bluuebunny/crossref_metadata_2025 huggingface dataset:
Alzheimer's disease classification using cluster‐based labelling for graph neural network on heterogeneous data
Authors: McCombe Niamh , Bamrah Jake , Sanchez‐Bornot Jose M. , Finn David P. , McClean Paula L. , Wong‐Lin KongFatt ,   Alzheimer's Disease Neuroimaging Initiative (ADNI)
Published: October 2022

Biomarkers for Alzheimer's disease (AD) diagnosis do not always correlate reliably with cognitive symptoms, making clinical diagnosis inconsistent. In this study, the performance of a graphical neural network (GNN) classifier based on data‐driven diagnostic classes from unsupervised clustering on heterogeneous data is compared to the performance of a classifier using clinician diagnosis as an outcome. Unsupervised clustering on tau‐positron emission tomography (PET) and cognitive and functional assessment data was performed. Five clusters embedded in a non‐linear uniform manifold approximation and project (UMAP) space were identified. The individual clusters revealed specific feature characteristics with respect to clinical diagnosis of AD, gender, family history, age, and underlying neurological risk factors (NRFs). In particular, one cluster comprised mainly diagnosed AD cases. All cases within this cluster were re‐labelled AD cases. The re‐labelled cases are characterized by high cerebrospinal fluid amyloid beta (CSF Aβ) levels at a younger age, even though Aβ data was not used for clustering. A GNN model was trained using the re‐labelled data with a multiclass area‐under‐the‐curve (AUC) of 95.2%, higher than the AUC of a GNN trained on clinician diagnosis (91.7%; p = 0.02). Overall, our work suggests that more objective cluster‐based diagnostic labels combined with GNN classification may have value in clinical risk stratification and diagnosis of AD.
Influence analysis of calculated horizontally layered soil parameters on grounding parameters
Authors: Dan Yihua , Yin Junjun , Yang Jian , Yang Huizhang
Published: October 2022

Calculated parameters (soil layer resistivity, soil layer thickness, and the number of soil layers) of horizontally layered soil are usually obtained based on the measured apparent resistivity under different measurement distances, which are significant for the design, operation, and maintenance of grounding grids. Most existing calculation methods of soil parameters are just trying to make the calculation results approach the measurement data, ignoring the relationship among measurement data, the calculated soil parameters, and grounding parameters, which would increase the workload of the measurement. To better balance the distance range of the measurement data and the influence of the calculated horizontally layered soil on grounding parameters, this paper systematically studies the relationship among measured apparent soil resistivity, calculated horizontally layered soil parameters, and grounding parameters. The basic theories of apparent resistivity measurement, soil parameter calculation, and grounding parameter calculation are given, the influence of soil layer thickness on the measured apparent resistivity is studied, and the influence of the calculated soil parameters on the grounding resistance of different grounding models is analysed. Based on different scales of grounding grids, the results give a corresponding reference distance range of measured apparent soil resistivity. Therefore, this paper can help decrease the workload of soil resistivity measurement during grounding parameters analysis, which has far‐reaching engineering significance.
Effect of multiphase content on temperature‐dependent electrical conductivity in silicone rubber composites
Authors: Lin Ying , Liu Yuhao , Cao Bin , Xue Jianyi , Wang Liming , Wang Jianing , Ding Lijian
Published: October 2022

To investigate how the multiphase structures affect the electrical conductivity in semi‐crystalline polymer composites, herein, an accurate multiphase content calculation method is proposed and verified, which combines amorphous phase information in broadband dielectric spectroscopy and crystalline phase information in differential scanning calorimetry. Taken aluminium hydroxide (ATH) filled silicone rubber as an example, it is found that the rigid amorphous fraction (RAF) corresponding to the chains constrained by crystals (RAFcry) is not linearly increased with crystalline fraction (CF). Compared to non‐isothermal crystallisation, RAF caused by ATH/silicone rubber interface (RAFint) after isothermal crystallisation at 213 K changes little, while mobile amorphous fraction and RAFcry is attenuated and CF is strengthened. Based on the calculated structures of ATH filled silicone rubber, activation energy of conductivities during cooling is dominated by the thermal transition for conductive ions and shortened distance among the conductive ions through shrunk volumes of the amorphous phase. Our findings deepen the understanding of multiphase content in semi‐crystalline polymer composites and its relationship with electrical conductivity, which can be applied in manipulating electrical performance of semi‐crystalline polymers by fillers.
Power system stability improvement considering drive train oscillations of virtual synchronous generator‐regulated type‐4 wind turbines
Authors: Yazdi Seyed Saeied Heidari , Shokri‐Kalandaragh Yaser , Bagheri Mehdi
Published: October 2022

