bluuebunny/crossref_metadata_2025 huggingface dataset:
Oriental Consciousness in André Masson’s Automatic Paintings
Authors: Qian Xingyu
Published: March 2024

André Masson has long been regarded as a representative figure of surrealist and automatism painting, but a closer look at his works makes it easy to find a dialogic nature with ancient Chinese calligraphy and painting. Influenced by Breton's concept of automatic writing, his works also draw on Chinese ink paintings of the Song Dynasty, abandoning perspective and playing the important role of white space. This paper tries to sort out the lineage of the emergence of Oriental consciousness in Masson's automatic paintings and explains the specific expression of Chinese painting in his art.
A Study of Artificial Intelligence in the Production of Film
Authors: Sun Peiming
Published: March 2024

As a key branch of the intelligence field, Artificial Intelligence (AI) is a technical science with the goal of understanding the nature of intelligence and inventing new types of intelligent machines that can act similarly to human intelligence. The study of AI technology includes robotics, natural language processing, speech and image recognition, etc. In recent years, AI has been rapidly developed and widely deployed in a variety of applications in different industries such as autonomous driving, healthcare, financial services, and film production. The application of AI in films is studied in this article, and according to analysis, it can be concluded that in the process of film production, AI technology has its advantages in increasing efficiency and cost-effectiveness in film production. It can also enhance the overall quality of films, impressing the audience by generating special effects and providing filmmakers with new tools and techniques to explore and experiment with. Meanwhile, AI technology also has its disadvantages such as a lack of human touch and depth in the the works produced by AI.
The study on The Philosophy of Zhao Lun
Authors: Li Yan
Published: March 2024

Zhaolun is the master work written by Sengzhao. I will choose one of most precious commentaries, Zhao Lun Ji Jie Ling Mo Chao, which I study, and translate into English, as nobody has done this work till now. In the studies of Zhaolun, some unsolved questions and divergences still exist. Based on the works of scholars in China and abroad, I try to explain some questions more properly on grounds. Zhaolun deeply affected the Buddhism in China, as well in Korea and Japan. I study Zhaolun based on the general explanation to the notes and commentaries in different Dynasties.
Exploring “Galant Style” in 18th-Century German, French, and Italian Composers’ Pieces
Authors: Jing Xiao
Published: March 2024

This paper explores the Galant style of music, which emerged in the mid-18th century as a bridge between the Baroque and Classical periods. The characteristics of this style are simplicity and elegance, and it focuses on melody and harmony over complex counterpoint. Most people would classify the Galant style as Rococo, and this paper proves this opinion is wrong. Compared to the Galant style, the Rococo style is associated with visual arts. Comprehensive research of the Galant style illustrates that this style prioritizes clarity and musical structure rather than ornamental and decorative features. In order to demonstrate the Galant style, this paper chose pieces from three renowned composers, Domenico Scarlatti, Francois Couperin, and Georg Philipp Telemann, representing different nationalities; those composers come from Italy, France, and Germany. These pieces, including Scarlatti's piano sonatas (K.29 and K.145), “Le Bavolet Flottant” by Francois Couperin, and Telemann's Fantasia TWV33 no.8 in G minor, above of these pieces illustrate the distinct characteristics and nuances of the Galant style.
Bacteriological and Antimicrobial Susceptibility Profile in Biliary Tract Infections: A Retrospective Study
Authors: Gupta Veenu , Gupta Rama , Aggarwal Manisha , Singh Satpal , Kaur Harpreet , Chaudhary Jyoti , Gupta Menal , Singla Saurabh , Kaur Harmandeep
Published: March 2024

Introduction In the past few years, although there has been no change in the bacteriological profile of organisms responsible for biliary tract infections (BTIs), changes in the drug susceptibility pattern of these organisms have been reported.

Material and Methods We planned a retrospective study to evaluate the microbiological profile and antibiotic susceptibility patterns of isolates from patients with BTI.

The study was conducted in the Department of Microbiology over a period of 1 year. We recorded the culture positivity rates, organisms identified, and the pattern of antibiotic susceptibility.

Results Out of 226 bile samples received, 60.2% samples were found to be culture positive. Most of the patients were older than 40 years. Hypertension (33.1%), diabetes (28.7%), and cardiovascular diseases (8.1%) were the common underlying diseases. Common patient symptoms were abdominal pain (77.89%), jaundice (42.24%), and fever (41.52%). Cholangitis was present in 20.6% patients. Cholelithiasis or choledocholithiasis was the most common underlying etiology (39%). A total of 142 isolates were obtained, with most patients with a predominance of gram-negative isolates. Tigecycline and aminoglycosides were found to be effective against gram-negative isolates with a susceptibility of 93.4 and 95.7%, respectively. Of the gram-negative isolates, approximately 70% were multidrug resistant (MDR), with approximately 80 and 75% being extended spectrum beta-lactamases (ESBLs) and carbapenemase producers, respectively. Enterococci were 100% susceptible to linezolid and 25% of these were vancomycin-resistant enterococci (VRE).

