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Investigation of wake-induced vibration interference between two staggered wave-cone cylinders at subcritical Reynolds number

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Journal of Hydrodynamics 2024年第2期36卷 378-393页

作者： lin Zou Di-wei Liu Jian Liu Hong-cheng Zuo yin-huan Zheng Hao Xia School of Mechanical and Electronic Engineering Wuhan University of TechnologyWuhan430070China Department of Aeronautical and Automotive Engineering Loughborough UniversityLoughboroughUK

The wake induced vibration(WIV)of a one-and two-degree-of-freedom(1DOF,2DOF)downstream wave-cone cylinder(WCC)behind a stationary equal-size upstream wave-cone cylinder in the staggered arrangement is numerically investigated at subcritical Reynolds number of 3900 by using shear stressed transfer(SST)k-ωturbulence *** streamwise pitch ratios(P/Dm)vary from 4 to 6 with a fixed incident angleα=8°.Experimental measurements were also performed for the validation of the present numerical *** is found that the largest vibration amplitude in crossflow direction occurred at P/Dm=4,Ur=8 with small difference of streamwise vibration at P/Dm=4,*** from single wavy-cone cylinder(SWCC),the downstream flexible one of a pair staggered WCCs got larger vibration amplitude during phase switching stage instead of in-phase *** upstream wake will suppress the triple frequency of main frequency in the power spectra density(PSD)functions of Cl but stimulate the double one of *** intriguing vibration mechanism happened in all 2DOF cases where the trajectory of downstream WCC is a significant ellipse rather than a figure of *** transformation of phase switching and the variation of the main frequency of drag coefficient(Cd)can be explained by the vortex-shedding modes of downstream WCC.

关键词： Two wave-cone cylinders staggered arrangement wake induced vibration phase switching vortex shedding

The Existence of a Meridional Curve in Closed Incompressible Surfaces in Fully Alternating link Complements

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Chinese Annals of Mathematics,Series B 2024年第1期45卷 73-80页

作者： wei lin School of Mathematical Sciences Dalian University of TechnologyDalian 116024LiaoningChina

Menasco showed that a closed incompressible surface in the complement of a non-split prime alternating link in S^(3) contains a circle isotopic in the link complement to a meridian of the *** on this result,he was able to argue the hyperbolicity of non-split prime alternating links in *** et *** that if F■S×I\L is an essential torus,then F contains a circle which is isotopic in S×I\L to a meridian of *** author generalizes his result as follows:Let S be a closed orientable surface,L be a fully alternating link in S×I\If F ■ S×I\L is a closed essential surface,then F contains a circle which is isotopic in S×I\L to a meridian of L.

关键词： Fully alternating Incompressible surfaces Meridionally incompressible

Nutrient transport following water transfer through the world's largest water diversion channel

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Journal of Environmental Sciences 2024年第1期135卷 703-714页

作者： Yuanhui Cheng Hong Zhang wei yin State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085 China Changjiang Water Resources Protection Institute Wuhan 430051China University of Chinese Academy of Sciences Beijing 100049China

Nutrient levels in the artificial channel constructed for the Middle Route Project are significant indicators of water quality safety and aquatic ecological integrity for this large,interbasin ***,the distribution and transport of nutrients along the channel were poorly *** on a time-series dataset as well as mass balance and material flow analysis methods,the water and nutrient transport fluxes in the Middle Route of the South-to-North Water Diversion Project were identified in this *** results indicate that the nutrient concentrations varied considerably with time,but there was no significant difference among the 30 stations of the main *** temperature difference was the major factor in the large fluctuations of water quality indicators over *** nutrient loadings varied with the water volume outputs from the main channel to the waterreceiving *** deposition was an important source of nutrients in the main channel,accounting for 9.13%,20.6%,and 0.635%of the nitrogen,phosphorus,and sulfur input from the Danjiangkou Reservoir,*** 2021,a net accumulation of 988 tons of N,29 tons of P,and 2,540 tons of S,respectively,were present in the main *** increase of these external and internal nutrient loadings would cause water quality fluctuation and deterioration in some local sections of the main *** study quantified the spatial and temporal patterns of nutrient transport in the Middle Route and revealed the ecological effects on the aquatic environment,assisting authorities on the project to develop effective water conservation strategies.

