bluuebunny/crossref_metadata_2025 huggingface dataset:
Anisotropy effect on the motion of edge dislocation in body-centered-cubic Fe
Authors: Sun Xu , Cheng Haixia , Cheng Songqi , Xie Hongxian
Published: April 2024

The mechanical properties of metallic materials can be dictated by nucleation, multiplication, and motion of dislocations under stress. We employed the molecular dynamics (MD) method to investigate the motion of an 1/2[111](112̄) edge dislocation in body-centered-cubic (BCC) Fe under normal stress on the 112̄ plane. Our MD results confirm that the motion of the edge dislocation can be attributed to the normal stress induced shear stress (NSISS) effect. The magnitude of this effect varies across different cubic metals. Further studies reveal that this effect is limited to the {112} planes and is associated with the disobedience of Schmid’s law in the case of twinning of BCC Fe. To summarize, the NSISS effect may be traced back to the anisotropy of cubic metals and should be considered when the twinning process in anisotropic BCC metals is studied.
Fully passive model-based numerical analysis of the trailing-edge flexibility of hydrofoil on energy harvesting performance
Authors: Xu Jianan , Yao Yuzhi , Yi Bailin , Zhang Zenglei , Zong Chaoyong
Published: April 2024

The oscillating hydrofoil, a device used for collecting environmentally friendly tidal energy, is the focus of the study. The flexibility of the hydrofoil's trailing edge can impact its surface pressure distribution, lift, and moment characteristics. To improve the energy harvesting performance of oscillating hydrofoils, it is important to conduct thorough research on their energy harvesting mechanism. Therefore, numerical analysis is employed to develop a numerical model of the fully passive oscillating hydrofoil with the flexible trailing edge. The dynamic development behavior of surface vortices on hydrofoils is analyzed, demonstrating that the fluid–structure interaction between the hydrofoil and the surrounding fluid alters the hydrofoil's motion. The vortex patterns and pressure distribution on the hydrofoil surface are also affected, ultimately influencing the energy harvesting performance. By optimizing the flexibility coefficient of the fully passive oscillating hydrofoil with a flexible trailing edge, the energy harvesting performance of the oscillating hydrofoil is improved. When the maximum chord offset δm= 0.1c and the flexibility coefficient n= 2, the energy harvesting efficiency is 31.37%, and the average power coefficient is 1.17. Therefore, increasing the tail flexibility can be considered to enhance energy harvesting performance when designing the fully passive oscillating hydrofoil. The research provides a comprehensive analysis of energy harvesting performance, addressing the dynamic problem of the fully passive oscillating hydrofoils with flexible trailing edges. The findings of this study may provide guidance for the design and optimization of tidal energy harvesting devices with similar structures.
Experiments investigation on atomization characteristics of a liquid jet in a supersonic combustor
Authors: Zhou Yaozhi , Li Chenyang , Cai Zun , Li Qinglian , Li Ziguang , Chen Zihang , Sun Mingbo
Published: April 2024

The atomization characteristics of a liquid jet in a supersonic combustor were studied experimentally for the first time. A phase doppler anemometry (PDA) system was utilized for the measurement of droplets properties along the cross-sectional area of spray plumes inside the cavity. The results were obtained under the inflow conditions of Ma = 2.0 supersonic crossflow with a stagnation pressure of 0.55 MPa and a stagnation temperature of 300 K. The size and velocity distribution of droplet inside the cavity are obtained based on the PDA measurements. It was found that the Sauter Mean Diameter (SMD) distribution of droplets inside the cavity ranged from 30 to 55 μm. The average streamwise velocity ranged from −20 to 150 m/s and the average vertical velocity ranged from −20 to 30 m/s. Large droplets distribute in the central area of the cavity. Small droplets spread around the central area of the bottom and sidewall areas of the cavity. The area near the sidewall may be an ideal ignition location due to the lower SMD and velocity of droplets. The time-averaged motion trend of droplets in the cavity is proposed experimentally based on the streamwise and spanwise velocity distribution profiles of droplets. The presence of a recirculation zone within the cavity is confirmed. The recirculation area inside the cavity is mainly distributed in the front half of the cavity. The droplets in the cavity show a good tracking performance. With the effect of the airflow, the droplets in the top area of the cavity move toward the bottom and rear wall of the cavity. In addition, the droplets in the middle and bottom area of the cavity move toward the front wall of the cavity especially for droplets near the sidewall. These universal curves can potentially be used for the modeling of a liquid jet in a supersonic combustor.
Direct simultaneous measurement of electrocaloric effect and hysteresis loss heating in ferroelectrics
Authors: Fischer J. , Hägele D. , Rudolph J.
Published: April 2024

Electrocaloric effect and loss-induced self-heating are simultaneously investigated in single-crystalline relaxor 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3 by a direct, high-resolution method. Transients of the total temperature change for few-cycle electric field pulses allow to distinguish and individually determine the contributions from electrocaloric effect and self-heating with millikelvin temperature and submillisecond temporal resolution. Simultaneous dielectric measurements make the comparison of observed self-heating to hysteresis losses possible, where very good agreement is found. The loss factor as a figure of merit for electrocaloric materials is directly obtained from the combined determination of caloric temperature change and losses.
Self-supported flexible organic electrochemical synaptic transistors on self-healing composite electrolyte membranes
Authors: Yu Haoran , Xu Yunchao , Deng Zhonghui , Jin Chenxing , Liu Wanrong , Shi Xiaofang , Liu Jianzhou , Sun Jia , Yang Junliang
Published: April 2024

