bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring double perovskites Cs2AgSbX6 (X = Cl, Br, and I) as promising optoelectronic and thermoelectric materials: a first-principles study
Authors: Sajjad Asim , Faizan Muhammad , Alrebdi Tahani A. , Murtaza Ghulam , Rehman Javed , Shen Xingchen , Dong Yujing , Shaheen Kausar , Haidar Khan Shah
Published: February 2025

Cs2AgSbX6 (X = Cl, Br, I) double perovskites with excellent stability, optimal bandgaps, strong optical absorption, and high figures of merit are promising materials for optoelectronic and thermoelectric energy conversion.
Can we predict specific numbers of catalytically important molecules of water in H/D exchange in aromatic systems? A combined NMR and DFT study
Authors: Chalkidou Photini , Venianakis Themistoklis , Papamokos George , Siskos Michael , Gerothanassis Ioannis P.
Published: February 2025

Potential energy scan of the ionic form of taxifolin with three catalytically important molecules of H2O.
Advanced crystallography for structure determination of natural products
Authors: Song Jian-Guo , Ye Wen-Cai , Wang Ying
Published: February 2025

Four cutting-edge crystallography strategies for structure elucidation of natural products that are difficult to crystallize or in nanocrystalline form.
Laser-induced optical and structural modification in AgI thin films loaded with silver nanoparticles
Authors: Talebi Razieh , Gigli Lara , Veltruská Kateřina
Published: February 2025

Light-induced colouration and crystallinity promotion in Ag–AgI films.
Molecularly-anchored single PbS quantum dots as resonant tunnelling transistors
Authors: Wulandari Retno Dwi , Yin Dongbao , Septianto Ricky Dwi , Izawa Seiichiro , Iwasa Yoshihiro , Bisri Satria Zulkarnaen , Majima Yutaka
Published: February 2025

Ten negative differential resistances (NDRs) were demonstrated in the output characteristics of molecularly-anchored single PbS quantum dot resonant tunneling transistors, which utilized heteroepitaxial spherical Au/Pt nanogap electrodes.
Spin-state switching at the single-molecule level by distortion of the coordination sphere: validation based on quantum-chemistry calculations
Authors: Jaber El Lala Iman , Montenegro-Pohlhammer Nicolas , Sánchez-de-Armas Rocío , Calzado Carmen J.
Published: February 2025

Spin-crossover in the junction: validation of the switching mechanisms consisting of the distortion of the coordination sphere of the molecule.
Formation of drug–drug salt crystals and co-amorphous forms of levofloxacin and 4-aminosalicylic acid for pulmonary applications
Authors: Ueda Hiroshi , Tse Jun Yee , Miyano Tetsuya , Nakayama Yuzuki , Mo Peiwen , Hatanaka Yuta , Uchiyama Hiromasa , Tozuka Yuichi , Kadota Kazunori
Published: February 2025

Simultaneous delivery with improvement of inhalation properties of levofloxacin and 4-aminosalicylic acid through the formation of drug–drug salts.
Developing a highly sensitive electrochemical sensor for malathion detection based on green g-C3N4@LiCoO2 nanocomposites
Authors: Ahmad Nafis , Kumar Anjan , Rachchh Nikunj , Jyothi S Renuka , Bhanot Deepak , Kumari Bharti , Kumar Abhinav , Abosaoda Munthar Kadhim
Published: February 2025

Electrochemical sensor for malathion detection based on green g-C3N4@LiCoO2 nanocomposites.
Recommending reaction conditions with label ranking
Authors: Shim Eunjae , Tewari Ambuj , Cernak Tim , Zimmerman Paul M.
Published: February 2025

Label ranking is introduced as a conceptually new means for prioritizing experiments. Their simplicity, ease of application, and the use of ranking aggregation facilitate their ability to make accurate predictions with small datasets.
Unlocking delocalization: how much coupling strength is required to overcome energy disorder in molecular polaritons?
Authors: Liu Tianlin , Yin Guoxin , Xiong Wei
Published: February 2025

Polaritons lose delocalization in energetically disordered systems. A large Rabi splitting about 3–4 times of the inhomogeneous linewidths is required to restore delocalization. This study can guide future rational experiment designs.
Experimental models for cohesive granular materials: a review
Authors: Sharma Ram Sudhir , Sauret Alban
Published: February 2025

This review covers experimental approaches to induce controlled adhesive forces between particles and discusses the effects of inter-particle cohesion on granular mechanics across scales, from individual particles to bulk behavior.
Reusability Studies with Lewis and Brønsted Acid Catalysts for Dehydration of the Primary Alcohol 1-Hexanol under Energy-Saving Conditions
Authors: Allahverdiyev Adil , Gröger Harald
Published: February 2025

In general there is an urgent current need to switch from fossil-based materials to renewable sources and this is also the case for production of alkenes with a chain length...
Enhancing photocatalytic activity through the manipulation of intrinsic electric fields in yolk–shell hollow AuPd@TiO2 structures
Authors: Jiang Shan , Zhang Yihang , Wang Yunyang , Zhang Yanrong , Chen Yong , Yang Jiakuan , Chang Yoon-Seok , Escobedo Ericson , Gong Jianyu
Published: February 2025

