全文获取类型
收费全文 | 416篇 |
免费 | 30篇 |
国内免费 | 2篇 |
出版年
2017年 | 6篇 |
2014年 | 6篇 |
2013年 | 11篇 |
2012年 | 6篇 |
2011年 | 7篇 |
2010年 | 21篇 |
2009年 | 14篇 |
2008年 | 15篇 |
2007年 | 5篇 |
2006年 | 12篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 9篇 |
1999年 | 5篇 |
1998年 | 7篇 |
1997年 | 7篇 |
1996年 | 16篇 |
1995年 | 9篇 |
1994年 | 6篇 |
1993年 | 14篇 |
1992年 | 9篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 10篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1975年 | 7篇 |
1974年 | 7篇 |
1973年 | 4篇 |
1972年 | 7篇 |
1958年 | 21篇 |
1957年 | 17篇 |
1956年 | 13篇 |
1955年 | 7篇 |
1954年 | 10篇 |
1953年 | 9篇 |
1952年 | 6篇 |
1951年 | 5篇 |
1950年 | 11篇 |
1949年 | 8篇 |
1948年 | 3篇 |
1946年 | 3篇 |
排序方式: 共有448条查询结果,搜索用时 15 毫秒
151.
152.
JACKSON IJ GUEST MM ANDREWS C CELANDER DR 《Annals of the New York Academy of Sciences》1957,68(1):230-6; discussion 236-7
153.
154.
155.
Some results on tests of separate families of hypotheses 总被引:1,自引:0,他引:1
156.
This study aimed to provide recent data on the occurrence of non-strongyle intestinal parasite infestation in horses in the Riyadh region of Saudi Arabia as a basis for developing parasite control strategies. We conducted necropsy for 45 horses from September 2006 to November 2007 in the Riyadh region, Saudi Arabia. 39 out of 45 horses were infected with intestinal parasites with an infestation rate of 86.6%. Infestations with seven nematode species and two species of Gasterophilus larva were found. The most prevalent parasites were Strongyloides westeri (64.4%) and Parascaris equorum (28.8%) followed by Habronema muscae (22.2%). Trichostrongylus axei and Oxyuris equi were less common at (11.1%) and (8.8%), respectively. Habronema megastoma and Setaria equine were found in two horses only (4.4%). Gasterophilus intestinalis larvae were recovered from 39 horses (86.6%) and Gasterophilus nasalis larvae were found in 17 horses (37.7%). Season had a significant effect on the prevalence of P. equorum and G. nasalis, while age of horses had a significant effect only on the prevalence of P. equorum. The husbandry in Saudi Arabia appears to be conductive to parasites transmitted in stables or by insects rather than in pasture. 相似文献
157.
158.
159.
160.
FENESTRATE BRYOZOAN GENERA BASED ON SPECIES FROM IRELAND ORIGINALLY DESCRIBED BY FREDERICK M'COY IN 1844 总被引:1,自引:0,他引:1
Abstract: A large number of fenestrate bryozoan species were named in 'A Synopsis of the Characters of the Carboniferous Limestone Fossils of Ireland' by Frederick M'Coy (1844). At the same time, M'Coy named the bryozoan genera Ichthyorachis , Ptylopora and Polypora , each of which by monotypy or by subsequent designation was based on new species within that work. Subsequently, d' Orbigny (1849) named Fenestrellina with the type species Fenestella crassa M'Coy, 1844 as type species; Miller (1961) named Parafenestella with the type species Fenestella formosa M'Coy, 1844 as type species; and Wyse Jackson (1988) named Baculopora with the type species Vincularia megastoma M'Coy, 1844. We re-describe here in more detail than previously the fenestrate type species originally published in M'Coy (1844), provide diagnoses of the genera, and compare the nineteenth century genera with more recently named genera that have been discriminated specifically from them. 相似文献