Conclusion In summary, the predominant bacteria in our study were gram-negative bacteria that showed increased resistance to cephalosporins and carbapenems. This makes the treatment of bile duct infections increasingly difficult. A comprehensive analysis of the bacterial distribution and drug resistance profiles in patients with BTIs helps physicians to make better antibiotic policies for empiric treatment.
The impact of push-pull motives on internal tourists’ visit and revisit intentions to Egyptian domestic destinations: the mediating role of country image
Authors: Ayoub Doaa , Mohamed Dina Nasser Hassan Sayed
Published: March 2024

Purpose-The purpose of this study is to investigate the impact of the push motivational factors (rest & relaxation, enhancing the ego, and novelty & knowledge-seeking) and pull motivational factors (tourism facilities, environment & safety, and cultural & historical attraction) on internal tourists’ visit and revisit intentions to a domestic destination in Egypt. It also tested the mediation role of the country image in the relationship between the independent variables (push & pull motives) and the dependent variables (visit & revisit intentions). This study provides novelty for the context of travel motivation, especially in a global crisis like Corona and highlight the limited literature regarding the Arab context, especially Egypt. Data were collected using an online survey of internal tourists to test the proposed model empirically using structured questions. Structural equation model (SEM) was developed to test the research hypotheses with a sample of 349. The findings indicate that all the research hypotheses were statistically supported, except for the associations between rest-and-relaxation, tourism facilities and the internal tourists’ visit intention to a destination in Egypt.
Engaging disadvantaged students in a Chinese as a Foreign Language classroom: Bernstein’s pedagogic discourse as a bridge
Authors: Xu Wen
Published: March 2024

This study is part of practitioner inquiry undertaken in an underprivileged, low-achieving primary school in Sydney, Australia, based in a Chinese as a Foreign Language (CFL) classroom with 9–10-year-olds. The aim was to unpack pedagogic discourse at the micro level of interactions, while delving into students’ perceptions of language learning experiences. Two data sources were used: an audio recording of lessons and students’ focus groups. By applying Bernstein’s pedagogic discourse and Fair Go Project’s (FGP) engagement framework, the findings reveal that consistently shifting pedagogic discourses were likely to overcome students’ social backgrounds and offer them engaging CFL learning experiences. The study makes an original contribution to providing CFL practitioners and pre-service teachers with a delicate, precise language to plan and chart courses, while guiding disadvantaged students through pedagogic mazes. This paper concludes with pedagogic implications for the social inclusion agenda.
Isoelectric focusing technique enables protein detection beyond standard limits
Authors: Thompson Avery
Published: March 2024

The technique is an inexpensive and versatile means of enhancing existing detection methods.
Structure and thermal conductivity of high-pressure-treated silica glass. A molecular dynamics study
Authors: Puchalski Adam , Hul Anton , Nie Jihui , Pietrzak Tomasz K. , Keblinski Pawel
Published: March 2024

High-pressure treatment of oxide glasses can lead to significant alteration of various material properties such as increased density, ductility, and elastic moduli. In this study, a model of melt-quenched bulk silica glass was subject to high-pressure treatments (up to 16 GPa) using molecular dynamics simulations. The thermal conductivity of such prepared glass structures was determined using the equilibrium Green–Kubo method. We observed that, up to the pressure treatments of ∼6 GPa, the structure exhibits moderate density increase and a much steeper increase between 6 and 16 GPa, with associated density increase of fivefold silicon atoms. We also observed a noticeable increase (up to 20%) of the thermal conductivity in samples subjected to high-pressure treatments. The observed increases are somewhat, but not significantly, larger than those predicted by the minimum thermal conductivity model, accounting for density and elastic moduli increase.
Understanding characteristics of gravitational particle settling using particle image velocimetry
Authors: Hafez Mazen , Ghazvini Mahyar , Ostapchuk Kostiantyn , Kavosi Mohammadhassan , Li Yaofa , Ratanpara Abhishek , Kim Myeongsub
Published: March 2024

A significant challenge to hydraulic fracturing is premature particle settling and uneven particle distribution in a formation during injection. Even though various research work were conducted on particle transport, gaps still exist in the fundamental proppant–proppant interaction mechanisms. This study utilizes an experimental approach to understand proppant interactions during gravitational settling in various test conditions. High-speed imaging coupled with particle image velocimetry (PIV) was implemented to provide a space and time-resolved investigation of multi-proppant interactions. The multi-perspective experimental study uncovered the coupled effect of viscosity and multi-particle mix ratio on slurry velocity. The PIV analysis highlights unique agglomeration and particle interactive patterns. The results indicate that the mix ratio has a significant effect on proppant interactive behavior and settling characteristics, especially as the solution viscosity increases. This conclusion was drawn from observing no signs of agglomeration in the low viscosity regime, although slight differences in proppant interactions were noted as the mix ratios were altered. On the other hand, the intermediate regime demonstrates formed agglomerates with unique patterns for different viscosity and mix ratios. The observed patterns were quantified using both velocity and proppant concentration analysis. Finally, the results indicate the existence of a reduced velocity condition at a given viscosity and particle mix ratio.
Al-rich AlGaN high electron mobility transistor gate metallization study up to 600 °C in air
Authors: Klein B. A. , Allerman A. A. , Armstrong A. M.
Published: March 2024

