bluuebunny/crossref_metadata_2025 huggingface dataset:
Intelligent mechanical manufacturing technology based on intelligent manufacturing technology
Authors: Zheng Kang
Published: June 2023

With the development of intelligent manufacturing technology, the application of intelligent machinery manufacturing technology has been widely promoted. Intelligent machinery manufacturing technology is a technology that integrates advanced manufacturing technology and intelligent control technology. It can realize the intelligent control of the entire manufacturing process, improve the manufacturing efficiency and product quality, and reduce the manufacturing cost. Based on intelligent manufacturing technology, intelligent machinery manufacturing technology has been developed rapidly and has been widely applied in various fields such as automotive, aviation and so on. It can achieve the goals of automation, intelligence, high efficiency, and personalization, and promote the development of various industries towards intelligent manufacturing. However, there are still challenges in the development and application of intelligent machinery manufacturing technology, such as the high cost of equipment, the difficulty in controlling the manufacturing process, and the lack of skilled workers. Future research should focus on solving these challenges and promoting the further development and application of intelligent machinery manufacturing technology.
Study on looseness characteristics of bolted joints of transmission towers under lateral vibration
Authors: Zhu Binrong , Huang Guo , Su Zhigang , Chen Bin , Liao Hailin
Published: June 2023

transmission towers have been subjected to alternating loads caused by the galloping of iced conductors for a long time, and their fastening bolts are easy to loosen or break, which seriously threatens the safe operation of transmission lines. Through the transverse vibration test of M20 bolts commonly used in transmission towers, the vibration frequency and amplitude are changed, and the change law of the preload of bolt joints is studied. The results show that with the increase of the initial preload, the decline speed of bolt clamping force decreases significantly; The clamping force drop curve of M20 bolt is fitted by shivakumar crews model, which is very consistent with the actual test curve.
Influence of Material Characteristics of Hoppers on Particle Flow Behavior
Authors: Zhang Panpan , Huang Guoqing , Chen Qingwei
Published: June 2023

In the previous study, different structures of hoppers were proposed. And the dust suppression performance of hoppers were evaluated. In this paper, different materials of hoppers were selected.And influence of different material on particle behaviors were studied based on the discrete element method (DEM). Results shows that the wall material with low collision recovery coefficient for the hopper has positive effect on suppressing dust diffusion.and the wall material with high static friction coefficient showed little effect on the particle flow state through the hopper.
Research on privacy protection of intelligent construction
Authors: Shang Jingshi , Li Xiuwen , Wang Qingyong
Published: June 2023

With the application of new generation intelligent technologies such as big data, cloud computing and numerical simulation in engineering, the level of intelligent construction has been gradually improved. In the development process of intelligent construction, it faces many problems, such as new technology, safety, human recognition and so on. This paper studies the privacy protection of intelligent construction, analyses the causes of privacy disclosure on the basis of information classification, and then puts forward privacy protection methods. The research shows that the privacy security of intelligent construction needs to clarify the scope and formulate effective protection strategies.
Study on the Measuring and Reading Mode of High Precision Thermometer in Hydraulic Engineering
Authors: Zhen Shisen , Wu Hao
Published: June 2023

After the operation of large water conservancy projects, water temperature changes will have a significant impact on the surrounding ecological environment. In order to monitor the water temperature, a water temperature monitoring system covering the whole flow channel has been established in China's giant hydropower stations. In order to accurately measure the water temperature in the water level fluctuation area, a ± 0.1 ℃ water temperature gauge is selected as the front sensing device. Compared with traditional thermometers, high-precision thermometers are rarely used in projects. After investigation and comparison, platinum resistance thermometer has been applied in water conservancy projects. In view of the fact that there is no special manual measuring and reading equipment for the platinum resistance thermometer before the automation is connected during the construction period, a four wire temperature measuring and reading mode is proposed, which is applicable to the platinum resistance thermometer by using the existing hydraulic bridge, and the rationality of the measuring and reading mode is verified through the comparison of indoor tests.
Experimental Platform Design for Particle Behavior Investigation
Authors: Zhang Panpan , Zhou Siyang , Chen Qingwei
Published: June 2023

The hopper is a kind of important equipment in bulk handling process. In this paper, an experimental platform was designed. The experimental platform was mainly composed of a feeding head, a vertical conveying screw machine, a horizontal conveying screw and a lifting device, a supporting structure, the visual experimental system,the electrical system and the acquisition system. the particle behavior for hoppers can be assessed by the experimental platform. And the visual experimental system will help to investigate the real particle flow behavior and will provide instructions for hopper design in future
Meta-analysis of Cerebrospinal Fluid Cell Count and Biochemistry to Diagnose Meningitis in Infants Aged < 90 Days
Authors: Anne Rajendra P. , Dutta Sourabh , Balasubramanian Haribalakrishna , Aggarwal Ashutosh N. , Chadha Neelima , Kumar Praveen
Published: June 2023

Objective Cerebrospinal fluid (CSF) white blood cell (WBC) count, protein, and glucose (cytochemistry) are performed to aid in the diagnosis of meningitis in young infants. However, studies have reported varying diagnostic accuracies. We assessed the diagnostic accuracy of CSF cytochemistry in infants below 90 days and determined the certainty of evidence.

