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11.
Richards林木生长模型及其适用性   总被引:3,自引:0,他引:3  
该文简述了Richards生长方程的可塑性,以毛白杨、华北落叶松、刺槐与斑克松的生长资料,讨论了描述林木生长过程的适用性。  相似文献   
12.
Multi-objective forest planning is a multi-methodological endeavor whose success largely depends on how well the combined use of different methods contributes to the goals of the planning. This review assessed the benefits of mixing methods in natural resources planning. A sample of 30 peer-reviewed research articles was analyzed using an evaluation framework, designed based on democracy and planning theories, and participatory planning literature, including four dimensions: transparency, flexibility, consensus building, and operability. According to analyses, mixing different types (i.e. qualitative and quantitative) of methods generally yields greater benefits than the combination of similar methods. The subsample of 12 planning cases that utilized simulation-optimization software (SOS) appeared operable and moderately transparent, whereas flexibility and consensus building were often lacking. In comparison to the wide scholarly discussion on multi-methodology and mixing methods, it was observed that successful mixing examples in natural resource planning are still scarce and there are weaknesses in bridging the methods together. There is an evident need to pursue and to better communicate the benefits of mixing. Some good mixing examples utilizing SOS provided evidence that forest planning processes would make an excellent venue for studying the benefits and caveats of using mixed methods.  相似文献   
13.
动物毛发的形态结构及其功能特性研究   总被引:10,自引:0,他引:10  
对人发及其他14种动物毛发的扫描电镜(SEM)照片进行分析,根据它们形态结构特征将其分为指状结构、芽状结构、鳞状结构和波状结构4类,并就每种毛发结构的保温性、疏水性及其柔性进行了比较分析。分析结果表明,具有指状细观结构形态的毛发在保温性、疏水性及柔韧性方面具有明显优势,这一信息对研究开发新型功能材料具有借鉴作用  相似文献   
14.
This paper argues that there is a need to better acknowledge and problematise the manner in which individuals, households, organisations and governments in small island jurisdictions develop mechanisms that allow them to exploit the benefits, and/or minimise the losses, of episodic economic lurches. A ‘strategic flexibility’ approach is proposed to explain how actors practise intersectoral migration: cleverly shifting focus, interest and scope, not just out of necessity (reactively) but in ‘smelling’ promising opportunities (proactively). In a scenario where change is taken as a given, managing and coping with such change become the hallmarks of economic survival: just like surfers handling the ocean swell.  相似文献   
15.
现代图书馆建筑设计中的人本思想   总被引:5,自引:0,他引:5  
本文从人们对现代图书馆需求的分析,以苏州大学新图书馆建筑设计为例,提出以人为本的现代图书馆建筑必须具备灵活性、多功能性。  相似文献   
16.
报道2003年至2004年10个引进亚麻品种在云南省8个试验点的纤维产量和品质测定结果。3个国外品种的长麻率、总麻率、纤维产量明显高于国内品种;方差分析显示,不同地点间、不同品种间纤维产量差异显著。10个亚麻品种的平均分裂度变幅为344~407公支,平均断裂强力变幅为200~248 N,平均可挠度介于49.6~56.6 mm;同一品质指标在不同试点的变幅较大。方差分析结果表明,正麻品种间的纤维品质差异不显著,地点间的纤维品质差异显著。  相似文献   
17.
In this paper, based on Guyon''s and Massonnet''s method, the multi-span continuous curved girder bridge with the variable cross section is simulated as a thick-varied transversal|y sector plate. And then by means of the flexibility method, the middle suppo  相似文献   
18.
揉捻过程中茶叶物理特性的变化规律   总被引:1,自引:0,他引:1  
张哲  牛智有 《湖北农业科学》2012,51(13):2767-2770
为研究揉捻过程中茶叶含水率、柔软性、弹塑性及孔隙率等物理特性的变化规律,以华农绿茶鲜叶为原料,经萎凋、杀青并回潮之后进行揉捻加工,分别采用103℃恒重法、质构仪法、仪器法对以上几个茶叶物理性质进行测定,分析它们的变化规律.结果表明,揉捻过程中茶叶的含水率与揉捻时间呈负相关,(y)=-0.032 7 x+46.421,决定系数r2=0.959;揉捻过程中茶叶的弹性与揉捻时间基本呈线性正相关,(y)=0.134 2x+12.92,决定系数r2=o.956;而柔软性和塑性都是先增加后减小,25 min左右时最小,若着重考虑茶叶外形,则茶叶成形的最佳揉捻时间是25 min左右;揉捻过程中茶叶的孔隙率随揉捻时间呈开口向上的抛物线趋势,两者的关系可以用(y)=0.0006 x3-0.021 5 x2-0.057 x+69.86来表示,决定系数r2=0.964.  相似文献   
19.
提出以ATV(全地形车)为移动平台,搭载各种灭火、通讯装备,组成一种反应迅速的草原消防灭火系统,并将复杂地形移动技术、灭火技术和遥控通讯技术有机地融合在一起.对系统方案做了详细介绍,该系统有助于实现草原防火“早发现、早扑灭”的目标,可大大减少火灾损失.  相似文献   
20.
Worker division of labor is a defining trait in social insects. Many species are characterized by having behavioral flexibility where workers perform non-typical tasks for their age depending on the colony’s needs. Worker division of labor and behavioral flexibility were examined in the little fire ant Wasmannia auropunctata (Roger, 1863), for which age-related division of labor has been found. Young workers perform nursing duties which include tending of brood and queens, and colony defense, while older workers forage. When nurses were experimentally removed from the colony, foragers were observed carrying out nursing and colony defense duties, yet when foragers were removed nurses did not forage precociously. We also administered juvenile hormone analog, methoprene, to workers. When methoprene was applied, foragers increased their nursing and defense activities while nurses became mainly idle. The behavioral flexibility of foragers of the little fire ant may be evidence of an expansion of worker’s repertoires as they age; older workers can perform tasks they have already done in their life while young individuals are not capable of performing tasks ahead of time. This may be an important adaptation associated with the success of this ant as an invasive species.  相似文献   
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