The yolk–shell AuPd@TiO2 photocatalyst optimized the built-in electric field by controlling Au/Pd ratios, leading to d-band center closer to the Fermi level, thus enhancing electronic interactions and stabilizing antibonding orbitals.
Ultra-high stretchable hydrogels with wet adhesion properties as wearable electronic devices for underwater environments
Authors: Luo Jijun , Yin Mengwei , Du Bin , Wang Xupeng , Zhou Shisheng
Published: February 2025

We report a hydrophobically associating hydrogel. This conductive hydrogel boasts excellent stretchability, outstanding anti-swelling ability, and strong underwater adhesion. The hydrogel-based sensor holds great promise for underwater communication.
Overcoming kinetic barriers of remote electrochemiluminescence on boron-doped diamond via catalytic coreactant oxidation
Authors: Fracassa Alessandro , Mariani Chiara , Fiorani Andrea , Einaga Yasuaki , Hogan Conor F. , Paolucci Francesco , Sojic Neso , Francis Paul S. , Valenti Giovanni
Published: February 2025

Using an Ir(iii)-based redox mediator ([Ir(sppy)3]3-) overcomes the traditional kinetic barrier of tri-n-propylamine oxidation on BDD, enhancing the ECL from Ru(ii)-labeled beads by up to 46-fold.
Oxygen self-supplying porphyrinic MOFs to alleviate tumor hypoxia for starvation-amplified photodynamic therapy
Authors: Zhu Shajun , An Jian , Pu Jia , Liang Xufeng , Zhang Shiyue , Ma Jingjing , Zhang Jianxia , Meng Yujia , Bai Yiqiao , Yu Wenqiang , Gao Yunhan , Yao Yong , Chen Tingting , Wang Yang
Published: February 2025

An oxygen self-supplying nanoplatform utilizing perfluorocarbon-functionalized porphyrinic MOFs was developed to alleviate tumor hypoxia for starvation-enhanced photodynamic therapy under near infrared light irradiation.
Does Successful Surgical Treatment of Velopharyngeal Insufficiency Aid in the Remediation of Compensatory Misarticulation Errors?
Authors: Chee-Williams Jessica L. , Bunton Kate , Alvarez-Montoya Elizabeth , Cordero Kelly Nett , Perry Jamie L. , Philp Jenny , Singh Davinder J. , Sitzman Thomas J.
Published: February 2025

Purpose:

The aim of this study was to investigate whether successful surgical management of velopharyngeal insufficiency (VPI) aids in the remediation of compensatory misarticulation errors (CMAs) among children with VPI and CMAs.

Method:

Fourteen participants with VPI and use of CMAs from a larger study were included in this retrospective cohort study. The mean age at the time of preoperative evaluation was 8.9 years (
SD
= 1.1). Perceptual ratings of hypernasality, phonetic transcription, and anatomic measurements from magnetic resonance imaging were performed by raters blinded to the participants' medical and surgical history. The mean percentage of CMAs produced on the American English Sentence Sample was calculated. The Wilcoxon signed-ranks test was used to compare the change in CMA use pre- and postoperatively. During the study period, 71% (
n
= 10) of participants received speech therapy.

Results:

Nine participants had resolved hypernasality after surgery, and five had persistent hypernasality. Among those with resolved hypernasality, the mean percentage of CMAs significantly decreased from 14.6% preoperatively to 1.1% postoperatively (
p
= .028). For participants with persistent hypernasality, the mean percentage of CMAs decreased from 27.6% to 22%; this change was not significant (
p
= .586).

Conclusions:

Correction of VPI may aid in the remediation of CMAs as participants have more normal anatomy to achieve velopharyngeal closure. These findings suggest correction of VPI may reduce the amount of speech therapy needed to treat CMAs.
Study on hot deformation behavior of 9Cr18Mo stainles bearing steel
Authors: ZHANG Yu , WANG Jianguo , LIU Dong , LIANG Zhirui , ZHAO Jiahang
Published: February 2025

The microstructure evolution and hot deformation behavior of 9Cr18Mo stainless bearing steel were studied with the hot compression test at the temperature ranging from 1 223 to 1 423 and strain rates from 0.01 to 10 s-1. The results indicate that the 9Cr18Mo stainless steel shows strong positive strain rate sensitivity and negative temperature sensitivity. The softening mechanism is dynamic recrystallization and dynamic recovery mechanism. A constitutive equation with the strain compensation considered was developed and the prediction value is in good agreement with the experimental value. The processing map of 9Cr18Mo stainless steel was established with the Murty criteria. Combined with microstructure analysis, the optimal hot processing parameter range is between 1 050 ℃ and 1 120 ℃ and the strain rate is between 0.1 and 1 s-1. The composition distribution of the microstructure of 9Cr18Mo stainless steel was analyzed with the EDS. In combination with the calculation results of the JMAPTPRO software, it was determined that the coarse banded carbides were not dissolved in the matrix at high temperature were composed of M7C3 carbide and M23C6 carbide.
Novel static calculation approach for reciprocal structures assembled by Archimedes paving curved rods
Authors: XIA Yongqiang , XU Yimin , NI Keyi , XIAO Nan , FAN Lei , SONG Fangyuan , JIN Hui
Published: February 2025