Study Design We searched PubMed, Embase, Cochrane Library, Ovid, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Scopus databases in August 2021. We included studies that evaluated the diagnostic accuracy of CSF cytochemistry compared with CSF culture, Gram stain, or polymerase chain reaction in neonates and young infants <90 days with suspected meningitis. We pooled data using the hierarchical summary receiver operator characteristic (ROC) model.

Results Of the 10,720 unique records, 16 studies were eligible for meta-analysis, with a cumulative sample size of 31,695 (15 studies) for WBC, 12,936 (11 studies) for protein, and 1,120 (4 studies) for glucose. The median (Q1, Q3) specificities of WBC, protein, and glucose were 87 (82, 91), 89 (81, 94), and 91% (76, 99), respectively. The pooled sensitivities (95% confidence interval [CI]) at median specificity of WBC count, protein, and glucose were 90 (88, 92), 92 (89, 94), and 71% (54, 85), respectively. The area (95% CI) under ROC curves were 0.89 (0.87, 0.90), 0.87 (0.85, 0.88), and 0.81 (0.74, 0.88) for WBC, protein, and glucose, respectively. There was an unclear/high risk of bias and applicability concern in most studies. Overall certainty of the evidence was moderate. A bivariate model-based analysis to estimate the diagnostic accuracy at specific thresholds could not be conducted due to a paucity of data.

Conclusion CSF WBC and protein have good diagnostic accuracy for the diagnosis of meningitis in infants below 90 days of age. CSF glucose has good specificity but poor sensitivity. However, we could not identify enough studies to define an optimal threshold for the positivity of these tests.

Key Points
Synthesis of 3-Aminoalkylated Indoles Using Heterogeneous MgFe2O4 Nanoparticles Under Microwave Irradiation in One-Pot Three-Component System
Authors: Singh Prabal P. , Gupta Deeksha
Published: June 2023

A series of 3-aminoalkylated indoles are efficiently synthesised in a one-pot three-component reaction under microwave irradiation. Magnesium ferrite (MgFe2O4) nanoparticles (10 mol%) have been used as heterogeneous catalyst, which may easily be recovered by application of an external magnet and the recovered catalyst can be reused at least for five runs without affecting the efficiency of the catalyst. The solvent-free protocol developed has advantages of less reaction time, high yields, and easy workup, and the protocol is applicable to various acid base sensitive functional groups present in the substrate. The reported methodology is highly suitable especially for primary amines in addition to secondary amines as one of the components.
The Association between Fetal Growth Restriction and Maternal Morbidity
Authors: Hage Diab Yara , Martins Juliana G. , Saade George , Kawakita Tetsuya
Published: June 2023

Objective This study aimed to compare adverse maternal outcomes between pregnancies complicated by fetal growth restriction (FGR) and those without FGR.

Study Design This was a secondary analysis of the data from the Consortium on Safe Labor, which was conducted from 2002 to 2008 in 12 clinical centers with 19 hospitals across 9 American College of Obstetricians and Gynecologists districts. We included singleton pregnancies without any maternal comorbidities or placenta abnormalities. We compared the outcomes of individuals with FGR with individuals without FGR. Our primary outcome was severe maternal morbidity. Our secondary outcome included various adverse maternal and neonatal outcomes. Multivariable logistic regression was performed to obtain adjusted odds ratios (aOR) and 95% confidence intervals (95% CI), adjusting for confounders. Missing values for maternal age and body mass index were imputed.

Results Of 199,611 individuals, 4,554 (2.3%) had FGR and 195,057 (97.7%) did not have FGR. Compared with the individuals without FGR, individuals with FGR had increased odds of severe maternal morbidity (0.6 vs. 1.3%; aOR: 1.97 [95% CI: 1.51–2.57]), cesarean delivery (27.7 vs. 41.2%; aOR: 2.31 [95% CI: 2.16–2.48]), pregnancy-associated hypertension (8.3 vs. 19.2%; aOR: 2.76 [95% CI: 2.55–2.99]), preeclampsia without severe features (3.2 vs. 4.7%; aOR: 1.45 [95% CI: 1.26–1.68]), preeclampsia with severe features (1.4 vs. 8.6%; aOR: 6.04 [95% CI: 5.39–6.76]), superimposed preeclampsia (18.3 vs. 30.2%; aOR: 1.99 [95% CI: 1.53–2.59]), neonatal intensive care unit admission (9.7 vs. 28.4%; aOR: 3.53 [95% CI: 3.28–3.8]), respiratory distress syndrome (2.2 vs. 7.7%; aOR: 3.57 [95% CI: 3.15–4.04]), transient tachypnea of the newborn (3.3 vs. 5.4%; aOR: 1.62 [95% CI: 1.40–1.87]), and neonatal sepsis (2.1 vs. 5.5%; aOR: 2.43 [95% CI: 2.10–2.80]).

Conclusion FGR was associated with increased odds of severe maternal outcomes in addition to adverse neonatal outcomes.

