某公路隧道围岩稳定性及支护方式分析

跟踪某隧道施工,进行地质素描和节理统计,通过赤平投影分析节理发育分布规律,建立岩体结构模型;根据隧道围岩结构模型,运用离散元分析方法计算围岩稳定性,并结合现场塌方分析围岩破坏模式。通过离散元分析及时支护和无支护情况下围岩稳定性,探讨钢格栅锚杆组合进行初次支护的力学机理;根据现场钢格栅承受压力和隧道收敛监测,分析某隧道施工中围岩和支护体系的稳定性,总结出隧道施工中安全事故的主要原因,并给出合理的支护建议。     

用于早期火灾分类的非线性决策树支持向量机

对早期火灾信息进行研究,提出了一种基于非线性决策树的支持向量机多类分类模型。该模型利用非线性映射将样本投影到高维特征空间,比较每类样本在高维空间的分布情况,进行聚类构造出一个二叉决策树,使容易区分的类别从根节点逐层分类出来,有效克服了错分积累和避免不可分情况;同时,各个节点采用二值最小二乘小波支持向量机,以获得较高的泛化能力。该文将该模型用于早期火灾分类,并与BP神经网络、K近邻法和决策树方法进行比较,实验结果表明,该模型对早期火灾的识别率更高。     

地面超载对支护结构的影响

通过对超载所引起的作用在支护结构上的土压力的分析,提出超载较大时按应力扩散的方法确定超载作用的影响范围,建立了超载对支护结构土压力的计算模型,推导了支护结构土压力的计算公式,该计算模型可以较好地解释经典土压力理论计算中支护结构主动土压力偏大、被动土压力偏小的问题。该计算模型成功地用于工程实践后,大幅度降低了基坑支护的造价,表明其具有明显的适用性和经济性,因而对基坑支护和边坡支护的理论研究和工程实践具有借鉴意义。     

基于农业用地和地形约束的陇南山区适宜人口规模估算

陇南山区地形复杂,耕地不足,经济贫困,人口对资源环境的压力较大。研究适度人口容量对于地震灾后重建、缓解贫困以及保护长江上游的生态安全具有重要意义。以人均粮食和经济水平两个指标来估算温饱、宽裕和小康3个水平上的人口承载量,测度人口和农业资源的关系。并基于地形复杂度计算劳动用工及可抚养人口。结果表明:目前陇南10县(区)的人口在温饱生活水平下尚有超载。以小康生活为标准,适宜人口规模约为135万。经营现有的农耕地和林地需要100.81万劳动力,可抚养人口191.54万人,加上城镇人口总人口为231.03万。这个人口规模实现温饱有余而宽裕不足,难达小康目标。"人口-农业用地-劳动力"之间形成了一个怪圈,决定了陇南山区农村实现小康目标的艰巨性和复杂性。为此,陇南山区的灾后重建和区域可持续发展需要创新思路,多方并举。     

Children and fighting forces: 10 years on from Cape Town

It is 10 years since the adoption of the Cape Town Principles and Best Practices on the Prevention of Recruitment of Children into the Armed Forces and on Demobilization and Social Reintegration of Child Soldiers in Africa. The field of programming for the reintegration of children associated with armed forces and armed groups has made significant strides in this period. However, important gaps in the knowledge base remain. This paper examines empirical evidence that supports lessons learned from work with children formerly connected with fighting forces. It evaluates what is known, where promising practice exists, and lacunae in five programming areas: psychosocial support and care; community acceptance; education, training and livelihoods; inclusive programming for all war-affected children; and follow-up and monitoring. While the 2007 Paris Commitments to Protect Children from Unlawful Recruitment or Use by Armed Forces or Groups mark an emerging consensus on many issues, there is still a critical need for more systematic studies to develop the evidence base supporting intervention in this area.     

Sustainable decisions on the agenda – a decision support tool and its application on climate-change adaptation

A decision support tool aiming to facilitate discussion and transparency in land-use planning processes has been developed. It includes process steps initiating with an analysis of the current situation, identification of relevant actions and sustainability analysis steps. The sustainability was subdivided into human health and environment, resources, and social and economic impacts. The main difference between this risk analysis tool and others is the allowance of comparisons of present risks and consequences of measures early in the process. It also includes assessments from short- and long-term perspectives, such as taking into account climate change. It combines classic risk analysis with life-cycle assessment procedure. It has been developed and tested in co-operation with municipalities. The tests show that the tool is applicable and can be relevant in the planning process. It offers an iterative discussion framework that is systematic, condensed and yet a simplistic way of describing consequences. The criticism is that it is regarded as time demanding, but this can be managed by preparatory work.     

