The distribution and heat stability of nitrogen in coal tar refined soft pitch were discussed by element analysis,and unstable nitrogen was analyzed by IR.
以高温煤焦油为原料,经蒸馏、溶剂萃取沉降以制得煤焦油精制软沥青,再经溶剂索氏提取制备族组成;通过元素分析来研究杂原子氮的分布和热稳定性,通过红外光谱(IR)鉴别不稳定性氮基团的结构。
Radiographic Inspection of Welded Joints of Large-diameter Thick-walled Pipelines Using Ir-192;
Ir-192射源的大口径厚壁管道焊口射线探伤
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