Key Points
RETRACTED ARTICLE: The impact of augmented reality on student attitudes, motivation, and learning achievements—a meta-analysis (2016–2023)
Authors: Cao Wenwen , Yu Zhonggen
Published: June 2023

In light of the COVID-19 pandemic, a significant number of students have been compelled to remain at home while receiving education supported by augmented reality (AR) technologies. To determine the impact of AR technologies on educational outcomes, the present study undertook a meta-analysis utilizing Stata/MP 14.0. The study found that the attitudes of learners towards AR-assisted education were more positive, and their learning achievements were significantly higher compared to those who did not use AR technologies. However, there was no significant difference in motivation levels between the AR-assisted and non-AR-assisted educational models. The researchers explored several reasons for this result, but they could not identify any clear explanation. Future studies could take into account other factors that might affect education outcomes such as learning styles and learner personality. Doing so could shed more light on the impact of AR technologies on education.
Nonequilibrium quantum solvation with a time-dependent Onsager cavity
Authors: Kirchberg H. , Nalbach P. , Thorwart M.
Published: June 2023

We formulate a theory of nonequilibrium quantum solvation in which parameters of the solvent are explicitly depending on time. We assume in a simplest approach a spherical molecular Onsager cavity with a time-dependent radius. We analyze the relaxation properties of a test molecular point dipole in a dielectric solvent and consider two cases: (i) a shrinking Onsager sphere and (ii) a breathing Onsager sphere. Due to the time-dependent solvent, the frequency-dependent response function of the dipole becomes time-dependent. For a shrinking Onsager sphere, the dipole relaxation is in general enhanced. This is reflected in a temporally increasing linewidth of the absorptive part of the response. Furthermore, the effective frequency-dependent response function shows two peaks in the absorptive part which are symmetrically shifted around the eigenfrequency. By contrast, a breathing sphere reduces damping as compared to the static sphere. Interestingly, we find a non-monotonous dependence of the relaxation rate on the breathing rate and a resonant suppression of damping when both rates are comparable. Moreover, the linewidth of the absorptive part of the response function is strongly reduced for times when the breathing sphere reaches its maximal extension.
Transient intermediates are populated in the folding pathways of single-domain two-state folding protein L
Authors: Maity Hiranmay , Reddy Govardhan
Published: June 2023

Small single-domain globular proteins, which are believed to be dominantly two-state folders, played an important role in elucidating various aspects of the protein folding mechanism. However, recent single molecule fluorescence resonance energy transfer experiments [H. Y. Aviram et al. J. Chem. Phys. 148, 123303 (2018)] on a single-domain two-state folding protein L showed evidence for the population of an intermediate state and it was suggested that in this state, a β-hairpin present near the C-terminal of the native protein state is unfolded. We performed molecular dynamics simulations using a coarse-grained self-organized-polymer model with side chains to study the folding pathways of protein L. In agreement with the experiments, an intermediate is populated in the simulation folding pathways where the C-terminal β-hairpin detaches from the rest of the protein structure. The lifetime of this intermediate structure increased with the decrease in temperature. In low temperature conditions, we also observed a second intermediate state, which is globular with a significant fraction of the native-like tertiary contacts satisfying the features of a dry molten globule.
Impact of fin aspect ratio on enhancement of external quantum efficiency in single AlGaN fin light-emitting diodes pixels
Authors: Nikoobakht Babak , Zong Yuqin , Koksal Okan , Agrawal Amit , Montgomery Christopher , Rumsey Jaime , Leach Jacob , Shur Michael
Published: June 2023

Previously, we showed within a sub-micron fin shape heterojunction, as current density increases, the non-radiative Auger recombination saturates mediated by the extension of the depletion region into the fin, resulting in a droop-free behavior. Here, we investigate the dependence of the fin aspect ratio (height to width ratio) on external quantum efficiency (EQE) of single n-AlGaN fin/p-GaN heterojunctions. Fins are arranged in an array format varying in width from 3000 to 200 nm. In this architecture, an n-metal contact is interfaced with the non-polar side facet of the fin. At a fixed current density, as the aspect ratio increases from 0.2 to 3 (the fin width reduces), we systematically observe an increase in the ultraviolet (UV) excitonic emission of the AlGaN fin and a 7× enhancement in the EQE. We explain this phenomenon by conserving the volume of the carrier depletion region within a fin. As the fin gets thinner, the base area of the depletion volume shrinks, whereas its height increases within the fin. This geometrical advantage allows a 200 nm wide fin to operate at 1/3rd the current density compared to a 3000 nm wide fin while generating a UV emission with a comparable power of 1 μW. These findings show additional parameters that can be used for developing brighter light sources, including the shape and aspect ratio of a heterojunction at the micro- or nano-scale.
Field-free switching and high spin–orbit torque efficiency in Co/Ir/CoFeB synthetic antiferromagnets deposited on miscut Al2O3 substrates
Authors: Fan Haodong , Jin Menghao , Wu Birui , Wei Mingzhang , Wang Jiale , Shao Ziji , Yu Changqiu , Wen Jiahong , Li Hai , Li Wenjun , Zhou Tiejun
Published: June 2023

