bluuebunny/crossref_metadata_2025 huggingface dataset:
Patterned magnetophotonic crystal for all-optical magnetization precession generation
Authors: Borovkova O. , Kolosvetov A. , Kalish A. , Chernov A. , Belotelov V.
Published: January 2024

A magnetophotonic crystal (MPC) with a locally etched magnetic layer is proposed for all-optical excitation of magnetization precession in the confined area. When the sample is illuminated by circularly polarized monochromatic plane wave, the optical MPC mode and the effective magnetic field excited by the inverse Faraday effect are localized inside the etched area. Therefore, the optical impact on the spin system in a magnetically ordered medium becomes confined in both lateral directions on the order of tens of nanometers and along the film thickness serving as a nanoconfined source of spin waves. The dependence of the spatial distribution of the effective magnetic field and magnetization precession amplitude on the depth and dimensions of the etched area are addressed. A proposed design of the MPC can find its applications in the field of magnetization dynamics generation as a compact and stable source of the spin waves that allows compact arrangement of the sources for some complex spin waves excitations.
Understanding of magnetization reversal mechanism of precipitation-hardening samarium-cobalt magnets from micromagnetic simulation
Authors: Liu Manying , Li Yuqing , Zhang Dongtao , Wu Qiong , Yang Jianjun , Zhang Hongguo , Zhang Lele , Yue Ming
Published: January 2024

The precipitation-hardening Sm-Co magnets not only have irreplaceable applications under extreme conditions such as high temperatures, but are also the most typical magnets with pinning-controlled magnetization reversal mechanism. However, there have always been two views on this type of pinning, attractive or repulsive. In this article, the modification of the parallel interface to the titled interface, led to occurrence of quasi-repulsive and quasi-attractive pinning modes, by employing micromagnetic simulation methods. The corresponding domain wall energy relationship between the pinning phase and main phase was analyzed for different pinning modes, according to the morphology of domain wall from the simulation results. The analysis results indicated that relatively small difference in domain wall energy between the two phases led to quasi-repetitive and quasi-attractive pinning modes. Our findings can provide a reference for further understanding of the magnetization reversal mechanism of precipitation-hardening Sm-Co magnets. The emphasis on the influence of 1:5/2:17 interface orientation on pinning also provided a perspective on the magnetization reversal mechanism of other nanostructured permanent magnet materials.
Adaptive control of transonic buffet and buffeting flow with deep reinforcement learning
Authors: Ren Kai , Gao Chuanqiang , Xiong Neng , Zhang Weiwei
Published: January 2024

The optimal control of flow and fluid–structure interaction (FSI) systems often requires an accurate model of the controlled system. However, for strongly nonlinear systems, acquiring an accurate dynamic model is a significant challenge. In this study, we employ the deep reinforcement learning (DRL) method, which does not rely on an accurate model of the controlled system, to address the control of transonic buffet (unstable flow) and transonic buffeting (structural vibration). DRL uses a deep neural network to describe the control law and optimizes it based on data obtained from interaction between control law and flow or FSI system. This study analyzes the mechanism of transonic buffet and transonic buffeting to guide the design of control system. Aiming at the control of transonic buffet, which is an unstable flow system, the control law optimized by DRL can quickly suppress fluctuating load of buffet by taking the lift coefficient as feedback signal. For the frequency lock-in phenomenon in transonic buffeting flow, which is an unstable FSI system, we add the moment coefficient and pitching displacement to feedback signal to observe pitching vibration mode. The control law optimized by DRL can also effectively eliminate or reduce pitching vibration displacement of airfoil and buffet load. The simulation results in this study show that DRL can adapt to the control of two different dynamic modes: typical forced response and FSI instability under transonic buffet, so it has a wide application prospect in the design of control laws for complex flow or FSI systems.
Self-terminating, heterogeneous solid–electrolyte interphase enables reversible Li–ether cointercalation in graphite anodes
Authors: Xia Dawei , Jeong Heonjae , Hou Dewen , Tao Lei , Li Tianyi , Knight Kristin , Hu Anyang , Kamphaus Ethan P. , Nordlund Dennis , Sainio Sami , Liu Yuzi , Morris John R. , Xu Wenqian , Huang Haibo , Li Luxi , Xiong Hui , Cheng Lei , Lin Feng
Published: January 2024

Ether solvents are suitable for formulating solid-electrolyte interphase (SEI)-less ion-solvent cointercalation electrolytes in graphite for Na-ion and K-ion batteries. However, ether-based electrolytes have been historically perceived to cause exfoliation of graphite and cell failure in Li-ion batteries. In this study, we develop strategies to achieve reversible Li–solvent cointercalation in graphite through combining appropriate Li salts and ether solvents. Specifically, we design 1M LiBF
4
1,2-dimethoxyethane (G1), which enables natural graphite to deliver ~91% initial Coulombic efficiency and >88% capacity retention after 400 cycles. We captured the spatial distribution of LiF at various length scales and quantified its heterogeneity. The electrolyte shows self-terminated reactivity on graphite edge planes and results in a grainy, fluorinated pseudo-SEI. The molecular origin of the pseudo-SEI is elucidated by ab initio molecular dynamics (AIMD) simulations. The
operando
synchrotron analyses further demonstrate the reversible and monotonous phase transformation of cointercalated graphite. Our findings demonstrate the feasibility of Li cointercalation chemistry in graphite for extreme-condition batteries. The work also paves the foundation for understanding and modulating the interphase generated by ether electrolytes in a broad range of electrodes and batteries.
Coexistence of many species under a random competition–colonization trade-off
Authors: Miller Zachary R. , Clenet Maxime , Della Libera Katja , Massol François , Allesina Stefano
Published: January 2024

