基于自组织映射与随机森林耦合模型的流域水质空间差异性评估

流域水环境质量空间分布特征分析是推进流域精细化管理的基础.本研究基于流域特征指标与水质的关联性,以子流域为分析单元,利用自组织映射人工神经网络模型（SOM）对苕溪流域水质数据聚类分析为3类后与随机森林模型（RF）进行耦合,对全流域水质进行了空间差异性评估.研究结果显示,上游山地区域水质较好,而平原河网人口集聚区的COD_Mn、NH₃-N及TP浓度较高,山地与平原过渡地带水质则主要受到COD_Mn和TN的影响.采用自然环境、社会经济及土地利用/覆盖指标作为流域特征进行水质分级模式识别,SOM与RF模型耦合模型的准确率稳定在80%左右;在对强相关性特征进行筛选识别后,将蒸发蒸腾量、坡度、人口密度、大于10℃积温、旱地占比、城镇用地占比及景观多样性指数为作为输入特征,准确率可达83%,可以有效地开展全流域水质分级评估.     

邻苯二甲酸二异癸酯联合甲醛致小鼠学习记忆障碍的氧化损伤机制研究

为了探究邻苯二甲酸二异癸酯(Diisodecyl Phthalate,DIDP)、甲醛(Formaldehyde,FA)二者联合暴露致小鼠学习记忆障碍的氧化损伤机制,以及维生素E(Vitamin E,Vit E)对二者所致氧化损伤的保护作用,将80只SPF级3周龄雄性KM小鼠随机平均分为8组:(A)阴性对照组;(B)0.15 mg·kg~(-1)·d~(-1)DIDP组;(C)1.5 mg·kg~(-1)·d~(-1)DIDP组;(D)15 mg·kg~(-1)·d~(-1)DIDP组;(E)150 mg·kg~(-1)·d~(-1)DIDP组;(F) 1 mg·m~(-3)FA组;(G)1 mg·m~(-3)FA+15 mg·kg~(-1)·d~(-1)DIDP组;(H)1 mg·m~(-3)FA+15 mg·kg~(-1)·d~(-1)DIDP+100 mg·kg~(-1)·d~(-1)Vit E组.连续染毒3周.于染毒第13 d开始进行水迷宫实验,末次给药后24 h内取小鼠脑组织制作切片和组织匀浆,检测脑组织匀浆中活性氧(ROS)、还原型谷胱甘肽(GSH)、丙二醛(MDA)、8-羟基脱氧鸟苷(8-OHdG)的含量.结果表明,(A)组～(E)组小鼠脑海马组织氧化损伤逐渐加重,小鼠学习记忆能力逐渐下降;(G)组较(F)组小鼠脑海马组织氧化损伤加重,小鼠学习记忆能力下降;(H)组较(G)组小鼠脑海马组织氧化损伤减轻,小鼠学习记忆能力有所提高.研究显示,DIDP可通过氧化应激作用,引起脑海马组织损伤,导致小鼠学习记忆能力下降.     

Complex dynamics in the uptake of new farming practices: a case study for organic waste application

Adverse environmental effects of intensive agriculture, together with scarcity in phosphates and water, urge farmers to find more sustainable practices. An example of such a sustainable practice is on-farm processing of organic waste. This paper explores three mechanisms that can lead to a widespread uptake of this technique: (1) economies of scale, (2) information sharing, and (3) adjustment of social norms. Although each of these mechanisms has been studied before, this paper provides new insights by considering the interactions that might exist between the different mechanisms when they are applied to real-life situations. Based on a pilot study, we developed a multi-criteria mathematical programming model at individual farm level. We used this model to simulate the uptake of on-farm processing of organic waste, as a result of the three mechanisms and their interactions. Our results show that each mechanism results in an increased uptake, but is not likely to cause a widespread uptake. Interaction between the mechanisms, will lead to a much higher uptake. This result suggests that simultaneous consideration of multiple mechanisms is essential to understand the behaviour of social–ecological systems.     

Reflexive governance: exploring the concept and assessing its critical potential for sustainable development. Introduction to the special issue

ABSTRACT

Elaborated in publications on transition management, sustainability governance and deliberative environmental governance, ‘reflexive governance’ addresses concerns about social-ecological vulnerabilities, flawed conceptualisations of human-nature relations fragmented governance regimes and conditions for a sustainability transition. Key barriers to reflexive government include unavoidable politics; the influence of broader discursive systems that shape actors’ strategic interests; and structural and deliberate limitations to the range of admitted epistemological understandings, normative perspectives and material practices. Against this background, the contributions to the special issue provide novel conceptual linkages between reflexive governance and boundary objects, intercultural dialogue, conflict management heuristics, discourse linguistics, theories of the policy cycle and reflexive law, network and learning theories, and Lasswell’s ‘developmental constructs’. Based on the contributions, we identify five inherent conceptual tensions of reflexive governance: between the openness of horizontal learning processes and the desired direction towards sustainable development; between reflexive governance as a normative or procedural concept; between expected learning orientations and other, strategic orientations; between governance as a precondition for reflexivity and reflexive learning as a precondition for reorganized governance structures; and between reflexivity as an open-ended, evolutionary process and the need to strategically defend the space for reflexivity against powerful groups with an interest in the status quo.     

