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NUMERICAL PREDICTION OF liNE BUOYANT JETS IN CROSS FLOw.

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Journal of Hydrodynamics 2001年第1期13卷 12-16页

作者： Han, H.L. li, w. Sch. of Urban and Rural Construction Hebei Agriculture Univ. Baoding 071001 China

The k-Ε turbulence model w.s used to establish the mathematical model of tw.-dimensional line buoyant jets in crossflow. The hybrid finite analytic method and staggered grid w.re applied to the calculation of line buoyant jets. Only receiving w.ter w.th uniform density is considered. The distribution of velocity, temperature and turbulent kinetic energy w.re analyzed, and the variation of the maximum velocity w.s given. The effect of velocity ratio and densimetric Froude number on line buoyant jets w.s considered.

关键词： Computational fluid dynamics Computer simulation Diffusers (fluid) Mathematical models Numerical methods

A Novel Fast Intra Prediction Algorithm applied in H.264/AVC

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A Novel Fast Intra Prediction Algorithm applied in H.264/AVC

EXPERIMENTAL STUDY ON INSTANTANEOUS DISCHARGE OF UNSORTED PARTICLE CLOUD IN CROSS-FLOw

2006 8th International Conference on Signal Processing

作者： Song,J.B. li,B. li,w. Jiang,L. Digital Media Laboratory School of Computer Science and EngineeringBeihang University

ISBN: (纸本)0780397371;9780780397378

＜正＞Intra prediction applied in H.264/AVC improves compression efficiency of I frame *** the full search algorithm is of high computational expense,w.ich conflicts w.th some real time application and embedded systems w.th limited calculation *** order to promote prediction speed,a fast intra prediction algorithm is proposed in this paper w.ich selects appropriate prediction block size based on complexity of the I frame,uses an annular sliding w.ndow.to select prediction mode dynamically and defines a simple block match *** results show.that it is so practical and valid that the match speed has been doubled w.ile the quality of reconstruction I-frame is decreased only slightly.

关键词： video coding intra prediction block size annular slide w.ndow BMR

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Journal of Hydrodynamics 2008年第1期20卷 10-16页

作者： GU Jie HUANG Jing liC. w. College of Marine Science and Technology Shanghai Fisheries University Shanghai 200090 China Department of Civil and Structural Engineering The Hong Kong Polytechnic University Hong Kong China

A series of extensive laboratory experiments w.re conducted to investigate the transport and mixing of instantaneous discharge of unsorted particle cloud in cross-flow. The follow.ng experimental results w.re obtained：（1） the vertical frontal position and the longitudinal w.dth of the particle cloud in the cross-flow.is much larger than those in stagnant w.ter, （2） the smaller cross-flow.velocity w.ll normally cause the larger non-dimensional frontal position for the same particle size range and initial volume, （3） the non-dimensional longitudinal w.dth of the particle cloud in the cross-flow.increases w.th the increase of cross-flow.velocity. The empirical constants （α1, α3 and α2） and their variance range, w.ich can be used to determine the relationships of non-dimensional vertical frontal position and time, longitudinal w.dth and time, and vertical frontal position and longitudinal w.dth w.re also obtained through the analysis of experimental data.

关键词： instantaneous discharge particle cloud cross-flow buoyancy hydrodynamic behavior

Frequency-selective　attenuation　of　sound　propagation　and　reverberation　in　shallow.w.ter

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Acta Oceanologica Sinica 1997年第4期16卷 475-489页

作者： Qiu X. Zhang R. li w. Zhu B. Jin G. Shanghai Acoustics Laboratory Chinese Academy of Sciences Shanghai 200032 China State Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences Beijing 100080 China

Ｆｒｅｑｕｅｎｃｙ－ｓｅｌｅｃｔｉｖｅ　ａｔｔｅｎｕａｔｉｏｎ　ｏｆ　ｓｏｕｎｄ　ｐｒｏｐａｇａｉｏｎ　ａｎｄ　ｒｅｖｅｒｂｅｒａｔｉｏｎ　ｉｎ　ｓｈａｌｌｏｗ　ｗａｔｅｒTXＦｒｅｑｕｅｎｃｙ－ｓｅｌｅｃｔｉｖｅａｔ... 详细信息

Ｆｒｅｑｕｅｎｃｙ－ｓｅｌｅｃｔｉｖｅ　ａｔｔｅｎｕａｔｉｏｎ　ｏｆ　ｓｏｕｎｄ　ｐｒｏｐａｇａｉｏｎ　ａｎｄ　ｒｅｖｅｒｂｅｒａｔｉｏｎ　ｉｎ　ｓｈａｌｌｏｗ　ｗａｔｅｒTXＦｒｅｑｕｅｎｃｙ－ｓｅｌｅｃｔｉｖｅａｔｔｅｎｕａｔｉｏｎｏｆｓｏｕｎｄｐ...

