bluuebunny/crossref_metadata_2025 huggingface dataset:
The function of BK channels extracted and purified within SMALPs
Authors: Patel Jaimin H. , Pollock Naomi L. , Maher Jacqueline , Rothnie Alice J. , Allen Marcus C.
Published: July 2022

Human BK channels are large voltage and Ca2+-activated K+ channels, involved in several important functions within the body. The core channel is a tetramer of α subunits, and its function is modulated by the presence of β and γ accessory subunits. BK channels composed of α subunits, as well as BK channels composed of α and β1 subunits, were successfully solubilised from HEK cells with styrene maleic acid (SMA) polymer and purified by nickel affinity chromatography. Native SMA–PAGE analysis of the purified proteins showed the α subunits were extracted as a tetramer. In the presence of β1 subunits, they were co-extracted with the α subunits as a heteromeric complex. Purified SMA lipid particles (SMALPs) containing BK channel could be inserted into planar lipid bilayers (PLB) and single channel currents recorded, showing a high conductance (≈260 pS), as expected. The open probability was increased in the presence of co-purified β1 subunits. However, voltage-dependent gating of the channel was restricted. In conclusion, we have demonstrated that SMA can be used to effectively extract and purify large, complex, human ion channels, from low expressing sources. That these large channels can be incorporated into PLB from SMALPs and display voltage-dependent channel activity. However, the SMA appears to reduce the voltage dependent gating of the channels.
Wafer map defect patterns classification based on a lightweight network and data augmentation
Authors: Yu Naigong , Chen Huaisheng , Xu Qiao , Hasan Mohammad Mehedi , Sie Ouattara
Published: July 2022

Accurately identifying defect patterns in wafer maps can help engineers find abnormal failure factors in production lines. During the wafer testing stage, deep learning methods are widely used in wafer defect detection due to their powerful feature extraction capabilities. However, most of the current wafer defect patterns classification models have high complexity and slow detection speed, which are difficult to apply in the actual wafer production process. In addition, there is a data imbalance in the wafer dataset that seriously affects the training results of the model. To reduce the complexity of the deep model without affecting the wafer feature expression, this paper adjusts the structure of the dense block in the PeleeNet network and proposes a lightweight network WM‐PeleeNet based on the PeleeNet module. In addition, to reduce the impact of data imbalance on model training, this paper proposes a wafer data augmentation method based on a convolutional autoencoder by adding random Gaussian noise to the hidden layer. The method proposed in this paper has an average accuracy of 95.4% on the WM‐811K wafer dataset with only 173.643 KB of the parameters and 316.194 M of FLOPs, and takes only 22.99 s to detect 1000 wafer pictures. Compared with the original PeleeNet network without optimization, the number of parameters and FLOPs are reduced by 92.68% and 58.85%, respectively. Data augmentation on the minority class wafer map improves the average classification accuracy by 1.8% on the WM‐811K dataset. At the same time, the recognition accuracy of minority classes such as Scratch pattern and Donut pattern are significantly improved.
Fast robust fuzzy clustering based on bipartite graph for hyper‐spectral image classification
Authors: Liu Han , Wu Chengmao , Li Changxing , Zuo Yanqun
Published: July 2022

Hyper‐spectral image (HSI) clustering has become a hot spot in remote sensing image research. However, due to the large amount and high dimension of HSI data, some traditional image clustering methods are no longer suitable, and even lead to poor clustering performance and long computing time. Therefore, this paper proposes a novel clustering method for HSI to make up for the shortcomings of traditional clustering methods. Firstly, a fuzzy similarity matrix is constructed by using the bipartite graph to obtain low‐dimensional hyper‐spectral data, which can reduce the complexity and the operation time of the algorithm. Secondly, fuzzy membership mapping is carried out through the constructed bipartite graph, and a non‐negative regularization term is added to limit ill‐conditioned problems. Thirdly, this paper uses the Geman‐McClure function to optimize Euclidean distance. Finally, in this paper, the spectral information of HSI is considered while the neighbourhood information of HSI is added to achieve the unity of space spectrum, which enhances the robustness of the algorithm and improves the clustering performance of the algorithm. Compared with existing HSI clustering algorithms, the proposed algorithm has higher clustering accuracy and efficiency.
Chaleur urbaine et industrielle : les promesses de la cogénération
Authors: Le Gros Gaïc
Published: July 2022

Si l’électricité tient une place centrale dans les stratégies nationales de décarbonation des besoins en énergie, le développement d’autres vecteurs énergétiques, comme la chaleur ou l’hydrogène, est crucial. Plusieurs pays étudient aujourd’hui les atouts du nucléaire pour décarboner la chaleur industrielle et urbaine.
L’expertise du nucléaire au service de la lutte contre le cancer
Authors: Fabre Pierre
Published: July 2022

L’usage de la technologie nucléaire dans le traitement en oncologie est incontournable. Depuis vingt ans, Orano développe cette activité visant à associer des atomes radioactifs à des vecteurs spécifiques pour agresser les tumeurs au plus près. L’entreprise porte en particulier ses efforts sur le plomb 212.
Berberine Induces Autophagic Cell Death by Inactivating the Akt/mTOR Signaling Pathway
Authors: Park Gil-Sun , Park Bokyung , Lee Mi-Young
Published: July 2022