The type‐4 wind turbine generators (WTGs) can provide inertial frequency response by implementing the virtual synchronous generator (VSG) concept. However, unstable torsional oscillations (TOs) would be induced in the multi‐mass‐spring drive‐train which can destabilize the entire power system. In this study, participation factor analyses are performed for a power system inclusive of a thermal unit and aggregated WTG system. The system's eigenvalues are characterized and the possible detrimental impacts of TOs on the inertia provision process and overall power system stability are demonstrated and the related stability limits are identified. A comprehensive active torsional oscillations damper (CA‐TOD) and a supercapacitor‐based energy storage system (ESS) are presented and discussed to implement the CA‐TOD. A state of charge (SoC) regulator is also employed to set the reference speed difference for the turbine‐generator. Small‐signal studies and electro‐magnetic transient (EMT) simulations are performed to evaluate the functionality of the CA‐TOD and SoC controller and estimate their impacts on the system's dynamics. The robust performance of the CA‐TOD is compared to the band‐pass filter‐based TOD by sweeping key control parameters of the VSG and emulating drive‐train parameter uncertainty. Key results are cross‐verified by EMT simulations of a multimachine power system.
Kinematic analysis of the Large Magellanic Cloud using Gaia DR3
Authors: Jiménez-Arranz Ó. , Romero-Gómez M. , Luri X. , McMillan P. J. , Antoja T. , Chemin L. , Roca-Fàbrega S. , Masana E. , Muros A.
Published: October 2022

Context. The high quality of the Gaia mission data has allowed for studies of the internal kinematics of the Large Magellanic Cloud (LMC) to be undertaken in unprecedented detail, providing insights into the non-axisymmetric structure of its disc. Recent works by the Gaia Collaboration have already made use of the excellent proper motions of Gaia DR2 and Gaia EDR3 for a first analysis of this sort, but these were based on limited strategies aimed at distinguishing the LMC stars from the Milky Way foreground that did not use all the available information. In addition, these studies could not access the third component of the stellar motion, namely, the line-of-sight velocity – which has now become available via Gaia DR3 for a significant number of stars.

Aims. Our aim is twofold: 1) to define and validate an improved, more efficient and adjustable selection strategy to distinguish the LMC stars from the Milky Way foreground; 2) to check the possible biases that assumed parameters or sample contamination from the Milky Way can introduce in analyses of the internal kinematics of the LMC based on Gaia data.

Methods. Our selection was based on a supervised neural network classifier, using as much as of the Gaia DR3 data as possible. Based on this classifier, we selected three samples of candidate LMC stars with different degrees of completeness and purity. We validated these classification results using different test samples and we compared them with the results from the selection strategy used in the Gaia Collaboration papers, based only on the proper motions. We analysed the resulting velocity profiles and maps for the different LMC samples and we checked how these results change when we use the line-of-sight velocities that are available for a subset of stars.

Results. We show that the contamination in the samples from Milky Way stars basically affects the results for the outskirts of the LMC. We also show that the analysis formalism used in absence of line-of-sight velocities does not bias the results for the kinematics in the inner disc. Here, for the first time, we performed a kinematic analysis of the LMC using samples with the full three dimensional (3D) velocity information from Gaia DR3.

Conclusions. The detailed 2D and 3D kinematic analysis of the LMC internal dynamics demonstrate that: 1) the dynamics in the inner disc is mainly bar dominated; 2) the kinematics on the spiral arm overdensity seems to be dominated by an inward motion and a rotation that is faster than that of the disc in the part of the arm attached to the bar; 3) the contamination of Milky Way stars seem to dominate the outer parts of the disc and mainly affects old evolutionary phases; and 4) uncertainties on the assumed disc morphological parameters and line-of-sight velocity of the LMC can (in some cases) have significant effects on the results of the analysis.
Safety, Efficacy, and Predictors for Late Reintervention After Embolization of Renal Angiomyolipomas – Embolization renal angiomyolipoma
Authors: Claesen Evelien , Bonne Lawrence , Laenen Annouschka , Bammens Bert , Albersen Maarten , De Wever Liesbeth , Maleux Geert
Published: October 2022

Purpose To retrospectively analyze the procedural and long-term clinical outcome of the selective embolization of renal angiomyolipoma. In addition, potential predictive factors for higher risk of late re-intervention were analyzed.

Methods Retrospective monocentric study, including 34 consecutive patients, analyzing the safety, efficiency, and long-term clinical outcome of catheter-directed embolization of renal AML. Additionally, the difference in postembolization renal function between patients embolized in the acute and in the elective setting was analyzed. Secondly, we also evaluated whether volume/diameter of the AML and presence of intralesional aneurysms are risk factors for late re-intervention.

Results Embolization of renal AML was performed to control volume (n = 21; 62 %) or to stop spontaneous hemorrhage (n = 13; 38 %) with angiographic success in all cases but was associated with renal abscess (n = 1) and pulmonary embolism (n = 1) without a significant difference in renal function before and after embolization (P = 0.513). Volume/diameter (P = 0.276/P = 0.21) and presence of aneurysms before embolization (P = 0.37) are not predictive for a higher risk of late re-intervention.

Conclusion Catheter-directed embolization is a safe and effective treatment modality for asymptomatic and bleeding renal AML, without a negative impact on renal function. Initial mass volume/diameter or presence/absence of intralesional aneurysms does not seem to be predictive for late re-intervention.

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Patellar Tendon Repair Using a Patellar Tendon Allograft and External Fixator in Three Dogs
Authors: Tidwell Samuel J. , Franklin Samuel P.
Published: October 2022

Objective The aim of this study was to report on complications and outcomes with repair of ruptured canine patellar tendons using primary tenorrhaphy coupled with patellar tendon allograft transplantation and use of a transarticular external skeletal fixator.

