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   47326篇
  免费   930篇
  国内免费   12篇
  48268篇
  2019年   277篇
  2018年   3711篇
  2017年   3075篇
  2016年   2591篇
  2015年   527篇
  2014年   444篇
  2013年   2146篇
  2012年   1236篇
  2011年   3023篇
  2010年   2876篇
  2009年   1882篇
  2008年   2321篇
  2007年   2683篇
  2006年   569篇
  2005年   754篇
  2004年   653篇
  2003年   613篇
  2002年   575篇
  2001年   739篇
  2000年   746篇
  1999年   510篇
  1998年   300篇
  1997年   278篇
  1992年   493篇
  1991年   472篇
  1990年   486篇
  1989年   478篇
  1988年   430篇
  1987年   438篇
  1986年   465篇
  1985年   507篇
  1984年   435篇
  1983年   398篇
  1982年   302篇
  1981年   343篇
  1980年   264篇
  1979年   466篇
  1978年   333篇
  1977年   306篇
  1976年   290篇
  1975年   424篇
  1974年   471篇
  1973年   498篇
  1972年   416篇
  1971年   412篇
  1970年   388篇
  1969年   411篇
  1968年   503篇
  1967年   483篇
  1966年   465篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
171.
Aristotle considers all examples, as far as they are used as rhetorical arguments, to be inductions (Rhetoric 1, 2, 8). On the other hand, he finds it worthwhile to distinguish different kinds of examples (viz., historical example, comparison, and fable). Moreover, comparisons and fables are said to be made by the orator, whereas historical examples are not (Rhetoric 2, 20, 2s). The present article attempts to explain this opposition.A close examination of what can be meant by induction reveals that this term applies differently to historical examples and to comparisons and fables. In a broader sense, all examples can be called inductions, insofar as a certain logical relation, different from the syllogistic one, obtains between conclusion and premises. This relation, however, is unable to explain why examples can serve as arguments. Applied to historical examples only, the term induction preserves its original meaning of checking samples in a number sufficient to yield generalization. In its narrow sense, induction gives a satisfactory account of how historical examples work. As for comparisons and fables — to which induction applies in a broader sense only — Aristotle fails to explain what makes them arguments. The explanation, missing in Rhetoric 2, 20, can, however, be given according to the general lines of Aristotelian dialectics and rhetorics. The main task of comparison and fable is to elaborate a so far unconsidered middle term (M) meeting the following conditions: the hearer is prepared to agree that M applies to the subject of the conclusion and that the predicate of the conclusion applies to M. All examples make use of a general proposition from which their conclusion can be inferred. Historical examples (like real inductions) produce instances, in order to confirm a proposition previously admitted as suitable premise, provided that its truth can be proved. Comparison and fables, by introducing a new middle term, try to form a premise susceptible of being admitted without proof.
La classification des exemples d'après Aristote (Rhétorique 2,20)
  相似文献   
172.
173.
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   
174.
175.
176.
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   
177.
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   
178.
The field of applied behavior analysis has devoted considerable effort to the problem of educating America's youth. In addition to developing a wide range of procedures to improve children's academic and classroom survival skills, behavioral researchers have discussed a wide range of technological characteristics that are likely to facilitate the adoption of their procedures by educational decision-makers and practitioners. A movement to restructure American schools has become highly popularized within educational, political, and public media forums over the past several years. One general characteristic of this movement is its failure to recommend the more frequent implementation of applied behavior analysis techniques to educate America's youth. A close inspection of three global models for school reform, however, reveals notable compatibilities with the focus and goals of applied behavior analysis. Applied behavior analysts can collaborate with and contribute to the school restructuring movement by pursuing the more formal and systematic analyses of characteristics essential to the adoption process.  相似文献   
179.
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   
180.
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   
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