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1.
In order to determine the distribution and enable the elimination of quinalphos, a popular active pesticide compound used in the Mekong Delta, an experiment was set up in a rice-fish integration system in Can Tho City, Vietnam. Fish was stocked into the field when the rice was two-months old. Quinalphos was applied twice in doses of 42.5 g per 1000 m2. Water, fish and sediment samples were collected at time intervals and analyzed by a Gas Chromatography Electron Capture Detector system. The results show that quinalphos residues in fish muscles were much higher than those of the water and the bioconcentration factor (logBCF) was above 2 for the fish. The half-life of first and second quinalphos applications were 12.2 and 11.1 days for sediment, 2.5 and 1.1 days for silver barb, 1.9 and 1.3 days for common carp, and 1.1 and 1.0 days for water, respectively.  相似文献   
2.
阐述了水生态健康的内涵与意义,从江苏省率先在太湖流域开展水生态环境功能分区管理的顶层设计,构建以水生态健康指标为核心的水生态健康评估技术体系,地方对照水生态环境功能区划的水生态分级管控目标开展的应用与实践结果等3个方面,回顾了江苏省太湖流域水生态健康评估工作的主要进展,提出了完善水生态健康评估技术体系和推进流域水生态健康评估工作的建议。  相似文献   
3.
分析国内外生态环境科技创新的发展现状,相比较国外以市场机制为导向、以企业为创新主体、政府通过政策和管辖支撑创新的体系特征,我国已形成四大类环境类科创载体,但尚未形成成熟有效的技术成果产业化机制以及市场与政策协同促进科技创新的发展模式。本文根据生态环境科技创新的强政策驱动性、技术验证放大周期长以及集成性强的特点,重点通过环境技术研发、技术成果转化、技术放大与赋能、产业拓展与推广四个方面阐述了生态环境科技创新体系建设的主要环节:环境技术的研发由以科研机构为主的传统自发性研发、企业迭代性研发和联合应用型研发组成;技术成果的转化经历挖掘发现、技术识别与判断、知识产权评估评价后进入已成立的企业或新设公司,在这一过程中,成果转化专业队伍起着至关重要的作用;技术放大与赋能旨在为有创新技术的企业提供科技创新政策、二次研发中试验证、首台套工程案例、投融资等资源的对接,以协助初创企业成长;产业的拓展与推广则通过为解决环境问题形成集成方案、孵化平台为企业背书和产业政策匹配等方式助力企业长期发展。最后从加强专业化创新平台、技术评估体系、成果转化人才培养体系建设以及疏通投融资渠道等方面对中国未来生态环境科技创新发展提出相关建议。  相似文献   
4.
通过对我国辐射环境监测相关法规的调研,在深入分析当前辐射环境监测法规框架结构和突出问题的基础上,构建我国辐射环境监测法规体系,重点关注辐射环境质量监测、核与辐射监督性监测及应急监测等方面的工作需求,提出完善部门规章、健全核安全导则及规范性文件的建议。  相似文献   
5.
试论生态文明制度体系的构建   总被引:3,自引:2,他引:1       下载免费PDF全文
建立健全生态文明制度体系是推进我国生态文明建设的重点。党的十八届三中全会通过的《中共中央关于全面深化改革若干重大问题的决定》指出,生态文明制度体系应当包括决策制度、评价制度、管理制度与考核制度等内容。立足社会主义制度建设的中国特色,针对我国生态文明建设的具体需求,本文将生态文明制度体系解构为四大板块:绿色高效决策制度、生态有价评估制度、生态环境监管制度与生态优先考核制度,并进一步明确了各项制度构建工作的具体内容。生态文明制度体系的构建和不断完善,将为全面建成人与自然和谐的美丽中国提供系统保障。  相似文献   
6.
Fault detection (FD) and diagnosis in industrial processes is essential to ensure process safety and maintain product quality. Partial least squares (PLS) has been used successfully in process monitoring because it can effectively deal with highly correlated process variables. However, the conventional PLS-based detection metrics, such as the Hotelling's T2 and the Q statistics are ill suited to detect small faults because they only use information from the most recent observations. Other univariate statistical monitoring methods, such as the exponentially weighted moving average (EWMA) control scheme, has shown better abilities to detect small faults. However, EWMA can only be used to monitor single variables. Therefore, the main objective of this paper is to combine the advantages of the univariate EWMA and PLS methods to enhance their performances and widen their applicability in practice. The performance of the proposed PLS-based EWMA FD method was compared with that of the conventional PLS FD method through two simulated examples, one using synthetic data and the other using simulated distillation column data. The simulation results clearly show the effectiveness of the proposed method over the conventional PLS, especially in the presence of faults with small magnitudes.  相似文献   
7.
