bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Cyclodextrin Cross-linked Polymers Used in Environmental Applications by Solid-state NMR Spectroscopy: a Historical Review
Authors: Lacalamita D. , Bertini S. , Mongioví C. , Cosentino C. , Morin-Crini N. , Torri G. , Fourmentin M. , Naggi A. , Fourmentin S. , Guerrini M. , Crini G.
Published: March 2024

Cross-linked cyclodextrin polymers are attracting increasing interest not only from the scientific community but also from industry. These commercial polymers, discovered in the late 1960s, have applications in many fields, from pharmaceuticals to food processing, chromatography, cosmetics, membrane materials, and the environment. More recently, this class of functional polymers have been proposed as biosorbents to treat wastewater contaminated by conventional pollutants, such as metals, polycyclic aromatic hydrocarbons, phenols, and dyes, or emerging pollutants such as hormones, antibiotics, alkylphenols, and fluorine derivatives. However, although many results have been published, many questions remain not only on the chemical structure of the macromolecular networks of these polymers but also on the biosorption mechanisms involved in their use as biosorbents to treat pollutants. Solid-state NMR spectroscopy can help to answer these questions. This chapter aims to summarize and discuss the role of solid-state NMR spectroscopy in characterizing the structure of cross-linked cyclodextrin polymers and the interactions involved in biosorption using the state of the art and our own research results obtained over 25 years.
Anomalous proton transfer of a photoacid HPTS in nonaqueous reverse micelles
Authors: Jang Taehyung , Lee Sebok , Pang Yoonsoo
Published: March 2024

Excited-state proton transfer of a photoacid HPTS becomes solvent-independent in small methanol- and water-in-oil reverse micelles. We attribute anomalous proton transfers from the bulk solutions to the limited solvation dynamics inside the micelles.
A novel method of alkoxyamine homolysis activation via photochemical rearrangement
Authors: Cherkasov Sergey , Parkhomenko Dmitriy , Morozov Denis , Bagryanskaya Elena
Published: March 2024

Photorearrangement of the nitrone group into the oxaziridine one in the nitroxide part of alkoxyamines leads to a decrease in the homolysis activation energy of up to 10 kJ mol−1.
Core–shell magnetic zinc-based molecularly imprinted polymer: a robust heterogeneous catalytic nanoreactor toward the CO2 fixation reaction
Authors: Nasiriani Tahereh , Adabi Nigjeh Neda , Shaabani Ahmad
Published: March 2024

This study deals with the synthesis of a core–shell magnetic zinc-based molecularly imprinted polymer (M-Zn-MIP) as a robust heterogeneous catalytic nanoreactor. The catalytic activity of the M-Zn-MIP was explored in the CO2 fixation reaction.
Composite materials based on halloysite clay nanotubes and cellulose from Posidonia oceanica sea balls: from films to geopolymers
Authors: Calvino Martina Maria , Cavallaro Giuseppe , Milioto Stefana , Lazzara Giuseppe
Published: March 2024

The combination of natural halloysite nanotubes and cellulose recovered from egagropili is effective to fabricate composite films and geopolymers promising for packaging and building applications, respectively.
Liquid-based electronic materials for bioelectronics: current trends and challenges
Authors: Park Kijun , Park Sangwoo , Jo Yejin , Kim Soo A. , Kim Tae Young , Kim Sangwon , Seo Jungmok
Published: March 2024

Liquid-based electronic materials take bioelectronics a step forward to a seamlessly integrated human–machine interface owing to their conformability, durability, biocompatibility and flexibility.
Moisture-cured solvent free silylated poly(ether-urea) pressure-sensitive adhesives (PSAs) for use as skin adhesives for application in transdermal drug delivery (TDD)
Authors: Efstathiou Spyridon , Nurumbetov Gabit , Ross Andrew , Li Yongguang , Haddleton David M.
Published: March 2024

Improving the adhesion and tack of pressure-sensitive adhesives (PSAs) in the absence of tackifier resins or fillers remains an ongoing challenge.
Enlisting electrochemistry to reveal melanin's redox-related properties
Authors: Kim Eunkyoung , Wang Zheng , Phua Jun Wei , Bentley William E. , Dadachova Ekaterina , Napolitano Alessandra , Payne Gregory F.
Published: March 2024

Melanins have complex structures, difficult-to-characterize properties, and poorly understood biological functions. Electrochemical methods are revealing how melanin's redox-state molecular-switching is coupled to its electron-transfer activities.
Chemical tools for the Gid4 subunit of the human E3 ligase C-terminal to LisH (CTLH) degradation complex
Authors: Yazdi Aliakbar Khalili , Perveen Sumera , Dong Cheng , Song Xiaosheng , Dong Aiping , Szewczyk Magdalena M. , Calabrese Matthew F. , Casimiro-Garcia Agustin , Chakrapani Subramanyam , Dowling Matthew S. , Ficici Emel , Lee Jisun , Montgomery Justin I. , O'Connell Thomas N. , Skrzypek Grzegorz J. , Tran Tuan P. , Troutman Matthew D. , Wang Feng , Young Jennifer A. , Min Jinrong , Barsyte-Lovejoy Dalia , Brown Peter J. , Santhakumar Vijayaratnam , Arrowsmith Cheryl H. , Vedadi Masoud , Owen Dafydd R.
Published: March 2024

