全文获取类型
收费全文 | 220篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
林业 | 128篇 |
农学 | 3篇 |
3篇 | |
综合类 | 80篇 |
农作物 | 3篇 |
畜牧兽医 | 3篇 |
园艺 | 2篇 |
出版年
2022年 | 1篇 |
2020年 | 2篇 |
2019年 | 6篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 10篇 |
2013年 | 5篇 |
2012年 | 3篇 |
2011年 | 12篇 |
2010年 | 9篇 |
2009年 | 11篇 |
2008年 | 9篇 |
2007年 | 8篇 |
2006年 | 8篇 |
2005年 | 8篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 11篇 |
2001年 | 10篇 |
2000年 | 10篇 |
1999年 | 13篇 |
1998年 | 7篇 |
1997年 | 12篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 9篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 2篇 |
排序方式: 共有222条查询结果,搜索用时 46 毫秒
221.
An investigation of seed germination and early seedling growth ofEucalyptus microtheca was based on seed collection from 10 widely separated provenances in Australia. Genetic variation of seed germination and
early seedling growth was observed among a series of provenances whose natural habitats range from different climatic condition.
In the ten provenances, both the model of seed relative germination percentage and the model of seed total germination percentage
fitted Logistic regression [y=a/(1+exp(-ex+b))]. In comparison with provenances from four high temperature (mean annual maximum
temperature >30.0 °C; mean annual minimum temperature >17.0 °C) areas, six low temperature (mean annual maximum temperature
<30.0 °C; mean annual minimum temperature <17.0 °C) areas showed the fast germination rate and the high total germination
percentage. For each provenance we have 45 seedlings equally divided into three watering levels (100%, 50%, and 25% of field
capacity), and studies on relationship between early seedling growth and climatic factors of the natural habitat of provenance.
In control treatment, height growth of the seedling has been associated with intrinsically the driest quarter precipitation
in the seed collection areas of provenance. In all the treatments, length growth of the biggest leaf of the seedling was related
to mean annual maximum temperature and mean annual minimum temperature in origin of provenance. In contrast, basal diameter
growth of the seedling was related to mean annual minimum temperature of the seed collection areas in water stress treatment.
From an ecological viewpoint, the fast germination rate and the high total germination percentage of the seed and rapid early
growth of the seedling appear to be favourable adaptations to the climatic conditions prevailing in the natural habitat of
provenance.
Responsible Editor: Chai Ruihai 相似文献
222.
Wang Yingli 《林业研究》1994,5(3):13-20
This paper summarizes the result from the provenance test of eight years oldPinus sylvestris var.mongolica in Liangshui Natural Reserve comprehensively. The main contents include:(l) the geographic variation of the growth characters
ofPinus sylvestris var. mongolica, tends to negative change gradually at latitude and has obvious climatic nature, (2) no significant difference
exists in the morphological adaptability and resistant characteristics and so on; (3)on the basis of the geographic variation
study on the growth characteristics, the provenances ofPinus sylvestris var.mongolica were classified into two geographic populations and two subpopulations as follows: the northern population of the Daxing’an
Mountain (I) and the southern population of the Daxing’an Mountain as well as the Xiaoxing’an Mountain (II), which includes
Honghuarji subpopulation (II -1) and Kalunshan subpopulation (II-2). (4) the height growth rhythm was analyzed according to
the divided population and subpopulation; (5) the best provenance was selected for the Liangshui Natural Reserve and its neighborhood
according to the results from SSR test of the growth characteristics (the breast height diameter and height of eight year
old trees), the possibility of the early provenance selection was also verified by the method of order correlation analysis
on the height growth of three, five, seven and eight years old provenances. 相似文献