We report a comparative study of three rectifying gate metals, W, Pd, and Pt/Au, on ultrawide bandgap Al0.86Ga0.14N barrier/Al0.7Ga0.3N channel high electron mobility transistors for use in extreme temperatures. The transistors were electrically characterized from 30 to 600 °C in air. Of the three gate metals, the Pt/Au stack exhibited the smallest change in threshold voltage (0.15 V, or 9% change between the 30 and 600 °C values, and a maximum change of 42%), the highest on/off current ratio (1.5 × 106) at 600 °C, and a modest forward gate leakage current (0.39 mA/mm for a 3 V gate bias) at 600 °C. These favorable results showcase AlGaN channel high electron mobility transistors' ability to operate in extreme temperature environments.
Modulating molecular aggregation of luminogens: Bridging the gap between solutions and solids
Authors: Meng Peng , Lau Andreis , Miyajima Daigo , Zhao Zheng , Alam Parvej , Qiu Zijie , Tang Ben Zhong
Published: March 2024

In the past two decades, the advancement of aggregation-induced emission (AIE) has greatly advanced our understanding of organic luminescence and facilitated the application of organic luminescent materials. AIE luminogens (AIEgens) emit weakly in solutions but strongly in aggregated states. This significant difference in luminescence between solutions and aggregated states of AIEgens has shown that there is much to explore in the mesoscopic world (the intermediary phase). Accordingly, the research paradigm of aggregate science is proposed. The path to new aggregate materials relies not only on molecule syntheses but also on the control of molecular aggregation, which bridges the gap between solutions and solids. In this Perspective, we outline three general strategies for managing molecular aggregation to stimulate new ideas and provide guidance on controllable molecular aggregation.
Numerical investigation on cooperative evaporation from microdroplet array on heated substrate
Authors: Ma Binjian , Li Hao , Li Dafeng , He Xiaoyu , Yang Huizhu
Published: March 2024

The evaporative heat and mass transport characteristics from an array of continuously fed microdroplet on a heated substrate are investigated numerically by a Multiphysics model, which incorporates heat conduction, buoyant flow, Marangoni flow, Stefan flow, and vapor diffusion. The effects of droplet spacing, contact angle, and droplet size on the evaporation rate, heat flux, and convection strength were analyzed in detail with a fixed thermal and vapor concentration boundary condition. The results revealed the existence of extremely strong convection current in the ambient gas domain for evaporation from droplet array. This convection effect dominates the vapor transport process, overcomes the suppression effect from neighboring droplet, and causes the total evaporation rate to exceed the prediction from traditional diffusion-based model by up to ten times. The strength of the convective vapor transport is characterized by a dimensionless parameter, which increases first from 2.3 to 7 and then decrease to 4 with increasing contact angle from 30° to 150°, but remains invariant at 6.3 for hemispherical droplet irrespective of the change in droplet dimension. Finally, the numerical results demonstrate potential for microdroplet array evaporation to resolve the thermal management challenge of ultrahigh power electronics with heat flux up to 1 kW/cm2.
Coupling between the deformation of a liquid convex object and the resulting scattered acoustic field
Authors: Herrera Leclerc Rafael-Alejandro , Blaisot Jean-Bernard , Baillot Françoise
Published: March 2024

This paper presents a semi-analytical model for calculating the mean deformation of a cylindrical or quasi-spheroidal liquid object placed in standing acoustic waves under the near-field approach. The interaction between the waves and the object is characterized by the angular distribution of the radiation pressure Prad(θ) over the object surface. The key parameters of the model are the Helmholtz number, α, and the object shape aspect ratio, called ϵ for elliptic shapes and ϵg for arbitrary shapes. For elliptic cross-sectional rigid objects, effects are globally dominated by suction for small α or compression for large α, whatever ϵ. When suction predominates, two opposed compression maxima and two opposed suction minima are observed. When compression predominates, an interference pattern with several extrema is observed. For potentially deformable objects, a potential flattening is found whatever α, which is all the more important as ϵ decreases. A general deformation model is developed to quantify the action/reaction loop between the acoustic field and the deformable object of the aspect ratio, ϵg. The acoustic Bond number Boa and a curvature-based parameter, ϵκ, are introduced. As Boa increases, the object flattens whatever α. For small α, convex deformation is observed until a maximum Bond number is reached when ϵg = ϵκ = 0. There, an abrupt change occurs from a convex shape to a planar liquid sheet. Otherwise, a local transition from a convex to a concave shape occurs, for which ϵκ = 0, while ϵg≠0. Our model successfully predicts numerical and experimental results from the literature.
The hydrothermal performance of non-Newtonian fluids in superhydrophobic microchannels
Authors: Shahsavari Arghavan , Pakzad Hossein , Moosavi Ali
Published: March 2024

Investigating the thermal performance of non-Newtonian fluids is of great importance as these fluids are ubiquitous in industry. In this regard, we perform a series of numerical simulations to investigate the effect of superhydrophobic microstructures in a microchannel containing Newtonian, shear-thinning, and shear-thickening fluids on their hydrothermal performances. To this end, three different cases are considered. In the first case, the upper wall is subjected to various heat fluxes and temperatures in the range of 104–106 W/m2 and 303.15–323.15 K, respectively. In the second case, the working fluid's Reynolds number varies while the upper wall's thermal condition is fixed. In the last case, the temperature of the computational zone is set to a constant value. As the air pockets are absent near the upper wall, the thermal energy is transferred without any loss, increasing the working fluid's temperature and, consequently, plummeting the viscosity and resulting in smaller shear stresses. It is revealed that this channel can reduce the pressure drop up to 31.9% and 29.9% for constant heat flux and constant temperature conditions, respectively. The higher the Reynolds number, the lesser the drag reduction performance. The rise in the computational zone's temperature can profoundly improve the pressure drop plummeting performance. For all cases, the recirculation of the air within the bottom surface features is responsible for slip velocity and smaller shear stress at the bottom wall. The results show that the overall performance of the proposed channel is better than the smooth one.
Identification of local structures in water from supercooled to ambient conditions
Authors: Foffi Riccardo , Sciortino Francesco
Published: March 2024

