bluuebunny/crossref_metadata_2025 huggingface dataset:
Southern Ocean drives multidecadal atmospheric CO
2
rise during Heinrich Stadials
Authors: Wendt Kathleen A. , Nehrbass-Ahles Christoph , Niezgoda Kyle , Noone David , Kalk Michael , Menviel Laurie , Gottschalk Julia , Rae James W. B. , Schmitt Jochen , Fischer Hubertus , Stocker Thomas F. , Muglia Juan , Ferreira David , Marcott Shaun A. , Brook Edward , Buizert Christo
Published: May 2024

The last glacial period was punctuated by cold intervals in the North Atlantic region that culminated in extensive iceberg discharge events. These cold intervals, known as Heinrich Stadials, are associated with abrupt climate shifts worldwide. Here, we present CO
2
measurements from the West Antarctic Ice Sheet Divide ice core across Heinrich Stadials 2 to 5 at decadal-scale resolution. Our results reveal multi-decadal-scale jumps in atmospheric CO
2
concentrations within each Heinrich Stadial. The largest magnitude of change (14.0 ± 0.8 ppm within 55 ± 10 y) occurred during Heinrich Stadial 4. Abrupt rises in atmospheric CO
2
are concurrent with jumps in atmospheric CH
4
and abrupt changes in the water isotopologs in multiple Antarctic ice cores, the latter of which suggest rapid warming of both Antarctica and Southern Ocean vapor source regions. The synchroneity of these rapid shifts points to wind-driven upwelling of relatively warm, carbon-rich waters in the Southern Ocean, likely linked to a poleward intensification of the Southern Hemisphere westerly winds. Using an isotope-enabled atmospheric circulation model, we show that observed changes in Antarctic water isotopologs can be explained by abrupt and widespread Southern Ocean warming. Our work presents evidence for a multi-decadal- to century-scale response of the Southern Ocean to changes in atmospheric circulation, demonstrating the potential for dynamic changes in Southern Ocean biogeochemistry and circulation on human timescales. Furthermore, it suggests that anthropogenic CO
2
uptake in the Southern Ocean may weaken with poleward strengthening westerlies today and into the future.
The effects of Facebook and Instagram on the 2020 election: A deactivation experiment
Authors: Allcott Hunt , Gentzkow Matthew , Mason Winter , Wilkins Arjun , Barberá Pablo , Brown Taylor , Cisneros Juan Carlos , Crespo-Tenorio Adriana , Dimmery Drew , Freelon Deen , González-Bailón Sandra , Guess Andrew M. , Kim Young Mie , Lazer David , Malhotra Neil , Moehler Devra , Nair-Desai Sameer , Nait El Barj Houda , Nyhan Brendan , Paixao de Queiroz Ana Carolina , Pan Jennifer , Settle Jaime , Thorson Emily , Tromble Rebekah , Velasco Rivera Carlos , Wittenbrink Benjamin , Wojcieszak Magdalena , Zahedian Saam , Franco Annie , Kiewiet de Jonge Chad , Stroud Natalie Jomini , Tucker Joshua A.
Published: May 2024

We study the effect of Facebook and Instagram access on political beliefs, attitudes, and behavior by randomizing a subset of 19,857 Facebook users and 15,585 Instagram users to deactivate their accounts for 6 wk before the 2020 U.S. election. We report four key findings. First, both Facebook and Instagram deactivation reduced an index of political participation (driven mainly by reduced participation online). Second, Facebook deactivation had no significant effect on an index of knowledge, but secondary analyses suggest that it reduced knowledge of general news while possibly also decreasing belief in misinformation circulating online. Third, Facebook deactivation may have reduced self-reported net votes for Trump, though this effect does not meet our preregistered significance threshold. Finally, the effects of both Facebook and Instagram deactivation on affective and issue polarization, perceived legitimacy of the election, candidate favorability, and voter turnout were all precisely estimated and close to zero.
Visitor experience as translation
Authors: Neather Robert
Published: May 2024

This paper explores the museum visitor experience as a form of translation. It argues that if a given exhibition can be seen as a cultural translation, then it is also true that the visitor’s reading of that exhibition constitutes a further layer of translation, as the visitor enacts their own transformation of the culture on display. The paper draws on intertextuality as a means to understand the ways in which this transformation occurs. It delineates a three-level typology of intertexts employed by the visitor and considers how the use of such intertexts constructs the visitor’s positionality in regard to the exhibition. The paper focuses on data from a diasporic museum, the Museum of Chinese in America, and applies a methodology involving analysis of TripAdvisor reviews and post-visit diaries to the online museum. The paper concludes that diaspora museums are a case in which the particular nexus of identity issues at work provide a more complex view of the visitor experience as translation.
“So if you’re going fossil hunting, that’s where you should look”
Authors: Sezzi Annalisa , Nocella Jessica Jane
Published: May 2024

