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The effects of caudal fin deformation on the hydrodynamics of thunniform swimming under self-propulsion

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Journal of Hydrodynamics 2020年第6期32卷 1122-1137页

作者： Yi-kun Feng yu-min Su Huan-xing Liu yuan-yuan Su College of Shipbuilding Engineering Harbin Engineering UniversityHarbin150001China Beijing Institute of Specialized Machinery Beijing100081China Science College Harbin Engineering UniversityHarbin150001China

To investigate the effects of the caudal fin deformation on the hydrodynamic performance of the self-propelled thunniform swimming,we perform fluid-body interaction simulations for a tuna-like swimmer with thunniform *** 3-D vortices are visualized to reveal the role of the leading-edge vortex(LEV)in the thrust *** comparing the swimming velocity of the swimmer with different caudal fin flexure amplitudes fa,it is shown that the acceleration in the starting stage of the swimmer increases with the increase of fa,but its cruising velocity *** results indicate that the caudal fin deformation is beneficial to the fast start but not to the fast cruising of the *** the entire swimming process,the undulation amplitudes of the lateral velocity and the yawing angular velocity decrease as fa *** is found that the formation of an attached LEV on the caudal fin is responsible for generating the low-pressure region on the surface of the caudal fin,which contributes to the ***,the caudal fin deformation can delay the LEV shedding from the caudal fin,extending the duration of the low pressure on the caudal fin,which will cause the caudal fin to generate a drag-type force over a time period in one swimming cycle and reduce the cruising speed of the swimmer.

关键词： Computational fluid dynamics(CFD)numerical simulation self-propulsion caudal fin deformation

NUMERICAL AND EXPERIMENTAL STUDIES OF INFLUENCE OF THE CAUDAL FIN SHAPE ON THE PROPULSION PERFORMANCE OF A FLAPPING CAUDAL FIN

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Journal of Hydrodynamics 2011年第3期23卷 325-332页

作者： ZHANG Xi SU yu-min WANG Zhao-li State Key Laboratory of Autonomous Underwater Vehicle Harbin Engineering University Harbin 150001 China

This article presents a comprehensive study of the effects of the caudal fin shape on the propulsion performance of a candal fin in harmonic heaving and pitching. A numerical simulation based on an unsteady panel method was carried out to analyze the hydrodynamic performance of flapping caudal fins of three shapes （the whale caudal fin with the largest projected area, the dolphin caudal fin with the median projected area, and the tuna caudal fin with the smallest projected area）. Then, a series of hydrodynamic experiments for three caudal fin shapes were performed. Both computational and experimental results indicate that the tuna caudal fin produces the highest efficiency. However the mean thrust coefficient of the tuna caudal fin is the smallest. It is found that although the mean thrust coefficient for the tuna caudal fin is not large, the input power of the tuna caudal fin is also quite small. So the tuna caudal fin achieves a high efficiency.

关键词： flapping caudal fin caudal fin shape numerical simulations hydrodynamic experiments hydrodynamic performance

Lifetime Prediction and Reliability Evaluation of Si_(3)N_(4) Ceramic

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Chinese Physics Letters 1998年第6期15卷 441-443页

作者： ZONG Xiang-fu WANG Xu WENG yu-min Institute of Materials Science Fudan UniversityShanghai 200433

In this study,non-equilibrium statistical physics is used to estimate the time-dependent fracture of inhomogeneous Si_(3)N_(4) *** effects of structural inhomogeneity on mechanical properties of the Si3N4 ceramic are *** numerical calculations show that the average lifetime will increase by means of introducing suitable inhomogeneity in materials,but it is not monotonous.

关键词： ceramic

Electrooxidation of Hydroxypivalaldehyde in an Undivided Cell

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Chemical Research in Chinese Universities 2006年第5期22卷 626-630页

作者： yu Jian-guo CAO Xue-jing ZHANG Heng-bin ZHANG yu-min LI Ke-chang College of Chemistry Jilin University Changchun 130021 P. R. China

The factors affecting the electrooxidation of hydroxypivalaldehyde（HPAL） in an undivided cell were studied by using cyclic voltammetry（CV）, linear scan voltammetry（ LSV）, and potentiostatic electrolysis. The electrocatalytic activity and stability of a PbO2 electrode in sulfuric acid, acetic acid, and phosphoric acid were studied. The selectivity and the current efficiency for producing hydroxypivalic acid were explored with different supporting electrolytes, concentrations of HPAL, and pH values. The results show that higher selectivity and current efficiency for producing hydroxypivalic acid can be achieved when sulfuric acid with a high concentration is used as the supporting electrolyte and the selectivity and the current efficiency can reach 80% and 60%. resvectively.

关键词： Hydroxypivalaldehyde Hydroxypivalic acid Electrooxidation Electrosynthesis

Roles of Carbohydrate Supply and Ethylene,Polyamines in Maize Kernel Set

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Journal of Integrative Plant Biology 2011年第5期53卷 388-398页

作者： Han-yu Feng Zhi-min Wang Fan-Na Kong min-Jie Zhang Shun-Li Zhou College of Agronomy & Biotechnology China Agricultural University Beijing 100193 China

Glucose appears to have an antagonistic relationship with ethylene and ethylene and polyamines appear to play antagonistic roles in the abortion of seeds and fruits. Moreover, ethylene, spermidine, and spermine share a common biosynthetic precursor. The synchronous changes of them and the relationships with kernel set are currently unclear. Here, we stimulated maize （Zea mays L.） apical kernel set and studied their changes at 4, 8, 12, and 16 d after pollination （DAP）. The status of the apical kernels changed from abortion to set, showing a pattern similar to that of the middle kernels, with slow decrease in glucose and rapid decline in ethylene production, and a sharp increase in spermidine and spermine after four DAP. Synchronous changes in ethylene and spermidine were also observed. However, the ethylene production decreased slowly in the aborted apical kernels, the glucose and polyamines concentrations were lower. Ethephon application did not block the change from abortion to set for the setting apical kernels. These data indicate that the developmental change may be accompanied by an inhibition of adequate glucose to ethylene synthesis and subsequent promotion of spermidine and spermine synthesis, and adequate carbohydrate supply may play a key role in the developmental process.

