bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical coherence tomography imaging and noise characterization based on 1-μm microresonator frequency combs
Authors: Melton T. , McMillan J. F. , Yang J. , Wang W. , Lai Y. , Gerber M. , Rodriguez M. , Hubschman J. P. , Nouri-Mahdavi K. , Wong C. W.
Published: August 2024

Spectral-domain optical coherence tomography is a pervasive, non-invasive, in vivo biomedical imaging platform that currently utilizes incoherent broadband superluminescent diodes to generate interferograms from which depth and structural information are extracted. Advancements in laser frequency microcombs have enabled the chip-scale broadband generation of discrete frequency sources, with prior soliton and chaotic comb states examined in discrete spectral-domain optical coherence tomography at 1.3 μm. In this work, we demonstrate coherence tomography through Si3N4 microresonator laser frequency microcombs at 1 μm, achieving imaging qualities on-par with or exceeding the equivalent commercial optical coherence tomography system. We characterize the noise performance of our frequency comb states and additionally show that inherent comb line amplitude fluctuations in a chaotic state and the resultant tomograms can be compensated via multi-scan averaging.
Surface reconstructions and electronic structure of metallic delafossite thin films
Authors: Song Qi , He Zhiren , Faeth Brendan D. , Parzyck Christopher T. , Scheid Anna , Mowers Chad J. , Feng Yufan , Xu Qing , Hasko Sonia , Park Jisung , Barone Matthew R. , Suyolcu Y. Eren , van Aken Peter A. , Pamuk Betül , Fennie Craig J. , King Phil D. C. , Shen Kyle M. , Schlom Darrell G.
Published: August 2024

The growing interest in the growth and study of thin films of low-dimensional metallic delafossites, with the general formula ABO2, is driven by their potential to exhibit electronic and magnetic characteristics that are not accessible in bulk systems. The layered structure of these compounds introduces unique surface states as well as electronic and structural reconstructions, making the investigation of their surface behavior pivotal to understanding their intrinsic electronic structure. In this work, we study the surface phenomena of epitaxially grown PtCoO2, PdCoO2, and PdCrO2 films, utilizing a combination of molecular-beam epitaxy and angle-resolved photoemission spectroscopy. Through precise control of surface termination and treatment, we discover a pronounced 3×3 surface reconstruction in PtCoO2 films and PdCoO2 films, alongside a 2 × 2 surface reconstruction observed in PdCrO2 films. These reconstructions have not been reported in prior studies of delafossites. Furthermore, our computational investigations demonstrate the BO2 surface’s relative stability compared to the A-terminated surface and the significant reduction in surface energy facilitated by the reconstruction of the A-terminated surface. These experimental and theoretical insights illuminate the complex surface dynamics in metallic delafossites, paving the way for future explorations of their distinctive properties in low-dimensional studies.
Elastocaloric effect and cooling performance of NiTi sheets in a continuous rotating bending elastocaloric cooler
Authors: Cheng Siyuan , Sun Wanju , Li Xueshi , Zhang Jiongjiong
Published: August 2024

Elastocaloric cooling technology has the prospect of becoming a commercialized green alternative to current vapor-compression technology, and the systematic characterization of the elastocaloric effect and microstructure has become increasingly significant for the optimization of elastocaloric coolers and heat pumps. In this work, a comprehensive elastocaloric effect characterization for a dog-bone shaped NiTi sheet with a thickness of 0.5 mm was performed for the application in a compact continuous rotating bending elastocaloric cooler. The elastocaloric effect was found to be nearly identical under Brayton-like and sinusoidal force-controlled cyclic tensile loadings. The maximum adiabatic temperature change values of 31 and 23 K were recorded in Brayton-like cyclic loadings under maximum applied stress of 600 and 400 MPa, respectively, with an applied strain rate of 0.1 s−1. During fatigue tests, large applied stress (>600 MPa) and high applied strain rates (>0.1 s−1) tended to result in premature failure of the NiTi sheet samples. In the continuous rotating bending elastocaloric cooler, the sheets generated a temperature span of 6 K between the copper heat sink and heat source. The results of this work provide a set of thermophysical property data for the elastocaloric solid refrigerant and insights for the optimization of structural and operational parameters in elastocaloric coolers and heat pumps.
Dynamic mode decomposition of a flexible flag behind a semi-circular cylinder
Authors: Qadeer Abdul , Uddin Emad , Shahid Hanzla , Farukh Farukh , Awais Muhammad
Published: August 2024

