排序方式: 共有9条查询结果,搜索用时 31 毫秒
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机床导轨表面相互运动产生摩擦,导致轨面磨损是造成主要啮合零部件间隙过大、影响产品加工件精度的重要因素。本文提出了修复磨损的几种有效方法,并详细分析了贴塑导轨用料四氟乙烯材料的优点和贴塑导轨的工艺。 相似文献
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浅析中职轮机英语教学中存在的问题与对策 总被引:1,自引:0,他引:1
目前在中职轮机英语教学中,依然存在教材陈旧、偏重语法、忽视口语听力培训等问题。针对这一情况,讨论如何转变教学内容,改善教学方法。 相似文献
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1/4 圆弧面沉箱防波堤设计分项系数研究(英文) 总被引:1,自引:0,他引:1
The quarter-circular caisson breakwater (QCB) is a new type of breakwater, and it can be applied in deepwater. The stability of QCB under wave force action can be enhanced, and the rubble mound engineering can be less than that of semi-circular breakwaters in deepwater. In order to study the wave force distribution acting on the QCB, to find wave force formula for this type of breakwater, firstly in this paper, the distribution characteristics of the horizontal force, the downward vertical force and the uplift force on the breakwater were gotten based on physical model wave flume experiments and on the analysis of the wave pressure experimental data. Based on a series of physical model tests acted by irregular waves, a kind of calculation method, which was modified by Goda formula, was proposed to carry out the wave force on the QCB. Secondly, the reliability method with correlated variables was adopted to analyze the QCB, considering the high correlation between wave forces or moments. Utilizing the observed wave data in engineering field, the reliability index and failure probability of QCB were obtained. Finally, a factor Q=0.9 is given to modify the zero pressure height above SWL of QCB, and wave force partial coefficient 1.34 to the design expressions of QCB for anti-sliding, as well as 1.67 for anti-overturning, were presented. 相似文献
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运用成熟的CFD商业软件FLUENT,对高位喷嘴在地铁隧道事故通风中的应用效果进行了数值模拟,得出喷口形式、射流风速对事故区间通风效果的影响情况;与模型实验相比较,验证数值模拟的可行性;对喷口射流造成的气流高速区对乘客逃生的影响情况进行分析。 相似文献
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环形试验线为保证开通速度达到120 km/h进行了大修改造作业。通过对线路道床测试数据的分析,对大修后道床状态进行评估,建议加强试验线道床的动力稳定作业,以保证线路竖向平顺性良好,确保120 km/h开通速度下列车运行安全。 相似文献
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桥梁结构中多用索和桁架来编织网格,勾勒造型。该文以某钢桁架人行桥为实例,对其空间受力特征进行了分析和探讨,突出了其空间网格桁架钢桥的特点,而非传统的钢拱桥和桁架桥。 相似文献
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带1/4圆弧面胸墙的沉箱防波堤的波浪力研究 总被引:1,自引:1,他引:0
基于带1/4圆弧面胸墙的沉箱防波堤的波浪水槽物理模型试验,通过对试验中获取的堤身及上部结构波浪压力数据的分析,得出波浪作用下防波堤水平力、胸墙竖向力和防波堤基底浮托力的分布特性,并通过对试验结果的计算分析,提出对合田公式的修正方法,该修正公式适用于带1/4圆弧面胸墙的沉箱防波堤的波浪力计算。 相似文献
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