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Study on Hydrodynamic Characteristics of Wave Turbulent Bottom Boundary Layer Using A Large-Sized Wave Flume

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China Ocean Engineering 2021年第5期35卷 759-766页

作者： zhang Hong-qian XIE Ming-xiao zhang Chi LI Shao-wu zhang hua-qing SUN Yu-chen State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China Tianjin Research Institute for Water Transport Engineering M.O.T..Tianjin 300456China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai UniversityNanjing 210098China

Experimental studies were conducted in a super-large wave flume,aiming at uncovering the hydrodynamic characteristics involved in the turbulent wave boundary layer of full scale *** explicit formula of boundary layer thickness on rough turbulent flow was presented based on the measured velocity data of the present study and collected experimental data on wave boundary *** was found that the bottom wave-associated nominal stresses under the conditions of prototype scale tests suppress the vertical turbulence scattering upward over the boundary layer,which accounts for thickening of the boundary layer under wave *** effect has yet not been reported in the literatures using oscillatory U-tube or small-sized wave *** phase inconsistency in the turbulent boundary layer to the free stream velocity(velocity immediately outside the boundary layer)is within15°,which is remarkably smaller than the results from oscillatory U-tubes,as well as the larger wave flume experiment presented by Xie et al.(2021),showing that the coarser bed would further reduce the phase *** intensity of the vertical turbulent component is approximately 1/2 of the horizontal component,which has larger ratio compared with the value of 1/5 reported by previous ***,it was also found that the vertical turbulent energy was approximately 3/4 of the turbulent energy in spanwise directions(y-direction).This means that the turbulent fluctuation has similar order in all three-directions(x,y,z)in a full scale environment and highlights that the turbulent components in all the three directions should not be neglected when calculating the total turbulent energy.

关键词： large wave flume wave boundary layer hydrodynamic mechanism turbulent

Experimental Study on Hydrodynamic Load Characteristics for A Typical Cross-Section of A Submerged Floating Tunnel

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China Ocean Engineering 2024年第5期38卷 893-903页

作者： zhang Hong-qian YANG Zhi-wen LI Shao-wu YUAN Chun-guang zhang hua-qing National Engineering Research Center for Port Hydraulic Construction Technology Tianjin UniversityTianjin 300072China National Engineering Research Center for Port Hydraulic Construction Technology Tianjin Research Institute for Water Transport EngineeringM.O.T.Tianjin 300072China

The typical cross-sectional form of a submerged floating tunnel plays a significant role in the dynamic response of the tunnel itself,which directly affects the overall *** this work,a series of experiments involving wave action on a submerged floating tube cross section is reported to study its hydrodynamic load *** typical cross section tube cylinders,circular and rectangular,are *** are carried out in a wave flume with waves of relatively low Keulegan-Carpenter(KC)*** relative depths of submergence of 0,0.25 and 0.5 are *** measured wave forces in regular waves are used to analyze the horizontal force,vertical force and torque,and then the drag coefficient(Cd)and inertia coefficient(Cm)are *** results show that the drag coefficients at low KC numbers are large and decrease sharply with increasing KC *** inertial coefficient Cm values in the vertical direction are about 70%larger than those in the horizontal *** an increase in aspect ratio(the ratio of the height to width of the structure),the ratio of inertia coefficient in the horizontal direction to that in the vertical direction increases *** inertia force coefficient is very sensitive to the submerged water depth and aspect *** existing results may overestimate the actual force value.

关键词： submerged floating tunnel tube cylinder wave force coefficient physical experiments

KUROSHIO INTRUSION INTO THE SOUTH CHINA SEA

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Journal of Hydrodynamics 2006年第6期18卷 702-713页

作者： zhang qing-hua FAN Hai-mei QU Yuan-yuan Institute of Physical Oceanography Ocean University of China Qingdao 266003 China Key Laboratory of Marine Science and Numerical Modeling State Oceanic Administration Qingdao 266061China

