bluuebunny/crossref_metadata_2025 huggingface dataset:
Fast and accurate identification of pathogenic bacteria using excitation–emission spectroscopy and machine learning
Authors: Henry Jacob , Endres Jennifer L. , Sadykov Marat R. , Bayles Kenneth W. , Svechkarev Denis
Published: July 2024

Integration of multidimensional fluorescence spectroscopy of an environmentally sensitive dye and pattern recognition offers a quick and accurate approach to identification of pathogenic bacteria.
Chemically tuned cellulose nanocrystals/single wall carbon nanosheet based electrodes for hybrid supercapacitors
Authors: Choudhary Nitesh , Singh Shiva , Malik Gaurav , Bhardwaj Shakshi , Sharma Siddharth , Tomar Akshay , Issar Sheetal , Chandra Ramesh , Maji Pradip Kumar
Published: July 2024

Adopting a green and environmentally friendly strategy requires the development of supercapacitor electrodes using sustainable, renewable, and environmentally beneficial materials.
Near-zero environmental impact aircraft
Authors: Prashanth Prakash , Elmourad Jad , Grobler Carla , Isaacs Stewart , Zahid Syed Shayan , Abel James , Falter Christoph , Fritz Thibaud , Allroggen Florian , Sabnis Jayant S. , Eastham Sebastian D. , Speth Raymond L. , Barrett Steven R. H.
Published: July 2024

The fundamental challenge facing the aviation industry is to achieve near-zero environmental impacts while sustaining growth. We propose a near-zero impact aircraft, taking a lifecycle perspective across fuels, aircraft design, and operation.
Electronic delocalization engineering of bismuth-based materials for catalytic electrochemical CO2and N2conversion
Authors: Peng Ming , Zhang Junfeng , Ren Jianwei , Tan Yongwen
Published: July 2024

This review focuses on the electronic delocalization engineering of Bi-based materials for the electrocatalytic reduction of CO2and N2, including facet engineering, alloying, defect engineering, atomic engineering, and others.
Carbon nanotube cross-linked phosphorus-doped MXene for capacitive pressure microsensors
Authors: Yang Wenshuai , Zhu Shifan , Hao Chenyang , Ji Tailong , Liu Yuanyuan , Wang Yuqiao
Published: July 2024

The flexibility, integration and wearability of one-dimensional carbon-based cross-linked two-dimensional MXenes can exactly meet the rapid development of microelectronic technology, thereby achieving miniaturization and multi-functionality.
Magnetic lanthanide sensor with self-ratiometric time-resolved luminescence for accurate detection of epithelial cancerous exosomes
Authors: Zeng Yating , Wang Xuekang , Zhu Nanhang , Yu Yue , Wang Xingyou , Kang Ke , Wu Yao , Yi Qiangying
Published: July 2024

The structure of MLS and its working principle for detection of exosomal EpCAM.
Design and evaluation of nanoscale materials with programmed responsivity towards epigenetic enzymes
Authors: Ray Priyanka , Sedigh Abbas , Confeld Matthew , Alhalhooly Lina , Iduoku Kweeni , Casanola-Martin Gerardo M. , Pham-The Hai , Rasulev Bakhtiyor , Choi Yongki , Yang Zhongyu , Mallik Sanku , Quadir Mohiuddin
Published: July 2024

This study presents the synthesis of enzyme-responsive nanoparticles targeting HDAC8, an epigenetic enzyme, through a deacetylation reaction. This first-time report highlights the potential for these particles to mimic synthetic histones.
Functionalized cyanostilbene-based nano-AIEgens: multipoint binding interactions for improved sensing of gallic acid in real-life food samples
Authors: Barkale Harshal V. , Dey Nilanjan
Published: July 2024

Cyano-substituted stilbene (CSS) derivatives have been synthesized that can form luminescent nanoscopic assemblies in an aqueous medium.
Enhancing the water splitting performance of a reduced graphene oxide–platinum nanoparticle hybrid using an intercalating ethylenediamine polar space group
Authors: Karim Mohammad Razaul , Ahmed Guljar , Al-Humaidi Jehan Y. , Hossain Neamot , Chowdhury Mohammad Shahadat Hussain , Uddin Md. Nizam , Khan M. Nuruzzaman , Rahman Mohammed M.
Published: July 2024

Ethylenediamine (EDA) introduced into rGO-platinum hybrid could lower the band gap and enhance the proton–electron conductivity. rGO-Pt-EDA thus displayed optimum surface area and significantly enhanced photocatalytic hydrogen generation efficiency.
Research on the design and control of an anthropomorphic waist structure for life support robots
Authors: Li Zufeng , Du Lei , Ao Wengang , Qiu Xuan
Published: July 2024

In the humanoid robots, waist mechanism is an important structure to realize the whole body coordinated movement. This paper proposes a series–parallel mechanism of waist structure, and its kinematics and dynamics characteristics are studied. Based on the dynamic model, a backstepping sliding mode controller is designed to simulate control performance. Under the continuous disturbance force, the stability and accuracy of the mechanism are verified. Compared with the experiment, the results prove that the waist mechanism has the biomimetic spine movements and desired control performance, which can be applied to life support robots in the future.
Rotor speed signature analysis‐based inter‐turn short circuit fault detection for permanent magnet synchronous machines
Authors: Wei Dong , Liu Kan , Zhu Zi‐Qiang , Zhou Shichao , Wang Jianbo , Chen Yongdan
Published: July 2024