Materials and Methods This report includes three dogs with acutely ruptured patellar tendons, all of whom had surgical repair using a patellar tendon allograft. Dogs were assessed postoperatively by physical examination, owner input, and/or video review. Functional outcomes were classified as full, acceptable, or unacceptable based on previously established criteria.

Results Follow-up time was between 24 and 46 weeks. Two dogs obtained full function and one dog reached acceptable function. The acrylic connecting bars of the external fixator fractured and needed to be replaced in one dog. There were no other problems or complications. There was no evidence of rejection of any allograft.

Clinical Significance Primary tenorrhaphy supported by patellar tendon allograft transplantation and transarticular skeletal fixation appears to be a viable option without evidence of patellar tendon allograft rejection and acceptable or full recovery in the three dogs of this report.
Butterfly Graft Technique for Addressing the Internal Nasal Valve
Authors: Varman Rahul , Clark Madison
Published: October 2022

Nasal airway obstruction is a common presenting complaint to otolaryngology clinics, with the internal valve a commonly implicated anatomic area of obstruction. The nasal butterfly graft is a robust technique to address this subsite with good reported functional and aesthetic outcomes in both primary and secondary rhinoplasty. We describe our approach to patient evaluation, surgical candidate selection, operative technique, and outcomes assessment for this technique.
Talking with racists: insights from discourse and communication studies on the containment of far-right movements
Authors: Herzog Benno , Lance Porfillio Arturo
Published: October 2022

The rise of the far right is threatening the antifascist consensus that helped rebuild Europe and the world following World War II. Discourse studies have done much to further the understanding of the success as well as the fallacies of the discourses of far-right movements and have provided the means by which to comprehend right-wing communicative strategies. However, it has also been said that the reactions of the democratic majority and the mainstream media have contributed—mainly involuntarily—to the success of right-wing politics. The role of the reactions of society, the democratic majority and the mainstream media in trying to counter right-wing discourses is widely underexplored. The aim of this contribution is to understand the diverse material and symbolic effects of certain practices of political contestation. It aims to help elaborate counterstrategies against the threat of the far right and to present communicative strategies against hate. With the help of such diverse authors as Foucault, Goffman or Habermas, we will show how democratic positions seem to be in an ideological dilemma in which the speech acts that try to counter far-right discourses very often produce the opposite effect. The article can help to overcome the pitfalls and performative contradictions of some discursive practices especially in public communications.
An automated system for the assessment and grading of adolescent delinquency using a machine learning-based soft voting framework
Authors: Jenasamanta Abhinash , Mohapatra Subrajeet
Published: October 2022

Adolescent (or juvenile) delinquency is defined as the habitual engagement in unlawful behavior of a minor under the age of majority. According to studies, the likelihood of acquiring a deviant personality increases significantly during adolescence. As a result, identifying deviant youth early and providing proper medical counseling makes perfect sense. Due to the scarcity of qualified clinicians, human appraisal of individual adolescent behavior is subjective and time-consuming. As a result, a machine learning-based intelligent automated system for assessing and grading delinquency levels in teenagers at an early stage must be devised. To solve this problem, a soft voting-based ensemble classification model has been developed that includes a Decision Tree, Multi-layer Perceptron, and Support Vector Machine as base classifiers to accurately classify teenagers into three groups based on severity levels, viz., low, medium, and high. Over the normalized structured behavioral data, the proposed soft voting-based model outperforms all other individual classifiers with 87.50% accuracy, an AUC of 0.94, 0.81 Kappa value, and an F-score of 0.88.
“The war phone”: mobile communication on the frontline in Eastern Ukraine
Authors: Horbyk Roman
Published: October 2022

One of the problems in the growing subfield of mediatization of war is evidence on how exactly civilian communication devices become integrated with warfare. In this article, I focus on patterns of use of mobile phones on the frontline in Eastern Ukraine. Based on qualitative in-depth interviews with Ukrainian servicemen and women, this article presents a typology for the frontline use of mobiles in the spirit of actor–network theory. The omnipresence of mobiles on the battlefield creates a set of unique participatory media practices. A variety of personal purposes, such as private communication and entertainment, are combined in the same device with wiretapping, fire targeting, minefield mapping and combat communication. Mobiles supplant old or unavailable equipment and fill gaps in military infrastructure, becoming weaponized and contributing to the hybridization of the military and the intimate, and of war and peace. These results imply the role of mobiles as a mediated extension of battlefield and question the very definition of what constitutes weapon as tool of combat.
Spin wave computing using pre-recorded magnetization patterns
Authors: Rivkin Kirill , Montemorra Michael
Published: October 2022