The competition–colonization (CC) trade-off is a well-studied coexistence mechanism for metacommunities. In this setting, it is believed that the coexistence of all species requires their traits to satisfy restrictive conditions limiting their similarity. To investigate whether diverse metacommunities can assemble in a CC trade-off model, we study their assembly from a probabilistic perspective. From a pool of species with parameters (corresponding to traits) sampled at random, we compute the probability that any number of species coexist and characterize the set of species that emerges through assembly. Remarkably, almost exactly half of the species in a large pool typically coexist, with no saturation as the size of the pool grows, and with little dependence on the underlying distribution of traits. Through a mix of analytical results and simulations, we show that this unlimited niche packing emerges as assembly actively moves communities toward overdispersed configurations in niche space. Our findings also apply to a realistic assembly scenario where species invade one at a time from a fixed regional pool. When diversity arises de novo in the metacommunity, richness still grows without bound, but more slowly. Together, our results suggest that the CC trade-off can support the robust emergence of diverse communities, even when coexistence of the full species pool is exceedingly unlikely.
Engineering peroxisomal biosynthetic pathways for maximization of triterpene production in
Yarrowia lipolytica
Authors: Ma Yongshuo , Shang Yi , Stephanopoulos Gregory
Published: January 2024

Constructing efficient cell factories for product synthesis is frequently hampered by competing pathways and/or insufficient precursor supply. This is particularly evident in the case of triterpenoid biosynthesis in
Yarrowia lipolytica
, where squalene biosynthesis is tightly coupled to cytosolic biosynthesis of sterols essential for cell viability. Here, we addressed this problem by reconstructing the complete squalene biosynthetic pathway, starting from acetyl-CoA, in the peroxisome, thus harnessing peroxisomal acetyl-CoA pool and sequestering squalene synthesis in this organelle from competing cytosolic reactions. This strategy led to increasing the squalene levels by 1,300-fold relatively to native cytosolic synthesis. Subsequent enhancement of the peroxisomal acetyl-CoA supply by two independent approaches, 1) converting cellular lipid pool to peroxisomal acetyl-CoA and 2) establishing an orthogonal acetyl-CoA shortcut from CO
2
-derived acetate in the peroxisome, further significantly improved local squalene accumulation. Using these approaches, we constructed squalene-producing strains capable of yielding 32.8 g/L from glucose, and 31.6 g/L from acetate by employing a cofeeding strategy, in bioreactor fermentations. Our findings provide a feasible strategy for protecting intermediate metabolites that can be claimed by multiple reactions by engineering peroxisomes in
Y. lipolytica
as microfactories for the production of such intermediates and in particular acetyl-CoA-derived metabolites.
Boosted hydrogen evolution kinetics of heteroatom-doped carbons with isolated Zn as an accelerant
Authors: Li Yang , Zuo Shouwei , Wei Fen , Chen Cailing , Zhang Guikai , Zhao Xiaojuan , Wu Zhipeng , Wang Sibo , Zhou Wei , Rueping Magnus , Han Yu , Zhang Huabin
Published: January 2024

Carbon-based single-atom catalysts, a promising candidate in electrocatalysis, offer insights into electron-donating effects of metal center on adjacent atoms. Herein, we present a practical strategy to rationally design a model catalyst with a single zinc (Zn) atom coordinated with nitrogen and sulfur atoms in a multilevel carbon matrix. The Zn site exhibits an atomic interface configuration of ZnN
4
S
1
, where Zn's electron injection effect enables thermal-neutral hydrogen adsorption on neighboring atoms, pushing the activity boundaries of carbon electrocatalysts toward electrochemical hydrogen evolution to an unprecedented level. Experimental and theoretical analyses confirm the low-barrier Volmer–Tafel mechanism of proton reduction, while the multishell hollow structures facilitate the hydrogen evolution even at high current intensities. This work provides insights for understanding the actual active species during hydrogen evolution reaction and paves the way for designing high-performance electrocatalysts.
PIGB maintains nuclear lamina organization in skeletal muscle of Drosophila
Authors: Yamamoto-Hino Miki , Ariura Masaru , Tanaka Masahito , Iwasaki Yuka W. , Kawaguchi Kohei , Shimamoto Yuta , Goto Satoshi
Published: January 2024

The nuclear lamina (NL) plays various roles and participates in nuclear integrity, chromatin organization, and transcriptional regulation. Lamin proteins, the main components of the NL, form a homogeneous meshwork structure under the nuclear envelope. Lamins are essential, but it is unknown whether their homogeneous distribution is important for nuclear function. Here, we found that PIGB, an enzyme involved in glycosylphosphatidylinositol (GPI) synthesis, is responsible for the homogeneous lamin meshwork in Drosophila. Loss of PIGB resulted in heterogeneous distributions of B-type lamin and lamin-binding proteins in larval muscles. These phenotypes were rescued by expression of PIGB lacking GPI synthesis activity. The PIGB mutant exhibited changes in lamina-associated domains that are large heterochromatic genomic regions in the NL, reduction of nuclear stiffness, and deformation of muscle fibers. These results suggest that PIGB maintains the homogeneous meshwork of the NL, which may be essential for chromatin distribution and nuclear mechanical properties.
Intense Mid-Infrared Laser Pulse Generated via Flying-Mirror Red-Shifting in Near-Critical-Density Plasmas
Authors: Lu 鲁 Yu 瑜 , Li 李 Dong-Ao 东澳 , Li 李 Qian-Ni 倩妮 , Shao 邵 Fu-Qiu 福球 , Yu 余 Tong-Pu 同普
Published: January 2024

