bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design, fabrication and experimental verification of a drag sail based on thermal-driven controllable bi-stable shape memory polymer composite booms
Authors: Ming Guangqing , Chen Siling , Li Bingxun , Li Fengfeng , Liu Liwu , Liu Yanju , Leng Jinsong 
Published: April 2024

Abstract
Deployable drag sails are used for passively deorbiting defunct satellites and other spacecraft. Designing the deployable boom is the main challenge in this technology. We present a bi-stable shape memory polymer composite (Bi-SMPC) boom with high stiffness, a high unfolding/folding ratio, and consistent roll-out deployment. It was designed and fabricated by a strategy of controlling the gradual release of elastic energy stored in a bi-stable composite structure through thermal-driven SMP matrix. Two heating layer strategies were investigated experimentally to determine the optimal driving layer and driving parameters. Based on these parameters, verification tests of a four-stage deployment Bi-SMPC boom were conducted. Meanwhile, a proof-of-concept prototype of a four-stage deployment drag sail based on the Bi-SMPC booms was designed and fabricated. Tests were conducted to verify the effectiveness of the drag sail deployed by the booms. It was found that SMPs can effectively control the deployment of bistable composite structures. The nickel-chromium alloy heating layer offers a more uniform driving temperature field compared to carbon fiber. The drag sail can be deployed successfully under the driving of four Bi-SMPC booms.
Does anti-Unruh effect assist quantum entanglement and coherence?
Authors: Wu Shu-Min , Teng Xiao-Wei , Li Jin-Xuan , Zeng Hao-Sheng , Liu Tonghua 
Published: April 2024

Abstract
In this paper, we use the concepts of quantum entanglement and coherence to analyze the Unruh and anti-Unruh effects based on the model of Unruh–DeWitt detector. For the first time, we find that (i) the Unruh effect reduces quantum entanglement but enhances quantum coherence; (ii) the anti-Unruh effect enhances quantum entanglement but reduces quantum coherence. This surprising result refutes the notion that the Unruh effect can only destroy quantum entanglement and coherence simultaneously, and that the anti-Unruh can only protect quantum resources. Consequently, it opens up a new source for discovering experimental evidence supporting the existence of the Unruh and anti-Unruh effects.
Switching of topological phase and topological channel via asymmetric hopping modulations in a one-dimensional superconducting circuit lattice
Authors: Li Zi-Meng , Xiang Lü , Wang He , Wang Yi-Ping 
Published: April 2024

Abstract
We propose a theoretical scheme for a one-dimensional superconducting circuit lattice system to achieve that topological phase transition and topological multi-channel transfer, which is adjusted by the asymmetric hopping modulations. The system consists of an array of coupled superconducting microwave cavities, the hopping between its can be modulated by the qubits. Here, we explore topological stages by introducing parameters to expand the hopping modulation range. We found that the energy bands in the system exhibit different structural characteristics, which can achieve topological phase switching. Meanwhile, the edge modes can undergo a flipping process, which can not only realize dual-channel topological quantum information transfer, but also can achieve four-channel. Furthermore, it is noted that the defect can induce new topological phases, which can be optimized by adjusting the hopping parameters, while disorder can only cause band fluctuations and inversions, but does not change the position and period of edge states, verifying that the edge state transport is robust. The results obtained in this work can be applied to the storage and transmission of quantum information, and have a guiding role in the future development of quantum technology.
Systematic study of α-decays from the ground and isomeric states of the nuclei with 67 ≤ Z ≤ 106
Authors: Anjali V K , Santhosh K P , Zuhail K P 
Published: April 2024

Abstract
The Modified Generalised Liquid Drop Model (MGLDM) is employed to analyze both the favored and unfavored α-decays in the ground states (g.s.) and isomeric states (i.s.) of some nuclei having proton numbers, 67 ≤ Z ≤ 106. The calculated half-lives closely match the experimental results, with a least standard deviation, 0.3598, which shows that the g.s. model ‘MGLDM’ with some improvements can effectively be applied to the isomeric state decay. Royer’s formula and Qian’s formula are employed in our calculations and the reported results of the Two Potential Approach (TPA) and the GLDM are included, to compare the half-lives reproduced by MGLDM. The straight-line behaviour of New Geiger-Nuttall (New G-N) plots for various isotopes for different kinds of transitions shows the New G-N law can be applied successfully in the isomeric state α-decays also.
On the heart rhythm analysis using a nonlinear dynamics perspective: analytical study and electronic simulation
Authors: Fonkou R F , Kengne Romanic , Wamba M D , Fotsing Kamgang Herton Carel , Talla P K 
Published: April 2024

