bluuebunny/crossref_metadata_2025 huggingface dataset:
Un corpus pour observer le traitement orthographique des formes verbales dans les rédactions des collégiens
Authors: Furman Agnès
Published: March 2024

Le verbe est la classe de mots qui présente les variations les plus complexes, à la fois du point de vue des formes et du point de vue des paramètres qui déterminent ces variations. Afin d’observer le traitement des formes verbales par des élèves de collège, nous avons recueilli un corpus constitué de rédactions, écrites par des élèves de 6ème et de 3ème. L’analyse des données montre des zones de fragilité dont on peut penser qu’elles tiennent en partie à la dynamique rédactionnelle. Cet article s’attache à relever et à analyser les désinences de P2 ainsi que les désinences de P3 du passé simple, dont on sait qu’elles sont toujours sources de difficultés pour les élèves en fin de scolarité obligatoire. L’examen de l’ensemble du corpus fait apparaitre que les élèves, soumis à la tension qu’exige la production d’un texte, semblent régler les points problématiques d’ordre morphologique en faisant appel à l’analogie et aux formes les plus fréquentes. Dans une perspective didactique, cet article propose de faire émerger les formes verbales à la personne 2 ainsi que les formes verbales à la personne 3 au passé simple qui sont les plus soumises aux erreurs.
Des traces écrites aux discours des enseignants : quelles sont les fonctions de la correction des copies ?
Authors: Moysan Arnaud
Published: March 2024

Dans cet article, nous cherchons à mieux appréhender un geste professionnel en tension : la correction des copies d’élèves. L’analyse croisée de textes d’élèves et d’entretiens menés auprès de professeurs de français exerçant au collège mettent au jour les fonctions que peut reve^tir cette activité, bien éloignée des conceptions selon laquelle elle serait utile aux élèves dans le cadre de leur apprentissage de l’écriture de textes.
Traces du discours évaluatif : analyse linguistique d’annotations de copies d’étudiants de master MEEF
Authors: Dal Bo Beatrice , Gomila Corinne
Published: March 2024

Inscrite dans le champ des travaux qui envisagent les pratiques professionnelles de correction de copies, notre étude tente d’analyser les différents énoncés évaluatifs qu’inscrivent deux enseignantes sur les copies d’examen blanc de leurs étudiants de master MEEF préparant le concours de professeur des écoles. Il s’agit de mettre au jour les formes et les fonctionnements des différentes interventions, locales et globales, que les enseignantes privilégient pour évaluer cet écrit.
Antecedents and consequences of telework during the COVID-19 pandemic: a natural experiment in Japan
Authors: Domae Hiina , Nakayama Masataka , Takemura Kosuke , Watanabe Yasushi , Gobel Matthias S. , Uchida Yukiko
Published: March 2024

Amidst the global COVID-19 pandemic, telework (remote work) has become a widespread practice adopted by companies worldwide. However, Japan has notably maintained a low rate of telework implementation, suggesting cultural factors hindering its adoption. This study aimed to elucidate the antecedents and consequences of teleworking in Japan. Leveraging the natural experiment created by the COVID-19 pandemic, we addressed two key questions: (1) What socio-psychological factors in Japanese workplaces were important for implementing telework in the first place? and (2) How did the implementation of telework subsequently influence socio-psychological factors in these workplaces? Employees from various Japanese companies completed three waves of an online survey before and during the pandemic. Results showed that telework was more likely to be implemented in organizations characterized by a meritocracy. Results also showed that the implementation of telework demonstrated no measurable negative effects but instead increased levels of independence, organizational commitment, and perceived hierarchy mutability.
Coarse-grained model simulates DNA-RNA hybrids for biological research, nanoengineering
Authors: Thompson Avery
Published: March 2024

The model allows for studying larger molecular systems over longer timescales than finer-detailed atomistic simulations.
Making the unreal real in quantum computing
Authors: Lim Alane
Published: March 2024

Review proposes ways to realize spin-based qubits with floating electrons, which could enable universal quantum computation.
A field programmable gate array based Langmuir probe system for measurement of plasma parameters at 500 kHz in a high-power impulse magnetron sputtering plasma
Authors: Hickling C. J. , Hall S. , Harrison J. R. , Sharples R. , Bradley J. W.
Published: March 2024

By utilizing Field Programmable Gate Arrays in a configuration similar to that of the Mirror Langmuir Probe, it is possible to bias a single probe at three precise voltages in sequence. These voltages can be dynamically adjusted in real-time based on the measured plasma electron temperature to ensure the transition region is always sampled. The first results have been obtained by employing this method and have generated real-time outputs of electron temperature, ion saturation current, and floating potential on a low temperature pulsed-DC magnetron at 500 kHz. These results are in good agreement with the analysis of a conventionally swept Langmuir probe. This probe is designed with the intention of being implemented on MAST-U to aid in the study of exhaust physics and enable further investigation into filamentary behavior.
Effect of correlation time of combustion noise on early warning indicators of thermoacoustic instability
Authors: Vishnoi Neha , Gupta Vikrant , Saurabh Aditya , Kabiraj Lipika
Published: March 2024

