bluuebunny/crossref_metadata_2025_split huggingface dataset:
Constructing an integrable spin–boson model with open boundary conditions
Authors: Yao Hongjia , Hao Kun 
Published: November 2024

Abstract
We investigate the integrability of the Rabi model, which is traditionally viewed as not Yang–Baxter-integrable despite its solvability. Building on efforts by Bogoliubov and Kulish (2013 J. Math. Sci.
192 14–30), Amico et al (2007 Nucl. Phys. B
787 283–300), and Batchelor and Zhou (2015 Phys. Rev. A
91 053808), who explored special limiting cases of the model, we develop a spin–boson interaction Hamiltonian under more general boundary conditions, particularly focusing on open boundary conditions with off-diagonal terms. Our approach maintains the direction of the spin in the z direction and also preserves the boson particle number operator a
†
a, marking a progression beyond previous efforts that have primarily explored reduced forms of the Rabi model from Yang–Baxter algebra. We also address the presence of ‘unwanted’ quadratic boson terms a
2 and a
†2, which share coefficients with the boson particle number operator. Interestingly, these terms vanish when spectral parameter u = ± θ

s
, simplifying the model to a limiting case of operator-valued twists, a scenario previously discussed by Batchelor and Zhou (2015 Phys. Rev. A
91 053808).
Angularity in Higgs boson decays via H→gg at NNLL' accuracy*
Authors: Zhu 朱 Jiawei 佳伟 , Song 宋 Yujin 昱锦 , Gao 高 Jun 俊 , Kang Daekyoung , Maji Tanmay 
Published: November 2024

Abstract
We present improved predictions of a class of event-shape distributions called angularity for a contribution from an effective operator

in Higgs hadronic decay that suffers from large perturbative uncertainties. In the framework of the soft-collinear effective theory, logarithmic terms of the distribution are resummed at NNLL' accuracy, for which a two-loop constant of gluon-jet function for angularity is independently determined using a fit to the fixed-order distribution at the NLO corresponding to

relative to the Born rate. Our determination has reasonable agreement with the value in a recently released thesis. In the fit, we use an asymptotic form with a fractional power conjectured from recoil corrections at one-loop order, and it improves the accuracy of determining positive values of the angularity parameter a. The resummed distribution is matched to the NLO fixed-order results to make our predictions valid at all angularity values. We also discuss the first and subtracted moments of angularity as a function of a that enable the extraction of information on leading and subleading nonperturbative corrections associated with gluons.
On the rationale for recent updates to the SI Brochure concerning angles and quantities with the unit one
Authors: Brown Richard J C , Stock Michael 
Published: November 2024

Abstract
This paper documents the recent evolution of the International System of Units (SI) Brochure, the official document describing the SI, the only globally agreed system of units. In particular, the changes implemented in the most recent version of the 9th edition of the SI Brochure, version 3.01, published in August 2024 are described, along with the rationale for these updates. It is explained that these updates originated from work done by the International Committee for Weights and Measures’ Consultative Committee for Units and have concentrated on the treatment of angle and quantities with the unit one. The aim of the changes in these specific areas has been to provide clarification, harmonise language, improve understanding, acknowledge nuance and reflect new consensus in the understanding of these quantities and their application. By outlining the process and rationale behind these updates, it is hoped that users of the SI Brochure are provided with improved transparency and a better understanding of the ongoing development of this essential document.
Atomic frequency standards, physical constants, and metrology
Authors: Vanier Jacques 
Published: November 2024

Abstract
The paper describes the physics behind the change that has taken place recently of the nature of the International System of Units, commonly called SI. This change took place in 2019 in the definition of the units forming the basis of the System: those base units, some of them defined originally by means of laws and artefacts, are now all defined in terms of physical constants. An important aspect of this fundamental change is the role played by the base unit, the second, associated with frequency and time measurements. Its definition in terms of the ground state hyperfine frequency of the 133Cs atom plays now a central role entering into the definition of all base units, except the mol. The paper shows how this is done and consequently shows the importance of the developments of atomic frequency standards for obtaining the greatest precision and accuracy in the field of metrology.
Development of a molecular Hg2 clock to investigate fundamental physics
Authors: Witkowski M. , Linek A. , Zawada M. , Ciuryło R. 
Published: November 2024

