OSI参考模型与现场总线通信模型的发展与应用

主要介绍了OSI参考模型与现场总线的基本概念及其发展和在工业中的应用，介绍了几种主要的现场总线通信模型与OSI参考模型之间的相互关系。根据现场总线技术在现实中的应用，指出控制系统的开放互连是发展的必然。     

一种MPEG4视频压缩和传输系统

介绍了一种以AT91RM9200为核心的实时视频压缩和传输系统，详细讨论了其结构与软、硬件实现。该系统成本较低、使用灵活，可方便的嵌入到需要视频监控的监测系统中。     

浅议网络安全技术问题

本文首先阐述了信息安全对国家安全的重要性，然后针对互联网络中存在的安全隐患问题提出一些解决技术，并对网络信息这安系统体系结构及功能作了一些介绍。最后，对网络安全管理的关键问题提出了一些探讨。     

Dante技术：音频传输技术发展的趋势（李薇约）

随着科学技术的快速发展,千兆以太网的普及和爆炸式增长,音频技术的创新和普及也步入了崭新的阶段。录音师们总是希望通道数量增多、传输速度加快、调音台性能更多、音频接口归一化、系统集成性能越来越高,并逐渐不能满足传统物理性的模拟化电缆信号传输或者数字化的电缆以及光缆信号传输,数字化二进制码的网络化信号传输进入了人们的视线。现对音频信号的传输与分配的三个阶段进行分析比较,以Dante技术为例,浅析音频信号传输与分配的网络化发展趋势。     

Flow injection analysis as a tool for enhancing oceanographic nutrient measurements—A review

Macronutrient elements (C, N and P) and micronutrient elements (Fe, Co, Cu, Zn and Mn) are widely measured in their various physico-chemical forms in open ocean, shelf sea, coastal and estuarine waters. These measurements help to elucidate the biogeochemical cycling of these elements in marine waters and highlight the ecological and socio-economic importance of the oceans. Due to the dynamic nature of marine waters in terms of chemical, biological and physical processes, it is advantageous to make these measurements in situ and in this regard flow injection analysis (FIA) provides a suitable shipboard platform. This review, therefore, discusses the role of FIA in the determination of macro- and micro-nutrient elements, with an emphasis on manifold design and detection strategies for the reliable shipboard determination of specific nutrient species. The application of various FIA manifolds to oceanographic nutrient determinations is discussed, with an emphasis on sensitivity, selectivity, high throughput analysis and suitability for underway analysis and depth profiles. Strategies for enhancing sensitivity and minimizing matrix effects, e.g. refractive index (schlieren) effects and the important role of uncertainty budgets in underpinning method validation and data quality are discussed in some detail.     

SDH管理系统的原理与实现

本文从ＩＴＵ－Ｔ标准和具体实现两个方面论述ＳＤＨ管理系统的体系结构、管理服务功能、通信协议和信息模型。兼述目前国际电联对于电信管理网ＴＭＮ中几个管理接口的标准讨论。     

Distributed resource management and connection control for a multi-access interface to a broadband ISDN (BISDN)

A customer premises network (CPN) provides a common communications fabric to efficiently integrate the traffic of multiple terminals on a common access interface to a BISDN. An important consideration in choosing a CPN architecture is to facilitate terminal portability and application transparency, so as to accommodate standard broadband terminals and applications, requiring only minor modification to adapt them from the standard BISDN interface to the multi-terminal environment. This paper explores the multi-faceted issues of CPN transparency with an emphasis on the evolving BISDN control and management architecture. We introduce a control architecture that conforms to a rigorous separation between ‘call control’ and ‘connection management’. This allows the CPN to be transparent to the user to network signalling exchange, and to participate only in the connection management via a remote resource management protocol. More generally, this scheme allows a call control entity located in a local exchange node (LEN) to manage a distributed set of resources such as switches and multiplexors (and CPNs). This is achieved through the definition of a standard interoperable interface between the central call control entity and the connection control entities which may be remotely located in various network elements. The features and functionality for such an interface, which we term the bearer connection control interface, are described within the framework of the OSI remote management architecture. A standard remote resource management protocol allows for the co-operative sharing of resources across administrative domains. Although the importance of such a scheme is particularly visible as applied to remote CPN management, it is useful in other application domains where it is advantageous to distribute management processes.     

The orthosomycin family of antibiotics—I : The constitution of flambamycin

The antibiotic, flambamycin, is shown to have the novel oligosaccharide structure (1) associated with two orthoester linkages. It is proposed that flambamycin (1), the everninomicins (28), curamycin, avilamycin, destomycin A (29a), destomycin C (29b), destomycin B (30), hygromycin B (29c), the antibiotics A-396-I (29d) and SS-56C (29e), belong to a new family of antibiotics called the orthosomycins.     

Challenges in preparing water-matrix reference materials for PAHs and pesticides: examples from SWIFT-WFD proficiency-testing schemes

In accordance with Article 8 of the European Union (EU) Water Framework Directive (WFD), EU Member States are required to establish monitoring programs for the quality of the surface water and the groundwater within each river-basin district. As such data are the basis for regulatory decisions and measures required to achieve WFD environmental objectives, appropriate analytical quality-assurance and quality-control tools have to be implemented by the monitoring laboratories. In this respect, reference materials (RMs) play a key role. Within the framework of the SWIFT-WFD project (Screening methods for Water data InFormation in support of the WFD), several approaches to the preparation of matrix RMs for the analysis of polycyclic aromatic hydrocarbons and pesticides in water have been used in wide-scale proficiency-testing (PT) schemes. We present the different strategies employed in preparing water-matrix RMs for organic analytes. By reviewing the results from the SWIFT-WFD PT schemes, we reflect on the applicability and the suitability of the different approaches.