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   31744篇
  免费   1359篇
  国内免费   25篇
  2020年   344篇
  2019年   436篇
  2018年   620篇
  2017年   596篇
  2016年   672篇
  2015年   446篇
  2014年   552篇
  2013年   2482篇
  2012年   1041篇
  2011年   1024篇
  2010年   608篇
  2009年   687篇
  2008年   876篇
  2007年   887篇
  2006年   779篇
  2005年   684篇
  2004年   666篇
  2003年   616篇
  2002年   633篇
  2001年   1061篇
  2000年   1067篇
  1999年   782篇
  1998年   340篇
  1997年   311篇
  1995年   321篇
  1992年   630篇
  1991年   590篇
  1990年   572篇
  1989年   548篇
  1988年   545篇
  1987年   483篇
  1986年   483篇
  1985年   536篇
  1984年   440篇
  1983年   405篇
  1982年   312篇
  1979年   474篇
  1978年   332篇
  1977年   304篇
  1976年   319篇
  1975年   362篇
  1974年   433篇
  1973年   462篇
  1972年   399篇
  1971年   341篇
  1970年   318篇
  1969年   334篇
  1968年   416篇
  1967年   370篇
  1966年   357篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
291.
292.
The naturalistic fallacy occurs when a person reads a report of scientific research and concludes that the moral implication of the research was included in the article when, in fact, it was not. For example, the fallacy is committed when a study contains the conclusion that TV advertising increases preference for sugar-based foods, but the reader later believes that the study concluded that TV advertising should be controlled. Previous research indicates that the commission of the fallacy was strong when memory for social research was tested. The present study showed that the commission of the fallacy was stronger when the research which was read involved children as subjects compared to adult subjects. Increased empathy for the subjects of a research article strengthens commission of the fallacy.  相似文献   
293.
294.
This article provides a comprehensive review of the research on smoking and body weight. The relationships between smoking and body weight are evaluated in 70 cross-sectional and longitudinal investigations. The mechanisms responsible for differences in body weight are discussed, the weight-related issues that promote smoking behavior are reviewed, methods for reducing postcessation weight gain are summarized, and future research directions are proposed. A proposed working research model for studying the relationship between smoking, energy balance, and weight gain is offered. It is concluded that smoking and body weight relationships are closely related and pose significant challenges for smoking researchers.  相似文献   
295.
The "crossroads families" are caught between old value systems and American mainstream goals. Traditional family and sex-related roles and orientations conflict with those of the new social system. In turn, neither of the teenager's orientations--toward home or toward peer activity--is validated. In the clinical case presented, Anna, at adolescence, wants to relinquish many of her household chores and enter her social world more fully. She needs unconflictual support for such a move. If this does not take place, her autonomous movement represents an unconscious betrayal of her depleted and controlling mother as well as an abandonment of the parental coalition. This leaves her feeling resentful, guilty, and ultimately unlovable. Attitudes marked by helplessness and confusion are thus significant to the depressed affect that brings this teenager into family therapy. Teenagers of non-Hispanic background who enter family therapy reveal gross overlap with teenagers of the Hispanic "crossroads" family model. Here, the family gives mixed messages for homebound and intimate closeness as well as accomplishment in the societal mainstream. A primary difference between ethnic groups involves the freer expressions of anger and pain between husband and wife in the non-Hispanic families. This is not similar to the backgrounds of the more individuated Hispanic teenagers. While more open expressions of anger within the family do indicate higher levels of autonomy, the hostility that is expressed by the parents presents serious complications when this includes "triangulating" the child into the family tension. Here, as cited, the mother often uses her daughter as a confidant and ally at times of severe parental discord. This places additional strain on the child's conflict with separation. Importantly, the daughter experiences renewed rejection and betrayal when the mother "submits" to her spouse. These are significant family processes that heighten mixed messages around autonomy. Milagros, a depressed (more individuated) adolescent, is consistently entangled into her parent's abrasive relationship. Her interpersonal family struggles have become intrapsychic and, ultimately, transferential.  相似文献   
296.