关键词： Nutrient transport Spatiotemporal patterns The Middle Route The South-to-North Diversion Project Hydro-ecological effects Water-receiving cities

Monotonic mechanical behaviour of compacted completely decomposed granite with various inclusion levels of incineration bottom ash

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第8期25卷 670-679页

作者： Han-lin WANG Cheng-Shuang yin Qian-Yi ZHANG Qi-wei LIU Zhen-Yu yin Dong-Xing XUAN Askar KHASANOV Research Center for Advanced Underground Space Technologies of Hunan University Changsha 410082China Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education Hunan UniversityChangsha 410082China College of Civil Engineering Hunan UniversityChangsha 410082China School of Civil Engineering Zhengzhou UniversityZhengzhou 450001China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Department of Applied and Theoretical Mechanics Samarkand State UniversitySamarkandUzbekistan

1 Introduction Completely decomposed granite(CDG)is widely distributed in South China(Xu et al.,2022;Wang et al.,2023).The parent granite rock mass gradually loses features during the weathering process,and thus needs to be reinforced when used(Lan et al.,2003;Dassekpo et al.,2017;Alamanis et al.,2021).On the other hand,considering the huge demand for construction materials and limited natural resources,it is increasingly important to fully utilize solid waste(Gruhler et al.,2019;Anagnostopoulos et al.,2020;Jiang et al.,2022,2023a,2023b).With high strength and environment-friendly characteristics,incineration bottom ash(IBA)seems to be a suitable reinforcement material for CDG(Ahmed and Khalid,2011;Alhassan and Tankó,2012;Toraldo et al.,2013;Lynn et al.,2017;Xuan et al.,2018;Tang et al.,2020).

关键词： incineration behaviour utilize

Analytic optimal pose tracking control in close-range proximity operations with a non-cooperative target

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Chinese Journal of Aeronautics 2024年第5期37卷 410-425页

作者： Caisheng wei Guanhua HUANG Zeyang yin Qifeng CHEN School of Automation Central South UniversityChangsha 410083China

This paper investigates an analytical optimal pose tracking control problem for chaser spacecraft during the close-range proximity operations with a non-cooperative space target subject to attitude tumbling and unknown orbital ***,the relative translational motion between the orbital target and the chaser spacecraft is described in the line-of-Sight(LOS)coordinate frame along with attitude quaternion ***,based on the coupled 6-Degree of Freedom(DOF)pose dynamic model,an analytical optimal control action consisting of constrained optimal control value,application time and its duration are proposed via exploring the iterative sequential action control ***,the global closed-loop asymptotic stability of the proposed predictive control action is presented and *** with traditional proximity control schemes,the highlighting advantages are that the application time and duration of the devised controller is applied discretely in light of the influence of the instantaneous pose configuration on the pose tracking performance with less energy consumptions rather than at each sample ***,three groups of illustrative examples are organized to validate the effectiveness of the proposed analytical optimal pose tracking control scheme.

关键词： Optimal control Close-range proximity operation Non-cooperative space target Coupled attitude and orbit control Iterative sequential action control

Low-Brightness Object Recognition Based on Deep Learning

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Computers, Materials & Continua 2024年第5期79卷 1757-1773页

作者： Shu-yin Chiang Ting-Yu lin Department of Information and Telecommunications Engineering Ming Chuan UniversityTaoyuan City333Taiwan

This research focuses on addressing the challenges associated with image detection in low-light environments,particularly by applying artificial intelligence techniques to machine vision and object recognition *** primary goal is to tackle issues related to recognizing objects with low brightness *** this study,the Intel RealSense Lidar Camera L515 is used to simultaneously capture color information and 16-bit depth information *** detection scenarios are categorized into normal brightness and low brightness *** the system determines a normal brightness environment,normal brightness images are recognized using deep learning *** low-brightness situations,three methods are proposed for *** first method is the SegmentationwithDepth image(SD)methodwhich involves segmenting the depth image,creating amask from the segmented depth image,mapping the obtained mask onto the true color(RGB)image to obtain a backgroundreduced RGB image,and recognizing the segmented *** second method is theHDVmethod(hue,depth,value)which combines RGB images converted to HSV images(hue,saturation,value)with depth images D to form HDV images for *** third method is the HSD(hue,saturation,depth)method which similarly combines RGB images converted to HSV images with depth images D to form HSD images for *** experimental results,in normal brightness environments,the average recognition rate obtained using image recognition methods is 91%.For low-brightness environments,using the SD method with original images for training and segmented images for recognition achieves an average recognition rate of over 82%.TheHDVmethod achieves an average recognition rate of over 70%,while the HSD method achieves an average recognition rate of over 84%.The HSD method allows for a quick and convenient low-light object recognition *** research outcome can be applied to nighttime surveillance systems or nighttime road safety systems

关键词： Low-brightness depth image image segmentation image recognition HDV HSD

Polyelectrolytes of Inorganic Polyoxometalates:Prospecting New Charged Polymers for Advanced Applications

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Chinese Journal of Polymer Science 2024年第9期42卷 1254-1269,I0005页

作者： De-yin Wang Zhuo-Qun Lu wei Wang College of Medical Linyi UniversityLinyi276000China Center for Synthetic Soft Materials Key Laboratory of Functional Polymer Materials of the Ministry of EducationInstitute of Polymer ChemistryNankai UniversityTianjin300071China