A chemical probe (PFI-7) for the Gid4 subunit of the human E3 ligase CTLH degradation complex.
Optimization of CoFe2O4 nanoparticles and graphite fillers to endow thermoplastic polyurethane nanocomposites with superior electromagnetic interference shielding performance
Authors: Anju  , Masař Milan , Machovský Michal , Urbánek Michal , Šuly Pavol , Hanulíková Barbora , Vilčáková Jarmila , Kuřitka Ivo , Yadav Raghvendra Singh
Published: March 2024

TPU-based nanocomposites containing graphite and CoFe2O4 nanoparticles for EMI shielding application.
Bimetallic metal organic framework/Ni doped ZnO nanomaterials modified carbon paste electrode for selective electrochemical determination of ciprofloxacin
Authors: Sadeghi Susan , Javanshiri-Ghasemabadi Javad
Published: March 2024

In this work, an efficient and sensitive electrochemical sensor based on Cu/Ce-MOF/NZP/CPE for the determination of ciprofloxacin (CIP) is reported.
Advanced MnOx/MnWO4 hetero-nanoflakes with abundant oxygen vacancies for high-performance flexible asymmetric supercapacitors with high energy density
Authors: Yin Yanli , Wang Jingli , Chen Sihao , Han Nengneng , Chen Zhiliang , Jing Yuezhou , Zhang Yahui , Xu Juan , Li Zhongyang
Published: March 2024

High-performance flexible supercapacitors assembled with MnOx/MnWO4@C-3 hetero-nanoflake anodes, exhibiting a maximum areal energy density of 48.49 mW h cm−2.
Polymeric polyiodo-chlorotellurates(iv): new supramolecular hybrids in halometalate chemistry
Authors: Korobeynikov Nikita A. , Usoltsev Andrey N. , Sokolov Maxim N. , Novikov Alexander S. , Adonin Sergey A.
Published: March 2024

Reaction between TeO2 and I2 in HCl afforded a series of supramolecular hybrids Cat2{[TeCl6](I2)} (1–5) where diiodine fragments are linked to [TeCl6]2− octahedra via halogen bonds (XB).
Host compounds based on the rigid 9,10-dihydro-9,10-ethanoanthracene framework: selectivity behaviour in mixed isomeric dichlorobenzenes
Authors: Barton Benita , Caira Mino R. , Senekal Ulrich , Hosten Eric C.
Published: March 2024

Two anthracenyl-derived host compounds (H2, H3), present in their inactive forms in the H2·o-DCB, 3(H2)·m-DCB and H3·m-DCB complexes (where DCB is dichlorobenzene), were shown to possess separation ability for these DCBs.
Determining the mechanical and decomposition properties of high energetic materials (α-RDX, β-HMX, and ε-CL-20) using a neural network potential
Authors: Wen Mingjie , Chang Xiaoya , Xu Yabei , Chen Dongping , Chu Qingzhao
Published: March 2024

NNP models covering three typical C/H/N/O element HEMs were developed to capture the mechanical and decomposition properties of RDX, HMX and CL-20. The decomposition trajectory is mainly divided into two stages: pyrolysis and oxidation.
Memory effect and coexistence of negative and positive photoconductivity in black phosphorus field effect transistor for neuromorphic vision sensors
Authors: Kumar Arun , Intonti Kimberly , Viscardi Loredana , Durante Ofelia , Pelella Aniello , Kharsah Osamah , Sleziona Stephan , Giubileo Filippo , Martucciello Nadia , Ciambelli Paolo , Schleberger Marika , Di Bartolomeo Antonio
Published: March 2024

Black phosphorus (BP) field-effect transistors with ultrathin channels exhibit unipolar p-type electrical conduction over a wide range of temperatures and pressures.
3D net-like Co3O4@NiO nanostructures for high performance supercapacitors
Authors: Sun Xiaochen , Jian Zengyun
Published: March 2024

In this paper, Co3O4@NiO composite electrode materials were successfully synthesized by a two-step hydrothermal method followed by annealing treatment.
Slow magnetization relaxation of a high-spin iron(iii) in mayenite Ca12Al14O33
Authors: Sharifullin Timur Z. , Vasiliev Alexander V. , Dolzhenko Vladimir D. , Bette Sebastian , Dinnebier Robert E. , Kremer Reinhard K. , Kazin Pavel E.
Published: March 2024

High-spin Fe3+ ion imbedded in the extended solid displays field-induced slow relaxation of magnetization with enhanced relaxation time values.
Palladium-catalyzed siloxycarbonylation of alkenes to synthesize silyl esters
Authors: Wu Fei , Zhong Yi-Chuan , Wang Bo , Ren Zhi-Hui , Guan Zheng-Hui
Published: March 2024

Synthesis of stable acyl intermediates and their transformation for the synthesis of carbonyl derivatives is highly desirable. We have developed a method for the synthesis of stable acyl intermediates, silyl esters, through siloxycarbonylation.
Modular synthetic strategies for dipyrrolopyrazines
Authors: Kahle Justin , Mackenroth Alexandra V. , Hüßler Christopher , Römgens Patrick D. , Schimanski Paul , Krämer Petra , Brückner Margit , Oeser Thomas , Rominger Frank , Rudolph Matthias , Hashmi A. Stephen K.
Published: March 2024

Our work presents novel synthetic approaches for dipyrrolopyrazines. Modifying pyrrole and NH-moieties enhances versatility, facilitating their utilisation in materials science applications.
Capture of mechanically interlocked molecules by rhodium-mediated terminal alkyne dimerisation
Authors: Hood Thomas M. , Lau Samantha , Chaplin Adrian B.
Published: March 2024