A rotor speed signature analysis‐ (RSSA‐)based inter‐turn short circuit (ITSC) fault diagnostic method is proposed, which is robust with regard to speed‐ and current‐loop bandwidths of permanent magnet synchronous machine (PMSM) drive systems. Conventional ITSC fault detection solutions that rely on current signals or extra devices. Thus, an initial step of investigation on the validity of RSSA is taken for residual insulation capacity monitoring of the ITSC fault at the incipient stage. The Vold–Kalman filtering order tracking method is employed for the real‐time extraction of fault features. Besides, the impact of speed‐ and current‐loop controller bandwidths on ITSC fault diagnosis is also analysed and an Adaline estimator is designed to decouple their impacts. Finally, the effectiveness of the proposed method is verified on a faulty PMSM, which exhibits satisfying results in tracking the degradation of residual insulation, even if the phase currents are significantly distorted due to low switching frequency of the inverter.
Ferrofluid‐based electrical machines: Conceptualization and experimental evaluation
Authors: Darabi Ahmad , Pourmirzaei Deylami Fazel , Sheikhian Morteza , Taheripour Mohammad Ali
Published: July 2024

This article intends to propose a new concept of electric machines that works based on a category of magnetic fluids called “ferrofluids”. For this purpose, a disc‐shaped rotor filled with ferrofluid material is employed instead of a common rotor of an axial‐flux machine, and the conceptual design of the new machine named here “axial‐flux ferrofluid electric machine (FFEM)” is presented. The operation principle of the FFEM is described and a dynamic‐transient model built on the d–q axes equivalent circuits is presented. Simulations are carried out by applying the given model in MATLAB and the results are investigated in different operating conditions. In order to identify the basic parameters and validate the simulation results, a prototype of the FFEM has been designed and manufactured, and some preliminary functional tests have been performed on the prototype. All simulation and experimental results indicate some distinguished excellent performances of the new machine. In the end, it can be stated briefly with some confidence that ferrofluid electric machines can have a high potential for future research and applications in various industries due to the simplicity of the structure, self‐starting capability, ability to work at a wide range of speeds and a flat torque profile.
Transitions in magnetic behavior at the substellar boundary
Authors: Magaudda E. , Stelzer B. , Osten R. A. , Pineda J. S. , Raetz St. , McKay M.
Published: July 2024

We aim to advance our understanding of magnetic activity and the underlying dynamo mechanism at the end of the main sequence. To this end, we have embarked on collecting simultaneous X-ray and radio observations for a sample of M7..L0 dwarfs in the solar neighborhood using XMM-Newton jointly with the Jansky Very Large Array (JVLA) and the Australia Telescope Compact Array (ATCA). We supplemented the data from these dedicated campaigns with X-ray data from the all-sky surveys of the ROentgen Survey with an Imaging Telescope Array (eROSITA) on board the Russian Spektrum-Roentgen-Gamma mission (SRG). Moreover, we complement this multiwavelength data set with rotation periods that we measured from light curves acquired with the Transiting Exoplanet Survey Satellite (TESS). We limited the sample to objects with rotation period of < 1 day, focusing on the study of a transition in magnetic behavior suggested by a drastic change in the radio detection rate at υ sin i ≈ 38 km s−1, corresponding to Prot ≈ 0.2 day for a typical ultracool dwarf (UCD) radius of R★ = 0.15 R⊙. Finally, to enlarge the target list, we have compiled archival X-ray and radio data for UCDs from the literature, and we have analyzed the abovementioned ancillary eROSITA and TESS observations for these objects’ analogous to the targets from our dedicated X-ray/radio campaigns. We compiled the most up to date radio/X-ray luminosity (LR,ν − Lx) relation for 26 UCDs with rotation periods (Prot) lower than 1 day, finding that rapid rotators lie the furthest away from the “Güdel-Benz” relation previously studied for earlier-type stars. Radio bursts are mainly (although not exclusively) experienced by very fast UCDs (Prot ≤ 0.2 day), while X-ray flares are seen by objects spanning the whole range of rotation. Finally, we examined the Lx/Lbol versus Prot relation, where our sample of UCDs spans a large activity level range, that is log(Lx/Lbol) = −5.5 to log(Lx/Lbol) = −3. Although they are all fast rotating, X-ray activity evidently decouples from that of normal dynamos. In fact, we found no evident relation between the X-ray emission and rotation, reinforcing previous speculations on a bimodal dynamo across late-type dwarfs. One radio-detected object, 2MJ0838, has a rotation period consistent with the range of auroral bursting sources; while it displays moderately circularly polarized emission, there is no temporal variation in the polarized flux. A radio flare from this object is interpreted as gyrosynchrotron emission, and it displays X-ray and optical flares. Among the ten UCDs observed with the dedicated X-ray/radio campaigns, we found a slowly rotating apparent auroral emitter (2MJ0752) that is also one of the X-ray brightest radio-detected UCDs. We speculate that this UCD is experiencing a transition in its magnetic behavior since it produces signatures expected from higher-mass M dwarfs along with emerging evidence of auroral emission.
Comparative study on suction obtained using the membrane filter method from triaxial apparatus and pressure plate apparatus
Authors: Chowdepalli Bhargavi , Watanabe Kenji
Published: July 2024

