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Numerical and experimental studies of hydrodynamics of flapping foils

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Journal of Hydrodynamics 2018年第2期30卷 258-266页

作者： Kai Zhou Jun-kao Liu wei-shan Chen College of Mechanical and Electronic Engineering Shandong Agricultural University Taian 271018 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin 150001 China

The flapping foil based on bionics is a sort of simplified models which imitate the motion of wings or fins of fish or birds. In this paper, a universal kinematic model with three degrees of freedom is adopted and the motion parallel to the flow direction is considered. The force coefficients, the torque coefficient, and the flow field characteristics are extracted and analyzed. Then the propulsive efficiency is calculated. The influence of the motion parameters on the hydrodynamic performance of the bionic foil is studied. The results show that the motion parameters play important roles in the hydrodynamic performance of the flapping foil. To validate the reliability of the numerical method used in this paper, an experiment platform is designed and verification experiments are carried out. Through the comparison, it is found that the numerical results compare well with the experimental results, to show that the adopted numerical method is reliable. The results of this paper provide a theoretical reference for the design of underwater vehicles based on the flapping propulsion.

关键词： Biological fluid dynamics flapping foil hydrodynamic performance numerical simulation

Costal cartilage graft in Asian rhinoplasty: surgical techniques

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Plastic and Aesthetic Research 2019年第4期6卷 1-10页

作者： Sarina Rajbhandari Chuan-Hsiang kao Department of Otolaryngology-Head and Neck Surgery Himal HospitalKathmandu 44600Nepal Department of Otolaryngology-Head and Neck Surgery Tri-Service General HospitalTaipei 11490Taiwan.

Asian rhinoplasty is a very common cosmetic *** Asians desire a higher nasal bridge,for which they undergo several procedures,including filler injections,implantations and insertion of *** encounter many patients who have had several procedures done on them *** this paper,we introduce the use of autologous grafts for Asian rhinoplasty(primary and secondary),and discuss the rib carving techniques and difficulties encountered during harvesting,carving and placements of grafts and how to overcome these problems and prevent complications.

关键词： Rhinoplasty costal cartilage Asians warping

Nitrogen fertilization has minimal influence on rhizosphere effects of smooth crabgrass (Digitaria ischaemum) and bermudagrass (Cynodon dactylon)

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Journal of Plant Ecology 2015年第4期8卷 390-400页

作者： Biao Zhu Kevin Panke-Buisse Jenny kao-Kniffin Earth Sciences Division Lawrence Berkeley National LaboratoryCyclotron RoadBerkeleyCA 94720USA School of Integrative Plant Science Cornell University134 Plant Sciences BuildingIthacaNY 14853USA

Aims Plants generally respond to nitrogen(N)fertilization with increased growth,but N addition can also suppress rhizosphere effects,which consequently alters soil *** quantified the influence of N addition on rhizosphere effects of two C4 grasses:smooth crabgrass(Digitaria ischaemum)and bermudagrass(Cynodon dactylon).Methods Plants were grown in nutrient-poor soil for 80 days with either 20 or 120μg NH4No3-N g dry soil−1.N mineralization rates,microbial biomass,extracellular enzyme activities and bacterial community structure were measured on both rhizosphere and bulk(unplanted)soils after plant *** Findings Fertilization showed nominal differences in net N mineralization,extracellular enzyme activity and microbial biomass between the rhizosphere and bulk soils,indicating minimal influence of N on rhizosphere ***,the presence of plant roots showed the strongest impact(up to 80%)on rates of net N mineralization and activities of three soil enzymes indicative of N release from organic *** component analysis of terminal restriction fragment length polymorphism(t-rFlP)also reflected these trends by highlighting the importance of plant roots in structuring the soil bacterial community,followed by plant species and N fertilization(to a minor extent).overall,the results indicate minor contributions of short-term N fertilization to changes in the magnitude of rhizos-phere effects for both grass species.