Relativistic femtosecond mid-infrared pulses can be generated efficiently by laser interaction with near-critical-density plasmas. It is found theoretically and numerically that the radiation pressure of a circularly polarized laser pulse first compresses the plasma electrons to form a dense flying mirror with a relativistic high speed. The pulse reflected by the mirror is red-shifted to the mid-infrared range. Full three-dimensional simulations demonstrate that the central wavelength of the mid-infrared pulse is tunable from 3 μm to 14 μm, and the laser energy conversion efficiency can reach as high as 13%. With a 0.5–10 PW incident laser pulse, the generated mid-infrared pulse reaches a peak power of 10–180 TW, which is interesting for various applications in ultrafast and high-field sciences.
Sub-Doppler laser cooling and magnetic trapping of natural-abundance fermionic potassium
Authors: Bocheński Mateusz , Semczuk Mariusz
Published: January 2024

We demonstrate the largest number of 40K atoms that has ever been cooled to deeply sub-Doppler temperatures in a single-chamber apparatus without using an enriched source of potassium. With gray molasses cooling on the D
1-line following a standard D
2-line magneto-optical trap, we obtain

3
×

10
5

atoms at 10(2) µK. We reach densities high enough to measure the temperature via absorption imaging using the time-of-flight method. We magnetically trap a mixture of

m
F

=
−
3

/

2
,
−
5

/

2

and

−
7

/

2

Zeeman states of the

F
=
7

/

2

hyperfine ground state confining

5
×

10
4

atoms with a lifetime of 0.6 s or

∼

10
3

atoms with a lifetime of 2.8 s—depending on whether the temperature of the potassium dispensers was chosen to maximize the atom number or the lifetime. The background pressure-limited lifetime of 0.6 s is a reasonable starting point for proof-of-principle experiments with atoms and/or molecules in optical tweezers as well as for sympathetic cooling with another species if transport to a secondary chamber is implemented. Our results show that unenriched potassium can be used to optimize experimental setups containing 40K in the initial stages of their construction, which can effectively extend the lifetime of enriched sources. Moreover, the demonstration of sub-Doppler cooling and magnetic trapping of a relatively small number of potassium atoms might influence experiments with laser-cooled radioactive isotopes of potassium.
Statistical RTA simulations of atomic data for astrophysical opacity modeling in the context of kilonova emission
Authors: Carvajal Gallego H , Pain J-C , Godefroid M , Palmeri P , Quinet P
Published: January 2024

When considering some complex lanthanide ions characterized by a half-filled 4f subshell, the atomic structure Hamiltonian matrix sizes are so large that their diagonalization is challenging and therefore the atomic data of these ions are only used to compute the expansion opacity of a kilonova with difficulty. To avoid this problem, we propose a statistical simulation method to compute kilonova expansion opacities based on the resolved transition array (RTA) method of Bauche et al (1991 Phys. Rev. A 44 5707). The atomic structure relativistic Hartree–Fock (HFR) method has been employed to compute the radial integrals necessary for our statistical RTA simulations where the atomic data are randomly drawn using their corresponding statistical distributions and to determine the exact expansion opacities where the atomic data are obtained by the diagonalization of the Hamiltonian matrix. The statistical RTA simulations carried out for two specific ions, i.e. Sm VIII and Eu VI, for which it is still possible to diagonalize the Hamiltonian matrix, reproduce well the expansion opacities computed using HFR atomic data. Based on this good agreements, the statistical RTA method was used to compute the expansion opacity of Dy VIII, which is determined through diagonalization with difficulty. The proposed statistical RTA simulation method allows the computation of reliable astrophysical expansion opacities which are of paramount importance for kilonova light curve modeling and spectral analysis.
On the magnetization of the 120° order of the spin-1/2 triangular lattice Heisenberg model: a DMRG revisited
Authors: Huang Jiale , Qian Xiangjian , Qin Mingpu
Published: January 2024

We revisit the issue about the magnetization of the 120° order in the spin-1/2 triangular lattice Heisenberg model with density matrix renormalization group (DMRG). The accurate determination of the magnetization of this model is challenging for numerical methods and its value exhibits substantial disparities across various methods. We perform a large-scale DMRG calculation of this model by employing bond dimension as large as

D
=
24
000

and by studying the system with width as large as

L

y

=
12

. With careful extrapolation with truncation error and suitable finite size scaling, we give a conservative estimation of the magnetization as

M
0

=
0.208
(
8
)

. The ground state energy per site we obtain is

E

g

=
−
0.5503
(
8
)

. Our results provide valuable benchmark values for the development of new methods in the future.
Defects in epitaxial 4H-SiC revealed by exciton recombination
Authors: Migliore Francesca , Cannas Marco , Mario Gelardi Franco , Vecchio Daniele , Brischetto Andrea , Agnello Simonpietro
Published: January 2024

