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971.
The BIA has now 15 years of experience with the certification of complex electronic systems for safety-related applications in the machinery sector. Using the example of machining centres, this presentation will show the systematic procedure for verifying and validating control systems using Application Specific Integrated Circuits (ASICs) and microcomputers for safety functions.

One section will describe the control structure of machining centres with control systems using “ integrated safety.” A diverse redundant architecture combined with crossmonitoring and forced dynamisation is explained. In the main section the steps of the systematic certification procedure are explained showing some results of the certification of drilling machines. Specification reviews, design reviews with test case specification, statistical analysis, and walk-throughs are the analytical measures in the testing process. Systematic tests based on the test case specification, Electro Magnetic Interference (EMI) and environmental testing, and site acceptance tests on the machines are the testing measures for validation.

A complex software driven system is always undergoing modification. Most of the changes are not safety-relevant but this has to be proven. A systematic procedure for certifying software modifications is presented in the last section of the paper.  相似文献   
972.
赤水河流域位于川、滇、黔3省接壤地带,流域面积 18 932 km2,流经贵州、云南、四川的13个县市。目前,赤水河流域依然是长江上游生态环境、水质最好的一级支流。促进流域环境保护与经济的协调发展,是地区在进行流域管理的难题。通过研究发现,赤水河流域上、中、下游具有显著的产业特点。上游主要以煤电行业为主,污染大,过度垦殖导致水土流失严重;中游以优质白酒为主导的轻工产业为主,但政府发展规划上却突出了重工业发展的重要性;下游地区具有良好的生态环境并开展了初步规模的自然生态旅游,但在产业发展上受到上、中游地区的严重影响和限制。因此,流域的产业发展对整个流域的环境保护和经济可持续发展的影响很大,而现行的流域管理却忽视了产业布局的整体考虑。通过赤水河流域环境问题和产业发展以及相互之间关系的分析,通过综合流域管理的思想,提出建立全流域统一的环境保护机制的策略,把流域的环境特点转化为经济发展的要素,促进流域环境的保护和经济的协调发展。  相似文献   
973.
Abstract:  Among the major agricultural crops in the southeastern United States, cotton ( Gossypium hirsutum L.) generally provides the least suitable habitat for most early successional songbirds. Newer cropping approaches, such as use of conservation tillage and stripcover cropping, offer hope for improving the ecological value of cotton fields. We examined the effects of clover stripcover cropping with conservation tillage versus conventionally grown cotton with either conventional or conservation tillage on avian and arthropod species composition and field use in east-central Georgia. Stripcover fields had higher bird densities and biomass and higher relative abundance of arthropods than both conservation tillage and conventional fields. During migration and breeding periods, total bird densities on stripcover fields were 2–6 times and 7–20 times greater than on conservation and conventional fields, respectively. Abundance and biomass for epigeal arthropods were also greatest on stripcover fields during much of the breeding season. Although the clover treatment attracted the highest avian and arthropod densities, conservation fields still provided more wildlife and agronomic benefits than conventional management. Our findings suggest that both conservation tillage and stripcropping systems will improve conditions for birds in cotton, with stripcropped fields providing superior habitat. The reduction of inputs possible with the clover system could allow farmers to lower costs associated with conventional cotton production by $282–317/ha. This reduction of input, coupled with similar or possibly increased yield over conventional systems makes stripcover cropping not only a good choice for reducing negative impacts on wildlife and surrounding ecosystems, but also an economically desirable one.  相似文献   
