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   50030篇
  免费   1725篇
  国内免费   23篇
  2018年   632篇
  2017年   691篇
  2016年   757篇
  2015年   566篇
  2014年   669篇
  2013年   3716篇
  2012年   1219篇
  2011年   1286篇
  2010年   820篇
  2009年   819篇
  2008年   1222篇
  2007年   1106篇
  2006年   1040篇
  2005年   975篇
  2004年   917篇
  2003年   934篇
  2002年   958篇
  2001年   1289篇
  2000年   1268篇
  1999年   967篇
  1998年   527篇
  1997年   515篇
  1996年   503篇
  1992年   927篇
  1991年   874篇
  1990年   891篇
  1989年   872篇
  1988年   814篇
  1987年   804篇
  1986年   863篇
  1985年   882篇
  1984年   769篇
  1983年   700篇
  1982年   532篇
  1981年   587篇
  1980年   491篇
  1979年   836篇
  1978年   647篇
  1977年   571篇
  1976年   574篇
  1975年   732篇
  1974年   874篇
  1973年   917篇
  1972年   721篇
  1971年   740篇
  1970年   687篇
  1969年   738篇
  1968年   900篇
  1967年   829篇
  1966年   824篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
Six tasks administered on a MINC-11 minicomputer were used in studying the effects of long, continuous work periods and fatigue on physical and cognitive task performance. Submaximal physiological workload measurement was done during one of these tasks for a subject walking on a treadmill. The MINC-11 system is described, as are the six tasks programs. Four of these tasks measured various types of reaction times, another involved complex information processing, and one appraised moods, physical symptoms, fatigue, and the physiological status of subjects.  相似文献   
912.
The recent Supreme Court decision upholding Roe v. Wade and in particular, the dissent by Justice Sandra Day O'Connor, sheds new light on the issue of abortion. Let us consider any stage of a pregnancy when abortion is medically safe for the mother. If at that stage it is also medically viable to save the fetus, is an abortion performed at that stage of pregnancy morally justifiable? For example, if it is, or becomes, medically safe to perform abortions after first trimester of pregnancy and at the same time saving a fetus is, or becomes, medically viable or not unusual during some stage of the second trimester, can abortions during and after that stage of pregnancy be justified? With a number of qualifications I shall argue the thesis that as a general rule, but not an absolute rule, abortion in these instances is not usually justifiable. For if it is, then one will also have to grant the moral justification for a number of other highly questionable medical practices. This thesis is not to be identified with the stronger claim that abortions of viable fetuses can never be performed. There are surely exceptions such as when the life or health of the mother is in danger. But, I shall argue, the justification for making such exceptions is on different grounds than is sometimes claimed because one must weigh the health of the mother against the life of another human being.  相似文献   
913.
Prior surgical implantation of a venous catheter sensitized rats to coldimmobilization stress. Three of six catheterized females succumbed during the stress. The remaining rats fell into two groups in terms of their core temperature at the end of the stress period: Male uncatheterized rats had higher temperatures than rats in the other three groups. No relation was found between catheter patency and magnitude of hypothermia. Degree of gastric disease paralleled the core temperature findings in that the male uncatheterized rats had significantly fewer gastric erosions than the rats in the other three groups. Additionally, a robust effect of gender was found with uncatheterized females showing more hypothermia and more gastric disease than uncatheterized males. A subsequent experiment was conducted to evaluate whether anesthesia or wearing the protective spring was responsible in part for the sensitization seen. Here, the gender difference was less although females consistently averaged lower core temperatures after stress than did males. Despite similar core temperatures after stress, females that were prepared with the protective spring apparatus developed more gastric disease than female controls or similarly treated males. Thus, the additional sensitization exhibited by females in the first experiment may relate to the fact that both catheterization and the taping procedure were sensitizers while only catheterization was a sensitizer for males.  相似文献   
914.
