Incentive mechanisms to enforce sustainable forest exploitation

Using a two-player differential game approach, this paper deals with the issue of tropical deforestation. The assumption is that developing forestry countries (called the South) do not, or cannot, necessarily have the same utility for forest conservation than the developed countries (called the North). Given the global nature of the problem, we assume that it may be wise that the North offers financial support to the South to help in achieving a sustainable forest policy. We derive sustainable and short-run deforestation policies and provide a transfer mechanism which insures that the South will indeed implement the sustainable one.     

Modified Whittaker plots as an assessment and monitoring tool for vegetation in a lowland tropical rainforest

Resource exploitation in lowland tropical forests is increasingand causing loss of biodiversity. Effective evaluation and management of the impacts of development on tropical forests requires appropriate assessment and monitoring tools. We proposethe use of 0.1-ha multi-scale, modified Whittaker plots (MWPs) to assess and monitor vegetation in lowland tropical rainforests.We established MWPs at 4 sites to: (1) describe and comparecomposition and structure of the sites using MWPs, (2) compare these results to those of 1-ha permanent vegetation plots (BDPs),and (3) evaluate the ability of MWPs to detect changes in populations (statistical power). We recorded more than 400 species at each site. Species composition among the sites was distinctive, while mean abundance and basal area was similar. Comparisons between MWPs and BDPs show that they record similarspecies composition and abundance and that both perform equallywell at detecting rare species. However, MWPs tend to record morespecies, and power analysis studies show that MWPs were more effective at detecting changes in the mean number of species of trees 10 cm in diameter at breast height (dbh) and in herbaceous plants. Ten MWPs were sufficient to detect a change of 11% in the mean number of herb species, and they were able to detect a 14% change in the mean number of species of trees 10 cm dbh. The value of MWPs for assessment and monitoringis discussed, along with recommendations for improving the sampling design to increase power.     

陕西龙卷、尘卷风时空分布和日变化规律分析

本文整理分析了陕西的7次龙卷天气,重点分析了陕西尘卷风的时空变化特点和日变化规律,并与以前的一些研究成果进行了比较.     

旋风分离器磨损与防磨措施的研究

旋风分离器作为一种重要的气固分离设备,在石油化工、高炉喷煤、燃煤发电和环境保护等许多行业得到了广泛的应用.当旋风分离器分离煤、砂、飞灰、焦粉和氧化铝基催化剂等腐蚀性颗粒时,磨损是造成非计划停机的主要原因之一.就旋风分离器的结构、工作原理、磨损产生的机理与防磨措施问题展开讨论.     

旋风除尘器的性能及改进方案

介绍了旋风除尘器内部流场和除尘机理。针对旋风除尘器除尘效率问题分析、总结了现有的改进方法，指出了存在的不足，并结合前人的改进思路提出了新的改进方案，以提高旋风除尘器的分离效率，为进一步挖掘旋风除尘器的潜在性能开辟新的思路。     

珠江三角洲地区热带气旋逐时雨量分布特征

利用广东省自动观测站、常规地面站的逐时降水量资料,对1999-2002年登陆珠江三角洲地区的热带气旋进行了动态合成等分析.结果表明,登陆前后广东的逐时雨量和热带气旋本身的逐时雨量都发生了变化;热带气旋降水具有明显的不对称性,降水量级越强,分布不对称性越明显;随着降水量级的减弱,最大出现概率圈有外移的趋势;极强和强等级时雨量的落区与热带气旋移动方向有关.     

钢在热带海洋大气中的腐蚀

研究低碳钢和中碳钢在新加坡陆地与海上浮筏的大气腐蚀，浮筏上低碳钢的腐蚀比在陆地上快，含碳量高的钢腐蚀慢，此文试图将温度，湿度，润湿时间，降雨量，太阳辐射与干喷砂低碳钢在陆地试验点的腐蚀率联系起来，提出了冬季暴露几个月的样品失重的腐蚀深度表达式0．1078＋0．000596xum，扫描电镜检查显示在陆地曝露的样品氧化膜呈斑状，而浮筏上的样品有连续的氧化膜且氧化膜上裂纹也是连续的，能谱分析表明，浮筏上样品的氧化膜含有大量的氯化物和原子吸附，研究认为氧化膜是由FeOOH构成的，在陆地暴露2年的试样腐蚀率为0．016mm/year，浮筏上海洋大气曝露0．6年的腐蚀率为0．659mm/year。     

热带森林火灾产生的特点分析

在分析我国热带气候特征，植物种类，植物燃料特性和对几种典型热带林木枝，叶进行热解实验的基础,计算了南粤地区热带森林火险区划等级和林火蔓延速度，并讨论了热带森林火灾产生的特点。     

旋风炉附烧处理后解毒铬渣的安定性研究

着重阐明了铬渣经肇风炉附烧及炉餐水淬处理后生成的玻璃体粒化解毒渣的安定性问题，通过对解毒渣的物相结构，浸溶性和高温稳定性等试验分析，最终判明解毒渣在≤５００℃条件下没有玻璃化倾向，在自然环境中储放和用作建材，都是安定和安全的。     

旋风预收尘器对多级收尘系统的若干影响

论述了旋风预收尘器对多级收尘系统的若干影响因素，着重讨论了旋风除尘器出口旋转气流对系统性能的影响，并提出了具体改进措施。