bluuebunny/crossref_metadata_2025_split huggingface dataset:
Balance of osmotic pressures determines the nuclear-to-cytoplasmic volume ratio of the cell
Authors: Deviri Dan , Safran Samuel A. 
Published: May 2022

SignificanceFor over a century, it has been known that the ratio of the nuclear and cytoplasm volumes (NC ratio), rather than the separate volumes, is constant among cells of many types of organisms. Changes of the NC ratio are associated with cancerous transformations, suggesting that the ratio has physiological importance. Notably, the dominant regulatory mechanism of the NC ratio has not been identified. Here, we use physical estimates of the forces implicated in nuclear volume determination and show that they are dominated by the osmotic pressure of actively transported proteins. Inspired by this, we formulate a minimal model for the cytoplasmic and nuclear volumes that predicts the NC ratio and the factors that modulate it, in agreement with published experiments.
Comparison of moderate and vigorous walking exercise on reducing depression in middle‐aged and older adults: A pilot randomized controlled trial
Authors: Yu Danny J. , Yu Angus P. , Leung Chit K. , Chin Edwin C. , Fong Daniel Y. , Cheng Calvin P. , Yau Suk Y. , Siu Parco M. 
Published: May 2022

ABSTRACTThe optimal intensity of physical activity for alleviating depression in middle‐aged and older adults remains unclear. The World Health Organization (WHO) physical activity guidelines recommend adults and older adults to accumulate at least 150–300 minutes of moderate or 75–150 minutes of vigorous aerobic‐type physical activity weekly or an equivalent combination of both for health benefits including reduced risk of depression. This parallel, assessor‐blinded, pilot randomized controlled trial preliminarily compared the effectiveness of the minimal volume of aerobic‐type physical activity at different intensities as recommended by WHO (150 minutes of moderate walking exercise and 75 minutes of vigorous walking exercise weekly) on alleviating depression in middle‐aged and older adults. Thirty‐five participants were randomized to the control group (CON), moderate walking exercise group (MOD), or vigorous walking exercise group (VIG). The exercise frequency was three times a week and the intervention duration was 12 weeks. The primary outcome was the severity of depression assessed by Beck Depression Inventory. Secondary outcomes included severity of anxiety, sleep quality, quality of life, and cardiorespiratory fitness. Thirty participants completed the study (CON: n = 10, MOD: n = 10, VIG: n = 10). Participants in both MOD and VIG had significantly decreased depression severity after the intervention compared to CON (both p < 0.001). There was no significant difference between MOD and VIG (p = 0.92). Both MOD and VIG interventions also mitigated anxiety severity, improved quality of life and cardiorespiratory fitness. The minimum volume of walking exercise at either moderate or vigorous intensity was found to alleviate depression in middle‐aged and older adults.Trial registration: ClinicalTrials.gov identifier: NCT04403373.Highlights
The 12‐week 150‐minute moderate walking exercise and 75‐minute vigorous walking exercise (the minimal weekly volumes of aerobic‐type physical activity recommended by WHO guidelines) similarly reduced the severity of depression in middle‐aged and older adults.
The 12‐week walking exercise interventions significantly reduced anxiety severity concomitant with improved quality of life and cardiorespiratory fitness in middle‐aged and older adults with depression.
Bound states of central force system in special relativity
Authors: Setiawan Iwan , Sugihakim Ryan , Gunara Bobby Eka 
Published: May 2022

Abstract
In this paper we consider the central force problem in the special theory of relativity. We derive the special relativistic version of the Binet equation describing the orbit of a massive body. Then, the motion of a planet in a solar-like system where the gravitational potential is modified by adding a term that is proportional to the inverse of the square of the radial coordinate is discussed. Using perturbative method, we obtain the explicit orbital function. At the end, the orbital precession of the planet and its relation to the result from general relativity are also discussed.
The transverse magnetic electromagnetic bound mode in a black phosphorene inserted multilayer dielectric structure
Authors: Yang C H , Yang J T , Peng K K , Li Q F 
Published: May 2022