关键词： rhizosphere effect N fertilization belowground carbon allocation microbial biomass extracellular enzyme net N mineralization microbial community composition

AN EXPERIMENTAL OBSERVATION OF A SOLITARY WAVE IMPINGE-MENT,RUN-UP AND OVERTOPPING ON A SEAWALL

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Journal of Hydrodynamics 2012年第1期24卷 76-85页

作者： LIN Ting-Chieh HWANG kao-Shu HSIAO Shih-Chun YANG Ray-Yeng Tainan Hydraulics Laboratory National Cheng Kung UniversityTainan 701 Department of Hydraulic and Ocean Engineering National Cheng Kung UniversityTainan 701 Tainan Hydraulics Laboratory and Department of Hydraulic and Ocean Engineering National Cheng Kung UniversityTainan 701

A sequence of laboratory experiments using solitary waves was performed to model the effect of leading form of three types of tsunamis（a bore,an impinging wave and an overtopping wave）on a seawall on a sloping *** wave evolution process,impinging pressure along the seawall surface,total overtopping discharge behind the seawall and the maximum run-up height on the rear slope were measured and *** data were employed to re-examine relevant empirical formulae in the *** effect of the presence of the seawall in reducing maximum run-up height using the present setup was briefly *** present data can be used for calibrating numerical and mathematical models.

关键词： solitary wave tsunami wave force run-up overtopping

A novel structural modeling and analysis of VLSI interconnect with an RLC tree network system using a BG/SEBD approach

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Science China(Information Sciences) 2011年第9期54卷 1968-1985页

作者： CHANG RueyFong kao wenShiow TSENG KuoHsiung HUANG ShihYing Department of Electrical Engineering National Taipei University of Technology Department of Environmental Resources Management Transworld Institute of Technology

A practical and effective novel graphical structural modeling and analysis approach is *** approach is used for solving the state interactions modeling problem caused by the model approximations in VLSI interconnect for RLC tree network *** bond graph (BG) energy model with a simulink energy-based block diagram (SEBD) algorithm is *** dynamic behaviors of an example of VLSI interconnect with a 20th-order RLC tree are *** of sequent structuring and the delineation of dynamic interactions can be provided for users applying the BG/SEBD algorithms in the development of structural *** is shown that the new BG/SEBD structural modeling approach requires neither mathematical higher-order reduction nor physically based model ***,useful information can be extracted from the BG/SEBD representation of physical RLC tree network *** time-domain and frequency-domain simulation results are applied to analyze the dynamic response of energy-storing elements using BG/SEBD algorithm combined with Matlab/Simulink ***,a causal analysis of the system zeros plot from the shortest causal path method is proposed,to predict the dynamic response of energy-storing elements and the system performance for design and verification *** dynamic response outputs from different node points were revealed,and the obtained physical information is significant which suggests feasible directions for design (re-design) improvement toward better overall system performance.

关键词： higher-order RLC tree interconnect network (RLC-TIN) bond graph (BG) structural modeling time-domain and frequency-domain analysis causality analysis

Coupled modified Kd V equations, skew orthogonal polynomials, convergence acceleration algorithms and Laurent property

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Science China Mathematics 2018年第6期61卷 1063-1078页

作者： Xiangke Chang Yi He Xingbiao Hu Shihao Li hon-wah Tam Yingnan Zhang LSEC ICMSEC Academy of Mathematics and Systems ScienceChinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Department of Computer Science Hong Kong Baptist University School of Mathematical Sciences Nanjing Normal University

In this paper, we show that the coupled modified Kd V equations possess rich mathematical structures and some remarkable properties. The connections between the system and skew orthogonal polynomials,convergence accel... 详细信息

关键词： integrable system skew orthogonal polynomial convergence acceleration algorithm Laurent prop-erty

Guided Intra-Patch Smoothing Graph Filtering for Single-Image Denoising

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Computers, Materials & Continua 2021年第10期69卷 67-80页

作者： Yibin Tang Ying Chen Aimin Jiang Jian Li Yan Zhou hon Keung Kwan College of Internet of Things Engineering Hohai UniversityChangzhou213022China School of Microelectronics and Control Engineering Changzhou UniversityChangzhou213022China Department of Electrical Engineering University of WindsorOntarioN9B 3P4Canada

Graph filtering is an important part of graph signal processing and a useful tool for image *** graph filtering methods,such as adaptive weighted graph filtering(AWGF),focus on coefficient shrinkage strategies in a graph-frequency ***,they seldom consider the image attributes in their graph-filtering ***,the denoising performance of graph filtering is barely comparable with that of other state-of-the-art denoising *** fully exploit the image attributes,we propose a guided intra-patch smoothing AWGF(AWGF-GPS)method for single-image *** AWGF,which employs graph topology on patches,AWGF-GPS learns the topology of superpixels by introducing the pixel smoothing attribute of a *** operation forces the restored pixels to smoothly evolve in local areas,where both intra-and inter-patch relationships of the image are utilized during patch ***,a guided-patch regularizer is incorporated into *** guided patch is obtained in advance using a maximum-a-posteriori probability *** the guided patch is considered as a sketch of a denoised patch,AWGF-GPS can effectively supervise patch restoration during graph filtering to increase the reliability of the denoised *** demonstrate that the AWGF-GPS method suitably rebuilds denoising *** outperforms most state-of-the-art single-image denoising methods and is competitive with certain deep-learning *** particular,it has the advantage of managing images with significant noise.