A variety of organic electrochemical transistors have been recently developed; however, their self-healing performance has been largely ignored. In this study, we propose the use of a lithium-ion composite electrolyte membrane as a dielectric layer and the use of poly(3-hexylthiophene) (P3HT) as a channel layer to fabricate flexible self-supporting organic synaptic transistors. A variety of synaptic behaviors were emulated within the proposed organic synaptic transistors. By leveraging the self-healing features of polymer electrolytes, along with cross-linking reactions and low-resistance lithium-ion transmission, the device maintained its electrical performance. Testing involving different curvatures also revealed the device's potential for use in flexible electronics. Significantly, due to the device's self-healing ability, consistent dataset recognition rates were sustained. This work highlights its vast prospects in the field of flexible and wearable electronics.
Photodissociation dynamics of SO2 via the G̃1B1 state: The O(1D2) and O(1S0) product channels
Authors: Wu Yucheng , Sun Jitao , Li Zhenxing , Zhang Zhaoxue , Luo Zijie , Chang Yao , Wu Guorong , Zhang Weiqing , Yu Shengrui , Yuan Kaijun , Yang Xueming
Published: April 2024

Produced by both nature and human activities, sulfur dioxide (SO2) is an important species in the earth’s atmosphere. SO2 has also been found in the atmospheres of other planets and satellites in the solar system. The photoabsorption cross sections and photodissociation of SO2 have been studied for several decades. In this paper, we reported the experimental results for photodissociation dynamics of SO2 via the G̃1B1 state. By analyzing the images from the time-sliced velocity map ion imaging method, the vibrational state population distributions and anisotropy parameters were obtained for the O(1D2) + SO(X3Σ−, a1Δ, b1Σ+) and O(1S0) + SO(X3Σ−) channels, and the branching ratios for the channels O(1D2) + SO(X3Σ−), O(1D2) + SO(a1Δ), and O(1D2) + SO(b1Σ+) were determined to be ∼0.3, ∼0.6, and ∼0.1, respectively. The SO products were dominant in electronically and rovibrationally excited states, which may have yet unrecognized roles in the upper planetary atmosphere.
Blue light regulated lignin and cellulose content of soybean petioles and stems under low light intensity
Authors: He Wei , Chai Qiang , Zhao Cai , Yu Aizhong , Fan Zhilong , Yin Wen , Hu Falong , Fan Hong , Sun Yali , Wang Feng
Published: April 2024

To improve light harvest and plant structural support under low light intensity, it is useful to investigate the effects of different ratios of blue light on petiole and stem growth. Two true leaves of soybean seedlings were exposed to a total light intensity of 200 μmol m−2 s−1, presented as either white light or three levels of blue light (40 μmol m−2 s−1, 67 μmol m−2 s−1 and 100 μmol m−2 s−1) for 15 days. Soybean petioles under the low blue light treatment upregulated expression of genes relating to lignin metabolism, enhancing lignin content compared with the white light treatment. The low blue light treatment had high petiole length, increased plant height and improved petiole strength arising from high lignin content, thus significantly increasing leaf dry weight relative to the white light treatment. Compared with white light, the treatment with the highest blue light ratio reduced plant height and enhanced plant support through increased cellulose and hemicellulose content in the stem. Under low light intensity, 20% blue light enhanced petiole length and strength to improve photosynthate biomass; whereas 50% blue light lowered plants’ centre of gravity, preventing lodging and conserving carbohydrate allocation.
Selective social interactions and speed-induced leadership in schooling fish
Authors: Puy Andreu , Gimeno Elisabet , Torrents Jordi , Bartashevich Palina , Miguel M. Carmen , Pastor-Satorras Romualdo , Romanczuk Pawel
Published: April 2024

Animals moving together in groups are believed to interact among each other with effective social forces, such as attraction, repulsion, and alignment. Such forces can be inferred using “force maps,” i.e., by analyzing the dependency of the acceleration of a focal individual on relevant variables. Here, we introduce a force map technique suitable for the analysis of the alignment forces experienced by individuals. After validating it using an agent-based model, we apply the force map to experimental data of schooling fish. We observe signatures of an effective alignment force with faster neighbors and an unexpected antialignment with slower neighbors. Instead of an explicit antialignment behavior, we suggest that the observed pattern is the result of a selective attention mechanism, where fish pay less attention to slower neighbors. This mechanism implies the existence of temporal leadership interactions based on relative speeds between neighbors. We present support for this hypothesis both from agent-based modeling as well as from exploring leader–follower relationships in the experimental data.
Phonological, lexical and grammatical borrowings and replications in Hyow, a language of the Bangladesh-Burma border
area
Authors: Zakaria Muhammad
Published: April 2024

