全文获取类型
收费全文 | 50947篇 |
免费 | 1956篇 |
国内免费 | 28篇 |
专业分类
52931篇 |
出版年
2019年 | 638篇 |
2018年 | 888篇 |
2017年 | 953篇 |
2016年 | 951篇 |
2015年 | 714篇 |
2014年 | 795篇 |
2013年 | 4013篇 |
2012年 | 1404篇 |
2011年 | 1538篇 |
2010年 | 974篇 |
2009年 | 956篇 |
2008年 | 1323篇 |
2007年 | 1308篇 |
2006年 | 1183篇 |
2005年 | 1041篇 |
2004年 | 960篇 |
2003年 | 1001篇 |
2002年 | 973篇 |
2001年 | 1798篇 |
2000年 | 1744篇 |
1999年 | 1272篇 |
1998年 | 561篇 |
1997年 | 476篇 |
1996年 | 489篇 |
1992年 | 1079篇 |
1991年 | 1052篇 |
1990年 | 1001篇 |
1989年 | 944篇 |
1988年 | 930篇 |
1987年 | 895篇 |
1986年 | 874篇 |
1985年 | 953篇 |
1984年 | 755篇 |
1983年 | 650篇 |
1982年 | 485篇 |
1981年 | 493篇 |
1979年 | 776篇 |
1978年 | 572篇 |
1977年 | 511篇 |
1976年 | 489篇 |
1975年 | 657篇 |
1974年 | 744篇 |
1973年 | 797篇 |
1972年 | 644篇 |
1971年 | 582篇 |
1970年 | 556篇 |
1969年 | 552篇 |
1968年 | 692篇 |
1967年 | 619篇 |
1966年 | 640篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
191.
A plate-pushing task was used to measure endogenous pain in the wrist from different loci. Practical application in rehabilitation seems reasonable. 相似文献
192.
Ratings of pre-morbid intelligence level, derived from the hospital charts of 26 chronic schizophrenics, were correlated with the post-mortem brain volume measures of cortex, white matter, central grey matter, and ventricles. Contrary to hypothesis, no significant correlations were found. 相似文献
193.
This paper provides a review of recent Supreme Court decisions stemming from the implementation of voluntary AAPs that include preferential treatment as a remedy; the evidence and proof required to establish and defend against reverse discrimination claims is identified. Overall, the courts sanctioned the use of preferential treatment if it occured as part of a well-conceived AAP. However, differences were found in the manner in which the courts adjudicated Title VII and constitutional claims of preferential treatment. The discussion examines research on the potential effects of voluntary AAPs on important organizational and societal outcome variables. We conclude that the impact of AAPs is likely to be far-reaching, exerting an effect possibly well beyond the limits considered in court decisions. 相似文献
194.
195.
This article is concerned with the use of base-rate information that is derived from experience in classifying examples of a category. The basic task involved simulated medical decision making in which participants learned to diagnose hypothetical diseases on the basis of symptom information. Alternative diseases differed in their relative frequency or base rates of occurrence. In five experiments initial learning was followed by a series of transfer tests designed to index the use of base-rate information. On these tests, patterns of symptoms were presented that suggested more than one disease and were therefore ambiguous. The alternative or candidate diseases on such tests could differ in their relative frequency of occurrence during learning. For example, a symptom might be presented that had appeared with both a relatively common and a relatively rare disease. If participants are using base-rate information appropriately (according to Bayes' theorem), then they should be more likely to predict that the common disease is present than that the rare disease is present on such ambiguous tests. Current classification models differ in their predictions concerning the use of base-rate information. For example, most prototype models imply an insensitivity to base-rate information, whereas many exemplar-based classification models predict appropriate use of base-rate information. The results reveal a consistent but complex pattern. Depending on the category structure and the nature of the ambiguous tests, participants use base-rate information appropriately, ignore base-rate information, or use base-rate information inappropriately (predict that the rare disease is more likely to be present). To our knowledge, no current categorization model predicts this pattern of results. To account for these results, a new model is described incorporating the ideas of property or symptom competition and context-sensitive retrieval. 相似文献
196.