In this paper, we analyze the effects of finite correlation time (noise color) of combustion noise on noise-induced coherence and early warning indicators (EWIs) via numerical and experimental studies. We consider the Rijke tube as a prototypical combustion system and model combustion noise as an additive Ornstein–Uhlenbeck process while varying noise intensity and correlation time. We numerically investigate corresponding effects on coherence resonance and multi-fractal properties of pressure fluctuations. Subsequently, we experimentally validate results and elucidate the influence of noise color and intensity on trends in coherence resonance and multi-fractal measures that can be expected in a practical scenario using an electroacoustic simulator. We find that the coherence factor, which quantifies the relative contribution of coherent oscillations in a noisy signal, increases as the system approaches the thermoacoustic instability—irrespective of the correlation time. It works at most levels of combustion noise (except for too low and too high noise levels). The Hurst exponent reduces as the system approaches thermoacoustic instability only when the correlation time is small. These results have implications on the prediction and monitoring of thermoacoustic instability in practical combustors.
Effects of Kelvin–Helmholtz instability on the material mixing in the double-cone ignition
Authors: Zhang Qi , Wu Fuyuan , Yang Xiaohu , Ma Yanyun , Cui Ye , Jiang Bofang , Zhang Jie
Published: March 2024

The Kelvin–Helmholtz instability (KHI) occurs on the interface of gold cones and embedded fuels for fusion schemes with gold cones. The development of KHI on the inner surface of gold cones in the double-cone ignition scheme is investigated with two-dimensional radiation hydrodynamic simulations. It has been found that the colliding high-density fuel plasma between the tips of the two cones is spatiotemporally separated from the mixed gold ions from the inner surface of the gold cones due to the KHI. Furthermore, it is found that fuel layers coated on the inner surface of the cones can effectively mitigate the energy loss in the compression process. These results could provide a reference for fast ignition schemes with gold cones.
Development of a multi-stage fog droplet screening system based on the virtual impact principle
Authors: Sun Liansi , Cheng Yin , Zhang Jiaoshi , Wu Dexia , Wang Jie , Yang Yixin , Gui Huaqiao
Published: March 2024

Accurately measuring fog droplet spectra is essential for understanding fog’s formation, dissipation, and composition, which makes a challenge to the performance of droplet sampling and measurement systems. Standard particles such as glass beads are widely used to characterize their performance. However, the disparities between glass beads and fog droplets, including refractivity, size distribution, and composition, may lead to calibration errors. In this context, we developed a three-stage fog droplet screening system based on the virtual impact principle. We determined the Stokes number and the diameter of the acceleration nozzle through theoretical analysis. Subsequently, we utilized the computational fluid dynamics software Fluent to explore the influence of key system parameters on screening efficiency, including the diameter of the collection nozzle (D1) and the distance between the acceleration nozzle and the collection nozzle (S). The simulation results indicated that the screening efficiency improved with S. The best performance was achieved when D1 = 1.35 D0 and S = 1.90 D0 (where D0 represents the diameter of the acceleration nozzle), resulting in an average screening efficiency of 75.4%. Finally, we conducted experiments to validate the effectiveness of the screening system. The screening efficiency of each outlet was estimated at 42.2%, 66.1%, 84.0%, and 95.3%, with differences of 2.0%, 3.3%, 4.1%, and 4.7% compared to the simulations. The average screening efficiency was 71.9%, with a deviation of 3.5% from the simulation. These findings demonstrated that the screening system could provide an alternative technical apparatus for characterizing droplet sampling and measurement systems.
Quantum computing using floating electrons on cryogenic substrates: Potential and challenges
Authors: Jennings A. , Zhou X. , Grytsenko I. , Kawakami E.
Published: March 2024

In this review, we introduce a developing qubit platform: floating-electron-based qubits. Electrons floating in a vacuum above the surface of liquid helium or solid neon emerge as promising candidates for qubits, especially due to their expected long coherence times. Despite being in the early stages, a variety of recent experiments from different groups have shown substantial potential in this role. We survey a range of theoretical proposals and recent experiments, primarily focusing on the use of the spin state as the qubit state, wherein the spin and charge states are hybridized. Throughout these proposals and experiments, the charge state is coupled to an LC resonator, which facilitates both the control and readout mechanisms for the spin state via an artificially introduced spin–charge coupling.
Tailoring of colloidal quantum dot layer thickness for highly efficient short-wavelength infrared photodiode
Authors: Choi Gi-Sang , Lim Myung Jin , Sutcu Irem , Yu Jehyeok , Malinowski Pawel , Lee Sang Yeon , Lieberman Itai
Published: March 2024

Colloidal quantum dots (CQDs) have emerged as promising materials for thin film photodiodes (TFPDs) in the short-wavelength infrared detection range, offering an alternative to III–V and HgCdTe-based TFPDs. However, optimizing the structure of CQD-based TFPDs remains a challenge, as it involves a delicate balance between reducing dark currents and enhancing carrier extraction efficiency. In this study, we explore the influence of varying the thickness of CQD layers to achieve a highly efficient photodiode. Our investigations reveal a continuous reduction in the dark current as the CQD layers become thicker, but we observe fluctuation in the external quantum efficiency (EQE). To shed light on this relationship between dark current density (Jdark) and EQE, we conduct capacitance measurements and employ optical simulations. From the capacitance measurements, they demonstrate an increased depletion width with varying CQD thickness, apart from layers exceeding 500 nm in thickness. Leveraging optical simulations, we propose an optimal thickness for CQD-based TFPDs and compare its EQE performance. The optimized CQD-based TFPD exhibits a Jdark of 4.1 μA/cm2 and EQE of 56.5%, and the highest specific detectivity, based on the assumption of shot noise dominance, is 1.78 × 1012 Jones at a wavelength of 1420 nm.
Feedback cooling of an insulating high-Q diamagnetically levitated plate
Authors: Tian S. , Jadeja K. , Kim D. , Hodges A. , Hermosa G. C. , Cusicanqui C. , Lecamwasam R. , Downes J. E. , Twamley J.
Published: March 2024

