Elemental Mercury Control by Novel Oxidant and Sorbent in an Entrained-Flow System

An entrained-flow system has been designed and constructed to simulate in-flight mercury capture by sorbents in ducts of coal-fired utility plants. The test conditions of 1.5 s residence time, 140°C temperature, 4.5 ppbv inlet Hg⁰ concentration, and 0–20 lb/MMacf sorbent injection rates were chosen to simulate conditions in the ducts. Novel oxidants developed in previous fixed-bed tests and novel sorbents derived from the novel oxidants were tested for their Hg⁰ capture in the entrained-flow system to examine the possibility of using those sorbents in a full-scale system. Darco-FGD and Darco Hg-LH served as benchmark sorbents with which mercury control capability of the novel oxidants and novel sorbents could be compared. The test results showed that the novel oxidants have remarkable Hg⁰ oxidation capability, and the novel sorbents showed a better performance in Hg⁰ removal than Darco Hg-LH.     

NAFTA and member country strategies for maritime trade and marine invasive species

Maritime shipping has two vectors of spreading marine invasive species: ballast water inside the ship and biofouling on the hulls outside the ship. While some attention has focused on ballast water, virtually none is focused on biofouling. This paper offers a quantitative analysis of economic incentives for shippers and regulating ports to address both pollution vectors. The strategies to address the vectors are induced by incentive mechanisms involving liability, subsidies and taxes. Results show these offer ample incentives in order to truly foster abatement of both vectors. Data from North America's Pacific coast is included in the analysis.     

A2/O工艺中的反硝化除磷

A2/O工艺是一种最简单的同步脱氮除磷工艺,但由于其系统中固有的基质竞争和污泥龄等矛盾,在实际应用中特别是处理低C/N比污水时脱氮除磷效率较低.反硝化除磷工艺作为近年来颇受关注的污水生物处理新技术.由于在脱氮除磷过程中可以在碳源利用上耦合,可从一定程度上缓解A2/O工艺中的基质竞争矛盾,使得其在处理低C/N比污水时也能实现较高的脱氮除磷效率.就反硝化除磷的技术原理,结合其在A2/O工艺中的最新研究成果及其控制策略,对A2/O工艺中的反硝化除磷的实现、维持及影响因素进行了分析和探讨,并对其发展方向进行了展望.     

锌精炼铅塔燃烧系统烟气温度模糊控制研究

针对锌精馏铅塔动态过程中的非线性、非最小相位特征、不稳定性、时滞和负荷干扰,基于模糊控制策略下给出了锌精馏铅塔燃烧系统新的控制方法.运用模糊控制系统对锌精馏铅塔的烟气温度进行仿真研究和实时控制结果表明,该研究所设计的模糊控制器能够克服许多干扰因素,产生了良好的控制效果.     

论近年来畜禽疫病的特点及其预防对策

随着畜牧业的快速发展,大规模、高密度、集约化的饲养和频繁的调运等,使畜禽更易发生流行性、群发性的疫病.畜禽疫病造成的损失影响了人类的生活需要,而且某些人畜共患的疫病还给人类健康带来了严重的威胁.要保证畜牧业可持续发展和保护人类健康,控制畜禽疫病就是关健措施.由于近年畜禽疫病的变化,我们的防治对策应发生相应变化.     

防洪物资储备决策方法初探

根据防洪抢险物资储备属于一种信息不全型决策问题的特点,本文提出了一种用于确定每年防灾物资准备量概率排序决策模型,并以孙不河流泥石流灾害预报火灾决策为例进行说明。     

生物资源在减轻农业草害中的作用与技术对策

论述了生物资源在减轻农业草害和促进农业可持续发展中所具有的生态效益和经济效益,提出了开发生物资源防治农业草害的技术对策。     

江西农田鼠害及其防治措施

农田鼠害是江西农业生物灾害中的主要灾种之一,它具有发生面积之、造成损失重、灾情越来越严重的特点,本文在回顾了江西农田鼠发生概况的基础上,简述了农田害鼠的种类、分布、主要特征及其发生发展规律,并从自然因素和人为因素等方面分析了鼠害成灾的主要原因,最后,提出了农田鼠害的防治措施。     

钻孔灌注桩的超声波透射法检测

大直径超长桩的桩身混凝土质量检测一直是困扰工程界的一个难题。本文提出和探讨了大直径超长桩桩身混凝土质量的超声波透射检测方法、技术及可靠程度。工程实践证明采用超声波透射法对大直径超长桩检测 ,其检测精度高 ,结果直观可靠 ,可以较详细查明桩身内部缺陷的性质、深度位置、范围大小及严重程度 ,为控制大直径超长桩桩身混凝土质量提供了一种有效的检测方法。     

Natural control mechanisms in models of aquatic ecosystems

Based on cybernetic categories of natural control mechanisms, four generations of ecosystem models are distinguished: feed-forward, feedback, self-adaptation and self-organization models. The analysis of the natural control mechanisms in aquatic ecosystems suggests that different processes are controlled in different ways, and, although the four mechanisms were identified in historical sequence, they all operate simultaneously. The concept of self-organization of an ecosystem is introduced and specified for a model of an aquatic pelagic ecosystem. The concept of the ecosystem as a multilayer, multigoal and multiechelon hierarchical system with hierarchy of the levels of biological organization is also introduced.