基于模糊评判和RCM的CTCS-3级车地通信子系统维修决策

CTCS-3级车地通信子系统是列控系统的重要组成部分之一,且列控系统需求的列车位置、行车许可、临时限速等安全信息都由其提供,因此,对其进行可靠性分析具有十分重要的意义。采用贝叶斯网络对系统进行可靠性分析,并对维修方式进行了讨论。首先,根据车地通信子系统的功能与结构构建其贝叶斯网络模型。然后,综合考虑维修性、共因失效等因素,对车地通信子系统进行可靠性分析。最后,在可靠性分析的基础上运用模糊综合评判法对其进行维修决策。结果表明:利用贝叶斯网络的双向推理,不仅可以计算出车地通信子系统的可靠度,还可以有效识别系统的薄弱环节;若不考虑车地通信系统冗余结构中的共因失效,则得到的可靠性指标会偏于乐观。地面GSM-R单元失效是引起车地通信子系统失效的关键事件,因此针对此薄弱环节进行状态维修检查能够有效降低事故的发生概率。     

环境监测水中石油类、动植物油实验分析常见问题探讨

针对环境监测水中石油类、动植物油实验分析常出现的问题,从仪器、废水中的乳化现象、分析试剂的精制、地表水采样、准确度分析、测油的危害及安全防护等多个方面进行探讨,并提出对策。     

Creation of a Gilded Trap by the High Economic Value of the Maine Lobster Fishery

Abstract: Unsustainable fishing simplifies food chains and, as with aquaculture, can result in reliance on a few economically valuable species. This lack of diversity may increase risks of ecological and economic disruptions. Centuries of intense fishing have extirpated most apex predators in the Gulf of Maine (United States and Canada), effectively creating an American lobster (Homarus americanus) monoculture. Over the past 20 years, the economic diversity of marine resources harvested in Maine has declined by almost 70%. Today, over 80% of the value of Maine's fish and seafood landings is from highly abundant lobsters. Inflation‐corrected income from lobsters in Maine has steadily increased by nearly 400% since 1985. Fisheries managers, policy makers, and fishers view this as a success. However, such lucrative monocultures increase the social and ecological consequences of future declines in lobsters. In southern New England, disease and stresses related to increases in ocean temperature resulted in more than a 70% decline in lobster abundance, prompting managers to propose closing that fishery. A similar collapse in Maine could fundamentally disrupt the social and economic foundation of its coast. We suggest the current success of Maine's lobster fishery is a gilded trap. Gilded traps are a type of social trap in which collective actions resulting from economically attractive opportunities outweigh concerns over associated social and ecological risks or consequences. Large financial gain creates a strong reinforcing feedback that deepens the trap. Avoiding or escaping gilded traps requires managing for increased biological and economic diversity. This is difficult to do prior to a crisis while financial incentives for maintaining the status quo are large. The long‐term challenge is to shift fisheries management away from single species toward integrated social‐ecological approaches that diversify local ecosystems, societies, and economies.     

Defect and Innovation of Water Rights System

The rare deposition of water resources conflicts with its limitless demand. This determined the existence of the water rights transaction system. The implementation of the water rights transaction system requires clarifying the definition of water resource right above all distinctly. At present, it is a kind of common right system arrangement which needs the Chinese government to dispose of water resources. Though a series of management systems guaranteed the government＇s supply of water resource, it hindered the development of the water market seriously and caused the utilization of water resources to stay in the inefficient or low efficient state for a long time. Thus, we should change the government＇s leading role in the resource distribution and really rely on the market to carry on the water rights trade and transaction. In this way, the water rights could become a kind of private property right relatively, and circulate freely in the market. As a result of this, we should overcome the defects of common right, make its external performance internalized maximally and achieve the optimized water resource disposition and use it more effectively.     

