什么是光谱学
一种分析技术,用於鉴别化学元素和化合物,测量物质在外部能源的激发下,吸收或发射电磁波谱(包括γ射线、X射线、紫外辐射、可见光、红外辐射、微波以及无线电频率的辐射)中特徵波长的辐射能量,从而阐明其原子和分子结构。所用的仪器是分光镜(用於直接观察)和摄谱仪(用於记录光谱)。实验包括一个光源、一块用来形成光谱的棱镜或光栅、用来观察或记录光谱细节的探测器(视觉的、光电的、测辐射的或者摄影的)、测量波长和强度的装置以及对测得的量作出解释以识别它的化学身分,或给出关於它的原子和分子结构的线索。19世纪中叶用光谱技术分析太阳光谱而发现了氦、铯和铷。专门的光谱技术有拉曼光谱(参阅Raman, Chandrasekhara Venkata)、核磁共振、原子核四极矩共振、动态反射光谱、微波和γ射线光谱,以及电子自旋共振。亦请参阅mass spectrometry、spectrophotometry。
spectroscopy
Branch of analysis devoted to identifying elements and compounds and elucidating atomic and molecular structure by measuring the radiant energy absorbed or emitted by a substance at characteristic wavelengths of the electromagnetic spectrum (including gamma ray, X ray, ultraviolet, visible light, infrared, microwave, and radio-frequency radiation) on excitation by an external energy source. The instruments used are spectroscopes (for direct visual observation) or spectrographs (for recording spectra). Experiments involve a light source, a prism or grating to form the spectrum, detectors (visual, photoelectric, radiometric, or photographic) for observing or recording its details, devices for measuring wavelengths and intensities, and interpretation of the measured quantities to identify chemicals identifications or give clues to the structure of atoms and molecules. Helium, cesium, and rubidium were discovered in the mid-19th century by spectroscopy of the sun's spectrum. Specialized techniques include Raman spectroscopy (see Chandrasekhara Venkata Raman), nuclear magnetic resonance (NMR), nuclear quadrupole resonance, dynamic reflectance spectroscopy, microwave and gamma ray spectroscopy, and electron spin resonance (ESR). See also mass spectrometry, spectrophotometry.
-
野无遗贤是什么意思?
意思是:民间没有被弃置不用的人才。指任人唯贤,人尽其才。成语名字:野无遗贤成语发音:yěwúyíxián成语解释:民间没有被弃置不用的人才。指任人唯贤,人尽其才。成语出处:《尚书大禹漠》:“野无遗贤,万邦咸宁。”成语繁体:野無遺賢感情色彩:褒义成语成语用法:主谓式;作定语...
-
野无遗才是什么意思?
意思是:见“野无遗贤”。成语名字:野无遗才成语发音:yěwúyícái成语解释:见“野无遗贤”。成语出处:《魏书·阳尼传》:“举贤良,黜不肖,使野无遗才,朝无素餐。”成语繁体:野無遺才感情色彩:中性成语成语用法:作宾语、定语;指爱惜人才成语结构:偏正式成语产生年代:古代成语...
-
穷途之哭是什么意思?
意思是:因车无路可行而悲伤,后指处于困境所发的绝望的哀伤。成语名字:穷途之哭成语发音:qióngtúzhīkū成语解释:因车无路可行而悲伤,后指处于困境所发的绝望的哀伤。成语出处:《晋书阮籍传》:“时率意独驾,不由径路,车迹所穷,辄痛哭而返。”成语繁体:窮途之哭感情色彩:中...
-
一如既往是什么意思?
意思是:指态度没有变化;完全像从前一样。一:完全;如:像;既往:从前。成语名字:一如既往成语发音:yīrújìwǎng成语解释:指态度没有变化;完全像从前一样。一:完全;如:像;既往:从前。成语出处:《第二次握手六》:“清末以来,到海外求学的中国人何止千百,在学业上有成就的也大有人在,可...