Studies of water thermodynamics have long been tied to the identification of two distinct families of local structures, whose competition could explain the origin of the many thermodynamic anomalies and the hypothesized liquid–liquid critical point in water. Despite the many successes and insights gained, the structural indicators proposed throughout the years were not able to unequivocally identify these two families over a wide range of conditions. We show that a recently introduced indicator, Ψ, which exploits information on the hydrogen bond network connectivity, can reliably identify these two distinct local environments over a wide range of thermodynamic conditions (188–300 K and 0–13 kbar) and that close to the liquid–liquid critical point, the spatial correlations of density fluctuations are identical to those of the Ψ indicator. Our results strongly support the idea that water thermodynamic properties arise from the competition between two distinct and identifiable local environments.
Emergence of innovations in networked populations with reputation-driven interactions
Authors: Gallarta-Sáenz Pablo , Pérez-Martínez Hugo , Gómez-Gardeñes Jesús
Published: March 2024

In this work, we analyze how reputation-based interactions influence the emergence of innovations. To do so, we make use of a dynamic model that mimics the discovery process by which, at each time step, a pair of individuals meet and merge their knowledge to eventually result in a novel technology of higher value. The way in which these pairs are brought together is found to be crucial for achieving the highest technological level. Our results show that when the influence of reputation is weak or moderate, it induces an acceleration of the discovery process with respect to the neutral case (purely random coupling). However, an excess of reputation is clearly detrimental, because it leads to an excessive concentration of knowledge in a small set of people, which prevents a diversification of the technologies discovered and, in addition, leads to societies in which a majority of individuals lack technical capabilities.
Electric manipulation of the magnetization in heterostructure Pt/Co/Bi2Se3
Authors: Wang Zhen , Wang Fenglong , Shen Hao , Hou Zhaoyang , Wang Jinguo , Shi Gang , Xu Chunlong
Published: March 2024

Spin–orbit torque (SOT) can provide efficient electrical manipulation of magnetism via applying electrical current to breaking the symmetry of damping-like torque. In the heterojunction of heavy and ferromagnetic metal, Dzyaloshinskii–Moriya interaction (DMI) is one of the key ingredients for stabilizing chiral spin structures, like chiral domain walls. Meanwhile, materials with larger charge-spin conversion rates are also highly expected for the efficient SOT. In this paper, spin–orbit torque magnetic switching is observed in the perpendicularly magnetized Pt/Co/Bi2Se3 and shows relatively high efficiency with low critical switching current density of about 5 × 105 A cm−2. The SOT efficiency and DMI in perpendicularly magnetized Pt/Co/Bi2Se3 were quantitatively investigated by electrical detection of the effective spin Hall field. The DMI constant is about 2.6 mJ m−2, and the effective spin Hall angle of Pt/Co/Bi2Se3 is about 0.14. The work also demonstrates that the Bi2Se3 layer takes the main responsibility for SOT, and the Pt/Co interface is the main source of DMI in Pt/Co/Bi2Se3 structures, which makes it possible to achieve independent optimization of DMI and SOT in the Pt/Co/Bi2Se3 structure at room temperature for the advanced application of spintronic devices.
Water molecule elimination from the protonated methanol dimer ion—An example of a size-selective intracluster reaction
Authors: Salbaing Thibaud , Comte Denis , Lavy Léo , Lissillour Hector , Ospina Laura Parrado , Bertier Paul , Feketeová Linda , Calvo Florent , Farizon Bernadette , Farizon Michel , Märk Tilmann
Published: March 2024

The abundance of extraterrestrial methanol makes the reaction between methanol molecules in a molecular cluster a possible key step in the search for mechanisms for the formation of more complex molecules under the conditions of the interstellar medium as well as circumstellar and planetary atmospheres. The reaction leading to the formation of the dimethyl ether ion from a methanol molecule interacting with a protonated methanol ion via the elimination of a water molecule is a basic mechanism for the formation of complex organic molecules. Here, we experimentally examine such reactions in the gas phase, analyzing the production and reactivity of protonated cluster ions formed by the ionization of a supersonic jet of methanol. Focusing especially on the post-collisional relaxation of the protonated methanol dimer and trimer ions after high-energy single collisions, the results indicate a strong size selectivity favoring the occurrence of this reaction only in the dimer ion. To elucidate this behavior, the velocity distribution of the eliminated water molecule was measured using an event-by-event coincidence analysis. These results are interpreted using quantum chemical calculations of the dissociation pathways. It turns out that in the dimer case, two transition states are able to contribute to this intracluster reaction. In the trimer case, methanol evaporation appears as the most energetically favorable relaxation pathway.
Self-powered high responsivity ultraviolet radiation sensor by coupling ZnO based piezoelectric nanogenerator and photodetector
Authors: Mahapatra Abhinav , Ajimsha R. S. , Misra Pankaj
Published: March 2024