Abstract
Biological systems are highly complex, so understanding them requires extensive analysis. Cardiac rhythms are one such analysis. These rhythms are linked to a complex dynamic system defined on the basis of the electrical activity of cardiac cells. This electrical activity is essential to human physiology, defining numerous behaviours that include normal or pathological rhythms, generally measured by the electrocardiogram (ECG). This article presents a mathematical model to describe the electrical activity of the heart, using a nonlinear dynamics perspective. The stability analysis of this model in its autonomous state, uni-directionally coupled, shows a very rich dynamical behaviour characterized by periodical regions of stability and unstability. The model studied makes it possible to construct synthetic ECGs. These ECGs demonstrate a variety of responses, including normal and pathological rhythms: ventricular flutter, ventricular fibrillation, ventricular tachycardia and ventricular extrasystole. A quantitative analysis of the model is also carried out using bifurcation diagrams and the corresponding maximum Lyapunov exponents. In addition, variations in sinus rhythm are described by a time-dependent frequency (a dynamic variable varying in a disordered manner or following a given law), representing transient disturbances. This type of situation can represent transitions between different pathological behaviours or between normal and pathological physiologies. In this respect, the perspective of nonlinear dynamics is used to describe cardiac rhythms, which makes it possible to represent normal or pathological behaviours. An electronic simulation performed with the OrCAD-Pspice software for a real implementation of the cardiac system is carried out. The results obtained are in agreement with those obtained numerically.
Benchmarking discrete truncated Wigner approximation and neural network quantum states with the exact dynamics in a Rydberg atomic chain
Authors: Shenoy Varna , Dattatraya Naik Vighnesh , Li Weibin , Nath Rejish 
Published: April 2024

Abstract
We benchmark the discrete truncated Wigner approximation (DTWA) and Neural quantum states (NQS) based on restricted Boltzmann-like machines with the exact excitation and correlation dynamics in a chain of ten Rydberg atoms. The initial state is where all atoms are in their electronic ground state. We characterize the excitation dynamics using the maximum and time-averaged number of Rydberg excitations. DTWA results are different from the exact dynamics for large Rydberg-Rydberg interactions. In contrast, by increasing the number of hidden spins, the NQS can be improved but still limited to short-time dynamics. Interestingly, irrespective of interaction strengths, the time-averaged number of excitations obtained using NQS is in excellent agreement with the exact results. Concerning the calculation of quantum correlations, for instance, second-order bipartite and average two-site Rényi entropies, NQS looks more promising. Finally, we discuss the existence of a power law scaling for the initial growth of average two-site Rényi entropy.
Probing scalar induced gravitational waves with PTA and LISA: the importance of third order correction
Authors: Chang Zhe , Kuang Yu-Ting , Wu Di , Zhou Jing-Zhi 
Published: April 2024

Abstract
We revisit the calculation of third order scalar induced gravitational waves (SIGWs) and extend it from a monochromatic primordial power spectrum to a more general log-normal one. We investigate the impact of third order SIGWs on signal-to-noise ratio (SNR) of
Laser Interferometer Space Antenna (LISA) and pulsar timing array (PTA) observations, and find that third order SIGWs significantly contribute to the total energy density spectrum of gravitational waves (GW) in high-frequency region. For a primordial power spectrum amplitude of Aζ
= 10-2 ∼ 10-1, the effects of third order SIGWs lead to a 40% to 400% increase in the SNR for LISA. Additionally, our PTA data analysis reveals that third order SIGWs diminish both the amplitude Aζ
and the peak frequency f
* of the primordial power spectrum.
On the Galactic radio signal from stimulated decay of axion dark matter
Authors: Bhupal Dev P.S. , Ferrer Francesc , Okawa Takuya 
Published: April 2024