Levitated systems in vacuum have many potential applications ranging from new types of inertial and magnetic sensors through to fundamental issues in quantum science, the generation of massive Schrödinger cats, and the connections between gravity and quantum physics. In this work, we demonstrate the passive, diamagnetic levitation of a centimeter-sized massive oscillator, which is fabricated using a method that ensures that the material, though highly diamagnetic, is an electrical insulator. Electrical conductors moving in a magnetic field experience eddy damping—which can severely reduce their motional quality factor. By chemically coating a powder of microscopic graphite beads with silica and embedding the coated powder in high-vacuum compatible wax, we form a centimeter-sized thin square plate which magnetically levitates over a checkerboard magnet array. The insulating coating reduces eddy damping by almost an order of magnitude compared to uncoated graphite with the same particle size. These plates exhibit a different equilibrium orientation from pyrolytic graphite due to their isotropic magnetic susceptibility. We measure the motional quality factor to be Q∼1.58×105 for an approximately centimeter-sized composite resonator with a mean particle size of 12 μm. Furthermore, we apply delayed feedback to cool the vertical motion of frequency ∼19  Hz and achieve center-of-mass temperature decrease by three orders of magnitude.
Nano-infrared imaging of epitaxial graphene on SiC revealing doping and thickness inhomogeneities
Authors: Fralaide M. , Chi Y. , Iyer R. B. , Luan Y. , Chen S. , Shinar R. , Shinar J. , Kolmer M. , Tringides M. C. , Fei Z.
Published: March 2024

We report on a nano-infrared (IR) imaging and spectroscopy study of epitaxial graphene on silicon carbide (SiC) by using scattering-type scanning near-field optical microscopy (s-SNOM). With nano-IR imaging, we reveal in real space microscopic domains with distinct IR contrasts. By analyzing the nano-IR, atomic force microscopy, and scanning tunneling microscopy imaging data, we conclude that the imaged domains correspond to single-layer graphene, bilayer graphene (BLG), and higher-doped BLG. With nano-IR spectroscopy, we find that graphene can screen the SiC phonon resonance, and the screening is stronger at more conductive sample regions. Our work offers insights into the rich surface properties of epitaxial graphene and demonstrates s-SNOM as an efficient and effective tool in characterizing graphene and possibly other two-dimensional materials.
Temperature and density dependence of Kr L-shell spectrum in hot dense plasmas
Authors: Gallardo-Diaz E. , Mancini R. C. , Carpenter K. R. , Adrian P. , Frenje J. , Florido R.
Published: March 2024

Kr L-shell spectroscopy modeling results are discussed in this paper, focusing on the n = 4 to n = 2 line transitions of Be- and Li-like Kr ions. Collisional radiative atomic kinetic and Stark-broadened spectral line shape calculations show electron temperature Te and density ne sensitivity in the spectrum. The combination of the Te dependence due to the relative intensity of Be-like to Li-like line emissions in the range from 1.5 to 3 keV and the ne sensitivity from the Stark broadening effect on the line shapes in the range from 5×1023 to 2×1024/ cc results in a spectrum that can be employed to diagnose Te and ne. Two different collisional radiative atomic kinetic models i.e., Prismspect [J. J. MacFarlane, et al., Int. Fusion Sci. Appl. Conf. Proc. 457 (2003)] and ABAKO [Florido, et al., PRE, 80, 056402 (2009)] produce similar results in level populations and spectra. In x-ray spectroscopy of implosion cores, this Kr L-shell spectrum may prove useful in an intermediate Te range in which Ar is too ionized for its K-shell to be of diagnostic value and Kr is not ionized enough for its K-shell emission to be useful.
Adjustable artificial neuron based on vortex magnetic tunnel junction
Authors: Wu Yuxuan , Luo Yanxiang , Zhang Like , Dai Shige , Zhang Baoshun , Zhou Yan , Fang Bin , Zeng Zhongming
Published: March 2024

In this Letter, we demonstrate an adjustable artificial neuron based on vortex magnetic tunnel junction (MTJ). By applying a bias current to vortex MTJ, the device exhibits splendid characteristics of stochastic switching and nonlinear rectification. The stochastic switching probability induced by spin transfer torque as a function of bias current can simulate sigmoid activation functions. The nonlinear spin-torque microwave rectification through injection locking is similar to a ReLU-like activation function. These two behaviors further are used to perform the recognition of handwritten digits in the Mixed National Institute of Standards and Technology database, with a produced accuracy of up to 93.56% and 93.25%, respectively. Our work provides a potential way for the construction of artificial neuron based on vortex MTJ.
A bio-inspired two-stage bionic drag reduction method
Authors: Luo Zhengjie , Jia Xuguang , Zhu Shining , Zhao Pengfei , Zhang Kaisheng , Guo Hao
Published: March 2024

