“umbra”的概念、定义、翻译、参考文献-科学参考

单词	umbra
释义	umbra [`ǝm·brǝ] ^ASTRONOMY The dark, central region of a sunspot. ^OPTICS That portion of a shadow which is screened from light rays emanating from any part of an extended source.
随便看	painter pain threshold paint pot paint program paint remover paint vehicle pair paired cable paired comparison paired electron paired terrace pairing pairing element pairing energy pairing isomer pair production paisanite Palaeacanthaspidoidei Palaeacanthocephala Palaechinoida Palaemonidae Palaeocaridacea Palaeocaridae Palaeoconcha Palaeocopida

科学参考收录了103327条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。