This paper presents a discussion of contact-induced borrowings and replications in Hyow, a Southeastern South
Central (SC) Tibeto-Burman language spoken in the Chittagong Hill Tracts of Bangladesh. Hyow shows two layers of contact-induced
changes: an earlier layer under the influence of Burmese, and a more recent layer under the influence of Bangla. The Hyow
desiderative -sháng closely resembles the suffix shɔn ‘want to’ in the Burmese variety of
Rakhine State, suggesting that Hyow speakers previously lived in Rakhine State. In its current location, Hyow speakers are in
contact with Bangla, and the presence of Indo-Aryan type relative-correlative clauses in Hyow – not found in any of the SC
languages in Burma – reveals the effect of this recent contact with Bangla. Apart from demonstrating the respective antiquity of
Hyow contact with Burmese and Bangla, the two examples of the borrowing of the desiderative suffix -sháng and
relative-correlative clauses also show borrowing and replication as two distinct types of contact-induced change (Heine and Kuteva, 2005, 2006). This paper
gives the first account of phonological, lexical and grammatical borrowings and replications to understand how language contact
has shaped Hyow.
Ad-hoc-compounds in spoken German
Authors: Helmer Henrike
Published: April 2024

Occasionalisms, i.e., non-lexicalized ad-hoc-expressions that are coined for a specific occasion, are a recurrent phenomenon in verbal interactions. Even though recipients have not heard those novel word formations before, they can still understand them. This paper reports on a study from an Interactional Linguistics perspective which explores ad-hoc-expressions in spoken German, such as streichelmichbärchenpärchen (‘stroke-me-little-bear-couple’) and windeldroge (‘diaper-drug’). It draws on an analysis of 934 ad-hoc-compounds in a corpus of German interaction. These typically do not cause a problem of understanding, because their meaning is inferable due to different resources that help recipients understand unfamiliar expressions: a specific word formation with a high degree of compositionality, cues or anchoring in the prior context or common ground. While a compositional word formation is not always necessary to sufficiently understand meaning in interaction due to other resources, opaque word formation has its limits when it comes to understanding the meaning of an expression especially when recipients cannot rely on other resources to understand the expression.
More matters of typology
Authors: Iyengar Arvind
Published: April 2024

Since their coinage a quarter-century ago, the terms abugida and alphasyllabary
(Bright 1999; Daniels & Bright 1996)
have revolutionised our conceptualisation of writing systems. Together with alphabet, these terms have proven
invaluable in classifying subtypes of segmentaries–writing systems whose grain size is the phonological segment (Gnanadesikan 2017). Nevertheless, there remain areas of ambiguity. Segmentaries that are
either abugidas or alphasyllabaries–but not both–may be classified under various labels, and inconsistently so. Moreover, certain
minoritised writing systems such as those based on Canadian Aboriginal Syllabics or Braille are only rarely covered in typological
studies, despite the potential insights they offer.

In this paper, I use Bright’s (1999) and Gnanadesikan’s (2017) typology of vowelled segmentaries as the point of departure to propose an augmented
classification based on specific graphematic criteria. Aside from illustrating the proposed typology by applying it to various
writing systems, I also identify avenues for further refinement.
Dual fluorescence reporter mice for Ccl3 transcription, translation, and intercellular communication
Authors: Rodrigo Maria Belen , De Min Anna , Jorch Selina Kathleen , Martin-Higueras Cristina , Baumgart Ann-Kathrin , Goldyn Beata , Becker Sara , Garbi Natalio , Lemmermann Niels A. , Kurts Christian
Published: April 2024

Chemokines guide immune cells during their response against pathogens and tumors. Various techniques exist to determine chemokine production, but none to identify cells that directly sense chemokines in vivo. We have generated CCL3-EASER (ErAse, SEnd, Receive) mice that simultaneously report for Ccl3 transcription and translation, allow identifying Ccl3-sensing cells, and permit inducible deletion of Ccl3-producing cells. We infected these mice with murine cytomegalovirus (mCMV), where Ccl3 and NK cells are critical defense mediators. We found that NK cells transcribed Ccl3 already in homeostasis, but Ccl3 translation required type I interferon signaling in infected organs during early infection. NK cells were both the principal Ccl3 producers and sensors of Ccl3, indicating auto/paracrine communication that amplified NK cell response, and this was essential for the early defense against mCMV. CCL3-EASER mice represent the prototype of a new class of dual fluorescence reporter mice for analyzing cellular communication via chemokines, which may be applied also to other chemokines and disease models.
Regulation of pulmonary plasma cell responses during secondary infection with influenza virus
Authors: MacLean Andrew J. , Bonifacio Joao P.P.L. , Oram Sophia L. , Mohsen Mona O. , Bachmann Martin F. , Arnon Tal I.
Published: April 2024

