首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   54453篇
  免费   656篇
  国内免费   2篇
  55111篇
  2020年   346篇
  2019年   488篇
  2018年   3903篇
  2017年   3269篇
  2016年   2771篇
  2015年   651篇
  2014年   664篇
  2013年   2624篇
  2012年   1588篇
  2011年   3374篇
  2010年   3044篇
  2009年   2072篇
  2008年   2594篇
  2007年   2983篇
  2006年   912篇
  2005年   996篇
  2004年   937篇
  2003年   821篇
  2002年   792篇
  2001年   1069篇
  2000年   1001篇
  1999年   739篇
  1998年   414篇
  1997年   349篇
  1996年   326篇
  1992年   557篇
  1991年   565篇
  1990年   542篇
  1989年   550篇
  1988年   540篇
  1987年   500篇
  1986年   531篇
  1985年   582篇
  1984年   463篇
  1983年   442篇
  1982年   366篇
  1981年   349篇
  1979年   527篇
  1978年   381篇
  1976年   366篇
  1975年   438篇
  1974年   493篇
  1973年   513篇
  1972年   412篇
  1971年   386篇
  1970年   382篇
  1969年   413篇
  1968年   494篇
  1967年   423篇
  1966年   427篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
22.
In recent years in research on intergroup relationships, the assumption has increasingly been made that discrimination dominates decisions when individuals allocate resources between (members of) own and other group. Conversely, in empirical studies of interpersonal decision-making, including an extensive literature on the development of children's allocation rules within dyadic relationships, it has been repeatedly observed that in dyadic relationships choices though responsive to various changes in the environment, are more strongly governed by fairness rules. The present research extends the interpersonal fairness paradigm to the intergroup case, and examines the effects of some of those variables, namely, children's age, input and attitudes toward other, that have been observed to influence choice behaviour within interpersonal relationships. The findings indicate that as children are socialized, fairness rules also play an increasing dominant role in intergroup allocation decisions, and that both relative input and the language of the outgroup influence such decisions. At the same time, there is some preliminary evidence to indicate that the relative strength of self-interest may be somewhat stronger in intergroup than in interpersonal relationships. Finally, a number of the issues that must be confronted in comparing the two more important forms of human social choices, interpersonal and intergroup decision-making, are considered.  相似文献   
23.
The relationship between anxiety and depression was examined in a sample of 106 children and adolescents referred to an outpatient anxiety disorder clinic for children. Twenty-eight percent of patients with DSM-III diagnoses of anxiety disorders displayed a concurrent major depression. Children with anxiety disorders plus major depression were found (1) to be older, (2) to demonstrate more severe anxiety symptomatology, and (3) to be diagnosed with different rates of certain anxiety-disorder subtypes, when compared to anxious patients without major depression. Nondepressed anxious children and adolescents did not differ from a psychopathological control group in severity of either anxiety or depression symptoms.  相似文献   
24.
Serotonergic and opiate interactions in the modulation of drug- and environmental-induced analgesia were assessed in 6-day-old Sprague-Dawley-derived rat pups using tail-flick testing procedures. In these experiments the serotonergic antagonist metergoline was observed to attenuate both the analgesia induced by the opiate agonist morphine and the analgesia induced by isolation from siblings and the dam, an environmental manipulation which has previously been shown to be associated with increases in opiate activity. In contrast, the opiate antagonist naloxone was observed to be ineffective in blocking not only analgesia induced by the serotonergic agonist quipazine, but also analgesia induced by long-term deprivation from the dam and food, a manipulation that has been previously reported to induce increases in serotonergic utilization. These results suggest that in the neonate, as in the adult, the serotonergic modulation of nociception appears to occur "downstream" from the opiate systems serving to regulate nociception following both drug- and environmental-induced alterations in pain sensitivity. Analgesia induced by long-term deprivation from food and the dam appears to be strongly related to increases in serotonergic activity and relatively unaffected by opiate antagonism, whereas analgesia induced by isolation from siblings and the dam may be related to increases in opiate activity, but modulated by serotonergic systems serving to regulate pain responsivity. Thus alterations in the environment, mediated at least in part by alterations in opiate and serotonergic activity, appear to play an important role in influencing the sensitivity of the neonate to pain stimuli.  相似文献   
25.
The vocationally-indecisive individual presents a major counselling problem. The theory and research behind career indecision is discussed and a counselling approach based on identity formation is outlined. Four identity statuses — Identity Achievements, Foreclosures, Identity Diffusions, and Moratoriums — are described and counselling approaches for each are explored.  相似文献   
26.
Pigeons and other animals soon learn to wait (pause) after food delivery on periodic-food schedules before resuming the food-rewarded response. Under most conditions the steady-state duration of the average waiting time, t, is a linear function of the typical interfood interval. We describe three experiments designed to explore the limits of this process. In all experiments, t was associated with one key color and the subsequent food delay, T, with another. In the first experiment, we compared the relation between t (waiting time) and T (food delay) under two conditions: when T was held constant, and when T was an inverse function of t. The pigeons could maximize the rate of food delivery under the first condition by setting t to a consistently short value; optimal behavior under the second condition required a linear relation with unit slope between t and T. Despite this difference in optimal policy, the pigeons in both cases showed the same linear relation, with slope less than one, between t and T. This result was confirmed in a second parametric experiment that added a third condition, in which T + t was held constant. Linear waiting appears to be an obligatory rule for pigeons. In a third experiment we arranged for a multiplicative relation between t and T (positive feedback), and produced either very short or very long waiting times as predicted by a quasi-dynamic model in which waiting time is strongly determined by the just-preceding food delay.  相似文献   
27.
Magnitude estimation and sensory matching   总被引:2,自引:0,他引:2  
  相似文献   
28.
29.
30.
Fixation accuracy was related to perception of laterally presented consonants. Small left-eye fixation inaccuracy influenced perceptual performance of 8 men and 8 women.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号