Targets related to ambiguous primes were projected to the left and right visual fields in a lexical priming experiment with stimulus onset asynchronies (SOA) of 35 and 750 msec. Right visual field results were similar to our earlier results with central projection (G. B. Simpson & C. Burgess, 1985, Journal of Experimental Psychology: Human Perception and Performance, 11, 28-39). Facilitation was found for the more frequent meaning at both SOAs and a decrease in facilitation for the less frequent meaning at the longer SOA. In contrast, left visual field results indicated a decay of facilitation for the more frequent meaning at the longer SOA, while activation for the subordinate meaning increased. Results suggest that, while automatic processing occurs in both hemispheres, only the left hemisphere engages in controlled processing of ambiguous word meanings. In addition, the present results support the idea that the right hemisphere has a special role in ambiguity resolution and that the right hemisphere lexicon possesses a richer endowment than earlier thought. 相似文献
197.
S J Behrens 《Brain and language》1988,33(1):104-127
Recent research has proposed a general prosodic disturbance associated with right hemisphere damage (RHD), one encompassing both affective and linguistic functions. The present study attempted to explore whether the ability to produce linguistic prosody was impaired in this patient population. Productions of phonemic stress tokens (e.g., Re'dcoat vs. red coa't) as well as examples of contrastive stress, or sentential emphasis (e.g., Sam hated the movie), were elicited from eight male speakers with unilateral right hemisphere CVAs and seven male control subjects. Two types of analyses were conducted on these utterances. Acoustic analysis focused on the correlates associated with word stress, namely changes in amplitude, duration, and fundamental frequency. The perceptual saliency of emerging cues to stress was also examined by presentation of test tokens to phonetically trained listeners for identification of stress placement. The patients as a group produced fewer acoustic cues to stress compared to the normal subjects, but no statistical differences were found between groups for either stress at the phrase level or at the sentence level. In the perceptual analysis, stress produced by the patient group was judged to be less salient than that for the normal group, although a high degree of variability was evident in both populations. The data suggest a spared processing mechanism for linguistic prosody in RHD speakers, thus mitigating against the view of a general dysprosody tied to RHD. 相似文献
198.
Fighting pairs of isolated DBA/2 mice showed a significant increase in tail-flick response latencies independent of whether opponents were losing or winning the combat. The effect lasted less than 10 min in both animals. Elevated pain thresholds were also found in isolates that attacked a nonaggressive conspecific, and were prevented by naltrexone (0.2 mg/kg), while a larger dose (1.0 mg/kg) inhibited the attack behavior. A small increase in pain threshold was observed after exposure of isolates to the test box alone, while isolation per se had no effect on baseline tail-flick latencies. The data demonstrate that endogenous pain suppressing systems are activated during attack and suggest that this opioid-mediated antinociception is a correlate of the isolation syndrome, reflecting enhanced arousal of the attacking animal. 相似文献
199.
D L Fisher S A Duffy C Young A Pollatsek 《Journal of experimental psychology. Human perception and performance》1988,14(2):253-266
Effects of load (i.e., the number of stimuli in the display) have been observed in multiple-frame studies using a consistent mapping of stimuli to responses (e.g., Fisher, 1982, 1984). In a series of four experiments, it is shown that these effects are not the consequence of differences across the high- and low-load conditions in either decision noise or peripheral masking. Additionally, it is shown that of two modes of limited capacity (a limited-channel and divided-capacity model) considered as possible explanations of load effects in tasks where subjects are required to locate a target, only one--the limited-channel model--is consistent with the results from all three location tasks. Finally, it is argued that the limited-channel model predicts not only the behavior observed in the four consistent-mapping experiments reported in this article but also the behavior observed in several related consistent-mapping tasks (Kleiss & Lane, 1986; Shiffrin & Gardner, 1972). 相似文献
200.
James B. Wade Ph.D. Robert P. Hart Ph.D. Donald F. Kirby M.D. Peter R. Mills M.D. 《Group》1988,12(3):172-178
This study evaluated the efficacy of the Garren-Edwards Behavior Modification Program, which uses the Garren-Edwards Gastric Bubble as an adjunct to treatment. Group therapy sessions were conducted with 23 morbidly obese subjects for 6 months on a biweekly basis. Each therapy session used a five-stage problem-solving sequence designed to facilitate adaptive behavioral alternatives. In evaluating weight change, a multivariate analysis of variance was conducted along with two preplanned orthogonal comparisons. Patients lost significant amounts of weight between initial to 3-month (p<.0001) and 3- to 6-month intervals (p<0001). A similar treatment effect was noted in an additional sample of 24 morbidly obese subjects following 3 months of treatment (p<0005). The findings support the value of longer goal-oriented programs in promoting continued weight loss. Implications for treatment process and therapist interventions prompted by this new format are discussed. 相似文献