During secondary infection with influenza virus, plasma cells (PCs) develop within the lung, providing a local source of antibodies. However, the site and mechanisms that regulate this process are poorly defined. Here, we show that while circulating memory B cells entered the lung during rechallenge and were activated within inducible bronchus-associated lymphoid tissues (iBALTs), resident memory B (BRM) cells responded earlier, and their activation occurred in a different niche: directly near infected alveoli. This process required NK cells but was largely independent of CD4 and CD8 T cells. Innate stimuli induced by virus-like particles containing ssRNA triggered BRM cell differentiation in the absence of cognate antigen, suggesting a low threshold of activation. In contrast, expansion of PCs in iBALTs took longer to develop and was critically dependent on CD4 T cells. Our work demonstrates that spatially distinct mechanisms evolved to support pulmonary secondary PC responses, and it reveals a specialized function for BRM cells as guardians of the alveoli.
A flat-top arrayed waveguide grating base on cascading ‘A’ shape multimode interference
Authors: Zhou Kanglu , Liu Xiaochun , Zhang Jialiang , Chen Changshui
Published: April 2024

Today, large bandwidth is required to increase data transmission speeds, this requires an optimized design of the photonic devices. To achieve increasing bandwidth in the wavelength division multiplexing device’s arrayed waveguide grating (AWG). We have cascaded a special ‘A’ shape multimode interference (MMI) structure at the end of the input waveguide. ‘A’ shape structure is better able to get the ideal light field distribution, making the flattening effect more perfect. The ‘A’ shape MMI is designed by the linear spreading equation, the structure of the MMI can be easily and conveniently manufactured in a practical application. Simulation results show that increasing the 1 dB bandwidth to 0.7 nm and the 3 dB bandwidth to 1.6 ± 0.2 nm, the insertion loss is measured at 3.5 ± 0.3 dB, and the channel crosstalk is below −30 dB. It paves the path to achieve increasing bandwidth of AWG.
Spin–orbit torques due to topological insulator surface states: an in-plane magnetization as a probe of extrinsic spin–orbit scattering
Authors: Farokhnezhad Mohsen , Cullen James H , Culcer Dimitrie
Published: April 2024

Topological insulator (TI) surface states exert strong spin–orbit torques. When the magnetization is in the plane its interaction with the TI conduction electrons is non-trivial, and is influenced by extrinsic spin–orbit scattering. This is expected to be strong in TIs but is difficult to calculate and to measure unambiguously. Here we show that extrinsic spin–orbit scattering sizably renormalizes the surface state spin–orbit torque resulting in a strong density dependence. The magnitude of the renormalization of the spin torque and the effect of spin–orbit scattering on the relative sizes of the in-plane and out-of-plane field-like torques have strong implications for experiment: We propose two separate experimental signatures for the measurement of its presence.
Structural and electronic transport properties of Zn- and Ga-doped Bi2−
x
Sb
x
Te3−
y
Se
y
topological insulator single crystals
Authors: Pradhan Sanand Kumar , Mal Priyanath , Pradhan Sharadnarayan , Lakhani Archana , Das Bipul , Rambabu P , Turpu G R , Das Pradip
Published: April 2024

A comprehensive study of structural and magnetotransport properties of pristine Bi2−x
Sb
x
Te3−y
Se
y
(BSTS) single crystals and doped with Zn (BSTS:Zn) and Ga (BSTS:Ga) are presented here. Magnetic field dependent Hall resistivities of the single crystals indicate that the holes are the majority carriers. The field dependent resistivity curves at different temperatures of the crystals display cusp-like characteristics at low magnetic fields, attributed to two-dimensional (2D) weak antilocalization (WAL) effect. We fit the observed low-field WAL effects at low temperatures using 2D and three-dimensional (3D) Hikami-Larkin-Nagaoka (HLN) equations. The 2D HLN equation fits the data more closely than the 3D HLN equation, indicating a 2D nature. The 2D HLN equation fit to the low field WAL effects at various temperatures reveal a phase coherence length (l
φ) that decreases as temperature increases. The variation of l
φ with temperature follows T
−0.41 power law for BSTS:Zn, suggesting that the dominant dephasing mechanism is a 2D electron–electron (e−e) interactions. For pristine BSTS and BSTS:Ga, l
φ(T) is described by considering a coexistence of 2D e−e and electron–phonon (e−p) interactions in the single crystals. The temperature variation of the longitudinal resistance in BSTS:Ga is described by 3D Mott variable range hoping model. In contrast, the transport mechanisms of both pristine BSTS and BSTS:Zn are described by a combination of 2D WAL/EEI models and 3D WAL.
Research on fire detection method of complex space based on multi-sensor data fusion
Authors: Su Qian , Hu Guangzhou , Liu Zhenxing
Published: April 2024

Efficient and reliable fire detection methods are essential for addressing complex spatial characteristics of older residential communities, which often face poor fire safety conditions, various fire types, and challenges in rescue operations. In response to the problem of lacking comprehensive analysis of multidimensional data in traditional fire detection, which often leads to false alarms and missed alarms, this paper proposes a fire detection method based on multi-sensor data fusion. Various sensors are employed, including smoke sensors, temperature sensors, CO sensors, and flame sensors. These sensors collect multidimensional data, which are fused using improved adaptive filters and fuzzy Bayesian logical reasoning algorithms to establish a fire detection model based on multi-sensor data fusion. To additionally, false alarms and missed detections caused by sensor damage are further solved by exploring hidden spaces. Experimental results demonstrate that the proposed fire detection system based on multi-sensor data fusion effectively analyses fire occurrence and progression in older residential communities, and performs stability, accuracy and real-time property.
Intelligent fault diagnosis methods for hydraulic components based on information fusion: review and prospects
Authors: Guan Hanlin , Ren Yan , Tang Hesheng , Xiang Jiawei
Published: April 2024