Ir-CoFeB-based synthetic antiferromagnets (SAFs) are potential candidates as the free layer of the next-generation magnetic tunnel junctions (MTJs) for high speed and density memories due to their perpendicular magnetic anisotropy and strong interlayer exchange coupling. However, the field-free spin–orbit torque (SOT) switching of Ir-CoFeB-based SAFs has rarely been reported, especially in the Co/Ir/CoFeB system with high anti-interference capability and being readily integrated with MTJs. In this paper, SOT-induced magnetization switching and SOT efficiency in Co/Ir/CoFeB SAFs with perpendicular anisotropy and tunable exchange coupling are systemically investigated. A full field-free switching of perpendicular Co/Ir/CoFeB SAFs is realized by depositing them onto crystal miscut Al2O3 substrates, which induce a tilted magnetic anisotropy. Furthermore, by introducing crystalline MgO or amorphous HfO2/SiO2 as the seed layers, the source of the tilted magnetic anisotropy was proved to be from the transverse asymmetry caused by the crystal miscut. Moreover, the crystal miscut enhances the SOT efficiency. The findings provide an approach to reliable field-free switching and high SOT efficiency of Ir-CoFeB-based SAFs for memories as well as logics with low power, fast speed, and high density.
An integrated RF energy–harvesting system with broad input voltage range and high power conversion efficiency
Authors: Wang Shuren , Jiang Xiaoxue , Pan Heng , Ye Xuanjie , Chen Jie
Published: June 2023

By 2050, countries around the world are expected to be gradually phasing out fossil fuels and implementing greener energy technologies. In this work, we present a system employing Energy harvesting, a self-powered technology that can recycle energy from the surrounding environment. A high-efficiency radio frequency (RF) energy–harvesting chip was designed and fabricated. With an off-chip antenna and rectifier, the system scavenges ambient RF energy and converts it into usable energy, which is then stored in energy storage elements (such as a supercapacitor or a rechargeable battery). The system can further be implemented as an energy source for charging smart devices. The system-on-chip design consists of a cold start block, a boost converter with maximum power point tracking functionalities, and a charging block. The chip was fabricated using AMS 350 nm technology. Although the system was optimized for harvesting RF energy, it can be easily adapted to harvest other energy sources (i.e., mechanical and thermal energy sources). Using an optimized cold start architecture, the circuit has a cold start voltage of 380 mV. With an improved control strategy of power conversion, the system is capable of continuously charging up to 4.5 V with a broad input voltage range of 100 mV to 10 V and has a peak charging efficiency of 82%.
On the verge of domestication: Early use of C4plants in the Horn of Africa
Authors: Ruiz-Giralt Abel , Nixon-Darcus Laurie , D’Andrea A. Catherine , Meresa Yemane , Biagetti Stefano , Lancelotti Carla
Published: June 2023

The earliest evidence of agriculture in the Horn of Africa dates to the Pre-Aksumite period (ca. 1600 BCE). Domesticated C3cereals are considered to have been introduced from the Near East, whereas the origin (local or not) and time of domestication of various African C4species such as sorghum, finger millet, or t’ef remain unknown. In this paper, we present the results of the analysis of microbotanical residues (starch and phytoliths) from grinding stones recovered from two archaeological sites in northeastern Tigrai (Ethiopia), namely Mezber and Ona Adi. Together, both sites cover a time period that encompasses the earliest evidence of agriculture in the region (ca. 1600 BCE) to the fall of the Kingdom of Aksum (ca. 700 CE). Our data indicate that these communities featured complex mixed economies which included the consumption of both domestic and wild plant products since the Initial Pre-Aksumite Phase (ca. 1600 to 900 BCE), including C3crops and legumes, but also C4cereals and geophytes. These new data expand the record of C4plant use in the Horn of Africa to over 1,000 y. It also represents the first evidence for the consumption of starchy products in the region. These results have parallels in the wider northeastern African region where complex food systems have been documented. Altogether, our data represent a significant challenge to our current knowledge of Pre-Aksumite and Aksumite economies, forcing us to rethink the way we define these cultural horizons.
Synthetic molecular motor activates drug delivery from polymersomes
Authors: Guinart Ainoa , Korpidou Maria , Doellerer Daniel , Pacella Gianni , Stuart Marc C. A. , Dinu Ionel Adrian , Portale Giuseppe , Palivan Cornelia , Feringa Ben L.
Published: June 2023

The design of stimuli-responsive systems in nanomedicine arises from the challenges associated with the unsolved needs of current molecular drug delivery. Here, we present a delivery system with high spatiotemporal control and tunable release profiles. The design is based on the combination of an hydrophobic synthetic molecular rotary motor and a PDMS-
b
-PMOXA diblock copolymer to create a responsive self-assembled system. The successful incorporation and selective activation by low-power visible light (λ = 430 nm, 6.9 mW) allowed to trigger the delivery of a fluorescent dye with high efficiencies (up to 75%). Moreover, we proved the ability to turn on and off the responsive behavior on demand over sequential cycles. Low concentrations of photoresponsive units (down to 1 mol% of molecular motor) are shown to effectively promote release. Our system was also tested under relevant physiological conditions using a lung cancer cell line and the encapsulation of an Food and Drug Administration (FDA)-approved drug. Similar levels of cell viability are observed compared to the free given drug showing the potential of our platform to deliver functional drugs on request with high efficiency. This work provides an important step for the application of synthetic molecular machines in the next generation of smart delivery systems.
Structural evolution of an immune evasion determinant shapes pathogen host tropism
Authors: Marcinkiewicz Ashley L. , Brangulis Kalvis , Dupuis Alan P. , Hart Thomas M. , Zamba‐Campero Maxime , Nowak Tristan A. , Stout Jessica L. , Akopjana Inara , Kazaks Andris , Bogans Janis , Ciota Alexander T. , Kraiczy Peter , Kolokotronis Sergios-Orestis , Lin Yi-Pin
Published: June 2023

