全文获取类型
收费全文 | 886篇 |
免费 | 18篇 |
出版年
2015年 | 8篇 |
2014年 | 8篇 |
2013年 | 19篇 |
2012年 | 12篇 |
2011年 | 14篇 |
2010年 | 28篇 |
2009年 | 22篇 |
2008年 | 27篇 |
2007年 | 44篇 |
2006年 | 13篇 |
2005年 | 19篇 |
2004年 | 12篇 |
2002年 | 13篇 |
1999年 | 13篇 |
1998年 | 9篇 |
1997年 | 16篇 |
1996年 | 13篇 |
1995年 | 12篇 |
1994年 | 12篇 |
1993年 | 17篇 |
1992年 | 9篇 |
1991年 | 18篇 |
1990年 | 16篇 |
1989年 | 11篇 |
1988年 | 10篇 |
1987年 | 17篇 |
1986年 | 13篇 |
1985年 | 11篇 |
1984年 | 13篇 |
1982年 | 13篇 |
1980年 | 12篇 |
1979年 | 11篇 |
1976年 | 12篇 |
1975年 | 10篇 |
1974年 | 15篇 |
1973年 | 18篇 |
1972年 | 16篇 |
1971年 | 10篇 |
1970年 | 8篇 |
1969年 | 9篇 |
1968年 | 10篇 |
1965年 | 36篇 |
1964年 | 19篇 |
1963年 | 32篇 |
1962年 | 23篇 |
1961年 | 33篇 |
1960年 | 21篇 |
1959年 | 27篇 |
1958年 | 27篇 |
1957年 | 12篇 |
排序方式: 共有904条查询结果,搜索用时 31 毫秒
91.
An Ethnographic Filmflam: Giving Gifts, Doing Research, and Videotaping the Native Subject/Object 总被引:1,自引:0,他引:1
JOHN L. JACKSON JR. 《American anthropologist》2004,106(1):32-42
Using the discussion of self-reflexivity as an organizing principle, this article examines how mobilizing digital video technology during fieldwork opens up empirical and theoretical space for reconceptualizing the relationship between anthropologists and informants. Placing the field of visual anthropology into critical conversation with long-standing theoretical arguments about the objectivist limitations of native anthropologists, I argue that the slipperiness of nativity as an anthropological designation helps to provide analytical tools for examining filmmaking as a kind of gift-giving process between native ethnographic filmmakers and the subjects of their films. This article highlights some of the ways in which my own filmic and videographic exploits in Harlem, New York, mark integral connections between seeing and being the proverbial other, probing social exchanges predicated on the usefulness of low-budget digital technology as a means of fostering politically and epistemologically valuable ethnographic collaborations. 相似文献
92.
93.
94.
The Avian Shoulder: An Experimental Approach 总被引:2,自引:0,他引:2
GOSLOW G. E. JR.; DIAL K. P.; JENKINS F. A. JR. 《Integrative and comparative biology》1989,29(1):287-301
SYNOPSIS. This essay is in two parts. The first describes functionalstudies of the shoulder in modern vertebrates that led to theformulation of the hypotheses that motor patterns of homologousmuscles have been maintained during the evolution of the tetrapodshoulder, and that a primitive organization of the neural controlcomponents has persisted in derived groups. The second part of this essay focuses upon a longstanding questionin vertebrate evolution: what neuromuscular and musculoskeletalchanges in the tetrapod shoulder accompanied the evolution offlight in birds? The lack of empirical data on shoulder functionin extant birds limited our insight into this question, andprompted our initiation of experimental studies. Preliminarykinematics of the furcula and humerus of European starlings(Sturnus vulgaris) flying in a wind tunnel, as revealed by highspeed cineradiography, are presented. The two halves of thefurcula, which contact the coracoids dorsally, are bent laterallyduring downstroke and medially during upstroke by as much as60% of the intrafurcular resting distance. High speed film andelectromyographic studies of freeflying pigeons (Columba livia)reveal that the supracoracoideus muscle is strongly activatedduring wing elevation and, as predicted from studies of Varanusand Didelphis, an additional activation burst occurs at mid-downstrokein 48% of the recordings. 相似文献
95.