974.
ABSTRACT: The Pacific Northwest (PNW) regional assessment is an integrated examination of the consequences of natural climate variability and projected future climate change for the natural and human systems of the region. The assessment currently focuses on four sectors: hydrology/water resources, forests and forestry, aquatic ecosystems, and coastal activities. The assessment begins by identifying and elucidating the natural patterns of climate vanability in the PNW on interannual to decadal timescales. The pathways through which these climate variations are manifested and the resultant impacts on the natural and human systems of the region are investigated. Knowledge of these pathways allows an analysis of the potential impacts of future climate change, as defined by IPCC climate change scenarios. In this paper, we examine the sensitivity, adaptability and vulnerability of hydrology and water resources to climate variability and change. We focus on the Columbia River Basin, which covers approximately 75 percent of the PNW and is the basis for the dominant water resources system of the PNW. The water resources system of the Columbia River is sensitive to climate variability, especially with respect to drought. Management inertia and the lack of a centralized authority coordinating all uses of the resource impede adaptability to drought and optimization of water distribution. Climate change projections suggest exacerbated conditions of conflict between users as a result of low summertime streamfiow conditions. An understanding of the patterns and consequences of regional climate variability is crucial to developing an adequate response to future changes in climate.  相似文献   
975.
污水性质是影响人工湿地微生物特征的重要因子,而微生物对人工湿地污染物净化功能的发挥至关重要. 运用两组IVCW(复合垂直流人工湿地)分别处理模拟生活污水和污水处理厂尾水,比较研究两组系统下行流、上行流池的基质酶活性及硝化反硝化强度,并通过脂肪酸甲酯图谱分析系统中的微生物群落结构,以解析人工湿地微生物特征对两种污水的响应差异. 结果表明:处理生活污水的IVCW下行流池中脱氢酶、过氧化氢酶、脲酶及硝酸盐还原酶活性均显著高于其他单元,四者平均值分别为其他单元的2.8~4.6、7.9~10.3、19.3~41.7和4.5~10.8倍. 处理生活污水IVCW基质的硝化强度是尾水处理系统对应单元的1.4~5.3倍(下行流)和1.3~3.9倍(上行流),而两组IVCW对应单元基质的反硝化强度之间无显著差异. IVCW下行流池中特征脂肪酸比值及微生物群落结构受污水类型的影响较小,均以厌氧细菌和革兰氏阳性菌为优势菌;上行流池微生物群落结构则受到污水类型的一定影响,真菌的相对丰度较高. 两种污水对IVCW基质酶活性和硝化强度的影响高于对反硝化强度和微生物群落结构的影响.   相似文献   
976.
刘旭东  姜凤  冯欣  郭烂林 《环境工程》2016,34(12):38-42
依据我国村镇污水处理的技术要求及村镇污水水质、水量特点,提出了一种新型一体化装置。该装置采用活性污泥法与厌氧/缺氧相结合,并运用一体化的设计理念,集好氧、缺氧、厌氧于同一反应池。通过模拟村镇污水的运行,研究了新型一体化装置曝气/搅拌交替运行的最佳条件。结果表明:在水力停留时间为6 h,当曝气/搅拌交替运行的循环周期和时间比例分别为120 min和40∶80条件下,装置能同时实现对COD、TN、TP的去除,COD、TN、TP的平均去除率分别为86.1%、84.3%、77.4%,且出水水质保持稳定,出水COD、TN达到GB 18918—2002《城镇污水处理厂污染物排放标准》一级A标准,出水TP达到一级B标准。  相似文献   
977.
Objective: Traffic crashes are one of the leading causes of fatalities among Chinese children. Booster cushion usage in China is low, and there are no studies showing how a population with limited experience handles booster cushions during buckling up. The purpose of this study was to evaluate the handling of and explore the attitudes toward booster cushions among children, parents, and grandparents in Shanghai.

