检索结果-南通市图书馆

同方期刊数据库

Kármán vortex street in a spin–orbit-coupled Bose–Einstein condensate with PT symmetry

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第6期33卷 289-296页

作者：邵凯花席保龙席忠红涂朴王青青马金萍赵茜石玉仁 college of Physics and Electronic engineering Northwest Normal UniversityLanzhou 730070China college of Physics and Hydropower engineering Gansu Normal College For NationalitiesHezuo 747000China college of Intelligent Manufacturing Sichuan University of Arts and ScienceDazhou 635000China

The dynamics of spin–orbit-coupled Bose–Einstein condensate with parity-time symmetry through a moving obstacle potential is simulated numerically. In the miscible two-component condensate, the formation of the Kármán vortex street is observed in one component, while ‘the half-quantum vortex street' is observed in the other component. Other patterns of vortex shedding, such as oblique vortex dipoles, V-shaped vortex pairs, irregular turbulence, and combined modes of various wakes, can also be found. The ratio of inter-vortex spacing in one row to the distance between vortex rows is approximately0.18, which is less than the stability condition 0.28 of classical fluid. The drag force acting on the obstacle potential is simulated. The parametric regions of Kármán vortex street and other vortex patterns are calculated. The range of Kármán vortex street is surrounded by the region of combined modes. In addition, spin–orbit coupling disrupts the symmetry of the system and the gain-loss affects the local particle distribution of the system, which leads to the local symmetry breaking of the system, and finally influences the stability of the Kármán vortex street. Finally, we propose an experimental protocol to realize the Kármán vortex street in a system.

关键词： Kármán vortex street Bose–Einstein condensate spin–orbit-coupled parity-time symmetry

Examining the Use of Scott’s Formula and Link Expiration Time Metric for Vehicular Clustering

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in engineering & Sciences 2024年第3期138卷 2421-2444页

作者： Fady Samann Shavan Askar Department of Energy engineering Technical College of EngineeringDuhok Polytechnic UniversityDuhok42001Iraq Department of Information System engineering Technical College of EngineeringErbil Polytechnic UniversityErbil44001Iraq

Implementing machine learning algorithms in the non-conducive environment of the vehicular network requires some adaptations due to the high computational complexity of these algorithms.K-clustering algorithms are simplistic,with fast performance and relative ***,their implementation depends on the initial selection of clusters number(K),the initial clusters’centers,and the clustering *** paper investigated using Scott’s histogram formula to estimate the K number and the Link Expiration Time(LET)as a clustering *** traffic flows were considered for three maps,namely Highway,Traffic Light junction,and Roundabout junction,to study the effect of road layout on estimating the K number.A fast version of the PAM algorithm was used for clustering with a modification to reduce time *** Affinity propagation algorithm sets the baseline for the estimated K number,and the Medoid Silhouette method is used to quantify the ***++,Veins,and SUMO were used to simulate the traffic,while the related algorithms were implemented in *** Scott’s formula estimation of the K number only matched the baseline when the road layout was ***,the clustering algorithm required one iteration on average to converge when used with LET.

关键词： Clustering vehicular network Scott’s formula FastPAM

Image Fusion Based on Bioinspired Rattlesnake Visual Mechanism Under Lighting Environments of Day and Night Two Levels

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Bionic engineering 2024年第3期21卷 1496-1510页

作者： Yong Wang Hongmin Zou college of Communication engineering Jilin UniversityChangchun130012China

This study,grounded in Waxman fusion method,introduces an algorithm for the fusion of visible and infrared images,tailored to a two-level lighting environment,inspired by the mathematical model of the visual receptive field of rattlesnakes and the two-mode cells'*** research presented here is segmented into three *** the first segment,we design a preprocessing module to judge the ambient light intensity and divide the lighting environment into two levels:day and *** second segment proposes two distinct network structures designed specifically for these daytime and nighttime *** the daytime images,where visible light information is predominant,we feed the ON-VIS signal and the IR-enhanced visual signal into the central excitation and surrounding suppression regions of the ON-center receptive field in the B channel,***,for nighttime images where infrared information takes precedence,the ON-IR signal and the Visual-enhanced IR signal are separately input into the central excitation and surrounding suppression regions of the ON-center receptive field in the B *** outcome is a pseudo-color fused *** third segment employs five different no-reference image quality assessment methods to evaluate the quality of thirteen sets of pseudo-color images produced by fusing infrared and visible *** images are then compared with those obtained by six other methods cited in the relevant *** empirical results indicate that this study's outcomes surpass the comparative results in terms of average gradient and spatial *** one or two sets of fused images underperformed in terms of standard deviation and entropy when compared to the control *** sets of fused images did not perform as well as the comparison in the QAB/F *** conclusion,the fused images generated through the proposed method show superior performance in terms of scene detail,visual perception,and image sharpness

关键词： Rattlesnake Visible image Infrared image Daylight Bionic

Study on force chain evolution of rice straw with different length during vibrational compression

