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   44166篇
  免费   1733篇
  国内免费   21篇
  2019年   444篇
  2018年   714篇
  2017年   682篇
  2016年   722篇
  2015年   487篇
  2014年   663篇
  2013年   3175篇
  2012年   1159篇
  2011年   1242篇
  2010年   744篇
  2009年   794篇
  2008年   1146篇
  2007年   1086篇
  2006年   1032篇
  2005年   896篇
  2004年   874篇
  2003年   877篇
  2002年   841篇
  2001年   1346篇
  2000年   1350篇
  1999年   1030篇
  1998年   464篇
  1997年   466篇
  1996年   441篇
  1992年   922篇
  1991年   827篇
  1990年   868篇
  1989年   777篇
  1988年   767篇
  1987年   731篇
  1986年   799篇
  1985年   829篇
  1984年   675篇
  1983年   590篇
  1982年   446篇
  1981年   436篇
  1979年   690篇
  1978年   554篇
  1977年   463篇
  1976年   469篇
  1975年   596篇
  1974年   742篇
  1973年   763篇
  1972年   592篇
  1971年   585篇
  1970年   515篇
  1969年   566篇
  1968年   700篇
  1967年   622篇
  1966年   655篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
921.
922.
A computer system, based on the Radio Shack Color Computer, for running experiments in cognitive psychology is described. The system was designed according to the following principles: first, all of the equipment should consist of inexpensive, off-the-shelf components; second, the language used to implement experiments should have real-time commands embedded within the character strings to be displayed, and these real-time commands should be interpreted at run time; third, the system should serve multiple subjects, yet one host should be able to run display terminals for several subjects on independent experiments; and fourth, the system should be able to interface to other display devices and other response-recording devices. Two examples of other devices are discussed: an oscilloscope for rapid visual display and an Apple Macintosh for display of pictures.  相似文献   
923.
924.
The ability of infants to perceive three-dimensional structure from transformations of linear perspective was investigated in two studies. Infants were habituated to the pattern of linear perspective transformations corresponding to a particular three-dimensional object, and their relative preference for that object as compared with a different three-dimensional object was assessed both before and after habituation. The habituation displays showed the distorting shadow cast by a rotating object and therefore provided only transformations of linear perspective as information specifying three-dimensional form. The pre- and posttest displays involved the actual three-dimensional objects and provided binocular, shading, and texture information specifying three-dimensional form, but did not provide informative transformations of linear perspective. In Study 1, 6-month-olds showed changes in preference from pre- to posttest that were related to the identity of the object whose shadow they had seen during habituation; 4-month-olds, however, did not show preference changes related to the habituation object. In Study 2, rhythm information that may have served as a basis for responding in Study 1 was eliminated from the test displays. Six-month-olds again showed changes in preference that were dependent on their habituation experience. It is concluded that, by 6 months of age, infants are able to perceive object structure from the isolated cue of transformations of linear perspective. The findings are discussed with reference to infants’ three-dimensional form perception based on other cues and also with reference to the emergence of certain spatially related moter activities.  相似文献   
925.
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   
926.
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   
927.
928.
The present study examined some previously reported relationships between drug use by adolescents and perceived attitudes and behaviors of their parents. An anonymous questionnaire was administered to the student body of an inner-city secondary school for difficult students. Relationships between parental use of drugs and adolescent use of the same drugs were moderate and roughly equivalent across drugs. However, parental use of marijuana was strongly related to the adolescent's use of other, harder drugs such as opiates, cocaine, amphetamines, and barbiturates. This finding is explained within the framework of Kandel's postulated stages of drug initiation. It points to a need for further study of parental influences, which may be increasingly problematic as more individuals who have grown up in our marijuana-accepting society become parents of adolescents.  相似文献   
929.
D Klein  P Belcastro  R Gold 《Adolescence》1984,19(76):805-815
Several inherent limitations to secondary school sex education program evaluations are: limited generalizability, lack of longitudinal research, and no clear consensus of program outcomes. With a Bureau of Health Education, Center for Disease Control study as the criterion for program outcomes, a study was undertaken to examine the immediate and long-term impact of sex education upon program participants. Two of the 20 schools in the CDC study identified as having exemplary sex education programs provided access to their students and alumni. Inventories which measured perceived achievement of 33 sex education outcomes were piloted for reliability and validity. Each inventory examined participant changes in knowledge, understanding of self, values, interaction skills, self-esteem, and fear of sex-related activities. Students were surveyed in school; alumni were surveyed through the mail. Response rates ranged from 30 to 100 percent for students and alumni at both schools. Overall there was no statistically significant difference between the perceptions of students and alumni as to achievement of investigated outcomes. Alumni responses at one school did, however, indicate some potentially weak areas of their school's program with respect to values and interaction skills outcomes. It appears that program impact may decrease with time. Thus, isolating and addressing the factors involved may be necessary. This would assist program planners and instructors to strengthen curricula and program activities in order to enhance the overall impact of sex education. The present study supports the notion that positive gains are achieved as a result of each school's sex education program, and these gains remained over time.  相似文献   
930.
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   
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