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   80329篇
  免费   1429篇
  国内免费   8篇
  81766篇
  2020年   1029篇
  2019年   1291篇
  2018年   1522篇
  2017年   1515篇
  2016年   1819篇
  2015年   1301篇
  2014年   1376篇
  2013年   6511篇
  2012年   2448篇
  2011年   2608篇
  2010年   1565篇
  2009年   1609篇
  2008年   2322篇
  2007年   2282篇
  2006年   2039篇
  2005年   1816篇
  2004年   1794篇
  2003年   1620篇
  2002年   1679篇
  2001年   2496篇
  2000年   2435篇
  1999年   1852篇
  1998年   940篇
  1997年   828篇
  1996年   763篇
  1995年   771篇
  1994年   720篇
  1993年   750篇
  1992年   1477篇
  1991年   1401篇
  1990年   1367篇
  1989年   1258篇
  1988年   1241篇
  1987年   1175篇
  1986年   1179篇
  1985年   1268篇
  1984年   1021篇
  1983年   899篇
  1982年   736篇
  1979年   1040篇
  1978年   769篇
  1975年   873篇
  1974年   1008篇
  1973年   988篇
  1972年   877篇
  1971年   769篇
  1969年   722篇
  1968年   910篇
  1967年   862篇
  1966年   779篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
331.
This project studied the effects of weather variables and size of the population on minor and major violence rates within six prisons in the Kingston, Ontario, Canada area from January, 1980 through December, 1983. While weather variables have been studied in relation to mood changes within the general population, this study was the first to analyze the impact of weather variables on rates of violence within the prison setting using forward inclusion multiple regression. Analysis showed that population size consistently appeared positively correlated with assaults on other inmates among the male medium-security prisoners during the summer months. In the summer months, temperature tended to be positively related to some minor kinds of offenses, but in the winter months the relationship was negative. Humidity, rain, sunshine hours, snow, and snow on the ground were not consistently related to incidences of minor and major violence. Indices of geomagnetic disturbances had statistically significant inverse relationships with attempted suicide/self-inflicted injury rates among the male prisoners during the summer months. Over 12 months, wind was generally negatively correlated with incidences of major and minor violence among the male inmates. For 6-mo. periods, wind was generally positively correlated with violence rates during the winter months and negatively correlated during the summer months among the male inmates. The findings relating weather variables to violence rates in the women's prison were consistently in opposition to those found for male prisoners during the 4-yr. period.  相似文献   
332.
Individuals with brain damage often encounter visual perceptual and visuo-motor difficulties. Studies have indicated an improvement in exceptional individuals' performances when the colors of figure-ground materials were reversed. Effects of reversals were studied for spastic cerebral palsied and normal children's scores on the Developmental Test of Visual-motor Integration and the Motor-free Visual Perception Test. Normal children performed better than the cerebral palsied children on all tests; the cerebral palsied children performed best on the reversed-format Motor-free Visual Perception Test. Reversal affected neither group's scores on visual-motor integration.  相似文献   
333.
40 women were taught to use self-statements to cope with pain caused by ice water. The trainer used four different strategies for reassigning a homework task of using self-statements to cope with pain produced by immersing one hand in ice water. The strategies were equally effective in eliciting compliance with the homework assignment.  相似文献   
334.
The relationship between cognitive style and illusion magnitude was examined using the assimilation and contrast Delboeuf distortions. As in previous research, field dependence correlated positively with assimilation; however, a significant negative correlation with contrast was also found, suggesting that, while field dependence may involve the illusory integration of the stimulus field, field independence may involve its equally illusory differentiation.  相似文献   
335.
Since traumas leading to severe and permanent physical handicaps affect the whole personality, the psychological approach plays a major role in the rehabilitation of patients with locomotory handicaps owing to injury. The harmful effects become apparently more easily on account of the disturbed personality development of the cripple, and the consequent mental changes complicate his or her reintegration into society. Rehabilitation measures intended to restore, as far as possible, the physical functions can only yield satisfactory results if they prepare the whole personality of the cripple--as a combined psychological and somatic entity--for life of a different quality.  相似文献   
336.
Lewis Henry Morgan never used the term evolution in any of his major sociological works. If he may be labeled an evolutionist, the specificity of his views must be taken into account. The main "evolutionist" issue that concerned him was that of the unity or diversity of the human species. This was an urgent political and theological issue in the America of his day, and it impinged also on research on the American Indians. Morgan's first major study was designed to demonstrate the unity of origin of the American aborigines and their "Asian" origins. His methods were derived from the tradition of Indo-European philology. It was virtually as an afterthought that he added a social evolutionary component to what he conceived of as an exercise in philology. Later he came under the direct influence of the English evolutionists, and this was crucial for the conception of Ancient Society.  相似文献   
337.
Rats were given backward pairings of a tone (CS) and shock (US) and were then tested for response to the CS in a lick suppression test. Animals given a cuing or reminder treatment prior to the test exhibited enhanced suppression in the presence of the tone relative to a variety of control conditions. The cue-induced suppression enhancement did not appear to result from sensitization or short-term motivational changes nor did it seem to depend on second-order conditioning of the test context. The effect appeared more robust as the number of backward conditioning trials preceding the cue increased. The results were discussed in terms of current explanations of backward conditioning effects.  相似文献   
338.
Distributions of reinforcers between two components of multiple variable-interval schedules were varied over a number of conditions. Sensitivity to reinforcement, measured by the exponent of the power function relating ratios of responses in the two components to ratios of reinforcers obtained in the components, did not differ between conditions with 15-s or 60-s component durations. The failure to demonstrate the “short-component effect,” where sensitivity is high for short components, was consistent with reanalysis of previous data. With 60-s components, sensitivity to reinforcement decreased systematically with time since component alternation, and was higher in the first 15-s subinterval of the 60-s component than for the component whose total duration was 15 s. Varying component duration and sampling behavior at different times since component transition may not be equivalent ways of examining the effects of average temporal distance between components.  相似文献   
339.
This essay presents the findings from a study of the effect of divorce on spiritual growth among Protestants. Looking at movement in the areas of love of God, self, and others, it shows that the divorce experience can have varying levels of impact which relate at least partially to the traumatic intensity of the experience itself.Excerpted from The Effect of Divorce on Spiritual Growth: A Study in Protestant Spirituality (unpublished thesis), (c) 1984 Jean M. Blomquist. All rights reserved.  相似文献   
340.
The present experiments studied a three-event delayed sequence-discrimination (DSD) task: one arrangement (order) of two stimuli (red and yellow overhead lights) taken three in succession (e.g., red, yellow, red) was the positive sequence and the remaining seven arrangements were the negative sequences for responding and reward during the subsequent test stimulus. In Experiment 1, the final stimulus (recency) and the order of stimuli in the positive sequence controlled acquisition of discrimination. In Experiment 2, increasing the duration of memory intervals between stimuli reduced the discriminability of those negative sequences identical to the positive sequence after the delay. Three-event DSD performance in Experiments 1 and 2 was similar to two-event DSD performance in comparable published experiments. Models developed to explain pigeon performance in two-event DSD were extended to the three-event task. Results from both two- and three-event versions of the DSD task falsified a noncumulative model and several cumulative integration models (i.e., adding, averging, and some multiplying models), but corroborated one cumulative, multiplying model.  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