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第2期85卷 310-322页

作者： Han Tang Wenlong Xu Guixuan Zhu Changsu Xu Jinwu Wang college of engineering Northeast Agricultural UniversityHarbin150030China

This paper explores the mechanism of force chain evolution and voidage change under vibrational and non-vibrational compression conditions of rice straw of different *** were used to explore the force chain evolution and voidage variation mechanism under different *** re-sults show that under non-vibrational compression,the strong force chain passes from top to bottom in vertical direction and from center to periphery in tangential *** vibrational compression,the force chain passes from top and bottom to center in vertical direction and the force chain evolves from outer ring to interior and exterior in tangential *** number of strong chains,voidage and standard deviation of the mean pressure under vibratory compression are lower than the values under non-vibratory *** promotes stress transfer and enhancement,velocity enhancement and density *** study analyzes the mechanical properties of different lengths straw during vibrational and non-vibrational compression from a detailed viewpoint.

关键词： Straw compression Voidage Discrete element method Mechanical properties Force chain transmission

Anti-abrasion collagen fiber-based membrane functionalized by UiO-66-NH_(2)with ultra-high efficiency and stability for oil-in-water emulsions separation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical engineering 2024年第2期66卷 285-297页

作者： Xiaoxia Ye Rixin Huang Zhihong Zheng Juan Liu Jie Chen Yuancai Lv college of Environmental and Safety engineering Fuzhou UniversityFuzhou 350108China college of Chemical engineering Fuzhou UniversityFuzhou 350108China

Membrane separation strategies offer promising platform for the emulsion ***,the low mechanical strength of membrane separation layers and the trade-off between separation flux and efficiency present significant *** this study,we report a CFM@UiO-66-NH_(2)membrane with high separation flux,efficiency and stability,through utilizing a robust anti-abrasion collagen fiber membrane(CFM)as the multifunctional support and UiO-66-NH_(2)by an in-situ growth as the separation *** high mechanical strength of the CFM compensated for the weakness of the separation layer,while the charge-breaking effect of UiO-66-NH_(2),along with the size sieving of its constituent separating layers and the capillary effect of the collagen fibers,contributed to the potential for efficient ***,the CFM@UiO-66-NH_(2)membrane exhibited superhydrophilic properties,making it suitable for separating oil-in-water microemulsions and nanoemulsions stabilized by anionic *** membrane demonstrated remarkable separation efficiencies of up to 99.960%and a separation flux of370.05 L·m^(-2)·h^(-1).Moreover,it exhibits stability,durability,and abrasion resistance,maintaining excellent separation performance even when exposed to strong acids and alkalis without any damage to its structure and *** six cycles of reuse,it achieved a separation flux of 417.97 L·m^(-2)·h^(-1)and a separation efficiency of 99.747%.Furthermore,after undergoing 500 cycles of strong abrasion,the separation flux remained at 124.39 L·m^(-2)·h^(-1),with a separation efficiency of 99.992%.These properties make it suitable for the long-term use in harsh operating *** attribute these properties to the electrostatic effect resulting from the amino group on UiO-66-NH_(2)and its in-situ growth on the CFM,which forms a size-screening separation *** work highlights the potential of the CFM@UiO-66-NH_(2)membrane as an environmentally friendly size-screening

关键词： Collagen fibers Metal-organic frameworks Oil-in-water emulsion separation Size sieving

Damage Characteristics Analysis and Fractal Study of Shale With Prefabricated Fractures under Thermal-mechanical Coupling

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 570-586页

作者：张辉邬忠虎 SONG Huailei WANG Wentao TANG Motian CUI Hengtao college of Civil engineering Guizhou UniversityGuiyang 550025China

To study the damage and failure of shale with different fracture inclination angles under uniaxial compression loading,in this work,RFPA2D-Thermal,a two-dimensional real failure process analysis software,was used for numerical *** simulation results show that quartz in shale mainly affects the tensile and compressive strength of shale by increasing rock *** coupling of temperature and pressure will cause lateral and volume destruction of shale,which enables the shale body to be more easily *** inclination is the key factor affecting shale damage *** failure mode of shale with low-and high-angle fractures is mainly shear failure,and the compressive strength does not vary with crack *** damage mode of obliquely intersecting fractured shale is slip damage along the fracture face,the compressive strength decreases and then increases with the fracture inclination,and a minimum value *** acoustic emission simulation results of the damage process effectively reflect the accumulated internal damage and macroscopic crack appearance until fracture instability when the prefabricated fractured shale is subjected to uniaxial compressive *** crack inclinations of 0°and 120℃ corresponds to the most complex"N"shape damage *** crack inclinations of 30°and 60°,and the damage mode is an inverted"λ"shape.

