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   1588篇
  免费   122篇
  2023年   19篇
  2022年   16篇
  2021年   29篇
  2020年   56篇
  2019年   43篇
  2018年   71篇
  2017年   69篇
  2016年   83篇
  2015年   67篇
  2014年   50篇
  2013年   246篇
  2012年   82篇
  2011年   93篇
  2010年   64篇
  2009年   66篇
  2008年   106篇
  2007年   80篇
  2006年   62篇
  2005年   44篇
  2004年   33篇
  2003年   50篇
  2002年   48篇
  2001年   41篇
  2000年   26篇
  1999年   18篇
  1998年   11篇
  1997年   10篇
  1996年   13篇
  1995年   6篇
  1994年   5篇
  1993年   7篇
  1991年   6篇
  1990年   6篇
  1989年   5篇
  1988年   3篇
  1986年   4篇
  1985年   6篇
  1984年   4篇
  1983年   5篇
  1982年   6篇
  1980年   3篇
  1978年   4篇
  1976年   2篇
  1975年   7篇
  1974年   2篇
  1973年   3篇
  1972年   3篇
  1971年   3篇
  1938年   3篇
  1937年   3篇
排序方式: 共有1710条查询结果,搜索用时 31 毫秒
171.
In this study we explored the temporal origin of processing differences between first and second language production. Forty highly proficient bilinguals named objects of high and low lexical frequency aloud for both L1 and L2 separately while event-related brain potentials (ERPs) were recorded. The first electrophysiological differences elicited by response language occurred at the same early P2 peak (∼140–220 ms) where we observed the onset of the lexical frequency effect, but only for those bilinguals who started naming in an L1 context and afterwards switched to an L2 naming context. The bilinguals who named objects in the reverse direction did not display a language effect in the ERPs. Taken together, the data show that the L2 naming disadvantage originates during the onset of lexical access and seems to be driven by both representational strength, which is lower for L2 words, and language control demands, which are higher for L2 words.  相似文献   
172.
173.
A theory of definitions which places the eliminability and conservativeness requirements on definitions is usually called the standard theory. We examine a persistent myth which credits this theory to Le?niewski, a Polish logician. After a brief survey of its origins, we show that the myth is highly dubious. First, no place in Le?niewski's published or unpublished work is known where the standard conditions are discussed. Second, Le?niewski's own logical theories allow for creative definitions. Third, Le?niewski's celebrated ‘rules of definition’ lay merely syntactical restrictions on the form of definitions: they do not provide definitions with such meta-theoretical requirements as eliminability or conservativeness. On the positive side, we point out that among the Polish logicians, in the 1920s and 1930s, a study of these meta-theoretical conditions is more readily found in the works of ?ukasiewicz and Ajdukiewicz.  相似文献   
174.
Abstract

Pituitary-adrenal axis was studied in terms of Type A behaviour, hostility and vital exhaustion among 69 healthy middle-aged men. The results showed that psychological factors could explain a significant proportion of the biologically manipulated responses of HPA axis, but they worked in different ways. Type A behaviour was related to a high level of mean basal ACTH and a low level of cortisol response to ACTH stimulation after dexamethasone suppression; hostility was related to a high level of mean basal cortisol and a high cortisol in cortisol/ACTH ratio, while vital exhaustion was characterized by a low level of mean basal ACTH and a decreased ACTH in relation to cortisol. The adrenocortical patterns, i.e. a high ACTH-low cortisol; a high cortisol; and a low ACTH-low mean basal cortisol, as related to Type A behaviour, hostility and exhaustion, respectively, are in line with the traditional physiological stress model and suggest that different adrenocortical responses might be able to identify different mental stress processes. Sense of control has been suggested to be a key concept for psychological understanding of this finding.  相似文献   
175.
Single-crystal (0 0 0 1) GaN samples have been deformed with a Vickers indenter at room temperature using loads in the range from 0.02 to 4.90 N. Dislocations and cracks at the indentations were examined by means of scanning electron microscopy, cathodoluminescence, light microscopy and transmission electron microscopy. Geometrical relations could be found between the dislocation arrangement, cracks and the orientation of the indenter. The orientation of the indenter has only a slight effect on the dislocation pattern, but the crack system is predominantly determined by the symmetry and the orientation of the indenter.  相似文献   
176.
This article describes a design strategy deployed in developing ultra-ductile Mg alloys based on a microalloying concept, which aims to restrict grain growth considerably during alloy casting and forming. We discuss the efficiency of the design approach, and evaluate the resulting microstructural and mechanical properties. After processing, the so-designed alloys ZQCa3 (Mg–3Zn–0.5Ag–0.25Ca–0.15Mn, in wt.%) and ZKQCa3 (Mg–3Zn–0.5Zr–0.5Ag–0.25Ca–0.15Mn, in wt.%) reveal very fine grains (<10 µm), high ductility (elongation to fracture of up to 30%) at moderate strength or high strength (ultimate tensile strength of up to 350 MPa) at reasonable ductility. These properties are explained based on thermodynamic modelling, microstructure analysis including transmission electron microscopy studies, and microstructural and mechanical testing after annealing, and are compared to a related commercial alloy (ZK31).  相似文献   
177.
Abstract