The dynamics of a single flexible flag behind a semi-circular cylinder are investigated using vortex interaction study and dynamic mode decomposition (DMD). The problem is numerically solved using the immersed boundary method. For Reynolds number 300, by the variation of the streamwise gap between flag and bluff body (Dx), five regions, each exhibiting its unique pattern of flapping, from symmetric and periodic to chaotic, are identified by vortex interaction study. DMD and kernel-DMD are utilized for modal analysis and reconstruction of a viscous flow behind a semi-circular cylinder with a flexible flag located at a streamwise distance of Dx = 1.8 for moderate Reynolds number (Re = 30–500) with emphasis on representing the dynamics of the system using as few DMD modes as is practically possible. Sampling rate sensitivity study shows that low sampling rate data induce an additional frequency in the decomposition, which actually make up for the high frequency content in the vicinity of the flag and single frequency system is decomposed as the quasiperiodic system. According to the modal analysis, the fundamental frequency mode conjugate pair has the same frequency as the flag's vertical flapping and lift. It accounts for vortex production and advection from the bluff and flag and lift phenomenon. The first harmonic mode contains information regarding vortex shedding from the bluff body edges and flag tip and drag as they share same frequencies. DMD reconstruction demonstrates that 97.65% of the Re 100 post-transient system can be reconstructed using 28 DMD modes, whereas 86.71% of the Re 300 post-transient system requires 25 DMD modes. For fully transient cases, poor performance is achieved when using the DMD. The kernel-DMD application to full transient cases yields a non-oscillatory “mean mode,” a “shift mode,” and stable harmonic modes that are also present in post-transient analysis. The shift mode is famous in the modal analysis community, and it accounts for the correction to the mean mode for the transient region. In addition, these modes, there are additional modes that represent the transient dynamics of the system. 50 DMD modes reconstruct 86.98% and 77.65% of the Re 100 and Re 300 full-transient system, respectively.
Symmetry change in LaNiO3 films caused by epitaxial strain from LaAlO3, SrTiO3, and DyScO3 pseudocubic (001) surfaces
Authors: Izumisawa Fumiya , Ishii Yuta , Kimura Masatoshi , Katase Takayoshi , Kamiya Toshio , Yamaura Jun-ichi , Wakabayashi Yusuke
Published: August 2024

To elucidate the epitaxial strain effect over a wide range of lattice mismatch, we investigated the structures of ∼25 nm thick LaNiO3 films grown on the pseudocubic (001) surfaces of three different substrates, namely, LaAlO3 (LAO), SrTiO3 (STO), and DyScO3 (DSO). Such structural information had been inferred from the intensities of a small number of Bragg reflections that relate to the NiO6 octahedral tilting in previous studies. Here, we measured more than 100 reciprocal lattice points to derive reliable structural information. The procedure of ordinary crystal structure analysis is hampered by the multidomain structure and limited volume of measurable reciprocal space, both caused by a huge, highly symmetric substrate. To overcome this difficulty, we employed the Bayesian inference to obtain the detailed atomic positions in film samples. Octahedral tilting about the c axis was dominant for the compressively strained film grown on LAO, whereas tilting about the a and b axes was dominant for the tensile strained films grown on STO and DSO. The film lattice parameters of the samples grown on STO and DSO were nearly identical, whereas additional twofold lattice modulation, including cation displacement, was only observed in the latter.
Room temperature chiral magnetoresistance in a chiral-perovskite-based perpendicular spin valve
Authors: Kang Min-Gu , Hwang In-Kook , Kyung Hee-Chang , Kang Jaimin , Han Donghyeon , Lee Soogil , Kwon Junyoung , Lee Kyung-Jin , Yeom Jihyeon , Park Byong-Guk
Published: August 2024

Chirality-induced spin selectivity (CISS) allows for the generation of spin currents without the need for ferromagnets or external magnetic fields, enabling innovative spintronic device designs. One example is a chiral spin valve composed of ferromagnetic and chiral materials, in which the resistance depends on both the magnetization direction of the ferromagnet and the chirality of the chiral material. So far, chiral spin valves have predominately employed chiral organic molecules, which have limited device applications. Chiral perovskites, which combine the properties of inorganic perovskites with chiral organic molecules, provide an excellent platform for exploring CISS-based devices. However, previous chiral perovskite-based spin valves exhibited magnetoresistance (MR) only at low temperatures. Here, we report room temperature MR in a chiral spin valve consisting of chiral perovskites/AlOx/perpendicular ferromagnet structures. It is observed that the chiral MR increases with rising temperature, suggesting the crucial role of phonon-induced enhancement of spin–orbit coupling in CISS in our device. Furthermore, we enhanced the chiral MR by introducing chiral molecules with amplified chirality. This highlights the potential of chirality engineering to improve CISS and the associated chiral MR, thereby opening possibilities for chiral spin valves tailored for cutting-edge spintronic applications.
Interpretable machine learning for materials discovery: Predicting CO2 adsorption properties of metal–organic frameworks
Authors: Teng Yukun , Shan Guangcun
Published: August 2024

Metal–organic frameworks (MOFs), as novel porous crystalline materials with high porosity and a large specific surface area, have been increasingly utilized for CO2 adsorption. Machine learning (ML) combined with molecular simulations is used to identify MOFs with high CO2 adsorption capacity from millions of MOF structures. In this study, 23 structural and molecular features and 765 calculated features were proposed for the ML model and trained on a hypothetical MOF dataset for CO2 adsorption at different pressures. The calculated features improved the prediction accuracy of the ML model by 15%–20% and revealed its interpretability, consistent with the analysis of the interaction potential. Subsequently, the importance of the relevant features was ranked at different pressures. Regardless of the pressure, the molecular structure and pore size were the most critical factors. van der Waals force-related descriptors gained more competitive advantages at low pressures, whereas electrical-field-related descriptors gradually dominated at high pressures. Overall, this study provides a novel perspective to guide the initial high-throughput screening of MOFs as high-performance CO2 adsorption materials.
Numerical modeling of wave interaction with a porous floating structure consisting of uniform spheres
Authors: Dong Yiyong , Tan Weikai , Chen Hao , Yuan Jing
Published: August 2024