A self-powered UV sensor with high responsivity was developed by coupling ZnO based piezoelectric nanogenerator and photodetector for uninterrupted real-time monitoring of UV radiation. Unlike conventional UV photodetectors, our approach couples a ZnO based metal-semiconductor-metal photodetector as a variable load resistor with a flexible ZnO:PVDF piezoelectric nanogenerator through impedance matching to realize self-powering of photodetector. The as fabricated UV photodetector exhibits a dark resistance of approximately 55 MΩ and change of resistance from 12 to 2 MΩ in response to UV illumination ranging from 1.5 to 14.5 mW/cm2. Under UV exposure of 1.5 mW/cm2, the output voltage of self-powered UV sensor drops from ∼14.6 V (dark) to ∼3.88 V. With increasing UV intensity from 1.5 to 14.5 mW/cm2, the output voltage gradually decreases from ∼3.88 to ∼1.04 V due to reduced ZnO photodetector resistance. This self-powered UV sensor exhibits excellent performance with a sensitivity of ∼93%, a voltage responsivity of 7.14 V (mW−1 cm−2), a response time of 0.67 s, and a recovery time of 4 s, which are better than the previous reports. The environmentally stable and biocompatible nature of ZnO based system makes it a promising candidate for self-powered real time ultraviolet remote sensing applications.
Influence of magnetohydrodynamics configuration on aerothermodynamics during Martian reentry
Authors: Sharma Vatsalya , Giangaspero Vincent F. , Poedts Stefaan , Lani Andrea
Published: March 2024

This paper investigates the role of magnetohydrodynamics (MHD) on the aerothermodynamics (ATD) of a representative entry vehicle while flying into the Martian atmosphere. By strategically placing a flight-ready superconducting magnet at varied positions in the Schiaparelli reentry capsule of the ExoMars mission, we discern its impact on essential flow properties. The primary consequence of MHD during atmospheric entry is the generation of the Lorentz force, which increases the shock standoff distance resulting in a reduction of the heat flux on the spacecraft by pushing high-energy plasma particles away. Through different magnet configurations, three distinct cases are formed to comprehensively understand the effects and implications of each setup. The study is performed using the COOLFluiD MHD for EnTries, an in-house ATD solver. For case 1, the magnet's placement behind the ExoMars forebody at the stagnation point reduces the heat flux. In case 2, the magnet's relocation to the shoulder region explores its potential to mitigate communication blackouts by influencing the wake region's flow. However, this positioning also induces shock bending, leading to variations in post-shock species mass fractions and heat flux spikes in the post-shock region. Case 3, involving an additional magnet where the shock bends in case 1, showcases a consistent increase in shock standoff distance across the forebody, providing a longer relaxation zone for species equilibration. Our findings highlight that while the strength of the applied magnetic field is crucial, the magnet's size is equally pivotal in determining ATD behavior. Case 3 emerges as the most promising configuration, consistently reducing heat flux across the forebody and maintaining it in the afterbody. This study underscores the potential of multi-magnet configurations as next-generation MHD heat shields for Martian atmospheric entry, emphasizing the criticality of magnet placement and configuration in enabling future MHD-enhanced deep space exploration missions.
A flow model in CoCrFeMnNi high-entropy alloys during high-temperature tension
Authors: Hao Rong , Wang Zhong , Jin Xi , Lan Aidong , Qiao Junwei
Published: March 2024

At high temperatures, serrated flows are frequently observed on the stress–strain curves of single-phase high-entropy alloys, indicating their unique mechanical behavior. In the current study, the CoCrFeMnNi (Cantor alloy) alloy was selected as a model material to further verify the temperature dependence on the serrated flow behavior through continuous temperature variation during tensile tests, which shows a certain strengthening effect of the serrated flow. The lattice strain and dislocation density were calculated at different conditions using the Williamson–Hall (W-H) analysis method. Based on the strain dependence of mobile dislocation density and forest dislocation density, a flow stress model related to the Portevin–Le Chatelier (PLC) effect was proposed to quantify the variation in the PLC behavior with the temperature and its influence on flow stress. The model is beneficial to accurately account for the flow stress during plastic deformation at high temperatures.
Nonvolatile memory cells from hafnium zirconium oxide ferroelectric tunnel junctions using Nb and NbN electrodes
Authors: Haglund-Peterson Jessica , Aronson Benjamin L. , Jaszewski Samantha T. , Habermehl Scott , Esteves Giovanni , Conley John F. , Ihlefeld Jon F. , Henry M. David
Published: March 2024

Ferroelectric tunnel junctions (FTJs) utilizing hafnium zirconium oxide (HZO) have attracted interest as non-volatile memory for microelectronics due to ease of integration into back-end-of-line (BEOL) complementary metal oxide semiconductor fabrication. This work examines asymmetric electrode NbN/HZO/Nb devices with 7 nm thick HZO as FTJs in a memory structure, with an output resistance that can be controlled by read and write voltages. The individual FTJs are measured to have a tunneling electroresistance of 10 during the read state without significant filament conduction formation and reasonable ferroelectric performance. Endurance and remanent polarizations of up to 105 cycles and 20 μC/cm2, respectively, are measured and are shown to be dependent on the cycling voltage. Electrical measurements demonstrate how magnitude of the write pulse can modulate the high state resistance and the read pulse influences both resistance values as well as separation of resistance states. Then, by using two opposite switching FTJ devices in series, a programmable nonvolatile resistor divider is demonstrated. Measurements of these two FTJ unit memory cells show wide applicability to a BEOL microfabrication process for a re-readable, rewritable, and nonvolatile memory cell.
Water droplet impact dynamics comparison on solid and hollow square micropillared substrates
Authors: Yadav Mukesh Kumar , Patil Nagesh D.
Published: March 2024