Abstract
We describe the development of an experimental system based on ultra-cold Hg atoms. We will use it to explore search possibilities for new interactions beyond the Standard Model. For this proposal, we will use two-color photoassociation and molecular clock transitions, and we will test the linearity of King’s plot with clock transitions in ultra-cold mercury.
Atomic Clock Ensemble in Space
Authors: Cacciapuoti L. , Busso A. , Jansen R. , Pataraia S. , Peignier T. , Weinberg S. , Crescence P. , Helm A. , Kehrer J. , Koller S. , Lachaud R. , Niedermaier T. , Esnault F.-X. , Massonnet D. , Goujon D. , Pittet J. , Perri A. , Wang Q. , Liu S. , Schaefer W. , Schwall T. , Prochazka I. , Schlicht A. , Schreiber U. , Laurent P. , Lilley M. , Wolf P. , Salomon C. 
Published: November 2024

Abstract
The Atomic Clock Ensemble in Space (ACES) mission is developing high performance clocks and links for space to test Einstein’s theory of general relativity. From the International Space Station, the ACES payload will distribute a clock signal with fractional frequency stability and accuracy of 1 × 10−16 establishing a worldwide network to compare clocks in space and on the ground. ACES will provide an absolute measurement of Einstein’s gravitational redshift, it will search for time variations of fundamental constants, contribute to test topological dark matter models, and perform Standard Model Extension tests. Moreover, the ground clocks connected to the ACES network will be compared over different continents and used to measure geopotential differences at the clock locations.
After solving some technical problems, the ACES flight model is now approaching its completion. System tests involving the laser-cooled Cs clock PHARAO, the active H-maser SHM and the on-board frequency comparator FCDP have measured the performance of the clock signal delivered by ACES. The ACES microwave link MWL is currently under test. The single-photon avalanche detector of the optical link ELT has been tested and will now be integrated in the ACES payload.
The ACES mission concept, its scientific objectives, and the recent test results are discussed here together with the major milestones that will lead us to the ACES launch.
Low-noise optical frequency divider for precision measurement
Authors: Jiang Yanyi , Shi Haosen , Yao Yuan , Yu Hongfu , Ma Longsheng 
Published: November 2024

Abstract
We describe the development of an accurate optical frequency divider based on a Ti:Sapphire optical frequency comb. The division instability and uncertainty of the optical frequency divider are demonstrated to be 10−18 at 1 s averaging time and 3 × 10−22, respectively. The ability of coherence transfer is also demonstrated by resolving a hertz-level-linewidth spectroscopy.
Progress on Optical Clock Technology for Operational Timescales
Authors: Peil S. , Tobias W. , Whalen J. , Hemingway B. , Akin T. G. 
Published: November 2024

Abstract
While optical clock technology has advanced rapidly in recent years, incorporating the technology into operational timescales has progressed more slowly. The highest accuracy frequency standards for groundbreaking measurements do not easily translate to critical timing where continuous, uninterrupted operation over many months and years is required. For example, intermittent steering of a hydrogen maser with an optical standard fails to harness all of the dramatic improvements possible with optical technology. Here we present progress on development and integration of optical-clock technology for operational timescales. An optical oscillator steered to an atomic fountain comprises a hybrid clock with optical-level stability at short times and a reliable long-term reference, and obviates the need for a steered maser. Atomic-beam optical clocks are being developed to support 24/7 operations at a level that improves upon the performance of the U.S. Naval Observatory’s rubidium fountains. An optical-lattice is being developed as a gold-standard frequency reference, complementing the role of the atomic beam clocks.
171Yb+ ion optical clock at NPL: advances in automation and assessment of the trap-induced ac Zeeman shift in an endcap trap geometry
Authors: Curtis E. A. , Tofful A. , Parsons A. O. , Robertson B. I. , Godun R. M. 
Published: November 2024