Porous materials are increasingly being used in the design of floating structures in coastal and ocean engineering, but there is a lack of numerical tools that can aid in the design of a movable floating porous structure. To close this gap, the existing volume-averaged numerical model for flow interacting with a fixed porous body was extended to floating scenarios by (1) using the relative velocity in the porous friction force, (2) calculating rigid body motion using volume integral of porous body force, and (3) modifying a dynamic mesh algorithm for a mobile porous body. As a demonstration, the developed model was applied to a porous floating structure consisting of cubically packed uniform spheres. Two sets of model applications were involved. The first set considered three-dimensional flow around a fixed porous block placed beneath the free surface. The measured total force on the block under wave or steady flows was predicted accurately with an error less than 10%. The second set involved a two-dimensional wave interacting with a floating porous block representing a breakwater. For free-floating conditions, the model can accurately predict the dynamic response of the structure, including the time varying movement of its rigid body and the mean drift. For mooring-restrained conditions, the mooring force and wave transmission coefficients were also predicted well with an error less than 20%. The proposed numerical approach can be applied to other floating structures with a rigid volumetric porous body. Future research is also required to study the microscopic pore flows, upon which more detailed parameterization of the porous media can be derived.
Electronic and vibrational spectroscopy of benzonitrile cation for astrochemical consideration
Authors: Daly F. C. , Douglas-Walker T. E. , Palotás J. , Anstöter C. S. , Zheng A. , Campbell E. K.
Published: August 2024

The electronic and vibrational spectra of benzonitrile cation, C6H5CN+ (BZN+), in the gas phase at low temperatures are reported. Measurements were carried out using a cryogenic ion trapping apparatus. The mid-infrared spectrum shows a strong CN stretch at 2130 ± 1 cm−1 (4.694 ± 0.002 µm). The electronic spectrum is reported in the range 5040–5750 Å. This covers the forbidden B2B2 ← X2B1 and allowed C2B1 ← X2B1 transitions. The spectrum is dominated by a broad absorption feature at wavelengths shorter than 5250 Å, with the strongest absorption located at 5140 Å. Experimental data are complemented with quantum chemical calculations carried out at the density functional theory and extended multi-configurational quasi-degenerate perturbation theory level. The spectroscopic results are discussed in the context of astronomical observations in the infrared and visible.
Designing building blocks of covalent organic frameworks through on-the-fly batch-based Bayesian optimization
Authors: Yao Yuxuan , Oberhofer Harald
Published: August 2024

In this work, we use a Bayesian optimization (BO) algorithm to sample the space of covalent organic framework (COF) components aimed at the design of COFs with a high hole conductivity. COFs are crystalline, often porous coordination polymers, where organic molecular units—called building blocks (BBs)—are connected by covalent bonds. Even though we limit ourselves here to a space of three-fold symmetric BBs forming two-dimensional COF sheets, their design space is still much too large to be sampled by traditional means through evaluating the properties of each element in this space from first principles. In order to ensure valid BBs, we use a molecular generation algorithm that, by construction, leads to rigid three-fold symmetric molecules. The BO approach then trains two distinct surrogate models for two conductivity properties, level alignment vs a reference electrode and reorganization free energy, which are combined in a fitness function as the objective that evaluates BBs’ conductivities. These continuously improving surrogates allow the prediction of a material’s properties at a low computational cost. It thus allows us to select promising candidates which, together with candidates that are very different from the molecules already sampled, form the updated training sets of the surrogate models. In the course of 20 such training steps, we find a number of promising candidates, some being only variations on already known motifs and others being completely novel. Finally, we subject the six best such candidates to a computational reverse synthesis analysis to gauge their real-world synthesizability.
Controllable growth of two-dimensional wrinkled WSe2 nanostructures via chemical vapor deposition based on thermal mismatch strategy
Authors: Hao Shijie , Hao Yulong , Li Jin , Wang Kaiyi , Fan Chen , Zhang Shiwei , Wei Yuehua , Hao Guolin
Published: August 2024

Two-dimensional (2D) transition metal dichalcogenides (TMDs) semiconductors are considered to be promising candidates for extending Moore's law. 2D TMDs with tunable wrinkled nanostructures can effectively modulate their optoelectronic properties. However, the controlled synthesis of large-area TMDs wrinkled nanostructures remains a major challenge. In this work, 2D WSe2 wrinkled nanostructures were prepared on soda-lime glass substrate by ambient pressure chemical vapor deposition based on the thermal mismatch-induced strategy. WSe2 wrinkled nanostructures can be further precisely controlled by adjusting the growth temperature and substrate thickness. In addition, the growth mechanism of WSe2 wrinkled nanostructures was revealed according to systematic experimental characterization. Corresponding results indicate that the photoluminescence and surface potential of WSe2 were associated with wrinkled nanostructures. The controllable synthesis strategy of 2D WSe2 wrinkled nanostructures has been developed, which can provide important experimental and theoretical support for exploring the applications of 2D wrinkled nanostructures in the field of strain sensing, optoelectronics, and nonlinear optical devices.
The importance of the location of the N-terminus in successful protein folding in vivo and in vitro
Authors: Dall Natalie R. , Mendonça Carolina A. T. F. , Torres Vera Héctor L. , Marqusee Susan
Published: August 2024