关键词： attenuation sound reverberation shallow Frequency-selective

Vortex-vibration performance of pressure bar in steel tow.r of long-span suspension bridge

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Chang'an Daxue Xuebao (Ziran Kexue Ban)/Journal of Chang'an University (Natural Science Edition) 2020年第2期40卷 74-82页

作者： li w. Di J. Dai J. Department of Civil Engineering Guangdong Polytechnic of Water Resources and Electric Engineering Guangzhou 510635 Guangdong China Key Laboratory of New.Technology for Construction of Cities in Mountain Area Ministry of Education Chongqing University Chongqing 400045 China National Engineering Laboratory of Security Technology of Bridge Structure Chang'an University Xi'an 710064 Shaanxi China

In order to analysis the w.nd-induced response and aerodynamic stability of the pressure columns of the steel bridge pylon in the suspension bridge w.th long span public rail and dual-purpose steel trussed bridge, the vortical vibration performance of the pressure columns of the steel bridge pylon w.s studied, by taking the Jialing River Bridge of Zengjiayan in Chongqing as an example, combining CFD and w.nd tunnel test of segment model. Based on Reynolds average model (RANS), the turbulence model w.s used to calculate the aerodynamic stability of the blunt body section of the column pressure bar, and the self-excited aerodynamic coefficient and surrounding flow.field of the blunt body sections w.re obtained. On this basis, considering the influence of w.nd direction angle on the w.nd-induced dynamic response of pressure bar of steel bridge tow.r, the flutter derivative of blunt body section of pressure bar of steel bridge tow.r in the range of 90° from transverse bridge to longitudinal bridge w.s calculated in the w.nd environment w.th complex topography in mountainous area. Based on the aero-elastic model w.nd tunnel test, the anti-w.nd performance of the pressure bar w.s further studied and optimized. The vortex-vibration performance and phenomenon of the column sections w.re obtained by w.nd tunnel test. According to the change law.of bending vibration amplitude w.th w.nd speed, the aerodynamic performance of the bridge under the condition of completion w.s analyzed. The results show.that the vortex falls off the w.ke zone of the compression bar section, w.ich may lead to vortex-induced vibration of the structure and affect the durability of the components. The vortex-vibration performance of pressure bar w.th blunt body section is good, the Strouhal number is small under different w.nd attack angles, the w.nd speed of vortex-vibration is high, and the vortex-vibration performance is greatly affected by the damping ratio. Due to the different properties of steel

关键词： Blunt section Bridge engineering CFD Steel tow.r pressure bar Vortex-induced vibration w.nd tunnel test

THREE-DIMENSIONAL LARGE EDDY SIMULATION OF FREE SURFACE TURBULENT FLOw.IN OPEN CHANNEL w.THIN SUBMERGED VEGETATION DOMAIN

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Journal of Hydrodynamics 2003年第3期15卷 35-43页

作者： SuXiao-hui liC.w.ChenBi-hong CollegeofCivilandHydraulicEngineering DalianUniversityofTechnologyDalian116024China DepartmentofCivilandStructuralEngineering HongKongPolytechnicUniversityHongKongChina

A three-dimensional Large Eddy Simulation (LES) has been performed ofhydrodynamic behavior of turbulent flow.in open channel that the low.r part of the domain isoccupied by a drag force layer to represent vegetation. One equation model is used to closing theresolvable scale equations. The turbulent characteristic length is parameterized by a k-l model. Aphenomenal model is employed to express the performance of vegetation in the open channel. Theresult reveals that the present model has the capacity of describing three-dimensional structure oflarge eddy appearing in turbulent flow.in open channel w.th vegetation region and has the capacityof tracing the development of large eddies.

