bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on the fiber intensity modulation model of superconducting magnetic levitation rotor
Authors: Cui Xu , Hu Xinning , Cui Chunyan , Zhang Yuan , Wang Qiuliang
Published: May 2024

The measurement of the pole axis deviation angle of superconducting magnetic levitation rotors plays a crucial role in the field of high-precision navigation. This article conducts theoretical analysis and experimental research on the diffuse reflection intensity modulation principle of optical fiber sensors and the ideal diffuse reflection modulation model under ideal conditions. First, the structural distribution of optical fiber sensors is presented, and the principle of measuring the polar deviation angle of superconducting magnetic levitation rotors is analyzed. Then, based on the diffuse reflection intensity modulation principle, an optical fiber intensity modulation model for ideal superconducting magnetic levitation rotors is established. The correctness of this model was verified through simulation and calibration experiments, and the error between the simulation and experimental results was less than 8%.
Comparative simulations of Kelvin–Helmholtz induced magnetic reconnection at the Earth's magnetospheric flanks
Authors: Ferro Silvia , Faganello Matteo , Califano Francesco , Bacchini Fabio
Published: May 2024

This study presents three-dimensional (3D) resistive Hall-magnetohydrodynamic simulations of the Kelvin–Helmholtz instability (KHI) dynamics at Earth's magnetospheric flanks during northward interplanetary magnetic field periods. By comparing two simulations with and without initial magnetic shear, we analyze the impact of distinct magnetic field orientations on plasma dynamics and magnetic reconnection events taking into account 3D mechanisms, such as KHI high latitude stabilization. The identical nature of the simulations, except for the presence/absence of an initial magnetic shear, enables, for the first time, a complete and coherent comparative analysis of the latitudinal distribution of KH vortices, current sheets, reconnection events, and the evolution of the mixing layer. In one configuration, a uniform magnetic field leads to double mid-latitude reconnection (MLR), while in the other, magnetic shear induces both type I vortex-induced reconnection (VIR) and MLR. Notably, the type I VIR observed in this second scenario results from the combined action of line advection and vortex-induced current sheet pinching (the classic mechanism driving two-dimensional type I VIR). Of particular importance is our quantification of newly closed field lines that experienced double reconnection, ultimately becoming embedded in solar wind plasma at low latitudes while remaining connected to magnetospheric plasma at high latitudes. The varying abundance of such lines in the two simulations holds implications for plasma transport at the magnetopause.
Defect/disorder correlated modification of transport properties from hopping to tunneling processes in BaTiO3–LaFeO3 solid solution
Authors: Maneesha P. , Samantaray Koyal Suman , Baral Suresh Chandra , Mittal R. , Gupta Mayanak K. , Sen Somaditya
Published: May 2024

Crystal structure, bandgap, and the changes in the charge conduction mechanisms in ceramics are interrelated, and the underlying physics unifies all these different phenomena. The experimental and theoretical evaluation of the electronic properties of the solid solution of (1 − x)BaTiO3–(x)LaFeO3 (x = 0, 0.015, 0.031, 0.062) is attempted in this work. Bandgap was observed to be tunable with La/Fe doping from 3.2 eV (x = 0) to 2.6 eV (x = 0.06), while the lattice disorder was found to increase. A theoretical assessment confirms a considerable shift of valence band maxima and conduction band minima with an introduction of additional defect states within the bandgap. Electron localization was also confirmed theoretically with doping. Such changes in the electronic properties were experimentally confirmed from dielectric/AC - conductivity/impedance spectroscopy studies. From different transportation models, hopping is a preferred mechanism in the less distorted BaTiO3. However, a large polaron tunneling process can be justified for the doped samples at lower temperatures. Only at higher temperatures, a small polaron tunneling can be justified for the doped samples. The transportation is affected by the grain boundaries as much as the grains themselves. A complete analysis using Nyquist plots reveals the competing contributions of these regions to the transportation mechanism and is correlated to the disorder/distortions in the lattice in terms of the formation of oxygen vacancies.
MOSARIX: Multi-crystal spectrometer in the tender x-ray range at SOLEIL synchrotron
Authors: Ismail Iyas , Moussaoui Roba , Vacheresse Régis , Marchenko Tatiana , Travnikova Oksana , Guillemin Renaud , Verma Abhishek , Velasquez Nicolas , Peng Dawei , Ringuenet Hugues , Penent Francis , Püttner Ralph , Céolin Denis , Rueff Jean-Pascal , Simon Marc
Published: May 2024

We have built and commissioned a novel standalone multi-crystal x-ray spectrometer (MOSARIX) in the von Hamos configuration based on highly annealed pyrolytic graphite crystals. The spectrometer is optimized for the energy range of 2–5 keV, but this range can be extended up to 20 keV by using higher reflection orders. With its nine crystals and a Pilatus detector, MOSARIX achieves exceptional detection efficiency with good resolving power (better than 4000), opening the door to study small cross section phenomena and perform fast in situ measurements. The spectrometer operates under a He atmosphere, which provides a flexible sample environment for measurements in gas, liquid, and solid phases.
Experimental research into the dynamics of underwater explosion bubbles near mutually perpendicular walls
Authors: Yan Ze-Chen , Wang Ming-Yang , Zhao Yue-Tang , Qiu Yan-Yu , Yue Song-Lin , Wang Jian-Ping
Published: May 2024

