Economic Valuation of a Mangrove Ecosystem Threatened by Shrimp Aquaculture in Sri Lanka

Mangrove ecosystems in Sri Lanka are increasingly under threat from development projects, especially aquaculture. An economic assessment is presented for a relatively large (42 ha) shrimp culture development proposed for the Rekawa Lagoon system in the south of Sri Lanka, which involved an extended cost–benefit analysis of the proposal and an estimate of the “total economic value” (TEV) of a mangrove ecosystem. The analysis revealed that the internal benefits of developing the shrimp farm are higher than the internal costs in the ratio of 1.5:1. However, when the wider environmental impacts are more comprehensively evaluated, the external benefits are much lower than the external costs in a ratio that ranges between 1:6 and 1:11. In areas like Rekawa, where agriculture and fisheries are widely practiced at subsistence levels, shrimp aquaculture developments have disproportionately large impacts on traditional livelihoods and social welfare. Thus, although the analysis retains considerable uncertainties, more explicit costing of the environmental services provided by mangrove ecosystems demonstrates that low intensity, but sustainable, harvesting has far greater long-term value to local stakeholders and the wider community than large shrimp aquaculture developments.     

"扩大生产者责任"原则及其在循环经济发展中的作用

循环经济是我国实现“走新型工业化道路”的具体实践模式,是有效协调我国社会进步、经济发展、资源利用与环境保护的重要手段。“扩大生产者责任”（EPR）原则符合循环经济的基本理念,是实现循环型社会的主要政策工具。从“扩大生产者责任”原则的目的和定义入手,指出扩大生产者责任是手段而不是目的。鉴于生产者在产品生命链中的核心作用。扩大生产者责任可以有效地实现废弃产品回收责任在不同利益群体之间的分配,实现产品废弃物回收成本的最小化,从根本上改变现有的生产和生活摸式。     

扩展性案例在《Web应用开发技术》课程教学中的应用

《Web应用开发技术》是一门实践性和综合性较强的课程,扩展性案例的选取对课程教学具有重要作用。以＂登录注册系统＂为例,通过不断扩展该案例的功能,把各章知识点逐步融入到扩展性案例当中,使学生对各章主要知识点的应用有一个清晰的整体认识,激发学生求知、求技、求异、求新的兴趣,实现理论与实践的统一。     

基于TPB的通航企业事件信息自主上报意愿影响因素研究*

为探讨通航企业不安全事件信息自主上报意愿的影响因素,基于扩展计划行为理论的分析框架,采用结构方程模型和差异显著性分析,对我国通航企业170份样本数据进行分析。结果表明:企业性质、规模和成立年限显著影响企业事件信息报告行为意向。其中,国有企业行为意向显著高于民营企业,500人以上较大规模企业行为意向显著高于500人以下较小规模企业,成立3 a以上企业的行为意向显著高于成立3 a以下的企业。此外,通航企业不安全事件自主上报的行为意向直接影响因素包括行为态度、主观规范、知觉行为控制、感知成本及认知,间接影响因素是感知成本与感知收益、示范性规范与指令性规范。