关键词： Graph filtering image denoising MAP estimation superpixel

A rotary ultrasonic motor using radial bending mode of ring with nested PZT excitation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第3期13卷 189-196页

作者： Ying-xiang LIU Jun-kao LIU wei-shan CHEN Xiao-hui YANG State Key Laboratory of Robotics and System Harbin Institute of Technology Horbin 150001 China

This study presents and verifies a new idea for constructing a rotary traveling wave ultrasonic motor （USM） that uses the radial bending mode of a ring. In the new design, 20 trapezoid cross section slots are cut symmetrically in the outer surface of a thick duralumin alloy ring, where 20 PZT stacks are nested. In each slot, two wedging blocks are set between the PZT stack and the two sides of the slot respectively to apply preloading on the PZT ceramics. Two radial bending modes of the stator that have a phase difference of a quarter wavelength on space are generated by using the d33 operating mode of the PZT elements, and then a flexural traveling wave is formed by the superimposing of two standing waves whose amplitudes are equal and phases are different by 90~ temporally. Two conical rotors are pressed to each end of the ring type stator by a coiled spring. The finite element method （FEM） simulation is developed to validate the feasibility of the proposed motor. The maximal speed and torque of the prototype are tested to be 126 r/rain and 0.8 N＇m, respectively.

关键词： Rotary ultrasonic motor Radial bending mode Traveling wave wedging block clamped structure

Taxonomic composition, abundance and biomass of mesozooplankton in the Zhelin Bay—an estuary with intensive aquaculture

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Acta Oceanologica Sinica 2006年第5期25卷 92-111页

作者： DONG Qiaoxiang LIN Xiaoping HE Xin KELSO we HUANG Changjiang School of Environmental Science and Public Health Wenzhou Medical College Wenzhou 325035 China Institute of Marine Biology Shantou University Shantou 515063 China School of Renewable Natural Resources Louisiana State University Agricultural Center Baton Rouge Louisiana 70803 USA

The Zhelin Bay is an estuary that supports intensive aquaculture in South China. Aside from traditional nutrient inputs derived from waste water and agriculture, the increased intensification of aquaculture has accelerated eutrophication during the past deeade, jeopardizing aquacultural production. Annual variations of mesozooplankton in the Zhelin Bay were described, providing baseline data for long-term ecological studies. The taxonomic composition, abundance and biomass of mesozooplankton were stud- ied monthly from July 2001 to July 2002 at 19 stations. Collections yielded 73 taxa, including 60 species of eopopods, three species of cladocerans, as well as tunieates, ehaetognaths, polyehaetes, medusae, ostraceds, rotatori, amphipods, planktonic mollusks, pelagic larvae, and planktonic shrimps. The Zhelin Bay was dominated by small mesozooplankton, with 76% of the species smaller than 1.4 mm, and 97% of the individuals smaller than 1.0 nun. Dominant species （ Paracalanus crassirostris, Oithona brevicornis, and Penilia avirostria） accounting for 60% of the total abundance were less than 0.6 mm in body length. Species diversity, biomass, and total abundance of mesozooplankton were greater in the samples collected outside the bay than inside the bay. Samples from the outer and eastern boundaries of the bay had greater biomass, diversity, and abundance than those from the inner and western boundaries. Total abundance and biomass had a unimodal annual pattern and were the greatest in August 2001 when water temperature was maximum, and the least in February 2002 when water temperature was minimum. Canonical correspondence analysis （CCA） revealed that temperature, turbidity, nutrients and salinity were the main determinants of spatial and temporal distributions of mesozooplankton in the Zhelin Bay, and six distinct zones were identified across the 19 sampling stations.

关键词： Zhelin Bay mesozooplankton community structure spatial and temporal distribution aquaculture