Hydraulic component faults have the characteristics of nonlinear time-varying signal, strong concealment, and difficult feature extraction, etc. Timely and accurately fault diagnosis of hydraulic components is helpful to curb economic losses and accidents, so researches have carried out a lot of research on hydraulic components. Information fusion technology can combine multi-source data from multiple dimensions to mine fault data features, which effectively improves the accuracy and reliability of fault diagnosis results. However, there is currently a lack of a comprehensive and systematic review in this domain. Therefore, in this paper, the hydraulic components information fusion fault diagnosis technologies are summarized and analyzed, encompassing the main process information fusion fault diagnosis and the research status of information fusion fault diagnosis of hydraulic system. The methods and techniques involved in the fusion process, data source and fusion method of fault diagnosis of hydraulic components information fusion are elaborated and summarized. The problems of information fusion in fault diagnosis of hydraulic components are analyzed, the solutions are discussed, and the research ideas of improving information fusion fault diagnosis are put forward. Finally, digital twin (DT) technology is introduced, and the advantages and research status of intelligent fault diagnosis based on DT are summarized. On this basis, the intelligent fault diagnosis of hydraulic components based on information fusion is summarized, and the challenges and future research ideas of applying information fusion and DT to intelligent fault diagnosis of hydraulic components are put forward and analyzed comprehensively.
Calibration method for binocular vision system with large field of view based on small target image splicing
Authors: Li Guang , Xu Zili , Zhang Yiming , Xin Cun , Wang Jun , Yan Song
Published: April 2024

In vision measurement, camera calibration has a significant impact on measurement precision. The classical target-based calibration methods require the target to occupy more than one-third of the field of view. A small-size target that does not meet the requirements results in poor calibration accuracy, while an appropriate large-size target is difficult to manufacture and inconvenient to operate. In view of the above problem, we propose a flexible and accurate calibration method based on small target image splicing to calibrate the binocular vision system with a large field of view. The spliced images and virtual large targets are constructed to extend the target size, providing better flexibility for calibration. Moreover, an optimization objective function integrating two constraints in the imaging plane and measurement space is presented to improve the calibration accuracy during the parameter optimization process. The simulation experiments and actual experiments are carried out to test the performance of the proposed method. The results demonstrate that the calibration accuracy of the proposed method using a small target is equivalent to that of Zhang’s method using a large target. Additionally, when using a same-size target, the parameter error of the proposed method is less than that of Zhang’s method, and the proposed method reduces the distance measurement error from 1.169 mm to 0.208 mm compared to Zhang’s method.
Detection of dislocation motion in atomistic simulations of nanocrystalline materials
Authors: Dimanstein Firman Noya , Engelberg Eliyahu Zvi , Ashkenazy Yinon
Published: April 2024

A method for identifying dislocation motion in atomistic simulations is presented. While identifying static and moving dislocations within a single crystal or a combination of such is well established, the method described here is tailored to identify dislocation motion by correlating the displacements of individual atoms. This facilitates the identification of dislocation motion in complex structural arrangements, and allows the specific contribution to plastic deformation, due to dislocation motion, to be separated from that of other mechanisms. The method is applied to test cases in crystals and grain boundaries (GBs), in which irradiation-induced creep (IIC) was induced. It is shown that the method singles out the moving dislocations from among the dislocation forest at GBs, thus identifying the specific reactions driving the distortion at any given time. This enables the study of dislocation processes in the presence of realistic obstacles, and the study of the effects of microstructure on dislocation mobility. As an example of such a study, the method is applied to rule out intragranular slip, and to estimate the contribution of dislocation motion to strain, in a NC undergoing IIC.
Preparation, biological activity and antibacterial properties of tantalum surface-doped Ca2+/Zn2+ nanorods
Authors: Cai Anqi , Yin Hairong , Wang Cuicui , Chen Qian , Yin Ruixue , Yuan Xin , Kang Haoran , Guo Hongwei
Published: April 2024

In this research, we utilize porous tantalum, known for its outstanding elastic modulus and biological properties, as a base material in biomedical applications. The human skeletal system is rich in elements like Ca and Zn. The role of Zn is crucial for achieving a spectrum of sterilizing effects, while Ca is known to effectively enhance cell differentiation and boost cellular activity. The focus of this study is the modification of porous tantalum using a hydrothermal method to synthesize Ca2+/Zn2+-doped Ta2O5 nanorods. These nanorods are subjected to extensive characterization techniques to confirm their structure and composition. Additionally, their biological performance is evaluated through a range of tests, including antibacterial assessments, MTT assays, and bacteria/cell scanning electron microscopy (SEM) analyses. The objective is to determine the most effective method of surface modification for porous tantalum, thereby laying a foundational theoretical framework for its surface enhancement.
Application of portable sleep monitoring devices in pregnancy: a comprehensive review
Authors: Balkan Nürfet , Çavuşoğlu Mustafa , Hornung René
Published: April 2024