We propose a novel type of spin wave computing device, based on a bilayer structure that includes a “bias layer” made from a hard magnetic material and a “propagation layer” made from a magnetic material with low damping, for example, yttrium garnet or permalloy. The bias layer maintains a stable pre-recorded magnetization pattern, which generates a bias field with a desired spatial dependence, which in turn sets the equilibrium magnetization inside the propagation layer. When an external source applies an RF field to the propagation layer, excited spin waves scatter on the magnetization's inhomogeneities resulting in complex interference behavior. This scattering interference can be utilized to perform a variety of mathematical operations including Vector-Matrix multiplication. The spatial dependence of such magnetization patterns can be estimated via perturbation theory.
Experimental demonstration of virtual critical coupling to a single-mode microwave cavity
Authors: Delage Théo , Pascal Olivier , Sokoloff Jérôme , Mazières Valentin
Published: October 2022

We present an experimental realization of virtual critical coupling in microwave, i.e., virtual perfect absorption of an incident wave by a resonant cavity, through transient time modulation of its amplitude. The design of a waveform matched to the ignition process of a plasma, characterized in a simplified way by two operating modes over time (plasma off/plasma on), motivates this first step in practical realization of virtual critical coupling in microwaves. We propose a time domain method for extracting necessary parameters for realization of virtual critical coupling, especially the complex frequency called zero of the S-matrix. To this end, we start from the experimental characterization of a single-mode and single-access microwave cavity including metal protrusions for future plasma ignition. Then, the method relies on the analysis of harmonic response of the overcoupled cavity during three time periods: the transient under excitation, the steady state under excitation, and the transient after excitation cutoff. Finally, an experimental demonstration of virtual critical coupling is performed.
Electronic excitation spectra of jet-cooled phenyl isocyanate, m-tolyl isocyanate, and p-phenylene diisocyanate: Assignment of the cis and trans rotational isomers
Authors: Chiba Kohei , Naganuma Yuto , Ishibashi Daisuke , Okuyama Katsuhiko
Published: October 2022

To assign cis and trans isomers of m-tolyl isocyanate (mTI) and p-phenylene diisocyanate (pPDI) in the electronic excitation transition, we measured the time-of-flight mass-selected resonant ionization spectra of jet-cooled phenyl isocyanate (PI), mTI, and pPDI in the region of the 275 nm first ππ* absorption system. In the excitation spectra of jet-cooled mTI and pPDI, cis- and trans-rotational isomers appeared as doublets. Isomers were assigned by analyzing the methyl-group internal rotation for mTI and by applying low-frequency bending vibrations to the mutual exclusion rule between the one- and two-photon spectra for pPDI. The electronic spectra of the three molecules observed in the jet were assigned to the transition to the first ππ* and third singlet excited states with the aid of time-dependent (TD)-B3LYP/aug-cc-pVDZ and TD-CAM-B3LYP/aug-cc-pVDZ calculations. The 0 − 0 band of PI was observed at 36 354 cm−1, those of the cis and trans isomers of mTI at 36 018 and 35 853 cm−1, respectively, and those of the cis and trans isomers of pPDI at 34 437 and 34 383 cm−1, respectively. All vibronic bands were diffuse, probably because of internal conversion to two singlet nπ* states. For mTI, based on changes in the barrier height of methyl-group internal rotation upon excitation, the Hammett-σm of PI was determined to be −0.12.
Molecular-orbital-based machine learning for open-shell and multi-reference systems with kernel addition Gaussian process regression
Authors: Cheng Lixue , Sun Jiace , Deustua J. Emiliano , Bhethanabotla Vignesh C. , Miller Thomas F.
Published: October 2022

We introduce a novel machine learning strategy, kernel addition Gaussian process regression (KA-GPR), in molecular-orbital-based machine learning (MOB-ML) to learn the total correlation energies of general electronic structure theories for closed- and open-shell systems by introducing a machine learning strategy. The learning efficiency of MOB-ML(KA-GPR) is the same as the original MOB-ML method for the smallest criegee molecule, which is a closed-shell molecule with multi-reference characters. In addition, the prediction accuracies of different small free radicals could reach the chemical accuracy of 1 kcal/mol by training on one example structure. Accurate potential energy surfaces for the H10 chain (closed-shell) and water OH bond dissociation (open-shell) could also be generated by MOB-ML(KA-GPR). To explore the breadth of chemical systems that KA-GPR can describe, we further apply MOB-ML to accurately predict the large benchmark datasets for closed- (QM9, QM7b-T, and GDB-13-T) and open-shell (QMSpin) molecules.
Evaluation of thermophysical properties and structure of heat dissipation sheets as thermal interface materials
Authors: Tajima Kazuki , Taguchi Hitoshi , Jeong Chan Yang , Akiyama Haruhisa
Published: October 2022

Thermal interface materials (TIMs) are used in the mounting of semiconductor devices for rapid heat transfer from heat source to heat sink. The advantages of using TIMs include a lower total cost, elimination of liquid cooling, lower system cooling, lower power consumption, longer operating life and safety, and improved performance. However, there exist various interfaces called “air gaps” between the heat source and heat sink, resulting in reduced heat transfer at the interface depending on the thermal conductivity of the air layer. In this study, the structure of a typical heat dissipation sheet was examined, and the results were correlated with the distribution characteristics of the thermophysical properties. The distribution of the thermal diffusivity depended on the dispersion and orientation of graphite in the resin, making it difficult to obtain uniform thermal properties. These results suggest the need to develop new TIMs that can adequately fill the voids at the device interface, especially in a heat-dissipating adhesive that is in the liquid form at the time of use.
Pr3+–Gd3+ co-doped Ba2SiO4 for multilevel anti-counterfeiting encryption
Authors: Yin Bo , Lv Pinshu , Yang Yanmin , Li Leipeng
Published: October 2022