In order to more efficiently solve the internal forces and deformations of the curved rod reciprocal structures transformed from the Archimedes paving, the reference point is defined on the curved rod element in this paper. On the basic of the static equilibrium relationship between the forces at the reciprocal articulated joints and the generalized nodal loads at the reference point, the static equilibrium equation of the curved rod reciprocal structure is established. By solving the equilibrium equation, the nodal forces of the curved rod reciprocal structure can be obtained. Furthermore, the internal forces and deformations of the reciprocal curved rod in the cylindrical coordinate system are derived by coordinate transformations. Finally, a quadrilateral curved rod reciprocal frame and a curved rod reciprocal structure transformed from the 63 type of Archimedes paving are studied respectively by proposed method and finite element method with ANSYS software. Results shows that the error rate of the nodal forces and nodal displacements between the numerical simulation and the theoretical calculation is less than 5%. The proposed method is not only reliable in static forces calculation, but also simplicity and efficiency in solution process.
Radiographie du thorax en pédiatrie : justification et doses d’entrée à Parakou en 2021
Authors: Akanni D.W.M.M. , Fachinan O.H. , Adjadohoun S.B.M.G. , Zamba A.K.J.J. , Kiki S.M. , Savi de Tové K-M.
Published: February 2025

Cette étude visait à évaluer la pertinence des indications des radiographies thoraciques pédiatriques selon le Guide de Bon Usage (GBU), à déterminer les doses d'entrée à la peau au CHUD-B/A de Parakou, et à comparer les doses administrées aux Niveaux de Référence Diagnostiques (NRD). La dose d’entrée a été calculée via le logiciel MICADO (IRSN) pour 115 enfants, dont l'âge moyen était de 34,7 ± 39,1 mois. Selon le GBU, 73,04 % des examens étaient justifiés. Les doses moyennes étaient de 0,17 mGy pour les enfants de [0 à 1[an, 0,18 mGy pour ceux de [1 à 5[ans, 0,20 mGy pour les [5 à 10[ans, et 0,21 mGy pour les [10 à 15[ans. Les doses mesurées étaient globalement plus élevées que les NRD françaises mais comparables aux données subsahariennes, soulignant la nécessité d'optimiser les pratiques radiologiques pour réduire l’exposition aux rayonnement des enfants.
Stressfraktur als Überlastungsreaktion bei Frauen
Authors: Bode Lisa , Fritz Johanna , Maletzke Saskia , Siegel Markus
Published: February 2025

Stressfrakturen treten häufiger bei Frauen auf als bei Männern. Weil es viele mögliche Ursachen gibt, gestaltet sich die Therapie nicht ganz einfach. Alle Beteiligten – von der Betroffenen über das ärztliche Team bis hin zu den Physiotherapeut*innen – müssen an einem Strang ziehen, wenn eine Sportlerin nach einer Stressfraktur wieder in den Sport zurückkehren will.
Synthesis and Evaluation of Bakuchiol Tethered Triazoles as Cytotoxic Agents
Authors: Sengar Neha , Chatterjee Joydeep , Kumar Raj , Singh Inder Pal
Published: February 2025

A novel series of bakuchiol tethered triazole compounds was synthesized by reaction of azido bakuchiol with different substituted alkynes. The anticancer activity of all synthesized compounds was evaluated against A549 (lung), MCF-7, and MDA-MB-231 (breast) human tumor cells. Cytotoxicity screening showed that several compounds displayed notable cytotoxic effects against tumor cells compared to the parent molecule bakuchiol. The prominent effects were produced by compounds 16 and 17 with IC50 values of 8.9 µM and 8.2 µM against the MCF-7 and A-549 cells, respectively.
Observing the flow of porridge: a physical and rheological analysis
Authors: Daniel Hannah
Published: February 2025

Profiling the rheology of foods with millimeter-sized ingredients, provided to sick patients with trouble swallowing, can help improve safety.
Enhancing the energy harvesting of micro-notched turbine for applications in low power devices
Authors: Bin Li , Shahzad Muhammad , Arsalan Aziz Hafiz Muhammad , Rakha Allah , Safdar Nouman , Saif Mubaarak , Farhan Muhammad
Published: February 2025

It is the future trend to energize small home appliances, medical devices, micro-devices, etc. through miniature generation. Micro-Notched turbine (MiNT) converts mechanical energy to electrical energy for portal devices. The current challenge is to harness the maximum energy by modifying its design, model, blade size, and casing. The MiNT presented in this research is one of the few specialized miniature harvesters with desirable characteristics and the potential to be optimized for maximum power generation. To reap maximum benefit from MiNT, the design of the turbine, the shape of the blades, and the tracking system were modified. Similarly, the size of the MiNT turbine was decreased, and its efficiency was enhanced. In this research, the particle swarm optimization algorithm and resistor emulation technique were employed to enhance Maximum Power Point Tracking (MPPT). Meanwhile, the converter efficiency was also observed. For the validation of results, the proposed technique was compared with passive MPPT and adaptive MPPT techniques. During the simulation, micro-notched-based energy collection devices with upgraded MPPT technology were used. By implementing this hybrid system, the maximum power point was accurately tracked, resulting in improved power output, reduced system size, and improved converter efficiency.
An elbow passive exoskeleton with controllable assistance: Design and experimental
Authors: Yang Xuxu , Zhang Jing , Shen Cheng , Wang Chen , Che Tao , Liang Zilin , Cui Tong
Published: February 2025