It is of great significance to characterize the dynamics of underwater explosive bubbles in close proximity to mutually perpendicular walls for ensuring the safety of important underwater structures. In this paper, a dynamic experiment on underwater explosion bubbles was carried out near constructed mutually perpendicular walls. High-speed cameras were utilized to capture high-resolution images, while pressure sensors recorded pressure–time history curves. The main focus was on studying the evolution process of bubble morphology and pulse characteristics. When the position of the charge's center relative to the horizontal wall remained fixed, decreasing the distance between the charge's center and the vertical wall resulted in a reduction in the equivalent maximum radius of bubbles and an increase in its pulsation period. Additionally, the asymmetric collapse of bubbles on a single wall transformed into asynchronous collapse on two walls, with most collapsed bubbles tending to migrate and expand toward the corner formed by mutually perpendicular walls. The resulting jet from the collapse of bubbles exhibited deflection toward the vertical wall, with an inclination angle increasing approximately proportionally with dimensionless distance ratio γh/γv. Moreover, it became more difficult for achieving effective focusing of bubble energy as the jet approached the corners formed by mutually perpendicular walls. The experiments also implied that reducing the dead weight of the vertical wall weakened its contact with the horizontal wall, causing an increase in the equivalent maximum radius of bubbles and jet inclination, as well as a decrease in the bubble pulsation period, under the same dimensionless distance γv.
Nitrogen-polar growth of AlN on vicinal (0001) sapphire by MOVPE
Authors: Pampili Pietro , Pristovsek Markus
Published: May 2024

We report about metalorganic vapor phase epitaxy of smooth nitrogen-polar AlN templates on vicinal (0001) sapphire substrates. The influence of the V/III ratio, growth temperature, growth rate, as well as sapphire-nitridation time and temperature, were studied. With 4° offcut sapphire, step-flow growth was possible only with V/III ratios below 2. However, the optimal V/III ratio required precise adjustment, possibly dependent on reactor history and geometry. A rather narrow temperature window of less than 40 °C existed for smooth surface morphology. Reducing the temperature affected adatom mobility, eventually disrupting step-flow growth; increasing the temperature favored the formation of high-aspect-ratio defects on the epilayer. A low thermal-budget nitridation step with a short nitridation time of 15 s proved to be effective in controlling polarity without inducing excessive surface damage on the sapphire substrate. The growth rate also influenced surface morphology, with an increase in RMS roughness and step-bunching for faster growths until at growth rates above 1.4 μm/h step-flow growth could no longer occur. Finally, we developed a V/III ratio fine-tuning procedure, whereby the reactor-specific value that induces optimal growth is inferred by growth-rate variations. With this method, N-polar AlN templates with sub-nanometer RMS roughness were demonstrated for both 4° and 2° offcut sapphire substrates.
A state-selected continuous wave laser excitation method for determining CO2’s rotational state distribution in a supersonic molecular beam
Authors: Jansen Charlotte , Juurlink Ludo B. F. , van Lent Richard , Chadwick Helen
Published: May 2024

State-resolved experiments can provide fundamental insight into the mechanisms behind chemical reactions. Here, we describe our methods for characterizing state-resolved experiments probing the outcome of the collision between CO2 molecules and surfaces. We create a molecular beam from a supersonic expansion that passes through an ultra-high vacuum system. The CO2 is vibrationally excited by a continuous wave infrared (IR) laser using rapid adiabatic passage. We attenuate the fractional excitation using a CO2 absorption cell in the IR beam path. We combine Monte Carlo simulations and molecular beam energy measurements to find the initial rotational state distribution of the molecular beam. We find that our pure CO2 beam from a 300 K source has a rotational temperature of ∼26 K.
The impact of alcohol and ammonium fluoride on pressure-induced amorphization of cubic structure I clathrate hydrates
Authors: Fidler Lilli-Ruth , Posch Paul , Klocker Johannes , Hofer Thomas S. , Loerting Thomas
Published: May 2024

We have investigated pressure-induced amorphization (PIA) of an alcohol clathrate hydrate (CH) of cubic structure type I (sI) in the presence of NH4F utilizing dilatometry and x-ray powder diffraction. PIA occurs at 0.98 GPa at 77 K, which is at a much lower pressure than for other CHs of the same structure type. The amorphized CH also shows remarkable resistance against crystallization upon decompression. While amorphized sI CHs could not be recovered previously at all, this is possible in the present case. By contrast to other CHs, the recovery of the amorphized CHs to ambient pressure does not even require a high-pressure annealing step, where recovery without any loss of amorphicity is possible at 120 K and below. Furthermore, PIA is accessible upon compression at unusually high temperatures of up to 140 K, where it reaches the highest degree of amorphicity. Molecular dynamics simulations confirm that polar alcoholic guests, as opposed to non-polar guests, induce cage deformation at lower pressure. The substitution of NH4F into the host-lattice stabilizes the collapsed state more than the crystalline state, thereby enhancing the collapse kinetics and lowering the pressure of collapse.
Particle size effect on surface/interfacial tension and Tolman length of nanomaterials: A simple experimental method combining with theoretical
Authors: Zhang Shengjiang , Xin Yujia , Sun Yanan , Xi Ziheng , Wei Gan , Han Meng , Liang Bing , Ou Panpan , Xu Kangzhen , Qiu Jiangyuan , Huang Zaiyin
Published: May 2024

