化学研究尤其是原子和分子系统物质的组成、结构、属性及反应的科学 The science of the composition, structure, properties, and reactions of matter, especially of atomic and molecular systems.
射影的指定几何图形属性的，以便当这个图形经受影射时不发生变化 Designating a property of a geometric figure that does not vary when the figure undergoes projection.
