全文获取类型
收费全文 | 278578篇 |
免费 | 25431篇 |
国内免费 | 270篇 |
出版年
2021年 | 2377篇 |
2018年 | 3199篇 |
2017年 | 3071篇 |
2016年 | 4287篇 |
2015年 | 5105篇 |
2014年 | 6149篇 |
2013年 | 8517篇 |
2012年 | 9841篇 |
2011年 | 10573篇 |
2010年 | 7054篇 |
2009年 | 6370篇 |
2008年 | 9117篇 |
2007年 | 9365篇 |
2006年 | 8868篇 |
2005年 | 8404篇 |
2004年 | 8311篇 |
2003年 | 8008篇 |
2002年 | 7806篇 |
2001年 | 12392篇 |
2000年 | 12223篇 |
1999年 | 9530篇 |
1998年 | 3122篇 |
1997年 | 3074篇 |
1996年 | 2992篇 |
1995年 | 2738篇 |
1994年 | 2652篇 |
1993年 | 2567篇 |
1992年 | 7394篇 |
1991年 | 7145篇 |
1990年 | 7211篇 |
1989年 | 7005篇 |
1988年 | 6490篇 |
1987年 | 6131篇 |
1986年 | 5453篇 |
1985年 | 5789篇 |
1984年 | 4613篇 |
1983年 | 3969篇 |
1982年 | 2795篇 |
1981年 | 2605篇 |
1980年 | 2396篇 |
1979年 | 4165篇 |
1978年 | 3204篇 |
1977年 | 2945篇 |
1976年 | 2866篇 |
1975年 | 3300篇 |
1974年 | 3530篇 |
1973年 | 3563篇 |
1972年 | 3077篇 |
1971年 | 2858篇 |
1970年 | 2542篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
N B Terenina 《Parazitologiia》1988,22(6):476-480
Identification of serotonin and dopamine in M. salmonis was conducted by means of some fluorometric methods. The presence of negligible amount of a serotonin-like component and substance close in its spectral characteristics to dopamine was shown. 相似文献
93.
E A Rybnikova V G Shaliapina O N Zamuruev 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》1999,49(1):77-83
The effects of corticotropin-releasing hormone (CRH) injected into the dorsal neostriatum on the open-field and shuttle-box behavior were studied in rats with high (Koltushi high avoidance, KHA) and low (Koltushi low avoidance, KLA) capability for avoidance learning. The effects of this hormone on the behavior of these rat strains were different. In KLA rats with passive strategy of behavior the CRH injection led to a rapid locomotor activation in the open field, while the rats with active behavioral strategy (KHA) reacted to the injection by a significant decrease in locomotion and change for the passive mode of behavior. The same CRH effects on locomotion were obtained in the shuttle-box experiments. Moreover, in the KLA rats the neurohormone injection resulted in an improvement of avoidance learning in contrast to the KHA rats, in which CRH substantially impaired avoidance learning. The obtained evidence is discussed in terms of the important role of striatal CRH in the choice of behavioral strategy in stress. 相似文献
94.
95.
96.
97.
98.
99.
100.
E M Nikulina O V Trapezov N K Popova 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》1985,35(6):1142-1146
Content of dopamine in the striatum; of serotonin, 5-hydroxyindolacetic acid and noradrenaline in the hypothalamus, striatum and midbrain was studied in three groups of minks from population of an animal farm, differing by their reaction to humans (cowardly, calm, aggressive). The reaction to humans was estimated by a system of marks at the attempt to catch the mink with a mitten. Aggressive animals had a lowered level of serotonin in the hypothalamus and striatum, a lesser content of serotonin metabolite--5-hydroxyindolacetic acid in the striatum. Minks of different groups did not differ by noradrenaline content, but dopamine level in the striatum of cowardly minks was higher than in calm and aggressive animals. Conclusion is made that polymorphism of behaviour corresponds to polymorphism of the state of monoaminergic systems. 相似文献