bluuebunny/crossref_metadata_2025 huggingface dataset:
Solutions for a quasilinear Schrödinger equation: Subcritical and critical cases
Authors: dos Santos Gelson C. G. , Fontinele Laila C. , Nascimentoa Rubia G. , Arrudab Suellen Cristina Q.
Published: May 2023

In this paper, we establish the existence of standing wave solutions for quasilinear Schrödinger equations involving nonlinearity with subcritical and critical growth. To apply the variational method and circumvent the “lack of compactness” of the problem, we combine the dual approach developed by Colin–Jeanjean [Nonlinear Anal. 56, 213–226 (2004)], Fang–Szulkin [J. Differ. Equations, 254, 2015–2032 (2013)], and Liu–Wang–Wang [J. Differ. Equations 187, 473–493 (2003)] with Del Pino–Felmer’s penalization technique [Calc. Var. Partial Differ. Equations 4, 121–137 (1996)], Moser’s iteration method, and an adaptation of Alves’ arguments [J. Elliptic Parabol. Equations 1, 231–241 (2015)] of the semilinear case.
Light-triggered cardiac microphysiological model
Authors: Vurro V. , Shani K. , Ardoña H. A. M. , Zimmerman J. F. , Sesti V. , Lee K. Y. , Jin Q. , Bertarelli C. , Parker K. K. , Lanzani G.
Published: May 2023

Light is recognized as an accurate and noninvasive tool for stimulating excitable cells. Here, we report on a non-genetic approach based on organic molecular phototransducers that allows wiring- and electrode-free tissue modulation. As a proof of concept, we show photostimulation of an in vitro cardiac microphysiological model mediated by an amphiphilic azobenzene compound that preferentially dwells in the cell membrane. Exploiting this optical based stimulation technology could be a disruptive approach for highly resolved cardiac tissue stimulation.
Influence of collisions on the validation of global gyrokinetic simulations in the edge and scrape-off layer of TCV
Authors: Ulbl Philipp , Body Thomas , Zholobenko Wladimir , Stegmeir Andreas , Pfennig Jan , Jenko Frank
Published: May 2023

Understanding and predicting turbulent transport in the edge and scrape-off-layer (SOL) of magnetic confinement fusion devices is crucial for developing feasible fusion power plants. In this work, we present the latest improvements to the gyrokinetic turbulence code GENE-X and validate the extended model against experimental results in the TCV tokamak (“TCV-X21”). GENE-X features a full-f electromagnetic gyrokinetic model and is specifically targeted for edge and SOL simulations in diverted geometries. GENE-X can model the effect of collisions using either a basic Bhatnagar–Gross–Krook (BGK) or more sophisticated Lenard–Bernstein/Dougherty (LBD) collision operator. We present the results of a series of GENE-X simulations using the BGK or LBD collision models, contrasting them to collisionless simulations. We validate the resulting plasma profiles, power balance, and SOL heat flux against experimental measurements. The match to the experiment significantly improves with the fidelity of the collision model chosen. We analyze the characteristics of the turbulence and find that in almost all cases in the confined region the turbulence is driven by trapped electron modes (TEM). Both the simulations without collisions and those with the BGK collision operator do not accurately describe turbulence driven by TEMs. The more sophisticated LBD collision operator presents a minimum requirement for accurate gyrokinetic edge turbulence simulations.
Ultrafast electron diffraction instrument for gas and condensed matter samples
Authors: Wang Yibo , Saha Sajib Kumar , Li Tianlin , Xiong Yanwei , Wilkin Kyle , Adhikari Anil , Loes Michael , Abourahma Jehad , Hong Xia , Adenwalla Shireen , Sinitskii Alexander , Centurion Martin
Published: May 2023

We report the modification of a gas phase ultrafast electron diffraction (UED) instrument that enables experiments with both gas and condensed matter targets, where a time-resolved experiment with sub-picosecond resolution is demonstrated with solid state samples. The instrument relies on a hybrid DC-RF acceleration structure to deliver femtosecond electron pulses on the target, which is synchronized with femtosecond laser pulses. The laser pulses and electron pulses are used to excite the sample and to probe the structural dynamics, respectively. The new system is added with capabilities to perform transmission UED on thin solid samples. It allows for cooling samples to cryogenic temperatures and to carry out time-resolved measurements. We tested the cooling capability by recording diffraction patterns of temperature dependent charge density waves in 1T-TaS2. The time-resolved capability is experimentally verified by capturing the dynamics in photoexcited single-crystal gold.
Combination of 3D current collectors and in situ polymerized electrolytes enabling high-mass-loading cathodes for solid-state lithium batteries
Authors: Sun Qifu , Tufail Muhammad Khurram , Li Wenkai , Zhao Ning , Bi Zhijie , Guo Xiangxin
Published: May 2023