Surface tension and interfacial tension are crucial to the study of nanomaterials. Herein, we report a solubility method using magnesium oxide nanoparticles of different radii (1.8–105.0 nm, MgO NPs) dissolved in pure water as a targeted model; the surface tension and interfacial tension (and their temperature coefficients) were determined by measuring electrical conductivity and combined with the principle of the electrochemical equilibrium method, and the problem of particle size dependence is discussed. Encouragingly, this method can also be used to determine the ionic (atomic or molecular) radius and Tolman length of nanomaterials. This research results disclose that surface/interfacial tension and their temperature coefficients have a significant relationship with particle size. Surface/interfacial tension decreases rapidly with a radius <10 nm (while the temperature coefficients are opposite), while for a radius >10 nm, the effect is minimal. Especially, it is proven that the value of Tolman length is positive, the effect of particle size on Tolman length is consistent with the surface/interfacial tension, and the Tolman length of the bulk does not change much in the temperature range. This work initiates a new era for reliable determination of surface/interfacial tension, their temperature coefficients, ionic radius, and Tolman length of nanomaterials and provides an important theoretical basis for the development and application of various nanomaterials.
Comparison of high-order numerical methodologies for the simulation of the supersonic Taylor–Green vortex flow
Authors: Chapelier Jean-Baptiste , Lusher David J. , Van Noordt William , Wenzel Christoph , Gibis Tobias , Mossier Pascal , Beck Andrea , Lodato Guido , Brehm Christoph , Ruggeri Matteo , Scalo Carlo , Sandham Neil
Published: May 2024

This work presents a comparison of several high-order numerical methodologies for simulating shock/turbulence interactions based on the supersonic Taylor–Green vortex flow, considering a Reynolds number of 1600 and a Mach number of 1.25. The numerical schemes considered include high-order Finite Difference, Targeted Essentially Non-Oscillatory, Discontinuous Galerkin, and Spectral Difference schemes. The shock capturing methods include high-order filtering, localized artificial diffusivity, non-oscillatory numerical fluxes, and local low-order switching. The ability of the various high-order numerical methodologies to both capture shocks and represent accurately the development of turbulent vortices is assessed.
Unsupervised contrastive learning: Shale porosity prediction based on conventional well logging
Authors: Qiao Lu , Yang Shengyu , Hu Qinhong , Wang Huijun , He Taohua
Published: May 2024

Porosity is a pivotal factor affecting the capacity for storage and extraction in shale reservoirs. The paucity of labeled data in conventional well logs interpretation and supervised learning models leads to inadequate generalization and diminished prediction accuracy, thus limiting their effectiveness in precise porosity evaluation. This study introduces a contrastive learning – convolutional neural network (CL-CNN) framework that utilizes CL for pretraining on a vast array of unlabeled data, followed by fine-tuning using a traditional CNN on a curated set of labeled data. Applied to the Subei Basin in Eastern China, the framework was tested on 130 labeled data and 2576 unlabeled data points from well H1. The results indicate that the CL-CNN framework outperforms traditional CNN-based supervised learning and other machine learning models in terms of prediction accuracy for the dataset under consideration. Furthermore, it demonstrates the potential for extensive porosity assessment across different logged depths. Due to its efficacy and ease of use, the proposed framework is versatile enough for application in reservoir evaluation, engineering development, and related fields. The innovative contribution of this research is encapsulated in its unique methodology and procedural steps for the accurate prediction of shale reservoir porosity, thus significantly enriching the existing body of knowledge in this domain.
Ancillary services from wind and solar energy in modern power grids: A comprehensive review and simulation study
Authors: Ullah Kaleem , Tunio Majid Ali , Ullah Zahid , Ejaz Muhammad Talha , Anwar Muhammad Junaid , Ahsan Muhammad , Tandon Ritesh
Published: May 2024

Renewable energy sources like wind and solar have increased demand for surplus power capacity. The demand is primarily fueled by the growing impact of forecasting errors associated with these intermittent energy sources. Implementing advanced control methods for automatic generation control (AGC) is essential to integrate wind and solar power with conventional generation sources to balance the power system and reduce reliance on traditional reserves. Therefore, this paper comprehensively overviews solar and wind energy integration in the AGC framework to provide optimal grid ancillary services. Initially, the paper presents an overview of the basic equations used to integrate reserve power from the photovoltaic (PV) system by employing the de-loading strategy. Subsequently, a comprehensive review is conducted on integrating the PV system in AGC strategies to provide grid ancillary services. The study also analyzes the contribution of wind power in AGC services using relevant equations and past practices. The paper presents a real-time dynamic control strategy to optimize the dispatch of the AGC unit by integrating the operating reserves from wind energy systems in conjunction with thermal power systems. The study simulates an 8-bus, 5-machine model using the Dig-SILENT Power Factory. The findings reveal that utilizing operating reserves from wind power can significantly reduce large-scale forecasting errors in massively renewable energy resources (RES) integrated power systems, thereby ensuring the necessary system operational security and reducing the reliance on traditional generating units.
High-temperature dielectric with excellent capacitive performance enabled by rationally designed traps in blends
Authors: Zhao Zhonghua , Zhang Shuo , Li Mingru , Feng Yang , Yang Liuqing , Li Shengtao
Published: May 2024

