88.1 Introduction 88.2 Memory Hierarchies 88.3 Cache Memories 88.4 Parallel and Interleaved Memories 88.5 Virtual Memory 88.6 Research Issues

Positional and Polynomial Representations • Unsigned Binary Number System • Unsigned Binary-Coded Decimal, Hexadecimal, and Octal Systems • Conversion between Number Systems • Signed Binary Numbers • Floating-Point Number Systems 86.2 Computer Arithmetic Number Representation • Algorithms for Basic Arithmetic

84.1 Introduction 84.2 The Analog and Digital Signal Interface 84.3 Analog Signal Conditioning 84.4 Sample-and-Hold and A/D Techniques in Data Acquisition

containing the components of a computer central processor, complete with instruction processing unit, arithmetic, interrupt , and basic communication facilities. Such devices have been around since the early 1970s and have greatly benefitted from the continuing

100.1 Models Classes of Systems to Be Modeled • Two Major Approaches to Modeling • Forms of the Model • Nonuniqueness • Approximation of Continuous Systems by Discrete Models 100.2 Dynamic Response

98.1 Introduction 98.2 Definitions of Failure, Fault, and Error 98.3 Failure Rate and Reliability 98.4 Relationship Between Reliability and Failure Rate 98.5 Mean Time to Failure 98.6 Mean Time to Repair 98.7 Mean Time Between Failures

96.1 Introduction 96.2 Types of Operating Systems 96.3 Distributed Computing Systems 96.4 Fault-Tolerant Systems 96.5 Parallel Processing 96.6 Real-Time Systems 96.7 Operating System Structure 96.8 Industry Standards 96.9 Conclusions

94.1 Databases Database Abstraction • Data Models • Relational Databases • Hierarchical Databases • Network Databases • Architecture of a DBMS • Data Integrity and Security • Emerging Trends 94.2 Rule-Based Expert Systems

环境现状调查是环境影响评价的组成部分，一般情况下应根据建设 项目所在地区的环境特点，结合环境要素影响评价的工作等级，确定 各环境要素的现状调查范围，并筛选出应调查的有关参数。 环境现状调查中，对环境中与评价项目有密切关系的部分（如大气、 地面水、地下水等）应全面、详细，对这些部分的环境质量现状应有 定量的数据并做出分析或评价；对一般自然环境与社会环境的调查， 应根据评价地区的实际情况进行调查

一、概述 《环境影响评价技术导则—地面水》规定了建设项目环境影响评价的一般性 原则、方法、内容及要求。适用于厂矿企业、事业单位建设项目的环境影响评价 工作， 其它建设项目的环境影响评价工作也可参照本导则所规定的原则和方法 进行