We experimentally investigate microliter-sized water droplet impact on solid and hollow square micropillared polydimethylsiloxane substrates. Micropillared substrates with different values of pitch (34, 47, and 62 μm) and hole sizes (0, 3, 6, and 10 μm) of pillars are fabricated using soft lithography following direct laser writer maskless photolithography. We observe that hollow micropillared substrates exhibit increased hydrophobicity as compared to the solid micropillared substrates. Interestingly, we find that hydrophobicity is further enhanced as the hole size is increased. To understand the impact dynamics, we perform high-speed visualization to acquire the transient evolution of the impacting droplets. Based on the impact velocity (0.22–0.62 m/s), pitch, and hole size, we identify various regimes, namely, non-bouncing, partial bouncing, and complete bouncing. At a given impact velocity and pitch value, non-bouncing and bouncing regimes are observed for solid and hollow micropillared substrates, respectively. We find that the hollow micropillared substrate exhibits higher values for capillary pressure, impalement pressure, and the energy barrier associated with the Cassie–Baxter to Wenzel transition toward the impacting droplets. This is due to a decrease in the solid fraction owing to the incorporation of circular holes in pillars. The analysis shows the energy loss due to viscous dissipation decreases with an increase in hole size, which enhances the bouncing fate possibility. The fundamental insights gained from this study can be effectively leveraged by modulating the surface morphology to realize the desired droplet impact characteristics for various potential applications such as self-cleaning and energy harvesting.
Static and shock compression studies of eutectic high-entropy alloy AlCoCrFeNi2.1 to ultrahigh pressures
Authors: Katagiri Kento , Irvine Sara J. , Hari Anirudh , Kodama Ryosuke , Ozaki Norimasa , Sano Takayoshi , Ren Jie , Yang Wuxian , Chen Wen , Clay Matthew P. , Pope Andrew D. , Iwan Seth , Dresselhaus-Marais Leora E. , Vohra Yogesh K.
Published: March 2024

The high-entropy alloy with composition AlCoCrFeNi2.1, additively manufactured with the laser powder-bed fusion technique, has a far-from-equilibrium BCC/FCC eutectic nanolamellar structure. We studied the high-pressure response of this alloy under both static compression and high-strain rate shock compression. The response to static compression using a diamond anvil cell was studied at pressures up to 302 GPa with synchrotron x-ray diffraction at the advanced photon source. The high-pressure FCC-only phase of the EHEA previously observed by Pope et al. [AIP Adv. 13, 035124 (2023)] is found to be stable up to the highest pressure achieved in this study with a volume compression of V/V0 = 0.587 at ambient temperature. The shock experiments were performed by using GEKKO XII lasers at the Institute of Laser Engineering, Osaka University. The principal Hugoniot equation-of-state of the EHEA was measured up to a pressure of 515 GPa and a compression of V/V0 = 0.613. Additionally, the thermal equation of state of the EHEA was measured up to 6.2 GPa and 1623 K using a large-volume Paris–Edinburgh cell to obtain the temperature dependence of bulk modulus and thermal expansion coefficients. The melting temperature for EHEA AlCoCrFeNi2.1 at a pressure of 5.6 GPa was measured to be 1648 ± 25 K. These results can be used to refine stochastic (or special) quasi-random structure (SQS) models for high-pressure high-temperature behavior of high-entropy alloys.
Prediction of unsteady flows in turbomachinery cascades using proper orthogonal decomposition
Authors: Krath Elizabeth H. , Carpenter Forrest L. , Cizmas Paul G. A.
Published: March 2024

A reduced-order model based on the proper orthogonal decomposition (POD) method is used to assess whether it can predict the highly unsteady flow in turbomachinery cascades. Three cases are considered: a transonic fan rotor called the National Aeronautics and Space Administration Rotor 67, a cascade of oscillating compressor blades called the 10th Standard Configuration, and a cascade of oscillating turbine blades called the 11th Standard Configuration. The governing equations used in this POD model, called zeta-POD, are written using the specific volume instead of density. This formulation of the governing equations allows the precomputation of the coefficients of the system of ordinary differential equations prior the flow simulation. Consequently, a significant speedup is obtained compared to the full-order model and a traditional, density-based POD. In addition, the accuracy of the zeta-POD model is compared against the full-order model and the density-based POD.
The evolution of second harmonic waves in oblique transition
Authors: Jiao Yuxin , Tao Jianjun
Published: March 2024