Solid-state lithium batteries (SSLBs) are promising energy storage devices in the future due to their high theoretical energy density and enhanced safety. However, the practical energy density of SSLBs is severely constrained by the limited mass loading of cathode materials, which is related to sluggish charge transfer inside the thick cathodes. In this work, the solid-state batteries with high-mass-loading cathodes are realized by introduction of three-dimensional (3D) electronic-conductivity current collectors and in situ solidification of polymer electrolytes. The porous electronic current collectors of 3D carbon felts accommodate the flowing cathode slurry with considerably increased loading of cathode materials. Subsequently, the in situ solidified polymer electrolytes ensure conformal ionic conducting channels inside the cathodes, along with the formation of intimate and flexible contacts at cathode/electrolyte interfaces. In this way, the solid-state LiFePO4/garnet/Li batteries with cathode loading of 6.2 mg cm−2 show an initial discharge capacity of 159.4 mAh g−1 and a capacity retention of 92.1% after 100 cycles at 30 °C and 0.1 C. Furthermore, the cathode mass loading as high as 27.8 mg cm−2 is achieved with a corresponding areal capacity of approximately 4.2 mAh cm−2. This work proposes a promising unique cathode architecture for solid-state lithium batteries with high mass loading of the cathode.
Electro-optical modulation of terahertz beam by drifting space-charge domains in n-GaN epilayers
Authors: Balagula Roman M. , Subačius Liudvikas , Prystawko Paweł , Kašalynas Irmantas
Published: May 2023

Electro-optical modulation of a terahertz beam by drifting space-charge domains in n-GaN epilayers under pulsed electric field excitation was found and investigated at a temperature of 77 K. The free charge carrier contribution was observed as the attenuation of terahertz (THz) transmission whose value independently on THz beam polarization increased with the electric field, in the presence of drifting space-charge domains, up to 10%. The electro-optical contribution, on the other hand, was sensitive to beam polarization and demonstrated a nonlinear increase in THz transmission up to 50% under the external electric field up to 1.6 kV/cm, while higher field values led to an electrical breakdown of samples operating in the presence of drifting space-charge domain.
Mechanical multi-level memory from multi-stable metamaterial
Authors: Pechac Jack E. , Frazier Michael J.
Published: May 2023

In this Letter, we consider the dynamics of a multi-stable metamaterial with an elastic substrate to realize a mechanical system within which the position of a transition wavefront can be precisely controlled and remotely determined. This ability is enabled, in part, by a (strain-)tunable potential energy landscape that conveys the wavefront from one stabilizing defect site to another. In separating two acoustically distinct domains, the wavefront reflects small-amplitude waves of appropriate frequency back toward the source whereupon the time interval between excitation and echo reveals the position of the front. In a numerical study, we exploit these mechanisms for mechanical multi-level memory, which may find applications, e.g., in soft robots as a flexible alternative to current rigid memory technologies. More generally, we anticipate that the concepts presented here toward a command of the transition wave position will enhance the development and applicability of multi-stable metamaterials.
Numerical modelling of soil–landscape relationships using diversity indices and conditional probability: a case study from an Iranian arid region
Authors: Bagheri-Bodaghabadi Mohsen , Jafari Azam , Zeraatpisheh Mojtaba , Owliaie Hamidreza , Finke Peter , Xu Ming
Published: May 2023

Context Quantitative and numerical modelling of conceptual and qualitative concepts in the soil–landscape relationship is of great interest for soil mapping. Aims We quantified some conceptual and qualitative concepts concerning soil–landscape relationships by numerical analysis of landforms in soil identification using diversity indices (DIs) and conditional probability (CP). Method The geomorphology map was prepared based on the method of Zinck (1989) and used as a basic design for soil sampling. Finally, 200 soil profiles were excavated and described. The DIs and CP were calculated based on soil taxonomic and geomorphological hierarchies. Key results The DIs increased from landscape to landform level. The lowest and highest DIs were obtained for the soil order and soil family at each geomorphic level. The geomorphic diversity based on the soil taxonomy hierarchy showed that soil orders, including Entisols and Inceptisols, were observed in various landscapes and landforms. In contrast, some soil classes, such as Mollisols and its lower levels, did not have geomorphic diversity. The CP based on the geomorphological hierarchy indicated that the present possibility of a specific soil at the higher level (landscape) was less than at the lower level (landform), indicating more soil homogeneity at lower geomorphic levels. However, the probability of observing a certain geoform increased according to the soil classification hierarchy, consistent with the DI results. Conclusions The efficiency of DIs and CP in showing the distribution and possibility of soil separation depends on the alignment of soil and geomorphological processes and the diagnosis of these processes.
The role of spoken vocabulary knowledge in language minority students’ incidental vocabulary learning from captioned television
Authors: Teng Mark Feng , Mizumoto Atsushi
Published: May 2023

This study was to assess the spoken vocabulary knowledge and its role in incidental vocabulary learning from captioned television. The participants were a total of 87 minority students learning English as a foreign language in Australia. The breadth of their vocabulary knowledge was measured with a vocabulary size test, while the depth of their vocabulary knowledge was through an assessment of collocational and semantic relationships. The results indicated that (1) captioned videos are helpful for incidental vocabulary learning; (2) scores on the breadth and depth of vocabulary knowledge and incidental vocabulary learning from viewing captioned television are highly and positively correlated; and (3) scores on the depth of vocabulary knowledge can make a unique contribution to the prediction of incidental vocabulary learning at the form and meaning recognition level, in addition to the prediction afforded by scores on the breadth of vocabulary knowledge. The findings highlight a need to improve the depth of vocabulary knowledge for incidental vocabulary learning from captioned viewing.
Translation policies in times of a pandemic
Authors: Bouyzourn Kadija , Macreadie Rachel , Zhou Shuxia , Meylaerts Reine , Pym Anthony
Published: May 2023