The incidence of skin cancer has been increasing over the past decades, and melanoma is considered highly malignant because of its high rate of metastasis. Plant-derived berberine, an
isoquinoline quaternary alkaloid, has been reported to possess multiple pharmacological effects against various types of cancer cells. Therefore, we treated melanoma B16F10 cells with
berberine to induce cell death and understand the cell death mechanisms. The berberine-treated cells showed decreased cell viability, according to berberine concentration. However, western
blot analysis of apoptosis-related marker proteins showed that the expression of Bcl-2, an apoptosis inhibitory protein, and the Bcl-2/Bax ratio were increased. Therefore, by adding
3-methyladenine to the berberine-treated cells, we investigated whether the reduced cell viability was due to autophagic cell death. The results showed that 3-methyladenine restored the cell
viability decreased by berberine, suggesting autophagy. To clarify autophagic cell death, we performed transmission electron microscopy analysis, which revealed the presence of
autophagosomes and autolysosomes in the cells after treatment with berberine. Next, by analyzing the expression of autophagy-related proteins, we found an increase in the levels of light
chain 3A-II and Atg12-Atg5 complex in the berberine-treated cells. We then assessed the involvement of the Akt/mTOR signaling pathway and found that berberine inhibited the expression of
phosphorylated Akt and mTOR. Our data demonstrated that berberine induces autophagic cell death by inactivating the Akt/mTOR signaling pathway in melanoma cells and that berberine can be
used as a possible target for the development of anti-melanoma drugs.
Klinische Outcomes der Akutrehabilitation – eine
Kohortenstudie von 1.018 Fällen der fachübergreifenden
Frührehabilitation im Akutkrankenhaus
Authors: Liebl Max Emanuel , Elmer Nancy , Schuester Leon , Schwedtke Christine , Brehm Katharina , Reißhauer Anett
Published: July 2022

Hintergrund Die fachübergreifende Frührehabilitation (FR)
im Akutkrankenhaus (Akutrehabilitation) ist der frühestmögliche
Einsatz der Rehabilitation im akutmedizinischen Verlauf, wobei sie
indikationsübergreifend und primär im nicht-geriatrischen,
nicht-neurologischen Indikationsspektrum angewendet wird. Sie schließt
die Rehabilitationslücke zwischen akutmedizinischer Versorgung und
Rehabilitationsklinik. In dieser Studie soll die Verbesserung der klinischen
Outcomes Mobilität und Selbsthilfefähigkeit in der FR an einer
großen Stichprobe gezeigt werden.

Material und Methoden Retrospektive Analyse von n=1.018
Fällen, die zwischen 2011 und 2020 auf einer spezialisierten Station
für FR behandelt wurden. Primäre klinische Outcome-Parameter
waren die Mobilität (gemessen mit dem Charité Mobility Index
CHARMI) und die Selbsthilfefähigkeit (Barthel-Index) sowie die
Entlass-Umgebung der Patient:innen.

Ergebnisse Im Verlauf der FR verbesserten sich die Mobilität
(p<0,001; r=0,6) und die ADL-Kompetenz (p<0,001;
r=0,6) hoch signifikant und mit großer Effektstärke. Ein
Großteil der Patient:innen konnte nach Hause (45%) oder in eine
Anschlussrehabilitation (42%) entlassen werden.

Schlussfolgerung Eine Aufgabe der Frührehabilitation in der
Rehabilitationskette besteht darin, die Rehabilitationsfähigkeit im
Sinne einer weiterführenden Rehabilitation herzustellen. Die Analyse
zeigt, dass die FR dieser Aufgabe indikationsübergreifend gerecht wird.
Es wurde gezeigt, dass eine Stichprobe von Patient:innen mit komplexem
Versorgungsbedarf in der Akutrehabilitation hinsichtlich der Mobilität
und ADL-Fähigkeit große Funktionsgewinne erzielt.
COVID-19 Infections in Gonads: Consequences on
Fertility?
Authors: Bechmann Nicole , Maccio Umberto , Kotb Reham , Dweik Rania Al , Cherfane Michele , Moch Holger , Bornstein Stefan R. , Varga Zsuzsanna
Published: July 2022

COVID-19 may influence human fertility and sexuality in several ways. Different
cell types in gonads show a constitutive expression of angiotensin-converting
enzyme 2 (ACE2) and transmembrane protease serine subtype 2 (TMPRSS2), which
provide potential entry pathways for SARS-CoV-2. In addition to the biological
effects of a COVID-19 infection on the gonads, the impact of the ongoing
COVID-19 pandemic on mental health issues and sexual behavior may affect
reproduction. This review summarizes the current knowledge on the influence of
COVID-19 on the gonads and discusses possible consequences on human fertility.
In this context, the close interaction between the
hypothalamic-pituitary-adrenal axis and the hypothalamic-pituitary-gonadal axis
in response to COVID-19-related stress is discussed. Some women noticed changes
in their menstrual cycle during the COVID-19 pandemic, which could be due to
psychological stress, for example. In addition, occasional cases of reduced
oocyte quality and ovarian function are described after COVID-19 infection. In
men, COVID-19 may cause a short-term decrease in fertility by damaging
testicular tissue and/or impairing spermatogenesis. Moreover, decreased
ratio testosterone/LH and FSH/LH in COVID-19 compared to
aged-matched healthy men has been reported. Available data do not suggest any
effect of the available SARS-CoV-2 vaccines on fertility. The effects of long
COVID on human fertility have been reported and include cases with premature
ovarian failure and oligomenorrhoea in women and erectile dysfunction in men.
Despite the increasing knowledge about the effects of COVID-19 infections on
human gonads and fertility, the long-term consequences of the COVID-19 pandemic
cannot yet be assessed in this context.
Synthesis and Antiviral Evaluation of 2′,3′-β-C-Disubstituted Nucleoside Analogue ProTides to Test a Conformational Model of Potency Against Hepatitis C
Authors: Liotta Dennis C. , Dentmon Zackery W. , Butch Christopher J. , Gold Hannah B.
Published: July 2022

