全文获取类型
收费全文 | 27318篇 |
免费 | 909篇 |
国内免费 | 12篇 |
专业分类
28239篇 |
出版年
2019年 | 262篇 |
2018年 | 322篇 |
2017年 | 381篇 |
2016年 | 412篇 |
2015年 | 332篇 |
2014年 | 348篇 |
2013年 | 2062篇 |
2012年 | 672篇 |
2011年 | 695篇 |
2010年 | 436篇 |
2009年 | 451篇 |
2008年 | 645篇 |
2007年 | 595篇 |
2006年 | 535篇 |
2005年 | 519篇 |
2004年 | 476篇 |
2003年 | 492篇 |
2002年 | 512篇 |
2001年 | 708篇 |
2000年 | 690篇 |
1999年 | 490篇 |
1998年 | 262篇 |
1992年 | 491篇 |
1991年 | 482篇 |
1990年 | 470篇 |
1989年 | 470篇 |
1988年 | 422篇 |
1987年 | 438篇 |
1986年 | 468篇 |
1985年 | 505篇 |
1984年 | 434篇 |
1983年 | 401篇 |
1982年 | 304篇 |
1981年 | 334篇 |
1980年 | 268篇 |
1979年 | 462篇 |
1978年 | 338篇 |
1977年 | 307篇 |
1976年 | 295篇 |
1975年 | 424篇 |
1974年 | 486篇 |
1973年 | 507篇 |
1972年 | 421篇 |
1971年 | 418篇 |
1970年 | 392篇 |
1969年 | 410篇 |
1968年 | 500篇 |
1967年 | 485篇 |
1966年 | 463篇 |
1958年 | 255篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
161.
This article aims tt providing some conceptual tools for dealing adequately with relevance in argumentative discourse. For this purpose, argumentative relevance is defined as a functional interactional relation between certain elements in the discourse. In addition to the distinction between interpretive and evaluative relevance that can be traced in the literature, analytic relevance is introduced as an intermediary concept. In order to classify the various problems of relevance arising in interpreting, analyzing and evaluating argumentative discourse, a taxonomy is proposed in which the concept of relevance is differentiated along three co-ordinate dimensions: object, domain and aspect. With the help of this taxonomy, it can be shown that the problems of evaluative relevance with which the standard approach to fallacies cannot satisfactory deal can be more systematically approached within a pragma-dialectical framework. This is demonstrated for the argumentum and hominem, which is erroneously treated as a homogenous type of relevance fallacy in logico-centric analyses, so that cases where this is not justified must be treated as ad hoc exceptions. 相似文献
162.
163.
164.
M H Huang S S Hull R D Foreman R Lazzara S Wolf 《Integrative Physiological and Behavioral Science》1992,27(1):6-12
The shortening of the QT interval of the electrocardiogram coincident with acceleration of heart rate and vice versa has been accepted for many years as evidence that the action potential duration and hence QT are necessarily dependent on heart rate. Exceptions to this rule have been attributed to the intervention of counteracting autonomic effects. In order to test this assumption, 26 conscious dogs divided into three groups were tested during baroreceptor stimulation by a bolus injection of phenylephrine. Seventeen dogs had been used in earlier studies in which they had undergone an experimental anterior myocardial infarction with apparent full recovery. A group of those dogs underwent beta-adrenergic blockade by intravenous atenolol 30 min prior to the baroreceptor activation. To test the intactness of the baroreceptor responses in the previously infarcted dogs, a third group of nine dogs that had had no prior myocardial infarction was included. All dogs were adapted to the laboratory environment and were not sedated during experiments. Simultaneous recordings of RR, QT interval, and phasic arterial pressure were made in all dogs before and during baroreceptor stimulation. In the normal group, and the previously infarcted group that received no atenolol, baroreceptor stimulation elicited a small (8/msec), but significant prolongation of the QT associated with a nearly 50% reduction in heart rate. The QT interval of the atenolol-treated dogs, although significantly more prolonged before stimulation, remained unchanged during the reflex. The data indicate that withdrawal of ventricular sympathetic tone may prolong the QT interval, thereby confirming the role of sympathetic innervation in the control of QT.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
165.