Abstract
We study the full-sky distribution of the radio emission from the stimulated decay of
axions which are assumed to compose the dark matter in the Galaxy. Besides the constant
extragalactic and CMB components, the decays are stimulated by a Galactic radio emission with a
spatial distribution that we empirically determine from observations. We compare the diffuse
emission to the counterimages of the brightest supernovæ remnants, and take into account the
effects of free-free absorption. We show that, if the dark matter halo is described by a cuspy NFW
profile, the expected signal from the Galactic center is the strongest. Interestingly, the
emission from the Galactic anti-center provides competitive constraints that do not depend on
assumptions on the uncertain dark matter density in the inner region. Furthermore, the anti-center
of the Galaxy is the brightest spot if the Galactic dark matter density follows a cored
profile. The expected signal from stimulated decays of axions of mass ma
∼ 10-6 eV is within reach of the Square Kilometer Array for an axion-photon coupling
gaγ
≳ (2-3) × 10-11 GeV-1.
Characterization and Optimization of Skipper CCDs for the SOAR Integral Field Spectrograph
Authors: Villalpando Edgar Marrufo , Drlica-Wagner Alex , Plazas Malagón Andrés A. , Bakshi Abhishek , Bonati Marco , Campa Julia , Cancino Braulio , Chavez Claudio R. , Estrada Juan , Fernandez Moroni Guillermo , Fraga Luciano , Gaido Manuel E. , Holland Stephen , Hur Rachel , Jonas Michelle , Moore Peter , Tiffenberg Javier 
Published: April 2024

Abstract
We present results from the characterization and optimization of Skipper charge-coupled devices (CCDs) for use in a focal plane prototype for the Southern Astrophysical Research Integral Field Spectrograph (SIFS). We tested eight Skipper CCDs and selected six for SIFS based on performance results. The Skipper CCDs are 6k × 1k, 15 μm pixels, thick, fully depleted, p-channel devices that have been thinned to ∼250 μm, backside processed, and treated with an anti-reflective coating. We demonstrate a single-sample readout noise of <4.3 e− rms pixel−1 in all amplifiers. We optimize the readout sequence timing to achieve a readout noise of 0.5 e− rms pixel−1 after 74 non-destructive measurements, which can be accomplished in a region covering 5% of the detector area in a readout time of <4 minutes. We demonstrate single-photon-counting in all 24 amplifiers (four amplifiers per detector) with a readnoise of σ

N
∼ 0.18 e− rms pixel−1 after N
samp = 400 samples, and we constrain the degree of nonlinearity to be ≲1% at low signal levels (0 e− to 50 e−). Clock-induced charge (CIC) remains an important issue when the Skipper CCD is configured to provide a large full-well capacity. We achieve a CIC rate of <1.45 × 10−3 e− pixel−1 frame−1 for a full-well capacity of ∼900 e−, which increases to a CIC rate of ∼3 e− pixel−1 frame−1 for full-well capacities ∼40,000–65,000 e−. We also perform conventional CCD characterization measurements such as charge transfer inefficiency (3.44 × 10−7 on average), dark current (∼2 × 10−4 e− pixel−1 s−1), photon transfer curves, cosmetic defects (<0.45% “bad” pixels), and charge diffusion (point-spread function < 7.5 μm) to verify that these properties are consistent with expectations from conventional p-channel CCDs used for astronomy. Furthermore, we provide the first measurements of the brighter-fatter effect and absolute quantum efficiency (≳80% between 450 and 980 nm; ≳90% between 600 and 900 nm) using Skipper CCDs.
Stellar Populations of AGN-host Dwarf Galaxies Selected with Different Methods
Authors: Li Xiejin , Zhao 赵 Yinghe 应和 , Bai Jinming 
Published: April 2024