In this article, the circulation of the South China Sea （SCS）, which is idealized as the rectangular basin with constant depth, is studied under Kuroshio boundary forces. Starting from the linearly quasi-geostrophic vorticity equation, the solution of the SCS circulation is given in the form of corrected Fourier series under proper boundary conditions. The results show that the intruded current flows westward and separates into the northward branch and the southward branch before arriving at the western boundary. The southward branch flows out of the SCS through the southwestern passage, at the same time, the induced cyclonic （anti-clockwise） ring almost occupies the middle and southern parts, and concomitant anti-cyclonic （clockwise） vortex appears between the cyclone and the western boundary. While the northward branch outflows through the northeastern passage, the anti-cyclonic （clockwise） ring is triggered at the northern part of the SCS. The above two vortexes are both intensified if the south-entering and the north-leaving current loop intrusion are superposed. The outer flow of the northern vortex flows westward, then northward, and then eastward, and it is very similar to the configuration of the SCS Warm Current （SCSWC） at the northern part of the SCS, thus, a kind of generating mechanism of the SCSWC is presented.

关键词： Kuroshio boundary forces South China Sea (SCS) SCS Warm Current (SCSWC)

Study on contactless ultrasonic sensor and seam tracking

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China Welding 1995年第1期4卷 51-56页

作者： Hou Wenkao Hu Shengsun and Zhao Jiarui Tianjin University zhang Shaobin (qing hua University,Beijing)

The sensitivity of contactless ultrasonic sensor is improved from 3.3% to 26% through acoustic and electric matching technique in this *** dual crest lines auto seam tracking is firstly realized with contactless ultrasonic *** focused acoustic lens is accurately designed, and a sonic beam with 0.5 mm in diameter is achieved. By means of software and hardware technique the accuracy of seam tracking with ultrasonic sensing is 0.5 mm in lateral direction and 0.2 mm in longitudinal direction respectively.

关键词： ultrasonic sensor contactless seam tracking arc welding

A STUDY ON NONEQUILIBRIUM TRANSPORT OF NONUNIFORM BEDLOAD IN STEADY FLOW

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Journal of Hydrodynamics 1992年第2期4卷 111-118页

作者： Lu Yong-jun zhang hua-qing, Tianjin Research Institute of Water Transport Engineering, Tianjin 300456, P. R. China Tianjin Research Inst of Water Transport Engineering Tianjin China

In the case of steady flow, an equilibrium state for an alluvial reach referring to the input of sediment over a sufficiently long time (time interval in the order of months) is equal to the output of sediment. A nonequilibrium state exists under steady flow when the sediment transport rate changes with time and space, so that there is no balance between input and output of sediment. The experiments were performed in an open circuit tilting flume with the bed slope of 0. 001-0. 009, the flume length of 30m and flume width of 0. 5m. The boundary condition at upstream and in all experiments, the rate of sedimant supply was zero. The coal or sand was se- lected as the Wed material. The grain diameter of the bed material varied in the range of 0.05- 20. 00ram. The equation of nonequilibrium transport of nonuniform bedload is derived. The grain distribution of the size distribution of bedload is calculated by modified Gessler's formula. The grain size distribution of bed material is calculated by CARICHAR mixed layer model. These equations are applied to numerical simulation of armoring of riverbeds. The results of the bedload transport rate and the grain size distribution of the bedload at the end of the down- stream in the process of time, as well as the grain size distribution of the bed material in the pro- cess of time and distance are all in close agreement with the measurements.

关键词： nonuniform bed load nonequilibrium transport armoring of riverbeds size distribution

Carbendazim sensitivity in populations of Colletotrichum gloeosporioides complex infecting strawberry and yams in Hubei Province of China

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Journal of Integrative Agriculture 2018年第6期17卷 1391-1400页

作者： HAN Yong-chao ZENG Xiang-guo XlANG Fa-yun zhang qing-hua GUO Cong CHEN Feng-ying GU Yu-chen Institute of Industrial Crops Hubei Academy of Agricultural SciencesWuhan 430064P.R.China Hubei Key Laboratory of Crop Diseases Insect Pests and Corp Weeds Control/Key Laboratory of Integrated Pest Management on Crops in Central ChinaWuhan 430064P.R.China