A passive exoskeleton is a wearable robotic device that is worn on the exterior of the user’s body to provide physical support and facilitate movement. Existing elbow passive exoskeletons have limitations in their assistance capabilities and range of applications. In this paper, we propose a controllable elbow passive exoskeleton (CEPE) to address these limitations. The CEPE features a ratchet-based self-energy storage mechanism (RSSM) and a Candan gravity compensation mechanism (CGCM). The CGCM counteracts gravitational forces, while the RSSM stores and releases motion energy. This paper establishes a mathematical model for the RSSM, outlines design specifications for both the RSSM and CEPE, and analyzes the influence of design parameters on the power assistance performance. Three experiments were conducted to validate the feasibility of CEPE, including static strength testing, power assistance without load, and power assistance with load. Results show that, without loading, the CEPE provides compensation effects on elbow joint torque of 68.8%, 93.8%, and 70.7% at shoulder joint angles of 0°, 30°, and 60°, respectively. With a 5 kg loading, adjusting the shoulder joint angle from 30° to 60° results in an increase in the decrease of the average absolute torque directly acting on the elbow joint, from 86% to 91.2%. The adjustable RSSM enables the CEPE to operate in four different modes, expanding its potential applications.
High resolution, sub-picosecond x-ray spectroscopy of K-shell emitters to characterize plasma emissivity measurement
Authors: Magee E. , Shepherd R. , Beiersdorfer P. , Clark J. , MacDonald M. , Hell N. , Brown G. V. , Hobbs L. , Brown C. R. D. , Hill M. , Hoarty D. , Hollinger R. , Rocca J. J.
Published: February 2025

Short pulse laser (SPL) heated matter has opened an avenue to studying matter at conditions previously unattainable. While SPLs can generate matter at extreme densities and temperatures, characterization of the heated matter can be extremely challenging. The conditions are dynamic and require careful monitoring of the plasma evolution. Atomic processes under these conditions can provide a powerful tool to study fundamental plasma properties as they evolve. When utilizing the x-ray emission from these plasmas, it is often useful to resolve spectral details with high resolution. Sub-picosecond, time-resolved, high-resolution spectroscopy has previously been reported. We present a similar diagnostic (STreaked Orion High-Resolution X-ray spectrometer, or STOHREX) to measure the temporal evolution of spectral features with high spectral resolution. The diagnostic is the result of combining a high-resolution x-ray spectrometer with the LLNL sub-picosecond x-ray streak camera. The diagnostic was demonstrated in two campaigns: (1) To study spectral lineshapes using the 40 fs, 400 nm, Colorado State University ALEPH laser, and (2) to study buried layers using the 500 fs, 532 nm Atomic Weapons Establishment’s Orion laser.
Game optimization for photovoltaic microgrid group and the shared energy storage operator considering energy storage frequency modulation–cost loss and source–load uncertainty
Authors: Zhu Chunxu , Yang Shuxia , Li Songrui
Published: February 2025

The high uncertainty of power generation in photovoltaic microgrids and the high cost of energy storage allocation limit the development of photovoltaic microgrids. Therefore, this study proposes a trading strategy mechanism for multiple photovoltaic microgrids (PMs) and shared energy storage operator (SESO) based on the Stackelberg game. The trading mechanism fully considers the loss cost of shared energy storage operation, the benefits of participating in the frequency regulation auxiliary service market, and the demand response characteristics of photovoltaic microgrids. Then, a source–load uncertainty risk model is constructed based on the information intermittent decision theory, which is improved by the confidence interval fuzzy set. Finally, a distributed combinatorial algorithm using mixed integer linear programming with an improved multiverse algorithm is used for the solution. The results show that introducing SESO effectively reduces all the operating costs of PMs, and the daily operational benefits of SESO reach 8774.56 yuan. Second, the frequency modulation (FM) performance score of the energy storage device is improved by 14.45%. The proposed game optimization model not only achieves a win-win situation for multiple players but also broadens the physical function of shared energy storage participating in FM service and realizes the risk preference regulation of operating players.
Space–time decay rates of a nonconservative compressible two–phase flow model
Authors: Yang Tianzheng , Zhang Yinghui
Published: February 2025

This paper concerns the space–time decay rates of strong solution to a nonconservative compressible two–phase flow model in the whole space R3. Based on the previous temporal decay results, it is shown that the space–time decay rate of k(0 ≤ k ≤ N)–order spatial derivative of the strong solution in weighted Lebesgue space Lγ2 is t−34−k2+γ for any integer N ≥ 2. The methods mainly involve delicate weighted energy estimates and interpolation tricks.
Photoionization-induced charge separation for efficient solar energy conversion
Authors: Katoh Ryuzi
Published: February 2025

The most important primary process in solar energy conversion systems is photo-induced charge separation. This Perspective summarizes our current understanding of the photoionization-induced charge separation process, which involves the transfer of an electron from a discrete to a continuous electronic state with particular emphasis on the threshold energy and efficiency of photoionization. Based on our understanding of alkane solutions and in aromatic organic crystals, the charge separation mechanism in dye-sensitized solar cells is discussed as a photoionization-induced solar energy conversion system.
Exploring quasi-periodic shrimps in the parameter space of a discrete-time food chain model
Authors: Pati N. C. , Datta Prabal , Ghosh Bapan
Published: February 2025

