竹材原态多方重组材指接设备优化设计

对竹材原态多方重组材料纵向指接机进行了优化设计,阐述了指接机的工作原理、液压结构及设计原理,对指接机进行了运行试生产.将铣指加工的短料坯件涂胶后对接,通过指接机加压挤压,经过冷固化后使其成型.试验表明,竹材原态多方重组纵向指接机设计压力合理,运行平稳,能有效阻止多方重组材对接后因受压而产生的错位与滑动,生产的多方重组竹材的力学性能可达到相关标准的要求.     

The Evolution of Watershed Councils and the Oregon Plan

Summary

Revisiting the history of Oregon politics, especially environmental policy, shows that populist tradition and innovative government are tied together. Political innovation through massive reform led to the Oregon System, a governmental approach that allows a good deal of direct, or participatory, democracy. The degree of direct democracy in Oregon, or at least the threat of voters bypassing the legislature, led to a series of environmental laws passed in the 1970s. Along with similar federal laws, these set a regulatory baseline from which to build a watershed protection strategy. Key to this Watershed Health Program is the role of community-based watershed councils, which provide a good example of local, inclusive, participatory democracy. Utilizing watershed councils as the key component of a state watershed restoration strategy within the context of a regulatory baseline is an example of a hybrid centralized/decentralized approach to environmental policy. This hybrid approach is a political innovation that serves as an incremental response to competing environmental and anti-government populism. This approach will be severely tested by the 1997 Oregon Plan for Salmon and Healthy Watersheds, a state conservation plan designed to head off a listing of salmonid species under the Endangered Species Act. If this approach is successful, community-based ecosystem management groups and states that wish to copy Oregon's example will have new ideas to foster maintenance and restoration of ecosystems through state-administered conservation plans.     

Structure and properties of the cellulose microfibril

The current structural models of the cellulose microfibril as well as its mechanical and thermal properties are reviewed. The cellulose microfibril can be considered as a single thin and long crystalline entity with highly anisotropic physical properties. The contribution and limit of different methods employed such as electron microscopy, infrared spectroscopy, X-ray scattering and diffraction, solid state nuclear magnetic resonance spectroscopy, and molecular modeling are also discussed.     

兰考泡桐和刺槐幼苗最适营养需要的研究

按稳态营养理论和方法,本文研究了兰考泡桐(Paulownia elongata)和刺槐(Robinia pseudoacacia)幼苗的最适营养需要。通过每天测定和调整培养液pH值和电导率,及时补偿消耗的营养物,幼苗体内营养状况和最大生长速率均保持稳定。兰考泡桐幼苗每天生长率高达25％以上,刺槐达15％。营养物利用率90％以上。确定兰考泡桐幼苗最适营养物比例为100N:75K:18P:7Ca:8.5Mg;刺槐为100N:60K:15P:8Ca:9Mg。本文还讨论了最适营养研究在育苗和林地施肥应用的前景。     

宿迁市生态系统健康遥感监测研究

利用1989年和2001年2期TM卫星遥感数据及辅助数据,运用遥感和地理信息系统技术,通过植被指数、土地利用变化、景观格局变化3个方面的监测分析,研究宿迁市生态系统健康状况的变化趋势．结果表明,10年间农田减少,城乡居住地增多,植被指数略有下降,景观格局发展趋势良好,宿迁市生态系统健康有下降趋势．     

油茶枯饼固态发酵技术的研究

对油茶枯饼的脱毒和发酵技术进行了研究.结果表明乙醇对油茶枯饼中的皂素有较高的脱除率，枯饼中的营养成分损失少；黑曲霉、毛霉和117假丝酵母能在脱皂油茶枯饼上正常生长，枯饼固态发酵后，其蛋白质含量有一定程度的提高，提高程度为66.7%～99.7%；平菇、紫木耳能在油茶枯饼中正常生长，而金针菇则生长不正常；紫木耳对枯饼中蛋白的提高程度在各食用菌中最高，为74.2%～110.7%；以毛霉、平菇和紫木耳的一次发酵产品再经117产朊假丝酵母二次发酵，其粗蛋白质含量接近20%，氨基酸组成趋向平衡.     

基于TM影像纹理与光谱特征的红树林生物量估算

为研究红树林生物量的遥感估算方法,提取了广西和海南红树林TM遥感影像的光谱及纹理特征,结合地面调查所得126个样地生物量数据,进行多元逐步回归分析。结果表明,建立的生物量估算模型通过相关检验,可以高效、快速地进行红树林生物量的估测。     

谈国有建筑施工企业的经营管理创新

加强和创新国有建筑施工企业的经营管理机制的改革,是使企业具有抵御风险能力,不断增强综合竞争实力的需要,也是维持企业生存和发展的需要.     

浅谈当前森林覆盖率计算的两个公式

介绍计算森林覆盖率的2个公式,指出应该用(2)式计算森林覆盖率.分析了有林地面积、国家特别规定灌木林地面积、灌木林地面积与森林覆盖率的关系.     

冷态鼓泡流化床中木屑流化速度的研究

冷态条件下,在鼓泡流化床中采用木屑为原料,分布板在 2%～4% 不同开孔率的条件下,分别考察了原料粒径和床层高度对木屑流化速度的影响.得出结论:分布板压降和流速成二次函数关系;以木屑为原料,分布板开孔率和床层高度对临界液化速度的影响不大,粒径分布对临界流化速度随粒径的增大而增加.