名词

1. (原子)核
The nucleus of an atom or cell is the central part of it.

2. (组织的)核心，中心
The nucleus of a group of people or things is the small number of members which form the most important part of the group.

1. the central structure of the lens that is surrounded by the cortex

Synonym: lens nucleus

2. a part of the cell containing DNA and RNA and responsible for growth and reproduction

Synonym: cell nucleuskaryon

3. any histologically identifiable mass of neural cell bodies in the brain or spinal cord

4. a small group of indispensable persons or things

e.g. five periodicals make up the core of their publishing program

Synonym: corecore group

5. the positively charged dense center of an atom

6. (astronomy) the center of the head of a comet
consists of small solid particles of ice and frozen gas that vaporizes on approaching the sun to form the coma and tail