【摘 要】
：
Forest management may have significant effects on forest connectivity and natural population sizes.Harvesting old-growth single trees may also change natural patterns of genetic variation and spatial genetic structure.This study evaluated the impacts of f
【机 构】
：
DepartmentofForestScience,DepartmentofForestScience
【基金项目】
：
supported by the Fundacao de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG)[CRA APQ-02641-14],in part by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior-Brasil(CAPES)-Finance Co
论文部分内容阅读
Forest management may have significant effects on forest connectivity and natural population sizes.Harvesting old-growth single trees may also change natural patterns of genetic variation and spatial genetic structure.This study evaluated the impacts of f
其他文献
为了探究采空区地震耦合作用下碳纤维加固对框架结构的抗震、抗倾斜能力的影响,设计了三种工况,分别对应框架结构倾斜2,4,6mm/m。基于结构动力学和相似理论,制作了缩尺比为1/10的框架结构模型,并用碳纤维对其梁端和柱端加固。通过对未加固结构和加固结构进行振动台试验,分别对结构的动力特性、地震反应等情况进行对比分析研究。结果表明:碳纤维加固有效地约束了结构的变形,使结构层间位移、层间位移角及顶点位移明显减小,结构的延性得到优化;碳纤维加固提高了结构的整体刚度和抗侧能力,延缓了刚度的退化,提高了结构的抗震、抗
Populus alba × P. glandulosa clone 84 K, derived from South Korea, is widely cultivated in China and used as a model in the molecular research of woody plants
Chinquapin(Castanea henryi) is a dual-purpose tree species in China valued for as a source of timber and starch.We investigated the effect of four cutting mediums(pure vermiculite;peat:river sand at 3:1 v/v;peat:krasnozem at 1:1 v/v;and pure krasnozem) an
Hybrid combinations of Eucalyptus have increased due to expansion of plantations into unconven-tional areas and to the search for higher quality timber. How-eve
In order to found new carriers of pine wood nem-atode (PWN), Bursaphelenchus xylophilus , beetles were col-lected from pine wilt disease-affected areas in six p
Subtropical forest in China has received much attention due to its complex geologic environment and bioclimatic heterogeneity.There have been very few studies addressing which climatic factors have shaped both distribution patterns and niche differentiati
通过对“8.8九寨沟地震”震后8栋山地建筑沉降倾斜原因进行分析,提出震后建筑物地基基础加固设计方法,采用弹簧支座模拟分析倾斜后建筑变形并计算千斤顶顶升力,采用剪力墙体内顶升并分析不同阶段墙体受力情况,运用一种简易的单向抗侧装置抵抗水平荷载并限制墙体平面外错位。实践证明,采用该方法进行山地建筑物震后纠倾加固可保障安全、缩短工期、得到良好效果。
Development of strategies to deconstruct lignocellulosic biomass in tree species is essential for biofuels and biomaterials production.We applied a wood forming tissue-specific system in a hybrid poplar to express both PdSuSy(a sucrose synthase gene from
通过对2根经环氧注浆裂缝修补后的钢筋混凝土梁进行由下向上两点加载试验,研究对比修补前后裂缝开展宽度、位置及荷载-挠度曲线等的变化规律。结果表明,环氧树脂因良好的渗透性,不仅使经环氧树脂修补后的裂缝及周边混凝土得到有效加强,实现了“被粘物破坏”机制;而且可显著提高钢筋混凝土梁的初裂荷载,增强其抗弯刚度和抗裂性,对受力裂缝有着良好的修补效果。同时,基于现场注浆实际操作时间,引入折减系数,提出了修正后的计算注浆扩散半径公式。
发芽率是种子检测中是重要的环节之一,直接关系到种子价格与田间出苗情况.涉种单位和个人的发芽率检测技术操作规范性与检测部门相比多有不足,因此,将仟样、样品配置、置床试