There is a group of compounds in which carbon forms only two bonds. These neutral divalent carbon compounds are called carbenes. Most carbenes are highly unstable compounds that are capable of only fleeting existence. Soon after carbenes are formed they usually react with another molecule

These spectra are often called carbon magnetic resonance (CMR) spectra or 13C NMR spectra. In some important ways 13C spectra are usually les complex and easier to interpret than proton (1H) NMR spectra

A mass spectrometer produces a spectrum of masses based on the structure of a molecule. It is a spectrum or plot of the distribution of ion masses corresponding to the formula weight of a molecule, fragments derived from the molecule, or both

§14-3 对称及反对称性质的应用 (Application about symmetrical and antisymmetrical properties ) §14-1 静不定结构概述(Instruction about statically indeterminate structure) §14-2 用力法解静不定结构(Solving statically indeterminate structure by force method)

§1-1 材料力学的任务及研究对象(The tasks and research objects of mechanics of materials) §1-2 变形固体的基本假设(The basic assumptions of deformable body ) §1-3 力、应力、应变和位移的基本概念 ( Basic concepts of force、stress、 strain and displacement) §1-4 杆件变形的基本形式 (The basic forms of deformation)

§8-1组合变形和叠加原理 (Combined deformation and superposition method) §8-2拉伸(压缩)与弯曲的组合 (Combined axial and flexural loads) §8-3偏心拉(压)截面核心(Eccentric loads &the kern (or core) of a section) §8-4扭转与弯曲的组合 (Combined torque and flexural loads)

13.1 Photosynthesis 13.2 Chlorophylls and Bacteriochlorophylls 叶绿素与菌绿素 13.3 Accessory pigments 其它色素 13.4 Anoxygenic Photosynthesis: purple bacteria as example 不产氧光合作用 13.5 Oxygenic photosythesis 产氧光合作用

13.6 The Energetics of Chemolithotrophy 13.7 Hydrogen Oxidation 氢的氧化 13.8 Oxidation of reduced sulfur compounds 还原态硫的氧化 13.9 Iron Oxidation 铁氧化 13.10 Nitrifying bacteria 硝化细菌 13.11 Anammox Major Biosyntheses: Autotrophy and Nitrogen Fixation 13.12 Autotrophic CO2 fixation: The Calvin cycle卡尔文循环固定CO2 13.13 Autotrophic CO2 fixation: Other autotrophic pathways in phototrophs 13.14 Nitrogenase and nitrogen fixation 固氮酶与固氮作用

14.1 Enrichment and Isolation 14.2 Isolation 14.3 General Staining Methods 14.4 Phylogenetic staining using FISH 系统发育学染色: FISH技术 14.5 PCR Methods of Microbial Community Analysis 14.6 Microarrays and Microbial Diversity: Phylochips 系统发育学微阵列（芯片） 14.7 Environmental Genomics and Related Methods

I. Symbioses between Microorganisms II. Plants as Microbial Habitats 2. The Legume–Root Nodule Symbiosis 3. Agrobacterium and Crown Gall Disease 4. Mycorrhizae III. Animals as Microbial Habitats 5. The Mammalian Gut 6. The Rumen and Ruminant Animals 7. The Human Microbiome 8. Termites