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应⽤化学专业英语第⼆版万有志主编版课后答案和课⽂翻译Unit 1 The Roots of ChemistryI. Comprehension.1.C2. B3. D4. C5. BII. Make a sentence out of each item by rearranging the words in brackets.1.The purification of an organic compound is usually a matter of considerable difficulty,and it is necessary to employ various methods for this purpose.2.Science is an ever-increasing body of accumulated and systematized knowledge and isalso an activity by which knowledge is generated.3.Life, after all, is only chemistry, in fact, a small example of chemistry observed on asingle mundane planet.4.People are made of molecules; some of the molecules in people are rather simplewhereas others are highly complex.5.Chemistry is ever present in our lives from birth to death because without chemistrythere is neither life nor death.6.Mathematics appears to be almost as humankind and also permeates all aspects ofhuman life, although many of us are not fully aware of this.III. Translation.1.(a) chemical process (b) natural science (c) the technique of distillation2.It is the atoms that make up iron, water, oxygen and the like/and so on/and soforth/and otherwise.3.Chemistry has a very long history, in fact, human activity in chemistry goes back toprerecorded times/predating recorded times.4.According to/From the evaporation of water, people know/realized that liquids canturn/be/change into gases under certain conditions/circumstance/environment.5.You must know the properties of the material before you use it.IV. Translation化学是三种基础⾃然科学之⼀，另外两种是物理和⽣物。
纳米材料的现代表征技术-课件电子能谱石建英中山大学化学与化学工程学院电子能谱分类X射线光电子能谱(简称XPS)(X-Ray Photoelectron Spectrometer)紫外光电子能谱(简称UPS) (Ultraviolet Photoelectron Spectrometer)俄歇电子能谱(简称AES)(Auger Electron Spectrometer)对固体样品，必须考虑晶体势场和表面势场对光电子的束缚作用，通常选取费米(Fermi)能级为的参考点。
b E 0k时固体能带中充满电子的最高能级对孤立原子或分子，就是把电子从所在轨道移到真空需的能量，是以真空能级为能量零点的。
b E φ++=b k E E hv 功函数φ++=b k E E hv 功函数为防止样品上正电荷积累，固体样品必须保持和谱仪的良好电接触，两者费米能级一致。
实际测到的电子动能为：spb s sp k k E hv E E φφφ−−=−−=)('spkb E hv E φ−−='仪器功函数特征：XPS采用能量为的射线源，能激发内层电子。
各种元素内层电子的结合能是有特征性的，因此可以用来鉴别化学元素。
eV 1500~1000UPS采用或作激发源。
与X 射线相比能量较低，只能使原子的价电子电离，用于研究价电子和能带结构的特征。
I(21.2eV) He II(40.8eV) He AES大都用电子作激发源，因为电子激发得到的俄歇电子谱强度较大。
光电子或俄歇电子，在逸出的路径上自由程很短，实际能探测的信息深度只有表面几个至十几个原子层，光电子能谱通常用来作为表面分析的方法。
X-ray Photoelectron Spectroscopy (XPS)XPS BackgroundXPS technique is based on Einstein’s idea about the photoelectric effect, developed around 1905\The concept of photons was used to describe the ejection of electrons from a surface when photons were impinged upon itDuring the mid 1960’s Dr. Siegbahn and his research group developed the XPS technique.\In 1981, Dr. Siegbahn was awarded the Nobel Prize in Physics for the development of the XPS techniqueIntroduction•X-ray photoelectron spectroscopy works by irradiating a sample material with monoenergetic soft x-rays causing electrons to be ejected.•Identification of the elements in the sample can be made directly from the kinetic energies of these ejected photoelectrons.•The relative concentrations of elements can be determined from the photoelectron intensities.Introduction (XPS)---Analysis capabilities•Elements detected from Li to U.•None destructive (some damage to x-ray beam sensitive materials)•Quantitative.•Chemical state analysis (some exceptions)•Surface sensitivity from 5 to 75 angstroms.•Conducting and insulating materials.•Detection limits that range form 0.01 to 0.5 atom percent.•Spatial resolution for surface mapping from >10 mm •Depth profiling capabilities.Photoemission of ElectronsConduction BandValence BandL2,L3L1K Fermi LevelFree Electron Level (vacuum)Incident X -ray Ejected Photoelectron1s 2s2p¾XPS spectral lines are identified by the shell from which the electron was ejected (1s, 2s, 2p, etc.).¾The ejected photoelectron has kinetic energy:¾KE= hv –BE -φ¾Following this process, the atom willrelease energy by the emission of aphoton or Auger Electron.XPS Energy Scale -Binding energyBE = hv-KE -ΦspecWhere: BE= Electron Binding EnergyKE= Electron Kinetic EnergyΦ= Spectrometer Work FunctionspecPhotoelectron line energies: Not Dependent on photon energy.X-RaysIrradiate the sample surface, hitting the core electrons (e-) of the atoms.The X-Rays penetrate the sample to a depth on the order of a micrometer.Useful e-signal is obtained only from a depth of around 10 to 100 Åon the surface.The X-Ray source produces photons with certain energies: \MgKαphoton with an energy of 1253.6 eV\AlKαphoton with an energy of 1486.6 eVNormally, the sample will be radiated with photons of a single energy (MgKαor AlKα). This is known as a monoenergetic X-Ray beam.Why the Core Electrons?An electron near the Fermi level is far from the nucleus, moving in different directions all over the place, and will not carry information about any single atom.\Fermi level is the highest energy level occupied by an electron in a neutral solid at absolute 0 temperature.\Electron binding energy (BE) is calculated with respect to the Fermi level. The core e -s are local close to the nucleus and have binding energies characteristic of their particular element.The core e -s have a higher probability of matching the energies of AlK αand MgK α.Core e -Valence e -Atom电离截面σ: 光电离过程发生的几率•由于光电子发射必须由原子的反冲来支持，所以同一原子中轨道半径愈小的壳层σ愈大。