Abstract
Ensuring robust operation of optical clock systems requires increasingly complex automation of experimental protocols. This includes real-time monitoring of system output for data validation and for high accuracy assessment of systematic frequency shifts. We report here on recent advances in the control system of the 171 Yb+ ion optical clock at NPL (National Physical Laboratory, UK) and describe how this has led to improvements in systematic shift metrology and reduced the overall uncertainty budget for the optical clock. Additionally we present an assessment of the rf trap drive-induced ac Zeeman effect for our experimental system. These system advances enable us to provide improved contributions to the international efforts in the redefinition of the SI second and other applications such as tests of fundamental physics.
Development of commercial fountain clocks in NIM
Authors: Liu Kun , Zheng Fasong , Chen Weiliang , Yacong Xiao , Dai Shaoyang , Fang Fang 
Published: November 2024

Abstract
A new Rb fountain clock has been built in NIM aiming to operate semi-continuously and achieve an excellent long-term instability for time keeping. A double metal microwave cavity with a thermal expansion self-compensating mechanism is used for Ramsey interrogation to reduce the sensitivity to ambient temperature fluctuations and increase the operating temperature range. With an optimized design, the thermal coefficient of the resonance frequency has been reduced to less than 10 kHz/°C. This represents an improvement of more than an order of magnitude compared to a copper cavity. The optical system with two independent frequency stabilized lasers with automatic re-locking system is located on a 400×600 mm optical breadboard with special designed optical mounts to ensure stable output light powers, which ensure to resume operating without any realignment of optical system after transportation. The clock has been operated for more than a year without any failure. A long-term instability of 3.7×10−16 was achieved compared with NIM5 Cs fountain clock. By implementing feedback of the frequency difference to the Voltage Controlled Crystal Oscillator within a servo-loop, the fountain clock can generate a standard frequency output, the instability of which can enter 10−16 order at 40000 seconds.
Ultrastable lasers: investigations of crystalline mirrors and closed cycle cooling at 124 K
Authors: Ma C Y , Yu J , Legero T , Herbers S , Nicolodi D , Kempkes M , Riehle F , Kedar D , Robinson J M , Ye J , Sterr U 
Published: November 2024

Abstract
We have investigated crystalline AlGaAs/GaAs optical coatings with three ultra-stable cavities operating at 4 K, 16 K, 124 K and 297 K. The response of the cavities’ resonance frequencies to variations in optical power indicates non-thermal effects beyond the photo-thermo-optic effect observed in dielectric coatings. These effects are strongly dependent on the intensity of the intracavity light at 1.5 μm. When the rear side of the mirrors is illuminated with external light, we observe a prominent photo-modified birefringence for photon energies above the GaAs bandgap, which points to a possible mechanism relating our observations to the semiconductor properties of the coatings. Separately, we also present a low maintenance evolution of our 124 K silicon cavity system where the liquid nitrogen based cooling system is replaced with closed cycle cooling from a pulse-tube cryo-cooler.
Limitations of Electric Drive and Local Control Systems in Asymmetric Rolling of Fine-Grained Steels
Authors: Pesin A.M. , Kornilov G.P. , Bochkarev A.A. , Pustovoytov D.O. 
Published: November 2024

Abstract
Rolling with different circumferential speeds of work rolls, each of which is driven by two independent motors, is the most suitable way to implement asymmetric rolling technology. The paper studies the limiting capabilities of an induction motor electric drive of an asymmetric rolling mill. It has been investigated that during asymmetric rolling in the torque limitation zone, the drive roll speed significantly decreases relative to the specified speed. This is due to the limitation of the current consumed by the work roll motor rotating at a higher speed. This phenomenon significantly limits the real range of the asymmetry factor at large thickness reductions. An improved control system for the work roll electric drive for the speed asymmetry mode has been developed. Such a system can be used, among other things, on multi-stand asymmetric rolling mills. Using low-carbon steel as an example, a study was carried out on the relationship between the actual asymmetry factor and the grain refinement capabilities during asymmetric hot rolling. Fine-grained microstructure with an average grain size of 1.45 μm (grain size number G=15.57 according to ASTM E1382) was obtained. It is expected that increase of the actual asymmetry factor above 1.6 in asymmetric hot rolling has the potential to further refine the average grain size in the processed steels to 1 μm or even lower.
Influence of Wear on Surface Crack Growth of PPS Thrust Bearing in Water Lubrication under 2300 N at 1200 rpm
Authors: Kajiwara Shuhei , Machino Sasuga , Kida Katsuyuki 
Published: November 2024

