Size-Dependent Selective Leaf Damage by Insects and Some Methodological Implications of This Phenomenon

The area of leaves on birch (Betula pubescens ssp. tortuosa) auxiblasts and brachyblasts and the degree of their damage by the complex of leaf-gnawing and leaf-mining insects were studied in a light birch forest. The results showed that phyllophagous insects, primarily snout beetles, prefer young leaves on the apexes of auxiblasts. Thus, selective damage is inflicted on smaller leaves, both on the auxiblasts and in the entire sample. This phenomenon is widespread and may manifest itself in different ways, depending on the pattern of leaf area distribution along the extended shoot and the feeding preferences of the insects. Thus, it is necessary to reconsider research methods and approaches based on the assumption that insects damage leaves nonselectively, irrespective of their size.     

Assessing Anchor Damage on Coral Reefs: A Case Study in Selection of Environmental Indicators

Because environmental conservation can remove scarce natural resources from competing uses, it is important to gain support for conservation programs by demonstrating that management actions have been effective in achieving their goals. One way to do this is to show that selected significant environmental variables (indicators) vary between managed and unmanaged areas or change over time following implementation of a management regime. However, identifying indicators that reflect environmental conditions relevant to management practices has proven difficult. This paper focuses on developing a framework for choosing indicators in a coral reef habitat. The framework consisted of three phases: (1) information gathering to identify candidate variables; (2) field-testing candidate variables at sites that differ in intensity of human activity, thus identifying potential indicators; and (3) evaluating potential indicators against a set of feasibility criteria to identify the most useful indicators. To identify indicators suitable to measure the success of a management strategy to reduce anchor damage to a coral reef, 24 candidate variables were identified and evaluated at sites with different intensities of anchoring. In this study, measures that reflected injuries to coral colonies were generally more efficient than traditional measures of coral cover in describing the effects of anchoring. The number of overturned colonies was identified as the single most useful indicator of coral reef condition associated with anchoring intensities. The indicator selection framework developed here has the advantages of being transparent, cost efficient, and readily transferable to other types of human activities and management strategies.     

火灾后钢筋混凝土损伤程度的灰关联分析

由于火灾对钢筋混凝土结构的影响存在不确定性,使得人们不能准确地确定火灾后钢筋混凝土结构的损伤程度,给评估和加固修复带来很大困难。本文运用灰色系统理论中灰关联分析数学模型定量分析了高温下钢筋混凝土梁的3种影响因素,并确定了各因素间的主次关系,为高温后钢筋混凝土结构的安全评估及修复加固提供了理论依据。     

某厂化学装置爆炸对设备房结构的损坏——调查与模拟分析

在对某厂化学爆炸所作的现场调查的基础上，对设备房钢筋混凝土框架结构构件的受损状况进行了分类描述，采用有限元方法对框架结构在静力和爆炸冲击荷载下的反应进行了模拟分析，分析结果与现场调查情况基本一致，给出了一些有意义的结论。     

基于3S技术的震害快速评估

地震是人类面临的重大自然灾害之一，破坏性地震发生后，对震害的快速评估有利于政府及有关部门对灾情迅速做出应急反应，实施救援。地理信息系统（GIS）、遥感（RS）和全球定位系统（GPS）合称为3S技术。随着计算机技术和地球空间科学的发展。3S技术已逐渐应用于防灾减灾领域。探讨了应用3S技术替代传统的经验性估计决速评估震害的技术路线、方法和前景。首先，归纳了目前防震减灾信息及辅助决策系统建设取得的成绩和存在的问题。通过两个破坏性地震的震害实例，说明了应用基于GIS的系统快速评估震害的可能性和有待重点解决的问题。然后。通过新疆一次地震的遥感图像的变化检测，展示了震害快速评估中借助遥感数字图像处理技术的前景。在上述综合分析的基础上，讨论了三者结合的重要性、潜在功能和优点。     

齿轮轴修复安全性探讨

对催化装置四机组运行状态进行分析,介绍了齿轮箱高速轴及轴瓦损坏的情况,并分析说明了引起损坏的原因。结合生产实际确定合理的齿轮轴修复工艺方案,即采用激光融敷表面修复高新技术,迅速可靠地对齿轮轴进行修复,保证了设备运行的可靠性,从而实现安全生产、节能降耗、效益增长。     

西安市大气和水污染对人群健康损害的经济价值损失研究

环境污染对人群健康造成损害的经济价值评价一直是学术界讨论的热点．采用不同的价值评估方法-VPLL潜在寿命损失年法、VSL统计生命价值法、WTP支付意愿法对西安市1996—2003年的大气和水污染对人群健康造成的经济损失进行评价。结果表明：1996—2003年。西安市大气和水污染健康损失年平均为228792万-434237万元，占GDP的3．69％-7％。对居民健康有显着影响。     

SRHSC梁主要设计参数损伤敏感度分析

以型钢高强混凝土(SRHSC)梁为研究对象,结合SRHSC梁受力机理及承载能力的试验研究成果,提出了极限状态下的承载能力是评价梁力学性能的关键指标,将损伤前后梁正截面抗弯承载力之比和斜截面抗剪承载力之比的均值作为自变量,给出了SRHSC梁损伤表征函数,并借助"预定损伤法",揭示了主要设计参数对SRHSC梁损伤演化的影响规律。研究成果将为建立地震激励下SRHSC框架结构楼层损伤模型提供理论和数据支持。