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   7969篇
  免费   124篇
  8093篇
  2020年   86篇
  2019年   96篇
  2018年   138篇
  2017年   143篇
  2016年   166篇
  2015年   128篇
  2014年   132篇
  2013年   773篇
  2012年   277篇
  2011年   283篇
  2010年   184篇
  2009年   217篇
  2008年   283篇
  2007年   314篇
  2006年   284篇
  2005年   258篇
  2004年   246篇
  2003年   300篇
  2002年   267篇
  2001年   110篇
  2000年   108篇
  1999年   131篇
  1998年   103篇
  1997年   118篇
  1996年   116篇
  1995年   126篇
  1994年   97篇
  1993年   120篇
  1992年   104篇
  1991年   97篇
  1990年   77篇
  1989年   79篇
  1988年   84篇
  1987年   99篇
  1986年   80篇
  1985年   92篇
  1984年   114篇
  1983年   121篇
  1982年   109篇
  1981年   106篇
  1980年   109篇
  1979年   108篇
  1978年   117篇
  1977年   108篇
  1976年   119篇
  1975年   91篇
  1974年   96篇
  1973年   90篇
  1972年   59篇
  1971年   47篇
排序方式: 共有8093条查询结果,搜索用时 15 毫秒
871.
Old age is associated with poorer movement skill, as indexed by reduced speed and accuracy. Nevertheless, reductions in speed and accuracy can also reflect compensation as well as deficit. We used a manual tracing and a driving task to identify generalized spatial and temporal compensations and deficits associated with old age. In Experiment 1, participants used a hand-held stylus to trace a path. In Experiment 2, participants steered along paths in a virtual reality driving simulator. In both experiments, participants were required to stay within the boundaries while we manipulated task difficulty by changing path width or movement speed. The older group showed worse performance in the highly constrained conditions. Corner cutting effectively reduces the curvature of bends but yields a greater risk of error (i.e., clipping the path or road edge). Corner cutting is thus less risky on wider paths, and we found that corner cutting increased for both age groups in both tasks when paths were wider. Crucially, we observed a greater degree of corner cutting in the young group compared with the old, suggesting the old group compensated for decreased motor skill with "middle-of-the-road" behavior. Enforcing increased speed caused all participants to increase corner cutting. Thus, older participants showed spatial compensation for decreased skill by biasing their position toward the middle of the path in both a manual and steering task. External constraints (narrow paths and fast speeds) prevented this strategy and revealed age-related declines in skills central to manual control and driving.  相似文献   
872.
ABSTRACT— The controversy regarding recovered memories of childhood sexual abuse (CSA) has been characterized by two perspectives. According to one perspective, some people repress their memories of abuse because these experiences have been so emotionally traumatic, and they become capable of recalling the CSA only when it is psychologically safe to do so many years later. According to the other perspective, many reports of recovered memories of sexual abuse are false memories, often inadvertently fostered by therapists. In this article, we provide evidence for a third interpretation that applies to a subset of people reporting recollections of CSA; it does not require the concepts of repression, trauma, or false memory. These people did not experience their CSA as traumatic; they either failed to think about their abuse for years or forgot their previous recollections, and they recalled their CSA spontaneously after encountering reminders outside of psychotherapy. Their recovered memories are corroborated at the same rate as those of people who never forgot their abuse. Hence, recalling CSA after many years is not the same thing as having recalled a previously repressed memory of trauma.  相似文献   
873.
John Searle and Susanna Siegel have argued that cases of aspect-switching show that visual experience represents a richer range of properties than colours, shapes, positions and sizes. I respond that cases of aspect-switching can be explained without holding that visual experience represents rich properties. I also argue that even if Searle and Siegel are right, and aspect-switching does require visual experience to represent rich properties, there is reason to think those properties do not include natural-kind properties, such as being a tomato.  相似文献   
874.
This article explores the structure of world order fromthe perspective of the Treaty of Westphalia, which is treated asthe benchmark for the emergence of the modern system of sovereignstates. Emphasis is placed on Westphalia as historical event, ideaand ideal, and process of evolution, and also on developments thatsupersede this framing of world politics, especially, globalizationand the megaterrorist challenge of September 11, 2001. At issue is whether the state system is resilient enough to adapt to new globalconditions or is in the process of being supplanted, and whether thesequel to Westphalia is moving toward humane global governance orsome dysutopic variant, or both at once.  相似文献   
875.
