嗜热地芽孢杆菌DM-2烃降解特性研究

从油田地层水中分离到1株嗜热解烃菌(地芽孢杆菌DM-2),通过研究该菌株在不同条件下降解原油的性能以及在最适条件下降解烃的特性发现：地芽孢杆菌DM-2可在45～70℃、pH 4.0～10.0、 0.2%～3.0%的盐离子浓度缺氧条件下降解原油烃类,其降解原油烃的最适温度和pH值分别为60℃和7.0.在此条件下,该菌可乳化液体石蜡作为碳源进行生长;气相色谱和红外光谱进一步分析表明,其能降解原油中的C14～C30的直链烷烃、支链烷烃和芳香烃类,并能降解C16～C36的长链单烷烃,其中对C28的降解量最高,达88.95%.DM-2菌株代谢烷烃的产物之一为脂肪酸,经液相色谱和质谱分析代谢十六烷产生的脂肪酸为乙酸,5 d产量达0.312 g/L,说明其采用次末端氧化途径氧化烷烃,之后进入β-氧化途径代谢.DM-2菌株在高温缺氧的极端环境下对烃的乳化、降解和产酸特性使其在高温石油污水的生物处理和开采重质原油方面具有潜在的应用价值.     

API standard 521 guidance on mixing of hot/cold liquids and prevention of superheat limit explosions

American Petroleum Institute (API) standards and recommended practices have identified inadvertent mixing of hot and cold liquids as a potential cause for equipment overpressure since 1955. The limited guidance has been informative but provides minimal if any details on conditions that could cause an overpressure and its potential severity. Therefore, the user must interpret how and when to prevent and/or mitigate the scenario. This guidance has changed little over the years. In June 2020, API published the 7th Edition of API Standard 521 which now provides specific guidance as to conditions whereby pressure relief devices can be considered for protection and conditions where prevention remains as the only recourse. This paper discusses the basis for the revised guidance in API Standard 521 and includes supplemental guidance.     

油气长输管道工程风险评价发展及现状

介绍了油气长输管道工程风险评价的国内外研究概况、进展、主要评价方法及存在的问题.     

探索齐齐哈尔发展循环经济促进经济转型的思路

为改变传统的粗放型的生产方式,保护生态环境,现就齐齐哈尔发展循环经济促进经济转型的思路进行探索.     

Towards a natural disaster intervention and recovery framework

Contemporary responses to facilitate long‐term recovery from large‐scale natural disasters juxtapose between those of humanitarian agencies and governments and those of the affected community. The extent to which these mechanisms articulate is crucial to the recovery propensity of the affected communities. This research examines such action by exploring the relationship between the scale of post‐disaster response interventions, the extent of community participation in them, and their impact on community recovery, using a community wealth capital framework. The investigation was applied to a study of the longer‐term community recovery of the island of Vilufushi, Republic of Maldives, which was almost completely destroyed by the Indian Ocean tsunami of 26 December 2004. Data were analysed through the employment of a pattern match technique and a holistic recovery network analysis. The research framework, informed by the case‐study results, other long‐term recovery evaluations, and existing resilience theory, is reconfigured as a testable roadmap for future post‐disaster interventions.     

HDPE土工膜长期性能稳定性的研究进展

垃圾填埋场底部高密度聚乙烯(HDPE)土工膜会因氧化降解而使防渗性能降低,对环境带来二次污染风险,因此,HDPE膜的长期稳定性是值得关注的问题,但国内相关研究甚少。HDPE膜的降解过程可分为3个阶段,主要受自身性质、温度、接触介质和衬垫结构等因素的影响。文章重点综述了国外研究HDPE膜长期稳定性的试验方法,归纳了相关的数学模型,并根据存在的问题提出了建议。室内试验一般采用老化试验,包括浸泡试验和模拟试验,二者均能加快HDPE膜的老化进程。前者一般将试样完全浸泡于研究介质中试验,试验值较为保守;后者将样品置于模拟的衬垫构造中试验,结果更接近实际。数学模型采用Arrhenius模型,精度和所需参数取决于老化试验,现阶段大部分计算结果较片面,完善试验是后续工作的重点。     