Modern infectious disease outbreaks often involve changes in host tropism, the preferential adaptation of pathogens to specific hosts. The Lyme disease-causing bacterium
Borrelia burgdorferi
(
Bb
) is an ideal model to investigate the molecular mechanisms of host tropism, because different variants of these tick-transmitted bacteria are distinctly maintained in rodents or bird reservoir hosts. To survive in hosts and escape complement-mediated immune clearance,
Bb
produces the outer surface protein CspZ that binds the complement inhibitor factor H (FH) to facilitate bacterial dissemination in vertebrates. Despite high sequence conservation, CspZ variants differ in human FH-binding ability. Together with the FH polymorphisms between vertebrate hosts, these findings suggest that minor sequence variation in this bacterial outer surface protein may confer dramatic differences in host-specific, FH-binding-mediated infectivity. We tested this hypothesis by determining the crystal structure of the CspZ–human FH complex, and identifying minor variation localized in the FH-binding interface yielding bird and rodent FH-specific binding activity that impacts infectivity. Swapping the divergent region in the FH-binding interface between rodent- and bird-associated CspZ variants alters the ability to promote rodent- and bird-specific early-onset dissemination. We further linked these loops and respective host-specific, complement-dependent phenotypes with distinct CspZ phylogenetic lineages, elucidating evolutionary mechanisms driving host tropism emergence. Our multidisciplinary work provides a novel molecular basis for how a single, short protein motif could greatly modulate pathogen host tropism.
Dryocosmus kuriphilus Yasumatsu. [Distribution map].
Authors: CABI  , EPPO
Published: June 2023

A new distribution map is provided for Dryocosmus kuriphilus Yasumatsu. Hymenoptera: Cynipidae. Host: chestnut (
Castanea
spp.).
Nuclear pore complexes mediate subtelomeric gene silencing by regulating PCNA levels on chromatin
Authors: Choudhry Sanjeev Kumar , Neal Maxwell L. , Li Song , Navare Arti T. , Van Eeuwen Trevor , Wozniak Richard W. , Mast Fred D. , Rout Michael P. , Aitchison John D.
Published: June 2023

The nuclear pore complex (NPC) physically interacts with chromatin and regulates gene expression. The Saccharomyces cerevisiae inner ring nucleoporin Nup170 has been implicated in chromatin organization and the maintenance of gene silencing in subtelomeric regions. To gain insight into how Nup170 regulates this process, we used protein–protein interactions, genetic interactions, and transcriptome correlation analyses to identify the Ctf18-RFC complex, an alternative proliferating cell nuclear antigen (PCNA) loader, as a facilitator of the gene regulatory functions of Nup170. The Ctf18-RFC complex is recruited to a subpopulation of NPCs that lack the nuclear basket proteins Mlp1 and Mlp2. In the absence of Nup170, PCNA levels on DNA are reduced, resulting in the loss of silencing of subtelomeric genes. Increasing PCNA levels on DNA by removing Elg1, which is required for PCNA unloading, rescues subtelomeric silencing defects in nup170Δ. The NPC, therefore, mediates subtelomeric gene silencing by regulating PCNA levels on DNA.
FREEDA: An automated computational pipeline guides experimental testing of protein innovation
Authors: Dudka Damian , Akins R. Brian , Lampson Michael A.
Published: June 2023

Cell biologists typically focus on conserved regions of a protein, overlooking innovations that can shape its function over evolutionary time. Computational analyses can reveal potential innovations by detecting statistical signatures of positive selection that lead to rapid accumulation of beneficial mutations. However, these approaches are not easily accessible to non-specialists, limiting their use in cell biology. Here, we present an automated computational pipeline FREEDA that provides a simple graphical user interface requiring only a gene name; integrates widely used molecular evolution tools to detect positive selection in rodents, primates, carnivores, birds, and flies; and maps results onto protein structures predicted by AlphaFold. Applying FREEDA to >100 centromere proteins, we find statistical evidence of positive selection within loops and turns of ancient domains, suggesting innovation of essential functions. As a proof-of-principle experiment, we show innovation in centromere binding of mouse CENP-O. Overall, we provide an accessible computational tool to guide cell biology research and apply it to experimentally demonstrate functional innovation.
High-Temperature Superconductivity in Doped Boron Clathrates
Authors: Ma Liang , Wang Lingrui , Yuan Yifang , Guo Haizhong , Wang Hongbo
Published: June 2023

The recent discoveries of near-room-temperature superconductivity in clathrate hydrides present compelling evidence for the reliability of theory-orientated conventional superconductivity. Nevertheless, the harsh pressure conditions required to maintain such high T
c limit their practical applications. To address this challenge, we conducted extensive first-principles calculations to investigate the doping effect of the recently synthesized LaB8 clathrate, intending to design high-temperature superconductors at ambient pressure. Our results demonstrate that these clathrates are highly promising for high-temperature superconductivity owing to the coexistence of rigid boron covalent networks and the tunable density of states at the Fermi level. Remarkably, the predicted T
c of BaB8 could reach 62K at ambient pressure, suggesting a significant improvement over the calculated T
c of 14K in LaB8. Moreover, further calculations of the formation enthalpies suggest that BaB8 could be potentially synthesized under high-temperature and high-pressure conditions. These findings highlight the potential of doped boron clathrates as promising superconductors and provide valuable insights into the design of light-element clathrate superconductors.
Ambipolar Doping of Monolayer FeSe by Interface Engineering
Authors: Cheng Fang-Jun , Zhang Yi-Min , Fan Jia-Qi , Song Can-Li , Ma Xu-Cun , Xue Qi-Kun
Published: June 2023