In this work, we conducted an analysis of 4H-SiC epitaxial layer grown on two distinct 4H-SiC substrates (both 6 inches in diameter) using non-invasive techniques such as micro-Raman spectroscopy, steady-state absorption spectroscopy and time-resolved photoluminescence spectroscopy. We have shown that despite the doping homogeneity, confirmed by micro-Raman and steady-state absorption spectroscopy, the carrier lifetime, assessed by monitoring the excitonic band at 3.2 eV by time-resolved photoluminescence spectroscopy, depends on the position on the wafer. This variability is attributed to the presence of defects, such as impurities or point defects, which are not uniformly distributed on the epitaxial layer and that, in addition to extended defects, affect the charge carrier recombination. Additionally, it is found that interactions with the underlying substrate could contribute to these effects as evidenced in regions of the substrate characterized by differences of doping.
Intelligent fault diagnosis of double-aligned domain adaptation based on multi-structure fusion and multi-attention mechanism
Authors: Shang Zhiwu , Wu Changchao , Pan Cailu , Li Wanxiang , Cheng Hongchuan
Published: January 2024

Currently, most fault diagnosis methods based on domain adaptation (DA) reduce the distribution discrepancy between the source and target domains by aligning their high-dimensional features, but do not consider the impact of the source domain decision boundary on the distribution of the target domain, which leads to slow convergence and poor generalization. Aiming at the above-mentioned issues, this paper proposes a double-aligned DA deep transfer model (MSADA) based on multi-structure fusion and multi-attention mechanism. Firstly, a multi-structure fusion network with Inception module is constructed to increase the information capacity in the extracted features and enhance the representation of deep features. Then, the multi-attention mechanism is embedded into different convolutional channels separately to learn globally and locally important information and reduce the influence of the source domain decision boundary on the target domain distribution. Finally, the multi-kernel maximum mean discrepancy and KL divergence are combined as a new double-aligned distribution discrepancy metric to align the samples and probability distributions of the source domain and the target domain, respectively. At the same time, a dynamic adaptive factor is designed to adjust the contribution of the two types of distributions, thus effectively improving the training efficiency and the robustness of the model. Through the validation analysis of two rolling bearing dataset cases, the proposed MSADA has better cross-domain diagnostic performance than other DA methods.
A water track laser Doppler velocimeter for use in underwater navigation
Authors: Huang Rong , Wang Qi , Xiang Zhiyi , Nie Xiaoming , Zhou Jian , Luo Hui
Published: January 2024

Doppler velocity log (DVL) is usually employed to suppress the divergency of the Strapdown Inertial Navigation System (SINS) in underwater navigation, which is not concealable due to high transmittance for acoustic wave in the water. To conduct underwater navigation task with high concealment, a differential laser Doppler velocimeter (LDV) working at water track mode is integrated with SINS in this paper. The developed LDV measures the advance velocity of the underwater carrier with respect to the surrounding water in underwater navigation scenario with advantages of high concealment, high real-time performance, high update rate, light weight, and small dimension. A dynamic river test was conducted to validate the underwater navigation performance of SINS/LDV integrated system. The experimental results show that during the voyage of 4493s and 5271.8 m, the maximum horizontal positioning errors of the proposed SINS/LDV integrated underwater navigation system is 27.8 m and the relative position error is less than 0.6% with respect to total distance. Therefore, the water track LDV is practical to aid SINS in underwater navigation environment.
Conductivity enhancement of Ag nanowire ink by decorating in situ formed Ag particles under low-temperature sintering
Authors: Feng Junyan , Xing Bo , Xu Jiahao
Published: January 2024

Silver nanowires (AgNWs) have attractive applications in the fabrication of flexible electronics because of their adequate electrical conductivity, mechanical properties, and oxidation resistance. However, the film produced by AgNW ink needs to be sintered at temperatures above 200 °C to obtain high electrical conductivity, which is incompatible with commonly used flexible substrates such as paper or polymer materials. In this study, the AgNW network was decorated by in situ reduced Ag particles (AgPs) to improve the structural integrity and conductivity of the film. After sintering at 80 °C, the pores and voids within the AgNW network were filled with Ag particles smaller than 200 nm, and the porosity of the film was markedly reduced. The lowest resistivity value was 3.9 × 10–5 Ω cm after sintering at 100 °C, only 10.8% and 8.5% of the resistivity values of the films produced from AgNW and ion inks, respectively. During sintering, Ag nucleated on the surface of AgNWs, and its growth and agglomeration resulted in interconnections between the AgNWs and Ag particles. Thereafter, the bridging and filling effect of the Ag particles facilitated the formation of a compact and firm network, improving the film conductivity. The line film printed from the composite ink with 10 layers exhibited a low resistivity of 7.3 × 10–7 Ω·m. Even after 5000 bending cycles, the resistivity of the line only increased by 4.47 × 10–6 Ω·cm from the initial value. The composite ink reported in this study is a promising candidate for the low-cost printing of ultralow-power-consumption wearable electronic devices.
Three-dimensional ordered macroporous design of heterogeneous cobalt–iron phosphides as oxygen evolution electrocatalyst
Authors: Zhao Songan , Cao Weijin , Lu Lu , Tan Zhaoyang , Wang Yanji , Wu Lanlan , Li Jingde
Published: January 2024

