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   12575篇
  免费   588篇
  国内免费   6篇
  2023年   99篇
  2022年   139篇
  2021年   190篇
  2020年   248篇
  2019年   288篇
  2018年   425篇
  2017年   424篇
  2016年   385篇
  2015年   281篇
  2014年   307篇
  2013年   1373篇
  2012年   684篇
  2011年   692篇
  2010年   453篇
  2009年   333篇
  2008年   551篇
  2007年   456篇
  2006年   437篇
  2005年   369篇
  2004年   278篇
  2003年   275篇
  2002年   263篇
  2001年   271篇
  2000年   289篇
  1999年   208篇
  1998年   84篇
  1997年   72篇
  1996年   73篇
  1993年   73篇
  1992年   149篇
  1991年   138篇
  1990年   135篇
  1989年   122篇
  1988年   117篇
  1987年   113篇
  1986年   112篇
  1985年   122篇
  1984年   105篇
  1983年   85篇
  1979年   123篇
  1976年   73篇
  1975年   85篇
  1974年   112篇
  1973年   100篇
  1972年   89篇
  1971年   89篇
  1970年   84篇
  1969年   92篇
  1968年   86篇
  1967年   96篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
941.
This work extend to residuated lattices the results of [7]. It also provides a possible generalization to this context of frontal operators in the sense of [9]. Let L be a residuated lattice, and f : L k ?? L a function. We give a necessary and sufficient condition for f to be compatible with respect to every congruence on L. We use this characterization of compatible functions in order to prove that the variety of residuated lattices is locally affine complete. We study some compatible functions on residuated lattices which are a generalization of frontal operators. We also give conditions for two operations P(x, y) and Q(x, y) on a residuated lattice L which imply that the function ${x \mapsto min\{y \in L : P(x, y) \leq Q(x, y)\}}$ when defined, is equational and compatible. Finally we discuss the affine completeness of residuated lattices equipped with some additional operators.  相似文献   
942.
The literature on quantum logic emphasizes that the algebraic structures involved with orthodox quantum mechanics are non distributive. In this paper we develop a particular algebraic structure, the quasi-lattice ( \mathfrakI{\mathfrak{I}}-lattice), which can be modeled by an algebraic structure built in quasi-set theory \mathfrakQ{\mathfrak{Q}} . This structure is non distributive and involve indiscernible elements. Thus we show that in taking into account indiscernibility as a primitive concept, the quasi-lattice that ‘naturally’ arises is non distributive.  相似文献   
943.
The present paper offers a reflection on school textbooks produced and introduced by the Palestinian Authority in the West Bank and Gaza Strip from the year 2000 onward. The aim is to examine the debates over these textbooks, by situating them over the backdrop of larger geopolitical dynamics and intra-Palestinian social and political struggles.  相似文献   
944.
945.
The purpose of this study was to examine the effects of expertise on motion anticipation. We conducted 2 experiments in which novices and expert pilots viewed simulated aircraft landing scenes. The scenes were interrupted by the display of a black screen and then started again after a forward or backward shift. The participant's task was to determine whether the moving scene had been shifted forward or backward. A forward misjudgment of the final position of the moving scene was interpreted as a representational momentum (RM) effect. Experiment 1 showed that an RM effect was detected only for experts. The lack of motion anticipation on the part of novices is a surprising result for the RM literature. It could be related to scene unfamiliarity, encoding time, or shift size. Experiment 2 was run with novices only. It was aimed at testing the potential impact of 2 factors on the RM effect: scene encoding time and shift size. As a whole, the results showed that encoding time and shift size are important factors in anticipation processes in realistic dynamic situations.  相似文献   
946.