An analysis of nucleoside active metabolite potencies against Hepatitis C virus (HCV) versus their parent ground-state energetic conformational bias as calculated by density functional theory suggested that nucleotides with a small difference between their antipodal energies are more likely to have potent antiviral activity compared to those with larger energetic differences. This energetic conformational bias was thought to be manipulated with substitutions along the ­ribofuranose ring. From 2′-C-methyluridine, a representative nucleoside with fair anti-HCV activity, two C3′ modifications in particular (ethyne and methyl) showed contrasting antipodal biases relative to each other while originating from a common synthetic intermediate, allowing a test of reasonable extremes of the computational model with a divergent nine-step synthesis. Antiviral activity of the compounds contradicted that suggested by the model, indicating a need for further refinement with additional biostructural considerations.
Anal Botulinum Toxin in Children with Hirschsprung Disease and Functional Constipation: A Prospective Cohort study
Authors: Baaleman Desiree F. , Hallagan Alexandra , Halleran Devin R. , Orsagh-Yentis Danielle K. , Levitt Marc A. , Wood Richard J. , Benninga Marc A. , Bali Neetu , Vaz Karla H. , Yacob Desale , Di Lorenzo Carlo , Lu Peter L.
Published: July 2022

Introduction Anal sphincter botulinum toxin injections (BTIs) are used in the treatment of children with severe defecation disorders, including Hirschsprung disease (HD) and functional constipation (FC). Our objective was to evaluate the outcomes of BTI in these children.

Materials and Methods We performed a prospective cohort study of children undergoing BTI from July 2018 to December 2018. We recorded perceived effect of the BTI, including effectiveness ranging from 0 (not at all effective) to 4 (extremely effective). In addition, we recorded symptoms and the Cleveland Clinic Constipation Score (CCCS). Data were collected at baseline and at 2 weeks, 2 months, and 4 months post-injection.

Results Forty-two children (HD = 25, FC = 17) were included in the study (median age 4.3 years, IQR 2.4–7.2, 52% male). Twenty-two (88%) children with HD and eight (47%) children with FC had previously undergone a BTI. BTIs were perceived effective in 16 (76%) and 12 (71%) children with HD and eight (47%) and seven (47%) children with FC at 2-week and 2-month follow-up, respectively. Effectiveness was not rated differently between groups except at the 2-month follow-up, when patients with HD rated the BTI more effective compared to those with FC (median 2 [HD] vs. median 1 [FC], p = 0.022). Over the course of the study, 17/39 (44%) children reported self-limiting adverse effects such as fecal incontinence and pain at the injection site.

Conclusion Anal sphincter BTIs can be effective in the treatment of constipation in both HD and FC patients.
Generalized fourth-order decompositions of imaginary time path integral: Implications of the harmonic oscillator
Authors: Wang Cong , Zhang Lihan , Liu Jian , Shao Jiushu
Published: July 2022

The imaginary time path integral formalism offers a powerful numerical tool for simulating thermodynamic properties of realistic systems. We show that, when second-order and fourth-order decompositions are employed, they share a remarkable unified analytic form for the partition function of the harmonic oscillator. We are then able to obtain the expression of the thermodynamic property and the leading error terms as well. In order to obtain reasonably optimal values of the free parameters in the generalized symmetric fourth-order decomposition scheme, we eliminate the leading error terms to achieve the accuracy of desired order for the thermodynamic property of the harmonic system. Such a strategy leads to an efficient fourth-order decomposition that produces third-order accurate thermodynamic properties for general systems.
Development of a load frame for neutron diffraction and fluorescent thermometry at cryogenic temperature
Authors: Yang Jinbo , Li Jian , Liu Wei , Li Yihao , Huang Yalin , Zhou Jun , Zhang Xingyi
Published: July 2022

Over the years, rapidly rising interest in the mechanical properties of various materials at low temperatures has been simulated because of the growing cryogenic applications in modern engineering fields of space technology, environmental engineering, and superconductivity engineering. Realizing in situ measurement of the internal strain and the full-field strain and the temperature distribution of related materials in a cryogenic loading environment is a significant requirement for safety assessment and related research of some new large science facility projects. Here, we present a novel cryogenic load frame, which is suitable for neutron scattering measurements of internal stress at the temperature range of 6–300 K. The loading capacity is 2500 N, and the slowest loading speed is 0.001 mm/s. By replacing the vacuum chamber sealing plate with a K9 glass window, the in situ digital image correlation strain measurement can be realized. Furthermore, fluorescence thermometry has also been investigated during a heating and cooling process without deformation. Using the present design, some typical results of the 316LN stainless steel and the YBCO tape at low temperatures were introduced.
Quantum and classical dynamical semigroups of superchannels and semicausal channels
Authors: Hasenöhrl Markus , Caro Matthias C.
Published: July 2022