Oxygen evolution reaction (OER) plays a key role in electrochemical conversion, which needs efficient and economical electrocatalyst to boost its kinetics for large-scale application. Herein, a bimetallic CoP/FeP2 heterostructure with a three-dimensional ordered macroporous structure (3DOM-CoP/FeP2) was synthesized as an OER catalyst to demonstrate a heterogeneous engineering induction strategy. By adjusting the electron distribution and producing a lot of active sites, the heterogeneous interface enhances catalytic performance. High specific surface area is provided by the 3DOM structure. Additionally, at the solid–gas-electrolyte threephase interface, the electrocatalytic reaction exhibits good mass transfer. In sit
u Raman spectroscopy characterization revealed that FeOOH and CoOOH reconstructed from CoP/FeP2 were the true OER active sites. Consequently, the 3DOM-CoP/FeP2 demonstrates superior OER activity with a low overpotentials of 300/420 mV at 10/100 mA cm–2 and meritorious OER durability. It also reveals promising performance as the overall water splitting anode.
Hardy inequalities for magnetic p-Laplacians
Authors: Cazacu Cristian , Krejčiřík David , Lam Nguyen , Laptev Ari
Published: January 2024

We establish improved Hardy inequalities for the magneticp-Laplacian due to adding nontrivial magnetic fields. We also prove that for Aharonov–Bohm magnetic fields the sharp constant in the Hardy inequality becomes strictly larger than in the case of a magnetic-freep-Laplacian. We also post some remarks with open problems.
Students’ scaling of axes when constructing qualitative graphs that represent a physics scenario
Authors: Condon Orlaith , Kelly T J , Power Stephen R , van Kampen Paul
Published: January 2024

We have studied how first-year university science students construct graphs based on hypothetical qualitative physics scenarios. We gave students a questionnaire that asked them to complete two Cartesian graphs in one of three different scenarios (a ball rolling down a track, a beaker being filled with water, the resistance between different points on a metal bar) given as a written piece of text accompanied by a diagram of a hypothetical experiment that included three evenly spaced points on the set-up. Two of the three points were also indicated on the position axis of the partially drawn graph. We found that students can find it hard to translate equal spatial intervals in the experiment to a line graph. We found that most students either did not explain why they put the third point on the graph where they did, or did not plot the point at all. Some students drew unequal intervals on the position axis to indicate unequal time or resistance intervals. The difficulties became more prevalent as the levels of abstraction increased. Our findings suggest that constructing a scale on a qualitative graph requires significant mental effort from the students.
Validating light phenomena conceptual assessment through the lens of classical test theory and item response theory frameworks
Authors: Santoso Purwoko Haryadi , Istiyono Edi , Haryanto  , Retnawati Heri
Published: January 2024

The light phenomena conceptual assessment (LPCA) is a conceptual survey of light phenomena that has been recently established by physics education research (PER) scholars. Studying the LPCA psychometric properties is imperative to inform its measurement validity to potential LPCA users as well as general educational researchers. Classical test theory (CTT) and item response theory (IRT) are two popular statistical frameworks that can be utilized to explore the LPCA measurement validity. To our knowledge, no PER studies have attempted to make a head-to-head comparison of these methods while validating the LPCA. This study is the first to delineate the LPCA measurement by statistically comparing CTT- and IRT-based analyses. The LPCA dataset was drawn from physics students from eight secondary schools presented by Ndihokubwayo and Uwamahoro (2020 Phys. Educ.
55 035009). Our results accomplish harmony between the CTT and IRT arguments to estimate the LPCA item performance and student ability probed by the LPCA. They support the idea that the LPCA may be used as an inventory for evaluating conceptual understanding of light phenomena from the low to high ability range of students, and even some LPCA items should be flagged based on CTT- and IRT-based validity arguments. Special considerations for further refinement related to the discriminating power of problematic LPCA items are discussed.
From caged compounds with isolated U atoms to frustrated magnets with 2- or 3-atom clusters: a review of Al-rich uranium aluminides with transition metals
Authors: Pasturel Mathieu , Pikul Adam
Published: January 2024

Crystal structures and physical properties of four families of Al-rich ternary uranium compounds with transition metals (TE) are reviewed, namely UTE
2Al20, UTE
2Al10, U6
TE
4Al43, and U3
TE
4Al12. The compounds can be described as consisting of 1 (isolated), 2 (dumbbells) or 3 (triangles) uranium atom clusters, surrounded (1–2–20, 1–2–10 and 6–4–43) or not (3–4–12) by large cages, which strongly influence their magnetic and related properties. Indeed, the ground states of the described systems evolve from Curie-like paramagnetism in the case of the phases with well-isolated, single U-atoms, to complex magnetic order or possible frustrated magnetism in the case of the systems with uranium triangles forming a breathing kagome lattice. We argue that the four families of uranium aluminides described in this review provide a unique opportunity to study magnetic interactions between U magnetic moments while gradually increasing the number of their nearest magnetic neighbors, and may also be helpful in understanding the fundamental origin of magnetic freezing phenomena.
Explicit model predictive control of magnetorheological suspension for all-terrain vehicles with road preview
Authors: Li Wei , Liang Huijun , Xia Dongbin , Fu Jie , Yu Miao
Published: January 2024