To investigate the stability of the earth embankments and slope failures during natural disasters, it is necessary to consider that soil is naturally unsaturated. Hence, it is essential to understand the variations of pore air pressure and pore water pressure, in terms of suction. The relationship between soil suction and soil moisture content is generally attained by soil water characteristic curve (SWCC), which is critically important in characterizing the mechanical behaviour of unsaturated soils. The SWCC is obtained from pressure plate apparatus by imposing the suction continuously by draining water from the saturated specimen and/or supplying water to unsaturated soil, which differs from the actual soil compaction process at the site. Therefore, the current study employs a methodology of suction measurement directly at a certain degree of compaction and degree of saturation using the membrane filter method in the triaxial apparatus, to meet the realistic conditions in the field. A comparative study has been done using SWCC with the imposed suction and the measured suction (Natural suction) at each compacted state. The results from both the methods exhibited an increase in the suction and air entry value with the increase in the degree of compaction, proving that an increasingly positive effect of suction contributed while increasing the density. Whereas the suction measured immediately after the compaction (Natural suction) in triaxial apparatus is more consistent with the suction imposed in the wetting process of SWCC. Further deep understanding of the microstructure behaviour of each compacted state and the SWCC is necessary.
Investigation on the effect of intermediate principal stress on shear behaviour of unsaturated soils
Authors: Jafarzadeh Fardin , Poorakbar Amirsajjad , Moghayad Mahdi
Published: July 2024

Directional-dependent properties of the soil, like shear strength, stiffness and hydraulic conductivity, are known as anisotropy in soils. Shape and size of the soil particles and void distribution as microstructure characteristics and external factors such as stress history, environmental and geological conditions, and present stress condition can be the causes of the anisotropy in soils. In this paper, the behaviour of soil has been studied in stress-strain plain under monotonic anisotropic loading to investigate the effect of induced anisotropy on brittleness index of soil sample. The brittleness index of the soil is defined as the difference between the ultimate and peak shear strength divided by the peak shear strength of the soil. The two major parameters describing induced anisotropy or anisotropic loading are intermediate principal stress (b) and principal stress direction (α) which are representative of the difference between intermediate, maximum and minimum principal stresses and the rotation angle of the principal stresses’ axis, respectively. This paper only takes the effect of intermediate principal stress with the values of 0.25, 0.5, 0.75. In addition, the soil is in the unsaturated state with the saturation degree of 80% using the constant water (C.W.) method.
Hydromechanical characterization of the behaviour of Chateau-Landon chalk
Authors: Pajiep Ngongang Danielle Rita , Conil Nathalie , Shao Jian-Fu , Souley Mountaka , Gombert Philippe
Published: July 2024

This paper presents an experimental investigation on the hydromechanical behaviour of a partially saturated soft rock (a porous chalk), the Chateau-Landon chalk. Such conditions correspond to those of a chalk mine known as Royer located in the North-centre of France in Paris basin, subjected to shrinking, drying and potential flooding cycles. To study this rock, we apply a method usually used in soils whose hydromechanical behaviour is strongly modified by changes in suction, according to the degree of water saturation. Different degrees of saturation are imposed by controlled relative humidity conditions with continuous measurement of physical parameters. Hydrostatic compression and conventional triaxial compression tests are performed under drained conditions for saturation degrees up to 100% under low confining pressures. The obtained results have allowed to show fundamental aspects of the chalk behaviour. Correlations between water saturation degree, confining pressure and the mechanical behaviour of the chalk are discussed.
Clay micromechanics: Experimental challenges and perspectives
Authors: Pedrotti Matteo , Dieudonné Anne-Catherine , Dijkstra Jelke , Musso Guido , Hattab Mahdia , Viggiani Gioacchino
Published: July 2024

The importance of physico-chemical processes at the particle scale for the engineering scale behaviour of fine-grained geomaterials is undisputed. Yet, despite great advances in the discipline, experimental evidence that fully resolves the clay micromechanics i.e. linking the evolving microstructure and interparticle actions under loading, is lacking. This paper will discuss the challenges ahead in quantifying the evolving kinematics and interparticle interactions of fine-grained geomaterials. As such, the current limitations, and the potential opportunities of experimental methodologies for manipulating, monitoring and (post-mortem) analysing fine-grained materials at the particle scale will be discussed. In addition to the need of integrating multiple experimental techniques that span several length scales and modalities, the critical role of advanced data reduction and analysis is highlighted, as required for a measurement as opposed to qualitative observation. Throughout the paper, the link between experimental clay micromechanics and modelling will be discussed.
Stress‒dilatancy behaviour of calcareous sand
Authors: Szypcio Zenon
Published: July 2024