SCR脱硝蜂窝陶瓷催化剂载体的制备

以二氧化钛、氧化铝作为主要原料,通过柱塞式挤压成型法制备了0.15 m×0.15 m×1 m规格的蜂窝陶瓷催化剂载体。通过对不同原料组成的载体性能对比,研究了各配方组分对载体性能的影响。为了提高载体活性,在21号配方的基础上加入A、B 2种商用造孔剂,考察了不同造孔剂的造孔性能。考察了蜂窝陶瓷载体负载催化剂后选择性催化还原(SCR)NO的活性,结果负载催化剂后的载体21a的在300℃时NO转化率达到最大96.5%。     

一种新型的矿井突水分析与预测的支持向量机模型

针对矿井突水样本数少,信息不完整的特点,提出了矿井突水分析的线性核H-SVMs模型。推导模型的理论推广误差公式,设计自顶向下基于SVM最大间隔逐层分类构造H-SVMs的新方法,并应用于实际的矿井突水预测。实验结果表明,线性核H-SVMs模型结构简单、泛化能力强,不仅能很好地预测矿井突水,而且其层次结构能正确反映突水的等级关系,各判别函数的法向量还可以指示各突水影响因素的权重,通过判决函数能有效分析突水影响因素并提取突水预测规则,为矿井突水预测提供了新的方法。     

Scenario-based stakeholder engagement: incorporating stakeholders preferences into coastal planning for climate change

Climate change poses many challenges for ecosystem and resource management. In particular, coastal planners are struggling to find ways to prepare for the potential impacts of future climate change while dealing with immediate pressures. Decisions on how to respond to future risks are complicated by the long time horizons and the uncertainty associated with the distribution of impacts. Existing coastal zone management approaches in the UK either do not adequately incorporate changing stakeholder preferences, or effectively ensure that stakeholders are aware of the trade-offs inherent in any coastal management decision. Using a novel method, scenario-based stakeholder engagement, which brings together stakeholder analysis, climate change management scenarios and deliberative techniques, the necessary trade-offs associated with long term coastal planning are explored. The method is applied to two case studies of coastal planning in Christchurch Bay on the south coast of England and the Orkney Islands off the north coast of Scotland. A range of conflicting preferences exist on the ideal governance structure to manage the coast under different climate change scenarios. In addition, the results show that public understanding of the trade-offs that have to be made is critical in gaining some degree of public support for long term coastal decision-making. We conclude that scenario-based stakeholder engagement is a useful tool to facilitate coastal management planning that takes into account the complexities and challenges of climate change, and could be used in conjunction with existing approaches such as the Shoreline Management Planning process.     

Land-Use Planning in the Chaco Plain (Burruyacú, Argentina): Part 2: Generating a Consensus Plan to Mitigate Land-Use Conflicts and Minimize Land Degradation

The Burruyacú district (Tucumán province, Northwest Argentina) has been traditionally an area with rural activities based on the exploitation of the Chaco forest for timber and livestock browsing. Since the 1960s, local institutions started promoting soybean due to favorable land conditions and good market prices. Soybean extension, as from the 1970s, has resulted in important reduction of the Chaco forest and also caused physical soil degradation, especially soil compaction and erosion. A land-use-planning exercise was carried out using the Land-Use Planning and Information System (LUPIS) as a spatial decision support system. LUPIS facilitates the generation of alternative land-use plans by adjusting the relative importance attributed by multiple stakeholders to preference and avoidance policies. The system leads to the allocation of competing land uses to land map units in accordance with their preferred resource requirements, conditional upon the resource base of the area and the stakeholders' demands. After generating a land use plan for each stakeholder category identified in the study area, including commercial farmers, conservative/conventional farmers, and conservationists, a consensus plan was established to address the land-use conflicts between mechanized agriculture, traditional agriculture and forest conservation, and to mitigate soil degradation caused by extensive dry-farming. Although the planning exercise did not directly involve the stakeholders, the results are sufficiently practical and realistic to suggest that the approach could be extended to the entire Chaco plain region.