The integration of magnetorheological (MR) semi-active suspension systems in all-terrain vehicles (ATV) has garnered significant attention due to their ability to enhance damping performance and off-road capabilities. However, traditional control strategies result in poor control accuracy and limited vibration reduction effects when facing complex road excitations and impact disturbances. With technological advancements, enhanced vehicle environmental perception and road sensing capabilities have made it possible to implement model predictive control (MPC) for vehicle suspensions. Nevertheless, traditional MPC is limited in vehicle suspension applications due to its high computational complexity. To address these issues, this study introduces an explicit model predictive control based on road preview (EMPC-P). Firstly, road data obtained through a non-contact measurement method enables the system to perceive road excitation information in advance. Subsequently, a 7 Degree-of-Freedom (7-DOF) suspension model incorporating road excitations is constructed. By adhering to system constraints and employing a multiparameter optimization method, the control problem based on rolling optimization is transformed into an explicit polyhedral system. The offline precomputation of control state relations enhances the computational efficiency of the control system. Through this approach, the designed EMPC allows the vehicle suspension system to make optimal control decisions quickly and accurately in response to complex driving conditions, thus improving the damping effect of the system. Through a combined approach of simulation and experimental validation, the designed EMPC-P controller is compared with the Skyhook controller under preview and non-preview states, respectively. Empirical testing confirms that the EMPC-P exhibits superior damping effects, significantly improving vehicle ride comfort and handling stability.
Exploring the quantum vacuum via ultraintense laser-induced refraction of light
Authors: Wang J , Chen G Y , Lei B F , Jin S , Yang L Y , Gan L F , Zhou C T , Zhu S P , He X T , Qiao B
Published: January 2024

The rapid progress of ultraintense laser technology provides a novel route to explore the quantum vacuum effect in the laboratory. Here, we propose using oblique collisions between an ultraintense pump laser and an x-ray probe laser to experimentally identify the quantum vacuum effect, where the change of the refraction properties including the refraction angle of the probe laser is taken as a detectable signature. The theoretical basis of the proposed scheme are analyzed in details, where a reasonable estimation of the scheme is given. To verify the proposed scheme, a series of two-dimensional particle-in-cell (PIC) simulations, with the vacuum polarization effect self-consistently taken into account, are carried out.
On the complex solution of the Schrödinger equation with exponential potentials
Authors: Garcia Javier
Published: January 2024

We study the analytical solutions of the Schrödinger equation with a repulsive exponential potential λ
e
−r
, and with an exponential wall λ
e

r
, both with λ > 0. We show that the complex eigenenergies obtained for the latter tend either to those of the former, or to real rational numbers as λ → ∞ . In the light of these results, we explain the wrong resonance energies obtained in a previous application of the Riccati-Padé method to the Schrödinger equation with the repulsive exponential potential, and further study the convergence properties of this approach.
Effects of boron doping in InSe single crystals on optical limiting performance in the near-infrared region
Authors: Doğan Anıl , Pepe Yasemin , Bilgili Meliha Yağmur , Karatay Ahmet , Ertap Hüseyin , Karabulut Mevlüt , Elmali Ayhan
Published: January 2024

Identification of photonic materials with high infrared transmittance and high nonlinear optical coefficients is one of the main emphases in material science as a result of the rapid advancement in infrared photonics. In this study, undoped and B (boron) -doped InSe single crystals were grown by using the modified vertical Bridgman method, and their nonlinear optical properties were investigated to reveal their usability as an optical limiter in the near-infrared region. The decreasing band gap energies and increasing defect states were determined with increasing B concentration in InSe single crystals. The effect of the B concentration on the nonlinear absorption (NA) and optical limiting properties of the InSe single crystals was investigated via open aperture (OA) Z-scan experiments under ultrafast laser excitation at 1200 nm wavelength with 100 femtosecond pulse duration. Two-photon absorption (TPA) was the dominant NA mechanism at 1200 nm excitation wavelength in the femtosecond domain. The results revealed that the NA became stronger with increasing input intensity and increasing amount of B dopant atoms in the InSe single crystal. The observed enhanced NA can be attributed to two possible events (i) increasing input intensity induced more excited electrons which led to more contribution to NA through TPA and (ii) increasing B dopant atoms in InSe single crystal induced more defect states. The NA may be more enhanced with the contribution of these defect states related NA mechanisms. The high transparency and strong NA behavior at the near-infrared region make these single crystals exceptional potential candidates for developing various optoelectronics and filters at the near-infrared spectral region.
Enhancement of gravitational waves at Q-ball decay including non-linear density perturbations
Authors: Kawasaki Masahiro , Murai Kai
Published: January 2024

The existence of a stochastic gravitational wave background is indicated by the recent pulsar timing array (PTA) experiments.
We study the enhanced production of second-order gravitational waves from the scalar perturbations when the universe experiences a transition from the early matter-dominated era to the radiation-dominated era due to Q-ball decay.
We extend the analysis in previous work by including the frequency range where density perturbations go non-linear and find that the resultant gravitational wave spectrum can be consistent with that favored by the recent PTA experiment results.
A Novel Eccentricity Parameterization for Transit-only Models
Authors: Eastman Jason D.
Published: January 2024