In 2020–22, multilingual vaccination communication became an urgent priority around the world, requiring trusted communication in non-official languages. In Brussels, Melbourne and Shanghai, quite different legal frameworks and language policies were challenged by the need for behavior-change communication in a wide range of culturally and linguistically diverse communities. In all three cases, practices were developed that showed the limitations of existing translation policies. Here we use policy analysis to explore the nature of those challenges, to compare the different solutions found in the three cities, and to propose how policies might be developed and adjusted to enhance time-pressured trust-building communication.
A case for metonymic synesthesia
Authors: Tóth Máté
Published: May 2023

Verbal synesthesia is generally considered to be a special type of metaphor involving concepts stemming from distinct sensory domains. However, with the upsurge of metonymy research some authors have proposed a metonymic motivation for synesthetic expressions. In line with these proposals, I argue in my paper that (i) a considerable portion of synesthetic expressions are in fact metonymic and (ii) they are based either on co-occurrence or on an intra-modal resemblance of sensory stimuli. Since olfaction offers itself as an ideal terrain to study synaesthetic expressions due to its relatively poor lexicalization in most languages, in order to test my hypotheses, I present the results of a corpus study on German synesthetic attribute-noun constructions combining gustatory adjectives with olfactory nouns. My results suggest that the heterogeneity of verbal synesthesia regarding its conceptual background cannot be grasped simply by proposing that it is a metaphorical phenomenon.
Assessing learning related to an intersectional feminist perspective: an instrument of analysis (La evaluación de aprendizajes relacionados con una perspectiva feminista interseccional: un instrumento de análisis)
Authors: Nieto Mara , Martín Elena , Solari Mariana
Published: May 2023

There is a broad consensus about the need to educate students in ecosocial skills and intersectional feminist perspectives, which implies designing, developing and assessing interventions that address this learning in different curricular subjects. Initiatives to educate in these issues generally lack tools to assess what students have learned. In this conceptual and methodological paper, we present a theoretically grounded and empirically verified tool based on the theoretical framework of teaching and learning conceptions and designed to analyse and assess what the students have learned related to an intersectional feminist perspective. The tool distinguishes three dimensions of learning: functionality (with domains such as inequality, sexist violence and feminism), complexity and generalization, each of them with different competence levels. This makes it possible to study the impact of feminist educational interventions and can guide teachers in the design of proposals of this type.
Microstructure and second-phase strengthening mechanisms of CuTeCrY alloy
Authors: Deng Lixun , Gong Liukui , Song Shixin , Zhang Yansong , Feng Hongwei , Chen Ziming , Yuan Hefeng , Huang Wei
Published: May 2023

A CuTeCrY alloy prepared by homogenising annealing, hot extrusion, solution treatment, cold drawing, and a heat ageing treatment has tensile strength and electrical conductivity of 430 MPa and 78.9% IACS, respectively. Electron microscopy analyses show that a metastable CrCu2Te phase in the solid solution alloy is eliminated by the ageing treatment, and a 3–5 nm granular bcc-Cr phase becomes distributed in the matrix. This nanometre Cr second phase is the main contributor to the strengthening of the alloy whereas the second-phase strengthening effects of micrometre Cr and Te phases are weak.
Differences in kick‐leg kinematics in various side‐kick heights
Authors: Lin Yi‐Chun , Tang Wen‐Tzu , Peng Yi‐Chien , Liu Tsun‐Te , Chang Wei‐Gang , Huang Tsung‐Yu , Hamill Joseph
Published: May 2023

This study aims to explore the variation of lower extremity kinematic characteristics when elite taekwondo athletes perform the side‐kick on protective gear placed at various heights. Twenty distinguished male national athletes were recruited and were asked to kick targets at three different heights adjusted according to their body height. A three‐dimensional (3D) motion capture system was used to collect kinematic data. Kinematic parameters differences in the side‐kick at three different heights were analyzed by using a one‐way ANOVA (p < .05). The results revealed significant differences in the peak linear velocities of the pelvis, hip, knee, ankle, and centre of gravity of the foot during the leg‐lifting phase (p < .05). Significant differences between heights were noted in the maximum angle of pelvis left tilting and hip abduction in both phases. In addition, the maximum angular velocities of pelvis left tilting and hip internal rotation were only different in the leg‐lifting phase. This study found that, to kick at a higher target, athletes increase the linear velocities of their pelvis and all lower extremity joints of attacking leg in the leg‐lifting phase; however, they only increase rotational variables on the proximal segment at the peak angle of the pelvis (left tilting) and hip (abduction and internal rotation) in the same phase. As an application in actual competitions, according to the opponent's body height, athletes can adjust both linear and rotational velocities of their proximal segements (pelvis and hip) and deliver into distal segements (knee, ankle, foot) linear velocity to perform accurate and rapid kicks.
Political value-congruent climate change communication: an efficacy study from Germany and Austria (Congruencia de valores en la comunicación política del cambio climático: un estudio de eficacia de Alemania y Austria)
Authors: Ulmke Naara , Klackl Johannes , Hansen Jochim , Lempe Pascal , Finsterwalder Verena , Hagedorn Lucas , Rosenzweig Tom , Ramstetter Lena , Hüppauf Tilmann , Jonas Eva
Published: May 2023

