semi-annual variation

The variation principle in semi-metric space and Application

半度量空间中变分原理及应用

A week a semi-annual variation of the atomic oxygen in the upper atmosphere

高层大气原子氧的半年周变

So the phloem is suitable source of callus and the infusion method is the better method. The calluses of phloem were treated by EMS to determine the semi-lethal concentration and get the variation plants.

说明韧皮部为愈伤组织的合适来源，浸泡法为较好的诱变处理方法。

The mechanisms of semi-periodic variation of chip thickness were discussed, and combining with shear angle changing and dynamic behaviour of microcracks, models of chip forming process were established for SiC_p/ Al composites with different reinforcement volume fraction. 2.

探讨了切屑厚度准周期变化的内在机制，将剪切角周期变化和微裂纹的动态影响相结合，建立了适应含不同颗粒体分比的该材料的切屑形成过程模型。

Thickness Variation Research of Drawing Process of Thick-Wall Semi-Spherical Heads

半球形厚壁封头拉深成形壁厚变化规律研究