持久极限

Based on the characteristics of stress distribution in high-pressure cylinder ,the formula of calculating the maximal equivalent stress is educed according to the fourth strength theory and the quantitative relationship between cylinder's inside pressure and diametrical ratio and the fatigue limit were founded.

基于高压缸的应力分布特点，由第四强度理论推导出了高压缸最大应力的当量应力的计算公式，建立了缸筒内压与缸筒径比及持久极限的量化关系。

Many nonferrous materials do not have a definite endurance limit.

许多有色金属材料没有确定的持久极限。

We study the profile alloy fatigue endurance limit for product design fatigue performance indicators.

研究铝合金型材的疲劳持久极限，为产品设计提供疲劳性能指标。

Through the analysis of the figure of the endurance limit of components, a correct expression about the working safe coefficient of components is obtained.

通过对构件持久极限图的分析，进行了推导，得出了构件工作安全系数的正确表达式，并分析了两者之间的误差。

The high temperature endurance limit and creep rupture strength,organization change in high temperature and the crack resistance are systematically studied.

结果表明：FNA组合接头具有较高的高温持久强度和蠕变极限，可大幅度提高设备的服役寿命，是取代旧接头形式的理想技术方案

In terms of material mechanics, the working safe coefficient of components under the same circle feature is found by two points on the same projecting line in the endurance limit figure.

由材料力学可知，在简化的构件持久极限图上，同一循环特征下，构件的工作安全系数是由同一射线上的两点得到的。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。