Respiratory rate, respiration amplitude, and vocal responses were recorded in cats of different ages during classic conditioning. Vocal responses to the conditional stimulus (CS) appeared first in 8-week-old kittens, and became prominent at older ages. An increase in respiration rate occurred after the onset of the CS in cats of all ages. Similarly, the decrease of respiration amplitude was observed at all ages, but only in 8-week-old and older subjects did this response resemble an adult pattern. In 4-week-old kittens the response was characterized by an early and brief peak, suggesting an alpha conditional response (CR). Clear and significant discrimination between a warning and a safety signal was present in both respiratory and vocal responses after the age of 8 weeks.  相似文献   
915.
916.
An experiment which employed each of 18 subjects in four days of testing was used to examine acute secobarbital dose treatment effects on choice reaction time in a Cooper and Shepard (1973) character recognition task. Manipulations of visual stimulus degradation, character difficulty, 180 degree rotation, and mirror-image reversal were included in order to evaluate the hypothesis that the drug affects performance by disrupting early stimulus input processing. The results indicate significant increases in the effect of secobarbital on reaction time and errors under conditions of visual stimulus degradation. The effects of the drug, however, were not changed by 180 degree rotation of the target character or by the other task variables. The results were interpreted to indicate that secobarbital impairs performance primarily by placing selective stress on hypothetical early encoding activities and that later processing operations (associated with use of an internal representation of the target character) are not affected by the drug. Strengths and weaknesses of the two-stage model of visual stimulus processing are discussed and implications of the model for future drug research are indicated.  相似文献   
917.
The relationship between the availability of visual information and attention demands during the production of a discrete motor act was examined. Subjects were required to move a linear slide a distance of 15 cm in both 150 and 600 msec conditions under three light manipulations, viz., light always on; light always terminated as movement began; or, subject was unsure as to whether light would stay on or terminate. A simple key press by the index finger of the opposite hand to a tone was used as a secondary task and a measure of attention demands. The light manipulation influenced attention demands on the rapid 150 msec movement such that more attention was demanded when the subject knew the light would terminate. No such attentional strategy differences were found with the slow 600 msec movement. These findings suggest that task constraints in the form of kinematic criteria, together with the perceived availability of visual information, contribute to determining attentional strategy in movement production.  相似文献   
918.
It is by the application of the principle of neutrality, born of his respect for the essential otherness of the patient, that the analyst focuses the dyadic analytic work in the service of the patient's growing self-analytic capacity. Thus, the general principle of neutrality is distinguished from the technical tactic of abstinence, the latter being a specific function utilized to facilitate and foster analytic regression. Neutrality can be defined as it applies to the major subfunctions of the analyst's work ego. Perception of the patient's intrapsychic processes (both empathically and cognitively) requires a neutrality of appearance on the analyst's part in order to minimize the distortion of the unfolding transference neurosis. Integration and understanding of the patient's communications require mastery and neutralization of the analyst's own internal processes in order to minimize countertransferential distortions. Appropriate interpretive intervention requires neutrality of action, i.e., mastery of impulses related to power, neutralizing them into the service of the analytic work; tact is defined as a specific psychoanalytic function in this regard. Collaborative ignorance is examined as a specific instance of false neutrality. In this an analytic guise serves to mask a countertransferential conflict. Neutrality serves as an overriding technical principle, not an imperative for perfectionism . Factors intrinsic to the analytic process also influence the application of this principle.  相似文献   
919.
920.
The Wundt Myths     
Three myths about Wundt have been perpetuated in English language accounts of his work. First, he is said to have founded a Psychologisches Institut (a formally recognized psychological research laboratory) in 1879. Second, he is said to be the first psychologist, as distinct from the first contributor to psychology. Third, he is said to have formulated an elementarist psychology of mental content or experience. The first and second are trivial myths which in isolation would be scarcely worth a comment. The third is a gross misrepresentation which ignores the purposivist-voluntarist underlay of his experimental cognitive psychology and the humanistic, cultural concern of his Völkerpsychofogie.  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