We report on ambipolar modulation doping of monolayer FeSe epitaxial films grown by molecular beam epitaxy and in situ spectroscopic measurements via a cryogenic scanning tunneling microscopy. It is found that hole doping kills superconductivity in monolayer FeSe films on metallic Ir(001) substrates, whereas electron doping from polycrystalline IrO2/SrTiO3 substrate enhances significantly the superconductivity with an energy gap of 10.3 meV. By exploring substrate-dependent superconductivity, we elucidate the essential impact of substrate work functions on the superconductivity of monolayer FeSe films. Our results therefore offer a valuable reference guide for further enhancement of the transition temperature T
c in FeSe-based superconductors by interface engineering.
A charged particle must be treated relativistically in classical theory
Authors: Boyer Timothy H
Published: June 2023

A charged particle which is allowed to accelerate must have relativistic behavior because it is coupled to electromagnetic radiation which propagates at the speed of light. We treat the simple steady-state situation of a charged particle moving in a circular orbit with counter-propagating plane waves providing the power which balances the energy radiated away by the accelerating charge. It is emphasized that only an electromagnetic arrangement, such as a Coulomb potential or a constant magnetic field, can provide the relativistic central force for the particle motion.
Excitation and quasi-transition of rogue waves in a one-dimensional quantum droplet
Authors: Lv Li-Zheng , Gao Peng , Yang Zhan-Ying , Yang Wen-Li
Published: June 2023

We study the dynamics of rogue wave excitations and quasi-transitions in one-dimensional quantum droplets, whose homogeneous-density flat top provides an applicable background wave for nonlinear excitation. Using a quenching technique and a localized space modulation technique for the nonlinear effect coefficient, the rogue wave is excited on droplets. The excitation modes of rogue waves can be transitioned to dispersive shock waves or Kuznetsov–Ma breathers by regulating their modulation amplitude and width, and their maximal density and width can be regulated by modulation their amplitude. Meanwhile, two Gaussian modulations for droplets also bring the second-order rogue wave’s dynamics, whose maximal amplitude can approach 3.6 times that of the amplitude of droplets. Our results provide guidance for rogue wave excitation and transition on self-bound background waves and deepen our understanding of quantum droplets.
Radial characteristics of laser-induced plasma under the influence of air pressure
Authors: Yuan H , Ke W , Liu J Q , Chen M Y , Wang X H , Yang A J , Chu J F , Liu D X , Rong M Z
Published: June 2023

Air pressure is one of the key factors affecting laser-induced breakdown spectroscopy (LIBS), and the mechanism of its influence on the spatial–temporal evolution of laser-induced plasma (LIP) is still not fully understood due to complex physical processes. In this study, the spatially and temporally resolved LIP’s spectra at different pressures were collected from the direction of laser incidence, and the radial distribution characteristics of LIP along the target surface under the influence of air pressure were studied. Furthermore, the spatial–temporal evolution of the radial distribution of the electron density n
e and electron temperature T
e was studied using Stark broadening and a Boltzmann plot. Finally, the radial distribution of LIP satisfying the McWhirter criterion and the influence of air pressure on its spatial–temporal evolution were studied. It was found that air pressure has a significant effect on the radial distribution of LIP. The spectral intensity, electron density n
e, and the electron temperature T
e of the LIP decrease faster against distance r from the LIP core and slower with the delay time T
d in a higher air-pressure environment. Furthermore, the LIP will gradually fail to satisfy the McWhirter criterion with the increase in the radius r and delay time T
d; in addition, the lifetime of LIP, which satisfies the McWhirter criterion, is longer at higher pressure. This study is helpful in clarifying the influence of air pressure on the spatial–temporal evolution of LIP, optimizing the experimental parameters of LIBS, and providing a reference for application of LIBS.
Anisotropic hybridization probed by polarization dependent x-ray absorption spectroscopy in VI3 van der Waals Mott ferromagnet
Authors: Sant R , De Vita A , Polewczyk V , Pierantozzi G M , Mazzola F , Vinai G , van der Laan G , Panaccione G , Brookes N B
Published: June 2023

Polarization dependent x-ray absorption spectroscopy was used to study the magnetic ground state and the orbital occupation in bulk-phase VI3 van der Waals crystals below and above the ferromagnetic and structural transitions. X-ray natural linear dichroism and x-ray magnetic circular dichroism spectra acquired at the V