Whether directed at adults or children, popularization can be viewed as a process of “translating” and
“recontextualizing” expert discourse for a lay audience. In fact, knowledge dissemination for children appears to entail an
additional form of “translation,” given their limited background knowledge. This “re-translation” often occurs on dedicated
websites based on “edutainment.” While most museum websites function as promotional tools or as agents of knowledge dissemination,
a small number of them are targeted at children and offer texts that insert museum objects in a broader context. By means of a
small case study, this paper explores how knowledge is popularized and presented in two science museum websites: the Natural
History Museum (NHM) in London and OLogy, the science website for children of the American Museum of Natural
History (AMNH) in New York. From a corpus-linguistic and discourse-analysis perspective, our interest lies in how popularization
takes shape in these two websites, the former intended for different age groups and the latter explicitly addressing children.
Quantitative and qualitative results show similarities and dissimilarities, thus accounting for different types of popularization
as forms of translation. The analysis aims to grant insights to translators and interpreters engaged in museum adaptations and
translation of contexts.
Are f(R, Matter) theories really relevant to cosmology?
Authors: Lacombe Osmin , Mukohyama Shinji , Seitz Josef
Published: May 2024

We examine f(R, Matter) theories that directly couple the curvature R or R
μν with the matter sector in the action, in addition to the universal coupling. We argue that if the matter sector includes the Standard Model (SM), such theories are either inconsistent or already excluded by experiments unless they are a rewriting of f(R) gravity or general relativity. If these theories genuinely couple the SM to curvature, they suffer from the presence of ghost states at energies within their domain of application for cosmological purposes. Therefore, we raise questions about their relevance to cosmology. Moreover, if such theories do not include the SM, they should just be seen as scalar-tensor, vector-tensor, …, theories, depending on the additional degrees of freedom. They should thus be studied accordingly.
Axionic defects in the CMB: birefringence and gravitational waves
Authors: Ferreira Ricardo Z. , Gasparotto Silvia , Hiramatsu Takashi , Obata Ippei , Pujolàs Oriol
Published: May 2024

The evidence for a non-vanishing isotropic cosmic birefringence in recent analyses of the
CMB data provides a tantalizing hint for new physics. Domain wall (DW) networks have recently
been shown to generate an isotropic birefringence signal in the ballpark of the measured value
when coupled to photons. In this work, we explore the axionic defects hypothesis in more detail
and extending previous results to annihilating and late-forming networks, and by pointing out
other smoking-gun signatures of the network in the CMB spectrum such as the anisotropic
birefringent spectrum and B-modes. We also argue that the presence of cosmic strings in the
network does not hinder a large isotropic birefringence signal because of an intrinsic
environmental contribution coming from low redshifts thus leaving open the possibility that
axionic defects can explain the signal. Regarding the remaining CMB signatures, with the help of
dedicated 3D numerical simulations of DW networks, that we took as a proxy for the axionic
defects, we show how the anisotropic birefringence spectrum combined with a tomographic approach
can be used to infer the formation and annihilation time of the network. From the numerical
simulations, we also computed the spectrum of gravitational waves (GWs) generated by the network
in the post-recombination epoch and use previous searches for stochastic GW backgrounds in the CMB
to derive for the first time a bound on the tension and abundance of networks with DWs that
annihilate after recombination. Our bounds extend to the case where the network survives until the
present time and improve over previous bounds by roughly one order of magnitude. Finally, we show
the interesting prospects for detecting B-modes of DW origin with future CMB experiments.
Probing Gauss-Bonnet-corrected inflation with gravitational waves
Authors: Mudrunka Kamil , Nakayama Kazunori
Published: May 2024

The low energy effective action of quantum gravity may include the higher curvature terms such as the Gauss-Bonnet term.
The inflaton dynamics may be affected by the Gauss-Bonnet term if there is an inflaton-Gauss-Bonnet coupling.
We show that an inflation model with a simple power law potential is made viable if it is coupled to the Gauss-Bonnet term since the prediction on the scalar spectral index and the tensor-to-scalar ratio are modified.
We further point out that such a model predicts huge amount of gravitational waves at the high frequency range around 100 GHz–100 THz through the perturbative inflaton decay into gravitons induced by the Gauss-Bonnet term.
Thus the spectrum of high frequency gravitational background is a unique feature of the inflation models with a Gauss-Bonnet correction.
Effect of Lewis acid-base additive on lead-free Cs2SnI6 thin film prepared by direct solution coating process
Authors: Khan Saqib Nawaz , Wang 王 Yan 燕 , Zhong 钟 Lixiang 李祥 , Liang 梁 Huili 会力 , Du 杜 Xiaolong 小龙 , Mei 梅 Zengxia 增霞
Published: May 2024

Inorganic Cs2SnI6 perovskite has exhibited substantial potential for light harvesting due to its exceptional optoelectronic properties and remarkable stability in ambient conditions. The charge transport characteristics within perovskite films are subject to modulation by various factors, including crystalline orientation, morphology, and crystalline quality. Achieving preferred crystalline orientation and film morphology via a solution-based process is challenging for Cs2SnI6 films. In this work, we employed thiourea as an additive to optimize crystal orientation, enhance film morphology, promote crystallization, and achieve phase purity. Thiourea lowers the surface energy of the (222) plane along the 〈111〉 direction, confirmed by x-ray diffraction, x-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy studies, and density functional theory calculations. Varying thiourea concentration enables a bandgap tuning of Cs2SnI6 from 1.52 eV to 1.07 eV. This approach provides a novel method for utilizing Cs2SnI6 films in high-performance optoelectronic devices.
Evolution of anomalous Hall effect in ferromagnetic Weyl semimetal NbxZr1–xCo2Sn
Authors: Chen 陈 Bo-Wen 博文 , Shen 沈 Bing 冰
Published: May 2024