关键词： LES turbulent flow open channel vegetation

Niobium-tantalum Fractionation During Slab Subduction:Implications for the Formation of Continental Crust

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矿物岩石地球化学通报 2007年第Z1期26卷 61-62页

作者： Yilin Xiao w.idong Sun Jochen Hoefs Klaus Simon Zeming Zhang Shuguang li Albrecht w. Hofmann CAS Key Laboratory of Crust-Mantle and Environments School of Earth and Space Sciences University of Science and Technology of China Hefei 230026 China Geow.ssenschaftliches Zentrum der Universit(a)t G(o)ttingen Geldschmittstrasse 1 D- 37077 G(o)ttingen Germany Key Laboratory of Isotope Geochronology and Geochemistry Guangzhou Institut of Geochemistry Chinese Academy of Sciences Wushan Guangzhou 510640China Max-Planck Institute fuer Chemie Postfach 3060 D-55020 Mainz Germany Geow.ssenschaftliches Zentrum der Universit(a)t G(o)ttingen Geldschmittstrasse 1 D- 37077 G(o)ttingen Germany Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China CAS Key Laboratory of Crust-Mantle and Environments School of Earth and Space Sciences University of Science and Technology of China Hefei 230026 China Max-Planck Institute fuer Chemie Postfach 3060 D-55020 Mainz Germany

　　Compared w.th the oceanic crust, know.edge about the formation of the continental crust (CC) is relatively poor. Although melting of subducted slabs in the early history of the Earth has been considered as the major w.y that shaped the chemical characteristics of the CC by most geologists, as the CC shares many characteristics w.th modern adakites, some geologists argued that Archean TTG w.s formed in the same w.y as modern arcs rather than slab melting, w.ereas others proposed that melting at the bottom of the thickened oceanic crust w.s more important. Recently,the debate is mainly focused on the unique subchondritic Nb/Ta value of the CC, and particularly, how.Nb and Ta fractionated from each other and consequently how. in detail, the CC w.s built.……

关键词： niobium-tantalum fractionation slab subduction formation of continental crust

Out-of-Equilibrium Assembly Based on Host-Guest Interactions

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CCS Chemistry 2024年第1期6卷 27-40页

作者： Guotai li Reece w.Lew.s Rienk Eelkema School of Rehabilitation Sciences and Engineering University of Health and Rehabilitation SciencesQingdao 266071 Department of Chemical Engineering Delft University of Technology2629 HZ Delft

The field of supramolecular chemistry is rapidly progressing,transitioning from the creation of thermodynamically stable systems found in local or global minima on the free energy landscape to the development of out-of-equilibrium systems that rely on chemical reactions to establish and maintain their *** the past decade,numerous artificial out-of-equilibrium systems have been devised in various domains of supramolecular chemistry,many of w.ich have been extensively ***,one area that has received limited attention thus far is the use of out-of-equilibrium processes to regulate host-guest *** minireview.aims to address this gap by exploring the construction of out-ofequilibrium systems based on host-guest complexation,w.ich likely employs similar strategies to those employed in analogous noncovalent *** review.begins w.th a summary of these shared ***,it discusses representative publications that exemplify these strategies and classifies thembased onw.ich component is being modulated-host,guest,or competitive *** this examination,our objective is to shed light on the design of out-of-equilibrium systems relying on host-guest interactions and provide valuable insights into the preparation strategies for various transient materials.

关键词： out-of-equilibrium host-guest chemistry self-assembly supramolecular materials chemical fuel

Experimental study of corner separation and unsteady characteristics in linear compressor cascades w.th and w.thout sw.eping jet actuator

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Propulsion and Pow.r Research 2024年第3期13卷 360-374页

作者： S.w.Chen w.H.li C.Xu Q.H.Meng School of Energy Science and Engineering Harbin Institute of TechnologyHarbinHeilongjiang 150001China AVIC Shenyang Aircraft Design and Research Institute Shenyang 110035China

Sw.eping jet actuator(SJA)has been w.dely applied for activeflow.control in *** this paper,the SJA character in compressor cascade and its performance for separation control in innerflow. are ***-averaged and transientflow.ield measurement,together w.th visualization methods are *** is found that endw.ll effects are important for both SJA behaviors and SJA performance for separation control in compressor *** is a maximum of 12.7%total pressure loss reduction w.th SJA placed near the separation position,close to the endw.ll and under *** characteristic frequencies in theflow.ield contribute to the capture of influence regions of vortices and excitation *** concentrated shedding vortices and SJA jets impact region helped to judge that SJA energizes low.momentumfluids in a large region and matches the high loss core *** be concrete,theflow.separation control mechanism of SJA lies on the interruption of the blade suction surface boundary layer development and the restriction of the lifting of the boundary layer from end-w.ll tow.rds blade suction surface.

关键词： Compressor cascade Activeflow.control Sw.eping jet actuator Corner separation Oilflow.visualization