神秘的水下居民

当代有些科学家认为,在地球海洋深处的某些地方,可能存活着一些智力高度发达的生命体--海底人.近些年来,地球各大洋水域都曾出现过不明潜水物,它们也为海底人的假想提供了一些线索.……     

人造金刚石的故事

金刚石作为一种稀有的贵重物品,自古以来就是财富的重要象征。 在大自然中,金刚石以极少的矿藏量深埋在地底下。偏偏是这种少得出奇的金刚石,具有世界万物中独一无二的特性：它是自然界中最硬的一种矿石。金刚石的这一特性,使它具有广泛的社会用途：有人将它镶嵌在金光闪闪的戒指、耳环等首饰中,以象征坚贞不渝的爱情;     

Research progress of buckling propagation experiment of deep-water pipelines

In recent years, the extraction of fossil resources, especially oil and gas in deep and ultra-deep water areas has been playing a more important role and been paid more attention to. For this reason, the working depth of submarine pipelines, which are used for the transportation of oil and gas, has been increasing sharply. As the main failure pattern of deep-water pipelines, buckling and its propagation problem have drawn more attention of many research institutions and engineering units around the world. Based on the existing research, the summary of experiments and their outcomes of deep-water pipeline buckling failure is made in this paper. Research status and developing prospects of the experiments of buckling propagation and buckle arrestor are discussed in detail.