Objective. The physiological, hormonal and biomechanical changes during pregnancy may trigger sleep disordered breathing (SDB) in pregnant women. Pregnancy-related sleep disorders may associate with adverse fetal and maternal outcomes including gestational diabetes, preeclampsia, preterm birth and gestational hypertension. Most of the screening and diagnostic studies that explore SDB during pregnancy were based on questionnaires which are inherently limited in providing definitive conclusions. The current gold standard in diagnostics is overnight polysomnography (PSG) involving the comprehensive measurements of physiological changes during sleep. However, applying the overnight laboratory PSG on pregnant women is not practical due to a number of challenges such as patient inconvenience, unnatural sleep dynamics, and expenses due to highly trained personnel and technology. Parallel to the progress in wearable sensors and portable electronics, home sleep monitoring devices became indispensable tools to record the sleep signals of pregnant women at her own sleep environment. This article reviews the application of portable sleep monitoring devices in pregnancy with particular emphasis on estimating the perinatal outcomes. Approach. The advantages and disadvantages of home based sleep monitoring systems compared to subjective sleep questionnaires and overnight PSG for pregnant women were evaluated. Main Results. An overview on the efficiency of the application of home sleep monitoring in terms of accuracy and specificity were presented for particular fetal and maternal outcomes. Significance. Based on our review, more homogenous and comparable research is needed to produce conclusive results with home based sleep monitoring systems to study the epidemiology of SDB in pregnancy and its impact on maternal and neonatal health.
An open-access simultaneous electrocardiogram and phonocardiogram database
Authors: Kazemnejad Arsalan , Karimi Sajjad , Gordany Peiman , Clifford Gari D , Sameni Reza
Published: April 2024

Objective. The EPHNOGRAM project aimed to develop a low-cost, low-power device for simultaneous electrocardiogram (ECG) and phonocardiogram (PCG) recording, with additional channels for environmental audio to enhance PCG through active noise cancellation. The objective was to study multimodal electro-mechanical activities of the heart, offering insights into the differences and synergies between these modalities during various cardiac activity levels. Approach. We developed and tested several hardware prototypes of a simultaneous ECG-PCG acquisition device. Using this technology, we collected simultaneous ECG and PCG data from 24 healthy adults during different physical activities, including resting, walking, running, and stationary biking, in an indoor fitness center. The data were annotated using a robust software that we developed for detecting ECG R-peaks and PCG S1 and S2 components, and overseen by a human expert. We also developed machine learning models using ECG-based, PCG-based, and joint ECG-PCG features, like R–R and S1–S2 intervals, to classify physical activities and analyze electro-mechanical dynamics. Main results. The results show a significant coupling between ECG and PCG components, especially during high-intensity exercise. Notable micro-variations in S2-based heart rate show differences in the heart’s electrical and mechanical functions. The Lomb-Scargle periodogram and approximate entropy analyses confirm the higher volatility of S2-based heart rate compared to ECG-based heart rate. Correlation analysis shows stronger coupling between R–R and R-S1 intervals during high-intensity activities. Hybrid ECG-PCG features, like the R-S2 interval, were identified as more informative for physical activity classification through mRMR feature selection and SHAP value analysis. Significance. The EPHNOGRAM database, is available on PhysioNet. The database enhances our understanding of cardiac function, enabling future studies on the heart’s mechanical and electrical interrelationships. The results of this study can contribute to improved cardiac condition diagnoses. Additionally, the designed hardware has the potential for integration into wearable devices and the development of multimodal stress test technologies.
Vibration control by using active electromagnetic shunt damper
Authors: Chen Minghao , Mao Qibo , Yuan Weiting
Published: April 2024

It is well-known that the traditional electromagnetic shunt damping (EMSD) techniques are limited by the damping force of electronic components and require a negative resistance (NR) shunt circuit to enhance performance. However, the NR shunt circuit could lead to the EMSD system being unstable. Addressing this, this study proposes an advanced control system that employs active control technology combined with EMSD for vibration control. We first developed a dimensionless mathematical model of the control system, which was then finely tuned using an adaptive simulated annealing particle swarm optimization algorithm. Subsequently, the relationship between control gain and optimal shunt circuit parameters was predicted using a BP neural network. Finally, the proposed Active-EMSD (AEMSD) was experimentally verified. The experimental results demonstrate that the proposed AEMSD not only surpasses traditional thresholds but also excels in isolating low-frequency vibrations. Compared to traditional EMSD, the proposed AEMSD showed improved effectiveness.
Scattering of ultrashort electron wave packets: optical theorem, differential phase contrast and angular asymmetries
Authors: Morimoto Yuya , Madsen Lars Bojer
Published: April 2024