Developing anti-counterfeiting technology with a higher level of security is vital to boycott the fake commodities. Here, we report the detailed optical property of Ba2SiO4:Pr3+, Gd3+, and their potential applications in fluorescent anti-counterfeit. It has been confirmed that Pr3+ ions could emit the ultraviolet-C (UVC) photons upon excitation of a 450 nm laser, which originates from a two-photon upconverted mechanism. Moreover, the ultraviolet-B (UVB) light also appears simultaneously when co-doping Gd3+ into the host, due to the energy transfer from Pr3+ to Gd3+. Depending on the multimode emissions of Pr3+-Gd3+-codoped phosphors, including the routine magenta emission of Pr3+, as well as the UVC photons of Pr3+ and the UVB light of Gd3+, we successfully achieve multi-level anti-counterfeiting applications.
Susceptibility of multipactor discharges near a dielectric driven by a Gaussian-type transverse rf electric field
Authors: Wen De-Qi , Iqbal Asif , Zhang Peng , Verboncoeur John P.
Published: October 2022

Multipactor discharge near an rf window is a key limiting factor in high power microwave systems. In this work, we report special features of dielectric multipactor susceptibility under a Gaussian-type waveform as a function of the rf power density of the transverse rf electric field (P¯rf) and normal restoring field (Edc) via particle-in-cell (PIC) and multiple particle Monte Carlo (MC) simulations. The MC simulations show that, for a Gaussian waveform of a half peak width (Δτ), larger than Δτ/T=0.15 with T = 1 ns the rf repetition period, the susceptibility boundary is similar to that of the conventional sinusoidal waveform-driven multipactor, i.e., two inclined lines in the plane of (P¯rf,Edc). However, by decreasing Δτ, the susceptibility boundary converts to be a closed curve at Δτ/T=0.11 in the plane of (P¯rf,Edc) and further shrinks at Δτ/T=0.05. PIC simulations with a self-consistent surface and space charge effects also show a reduced Edc with increasing P¯rf when P¯rf exceeds a critical value, resulting in a closed curve in the plane of (P¯rf,Edc), and the maximum time-averaged Edc (multipactor strength) also decreases significantly with further decreasing Δτ in agreement with MC simulations. Accordingly, the fraction of the rf power density absorbed by the multipactor discharges also decreases nonlinearly with Δτ from the order of 10−2 to 10−3 (even 10−4), implying a significant improvement compared to the conventional sinusoidal waveform. The simulations also show that the multipactor susceptibility under a transverse Gaussian-type waveform for different frequencies follows the same scaling law in terms of the ratio of the electric field to the rf repetition rate.
Combining quasielastic neutron scattering and molecular dynamics to study methane motions in ZSM-5
Authors: Hawkins Alexander P. , Zachariou Andrea , Silverwood Ian P. , Yong Chin , Collier Paul , Todorov Ilian , Howe Russell F. , Parker Stewart F. , Lennon David
Published: October 2022

Quasi-elastic neutron scattering (QENS) and molecular dynamics (MD) simulations are applied in combination to investigate the dynamics of methane in H-ZSM-5 zeolite catalysts used for methanol-to-hydrocarbons reactions. Methane is employed as an inert model for the methanol reaction feedstock, and studies are made of the fresh catalyst and used catalysts with varying levels of coke buildup to investigate the effect of coking on reactant mobility. Measurements are made in the temperature range from 5 to 373 K. Methane mobility under these conditions is found to be extremely high in fresh ZSM-5, with the majority of movements occurring too fast to be resolved by the QENS instrument used. A small fraction of molecules undergoing jump diffusion on QENS time scales is identified and found to correspond with short-range jump diffusion within single zeolite pores as identified in MD simulations. Agreement between QENS and MD mobility measurements is found to be within 50%, validating the simulation approach employed. Methane diffusion is found to be minimally affected by moderate levels of coke buildup, while highly coked samples result in the confinement of methane to single pores within the zeolite with minimal long-range diffusion.
Seismic constraints and geodynamic implications of differential lithosphere-asthenosphere flow revealed in East Asia
Authors: Wu Shanshan , Guo Zhen , Chen Yongshun John , Morgan Jason P.
Published: October 2022

