共查询到19条相似文献,搜索用时 46 毫秒
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《实验室研究与探索》2016,(9)
对基材钢(1Cr12Mo、X20Cr13、2Cr12Ni Mo1W1V)、C1(长城1号)涂层、表面处理工艺(6 min与12 min钢丸强化)三类6种不同气轮机叶片材质在200~600℃的不同冲角条件下的冲蚀率进行了冲蚀实验。结果表明:叶片因冲蚀的失重均随冲蚀颗粒质量呈线性变化;15°~25°冲角冲蚀率最大,90°冲蚀率最小;实验基材的冲蚀率随实验温度提高呈先下降后升高趋势;2Cr12Ni Mo1W1V在200℃与300℃的冲蚀率高于另两种材质,耐冲蚀性差,但在400℃实验温度且冲角40°状态下冲蚀率低于另两种材质;钢丸强化表面处理工艺对于提升实验材质抗冲蚀特性无明显优势;C1涂层的冲蚀率随温度升高呈先升高后降低趋势,在高温条件下具有良好的抗冲蚀特性。 相似文献
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《实验技术与管理》2016,(2)
为研究和掌握机械密封端面的摩擦特性,理论上分析了其摩擦特性参数,通过摩擦磨损实验得到了这些参数的变化规律,并建立了磨损率的时间相关模型。研究表明:工作在70℃、N32液压油下、转速为3 000r/min、端面比载荷为0.558 44~1.675 32 MPa的机械密封处于混合摩擦状态;摩擦特性参数具有载荷相关性和时间相关性;摩擦力矩及摩擦系数随载荷增大而增大,随时间增加而减小;磨损率随载荷增大而增大,随时间呈指数下降趋势,实验条件下密封端面的预测寿命为191.5~464.8d。该研究有利于拓展机械密封摩擦机理的研究途径,为机械密封寿命预测提供一定思路。 相似文献
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《滨州学院学报》2020,(6):16-23
敏感栅作为金属丝式电阻应变片的核心测量元件,其疲劳特性直接影响测量工作的可靠性。为了探究敏感栅各结构参数对其疲劳寿命的影响,建立了简支梁-应变片三维有限元模型,采用正交试验法,研究了栅丝直径、栅丝长度、敏感栅弯数、栅丝间距对应变片疲劳寿命的影响。结果表明:随栅丝直径和栅丝间距增加及栅丝长度减小,应变片寿命增大;敏感栅弯数存在使应变片达到最大疲劳寿命的最优值;栅丝间距对应变片疲劳寿命的影响最大,而后依次为栅丝直径、弯数、栅丝长度;应变片寿命对栅丝直径的敏感度最高,对栅丝长度的敏感度最低。在所研究参数范围内,当栅丝直径为0.05mm、栅丝长度为7mm、弯数为5、栅丝间距为0.6mm时,应变片的疲劳寿命达到最大。 相似文献
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从已有胶黏剂、夹芯材料的剪切试验标准出发,制备金属点阵夹芯材料试样,开展金属点阵材料多种剪切实验方法的探索,同时采用有限元方法模拟各种剪切实验方案中材料的应力分布与变形特征.通过与理想剪切状态的分析对比,提出了一种适合金属点阵材料剪切实验的方法.该实验方案可将剪切力均匀作用在材料内部待剪切面内,消除附加弯矩影响,实现预... 相似文献
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利用控温仪器和加热炉组成恒温系统,再用双臂电桥和电位差计的方法分别测量了金属铜线的电阻,设计了实验测量的装置图,对测量结果进行了分析。 相似文献
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为改善和提高寒区河道护坡的生态功能,设计了5种生态护坡模式并进行现场试验区建设.通过流速为1.0~5.0 m·s-1有压恒定流连续冲刷试验,采集吸水性、水土流失率、糙率、破坏程度等试验监测数据,分析不同护坡模式抵抗水流侵蚀的能力.结果表明,生态护坡抗冲性能由强至弱依次为:环保草毯混种护坡、植生毯混种护坡、原土射干护坡、... 相似文献
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为了使学生能比较直观的看到一些金属的 电阻率随温度的变化而变化的现象,笔者用灯丝 和在电子商店能买到的热感电阻,制作了一套实 验器材,经过课堂教学,效果很好。 1 取材及制作 (1)把一个60W左右的灯泡,用布包住小心 地打碎玻璃泡,然后把灯丝作如图1所示的处 理。通过反复的实验得到:实验用的灯丝是把整 根灯丝折成三段并在一起效果最佳,制作中要相 当小心,因为灯丝非常易断。 (2)直接到电子商店买如图2所示的热感电 相似文献
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Experimental study on a cryosurgery apparatus 总被引:1,自引:0,他引:1
Cryosurgery is an effective way of curing many diseases including tumors and cancers. It can be applied using a variety of systems and cryogens. Cheap, convenient, reliable equipment still needs to be developed so that cryotherapy may be accepted by surgeons and hospitals. This paper presents a cryosurgery apparatus that utilizes an auto-cascade refrigeration system. Refrigerant mixture R50/R23/R600a was selected as the working fluid. The mixture composition was altered to achieve lower temperatures and higher capacity. The lowest temperature at the cryoprobe could be as low as -100℃, and 8 W refrigeration capacity could be obtained at -80 ℃. An ice ball of 11.6 mm diameter could be formed when the cryoprobe was immersed in a water bath at 37 ℃. 相似文献
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针对实际工程中废弃混凝土种类和原始强度等级,采用不同粗骨料取代率配制再生混凝土,测试其抗压强度.结果显示,在标准配合比下,原始混凝土来源和强度等级对再生混凝土抗压强度有影响,再生粗骨料取代率的影响相对较小. 相似文献
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Ju-li Fan Xian-guo Xu Shao-zhi Zhang Fa-ming Zhu Guang-ming Chen Li-xing Yan 《浙江大学学报(A卷英文版)》2009,10(5):697-703
A rehydration process for freeze-dried human platelets was studied on 1 ml of samples. The effects of prehydration duration, prehydration temperature, an rehydration solution on the recovery rate, mean platelet volume (MPV), and platelet distribution width (PDW) were investigated. The mass changes during the prehydration process were also studied. Three prehydration durations: 0, 1.5, and 3.5 h, and two rehydration solutions: platelet-poor plasma and phosphate-buffered saline (PBS), were tested. It was found that: (1) the prehydration was of significance; (2) 1.5 h of prehydration had better effects than 3.5 h of prehydration; (3) as a rehydration solution, the platelet-poor plasma behaved better than the PBS. The impacts of prehydration duration and temperature on the results were studied. There was almost no difference between 35 and 37 ℃. Among all the prehydration durations tested, 15, 30, 60, 90, and 120 min, the best result was achieved with the time duration of 15 min. The weights of prehydrated platelets at the end of each test were measured and the water contents were calculated. After 15 min ofprehydration, the water contents in the samples were about (4.8±0.01)% and (5.27±0.29)% (w/w) corresponding to the conditions of 35 and 37 ℃, respectively. These results will be helpful for further studies on the freeze-drying of mammalian cells. 相似文献