Calcareous sands are a special geomaterial primarily composed of calcium carbonate or other insoluble carbonate materials susceptible to breakage. Therefore, breakage has a crucial impact on the change of calcareous sand granulation and the shape of individual grains during shear. By analysing some triaxial tests results of some calcareous sands presented in the literature in the light of the Frictional State Concept (FSC), it can be shown that the stress‒dilatancy relationship in different shear phases can be approximated with straight lines. These lines are defined by a critical frictional state angle and two material parameters of the FSC. These parameters express the deviation between the stress‒dilatancy relationship for tested soil and the stress‒dilatancy relationship for isotropic granular material shear deformed without non-coaxiality of the stress tensor and strain increment tensor, breakage, and other effects affecting energy dissipation during shear. It will also be shown that the points representing failure states in the η - D plane lie on a straight line with a much higher slope than for silica sands due to the breakage effect. Using the FSC, the stress‒dilatancy relationship can be simply described in different shear phases and used to build new elasto-plastic models of calcareous sand in the future.
Centrifuge modelling of monotonic and cyclic lateral responses of monopiles in quartz and carbonate sands
Authors: Soares de Almeida Márcio de Sousa , Wamser Barra Maria Fernanda , Gomes Naiala Fidelis , Pereira Gomes José Wedney , Ferreira de Almeida Maria Cascão , Futai Marcos Massao
Published: July 2024

This study evaluates the soil-structure interaction of monopiles subjected to monotonic and cyclic lateral loading by means of centrifuge modelling. The monopile were installed in two types of dense sands: quarts and carbonate. To evaluate the static and dynamic properties, the two soils were characterized by index tests, as well as triaxial, resonant column and bender element tests. The triaxial tests showed that angles of internal friction were higher for the sand with higher carbonate content (CaCO3). Also, curved shear strength envelopes were observed in both soils, i.e., peak friction angles decreasing with confining stress. Regarding the dynamic soil properties, the stress history appears to affect the stiffness of the carbonate sands more than the quartz sands, i.e., the higher CaCO3 content soil exhibited greater shear modulus degradation. In the geotechnical centrifuge tests the lateral loading capacity about doubled after 4800 loading cycles, slightly more for the carbonate sand than for the quartz sand. Also, as a function of the cycling process, the secant stiffness increased for both sand types, especially in the first 500 loading cycles where the increase occurred exponentially.
A comparison between static and dynamic load tests of Tapered steel jacking piles in Baskarp sand
Authors: Zhou Junyu , Wu Yimo , Ibsen Lars Bo , Barari Amin
Published: July 2024

In this study, four full scale static compression tests were performed on a tapered steel jacking pile with diameters 76 mm and 89 mm in both dry and saturated soil conditions. Each test consists of multiple sub-tests with respect to determination of in-situ Baskarp Sand No.15 conditions and bearing capacities of the piles. Further, a finite element methodology has been developed to predict the load-displacement response of tapered piles installed in sand, incorporating the effects of jacking installation. The methodology is based on the identification of the failure mechanism and shear strain formation at failure around the pile as well as adoption of soil-soil interface elements. The nonlinear soil model parameters for a fully wished-in-place (fully-WIP) condition were obtained through piezocone penetration tests where various methods were applied to obtain the relative density, among which those providing best fit according to Jamiolokowski et al., (2003) were selected for further assessment. Finally, the hammer tests were performed from which the dynamic bearing capacities and the relation between static and dynamic bearing capacities were obtained.
Gradation and state effects on the strength and dilatancy of coarse-grained soils
Authors: Ahmed S. Sharif , Martinez Alejandro , DeJong Jason
Published: July 2024

Well-graded soils can be found in nature and in engineered structures, such as dams and embankments. Prediction of their behavior is still an engineering challenge in part due to the lack of data in the literature, arguably due to difficulties associated in testing these soils in the laboratory and in situ. Particularly, there is still debate over the effect of the increased range of particle sizes (i.e., widening gradation) on the shear strength and dilatancy of coarse-grained soils. This paper presents the results of drained and undrained isotropically-consolidated triaxial compression tests on six soil mixes of varying gradation. These soils were sourced from a single natural deposit and selectively sieved and mixed to isolate the effects of gradation from those of particle shape and mineralogy. The results indicate that the critical state lines in void ratio – mean effective stress space move downward as the gradation becomes wider. For the same state parameter, the soils with a wider gradation exhibit greater dilatancy and generate negative excess pore pressures with greater magnitudes than the poorly-graded soils. In drained conditions, the greater dilatancy of the well-graded soils leads to greater peak friction angles, while in undrained conditions it leads to greater undrained shear strengths. The results show that these differences in behavior can only be captured when interpreting the results in terms of the state parameter and normalized state parameter, while comparing the results in terms of the void ratio or relative density obscures the effect of differences in gradation.
Effect of Zr on the microstructure and properties of high-strength Ti-Mo microalloyed steel after quenching and tempering
Authors: Yang Lisheng , Zhang Fanlin , Luo Hanyu , Xu Chaoyong , Zhang Jinchang , Cao Jianchun
Published: July 2024

