Dynamic land use and land cover changes and their effect on forest resources in a coastal village of Matemwe,Zanzibar, Tanzania

Recent land cover change estimates show overall decline of tropical forests at the regional and global scales caused by multiple social, cultural and economic factors. There is an overall concern on the prevailing land use practices, such as shifting cultivation and extraction of forest materials as agents of forests losses, but also new, emerging land uses are threatening tropical forests. Understanding of the long-term development and driving forces of forest changes are needed, especially at local levels where many decisions on forest policies and land uses are made. This paper addresses the importance of such information for improved estimates of forest dynamics by studying local level land cover and land use changes during the last 50–70 years in the Eastern African tropical island of Zanzibar, Tanzania. The paper discusses the role of traditional and new land uses mainly subsistence farming, tourism and government interference through tree planting, in the long-term development of the forests at the village level. The material for the study is gathered from the interpretation of archival maps and aerial photographs combined with contemporary digital aerial photographs. The analyses are based on the mapping, spatial sampling and spatio-temporal change trajectory analysis (LCTA) of forest land cover, forest land uses and settlement patterns with GIS and statistics. Six distinct forest land cover change trajectories were identified and these illustrate dynamic and heterogeneous nature of the forests. Closed forest cover has dominated throughout due to cyclical land use patterns, but over 70% of the land area has been continuously transforming between closed, semi-open and open land cover conditions. Land use turnover rates indicate that hardly any forest areas are left untouched from the forces, which remove and re-establish forest vegetation in the long run. Land cover and land use change trajectories are spatially fragmented in the studied landscape. Majority of forest loss-gain dynamics is caused by shifting cultivation, while forest losses are most dramatic along the coast, where traditional and new land uses meet and land uses pressures are highest. The study suggests that landscape change trajectory analyses, where contemporary and historical information on land uses and land cover changes are spatially linked, can provide valuable aspects into local level forest land use planning and management strategies. For the case study, the findings suggest the following key forest management strategies for consideration: (1) establishment of a protected forest/scrubland in participation with the local stakeholders, especially the farmers, (2) promotion of areas for permanent agricultural practices, while simultaneously introducing management controls in the traditional slash-and-burn farming areas, and (3) promoting new livelihood opportunities for the farmers, who have traditionally been dependent on forest resources, meanwhile introducing alternatives for fuel wood for cooking.     

新一代入侵防御系统应用

IPS入侵防御系统目前已经得到大规模的应用,本文对迪普IPS2000型入侵防御系统的性能特性进行了详细研究,并在实际网络中部署了该系统。     

Reciprocity in Ranked Relationships: Does Social Structure Influence Social Reasoning?

Many economic and evolutionary theories have modeled cooperation as the evolutionary outcome of decisions made by autonomous, self-interested agents operating in a social vacuum. In this paper we consider the implications for cooperative interactions when prior social structures and corresponding social norms exist. In particular we investigate the influence of social rank/status on perceptions of fairness and tolerance of cheating. We review evidence from a series of experiments employing the Wason selection task (a test of conditional reasoning) and the ledger task (a decision making task) suggesting that people cued to adopt a perspective of high social rank are more tolerant of cheating and simultaneously believe that they have been more fairly treated (even when cheated) than people cued to adopt a perspective of low social rank. However, the evidence also suggests interesting cross-cultural differences in perceptions of fairness and tolerance of cheating in ranked relationships. This revised version was published online in August 2006 with corrections to the Cover Date.     

用螺纹量规检测产品产生争议时的解决方法

本文分析了检测结果合格的螺纹量规检测螺纹产品时出现的疑问,并解答这些疑问。     

检测环境对路面弯沉检测结果的影响

路面弯沉是路面及路基结构整体强度和刚度的直观反应,是工程整体强度质量的重要检测指标。因此,了解路面湾沉的变化规律,正确测试路面弯沉值,对于正确评价路面质量有着极其重要的意义。     

烷基酚聚氧乙烯醚应用在纺织品中对环境的影响

列举了APEO在纺织品中的一些应用和检测纺织品中其含量的检测方法。阐述了应用在纺织品中的APEO对环境的影响，并提出一些应对及补救措施。     

智能型面积测量仪

提出1种以MCS-51单片机为核心,集微电子、光电检测及电感检测技术为一体的面积测量方法,介绍了它的设计、组成和故障诊断方法,指出其采用容错技术、自校正技术和抗干扰技术后具有测量精度高、性能价格比高等特点,且少量传感器出现故障时不影响测量精度,适用于测量皮革及其他不规则片状物体的面积。     

工程报验在西部管道工程中的应用

对长庆石油勘探局建设工程总公司在西部管道工程中建立的报验模式作了介绍，并对运用报验来达到控制工程质量作了阐述。指出工程报验是质量控制的重要环节。     

充分运用量值溯源提高检测工作质量

根据笔者在实验室长期工作的经验,结合实验室的相关标准,按量值溯源的管理途径,进一步阐述了实验室充分运用量值溯源信息,对仪器设备和标准物质进行科学管理的具体方法和措施,为不断提高检测工作质量提供了有力的保证。     

微电子机械系统ADXL345的应用研究

微电子机械系统因其成本低、可靠性高、功耗低、体积小和重量轻等特点,在便携式电子设备中应用广泛。文章通过S3C2440针对美国ADI公司最新推出的三轴数字加速度计ADXL345进行运动特性的检测研究,为该器件的应用开发提供了一种方法。