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   21782篇
  免费   45篇
  国内免费   9篇
  2023年   9篇
  2022年   10篇
  2021年   18篇
  2020年   18篇
  2019年   29篇
  2018年   3559篇
  2017年   2860篇
  2016年   2306篇
  2015年   203篇
  2014年   96篇
  2013年   134篇
  2012年   600篇
  2011年   2458篇
  2010年   2571篇
  2009年   1519篇
  2008年   1752篇
  2007年   2250篇
  2006年   45篇
  2005年   237篇
  2004年   195篇
  2003年   120篇
  2002年   85篇
  2001年   67篇
  2000年   97篇
  1999年   36篇
  1998年   32篇
  1997年   26篇
  1996年   15篇
  1992年   18篇
  1991年   16篇
  1990年   43篇
  1989年   24篇
  1988年   14篇
  1987年   25篇
  1986年   31篇
  1985年   22篇
  1984年   22篇
  1983年   20篇
  1981年   12篇
  1980年   9篇
  1979年   13篇
  1978年   10篇
  1975年   15篇
  1974年   18篇
  1973年   21篇
  1972年   14篇
  1971年   17篇
  1970年   15篇
  1968年   9篇
  1967年   11篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Adults have unique problems in making career changes. They face crucial economic, educational, and psychological barriers that require special guidance services. In this article, barriers to adult career change are identified and a five-county regional learning service using paraprofessionals is described. Results in working with more than 200 adults making career changes is reported. Suggestions for overcoming some of the problems adults face in making career changes are explained.  相似文献   
62.
A nonrandom sample of 86 cases of Israel separation and divorce cases is compared with a Canadian sample of 369 having this experience. Impacts of sex-role changes, jobs and careers, children and sexuality are compared in these two national cases which exhibit many similarities and many differences. Sex-role conflicts were more frequent in Israel as were violence in separation and divorce in the Israeli sample. Adultery, though problematic in both cases, was frequently cited as a cause of divorce. Social-structural restraints and freedoms in each case are discussed as well as historical-cultural differences that help explain differing expectations and outcomes in both Israel and Canada.  相似文献   
63.
A vector graphic CRT display system for research in visual information processing is described. The vector graphic processor includes a 4K-byte display memory. The processor communicates with the controlling computer via a serial channel. The system is capable of exposure durations below 1 msec, and it allows on-line generation and modification of display files during an experiment. Brightness can be controlled separately for each vector of a picture. A graphic display editor in FORTRAN IV for interactive editing and debugging of display files has been developed.  相似文献   
64.
Perception of dynamic events of American Sign Language (ASL) was studied by isolating information about motion in the language from information about form. Four experiments utilized Johansson's technique for presenting biological motion as moving points of light. In the first, deaf signers were highly accurate in matching movements of lexical signs presented in point-light displays to those normally presented. Both discrimination accuracy and the pattern of errors were similar in this matching task to that obtained in a control condition in which the same signs were always represented normally. The second experiment showed that these results held for discrimination of morphological operations presented in point-light displays as well. In the third experiment, signers were able to accurately identify signs of a constant handshape and morphological operations acting on signs presented in point-light displays. Finally, in Experiment 4, we evaluated what aspects of the motion patterns carried most of the information for sign identifiability. We presented signs in point-light displays with certain lights removed and found that the movement of the fingertips, but not of any other pair of points, is necessary for sign identification and that, in general, the more distal the joint, the more information its movement carries.  相似文献   
65.
The long-term effects of a preschool intervention program for high-risk experimental children were assessed and compared to a high-risk placebo control group and low-risk normal controls. Seventy first-grade children were involved in this 2-year follow-up. The experimental treatment group was superior to that of the placebo control group at follow-up on the criteria measures of behavioral adjustment and achievement. The low-risk normal control group was significantly different from that of the placebo control groups, but generally not significantly different from that of the experimental groups, suggesting that the intervention had boosted the high-risk experimental treatment children to the point where their performance was comparable to that of children who had not experienced behavioral or learning difficulties.The study was supported by grants from the McGregor Fund and the Eloise and Richard Webber Foundation, and by the Detroit Public Schools, for which the authors express grateful appreciation. A version of this paper was presented at the Annual Meeting of the American Psychological Association, New York, September 1979.  相似文献   
66.