Investigation on the effects of Zr and quenching and tempering processes on the microstructure and properties of high-strength Ti-Mo microalloyed steel using SEM, TEM, mechanical property testing, and First-principles calculations. The results show that within the tempering temperature range of 550–650 °C, the microstructures of Ti-Mo microalloyed steel and Ti-Zr-Mo microalloyed steel consist of ultra-low carbon martensite and carbides. Specifically, the strength of Ti-Mo microalloyed steel initially increases and then decreases with the increase in tempering temperature, while the strength of Ti-Zr-Mo microalloyed steel increases with the increase in tempering temperature. During tempering, the addition of Zr element affects the diffusion of C element, delaying the martensitic tempering transformation process, and slowing down the nucleation, growth, and coarsening processes of alloy carbides. First-principles calculation results indicate that ZrC preferentially forms during tempering, resulting in a certain sequential gradient of precipitated microalloy carbides, thereby enhancing the tempering stability of microalloyed steel. Compared to Ti-Mo steel, Ti-Zr-Mo steel exhibits narrower lath martensite width and finer dispersed precipitation phases after tempering at 600 °C and 650 °C.
Exploring topological indices of oligothiophene dendrimer via neighborhood M-polynomials
Authors: Abubakar Muhammad Shafii , Aremu Kazeem Olalekan , Aphane Maggie , Siddiqui Muhammad Kamran
Published: July 2024

In this study, we give some theoretical results for studying the structural connectivity of oligothiophene dendrimer by utilizing the neighborhood M-polynomial. The main result of this article presents the closed formula of neighborhood M-polynomial of oligothiophene dendrimer which is used for computing the neighborhood topological indices of the dendrimer. Among the various indices considered, the forgotten index obtained the highest value, followed by the Sanskruti index, first Zagreb index, and second Zagreb index. These topological indices exhibited an increasing trend as the number of generation increases across the dendrimer structure. Conversely, the general Randic index, harmonic index, geometric-arithmetic index and atom bond connectivity index are the least dominant indices, they display minimal increase as the generation increases. The significance of adopting the neighborhood M-polynomial to compute the topological index lies in the fact that it facilitates the analysis of complex molecules in a timely manner and allows pendant vertex to contribute more effectively to the overall degree value of the dendrimer. Furthermore, the dataset resulting from these topological indices serves as a foundation for future studies aimed at predicting the physicochemical properties of the dendrimer.
Recurrence Risk of Pregnancy Complications in Twin and Singleton Deliveries
Authors: Granger Marion , Sevoyan Maria , Boghossian Nansi S.
Published: July 2024

Objective This study aimed to estimate and compare the recurrence risk of preterm birth (PTB), gestational diabetes mellitus (GDM), gestational hypertension (GH), and preeclampsia and eclampsia (PE and E) in subsequent pregnancy groups (index–subsequent) of singleton–singleton (n = 49,868), twin–singleton (n = 448), and singleton–twin (n = 723) pregnancies.

Study Design Birthing individuals from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Consecutive Pregnancy Study (2002–2010) with ≥ 2 singleton or twin deliveries were examined. Adjusted relative risks (aRR) and 95% confidence intervals (CI) for recurrent PTB, GDM, GH, and PE and E were estimated using Poisson regression models with robust variance estimators.

Results The aRR of PTB and GDM ranged from 1.4 to 5.1 and 5.2 to 22.7, respectively, with the greatest recurrence relative risk for both conditions in singleton–singleton subsequent pregnancies (PTB: aRR = 5.1 [95% CI: 4.8–5.5], GDM: aRR = 22.7 [95% CI: 20.8–24.8]). The aRR of GH and PE and E ranged from 2.8 to 7.6 and 3.2 to 9.2, respectively, with the greatest recurrence relative risk for both conditions in twin–singleton subsequent pregnancies (GH: aRR = 7.6 [95% CI: 2.8–20.5], PE and E: aRR = 9.2 [95% CI: 2.9–28.6]).

Conclusion Recurrence relative risk was increased for PTB, GDM, GH, and PE and E in all subsequent pregnancy groups, which varied in magnitude based on the birth number of the index and subsequent pregnancy. This information provides insight into risk management for subsequent pregnancies including multiples.

Key Points
Exploring the impact of customer concentration on stock price crash risk
Authors: Afghahi Mahla , Nassirzadeh Farzaneh , Askarany Davood
Published: July 2024

This paper, rooted in agency theory, explores the intricate relationship between stock price crash risk and customer concentration within the context of Iran, a developing nation. Utilising innovative indicators to measure corporate and government customers, we address inconsistent findings in existing research and offer fresh insights into stock price crash risk dynamics. Focusing on 82 companies listed on the Tehran Stock Exchange from 2013 to 2020, our study employs a robust methodological framework, including panel data, multiple regression and three distinct metrics to measure customer concentration. Specifically, we introduce the proportion of significant customer sales, the Herfindahl-Hirschman Index, and a Ranking Index based on substantial customer sales. Our investigation reveals a noteworthy inverse relationship between the highest concentration level of corporate customer concentration, as measured by the Ranking Index, and stock price crash risk. Similarly, we establish an inverse association between the Ranking Index for government customer concentration and stock price crash risk. Moreover, institutional investors positively influence the correlation between corporate customer concentration and stock price crash risk but do not exert a discernible impact on the relationship between government customer concentration and stock price crash risk.
Big data analytics capability and social innovation: the mediating role of knowledge exploration and exploitation
Authors: Wang Nan , Chen Baolian , Wang Liya , Ma Zhenzhong , Pan Shan
Published: July 2024

