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。     

太湖沉积物铁形态分布特征及磷铁相关性分析

通过对太湖藻型湖区、草藻过渡型湖区、草型湖区柱状沉积物进行铁的形态分级分析沉积物中不同提取态磷铁含量,获得不同形态铁的空间分布特征.结果表明:沉积物总铁含量藻型湖区31.57mg/g(SD=8.51) >过渡型湖区30.34mg/g(SD=11.97) >草型湖区25.25mg/g(SD=4.59),不同湖区沉积物中铁形态的含量依次为可还原(晶型)铁氧化物Fe_ox2 >碳酸盐铁Fe_carb >易还原(无定形)铁氧化物Fe_ox1 >低活性硅酸铁Fe_prs >磁铁矿Fe_mag >可吸附性Fe(Ⅱ),Fe_carb、Fe_ox1、Fe_ox2,3种铁形态属于高活性铁Fe(Ⅲ),含量为7.79,6.16,8.18mg/g,分别占总铁含量的28.56%,21.54%,29.53%,表明高活性铁(Ⅲ)是沉积物中最主要的铁形态;沉积物中各提取态磷含量大小比较为NH₂OH·HCl-P >MgCl₂-P >NaAc-P >Na₂S₂O₄-P >浓HCl-P >(NH₄)₂C₂O₄-P,含量较高的MgCl₂-P(0.067mg/g)、NaAc-P(0.061mg/g)、NH₂OH·HCl-P(0.068mg/g),分别占总提取磷的35.28%、31.97%和22.55%,是沉积物铁分级提取态磷中最主要的形态.磷-铁相关性分析表明,二者之间呈显著的正相关(P<0.05),进一步从铁形态分级角度证实铁是沉积物內源磷释放的关键因子.     

Spatially explicit models of land abandonment in the Amazon

Given growing concerns about biodiversity loss and carbon emissions stemming from tropical deforestation, it is important to identify the factors associated with land abandonment as they might indicate areas that were deforested but are unsuitable for long-term cultivation. This article utilizes a high-resolution, Landsat-based data-set called TerraClass to relate land abandonment to precipitation, slope, farmgate price of beef, market access, soil quality, and land tenure characteristics in the Brazilian Amazon. The spatially explicit statistical models reveal that rates of land abandonment increase with higher rainfall and slope values, even when controlling for distance to roads, farmgate prices, type of settlement, and soil quality. Moreover, land adjacent to a major road is more likely to be consistently cultivated, but land near large rivers and far from highways is more likely to be abandoned. Land ownership type also influences the likelihood of land abandonment as settlements based on communal property rights have higher rates of land abandonment than settlements with private lots. These results suggest that policies aimed at occupying tropical forests such as the Amazon must consider these biophysical and socioeconomic factors in order to foster human development aligned with sustainability principles.     

云南地区种子植物区系过渡性地理分布格局的群落尺度分析

探索植物区系过渡性的地理分布格局,对于理解植物区系的起源、迁移和分布具有重要意义。本研究利用620个植物群落样方,探讨了云南地区植物区系过渡性的地理分布格局及其生物地理意义。研究结果表明,随着纬度、海拔的升高,温带区系成分所占比重呈显著递增趋势,但在经度梯度上呈递减趋势;热带区系成分所占的比重在地理梯度上则表现为相反的变化趋势。地形格局较好地反映了区系成分的地理分布格局;热带区系成分所占比重与温带区系成分所占比重的比值从南到北呈递减趋势。区系过渡性的低值主要出现在滇西北地区和包括滇西南、滇东南与滇南在内的云南南部地区,而高值主要出现在云南中部地区和中海拔地区,这可能与区系迁移过程和海拔梯度有关。热带区系成分在云南地区基带植被中占主导地位;热带区系成分占优势地位的区域主要集中在低海拔地区,占云南土地面积的60％左右,而温带区系成分占优势地位的区域主要集中在高海拔的北部地区,占土地总面积的40％左右。本研究从基带植被的区系性质和温、热带植物区系成分占优势地位的土地面积的构成证实了云南地区可能是一个“热带山原”的假说。区系过渡性随着年平均温度的升高,呈先增强后减弱的单峰格局。当年均温在13．1℃左右时,出现区系平衡点。相对水平分布而言,云南地区植被的垂直分布可能更值得注意。     

Masters of the long haul: Pursuing long‐term work goals

We investigate work motivation in the unstudied domain of individuals who pursue very long‐term goals. We highlight the fact that the preponderance of research findings on the psychology of work motivation is based on short‐term studies and discuss the potential relevance to long‐term motivation of literatures including long‐term thinking and time horizons, long‐term goals and goal pursuit, and self‐regulation. We adopt the qualitative research strategy of theory elaboration, with a specific intention of elaborating goal‐setting theory. Analysis of interview data from a unique sample of scientists and others pursuing goals spanning decades or more yielded a structure of psychological factors that can enhance, support, and sustain motivation for the long term. Reconciling our findings with existing goal theories, we develop an integrative model of motivating factors and self‐regulation processes underlying long‐term goal pursuit. We discuss the implications, including an expanded focus for our field on motivating people for the long run. Copyright © 2012 John Wiley & Sons, Ltd.