Polymer dielectrics with excellent capacitive performance are urgently needed in advanced electrical and electronic systems. However, due to the dramatic increase in the conduction loss, the energy density and efficiency of polymers degrade severely at elevated temperatures, limiting their application in harsh environments up to 150 °C. Herein, an all-organic polyurea (PU)/polyetherimide (PEI) blend film is designed to prepare high-temperature polymer dielectric. It is found that carrier traps can be introduced by blending, and the hydrogen bond between PU and PEI increases the trap depth, leading to suppressed leakage current and enhanced breakdown strength, thus improving the energy storage performance. PU/30%PEI exhibits a high discharged energy density of ∼3.74 J/cm3 with an efficiency higher than 90% at 150 °C, which is 78% and 70% higher than pristine PU and PEI, respectively. This work provides a facile strategy to improve the energy storage performance of polymer dielectrics by introducing deep traps through blending.
Quasi-optical design for the cross-polarization scattering diagnostic on the HL-3 tokamak
Authors: Zhou Y. , Tong R. H. , Zhong W. L. , Tan Y. , Jiang M. , Shi Z. B. , Yang Z. C. , Shen Y. Q. , Wen J. , Liang A. S.
Published: May 2024

As the plasma beta (β) increases in high-performance tokamaks, electromagnetic turbulence becomes more significant, potentially constraining their operational range. To investigate this turbulence, a cross-polarization scattering (CPS) diagnostic system is being developed on the HL-3 tokamak for simultaneous measurements of density and magnetic fluctuations. In this work, a quasi-optical system has been designed and analyzed for the Q-band CPS diagnostic. The system includes a lens group for beam waist size optimization, a rotatable wire-grid polarizer for polarization adjustment, and a reflector group for measurement range regulation and system response enhancement. Laboratory tests demonstrated a beam radius of order 4 cm at the target measurement location (near the plasma pedestal), cross-polarization isolation exceeding 30 dB, and poloidal and toroidal angle adjustment ranges of ±40° and ±15°, respectively. These results verify the system’s feasibility through laboratory evaluations. The quasi-optical system has been installed on the HL-3 tokamak during the 2023 experimental campaign to support the development of CPS diagnostics.
Plasmon-assisted boosting of strong self-hybrid exciton–anapole coupling in bulk transition metal dichalcogenides nanoresonators
Authors: Xie Peng , Wang Wei , Cheng Yihan
Published: May 2024

Intrinsic strong coupling between excitons and anapole mode in self-hybridizing transition metal dichalcogenide (TMD) nanostructures has recently attracted much attention for their capability of improving exciton–anapole interactions as a consequence of the nonradiative feature of anapole mode and the excellent mode overlap in the self-hybridizing geometry. Here, we propose a strategy for further enhancing exciton–anapole coupling. By embedding Au dimers as plasmonic components in slotted bulk WS2 nanodisks, a plasmon-induced electric field strength enhancement over nearly 140 times is achieved compared to that of the bulk WS2 nanodisk, boosting the strong exciton–anapole hybridization with greatly enhanced Rabi splitting up to 532 meV. Importantly, we demonstrate not only the effect of the plasmon mode on the initial Rabi phase of the anapole mode but also the great reduction of the ultrafast energy transfer time by the constructed full-quantum model. The plasmon-assisted hybrid system proposed in this paper provides a promising approach for enhancing strong light–matter interactions and may pave the way for the development of high-performance TMD-based photonic devices.
Regulatory role of AGC genes in heat stress adaptation in maize (Zea mays)
Authors: Rehman Abdul , Alwutayd Khairiah Mubarak , Alshehri Dikhnah , Alsudays Ibtisam Mohammed , Azeem Farrukh , Rahman Shahroz , Abid Muhammad , Shah Asad Ali
Published: May 2024

Heat stress represents a significant environmental challenge that restricts maize (Zea mays) growth and yield on a global scale. Within the plant kingdom, the AGC gene family, encoding a group of protein kinases, has emerged as crucial players in various stress responses. Nevertheless, a comprehensive understanding of AGC genes in Z. mays under heat-stress conditions remains elusive. A genome-wide analysis was done using bioinformatics techniques to identify 39 AGC genes in Z. mays, categorising them into three subfamilies based on their conserved domains. We investigated their phylogenetic relationships, gene structures (including intron-exon configurations), and expression patterns. These genes are likely involved in diverse signalling pathways, fulfilling distinct roles when exposed to heat stress conditions. Notably, most ZmAGC1.5, ZmAGC1.9, ZmNDR3, ZmNDR5 and ZmIRE3 exhibited significant changes in expression levels under heat stress, featuring a high G-box ratio. Furthermore, we pinpointed a subset of AGC genes displaying highly coordinated expression, implying their potential involvement in the heat stress response pathway. Our study offers valuable insights into the contribution of AGC genes to Z. mays’s heat stress response, thus facilitating the development of heat-tolerant Z. mays varieties.
Establishing a biochemical understanding of the initiation of chromosome replication in bacteria
Authors: Stillman Bruce
Published: May 2024