Recent advances in electron microscopy allowed the generation of high-energy electron wave packets of ultrashort duration. Here we present a non-perturbative S-matrix theory for scattering of ultrashort electron wave packets by atomic targets. We apply the formalism to a case of elastic scattering and derive a generalized optical theorem for ultrashort wave-packet scattering. By numerical simulations with 1 fs wave packets, we find in angular distributions of electrons on a detector one-fold and anomalous two-fold azimuthal asymmetries. We discuss how the asymmetries relate to the coherence properties of the electron beam, and to the magnitude and phase of the scattering amplitude. The essential role of the phase of the exact scattering amplitude is revealed by comparison with results obtained using the first-Born approximation. Our work paves a way for controlling electron-matter interaction by the lateral and transversal coherence properties of pulsed electron beams.
Dual-parameter controlled reconfigurable metasurface for enhanced terahertz beamforming via inverse design method
Authors: Wu Qi , Fan Wen-Hui , Qin Chong , Jiang Xiao-Qiang
Published: April 2024

Recently, reconfigurable metasurfaces have emerged as a promising solution for wavefront manipulation in the terahertz (THz) region, providing enhanced beamforming capabilities. However, traditional single-parameter control methods fail to achieve independent phase and amplitude modulation, constraining their modulation capabilities. Meanwhile, forward design methods based on phase matching ignore the structural responses of the non-ideal unit, leading to degraded beamforming performance. Here, we introduce an electrically reconfigurable metasurface composed of bilayer graphene strips based on dual-parameter control. Full-wave simulations demonstrate independent amplitude and phase modulation, achieving the full 360° phase coverage and an adjustable amplitude range from 0 to 0.8 at 2.6 THz. To optimize beamforming performance, particularly for the responses of the non-ideal unit away from the designed frequency, we employed an inverse design method based on a hybrid evolutionary algorithm. This novel approach significantly enhances beam steering, achieving a maximum 60% increase in beam directivity and maintaining over 90% of ideal directivity across a broad frequency range from 1.6 THz to 5 THz. Especially, it achieves a maximum deflection angle of 75°. Meanwhile, the adaptability of the inverse design method is further demonstrated to various optimized objectives. For beam focusing, even with limited phase control (below 210°), this method significantly enhances the focusing quality (up to 150% enhancement) and increases the focusing efficiency from 25% to 40%. Additionally, it effectively mitigates the impact of quantized phase errors on beamforming. This research not only demonstrates potential applications in high-speed THz wireless communication and compact imaging systems but also paves the way for innovative designs in reconfigurable metasurfaces.
Role of oscillation frequency and amplitude on the microstructure and properties of linear friction welded nickel aluminium bronze joints
Authors: A K Lakshminarayanan , S Vishwa , Selvam Srecharan , Sivaraj P , Balasubramanian V
Published: April 2024

This study explores the influence of oscillation frequency and amplitude on the quality of linear friction welded joints using as-cast nickel aluminium bronze. Welding was conducted at 30 Hz, 50 Hz, and 70 Hz oscillated frequencies and amplitudes of 1.5 mm, 2 mm, and 3 mm. The joint’s performance was thoroughly investigated through systematic analysis, including macrostructure examination, peak interfacial temperature measurement, microstructure evaluation, strain assessment, cooling rate determination, microhardness testing, and tensile property characterization. The width of the weld zone varied from 183 μm to 297 μm, and the thermomechanical affected zone (TMAZ) area ranged from 4.48 mm2 to 14.79 mm2 across different process parameters. In the parent material, the volume fraction of the β-phase was as low as 20.2%, contrasting with the dominant α-phase at 79.8%. The average grain size of the lamellar and globular α-phase mixture was 26.4 μm. Notably, the weld zone exhibited extremely refined α-phase grains, with diameters less than 5 μm in all cases. The volume fraction of the β‘-phase increased significantly with higher frequencies, from 15.299% at 30 Hz to 26.98% at 50 Hz, peaking at 40.08% at 70 Hz, leading to varying k phases. This variation in microstructure had a substantial impact on mechanical properties. Tensile strength ranged from 503 MPa to 582 MPa, while ductility varied from 13.5% to 21.7%. Additionally, the hardness of the parent material increased from approximately 155 Hv to 260 Hv. This study demonstrates that controlling the oscillation frequency and amplitude in linear friction welding processes can yield consistent, high-quality welds in nickel aluminium bronze.
Observational signatures of rotating black holes in the semiclassical gravity with trace anomaly*
Authors: Zhang 张 Zhenyu 震宇 , Hou 侯 Yehui 业辉 , Guo 郭 Minyong 敏勇
Published: April 2024

In a recent work by Fernandes [Phys. Rev. D 108(6), L061502 (2023)], an exact stationary and axisymmetric solution was discovered in semiclassical gravity with type-A trace anomaly. This was identified as a quantum-corrected version of the Kerr black hole. In this study, we explore the observational signatures of this black hole solution. Our investigation reveals that prograde and retrograde light rings exist, whose radii increase monotonically with the coupling parameter α. When α is negative, the shadow area for the quantum-corrected black hole is smaller than that of the Kerr black hole, whereas when α is positive, the area is larger. For a near-extremal black hole, its high-spin feature (the NHEKline) is found to be highly susceptible to disruption by α. Furthermore, we discuss the images of the quantum-corrected black hole in the presence of a thin accretion disk and compare them to those of the Kerr black hole. Our study highlights the importance of near-horizon emission sources in detecting the effects of quantum corrections by black hole images.
Electronic origin of structural degradation in Li-rich transition metal oxides: The case of Li2MnO3 and Li2RuO3
Authors: Zhang Peng
Published: April 2024