Magnetic topological semimetal can host various topological non-trivial states leading to exotic novel transport properties. Here we report the systematic magneto-transport studies on the Heusler alloy Nb
x
Zr1−x
Co2Sn considered as a ferromagnetic (FM) Weyl semimetal. The cusp anomaly of temperature-dependent resistivity and large isotropic negative magneto-resistivity (MR) emerge around the FM transition consistent with the theoretical half-metallic predictions. The prominent anomalous Hall effect (AHE) has the same behavior with the applied field along various crystal directions. The Nb doping introduces more disorder resulting in the enhancement of the upturn for the temperature-dependent resistivity in low temperatures. With Nb doping, the AHE exhibits systemic evolution with the Fermi level lifted. At the doping level of x = 0.25, the AHE mainly originates from the intrinsic contribution related to non-trivial topological Weyl states.
Surface phonon resonance: A new mechanism for enhancing photonic spin Hall effect and refractive index sensor
Authors: Cheng 程 Jie 杰 , Wang 汪 Chenglong 承龙 , Li 李 Yiming 一铭 , Zhang 张 Yalin 亚林 , Liu 刘 Shengli 胜利 , Dong 董 Peng 鹏
Published: May 2024

Metal-based surface plasmon resonance (SPR) plays an important role in enhancing the photonic spin Hall effect (SHE) and developing sensitive optical sensors. However, the very large negative permittivities of metals limit their applications beyond the near-infrared regime. In this work, we theoretically present a new mechanism to enhance the photonic SHE by taking advantage of SiC-supported surface phonon resonance (SPhR) in the mid-infrared regime. The transverse displacement of photonic SHE is very sensitive to the wavelength of incident light and the thickness of SiC layer. Under the optimal parameter setup, the calculated largest transverse displacement of SiC-based SPhR structure reaches up to 163.8 μm, which is much larger than the condition of SPR. Moreover, an NO2 gas sensor based on the SPhR-enhanced photonic SHE is theoretically proposed with the superior sensing performance. Both the intensity and angle sensitivity of this sensor can be effectively manipulated by varying the damping rate of SiC. The results may provide a promising paradigm to enhance the photonic SHE in the mid-infrared region and open up new opportunity of highly sensitive refractive index sensors.
Loss Analysis of the Electromagnetic Metamaterial Applied to Antenna Size Reductions
Authors: Pang Xudong , Chen Qun , Cao Beibei , Zhu Shouzheng
Published: May 2024

The research of transformation electromagnetics uses spatial coordinate transformation method to transform Maxwell’s equations for the propagations of electromagnetic waves in space, thereby achieving the goal of designing the path of electromagnetic waves, which eventually leads to a more complex tensor design of its constitutive parameters of metamaterials. This demand for artificial design of material parameters has been combined with the rapid development of micro-scale, molecular-scale, and atomic-scale experimental engineering techniques in recent years, enabling metamaterials to be developed, fabricated, and applied in various frontier fields. In this paper, the metamaterial electromagnetic wave concentrator used to reduce the antenna size is mainly discussed and detailed simulations and researches on the electromagnetic lossy conditions of the metamaterial parameters are given, which can better verify the electromagnetic scattering performance under actual engineering conditions. Solutions and quantitative simulations for the attenuation characteristics are also provided, which can deepen the research on the engineering performance of the metamaterial electromagnetic transformation devices.
A Unified Model-Based System and Integrated Logistics Support Architecture Modeling Framework
Authors: Sun Shuhuan , Liu Peng , Liu Zhaoxing , Guo Yuqiang
Published: May 2024

Model-based system engineering(MBSE) uses the architecture model to drive system development. It has been widely used in aeronautical and aerospace systems development. Integrated Logistics Support(ILS) design is an essential part of system engineering. Still, there is no clear guidance on how to perform model-based ILS architecture modeling. This paper proposes a unified model-based system and ILS architecture modeling framework, which analyzes the relationship between the system and ILS in different life cycle concepts and gives a clear ILS architecture modeling approach. The unified system and ILS architecture modeling way will take full advantage of the model from the mission level to the system level to guarantee the different architecture perspectives consistency and save cost and time in the engineering practice.
Research on the Optimal Layout of Large Chicken Coop Chicken Rack Based on Ventilation Airflow Organization
Authors: Wu Shuyang , Shi Zhigang , Qu Zhiguang , Gao Xinming
Published: May 2024