While many organizations have successfully leveraged big data analytics capabilities to improve their performance, our understanding is limited on whether and how big data analytics capabilities affect social innovation in organizations. Based on the organizational information processing theory and the organizational learning theory, this study aims to investigate how big data analytics capabilities support social innovation, and how knowledge ambidexterity mediates this relationship. A total of 354 high-tech companies in China, this study shows that big data analytics management, big data analytics technology, and big data analytics personnel capabilities all have positive effects on social innovation. In addition, both knowledge exploration and knowledge exploitation play a mediating role in this process. Furthermore, a polynomial regression and response surface analysis shows that social innovation increases when knowledge exploration and knowledge exploitation are highly consistent but declines when knowledge exploration and knowledge exploitation are inconsistent. This study not only provides new perspectives for understanding how big data analytics capabilities contribute to social innovation, complementing the existing literature on big data analytics capabilities and social innovation, but also provides important practical guidance on how organizations can develop big data analytics capabilities to improve social innovation and solve social problems in the digital age.
Territorial control by non-state armed groups and gendered access to healthcare in conflict using a new complex adaptive systems framework
Authors: Lilja Jannie , Ferrari Giulia , Alvarado José , Fabich Laura-Alina , Kyzy Gulzhan Asylbek , Kenny Leah , Hossain Mazeda
Published: July 2024

The growing prevalence and influence of non-state armed groups (NSAGs) in armed conflict requires a deeper understanding of how their territorial control and contestation affect sub-national healthcare availability and outcomes, particularly with regards to gender dynamics. However, there are gaps in existing research in understanding how NSAG governance influences health care outcomes. Furthermore, a disconnect exists between the literature on international humanitarian interventions, NSAG governance and national health systems. Each perspective tends to prioritise a specific health service provider—whether NSAGs, State actors, or international humanitarian organisations—and often treats populations as homogenous. To address these gaps, we propose a complex adaptive system framework centred on the influence of territorial control for health services in intra-state conflict settings, with a gender lens. This systems framework accounts for the influence of all parties significant for health service delivery. It recognises that those governing the localised health system may differ from those physically delivering health services. Our framework enables empirical examination of health service delivery and outcomes. We apply the framework to three conflict-affected settings (Colombia, Iraq, Mali) using publicly available data and offer recommendations for policymakers and practitioners targeting health service provision in intra-state conflict contexts.
The singular limits of the Riemann solutions as pressure vanishes for a reduced two-phase mixtures model with non-isentropic gas state
Authors: Jiang W. , Jin D. , Li T. , Chen T.
Published: July 2024

We study the cavitation and concentration phenomena of the Riemann solutions for a reduced two-phase mixtures model with non-isentropic gas state in vanishing pressure limit. We solve the Riemann problem by constructing the regions in (p, u, s) coordinate system. Then we obtain the limiting behaviors of the Riemann solutions and the formation of δ-shock waves and vacuum as pressure vanishes. We conclude that, as pressure vanishes, the limit of Riemann solutions is the Riemann solutions of the reduced 2-dimensional pressureless gas dynamics model. Finally, we present numerical simulations which are consistent with our theoretical analysis.
A cyclical route linking fundamental mechanism and AI algorithm: An example from tuning Poisson's ratio in amorphous networks
Authors: Zhu Changliang , Fang Chenchao , Jin Zhipeng , Li Baowen , Shen Xiangying , Xu Lei
Published: July 2024

“AI for science” is widely recognized as a future trend in the development of scientific research. Currently, although machine learning algorithms have played a crucial role in scientific research with numerous successful cases, relatively few instances exist where AI assists researchers in uncovering the underlying physical mechanisms behind a certain phenomenon and subsequently using that mechanism to improve machine learning algorithms' efficiency. This article uses the investigation into the relationship between extreme Poisson's ratio values and the structure of amorphous networks as a case study to illustrate how machine learning methods can assist in revealing underlying physical mechanisms. Upon recognizing that the Poisson's ratio relies on the low-frequency vibrational modes of the dynamical matrix, we can then employ a convolutional neural network, trained on the dynamical matrix instead of traditional image recognition, to predict the Poisson's ratio of amorphous networks with a much higher efficiency. Through this example, we aim to showcase the role that artificial intelligence can play in revealing fundamental physical mechanisms, which subsequently improves the machine learning algorithms significantly.
Simulation of femtosecond laser-induced periodic surface structures on fused silica by considering intrapulse and interpulse feedback
Authors: Sun Jiaxin , Wang Sumei , Zhu Weihua , Li Xin , Jiang Lan
Published: July 2024