We present a novel eccentricity parameterization for transit-only fits that allows us to efficiently sample the eccentricity and argument of periastron, while being able to generate a self-consistent model of a planet in a Keplerian orbit around its host star. With simulated fits of 330 randomly generated systems, we demonstrate that typical parameterizations often lead to inaccurate and overly precise determinations of the planetary eccentricity. However, our proposed parameterization allows us to accurately—and often precisely—recover the eccentricity for the simulated planetary systems with only transit data available.
Keck Infrared Transient Survey. I. Survey Description and Data Release 1
Authors: Tinyanont S. , Foley R. J. , Taggart K. , Davis K. W. , LeBaron N. , Andrews J. E. , Bustamante-Rosell M. J. , Camacho-Neves Y. , Chornock R. , Coulter D. A. , Galbany L. , Jha S. W. , Kilpatrick C. D. , Kwok L. A. , Larison C. , Pierel J. R. , Siebert M. R. , Aldering G. , Auchettl K. , Bloom J. S. , Dhawan S. , Filippenko A. V. , French K. D. , Gagliano A. , Grayling M. , Howell D. A. , Jacobson-Galán W. V. , Jones D. O. , Le Saux X. , Macias P. , Mandel K. S. , McCully C. , Padilla Gonzalez E. , Rest A. , Rho J. , Rojas-Bravo C. , Skrutskie M. F. , Thorp S. , Wang Q. , Ward S. M.
Published: January 2024

We present the Keck Infrared Transient Survey, a NASA Key Strategic Mission Support program to obtain near-infrared (NIR) spectra of astrophysical transients of all types, and its first data release, consisting of 105 NIR spectra of 50 transients. Such a data set is essential as we enter a new era of IR astronomy with the James Webb Space Telescope (JWST) and the upcoming Nancy Grace Roman Space Telescope (Roman). NIR spectral templates will be essential to search JWST images for stellar explosions of the first stars and to plan an effective Roman SN Ia cosmology survey, both key science objectives for mission success. Between 2022 February and 2023 July, we systematically obtained 274 NIR spectra of 146 astronomical transients, representing a significant increase in the number of available NIR spectra in the literature. Here, we describe the first release of data from the 2022A semester. We systematically observed three samples: a flux-limited sample that includes all transients <17 mag in a red optical band (usually ZTF r or ATLAS o bands); a volume-limited sample including all transients within redshift z < 0.01 (D ≈ 50 Mpc); and an SN Ia sample targeting objects at phases and light-curve parameters that had scant existing NIR data in the literature. The flux-limited sample is 39% complete (60% excluding SNe Ia), while the volume-limited sample is 54% complete and is 79% complete to z = 0.005. Transient classes observed include common Type Ia and core-collapse supernovae, tidal disruption events, luminous red novae, and the newly categorized hydrogen-free/helium-poor interacting Type Icn supernovae. We describe our observing procedures and data reduction using PypeIt, which requires minimal human interaction to ensure reproducibility.
Tighter sum uncertainty relations via (α, β, γ) weighted Wigner–Yanase–Dyson skew information
Authors: Xu Cong , Wu Zhaoqi , Fei Shao-Ming
Published: January 2024

We establish tighter uncertainty relations for arbitrary finite observables via (α, β, γ) weighted Wigner–Yanase–Dyson ((α, β, γ) WWYD) skew information. The results are also applicable to the (α, γ) weighted Wigner–Yanase–Dyson ((α, γ) WWYD) skew information and the weighted Wigner–Yanase–Dyson (WWYD) skew information. We also present tighter lower bounds for quantum channels and unitary channels via (α, β, γ) modified weighted Wigner–Yanase–Dyson ((α, β, γ) MWWYD) skew information. Detailed examples are provided to illustrate the tightness of our uncertainty relations.
Ground-layer Adaptive Optics for the 2.5 m Wide-field and High-resolution Solar Telescope
Authors: Yang Ying , Zhang Lan-Qiang , Yan Nan-Fei , Yang Jin-Sheng , Li Zhen , Song Teng-Fei , Rao Xue-Jun , Rao Chang-Hui
Published: January 2024

The 2.5 m wide-field and high-resolution solar telescope (WeHoST) is currently under developing for solar observations. WeHoST aims to achieve high-resolution observations over a super-wide field of view (FOV) of 5′ × 5′, and a desired resolution of 0.3″. To meet the scientific requirements of WeHoST, the ground-layer adaptive optics (GLAO) with a specially designed wave front sensing system is as the primary consideration. We introduce the GLAO configuration, particularly the wave front sensing scheme. Utilizing analytic method, we simulate the performance of both classical AO and GLAO systems, optimize the wave front sensing system, and evaluate GLAO performance in terms of PSF uniformity and correction improvement across whole FOV. The results indicate that, the classical AO will achieve diffraction-limited resolution; the suggested GLAO configuration will uniformly improve the seeing across the full 5′ × 5′ FOV, reducing the FWHM across the axis FOV to less than 0.3″ (λ ≥ 705 nm, r
0 ≥ 11 cm), which is more than two times improvement. The specially designed wave front sensor schedule offers new potential for WeHoST’s GLAO, particularly the multi-FOV GLAO and the flexibility to select the detected area. These capabilities will significantly enhance the scientific output of the telescope.
Controllable growth of wafer-scale PdS and PdS2 nanofilms via chemical vapor deposition combined with an electron beam evaporation technique
Authors: Gao Hui , Zhou Hongyi , Hao Yulong , Zhou Guoliang , Zhou Huan , Gao Fenglin , Xiao Jinbiao , Tang Pinghua , Hao Guolin
Published: January 2024

