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   62954篇
  免费   2525篇
  国内免费   32篇
  2020年   699篇
  2019年   879篇
  2018年   1251篇
  2017年   1273篇
  2016年   1342篇
  2015年   917篇
  2014年   1137篇
  2013年   5786篇
  2012年   2018篇
  2011年   2208篇
  2010年   1307篇
  2009年   1337篇
  2008年   2025篇
  2007年   1976篇
  2006年   1778篇
  2005年   1642篇
  2004年   1613篇
  2003年   1494篇
  2002年   1562篇
  2001年   1938篇
  2000年   1802篇
  1999年   1436篇
  1998年   848篇
  1997年   760篇
  1996年   658篇
  1995年   673篇
  1994年   641篇
  1993年   672篇
  1992年   1153篇
  1991年   1076篇
  1990年   1066篇
  1989年   962篇
  1988年   914篇
  1987年   916篇
  1986年   904篇
  1985年   986篇
  1984年   837篇
  1983年   745篇
  1982年   639篇
  1981年   579篇
  1979年   763篇
  1978年   642篇
  1977年   553篇
  1976年   586篇
  1975年   714篇
  1974年   757篇
  1973年   689篇
  1972年   608篇
  1968年   598篇
  1967年   581篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
A new test for measuring the ability to perceive pictorial depth was used with children of two remote Bushman populations (!Xu and Kxoe), as well as with a sample of adult Bushmen drawn from these populations and a sample of urban Zulu children. The results show that subjects of apparently little sophistication are capable of perceiving depth when confronted with a ‘geometric’ figure. They also show surprising inter-group differences which cannot be easily explained by differences of environmental experience.  相似文献   
942.
The effects of the perceived accuracy of attributions of self blame and chance blame were examined in the context of health care. Health practitioners ( N = 147) rated interviews in which patients made self-or chance-blaming attributions for diseases with high (heart attack, stroke), or low (cancer, arthritis) life-style involvement, or acidental injuries. Three discriminant analyses yielded p < .001. Self-blaming heart and stroke patients were rated as coping better and acting more appropriately and typically than chance blamers. Other self blamers were rated as more depressed, poorly adjusted, coping poorly, not accepting disability, needing counselling and information. Additionally, self-blaming accident victims were judged as more dependent, less likeable, and having poorer prognoses than chance blamers. Realistic self blame for life-style diseases did not lead to victimization, but other self-blaming patients were stigmatized and the adaptiveness of self blame as a coping strategy was unrecognized.  相似文献   
943.
944.
Baron and Ransberger (1978) argue that civil violence increases as temperature rises into the mid 80s, and then decreases as temperatures rise further. Two experiments test this hypothesis using data on temperature and the incidence of crime for summer months in two midwestern cities. The crime data were divided into violent and nonviolent crimes, and then correlated with the maximum, minimum, and average temperatures, and several humidity measures. Violent crime correlated significantly with temperature; nonviolent crime did not. This relationship was linear in the first study, but curvilinear in the second. Inspection of the data suggests that the incidence of aggressive behavior (i.e., violent crime) does not drop off in the mid-80s as laboratory findings and Baron and Ransberger's results would suggest, but continues to increase as temperatures rise into the 90s. The mean incidence of violent crime was higher for days in the 90s than for days in the 80s. A hypothesis for resolving this contradiction between real world and laboratory findings is discussed.  相似文献   
945.
Testicular self-examination (TSE) can lead to early diagnosis and treatment of testicular cancer, the third leading cause of death in young men. We evaluated the effectiveness of a brief and specific checklist for teaching TSE skills. Ten men were videotaped while performing testicular self-examinations before and after training. The TSE training resulted in large and significant increases in the number of TSE steps completed and duration of the TSE. Two urological validation measures supported the improvements observed in the mens' self-examinations. Subjects reported continued performance of TSE during a follow-up telephone interview. This pilot study indicates that a brief and specific checklist is an effective strategy for teaching early cancer detection skills.  相似文献   
946.
Correlations between a job performance criterion and personality measures reflecting achievement motivation and an interpersonal orientation were examined at three points in time after completion of job training for a sample of airline reservations agents. Although correlations between the personality predictors and performance were small and nonsignificant for the 3-month period after beginning the job, by the end of 6 and 8 months a number of significant relationships had emerged. Implications for the utility of personality measures in selection and performance prediction are discussed.  相似文献   
947.
Because young children have poorer auditory temporal resolution than older children, they ought to have, according to the inverse relation between temporal and frequency resolution, narrower auditory filters than older children. Therefore, the auditory filters of two 6-year-olds, two 10-year-olds, and two adults were measured by having them detect a 400-ms sinusoid (500, 1000, or 3000 Hz) centered in a spectral notch in a band of noise. The signal power for 71% correct was determined as a function of notch width with the two-alternative, forced-choice procedure. The principal results showed a significant decrease in signal power with age and a significant interaction between age and notch width. The best-fitting parameters of a model of the auditory filter showed that the filter was significantly wider for the 6-year-olds than for the 10-year-olds or the adults.  相似文献   
948.
Pigeon's observational learning of successive visual discrimination was studied using within-subject comparisons of data from three experimental conditions. Two pairs of discriminative stimuli were used; each bird was exposed to two of the three experimental conditions, with different pairs of stimuli used in a given bird's two conditions. In one condition, observers were exposed to visual discriminative stimuli only. In a second condition, subjects were exposed to a randomly alternating sequence of two stimuli where the one that would subsequently be used as S+ was paired with the operation of the grain magazine. In a third experimental condition, subjects were exposed to the performance of a conspecific in the operant discrimination procedure. After exposures to conspecific performances, there was facilitation of discriminative learning, relative to that which followed exposures to stimulus and reinforcement sequences or exposures to stimulus sequences alone. Exposure to stimulus and food-delivery sequences enhanced performance relative to exposure to stimulus sequences alone. The differential effects of these three types of exposure were not attributable to order effects or to task difficulty; rather, they clearly were due to the type of exposure.  相似文献   
949.
The matching law applies to wagtails' foraging in the wild   总被引:2,自引:2,他引:0       下载免费PDF全文
Field data concerning the time budgets and foraging success of pied wagtails (Motacilla alba yarrelli, Gould) are reanalyzed. It is found that the data are well described by the generalized matching law, with a marked bias towards spending time on the territory. In this case matching is not the result of maximizing reward rate, but it remains possible that it results from an allocation of time that maximizes survival.  相似文献   
950.
The Social Relations Model: An integrative method for personality research   总被引:1,自引:0,他引:1  
As outlined by Snyder and Ickes (1985), the study of personality can be undertaken using one of three research approaches dispositional, situational, and interactive We show how the Social Relations Model provides an integrative method to estimate simultaneously dispositional, situational, and interactive effects Reviewed are component approaches to the study of personality The Social Relations Model is shown to be a component model (a special case of generalizability theory) applied in a social interaction context In the model, dispositional, situational, and interactive effects are termed actor, partner, and relationship effects, respectively The Social Relations Model can be used to answer a number of important issues in personality research The model can be used to assess reliability, measure the validity of self-ratings, and validate self-report inventories The model requires special designs in winch each person interacts with multiple partners Empirical examples are presented in which social anxiety, sex role inventories, and self-disclosure are studied  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