全文获取类型
收费全文 | 825篇 |
免费 | 69篇 |
出版年
2022年 | 10篇 |
2021年 | 14篇 |
2020年 | 12篇 |
2019年 | 13篇 |
2018年 | 16篇 |
2017年 | 13篇 |
2016年 | 20篇 |
2015年 | 41篇 |
2014年 | 43篇 |
2013年 | 40篇 |
2012年 | 45篇 |
2011年 | 62篇 |
2010年 | 38篇 |
2009年 | 24篇 |
2008年 | 43篇 |
2007年 | 28篇 |
2006年 | 27篇 |
2005年 | 40篇 |
2004年 | 27篇 |
2003年 | 30篇 |
2002年 | 33篇 |
2001年 | 16篇 |
2000年 | 19篇 |
1999年 | 9篇 |
1998年 | 12篇 |
1997年 | 6篇 |
1996年 | 10篇 |
1995年 | 11篇 |
1994年 | 5篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 14篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 9篇 |
1985年 | 5篇 |
1983年 | 7篇 |
1982年 | 9篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1976年 | 5篇 |
1974年 | 5篇 |
1973年 | 5篇 |
1972年 | 7篇 |
1970年 | 11篇 |
1968年 | 7篇 |
1966年 | 10篇 |
1964年 | 4篇 |
1947年 | 5篇 |
1946年 | 3篇 |
排序方式: 共有894条查询结果,搜索用时 0 毫秒
891.
Douglas G. Barron Jeffrey D. Brawn Luke K. Butler L. Michael Romero Patrick J. Weatherhead 《The Journal of wildlife management》2012,76(5):911-918
United States military bases provide habitat for a diverse suite of wildlife species despite intense anthropogenic disturbance inherent in training activities. Little research has examined how military activity affects wildlife reproduction. We compared parental investment, reproductive success, offspring and adult quality, and stress hormone concentrations of northern cardinals (Cardinalis cardinalis) breeding in areas that differed 10-fold in levels of on-ground military activity. We found no evidence of direct impacts of military activity on cardinals, nor did the reproductive success of several other passerine species appear to be affected. However, we observed American crows (Corvus brachyrhynchos) much less frequently in areas of high military activity, and cardinals nesting in those areas were less responsive to crow models. The apparent displacement of this nest predator suggests that military activity could indirectly benefit some wildlife. Although these results are promising for the conservation of birds that depend on military bases for breeding habitat, further assessment of direct and indirect effects of military training on a wider array of species is required before concluding that such activity is benign. © 2012 The Wildlife Society. 相似文献
892.
893.
894.
A review of records was conducted to examine the utility of doing routine laboratory testing (EEG and skull X rays) versus testing at the discretion of the attending neurologist on patients presenting for the nonpharmacological treatment of chronic headache. A total of 278 patients underwent neurological evaluation as part of a routine assessment prior to beginning self-regulatory treatment for headache. The first 112 subjects received routine laboratory tests of EEG and skull X-ray films. The second set of 166 subjects received laboratory tests only when deemed necessary by the neurologist. The rate of abnormal EEG in chronic headache sufferers was no greater than that found in the normal population, and only one or two potentially serious abnormalities were found on any laboratory test. A higher rate of abnormality was found when the CT scan was used in conjunction with clinical judgment. The majority of clients with abnormal laboratory tests (most of which were mildly abnormal) still saw substantial headache reduction with self-regulatory treatment for chronic headache. The authors suggest that routine laboratory testing may not be necessary and should be left to the discretion of a qualified neurologist. 相似文献