Active metal template synthesis of an enyne-based rotaxane and catenane.
Correction: Advances in metal–organic frameworks for water remediation applications
Authors: Lal Seema , Singh Parul , Singhal Anchal , Kumar Sanjay , Singh Gahlot Ajay Pratap , Gandhi Namita , Kumari Pratibha
Published: March 2024

Correction for ‘Advances in metal–organic frameworks for water remediation applications’ by Seema Lal et al., RSC Adv., 2024, 14, 3413–3446, https://doi.org/10.1039/D3RA07982A.
Optimizing 5-hydroxymethylfurfural production from biomass carbohydrates: ionic liquid-catalyzed pathways in deep eutectic solvents under sonication and thermal conditions
Authors: Karimi Sabah , Binglin Chen , Shekaari Hemayat
Published: March 2024

The synthesis of ionic liquid (IL)-based mesopore SBA-16 catalyst for the conversion of biomass-derived carbohydrates into 5-hydroxymethylfurfural (5-HMF) in the presence of 15 deep eutectic solvents (DESs) under sonication and thermal conditions.
Kinetics of phase separation and aging dynamics of segregating fluid mixtures in the presence of quenched disorder
Authors: Bhattacharyya Rounak , Sen Gupta Bhaskar
Published: March 2024

Phase separation of segregating fluid mixtures in the presence of quenched disorder.
An improved resource allocation method for mapping service function chains based on A3C
Authors: Huang Wanwei , Tian Haobin , Zhang Xiaohui , Huang Min , Li Song , Li Yuhua
Published: March 2024

Network function virtualization (NFV) technology deploys network functions as software functions on a generalised hardware platform and provides customised network services in the form of service function chain (SFC), which improves the flexibility and scalability of network services and reduces network service costs. However, irrational resource allocation during service function chain mapping will cause problems such as low resource utilisation, long service request processing time and low mapping rate. To address the unreasonable problem of service mapping resource allocation, an improved service function chain mapping resource allocation method (SA3C) based on the Asynchronous advantageous action evaluation algorithm (A3C) is proposed. This study proposes an SFC mapping model and a mathematical model for joint allocation, which modeled the minimization of processing time as a Markov process. The main network was trained and multiple sub‐networks were generated in parallel using the ternary and deep reinforcement learning algorithm A3C, with the goal of identifying the optimal resource allocation strategy. The experimental simulation results show that compared with the Actor‐Critic (AC) and Policy Gradient (PG) methods, SA3C algorithm can improve the resource utilisation by 9.85%, reduce the total processing time by 10.72%, and improve the mapping rate by 6.72%, by reasonably allocating node computational resources and link bandwidth communication resources.
V2X assisted co‐design of motion planning and control for connected automated vehicle
Authors: Li Jiahang , Chen Cailian , Yang Bo
Published: March 2024

The rapid development of vehicle‐to‐everything (V2X) communication technologies significantly promotes the revolution of intelligent transportation systems. V2X communication is expected to play a critical role in enhancing the safety and efficiency of connected and automated vehicles (CAVs), especially for mixed traffic scenarios. Additionally, the computational and storage capabilities of roadside units (RSUs) will be harnessed to effectively enhance the motion planning and control performance of CAVs within the constraints of limited on‐board computational resources. Thus, a V2X assisted co‐design of motion planning and control algorithm for CAVs to improve their situational awareness and computational efficiency is proposed. Under this architecture, a pre‐planning algorithm is proposed first to utilize the computational and storage capabilities of RSUs and generate feasible trajectories for different driving tasks. By analysing the relationship between driving risk index and motion planning performance, an online‐planning algorithm is derived to modify the pre‐planned trajectories in real‐time with static or dynamic obstacles. Furthermore, the lateral and longitudinal control of the vehicle using the Frenet coordinate system is decoupled. The lateral control employs an offline linear quadratic regulator (LQR) from RSUs to control the steering angle of the vehicle. The longitudinal control employs a dual‐loop PID to control the throttle opening of the vehicle. The performance of the proposed framework is evaluated and demonstrated by a Carsim‐Prescan simulation study in different mixed traffic scenarios. Compared with conventional methods, the proposed method improves the computational efficiency by 23% and reduces the collision rate by 13%.
Surveys of clumps, cores, and condensations in Cygnus X
Authors: Zhang X. , Qiu K. , Zhang Q. , Cao Y. , Cheng Y. , Liu J. , Wang Y. , Lu X. , Pan X.
Published: March 2024

Context. The physical properties, evolution, and fragmentation of massive dense cores (MDCs, ~0.1 pc) are fundamental pieces in our understanding of high-mass star formation.

Aims. We aim to characterize the temperature, velocity dispersion, and fragmentation of the MDCs in the Cygnus X giant molecular cloud and to investigate the stability and dynamics of these cores.

Methods. We present theKarl G. JanskyVery Large Array (VLA) observations of the NH3(J,K) = (1,1) and (2,2) inversion lines towards 35 MDCs in Cygnus X, from which we calculated the temperature and velocity dispersion. We extracted 202 fragments (~0.02 pc) from the NH3(1,1) moment-0 maps with the GAUSSCLUMPS algorithm. We analyzed the stability of the MDCs and their NH3fragments through evaluating the corresponding kinetic, gravitational potential, and magnetic energies and the virial parameters.