Shrimps are islands of regularity within chaotic regimes in bi-parameter spaces of nonlinear dynamical systems. While the presence of periodic shrimps has been extensively reported, recent research has uncovered the existence of quasi-periodic shrimps. Compared to their periodic counterparts, quasi-periodic shrimps require a relatively higher-dimensional phase-space to come into existence and are also quite uncommon to observe. This Focus Issue contribution delves into the existence and intricate dynamics of quasi-periodic shrimps within the parameter space of a discrete-time, three-species food chain model. Through high-resolution stability charts, we unveil the prevalence of quasi-periodic shrimps in the system’s unsteady regime. We extensively study the bifurcation characteristics along the two borders of the quasi-periodic shrimp. Our analysis reveals that along the outer border, the system exhibits transition to chaos via intermittency, whereas along the inner border, torus-doubling and torus-bubbling phenomena, accompanied by finite doubling and bubbling cascades, are observed. Another salient aspect of this work is the identification of quasi-periodic accumulation horizon and different quasi-periodic (torus) adding sequences for the self-distribution of infinite cascades of self-similar quasi-periodic shrimps along the horizon in certain parameter space of the system.
Dynamics of predatory effect on saturated plant–pollinator mutualistic relationship
Authors: Biswas Arpita , Medda Rakesh , Pal Samares
Published: February 2025

In the realm of pollinator declination, understanding the dynamics of plant–pollinator interactions is a critical area of research to maintain healthy ecosystems. This study employs a mathematical modeling approach to investigate the dynamics of a saturated plant–pollinator mutualism, particularly aiming on the effect of predation on pollinator species. Using dynamical system theory, stability analysis of various ecological equilibria is investigated, and bifurcation phenomena such as transcritical and hopf are revealed. Furthermore, numerical results suggest that higher initial predator density can lead to pollinator extinction, although the predator population may not survive eventually. However, increased mutualistic strengths along with reduced predation rate can promote stability and support the sustainability of the plant–pollinator–predator ecosystem. These findings can be helpful for conservation strategies aimed at preserving pollinators and enhancing biodiversity.
Self-starting of Mamyshev oscillator using an optical beam shutter
Authors: Nigam Anshuman , Bhuvnesh  , Singh C. P. , Gupta P. K. , Mukhopadhyay P. K. , Kaul R. , Dixit S. K.
Published: February 2025

A simple method to self-start a Mamyshev oscillator (MO) using an optical beam shutter (OBS) in the cavity is presented. OBS is placed inside the cavity to introduce a strong optical fluctuation by switching its state (open/close). Stable mode-locking operation is achieved in fiber MO by using an OBS without requiring any external mode-locked seed source or pump modulation.
Design and test of a robustness evaluation system for micro-vision tracking algorithms
Authors: Wang Ruizhou , Zhang Yulong , Wang Hua
Published: February 2025

Industrial applications of micro-vision tracking algorithms become increasingly prevalent. Unfortunately, out-of-focused-plane (OFP) disturbances negatively impact the in-focused-plane (IFP) tracking accuracy of the micro-vision. This paper proposes a robustness evaluation system for micro-vision tracking algorithms. The relationship between IFP accuracy degradation/improvement and OFP disturbances is quantified. First, a commercial spatial nanopositioning stage (com-SNPS) and an SNPS designed in the laboratory (lab-SNPS) were employed to build a robustness evaluation system. Two SNPSs were utilized to generate both IFP trajectories and specific OFP disturbances. Capacitive sensors were used to evaluate the IFP accuracy of micro-vision tracking algorithms. Second, traditional micro-vision tracking algorithms were selected. The combination of the constant-template matching method, constant-region-of-interest (constant-ROI) retrieval method, and constant-focused-plane focusing method acted as test examples. Third, robust micro-vision tracking algorithms were developed. The variable-template matching method, variable-ROI retrieval method, and variable-focused-plane focusing method were combined. Finally, the prototype of the proposed robustness evaluation system was tested. The focused plane was determined to be a benchmark for calculating OFP disturbances. The IFP accuracy of chosen algorithms under specific OFP excitation was measured. Test results demonstrate different IFP degradation or improvement characteristics of micro-vision algorithms. This paper contributes to developing a robust micro-vision tracking algorithm.
First-principles study on structural and electronic properties of MPX3 (M = Zn, Cd; X = S, Se) compounds
Authors: Zada Zeshan , Li Yufeng , Tao Ye , Li Xujing , Bu Kun , Wang Jian-Tao
Published: February 2025

Metal phosphorous trichalcogenides have been attracting significant scientific interest due to their unique physical properties and promising prospects for device applications. In this work, we perform systematical first-principles calculations to study the structural and electronic properties of MPX3 (M = Zn, Cd; X = S, Se) compounds in C2/m (α-phase) and R3̄ (β-phase) symmetries. The sequence of energetic stabilities of this series of compounds is revealed by total energy calculations, and their dynamical stabilities are confirmed by phonon band spectrum calculations. Electronic band structure calculations show that these MPX3 compounds are all indirect-gap semiconductors, and the bandgaps in sulfides (3.13–3.39 eV) are larger than those in selenides (2.14–2.27 eV). The orbital projected density of states calculations show that the electronic states in these compounds around the Fermi level are all mainly contributed by the p orbitals of chalcogen atoms and phosphorus atoms. Our work has given a systematical understanding of this series of MPX3 compounds, which will provide guidance for future theoretical and experimental studies in related fields.
Dynamic incentives and environmental feedback in public goods games: Promoting cooperation through critical thresholds
Authors: Hu Die , Liu Jinzhuo , Liu Chen , Chu Chen
Published: February 2025