Methods: An observational study including a convenience sample of 254 children aged 4–12 years was conducted in 2 passenger cars at a shopping center in Shanghai. Parents, grandparents, or the children themselves buckled up the child on 2 types of booster cushions, a 2-stage integrated booster cushion (IBC) and an aftermarket booster cushion (BC). The test participants were observed during buckling up, first without and then with instructions. The test leaders conducted structured interviews.

Results: Ninety-eight percent of the uninstructed participants failed to buckle up without identified misuse on the aftermarket booster cushion and 31% of those uninstructed on the integrated booster cushion. The majority of misuse was severe, including placing the belt behind the arm and the lap belt routing above the guiding loops. Instruction reduced misuse to 58% (BC) and 12% (IBC), respectively, and, in particular, severe misuse. Some misuse was related to limited knowledge of how to buckle up on the booster cushion, and some misuse was intentional in order to reduce discomfort.

The participants, both children and adults, reported that they preferred the IBC due to good comfort and convenience. Safety was reported as the main reason for adults using booster cushions in general, whereas children reported comfort as the most important motivation.

Conclusions: Education is needed to ensure frequent and correct use of booster cushions in China and to raise safety awareness among children and adults. Furthermore, it is important that the booster cushions offer intuitively correct usage to a population with limited experience of booster cushions.

This is the first study published on the handling of and attitude toward booster cushions after child restraints laws were introduced in Shanghai 2014.  相似文献   

978.
为研究不同火灾工况对宿舍楼火灾过程的影响,应用Pyrosim对某大学东六宿舍进行火灾动态模拟,对比分析了宿舍大楼所有门窗全开状态和着火房间窗户闭合、门在20 s后打开的状态下,宿舍楼各部分温度、烟气层高度、门窗热流量及烟气蔓延特点。Pyrosim模拟结果表明,在火灾爆发的前20 s内,火势发展与门窗开合状态无关。在火灾中后期,门窗全开状态下,着火房间的温度及热流量较低、烟气层离地的高度较高,着火房间上方的宿舍受烟气影响较为严重;而在着火房间窗户闭合、门在20 s后打开状态下,横向走廊及各层楼梯处受烟气影响较严重。  相似文献   
979.
Objective: The purpose of this article is to describe a public school–based educational intervention (EI) designed to increase knowledge, improve attitudes, and change practices related to road safety.

Methods: We used a mixed-methods evaluation of a road traffic safety baseline diagnosis conducted in 4 public schools, 2 primary and 2 secondary. Research was organized into 4 phases: (1) diagnosis, (2) EI design, (3) implementation, and (4) evaluation. We used convenience sampling (n = 219 students) across schools and applied a pre-/posttest design based on quantitative and qualitative data. The former related to surveys on road safety experiences, knowledge, attitudes, and practice and the latter to observation checklists, community mapping, ethnography, and focus groups. To compare pre–post scores, we used multilevel mixed-effect ordinal logistic regressions. We developed data matrices, field notes, and systematized community mapping. We also transcribed focus group discussions, generated categories, and carried out thematic analysis.

Results: Ethnography indicated poor sidewalk conditions, no helmet or seat belt use, overcrowded public transportation, and no traffic lights or proper signals. Pedestrians did not use sidewalks and crossed streets unsafely. Subsequent to the intervention, however, the study population showed significant changes in their knowledge, practices, and attitudes. They identified road traffic incidents (RTIs) as the first cause of death among children and youth, and most understood that the solution to the problem was incumbent upon each and every individual. They also displayed increased perceptions of danger in practices such as traveling on overcrowded public transportation, failing to wear seat belts in cars and helmets on motorcycles, crossing the street while using mobile phones or playing with friends, and riding with drunk drivers. Changes varied according to gender, and students reported being able to carry out safe practices only when they were in control of the situation; for instance, as pedestrians.

Conclusions: Because safe practices depend not only on children and youth but on the adults and social environment surrounding them, it is essential to engage parents, teachers, and decision makers in efforts to reduce RTIs. This will improve the establishment of commitments to impact social reality through consistent changes and mobilize greater resources for creating more secure communities in matters of road safety.  相似文献   

980.
采用磷酸铵镁(MAP)沉淀法对高氨氮7-ACA综合废水进行了预处理试验研究,以Na2HPO4和MgCl2.6H2O作为沉淀剂,探讨了初始反应pH值、n(Mg2+):n(PO43-)/:n(NH4+)投配比及反应时间等因素对氨氮去除效果的影响。结合结晶物SEM分析,确定预处理的最佳工艺条件为:初始反应pH 9.0、n(Mg2+):n(PO43-):n(NH4+)投配比1.0:1.1:1和反应时间20 min。平行试验结果表明,在最佳工艺条件下,当进水氨氮浓度为1 020~1 190 mg/L时,处理后出水氨氮浓度为小于150.0 mg/L,氨氮去除率在85.0%以上,残磷量小于40.0 mg/L,为7-ACA综合废水的后续生化处理创造了有利条件。  相似文献   
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