• 4.1 计算机安全性概论 • 4.2 数据库安全性控制 • 4.3 视图机制 • 4.4 审计(Audit) • 4.5 数据加密 • 4.6 统计数据库安全性

1.1 信息 1.1.1 信息概述 1.1.2 信息技术的发展 1.1.3 计算机技术的发展 1.2 计算机中的信息表示 1.2.1 进位计数制 1.2.2 不同计数制之间的转换 1.2.3 计算机使用二进制数 1.2.4 计算机信息编码技术 1.3 计算机系统 1.3.1 硬件系统 1.3.2 软件系统

How are molecular structures determined? One way is though the use of spectroscopic methods. Spectroscopy is the study of the interaction of energy with matter. When energy is applied to matter it can be absorbed, emitted, cause a chemical change, or be transmitted

11.1 羧酸衍生物的命名 Nomenclature of Carboxylic Acid Derivatives 11.2 羧酸衍生物的结构和反应性 Structure and Reactivity of Carboxylic Acid Derivatives 11.3 羧酸衍生物的制备 Preparation of Carboxylic Acid Derivatives 11.4 羧酸衍生物的水解 醇解 氨解反应 Hydrolysis, Alcoholysis and Amonolysis Reactions of Carboxylic Acid Derivatives 11.5 羧酸衍生物的其它反应 Other Reactions of Carboxylic Acid Derivatives 11.6 酯缩合反应 Ester Condensation Reactions 11.7 油脂和蜡 Fats and Waxes

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

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

1. The experimental conditions — temperature and acid concentration — that are required to being about dehydration are closely related to the structure of the individual alcohol. The relative ease with which alcohols undergo dehydration is in the following order:

The C—X bond of alkyl halides is polarized. The carbon atom bears a partial positive charge, The halogen atom a partial negative charge

The different arrangements of atoms caused by rotation about a single bond are called conformations (构象)of the molecule, and a specific conformation is called a conformer (构象异构体, conformation isomer). An analysis of the energy changes that a molecule undergoes as groups rotate about single bonds is called a conformational analysis (构象分析)