To successfully battle climate change, it is crucial to reach people across political camps and national borders. Research from dual-party systems indicates that climate change communication is most effective when it addresses how climate action promotes recipients’ political values. Yet, to our knowledge, there is no such evidence from multi-party systems. To fill this gap, we conducted three studies in two Central European, German-speaking countries: Germany and Austria. In Study 1, we framed conservative and liberal climate protection messages using values from Schwartz’s Theory of Basic Human Values. Liberals agreed more with the liberally framed than with the conservatively framed climate protection message. In Study 2, we framed the climate protection message based on moral foundations. Conservative participants agreed more with the conservatively framed climate protection message than with the liberally framed one. Study 3 integrated values from multiple frameworks, and ultimately conservatives as well as liberals agreed more to climate protection statements that touched on values reflecting their political ideology. Thus, empirical findings from dual-party systems hold for countries with more than two parties.
How bending deformation affects the performance of polarization converters based on slot waveguides
Authors: Wang Y , Wang K F , Wang B L
Published: May 2023

Polarization is an important characteristic of light and plays a critical role in many natural and industrial processes. In this paper, we present an optical gradient force actuated polarization converter based on a slot waveguide, which can convert linearly polarized light into circularly polarized light. The working principle of the presented polarization converter is that optical gradient forces deform the slot waveguide to adjust its birefringence, thus yielding a desired phase shift between two orthogonal components of light. An optomechanical model with all possible mechanical boundaries is developed to solve the bending deformation of polarization converters. The effective index method and dispersion relation method are used for the calculation of birefringence and optical gradient forces, respectively. The influences of the width of waveguides and the initial width of the slot on the working performance of polarization converters are discussed. It is found that these influences are independent of the mechanical boundaries. An empirical formula for describing the relation between the working power and length of polarization converters is given. This empirical formula may be helpful when designing such polarization converters.
Scenarios for the creation of hyperchaotic attractors in 3D maps
Authors: Shykhmamedov Aikan , Karatetskaia Efrosiniia , Kazakov Alexey , Stankevich Nataliya
Published: May 2023

We study bifurcation mechanisms for the appearance of hyperchaotic attractors in three-dimensional diffeomorphisms, i.e. such attractors whose orbits have two positive Lyapunov exponents in numerical experiments. In particular, periodic orbits belonging to the attractor should have two-dimensional unstable invariant manifolds. We discuss several bifurcation scenarios which create such periodic orbits inside the attractor. This includes cascades of supercritical period-doubling bifurcations of saddle periodic orbits and supercritical Neimark–Sacker bifurcations of stable periodic orbits, as well as various combinations of these cascades. These scenarios are illustrated by an example of the three-dimensional Mirá map.
Algorithm based determination of the Planck’s constant
Authors: Korpal Smita , Aggarwal Anmol , Arora Ajay Kumar , Anand Jyoti , Verma Maya , Haridas Divya
Published: May 2023

In this paper we report a novel method for determining the Planck’s constant experimentally. We have determined the Planck’s constant using light emitting diodes (LEDs) of four different colours (Red, Green, Yellow and Blue) with the aid of a python programming. The LEDs were not provided with a specific wavelength value, and they could have any arbitrary wavelength in their respective colour bands. We determined the wavelengths of the LED lights using a Python program and calculated the value of the Planck’s constant using them. The value obtained was compared with the Planck’s constant value determined using a traditional method being followed in undergraduate labs and its actual value. The relative error while reporting the value of Planck’s constant using traditional method was around 18% which was reduced to 6% by using the method reported in the present study.
Experiments and analysis of dynamic characteristics of liquid sloshing in horizontal Cassini tank
Authors: Luo Houlin , Wu Wenjun , Jiang Bingchao , Guo Shouyi , Huang Libing , Yue Baozeng
Published: May 2023

