主题：【分享】科研仪器英语口语每日一练 2017/5/29

科研仪器英语口语每日一练(适合化工英语，外企面试口语，出国留学交流，日常英语口语)
作者：chaos

This is Daily English Learning of Analytical Instrument. Today the topic is Ultraviolet-visible spectroscopy
NOW let's begin the
part 1
Vocabularies:
1.工作原理 working principle
2.紫外光灯 ultra-violet light
3.可见光谱  visible spectrum
4.紫外光吸收 ultraviolet light absorption
5.电子转移electronic transitions
6.π电子 π-electrons
7. 比尔朗博定律Beer-Lambert law
8.标准曲线 calibration curves
9.共轭 conjugation
10.分子轨道 molecular orbitals
二Sentence:
1.概述了紫外光谱法在研究金属配合物与DNA相互作用中的应用。
The application of the UV spectra in the interaction of DNA and metal complex was summarized.
2.解释了紫外光谱中的最大吸收波长与结构的关系。
The relationship between the wavelength of maximum absorption and structure was also explained.
3.其产品的特性用元素分析，红外和紫外光谱，NMR，DSC，TG等进行了详细地表征。
The product has been characterized in detail by elemental analysis, infrared, UV, NMR spectra, DSC and TG etc.
4.洛美沙星在酸性介质中的紫外光谱性质的研究及应用
The Study of the Property of Lomefloxacin UV Spectrum in Acid Media and Its Application
5.紫外光谱标准加入法测定胃液中维生素C的含量
The Standard Addition Method of the Determination Vitamin C in Human's Gastric Juice Under the Ultraviolet Spectra
三Principles:

Ultraviolet-visible spectroscopy or ultraviolet-visible spectrophotometry (UV-Vis or UV/Vis) refers to absorption spectroscopy or reflectance spectroscopy in the ultraviolet-visible spectral region. This means it uses light in the visible and adjacent ranges. The absorption or reflectance in the visible range directly affects the perceived color of the chemicals involved. In this region of the electromagnetic spectrum, atoms and molecules undergo electronic transitions. Absorption spectroscopy is complementary to fluorescence spectroscopy, in that fluorescence deals with transitions from the excited state to the ground state, while absorption measures transitions from the ground state to the excited state
UV/Vis spectroscopy is routinely used in analytical chemistry for the quantitative determination of different analytes, such as transition metal ions, highly conjugated organic compounds, and biological macromolecules. Spectroscopic analysis is commonly carried out in solutions but solids and gases may also be studied.
The Beer-Lambert law states that the absorbance of a solution is directly proportional to the concentration of the absorbing species in the solution and the path length. Thus, for a fixed path length, UV/Vis spectroscopy can be used to determine the concentration of the absorber in a solution. It is necessary to know how quickly the absorbance changes with concentration. This can be taken from references (tables of molar extinction coefficients), or more accurately, determined from a calibration curve.