Abstract
In this paper we investigate the stellar populations and star formation histories of 235 active galactic nucleus (AGN)-host dwarf galaxies, consisting of four samples identified separately with different methods (i.e., radio, X-ray, mid-IR and variability), utilizing the synthesis code STARLIGHT and spectra from the Sloan Digital Sky Survey Data Release 8. Our results show that the variability sample is the oldest, while the mid-IR sample is the youngest, for which the luminosity at 4020 Å is dominated (>50%) by the young population (t < 108 yr). The light-weighted mean stellar age of the whole sample is in general about 0.7 dex younger than the optical sample studied in Cai et al. We compare the population results between fitting models with and without a power-law (PL) component and find that the neglect of a PL component would lead to an under- and over-estimation by 0.2 and 0.1 dex for the light- and mass-weighted mean stellar age, respectively, for our sample of dwarf galaxies, which has a mean fractional contribution of ∼16% from the AGN. In addition, we obtain further evidence for a possible suppression of star formation in the host galaxy by the central AGN. We also find that there exists an anti-correlation between the extinction-corrected [O iii] luminosity and light-weighted mean stellar age, confirming our previous finding that there is a physical connection between AGN and star-forming activities in AGN-host dwarfs.
Spectral Index Distribution of Various Scale Components in Supernova Remnant Cassiopeia A
Authors: Lei Xianhuan , Zhu Hui , Yin Zongyao , Zhang Haiyan , Tian Wenwu , Yu Xianchuan 
Published: April 2024

Abstract
Cassiopeia A (Cas A) is a well-known candidate for studying cosmic-ray acceleration, in which compact features of various scales have attracted much attention. Based on observations by the Very Large Array of Cas A at 6 cm and 21 cm, we measure the spectral index distribution of various scale components using the observation of the 1998 epoch. We decompose its total density image into nine scale components, and map the temperature spectral index distribution of each component, which ranges from −2.48 ± 0.01 to −2.91 ± 0.05. We find that the spectral indices increase from the small scale to large scale components. A damped post-shock magnetic field model with a strength larger than ∼200 μG and a damping length scale less than ∼10% of the remnant radius can account for the spectral index variation naturally.
Plasma beta dependence of turbulent transport suggesting an advantage of weak magnetic shear from local and global gyrokinetic simulations
Authors: Ishizawa A. , Kishimoto Y. , Imadera K. , Nakamura Y. , Maeyama S. 
Published: April 2024

Abstract
A higher plasma β is desirable for realizing high performance fusion reactor, in fact, one of the three goals of JT-60SA project is to achieve a high-β regime. We investigate key physical processes that regulate the β dependence of turbulent transport in L-mode plasmas by means of both local and global gyrokinetic simulations. From local simulations, we found that the turbulent transport does not decrease as β increases, because the electromagnetic stabilizing effect is canceled out by the increase of the Shafranov shift. This influence of the Shafranov shift is suppressed when the magnetic shear is weak, and thus the electromagnetic stabilization is prominent in weak shear plasmas, suggesting an advantage of weak magnetic shear plasmas for achieving a high-β regime. In high β regime, local gyrokinetic simulations are suffered from the non-saturation of turbulence level. In global simulations, by contrast, the electromagnetic turbulence gets saturated by the entropy advection in the radial direction to avoid the zonal flow erosion due to magnetic fluctuations. This breakthrough enables us to explore turbulent transport at a higher β regime by gyrokinetic simulations.
Effects of cavity pre-detuning on RF power transients at injection into the LHC
Authors: Karlsen-Baeck B.E. , Argyropoulos T. , Butterworth A. , Calaga R. , Karpov I. , Timko H. , Zampetakis M. 
Published: April 2024

Abstract
At injection into the Large Hadron Collider (LHC), the radio
frequency (RF) system is perturbed by beam-induced voltage resulting
in strong RF power transients and the instant detuning of the
cavities. The automatic tuning system, however, needs time for the
mechanical compensation of the resonance frequency to take
place. Acting back on the beam, the transients in RF power are
expected to limit the maximum injected intensity by generating
unacceptable beam loss. Reducing them is therefore essential to
reach the target intensity during the High Luminosity (HL) LHC
era. At LHC flat bottom, the cavities are operated using the
half-detuning beam-loading compensation scheme. As implemented
today, the tuner control algorithm starts acting only after the
injection of the first longer bunch train which causes the bunches
for this injection to experience the largest power spikes. This
contribution presents an adapted detuning scheme for the RF cavities
before injection. It was proposed as a path to decrease the
transients, hence increasing the available intensity margin for the
available RF power. The expected gain is evaluated in particle
tracking simulations and measurements acquired during operation.
Evaluating the potential of iron-based interventions in methane reduction and climate mitigation
Authors: Meidan Daphne , Li Qinyi , Cuevas Carlos A , Doney Scott C , Fernandez Rafael P , van Herpen Maarten M J W , Johnson Matthew S , Kinnison Douglas E , Li Longlei , Hamilton Douglas S , Saiz-Lopez Alfonso , Hess Peter , Mahowald Natalie M 
Published: April 2024