In the mid-1950s, Arthur Kornberg elucidated the enzymatic synthesis of DNA by DNA polymerase, for which he was recognized with the 1959 Nobel Prize in Physiology or Medicine. He then identified many of the proteins that cooperate with DNA polymerase to replicate duplex DNA of small bacteriophages. However, one major unanswered problem was understanding the mechanism and control of the initiation of chromosome replication in bacteria. In a seminal paper in 1981, Fuller, Kaguni, and Kornberg reported the development of a cell-free enzyme system that could replicate DNA that was dependent on the bacterial origin of DNA replication,
oriC
. This advance opened the door to a flurry of discoveries and important papers that elucidated the process and control of initiation of chromosome replication in bacteria.
The multiple functions of the reflexive pronoun in Tujia
Authors: Man Lu , van de Weijer Jeroen
Published: May 2024

This paper investigates the functions of the reflexive pronoun ko
53
to
21/to
21 in Tujia, a Tibeto-Burman (TB) language. Apart from being used as a verb object, the reflexive pronoun in Tujia can be used as an intensifier, indicating “self, non-other”, but it can also be used to create “passive” or “causative” meaning. It is argued that both meanings created by the reflexive pronoun can be accounted for under a decomposition approach. Verbal reflexives isomorphic with anti-causative or passive morphemes have been reported for European languages, while a reflexive pronoun with causative meaning is quite rare. The present paper therefore contributes not only to the typology in this area but also to the expression of causative and passive in Tibeto-Burman languages.
Voice onset time in Rma
Authors: Sims Nathaniel A. , Jianqiong Bai , Adisiswoyo Ludwig
Published: May 2024

Rma (also called Qiang) is a Sino-Tibetan language spoken in Northwestern Sichuan, China.1 In the literature on Rma, all documented varieties of Rma have been reported to have a three-way voice onset timing (VOT) distinction between voiceless unaspirated, voiceless aspirated, and voiced unaspirated obstruents. This study reports a variety of Rma, which has a near merger of the voiceless unaspirated and voiced unaspirated stops. A pilot study was conducted with speakers from three different villages within Yonghe valley. The results of this empirical study suggest that the Lower Yonghe valley variety has innovated a near merger between voiced and voiceless unaspirated obstruents.
Methods for studying variation in partitives
Authors: Sleeman Petra
Published: May 2024

In the last sixty years, starting with the method of introspection to judge the acceptability of linguistic data, research methods in linguistics have become more varied and more sophisticated. This also holds for studies on partitivity. In this paper various methods are presented that have recently been used in the literature to study variation in the linguistic expression and the use of partitive constructions and partitive elements in Romance, Germanic and some other languages, language varieties and dialects. It is argued that different types of research call for adapted methods. It is shown that the use of different methods may lead to different results, although this is not always the case. The overview presented in this paper reveals that in recent years much progress has been made in the study of variation in partitives.
Bridging demand and supply of private investment capital for small and medium agribusinesses
Authors:   Commercial Agriculture for Smallholders and Agribusiness (CASA), Jayne T S , Ferguson Richard , Chimatiro Sloans
Published: May 2024

The UK Foreign, Commonwealth and Development Office's (FCDO's) Commercial Agriculture for Smallholders and Agribusiness (CASA) programme is working to increase economic opportunities for smallholders to step up and trade in growing commercial markets. The aim is to increase investment in agribusinesses that source from smallholder farmers, and to provide evidence-based guidance for creating synergistic relationships between agribusinesses and smallholders in ways that promote smallholders' productivity and commercial potential. This study is motivated by an apparent contradiction: suppliers of capital report a lack of investible opportunities in Africa, while demanders of capital cannot find willing partners to provide capital to them. In spite of significant amounts of private capital being available for investment worldwide (World Economic Forum, 2013; Vitón, 2018), institutional and impact investors have found it difficult to mobilize large amounts of private investment for agribusiness opportunities in Africa. This study identifies strategies for development and impact investment actors to bridge the gap between the risk-reward demands (or adjusted risk returns) of investment capital and the available supply of agribusinesses for investment. The study assesses whether what is needed is different forms of capital, or greater work to provide the pre-conditions for private investment in agri-food systems, or both of these. The resulting analysis addresses the needs and interests of both investors and investment support stakeholders.
Phase 1: State of play review of climate risk assessment guidance
Authors:   Commercial Agriculture for Smallholders and Agribusiness (CASA), Casey Jonathan
Published: May 2024