It was hypothesized that relative group status and endorsement of ideologies that legitimize group status differences moderate attributions to discrimination in intergroup encounters. According to the status-legitimacy hypothesis, the more members of low-status groups endorse the ideology of individual mobility, the less likely they are to attribute negative outcomes from higher status group members to discrimination. In contrast, the more members of high-status groups endorse individual mobility, the more likely they are to attribute negative outcomes from lower status group members to discrimination. Results from 3 studies using 2 different methodologies provide support for this hypothesis among members of different high-status (European Americans and men) and low-status (African Americans, Latino Americans, and women) groups.  相似文献   
876.
Four experiments explored the hypothesis that temporal processes may be represented and controlled explicitly or implicitly. Tasks hypothesized to require explicit timing were duration discrimination, tapping, and intermittent circle drawing. In contrast, it was hypothesized that timing control during continuous circle drawing does not rely on an explicit temporal representation; rather, temporal control is an emergent property of other control processes (i.e., timing is controlled implicitly). Temporal consistency on the tapping and intermittent drawing tasks was related, and performance on both of these tasks was correlated with temporal acuity on an auditory duration discrimination task. However, timing variability of these 3 tasks was not correlated with timing variability of continuous circle drawing. These results support the hypothesized distinction between explicit and implicit temporal representations.  相似文献   
877.
Three studies used videotaped harassment complaints to examine the impact of legal standards on the evaluation of social-sexual conduct at work. Study 1 demonstrated that without legal instructions, college students' judgment strategies were highly variable. Study 2 compared 2 current legal standards, the "severity or pervasiveness test" and a proposed utilitarian alternative (i.e., the rational woman approach). Undergraduate participants taking the perspective of the complainant were more sensitive to offensive conduct than were those adopting an objective perspective. Although the utilitarian altemative further increased sensitivity on some measures, it failed to produce a principled judgment strategy. Finally, Study 3 examined the kinds of errors that full-time workers make when applying the "severity or pervasiveness" test to examine more closely the sensitivity of the subjective approach.  相似文献   
878.
Participants were required to make a saccade to a uniquely colored target while ignoring the presentation of an onset distractor. The results provide evidence for a competitive integration model of saccade programming that assumes endogenous and exogenous saccades are programmed in a common saccade map. The model incorporates a lateral interaction structure in which saccade-related activation at a specific location spreads to neighboring locations but inhibits distant locations. In addition, there is top-down, location-specific inhibition of locations to which the saccade should not go. The time course of exogenous and endogenous activation in the saccade map can explain a variety of eye movement data, including endpoints, latencies, and trajectories of saccades and the well-known global effect.  相似文献   
879.
This study examined whether disinhibition shows similar relations with attention-deficit/hyperactivity disorder (ADHD) and conduct disorder (CD) symptomatology among male and female adolescents. The mixed-incentive or punishment condition of Newman's go/no-go task was administered to 172 adolescents. As expected, ADHD symptoms in boys and girls were predictive of disinhibition (i.e., commission errors) in the mixed-incentive but not punishment condition. Also consistent with expectations, CD symptoms in boys were predictive of disinhibition in the mixed-incentive but not punishment condition. In contrast, CD symptoms in girls were not predictive of disinhibition in either condition. These findings are discussed in terms of implications for understanding sex differences in the etiology of ADHD and CD.  相似文献   
880.
A growing literature has observed a significant reduction in pain sensitivity among hypertensive animals and humans. It is uncertain whether a reduced sensitivity to pain can be observed in nonnotensive individuals who go on to develop high blood pressure. Blood pressure (BP) was reassessed in one hundred fifteen 19-year-old boys initially tested at age 14, when they were also presented with a pain stimulus (mechanical finger pressure). Hierarchical regression analyses indicated that information regarding pain tolerance improved prediction of changes in systolic and diastolic blood pressure beyond that afforded by differences in BP at age 14, parental history of hypertension, and body mass index. These analyses suggest that pain sensitivity may be associated with physiological processes involved in the development of sustained high blood pressure.  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