Abstract
Keeping global surface temperatures below international climate targets will require substantial measures to control atmospheric CO2 and CH4 concentrations. Recent studies have focused on interventions to decrease CH4 through enhanced atmospheric oxidation. Here for the first time using a set of models, we evaluate the effect of adding iron aerosols to the atmosphere to enhance molecular chlorine production, and thus enhance the atmospheric oxidation of methane and reduce its concentration. Using different iron emission sensitivity scenarios, we examine the potential role and impact of enhanced iron emissions on direct interactions with solar radiation, and on the chemical and radiative response of methane. Our results show that the impact of iron emissions on CH4 depends sensitively on the location of the iron emissions. In all emission regions there is a threshold in the amount of iron that must be added to remove methane. Below this threshold CH4 increases. Even once that threshold is reached, the iron-aerosol driven chlorine-enhanced impacts on climate are complex. The radiative forcing of both methane and ozone are decreased in the most efficient regions but the direct effect due to the addition of absorbing iron aerosols tends to warm the planet. Adding any anthropogenic aerosol may also cool the planet due to aerosol cloud interactions, although these are very uncertain, and here we focus on the unique properties of adding iron aerosols. If the added emissions have a similar distribution as current shipping emissions, our study shows that the amount of iron aerosols that must be added before methane decreases is 2.5 times the current shipping emissions of iron aerosols, or 6 Tg Fe yr−1 in the most ideal case examined here. Our study suggests that the photoactive fraction of iron aerosols is a key variable controlling the impact of iron additions and poorly understood. More studies of the sensitivity of when, where and how iron aerosols are added should be conducted. Before seriously considering this method, additional impacts on the atmospheric chemistry, climate, environmental impacts and air pollution should be carefully assessed in future studies since they are likely to be important.
Dugong dugon (Muller 1776) and Its Habitat in Coastal Areas and Small Islands of East Java Province, Indonesia
Authors: Dewi C S U , Wahyudi S , Widodo  , Tarno H , Ciptadi G , Wiadnya D G R 
Published: April 2024

Abstract
Dugong dugon, an endangered marine mammal is listed the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Dugongs are classified as herbivorous mammals that live in the shallows associated with seagrass beds. The objectives of this study are (1) to collect data on dugong encounters in East Java, both direct encounters and literature studies; and (2) to analyze seagrass meadows that are potentially dugong grazing habitats in East Java. This study was conducted from January to July 2023 in the coastal area of East Java. Dugong and seagrass data, which were descriptively analyzed, were obtained from the literature, questionnaire interview, and by direct observation. Distribution of dugongs in East Java is known to be in the southeastern side of Banyuwangi, Situbondo, Sumenep, Lamongan, and Bawean Island. Direct encounters with live and dead dugongs in East Java have been recorded in several locations, including Bawean Island. Seagrass beds in East Java can be found on the coastal area of Lamongan, Bawean Island - Gresik, Sumenep, Bangkalan, Situbondo, Banyuwangi, Malang, and Pacitan. The seagrass species found in these eight areas are: E. acoroides, T. hemprichii, C. modocea rotundata, C. serrulata, H. pinifolia, H. uninervis, H. decipiens, H. ovalis, H. minor, S. iseotifolium, and T. ciliatum. Although, dugong status is fully protected in Indonesia, and its distribution is limited, further steps are needed to protect dugongs and their food habitats. Marine Protected Area is one of the policies that could be recommended to protect dugongs and their habitat.