Results. The MDCs in Cygnus X have a typical mean kinetic temperatureTKof ~20 K. Our virial analysis shows that many MDCs are in subvirialized states, indicating that the kinetic energy is insufficient to support these MDCs against their gravity. The calculated nonthermal velocity dispersions of most MDCs are at transonic to mildly supersonic levels, and the bulk motions make only a minor contribution to the velocity dispersion. Regarding the NH3fragments, withTK~19 K, their nonthermal velocity dispersions are mostly trans-sonic to subsonic. Unless there is a strong magnetic field, most NH3fragments are probably not in virialized states. We also find that most of the NH3fragments are dynamically quiescent, while only a few are active due to star formation activity.
Signature of the atmospheric asymmetries of hot and ultra-hot Jupiters in light curves
Authors: Falco Aurélien , Leconte Jérémy , Mechineau Alexandre , Pluriel William
Published: March 2024

With the new generation of space telescopes such as the James Webb Space Telescope (JWST), it is possible to better characterize the atmospheres of exoplanets. The atmospheres of Hot and ultra-hot Jupiters are highly heterogeneous and asymmetrical. The difference between the temperatures on the day and night sides is especially extreme in the case of ultra-hot Jupiters. We introduce a new tool to compute synthetic light curves from 3D general circulation model (GCM) simulations, developed in the Pytmosph3R framework. We show how rotation induces a variation in the flux during the transit that is a source of information on the chemical and thermal distribution of the atmosphere. We find that the day–night gradient linked to ultra-hot Jupiters has an effect close to stellar limb darkening, but opposite to tidal deformation. We confirm the impact of the atmospheric and chemical distribution on variations in the central transit time, though the variations found are smaller than those in available observational data, which could indicate that the east–west asymmetries are underestimated, due to the chemistry or clouds.
Distribution of the number of peaks within a long gamma-ray burst
Authors: Guidorzi C. , Sartori M. , Maccary R. , Tsvetkova A. , Amati L. , Bazzanini L. , Bulla M. , Camisasca A. E. , Ferro L. , Frontera F. , Li C. K. , Xiong S. L. , Zhang S. N.
Published: March 2024

Context. The variety and complexity of long duration gamma-ray burst (LGRB) light curves (LCs) encode a wealth of information about the way LGRB engines release their energy following the collapse of the progenitor massive star. Thus far, attempts to characterise GRB LCs have focused on a number of properties, such as the minimum variability timescale and power density spectra (both ensemble average and individual), or considering different definitions of variability. In parallel, a characterisation as a stochastic process has been pursued by studying the distributions of waiting times, peak flux, and fluence of individual peaks that can be identified within GRB time profiles. However, an important question remains as to whether the diversity of GRB profiles can be described in terms of a common stochastic process.

Aims. Here, we address this issue by extracting and modelling, for the first time, the distribution of the number of peaks within a GRB profile.

Methods. We analysed four different GRB catalogues: CGRO/BATSE, Swift/BAT, BeppoSAX/GRBM, and Insight-HXMT. The statistically significant peaks were identified by means of well tested and calibrated algorithm MEPSA and further selected by applying a set of thresholds on the signal-to-noise ratio. We then extracted the corresponding distributions of number of peaks per GRB.

Results. Among the different models considered (power-law, simple or stretched exponential), we find that only a mixture of two exponentials was able to model all the observed distributions. This suggests the existence of two distinct behaviours: (i) an average number of 2.1 ± 0.1 peaks per GRB (“peak-poor”), accounting for about 80% of the observed population of GRBs; and (ii) an average number of 8.3 ± 1.0 peaks per GRB (“peak-rich”), accounting for the remaining 20% of the observed population.

Conclusions. We associate the class of peak-rich GRBs with the presence of sub-second variability, which appears to be surprisingly absent among peak-poor GRBs. The two classes could result from two distinct regimes in which the inner engines of GRBs release their energy or otherwise dissipate that energy as gamma rays.
Improved algorithm of extreme gradient boosting for predicting silicon content in large proportion pellet smelting process
Authors: Tian Tielei , Yang Jiayi , Liu Yanjun , Zhang Yuzhu , Jin Xinyu , Kou Xinlin
Published: March 2024

The silicon content in molten iron is an important indicator, to characterize the temperature of blast furnace (BF) and the quality of molten iron, which is of great significance to the stable operation of large proportion pellets in the BF smelting. Aiming at the problem of poor prediction performance and insufficient accuracy of silicon content, a prediction model of silicon content in molten iron was established based on KMeans++ and improved XGBoost algorithm to divide the information from different BF conditions in the smelting process, The genetic algorithm(GA) was adopted to optimize the model iteratively, which improved the accuracy of the results and reduced the training time for optimal results. The experimental result showed that the prediction hit of the model was improved by clustering the data and reached above 90% on average, and the accurate prediction of silicon content in molten iron in case of a large proportion of pellets of BF smelting was realized.
Microstructure, texture and magnetic properties of the semi-processed strip-cast non-oriented electrical steel
Authors: Zhou You , Zhou Cheng , Xuan Dongpo , Jiang Tianliang , Fan Wenhao
Published: March 2024