L

2
,
3

edges are compared against multiplet cluster calculations within the frame of the ligand field theory to quantify the intra-atomic electronic interactions at play and evaluate the effects of symmetry reduction occurring in a trigonally distorted VI6 unit. We observed a non zero linear dichroism proving the presence of an anisotropic charge density distribution around the V3+ ion due to the unbalanced hybridization between the vanadium and the ligand states. Such hybridization acts as an effective trigonal crystal field, slightly lifting the degeneracy of the

t

2
g

2

ground state. However, the energy splitting associated to the distortion underestimates the experimental band gap, suggesting that the insulating ground state is stabilized by Mott correlation effects rather than via a Jahn–Teller mechanism. Our results clarify the role of the distortion in VI3 and establish a benchmark for the study of the spectroscopic properties of other van der Waals halides, including emerging 2D materials with mono and few-layers thickness, whose fundamental properties might be altered by reduced dimensions and interface proximity.
Janus monolayer ScXY (X≠Y = Cl, Br and I) for piezoelectric and valleytronic application: a first-principle prediction
Authors: Guo Xiao-Shu , Guo San-Dong , Si Shuo-Ning , Cheng Kai , Wang Ke , Ang Yee Sin
Published: June 2023

Coexistence of ferromagnetism, piezoelectricity and valley in two-dimensional (2D) materials is crucial to advance multifunctional electronic technologies. Here, Janus ScXY (X≠Y = Cl, Br and I) monolayers are predicted to be piezoelectric ferromagnetic semiconductors with dynamical, mechanical and thermal stabilities. They all show an in-plane easy axis of magnetization by calculating magnetic anisotropy energy (MAE) including magnetocrystalline anisotropy energy and magnetic shape anisotropy energy. The MAE results show that they intrinsically have no spontaneous valley polarization. The predicted piezoelectric strain coefficients d
11 and d
31 (absolute values) are higher than ones of most 2D materials. Moreover, the d
31 (absolute value) of ScClI reaches up to 1.14 pm V−1, which is highly desirable for ultrathin piezoelectric device application. To obtain spontaneous valley polarization, charge doping are explored to tune the direction of magnetization of ScXY. By appropriate hole doping, their easy magnetization axis can change from in-plane to out-of-plane, resulting in spontaneous valley polarization. Taking ScBrI with 0.20 holes per f.u. as an example, under the action of an in-plane electric field, the hole carriers of K valley turn towards one edge of the sample, which will produce anomalous valley Hall effect, and the hole carriers of Γ valley move in a straight line. These findings could pave the way for designing piezoelectric and valleytronic devices.
A novel fault diagnosis approach of rolling bearing using intrinsic feature extraction and CBAM-enhanced InceptionNet
Authors: Xu Shijie , Yuan Rui , Lv Yong , Hu Huangxing , Shen Tong , Zhu Weihang
Published: June 2023

Rolling bearings play a crucial role as components in mechanical equipment. Malfunctioning rolling bearings can disrupt the normal operation of the equipment and pose safety hazards. Traditional deep learning-based methods for diagnosing faults in rolling bearings present several issues, such as insufficient feature information of fault samples, high model complexity and low accuracy. To overcome these challenges, this paper introduces an intelligent approach for rolling bearing fault diagnosis using intrinsic feature extraction and convolutional block attention module (CBAM)-enhanced InceptionNet. In our researches, variational mode decomposition (VMD) is adopted to decompose the original signal into multiple band-limited intrinsic mode functions (BLIMFs). In the decomposition process of VMD, the number of decomposition layers k is determined by center frequency method and the optimal BLIMF is chosen based on minimum envelope entropy. Subsequently, the continuous wavelet transform is employed to transform the optimal BLIMFs into time-frequency images. Finally, the obtained time-frequency images are fed into the proposed CBAM-enhanced InceptionNet for fault state diagnosis. Experiments on two different datasets prove that the method has stable and reliable accuracy. Comparative experiments have demonstrated that this method can reduce network model parameters and improve diagnosis efficiency while achieving high accuracy.
A calibration method for line-structured light using mirror-based virtual binocular vision system
Authors: Yang Pei , Yang Ziyi , Zhang Jin , Xia Haojie
Published: June 2023

A calibration method for line-structured light (LSL) by using a virtual binocular vision system (VBVS) composed of one camera and a front coating plane mirror is promoted in this work. The front coating plane in the VBVS can generate much less coplanarity error in lithographic feature points and remarkably decline the imaging distortion during back coating. An encoded target is proposed to distinguish between real corners and virtual corners (mirrored corners) and achieve high-precision matching between real and virtual corners when the target is occluded during the VBVS calibration. A parameter optimization method based on 3D constraints is presented in the work to obtain accurate structural parameters and thus guarantee precise reconstruction of the LSL. Moreover, the laser stripe and its mirrored image meet the auto-epipolar constraint. Therefore, the matching between the real and virtual stripes can be realized based on the vanish point. The performance of our method is verified in the experiments.
Capacitively coupled nonthermal plasma synthesis of aluminum nanocrystals for enhanced yield and size control
Authors: Cameron Thomas , Klause Bailey , Andaraarachchi Himashi , Xiong Zichang , Reed Carter , Thapa Dinesh , Wu Chi-Chin , Kortshagen Uwe R
Published: June 2023