During the last 50 Ma, the East Asian continent has been a zone of massive continental collision and lithospheric deformation. While the consequences of this for Asian surface and lithospheric deformation have been intensively studied over the past 4 decades, the relationships between lithospheric deformation and underlying asthenospheric flow have been more difficult to constrain. Here we present a high resolution 3-D azimuthal anisotropy model for the northeastern Tibetan Plateau and its eastward continuation based on surface-wave tomography and shear-wave splitting measurements. This model shows that eastward lateral flow of asthenosphere beneath the northeastern Tibetan Plateau is being blocked by thick Ordos and Sichuan cratonic keels. The damming effect of these keels induces flow to first rotate around the Ordos keel and then transition into strong east-west flow beneath the thinner lithosphere that forms the lithospheric suture between the two cratonic keels. We further find that asthenosphere flow directions can differ from those of overlying lithosphere, with the asthenosphere neither being passively dragged by overlying lithosphere, nor being able to drag the overlying plate to mimic its subsurface flow. Finally, the region of eastward-channeled asthenospheric flow from Tibet underlies a belt of stronger intracontinental deformation in eastern China.
Sunlight can convert atmospheric aerosols into a glassy solid state and modify their environmental impacts
Authors: Baboomian Vahe J. , Crescenzo Giuseppe V. , Huang Yuanzhou , Mahrt Fabian , Shiraiwa Manabu , Bertram Allan K. , Nizkorodov Sergey A.
Published: October 2022

Secondary organic aerosol (SOA) plays a critical, yet uncertain, role in air quality and climate. Once formed, SOA is transported throughout the atmosphere and is exposed to solar UV light. Information on the viscosity of SOA, and how it may change with solar UV exposure, is needed to accurately predict air quality and climate. However, the effect of solar UV radiation on the viscosity of SOA and the associated implications for air quality and climate predictions is largely unknown. Here, we report the viscosity of SOA after exposure to UV radiation, equivalent to a UV exposure of 6 to 14 d at midlatitudes in summer. Surprisingly, UV-aging led to as much as five orders of magnitude increase in viscosity compared to unirradiated SOA. This increase in viscosity can be rationalized in part by an increase in molecular mass and oxidation of organic molecules constituting the SOA material, as determined by high-resolution mass spectrometry. We demonstrate that UV-aging can lead to an increased abundance of aerosols in the atmosphere in a glassy solid state. Therefore, UV-aging could represent an unrecognized source of nuclei for ice clouds in the atmosphere, with important implications for Earth’s energy budget. We also show that UV-aging increases the mixing times within SOA particles by up to five orders of magnitude throughout the troposphere with important implications for predicting the growth, evaporation, and size distribution of SOA, and hence, air pollution and climate.
APC/CCdc20-mediated degradation of Clb4 prompts astral microtubule stabilization at anaphase onset
Authors: Zucca Federico , Visintin Clara , Li Jiaming , Gygi Steven P. , Visintin Rosella
Published: October 2022

Key for accurate chromosome partitioning to the offspring is the ability of mitotic spindle microtubules to respond to different molecular signals and remodel their dynamics accordingly. Spindle microtubules are conventionally divided into three classes: kinetochore, interpolar, and astral microtubules (kMTs, iMTs, and aMTs, respectively). Among all, aMT regulation remains elusive. Here, we show that aMT dynamics are tightly regulated. aMTs remain unstable up to metaphase and are stabilized at anaphase onset. This switch in aMT dynamics, important for proper spindle orientation, specifically requires the degradation of the mitotic cyclin Clb4 by the Anaphase Promoting Complex bound to its activator subunit Cdc20 (APC/CCdc20). These data highlight a unique role for mitotic cyclin Clb4 in controlling aMT regulating factors, of which Kip2 is a prime candidate, provide a framework to understand aMT regulation in vertebrates, and uncover mechanistic principles of how the APC/CCdc20 choreographs the timing of late mitotic events by sequentially impacting on the three classes of spindle microtubules.
Growing self-assisted GaAs nanowires up to 80 μm long by molecular beam epitaxy
Authors: Becdelievre Jeanne , Guan Xin , Dudko I , Regreny Philippe , Chauvin Nicolas , Patriarche Gilles , Gendry Michel , Danescu Alexandre , Penuelas José
Published: October 2022

Ultralong GaAs nanowires were grown by molecular beam epitaxy using the vapor–liquid–solid method. In this ultralong regime we show the existence of two features concerning the growth kinetic and the structural properties. Firstly, we observed a non-classical growth mode, where the axial growth rate is attenuated. Secondly, we observed structural defects at the surface of Wurtzite segments located at the bottom part of the nanowires. We explain these two phenomena as arising from a particular pathway of the group V species, specific to ultralong nanowires. Finally, the optical properties of such ultralong nanowires are studied by photoluminescence experiments.
Extreme on-demand contactless modulation of elastic properties in magnetostrictive lattices
Authors: Singh A , Mukhopadhyay T , Adhikari S , Bhattacharya B
Published: October 2022