The testing of Convulsofin carried out in 220 patients at 14 clinics over a period of six months confirms the international experience gained with valproic acid and sodium valproinate. The main field of application of Convulsofin according to the experience gained will again be the treatment of fits in generalised primary epilepsy for which it permits to carry out a monotherapy to a remarkable extent. The favourable effect of the preparation in photosensitivity could be confirmed. Also in generalised secondary epilepsy and in fits of partial epilepsy. Convulsofin is partly effective, so that it can recommended as a co-medication in the treatment of therapy-resistant forms of these epilepsies which are difficult to treat. Decrease in thrombocytes, transient increase in serum transaminases, gastrointestinal disorders, loss of hair and undesired increases in body-weight were the more frequently occurring side-effects.  相似文献   
67.
The contribution describes a final neurological documentation system for in-patients that permits the computerized print-out of an epicrisis. The computer automatically summarizes the elementary findings and presents them as a number of important neurological syndromes. The structure of the documentation and the experience gained in the course of many years of routine application are described. The system has proved to be basically sound under the conditions existing at a university hospital and a specialized hospital for psychiatry and neurology and has proved applicable for a large proportion of the patients without major restrictions.  相似文献   
68.
Interactions between a drug discriminative stimulus ( D , 17.5 mg/kg of pentobarbital vs. N , saline) and exteroceptive stimulus conditions (light vs. dark) were examined in a T-maze, shock-escape task using conditioning procedures pertaining to the phenomena of "overshadowing" and "blocking". From an operational point of view, in the "overshadowing" procedure the stimulus compound is introduced from the outset of the training, whereas in the "blocking" procedure the stimuli components are introduced sequentially. When the compound discriminations were established, dose-generalization tests with various doses of pentobarbital (range 5.6–17.5 mg/kg) as well as saline (1 ml/kg) were carried out under both elements (light and dark) of the exteroceptive stimulus dimension. Prior training with drug ( D vs. N ) neutralized the potential influence of the exteroceptive dimension (light vs. dark); conversely training with the exteroceptive stimuli prior to the drug training accentuated the control over behavior by the visual stimuli. Dose-generalization results intermediate to those described above were observed in the group trained to discriminate the stimulus compound ( D plus light vs. N plus dark) from the outset of training. It may therefore be concluded that exteroceptive stimuli can compete with interoceptive drug stimuli for associative strength in the procedure used. Thus, the formal similarities between drug discriminative stimuli and more conventionally studied exteroceptive, sensory signals are furthered by the data.  相似文献   
69.
An experiment is described in which the effects of Psychoticism and Extraversion on classical eyelid conditioning were examined using a balanced design involving two levels of paraorbital shock intensity and two levels of response threshold. Questionnaire measures of Anxiety and Impulsivity were also analysed together with subjective ratings of the UCS. Results were broadly consistent with Eysenck's personality theory in that subjects scoring high on Psychoticism demonstrated lower levels of conditioning.  相似文献   
70.
Theoretical and technical considerations of measuring puff and inhalation volumes during cigarette smoking are reviewed. Measures of smoking behavior using a flowmeter and inductance plethysmography are described and demonstrated with seven subjects smoking over a 3-to 4-h period. Puff volume and duration, inhaled volume and duration, interpuff and intercigarette interval, and number of puffs varied for each individual over the session. The ratio of puff volume to inhaled volume changed with successive cigarettes. Smokers adjust the concentration of smoke by blending air with the smoke. Thus, to completely characterize smoking behavior, the volume of smoke and air inhaled into the lungs must be measured directly.  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