Reducing the surface resistance of underwater vehicles plays an important role in improving cruising speed and cruising mileage. The epidermis of loaches is not only covered with a layer of scale structure but also secretes mucus tissue with a lubricating effect, which makes loaches swim rapidly in muddy water. Study the morphology and structure of the skin of loach and establish a two-stage biomimetic drag reduction model. Adjust the different structural parameters of the model and select the parameters with the best drag reduction rate for the modeling design. The numerical simulation results show that the optimal drag reduction rate of the two-stage drag reduction structure is greater than 21%. In the flow channel test experiment, the drag reduction rate is slightly lower than the simulation results. Numerical simulation and experimental data show that the underwater drag reduction function can be realized by simulating the microstructure of loach skin. Finally, analyze the velocity gradient, vortices, etc., and search for the drag reduction mechanism. The simulation design of the microstructure of the loach skin can increase the thickness of the boundary layer, promote the vortex structure near the wall surface, change the flow mode of the solid–liquid interface, and reduce the wall resistance. At the same time, the drag reduction model provides key technical support for the practical application of reducing surface resistance, such as in underwater vehicles.
Piezoelectric response and ferromagnetic order in 2D Janus FeGeN3
Authors: Wang Zhicui , Yan Xu , Liu Yong , Yang Guochun
Published: March 2024

Two-dimensional (2D) materials with ferromagnetism and piezoelectricity have drawn great attention due to their promising application and fundamental significance. Using first-principles swarm structure search calculations, we have predicted a 2D Janus FeGeN3, with quintet atomic layers of N–Fe–N–Ge–N, demonstrating a desirable coexistence of ferromagnetism and piezoelectricity. It has an out-of-plane piezoelectric response of −0.31 pm/V, a robust ferromagnetic order with a Curie temperature (TC) of 302 K, and an excellent semiconductivity with a bandgap of 1.99 eV. Its ferromagnetic coupling is derived from the super-exchange interaction between Fe atoms mediated by multi-type N atoms. Moreover, the biaxial tensile strain is in the favor of the enhancement of ferromagnetism. These intriguing properties make Janus FeGeN3 an attractive candidate for spintronic devices with multifunctionality.
Scaling up in situ combustion process for enhanced oil recovery in water-flooded light oil reservoirs from laboratory to field implementation
Authors: Li Zongfa , Huang Lijuan , Zhou Xiaosong , Huang Xiaoyu , Chen Zhiwei , Ren Shaoran
Published: March 2024

Aiming at low permeability, high water content light reservoir with a recovery rate higher than 20%, an improved air injection enhanced heat flooding technology is applied by combining the combustion reaction flow and flue gas flooding mechanism. The method involves the injection of air into the reservoir, which reacts with the crude oil at temperatures ranging from 220 to 300 °C. This reaction consumes part of the oil, enabling effective evaporation and flow of the remaining oil. This process combines combustion reaction flow with flue gas flooding, using high-temperature oxidation reactions to mobilize residual oil. Experimental results from combustion tube tests demonstrate stable reaction fronts, peak temperatures reaching up to 550 °C, and a significant increase in recovery rates, reaching 73.8% in some cases. Field applications of this technology require maintaining high air flux and burning rates in low-permeability zones to ensure effective heat-driven evaporation. The geological model of the well group shows that the recovery factor of the target block can be increased by more than 20% by air injection based on the water drive recovery factor of 28%–30%. The oil exchange ratio can be less than 4000 sm3/m3 by optimizing the air injection rate and oxygen content. The research results provide technical feasibility for heat flooding to significantly improve oil flow and recovery in low-permeability light oil reservoirs.
Dynamic and relativistic effects on Pt–Pt indirect spin–spin coupling in aqueous solution studied by ab initio molecular dynamics and two- vs four-component density functional NMR calculations
Authors: Batista Patrick R. , Ducati Lucas C. , Autschbach Jochen
Published: March 2024

Treating 195Pt nuclear magnetic resonance parameters in solution remains a considerable challenge from a quantum chemistry point of view, requiring a high level of theory that simultaneously takes into account the relativistic effects, the dynamic treatment of the solvent–solute system, and the dynamic electron correlation. A combination of Car-Parrinello molecular dynamics (CPMD) and relativistic calculations based on two-component zeroth order regular approximation spin–orbit Kohn–Sham (2c-ZKS) and four-component Dirac–Kohn–Sham (4c-DKS) Hamiltonians is performed to address the solvent effect (water) on the conformational changes and JPtPt1 coupling. A series of bridged PtIII dinuclear complexes [L1–Pt2(NH3)4(Am)2–L2]n+ (Am = α–pyrrolidonate and pivalamidate; L = H2O, Cl−, and Br−) are studied. The computed Pt–Pt coupling is strongly dependent on the conformational dynamics of the complexes, which, in turn, is correlated with the trans influence among axial ligands and with the angle N–C–O from the bridging ligands. The J-coupling is decomposed in terms of dynamic contributions. The decomposition reveals that the vibrational and explicit solvation contributions reduce JPtPt1 of diaquo complexes (L1 = L2 = H2O) in comparison to the static gas-phase magnitude, whereas the implicit solvation and bulk contributions correspond to an increase in JPtPt1 in dihalo (L1 = L2 = X−) and aquahalo (L1 = H2O; L2 = X−) complexes. Relativistic treatment combined with CPMD shows that the 2c-ZKS Hamiltonian performs as well as 4c-DKS for the JPtPt1 coupling.
Manipulating topological charge of nested skyrmion bags by microwave magnetic fields
Authors: Li Shuang , Liu Jiabin , Zhu Qiyuan , Shi Xingqiang , Wang Jianglong , Wang Ruining , Jin Chendong
Published: March 2024