96.
Abstract. An earlier study on the blowfly Phormia regina (Meigen) demonstrated that the injection of amphetamine (12 μg) depletes biogenic amine levels in the CNS. In the present study, P. regina females were injected with amphetamine (12 μg), each female was placed with three males and insemination success was determined. Amphetamine inhibited female insemination by 43.3% at 2–90 min post-injection and by 70% at 10–60 min post-injection. At 180–270 min post-injection, there was no significant inhibition of female insemination. This study indicates a possible role in insects for the biogenic amines in female insemination. 相似文献
97.
98.
Don G. Benson JR. 《Biotechnic & histochemistry》1966,41(3):155-158
Paraffin sections from tissue fixed 4-12 hr in 10% formalin containing 0.5% cetyl pyridinium chloride, and washed 2 hr, were stained as follows: (1) Hydrolyze in 5 N HCl at room temperature for 8.5-9 min, or use standard Feulgen hydrolysis at 60 C. (2) Stain in azure A-Schiff, 0.5% in bisulfite bleach (1 N HCl, 5; 10% Na2S2O5, 5; and distilled water 90—parts by volume) for 10 min. (3) Place in bisulfite bleach 2 changes, 2 min each; wash in water, 1-2 min. (4) Stain in Alcian blue (0.1% in 0.01 2V HCl, pH 2.0) for 10 min. (5) Place in 0.01 N HCl for 2-3 min; wash in water for 1-2 min. (6) Oxidize in 0.5% HIO4 for 5 min; wash in water, 1-2 min. (7) Stain in Schiff's leucofuchsiu, 10 min. (8) Treat with bisulfite bleach as in step 3; wash in running water, 10 min. (9) Stain in naphthol yellow S (0.01% in 1% acetic acid) for 1-2 min. (10) Place in 1% acetic acid for 2 min, dehydrate in tertiary butanol, clear and cover. Result: DNA is deep blue; acidic mucins are light blue; neutral polysaccharides, red to magenta; and proteins, yellow. Proper timing of the hydrolysis for the Feulgen reaction is the most critical step. Overhydrolysis results in green nuclei (staining by naphthol yellow S) whereas purplish nuclei are the results of insufficient hydrolysis. 相似文献
99.
100.
HEATHER C. TIPTON VICTORIA J. DREITZ PAUL F. DOHERTY JR. 《The Journal of wildlife management》2008,72(4):1001-1006
Abstract: Concern over the decline of grassland birds has spurred efforts to increase understanding of grassland bird-habitat relationships. Previous studies have suggested that black-tailed prairie dogs (Cynomys ludovicianus) provide important habitat for shortgrass prairie avifauna, such as mountain plover (Charadrius montanus) and western burrowing owl (Athene cunicularia hypugaea), although such studies are lacking in Colorado (USA). We used methods to estimate occupancy (ψ) of mountain plover and burrowing owl on prairie dog colonies and other shortgrass prairie habitats in eastern Colorado. Mountain plover occupancy was higher on prairie dog colonies (ψ = 0.50, 95% CI = 0.36–0.64) than on grassland (ψ = 0.07, 95% CI = 0.03–0.15) and dryland agriculture (ψ = 0.13, 95% CI = 0.07–0.23). Burrowing owl occupancy was higher on active prairie dog colonies (ψ = 0.80, 95% CI = 0.66–0.89) compared with inactive colonies (ψ = 0.23, 95% CI = 0.07–0.53), which in turn was much higher than on grassland (ψ = 0.01, 95% CI = 0.00–0.07) and dryland agriculture (ψ = 0.00, 95% CI ψ 0.00–0.00). Mountain plover occupancy also was positively correlated with increasing amounts of prairie dog colony in the landscape. Burrowing owl occupancy was negatively correlated with increasing amounts of prairie dog colony in the surrounding landscape. Our results suggest that actions to conserve mountain plovers and burrowing owls should incorporate land management to benefit prairie dogs. Because managing for specific colony attributes is difficult, alternative management that promotes heterogeneity may ensure that suitable habitat is available for the guild of grassland inhabitants. 相似文献