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   4796篇
  免费   74篇
  国内免费   1篇
  4871篇
  2022年   38篇
  2021年   58篇
  2020年   96篇
  2019年   101篇
  2018年   191篇
  2017年   147篇
  2016年   134篇
  2015年   88篇
  2014年   105篇
  2013年   384篇
  2012年   183篇
  2011年   176篇
  2010年   106篇
  2009年   111篇
  2008年   125篇
  2007年   138篇
  2006年   107篇
  2005年   95篇
  2004年   101篇
  2003年   66篇
  2002年   62篇
  2001年   129篇
  2000年   92篇
  1999年   78篇
  1996年   40篇
  1993年   45篇
  1992年   61篇
  1991年   70篇
  1990年   60篇
  1989年   57篇
  1988年   63篇
  1987年   58篇
  1986年   50篇
  1985年   59篇
  1984年   59篇
  1983年   47篇
  1982年   51篇
  1981年   38篇
  1979年   57篇
  1978年   57篇
  1977年   51篇
  1976年   45篇
  1975年   64篇
  1974年   61篇
  1973年   56篇
  1972年   52篇
  1971年   52篇
  1968年   49篇
  1967年   60篇
  1966年   43篇
排序方式: 共有4871条查询结果,搜索用时 0 毫秒
81.
When temporal auditory acuity is estimated using time-reversed click pairs, the asymmetry of temporal masking may influence the results. To investigate this hypothesis, we first established normal-hearing listeners’ psychometric functions for the discrimination of time-reversed click pairs. An attempt to relate listeners’ performances in click-pair discrimination to their performances in forward and backward masking tasks was unsuccessful, probably due to the presence of spectral artifact in the temporal masking paradigms. We then investigated listeners’ abilities to discriminate time-reversed click pairs in which the intensity of the lower level click in one pair was altered. This alteration was introduced at random in order to minimize the influence of spectral artifact. Our results suggest that the course of temporal masking influenced the discriminability of the modified click pairs. Thus, the discrimination of time-reversed click pairs may yield a biased estimate of auditory temporal acuity.  相似文献   
82.
Hypersexual behavior was induced in adult male cats by repeatedly evoked limbic system seizures. Accentuation of Dopaminergic activity with drugs was used to facilitate development of the seizure induced hypersexuality. Hypersexuality consisted of biting knap of neck, mounting, thrusting and coital intromission. The gradual development and eventual disappearance of hypersexuality was correlated with the progressive prolongation of the seizures in their evolution. There are three stages of seizure evolution in relation to sexuality. First stage-normal sexuality, intermediate stage-hypersexuality and late stage-hyposexuality. A theoretical “hypersexual growth and decay curve” was constructed in relation to the evolution of limbic seizure durations in the intermediate stage. It was suggested that the observed hypersexuality was related to the early discharge activation of hypothalamic, preoptic and basal ganglia neurohumeral facilitatory mechanisms for sexuality, and the late effects were related to discharge activation of brain stem serotonergic inhibitory mechanisms. The discussion attempts also to use these experimental findings to explain clinically observed hyposexuality and hypersexuality. It was suggested that either hypersexuality or hyposexuality may be associated with psychomotor seizures and that the predominating sexual state at a given moment is dependent upon the evolutionary stage of the seizure at that moment. Consequently, psychomotor seizures with associated hypersexuality should not be considered a clinical anachronism. In fact, these observations support the impression that rape may be a manifestation of a psychomotor seizure.  相似文献   
83.