Nested skyrmion bags, as magnetic solitons with arbitrary integer topological charges (Q), hold potential for applications in data encoding. A crucial issue is the local manipulation of skyrmions within nested skyrmion bags to control the total Q. In this study, we explore different possible ground states and resonant excitation spectra of nested skyrmion bags through micromagnetic simulations. More importantly, we demonstrate that the manipulation of the Q of nested skyrmion bags can be achieved by using microwave magnetic fields, i.e., the inner, middle, and outer skyrmions within the nested skyrmion bags are selectively excited by using the diverse out-of-plane excitation modes. By calculating the energy of skyrmions, we further analyze the relationship between the annihilation of skyrmions at different positions and the out-of-plane microwave magnetic fields. Our findings present a promising approach for manipulating the Q of nested skyrmion bags, potentially advancing their application in storage and logic devices.
A framework for defining fire danger to support fire management operations in Australia†
Authors: Hollis Jennifer J. , Matthews Stuart , Anderson Wendy R. , Cruz Miguel G. , Fox-Hughes Paul , Grootemaat Saskia , Kenny Belinda J. , Sauvage Sam
Published: March 2024

Background Development of the Australian Fire Danger Rating System began in 2017 with a project aimed at demonstrating the feasibility of a new fire danger rating system through a Research Prototype (AFDRSRP) that accounted for variability in Australian vegetation types, was nationally applicable, modular and open to continuous improvement. Aims In this manuscript, we identify and define transition points and categories for the AFDRSRP. We discuss user responses to the categorisation during a live trial evaluation of the AFDRSRP and reflect on limitations and potential improvements. Methods A review of available literature, broad consultation with stakeholders and reanalysis of fire impact data were used to determine suitable thresholds for categorising fire danger within the AFDRSRP. Key results Fire danger categories within the AFDRSRP reflect transitions in fire behaviour that result in application of different fire management strategies or are associated with variation in serious consequences and impacts. Conclusions The AFDRSRP incorporated the best available science, supported by a well-defined framework for categorising and defining fire danger making it suitable for application across Australian fire jurisdictions and range of fuel types. Implications The framework allows fire managers to assess the accuracy and appropriateness of forecasted fire danger.
Expression of the monocarboxylate transporter MCT1 is required for virus-specific mouse CD8
+
T cell memory development
Authors: D’Aria Stefania , Maquet Céline , Li Shuang , Dhup Suveera , Lepez Anouk , Kohler Arnaud , Van Hée Vincent F. , Dadhich Rajesh K. , Frenière Marine , Andris Fabienne , Nemazanyy Ivan , Sonveaux Pierre , Machiels Bénédicte , Gillet Laurent , Braun Michel Y.
Published: March 2024

Lactate–proton symporter monocarboxylate transporter 1 (MCT1) facilitates lactic acid export from T cells. Here, we report that MCT1 is mandatory for the development of virus-specific CD8
+
T cell memory. MCT1-deficient T cells were exposed to acute pneumovirus (pneumonia virus of mice, PVM) or persistent γ-herpesvirus (Murid herpesvirus 4, MuHV-4) infection. MCT1 was required for the expansion of virus-specific CD8
+
T cells and the control of virus replication in the acute phase of infection. This situation prevented the subsequent development of virus-specific T cell memory, a necessary step in containing virus reactivation during γ-herpesvirus latency. Instead, persistent active infection drove virus-specific CD8
+
T cells toward functional exhaustion, a phenotype typically seen in chronic viral infections. Mechanistically, MCT1 deficiency sequentially impaired lactic acid efflux from activated CD8
+
T cells, caused an intracellular acidification inhibiting glycolysis, disrupted nucleotide synthesis in the upstream pentose phosphate pathway, and halted cell proliferation which, ultimately, promoted functional CD8
+
T cell exhaustion instead of memory development. Taken together, our data demonstrate that MCT1 expression is mandatory for inducing T cell memory and controlling viral infection by CD8
+
T cells.
Biodiversity mitigates drought effects in the decomposer system across biomes
Authors: Luan Junwei , Li Siyu , Liu Shirong , Wang Yi , Ding Liping , Lu Haibo , Chen Lin , Zhang Junhui , Zhou Wenjun , Han Shijie , Zhang Yiping , Hättenschwiler Stephan
Published: March 2024

Multiple facets of global change affect the earth system interactively, with complex consequences for ecosystem functioning and stability. Simultaneous climate and biodiversity change are of particular concern, because biodiversity may contribute to ecosystem resistance and resilience and may mitigate climate change impacts. Yet, the extent and generality of how climate and biodiversity change interact remain insufficiently understood, especially for the decomposition of organic matter, a major determinant of the biosphere–atmosphere carbon feedbacks. With an inter-biome field experiment using large rainfall exclusion facilities, we tested how drought, a common prediction of climate change models for many parts of the world, and biodiversity in the decomposer system drive decomposition in forest ecosystems interactively. Decomposing leaf litter lost less carbon (C) and especially nitrogen (N) in five different forest biomes following partial rainfall exclusion compared to conditions without rainfall exclusion. An increasing complexity of the decomposer community alleviated drought effects, with full compensation when large-bodied invertebrates were present. Leaf litter mixing increased diversity effects, with increasing litter species richness, which contributed to counteracting drought effects on C and N loss, although to a much smaller degree than decomposer community complexity. Our results show at a relevant spatial scale covering distinct climate zones that both, the diversity of decomposer communities and plant litter in forest floors have a strong potential to mitigate drought effects on C and N dynamics during decomposition. Preserving biodiversity at multiple trophic levels contributes to ecosystem resistance and appears critical to maintain ecosystem processes under ongoing climate change.
Synthesis of bioengineered heparin chemically and biologically similar to porcine-derived products and convertible to low MW heparin
Authors: Douaisi Marc , Paskaleva Elena E. , Fu Li , Grover Navdeep , McManaman Charity L. , Varghese Sony , Brodfuehrer Paul R. , Gibson James M. , de Joode Ian , Xia Ke , Brier Matthew I. , Simmons Trevor J. , Datta Payel , Zhang Fuming , Onishi Akihiro , Hirakane Makoto , Mori Daisuke , Linhardt Robert J. , Dordick Jonathan S.
Published: March 2024