{100}<0vw> texture is the favorable texture in non-oriented electrical steels (NOES). However, the conventional processes are difficult to produce NOES with strong {100}<0vw> texture. In this study, the 0.35 mm thick 3.1% Si NOES with strong {100}<0vw> texture was produced by the top-side pouring twin-roll casting, cold rolling with or without intermediate annealing, and final annealing process. The microstructure and texture were characterized by optical microscopy, X-ray diffraction and electron backscatter diffraction. Compared to the one-stage cold-rolled strip-cast NOES, the semi-processed (two-stage cold-rolled) strip-cast NOES with intermediate annealing at 650 °C and 700 °C have stronger {100}<0vw> texture and better magnetic properties. The reason is that the semi-processing method can avoid the encroachment on {100}<0vw> grains by other oriented grains, which can encroach on the {100}<0vw> grains by strain-induced grain boundary migration mechanism. Furthermore, the effect of intermediate annealing temperature on the microstructure, texture, and magnetic properties of the semi-processed strip-cast NOES were studied.
Trois images en une : comment la nanophotonique révolutionne le concept d’image imprimée
Authors: Dalloz Nicolas , Hebert Mathieu , Destouches Nathalie
Published: March 2024

Le traitement par laser de films photosensibles contenant des nanoparticules métalliques permet de produire de manière contrôlée des centaines de milliers de nanostructures, affichant chacune une palette de couleurs variées suivant l’angle de vue et d’éclairage. Un choix judicieux parmi ces nanostructures permet d’afficher différentes images au même endroit d’un support, une révolution dans le domaine de l’impression qui intéresse l’industrie des documents sécurisés.
Strengthening Democracy and Market Economies through Social Capital Building in Developing Countries
Authors: Wang Qingzheng
Published: March 2024

In developing countries, it is imperative to actively pursue the enhancement of social capital in order to fortify both democratic systems and market economies. Even when other conditions remain constant, countries with high social capital have more efficient economies and better social welfare. Additionally, in the context of globalization, with the growth of network capitalism, it is evident that social capital is being formed in impoverished emerging nations.
RANK and RANKL Expression in Tumors of Patients with Early Breast Cancer
Authors: Behrens Annika , Wurmthaler Lena , Heindl Felix , Gass Paul , Häberle Lothar , Volz Bernhard , Hack Carolin C. , Emons Julius , Erber Ramona , Hartmann Arndt , Beckmann Matthias W. , Ruebner Matthias , Dougall William C. , Fasching Peter A. , Huebner Hanna , Press Michael F.
Published: March 2024

The receptor activator of nuclear factor-κB (RANK) pathway was associated with the pathogenesis of breast cancer. Several studies attempted to link the RANK/RANKL pathway to prognosis;
however, with inconsistent outcomes. We aimed to further contribute to the knowledge about RANK/RANKL as prognostic factors in breast cancer. Within this study, protein expression of RANK and
its ligand, RANKL, in the tumor tissue was analyzed in association with disease-free survival (DFS) and overall survival (OS) in a study cohort of patients with early breast cancer.

607 samples of female primary and early breast cancer patients from the Bavarian Breast Cancer Cases and Controls Study were analyzed to correlate the RANK and RANKL expression with DFS
and OS. Therefore, expression was quantified using immunohistochemical staining of a tissue microarray. H-scores were determined with the cut-off value of 8.5 for RANK and 0 for RANKL
expression, respectively.

RANK and RANKL immunohistochemistry were assessed by H-score. Both biomarkers did not correlate (ρ = −0.04). According to molecular subtypes, triple-negative tumors and HER2-positive
tumors showed a higher number of RANK-positive tumors (H-score ≥ 8.5), however, no subtype-specific expression of RANKL could be detected. Higher RANKL expression tended to correlate with a
better prognosis. However, RANK and RANKL expression could not be identified as statistically significant prognostic factors within the study cohort.

Tumor-specific RANK and RANKL expressions are not applicable as prognostic factors for DFS and OS, but might be associated with subtype-specific breast cancer progression.
QFT with tensorial and local degrees of freedom: Phase structure from functional renormalization
Authors: Ben Geloun Joseph , Pithis Andreas G. A. , Thürigen Johannes
Published: March 2024

Field theories with combinatorial non-local interactions such as tensor invariants are interesting candidates for describing a phase transition from discrete quantum-gravitational to continuum geometry. In the so-called cyclic-melonic potential approximation of a tensorial field theory on the r-dimensional torus it was recently shown using functional renormalization group techniques that no such phase transition to a condensate phase with a tentative continuum geometric interpretation is possible. Here, keeping the same approximation, we show how to overcome this limitation amending the theory by local degrees freedom on Rd. We find that the effective r − 1 dimensions of the torus part dynamically vanish along the renormalization group flow while the d local dimensions persist up to small momentum scales. Consequently, for d > 2 one can find a phase structure allowing also for phase transitions.
Deep learning-based analysis of basins of attraction
Authors: Valle David , Wagemakers Alexandre , Sanjuán Miguel A. F.
Published: March 2024

This research addresses the challenge of characterizing the complexity and unpredictability of basins within various dynamical systems. The main focus is on demonstrating the efficiency of convolutional neural networks (CNNs) in this field. Conventional methods become computationally demanding when analyzing multiple basins of attraction across different parameters of dynamical systems. Our research presents an innovative approach that employs CNN architectures for this purpose, showcasing their superior performance in comparison to conventional methods. We conduct a comparative analysis of various CNN models, highlighting the effectiveness of our proposed characterization method while acknowledging the validity of prior approaches. The findings not only showcase the potential of CNNs but also emphasize their significance in advancing the exploration of diverse behaviors within dynamical systems.
Dynamical chaos in the integrable Toda chain induced by time discretization
Authors: Danieli Carlo , Yuzbashyan Emil A. , Altshuler Boris L. , Patra Aniket , Flach Sergej
Published: March 2024