In this paper, the evolution of second harmonic waves, whose streamwise wavenumbers are twice of the fundamental streamwise wavenumber, is studied during the oblique transition of plane Couette flow. At the initial stage of the transition, the second harmonic waves are amplified in turn by the Orr mechanism and the nonlinear convection of perturbations together with the working of perturbation pressure. At the middle and late stages, the second harmonic waves are reactivated by the instability of the mean flow in the presence of developed streamwise streaks, and their growth rates are dominated later by the nonlinear interactions of the fundamental oblique waves. When the spanwise kinetic energies of the streamwise vortices, streaks, and the fundamental oblique waves are exceeded by those of the second harmonic waves, the streak breakdown occurs, indicating that these second harmonic waves are essential for the oblique transition.
Higher-order topological charge detection using off-axis parabolic mirror
Authors: Dezfouli Ali Mardan , Skenderović Hrvoje
Published: March 2024

A method for determining the topological charge of an optical vortex using off-axis parabolic mirror (OPM) is reported. The results of the diffraction patterns obtained in the reflected focal point of an OPM show the intensity pattern and its orientation depend on the charge of the vortex as well as its sign. The experimental results agree well with the simulation results. The capability and robustness of this method are demonstrated by the detection of the topological charge as high as ±250.
Polarization-controlled generation of multiple orbital angular momentum modes
Authors: Ren Zhi-Cheng , Cheng Zi-Mo , Fan Li , Sun Ran , Zhu Wen-Zheng , Wan Pei , Dong Bo-Wen , Lou Yan-Chao , Ding Jianping , Wang Xi-Lin , Wang Hui-Tian
Published: March 2024

By concurrently manipulating the degrees of freedom associated with polarization and orbital angular momentum (OAM), a variety of vector fields can be generated, which exhibit unique characteristics and have found extensive application in both classical and quantum optics. However, the OAM dimensions in these fields have been predominantly confined to two. Different from high-order OAM with a large topological charge, broadening the OAM dimensions beyond this limit and generating OAM spectra with multiple OAM modes can significantly enhance the scope of research. In this study, we explore vector fields with OAM dimensions exceeding ten, achieving polarization-controlled spectra in higher-dimensional OAM. Our findings not only offer a method for controlling high-dimensional OAM through polarization but also pave the way for potential applications in both classical and quantum realms utilizing high-dimensional vector states.
Regulating the bipolar response of InAs nanowire photodetector and waveguide integration
Authors: Wang Zhiqiang , Liu Liwei , Zhong Zhipeng , Li Xiang , Chen Yan , Zhang Junju , Shi Wu , Zhang Xutao , Wang Jianlu , Chu Junhao , Huang Hai
Published: March 2024

III–V Indium Arsenide (InAs) nanowire photodetectors have attracted intensive research attention due to their high carrier mobility, direct and narrow bandgap, and nanoscale dimensions, offering immense potential in nanoscale optoelectronics, particularly for applications in photonic integrated circuits. Despite extensive studies on the properties of InAs nanowires, their photoresponse remains intricate, displaying bipolar behavior (i.e., positive and negative photoresponse) within the same device under varying conditions. However, the underlying driving mechanism remains unclear. In this work, we have systematically studied the transition between the negative photoresponse and positive photoresponse in the InAs nanowire photodetector under different conditions. We found the bipolar photoresponse is directly related to the occupation status of the surface trap states, and it could be effectively regulated by the gate voltage, power intensity, as well as the illumination duration. Furthermore, we developed a waveguide-integrated InAs nanowire photodetector using electron photoresist with an optical loss as low as 0.122 dB/μm. This achievement underscores its potential for application in photonic integrated photodetectors, laying the groundwork for future integration of InAs nanowire photodetectors into photonic integrated circuits.
Seafloor primary production in a changing Arctic Ocean
Authors: Attard Karl , Singh Rakesh Kumar , Gattuso Jean-Pierre , Filbee-Dexter Karen , Krause-Jensen Dorte , Kühl Michael , Sejr Mikael K. , Archambault Philippe , Babin Marcel , Bélanger Simon , Berg Peter , Glud Ronnie N. , Hancke Kasper , Jänicke Stefan , Qin Jing , Rysgaard Søren , Sørensen Esben B. , Tachon Foucaut , Wenzhöfer Frank , Ardyna Mathieu
Published: March 2024

Phytoplankton and sea ice algae are traditionally considered to be the main primary producers in the Arctic Ocean. In this Perspective, we explore the importance of benthic primary producers (BPPs) encompassing microalgae, macroalgae, and seagrasses, which represent a poorly quantified source of Arctic marine primary production. Despite scarce observations, models predict that BPPs are widespread, colonizing ~3 million km
2
of the extensive Arctic coastal and shelf seas. Using a synthesis of published data and a novel model, we estimate that BPPs currently contribute ~77 Tg C y
−1
of primary production to the Arctic, equivalent to ~20 to 35% of annual phytoplankton production. Macroalgae contribute ~43 Tg C y
−1
, seagrasses contribute ~23 Tg C y
−1
, and microalgae-dominated shelf habitats contribute ~11 to 16 Tg C y
−1
. Since 2003, the Arctic seafloor area exposed to sunlight has increased by ~47,000 km
2
y
−1
, expanding the realm of BPPs in a warming Arctic. Increased macrophyte abundance and productivity is expected along Arctic coastlines with continued ocean warming and sea ice loss. However, microalgal benthic primary production has increased in only a few shelf regions despite substantial sea ice loss over the past 20 y, as higher solar irradiance in the ice-free ocean is counterbalanced by reduced water transparency. This suggests complex impacts of climate change on Arctic light availability and marine primary production. Despite significant knowledge gaps on Arctic BPPs, their widespread presence and obvious contribution to coastal and shelf ecosystem production call for further investigation and for their inclusion in Arctic ecosystem models and carbon budgets.
Dynamic carriers for therapeutic RNA delivery
Authors: Berger Simone , Lächelt Ulrich , Wagner Ernst
Published: March 2024