Abstract
The electromagnetic wave of the bound mode along the black phosphorene (BP) interface and the field distribution in a BP inserted planar multilayer dielectric structure have been investigated. The dispersion results indicate that the transverse magnetic surface plasmon wave is a bound mode and anisotropic with different electric field polarization directions. The effective refractive index increases as a function of the incident optical energy. It can also be tuned by the chemical potential and the thickness of the middle dielectric layer. The variable coupling strength between the light and matter based on the BP intraband optical conductivity makes the influence of the thickness of the middle dielectric layer significant or negligible in the lower and higher frequency regimes, respectively. The presented results can be applied to design BP-based promising optoelectronic devices.
Quasinormal modes of Schwarzschild black holes in projective invariant Chern-Simons modified gravity
Authors: Boudet S. , Bombacigno F. , Olmo G.J. , Porfírio P.J. 
Published: May 2022

AbstractWe generalize the Chern-Simons modified gravity to the metric-affine case and impose projective invariance by supplementing the Pontryagin density with homothetic curvature terms which do not spoil topologicity. The latter is then broken by promoting the coupling of the Chern-Simons term to a (pseudo)-scalar field. The solutions for torsion and nonmetricity are derived perturbatively, showing that they can be iteratively obtained from the background fields. This allows us to describe the dynamics for the metric and the scalar field perturbations in a self-consistent way, and we apply the formalism to the study of quasinormal modes in a Schwarzschild black hole background. Unlike in the metric formulation of this theory, we show that the scalar field is endowed with dynamics even in the absence of its kinetic term in the action. Finally, using numerical methods we compute the quasinormal frequencies and characterize the late-time power law tails for scalar and metric perturbations, comparing the results with the outcomes of the purely metric approach.
Multivariate analysis reveals topography dependent relationships amongst neurite morphological features from dorsal root ganglia neurons
Authors: Nelson Derek W , Puhl Devan L , Funnell Jessica L , Kruger Uwe , Gilbert Ryan J 
Published: May 2022

Abstract

Objective. Nerve guidance scaffolds containing anisotropic architectures provide topographical cues to direct regenerating axons through an injury site to reconnect the proximal and distal end of an injured nerve or spinal cord. Previous in vitro cultures of individual neurons revealed that fiber characteristics such as fiber diameter and inter-fiber spacing alter neurite morphological features, such as total neurite length, the longest single neurite, branching density, and the number of primary neurites. However, the relationships amongst these four neurite morphological features have never been studied on fibrous topographies using multivariate analysis. Approach. In this study, we cultured dissociated dorsal root ganglia on aligned, fibrous scaffolds and flat, isotropic films and evaluated the univariate and multivariate differences amongst these four neurite morphological features. Main results. Univariate analysis showed that fibrous scaffolds increase the length of the longest neurite and decrease branching density compared to film controls. Further, multivariate analysis revealed that, regardless of scaffold type, overall neurite length increases due to a compromise between the longest extending neurite, branching density, and the number of primary neurites. Additionally, multivariate analysis indicated that neurite branching is more independent of the other neurite features when neurons were cultured on films but that branching is strongly related to the other neurite features when cultured on fibers. Significance. These findings are significant as they are the first evidence that aligned topographies affect the relationships between neurite morphological features. This study provides a foundation for analyzing how individual neurite morphology may relate to neural regeneration on a macroscopic scale and provide information that may be used to optimize nerve guidance scaffolds.
Identifying oscillations under multi-site sensory stimulation for high-level peripheral nerve injured patients: a pilot study
Authors: Geng Yanjuan , Qin Liuni , Li Yongcheng , Yu Zhebin , Li Linling , Asogbon Mojisola Grace , Zhan Yang , Yan Nan , Guo Xin , Li Guanglin 
Published: May 2022

