全文获取类型
收费全文 | 39459篇 |
免费 | 1599篇 |
国内免费 | 18篇 |
专业分类
41076篇 |
出版年
2020年 | 499篇 |
2019年 | 638篇 |
2018年 | 830篇 |
2017年 | 924篇 |
2016年 | 935篇 |
2015年 | 636篇 |
2014年 | 773篇 |
2013年 | 3165篇 |
2012年 | 1365篇 |
2011年 | 1356篇 |
2010年 | 878篇 |
2009年 | 825篇 |
2008年 | 1210篇 |
2007年 | 1231篇 |
2006年 | 1105篇 |
2005年 | 957篇 |
2004年 | 897篇 |
2003年 | 840篇 |
2002年 | 841篇 |
2001年 | 1181篇 |
2000年 | 1125篇 |
1999年 | 885篇 |
1998年 | 382篇 |
1997年 | 386篇 |
1996年 | 354篇 |
1995年 | 364篇 |
1993年 | 355篇 |
1992年 | 744篇 |
1991年 | 650篇 |
1990年 | 711篇 |
1989年 | 610篇 |
1988年 | 642篇 |
1987年 | 600篇 |
1986年 | 613篇 |
1985年 | 550篇 |
1984年 | 503篇 |
1983年 | 486篇 |
1979年 | 576篇 |
1978年 | 401篇 |
1977年 | 351篇 |
1975年 | 460篇 |
1974年 | 498篇 |
1973年 | 532篇 |
1972年 | 402篇 |
1971年 | 393篇 |
1970年 | 352篇 |
1969年 | 403篇 |
1968年 | 471篇 |
1967年 | 431篇 |
1966年 | 357篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
The Family System Functioning (FSF) scale is a new instrument for measuring dimensions of the intrafamilial environment thought to be important in recovery from major psychiatric illness. Modest statistical correlations were obtained when FSF ratings of laboratory-based family interactions were compared with researcher-guided therapist ratings of FSF based upon the family's behavior in family therapy sessions during the subsequent month. The data from these two settings provide support for the validity of some of the scales. Because of the modest size of the correlations, however, behavior in the laboratory setting may not always be an accurate indicator of how the family will behave in the early weeks of family therapy. 相似文献
83.
84.
Donald L. King 《Memory & cognition》1988,16(1):71-78
Contextual stimuli from one category increase the rated similarity of stimuli from a second category. In Experiment 1, associates of one of the members of pairs of target words increased the rated similarity of the members slightly more than did much less similar contextual stimuli. In Experiment 2, contextual category names and good exemplars increased the rated similarity of pairs of poor to medium target exemplars and were also rated as more similar to these targets than the targets were to each other. In both cases, the category names resulted in the stronger effect. This ability of contextually similar stimuli to increase rated similarity opposes the distance-density and averaging-judgmental theories of the effect of context on similarity. However, the theory that a positive association exists between the perceived similarity of stimuli and the strength of the category to which they belong explains how both contextually dissimilar and contextually similar stimuli can increase rated similarity. 相似文献
85.
Wolfgang Hell Gerd Gigerenzer Siegfried Gauggel Maria Mall Michael Müller 《Memory & cognition》1988,16(6):533-538
If subjects are asked to recollect a former response after having been informed about the correct response, their recollection tends to approach the correct response. This effect has been termedhindsight bias. We studied hindsight bias in an experiment requiring numerical responses to almanac-type questions for physical quantities. We varied (1) the time at which the correct information was provided, (2) the encoding of the original responses by asking/not asking subjects to give a reason for the respective response, and (3) the motivation to recall correctly. We found that hindsight is less biased if reasons are given and if the correct information is provided at an earlier time. Motivation had only interactive effects: (1) With high motivation to recall correctly, the time the correct information was provided had no influence. (2) With reasons given, the variation of motivation showed no effect. These results rule out purely motivational and purely automatic explanations. 相似文献
86.
87.
The modulation of attacks, genital sniffs, and mounts in male SJL/J mice by ovarian-dependent urogenital substances in the urine voided by estrous females was examined. Urogenital substances were applied onto the external urogenital areas of ovariectomized mice. When compared with urine voided by estrous females, which stimulated genital sniffing, mounting, and reduced aggression, bladder urine was ineffective. Genital sniffing and mounting was stimulated by estradiol-17 beta, vaginal fluids, and preputial extract. Aggression was reduced by estradiol-17 beta, urethral catheterized urine, and vaginal fluids. Preputialectomy reduced, but did not eliminate, urinary stimulation of genital sniffing and mounting. Preputial extract stimulated aggression. Urogenital substances from ovariectomized females were ineffective in reducing attacks and stimulating genital sniffs and mounts. It was concluded that the ovarian-dependent chemosignals in the urine voided by estrous females are contributed by the urethra, vagina, and preputial gland, perhaps in part through the excretion of unconjugated estrogens. 相似文献
88.
Serotonergic and opiate interactions in the modulation of drug- and environmental-induced analgesia were assessed in 6-day-old Sprague-Dawley-derived rat pups using tail-flick testing procedures. In these experiments the serotonergic antagonist metergoline was observed to attenuate both the analgesia induced by the opiate agonist morphine and the analgesia induced by isolation from siblings and the dam, an environmental manipulation which has previously been shown to be associated with increases in opiate activity. In contrast, the opiate antagonist naloxone was observed to be ineffective in blocking not only analgesia induced by the serotonergic agonist quipazine, but also analgesia induced by long-term deprivation from the dam and food, a manipulation that has been previously reported to induce increases in serotonergic utilization. These results suggest that in the neonate, as in the adult, the serotonergic modulation of nociception appears to occur "downstream" from the opiate systems serving to regulate nociception following both drug- and environmental-induced alterations in pain sensitivity. Analgesia induced by long-term deprivation from food and the dam appears to be strongly related to increases in serotonergic activity and relatively unaffected by opiate antagonism, whereas analgesia induced by isolation from siblings and the dam may be related to increases in opiate activity, but modulated by serotonergic systems serving to regulate pain responsivity. Thus alterations in the environment, mediated at least in part by alterations in opiate and serotonergic activity, appear to play an important role in influencing the sensitivity of the neonate to pain stimuli. 相似文献
89.
Developmental dyslexia and word retrieval deficits 总被引:5,自引:1,他引:4
Developmental dyslexics, selected on the basis of very slow naming rates on the Rapid Automatic Naming Tasks (RAN), were compared to normal readers on oral language, picture categorization, and reading tasks. Findings indicated that the dyslexics' word retrieval deficits were one symptom of a more generalized, however subtle, oral language deficit which involved both receptive and expressive oral language functioning. The dyslexics' word retrieval problem also seemed chiefly related to language processing and not to deficits in semantic memory as there were no significant differences between dyslexics and controls on a nonverbal semantic memory task (picture categorization). In naming and identifying printed words, the dyslexics appeared to rely considerably upon the "indirect" or "assembly-of-phonology" route; they were slower in naming irregularly spelled words compared to regularly spelled words and on a lexical decision task, the dyslexics were slower in making negative decisions for "pseudohomophones" (e.g., "braik") than for other matched nonwords. Results are discussed in terms of the logogen model with some consideration of a developmental model as well. 相似文献
90.