Creationism is a worldview that does not accept the undirected formation and development of life but requires intelligent (supernatural) intervention. We analyzed texts representing Young Earth creationism (YEC) and intelligent design (ID) for their theological content and implications by assessing their position in central issues of systematic theology. YEC proponents emphasize the young age of the Earth and the necessity of literal interpretation of Genesis as prerequisites for the Fall and redemption. ID accepts the geological age of the planet, but requires intervention during evolution. YEC maintained the traditional characteristics of the Christian God (omnipotence, omniscience, benevolence), while some ID authors refused to speculate on the nature of the alleged designer. YEC authors utilized reinterpretation of scientific data as evidence for creation and to legitimize their belief in the historicity of Genesis. This could be regarded a form of scientism. YEC theodicy concentrated on the Fall as the cause of evil and the eschatological resolution of suffering. In contrast, ID proponents attempted to solve theodicy by compensated benefits of, e.g., pain. ID did not take a clear stand regarding salvation and ecclesiology, but YEC authors considered the acceptance of evolutionary theory and Christian faith to be mostly inconsistent. YEC doctrine differed from major Christian denominations by accepting scientific evidence as a proof for the historicity of Genesis and showed signs of exclusivity regarding evolutionary proponents. In ID, no satisfactory theodicy could be observed and some ID theorists could be classified as agnostics because of doubting the identity of the designer and by limiting God's omnipotence and benevolence. Both YEC and ID demonized evolutionary theory and its proponents. Creationism seems to be on its way to becoming a new kind of denomination or an emerging novel religion.  相似文献   
178.
Abstract

Vertigo and dizziness may cause considerable discomfort and feelings of uncertainty. It is no surprise that vertigo is the most disabling symptom in Menière's disease, an inner ear disorder. The other two cardinal symptoms are tinnitus and hearing impairment. In this study, one severely disabled woman was treated with a cognitive-behavioural treatment comprising, among other components, relaxation training, stabilization of gaze, cognitive restructuring and behavioural task setting. The patient responded well to the treatment, during which her vertigo attacks disappeared. During the follow-up period, she experienced vertigo attacks again, but after two booster sessions the vertigo attacks vanished for the rest of the follow-up period. The results are further discussed.  相似文献   
179.
ABSTRACT

This study aimed to test the cognitive and affective benefits gained through the provision of educational materials at workstations in the Wilhelma Zoo in Stuttgart, Germany. Structured learning materials were developed for use with visiting school groups. The materials focused on the adaptations of 6 selected groups of bird species and were organized as a self-guided learning environment (workstations). The value of the materials was assessed in terms of cognitive (learning and retention) and emotional (interest, well-being, boredom, anxiety, contentedness) variables. The authors measured prior knowledge (1 week before the zoo visit), learning effect (1 week after the visit), and retention (8 to 9 weeks later). A total of 103 students (6th graders aged between 11–12 years) participated in the study, 77 receiving a treatment about adaptations in bird species and 26 receiving a treatment about reptiles which served as a control. Students had similar prior knowledge, but 1 week later students receiving the bird unit scored significantly better and this persisted into retention. Girls achieved higher scores than boys, both 1 week and 8 to 9 weeks after the visit. Surprisingly, students in the control group reported higher interest, well-being and contentedness, and lower boredom than those in the treatment group.  相似文献   
180.
Jan Almäng 《Axiomathes》2013,23(1):61-80
This paper explores the distinction between perceiving an object as extended in time, and experiencing a sequence of perceptions. I argue that this distinction cannot be adequately described by any present theory of time-consciousness and that in order to solve the puzzle, we need to consider perceptual content as having three distinct constituents: Explicit content, which has a particular phenomenal character, modal content, or the kind of content that is contributed by the psychological mode, and implicit content, which lacks phenomenal character. These notions are then further clarified and related to each other.  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