Protein folding in the cell often begins during translation. Many proteins fold more efficiently cotranslationally than when refolding from a denatured state. Changing the vectorial synthesis of the polypeptide chain through circular permutation could impact functional, soluble protein expression and interactions with cellular proteostasis factors. Here, we measure the solubility and function of every possible circular permutant (CP) of HaloTag in
Escherichia coli
cell lysate using a gel-based assay, and in living
E. coli
cells via FACS-seq. We find that 78% of HaloTag CPs retain protein function, though a subset of these proteins are also highly aggregation-prone. We examine the function of each CP in
E. coli
cells lacking the cotranslational chaperone trigger factor and the intracellular protease Lon and find no significant changes in function as a result of modifying the cellular proteostasis network. Finally, we biophysically characterize two topologically interesting CPs in vitro via circular dichroism and hydrogen–deuterium exchange coupled with mass spectrometry to reveal changes in global stability and folding kinetics with circular permutation. For CP33, we identify a change in the refolding intermediate as compared to wild-type (WT) HaloTag. Finally, we show that the strongest predictor of aggregation-prone expression in cells is the introduction of termini within the refolding intermediate. These results, in addition to our finding that termini insertion within the conformationally restrained core is most disruptive to protein function, indicate that successful folding of circular permutants may depend more on changes in folding pathway and termini insertion in flexible regions than on the availability of proteostasis factors.
An AAGAB-to-CCDC32 handover mechanism controls the assembly of the AP2 adaptor complex
Authors: Wan Chun , Puscher Harrison , Ouyang Yan , Wu Jingyi , Tian Yuan , Li Suzhao , Yin Qian , Shen Jingshi
Published: August 2024

Vesicular transport relies on multimeric trafficking complexes to capture cargo and drive vesicle budding and fusion. Faithful assembly of the trafficking complexes is essential to their functions but remains largely unexplored. Assembly of AP2 adaptor, a heterotetrameric protein complex regulating clathrin-mediated endocytosis, is assisted by the chaperone AAGAB. Here, we found that AAGAB initiates AP2 assembly by stabilizing its α and σ2 subunits, but the AAGAB:α:σ2 complex cannot recruit additional AP2 subunits. We identified CCDC32 as another chaperone regulating AP2 assembly. CCDC32 recognizes the AAGAB:α:σ2 complex, and its binding leads to the formation of an α:σ2:CCDC32 ternary complex. The α:σ2:CCDC32 complex serves as a template that sequentially recruits the µ2 and β2 subunits of AP2 to complete AP2 assembly, accompanied by CCDC32 release. The AP2-regulating function of CCDC32 is disrupted by a disease-causing mutation. These findings demonstrate that AP2 is assembled by a handover mechanism switching from AAGAB-based initiation complexes to CCDC32-based template complexes. A similar mechanism may govern the assembly of other trafficking complexes exhibiting the same configuration as AP2.
DNA-DISK: Automated end-to-end data storage via enzymatic single-nucleotide DNA synthesis and sequencing on digital microfluidics
Authors: Li Kunjie , Lu Xiaoyun , Liao Jiaqi , Chen Heng , Lin Wei , Zhao Yuhan , Tang Dongbao , Li Congyu , Tian Zhenyang , Zhu Zhi , Jiang Huifeng , Sun Jun , Zhang Huimin , Yang Chaoyong
Published: August 2024

In the age of information explosion, the exponential growth of digital data far exceeds the capacity of current mainstream storage media. DNA is emerging as a promising alternative due to its higher storage density, longer retention time, and lower power consumption. To date, commercially mature DNA synthesis and sequencing technologies allow for writing and reading of information on DNA with customization and convenience at the research level. However, under the disconnected and nonspecialized mode, DNA data storage encounters practical challenges, including susceptibility to errors, long storage latency, resource-intensive requirements, and elevated information security risks. Herein, we introduce a platform named DNA-DISK that seamlessly streamlined DNA synthesis, storage, and sequencing on digital microfluidics coupled with a tabletop device for automated end-to-end information storage. The single-nucleotide enzymatic DNA synthesis with biocapping strategy is utilized, offering an ecofriendly and cost-effective approach for data writing. A DNA encapsulation using thermo-responsive agarose is developed for on-chip solidification, not only eliminating data clutter but also preventing DNA degradation. Pyrosequencing is employed for in situ and accurate data reading. As a proof of concept, DNA-DISK successfully stored and retrieved a musical sheet file (228 bits) with lower write-to-read latency (4.4 min of latency per bit) as well as superior automation compared to other platforms, demonstrating its potential to evolve into a DNA Hard Disk Drive in the future.
Chinese parents’ involvement in their young children’s app-based language learning
Authors: Bang Hee Jin , Mackey Alison
Published: August 2024