This report reviews the current state of play of climate risk assessment practice and guidance for financial institutions. It assesses the guidance related to disclosures under a number of voluntary and regulatory frameworks (as set out in Annex 1: Summary of climate risk assessment guidance), and in particular sector-specific guidance for agriculture and agribusiness investments. The report assesses the key commonalities and differences of climate risk assessment guidance, and reviews how climate adaptation and resilience are considered and addressed in the guidance in terms of both transition risk and physical risks. It also presents an overview of case studies and guidance on emerging good practices in utilising data generated by smallholder farmers to inform more granular and timely climate risk assessments for family farming initiatives.
Flexible flow sensors-enabled intelligent life
Authors: Ma Zhiqiang , Shen Dawei
Published: May 2024

In our daily life, flexible flow sensors endow us with a ‘sixth sense’ capability, i.e. ‘touch’ the fluids, improving living quality. Although there are kinds of flexible flow sensors developed to implement this capability, they still have insufficient sensitivity and limited intelligent applications in daily life. Biomimetic engineering provides us with a powerful and effective approach to develop highly sensitive and intelligent flow sensing systems served in our life, comparable to that in creatures. Here, in this review, we present a comprehensive review of recent studies on the flexible flow sensors for human intelligent life. Firstly, we briefly introduce the excellent flow sensing systems selected by nature, and typical design strategies of artificial flexible flow sensors. Furthermore, we collect and exhibit kinds of flexible flow sensors and their applications in intelligent and digital life. Finally, we discuss the challenges and future perspectives of the flexible flow sensor for the metaverse applications.
Rotational and vibrational temperatures of transient atmospheric glow plasma
Authors: Shaffer James , Alvarez Luis F , Dumitrescu Cosmin E , Askari Omid
Published: May 2024

Plasma ignition can significantly improve the efficiency and performance of combustion devices through the enhancement of combustibility limits. Investigating plasma development for fundamental experimental flame conditions (i.e. spherical flame experiments) can provide insight into how plasma thermalizes the combustible mixture and, therefore a better understanding of flame development in future experimental studies. This study observed an ignition system designed to produce spherical flames in quiescent gas inside a constant-volume combustion chamber. Rotational and vibrational temperature measurements of dry atmospheric air glow plasma are reported. Measurements were taken for a transient discharge with currents less than 0.5 A. The electrode wire geometry and discharge variation resulted in an ellipsoid-shaped kernel and plasma region with an abnormal glow discharge. The measured temperatures were compared to the conductive thermal kernel boundary observed with Schlieren imaging. Maximum rotational and vibrational temperatures of 3000 K and 10 000 K, respectively, were observed near the anode electrode for a 0.5 A current. The temperature decreased with the axial distance from the anode, while a constant temperature was observed in the radial direction. Lower currents resulted in a smaller temperature, with minimum measured rotational and vibrational temperatures of 1500 K and 5000 K, respectively. The results were compared with available experimental literature and the variation observed was a result of the transient nature, which resulted in hysteresis in temperature vs discharge current measurements.
Pulse-to-pulse coupling in cylindrical discharges
Authors: Hazenberg T , van Dijk J , van Oijen J A
Published: May 2024

Several filamentary discharges can be applied to a combustible mixture, which can then ignite. The energy density of this discharge is a vital parameter, as it directly influences the local temperature rise and radical production. The goal of this article is to investigate how a previous discharge affects the energy density of a second discharge. To investigate the pulse-to-pulse coupling of filamentary discharges a one-dimensional numerical model is developed. In the developed model, the compressible Navier–Stokes equations are coupled to a plasma model. The plasma model is used to estimate the local energy density, while the compressible Navier–Stokes equations model the reactive flow. As a first step, skeletal air plasma chemistry is used, which includes fast gas heating, slow gas heating and the rapid generation of radicals. The skeletal plasma chemistry is combined with a detailed hydrogen combustion mechanism. Simulations in both air and hydrogen/air are conducted at several discharge energies and pressures. From the analysis of these results, we conclude that the main mechanism of pulse-to-pulse coupling is the reduction in molar density due to temperature rise.
Electrochemical study and structural comparison of Ni electrodepositions on W/Si and Cr/C multilayered structure films
Authors: Haixiang Chen , Kun Wang , Yuntian Xue , Zhanshan Wang
Published: May 2024

The Ni electrodeposition combined with multilayered structure film is a promising strategy in modern optical manufacturing, while less effort has been devoted to comprehending the electrochemical reaction process, which is essential for their practical applications. In view of this, the initial reduction dynamics and nucleation mechanisms of Ni electrodepositions on multilayer W/Si and Cr/C films were analyzed in this work, and the morphological, crystal, and mechanical characteristics of produced Ni electrodeposits were further determined and compared. The results show that the considerably irregular crystals accompanied by high tensile stress of 119.5 MPa were formed for the Ni electrodeposit on W/Si film, which were mainly attributed to the progressive nucleation process with more severe side reaction of hydrogen evolution. By contrast, the instantaneous nucleation mode with lower reduction resistance were revealed for the Ni electrodeposition on Cr/C film, which presented a comparatively fine–grained texture, less roughness, and smaller stress structure. To summarize, the more stable electrochemical reaction process and improved structure uniformity are obtained for the Ni electrodeposition on metal/C–based film, which offers a theoretical guidance for optimized fabrication of multilayer optical devices in extreme ultraviolet, x-ray, and neutron focusing fields.
Measurement of 144Sm(p,γ) cross-section at Gamow energies
Authors: Bar Tanmoy , Basak Dipali , Sahoo Lalit Kumar , Saha Sukhendu , Datta Jagannath , Dasgupta Sandipan , Basu Chinmay
Published: May 2024