关键词： Glucose Ethylene Spermine Spermidine Polyamines Abortion Antimetabolites Ethylene production Production Productivity

Simplicity, symmetry, and beauty of atomic nuclei

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Frontiers of physics 2018年第6期13卷 1-2页

作者： Jie Meng Takaharu Otsuka yu-min Zhao

Professor Akito Arima is an internationally renowned scientist, a most treasured and beloved colleague, friend and teacher to many nuclear physicists worldwide. Many colleagues have learned from him and enjoyed his be...

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An end-to-end text spotter with text relation networks

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Cybersecurity 2021年第1期4卷 91-103页

作者： Jianguo Jiang Baole Wei min yu Gang Li Boquan Li Chao Liu min Li Weiqing Huang Institute of Information Engineering Chinese Academy of SciencesBeijingChina School of Cyber Security University of Chinese Academy of ScienceBeijingChina Centre for Cyber Security Research and Innovation Deakin UniversityGeelongAustralia

Reading text in images automatically has become an attractive research topic in computer ***,end-to-end spotting of scene text has attracted significant research attention,and relatively ideal accuracy has been achieved on several ***,most of the existing works overlooked the semantic connection between the scene text instances,and had limitations in situations such as occlusion,blurring,and unseen characters,which result in some semantic information lost in the text *** relevance between texts generally lies in the scene *** the perspective of cognitive psychology,humans often combine the nearby easy-to-recognize texts to infer the unidentifiable *** this paper,we propose a novel graph-based method for intermediate semantic features enhancement,called Text Relation ***,we model the co-occurrence relationship of scene texts as a *** nodes in the graph represent the text instances in a scene image,and the corresponding semantic features are defined as representations of the *** relative positions between text instances are measured as the weights of edges in the established ***,a convolution operation is performed on the graph to aggregate semantic information and enhance the intermediate features corresponding to text *** evaluate the proposed method through comprehensive experiments on several mainstream benchmarks,and get highly competitive *** example,on the SCUT-CTW1500,our method surpasses the previous top works by 2.1%on the word spotting task.

关键词： Scene text spotting Graph convolutional network Visual reasoning

Moving Behavior of an Object in Gas-Solid Fluidized Beds

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Journal of China University of mining and Technology 2005年第1期15卷 7-11页

作者： WEILu-bin WANGGeng-yu HAOLiang ZHAOyue-min SchoolofChemicalandEnvironmentalEngineering ChinaUniversityofMining＆TechnologyBeijing100083China

The settling behavior of coarse particles in a gas-solid fluidized bed was experimentally studied by using magnetic tracer. It is well known that the calculation of terminal velocity is of interest in dense medium separation. However, this problem has not been completely solved up to now. In this work, the terminal velocity of an object mov-ing in a gas-solid fluidized bed was experimentally measured and theoretically calculated. The experimental results in-dicated that the plastic viscosity and yield stress of the bed increase as the size of fluidized particles increases, but it varies little when some coarser particles are mixed with the fluidized particles. The resistance to a rising object was an order magnitude greater than that to a settling object. The efficient buoyancy on a flaky object, which lies flatly on the gas distributor, was much less than that calculated by the Archimedes principle. The object does not always rise or set-tle with minimal projective area owing to radial motion of the fluidized particles. But in the lower part of the bed, the bar-shaped objects were likely with minimal projective area rising or settling.

关键词： object motion fluidized bed settling velocity coal dry beneficiation

t(4;11)translocation in hyperdiploid de novo adult acute myeloid leukemia:A case report

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World Journal of Clinical Cases 2022年第32期10卷 11980-11986页

作者： min-yu Zhang yue Zhao Ji-Hong Zhang Hematology Laboratory Shengjing Hospital of China Medical UniversityShenyang 110022Liaoning ProvinceChina

BACKGROUND MLL gene rearrangement is a common genetic abnormality of acute myeloid leukemia(AML),which predicts poor prognosis and is important in clinical *** rearrangement involves many chromosomes,among which,t(4;11)translocation is rare in *** present case was t(4;11)AML,accompanied by a hyperdiploid *** cases have not been reported *** SUMMARY An adult male with self-reported symptoms of fatigue,febrility and hyperleukocytosis was diagnosed with AML by morphology and confirmed by immunophenotype ***,chromosomal and fluorescence in situ hybridization(FISH)analysis showed a hyperdiploid karyotype with t(4;11)translocation and MLL rearrangement,and a negative MLL–AF4 fusion gene *** patient died of respiratory and circulatory failure 5 days after *** t(4;11)AML with hyperdiploid karyotype has not been *** this case,t(4;11)was only detected by karyotype analysis and FISH,suggesting their importance in MLL rearrangement detection.

关键词： Acute myeloid leukemia MLL gene rearrangement Translocation t(4 11) Hyperdiploid FISH Case report