Abstract
Many factors determine the fatigue life of mechanical components for transmission of rotational motion. In particular, since engineering polymer components exhibit complex tribological behaviours, a variety of studies are needed. For this reason, a large number of studies have been published on polymer components under rolling and sliding contacts. However, researches on the subject have been done for specific conditions. In addition, it is still unclear whether the finding can be applied to bearing based on industrial standards. For ball bearing based on the industrial standards, several studies suggest that the fatigue life of polymer bearings under water was caused by flaking with surface cracks. On the other hand, these studies did not discuss the initiation and propagation of the surface crack under the effect of wear. Therefore, fatigue tests under rolling contact were performed in this study to investigate the surface crack behaviour on the groove surface of PPS thrust bearing based on industrial standards.
Numerical modelling of gas flow in a random packed bed with a helical flow deflector
Authors: Marek Maciej 
Published: November 2024

Abstract
Random packed beds are often employed in chemical reactors as a means to increase the contact surface between reactants or a catalyst. The present work proposes a helical flow deflector placed within the bed and numerical simulations are performed to analyse the influence of the deflector on the tortuosity of the flow paths in the reactor and the pressure drop. The geometry of the packed bed is obtained in a separate numerical simulation with sequential deposition of ring-like equilateral particles. The flow equations are solved on a structured grid and the immersed boundary method accounts for the complex geometry of the random packing and the cylindrical walls of the reactor. The increase of the tortuosity leads to increase of the pressure drop along the reactor and the relation between them is studied as a function of the rise per revolution of the helical surface.
East–West asymmetry in intensity, duration, frequency of heatwaves over Northern India
Authors: Dalal Ganaraj , Chaudhary Shushobhit , Dutta Riya , Karmakar Subhankar , Koppa Akash , Hari Vittal 
Published: November 2024

Abstract
Anthropogenic global warming has led to widespread increase in the heatwave intensity, duration, and frequency (HIDF) of events across the globe. Although the three characteristics of heatwaves are closely interconnected, they are often studied separately, especially over the Indian subcontinent. Here, we assess the HIDF over India during the period 1961–2023, and show that there exists a systematic East–West asymmetry in their characteristics over northern India. Specifically, we show that a substantial increase (decrease) in HIDF exists over major cities in the western (eastern) parts of North India. For example, Ahmedabad (a city in the western part) shows a 67.5% increase in the likelihood of four-day heatwaves in the recent decades (1991–2023) compared to the reference period 1961–1990. On the other hand, in the city of Patna (in the eastern part), we notice a 78% decrease in the likelihood of four-day heatwaves in the recent decades. Furthermore, we show that the East–West asymmetry in the HIDF is caused by a major climatic mode, i.e. the Atlantic Niño. Overall, our study provides a first insight into the contrasting characteristics of heatwaves over Northern India and their potential drivers. Such information is vital for the design of regionally appropriate adaptation strategies across India.
Does artificial intelligence bias perceptions of environmental challenges?
Authors: van der Ven Hamish , Corry Diego , Elnur Rawie , Provost Viola Jasmine , Syukron Muh , Tappauf Niklas 
Published: November 2024

