全文获取类型
收费全文 | 46342篇 |
免费 | 2055篇 |
国内免费 | 32篇 |
出版年
2020年 | 545篇 |
2019年 | 653篇 |
2018年 | 931篇 |
2017年 | 884篇 |
2016年 | 991篇 |
2015年 | 696篇 |
2014年 | 810篇 |
2013年 | 3636篇 |
2012年 | 1521篇 |
2011年 | 1587篇 |
2010年 | 931篇 |
2009年 | 980篇 |
2008年 | 1274篇 |
2007年 | 1264篇 |
2006年 | 1123篇 |
2005年 | 987篇 |
2004年 | 961篇 |
2003年 | 896篇 |
2002年 | 902篇 |
2001年 | 1640篇 |
2000年 | 1630篇 |
1999年 | 1159篇 |
1998年 | 483篇 |
1997年 | 459篇 |
1995年 | 429篇 |
1992年 | 941篇 |
1991年 | 860篇 |
1990年 | 861篇 |
1989年 | 823篇 |
1988年 | 810篇 |
1987年 | 738篇 |
1986年 | 752篇 |
1985年 | 795篇 |
1984年 | 639篇 |
1983年 | 576篇 |
1982年 | 428篇 |
1979年 | 640篇 |
1978年 | 475篇 |
1977年 | 425篇 |
1976年 | 432篇 |
1975年 | 537篇 |
1974年 | 654篇 |
1973年 | 637篇 |
1972年 | 587篇 |
1971年 | 497篇 |
1970年 | 455篇 |
1969年 | 516篇 |
1968年 | 602篇 |
1967年 | 513篇 |
1966年 | 522篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
901.
Dating experiences, especially the type or stage of dating, have consistently been found to be related to premarital sexual behavior. Findings regarding the age at 1st date and sexual behavior have been less consistent. This paper examined the age at which dating began and the type of dating relationship as correlates of premarital sexual attitudes and behavior among mid-teen adolescents. The analyses were based on a sample of high school students (n=836), most of whom were between the ages of 15 and 18 when the surveys were conducted. Early dating, especially early steady dating, was related to permissive attitudes and to premarital sexual experience among both males and females. The relationship between early dating and intercourse experience was particulary strong among Mormons, a religious group which has institutionalized age 16 as the legitimate age to begin dating. 相似文献
902.
903.
This study investigated the relationship among anger, the Type A construct, and cardiovascular reactivity. The Novacco Anger Scale and the Jenkins Activity Survey (JAS) were used to measure anger proneness and Type A characteristics, respectively. Twenty-four college males were selected from the upper and lower quintiles of the JAS distribution. During the study, the subjects were exposed to varying levels of experimentally induced challenge, while measurements were taken of heart-rate and blood-pressure changes. The results showed a modest but significant correlation between scores on the Novacco Anger Scale and the JAS. More importantly, scores on the Novacco Anger Scale correlated significantly with heart rate and systolic blood pressure under all challenge conditions, while those on the JAS were unrelated to cardiovascular excitability. These results raise questions about the usefulness of the JAS as a predictor of CHD risk. They are also consistent with the beliefs of other investigators that anger and hostility are the most important Type A behaviors in predisposing patients to coronary heart disease. Additional implications of the study are discussed. 相似文献
904.
J K O'Hanlon B D Sachs 《Journal of comparative psychology (Washington, D.C. : 1983)》1986,100(2):178-187
Three experiments with rats (Rattus norvegicus) were conducted to examine the roles of the male's penile spines and penile cups (flaring of the distal glans) in the induction of luteal activity in the female, and in the removal of copulatory plugs from the vaginal tract. The results of Experiment 1 revealed no role for the cup in luteal induction but did suggest that elements of the ejaculatory reflex apart from cup formation contribute to the elicitation of this neuroendocrine response. The origin of this stimulatory effect was not directly determined, but indirect evidence suggested a role for penile spines. In Experiments 2 and 3, features of the glans penis that might help effect plug removal were investigated, and the experiments demonstrated that penile spines, perhaps in conjunction with penile cups, contribute to the extraction of plugs from the vagina. 相似文献
905.
906.
In a behavioral view, the purposes of science are primarily prediction and control. To the extent that a scientist embraces both of these as a unified and generally applicable criterion for science, certain philosophical and theoretical practices are counterproductive, including mentalism in both its metaphysical and metatheoretical forms. It is possible and often worthwhile to recast some mentalistic talk into an issue of behavior-behavior relations. When behavior-behavior relations are approached non-mechanistically, however, analysis cannot stop at the level of the relations themselves. Several analytic concepts common in the behavioral community share some of the dangers of mentalism if not employed properly, including such concepts as self-reinforcement, response-produced stimulation, and self-rules. 相似文献
907.
John E. Douglas Robert K. Ressler Ann W. Burgess Carol R. Hartman 《Behavioral sciences & the law》1986,4(4):401-421
Since the 1970s, investigative profilers at the FBI's Behavioral Science Unit (now part of the National Center for the Analysis of Violent Crime) have been assisting local, state, and federal agencies in narrowing investigations by providing criminal personality profiles. An attempt is now being made to describe this criminal-profile-generating process. A series of five overlapping stages lead to the sixth stage, or the goal of apprehension of the offender: (1) profiling inputs, (2) decision-process models, (3) crime assessment, (4) the criminal profile, (5) investigation, and (6) apprehension. Two key feedback filters in the process are: (a) achieving congruence with the evidence, with decision models, and with investigation recommendations, and (b) the addition of new evidence. 相似文献
908.
This paper reviews the literature on scapegoating, elaborating on the underlying mechanisms before describing the process of scapegoating as it occurred in a neonatal nurse support group. Illustrative vignettes are used to discuss how scapegoating was used by group members to avoid painful feelings arising from their care of extremely ill infants. Group process is related to the stages of the group's development as feelings were addressed more directly and the need to use scapegoating as a defense decreased. 相似文献
909.
The accommodative response to subthreshold blur and to perceptual fading during the Troxler phenomenon 总被引:2,自引:0,他引:2
A study is reported which shows that accommodation can be stimulated by a blur stimulus which is below the threshold for visual perception. It is also shown that perceptual fading of the target, caused by stabilization of the retinal image (Troxler phenomenon), can eliminate the accommodative response causing it to default to its resting level. The first finding suggests a way in which the visual system can filter the percept of blur out of our conscious awareness and still effectively utilize the blur as a steady-state error for the accommodative control system. The second finding is consistent with a locus for the Troxler phenomenon in the early afferent part of the visual pathway, ie the retinal ganglion cells. 相似文献
910.
The role of spatial-frequency channels in the perception of local and global structure 总被引:5,自引:0,他引:5
Adaptation and reaction-time techniques were used to examine the role of different spatial-frequency channels in the perception of local and global structure. Subjects were shown figures consisting of a large C composed of smaller Cs and asked to identify the orientation of either the global C or its local elements. Prior to performing the task subjects were adapted to different spatial frequencies and the effect on subsequent performance was assessed. Two main results were found. First, the adapting frequency that most affected the global task was often lower than that most affecting the local task, suggesting that high and low frequencies independently code the structure of an image. Second, reaction time to global figures was often faster than to local figures at all levels of detectability, again suggesting a role of low-frequency channels in global processing. 相似文献