The formation of hydrate will lead to serious flow assurance problems in deepwater submarine natural gas transmission pipelines. However, the accurate evaluation model of the hydrate blocking risk for submarine natural gas transportation is still lacking. In this work, a novel model is established for evaluating the hydrate risk in deepwater submarine gas pipelines. Based on hydrate growth-deposition mechanism, the mathematical model mainly consists of mass, momentum and energy conservation equations. Meantime, the model results are obtained by finite difference method and iterative technique. Finally, the model has been applied in the production of deepwater gas field (L Gas Field) in China, and the sensitivity analysis of relevant parameters has been carried out. The results show that: (a). The mathematical model can well predict the hydrate blockage risk in deepwater natural gas pipelines after verification. (b). Hydrate is easily formed at the intersection of horizontal pipeline and vertical riser, and the maximum blocking position often occurs in middle of the riser. (c). The hydrate blockage degree and length of hydrate formation region (HFR) decrease with the increase of gas transport rate. (d). The hydrate blockage degree and length of HFR decrease with the increase of gas transport temperature. (e). The hydrate blockage degree and length of HFR increase with the extension of horizontal pipeline. (f). Injecting inhibitors can effectively inhibit hydrate formation and blockage, but the improvement of transmission measures can significantly reduce the dosage of inhibitor. It is concluded that measures such as increasing gas transportation rate and temperature, shortening horizontal pipeline length, optimizing inhibitor injection point and injection rate can play a safe, economic and efficient role in hydrate preventing and controlling.  相似文献   
8.
The loss of yields from agricultural production due to the presence of pests has been treated over the years with synthetic pesticides, but the use of these substances negatively affects the environment and presents health risks for consumers and animals. The development of agroecological systems using biopesticides represents a safe alternative that contributes to the reduction of agrochemical use and sustainable agriculture. Microalgae are able to biosynthesize a number of metabolites with potential biopesticidal action and can be considered potential biological agents for the control of harmful organisms to soils and plants. The present work aims to provide a critical perspective on the consequences of using synthetic pesticides, offering as an alternative the biopesticides obtained from microalgal biomass, which can be used together with the implementation of environmentally friendly agricultural systems.  相似文献   
9.
In this paper, the inventory-routing problem is studied for a closed-loop supply chain. This closed-loop supply chain considers suppliers, manufacturers, whole-sellers, and disposal centers. To formulate this problem, a mixed integer linear programming model is proposed. This mathematical model minimizes the total costs of the supply chain, including the fixed and variable costs of vehicles, and holding inventory costs of final products and scraps. The proposed model considers the road roughness degree, multi-path setting and the heterogeneous fleet of vehicles, which increases its flexibility and the quality of solutions. Then, two symmetry-breaking constraints are proposed to reduce the complexity of the mathematical model. In order to evaluate the integrity of the proposed model, 20 instances of different sizes are randomly generated and solved. Finally, a comprehensive sensitivity analysis is conducted with respect to five key features of the problem, such as the impact of the symmetry-breaking constraints on the CPU time, multi-path setting, fixed cost of vehicles, heterogeneous fleet of vehicles, and lost sales. The results indicate that the consideration of multi-path setting and the heterogeneous fleet of vehicles improves the quality of solutions significantly.  相似文献   
10.
基于复杂系统建模的水管理政策研究进展   总被引:3,自引:0,他引:3  
基于Agent的建模方法(ABSS)通过自下而上的方式,考察系统中主体的不同状态和行为特征、主体与环境的作用、主体之间的作用,来表征系统的宏观特征,是进行复杂社会环境系统分析和政策研究的重要手段,在水资源、水环境管理系统中得到了有效的应用。本文在大量文献调研的基础上,讨论了ABSS建模方法的基本原理、主要特征、系统构成、分类方法和开发工具等特征,总结了其供水系统发展、水资源分配和流域水资源管理、农业土地和水资源利用、居民用水行为、农业污染控制及人类活动的水环境影响等方面的应用,分析了其在研究内容、研究方法、研究结果等方面的发展趋势,讨论了利用该方法研究我国水资源管理和水污染控制政策的必要性和重要性。  相似文献   
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