The formation of laser-induced periodic surface structures (LIPSSs) on fused silica upon irradiation with plane wave, double pulse, spot processing, and scanning processing (pulse duration tp = 35 fs, center wavelength λ = 800 nm, low repetition rate ≈1 kHz) is studied theoretically with an improved three-dimensional finite-difference time-domain plasma model. The model covers both intrapulse feedback under single shot and interpulse feedback under multi-shots, thus enabling better prediction of transient responses during laser–material interaction and the evolution of the ablated morphology and accumulated defects’ density with more shots. In simulations of a single plane wave, a double pulse can modulate LIPSS periodicity. In simulations of spot processing with Gaussian beam, an increase in the number of shots results in a noticeable ablation pattern where high-spatial-frequency LIPSS surrounds low-spatial-frequency LIPSS at a fluence of 2.8 J/cm2. Moreover, simulations of scanning processing with Gaussian beam showcase the broad applicability of this model, revealing that the orientation of the LIPSS depends on the polarization direction rather than the scanning path. This new model provides a powerful tool to simulate the formation of LIPSS on silica, particularly when temporally modulated laser is involved or predicting the evolution of morphology dependent on the number of shots.
Tailoring epsilon-near-zero wavelength and nonlinear absorption properties of CdO thin films by Mo doping
Authors: Wu Yi , Wang Ying , Wang Mengxia , Ma Hao , Jiang Hang , Yao Jianke , Zhao Yuanan , Yu Kin Man , Shao Jianda
Published: July 2024

Cadmium oxide (CdO) has recently attracted attention as a material with controllable properties tailored for optoelectronic and nanophotonic devices due to its superior mobility. However, its potential application in near-infrared (NIR) remains to be explored. In this work, we demonstrate that the epsilon-near-zero (ENZ) wavelength and nonlinear optical properties of CdO films can be effectively tuned by Mo doping. The results show that Mo doping increases the electron concentration as well as improve the crystalline quality of CdO. With increasing Mo doping, we achieve blueshifts of the ENZ wavelength from 2.89 to 1.56 μm. The nonlinear absorption (NLA) behavior at 1550 nm changes from reverse saturable absorption to saturable absorption with increasing Mo content. Moreover, significant improvement in NLA performance with nonlinear absorption coefficient β = −72 cm/GW is observed at the highest doping content. Our work shows that doped CdO films with tunable optoelectrical and nonlinear optical properties can be an ideal candidate for optoelectronic and nanophotonic application in the NIR region.
Broadband color routing with a single element nanoantenna for communication bands
Authors: Liu Xianghua , Li Ang , Liu Chenyang , Zhao Nengyang , Peng Jiahao , Gan Fengyuan , Lei Xinrui , Wang Ruxue , Wu Aimin
Published: July 2024

Spectral routing techniques have attracted plenty of research attention for the past decades, as they enable light manipulation in both the frequency domain and the spatial domain, which is crucial for applications in on-chip spectroscopy, optical switching, and modern communications. Here, we demonstrate an ultra-compact asymmetric nanoplasmonic router for communication bands that routes O and C bands to opposite positions. The nanorouter consists of two uneven grooves that create bidirectional scattered optical fields, utilizing the interference between different optical modes inside the grooves. A broadband spectrum exceeding 100 nm and a maximum extinction ratio of 31 dB are achieved, providing new opportunities for nanophotonic color routing solutions and extensions to other areas such as imaging sensors and spectral measurements.
A dynamically equivalent atomistic electrochemical paradigm for the larger-scale experiments
Authors: Aryanfar Asghar , Dhara Trina , DasGupta Sunando , Goddard William A.
Published: July 2024

Electrochemical systems possess a considerable part of modern technologies, such as the operation of rechargeable batteries and the fabrication of electronic components, which are explored both experimentally and computationally. The largest gap between the experimental observations and atomic-level simulations is their orders-of-magnitude scale difference. While the largest computationally affordable scale of the atomic-level computations is ∼ns and ∼nm, the smallest reachable scale in the typical experiments, using very high-precision devices, is ∼s and ∼μm. In order to close this gap and correlate the studies in the two scales, we establish an equivalent simulation setup for the given general experiment, which excludes the microstructure effects (i.e., solid–electrolyte interface), using the coarse-grained framework. The developed equivalent paradigm constitutes the adjusted values for the equivalent length scale (i.e., lEQ), diffusivity (i.e., DEQ), and voltage (i.e., VEQ). The time scale for the formation and relaxation of the concentration gradients in the vicinity of the electrode matches for both smaller scale (i.e., atomistic) equivalent simulations and the larger scale (i.e., continuum) experiments and could be utilized for exploring the cluster-level inter-ionic events that occur during the extended time periods. The developed model could offer insights for forecasting experiment dynamics and estimating the transition period to the steady-state regime of operation.
Large eddy simulation of shock wave/boundary layer interactions in a transonic compressor cascade
Authors: Meng Fanjie , Tang Jie , Li Jingyin , Zhong Junwei , Guo Penghua
Published: July 2024