H D Kimmel W D Kearns D E Anderson 《Integrative Physiological and Behavioral Science》1992,27(4):356-370
Two dogs received a single paired classical conditioning trial, with tone CS and 12 mA shock US. Both dogs then showed a conditioned blood pressure increase in response to the nonreinforced CS, which extinguished with additional nonreinforced presentations. The CR showed spontaneous recovery four days later, but reextinguished with additional nonreinforced presentations. The results were interpreted as not supporting Eysenck's theory of "incubation" following one-trial aversive conditioning. 相似文献
166.
Daniel D. Houlihan Robert N. Jones Howard N. Sloane Joni Cook 《Behavioral Interventions》1992,7(1):71-77
This brief report proposes an extension of the traditional Alternating Treatments Design that would be acceptable to use in hospital and residential settings where subjects are often not concurrently available. Concerns about the inability of traditional designs to work in these special situations and the emergence of a “scientist–practitioner split” are discussed. An example of how the Extended Alternating Treatments Design might be used is provided. 相似文献
167.
Howard L. Kaplan 《Behavior research methods》1992,24(2):373-384
A general way of describing multiple-choice questionnaires for on-line presentation is described. Some of the important features supported include random ordering of and sampling among questions, substitution of specific-question text into boilerplate question and response formats, a limited ability to bypass irrelevant questions, experimenter editing of response arrays, and automatic production of hard-copy versions of the questionnaire for use during computer breakdowns and for archival documentation. All editing operations on both questionnaires and response data create audit trails for future reference. 相似文献
168.
A running-wheel movement-detection method is described for use with a modified 1350 Commodore mouse and a Commodore 64, is described. The movement-detection method allows for the detection of partial revolutions and direction of movement, but requires no interface equipment. The modified running wheel is discussed as a new technique that may be useful for bridging empirical and theoretical differences between free-operant and discrete-trial runway procedures. 相似文献
169.
Bruno H. Repp 《Attention, perception & psychophysics》1992,51(1):14-32
This study investigated whether the apparent completeness of the acoustic speech signal during phonemic restoration derives from a process of auditory induction (Warren, 1984) or segregation, or whether it is an auditory illusion that accompanies the completion of an abstract phonological representation. Specifically, five experiments tested the prediction of the auditory induction (segregation) hypothesis that active perceptual restoration of an [s] noise that has been replaced with an extraneous noise would use up a portion of that noise’s high-frequency energy and consequently change the perceived pitch (timbre, brightness) of the extraneous noise. Listeners were required to compare the pitch of a target noise, which replaced a fricative noise in a sentence, with that of a probe noise preceding or following the speech. In the first two experiments, a significant tendency was found in favor of the auditory induction hypothesis, although the effect was small and may have been caused by variations in acoustic context. In the following three experiments, a larger variety of stimuli were used and context was controlled more carefully; this yielded negative results. Phoneme identification responses collected in the same experiments, as well as informal observations about the quality of the restored phoneme, suggested that restoration of a fricative phone distinct from the extraneous noise did not occur; rather, the spectrum of the extraneous noise itself influenced phoneme identification. These results suggest that the apparent auditory restoration which accompanies phonemic restoration is illusory, and that the schema-guided process of phoneme restoration does not interact with auditory processing. 相似文献
170.
In 1977 sex-trait stereotypes in Norway were measured at the young adult level and at the level of five-year-olds. At the young adult level the Adjective Check List was used, and the results were analysed according to an affective meaning scoring system, and a scoring system based on Transactional Analysis. The instrument used for children was a picture-story technique (Sex Stereotype Measure II). Persistence and change in sex-trait stereotypes were examined by replicating the study in 1987. Quantitatively, young adults' sex-trait stereotypes seemed to have changed little during the last decade, but qualitative analyses indicated that stereotypes have changed in the direction of greater favourability, activity and strength towards women and in the reverse direction towards men. The children in the 1987 sample expressed less stereotype knowledge than children in the 1977 sample concerning traits which traditionally have been ascribed to men. 相似文献