Heparins have been invaluable therapeutic anticoagulant polysaccharides for over a century, whether used as unfractionated heparin or as low molecular weight heparin (LMWH) derivatives. However, heparin production by extraction from animal tissues presents multiple challenges, including the risk of adulteration, contamination, prion and viral impurities, limited supply, insecure supply chain, and significant batch-to-batch variability. The use of animal-derived heparin also raises ethical and religious concerns, as well as carries the risk of transmitting zoonotic diseases. Chemoenzymatic synthesis of animal-free heparin products would offer several advantages, including reliable and scalable production processes, improved purity and consistency, and the ability to produce heparin polysaccharides with molecular weight, structural, and functional properties equivalent to those of the United States Pharmacopeia (USP) heparin, currently only sourced from porcine intestinal mucosa. We report a scalable process for the production of bioengineered heparin that is biologically and compositionally similar to USP heparin. This process relies on enzymes from the heparin biosynthetic pathway, immobilized on an inert support and requires a tailored
N
-sulfoheparosan with
N
-sulfo levels similar to those of porcine heparins. We also report the conversion of our bioengineered heparin into a LMWH that is biologically and compositionally similar to USP enoxaparin. Ultimately, we demonstrate major advances to a process to provide a potential clinical and sustainable alternative to porcine-derived heparin products.
Tuning Second Chern Number in a Four-Dimensional Topological Insulator by High-Frequency Time-Periodic Driving
Authors: Liu 刘 Zheng-Rong 峥嵘 , Chen 陈 Rui 锐 , Zhou 周 Bin 斌
Published: March 2024

Floquet engineering has attracted considerable attention as a promising approach for tuning topological phase transitions. We investigate the effects of high-frequency time-periodic driving in a four-dimensional (4D) topological insulator, focusing on topological phase transitions at the off-resonant quasienergy gap. The 4D topological insulator hosts gapless three-dimensional boundary states, characterized by the second Chern number C
2. We demonstrate that the second Chern number of 4D topological insulators can be modulated by tuning the amplitude of time-periodic driving. This includes transitions from a topological phase with C
2 = ±3 to another topological phase with C
2 = ±1, or to a topological phase with an even second Chern number C
2 = ±2, which is absent in the 4D static system. Finally, the approximation theory in the high-frequency limit further confirms the numerical conclusions.
First measurement of kaonic helium-4 M-series transitions
Authors: Sgaramella F , Sirghi D , Abbene L , Artibani F , Bazzi M , Bosnar D , Bragadireanu M , Buttacavoli A , Cargnelli M , Carminati M , Clozza A , Clozza F , Deda G , Del Grande R , De Paolis L , Dulski K , Fabbietti L , Fiorini C , Friščić I , Guaraldo C , Iliescu M , Iwasaki M , Khreptak A , Manti S , Marton J , Miliucci M , Moskal P , Napolitano F , Niedźwiecki S , Ohnishi H , Piscicchia K , Principato F , Scordo A , Silarski M , Sirghi F , Skurzok M , Spallone A , Toho K , Tüchler M , Vazquez Doce O , Yoshida C , Zmeskal J , Curceanu C
Published: March 2024

In this paper we present the results of a new kaonic helium-4 measurement with a 1.37 g l−1 gaseous target by the SIDDHARTA-2 experiment at the DAΦNE collider. We measured, for the first time, the energies and yields of three transitions belonging to the M-series. Moreover, we improved by a factor about three, the statistical precision of the 2p level energy shift and width induced by the strong interaction, obtaining the most precise measurement for gaseous kaonic helium, and measured the yield of the L
α
transition at the employed density, providing a new experimental input to investigate the density dependence of kaonic atoms transitions yield.
Intelligent fault diagnosis of railway pantograph using a novel graph construction methodology
Authors: Ma Zijie , Duan Huayu , Chen Ziyi , Bin Xing , Jian Liu
Published: March 2024

Railway pantographs provide power for railway vehicles by conducting electrical energy from overhead catenary. The failure of the pantograph tends to damage the contact quality between the pantograph and the catenary, reducing the transmission efficiency of electric energy. Hence, fault diagnosis of pantograph plays a significant role in expanding the service life of railway vehicles. In this work, a novel graph construction method is proposed for the fault diagnosis of pantographs combined with a graph neural network (GNN). In the graph construction method, 1D load signals collected from the test pantograph are firstly transformed into multiple 2D images with the same size in both time and frequency domains using Gramian angular field, Markov transition field and recurrence plot. Secondly, pixel values in images are regarded as features in vertexes of graphs, and graphs can be constructed by connecting neighbor vertexes. Finally, the GNN model is trained by constructed graphs for obtaining the fault diagnosis model of pantographs. Laboratory experiments are implemented to show the advantages of the proposed method by comparing it with other conventional methods.
Multiple species imaging from CFD fused H2O absorption spectral tomography and transfer learning
Authors: Wen Jinting , Cao Zhang , Zhang Xiaoqian , Xu Lijun
Published: March 2024