In this study, the sloshing behaviors and dynamic characteristics of liquid sloshing in a horizontal Cassini tank were studied. The forces and torques generated by the liquid sloshing in non-equilibrium states were experimentally measured with force transducers which have been mounted on the experiment platform. The experiments mainly focus on the sloshing forces and torques generated by liquid sloshing in the tank. And the effects of the magnitude and frequency of the external excitations and the liquid-filling ratios on the sloshing characteristics were also studied. The experiments results show that the liquid sloshing in the Cassini tank is highly correlated with the excitation frequency where small variation in the frequency leads to complex changes in the liquid sloshing characteristics. In the cases with low liquid-filling ratio, in resonance state, the rotational sloshing is easier to be excited, however, in the stable-state the amplitudes of longitudinal sloshing force and torque are more significant than those of other sloshing conditions. The transversal sloshing force and torque are very small in both, rotational and translational nonlinear sloshing of small amplitude. In small-amplitude rotational and translational nonlinear sloshing cases, the CFD simulations were in good agreement with the experimental data. However, as the transitional compound state between different modes of vibration at various orders, the dynamic ratio of longitudinal and transversal sloshing force became large and errors occurred and became obvious in CFD simulations.
Quantum correlations and thermal coherence in a two-superconducting charge qubit system
Authors: Benzahra Mourad , Mansour Mostafa , Oumennana Mansoura , Elghaayda Samira
Published: May 2023

Superconducting charge qubits represent a cutting-edge technology in the field of quantum computing, offering a promising platform for quantum processing. This study delves into the behaviors of thermal coherence and quantum correlations within a two-superconducting charge qubit system coupled by a fixed capacitance. Specifically, we investigate the effects of thermal noise on entanglement (measured by concurrence), nonclassical correlations (quantified by local quantum uncertainty), and quantum coherence (measured by correlated coherence) within the two-superconducting charge qubit capacitively coupled. Our analysis takes into account the interplay between the equilibrium temperature of the reservoir and various system parameters. Our findings demonstrate that an increase in temperature leads to a decrease in coherence and quantum correlations within the considered system. However, the behavior of these quantum resources is heavily dependent on the system parameters, and a careful selection of these parameters can help mitigate the negative effects of absolute temperature. Additionally, we observe that local quantum uncertainty and correlated coherence are more resilient than thermal entanglement to rising temperatures. These results provide insight into how a two-superconducting charge qubit system can be optimized for achieving quantum advantages.
Fluid-chemical modeling of the near-cathode sheath formation process in a high current broken in DC air circuit breaker
Authors: Peng 彭 Shi-Dong 世东 , Li 李 Jing 静 , Duan 段 Wei 薇 , Cao 曹 Yun-Dong 云东 , Liu 刘 Shu-Xin 树鑫 , Huang 黄 Hao 浩
Published: May 2023

When the contacts of a medium-voltage DC air circuit breaker (DCCB) are separated, the energy distribution of the arc is determined by the formation process of the near-electrode sheath. Therefore, the voltage drop through the near-electrode sheath is an important means to build up the arc voltage, which directly determines the current-limiting performance of the DCCB. A numerical model to describe the near-electrode sheath formation process can provide insight into the physical mechanism of the arc formation, and thus provide a method for arc energy regulation. In this work, we establish a two-dimensional axisymmetric time-varying model of a medium-voltage DCCB arc when interrupted by high current based on a fluid-chemical model involving 16 kinds of species and 46 collision reactions. The transient distributions of electron number density, positive and negative ion number density, net space charge density, axial electric field, axial potential between electrodes, and near-cathode sheath are obtained from the numerical model. The computational results show that the electron density in the arc column increases, then decreases, and then stabilizes during the near-cathode sheath formation process, and the arc column’s diameter gradually becomes wider. The 11.14 V–12.33 V drops along the 17 μm space charge layer away from the cathode (65.5 kV/m–72.5 kV/m) when the current varies from 20 kA–80 kA. The homogeneous external magnetic field has little effect on the distribution of particles in the near-cathode sheath core, but the electron number density at the near-cathode sheath periphery can increase as the magnetic field increases and the homogeneous external magnetic field will lead to arc diffusion. The validity of the numerical model can be proven by comparison with the experiment.
Free running period affected by network structures of suprachiasmatic nucleus neurons exposed to constant light
Authors: Zhou Jian , Gu Changgui , Song Yuxuan , Xu Yan
Published: May 2023

Exposed to the natural light-dark cycle, 24 h rhythms exist in behavioral and physiological processes of living beings. Interestingly, under constant darkness or constant light, living beings can maintain a robust endogenous rhythm with a free running period (FRP) close to 24 h. In mammals, the circadian rhythm is coordinated by a master clock located in the suprachiasmatic nucleus (SCN) of the brain, which is composed of about twenty thousand self-oscillating neurons. These SCN neurons form a heterogenous network to output a robust rhythm. Thus far, the exact network topology of the SCN neurons is unknown. In this article, we examine the effect of the SCN network structure on the FRP when exposed to constant light by a Poincaré model. Four typical network structures are considered, including a nearest-neighbor coupled network, a Newman–Watts small world network, an ErdÖs–Rényi random network and a Barabási–Albert (BA) scale free network. The results show that the FRP is longest in the BA network, because the BA network is characterized by the most heterogeneous structure among these four types of networks. These findings are not affected by the average node degree of the SCN network or the value of relaxation rate of the SCN neuronal oscillators. Our findings contribute to the understanding of how the network structure of the SCN neurons influences the FRP.
Bifurcations for counterintuitive post-inhibitory rebound spike related to absence epilepsy and Parkinson disease
Authors: Wang Xian-Jun , Gu Hua-Guang , Jia Yan-Bing , Lu Bo , Zhou Hui
Published: May 2023