Understanding the emergence and maintenance of cooperation in multiplayer games is a significant challenge across various theoretical disciplines. In this paper, we introduce an innovative model to study the impacts of environmental feedback in systems with critical thresholds. Different from prior studies on public goods games with environmental feedback, we propose that the system holds expectations for collective behavior, and the dynamic incentives are equal for all group members. Our findings reveal that dynamic incentives driven by environmental feedback significantly enhance cooperation, particularly in scenarios with low synergy factors. As incentives increase, the system shifts from the non-cooperative to cooperative state. Moreover, a faster rate of incentive growth leads to a higher level of cooperation, demonstrating a strong positive correlation between dynamic incentive levels and overall cooperation within the system. Counterintuitively, our study finds that introducing dynamic incentives from environmental feedback not only effectively promotes cooperation under high expectation levels but also surprisingly increases the success rate of cooperation as expectations rise.
Distributed algorithms of stochastic games for robot systems in smart manufacturing
Authors: He Xiongnan , Lin Zongli , Chang Qing
Published: February 2025

In this paper, we study the problem of distributed generalized stochastic Nash equilibrium seeking for robot systems over a connected undirected graph. We use the cost functions containing uncertainty to represent the system’s performance under varying conditions. To mitigate the challenges posed by this uncertainty, we employ the Tikhonov regularization scheme, which also helps us to relax the strongly monotone condition of the cost functions to the strictly monotone condition. We also consider the inequality constraints, which represent the feasible working space of robots. Additionally, auxiliary parameters are introduced in the control laws to facilitate seeing the variational generalized stochastic Nash equilibrium. The convergence of the proposed control laws is analyzed by using the operator splitting method. Finally, we demonstrate the effectiveness of the proposed algorithm through an example involving multiple robots connected through a communication network.
Demagnetization analysis of an 18 GHz electron cyclotron resonance ion source permanent magnet hexapole
Authors: McLain J. , Scott R. , Vondrasek R.
Published: February 2025

An upgrade of ECR2 at the Argonne Tandem Linac Accelerator System is under way, focusing on increasing the intensity capabilities of the facility. ECR2 is a room temperature electron cyclotron resonance ion source, and the upgrade has strict requirements to retain radial access to the plasma chamber and keep the ion source operating without the use of superconducting magnets. The upgrade design with respect to the magnet arrangement and magnetization vectors has recently been presented [R. C. Vondrasek, J. McLain, and R. H. Scott, J. Phys.: Conf. Ser. 2743, 012044 (2024)] using the same magnetic material as the current ECR2 hexapole. A thorough exploration of the demagnetization potential of this hexapole was carried out, and the risk of demagnetization was deemed too high, despite the magnetic performance meeting the requirements for the upgrade. Additional permanent magnet materials are considered with their respective performance evaluated. Magnet strength and demagnetization resistance are investigated and optimized with the final room temperature design demonstrating a high temperature transient demagnetization resistance and a radial magnetic field of 1.18 T at the plasma chamber wall. The simulations of this hexapole suggest that it will be sufficient to optimize intensity with a 14.5 GHz driving frequency and will allow 18 GHz operation, while keeping a high safety margin for maintaining magnet performance.
One-dimensional invariant measure in periodicity hubs: A tribute to Professor Jason A. C. Gallas
Authors: do Carmo R. B. , Rios Leite J. R. , de Aguiar F. M.
Published: February 2025

Chaotic behavior near a periodicity hub is characterized in five different three-dimensional systems, namely, the paradigmatic Rössler system, the Rosenzweig–MacArthur predator–prey model, a semiconductor laser model, the Gaspard–Nicolis chemical oscillator, and the Nishio–Inaba electronic circuit. Return maps of local maxima for a selected dynamical variable in each system were extracted from numerical solutions. By rescaling the data and assuming full ergodicity in the unit interval, we show that excellent fits to the ubiquitously U-shaped invariant densities are obtained with weighted combinations of the beta and Kumaraswamy distributions.
Particle-in-cell simulations of expanding high energy density plasmas with laser ray tracing
Authors: Lezhnin K. V. , Totorica S. R. , Hyder A. S. , Griff-McMahon J. , Adams M. B. P. , Tzeferacos P. , Diallo A. , Fox W.
Published: February 2025

The design and analysis of high energy density (HED) laser experiments typically rely on radiation hydrodynamics simulations. However, some laser–plasma interaction regimes are not collisional and cannot be adequately modeled with hydrodynamics. For example, strongly driven magnetic reconnection and magnetized collisionless shock experiments possess extended hydrodynamic or even kinetic properties, necessitating first-principles kinetic simulations. In this paper, we present the benchmarking and first results obtained with a laser-ray-tracing and inverse bremsstrahlung absorption module implemented in the particle-in-cell code PSC. The simulation results are compared to radiation hydrodynamic simulations using the FLASH code as well as analytical estimates. We successfully benchmark the energy deposition model and overall hydrodynamic evolution of the systems. We also consider possible kinetic effects that may be expected from laser-target ablation in the HED regime, including non-local transport and two-temperature effects.
Numerical simulation of surface charge accumulation under negative discharge of different humidities and pressures
Authors: Luo Yi , Zhang Cheng , Huang Bangdou , Ren Chengyan , Shao Tao
Published: February 2025