To address the challenges associated with airflow organization in chicken coops within the Chinese poultry industry, this study conducted on-site measurements and utilized Computational Fluid Dynamics (CFD) simulations. The validity of the simulation results was confirmed through root mean square error analysis in comparison to experimental data. Subsequently, the study assessed the influence of different chicken rack arrangements within the coops, both when wet curtains were closed and opened. The findings reveal that, when wet curtains are closed, the internal coop layout significantly impacts chicken welfare, especially concerning layout changes relative to coop length. When wet curtains are open, the impact of coop layout and a 10-meter reduction in coop length on chickens is approximately equivalent. The arrangement of chicken racks within the coop has a profound effect on airflow organization. Therefore, when designing coops, careful attention to chicken rack placement is essential to ensure proper airflow organization.
An accelerated hybrid Riemannian conjugate gradient method for unconstrained optimization
Authors: Zhang Jinchao , Zhu Wei , Wang Wei , Wu Zhaochong , Zhang Xiaojun
Published: May 2024

With the goal to deal with a series of optimization problems on general matrix manifolds with differentiable objective functions, we propose an accelerated hybrid Riemannian conjugate gradient technique. Specifically, the acceleration scheme of the proposed method using a modified stepsize which is multiplicatively determined by the Wolfe line search. The search direction of the proposed algorithm is determined by the hybrid conjugate parameter with computationally promising. We showed that the suggested approach converges globally to a stationary point. Our approach performs better than the state of art Riemannian conjugate gradient algorithms, as illustrated by computations on problems such as the orthogonal Procrustes problem and the Brockett-cost-function minimization problem.
Study on Rock Mechanical Properties of Deep Volcanic Rock Reservoir
Authors: Qiu Guozhou , Chang Xin , Li Jing , Xie Ruiyang , Liu Jingheng , Li Jing
Published: May 2024

Volcanic rocks exhibit complex mechanical properties due to their special diagenetic forms. Laboratory tests were conducted to study the influence of confining pressure changes on the mechanical properties of deep volcanic rocks, and outcrop volcanic rocks single triaxial tests were conducted simultaneously to study the mechanical properties of deep volcanic rocks. The maximum deviatoric stress and elastic modulus are used to study the variation of mechanical properties of volcanic rocks with confining pressure. The maximum deviatoric stress of underground core increases linearly with the increase of confining pressure. The elastic modulus reaches its maximum at 80MPa confining pressure. Although the variation trend of mechanical parameters of underground core with confining pressure is similar to that of outcrop core with confining pressure, the underground core shows a larger maximum deviatoric stress and elastic modulus. It can be seen from the 80MPa confining pressure comparison test that the mechanical properties of underground core under high confining pressure are superior to those of outcrop core. The mechanical properties of outcrop core under high confining pressure are significantly affected by natural fractures, while the mechanical properties of underground core are less affected by natural fractures.The brittleness index of volcanic rocks decreases with the increase of confining pressure, and the decreasing range is relatively low. The brittleness index of outcrop volcanic rocks decreases with the increase of confining pressure, but its sensitivity to confining pressure is much higher than that of underground core.
Experimental Study on Spray Uniformity
Authors: Chen Dianbin , Li Hongwei , Qu Guiying , Han Xiaobo , Han Dongfei
Published: May 2024

This study involves simulating rainfall conditions to analyze rainfall intensity and spray uniformity, conducting environmental experimental research. Using numerical analysis methods, water mass fraction cloud maps under different flow conditions were obtained to determine the relationship between uniformity, water flow rate, and water mass fraction. Based on the simulation results in accordance with relevant standards, two methods for measuring rainfall uniformity are selected based on water pressure, nozzle type, and spray height as basic parameters for setting measurement points, and rainfall environmental simulation experiments are conducted. The theoretical analysis provides a clearer representation of water quality distribution than steady-state analysis; water mass fraction is proportional to water flow rate, while uniformity is independent of water flow rate. Through comprehensive comparison of uniformity data for different nozzle models under varying water pressure and height conditions, recommendations are made for the placement of rain gauges in rainfall environmental experiments. Adjusting various test environment parameters can provide references for the test lab to accurately select test equipment, parameter measurement, and evaluation; the water mist environment generated during rainfall is simulated through spray towers, and the numerical uniformity test results of the water mist environment are consistent with the requirements, providing theoretical data support for developing more authoritative test methods for equipment sprinkler tests and ultra-fine water mist environment simulation in the future.
Modeling and Simulation of Unmanned Swarm System Based on Dynamic Structure DEVS
Authors: Zhang Wangyang , Li Qingwei , Xu Xin , Li Weiqing
Published: May 2024

As a complex system with collaborative cooperation and capability emergence, the unmanned swarm system plays an important role in military, agriculture, aerospace and other fields. With the increasing complexity of unmanned swarm systems, traditional modeling methods cannot effectively describe the dynamics of swarm systems. In order to effectively design, use and evaluate unmanned swarm systems, this article conducts modeling and simulation of unmanned swarm systems based on DSDEVS(Dynamic Structure Discrete Event System Specification). Describe the unmanned swarm system from both behavioral and structural aspects. Based on component modeling, the microscopic behaviors of the unmanned platforms that constitute the unmanned swarm are described, and coupling relationships are established to describe the collaborative structure between unmanned platforms. According to the state transfer and event interaction characteristics of the unmanned swarm system, a synchronization mechanism is added to support changes in the swarm structure. This enables the unmanned swarm system to make adaptive structural adjustments according to environmental changes and its own goals during simulation operation, so as to achieve a state of enhanced capabilities and structural stability to complete the task. Finally, the effectiveness and feasibility of this method were verified through a simulation experiment of joint reconnaissance by a UAV swarm.
Optimization of the Internal Ballistic Performance of Supercritical Nitrogen Ejection
Authors: Qian Hongjun , Niu Yusen , Jiang Yi , Zhang Jingli
Published: May 2024