The cross-section measurement of 144Sm(p, γ)145Eu (T1/2 = 5.93(4) days) reaction has been performed at proton energies around 2.6–6.8 MeV using the activation technique. Molecular deposition technique was used to prepare the 144Sm targets having thickness between 100 and 350 μg cm−2 on Al backing. The astrophysical S-factor of this reaction has been measured for the first time at

E
p
cm

=

2.57 ± 0.13 MeV, S-factor = 2.542 ± 1.152(×1010) MeV-b. Cross-section data were compared with the previously measured experimental data (2.8–7.5 MeV) from literature and the theoretical predictions obtained using Hauser-Feshbach statistical model. Obtained results were utilised to predict the reaction rates for 144Sm (p, γ) and 145Eu (γ, p) reactions.
Systematic shell-model study of structure and isomeric states in 204–213Bi isotopes
Authors: Shukla Sakshi , Srivastava Praveen C , Patel Deepak
Published: May 2024

In this work, we have performed systematic shell-model (SM) calculations for Bi isotopes with A = 204–213 using KHH7B and KHM3Y effective interactions. We have reported yrast and non-yrast SM states corresponding to the available experimental data. From the comparison with the experimental data, we could assign spin and parity of several unconfirmed states. We have also calculated electromagnetic properties and compared them with the available experimental data and predicted where experimental data are not available. This study also includes a detailed discussion of multiple isomeric states based on computed SM configurations and their respective half-lives.
Small electron polarons bound to interstitial tantalum defects in lithium tantalate
Authors: Pfannstiel Anton , Hehemann Tobias , Schäfer Nils A , Sanna Simone , Suhak Yuriy , Vittadello Laura , Sauerwein Felix , Dömer Niklas , Koelmann Julian , Fritze Holger , Imlau Mirco
Published: May 2024

The absorption features of optically generated, short-lived small bound electron polarons are inspected in congruent lithium tantalate, LiTaO3 (LT), in order to address the question whether it is possible to localize electrons at interstitial Ta

V

:V

Li

defect pairs by strong, short-range electron–phonon coupling. Solid-state photoabsorption spectroscopy under light exposure and density functional theory are used for an experimental and theoretical access to the spectral features of small bound polaron states and to calculate the binding energies of the small bound Ta

Li

4
+

(antisite) and Ta

V

4
+

:V

Li

(interstitial site) electron polarons. As a result, two energetically well separated (

Δ
E
≈
0.5

 eV) absorption features with a distinct dependence on the probe light polarization and peaking at 1.6 eV and 2.1 eV are discovered. We contrast our results to the interpretation of a single small bound Ta

Li

4
+

electron state with strong anisotropy of the lattice distortion and discuss the optical generation of interstitial Ta

V

4
+

:V

Li

small polarons in the framework of optical gating of Ta

V

4
+

:Ta

Ta

4
+

bipolarons. We can conclude that the appearance of carrier localization at Ta

V

:V

Li

must be considered as additional intermediate state for the 3D hopping transport mechanisms at room temperature in addition to Ta

Li

, as well, and, thus, impacts a variety of optical, photoelectrical and electrical applications of LT in nonlinear photonics. Furthermore, it is envisaged that LT represents a promising model system for the further examination of the small-polaron based photogalvanic effect in polar oxides with the unique feature of two, energetically well separated small polaron states.
Neural network driven sensitivity analysis of diffraction-based overlay metrology performance to target defect features
Authors: Wang Kai , Meng Kai , Zhang Hangying , Lou Peihuang
Published: May 2024

Overlay (OVL) is one significant performance indicator for the lithography process control in semiconductor manufacturing. The accuracy of the OVL metrology is extremely critical for guarantee the lithography quality. Currently, diffraction-based overlay (DBO) is one of the mainstream OVL metrology techniques. Unfortunately, the accuracy of the DBO metrology is largely affected by the defect features of the OVL target. Therefore, there is a strong need to investigate the impacts of these target defects on the DBO metrology performance. However, efficiently investigating the statistical and interactive impacts of various DBO target defects remains challenging. This study aims to address this issue through proposing an intelligent sensitivity analysis approach. A cumulative distribution based global sensitivity analysis (GSA) method is utilized to assess the nonlinear influences of multiple defects in the OVL target on the DBO inaccuracy. The scenarios with both known and unknown distributions of the OVL target defects are considered. For the former, a neural network driven forward model is constructed for fast calculating the optical diffraction responses to accelerate the GSA process. For the latter, another neural network based inverse model are built for efficiently estimating the distribution of the target defects. Finally, a series of simulation experiments are conduct for typical DBO targets with multiple common defect features. The results demonstrate the effectiveness and robustness of the proposed approach as well as give valuable insights into the DBO defect analysis. Our study provides a strong tool to assist the practitioners in achieving intelligent and efficient DBO analysis and thus in enhancing OVL metrology performance.
Weather-dependency of the thermographic flow visualization of the laminar-turbulent transition on wind turbines
Authors: Dorszewski C , Dieckmann J , Balaresque N , von Freyberg A , Fischer A
Published: May 2024