This study was conducted to investigate the effect of sexual stereotyping on the exercise of authority. The hypotheses were that the sexual composition of the group affects the authority behavior of group leaders when the task has low clarity but that sex characteristics have no effect on authority behavior when the task has high clarity. These predictions were expected to hold both in situations where there is a direct association between sex and the task ability and in situations where no such connection is established. As predicted, no significant difference was found in the number of high control acts made by male and female leaders in the high task clarity conditions, even when sex was directly related to the task ability. Also as hypothesized, sex effects did operate strongly in the low task clarity conditions. Male leaders made significantly more high control acts than female leaders, even in conditions where no prior relation was established between sex and the task ability. Thus, these results indicate that the effect of sex characteristics on the exercise of authority is enhanced in low task clarity situations and is neutralized in high task clarity situations.A preliminary version of this paaper was presented at the West Coast Conference for Small Group Research, San Francisco, California, April 24, 1974. We would like to acknowledge the comments made by Anne McMahon and Mary Walshok and the research assistance provided by Sue Aldrich, Patti Baird, Jim Hart, Debbie Jones, Glenn Kassel, Jane Morrison, Karen Scheblein, and Kay Smith.  相似文献   
84.
85.
In the last few years, a number of asymptotic results for the distribution of unrotated and rotated factor loadings have been given. This paper investigates the validity of some of these results based on simulation techniques. In particular, it looks at principal component extraction and quartimax rotation on a problem with 13 variables. The indication is that the asymptotic results are quite good.  相似文献   
86.
Eight volunteers maintained on daily methadone participated in a classical conditioning procedure to determine which if any of the elements of narcotic withdrawal could be conditioned. The unconditioned stimulus was the injection of a small dose of naloxone. The unconditioned response was a brief precipitated withdrawal syndrome. The conditioning stimulus was a tone, odor, and injection of saline. Conditioning was successful in the pilot study in 5 of 8 subjects. The conditioned response consisted of tearing, yawning, lacrimation, systolic blood pressure increase, respiratory irregularities and subjective feelings of narcotic withdrawal sickness (nausea, muscle aches, chills). A second group of 8 subjects showed, in addition to the above, evidence of conditioning of heart rate, respiratory rate and skin temperature decrease. These laboratory findings support the clinical reports of a conditioned withdrawal syndrome and suggest ways to improve treatment results by detecting and extinguishing or modifying conditioned responses.  相似文献   
87.
Three experiments investigated the effect of stimulus probability on same-different classification time. In Experiments I and II, subjects made same responses on the basis of name matches of simultaneously presented letters. Half of the same trials involved letters that were also physically identical. Experiment I showed that the presentation probability of specific letters affected name matches and different responses, but not physical matches. Experiment II varied stimulus contrast as well as probability. Contrast had a main effect but did not interact with probability at any level of processing. In Experiment III, subjects were switched to the physical level of processing. Stimuli that now had the same name but differed in case were called different. In this condition, the probability effects obs(irved in Experiment II disappeared. These results are interpreted as demonstrating that stimulus probability has its effect during the process that derives the name of the stimulus from the visual representation. This process takes place before the name comparison is made, and the name comparison process precedes the determination of the different response.  相似文献   
88.
Self-regulation is a highly adaptive, distinctively human trait that enables people to override and alter their responses, including changing themselves so as to live up to social and other standards. Recent evidence indicates that self-regulation often consumes a limited resource, akin to energy or strength, thereby creating a temporary state of ego depletion. This article summarizes recent evidence indicating that regular exercises in self-regulation can produce broad improvements in self-regulation (like strengthening a muscle), making people less vulnerable to ego depletion. Furthermore, it shows that ego depletion moderates the effects of many traits on behavior, particularly such that wide differences in socially disapproved motivations produce greater differences in behavior when ego depletion weakens the customary inner restraints.  相似文献   
89.
This study examined the influence of gender and Internet use on the sexual behavior orientation of young adults in Nigeria. Using an ex-post-facto design, data were collected from a total of 231 participants. Results of the hierarchical regression model provided support for the influence of gender and Internet use on sexual behavior orientation among young Nigerians. Further, results also revealed an interaction effect; as the use of the Internet increased, male participants reported a greater extent of risky sexual behavior orientation than their female counterparts. The findings were explained in the context of the theoretical foundations of the study, while practical implications for combating youths' risky sexual behavior orientation were highlighted.  相似文献   
90.
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