We use the Toda chain model to demonstrate that numerical simulation of integrable Hamiltonian dynamics using time discretization destroys integrability and induces dynamical chaos. Specifically, we integrate this model with various symplectic integrators parametrized by the time step τ and measure the Lyapunov time TΛ (inverse of the largest Lyapunov exponent Λ). A key observation is that TΛ is finite whenever τ is finite but diverges when τ→0. We compare the Toda chain results with the nonintegrable Fermi–Pasta–Ulam–Tsingou chain dynamics. In addition, we observe a breakdown of the simulations at times TB≫TΛ due to certain positions and momenta becoming extremely large (“Not a Number”). This phenomenon originates from the periodic driving introduced by symplectic integrators and we also identify the concrete mechanism of the breakdown in the case of the Toda chain.
Thermal, structural, and conductivity properties of As14Sb26S(60−x)–(AgI)x chalcogenide glasses
Authors: Prabhudessai Akila G. , Balaji Sathravada , Prasad Sakthi , Chahal Shweta , Biswas Kaushik , Ramesh K. , Yadav Anupama , Chakraborty Saswata , Kongar Partha Sarathi , Chatterjee Sayan , Dutta Sutanu , Dasgupta Rana , Sarkar Pratik , Annapurna K.
Published: March 2024

The present work describes the preparation of a new series of chalcogenide glasses in an As14Sb26S(60−x) (AgI)x system intending to explore its thermal, structural, optical, mechanical, and electrical properties. The differential scanning calorimetry results of the studied glasses show the sharp decrease in glass transition temperature (Tg) with the successive incremental inclusion of AgI in the composition, implying the structural changes in the glass network. A thorough Raman analysis corroborates the occurrence of changes in the glass network due to the formation of AsI3 units and Ag–S–As bonds with increasing AgI content. Also, structural changes can be reflected with the change in the optical bandgap (Eg) that was calculated using Tauc equations where it was found that Eg is in harmony with the observed structural variations of glasses. The studied glasses possess a transmittance window (∼0.68–12 μm) with transmittance above 60% in the mid-infrared region. These structural changes are closely related to the significant enhancement of conductivity of the present glasses from 10−8 to 10−6 S/cm at 373 K with a decrease in activation energies. Impedance spectra for the glass with highest AgI revealed the presence of two different relaxation processes. AC conductivity data followed an Arrhenius behavior as well as Jonscher’s power law. The present work provides insights into glass network modifications due to silver iodide inclusion and its role in the enhancement of conductivity.
Probabilistic locked mode predictor in the presence of a resistive wall and finite island saturation in tokamaks
Authors: Akçay C. , Finn John M. , Brennan Dylan P. , Olofsson K. E. J. , Cole A. J.
Published: March 2024

We present a framework for estimating the probability of locking to an error field in a rotating tokamak plasma. This leverages machine learning methods trained on data from a mode-locking model, including an error field, resistive magnetohydrodynamics modeling of the plasma, a resistive wall, and an external vacuum region, leading to a fifth-order ordinary differential equation (ODE) system. It is an extension of the model without a resistive wall introduced by Akçay et al. [Phys. Plasmas 28, 082106 (2021)]. Tearing mode saturation by a finite island width is also modeled. We vary three pairs of control parameters in our studies: the momentum source plus either the error field, the tearing stability index, or the island saturation term. The order parameters are the time-asymptotic values of the five ODE variables. Normalization of them reduces the system to 2D and facilitates the classification into locked (L) or unlocked (U) states, as illustrated by Akçay et al., [Phys. Plasmas 28, 082106 (2021)]. This classification splits the control space into three regions: L̂, with only L states; Û, with only U states; and a hysteresis (hysteretic) region Ĥ, with both L and U states. In regions L̂ and Û, the cubic equation of torque balance yields one real root. Region Ĥ has three roots, allowing bifurcations between the L and U states. The classification of the ODE solutions into L/U is used to estimate the locking probability, conditional on the pair of the control parameters, using a neural network. We also explore estimating the locking probability for a sparse dataset, using a transfer learning method based on a dense model dataset.
Kinetic closures for unmagnetized and magnetized plasmas
Authors: Park Kyoung-Chan , Ji Jeong-Young , Lee Yoonji , Na Yong-Su
Published: March 2024

Parallel and perpendicular closures with cyclotron resonance effects retained for the five-moment (density, temperature, and flow velocity) fluid equations are derived by solving the kinetic equation with the Bhatnagar–Gross–Krook operator in Fourier space. For parallel propagation, the parallel closures are reduced to those of Ji et al. [Phys. Plasmas 20, 082121 (2013)]. The closures when combined to the fluid equations reproduce the fully kinetic dispersion relation that can be directly derived from the kinetic equation. The closures for the five-moment fluid system can be utilized to derive closures for the extended fluid system, which is demonstrated by deriving closures for the ten-moment system consisting of density, flow velocity, temperature, and viscosity tensor equations.
Fingering of a cavitation bubble in a thin gap: Ejection of the reversed boundary layer into the bulk flow
Authors: Borich Anna , Denissenko Petr
Published: March 2024