Parents and other primary caregivers play a critical role in shaping the environment in which their children
develop language and literacy skills. Relatively little, however, is known about caregiver involvement in their children’s foreign
language learning, especially when using a self-guided language learning app. This study focuses on whether and how Chinese
parents and caregivers contribute to their young children’s English language learning as children use a digital game-based
learning app to develop their English skills. Data collected from a larger efficacy study through interviews, focus groups, and
surveys were examined to uncover information about how the app was effective and how parents and caregivers shaped their
children’s language learning experiences. Results indicated that parents can be and often are involved in their children’s
app-based language learning experiences, and that parental involvement can mediate learning. Results also suggest that time spent
on digital media can be effectively leveraged by parents for educational purposes and parents who allow their children greater
independence may more readily foster their children’s ability to achieve higher English language skills.
4.11-million Q-factor whole-angle MEMS hemispherical resonator gyroscope with 0.013°/h bias instability
Authors: Li Bei , Li ZhuoNan , Wang Xi , Huang ChengHao , Yang Bo
Published: August 2024

The MEMS μHRG offers high potential in achieving a high quality factor (Q-factor) and the corresponding detection accuracy, thus holding significant prospects for applications in the field of high-precision inertial measurement. This paper introduces a whole-angle (WA) mode MEMS hemispherical resonator gyroscope (WA-μHRG) with a high Q-factor (4.11 million) and presents a WA mode control scheme. Specifically, the paper establishes a frequency tuning technique that leverages precession angle control and quadrature control loop switching. Adjusting the quadrature control loop at special precession angles can effectively achieve alignment of the stiffness axis and reduction of frequency split. The impacts of frequency mismatch on the WA gyroscope were investigated through simulations, which validated the efficacy of mode matching in improving the accuracy and performance of gyro, as evidenced by the reduction in angle-dependent bias (ADB) drift. Experimental results demonstrate that this method can reduce the frequency difference from initial 110 mHz to 3.91 mHz. In the presence of mode matching, the ADBs drift dropped by 81.39%, from 2.586°s−1 to 0.481°s−1. Ultimately, the WA-μHRG exhibits an angular gain of 0.695, a bandwidth of 12 Hz, and a measurement range of ±500°s−1. More importantly, the gyro achieves a bias instability of 0.013°h−1.
Leukocyte-based delivery systems for enhanced nanotheranostics of inflammation and cancer
Authors: Li Helin , Song Fangyin , Chu Yu , Su Weike , Li Xin , Yang Mengshi
Published: August 2024

As a part of the immune system, leukocytes (LEs) have the features of circumvention of immunogenicity as well as recruitment to sites of inflammation during infection and tumorigenesis. Utilizing LEs as vehicles to carry theranostic agents is a promising strategy for highly efficient targeted delivery and treatment for inflammation and cancer. Specifically, the LEs, similar to ‘Trojan horses’, can bypass the immune system and thus enhance the therapeutic effects on inflammation and cancer. In this context, the latest progress of LEs-based delivery systems for improving theranostics of inflammations and cancers is summarized, including in vitro incubation and in vivo internalization strategy. Although the therapeutic efficacy of LEs-based delivery systems has been achieved, the system construction is complex and the effect is not fulfilling demand completely. Encouragingly, a most recent work reported that the supramolecular arrangement of proteins on the nanocarriers would drive them to be selectively uptaken by neutrophils, opening a new avenue for diagnosis and treatment of inflammation. Moreover, enucleated cells are considered as the biomimetic drug delivery vehicle to retain the organelles for a range of diseases in a safe, controllable and effective manner. These novel findings provide more opportunities for researchers to rethink and redesign the LEs-based delivery systems to overcome existing limitations and broaden their usage, especially in clinical medicine.
ThunderBoltz: an open-source direct simulation Monte Carlo Boltzmann solver for plasma transport, chemical kinetics, and 0D modeling
Authors: Park Ryan , Scheiner Brett S , Zammit Mark C
Published: August 2024

Plasma-neutral interactions, including reactive kinetics, are often either studied in 0D using ODE-based descriptions, or in multi-dimensional fluid or particle-based plasma codes. The latter case involves a complex assembly of procedures that are not always necessary to test effects of underlying physical models and mechanisms for particle-based descriptions. Here we present ThunderBoltz, a lightweight, publicly available 0D direct simulation Monte Carlo code designed to accommodate a generalized combination of species and arbitrary cross sections without the overhead of expensive field solves. It can produce electron, ion, and neutral velocity distributions in applied AC/DC E-field and/or static B-field scenarios. The code is built in the C++ standard library and includes a convenient Python interface that allows for input file generation (including compatibility with cross section data from the LXCat database), electron transport and reaction rate constant post-processing, input parameter constraint satisfaction, calculation scheduling, and diagnostic plotting. These codes can be accessed at the repository: https://github.com/lanl/ThunderBoltz. In this work we compare ThunderBoltz transport calculations against Bolsig+ calculations, benchmark test problems, and swarm experiment data, finding good agreement with all three in the appropriate field regimes. In addition, we present example use cases where the electron, ion, and background neutral particle species are self-consistently evolved to model the background kinetics, a feature that is absent in fixed-background Monte Carlo and n-term Boltzmann solvers. The latter functionality allows for the possibility of particle-based chemical kinetics simulations of the plasma and neutral species as a new alternative to ODE-based approaches.
The investigation of synergistic interactions between CO2 plasma and porous catalysts through 2-D fluid modeling
Authors: Li Kangkang , Lei Xiaoting , Cheng He , Zhang Wenchao , Lu Xinpei
Published: August 2024