Abstract
Artificial intelligence (AI) is reshaping how humans obtain information about environmental challenges. Yet the outputs of AI chatbots contain biases that affect how humans view these challenges. Here, we use qualitative and quantitative content analysis to identify bias in AI chatbot characterizations of the issues, causes, consequences, and solutions to environmental challenges. By manually coding an original dataset of 1512 chatbot responses across multiple environmental challenges and chatbots, we identify a number of overlapping areas of bias. Most notably, chatbots are prone to proposing incremental solutions to environmental challenges that draw heavily on past experience and avoid more radical changes to existing economic, social, and political systems. We also find that chatbots are reluctant to assign accountability to investors and avoid associating environmental challenges with broader social justice issues. These findings present new dimensions of bias in AI and auger towards a more critical treatment of AI’s hidden environmental impacts.
A q-version of the relation between the hypercube, the Krawtchouk chain and Dicke states
Authors: Bernard Pierre-Antoine , Poliquin Etienne , Vinet Luc 
Published: November 2024

Abstract
It is shown how the spin chain based on dual q-Krawtchouk polynomials is connected to a weighted hypercube through the use of q-Dicke states. The representation theoretic underpinnings based on the quantum algebra

U
q

(

su

(
2
)
)

are emphasized.
Designing quantum circuits for decoding binary linear codes
Authors: Yoo Hyungkee , Choi Whan-Hyuk , Lee Yoonjin 
Published: November 2024

Abstract
In the coding theory, it is one of the most important research problems to find an efficient algorithm for the decoding process. A quantum computer is an innovative computing device that performs calculations using the principles of quantum mechanics. In this paper, we find a decoding algorithm for binary linear codes using quantum circuits; this is the first time that quantum circuits are used as a main tool for decoding binary linear codes. Our decoding algorithm is mainly based on Grover’s search algorithm. In detail, we study the process of implementing the exhaustive search using quantum circuits for decoding binary linear codes. For our purpose, we design a modified Grover’s algorithm (algorithm 1) using three tools: the matrix multiplier, the Hamming weight counter, and the state indicator. We present algorithm 2, which is a quantum decoding algorithm for binary linear codes. We illustrate algorithm 1 using the [7, 4, 3] Hamming code, and algorithm 2 is implemented by IBM Quantum Composer.
Exploring the wear mechanism of surface hardfacing Stellite 6 alloy on the cast iron over the wide temperature range
Authors: Luo Changzeng , Li Zhijie , Zeng Xiaoxiao , Ma Xiaoyue , Qu Shengguan , Sun Pengfei 
Published: November 2024

Abstract
Cast iron is widely used as a heat-resistant material in the automotive industry, but it increasingly struggles to meet the demands of high-temperature friction applications. This study employs surface hardfacing with Stellite 6 alloy to improve the wear resistance of cast iron. By conducting sliding friction tests at various temperatures, we systematically investigate the friction behavior of both cast iron and hardfacing specimens over a broad temperature range. The results reveal that hardfacing-treated specimens exhibit exceptional wear resistance. At ambient temperatures, the hardfacing specimen shows a 65.5% reduction in wear loss compared to the cast iron specimen. This reduction increases to 83.8% at temperatures up to 600 °C. At room temperature, the wear mechanisms of cast iron include abrasive wear and fatigue wear. At medium temperatures, abrasive wear is the primary mechanism of cast iron. At high temperatures, the wear mechanisms of cast iron consist of abrasive wear, oxidative wear, and adhesive wear. In contrast, the wear mechanisms of the hardfacing specimens differ: at room and medium temperatures, abrasive wear is the predominant mechanism, while at high temperatures, the main mechanisms are abrasive wear and adhesive wear. The superior mechanical properties and enhanced resistance to high-temperature oxidation of the hardfacing specimens are the primary factors contributing to their improved friction performance across the temperature spectrum.
The problematic
Authors: Davies Wendy 
Published: November 2024

Abstract
This introduction sets the scene in time, place, and cultural contexts. After indicating the basic geography of the region and summarizing its political trends and ecclesiastical structures, it goes on to survey early medieval writing about gardens and garden practice in western Europe and in al-Andalus, with attention to the place of gardening in Visigothic monastic thinking and its biblical origins. It ends by posing the main questions that set the agenda for the book: Was gardening practised? What was grown? Who were the gardeners? Did they garden for a market? Did practice reflect the idealized descriptions of gardens in literature?