The present study assessed preferential attentional processing of animal fear-relevant stimuli in two procedures, Search and Interference tasks, which have been suggested to reflect on attentional capture due to the fear-relevance of the stimuli presented. In the Search task, participants (N = 154) searched fear-relevant (i.e., snakes and spiders) and non fear-relevant (i.e., fish and birds) backgrounds to determine the presence or absence of a deviant animal from the opposite category. In the Interference task, the same participants searched for the presence or absence of a neutral target (a cat) when either a snake, spider or no distracter were embedded amongst backgrounds of other animal stimuli. Replicating previous findings, preferential attentional processing of animal fear-relevant stimuli was evident in both procedures and participants who specifically feared one animal but not the other showed enhanced preferential processing of their feared fear-relevant animal. However, across the entire sample, there was no relationship between self-reported levels of animal fear and preferential processing which may reflect on the fact that substantial preferential attentional processing of fear-relevant animals was evident in the entire sample. Also, preferential attentional processing as assessed in the two tasks was not related. Delayed disengagement from fear-relevant stimuli appeared to underlie performance in the search task but not in the interference task.  相似文献   
947.
The present study used ERPs to compare processing of fear-relevant (FR) animals (snakes and spiders) and non-fear-relevant (NFR) animals similar in appearance (worms and beetles). EEG was recorded from 18 undergraduate participants (10 females) as they completed two animal-viewing tasks that required simple categorization decisions. Participants were divided on a post hoc basis into low snake/spider fear and high snake/spider fear groups. Overall, FR animals were rated higher on fear and elicited a larger LPC. However, individual differences qualified these effects. Participants in the low fear group showed clear differentiation between FR and NFR animals on subjective ratings of fear and LPC modulation. In contrast, participants in the high fear group did not show such differentiation between FR and NFR animals. These findings suggest that the salience of feared-FR animals may generalize on both a behavioural and electro-cortical level to other animals of similar appearance but of a non-harmful nature.  相似文献   
948.
To foveate a visual target, subjects usually execute a primary hypometric saccade (S1) bringing the target in perifoveal vision, followed by a corrective saccade (S2) or by more than one S2. It is still debated to what extent these S2 are pre-programmed or dependent only on post-saccadic retinal error. To answer this question, we used a visually-triggered saccade task in which target position and target visibility were manipulated. In one-third of the trials, the target was slightly displaced at S1 onset (so-called double step paradigm) and was maintained until the end of S1, until the start of the first S2 or until the end of the trial. Experiments took place in two visual environments: in the dark and in a dimly lit room with a visible random square background. The results showed that S2 were less accurate for shortest target durations. The duration of post-saccadic visual integration thus appears as the main factor responsible for corrective saccade accuracy. We also found that the visual context modulates primary saccade accuracy, especially for the most hypometric subjects. These findings suggest that the saccadic system is sensitive to the visual properties of the environment and uses different strategies to maintain final gaze accuracy.  相似文献   
949.
Adams’ thesis is generally agreed to be linguistically compelling for simple conditionals with factual antecedent and consequent. We propose a derivation of Adams’ thesis from the Lewis-Kratzer analysis of if-clauses as domain restrictors, applied to probability operators. We argue that Lewis’s triviality result may be seen as a result of inexpressibility of the kind familiar in generalized quantifier theory. Some implications of the Lewis-Kratzer analysis are presented concerning the assignment of probabilities to compounds of conditionals.  相似文献   
950.
The results of this study are part of an investigation to determine whether the cognitive-emotional process of emotional recognition is deficient as a function of the clinical condition and alexithymia in subjects with somatization. This investigation applied the self-assessment of emotion and used a procedure that minimizes the use of verbal skills and verbal comprehension. The specific goal of this study was to verify whether there were differences in the covariation between alexithymia and self-evaluation of the emotional reaction in clinical and nonclinical subjects. The results of this study highlight the significant differences between clinical and control subjects. There were inverse significant correlations with the affective valence in clinical subjects, whereas in the ratings of the TAS-20 in control subjects, there were direct correlations with activation. In the conclusions, we discuss whether the variability of the results of previous research of the relationship between alexithymia and emotional recognition is a characteristic feature of this relationship or an effect of the different sampling and procedures utilized.  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