Quantum devices are subject to natural decay. We propose to study these decay processes as the Markovian evolution of quantum channels, which leads us to dynamical semigroups of superchannels. A superchannel is a linear map that maps quantum channels to quantum channels while satisfying suitable consistency relations. If the input and output quantum channels act on the same space, then we can consider dynamical semigroups of superchannels. No useful constructive characterization of the generators of such semigroups is known. We characterize these generators in two ways: First, we give an efficiently checkable criterion for whether a given map generates a dynamical semigroup of superchannels. Second, we identify a normal form for the generators of semigroups of quantum superchannels, analogous to the Gorini-Kossakowski-Lindblad-Sudarshan form in the case of quantum channels. To derive the normal form, we exploit the relation between superchannels and semicausal completely positive maps, reducing the problem to finding a normal form for the generators of semigroups of semicausal completely positive maps. We derive a normal for these generators using a novel technique, which applies also to infinite-dimensional systems. Our work paves the way for a thorough investigation of semigroups of superchannels: Numerical studies become feasible because admissible generators can now be explicitly generated and checked. Analytic properties of the corresponding evolution equations are now accessible via our normal form.
Targeting attack hypergraph networks
Authors: Peng Hao , Qian Cheng , Zhao Dandan , Zhong Ming , Han Jianmin , Wang Wei
Published: July 2022

In modern systems, from brain neural networks to social group networks, pairwise interactions are not sufficient to express higher-order relationships. The smallest unit of their internal function is not composed of a single functional node but results from multiple functional nodes acting together. Therefore, researchers adopt the hypergraph to describe complex systems. The targeted attack on random hypergraph networks is still a problem worthy of study. This work puts forward a theoretical framework to analyze the robustness of random hypergraph networks under the background of a targeted attack on nodes with high or low hyperdegrees. We discovered the process of cascading failures and the giant connected cluster (GCC) of the hypergraph network under targeted attack by associating the simple mapping of the factor graph with the hypergraph and using percolation theory and generating function. On random hypergraph networks, we do Monte-Carlo simulations and find that the theoretical findings match the simulation results. Similarly, targeted attacks are more effective than random failures in disintegrating random hypergraph networks. The threshold of the hypergraph network grows as the probability of high hyperdegree nodes being deleted increases, indicating that the network’s resilience becomes more fragile. When considering real-world scenarios, our conclusions are validated by real-world hypergraph networks. These findings will help us understand the impact of the hypergraph’s underlying structure on network resilience.
Numerical simulation on controlling the front-side temperature of thinned SiC substrate during ohmic contact to Ni or Ti using back-side laser annealing
Authors: Ding Jianwen , Li Xin , Yang Kaiming , Zhu Yu
Published: July 2022

This study numerically simulates the temperature fields of metal/4H-SiC ohmic contacts during back-side laser annealing, especially once the 4H-SiC substrate has been thinned. The results show that the front-side temperature can be easily controlled by adjusting laser parameters with the formation of ohmic contact when Ni was used as the contact metal before and after thinning. However, the front-side temperature posed a problem in the case of Ti/SiC contact because of the lower capability of thermal conduction of Ti compared with that of Ni. The pulse width of the laser had no obvious effect on front-side temperature because the heat-affected depth in the substrate due to pulse width was limited at the same energy density. In addition, reducing the thickness of the Ti film to below 100 nm helped avoid melting of the Ti surface. Lastly, the thermal budget maps of Ti (30 nm)/SiC (30 μm) and Ni (100 nm)/SiC (30 μm) contacts were protracted, in which the energy density and pulse width of the laser could be obtained for a lower front-side temperature. This method can be used to control the whole temperature fields induced by laser annealing after thinning the SiC substrate. This study also discusses the size effect of the physical properties of the metallic contact films.
Effects of the information-driven awareness on epidemic spreading on multiplex networks
Authors: Wang Jun , Xiong Weijie , Wang Ruijie , Cai Shimin , Wu Die , Wang Wei , Chen Xiaolong
Published: July 2022

In this study, we examine the impact of information-driven awareness on the spread of an epidemic from the perspective of resource allocation by comprehensively considering a series of realistic scenarios. A coupled awareness-resource-epidemic model on top of multiplex networks is proposed, and a Microscopic Markov Chain Approach is adopted to study the complex interplay among the processes. Through theoretical analysis, the infection density of the epidemic is predicted precisely, and an approximate epidemic threshold is derived. Combining both numerical calculations and extensive Monte Carlo simulations, the following conclusions are obtained. First, during a pandemic, the more active the resource support between individuals, the more effectively the disease can be controlled; that is, there is a smaller infection density and a larger epidemic threshold. Second, the disease can be better suppressed when individuals with small degrees are preferentially protected. In addition, there is a critical parameter of contact preference at which the effectiveness of disease control is the worst. Third, the inter-layer degree correlation has a “double-edged sword” effect on spreading dynamics. In other words, when there is a relatively lower infection rate, the epidemic threshold can be raised by increasing the positive correlation. By contrast, the infection density can be reduced by increasing the negative correlation. Finally, the infection density decreases when raising the relative weight of the global information, which indicates that global information about the epidemic state is more efficient for disease control than local information.
On the kinetics of chemical reactions at the detonation of organic high explosives
Authors: Satonkina N. P. , Medvedev D. A.
Published: July 2022