Seizures are caused by increased neuronal firing activity resulting from reduced inhibitory effect and enhancement of inhibitory modulation to suppress this activity is used as a therapeutic tool. However, recent experiments have shown a counterintuitive phenomenon that inhibitory modulation does not suppress but elicit post-inhibitory rebound (PIR) spike along with seizure to challenge the therapeutic tool. The nonlinear mechanism to avoid the PIR spike can present theoretical guidance to seizure treatment. This paper focuses on identifying credible bifurcations that underlie PIR spike by modulating multiple parameters in multiple theoretical models. The study identifies a codimension-2 bifurcation called saddle--node homoclinic orbit (SNHOB), which is an intersection between saddle node bifurcation on invariant cycle (SNIC) and other two bifurcations. PIR spike cannot be evoked for the SNIC far from the SNHOB but induced for the SNIC close to the SNHOB, which extends the bifurcation condition for PIR spike from the well-known Hopf to SNIC. Especially, in a thalamic neuron model, increases of conductance of T-type Ca2+ (T
Ca) channel induce SNIC bifurcation approaching to the SNHOB to elicit PIR spikes, closely matching experimental results of the absence seizure or Parkinson diseases. Such results imply that, when inhibition is employed to relieve absence seizure and Parkinson diseases related to PIR spike, modulating SNIC to get far from the SNHOB to avoid PIR spike is the principle. The study also addresses the complex roles of T
Ca current and comprehensive relationships between PIR spike and nonlinear conceptions such as bifurcation types and shapes of threshold curve.
Pressure resistance analysis of multi-layer fluid-solid-coupling shell structure
Authors: Runkun Li , Tieshu Li , Pengrui Dai , Jingyu Yang
Published: May 2023

This paper focuses on the pressure resistance of underwater equipment. A shell structure that divided into multi-layer is proposed, the spaces between layers are filled with fluid medium, which is applied gradually decreasing pressure in outside-inside order that helps offsetting external pressure. Using the Finite Element Method, the Multi-layer Fluid-Solid-Coupling Shell Structure has been proved to be effective in improving the pressure resistance of underwater equipment without increasing the total thickness of material, in the scope of the study, the maximum equivalent stress of the whole structure decreased with increase of the number of layers without instability phenomenon.
Research progress of evaluation methods of failure criteria for fiber reinforced composites
Authors: Ettoumi Samya
Published: May 2023

Integration of composite materials in aviation applications undeniably offer multiple important benefits, and more modelling techniques and failure analysis tools are increasingly being developed in evaluated to reduce the high costs associated with investigating the mechanical characteristics and prediction of failure of fiber reinforced composites. This article evaluates and compares between some of the most common failure criteria, Hashin, Puck and maximum stress criteria. The conclusion of this article shows that the interactive failure criteria are more adequate to use in the prediction of failure although they are inherently more complex to describe.
A review on mechanical properties and simulation methods of stitched composites
Authors: Shi Lei , Zhang Yongjie
Published: May 2023

Stitching technology is an effective and advanced textile method to improve the interlayer performance of composites and has broad application prospects in aerospace, military, civil and other fields. In recent years, various aspects of sutured composites have been continuously updated. In this paper, the mechanical properties, failure mechanism and numerical simulation methods of stitched composites are introduced..
Design of flap/spoiler follower mechanism for civil aircraft
Authors: Feng Yunwen , Tang Jiaqiang , He Zhiyu , Xue Xiaofeng , Dong Meng
Published: May 2023

With the gradual development of the lift device to a simple and efficient direction, the drooped spoiler has become an emerging lift device. The drooped spoiler can improve the aerodynamic performance of the wing by reducing the air flow separation and increase the lift coefficient, which requires the spoiler to deflect a certain angle following the downward deflection of the flap. Aiming at this requirement, this paper proposes a design method of spoiler follower mechanism based on the relative pole method. The applicability and correctness of the method are verified by kinematics simulation. Moreover, the kinematic characteristics of the simple four-bar linkage and the complex four-bar linkage are compared, and the results show that the complex four-bar linkage is more stable in the motion process.
Reconfiguration control allocation of actuator faults for tailless aircraft with low aspect ratio
Authors: Li Gen , Sun Liguo , yang Bo , Yu Shuang , Yang Zhangmengke
Published: May 2023

The triaxial attitude control of the tailless aircraft depends heavily on the effectiveness of the actuators. Still, the actuators have redundancy characteristics, cross-coupling of rudder effect, and so on. Therefore, the reconfigurable control allocation of the tailless aircraft under typical actuator faults is deeply studied in this paper. The effectiveness and rationality of the incremental control allocation method based on quadratic programming are thoroughly verified for application to maximize the residual control ability of the aircraft, ensure that the aircraft can still complete the flight mission typically, and guarantee flight safety. According to the research principle of surface failures from slight to severe, three typical rudder surface faults are designed successively: Efficiency loss of single actuator, single actuator stuckness, and double actuators combined stuckness. On this basis, the mechanism of reconfiguration allocation after actuator failures is studied, and the residual control ability of the actuator after loss is fully explored. What’s more, the range of allowable reduction of efficiency of each actuator and the acceptable stuck angle range of each actuator are explored, and the most severe failure in the combination of double actuators stuck is obtained. The attitude controller is designed with incremental backstepping (IBKS). The reconstruction allocation adopts a quadratic programming allocation method based on an effective set solver, which can be seamlessly connected with the IBKS method to improve the control accuracy and disturbance immunity effectively.
Design of tandem wing layout of pneumatic cooperative lift train
Authors: Ding Shao-cheng , Chao-Gao  , Yan Ri-hua , Bin-Wu  , Ya-Liu  , Ni Zhang-song , Ming-Xue
Published: May 2023