The flow around a bubble, precipitously expanding in a thin gap between flat walls, was found to have a peculiar feature: distinct fingering occurs at the bubble wall, which was observed through the ultra-high speed optical visualization. The effect is attributed to the reversal of the flow within boundary layers, which provokes the growth of instabilities at the inflection point and, when the surface tension is low enough (the local Weber number is high enough), leads to the fingering. In this paper, we show the high speed recordings of the fingering and model the evolution of the radial velocity to quantitatively confirm feasibility of the proposed instability mechanism.
Electric fields near undulating dielectric membranes
Authors: Pogharian Nicholas , dos Santos Alexandre P. , Ehlen Ali , Olvera de la Cruz Monica
Published: March 2024

Dielectric interfaces are crucial to the behavior of charged membranes, from graphene to synthetic and biological lipid bilayers. Understanding electrolyte behavior near these interfaces remains a challenge, especially in the case of rough dielectric surfaces. A lack of analytical solutions consigns this problem to numerical treatments. We report an analytic method for determining electrostatic potentials near curved dielectric membranes in a two-dimensional periodic “slab” geometry using a periodic summation of Green’s functions. This method is amenable to simulating arbitrary groups of charges near surfaces with two-dimensional deformations. We concentrate on one-dimensional undulations. We show that increasing membrane undulation increases the asymmetry of interfacial charge distributions due to preferential ionic repulsion from troughs. In the limit of thick membranes, we recover results mimicking those for electrolytes near a single interface. Our work demonstrates that rough surfaces generate charge patterns in electrolytes of charged molecules or mixed-valence ions.
Experimental study on the an-isotropic critical current of REBCO tape
Authors: Ma Hongjun , Zhang Jingfeng , Zhang Shuqing , Zhang Xintao , Liu Huajun , Liu Fang , Shi Yi , Jin Huan
Published: March 2024

Superconducting magnets are widely used in nuclear fusion reactors, high-energy particle accelerators, steady-state high magnetic fields, etc. Higher magnetic fields and higher operating temperatures are two application trends. High temperature superconducting (HTS) materials are the only choice for high temperature and high field magnets in the future. The first- and second-generation HTS materials have a typical tape structure; their critical performance is magnetic field angle and temperature dependent. A new test facility is developed for an experimental study on the an-isotropic critical current. The field angle can be changed from 0° to 360° with a resolution of 1°. The rotation deviation angle is measured to be 0.2° when the upper part rotates 90°. The temperature can be changed from 4.2 to 80 K. The temperature errors are ±50, ±80, and ±135 mK for 4.2–20, 20–40, and 40–80 K, respectively. The angle dependence of critical current (Ic) of the tested rare-earth barium copper oxide tape within 0°–30° is strong. From 30° to 90°, the sample Ic almost does not change with the magnetic field angle. The implementation of the project will not only promote the structural optimization of HTS tapes but also promote the miniaturization and economical application of HTS magnets.
Effective splitting of invariant measures for a stochastic reaction diffusion equation with multiplicative noise
Authors: Lei Ting , Chen Guanggan
Published: March 2024

This work is concerned with the effective dynamics for the stochastic reaction diffusion equations with cubic nonlinearity driven by a multiplicative noise. By splitting the solution into the finite dimension kernel space and its complement space with some appropriate multi-scale, it derives the dominant solution and the effective invariant measure in the sense of the Wasserstein distance, which capture the complex dynamical behaviors of the original system as a singular parameter is enough small. Furthermore, the effective invariant measure is decomposed to a product of two invariant measures.
Stability of the gapless pure point spectrum of self-adjoint operators
Authors: Facchi Paolo , Ligabò Marilena
Published: March 2024

We consider a self-adjoint operator T on a separable Hilbert space, with pure-point and simple spectrum with accumulations at finite points. Explicit conditions are stated on the eigenvalues of T and on the bounded perturbation V ensuring the global stability of the spectral nature of T + ɛV, ε∈R.
A direct Monte Carlo approach for the modeling of neutrals at the plasma edge and its self-consistent coupling with the 2D fluid plasma edge turbulence model HESEL
Authors: Kvist Kristoffer , Thrysøe Alexander Simon , Haugbølle Troels , Nielsen Anders Henry
Published: March 2024

This paper presents a novel coupling of a kinetic description of neutrals with a fluid description of a fusion plasma. The code, plasma interacting super-atoms and molecules (PISAM), employs a grid-free Cartesian geometry and a direct simulation Monte Carlo approach to solve the kinetic equations of deuterium atoms and molecules. The grid-free geometry and the parallel nature of the neutral dynamics, in the absence of neutral–neutral interactions, allow for an unlimited and work-efficient parallelization of PISAM that always ensures a balanced workload. The highly optimized Python implementation obtains good performance while securing easy accessibility to new users. The coupling of PISAM with the edge turbulence model HESEL is outlined with emphasis on the technical aspects of coupling Message Passing Interface-parallelized Python and C++ codes. Furthermore, the paper presents and analyzes simulation results from running the coupled HESEL-PISAM model. These results demonstrate the impact of radial neutral transport and plasma–neutral dynamics perpendicular to the magnetic field. Specifically, they illustrate how the inward flow of neutral kinetic energy and the inhibition of radial electric shear, resulting from poloidal momentum transfer between atoms and ions, can affect the energy containment time. By comparing the results of the HESEL-PISAM model with those obtained from coupling HESEL with a diffusive-fluid-neutral model, the capabilities of diffusion models in predicting neutral transport in the plasma edge and scrape-off layer are elucidated.
Learning Markovian dynamics with spectral maps
Authors: Rydzewski Jakub , Gökdemir Tuğçe
Published: March 2024