The efficiency of plasma-coupled catalysis is believed to be higher than the sum of the efficiencies of the plasma and catalyst when acting independently. However, the underlying microscopic interaction mechanism responsible for this phenomenon remains systematically unexplored. This paper presents an initial demonstration of the combined effects of complex porous-structured catalysts and CO2 plasma using a two-dimensional fluid dynamics model. The study attests to the contribution of the catalyst’s porous structure in enhancing the electric field intensity, facilitating ‘hotspot’ formation, accelerating plasma development, improving ionization rate, as well as increasing the density of electrons, reactive heavy species, and products. It also uncovers the ability of plasma to penetrate into the surface pores of the catalytic bead, and the potential occurrence of micro-discharges within catalyst interior pores. Meanwhile, the reactive species of plasma such as the energetic electrons and the vibrationally/electronically excited CO2 in plasma may also impact the surface processes of the catalyst through mechanisms such as reducing reaction barriers. The successful replication of these interactions underscores the potential of this model as a valuable tool for investigating the efficiency optimization of plasma-enhanced catalytic conversion of CO2.
Observation ofγγ→ττin proton–proton collisions and limits on the anomalous electromagnetic moments of the τ lepton
Authors: CMS Collaboration The
Published: August 2024

The production of a pair of τ leptons via photon–photon fusion,γγ→ττ, is observed for the first time in proton–proton collisions, with a significance of 5.3 standard deviations. This observation is based on a data set recorded with the CMS detector at the LHC at a center-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 138 fb−1. Events with a pair of τ leptons produced via photon–photon fusion are selected by requiring them to be back-to-back in the azimuthal direction and to have a minimum number of charged hadrons associated with their production vertex. The τ leptons are reconstructed in their leptonic and hadronic decay modes. The measured fiducial cross section ofγγ→ττisσobsfid=12.4−3.1+3.8fb. Constraints are set on the contributions to the anomalous magnetic moment (aτ) and electric dipole moments (dτ) of the τ lepton originating from potential effects of new physics on theγττvertex:aτ=0.0009−0.0031+0.0032and|dτ|<2.9×10−17ecm(95% confidence level), consistent with the standard model.
Development of pre-magnetized magnetorheological elastomer for bidirectionally variable stiffness applications
Authors: Lee Choonghan , Yim Woosoon
Published: August 2024

Magnetorheological elastomers (MREs) are materials that leverage magnetic forces among ferromagnetic particles to induce variable stiffness and damping under external magnetic fields. However, conventional MREs have limitations in achieving reduced stiffness when exposed to an external magnetic field. In response to the need for rapid and bidirectional changes in stiffness, this research proposes a novel approach—pre-magnetized MREs—using permanently magnetized ferromagnetic particles instead of an external permanent magnet for magnetic bias. The pre-magnetized MRE, fabricated with silica-coated neodymium alloy particles and silicone elastomer, undergoes a comprehensive investigation of design parameters, including silicone resin selection, particle thickness, size, and weight ratio. The study explores the directional effects of pre-magnetization through simulations, considering forces among magnetized particles and the hyperelasticity of the elastomer. Experimental investigations involve measuring shear moduli for different shear strains under varying magnetization directions. The results highlight the impact of resin type, particle size, and weight ratio on the magnetorheological (MR) effect. Additionally, an application testbed is developed to assess bi-directional changes in stiffness for various core materials. The study reveals a correlation between MR effect/response time and the magnetic permeabilities of core materials, along with the attraction and repulsion forces between the core and magnetized particles. Observations indicate that the MR effect for different core materials ranges from 0.08% to 0.25%, with response times measured at 40 and 46 ms for forward and reverse currents, respectively. The findings contribute valuable insights into optimizing the design and performance of pre-magnetized MREs for enhanced bi-directional stiffness control in engineering applications.
Contraction of ZX diagrams with triangles via stabiliser decompositions
Authors: Koch Mark , Yeung Richie , Wang Quanlong
Published: August 2024

Recent advances in classical simulation of Clifford+T circuits make use of the ZX calculus to iteratively decompose and simplify magic states into stabiliser terms We improve on this method by studying stabiliser decompositions of ZX diagrams involving the triangle operation. We show that this technique greatly speeds up the simulation of quantum circuits involving multi-controlled gates which can be naturally represented using triangles. We implement our approach in the QuiZX library (2022 A. Kissinger amd J. van de Wetering Quantum Science and Technology
7, 044001), (2022 A. Kissinger et al F. Le Gall and T. Morimae, ed. 17th Conference on the Theory of Quantum Computation, Communication and Cryptography (TQC 2022), Leibniz International Proceedings in Informatics (LIPIcs) 232, Schloss Dagstuhl—Leibniz-Zentrum für Informatik, Dagstuhl, Germany, pp 5:1–5:13) and demonstrate a significant simulation speed-up (up to multiple orders of magnitude) for random circuits and a variation of previously used benchmarking circuits. Furthermore, we use our software to contract diagrams representing the gradient variance of parametrised quantum circuits, which yields a tool for the automatic numerical detection of the barren plateau phenomenon in ansätze used for quantum machine learning. Compared to traditional statistical approaches, our method yields exact values for gradient variances and only requires contracting a single diagram. The performance of this tool is competitive with tensor network approaches, as demonstrated with benchmarks against the quimb library (2018 J. Gray Journal of Open Source Software
3, 819).
First-principles study of vacancy-impurity (C, N, O) interactions in vanadium
Authors: Pan Shilong , Zhang Honglin , Wang Yanhui , Yang Ruizhe , Xu Bin , Ma Hui , Lv Xuewei , Sun Mingyue
Published: August 2024

