Impacts of Off-Road Vehicles (ORVs) on Macrobenthic Assemblages on Sandy Beaches

Sandy beaches are the prime sites for human recreation and underpin many coastal economies and developments. In many coastal areas worldwide, beach recreation relies on the use of off-road vehicles (ORVs) driven on the shore. Yet, the use of ORVs is not universally embraced due to social conflicts with other beach user groups and putative environmental consequences of vehicle traffic on sandy shores. Such ecological impacts of ORVs are, however, poorly understood for endobenthic invertebrates of the intertidal zone seawards of the dunes. Consequently, this study quantified the degree to which assemblages of intertidal beach invertebrates are affected by traffic. The study design comprised a series of temporally replicated spatial contrasts between two reference sites (no ORVs) and two beaches with heavy ORV traffic (in excess of 250,000 vehicles per year) located in South-East Queensland, Australia. Macrobenthic assemblages on ORV-impacted beaches had significantly fewer species at substantially reduced densities, resulting in marked shifts in community composition and structure. These shifts were particularly strong on the middle and upper shore where vehicle traffic was concentrated. Strong effects of ORVs were detectable in all seasons, but increased towards the summer months as a result of heavier traffic volumes. This study provides clear evidence that ORVs can have substantial impacts on sandy beach invertebrates that are manifested throughout the whole community. Demonstrating such an ecological impact caused by a single type of human use poses a formidable challenge to management, which needs to develop multi-faceted approaches to balance environmental, social, cultural, and economic arguments in the use of sandy shores, including management of “beach traffic.”     

基于远程数据的重型柴油车实际道路碳排放测算准确度

利用车载排放测试系统(PEMS),对3辆加装有车载诊断系统(OBD)远程监控设备的重型柴油车进行实际道路排放测试,以获取车辆实际道路基于电子控制器单元(ECU)的OBD远程油耗数据,分析碳排放结果的准确性及其影响因素.研究发现,基于碳平衡法获取的ECU油耗换算CO₂与车载排放测量系统(PEMS)直接测量的CO₂排放结果存在差异,二者偏差平均为2.06%.对影响ECU碳排放计算的关键因素(ECU油耗量和ECU行驶距离)的准确性进行了分析,发现ECU油耗的偏差均在3%以内,而ECU测量距离的平均偏差为2.41%.ECU油耗和行驶距离的准确度会受到车速、加速度和整个行程动态的影响.当车辆低速行驶时,其准确度较低.     

东北冷涡下两次雷电过程特性对比分析

利用卫星、闪电和电场等资料对2009年6月江苏的两次受东北冷涡影响所致的雷电过程进行对比分析,探讨了发生雷电过程的天气形势和卫星产品等对强对流天气的指示作用,初步得出了同一环流背景下的两次雷电过程的特征:两次雷电过程都具备了较好的不稳定条件,但由于能量分布的差异,过程影响范围有所不同;5日雷电过程伴随冰雹,其正闪比明显高于只有闪电发生的21日;相当黑体亮度温度高低预示着对流活动活跃程度,大部分闪电分布在云顶温度低值区,或者温度梯度较大的对流旺盛区域;两次过程电场快变抖动都提前于地闪发生。     

电弧焊防触电技术探讨

从电焊机保护接地（或接零）的规则、电源线与焊钳的安全技术、控制电器的安全技术、电焊工作业中的安全保障措施等四个方面,探讨了电弧焊作业中如何防范触电事故的技术措施,实践证明,所述的安全要求和技术方法对于电弧焊作业的安全管理和安全生产具有很高的实用价值。     

低压脉冲袋式除尘器在硅铁电炉烟气中的应用

介绍了低压脉冲袋式除尘器在6300 kVA半封闭式硅铁电炉烟气除尘系统中的应用,通过对铁合金半封闭式硅铁电炉烟气性质的分析,对除尘系统在运行过程中出现的问题以及解决方案进行了分析和阐述,最后指出低压脉冲袋式除尘器在半封闭式硅铁电炉除尘系统中使用时应该注意的问题。     

IEC61511标准及在石化行业安全管理中的应用

功能安全的定量评定技术已成为确保石化行业安全生产的重要手段。针对石化行业普遍存在的功能安全问题,笔者以国际电工学会(IEC)专门制定的功能安全评定标准IEC61508及IEC61511为指导,介绍其标准制定的背景、目的、体系结构以及如何利用标准开展石化行业安全联锁系统(Safety Instrumented System,SIS)的安全与误跳车定量分析。通过对SIS开展定量安全评估,可发现联锁功能存在的安全不足与误跳车现象,对于提高我国石化行业安全生产水平具有重要的促进作用,标准中有关寿命周期功能安全管理方法及重要的工程经验也对提高我国石化安全生产水平具有借鉴作用。     

运用模拟方法解决步行街人车混流区问题

在分析城市步行街及其周边存在人车混行、人员密度高、通行效率低、潜在的危险大的基础上,笔者用计算机模拟方法研究了沈阳市中街步行街的一个人车混行的交叉路口,实际勘察了十字路口道路格局、车流、人流状况,测量、估计通过路口的人数、流量,根据获得的数据,对不设置交通信号灯、设置信号灯、建设过街天桥或地下通道等几种情况进行模拟,得到各种情况下的通行效率,并对不同的过街方案的优缺点进行比较。最终选择过街方案需要综合考虑影响安全和效率的多种因素,包括地域、人流量、路口宽度、周边交通等因素,用较小的经济投入取得最大的通行效率。文中的模拟采用EXODUS软件。     

某钢厂大型电炉除尘系统设计

介绍了电炉除尘系统设计方面的一些经验,包括除尘系统工艺流程、产尘点风量确定和设备选型等.     

电力系统抗震可靠性研究与分析综述

地震是最可能造成电力系统遭受严重破坏的自然灾害。对电力系统的震害特点进行了一些研究和介绍,针对这些特点提出了提高电力系统抗震可靠性的措施和建议,并对电力系统抗震可靠性研究现状及发展趋势作了综述。     

Evaluation of the First Phase of Sulfur Dioxide and Nitrogen Oxides Provisions of the 1990 Clean Air Act: A Plant-Based Approach

Electric power generating plants that use coal were among the key targets of Title IV of the 1990 Clean Air Act. Under the first phase of the act, 110 coal-fired electric power plants were required to reduce their sulfur dioxide emissions by 1995 and nitrogen oxide emissions by 1996. Phase 2 of the act requires even greater reduction of sulfur dioxide emissions by 2000 and nitrogen oxide emissions by 2008. This study examines whether the 107 targeted plants (three plants went off-line) have achieved the desired sulfur dioxide and nitrogen oxide emission levels. The analysis of sulfur dioxide is based on data from 1990, 1995, and 1999. The findings show that although sulfur oxide increased by 3% from 1995 to 1999, it decreased by 45% over the 1990–1999 period at the firm level for the targeted firms. The findings also indicate that the overall reduction in sulfur dioxide was achieved by utilizing low sulfur coal and by purchasing emission allowances. So far as nitrogen oxides are concerned, there has been a reduction of 14% over the 1990–1999 period, of which 7% was achieved during the 1995–1999 period. An evaluation of emissions at the plant level indicates that several plants do not meet the emissions level for sulfur dioxide or nitrogen oxides. These results provide a mixed scorecard for reduction in emissions both for sulfur dioxide and nitrogen oxides. Even though there is reduction in the emissions on an overall basis at the firm level, several plants that have not been able to reduce emissions deserve special attention to meet the goals of the act in reducing emissions.