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将设计方法学的一般方法应用于摩擦磨损试验机的设计,这对确定设计方案是科学的和行之有效的。本讲通过一个设计实例说明了设计方法学在摩擦磨损试验机设计中的具体应用问题,并以举例的形式详细地介绍了在方案设计阶段的各个主要工作步骤的实施方法,即建立要求明细表-功能分析-建立设计模幅箱-方案选择-方案评价。其中,关键的是进行功能分析、建立设计模幅箱和方案评价。 相似文献
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三种腐蚀磨损试验机与两种不锈钢腐蚀磨损性能的研究 总被引:7,自引:2,他引:7
腐蚀磨损现象广泛发生在石油,化工,煤矿和电力等工业领域的机械设备中,是造成材料流失和设备失效的主要原因之一,尽管这种磨损现象越来越引起了人们的关注,并且已经对其进行了一些试验研究,然而由于所用的试验设备本身就存在着一定程度的腐蚀磨损,因而很难保持其长期稳定的工作状态,而且目前国内外都还没有定型的专用设备出售.针对这种情况,设计研制了3种可以用于不同研究目的并能长时间稳定工作的腐蚀磨损试验机──稳态 相似文献
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针对一次性医用口罩(DMMs)通气阻力测试结果不稳定情况,从测试设备稳定性、气体流量、样品不同位置、气流方向、预处理、测试时间方面展开了研究。结果表明,气体流量、样品不同位置和预处理对口罩的通气阻力有较大影响,测试时间和气流方向对口罩通气阻力无明显影响。研究结果对各生产厂商开发优异DMMs及生产过程质量控制有重要意义。 相似文献
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利用超声波声速测定仪测定出超声波在不同浓度NaCl溶液中的传播速度.实验给出,超声波在NaCl溶液中的传播速度与溶液浓度呈线性关系.溶液温度对超声波波速也有影响,并从理论作了分析研究,给出了合理的解释. 相似文献
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It is frequently assumed that sensitive museum materials follow the reciprocity principle of light exposures. Thus, equivalent exposure doses obtained by using either high-illuminance levels for short periods of time or lower illumination for longer exhibition periods are believed to cause similar degrees of damage to an object. Microfading spectrometry permitted the investigation of this phenomenon by evaluation of light-induced changes in a series of samples. The effects of equivalent exposure doses on materials such as Blue Wool 1, LightCheck Ultra, and various dyed silks from a reference collection were compared. The results indicate that reciprocity is obeyed by the most stable colorants, while materials with lower stability to light may experience deviations that are proportional to the intensity of illumination. This study confirms that reciprocity failure is associated with the use of high-intensity lamps during accelerated-aging trials. Therefore only those tests conducted at low-illumination intensity ranges where reciprocity holds should be employed when one estimates the extent of damage occurring in a museum environment. 相似文献
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Separating produced water is a key part of production processing for most crude oils. It is required for quality reasons, and to avoid unnecessary transportation costs and prevent pipework corrosion rates caused by soluble salts present in the water. A complicating factor is that water is often present in crude oil in the form of emulsions. Experiments were performed to evaluate the performance of ultrasonic fields in demulsifying crude oil emulsions using novel pipe-form equipment. A horn-type piezoelectric ultrasonic transducer with a frequency of 20 kHz and power ranging from 80 W to 1000 W was used for experimental purposes. The influences of the intensity of ultrasonic fields, ultrasonic irradiation time, and the initial water content of crude oils were evaluated to establish the rate of water segregation from oil. The experiments applied ultrasonic-field intensities of W/cm3, W/cm3, W/cm3 and W/cm3 to synthetic emulsions with 10%, 15%, 20%, and 25% of the water in crude oil. Crude oil demulsification occurred for each ultrasonic field intensity tested for all the samples tested. Function β involving adhesion coefficients was expressed in terms of wave-field intensity and initial concentration of water in each of the three crude oil samples tested. The experiments demonstrated that despite the absence of any chemical demulsifier involved, water separation caused by applying ultrasonic fields was effective and occurred rapidly. As the intensity of the ultrasonic field applied increased, the amount of water segregated from crude oil also increased. Subjected to constant field intensity, higher initial water cuts (up to 15% or so) in the crude oil samples and higher ultrasonic irradiation times, resulted in greater segregation of water from crude oil in percentage terms. However, in samples with initial water cuts of 20+% long irradiation times (~5 min), resulted in a decline in water separation compared to 2-min tests. Ultrasonic field treatments offer commercially-viable and environmentally-friendly alternatives to treatments using chemical demulsifiers as they reduce desalination requirements of wastewater. 相似文献