The surface discharge phenomenon of polymers severely limits their applications in electrical and electronic devices, especially in complex environments. In this study, a drift-diffusion model based on a hydrodynamic approach was developed to investigate the influence of humidity and gas pressure on the negative surface discharge. The results indicate that the discharge pattern did not change under different humidity conditions. The increased humidity accelerated the formation of discharges and increased the discharge pulse current. In particular, as the humidity increased, tiny pulses occurred at the tail of the first pulse, and the number of tiny pulses increased. The appearance of these tiny pulses changed the surface charge distribution from a “ring-like” distribution to a “spot-like” distribution. Meanwhile, the accumulation of surface charges significantly distorted the spatial electric field distribution and suppressed the electron multiplication stage of the subsequent discharges, thus reducing the current in the Trichel pulse discharge stage. It is precisely because the discharge is stronger under high humidity, resulting in more surface charges accumulating on the surface, which is in keeping with the experimental results. The measured charges at different humidities show a similar distinct spot-like distribution, illustrating a constant pattern of discharge. All these results demonstrated the correctness and applicability of the simulation. The surface discharge under different pressures exhibited some similarities with the case of different humidity levels. As the pressure increased, the number of discharge current pulses and the pulse amplitude decreased, resulting in a decrease in the surface charge density.
Spin glass and complex magnetism in a high-entropy spinel oxide with five cations at both tetrahedral and octahedral sites
Authors: Sharma Neha , Link J. , Heinmaa I. , Stern R. , Chakrabarty Tanmoy , Marik Sourav
Published: February 2025

We report the stabilization and investigation of a hitherto unexplored high-entropy spinel oxide with the composition (Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)(Cr0.4Mn0.4Fe0.4Al0.4Ga0.4)O4, representing the spinel compound with five distinct elements at both the tetrahedral and octahedral sites in the spinel structure. Detailed structural characterization using x-ray diffraction (and scanning electron microscopy) confirms the cubic crystal structure, while DC magnetic and AC susceptibility measurements reveal complex magnetic behavior below 150 K and spin glass state at 37 K. AC susceptibility measurements along with zero-field-cooled and field-cooled memory effect and aging effect confirm the spin glass state of the material. The power law and Vogel–Fulcher analyses confirm this material's cluster spin glass state. This work highlights the potential of entropy-driven design in tailoring multifunctional materials for advanced applications.
The role of model crowders in the salt resistance of complex coacervates
Authors: Vengallur Nayan , Giuntoli Andrea
Published: February 2025

Complex coacervation is the phase separation of oppositely charged polyelectrolytes, resulting in a polymer-dense coacervate phase and a polymer-depleted supernatant phase. Coacervation is crucial for many biological processes and novel synthetic materials, where the environment is often filled with other neutral molecules (crowders). Yet, the complex role of crowders in complex coacervation has not been studied systematically under controlled conditions. We performed coarse-grained molecular dynamics simulations of coacervation in the presence of polymeric crowders of varying concentrations and chain lengths. While short crowders do not have any significant effect on coacervation, larger crowders stabilize the coacervate against added salt, increasing its critical salt concentration. The change in critical salt concentration saturates for long crowders at a value determined by the crowder concentration. Rescaling all phase diagrams by their critical salt concentration leads to a collapse of the data, which demonstrates a universal phase behavior. Our simulation indicates that the inability of crowder chains to mix with the polyelectrolytes is the driving force behind crowding effects. These testable predictions provide a first step toward a comprehensive understanding of crowding effects in complex coacervation.
From chimeras to extensive chaos in networks of heterogeneous Kuramoto oscillator populations
Authors: Floriach Pol , Garcia-Ojalvo Jordi , Clusella Pau
Published: February 2025

Populations of coupled oscillators can exhibit a wide range of complex dynamical behavior, from complete synchronization to chimera and chaotic states. We can, thus, expect complex dynamics to arise in networks of such populations. Here, we analyze the dynamics of networks of populations of heterogeneous mean-field coupled Kuramoto–Sakaguchi oscillators and show that the instability that leads to chimera states in a simple two-population model also leads to extensive chaos in large networks of coupled populations. Formally, the system consists of a complex network of oscillator populations whose mesoscopic behavior evolves according to the Ott–Antonsen equations. By considering identical parameters across populations, the system contains a manifold of homogeneous solutions where all populations behave identically. Stability analysis of these homogeneous states provided by the master stability function formalism shows that non-trivial dynamics might emerge on a wide region of the parameter space for arbitrary network topologies. As examples, we first revisit the two-population case and provide a complete bifurcation diagram. Then, we investigate the emergent dynamics in large ring and Erdös–Rényi networks. In both cases, transverse instabilities lead to extensive space–time chaos, i.e., irregular regimes whose complexity scales linearly with the system size. Our work provides a unified analytical framework to understand the emergent dynamics of networks of oscillator populations, from chimera states to robust high-dimensional chaos.
Generalized time-fractional kinetic-type equations with multiple parameters
Authors: Angelani Luca , De Gregorio Alessandro , Garra Roberto
Published: February 2025

In this paper, we study a new generalization of the kinetic equation emerging in run-and-tumble models [see, e.g., Angelani et al., J. Stat. Phys. 191, 129 (2024) for a time-fractional version of the kinetic equation]. We show that this generalization leads to a wide class of generalized fractional kinetic (GFK) and telegraph-type equations that depend on two (or three) parameters. We provide an explicit expression of the solution in the Laplace domain and show that, for a particular choice of the parameters, the fundamental solution of the GFK equation can be interpreted as the probability density function of a stochastic process obtained by a suitable transformation of the inverse of a subordinator. Then, we discuss some particularly interesting cases, such as generalized telegraph models, fractional diffusion equations involving higher order time derivatives, and fractional integral equations.
Electric-dipole-momentum sensitive Coulomb explosion in doubly ionized CO dimer and trimer: An environmental effect at molecular-scale
Authors: Zhang C. J. , Zhang R. T. , Yan S. C. , Zou L. P. , Zhang S. F. , Hansen K. , Slavíček P. , Ma X.
Published: February 2025