This paper investigates a scheme of introducing TNT into a high-pressure chamber containing supercritical nitrogen as the working substance to enhance the utilization of the working substance and the mass of the ejection missile. Based on the S-R-K real gas state equation and the quasi-static pressure and temperature prediction model of TNT, the internal ballistic equations for supercritical nitrogen are established for a missile of 30000 kg, so as to demonstrate the scheme for ejecting a large mass missile and analyze its optimization. Meanwhile, the influence of the high-pressure chamber volume and TNT initiating time on internal ballistic performances is studied, respectively. Simulation results indicate that when the capacity of the high-pressure chamber decreases and the initiating time is delayed, the peak acceleration of the missile and its ejection velocity could be steadily lowered, but the utilization of nitrogen working substance increases. Moreover, the duration of high temperatures in the low-pressure chamber increases as the delay of the initiating time grows. These conclusions could be utilized as a reference for optimizing the design of ejectors.
Launch Dynamics Analysis of Amphibious Launch Vehicle on the Sea
Authors: Cai Yunlong , Ren Ruoyu , Yi Jiang
Published: May 2024

Due to its agility, concealment and excellent amphibious combat capability, amphibious vehicles can perform tasks in complex terrain and environment, and have important application value in the field of national defense and people ’s livelihood. In this paper, the method of experimental data-driven numerical simulation analysis is used, combined with batch simulation technology, and the frequency histogram in probability statistics is used to study the launch safety of amphibious vehicles under random waves, and the influence of missile launch sequence and launch time interval on missile launch is explored. The results show that the driving and sea launch of the amphibious vehicle are safe under the experimental conditions. The partial attitude angle of the car body and the attitude angle of the missile roughly conform to the normal distribution; considering the relationship between the weight of the vehicle body and the ejection load impulse, the launch sequence and the launch time interval will not have a great impact on the missile launch. By evaluating the driving safety of the amphibious vehicle and the launch safety of the missile, this paper can provide some theoretical significance and engineering application value for the sea launch of the amphibious vehicle.
Radiation Damage Simulation Using Molecular Dynamics in Ni-Based Alloy
Authors: Shen Yanxin , Yang Yue , Ou Xuelian , Wang Peng , You Zhenjiang , Tian Xiaofeng
Published: May 2024

In the present study, we investigated the irradiation-induced induction in Ni80Cr20, Ni80Fe20, Ni50Fe50, Ni40Fe40Cr20 by molecular dynamics (MD) simulation. A previously published modified potential is used to provide a detailed account of the process involved in the production and evolution of defects. Ni50Fe50 and Ni40Fe40Cr20 alloys exhibit comparable damage level and better radiation response compared to Ni80Cr20 and Ni80Fe20. The inhibition effect of interstitial clusters increases with the complexity of alloying elements. The alloying of Cr has resulted in Ni80Fe20 and Ni50Fe50 tend to form 1/3<111> dislocation loops while at the same time making Ni40Fe40Cr20 and Ni80Cr20 more susceptible to stacking fault tetrahedra formation than the remaining two alloys.
Comparative Analysis of Influencing Factors on Heat Extraction Performance of Multi-Type Shallow Borehole Heat Exchangers
Authors: Xue Yuze , Chen Fei , Sun Wan , Guo Siyu , Kong Yanlong , Cai Wanlong , Wang Fenghao
Published: May 2024

In this paper, the influence of design parameters and geological parameters on the heat extraction capacity of common coaxial type, single U-type, and double U-type borehole heat exchangers(BHEs) in shallow ground source heat pump system is analyzed, and the heat extraction performance of different types of BHEs is further compared. The results show that with the increase in borehole depth and ground temperature gradient, the outlet temperature of the three types increases at the end of the heating season, and the single U-type BHE increases most significantly. The increase in inlet flow rate will decrease the outlet temperature of the three BHEs, and the U-type is the most obvious decrease. The increase in inlet temperature will reduce the temperature difference between inlet and outlet of the three types BHEs. Given the same design parameters, coaxial-type BHE obtains the maximum heat.
Simulation Optimization on Multi-Well Fracturing Sequence of Chang 7 Formation
Authors: Weng Dingwei , Ma Zeyuan , Tian Zhuhong , He Chunming , Liang Hongbo , Guo Ying , Yan Xuemei , Yang Zhanwei , Chen Zhuxing
Published: May 2024