2D lattices are widely popular in micro-architected metamaterial design as they are easy to manufacture and provide lightweight multifunctional properties. The mechanical properties of such lattice structures are predominantly an intrinsic geometric function of the microstructural topology, which are generally referred to as passive metamaterials since there is no possibility to alter the properties after manufacturing if the application requirement changes. A few studies have been conducted recently to show that the active modulation of elastic properties is possible in piezoelectric hybrid lattice structures, wherein the major drawback is that complicated electrical circuits are required to be physically attached to the micro-beams. This paper proposes a novel hybrid lattice structure by incorporating magnetostrictive patches that allow contactless active modulation of Young’s modulus and Poisson’s ratio as per real-time demands. We have presented closed-form expressions of the elastic properties based on a bottom-up approach considering both axial and bending deformations at the unit cell level. The generic expressions can be used for different configurations (both unimorph or bimorph) and unit cell topologies under variable vertical or horizontal magnetic field intensity. The study reveals that extreme on-demand contactless modulation including sign reversal of Young’s modulus and Poisson’s ratio (such as auxetic behavior in a structurally non-auxetic configuration, or vice-versa) is achievable by controlling the magnetic field remotely. Orders of difference in the magnitude of Young’s modulus can be realized actively in the metamaterial, which necessarily means that the same material can behave both like a soft polymer or a stiff metal depending on the functional demands. The new class of active mechanical metamaterials proposed in this article will bring about a wide variety of design and application paradigms in the field of functional materials and structures.
Evanescent-field assisted photon collection from quantum emitters under a solid immersion lens
Authors: Bishop S G , Cannon J K , Yağcı H B , Clark R N , Hadden J P , Langbein W , Bennett A J
Published: October 2022

Solid-state quantum light sources are being intensively investigated for applications in quantum technology. A key challenge is to extract light from host materials with high refractive index, where efficiency is limited by refraction and total internal reflection. Here we show that an index-matched solid immersion lens can, if placed sufficiently close to the semiconductor, extract light coupled through the evanescent field at the surface. Using both numerical simulations and experiments, we investigate how changing the thickness of the spacer between the semiconductor and lens impacts the collection efficiency (CE). Using automatic selection and measurement of 100 s of individually addressable colour centres in several aluminium nitride samples we demonstrate spacer-thickness dependent photon CE enhancement, with a mean enhancement factor of 4.2 and a highest measured photon detection rate of 743±4kcps.
One hundred years ago Alfred Landé unriddled the Anomalous Zeeman Effect and presaged electron spin
Authors: Schmidt-Böcking Horst , Gruber Gernot , Friedrich Bretislav
Published: October 2022

In order to commemorate Alfred Landé’s unriddling of the anomalous Zeeman Effect a century ago, we reconstruct his seminal contribution to atomic physics in light of the atomic models available at the time. Landé recognized that the coupling of quantized electronic angular momenta via their vector addition within an atom was the origin of all the apparent mysteries of atomic structure as manifested by the anomalous Zeeman effect. We show to which extent Landé’s ideas influenced the development of quantum physics, particularly Wolfgang Pauli’s path to the exclusion principle. We conclude with Landé’s brief biography.
Simulation study of the effect of electrode embedded with magnesia-carbon material on the breakdown process in micro-gap and electric field in arc
Authors: Yan Zhaozhao , Zhang Jiongming , Liu Qiang , Yin Yanbin , Ma Haitao , Liu Huayang
Published: October 2022

The breakdown plays an important role in the process of arc striking, which can form an early conductive channel between electrode and molten pool. In this paper, a two-dimensional transient micro-gap breakdown model of argon gas under atmospheric pressure and a two-dimensional calculation model of electric field in arc were established, and the effect of the electrode embedded with magnesia-carbon material on the breakdown process and electric field in arc are studied. It is found that the breakdown process between the electrode and the molten pool develops in the form of positive streamer, whether using ordinary electrode or electrode embedded with magnesia-carbon material. The electrode embedded with magnesia-carbon material can accelerate the development of head of electron avalanche in the process of breakdown in micro-gap, increase the electron density of head of electron avalanche and shorten the time consumed in the process of breakdown. Under the external voltage in AC arc, the maximum value of electric field strength changes periodically, the region of the maximum value and maximum value increases with the increase of the radius of the magnesia-carbon material, resulting in serious distortion in the distribution of electric field, which can effectively reduce the breakdown voltage threshold.
Structural and spectroscopic analysis of HoMn2O5 multiferroics
Authors: Ahmad Javed , Afzal Vardah , Nissar Umair , Bukhari S H , Jamil M T , Khan J Alam , Abbas Hammad , Hina Maryam
Published: October 2022

HoMn2O5 was synthesized using sol-gel auto combustion method and characterized through X-ray diffraction, Fourier transform infrared reflectivity, Raman, UV–visible, Photoluminescence spectroscopies at room temperature and transport properties (utilising dc- and ac- electric fields) at high temperatures. The investigation validates the crystal structure by Rietveld refinement with orthorhombic symmetry, and structural characterizations indicated a single-phase nature (space group Pbnm). The Lorentz oscillator model fitted the reflectivity spectrum to account for the infrared active optical phonons. The Raman spectrum was also measured to calculate the optical phonons. The intermediate bandgap value (1.54 eV) of HoMn2O5 indicates its ability to absorb UV radiations and make it suitable for light harvesting material. At last, the transport (dc, ac) properties have been discussed in detail within the temperature range (293–473K) and the variable range hopping conduction mechanism is confirmed in this material.
New magnesium based half-metallic ferromagnetic chalcogenide MgFe2Z4 (Z = S, Se) spinels; a promising materials for spintronic applications
Authors: Bilal Muhammad , Noor N A , Iqbal M Waqas , Khan M Aslam , Niaz Shanawer , Sohail Amjad , Alanazi Yousef Mohammad , Aftab Sikandar , Neffati R
Published: October 2022