To study the self-projective representations expressed by diabetic children, aged between 10 and 15 yr., and to compare these with representations of a control group the Draw-a-person test associated with those for subsequent Draw-a-sick-person were administered to 23 children regularly checked by an Antidiabetic Centre. The diabetic subjects drew an image of "sick person" having projective elements with a regressive value and denoting a refuge in the past, together with depressive signs of retiring into themselves and of less consideration of the self. Also, the diabetic children seemed to be less prone to the cultural stereotype which requires a smiling and happy image of "the healthy person." At the same time there was also a transparent symbolic defense which allowed the diabetics to adapt variously and to move from their anxious state toward psychological recovery.  相似文献   
297.
Test of speech-sound discrimination are used by special educators, reading specialists and speech-language pathologists in assessing children's ability to differentiate between speech sounds occurring in standard English. Such tests are important in determining if speech-sound articulation errors are caused by difficulty in making such differentiations. However, during the past 10 years, these tests have been criticized on the basis of their reliability and validity. The purpose of this study was to examine the use of two alternative methods of assessing speech-sound discrimination with a school-aged population to determine if they elicited responses in a similar manner.  相似文献   
298.
Navon's (1977) global precedence hypothesis was based primarily on the joint occurrence of two effects: a response time (RT) advantage for identifying global targets, and interference by global distractors on responding to local targets. Although the hypothesis has been questioned on the basis of experiments in which it has been shown that a local RT advantage and local interference can occur, it is still frequently assumed that these two effects are a valid measure of the order in which local and global levels of structure are processed. In the present experiment, this assumption was examined. Subjects identified target letters that occurred randomly at the global or local level in a divided-attention task. The visual angle subtended by the stimulus pattern was varied, a manipulation known to affect the relative speed of response to local- or global-level information. Local targets were identified faster than global targets at the larger visual angles, but there was no difference in RT at the smallest visual angle. Despite this change in RT advantage, the interference effect did not change as a function of the visual angle of the stimulus pattern. Moreover, global distractors interfered with responding to local targets but local targets had no effect on responding to global targets, which is exactly the opposite of the finding one would expect if RT advantage and interference reflected order of processing. These findings are not consistent with the assumption that RT advantage and interference reflect order of processing in a simple way.  相似文献   
299.
We reported earlier that occlusion of the central retina and stationary edges have highly interactive effects on the gain of optokinetic nystagmus (OKN; Murasugi, Howard, & Ohmi, 1986). In this study, we explored this effect in more detail. A central occluding band of variable height, flanked by vertical bars, was superimposed onto an array of dots moving at 30 degrees per second. The height of the occluding band required to abolish OKN increased with the separation of the vertical bars. For bars 3.5 degrees apart, OKN was abolished in most subjects when a band only 6' high ran between them. For bars 75 degrees apart, a band at least 20 degrees in height was required to abolish the response. The effects of the stationary figure depended to some extent on the subject's attention, but only at intermediate values of bar separation. Both low- and high-level mechanisms are proposed to account for the results.  相似文献   
300.
The hypothesis that the two cerebral hemispheres are specialized for processing different visual spatial frequencies was investigated in three experiments. No differences between the left and right visual fields were found for: (1) contrast-sensitivity functions measured binocularly with vertical gratings ranging from 0.5 to 12 cycles per degree (cpd); (2) visible persistence durations for 1- and 10-cpd gratings measured with a stimulus alternation method; and (3) accuracy (d') and reaction times to correctly identify digitally filtered letters as targets (L or H) or nontargets (T or F). One significant difference, however, was found: In Experiment 3, a higher decision criterion (beta) was used when filtered letters were identified in the right visual field than when they were identified in the left. The letters were filtered with annular, 1-octave band-pass filters with center spatial frequencies of 1, 2, 4, 8, and 16 cpd. Combining four center frequencies with three letter sizes (0.5 degrees, 1 degree, and 2 degrees high) made some stimuli equivalent in distal spatial frequency (cycles per object) and some equivalent in proximal spatial frequency (cycles per degree). The effective stimulus in the third experiment seemed to be proximal spatial frequency (cycles per degree) not distal (cycles per object). We conclude that each cerebral hemisphere processes visual spatial frequency information with equal accuracy but that different decision rules are used.  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