Pneumatic lift train together is the concept of under the background of further accelerate the speed of high-speed train running speed, in order to under higher speed train the whole life cycle cost, the researchers put forward the concept of aerodynamic lift high-speed train together, break through the traditional high-speed train aerodynamic shape design concept, combined with high speed trains and aircraft their respective advantages, hope that through increasing train aerodynamic lift, It is hoped that by increasing the aerodynamic lift of the train, the overall energy saving and consumption reduction of the high-speed train can be achieved. In this paper, a high lift airfoil is optimized to improve the lift coefficient as much as possible while the drag coefficient is basically unchanged. The thickness and drag coefficient of the optimized airfoil are almost unchanged at the designed Angle of attack, and the lift coefficient is increased by 13%. A flat wing is designed based on the optimized airfoil, and the influence of wall effect and tandem wing layout on the lift drag coefficient of the wing is studied. A better aerodynamic lift cooperative train tandem wing layout is obtained, which can reduce the weight of a single train by 17%.
Sensitivity analysis of antenna gain loss to the disturbance of control moment gyroscope
Authors: Tan Shiyu , Gao Jingbo , Wang Cong , Shen Yingyong
Published: May 2023

The multi-body dynamic model of the SAR satellite and the Ruze formula are used to investigate the antenna gain loss’s sensitivity to the control moment gyroscope. First, by using the finite element method, the satellite’s dynamic model is created and the modal characteristic is then determined. Then the distribution of input disturbance and CMG diagram is established. And the effect of each CMG disturbance on the antenna gain is studied. The sensitivity parameters of gain loss to disturbance are computed by using the One-at-a-Time (OAT) method. The results show that for CMGs, although they are placed asymmetrically and have the same loading characteristics, their effects on the antenna gain are different and need to be considered separately. The method and ideas proposed in this paper can be used to quantify the influence of various disturbances’ sensitivity and control system design.
Transient study on filling characteristics of LOX dome
Authors: Xu Jiabao , Wu Yan , Zhu Qingcheng , Jin Ping , Wang Jue , Cai Guobiao
Published: May 2023

The 3D flow filling process of LOX (Liquid Oxygen) dome is studied in a liquid oxygen/methane rocket engine. The volume, flow field pressure and velocity distributions of liquid oxygen at different time are determined. The flow property of propellant and the injection characteristic time of liquid oxygen are obtained. The results show that when the LOX dome has not been filled, the LOX flow state is disorder, and flows around the annular wall in the middle dome. The static pressure near the equalizing orifice near the liquid oxygen inlet is high and the velocity is slow. When the LOX filling is completed, the pressure at the outlet of each equalizing orifice is the same. The liquid oxygen flow is in a stable state, and the flow rate decreases. The overall velocity distribution is more uniform. In addition, in the filling process of LOX dome, the time of arrival in each area is different. There are different injection delays in each area on the injection panel, and the time of arrival of liquid oxygen in the opposite area of the inlet section of LOX dome is the latest. This result leads to the inhomogeneity of injection characteristic time and flow rate in thrust chamber.
A multi-segment multi-pulse maneuver control method for micro satellite
Authors: Xu Gen , Zeng Nengwei , Chen Danhe
Published: May 2023

Aiming at the constraint due to micro satellite orbital maneuverability and relative navigation, a multi-segment multi-pulse maneuver control method is proposed for approaching a target satellite. Convert the along-track approaching trajectory into an impulsive control problem with fixed time and fixed distance. With time and distance from origin to destination as the optimization objectives, the time-distance optimal solution set is generated under the delta-v constraint and trajectory constraint. The planning function is obtained by fitting a segmented polynomial to the optimal solution set. In the approach mission, the maneuver time to reach the expected terminal is determined based on the planning function, and the approaching to the terminal is accomplished using fixed-time multi-pulse control. Based on the simulation scenario, a multi-segment maneuvering strategy is obtained according to the optimization result, and the mission simulation is completed using the three-pulse control. The results show that the proposed multi-segment multi-pulse maneuver control method can reliably complete the approach mission under the constraints.
Trajectory tracking control for unmanned helicopter based on RBFNN
Authors: Guo Yueru , Lei Zhongkui , Yang Zhuopeng , Li Yihang , Chen Kuiyu , Xu Yanqing
Published: May 2023