Barriers and enablers to climate change adaptation in hierarchical governance systems: the case of Vietnam

Governments fulfil important roles in increasing the adaptive capacity of local communities to respond to climate change impacts, particularly in developing countries. Existing studies on how governments enable and constrain the ways in which local level communities learn and build their adaptive capacity, however, generally adopt network or market-oriented types of governance. However, the most vulnerable regions to climate change impact in the world are generally governed through hierarchical policy systems. This research aims to understand how the hierarchical policy system in Vietnam creates enables and/or constrains the policy capacity of policy actors to contribute to effective climate change adaptation. We conducted interviews (n?=?26) with key actors at multiple levels of government. Our findings show the importance of clear legal institutions, available financing for implementing policies, and the training of governmental staff, particularly at district and commune levels where the policy capacities are generally too low to deal with climate change impacts. We conclude that any efforts to support local actors (i.e. smallholder farmers) should include investments in policy capacity to ensure uptake and upscaling of adaptation actions more broadly.     

水资源开发与利用科研工作的现实制约与对策建议

中国人均水资源量少、水资源时空分布不均,近年来经济社会对水资源需求日益增大。在相关领域科技成果的大力支撑下,中国走出了一条有效的水资源管理之路,实现了水资源的高效利用和有效保护。但目前在水资源开发利用的科技活动中仍存在一定的现实制约,本文进行了一定分析,并提出了对策建议。     

Mentoring with(in) care: A co‐constructed auto‐ethnography of mutual learning

Research into workplace mentoring is principally focussed on predictors and psychosocial and instrumental outcomes, while there is scarcely any in‐depth research into relational characteristics, outcomes and processes. This article aims to illustrate these relational aspects. It reports a co‐constructed auto‐ethnography of a dyadic mentoring relationship as experienced by mentor and protégé. The co‐constructed narrative illustrates that attentiveness towards each other and a caring attitude, alongside learning‐focussed values, promote a high‐quality mentoring relationship. This relationship is characterised, among other things, by person centredness, care, trust and mutual influence, thereby offering a situation in which mutual learning and growth can occur. Learning develops through and in relation and is enhanced when both planned and unplanned learning takes place. In addition, the narrative makes clear that learning and growth of both those involved are intertwined and interdependent and that mutual learning and growth enrich and strengthen the relationship. It is concluded that the narrative illustrates a number of complex relational processes that are difficult to elucidate in quantitative studies and theoretical constructs. It offers deeper insight into the initiation and improvement of high‐quality mentoring relationships and emphasises the importance of further research into relational processes in mentoring relationships. Copyright © 2015 John Wiley & Sons, Ltd.     

乌梁素海芦苇枯落物分解动态及营养元素释放研究

乌梁素海是内蒙古高原干旱区最典型的浅水草型湖泊,湖滨带芦苇分布广袤,其收割方式是在冬季湖泊结冰后将冰面上芦苇收割,冰面下芦苇则留存在水中,而水下部分的分解是造成湖泊生物淤积的重要原因,且分解过程中营养元素的释放亦加剧了湖泊富营养化。通过分解袋法研究了湖泊水面下芦苇枯落物的分解动态及营养元素的释放过程,并探讨了芦苇枯落物分解的影响因素。结果表明:1)芦苇枯落物分解270 d后质量残留率为52.44%,分解速率常数为0.002 68 d~(-1),其分解50%需要0.83 a,分解95%需要3.19 a;2)芦苇枯落物分解过程中,N元素的分解状态呈现释放-分解-再释放的规律,P元素和C元素均处于持续释放的分解状态;3)芦苇枯落物分解期间,分解速率和营养元素含量动态受枯落物自身质量和环境因子共同影响,且环境因子(温度、溶解氧、pH值)与芦苇枯落物分解速率及元素释放动态相关性显著。研究表明,芦苇枯落物分解释放大量营养物质,对湖泊富营养化有一定的贡献,要进一步加强芦苇植物的收割以减轻植物腐烂分解对湖泊造成的二次污染,减少生物淤积作用。     

从行为科学角度浅论家具生产企业安全管理

家具生产企业的安全状况如何,直接影响企业的经济效益,影响着生产员工的情绪稳定.本文旨在运用行为科学理论,剖析家具生产企业事故发生的原因,并提出了避免出现安全事故的相应措施,促进家具企业的健康发展.     

FLAC3D中复杂模型的三维建模技巧

在数值模拟中,模型是实体的简化而不失真的摹体.数值分析的合理性很大程度上取决于模型建立的正确性.解释了FLAC3D模型建模过程的一些问题.介绍了前期工作,及在FLAC3D中建模的特点,并进行了实例模拟.