and tropic‒extratropic partitioning and seasonal cycle in CO2 inversion
Authors: Liu Zhiqiang , Zeng Ning , Han Pengfei , Cai Qixiang
Published: September 2024

Credible regional carbon budget estimates from atmospheric CO2 measurements rely on the accuracy of atmospheric transport models (ATMs). However, the atmospheric transport in ATMs is usually simplified and spatiotemporally averaged, leading to systematic biases in simulating the atmospheric CO2 and estimating surface CO2 fluxes. We show that forward simulations of global CO2 using an ATM, GEOS-Chem, at a native resolution of 0.5° × 0.625° and a coarse resolution of 4° × 5° differ significantly near the surface in the Northern Hemisphere and the polar vortex, mainly because of advection in GEOS-Chem. Comparing observing system simulation experiments that assimilate synthetic observations sampled from the forward simulations, we separate the impact of coarse-resolution GEOS-Chem on regional flux estimates. The results suggest that a significant amount of annual carbon uptake from the ocean and tropics is improperly redistributed to the land and northern and southern extratropics, respectively. In addition, these errors lead to an underestimated seasonal amplitude in the northern extratropical land and a reversed sign of the seasonal cycle in the northern extratropical ocean. The reversed sign of the seasonal cycle has also been observed in a real data assimilation experiment and several state-of-the-art inversions, suggesting that reasonable ocean flux estimates depend strongly on the accuracy of the ATM.
ZnO-modified glass capillaries as a portable photocatalytic reactor for real-time measurements
Authors: Jayswal Shefali , Mohapatra Saswat
Published: September 2024

Here, we have developed a photocatalytic reactor using glass capillaries which acts both as a flow cell and a thin film-supported photocatalyst due to the Zinc Oxide (ZnO) nanostructures grown on the inner surface of the glass capillaries. The structural, morphological, elemental, and optical characteristics of the ZnO nanostructures were investigated through characterization methods such as x-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Energy-Dispersive x-ray spectroscopy (EDAX), UV–Visible spectroscopy, and Raman spectroscopy. Further, dye-sensitized ZnO nanostructures were used for photocatalytic application under visible light irradiation. A custom-made setup is developed using ZnO-modified glass capillaries for simultaneous decay and measurement of the dye degradation process under visible LED light. This developed model could have future technological applications in designing portable photocatalytic reactors that can accurately monitor the dye degradation process using real-time measurements.
Improvement on the onset voltage for electroluminescent devices based in a SiOx/SiOy bilayer obtained by sputtering
Authors: Salazar-Valdez A S L , Monfil-Leyva K , Morales-Morales F , Hernández Simón Z J , Muñoz-Zurita A L , Luna López J A , de la Luz J A D Hernández , Uribe González F , Morales-Sánchez A
Published: September 2024

This work is focused on the composition, optical and electroluminescent properties of silicon rich oxide (SiOx, x < 2) films monolayers and bilayers (SiOx/SiOy) deposited by Sputtering with silicon excess between 6.2 to 10.7 at.% were deposited on p-type (100) silicon substrates. As-deposited SiOx films emit a broad photoluminescence (PL) band where the maximum peak shifts from 420 to 540 nm as the Si-excess increases from 6.2 to 10.7 at.%, respectively. The PL intensity strongly increases and the main PL peak shifts to the red region when the SiOx films are thermally annealed. The PL emission band was dependent on silicon excess and the presence of Si-O bonds defects working as emission centers. MOS-like devices were fabricated (N+ polysilicon was used as top contact and aluminum as bottom contact) to study the EL of SiOx monolayers and SiOx/SiOy bilayers. It was found that the required voltage to obtain EL was reduced when SiOx/SiOy bilayers were used in light emitting capacitors (BLECs) as compared to those with SiOx monolayers.
Prediction of Sm- (Co, Cu, Fe, Zr) binary alloys’ thermodynamic parameters by improved miedema model
Authors: Zhu Zhi , Fang Yikun , Wu Wei , Zhao Bo , Zhang Jiashuo , Lei Ming
Published: September 2024

Currently, the original Miedema mixing enthalpy model yields calculation results that exhibit some discrepancies when compared to experimental data. Therefore, improving the precision of the Miedema model is essential to advance its development and application in developing samarium–cobalt permanent magnet alloys. To address this issue, the enthalpies of mixing for Sm–(Co, Cu, Fe, Zr) binary alloys were calculated using the modified model. In addition, the mixing enthalpy (ΔH), excess entropy (S

E
), excess Gibbs free energy (G

E
), component activity (α) and binary Gibbs free energy of Sm–Co and Sm–Fe were calculated. The results indicate that the improved Miedema model more accurately matches the experimental values. Sm– (Co, Fe, Cu) binary alloys tend to form intermetallic compounds easily, whereas Sm–Zr does not. The ΔH, S

E
and G

E
of Sm-(Co, Fe) are negative, and the activity of each component shows a considerable negative deviation from Raoult’s law in contrast to that of an ideal solution. In the range of 1550 ∼ 1620 K, the Gibbs free energy of SmCo5 and Sm2Co17 reactions is negative with the Sm2Co17 phase being thermodynamically more stable than the SmCo5 phase.
Profile improvement of blade coated circuits by the capillary force originating from the hydrophobic sidewalls
Authors: Tang Cheng , Liu Rui , Zhu Shanyou , Jiang Subin , Shui Ke , Lin Jian , Ma Chang-Qi
Published: September 2024

Restricting the diffusion of conductive inks plays a key role in printed electronics application. Micro-channels with different sidewall surface energies, which can be approximated as a capillary, are fabricated to restrict the blade-coated ink diffusion using both of the gravitational effect and the capillary force. The coffee ring effect of aqueous silver ink is inhibited by the capillary force when the hydrophobic sidewalls distance is no more than 50 μm in this paper. As a result, the conductive lines with improved cross-sectional profiles are obtained by this method, with the typical resistivity more than 108 times lower than the measured results with hydrophilic sidewalls. The capillary force was also found to lose its effect when the width is larger enough, which needs surfactant addition to improve the silver film property. I–V curves of the original aqueous ink and the ink improved by traditional methods shows that the profile improvement by the hydrophobic sidewall can be used with other ink improving methods cooperatively. These studies open up the possibility of improving the printed conductive patterns by this method as an auxiliary tool used together with the traditional methods reported before.