The model of electrical conductivity developed earlier allows one to use electrical properties as a tool for the diagnostics of the reaction zone at the detonation of organic high explosives. The comparison of experimental data on electrical conductivity with both the results of experimental research and numerical modeling using Arrhenius kinetics is carried out. The contradiction of the thermal concept of the mechanism of the development of a chemical reaction during detonation is clearly demonstrated. An alternative based on the ideas of A. N. Dremin, J. J. Dick, C. S. Coffey, and F. E. Walker is discussed.
Time-of-flight mass spectrometer for diagnostics of continuous plasma flow
Authors: Usmanov R. , Melnikov A. , Gavrikov A. , Antonov N. , Polistchook V.
Published: July 2022

This paper describes a version of the time-of-flight mass spectrometer based on a modified two-field acceleration approach of Wiley and McLaren. The aim of the device is a diagnostic of continuous plasma flow. The acceleration scheme idea, the construction of the spectrometer, and results of testing in plasma flow of Gd and CeO2 generated by vacuum arc discharge are described. The instrument function of the spectrometer was measured, and its mass resolution was evaluated as ∼20. With the use of the instrument function, how to interpret the registered signal in the case of intersection of mass peaks was suggested. The presented device has a simple construction and relatively low values of applied acceleration voltages, so it has fewer requirements in manufacturability and cost.
Theoretical comparison of real-time feedback-driven single-particle tracking techniques
Authors: van Heerden Bertus , Krüger Tjaart P. J.
Published: July 2022

Real-time feedback-driven single-particle tracking is a technique that uses feedback control to enable single-molecule spectroscopy of freely diffusing particles in native or near-native environments. A number of different real-time feedback-driven single-particle tracking (RT-FD-SPT) approaches exist, and comparisons between methods based on experimental results are of limited use due to differences in samples and setups. In this study, we used statistical calculations and dynamical simulations to directly compare the performance of different methods. The methods considered were the orbital method, the knight‘s tour (grid scan) method, and MINFLUX, and we considered both fluorescence-based and interferometric scattering (iSCAT) approaches. There is a fundamental trade-off between precision and speed, with the knight’s tour method being able to track the fastest diffusion but with low precision, and MINFLUX being the most precise but only tracking slow diffusion. To compare iSCAT and fluorescence, different biological samples were considered, including labeled and intrinsically fluorescent samples. The success of iSCAT as compared to fluorescence is strongly dependent on the particle size and the density and photophysical properties of the fluorescent particles. Using a wavelength for iSCAT that is negligibly absorbed by the tracked particle allows for an increased illumination intensity, which results in iSCAT providing better tracking for most samples. This work highlights the fundamental aspects of performance in RT-FD-SPT and should assist with the selection of an appropriate method for a particular application. The approach used can easily be extended to other RT-FD-SPT methods.
Some aspects of the plasma potential in 3D simulation of ECRIS operation
Authors: Lei Li , Jin Xiaolin , Li Jibo , Li Lixuan , Li Bin
Published: July 2022

A 3D particle-in-cell plus Monte Carlo collision (PIC/MCC) code is developed for the simulation of electron cyclotron resonance ion source (ECRIS). The self-consistent interaction between the plasma and the potential field is taken into account, as well as Coulomb collisions, stepwise ionization, and charge exchange collisions between particles. In addition, a precalculation module based on a single-particle approach is introduced to speed up simulations. The stable distributions of the high-energy electrons are obtained and then sent to the subsequent simulation of ECRIS operation as the well-confined warm and hot electrons. An implicit electrostatic PIC model in this simulation self-consistently describes the evolution of the ECR plasma. The results are obtained for the plasma potential in a steady state, including the global amplitude and distribution profiles. The potential distribution of the ECR plasma is characterized by magnetic fields. These results, together with those for the charge density, are analyzed and discussed from the perspective of plasma diffusion.
Theoretical routes for current-free magnetization switching induced by joint effects of strain and Dzyaloshinskii–Moriya interaction
Authors: Zhu Mingmin , Li Yiting , Hu Huimin , Cui Shuting , Qiu Yang , Yu Guoliang , Zhou Hao-Miao
Published: July 2022

Voltage-induced strain is regarded as an energy-efficient choice of tuning spin-dynamics. However, studies on the strain-mediated switching of magnetization in a perpendicular-magnetic-anisotropy layer are few because of the uncertainties that arise from the magnetization oscillation at high strain. In this work, we demonstrate theoretically how to deterministically switch the perpendicular magnetization in an ultrathin magnetic nanodisk by combining biaxial in-plane strain with the Dzyaloshinskii–Moriya interaction (DMI). The magnetization-switching process is carefully investigated under different strains and DMI strengths. The underlying switching mechanism is attributed to the remnant magnetization component, which deviates away from the film plane during the strain-pulse-impulsion period and which is also highly dependent on the DMI. Based on simulation results, a theoretical route for obtaining deterministic switching regarding strain and DMI is established. In this route, the minimum duration of the strain pulse can be shortened to a critical time of 2.5 ns as the strain increases to 7000 ppm at a DMI value of 0.6 mJ/m2. Moreover, nonvolatile and reversible switching between the spin-up and spin-down states of perpendicular magnetization is realized using pulses of biaxial in-plane isotropic strain. This switching occurs via an intermediate skyrmion and shows potential in overcoming the edge-roughness-related pinning that occurs in spin–orbit-torque current-induced switching. This study provides a robust insight into strain-induced current-free magnetization switching, providing a guide for experimental research into the strain-mediated voltage control of memory applications.
Comparing four hard-sphere approximations for the low-temperature WCA melting line
Authors: Attia Eman , Dyre Jeppe C. , Pedersen Ulf R.
Published: July 2022