In order to study the engineering problems of shale oil horizontal well platform fracturing mode, a three-dimensional geological model and a three-dimensional geomechanical model were constructed according to the characteristics of Chang 7 section in Ordos Basin. The fracture propagation under different well spacing, cluster spacing, and fracturing sequence was simulated. The PEBI grid was used to refine the local grid of the fractures and predict the performance of the multi-well pad. The finite element model was used to analyze the change of induced stress field. The numerical simulation analysis shows that: 1) Comparing the simulation results of sequence fracturing and zipper fracturing under the condition of 300 m well spacing, the induced stress generated by zipper fracturing is more conducive to the formation of complex fractures, improving the effect of transformation and higher production after fracturing. 2) Under the condition of 200 meters or 300 meters well spacing, zipper fracturing is carried out, and the cluster spacing is reduced from 5 meters to 3 meters. The stress shadow between wells and sections leads to adverse effects, and the production will decrease after fracturing. Therefore, 5 meters is recommended as the cluster spacing.
Research on Overload Early Warning System for Railcars
Authors: Zhu Lingfeng , Xue Shangqing , Chen Zixing , Bai Bingfeng , Mei Yueyuan , Chen Limin
Published: May 2024

Railcars are prone to suffer from overloading problems during its operation, which seriously affects the service life of railcars and rails, while posing a serious potential safety hazard. This paper In this paper, the weight of the car load is calculated by installation of a gravity sensor on the railcar and collection of the data from the gravity sensor through applying the A/D conversion module of the MCU. The overloading warning function of railcars is realized according to the drive alarm indicator of overloading information, and displaying the overloading information on the liquid crystal display screen.
The Experimental Method of Sparse Measurement Based on Target’s Radar Cross Section Data
Authors: Wei Ziran , Du Wei , Huang Yulu , Zhang Ting
Published: May 2024

In experiments of testing targets’ radar cross section (RCS), RCS is a measure of the target’s ability to reflect radar signals in the direction of radar reception. In order to take non blurry spatial-domain imaging of the target, sampling or measuring the target’s RCS signal must meet the Nyquist sampling theorem. However, RCS testing in microwave darkroom would produce a significant amount of sampling data, which requires a very long testing period. Based on the sparsity of spatial-domain RCS data after sparsifying transformation, a sparse projection measurement experimental method is designed for frequency-domain RCS data by sparsely sampling frequency-domain signals, fully utilizing the correlation between row and column information of two-dimensional frequency-domain data and the global sparsity of two-dimensional spatial-domain data. Finally, based on sparsely sampled data in the frequency-domain, the original RCS data is reconstructed by reconstruction algorithms, achieving the goal of effectively reducing RCS sampling data in RCS testing experiments.
Numerical-Study of Large-Liquid Rocket Plume-Flow-Field
Authors: Ren Fantao
Published: May 2024

Aiming at the complexity of plume field structure caused by plume collision in the rising section of multi-nozzle parallel rocket, this paper establishes an analytical model of the rising section of a nine-nozzle configuration rocket. The plume field phenomenon is studied at different heights through numerical simulation. The reliability of the numerical method is verified based on the comparison of simulation and wind tunnel test data. The analytical results. Show that violent collision occurs between the jets in the ascent section of the multi-nozzles rocket, and many phenomena such as circulating vortex, gas reflux, reflux back splash and so on occur at different altitudes. When the altitude is less than 25km, gas reflux and circulation vortex appear in the rocket base. With the increasing of altitude, the jet collision impacts the base. After the altitude reaches 45km, back splash appears in some areas of the rocket base. There is an obvious flow diversion phenomenon on the side wall surface. The higher the altitude, the greater the expansion angle of the jet after the gas exits the nozzle.
Numerical Simulation of Rapid Heat Storage in Plate-Fin Phase Change Heat Exchanger
Authors: Li Qiangqiang , Liu Shuo , Sun Xiaoxia , Shen Lili , Cheng Bin , Xing Haonan , Lin Min
Published: May 2024

Rapid phase change heat storage has significant application value in high-power density thermal management systems. This paper presents a comparative numerical simulation study of the rapid heat storage and release dynamics of two types of finned plate heat exchangers with different fin shapes. The study reveals that, under the same fin thickness and volume fraction, the contact surface area of triangular fins is 1.6 times that of rectangular fins, but the heat storage rate of triangular fin heat exchangers is 2 times that of rectangular fin heat exchangers. Due to the small characteristic scale and high material viscosity of the heat exchanger, the natural convection velocity of the liquid phase during the heat storage process is low, and its influence on enhancing the heat storage rate is weak.
Heavy Blimp-Based Simulation Research of Integral Tower Technology
Authors: Zhao Xingyan , Fan Rongquan , Wang Jie , Lv Junjie , Huang Jigang
Published: May 2024