Interstitial impurities of C, N, and O typically exist in V and its alloys, which have significant effects on the structure and properties of the materials due to their strong interaction with the vacancies. In this study, the structure and energy properties of vacancy-impurity complexes in V are comprehensively investigated by first principles calculations. The effects of impurity concentration and temperature on the concentration distribution of the complexes were studied using statistical methods. The results showed that the Vac

n

X
2 complexes exhibit a high sequential binding energy. There is an evident mutual attraction between the vacancy and the O atom, and it has a higher affinity than the C or N atom. The simple defect complexes of Vac
1
X
1–2 have always been the most abundant type of complex defect in V. The trapping effect of vacancy on C, N, and O atom is very significant at low temperatures rather than at high temperatures. This study would broaden the understanding of vacancy-impurity interactions in vanadium and provide new insights into the influence of C, N, and O on vacancy defect concentrations.
Consequence of coherent Cu5Zr precipitates and Cu2O passive layer formation on the corrosive behaviour of additively processed Cu-Cr-Zr alloy in simulated seawater
Authors: Jeyaprakash N , Kumar M Saravana , Alnaser Ibrahim A , Yang Che-Hua
Published: August 2024

The Cu-Cr-Zr copper alloy is known for its outstanding electrical conductivity and fatigue strength. However, the corrosion behaviour of the copper alloy should also be taken into account when adopting it in industrial applications, especially in the marine environments. This research aims to fabricate Cu alloy coupons using the Laser Powder Bed Fusion (LPBF) technique and subsequently test their corrosive performance in simulated seawater. This research confirms that the Cu5Zr precipitate formation during the LPBF process and the Cu2O passive layer formation were the main reason for the enhanced corrosive behavior of the LPBFed copper alloy. The OM (Optical Microscope), FESEM (Field Emission Scanning Electron Microscope) images supported in evaluating melt pool formations and irregularities, and also confirmed the polycrystalline structure. The diffraction pattern from the TEM (Transmission Electron Microscope) analysis confirmed the formation of Cu5Zr precipitate and grain size distribution, while their orientations were obtained from the EBSD (Electron Based Scattered Diffraction) EBSD analysis. Micro hardness was executed on the scanning and building directions, and it was found that the building direction possessed higher hardness of 54 HV0.3 which was 5% higher than in the scanning direction. This significant fluctuation in the hardness value is due to the closely packed equiaxed and columnar grains along the outer and inner regions of the melt pools. Potentio-dynamic polarization (PD) and electrochemical impedance spectroscopy (EIS) tests were performed on the printed copper alloy parts for various immersion periods of 0, 9, 18 and 38 h. Further, the XRD (x-ray Diffraction) analysis was performed on the corroded surface and it confirmed the Cu2O passive layer and the occurrence of Cu5Zr precipitate. The occurrence of Cu5Zr precipitates and Cu2O passive layer formation helped attain the maximum polarization resistance of 2033.8 ohm and minimum current density of 5.928 × 10−6 A cm−2 with minimum surface roughness of 3.447 μm.
Shannon entropy of a particle on a conical surface
Authors: Arvizu L M , Castaño E , Aquino N
Published: August 2024

In this work we solve the time-independent Schrödinger equation of a particle restricted to move on the surface of a circular cone of finite height. The energy eigenvalues, as well as the corresponding wave functions, are obtained analytically as a function of,

r

and

ϕ
,

the radial distance to the apex,

0
≤
r
≤

r

0

,

and the angular variable around the axis of the cone. We compute the Shannon entropy of this system in both configuration and momentum space as a function of

r

0

and

θ

0

,

the angular semi-aperture of the cone. In configuration space, the Shannon entropy decreases, signalling a more pronounced localization, as either

r

0

or

θ

0

diminish; in momentum space, an opposite behaviour happens, i.e., the Shannon entropy increases when either,

r

0

or

θ

0

,

decrease. We also compute the radial standard deviation; we find that the Shannon entropy better describes the localization-delocalization phenomena. The present results agree with those previously published for a particle confined to a circle of radius

r

0

,

which corresponds to

θ

0

=
π
/
2

in the present case.
Photovoltaic array fault detection based on a new model of series equivalent resistance
Authors: Pei Tingting , Wang Hao , Chen Wei , Wang Shuo , Pan Duoyi
Published: August 2024

To address the difficulty of detecting photovoltaic array faults using photovoltaic array model parameters in photovoltaic power stations, a photovoltaic array fault detection method based on a new series equivalent resistance model is proposed. In this method, first, a mathematical model of the series equivalent resistance of a photovoltaic module is established based on the single-diode model of the photovoltaic module using the characteristics of this module when it operates at the maximum power point, short circuit and open circuit. Second, a new model of the series equivalent resistance of the photovoltaic array is obtained based on the mathematical model of the series equivalent resistance of the newly constructed photovoltaic module, and a series equivalent resistance fault detection model is proposed under short-circuit, degradation and shadow faults. Finally, the proposed new model of the series equivalent resistance of photovoltaic arrays is compared with three existing mathematical models to verify its validity and accuracy. Simultaneously, the series equivalent resistance fault detection model is verified in the case of short-circuit, degradation and shadow faults of photovoltaic arrays.
A semi-analytical solutions of the multi-dimensional time-fractional Klein-Gordon equations using residual power series method
Authors: Meena Rakesh Kumar , Kumar Sushil
Published: August 2024