By combining interface-pinning simulations with numerical integration of the Clausius–Clapeyron equation, we accurately determine the melting-line coexistence pressure and fluid/crystal densities of the Weeks–Chandler–Andersen system, covering four decades of temperature. The data are used for comparing the melting-line predictions of the Boltzmann, Andersen–Weeks–Chandler, Barker–Henderson, and Stillinger hard-sphere approximations. The Andersen–Weeks–Chandler and Barker–Henderson theories give the most accurate predictions, and they both work excellently in the zero-temperature limit for which analytical expressions are derived here.
Effect of orifice shape on impinging synthetic jet
Authors: Bhapkar Udaysinh S. , Mishra Abhishek , Yadav Harekrishna , Agrawal Amit
Published: July 2022

The present experimental study investigated the synthetic jet flow characteristics issued from four different orifice shapes (Re = 4739–5588). The flow dynamics of the jet is examined using the particle image velocimetry technique for circular, rectangular, square, and elliptical orifice shapes and two different surface spacings (z/d = 3 and 8). The results are presented in terms of streamwise distribution of velocity, normal stress, and shear stress. Furthermore, the most dominant modes of higher energy containing structures are obtained using proper orthogonal decomposition and compared for different orifice shapes. The results show that for a lower nozzle to surface spacing, vortices formed in the wall jet from the elliptical orifice contain higher energy than the other orifice shapes. The higher energy-containing vortices cause a delay in attaining self-similarity. Therefore, the self-similarity in the wall jet for the elliptical orifice is delayed than that of the other orifice shapes. Also, the elliptical orifice shape has relatively higher normal and shear stresses than that of other orifice shapes. The elliptical orifice shows 30% and 17% higher crosswise normal and shear stress than that of the circular orifice, respectively. However, for the larger nozzle to surface spacing, the least dominant mode of the structure is observed for the rectangular orifice shape, which results in a shifting of the self-similarity location toward the stagnation point. The findings from the present work are used to explain the variation of the heat transfer rate from a synthetic jet having different orifice shapes and impinging at different surface spacings.
Time-domain simulation of charged particle diffraction by an electrostatically biased grating: Transmission tunability and shaping of the quantum point contact for protons
Authors: Barman Sushanta , Bhattacharjee Sudeep
Published: July 2022

A numerical simulation of a two-dimensional Gaussian wave packet of charged particles has been performed to investigate the diffraction phenomena from a single-, double-, and multi-slit grating biased with an electrostatic potential (Ve0). The wave packet dynamics are obtained by solving the time-dependent Schrödinger’s equation using the generalized finite difference time domain (GFDTD-Q) method for quantum systems. The effect of Ve0 on transmission properties, fringe pattern, motion of the peaks, and wave number distribution in the diffracted wave has been studied. It is found that Ve0 changes the shape of the quantum point contact of diffracting constriction, which controls the allowed quantum states in the diffracted wave and the transmission coefficient Tc can be tuned by Ve0. It is observed that the number of peaks, their relative intensity, and quantization of lateral wavenumber depend upon Ve0. This study will be helpful in optimizing the parameters for material grating-based matter–wave interferometers employing charged particle such as proton beams.
Bandwidth-enhanced magnetoelectric antenna based on composite bulk acoustic resonators
Authors: Yun Xiaofan , Lin Wenkui , Hu Rui , Liu Yizhang , Wang Xiaoyi , Yu Guohao , Zeng Zhongming , Zhang Xinping , Zhang Baoshun
Published: July 2022

A bulk acoustic wave (BAW) driven magnetoelectric (ME) antenna has narrow operating bandwidth due to its high Q factor, and an effective mechanism for bandwidth enhancement is yet to be explored. This article presents a bandwidth-enhanced magnetoelectric (BWE-ME) antenna made of a Mo/AlN/FeGa sandwich stack, which is composed of three different resonant regions. These resonant regions in the discrete device can be equated as a parallel connection of dual high-overtone bulk acoustic resonators (HBARs) and single film bulk acoustic resonators (FBARs) with tiny frequency shift among the three resonators resulting in bandwidth broadening of the BWE-ME antenna. The resonant mode and return loss curves (S11) are simulated in a two-dimensional finite element method and fitted with the Mason equivalent circuit model. The frequency domain analysis shows that the magnetic flux density bandwidth generated by the multi-resonant mode interaction is 18 MHz, which matches the bandwidth of the measured reference gain S21 curve of the BWE-ME antenna, and the far-field radiated power characterization also shows the corresponding effective bandwidth distributed. The fabricated microelectromechanical systems antenna achieves a fractional bandwidth of 2.7% while maintaining the advantage of small size (0.49 mm2). Discrete composite BAW resonators that effectively combine the multi-resonant regions of HBARs and FBARs have the potential to realize compact and broadband BAW-ME antennas in the future.
The influence of device structure on resistance switching in PbS QDs film inserted RRAM
Authors: Sun Yuxin , Gao Haixia , Wu Shuliang , Duan Yiwei , Qian Mengyi , Guo Jingshu , Yang Mei , Ma Xiaohua , Yang Yintang
Published: July 2022