Analyzing the airflow around wind turbines during operation requires an in-process-capable measurement approach that functions without modification of the rotor blade. Infrared–thermographic flow visualization is such a measurement approach. However, its measurement capabilities on wind turbines in operation are highly weather-dependent. Therefore, to understand the expected flow visualization quality in non-laboratory conditions, the dependence of the achievable contrast and contrast-to-noise ratio (CNR) of the laminar-turbulent transition on solar radiation and air temperature is studied, respectively. A linear dependence of the contrast on the absorbed solar radiation is derived as a first estimation from a theoretical study of the heat balance. While the air temperature variations are shown to have no effect under certain conditions. The slope of the linear dependence of about 0.025 m2K W−1 was validated by experiments. To further study the fundamental measurability limit, only the camera noise with constant variance is here applied to determine the achievable CNR, which is thus directly proportional to the contrast. As a result, the achievable contrast and CNR for visualizing the laminar-turbulent flow transition over the year, over the day, and for different yaw angles of the wind turbine are determined. For this investigation, a wind turbine location near in northern Germany, is assumed as an example, and a maximal achievable contrast and CNR of 4.2 K and 122, respectively, are estimated, which agree with previous measurements. The presented method applies to any other wind turbine location and thus enables planning thermographic flow measurements on any wind turbine in the world.
A new multiple mixed augmentation-based transfer learning method for machinery fault diagnosis
Authors: Ge Hangqi , Shen Changqing , Lin Xinhai , Wang Dong , Shi Juanjuan , Huang Weiguo , Zhu Zhongkui
Published: May 2024

With the continuous development of various industries, the diagnosis of industrial equipment faults has been receiving increasing attention in recent years. Considering the complex and variable working conditions, and the limited amount of fault data, transfer learning has become an effective solution for fault diagnosis. Data augmentation techniques, particularly generative adversarial networks, have achieved tremendous development within the field of transfer learning fault diagnosis. However, traditional data augmentation methods experience difficulty in extracting features conducive to fault diagnosis from fault data under complex operating conditions, particularly in the case of raw vibration data from bearings. Therefore, this study proposes a new multiple mixed augmentation-based transfer learning (MMATL) method for machinery fault diagnosis. First, an augmentation chain that dynamically adjusts data augmentation strategies in accordance with the model’s performance is constructed based on AutoAugment. Then, a multiple mixed augmentation strategy that integrates fault data into the augmented data from the augmentation chain to obtain enhanced data suitable for training is proposed. This strategy consists of multiple augmentations, augmentation mixing, and data mixing. Finally, experiments confirm the effectiveness of MMATL on the bearing datasets from the gearbox of the Chinese CRH380A high-speed train, the test rig at the University of Paderborn in Germany and the self-made bearing failure test platform. Results indicate that the method can adaptively extract features from fault data that are conducive to fault diagnosis under complex operating conditions.
Analysing the shape memory behaviour of GnP-enhanced nanocomposites: a comparative study between experimental and finite element analysis
Authors: Gupta Ritesh , Mittal Gaurav , Kumar Krishna , Pandel Upender
Published: May 2024

Shape memory polymers (SMPs) are capable of enduring significant deformations and returning to their original form upon activation by certain external stimuli. However, their restricted mechanical and thermal capabilities have limited their broader application in engineering fields. To address this, the integration of graphene nanoplatelets (GnPs) with SMPs has proven effective in enhancing their mechanical and thermal properties while maintaining inherent shape memory functions. The study evaluated shape memory nanocomposites (SMNCs) using dynamic mechanical, thermogravimetric, and static tensile, flexural, and shape memory tests, along with scanning electron microscopy to analyse tensile fractures. The results indicate that the optimal content of GnP is 0.6 wt%, resulting in excellent shape memory, thermal, and mechanical properties. Specifically, this composition demonstrates a shape recovery ratio of 94.02%, a storage modulus of 4580.07 MPa, a tensile strength of 61.42 MPa, and a flexural strength of 116.37 MPa. Additionally, the incorporation of GnPs into epoxy reduces recovery times by up to 52% at the 0.6 wt% concentration. While there is a slight decrease in the shape fixity ratio from 98.77% to 93.02%, the shape recoverability remains consistently high across all samples. Current finite element (FE) models often necessitate complex, problem-specific user subroutines, which can impede the straightforward application of research findings in real-world settings. To address this, the current study introduces an innovative finite element simulation method using the widely used ABAQUS software to model the thermomechanical behaviour of SMNCs, importantly incorporating the time-dependent viscoelastic behaviour of the material. The effectiveness of this new approach was tested by comparing experimental results from bending test of SMNCs cantilever beam with outcomes derived from FE simulations. The strong agreement between the experimental data and simulation results confirmed the precision and reliability of this novel technique.