Palladium (Pd)-based sulfides have triggered extensive interest due to their unique properties and potential applications in the fields of electronics and optoelectronics. However, the synthesis of large-scale uniform PdS and PdS2 nanofilms (NFs) remains an enormous challenge. In this work, 2-inch wafer-scale PdS and PdS2 NFs with excellent stability can be controllably prepared via chemical vapor deposition combined with electron beam evaporation technique. The thickness of the pre-deposited Pd film and the sulfurization temperature are critical for the precise synthesis of PdS and PdS2 NFs. A corresponding growth mechanism has been proposed based on our experimental results and Gibbs free energy calculations. The electrical transport properties of PdS and PdS2 NFs were explored by conductive atomic force microscopy. Our findings have achieved the controllable growth of PdS and PdS2 NFs, which may provide a pathway to facilitate PdS and PdS2 based applications for next-generation high performance optoelectronic devices.
Modeling of Optimizing Multi-Hole Drilling Toolpath Distance with Multiple Tool Dimensions
Authors: Abdul Rahman N. , Rashid M.F.F. Ab.
Published: January 2024

Multi-hole Drilling with Multiple Tool dimensions (MDMT) is a crucial technique in today’s industry, allowing manufacturers to satisfy the increasing demand for precise and high-quality components while adopting the latest technological advancements and environmental standards. This paper introduces and validates a computational model for MDMT, offering numerous advantages over conventional drilling methods, including enhanced efficiency, accuracy, cost-effectiveness, and flexibility. The computational model was developed for the MDMT problem using the Travelling Salesman Problem (TSP) concept to measure the total toolpath distance. The Ant Colony Optimization (ACO), Particle Swarm Optimization (PSO), and Genetic Algorithm (GA) are applied to solving 12 cases of MDMT problems with varying numbers of holes, classified as small, medium, and large, using MATLAB software R2022b. Note that the algorithms were evaluated based on their solution quality, with lower fitness values indicating better performance. Overall, GA performed the best across most hole configurations, achieving the optimal fitness value in 5 out of 12 cases (small, medium, and large), ACO performed better in 4 out of 12 cases (small and medium) and PSO performed better in 3 out of 12 cases (medium and large). The research emphasizes the potential of multi-dimensional tools for accomplishing intricate drilling tasks. Other than that, this paper contributes to the existing literature on MDMT and highlights the importance of multi-dimensional tools in modern manufacturing. Future research could optimize the proposed computational model for various materials and drilling scenarios in MDMT.
Determination of Tool Wear Drilling Process of Aluminum 6061 and Brass C3604 by using CNC Robodrill Machine
Authors: Salaam H.A. , Mu’tasim M.A.N.
Published: January 2024

Hole making process is a stimulating process as it impacts the drilling tool’s performance and wear. The main objective of this paper is to determine the drilling tool wear by using step-by-step drilling approaches used by most of the manufacturing companies. Two types of materials involved; Aluminum 6061 & Brass C3604. Firstly, the raw material grade was confirmed by testing it using an Oxford Spectrometer. Four types of drilling tools are used; center drill diameter 3.00 mm; drill diameter 10.00, 13.00 and 14.50 mm. The drilling tool material used is High-Speed Steel (HSS). The cutting parameter used is stated in detail in the methodology section. Two approach are used to determine the tool life; measuring the holes diameter produced by using Vernier caliper; graphical form with the help of the camera. The major finding of this research is the understanding on how the cutting process react with the drilling tool during the cutting process as discussed in the results and discussions. The tool life of a center drill, drilling tool diameter 10.00 mm, 13.00 mm and 14.50 mm in drilling Aluminum 6061 is 476, 250, 485 and 499 holes while for Brass C3604 is 360, 190, 360 and 375 holes.
Numerical Simulation on VIV Energy Harvesting of Four Cylinders in Close Staggered Formation with Different Mass Ratios
Authors: Alias F. , Zailani N.S.A.M , Mohd M.H. , Kasiman E.H. , Rahman M.A.A
Published: January 2024

Nowadays, the demand for marine renewable and clean energy from fluid flow in the oil and gas industry has made electricity the most sought-after and indispensable source of uncontrollable power worldwide. Vortex-Induced Vibrations (VIV) energy harvesting is a promising technology in harnessing energy from flowing water bodies. This study focuses on numerically investigating the VIV of rigid circular cylinders as a sustainable energy source, utilizing a Vortex-Induced Vibration Aquatic Clean Energy (VIVACE) converter to harvest energy from the ocean. Specifically, the research explores the vibration behavior of closely arranged cylinders with different mass ratios, both at low and high values. The study aims to understand the effects of mass ratios on the VIV converter’s performance with four cylinders in close staggered formation. The power conversion of the VIV energy converter model with varying mass ratios (ranging from 2.36 to 12.96) is thoroughly examined, with simulations conducted at a Reynolds number of 82000. The results demonstrate that the maximum converted power peaks at 7.48 W for a mass ratio of 2.36, whereas a higher mass ratio of 12.96 only yields 4.33 W. This emphasizes the significant impact of lower mass ratios in enhancing the power generation from VIV. Overall, the findings of this research provide essential insights to optimize the layout of VIVACE converters in a close staggered array, facilitating the efficient harvesting of energy from flowing water bodies for sustainable and clean energy resources.