This article focuses on the physical properties of MgFe2Z4 (Z = S, Se) spinels investigated by employing density functional theory calculations. To explore the magnetic and electronic properties, WIEN2k code was executed whereas thermoelectric properties were studied using the BoltzTraP. The determined negative formation energies and positive phonon frequencies show that the system under investigation is stable. The lowest possible ground state energies clearly indicate that spinels lie in ferromagnetic state. Studied spinels illustrated half-metallic nature upon employing the calculations of density of states (DOS) and spin-polarized band structures (BS). Ferromagnetic (FM) state was found to be stable ground state. Observation of ferromagnetism in these compounds was ensured by exchange energies, Jahn-Teller energy and hybridization and is attributed to electron spin in place of Fe2+ clustering. Curie temperature and spin polarization of these compounds is also comprehensively investigated in this study. Analysis of the thermoelectric properties showed a good fit between the ratio of electrical (σ/τ) and thermal conductivity (κ
e/τ). Thermoelectric efficiency of studied compounds is found to be appropriate as demonstrated by the thermoelectric power factors.
Meshfree-based physics-informed neural networks for the unsteady Oseen equations
Authors: Peng Keyi , Yue Jing , Zhang Wen , Li Jian
Published: October 2022

We propose the meshfree-based physics-informed neural networks for solving the unsteady Oseen equations. Firstly, based on the ideas of meshfree and small sample learning, we only randomly select a small number of spatiotemporal points to train the neural network instead of forming a mesh. Specifically, we optimize the neural network by minimizing the loss function to satisfy the differential operators, initial condition and boundary condition. Then, we prove the convergence of the loss function and the convergence of the neural network. In addition, the feasibility and effectiveness of the method are verified by the results of numerical experiments, and the theoretical derivation is verified by the relative error between the neural network solution and the analytical solution.
Analytical determination of non-local parameter value to investigate the axial buckling of nanoshells affected by the passing nanofluids and their velocities considering various modified cylindrical shell theories
Authors: Oveissi Soheil , Ghassemi Aazam , Salehi Mehdi , Eftekhari S. Ali , Ziaei-Rad Saeed
Published: October 2022

We analytically determine the nonlocal parameter value to achieve a more accurate axial-buckling response of carbon nanoshells conveying nanofluids. To this end, the four plates/shells’ classical theories of Love, Flügge, Donnell, and Sanders are generalized using Eringen’s nonlocal elasticity theory. By combining these theories in cylindrical coordinates, a modified motion equation is presented to investigate the buckling behavior of the nanofluid-nanostructure-interaction problem. Herein, in addition to the small-scale effect of the structure and the passing fluid on the critical buckling strain, we discuss the effects of nanoflow velocity, fluid density (nano-liquid/nano-gas), half-wave numbers, aspect ratio, and nanoshell flexural rigidity. The analytical approach is used to discretize and solve the obtained relations to study the mentioned cases.
Fractional Noether theorem and fractional Lagrange equation of multi-scale mechano-electrophysiological coupling model of neuron membrane
Authors: Wang Peng
Published: October 2022

Noether theorem is applied to a variable order fractional multiscale mechano-electrophysiological model of neuron membrane dynamics. The variable orders fractional Lagrange equation of a multiscale mechano-electrophysiological model of neuron membrane dynamics is given. The variable orders fractional Noether symmetry criterion and Noether conserved quantities are given. The forms of variable orders fractional Noether conserved quantities corresponding to Noether symmetry generators solutions of the model under different conditions are discussed in detail, and it is found that the expressions of variable orders fractional Noether conserved quantities are closely dependent on the external nonconservative forces and material parameters of the neuron.
Sparse identification method of extracting hybrid energy harvesting system from observed data
Authors: Sun Ya-Hui , Zeng Yuan-Hui , Yang Yong-Ge
Published: October 2022

Hybrid energy harvesters under external excitation have complex dynamical behavior and the superiority of promoting energy harvesting efficiency. Sometimes, it is difficult to model the governing equations of the hybrid energy harvesting system precisely, especially under external excitation. Accompanied with machine learning, data-driven methods play an important role in discovering the governing equations from massive datasets. Recently, there are many studies of data-driven models done in aspect of ordinary differential equations and stochastic differential equations (SDEs). However, few studies discover the governing equations for the hybrid energy harvesting system under harmonic excitation and Gaussian white noise (GWN). Thus, in this paper, a data-driven approach, with least square and sparse constraint, is devised to discover the governing equations of the systems from observed data. Firstly, the algorithm processing and pseudo code are given. Then, the effectiveness and accuracy of the method are verified by taking two examples with harmonic excitation and GWN, respectively. For harmonic excitation, all coefficients of the system can be simultaneously learned. For GWN, we approximate the drift term and diffusion term by using the Kramers-Moyal formulas, and separately learn the coefficients of the drift term and diffusion term. Cross-validation (CV) and mean-square error (MSE) are utilized to obtain the optimal number of iterations. Finally, the comparisons between true values and learned values are depicted to demonstrate that the approach is well utilized to obtain the governing equations for the hybrid energy harvester under harmonic excitation and GWN.