The long-time behavior of many complex molecular systems can often be described by Markovian dynamics in a slow subspace spanned by a few reaction coordinates referred to as collective variables (CVs). However, determining CVs poses a fundamental challenge in chemical physics. Depending on intuition or trial and error to construct CVs can lead to non-Markovian dynamics with long memory effects, hindering analysis. To address this problem, we continue to develop a recently introduced deep-learning technique called spectral map [J. Rydzewski, J. Phys. Chem. Lett. 14, 5216–5220 (2023)]. Spectral map learns slow CVs by maximizing a spectral gap of a Markov transition matrix describing anisotropic diffusion. Here, to represent heterogeneous and multiscale free-energy landscapes with spectral map, we implement an adaptive algorithm to estimate transition probabilities. Through a Markov state model analysis, we validate that spectral map learns slow CVs related to the dominant relaxation timescales and discerns between long-lived metastable states.
Magnon Bose–Einstein condensates: From time crystals and quantum chromodynamics to vortex sensing and cosmology
Authors: Mäkinen J. T. , Autti S. , Eltsov V. B.
Published: March 2024

Under suitable experimental conditions, collective spin-wave excitations, magnons, form a Bose–Einstein condensate (BEC), where the spins precess with a globally coherent phase. Bose–Einstein condensation of magnons has been reported in a few systems, including superfluid phases of 3He, solid state systems, such as yttrium-iron-garnet films, and cold atomic gases. The superfluid phases of 3He provide a nearly ideal test bench for coherent magnon physics owing to experimentally proven spin superfluidity, the long lifetime of the magnon condensate, and the versatility of the accessible phenomena. We first briefly recap the properties of the different magnon BEC systems, with focus on superfluid 3He. The main body of this review summarizes recent advances in the application of magnon BEC as a laboratory to study basic physical phenomena connecting to diverse areas from particle physics and cosmology to vortex dynamics and new phases of condensed matter. This line of research complements the ongoing efforts to utilize magnon BECs as probes and components for potentially room-temperature quantum devices. In conclusion, we provide a roadmap for future directions in the field of applications of magnon BEC to fundamental research.
Dual-layer volatile memristor with ultralow voltage slope
Authors: Li Pengtao , Wang Zijian , Xing Shengpeng , Wang Zhen , Xia Wentai , Fan Xuemeng , Gao Dawei , Zhang Yishu
Published: March 2024

In this Letter, we present a dual-layer oxide volatile memristor characterized by an Ag/TaOx/ZnO/Pt structure. This innovative design deviates from traditional Ag/ZnO/Pt devices, chiefly through the introduction of a thin TaOx layer between the electrolyte and the active electrode. Our devices exhibit remarkable features, including an unprecedentedly low switching voltage slope, measuring a mere 0.221 mV/dec, and a threshold voltage that can be reduced to as low as 0.177 V. To further elucidate the performance enhancement of the device, we utilize first-principles calculations. The results reveal that the relatively high formation energy of oxygen vacancies in the supplementary TaOx layer facilitates meticulous control over the rupture and formation of silver conductive nanofilaments.
Analytical solutions and classification of vesicle motion and deformation in shear flow: Uncovering new tank-treading modes
Authors: Azroul E. , Bouda S. , Diki G. , Guedda M.
Published: March 2024

Using a small deformation approach, a fractional ordinary differential system is proposed to investigate the motion and deformation of a vesicle in shear flow. Closed analytical expressions of the orientation angle and the ellipticity of the vesicle contour (shape deformation) are provided. Three different motions are identified, the classical tank-treading state, and two new types of motions, namely, the over-damped tank-treading mode, in which the vesicle’s orientation angle ψ and its shape deformation R tend more slowly toward equilibrium, and the under-damped tank-treading mode, in which ψ oscillates all the time along the flow direction with decreasing amplitude, while R starts making a breathing motion and then tends to an attractive amplitude. The implications of our findings extend widely within the field of fluid dynamics, revealing the potential for further advancements and applications in understanding complex fluid systems.
Dual interface strategies enable efficient wide bandgap perovskite solar cells
Authors: Hou Fuhua , Guo Haikuo , Yang Haoran , Ren Xiaoqi , Ning Xuli , Li Tiantian
Published: March 2024

High performance wide bandgap perovskite solar cells (WB-PSCs) have found widespread applications in tandem solar cells. In WB-PSCs, achieving a high conversion efficiency relies on the effective utilization of light absorption and minimization of electronic defects. In this work, electronic defects at the surface and grain boundaries of perovskite materials have been passivated by n-butylammonium bromide (BABr) to suppress carrier non-radiative recombination. Confirmed through x-ray powder diffraction and x-ray photoelectron spectroscopy spectra, ultra-thin two-dimensional (2D) perovskite layers were successfully generated on a perovskite surface. The BABr-treated devices exhibited an increased fill factor and open circuit voltage (VOC) compared to the references. Furthermore, a nanotextured electrode with a roughness of 22.98 nm was employed to trap light. The nanotextured buried interface not only promoted light utilization but also alleviated residual stress and micro-strain in the perovskite film compared to the smooth substrate. Finally, the champion WB-PSC achieved a power conversion efficiency of 20.46% in the reverse scan. These findings pave a promising path for the development of solution-processed perovskite films on nanotextured silicon substrates to improve the performance of monolithic tandem solar cells.