Carriers for RNA delivery must be dynamic, first stabilizing and protecting therapeutic RNA during delivery to the target tissue and across cellular membrane barriers and then releasing the cargo in bioactive form. The chemical space of carriers ranges from small cationic lipids applied in lipoplexes and lipid nanoparticles, over medium-sized sequence-defined xenopeptides, to macromolecular polycations applied in polyplexes and polymer micelles. This perspective highlights the discovery of distinct virus-inspired dynamic processes that capitalize on mutual nanoparticle–host interactions to achieve potent RNA delivery. From the host side, subtle alterations of pH, ion concentration, redox potential, presence of specific proteins, receptors, or enzymes are cues, which must be recognized by the RNA nanocarrier via dynamic chemical designs including cleavable bonds, alterable physicochemical properties, and supramolecular assembly–disassembly processes to respond to changing biological microenvironment during delivery.
Human paraneoplastic antigen Ma2 (PNMA2) forms icosahedral capsids that can be engineered for mRNA delivery
Authors: Madigan Victoria , Zhang Yugang , Raghavan Rumya , Wilkinson Max E. , Faure Guilhem , Puccio Elena , Segel Michael , Lash Blake , Macrae Rhiannon K. , Zhang Feng
Published: March 2024

A number of endogenous genes in the human genome encode retroviral
gag
-like proteins, which were domesticated from ancient retroelements. The paraneoplastic Ma antigen (PNMA) family members encode a
gag
-like capsid domain, but their ability to assemble as capsids and traffic between cells remains mostly uncharacterized. Here, we systematically investigate human PNMA proteins and find that a number of PNMAs are secreted by human cells. We determine that PNMA2 forms icosahedral capsids efficiently but does not naturally encapsidate nucleic acids. We resolve the cryoelectron microscopy (cryo-EM) structure of PNMA2 and leverage the structure to design engineered PNMA2 (ePNMA2) particles with RNA packaging abilities. Recombinantly purified ePNMA2 proteins package mRNA molecules into icosahedral capsids and can function as delivery vehicles in mammalian cell lines, demonstrating the potential for engineered endogenous capsids as a nucleic acid therapy delivery modality.
A 4,565-My-old record of the solar nebula field
Authors: Maurel Clara , Gattacceca Jérôme
Published: March 2024

Magnetic fields in protoplanetary disks are thought to play a prominent role in the formation of planetary bodies. Acting upon turbulence and angular momentum transport, they may influence the motion of solids and accretion onto the central star. By searching for the record of the solar nebula field preserved in meteorites, we aim to characterize the strength of a disk field with a spatial and temporal resolution far superior to observations of extrasolar disks. Here, we present a rock magnetic and paleomagnetic study of the andesite meteorite Erg Chech 002 (EC002). This meteorite contains submicron iron grains, expected to be very reliable magnetic recorders, and carries a stable, high-coercivity magnetization. After ruling out potential sources of magnetic contamination, we show that EC002 most likely carries an ancient thermoremanent magnetization acquired upon cooling on its parent body. Using the U-corrected Pb-Pb age of the meteorite’s pyroxene as a proxy for the timing of magnetization acquisition, we estimate that EC002 recorded a field of 60 ± 18 µT at a distance of ~2 to 3 astronomical units, 2.0 ± 0.3 My after the formation of calcium-aluminum-rich inclusions. This record can only be explained if EC002 was magnetized by the field prevalent in the solar nebula. This makes EC002’s record, particularly well resolved in time and space, one of the two earliest records of the solar nebula field. Such a field intensity is consistent with stellar accretion rates observed in extrasolar protoplanetary disks.
Chaotic turnover of rare and abundant species in a strongly interacting model community
Authors: Mallmin Emil , Traulsen Arne , De Monte Silvia
Published: March 2024

The composition of ecological communities varies not only between different locations but also in time. Understanding the fundamental processes that drive species toward rarity or abundance is crucial to assessing ecosystem resilience and adaptation to changing environmental conditions. In plankton communities in particular, large temporal fluctuations in species abundances have been associated with chaotic dynamics. On the other hand, microbial diversity is overwhelmingly sustained by a “rare biosphere” of species with very low abundances. We consider here the possibility that interactions within a species-rich community can relate both phenomena. We use a Lotka–Volterra model with weak immigration and strong, disordered, and mostly competitive interactions between hundreds of species to bridge single-species temporal fluctuations and abundance distribution patterns. We highlight a generic chaotic regime where a few species at a time achieve dominance but are continuously overturned by the invasion of formerly rare species. We derive a focal-species model that captures the intermittent boom-and-bust dynamics that every species undergoes. Although species cannot be treated as effectively uncorrelated in their abundances, the community’s effect on a focal species can nonetheless be described by a time-correlated noise characterized by a few effective parameters that can be estimated from time series. The model predicts a nonunitary exponent of the power-law abundance decay, which varies weakly with ecological parameters, consistent with observation in marine protist communities. The chaotic turnover regime is thus poised to capture relevant ecological features of species-rich microbial communities.