Abstract

Objective. For high-level peripheral nerve injuryed (PNI) patients with severe sensory dysfunction of upper extremities, identifying the multi-site tactile stimulation is of great importance to provide neurorehabilitation with sensory feedback. In this pilot study, we showed the feasibility of identifying multi-site and multi-intensity tactile stimulation in terms of electroencephalography (EEG). Approach. Three high-level PNI patients and eight non-PNI participants were recruited in this study. Four different sites over the upper arm, forearm, thumb finger and little finger were randomly stimulated at two intensities (both sensory-level) based on the transcutaneous electrical nerve stimulation. Meanwhile, 64-channel EEG signals were recorded during the passive tactile sense stimulation on each side. Main results. The spatial-spectral distribution of brain oscillations underlying multi-site sensory stimulation showed dominant power attenuation over the somatosensory and prefrontal cortices in both alpha-band (8–12 Hz) and beta-band (13–30 Hz). But there was no significant difference among different stimulation sites in terms of the averaged power spectral density over the region of interest. By further identifying different stimulation sites using temporal-spectral features, we found the classification accuracies were all above 89% for the affected arm of PNI patients, comparable to that from their intact side and that from the non-PNI group. When the stimulation site-intensity combinations were treated as eight separate classes, the classification accuracies were ranging from 88.89% to 99.30% for the affected side of PNI subjects, similar to that from their non-affected side and that from the non-PNI group. Other performance metrics, including specificity, precision, and F1-score, also showed a sound identification performance for both PNI patients and non-PNI subjects. Significance. These results suggest that reliable brain oscillations could be evoked and identified well, even though induced tactile sense could not be discerned by the PNI patients. This study have implication for facilitating bidirectional neurorehabilitation systems with sensory feedback.
Dynamics of charge-imbalance-resolved entanglement negativity after a quench in a free-fermion model
Authors: Parez Gilles , Bonsignori Riccarda , Calabrese Pasquale 
Published: May 2022

AbstractThe presence of a global internal symmetry in a quantum many-body system is reflected in the fact that the entanglement between its subparts is endowed with an internal structure, namely it can be decomposed as a sum of contributions associated to each symmetry sector. The symmetry resolution of entanglement measures provides a formidable tool to probe the out-of-equilibrium dynamics of quantum systems. Here, we study the time evolution of charge-imbalance-resolved negativity after a global quench in the context of free-fermion systems, complementing former works for the symmetry-resolved entanglement entropy. We find that the charge-imbalance-resolved logarithmic negativity shows an effective equipartition in the scaling limit of large times and system size, with a perfect equipartition for early and infinite times. We also derive and conjecture a formula for the dynamics of the charged Rényi logarithmic negativities. We argue that our results can be understood in the framework of the quasiparticle picture for the entanglement dynamics, and provide a conjecture that we expect to be valid for generic integrable models.
Numerical simulation of hovering flow field and interference characteristics of rotor system
Authors: Wang Yu , Sun Mao , Yan Chao 
Published: May 2022

Abstract
In order to investigate the aerodynamic interference characteristics of tandem rotor, this paper simulates the hovering flow field of single rotor and tandem rotor based on the dynamic structure overset grid method and unsteady Navier-Stokes equations in computational fluid dynamics (CFD). In the study of hover state of single rotor with twist, the trajectory of the blade vortex and the change pattern are briefly analyzed. Subsequently, the flow field disturbance of tandem rotor, the vortex structure, the pull coefficient and the downwash flow are investigated. The results show that there is obvious blade vortex interference in the overlapping area of the tandem rotor, where the downwash flow reduces the effective angle of attack of the blade and thus has a significantly effect on the pull coefficient. The rotor is less disturbed when it is far from the overlapping area, and the tension coefficient does not change significantly. After integrating the pull coefficient of the upper and lower rotors in one cycle, it was found that the loss of pull coefficient of the two rotors reached 5.7% and 10.7% respectively, which proved that the aerodynamic interference between the tandem rotor in hovering condition had an important effect on the aerodynamic performance of the vehicle.
Aircraft Condition Detection Based on Distributed Optical Fiber Sensing Technology
Authors: Zhang Zhen , Tian Zhenzi 
Published: May 2022