The introduction of PbS QD (quantum dot) films has been proved, dramatically, to optimize the resistive switching (RS) performance in oxide resistive random access memory. In order to optimize parameters to a greater extent, the necessity of in-depth understanding of the resistance switching mechanism is self-evident. In this paper, PbS QD layers were inserted into a Ta/AlOxNy/Pt structure device in different positions in order to investigate the influence of the device structure in the PbS QD film inserted device. The Ta/PbS QDs/AlOxNy/Pt device with a Ta anion reservoir and a PbS QD film anion reservoir in the same direction exhibits excellent optimization of parameters, which is ideal for low-power devices. A model is constructed to elaborate the resistive switching process. Moreover, modulation of PbS QD film thickness on RS has been studied. A device with middle thickness of the PbS QD films combines low voltage, low current, and excellent stability, which is believed to be a favorable structure for the PbS QD inserted device.
Near-ambient pressure velocity map imaging
Authors: Chien Tzu-En , Hohmann Lea , Harding Dan J.
Published: July 2022

We present a new velocity map imaging instrument for studying molecular beam surface scattering in a near-ambient pressure (NAP-VMI) environment. The instrument offers the possibility to study chemical reaction dynamics and kinetics where higher pressures are either desired or unavoidable, adding a new tool to help close the “pressure gap” between surface science and applied catalysis. NAP-VMI conditions are created by two sets of ion optics that guide ions through an aperture and map their velocities. The aperture separates the high pressure ionization region and maintains the necessary vacuum in the detector region. The performance of the NAP-VMI is demonstrated with results from N2O photodissociation and N2 scattering from a Pd(110) surface, which are compared under vacuum and at near-ambient pressure (1 × 10−3 mbar). NAP-VMI has the potential to be applied to, and useful for, a broader range of experiments, including photoelectron spectroscopy and scattering with liquid microjets.
Topological growth of multi-deck vortex structures above an elevated cross jet
Authors: Sau Amalendu
Published: July 2022

The present numerical study provides a detailed topology-based understanding of the three-dimensional vortical flow interaction process for an elevated square cross jet of low-to-moderate velocity ratio (0.25 ≤R≤ 4.0). For R≤ 0.5, a steady inner-vortex (Iv) formed in the jet pipe owing to the leading-edge jet shear layer roll up as a spiral node. The kinematics of the limiting streamlines and separation-attachment patterns along the jet shear layer confirm the presence of the Iv. For 0.5 < R≤ 1.2, the Iv partly escapes, as its front side remains attached to the pipe hole and the azimuthally extended lee side moved out in a tilted fashion. Moreover, the continuous vortex shedding from the stack created a dominant von Karman-like street that grew along the lower side of the jet wake. Distinctly for R = 4, the intruded convective crossflow pulled up the spiral front node/Iv out of the pipe, which also shifted the onset of the Kelvin–Helmholtz instability upward. Significantly, the pulled-up node/Iv facilitated the above-orifice anti-kidney vortical evolution of the issuing jet shear layer. For the first time, the study displays the triple-deck growth of the kidney and anti-kidney vortices above an elevated square cross jet for 2.5 ≤ R ≤ 4.0 and 1000 ≤ Re ≤ 2000. For 0.5 ≤ R ≤ 1.2, the double-decked kidney vortices involving the primary and the secondary pairs grew above the central jet column. However, the stronger primary pair fast entrained the secondary one close to the orifice edge. With R ≥ 2.5, the lateral jet shear layer experienced an unexpected windward concave warping and restructured to evolve as the anti-kidney third-deck situated above the mid-deck primary kidney vortices. The topological shear layer folding and created kidney/anti-kidney vortices above the elevated square cross jet, for 0.25 ≤R≤ 4.0, appear consistent with the past measurements for a high aspect ratio elliptic flush jet. The anti-kidney vortical growth though was not detected above a square flush jet. The dominating above-orifice topological node in the high-pressure area ensured the anti-kidney vortical growth via the generated local pressure-gradient induced flow acceleration.
Rheological identification of jetted fluid using machine learning
Authors: Maîtrejean G. , Samson A. , Roux D. C. D. , El-Kissi N.
Published: July 2022

The understanding of flowing properties of fluids and the knowledge of the related rheological properties are crucial from both a research and industrial point of view. To determine the complex rheological properties of fluids, many devices have thus been developed, the so-called rheometers. The main objective of the present paper is to identify the rheological properties of a fluid jetted using continuous inkjet (CIJ) printing process by comparing the morphology of the aforementioned jetted fluid to a dataset of known (rheologically speaking) fluid jet morphologies and properties of a fluid by the viscosity, the surface tension, and the density of fluids using large datasets and a CIJ printing process. When ejecting a fluid, the CIJ ejection process competes among several forces: inertial, viscous, surface tension, and elasticity, which affect the morphology of the resulting jet. Also, under certain conditions, the morphology of the jet is unique and directly related to the rheological properties of the fluid. We want to use this uniqueness to identify the fluid among a large dataset of known fluid jet morphologies to be compared with, to obtain its rheological properties. Using a large numerically generated dataset of Newtonian fluid jets, we show in this article that the identification of the viscosity using neural network is not only feasible but also proves to be very accurate with an average error of less than 1% for a large range of viscosities.
Spatial mapping of a low-frequency combination Raman mode in twisted bilayer graphene
Authors: Wang Li , Xie Zhen , Jiang Shenlong , Zhang Qun , Luo Yi
Published: July 2022