Polyelectrolytes are charged polymers comprising macromolecules in which substantial portions of the constituent units contain cationic(e.g.,pyridinium,ammonium)or anionic(e.g.,sulfonate,carboxylate)groups,which possess special functions from the features of counterions,such as dissociation to charged species,mechanical stability,phase behavior,***,functional polyelectrolytes have been widely applied in many *** this perspective,we present some progresses in the studies of poly(polyoxometalate)s,denoted as poly(POM)s,as a kind of new charged polymers/polyelectrolytes,by covalent bonding between the inorganic polyoxometalate(POM)clusters and the organic polymer *** to the distinct positions of POMs in polymer chain and functions of poly(POM)s,they are divided into the following four categories:crosslinked poly(POM);side-chain poly(POM);backbone poly(POM),including poly(POM)-conjugated polymer hybrid and block poly(POM)-polymer;and POM-based covalent organic framework(PCOF).This perspective introduces the synthesis methods of poly(POM)polyelectrolytes and their macromolecular and aggregate structural characteristics,while also focusing on their properties and *** application areas include catalysis,thermal resistance,optical functions,fuel cells and batteries,etc.

关键词： Charged polymer Polyelectrolyte Polyoxometalate Poly(polyoxometalate) Covalent organic framework

Transient features of graphitization and nitrogen-vacancy color centers in a diamond fabricated by localization femtosecond laser direct writing

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Science China(Technological Sciences) 2024年第8期67卷 2530-2536页

作者： CUI lin yin SiYu HU ZiFan WANG Lei State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130012China

Femtosecond laser direct writing provides an efficient approach to fabricating single nitrogen vacancy(NV) color centers with a relatively high yield. Different from previously reported NV color centers with a random distribution in a bulk diamond or nanocrystals, this gives an opportunity to study the photophysical properties of single NV color centers with precise numbers and positions. However, ultrafast studies on single NV color centers prepared by localization femtosecond laser direct writing are still rare, especially for the graphitization inside a diamond and its relationship with single NV color centers. Here, we report the broadband transient absorption(TA) spectroscopic features of the graphitization and NV color centers in a diamond fabricated by localization femtosecond laser direct writing at room temperature under 400 nm excitation. In comparison with the graphene oxide film, the bleaching features of the graphitization point array in a diamond are similar to reduced graphene oxide,accompanied by excited state absorption signals from local carbon atom vacancy defects in graphene-like structures induced by laser writing. On the other hand, transient features of laser processing array containing single NV color centers with a yield of~50% are different from those of the graphitization point array. Our findings suggest that for ultrashort pulse processing of diamonds, broadband TA spectral signals are sensitive to the surrounding atomic environment of processing sites, which could be applied to laser writing point defects in other materials used as solid-state single photon sources.

关键词： nitrogen-vacancy color center graphitization diamond femtosecond laser direct writing ultrafast spectroscopy

Magnetic Fields Reduce Apoptosis by Suppressing Phase Separation of Tau-441

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Research 2024年第1期2023卷 181-197页

作者： Wen-Juan lin Wen-Pu Shi Wan-Yi Ge Liang-Liang Chen wei-Hong Guo Peng Shang Da-Chuan yin Key Laboratory for Space Bioscience and Biotechnology School of Life SciencesNorthwestern Polytechnical University127 Youyixi RoadXi'an 710072ShaanxiPR China

The biological effects of magnetic fields(MFs)have been a controversial ***,in recent years,there has been increasing evidence that MFs do affect biological ***,the physical mechanism remains ***,we show that MFs(16 T)reduce apoptosis in cell lines by inhibiting liquid–liquid phase separation(LLPS)of Tau-441,suggesting that the MF effect on LLPS may be one of the mechanisms for understanding the“mysterious”magnetobiological *** LLPS of Tau-441 occurred in the cytoplasm after induction with *** phase-separated droplets of Tau-441 recruited hexokinase(HK),resulting in a decrease in the amount of free HK in the *** cells,HK and Bax compete to bind to the voltage-dependent anion channel(VDAC I)on the mitochondrial membrane.A decrease in the number of free HK molecules increased the chance of Bax binding to VDAC I,leading to increased Bax-mediated *** the presence of a static MF,LLPS was marked inhibited and HK recruitment was reduced,resulting in an increased probability of HK binding to VDAC I and a decreased probability of Bax binding to VDAC I,thus reducing Bax-mediated *** findings revealed a new physical mechanism for understanding magnetobiological effects from the perspective of *** addition,these results show the potential applications of physical environments,such as MFs in this study,in the treatment of LLPS-related diseases.

关键词： inhibited Apoptosis finding