超声波对条斑紫菜硅藻附着症的作用          下载免费PDF全文

李金波  阎斌伦  秦松  吕作舟 《海洋科学》2007,31(12):1-3

为使条斑紫菜(Porphyra yezoensis)上附着的硅藻脱落,从超声波的生物学效应出发提出了新的思路。选择生长状态较好的附着硅藻的紫菜分别在不同的输出功率和时间下用超声波处理。结果表明,当超声波的输出功率为300 W、处理时间25 s时,可以成功地去除附着的硅藻及黏质柄,而对条斑紫菜未产生不良影响。该研究结果在条斑紫菜的加工生产上有应用与推广价值。  相似文献   

应用单板计算机测试风速表距离常数的方法     

刘连吉 《中国海洋大学学报(自然科学版)》1987,(3)

鉴于微型计算机对数据采集和处理具有速度快、精度高和便于自动化的特点,我们研制了应用单板微型计算机自动测试风速仪的动态参数(时间常数、距离常数等)的测试系统。该系统的主要特点是能够对测试参数进行自动、连续和多次重复测定并实时获取参数的平均量,测得的时间常数的精度可达到毫秒数量级。本文介绍了该系统的基本组成、测试原理和方法,应用该系统对EY_1型电传风向风速仪和QDF型热球电风速计的距离常数和时间常数进行了测试,并给出测试结果,测试表明,在风洞内和在空旷的房间内在一定的风速下,两者分别测得的风速仪动态参数值十分相近  相似文献   

粘性土物理力学性质与超声波波速关系的试验研究   总被引：1，自引：0，他引：1  

王峥辉  杨凤根  徐建龙 《江苏地质》2007,31(3):247-250

含水量W和压缩系数α是粘性土的主要物理力学性质指标。运用HTY-C型超声波参数测定仪,测定了南京市河西地区不同状态粘性土的超声波波速值,对比得到其与含水量W和压缩系数α变化关系。试验研究结果表明:粘性土的纵波波速值随含水量的增大而增大;而横波波速值与含水量的相关性较差;在相同含水量下粘性土的纵横波波速值的比值之间呈线形关系;一定含水量条件下,粘性土的纵波波速与压缩系数之间呈指数函数关系,横波与压缩系数之间呈线性关系。  相似文献   

Examination of a Correction Procedure for the Flow Attenuation in Orthogonal Sonic Anemometers     

Takanori Shimizu  Masakazu Suzuki  Akira Shimizu 《Boundary-Layer Meteorology》1999,93(2):227-236

In this study we examine the calibration of wind speed measured by a sonic anemometer, with an orthogonal probe configuration, with regard to the approximation of the flow angle, and the wind-speed dependence of the flow attenuation attributed to the transducer shadow. The flow angle should be calculated by the iterative method when the attenuation is relatively high. For a probe manufactured by Kaijo Co. TR-61C, the wind-speed dependence of the transducer shadow effect is formulated from the results of the wind-tunnel experiment. Assuming the equation is applicable to field observations, significant errors possibly remain especially when the wind speed is low, and /or the angle between the flow vector and the sonic path is small, if the wind-speed dependence in measurement errors is neglected.  相似文献   

Analysis, in a free surface steady flow, of the interstitial velocity field inside a sedimentary bed     

Mustapha Kamel Mihoubi  Michel Blorgey  Ahmed Kettab 《Comptes Rendus Geoscience》2008,340(12):858-864

The objective of our study is to exploit ultrasonic Doppler velocimetry (UDV) to analyze the velocity field within a steady flow on a porous sedimentary bottom. Velocities are measured for several sedimentary beds, as well within the fluid vein as within the sediment. Our results highlight an exponential distribution of the velocities inside the sediment and a discontinuity of the velocity at the interface water–sediment, between the velocity in the free flow and the velocity within the sediment. These results highlight the need to base the analysis of sedimentary transport on the reality of the physical processes at the interface water–sediment.  相似文献   

The Effect of Heterogeneity on Rock‘s Ultrasonic Attenuation and Its Correction   总被引：2，自引：0，他引：2  

WANG Baoshan  Sun Daoyuan  LI Shengjie  Li Weidong  Shi Xingjue  Liu Bin 《中国地震研究》2001,15(3):222-229

INTRODUCTIONAs Intnns。c properlyd]ohs,Q value Is closely related to the physical cond。tlons(such aspressure,fluid saturalon,and v。scoslty,etc．)．And generally speaking,the。e attenuation Is。resensitive to the vanatlon of physical conditions than the velocity does(Best et al,1994),therefor。asure。nt Of Q value Is very m叩oltantlnl4。m扣y expenments．There re删Ww幼sic*t。"theQ value,such as spectral rat。。(Toks6z et al,1979),resonance bar(Wyllie et al,1962),andst。ss－st。。n on…  相似文献   

螺旋桨测风仪风洞测试及不确定度分析     

李松奎  贺晓雷  边泽强  刘昕 《气象科技》2021,49(4):524-528

本文借鉴国标GB/T-24559海洋螺旋桨式风向风速计中的测试方法及测试点,在低速直路风洞中,对螺旋桨测风仪进行测试,并依据JJF1059.1-2012测量不确定度的评定与表示要求,对风速7个校准点分别进行重复试验,采用极差法进行A类不确定度评定,并分析测试过程中的B类不确定来源,进行B类不确定度评定.结果表明:在WZ...  相似文献   

Predicting the excavation damaged zone within brittle surrounding rock masses of deep underground caverns using a comprehensive approach integrating in situ measurements and numerical analysis     

《地学前缘(英文版)》2022,13(2):101273

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