This study presents a novel approach to getting a semi-analytical solution to the multi-dimensional time-fractional linear and nonlinear Klein–Gordon equations with appropriate initial conditions using the residual power series method. The time-fractional derivative (β) is used in the context of the Caputo approach. Some test examples of KGEs are considered to illustrate the validity and efficiency of the employed RPS method. The RPS solutions are compared with the exact solutions for β = 2 to ensure the method’s reliability and precision. The error bound and convergence analysis of the proposed method are also examined. The effects of the distinct values of fractional order β ∈ (1, 2] on the behavior of the proposed equations are also discussed.
Laplacian and bilateral weighted relative total variation sparse angle CT reconstruction
Authors: Du Xiaoshuang , Kong Huihua , Pan Jinxiao , Qi Ziwen , Li Jiaxin
Published: August 2024

Reconstruction of computed tomography (CT) images under sparse data conditions often leads to compromised quality, which can result in diagnostic inaccuracies. This study introduces a novel iterative reconstruction algorithm that combines a second-order differential Laplacian operator with a bilateral weighted relative total variation model to enhance the CT image quality from sparse datasets. The approach is designed to efficiently capture sharp edges and fine textures while reducing noise and maintaining critical edge features. Numerical simulations and preliminary clinical testing demonstrate that the algorithm significantly reduces streak artifacts and improves edge clarity, outperforming traditional methods in both qualitative and quantitative analyses. In summary, the developed iterative reconstruction algorithm substantially enhances the reconstruction quality of CT images with sparse data, showing significant advantages over conventional techniques, and promises to significantly improve the accuracy and reliability of clinical imaging diagnostics.
Study on low-mid-frequency broadband sound absorption properties of bending acoustic metamaterials with embedded porous materials
Authors: Zeng Qiuyu , Xu Tao , Liu Yang , Dusengumuremyi Victor , Cheng Baozhu , Hou Hong
Published: August 2024

With the rapid development of the traffic industry, noise issues are becoming increasingly serious, and the traditional noise control technologies have the problems of poor low-frequency noise absorption and narrow bandwidth. This study proposes a variable-section bending acoustic metamaterial with an embedded porous material (VS_BAMP). A theoretical model of the VS_BAMP unit is developed based on the Johnson-Champoux-Allard (JCA) model and the impedance transfer method. The sound absorption unit with a thickness of 48 mm exhibits a quasi-perfect (α = 0.98) at 736 Hz, and an efficient sound absorption (α > 0.8) in the range of 574 Hz–966 Hz. Based on the complex frequency plane method, this work designs sound absorption units that exhibit perfect sound absorption at discrete frequencies. By connecting two different absorption units (PVS_BAMP) in parallel, efficient sound absorption from 424 Hz to 1500 Hz is achieved. Finally, the accuracy of the theoretical model is verified by experiments and simulations, confirming the effective sound absorption of PVS_BAMP structure in the middle and low frequency bands. The prepared PVS_BAMP is highly adjustable, has a wide bandwidth, and can be prepared through a simple manufacturing process. Our results can provide a theoretical basis for the design of compact low-mid-frequency broadband noise reduction structures for practical application.
Systematic investigation of physical properties of Mg3XO4 (X = Cr, Mn, Fe, Co, Ni); a computational approach
Authors: Al Selgin , İyigör Ahmet , Körlü Ali , Arikan Nihat
Published: August 2024

Material development is primarily dependent on their design and theoretical exploration. Density functional theory is a great tool to achieve this goal. Here, Mg3XO4 (X = Cr, Mn, Fe, Co, Ni) are considered in order to reveal their full characteristics using density functional theory. Mg3XO4 (X = Cr, Mn, Fe, Co, Ni) are investigated in terms of their structural, elastic, mechanical, thermodynamic, electronic, and dynamic properties. The formation energies for Mg3XO4 (X = Cr, Mn, Fe, Co, Ni) are found to be negative implying synthesisability and dynamic stability of these materials. The evolution of elastic constants of materials demonstrates that all materials satisfy the Born stability criterion, hence Mg3XO4 (X = Cr, Mn, Fe, Co, Ni) are mechanically stable. Several polycrystalline parameters are derived by using elastic constants and evaluated. All materials are found be brittle, hard (Vickers hardness) and magnetic. They exhibit some degree of anisotropy in Young/Shear modulus and Poisson’s ratio. The electronic band structures for Mg3CrO4, Mg3MnO4 and Mg3FeO4 indicated a semi-metallic nature whereas for Mg3CoO4 and Mg3NiO4 indicated metallic nature because both the majority and minority energy bands cut the Fermi level. The phonon modes are found to be in positive frequencies that confirms dynamical stability. The materials’ free energy, entropy, specific heat capacity, Debye and melting temperatures, minimum thermal conductivity and Grüneisen parameters are also obtained and discussed.