The exotic properties of twisted bilayer graphene (tBLG) are profoundly affected by interlayer interactions, which can be sensitively probed by the low-frequency Raman modes. However, conventional Raman spectroscopy lacks spatial resolution and, hence, can hardly disclose spatial-dependent inhomogeneous properties of interest. Herein, we demonstrate spatial mapping of low-frequency Raman modes in tBLG via micro-Raman spectroscopy (mRS) imaging. In our constructed tBLG, the shear (C) and out-of-plane breathing (ZO′) modes are directly mapped out, and, more importantly, a regional-dependent, highly localized awakening of the combination C+ZO′ mode is clearly visualized. Through a set of mRS-based analyses, including correlation of Raman G- and 2D-mode frequencies, G-band splitting, and polarization-dependent Raman intensity distributions, we reveal that its turning on/off correlates with the mechanical strain distributions in a sensitive fashion. The spatial mapping of this unique combination mode offers an indicator for scrutinizing the elusive strain in the tBLG system or the like.
Linking supersonic boundary layer separation to structural deformation using the Kármán–Pohlhausen momentum-integral equation
Authors: Becks A. , McNamara J. , Gaitonde D.
Published: July 2022

A first-order link between local separation of supersonic turbulent boundary layer flow and structural deformation is established. First, mathematical analysis of the Kármán–Pohlhausen momentum integral equation is carried out with the assumption of spatially varying surface topology in order to identify fluid-centric representations of structural deformation. Next, a data-driven approach is used to identify the dominant fluid-centric parameters. This ultimately yields a simple linear correlation between local skin friction coefficient and surface curvature, which is the unifying parameter relating deformation and separation. This link represents a key step toward deep understanding of the nuanced interplay between turbulent boundary layers and structural deformation and significantly improves fundamental understanding of fluid-structure interaction problems with prominent turbulent boundary layer dynamics.
Homogeneous ice nucleation rates for mW and TIP4P/ICE models through Lattice Mold calculations
Authors: Sanchez-Burgos Ignacio , Tejedor Andres R. , Vega Carlos , Conde Maria M. , Sanz Eduardo , Ramirez Jorge , Espinosa Jorge R.
Published: July 2022

Freezing of water is the most common liquid-to-crystal phase transition on Earth; however, despite its critical implications on climate change and cryopreservation among other disciplines, its characterization through experimental and computational techniques remains elusive. In this work, we make use of computer simulations to measure the nucleation rate (J) of water at normal pressure under different supercooling conditions, ranging from 215 to 240 K. We employ two different water models: mW, a coarse-grained potential for water, and TIP4P/ICE, an atomistic nonpolarizable water model that provides one of the most accurate representations of the different ice phases. To evaluate J, we apply the Lattice Mold technique, a computational method based on the use of molds to induce the nucleus formation from the metastable liquid under conditions at which observing spontaneous nucleation would be unfeasible. With this method, we obtain estimates of the nucleation rate for ice Ih and Ic and a stacking mixture of ice Ih/Ic, reaching consensus with most of the previously reported rates, although differing with some others. Furthermore, we confirm that the predicted nucleation rates obtained by the TIP4P/ICE model are in better agreement with experimental data than those obtained through the mW potential. Taken together, our study provides a reliable methodology to measure nucleation rates in a simple and computationally efficient manner that contributes to benchmarking the freezing behavior of two popular water models.
Theoretical and numerical simulation study on aerodynamics of V configuration high-pressure capture wing (HCW-V)
Authors: Wang Yulin , Wei Yingjie , Wang Cong , Yang Qian , Hu Xinyu , Wang Guilin
Published: July 2022

The high-pressure capture wing (HCW) configuration has excellent aerodynamic characteristics verified by theoretical, experimental, and numerical simulation methods. It has a good effect on improving vehicle lift at hypersonic speed. A HCW-V configuration based on the HCW was proposed in this paper. This configuration further increased the vehicle's lift by increasing the wedge angle of the capture wing and forming a compression plane on the lower surface. We obtained the pressure ratio relationship between the upper and lower surfaces of the HCW-V configuration concerning the free-stream airflow Mach number, the body compression angle, and the captive wing wedge angle based on theoretical derivation. It was nearly 60% higher than the HCW configuration pressure ratio. In addition, the influence of the HCW-V configuration on the vehicle's aerodynamic characteristics at different Mach numbers and body compression angles was studied through numerical simulation methods. The HCW-V configuration improved the lift-to-drag ratio by at least 25% compared with the HCW configuration. The expression of the lift coefficient of the vehicle CL = −0.095Ma∞tanδ + 2.352tanδ + 0.031θ + 0.010 under the model presented was obtained in this study. Meanwhile, the adaptability of this configuration to varied Mach number and attack angle was investigated further. The average lift-to-drag ratio of HCW-V was increased by 23.7% and 7.09% at varying Mach numbers and angles of attack. The lift-to-drag ratio of the three-dimensional HCW-V configuration is 14% higher than that of the HCW configuration when the wedge angle is 4.19°.