The power industry is the primary energy through the power generation equipment into electricity, and then through the transmission, transformation and distribution system to supply users as energy as the industrial sector, for the industrial and national economy and other sectors to provide basic power, is the first sector of national economic development[1]. As an important link to ensure the normal operation of the power industry, the importance of the power transmission system is self-evident[2]. The transmission tower, as the cornerstone to ensure the normal operation of the transmission system, has a large construction workload and faces problems such as complex construction environment and construction safety risks. Therefore, how to ensure the safe construction of transmission line in complex terrain is of great significance to power system construction. At present, in the construction of transmission tower, the suspension pole group tower and the whole lifting tower are the two main tower construction methods widely used. However, the pylon group tower has a great safety risk[3-4]. The State Grid has been trying to optimise the suspension of the tower. Secondly, due to the inconvenience of transportation, it is difficult for heavy lifting equipment to reach the construction site, which makes it difficult to promote the whole tower scheme using heavy lifting equipment in the mountainous terrain. In addition, the current construction of the tower group lacks scientific calculation and analysis of the force and deformation of the tower and key construction components, and there are hidden dangers such as overload and excessive deformation. Therefore, a new type of tower formation is needed to avoid the risk of personnel working at high altitudes and problems such as the inability of large heavy equipment to reach the construction site in mountainous areas[5]. In this paper, simulation technology is studied against the background of integral tower technology based on airship.
Research on the Drag Reduction Performance of Bionic Micro-gradient Surfaces
Authors: Cui Xianxian , Su Lin , Chen Dengke , Chen Huawei
Published: May 2024

Long range and high speed are important performance indicators for modern naval equipment such as submarines and ships. Taking the special shield scale structure of shark epidermis as the research object, models of riblets, discontinuous riblets, equal-gradient riblets and shark-like micro-gradient riblets were established, and their effects on flow field characteristics were analyzed. Compared with smooth surfaces, the bionic micro-gradient surface had a maximum drag reduction rate of 9.93% under the combined action of streamwise vortices and spanwise secondary vortices, and maintained a good drag reduction effect over a wide speed range. The bionic micro-gradient surface provides a potential reference for underwater mechanical drag reduction design.
Influence of external magnetic field on intraband transitions in lens-shaped quantum dot
Authors: Mkrtchyan M.A. , Sarkisyan H.A.
Published: May 2024

Intraband linear and nonlinear optical absorption in a strongly oblate lens-shaped Ge/Si quantum dot in the presence of an axial magnetic field was theoretically studied. Quantum transitions are considered in the heavy hole subband, when the scalar effective mass approximation is correct. The linear and nonlinear absorption coefficients, refractive index changes and the second harmonic generation coefficient were determined. The influence of the effects of temperature, size quantization and magnetic field on the behavior of the above parameters was revealed.
Development of wavelength-shifting PEN foils for next generation experiments
Authors: Kuźniak M. , Pawłowski S. , Abramowicz A. , Cortez A.F.V. , Kumosiński M. , Łęcki T. , Nieradka G.
Published: May 2024

Polyethylene naphthalate (PEN) foils have been demonstrated as a wavelength shifter suitable for operation in liquid argon. At the same time, wavelength shifting efficiency of technical grades of PEN, commercially available on the market, is lower than that of tetraphenyl butadiene (TPB). This paper reports on an R&D program focused on exploring the intrinsic limitations of PEN and optimizing it for the highest achievable wavelength shifting efficiency.
Cryogenic setup for the characterization of wavelength-shifting materials for noble element radiation detectors
Authors: Choudhary S. , Cortez A.F.V. , Kuźniak M. , Nieradka G. , Sworobowicz T. , Świderski Ł. , Szczęśniak T.
Published: May 2024

In the present work, we describe a new cryogenic setup for studies of wavelength-shifting materials for optimised light collection in noble element radiation detectors, and discuss the commissioning results. This SiPM-based setup uses
α
induced scintillation in gaseous argon as the vacuum ultraviolet light source with the goal of characterising materials, such as polyethylene naphthalate (PEN) and tetraphenyl butadiene (TPB), in terms of their wavelength-shifting efficiency. Preliminary results obtained with the system are consistent with the ones reported in literature: 0.5±0.05 in terms of WLS efficiency (PEN/TPB). A value of 1.24 μs was obtained for the triplet lifetime in Ar, which is a factor of 2.6 smaller than the one described in literature due to the presence of impurities. Further extensions of the system are currently being studied. The foreseen upgrades are expected to allow the study of GEM-like structures potentially interesting for rare-event searches. The design of the setup will be addressed along with the first results.
Development of a silicon-based thermal neutron detection system
Authors: Alsulimane A.Mohammad E. , Jon Taylor B. , Carlos Barajas C. , Alan Taylor D. , Gianluigi Casse E. , Ahmed Omar B. , Sergey Burdin F.
Published: May 2024

Neutron detection systems are of increasing importance in applications from basic science to medical applications and reactors. 3He proportional counters remain the most popular choice for monitoring thermal neutrons with a detection efficiency of around 60%, however, due to 3He global shortages, a new generation of detection technologies will be required to meet the rising demand. As a result, extensive research is being conducted to investigate alternative methods of neutron detection.

