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31.
简要分析了日本“3·11”大地震后发生的2起炼油厂火灾事故,对日本在地震中的一些经验教训进行了总结,根据本次及近几年地震对石化企业的破坏情况,分析了地震中石化装置的薄弱环节,并提出对石化行业的启示。  相似文献   
32.
Water quality is a critical challenge in Asia in the context of growing industrialization, urbanization, and climate change. Nature-based solutions (NbS) could play an important role in reducing urban water pollution, while generating multiple co-benefits that could make cities more liveable and resilient. In this regard, a number of pilot and demonstration projects have been set up to explore their potential across cities in Asia. Their effectiveness and impacts, however, have not been adequately documented, thus how they can be sustained, replicated and up-scaled remain poorly understood. This study aims to contribute to addressing this challenge by co-developing an integrated assessment framework and employing it to understand how existing evaluations of NbS in the region can be improved. It focuses specifically on a set of nature-based solutions that have been employed for water treatment across six cities in Southeast Asia (two in each Sri Lanka, the Philippines, and Vietnam), namely, floating wetlands, constructed wetlands and maturation ponds. The study also suggests specific methodologies for capturing a set of core indicators considered relevant for assessing the effectiveness and capturing the multi-faceted impacts of the examined NbS.  相似文献   
33.
通过试验研究,探索了焦化废水生物脱氮半生产性启动条件,指出了顺利启动的关键技术是适宜的接种污泥及必须提供的环境条件。  相似文献   
34.
检索了微生物燃料电池在中国的发明专利文献,综述了微生物燃料电池在废水处理中的应用及与现有技术中其他水处理技术耦合的专利进展,并对其实际应用的前景进行了展望。  相似文献   
35.
建立行星传动起升机构电动机飞车的模型,计算电动机失电后各瞬间重物的速度、加速度,电动机的转速,从而分析事故的原因。  相似文献   
36.
对几种浮选剂在荆门石化污水处理场的处理效果进行了对比,结果表明岳阳云溪XY-Ⅱ和江苏武进PAFC比现有PAC浮选剂的处理效果佳,且运行成本低.  相似文献   
37.
长江中游荆南三口断流时间演变特征及其影响机制   总被引:1,自引:0,他引:1  
研究河道断流演变特征对认识区域水文过程及人类活动具有重要作用。论文依据1951—2014年水文气候实测数据,运用Mann-Kendall检验法,以及蒸散发-断流天数和降水-径流双累积曲线统计模型等方法分析了长江中游荆南三口断流时间演变特征及其影响机制,结果表明:1)对各时期荆南三口平均断流天数而言,1951—2014年呈逐期増加趋势,且趋势性变化显著,而在2003—2014年间,断流天数虽也增加,但趋势性变化不显著,即增加趋势逐渐减缓;2)影响荆南三口断流天数增减変化的是径流变化过程,而导致径流变化的又是以降水和蒸散发为代表的气候因素和以水利工程、各行业(农业)用水为标志的人类活动;3)影响荆南三口断流天数持续增加的主要驱动因素是人类活动,以各自时段前一时段为基准期,1959—1966、1967—1972、1973—1980、1981—2002、2003—2014年的5个变异期中,气候波动对荆南三口断流天数增加的贡献率依次为24.93%、19.05%、6.36%、10.38%、7.56%;人类活动影响的贡献率分别为75.07%、80.95%、93.64%、89.62%、92.44%。  相似文献   
38.
39.
Numerous studies on eutrophication remediation have mainly focused on purifying water first, then restoring submerged macrophytes. A restoration-promoting integrated floating bed (RPIFB) was designed to combine the processes of water purification and macrophyte restoration simultaneously. Two outdoor experiments were conducted to evaluate the ecological functions of the RP1FB. Trial 1 was conducted to compare the eutrophication purification among floating bed, gradual-submerging bed (GSB) and RPIFB technologies. The results illustrated that RPIFB has the best purification capacity. Removal efficiencies of RPIFB for TN, TP,NH4+-N, NO3-N, CODcr, Chlorophyll-a and turbidity were 74.45%, 98.31%, 74.71%, 88.81%, 71.42%, 90.17% and 85%, respectively. In trial 2, influences of depth of GSB and photic area in RPIFB on biota were investigated. When the depth of GSB decreased and the photic area of RPIFB grew, the height of Potamogeton crispus Linn. increased, but the biomass of Canna indica Linn. was reduced. The mortalities of Misgurnus anguillicaudatus and Bellamya aeruginosa in each group were all less than 7%. All results indicated that when the RPIFB was embedded into the eutrophic water, the regime shift from phytoplankton-dominated to macrophyte-dominated state could be promoted. Thus, the RPIFB is a promising remediation technology for eutrophication and submerged macrophyte restoration.  相似文献   
40.

Introduction

This study presents a classification tree based alternative to crash frequency analysis for analyzing crashes on mid-block segments of multilane arterials.

Method

The traditional approach of modeling counts of crashes that occur over a period of time works well for intersection crashes where each intersection itself provides a well-defined unit over which to aggregate the crash data. However, in the case of mid-block segments the crash frequency based approach requires segmentation of the arterial corridor into segments of arbitrary lengths. In this study we have used random samples of time, day of week, and location (i.e., milepost) combinations and compared them with the sample of crashes from the same arterial corridor. For crash and non-crash cases, geometric design/roadside and traffic characteristics were derived based on their milepost locations. The variables used in the analysis are non-event specific and therefore more relevant for roadway safety feature improvement programs. First classification tree model is a model comparing all crashes with the non-crash data and then four groups of crashes (rear-end, lane-change related, pedestrian, and single-vehicle/off-road crashes) are separately compared to the non-crash cases. The classification tree models provide a list of significant variables as well as a measure to classify crash from non-crash cases. ADT along with time of day/day of week are significantly related to all crash types with different groups of crashes being more likely to occur at different times.

Conclusions

From the classification performance of different models it was apparent that using non-event specific information may not be suitable for single vehicle/off-road crashes.

Impact on Industry

The study provides the safety analysis community an additional tool to assess safety without having to aggregate the corridor crash data over arbitrary segment lengths.  相似文献   
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