Accumulation, distribution and transformation of DDT and PCBs by Phragmites australis and Oryza sativa L.: I. Whole plant study

Glasshouse experiments were conducted to determine the accumulation, distribution and transformation of o,p′-DDT, p,p′-DDT and PCBs by common reed (Phragmites australis) and rice (Oryza sativa L.) under hydroponic conditions. The culture solution was spiked with the organic pollutants and samples were collected daily. Analysis of the plants at harvest showed that both species had removed DDT and PCBs from the solution. DDT appeared to have accumulated within P. australis by both passive adsorption and active absorption. Both o,p′-DDT and p,p′-DDT were transformed within P. australis. DDD was the major metabolite and the transformation was mediated by reductive dehalogenation. Plant long-distance transportation systems may be involved in the translocation of PCBs within P. australis and the affinity of the PCBs for lipids is one of the major factors affecting their uptake and translocation within the plants. Similar but less pronounced results were found in O. sativa and suggest that these wetland plants may be used for the plant-mediated remediation of persistent organic pollutants.     

The (un)common good: diverging justifications for wilderness making in a modified landscape

ABSTRACT

Wilderness is most often conceived as comprising large remote areas where evidence of human influence is slight. Little attention has been afforded to the study of wilderness ‘making’ in smaller landscapes that have been heavily modified by human activity. This paper addresses this knowledge deficit by employing the pragmatic sociology of Boltanski and Thévenot to analyse a case study of wilderness making in the west of Ireland. The application of this framework illustrates how contending positions on ‘why’ wilderness making should occur and ‘how’ it should be conducted reflect ethical frameworks rooted in different conceptions of the ‘common good’ presented by the idea of wilderness. The paper demonstrates the difficulties with developing such a new nature-based concept in the absence of conventional (received) ideas of wilderness by revealing how the diverging justifications used suggest incommensurability in the competing notions of wilderness that are formulated and advanced.     

Relation of Lake Acidification and Recovery to Fish,Common Loon and Common Merganser Occurrence in Algoma Lakes

Models are needed that predict both spatial and temporal improvements to ecosystems following reductions of acidifying emissions that produce `acid rain'. Logistic regression models were developed for the occurrence of fish and two fish-eatingbirds, common loons (Gavia immer) and common mergansers(Mergus merganser), using monitoring data collected onlakes across Ontario. These models were applied in the Algomaregion, including the Turkey Lakes Watershed (TLW). Using theWaterfowl Acidification Response Modeling System (WARMS), severalSO₂ emission reduction scenarios were simulated, i.e. thosecontributing to measured 1982–1986 sulphate deposition levels, 1994levels (corresponding to full implementation of Canadian SO₂emission reductions as stipulated in the 1991 Canada/U.S. AirQuality Agreement), 2010 levels (1994 plus full U.S. reductions),and both a 50% and a 75% further reduction beyond 2010 levels. Some habitat improvements in Algoma were predicted under the 2010scenario for all biota, but substantial increases in habitatquality, especially for mergansers, would occur only under further reductions. The TLW showed little change in chemistry orbiota, while lakes near the Montreal River were predicted toimprove substantially.     

Dasibi1000空气自动监测系统的常见故障及排除

本文主要列举了美国Dasibi1000环境空气自动监测系统中的主要监测仪器氮氧化物、二氧化硫、可吸入颗粒物等分析仪在日常运行中容易出现的一些的常见故障。由于此套仪器设备具有自检功能。可通过仪器面板提示的故障信息找到故障所在。并对其形成原因进行了系统分析和总结。同时提出了一些排除故障的方法和步骤以及避免出现这些故障所需的日常维护。     

水生植物在含Cr废水处理中的作用

通过利用水葫芦去除Cr废水中Cr的试验，研究了溶液中Cr浓度对其迁移的影响、植物处理时间对迁移的影响、植物是否存活对溶液中Cr的处理效果、水温变化对迁移的影响、pH值变化对迁移的影响。     

数字地震仪观测系统常见故障及排除

在地震台站,地震计与模数转换器,计算机,通讯设备一起构成一个系统,系统中任何一个环节不能正常工作,都会影响整个系统。判断系统究竟是哪一部份有故障,需要冷静分析,对比试验,逐一排除。故障现象可能一样,但原因可能有多种。因此,不仅要了解系统的工作原理,还要有一定的工作积累,才能迅速准确地找到故障原因并排除。