This work presents such a system and demonstrates its calibration and evaluation using an AmBe neutron source. The detection system involves silicon sensors coated by converter layers to make the detectors sensitive to thermal neutrons via neutron capture and measurement of the resulting secondary charged particles. The detection system is presented in two configurations, a single and a multi-layer configuration, where the latter is used to increase the total detection efficiency. In addition, the system is capable of determining coincident signals from a single neutron capture, a feature which allows background suppression and an increase in the purity of the neutron signal which is particularly useful in mixed radiation environments.
Data reduction strategy in the PandaX-4T experiment
Authors: Zhou Yubo , Chen Xun ,   the PandaX-4T collaboration
Published: May 2024

The PandaX-4T experiment is designed for multiple purposes, including searches for solar neutrinos, weakly interacting massive particles, and rare double beta decays of xenon isotopes. The experiment produces a huge amount of raw data that needs to be stored for related physical analyses in a wide energy range. With the upgrading of the PandaX-4T experiment, the doubled sampling rate resulted in a larger data size, which challenges both the cost and the data processing speed. To address this issue, we propose a data reduction strategy by removing the noise tail of large signals and downsampling the remaining parts of them. This strategy reduces the requirement for storage by 65% while increasing data processing speed. The influences on physical analyses on different topics at different energy regions are negligible.
Machine learning evaluation in the Global Event Processor FPGA for the ATLAS trigger upgrade
Authors: Jiang Zhixing , Carlson Ben , Deiana Allison , Eastlack Jeff , Hauck Scott , Hsu Shih-Chieh , Narayan Rohin , Parajuli Santosh , Yin Dennis , Zuo Bowen
Published: May 2024

The Global Event Processor (GEP) FPGA is an area-constrained, performance-critical element of the Large Hadron Collider's (LHC) ATLAS experiment. It needs to very quickly determine which small fraction of detected events should be retained for further processing, and which other events will be discarded. This system involves a large number of individual processing tasks, brought together within the overall Algorithm Processing Platform (APP), to make filtering decisions at an overall latency of no more than 8ms. Currently, such filtering tasks are hand-coded implementations of standard deterministic signal processing tasks.

In this paper we present methods to automatically create machine learning based algorithms for use within the APP framework, and demonstrate several successful such deployments. We leverage existing machine learning to FPGA flows such as hls4ml and fwX to significantly reduce the complexity of algorithm design. These have resulted in implementations of various machine learning algorithms with latencies of 1.2 μs and less than 5% resource utilization on an Xilinx XCVU9P FPGA. Finally, we implement these algorithms into the GEP system and present their actual performance.

Our work shows the potential of using machine learning in the GEP for high-energy physics applications. This can significantly improve the performance of the trigger system and enable the ATLAS experiment to collect more data and make more discoveries. The architecture and approach presented in this paper can also be applied to other applications that require real-time processing of large volumes of data.
SPIRAL2 commissioning and operations
Authors: Orduz A.K. , Di Giacomo M. , Lagniel J-M. , Normand G. , Uriot D.
Published: May 2024

The SPIRAL2 linac is now successfully commissioned;
H+, 4He2+, D+ and 18O6+ have been
accelerated up to nominal parameters and 18O7+ and
40Ar14+ beams have been also accelerated up to
7 MeV/A. The main steps with 5 mA H+, D+ beams
and with 0.6 mA 18O6+ are described. The general results
of the commissioning of the RF, cryogenic and diagnostics systems,
as well as the preliminary results of the first experiments on NFS
are presented. In addition of an improvement of the matching to the
linac, the tuning procedures of the 3 Medium Energy Beam Transport
(MEBT) rebunchers and 26 linac SC cavities were progressively
improved to reach the nominal parameters in operation, starting from
the classical “signature matching method”. The different cavity
tuning methods developed to take into account our particular
situation (very low energy and large phase extension) are
described. The tools developed for an efficient linac tuning in
operation, e.g. beam energy and intensity changes are also
discussed.
Fine tuning of gas system and performance studies of RPC detectors in the INO's mini-ICAL detector
Authors: L Umesh , Shinde R.R. , Sharma Kirti Prakash , Majumder G. , Shah Manish , Ravindran K.C. , Saraf M.N. , Satyanarayana B.
Published: May 2024

The India-based Neutrino Observatory's (INO) Iron CALorimeter (ICAL) experiment will be instrumented with about 28,800 large area glass Resistive Plate Chambers (RPCs) as active detector elements. The mini-ICAL, which is a 600-times scaled-down prototype version of the ICAL, is currently in operation at the Inter Institutional Centre for High Energy Physics (IICHEP), a transit campus of the INO project in Madurai, India.
The 4 m×4 m detector comprises an ∼ 85 t magnet, built using 11 layers of iron plates to accommodate 10 layers of RPCs — two RPCs per layer. A closed-loop gas system (CLS) is designed to supply gas mixture of R134a (95.2%), isobutane (4.5%), and SF
6 (0.3%) to the mini-ICAL, collect the return gas from the RPCs, purify it using filters, and recirculate the mixture into the detector. Contamination of any kind into the gas mixture will severely affect the characteristics of the RPC detectors, such as the dark current and noise rates, and consequently deteriorate performance of the RPC detector. The contamination is mainly caused due to leaks within the gas system, in the gas lines and in the RPC gas gap volume. This paper deals with systematic identification and mitigation of leaks within the closed-loop gas system and performance improvement of the RPCs installed in the mini-ICAL detector.