Molecular clusters are aggregates of molecules weakly bound by the van der Waals force between molecules. Removing one electron from each constitutive molecule results in van der Waals bond cleavages through Coulomb explosion. This provides an ideal prototype to further study the environmental effects played by one fragmented ion on the other one at the molecular scale. Here, we report an experimental measurement of the two-body Coulomb explosion of (CO)22+ and (CO)32+, produced in a 40 keV Ar2+ double-electron capture collision with a CO dimer and trimer. Accurate reaction pathways are identified with the advanced ion–ion coincidence and momentum-imaging techniques. The measured kinetic energy release deviates from the calculated results based on the reciprocal of internuclear distance (i.e., Coulomb interaction only) and which, therefore, requires the inclusion of rotational energy of CO+ initiated by molecular electric-dipole momentum. Molecular dynamics simulations reveal that the separation defining the rotational energy takes place within a few hundred fs after the onset of dissociation. This molecular-scale environmental effect significantly brings calculations and measurements of the kinetic energy release into agreement.
State selective preparation and nondestructive detection of trapped O2+
Authors: Singh Ambesh Pratik , Mitchell Michael , Henshon Will , Hartman Addison , Lunstad Annika , Kuzhan Boran , Hanneke David
Published: February 2025

The ability to prepare molecular ions in selected quantum states enables studies in areas such as chemistry, metrology, spectroscopy, quantum information, and precision measurements. Here, we demonstrate (2 + 1) resonance-enhanced multiphoton ionization (REMPI) of oxygen, both in a molecular beam and in an ion trap. The two-photon transition in the REMPI spectrum is rotationally resolved, allowing ionization from a selected rovibrational state of O2. Fits to this spectrum determine spectroscopic parameters of the O2d1Πg state and resolve a discrepancy in the literature regarding its band origin. The trapped molecular ions are cooled by co-trapped atomic ions. Fluorescence mass spectrometry nondestructively demonstrates the presence of the photoionized O2+. We discuss strategies for maximizing the fraction of ions produced in the ground rovibrational state. For (2 + 1) REMPI through the d1Πg state, we show that the Q(1) transition is preferred for neutral O2 at rotational temperatures below 50 K, while the O(3) transition is more suitable at higher temperatures. The combination of state-selective loading and nondestructive detection of trapped molecular ions has applications in optical clocks, tests of fundamental physics, and control of chemical reactions.
Double gap surface plasmons enabled ultra-thin meta-F–P cavity for light filtering in the near-infrared
Authors: Wang Jiayi , Mao Yu , Gao Kaikai , Ma Ruize , Li Peiyang , Li Dong , Li Peng , Zhao Jianlin , Wen Dandan
Published: February 2025

Over the past years, metasurfaces have demonstrated remarkable and diverse capabilities in advanced control over light properties. Embedding metasurfaces into the Fabry–Pérot (meta-F–P) cavity reduces the required cavity length and provides new degrees of freedom for tuning. Most meta-F–P cavities exhibit excellent color filtering effects within the visible spectrum. However, achieving single mode-F–P resonance across the entire near-infrared range remains challenging due to the phase condition limitations of the metasurfaces. Here, we explore the integration of silver metasurfaces into an F–P cavity with a cavity length of only 150 nm. The very short cavity length allows for the existence of gap surface plasmons between the silver metasurfaces and both the top and bottom silver mirrors of the F–P cavity. This setup achieves narrowband filtering in an ultra-wide spectral range from 626.6 to 2548.3 nm while consistently maintaining single-mode resonance. Furthermore, we analyze the filtering effects of embedding anisotropic structures into the F–P cavity under x- and y-polarized incident light, revealing polarization-dependent filtering capabilities. Embedding the metasurface within the F–P cavity also allows for stable responses to different angles of incident light. This study underscores the potential of meta-F–P cavities in advancing optical filter technology for diverse applications in spectroscopy, telecommunications, and sensing.
Oxygen K-edge inner-shell calculations of polymers in solutions realized by the extraction of local structures from molecular dynamics simulations
Authors: Nagasaka Masanari , Yao Yifeng , Mochizuki Kenji
Published: February 2025

Inner-shell quantum chemical calculations of large molecular systems, such as polymers and soft matter in solution, were performed to understand the phase transition dynamics of these systems using soft x-ray absorption spectroscopy (XAS). The molecular structures of 40-mer poly(N-isopropylacrylamide) (PNIPAM) chains in solutions were obtained using molecular dynamics simulations. The 5-mer PNIPAM chains with terminated H atoms, including the second coordination shells of the solvent methanol and water molecules, were extracted from the 40-mer PNIPAM chains in solutions. The O K-edge inner-shell spectra of the 5-mer PNIPAM chains were obtained by averaging the inner-shell spectra of 9700 extracted polymer structures. This calculation method can be used to precisely evaluate the energy shifts of the C=O π* peaks of PNIPAM caused by the structural changes of the polymer chains, the substitutions of the hydrogen bonds of the C=O groups in PNIPAM from methanol to water molecules, and the increase in the coordination numbers of solvent molecules with the C=O groups, which were observed in the O K-edge XAS experiments.