Laser absorption spectroscopy (LAS) tomography is well-proved in combustion diagnosis but has difficulty especially in the simultaneous imaging of multi-species concentrations. A multiple species imaging method from single species LAS tomography was proposed on the basis of computational fluid dynamics (CFDs) and transfer learning. CFD simulation of the methane/air flat flame was conducted to reveal the relationship among multiple species. A back propagation neural network was pre-trained with the dataset obtained from CFD simulation to predict projection values of OH mole fractions from H2O absorption lines at 7185.6 cm−1 and 7444.4 cm−1. The measurement of flat flame by a single wavelength planar laser-induced fluorescence fused LAS tomography system was conducted for network fine-tuning and experiment verification. Distributions of OH mole fractions in lean-burn conditions and nearly complete combustion conditions were quantitatively reconstructed well, while annulus profiles in fuel-rich conditions were qualitatively retrieved. Reconstructed images with two-fifth experiment data used in the network fine-tuning showed a 31.3% decline in image error compared to those without fine-tuning. This proposed method enables LAS tomography of multiple species via only one species with enough measured projections, and also shows potential in image error reduction by introducing more projections.
Hundred-watts-level Ho:YLF slab laser with good beam quality
Authors: Mao Y F , Long Q L , Gao J M
Published: March 2024

We demonstrated a hundred-watts-level and good beam quality Ho:YLF slab laser with a hybrid cavity. When the incident pump power was 263 W, we obtained a maximum output power of 105 W. The slope efficiency with the incident pump power was 52.5%, and the optical-to-optical conversion efficiency was 39.9%. The instability of the maximum output power was measured to be 0.35% in 30 min. With the increase of the output power, the central wavelength of laser shifted from 2051 nm to 2063 nm. The beam quality factors M
2 were measured to be 1.13 in the stable direction and 2.45 in the unstable direction. Hundred-watts-level Ho:YLF slab laser with good beam quality has not been reported yet to the best of our knowledge.
Tailoring-compensated ferrimagnetic state and anomalous Hall effect in quaternary Mn–Ru–V–Ga Heusler compounds
Authors: Liang 梁 Jin-Jing 瑾静 , Xi 郗 Xue-Kui 学奎 , Wang 王 Wen-Hong 文洪 , Lau 刘 Yong-Chang 永昌
Published: March 2024

Cubic Mn2Ru
x
Ga Heusler compound is a typical example of compensated ferrimagnet with attractive potential for high-density, ultrafast, and low-power spintronic applications. In the form of epitaxial thin films, Mn2Ru
x
Ga exhibits high spin polarization and high tunability of compensation temperature by freely changing the Ru content x in a broad range (0.3 < x < 1.0). Herein Mn–Ru–Ga-based polycrystalline bulk buttons prepared by arc melting are systematically studied and it is found that in equilibrium bulk form, the cubic structure is unstable when x < 0.75. To overcome this limitation, Mn–Ru–Ga is alloyed with a fourth element V. By adjusting the content of V in the Mn2Ru0.75V
y
Ga and Mn2.25–y
Ru0.75V
y
Ga quaternary systems, the magnetic compensation temperature is tuned. Compensation is achieved near 300 K which is confirmed by both the magnetic measurement and anomalous Hall effect measurement. The analyses of the anomalous Hall effect scaling in quaternary Mn–Ru–V–Ga alloy reveal the dominant role of skew scattering, notably that contributed caused by the thermally excited phonons, in contrast to the dominant intrinsic mechanism found in many other 3d ferromagnets and Heusler compounds. It is further shown that the Ga antisites and V content can simultaneously control the residual resistivity ratio (RRR) as well as the relative contribution of phonon and defect to the anomalous Hall effect a″/a′ in Mn–Ru–V–Ga, resulting in a scaling relation a″/a′ ∝ RRR1.8.
Continuous wave and active Q-switched operation of Watt-level LED-pumped two-rod Nd,Ce:YAG laser
Authors: Shen 沈 Jian-Ping 建平 , Lu 芦 Peng 鹏 , Xu 徐 Shao-Cong 少聪 , Jiang 江 Rong-Rong 容容 , Chen 陈 Yang 阳 , Chen 陈 Liang 亮 , Xing 邢 Feng-Yang 凤阳
Published: March 2024

A high-performance LED-side-pumped two-rod Nd,Ce:YAG laser with continuous-wave (CW) and acousto–optical (A-O) Q-switched operation is demonstrated in this work. A symmetrically shaped flat–flat cavity with two identical LED-side-pumped laser modules is employed for power scalability. In the CW regime, the maximum output average power of laser at 1064 nm is 4.41 W, corresponding to a maximum optical conversion efficiency of 5.3% and a slope efficiency is 12.4%. In the active Q-switched regime, the pulse energy of laser reaches as high as 0.89 mJ at a repetition rate of 800 Hz with a pulse width of 457.2 ns, the corresponding highest peak output power is 1.94 kW and the M
2 factor is measured to be about 8.8. To the best of the authors’ knowledge, this is the first demonstration and the highest performance of a CW LED-side-pumped two-rod laser Nd,Ce:YAG with Watt-level output reported so far.
3D modeling of a double-driver ion source considering ion magnetization: an investigation of plasma symmetry modulation methods
Authors: Xing Si-Yu , Gao Fei , Zhang Yu-Ru , Zhao Miao , Lei Guang-Jiu , Wang You-Nian
Published: March 2024

