电镀金刚石钻头镀前超声清洗机理及工艺研究   总被引：4，自引：0，他引：4  

刘晓东  霍宇翔  李子章 《地质与勘探》2006,42(1):89-92

电镀金刚石钻头镀前清洗是钻头生产的关键制造工艺.超声清洗作为一种精清洗技术,在不少领域获得了成功.本文阐述了超声波对金刚石钻头镀前清洗工艺的适应性,分析了电镀金刚石钻头中的主要清洗对象及超声清洗机理,对超声清洗中的各项工艺参数及工艺流程进行了研究,说明了超声清洗的经济适用性及可操作性.  相似文献   

寒冻条件下花岗岩小块体的风化模拟实验及其分析   总被引：12，自引：0，他引：12  

朱立平 Whal.  WB 《冰川冻土》1997,19(4):312-320

５０ｍｍ×５０ｍｍ×５０ｍｍ的一些小花岗岩块体被单轴挤压使之表面出现裂隙，然后分别预处理成干燥、水饱和与硫酸钠溶液饱和的３组样品，使之经历不同温度变幅下的冻融过程。在冻融过程中，分别记录了样品表面、表面下１０ｍｍ及２５ｍｍ处的温度变化，同时在实验前后，对所有样品都进行了超声波传输速率测定和重量测定。实验结果表明，这些小的花岗岩块体表面与内部的温度变化没有明显差异，其温度变化随外界温度而变化，但在外界温度变幅整体低于０℃时，岩石温度逐渐趋于稳定。样品在实验前后的重量变化很小，但是仍能反映最大的变化发生在水饱和的一组样品中。所有样品在实验后的超声波传输速率都明显下降，特别是在垂直于微裂隙的方向，超声波传输速率下降大于平均下降幅度，表明冻融过程中岩石内部的孔隙可能增大而微裂隙具有明显的加剧作用。  相似文献   

Ultrasonic modelling research of earthquake response of underground lifeline engineering     

Jinzhong Sun  Yimin Peng  Hongru Zhao  Hongliang Li 《地震学报(英文版)》1992,5(3):617-624

Earthquake response of underground lifeline engineering is investigated by the method of ultrasonic model experiments in this paper. From general field conditions, two models of underground lifeline engineering, one for non-uniform field and the other for uniform field, are designed based on the similarity principle. Besides analysis of seismic phases, a series of analyses especially on particle vibration are carried out. The results show that: The shorter the epicentral distance, the greater are the intensity variation and the change rate of intensity variation of earthquake ground motion, so the more disadvantageous to underground pipelines. In soft covering layer, compressional waves mainly cause radial flexures deformation, but shear wave result in axial dilation deformation of the pipelines; when the thickness of the covering layer is smaller (less than seismic wave length), the rhythmic variation of the intensity of earthquake ground motion is controlled mainly by the wave length of seismic waves in the bedrock. The property of the covering layer has considerable effect on earthquake ground motion. For different covering layers, their effect on each component of earthquake ground motion is not the same. Owing to the effect of wave propagation, the ground is in different states of particle vibration at different times, and there is considerable difference in phase and intensity of particle vibration between two different covering layers near their junction line or surface. Because underground lifelines tend to vibrate with the particles of the earth around it, this results in different deformation of underground pipelines under different conditions. So, it is necessary to take corresponding anti-seismic countermeasures for pipelines according to their practical situations. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 104–110, 1992. This paper is part of the research supported by Funds of Doctoral Faculty of National Education Committee.  相似文献   

超声测风传感器在回路风洞中的测试     

黄敏  卢会国  王保强  刘俊宏 《气象科技》2016,44(1):14-18

超声测风仪因启动风速小、无转动部件、不破坏风场、测量精度高等特点,适用于多种行业的测风需求。超声波测风的相关检定规程当前在国内尚未正式制定。本文借鉴风杯检定规程所选择的风速测试点,在HDF-720低速回路风洞中,对超声测风仪在不同角度下进行了测试数据统计分析。结果表明:超声测风仪可以安装在工作段面较大的风洞中进行测试,由于超声探头存在阴影效应,对于同一风速,不同角度上的测量结果稍有差异,而且不同风速对应的差异也不同。利用超声测风仪进行风速实时测量时,必须结合上述测试分析,按照超声传感器的安装角度,对测量值进行相应修正。  相似文献   