关键词： shale temperature and pressure numerical simulation fracture dip angle fractal dimension

Unveiling protein corona composition:predicting with resampling embedding and machine learning

在线全文

学校读者我要写书评

暂无评论

Regenerative Biomaterials 2024年第1期3卷 27-33页

作者： Rong Liao Yan Zhuang Xiangfeng Li Ke Chen Xingming Wang Cong Feng Guangfu Yin Xiangdong Zhu Jiangli Lin Xingdong Zhang college of Biomedical engineering National Engineering Research Centre for BiomaterialsSichuan UniversityChengdu610065China

Biomaterials with surface nanostructures effectively enhance protein secretion and stimulate tissue *** nanoparticles(NPs)enter the living system,they quickly interact with proteins in the body fluid,forming the protein corona(PC).The accurate prediction of the PC composition is critical for analyzing the osteoinductivity of biomaterials and guiding the reverse design of ***,achieving accurate predictions remains a significant *** several machine learning(ML)models like Random Forest(RF)have been used for PC prediction,they often fail to consider the extreme values in the abundance region of PC absorption and struggle to improve accuracy due to the imbalanced data *** this study,resampling embedding was introduced to resolve the issue of imbalanced distribution in PC *** ML models were evaluated,and RF model was finally used for prediction,and good correlation coefficient(R^(2))and root-mean-square deviation(RMSE)values were *** ablation experiments demonstrated that the proposed method achieved an R^(2) of 0.68,indicating an improvement of approximately 10%,and an RMSE of 0.90,representing a reduction of approximately 10%.Furthermore,through the verification of label-free quantification of four NPs:hydroxyapatite(HA),titanium dioxide(TiO_(2)),silicon dioxide(SiO_(2))and silver(Ag),and we achieved a prediction performance with an R^(2) value>0.70 using Random ***,the feature analysis revealed that the composition of the PC is most significantly influenced by the incubation plasma concentration,PDI and surface modification.

关键词： nanoparticles protein corona machine learming resampling technique feature analysis

Temperature prediction model in multiphase flow considering phase transition in the drilling operations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第3期21卷 1969-1979页

作者： Yang Zhang Yong-An Li Xiang-Wei Kong Hao Liu Teng-Fei Sun college of Mechanical and Electrical engineering Beijing University of Chemical Technology School of Petroleum engineering Yangtze University

The study considers gas compression properties, gas slippage, back pressure(BP), phase transition(PT),well depth, and differences in gas-liquid physical properties. A new temperature model for multiphase flow is proposed by considering phase transition in the drilling process. The mathematical model of multiphase flow is solved using the finite difference method with annulus mesh division for grid nodes,and a module for multiphase flow calculation and analysis is developed. Numerical results indicate that the temperature varies along the annulus with the variation of gas influx at the bottom of the *** the process of controlled pressure drilling, as gas slips along the annulus to the wellhead, its volume continuously expands, leading to an increase in the gas content within the annulus, and consequently, an increase in the pressure drop caused by gas slippage. The temperature increases with the increase in BP and decreases in gas influx rate and wellbore diameter. During gas influx, the thermal conductivity coefficient for the gas-drilling mud two phases is significantly weakened, resulting in a considerable change in temperature along the annulus. In the context of MPD, the method of slightly changing the temperature along the annulus by controlling the back pressure is feasible.

关键词： Managed pressure drilling Phase transition Temperature Gas-drilling mud two phase

Stimulated Raman scattering tomography for rapid three-dimensional chemical imaging of cells and tissue

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Advanced Photonics 2024年第2期6卷 20-31页

作者： Weiqi Wang Zhiwei Huang National University of Singapore College of Design and EngineeringOptical Bioimaging LaboratoryDepartment of Biomedical EngineeringSingapore

Three-dimensional(3D)imaging is essential for understanding intricate biological and biomedical systems,yet live cell and tissue imaging applications still face challenges due to constrained imaging speed and strong scattering in turbid ***,we present a unique phase-modulated stimulated Raman scattering tomography(PM-SRST)technique to achieve rapid label-free 3D chemical imaging in cells and *** accomplish PM-SRST,we utilize a spatial light modulator to electronically manipulate the focused Stokes beam along the needle Bessel pump beam for SRS tomography without the need for mechanical z *** demonstrate the rapid 3D imaging capability of PM-SRST by real-time monitoring of 3D Brownian motion of polystyrene beads in water with 8.5 Hz volume rate,as well as the instant biochemical responses to acetic acid stimulants in MCF-7 ***,combining the Bessel pump beam with a longer wavelength Stokes beam(NIR-II window)provides a superior scattering resilient ability in PM-SRST,enabling rapid tomography in deeper tissue *** PM-SRST technique providestwofold enhancement in imaging depth in highly scattering media(e.g.,polymer beads phantom and biotissue like porcine skin and brain tissue)compared with conventional point-scan *** also demonstrate the rapid 3D imaging ability of PM-SRST by observing the dynamic diffusion and uptake processes of deuterium oxide molecules into plant *** rapid PM-SRST developed can be used to facilitate label-free 3D chemical imaging of metabolic activities and functional dynamic processes of drug delivery and therapeutics in live cells and tissue.

关键词： stimulated Raman scattering tomography deep tissue Raman imaging spatial light modulation