Abstract
This paper describes the principle of distributed optical fiber sensing technology and its application in the field of aircraft condition detection. Firstly, the differences between two kinds of distributed fiber sensing technologies are introduced, and the characteristics of the existing typical distributed fiber Bragg grating sensing system and the system type selection need system coverage, parameter sampling rate and reflected light demodulation mode. Then it introduces the principle and steps of using wavelet transform algorithm to analyze the aircraft state information. Finally, the system architecture suitable for the aircraft state detection environment is analyzed and proposed, and the integration scheme of the system with the state detection information acquisition system is discussed based on the characteristics of the system, and the problems needing attention such as time synchronization, data frame format and system interface are summarized.
Design and Research of Double-Wheeled Helicopter Tractor
Authors: Li Jing , Zheng Naibo 
Published: May 2022

Abstract
Due to the limited wheel size, existing domestic helicopter tractors are only applicable to some small and medium-sized single-wheeled helicopters. This paper introduces a double-wheeled helicopter tractor. The wheel holding mechanism can maximally hold a helicopter with a wheel diameter of 500mm, thus suitable for most common types of general aviation airports, such as Z-9, AS-365N, EC-155, AW -139, AS-332, etc. By improving stable torque output of the motor at low speed, self-developed reducer greatly increases the applicability and safety of helicopter traction.
Research on Simulation Method of Aircraft Design Based on Apriori Algorithm Analysis Research
Authors: Wang Hongsong 
Published: May 2022

Abstract
Aiming at the optimization problem of the aircraft design simulation method, in order to solve related problems, a new optimization method using gradient algorithm is proposed, and it is combined with Apriori algorithm analysis. Apriori algorithm analysis has advantages as well as some disadvantages. The advantage lies in its global optimization processing, while the limitation lies in its early maturity, and the local optimization performance needs to be improved. For this problem, this article adds the gradient algorithm to the experimental process. By accelerating the implementation of the gradient algorithm and retaining the optimal solution of the iterative process, global convergence is achieved, thereby increasing the calculation speed to a certain extent.
Numerical investigation of non-premixed H2-Air rotating detonation combustor with different equivalence ratios
Authors: Jiang Hanyu , Huang Yue 
Published: May 2022

Abstract
The initiation and propagation of rotating detonation waves (RDWs) are key techniques for the engineering application of rotating detonation engine (RDE). In this paper, the Naiver-Stokes equation of the three-dimensional unsteady reaction flow has been solved using one step hydrogen/air reaction mechanism to investigate the formation and propagation processes of RDWs under the non-premixed condition with different inlet equivalence ratios. The numerical results show that compared with RDWs generated by premixed propellants, less stable propagation processes and lower detonation fronts can be observed in RDWs generated under the non-premixed condition. It can be also concluded that the equivalence ratio has a great effect on the formation and propagation of RDWs. The formation time of stable RDWs increases when the ER changes from 1.0 to 1.3. However, under the conditions of the two ERs, similar re-initiation phenomena is observed in the evolution process of RDWs and a three-wave mode has been established.
Numerical Investigation on the Height of Detonation Wave in Rotating Detonation Engine
Authors: Xue Sainan , Ma Hu , Wang Fengming , Zhang Cuizhen , Xu Can , Zhuo ChangFei , Zhou Changsheng 
Published: May 2022

Abstract
Three-dimensional numerical simulations were conducted on a non-premixed rotating detonation engine (RDE) with different exhaust nozzles (i.e. without a nozzle, with a divergent nozzle, with a convergent nozzle, and with a Laval nozzle). Aside from describing the flow-field structure inside the chamber, the detonation wave height of the detonation wave, and the outlet Mach number were also investigated. It is found that the convergent and Laval nozzles make the flow-fields more complex in chamber by the reflected shock waves. The height rises with the increase of air mass flow rate when detonation chamber exit is in choke state, but it decrease when detonation chamber exit is not in choke state.
Design of a fuel-efficient scheme for space debris removal
Authors: Hu Wenjun , Yang Yueneng 
Published: May 2022