海产腹足类有机锡化合物的检测方法   总被引：3，自引：0，他引：3  

黄长江  雷瓒  董巧香 《海洋学报》2005,27(4):174-180

三丁基锡(TBT)等有机锡化合物因其毒性及结构上的特点被广泛应用于船舶、网箱渔排等的防污涂料中.它的主要作用是在水体中持久地释放出可以有效杀死海洋污损生物的毒性物质,从而达到防护船舶、渔排等体表的目的[1],然而进入海洋环境的有机锡化合物在防污的同时也会影响到许多非靶生物,并对海洋生态系统的结构与功能产生严重的危害,被认为是迄今为止人为引入海洋环境毒性最大的物质之一[2～4].因此,检测海洋生物体内的有机锡含量成为对有机锡污染生态效应调查与研究不可缺少的手段[5～7].  相似文献   

岩样孔隙汞渗入量超声法精密测定     

杨振华 《中国海洋大学学报(自然科学版)》1997,(4)

采用声学方法精密测定汞被高压强压入储油岩样的渗入体积，对岩芯孔隙结构测定中的汞体积计量方法作了重要改进。本方法以无水酒精作为计量工作介质，在其中发射声波，通过对汞界面反射声波的识别，进行非接触的声学测量，从根本上解决了当前国内外采用的电阻法，电容法无法避免的由于汞腐蚀或油污染而要求经常进行与有毒汞接触的清洗，并且确保了计量系统工作性能的长期稳定与准确可靠。在０．０１ＭＰａ至５０ＭＰａ压强范围内连续计量，量程０～１０ｍｌ，准确度０．０１ｍｌ。  相似文献   

SBY2-1型空气超声波浪仪     

孙强  孙军 《海洋技术学报》2007,26(4):4-7

SBY2-1型空气超声波浪仪是基于超声测距原理和海面高度变化时间序列数据分析技术的新型波浪仪。论文详细阐述了该仪器的原理、系统组成和工作流程,并介绍了该仪器的计量检定情况和现场的使用情况。  相似文献   

Movements of non-maturing cultured Atlantic salmon (Salmo salar) in a Canadian river     

Carr  J. W.; Lacroix  G. L.; Anderson  J. M.; Dilworth  T. 《ICES Journal of Marine Science》1997,54(6):1082-1085

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海洋环境要素的声光集成测量     

于连生 《海洋技术学报》2000,19(3):1-6

本文介绍海洋环境要素的声光集成测量原理和测量方法。文中以作者主持的海洋８６３项目“声光悬浮沙粒径谱测量仪”为例,列举了声速、声衰减、悬浮泥沙粒径谱的测量结果。海洋声速、声衰减、温度、盐度、悬浮物等都是海水的重要参数。这些参数的测量,对海洋开发、海洋环保、海洋军事有重要的意义。  相似文献   

Movement patterns and trajectories of ovigerous blue crabs Callinectes sapidus during the spawning migration     

Sarah D. Carr  Richard A. Tankersley  James L. Hench  Richard B. Forward  Jr.  Richard A. Luettich  Jr. 《Estuarine, Coastal and Shelf Science》2004,60(4):567-579

Female blue crabs (Callinectes sapidus Rathbun) migrate from low salinity estuarine regions to high salinity regions near the ocean to release larvae. During this migration, ovigerous females use ebb-tide transport, a vertical migratory behavior in which they ascend into the water column during ebb tides, to move seaward to larval release areas. In order to determine the relationship of ebb-tide vertical migrations to local currents and the influence of these vertical migrations on the horizontal transport of blue crabs in the estuary, ovigerous females with mature embryos (1–3 days from hatching) were tracked near Beaufort Inlet, North Carolina (USA), in July and August 2001 and 2002. Crabs were tagged and tracked using ultrasonic telemetry, and currents near the crabs were measured simultaneously with a shipboard acoustic Doppler current profiler.During the two seasons, eight crabs were successfully tracked for periods ranging from 3.9–37.0 h and for distances ranging from 1.9–10.6 km. All crabs migrated seaward during the tracking periods. Crabs moved episodically during all tidal phases with periods of movement on the order of minutes to an hour. They moved with local currents in terms of both speed and direction during ebb tides, consistent with ebb-tide transport, and moved down-estuary (seaward) in opposition to local currents during flood tides. The percentage of time that crabs were active was higher during night ebb tides than during day ebb tides or flood tides and increased with increasing ebb-tide current speed. Mean migratory speeds were 0.11, 0.04, 0.08 and 0.02 m s⁻¹ during night ebb, night flood, day ebb and day flood tides, respectively, and net migratory speeds were on the order of 5 km day⁻¹. Due to the episodic nature of the crabs' movements, the total distances that crabs traveled during ebb tides ranged from 10–40% of the distances that passive particles could have traveled under the same conditions.  相似文献