ot all the properties of alkenes are revealed by focusing exclusively on the func- tional group behavior of the double bond. A double bond can affect the proper- ties of a second functional unit to which it is directly attached. It can be a sub- stituent, for example, on a positively charged carbon in an allylic carbocation, or on a carbon that bears an unpaired electron in an allylic free radical, or it can

Generation of atP by using a across- membrane proton gradient, which is generated from electron flowing through chain of carriers

高分辨率电镜( High Resolution Electron Microscopy,HREM)直接 观察晶体中原子的规则排列

Conjugated unsaturated systems have a p orbital on a carbon adjacent to a double bond The p orbital can come from another double or triple bond The p orbital may be the empty p orbital of a carbocation or a p orbital with a single electron in it (a radical)

一、概述 generalization 二、X射线与X射线谱 X-ray and X-ray spectrum 三、X射线的吸收、散射和 衍射 absorption, diffuse and diffraction of X-ray

一、晶体特性 property of crystal 二、多晶粉末衍射分析法 multiple crystal powder diffraction analysis 三、单晶衍射分析法 single crystal diffraction analysis

§5-1. Saturated Polyatomic Molecules §5-2.Conjugate Molecules §5-3. Electron-deficient Molecules §5-4. Coordination Compounds §5-5. Quantum Chemical Computational Methods and Molecular Property Calculations

《固体物理学》课程教学资源（课外阅读材料）密度泛函理论 InhOmOgeIIeouS EleCtrOn Gaa

通过对镀有不同厚度（0、15、30、60 μm）Cr涂层的TC4钛合金在不同氧压下进行的富氧点燃试验，研究了镀Cr层厚度对TC4钛合金燃烧性能的影响规律，并通过扫描电子显微镜（Scanning electron microscope, SEM）、能谱分析（Energy dispersive spectrometer，EDS）和X射线衍射（X-ray diffraction, XRD）等手段进行显微组织分析。结果表明：当Cr层厚度为15 μm和30 μm时，对TC4的燃烧临界氧压无明显影响，而Cr层厚度增加到60 μm时，可将TC4的燃烧临界氧压由0.07 MPa提高至0.15 MPa。同时，燃烧速率随Cr层厚度的增加而降低，说明Cr层厚度的增加能有效抑制火焰传播速度。其作用机理可能是在燃烧的过程中，表层Cr元素通过固相扩散、熔化等方式进入熔池，与合金中的Al、V元素共同析出，形成了弥散分布的富Cr、Al、V相，并减少了Al与O的结合，对O元素的扩散有阻碍作用，从而降低了燃烧速率

A VNi atomic model for 3D periodic structure is posed based on T polyhedrons which are introduced. The fourier transform patterns of the atomic model may explain the 12-fold symmetry in electron diffraction patterns of V60Ni40 alloy. This is the first satisfactory explanation since the V60Ni40 alloy has been reported