Abstract
In view of the growing threat of space debris and the limitation of current debris removal method. A novel conceptual solution for multiple space debris removal is proposed, and a low-cost and miniaturized removal system is designed in this paper. And the structural composition of this removal system is designed and the space debris removal process is introduced, the system can be divided into two components including satellite platform and many mission CubeSats. The mission CubeSats can be re-launched into the transfer orbits of different space debris through a push-launch method, and the fuel consumptions on the removal mission for three space debris, using the proposed multiple removal system and traditional removal system are calculated and compared. The compared results demonstrated that the proposed solution for multiple space debris removal and the designed removal system can decrease the fuel consumptions effectively.
Adaptive Fault-tolerant and Anti-disturbance Attitude Control of the Reconfigurable Modular CubeSat
Authors: Shi Jian-Cai , Song Xiao-Dong , Yan Ming-Zheng , Shen Xiao-Peng 
Published: May 2022

Abstract
This paper addresses the dynamical coupling and attitude control problems caused by the large-scale abrupt changes of the system mass characteristics and the relative motion of the sub-body during the autonomous reconfiguration of the modular satellite in orbit, the attitude dynamics equations of the reconfigurable modular CubeSat system with time-varying mass characteristics parameters are derived. An improved adaptive fault-tolerant anti-disturbance control algorithm that does not rely on an accurate dynamics model and converges quickly in finite time is also proposed based on the composite control idea. In the attitude control of modular CubeSat with large external disturbances and large range of moment of inertia time variation, the method has a faster convergence speed and higher accuracy than the traditional sliding mode control. Without any fault detection and diagnostic information, the method is able to achieve fast and highly accurate attitude adaptive fault-tolerant control in the presence of large disturbances and actuator time-varying, stochastic-type faults through real-time observation of total disturbances inside and outside the system. The final simulation results verify the effectiveness and reliability of the method.
Star spot centroid extraction method in high dynamic condition based on difference hash algorithm
Authors: Di PAN , Qi ZHOU , Weizhi QU , Bing LIU , Pingchuan REN 
Published: May 2022

Abstract
In high dynamic conditions, star spot exhibits a tailing phenomenon, which makes it impossible to accurately extract the star centroid. Adjusting the exposure time can shorten the tail length but it will reduce the energy received by the detector, which also makes it difficult to extract the star target. Aiming at the above two problems, this paper proposes a star spot centroid extraction method under high dynamic conditions based on different hash algorithm. The method is divided into three steps. Firstly, establish a mathematical model of dynamic star spots. Then using difference hash algorithm and Hamming distance to realize coarse positioning of star targets in star tracking window. Finally, adopt threshold segmentation and connected domain method to extract star spot centroid in the coarse location area. The experimental results show that the proposed method can adapt to various exposure time, making the star sensor realize the stable tracking at the angular velocity of 3°/s. When the exposure time is 50ms and the angular velocity is 3°/s, the angular distance error is 13 arcseconds, the average extraction rate is 96%, which is 29.6% and 29.7% better than the traditional method.
Three-dimensional low-altitude flight trajectory planning technology based on digital map
Authors: Zerui CHAO , Ying NAN , Xin WANG 
Published: May 2022

Abstract
Aiming at the intricate terrain of Yunnan, a three-dimensional low-altitude flight trajectory planning technology based on digital maps is proposed. First, divide the map of Yunnan into 36 digital maps, use VC++ to write a program to read the longitude and latitude coordinates of each point in the digital map and the height of each point into the memory, generate a grid coordinate system based on the start and end points, and find the grid from the memory The height data corresponding to each point in the coordinate system; then, the dynamic planning algorithm and the simple method are used to perform terrain avoidance and terrain following in the grid coordinate system, and finally, use MATLAB to draw the planning path map in the geographic coordinate system.