A three-dimensional fluid model of a double-driver negative hydrogen ion source for China Fusion Engineering Test Reactor (CFETR) neutral beam injection is developed. In this model, the magnetic filter field is generated by 16 permanent magnets, which are surrounded by a soft iron. In order to accurately describe the transportation of charged species in the presence of strong magnetic field, both the electron magnetization and ion magnetization are taken into account, and the accuracy of the model has been proved by comparison with experimental data. By employing this model, the spatial distributions of the plasma parameters have been investigated, and three methods are proposed to optimize the symmetry at the bottom of the expansion region of a double-driver source. The results indicate that by adjusting the power of Driver I while keeping the power of Driver II constant, the symmetry of the electron density and negative hydrogen ion density could be improved. Furthermore, the inclusion of partition improves the symmetry of the electron temperature and density but has no impact on the regulation of the negative hydrogen ion density distribution. Finally, the application of magnetic shield can not only improve the symmetry of the electron density and negative hydrogen ion density, but also increase their densities at the bottom of the expansion region.
Spin Drude weight for the integrable XXZ chain with arbitrary spin
Authors: Ae Shinya , Sakai Kazumitsu
Published: March 2024

Using generalized hydrodynamics (GHD), we exactly evaluate the finite-temperature spin Drude weight at zero magnetic field for the integrable XXZ chain with arbitrary spin and easy-plane anisotropy. First, we construct the fusion hierarchy of the quantum transfer matrices (T-functions) and derive functional relations (T- and Y-systems) satisfied by the T-functions and certain combinations of them (Y-functions). Through analytical arguments, the Y-system is reduced to a set of non-linear integral equations, equivalent to the thermodynamic Bethe ansatz (TBA) equations. Then, employing GHD, we calculate the spin Drude weight at arbitrary finite temperatures. As a result, a characteristic fractal-like structure of the Drude weight is observed at arbitrary spin, similar to the spin-1/2 case. In our approach, the solutions to the TBA equations (i.e. the Y-functions) can be explicitly written in terms of the T-functions, thus allowing for a systematic calculation of the high-temperature limit of the Drude weight.
Exact steady states of the impurity-doped XXZ spin chain coupled to dissipators
Authors: Matsui Chihiro , Tsuji Naoto
Published: March 2024

We give an exact matrix product steady state and matrix product forms of local observables for the bulk impurity-doped XXZ spin model coupled to dissipators at both ends, whose dynamics is described by the Lindblad quantum master equation. We find that local magnetization is induced at the impurity site when the spin current flows, which is contrary to the usual situation where the current suppresses magnetization due to heating. It is proved that this current-induced magnetization survives in the thermodynamic limit, and the spin current does not depend on the impurity strength. We discuss the role of bulk integrability by comparing the results with those of non-integrable models solved numerically by the quantum trajectory method.
Hydrodynamic correlation and spectral functions of perfect cubic crystals
Authors: Mabillard Joël , Gaspard Pierre
Published: March 2024

We investigate the collective dynamics of the perfect cubic crystal by deriving from the hydrodynamic equations the time-dependent correlation and the spectral functions characterizing the fluctuations of mass and momentum densities. We show that the seven hydrodynamic modes of the perfect crystal can be identified from the resonances of these spectral functions. The comparison with those of a fluid is discussed. Using the numerical values of the thermodynamic, elastic, and transport coefficients computed in our previous paper (J Mabillard and P Gaspard 2024 J. Stat. Mech. 023208) for a system of hard spheres, the theoretical expressions for the correlation and spectral functions are compared to the same functions directly computed using molecular dynamics simulations. The excellent agreement between theory and simulation provides strong support for the microscopic hydrodynamic theory of perfect crystals based on the local-equilibrium approach. This work sheds light on the fundamental mechanisms governing the collective behavior of matter in the solid state.
Macroeconomic structural change likely increases inequality in India more than climate policy
Authors: Leimbach Marian , Hübler Michael , Mahlkow Hendrik , Montrone Lorenzo , Bukin Eduard , Felbermayr Gabriel , Kalkuhl Matthias , Koch Johannes , Marcolino Marcos , Pothen Frank , Steckel Jan Christoph
Published: March 2024

The decarbonization of India’s economy will have different effects across income groups. As India is in the middle of the transformation process from an agriculture-based economy towards an industry- and service-based economy, called economic structural change, the extent of income distribution across households strongly depends also on the speed of economic transformation. While a number of recent studies have analyzed the distributional effects of carbon pricing, the specific role of structural change across sectors has not been in the focus of the related literature. Our study contrasts distributional effects from climate policy with distributional effects from structural change in India and asks how far carbon pricing supports or hinders structural change and development. We develop and apply a comprehensive model framework that combines economic growth and international trade dynamics related to structural change with detailed household income and expenditure data for India. Our study shows that changes in income and inequality due to carbon pricing vary with changes in the sectoral structure of an economy. Our results indicate that carbon pricing tends to delay economic structural change by retarding the reallocation of economic activities from the agricultural sector to the manufacturing sector. Furthermore, the results emphasize that the increase in inequality due to structural change is substantially stronger than due to carbon pricing. Consequently, socially sensitive policies supporting the process of structural transformation appear to be more important for poor households than lowering climate policy ambitions.