全文获取类型
收费全文 | 355篇 |
免费 | 17篇 |
专业分类
372篇 |
出版年
2022年 | 5篇 |
2021年 | 7篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 6篇 |
2017年 | 6篇 |
2016年 | 13篇 |
2015年 | 17篇 |
2014年 | 20篇 |
2013年 | 22篇 |
2012年 | 30篇 |
2011年 | 32篇 |
2010年 | 21篇 |
2009年 | 15篇 |
2008年 | 15篇 |
2007年 | 13篇 |
2006年 | 28篇 |
2005年 | 19篇 |
2004年 | 12篇 |
2003年 | 18篇 |
2002年 | 11篇 |
2000年 | 3篇 |
1998年 | 2篇 |
1994年 | 5篇 |
1992年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1966年 | 2篇 |
1965年 | 1篇 |
1962年 | 1篇 |
1961年 | 2篇 |
1960年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有372条查询结果,搜索用时 0 毫秒
371.
Jiří Kamler Miloslav Homolka Radim Cerkal Marta Heroldová Jarmila Krojerová-Prokešová Miroslava Barančeková Jan Dvořák Karel Vejražka 《European Journal of Wildlife Research》2009,55(6):583-588
Large herbivores are the key species for game management in the Central Europe. Analyses of factors affecting the feeding
behaviour of herbivores and consequences of their browsing are therefore highly important both for farmers and for game managers
as the protective measurements should be focused on the most threatened fields. The influence of fallow (Dama dama) and roe deer (Capreolus capreolus) browsing during vegetation period on sunflower production was studied. The experiment was carried out in 2006 on a field
located near a forest complex. We marked out pairs of paired permanent plots and monitored deer impact regularly from the
emergence of plants until the harvest. Herbivores damaged the sunflower intensively immediately after the emergence at the
height of 1 to 2 cm above the ground. When the plants had reached approximately 15-40 cm in height, deer browsed the top shoots
and as the plants grew higher the browsing was restricted to leaves or to substitute stems of the previously browsed plants.
Sunflower ceased to attract big herbivores in flowering stage. Browsing significantly affected the yield of seeds. Approximately
one half of the plants that had been damaged in early stage died as well as 12.5% of plants that had been damaged at second
term; the rest produced substitute stems. Almost 33% of the substitute stems did not form disc florets; the second third of
them formed disc florets with a diameter of 6-8 cm, and the last third set disc florets with a diameter of 8-10 cm. 相似文献
372.
The strain of Aureobasidium pullulans NRRL Y-2311 (CCY 27-1-98), known as a hyperproducer of endo-1,4-β-xylanase, exhibited good growth on pectin or pectate. Growth
on these carbon sources is associated with an inducible production of significant amounts of pectolytic enzymes, of which
exopolygalacturonase (EC 3.2.1.67) and endopolygalacturonase (EC 3.2.1.15) were identified. The two enzymes are not produced
on D-glucose or under carbon starvation conditions. The enzymes can be induced in glucose-grown cells by D-galacturonic acid
and its oligomers. Thus, D-galacturonic acid, the monomer derived from the polysaccharide, appears to be the natural inducer
or a precursor of an inducer of pectolytic enzymes in the studied yeast.
Received: 4 November 1995 / Accepted: 11 December 1995 相似文献