The ascomycete fungus Colletotrichum gloeosporioides is a devastating plant pathogen with a wide host range and worldwide distribution. Carbendazim has been widely used to control anthracnose caused by the C. gloeosporioides complex in China for more than 30 years and resistance to carbendazim has been reported in China. A total of 125 Colletotrichum isolates of strawberry and yam were collected from different geographical regions in Hubei Province, China. Approximately 52.8％ of Colletotrichum spp. isolates showed resistance to carbendazim. The isolates tested in this study belong to four species, and the frequencies of resistant isolates differed across Colletotrichum species. Resistant isolates were found in C. siamense and C. fructicola. In contrast, all isolates of C. gloeosporioides and C. aenigma were sensitive to carbendazim. Highly carbendazim-resistant isolates harbored the E198A mutation in the β-tubulin 2 （TUB2） gene, whereas moderately carbendazim-resistant isolates harbored the F200Y mutation in the TUB2 gene. Carbendazim-sensitive Colletotrichum isolates in this study were not genetically similar enough to form a separate cluster from resistant isolates. The result of this study emphasizes the importance of knowing which Colletotrichum sp. is present, when strategies for disease control are made.

关键词： carbendazim resistance frequency Colletotrichum gloeosporioides Colletotrichum species point mutations anthracnose

Raman Spectra of Deuterated Potassium Dihydrogen Phosphate Crystals with Different Degrees of Deuteration

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Chinese Physics Letters 2013年第6期30卷 205-208页

作者： LIU Bao-An ZHOU Hai-Liang zhang qing-hua XU Ming-Xia JI Shao-hua ZHU Li-Li zhang Li-Song LIU Fa-Fu SUN Xun XU Xin-Guang State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100 School of Information Science and Engineering Shandong Agricultural UniversityTaian 271018 Chengdu Fine Optical Engineering Research Centre Chengdu 610041

The polarized Raman spectra of deuterated potassium dihydrogen phosphate crystals with different deuterium concentrations are *** the increasing deuterium concentration,the Raman peaks which are assigned as the internal vibrations of the(H/D)_(2)PO_(4)^(-)anion shift to lower *** red-shift contributes to the decrease in the bonding force of the P–O bond as a result of the substitution of deuterium for ***,the intensity of the strongest peak of these crystals decreases first,and reaches the minimum value while the mole percentage of the deuterium content in the crystal is about 74%.After that,the intensity increases with the increase of the deuterium concentration in the crystal.

关键词： bonding potassium substitution

ANALYTIC METHOD FOR INVERSING THE OPEN BOUNDARY CONDITIONS IN A SEMI-CLOSED SEA AREA—CASE I FOR INVERSING THE TIDAL LEVELS AT OPEN BOUNDARY

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Journal of Hydrodynamics 2004年第5期16卷 590-595页

作者： zhangqing-hua YINXun-qiang MAJian QUYuan-yuan KeyLaboratoryofMarineScienceandNumericalModeling TheFirstInstituteofOceanographyStateOceanicAdministrationQingdao266061China KeyLaboratoryofMarineScienceandNumericalModeling TheFirstInstituteofOceanographyStateOceanicAdministrationQingdao266061China

In this paper, a computational case was employed to describe thecomputational procedure for inversing the tidal level open boundary conditions using an analyticmethod. The area for finding the solution is a circular area with a circular arc with the openingangle 60°-being the open boundary and the other circular arc being the solid wall *** from the reestablished elliptic partial differential equation satisfied by the tidallevel function, the extended spectrum method was used to derive the general solution of the equationfor the sea of constant depth, and the impermeable solid wall condition (the second class boundarycondition) and the adequately specified open boundary conditions were then applied to determine theundetermined coefficients of the general solution, thus obtaining the tidal level distributionfunction. In this way, both the first and second class boundary values at the solid wall boundarywere obtained. With the above boundary values as the boundary conditions, the tidal level values atthe open boundary were then inversed by means of the general solution of tidal wave equation. Thevalidity of inversion method could be verified by comparing the inversed tidal level distributionswith the originally specified open boundary values.

关键词： semi-closed sea open boundary condition extended spectrum method generalsolution of equation in-version

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Vague值(集)相似度量的研究

电子与信息学报 2007年第8期29卷 1855-1859页

作者：张清华重庆邮电大学计算机科学与技术学院

该文对现有Vague集(值)相似度量方法进行研究,发现目前Vague值(集)相似度量方法存在一些缺陷,给出了Vague集(值)相似度的一种定义,提出了两种Vague值(集)相似度量的改进方法,最后通过数据分析验证了改进方法的有效性和优越性。

关键词： Vague值(集) 相似度量隶属函数模糊集