Li2MnO3 and Li2RuO3 represent two prototype Li-rich transition metal (TM) oxides as high-capacity cathodes for Li-ion batteries, which have similar crystal structures but show quite different cycling performances. Here, based on the first-principles calculations, we systematically studied the electronic structures and defect properties of these two Li-rich cathodes, in order to get more understanding on the structural degradation mechanism in Li-rich TM oxides. Our calculations indicated that the structural and cycling stability of Li2MnO3 and Li2RuO3 depend closely on their electronic structures, especially the energy of their highest occupied electronic states (HOS), as it largely determines the defect properties of these cathodes. For Li2MnO3 with low-energy HOS, we found that, due to the defect charge transfer mechanism, various defects can form spontaneously in its host structure as Li ions are extracted upon delithiation, which seriously deteriorates its structural and cycling stability. While for Li2RuO3, on the other hand, we identified that the high-energy HOS prevents it from the defect formation upon delithiation and thus preserve its cycling reversibility. Our studies thus illustrated an electronic origin of the structural degradation in Li-rich TM oxides and implied that it is possible to improve their cycling performances by carefully adjusting their TM components.
Gas viscosities from a semiconductor-manufacturing mass-flow controller
Authors: Gonzalez-Juez E , Price A , Publico W
Published: April 2024

We obtain gas viscosities with a pressure-based mass-flow controller used for semi-conductor manufacturing, a rate-of-change approach, and a physics-based calculation. The novelty of this method is that it is used in an industrial process whose main goal is not to measure viscosities. In this way, for pressures of the order of 10 kPa and 25 ∘C and 35 ∘C, we obtain for seven gases viscosities with mean absolute errors with respect to reference viscosities of less than 1%. Using this method, we report viscosities for two semiconductor-manufacturing gases not available in the open literature: hexafluoroisobutene (CAS # 382-10-5) and 1,1,3,3,3-pentafluoropropene (690-27-7).
Crucial impact of component Allee effect in predator-prey system
Authors: Sahoo Kalyanashis , Sahoo Banshidhar
Published: April 2024

Allee effect in models in interacting species of predator prey system has great significance in ecological context. Allee effect plays crucial role in population dynamics in ecology, where it is the challenging fact that per capita population growth rate is positively dependent on the population density of a species. In this paper, we inspect the famous Hastings and Powell (HP) (Hastings and Powell 1991 Ecology
72 896–903) model incorporating component Allee effect on top predator’s reproduction. We analyse the updated model with the help of both analytical and numerical phenomena. Considering cost of Allee effect, half-saturation constant of prey as the key parameters, the Hopf bifurcations are also analysed. The directions of Hopf bifurcations at the critical values of Allee parameter and half-saturation constant of prey are studied theoretically by using normal form theory introduced by Hassard et al (1981 Theory and Applications of Hopf Bifurcation vol 41 (CUP Archive)). The formulated model indicates that the system demonstrates chaotic, periodic and stable dynamics in the variation of key parameters. The chaos can be controlled for proper application of the large values of parameter used as the cost of Allee effect and also for small values of the parameter used as the half saturation constant of prey population. The results of this study are applicable in the field of marine and wild ecosystem dynamics.
An improved Fourier modal method for design of metasurface diffractive optical elements
Authors: Dai Xingang , Zhang Hongru , Hu Yanjun , Jing Gaoshan , Zhang Zhiping , Fan Guofang
Published: April 2024

An improved Fourier modal method (FMM) is developed for the design of metasurface diffractive optical elements (DOEs), which combines the iterative Fourier transform algorithm (IFTA) with FMM. In which, the IFTA is executed for a coarse solution; then, FMM is for a precise solution. We take a 5 × 5 metasurface DOE with nanorods as an example to explore the improved FMM (IFTA + FMM). By varying the diameter of the nanorods on the metasurface DOE, a 5 × 5 spot array DOE has been created with a diffraction angle of 48°× 48° in the far field. The analysis results show that the improved FMM (IFTA + FMM) requires fewer iterations, about 17 times, while direct FMM requires about 70 times. The DOE designed with an improved FMM achieves a diffraction efficiency of 79.6% with a uniformity of 24.2%, while the DOE designed with a direct FMM shows a diffraction efficiency of 76.9% with a uniformity of 27.7%. The improved FMM (IFTA + FMM) shows a similar accuracy, but is more timesaving, simple, and intuitive.
Vectorial adaptive optics for advanced imaging systems
Authors: Ma Yifei , Zhao Zimo , Cui Jiahe , Wang Jingyu , He Chao
Published: April 2024

Vectorial adaptive optics (V-AO) is a cutting-edge technique extending conventional AO into the vectorial domain encompassing both polarization and phase feedback correction for optical systems. However, previous V-AO approaches focus on point correction. In this letter, we extend this AO approach into the imaging domain. We show how V-AO can benefit an aberrated imaging system to enhance not only scalar imaging but also the quality of vectorial information. Two important criteria, vectorial precision and uniformity are put forward and used in practice to evaluate the performance of the correction. These experimental validations pave the way for real-world imaging for V-AO technology and its applications.