Lubricant used in the ball groove rolling sliding contact pair of a heavy load tracked vehicle is a lithium base grease which is waterproof and heat-resistant.
Quantum wave packet analysis in the rectangular billiard;
矩形弹子球中的量子波包分析(英文)
Quantum spectra and classical periodic orbits in a rectangular billiard;
矩形弹子球中的量子谱和经典周期轨道(英文)
The article analyzes the reasons and affecting elements for the traces left by duplicate keys compared with the traces left in spring locks by original keys , thus does some research in distinguishing unlocking traces.