In this paper, large eddy simulation (LES) was performed to investigate the shock wave/boundary layer interaction (SBLI) phenomenon in transonic compressor cascades with a chord Reynolds number of 2.12 × 106. A comprehensive analysis was conducted on both the SBLI structures inherent to the transonic compressor cascade and the coherent vortex structures within the boundary layer. The underlying mechanisms of the shock-induced boundary layer transition and the shock low-frequency unsteadiness in the transonic compressor cascade were elucidated through spectral and dynamic mode decomposition (DMD) analysis. The results revealed that boundary layer separation induced by the SBLI cannot reattach, leading to the formation of large-scale coherent vortex structures. Spectral analysis revealed that the shock-induced boundary layer transition in the transonic compressor cascade was dominated by inviscid Kelvin–Helmholtz (K–H) and secondary instability mechanisms, characterized by a dimensionless Strouhal number of 0.06. Additionally, pressure signals showed the variations in sub-frequency from the separated shear layer to the main flow. The oscillation amplitude of the shock foot was significantly greater than that of the shock main body, and the oscillation frequency of the shock foot was consistent with the sub-frequency. The oscillation frequency of the shock main body coincided with that of the compression ramp and flat plate configurations. Finally, DMD modal analysis indicated that high-frequency modes were correlated with turbulent fluctuations in the boundary layer, while medium- and low-frequency modes corresponded to shedding motion in the separated shear layer and low-frequency motion of the shock. This work promotes the understanding of the complex flow mechanisms of SBLI in the transonic compressor cascades.
High-Q magnetic toroidal dipole resonance in all-dielectric metasurfaces
Authors: Zhang Ying , Wang Lulu , He Haoxuan , Duan Hong , Huang Jing , Gao Chenggui , You Shaojun , Huang Lujun , Miroshnichenko Andrey E. , Zhou Chaobiao
Published: July 2024

High quality (Q) factor toroidal dipole (TD) resonances have played an increasingly important role in enhancing light–matter interactions. Interestingly, TDs share a similar far-field distribution as the conventional electric/magnetic dipoles but have distinct near-field profiles from them. While most reported works focused on the electric TD, magnetic TDs (MTDs), particularly high-Q MTD, have not been fully explored yet. Here, we successfully realized a high-Q MTD by effectively harnessing the ultrahigh Q-factor guided mode resonances supported in an all-dielectric metasurface, that is, changing the interspacing between silicon nanobar dimers. Other salient properties include the stable resonance wavelength but a precisely tailored Q-factor by interspacing distance. A multipole decomposition analysis indicates that this mode is dominated by the MTD, where the electric fields are mainly confined within the dielectric nanostructures, while the induced magnetic dipole loops are connected head-to-tail. Finally, we experimentally demonstrated such high-Q MTD resonance by fabricating a series of silicon metasurfaces and measuring their transmission spectra. The MTD resonance is characterized by a sharp Fano resonance in the transmission spectrum. The maximum measured Q-factor is up to 5079. Our results provide useful guidance for realizing high-Q MTD and may find exciting applications in boosting light–matter interactions.
Plasma pressure profiles in a sheared-flow-stabilized Z-pinch
Authors: Goyon C. , Bott-Suzuki S. C. , Youmans A. E. , Banasek J. T. , Morton L. A. , Levitt B. , Barhydt J. R. , Morgan K. D. , Liekhus-Schmaltz C. , Young W. C. , Higginson D. P. , Hossack A. C. , Meier E. T. , Nelson B. A. , Quinley M. , Taylor A. , Tsai P. , van Rossum N. , Shah A. , Stepanov A. D. , Sutherland D. A. , Weber T. R. , Shumlak U. , McLean H. S.
Published: July 2024

We report the plasma pressure reached inside the central plasma column of a sheared-flow-stabilized Z-pinch using Thomson scattering measurements. Building on previously reported experimental results and the analysis methods established for the high temperature and moderate density plasmas generated on the FuZE device, we show evidence of a central plasma region with higher electron temperature and density, which is consistent with a pinch behavior. Elevated electron temperatures up to 2.25 ± 0.8 keV and densities up to (4.9±0.2)×1017 cm−3 are observed to temporally coincide with the fusion neutron production from the plasma. Reconstructed plasma pressure profiles highlight the presence of a several millimeter-wide column with elevated pressure whose location varies shot-to-shot. The plasma pressure rises as neutron production from the deuterium plasma increases, reaching a peak value of 2.6 kBar. This peak value is consistent with a radially force-balanced pinch equilibrium model based on the measured ∼320 kA pinch current. Complete datasets were obtained at two axial locations, 10 and 20 cm axial position from the tip of the central electrode, which corroborate the estimated neutron source axial lengths.
Segment-based wall treatment model for heat transfer rate in smoothed particle hydrodynamics
Authors: Park Hyung-Jun , Kim Jaekwang , Kim Hyo-Jin
Published: July 2024

We propose a new smoothed particle hydrodynamics (SPH) model that applies a segment-based wall boundary treatment method (SBWM) for heat transfer applications. We begin by focusing on natural convection simulations, where accurately modeling heat-transferring wall boundaries is crucial as they are the energy source driving the flow. A conventional SPH approach that handles such tasks is the boundary particle (BP) method, which constructs wall boundaries by placing multiple layers of particles on and behind the walls. Despite its capability of imposing accurate boundary conditions, the BP approach becomes a non-trivial task when the fluid domain involves complex boundaries. Moreover, computational costs may significantly increase because of the increased number of SPH particles necessary for modeling walls. Therefore, we utilize the recent development of SBWM to efficiently model energy-transferring wall boundaries. Specifically, SBWM is applied to the energy conservation equation for the wall heat transfer model, using the boundary truncation terms derived in this work. The SBWM-SPH method is verified in various numerical examples, comparing the results with BP-SPH and finite volume method as well as experimental data in the literature. Our study finally extends to investigating a heat exchanger with an optimized shape, demonstrating how SBWM-SPH effectively handles practical issues associated with the BP method while providing accurate heat transfer calculations for the wall.