Regulating non-precious transition metal nitrides bifunctional electrocatalysts through surface/interface nanoengineering for air-cathodes of Zn-air batteries

Zn-air batteries (ZABs), especially the secondary batteries, have engrossed a great interest because of its high specific energy, economical and high safety. However, due to the insufficient activity and stability of bifunctional electrocatalysts for air-cathode oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) processes, the practical application of rechargeable ZABs is seriously hindered. In the effort of developing high active, stable and cost-effective electrocatalysts, transition metal nitrides (TMNs) have been regarded as the candidates due to their high conductivity, strong corrosion-resistance, and bifunctional catalytic performance. In this paper, the research progress in TMNs-based material as ORR and OER electrocatalysts for ZABs is discussed with respect to their synthesis, chemical/physical characterization, and performance validation/optimization. The surface/interface nanoengineering strategies such as defect engineering, support binding, heteroatom introduction, crystal plane orientation, interface construction and small size effect, the physical and chemical properties of TMNs-based electrocatalysts are emphasized with respect to their structures/morphologies, composition, electrical conductivity, specific surface area, chemical stability and corrosion resistance. The challenges of TMNs-based materials as bifunctional air-cathode electrocatalysts in practical application are evaluated, and numerous research guidelines to solve these problems are put forward for facilitating further research and development.     

基于CNN_LSTM模型的复杂支路故障电弧检测*

在低压交流配电系统中,当多支路并联的复杂系统的某1支路中出现串联电弧故障时,识别难度大幅提升。为了预防此类情况引发的电气火灾,提出1种卷积神经网络(CNN)与长短时记忆网络(LSTM)结合的串联故障电弧检测方法。首先,搭建实验平台用以采集不同负载在不同支路下发生故障时和正常工作时的干路电流数据;然后,构建CNN_LSTM模型并做出相应改进,将电流数据直接输入到模型中,由模型自主提取波形特征并进行分类。研究结果表明:该方法可以快速、准确地识别出电弧故障,准确率达99.04%以上,且能够较为准确地检测出是哪类负载所在的支路发生电弧故障,准确率达97.90%,可为复杂支路下的电弧故障识别研究提供参考。     

狼尾草根系对阿特拉津长期胁迫的氧化应激响应

通过盆栽实验研究了抗性植物狼尾草根部丙二醛(MDA)、脯氨酸(Pro)、抗坏血酸(As A)含量及超氧化物歧化酶(SOD)、谷胱甘肽还原酶(GR)等氧化应激生理指标对不同浓度阿特拉津长期(48 d)胁迫的响应规律。结果表明:当阿特拉津胁迫浓度分别高于20 mg·kg~(-1)和50 mg·kg~(-1)时,狼尾草根系的MDA与Pro含量较对照组显著升高(P0.05);随着阿特拉津胁迫浓度的增加,狼尾草根部SOD和GR活性呈先升高后降低的趋势,其中当阿特拉津胁迫浓度为20 mg·kg~(-1)时,SOD和GR活性达到最大值;供试植物根系中As A含量与阿特拉津胁迫浓度呈正相关。综上,中低浓度(≤20 mg·kg~(-1))阿特拉津处理没有对狼尾草的根系产生明显的氧化胁迫效应,狼尾草根系的上述抗氧化应激生理指标对于发挥阿特拉津抗性起着重要的作用。     

红—克长输玻璃管线沿程压力和温度分布影响因素分析

为确定红—克长输玻璃管线常温输送方案,根据现场管线工况,利用Pipephase 软件建立了管道数值仿真模型,分析了原油含水率、输送流量、管道内壁粗糙度、环境 温度、入口温度等因素对管线沿程压力和温度分布的影响规律。结果表明:原油含水率 、输送流量、管壁粗糙度的增加会导致管线沿程压降增大;环境温度、入口温度的增加 会造成管线沿程压降减小,且压降变化趋势基本一致;原油含水率、入口温度的增加, 会引起管线沿程温降的增大;输送流量、环境温度的增加,会造成管线沿程温降的减小 ;管壁粗糙度对管线沿程温降影响较小。该研究工作为玻璃钢管线长输方案的制定提供 了参考依据,对保障油气安全运输具有重要的工程意义。