A COMPARISON OF SURFACE RUNOFF AND SEDIMENT YIELDS FROM LOW- AND HIGH-SEVERITY SITE PREPARATION BURNS1

ABSTRACI:. Slash burning is a common site preparation technique used after timber harvest throughout the Southeastern United States. Little quantitative information exists on the hydrologic response to burn severity. This study compared the effects of low-severity and high-severity burns on runoff and sediment yields during rainfall simulation and during natural rainfall in the Southern Appalachian Mountains. Fire severity was largely determined by moisture conditions of the forest floor prior to ignition. Runoff and sediment yield variability was high between plots within the same treatment area due to differences in forest floor characteristics and infiltration rates. Conditions of high-severity resulted when burning was conducted with relatively dry fuels. Sediment yields were 40-times greater for the high-severity treatment areas than the low-severity treatment areas.     

磨料水射流切割与其它方法切割对金相组织影响的试验研究

本文以２０＃优质碳素结构钢为试件，介绍了磨料水射流切割与其它方法切割对金相组织影响的试验。试验结果表明，磨料水射流切割无热影响区。     

Rapid land use change threatens provisioning ecosystem services in miombo woodlands

Rural communities in sub‐Saharan Africa rely upon provisioning ecosystem services (ES) to support their livelihoods, yet in areas where rapid land use change is occurring the relationship between environmental change, provisioning ES availability and livelihoods is not fully understood. This relationship is explored here within a typical rural miombo woodland landscape in south‐west Tanzania, which is undergoing rapid land use change due to expanding tobacco cultivation. The types of provisioning ES used, who uses them, changes in their availability, and the possible future impacts of these changes were explored using a mixed‐method approach. Our findings identify 19 provisioning ES used by households regardless of economic status. Firewood, building materials, and fresh water are used by almost all households, and these are perceived to be declining in availability. Households identified this as a negative environmental impact of land use change and that provisioning ES loss would be ‘bad’ for their households. Given the multi‐purpose nature of miombo woodlands, an adaptive co‐management approach, which can achieve multiple objectives through encouraging participation, learning, and empowerment of local communities, could be an appropriate strategy to achieve sustainable land use management and maintain the provision of ES within miombo woodland landscapes of sub‐Saharan Africa.     

辽宁省产业结构对环境影响的初探

产业结构影响着一个地区社会经济以及环境等诸多方面。本文对辽宁省产业结构现状,主要行业产值及污染贡献率,以及产业结构调整对污染物排放强度变化影响进行剖析,较系统地分析了一个地区的产业结构对环境的影响,对环境管理及经济建设具有一定的借鉴意义。     

木材检查站建设与发展浅探

木材检查站既是林业部门的基层执法单位,也是森林资源保护和监督的主要屏障.通过分析湖南省木材检查站建设与发展现状,剖析木材检查站建设与发展中存在的问题.从检查站布局、检查方法、机构编制和经费、规范化建设等层面探讨木材检查站建设与发展存在的问题的解决对策.     

新疆建筑材料用工业废渣及其建材产品的辐射水平

报道了分布在新疆１３个地州市８０多个厂家的建材用工业废渣及其建材产品的放射性检测结果。多数废渣及其产品的放射性水平低于国家规定的限制（控制）标准，可以用作建筑材料，少数地区的部分工业废渣明显高于限制标准，不能用作建筑材料．必须健全放射性检测和管理制度．     

对一起矿井动力现象事故的分析探讨

本文对一起“矿井动力现象”事故,从发生这起事故的条件和可能性及其事故后的特征等多方面进行了分析论证,认为该次事故不是一起“矿井动力现象”——煤与瓦斯突出,而是一次因放炮引起的瓦斯爆炸事故。指出了发生这次事故的原因,总结了该次事故的经验及教训,同时也提出了防止这类事故的预防措施。     

软管隔振结构在噪声控制中应用的研讨

由膜和板自由振动的理论分析，可以证明布质或软橡胶质制造的连接管比普通金属刚性管隔振降噪效果提高10-20dB以上。但在设计手册及现有的书刊中未见有量化设计和运用技巧方面的介绍。软连接一般存在透声问题．只要合理运用也可化害为利。这取决于对安装位置和尺量的合理选择。当选择利用其透声时，管长L应不小于管径d；如需避免其透声时，应取L≤d／4。     

环境保护图书网络管理系统的开发及应用

在多年环保图书管理工作的基础上，自主研发了一套图书网络管理系统，该系统基于ASP VBScript语言开发，采用B／S结构设计模型，适合于中小型企事业单位局域网的图书自动化管理。     

SOS法检测环境中遗传毒物的应用和研究

随着社会工业化水平的日益提高,从各种渠道进入环境中的化学污染物的种类和数量也在急剧增加,污染物中不少具有致突变性、致畸性和致癌性,其存在能直接影响到人类的健康和安全,急需发展更为灵敏、经济和快速的检测方法来确定遗传毒物在环境中的存在和数量.在近年来建立的各种生物检测系统中,SOS 检测法以其独特的生物学原理和准确性而受到重视.本文从 SOS 法的原理、分类及优缺点等方面综述了其应用于环境检测的研究进展.