Uniform-size, non-native oxide-passivated metallic aluminum nanoparticles (Al NPs) have desirable properties for fuel applications, battery components, plasmonics, and hydrogen catalysis. Nonthermal plasma-assisted synthesis of Al NPs was previously achieved with an inductively coupled plasma (ICP) reactor, but the low production rate and limited tunability of particle size were key barriers to the applications of this material. This work focuses on the application of capacitively coupled plasma (CCP) to achieve improved control over Al NP size and a ten-fold increase in yield. In contrast with many other materials, where NP size is controlled via the gas residence time in the reactor, the Al NP size appeared to depend on the power input to the CCP system. The results indicate that the CCP reactor assembly, with a hydrogen-rich argon/hydrogen plasma, was able to produce Al NPs with diameters that were tunable between 8 and 21 nm at a rate up ∼ 100 mg h−1. X-ray diffraction indicates that a hydrogen-rich environment results in crystalline metal Al particles. The improved synthesis control of the CCP system compared to the ICP system is interpreted in terms of the CCP’s lower plasma density, as determined by double Langmuir probe measurements, leading to reduced NP heating in the CCP that is more amenable to NP nucleation and growth.
A patient-specific deep learning framework for 3D motion estimation and volumetric imaging during lung cancer radiotherapy
Authors: Hindley Nicholas , Shieh Chun-Chien , Keall Paul
Published: June 2023

Objective. Respiration introduces a constant source of irregular motion that poses a significant challenge for the precise irradiation of thoracic and abdominal cancers. Current real-time motion management strategies require dedicated systems that are not available in most radiotherapy centers. We sought to develop a system that estimates and visualises the impact of respiratory motion in 3D given the 2D images acquired on a standard linear accelerator. Approach. In this paper we introduce Voxelmap, a patient-specific deep learning framework that achieves 3D motion estimation and volumetric imaging using the data and resources available in standard clinical settings. Here we perform a simulation study of this framework using imaging data from two lung cancer patients. Main results. Using 2D images as input and 3D–3D Elastix registrations as ground-truth, Voxelmap was able to continuously predict 3D tumor motion with mean errors of 0.1 ± 0.5, −0.6 ± 0.8, and 0.0 ± 0.2 mm along the left–right, superior–inferior, and anterior–posterior axes respectively. Voxelmap also predicted 3D thoracoabdominal motion with mean errors of −0.1 ± 0.3, −0.1 ± 0.6, and −0.2 ± 0.2 mm respectively. Moreover, volumetric imaging was achieved with mean average error 0.0003, root-mean-squared error 0.0007, structural similarity 1.0 and peak-signal-to-noise ratio 65.8. Significance. The results of this study demonstrate the possibility of achieving 3D motion estimation and volumetric imaging during lung cancer treatments on a standard linear accelerator.
A simulation study of 1D U-Net-based inter-crystal scatter event recovery of PET detectors
Authors: Zou Jiaxuan , Ye Jianbo , Yu Jintao , Cui Ke
Published: June 2023

To achieve high spatial resolution of reconstructed images in positron emission tomography (PET), the size of the scintillation crystal element is set small in current PET systems, which greatly increases the inter-crystal scattering (ICS) frequency. The ICS is a type of Compton scattering of the gamma photons from one crystal element to its neighborhood element, which obscures the determination of the first interaction position. In this study, we propose a 1D U-Net convolutional neural network to predict the first interaction position, which provides a universal way to efficiently solve the ICS recovery problem. The network is trained using the dataset collected from the GATE Monte Carlo simulation. The 1D U-Net structure is applied due to its capability of synthesizing both low-level and high-level information, which shows superiority in solving the ICS recovery problem. After being well trained, the 1D U-Net can generate a prediction accuracy of 78.1%. Compared to the coincidence events only composed from two photoelectric gamma photons, the sensitivity is improved by 149%. The contrast-to-noise ratio of the reconstructed contrast phantom increases from 6.973 to 10.795 for the 16 mm hot sphere. Compared to the take-energy-centroid method, the spatial resolution of the reconstructed resolution phantom can obtain the best improvement of 33.46%. Compared with the previous deep learning method based on the fully connected network, the proposed 1D U-Net can work more stably with considerably fewer network parameters. The 1D U-Net network model shows good universality when predicting different phantoms, and the computation speed is fast.
Energy harvesting using ferroelectric/ferroelastic switching: the effect of pre-poling
Authors: Kang Wenbin , Cain Cameron , Wang Fan , Huber John E
Published: June 2023

Improved power output and energy density have been achieved in piezoelectric transducers by exploiting ferroelectric/ferroelastic switching. However, a problem is that stable working cycles with polarization switching normally cannot be driven by stress alone. This problem has been addressed by using internal bias fields in a partially poled ferroelectric: the material state is engineered such that compressive stress drives ferroelastic switching during mechanical loading, while residual fields restore the polarized state during unloading. However, although this method has been verified, the devices in engineering material states with the best performance have not been explored systematically. In this work, internal bias fields in a partially poled (pre-poled) ferroelectric are used to guide polarization switching, producing an effective energy harvesting cycle. Devices are tested and optimized in the frequency range 1–20 Hz, and the influence of the degree of pre-poling in the fabrication process on energy harvesting performance is explored systematically. It is found that pre-poling the ferroelectric ceramic to about 25% of the fully poled state results in a device that can generate a power density up to about 26 mW cm−3 of active material at 20 Hz, an improvement on prior work and an order of magnitude advance over conventional piezoelectrics. However, maximizing the power density can result in residual stresses that risk damage to the device during preparation or in service. The relationship between fabrication success rate and pre-poling level is studied, indicating that greater degrees of pre-poling correlate with higher survival rate. This provides a basis for balancing energy conversion with device robustness.