This paper proposes a nonlinear adaptive radial basis function neural network (RBFNN) control method for Unmanned Helicopter. The control objective is to reduce the trajectory tracking error of the unmanned helicopter in the presence of system uncertainty and external disturbances. Based on the backstepping control technique, the controller of the unmanned helicopter are designed in order of position kinematics, position dynamics, attitude kinematics and attitude dynamics, and the block processing is used in the last three steps above.Then, RBFNN is added to compensate the error caused by external interference. Meanwhile, the derivatives of virtual controls are obtained by second-order command filter, and the stability of the system is analyzed by Lyapunov stability theorems. Finally, the simulation results verify the stability and robustness of the control method.
Thermal control system design and analysis for a micro-nano satellite stays on target satellite
Authors: Chen Zhezheng , Yang Haibo , Yu Yongjun , Yang Songlin
Published: May 2023

Aiming at the future satellites on-orbit service requirements, this paper researched the thermal control system for a micro-nano satellite. The micro-nano satellite can be attached on target satellite. The extreme temperature conditions of the micro-nano satellite has been determined by analyzing the complex space heat environment and power consumption, the thermal control system of micro-nano satellite has been designed, the finite element model (FEM) of the satellite is established, and the temperature fields about the extreme temperature conditions are calculated. The simulation results proves the feasibility of the thermal control system.
Comprehensive evaluation of the climatic environment adaptability on the civil typical system in the alpine environment
Authors: Wang Binwen , Zhang Hui , Wu Jingtao , Tian Peiqiang , Tang Yanggang
Published: May 2023

The function and performance of the aviation equipment are greatly affected by the alpine climate conditions. Combine with the test data obtained from the extreme climatic environment test, the fuzzy comprehensive evaluation method can effectively evaluate the adaptability of the civil avionics system on the plateau alpine environment. By analyzing the influencing factors of the alpine environment on the civil avionics system, the evaluation index system was established; and the fuzzy comprehensive evaluation method was used to obtain the adaptability evaluation value of the civil avionics system on the alpine environment. The evaluation results of the climatic environment adaptability can provide technical support for the improvement design of the civil aircraft system.
Surge margin monitoring of one turboshaft engine with inlet distortion
Authors: Yan Siqi , Zhang Yun , Li Benwei , Liu Chenguang
Published: May 2023

In order to explore the engine surge when inlet distortion index and engine surge margin, the relationship between the parameter characteristics of research engine surge, strengthen safety monitoring assessment engine, this paper designed a kind of a certain type of engine bench test surge monitoring system, and unstable flow field of a certain type of vortex axis engine working parameters for monitoring and analysis. In this paper, a plug-plate distortion generator is used to induce a surge engine, and the circumferential static pressure changes of the inlet and outlet of the engine, the axial compressor and the centrifugal compressor under different working conditions are obtained. The changes of circumferential unevenness and mean turbulence, the pressure ratio at working point and the converted air flow rate at working point are analyzed with the increase of the height of the plug-plate under different working conditions. The results show that the distortion index of the working point increases and the surge margin decreases with the increase of the height of the plug-plate at the same rotating speed. When the height of the plug-plate is similar, the higher the speed is, the greater the distortion index of the working point is, and the smaller the surge margin is.
Regulating generation of multiple emulsion through double parallel-crank mechanism
Authors: Wang Meng , Zhu Li , Zhang Chuanwen
Published: May 2023

A method was proposed for preparing multiple emulsions based on a double parallel-crank mechanism. The dispersed phase flows into the glass capillary, and the glass capillary was driven to make a circular motion via connecting the crank structure. Then, the external phase shears the dispersed phase through the double parallel-crank mechanism to prepare water in oil (W/O) droplets, and the process of generation of droplets was simulated by CFD. The effects of rotating speed, capillary diameter, external flow rate, and external viscosity on droplet formation were investigated. The size and generation frequency of the droplets was controlled by the rotational speed. More importantly, Single or multicore droplets were generated by the rotation droplet generator, and the effects of rotational speed on the number of cores and droplet size were investigated. Finally, the multi-component microgels were produced by the pre-crosslinking method. This study provides a rotation droplet generation system that has the ability to generate various droplets, expanding the practicability and versatility of the rotation droplet generator, and providing a new platform for multiple emulsion preparations.
On a road map for technology qualification, innovation and cost reduction in floating offshore wind: learning from Hywind and Norwegian approach
Authors: Ibrion Michaela , Nejad Amir R.
Published: May 2023

The main aim of this paper is to synthetize and to learn from the existing road maps and the Norwegian approach on the floating offshore wind. It targets to identify main priorities, key challenges, and technological qualification for the floating offshore wind development. The Norwegian approach is evaluated in the view of the key success factors of the offshore wind market highlighted by the World Bank. One particularity of the national Norwegian offshore landscape is the usage of the Norwegian floating wind for decarbonification and “greenification” of the oil and gas industry. Learning from the Hywind projects and Norwegian approaches and experiences for the floating offshore wind on the national and international level has potential in contributing to enhance the road maps for floating offshore wind in terms of technology qualification, innovation and cost reduction. This article offers a handful of key take away points for industry and decision makers about development of the floating offshore wind.