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   5050篇
  免费   158篇
  国内免费   3篇
  2022年   48篇
  2021年   65篇
  2020年   102篇
  2019年   104篇
  2018年   183篇
  2017年   156篇
  2016年   164篇
  2015年   93篇
  2014年   105篇
  2013年   457篇
  2012年   176篇
  2011年   148篇
  2010年   109篇
  2009年   135篇
  2008年   135篇
  2007年   141篇
  2006年   115篇
  2005年   110篇
  2004年   102篇
  2003年   81篇
  2002年   82篇
  2001年   137篇
  2000年   102篇
  1999年   87篇
  1997年   48篇
  1996年   47篇
  1993年   53篇
  1992年   71篇
  1991年   75篇
  1990年   64篇
  1989年   60篇
  1988年   72篇
  1987年   64篇
  1986年   52篇
  1985年   64篇
  1984年   62篇
  1983年   57篇
  1982年   58篇
  1981年   46篇
  1979年   62篇
  1978年   63篇
  1977年   56篇
  1976年   48篇
  1975年   69篇
  1974年   61篇
  1973年   56篇
  1972年   50篇
  1971年   53篇
  1968年   50篇
  1967年   62篇
排序方式: 共有5211条查询结果,搜索用时 375 毫秒
931.
A plethora of studies on terrorism underscores the challenges of managing the psychological and behavioural impacts of terrorist events. This literature also emphasizes the idea that the global pending threat of terrorism, prior to the occurrence of any event, may also give rise to significant reactions among members of the public. Drawing from the literature on proactive coping, the current study presents the results of factor analyses performed on sections of a national survey that assessed appraisals of as well as actual responses to the threat of terrorism in Canada (N = 1,502). Findings revealed that items assessing individual response to terrorism were represented by three factors in this context: Individual Preparedness, Information Seeking, and Avoidance Behaviour. Further analyses demonstrated a tendency for actual preparedness behaviours to be associated with decreased psychological stress, and actual avoidance behaviours to be associated with heightened psychological stress. Furthermore, the divergent patterns of relationships of terrorism response appraisals and corresponding actual responses with psychological stress emphasized the need to distinguish different stages in the process of preventive coping with terrorism. Theoretical and practical implications of findings for individual preparedness in Canada are discussed.
Jennifer E. C. LeeEmail:
  相似文献   
932.
Two experiments employed experience sampling to examine the factors associated with a prospective and retrospective focus during mind wandering. Experiment One explored the contribution of working memory and indicated that participants generally prospect when the task does not require continuous monitoring. Experiment Two demonstrated that in the context of reading, interest in what was read suppressed both past and future-related task-unrelated-thought. Moreover, in disinterested individuals the temporal focus during mind wandering depended on the amount of experience with the topic matter—less experienced individuals tended to prospect, while more experienced individuals tended to retrospect. Together these results suggest that during mind wandering participants’ are inclined to prospect as long as the task does not require their undivided attention and raise the intriguing possibility that autobiographical associations with the current task environment have the potential to cue the disinterested mind.  相似文献   
933.
934.
Many studies have suggested that a word’s orthographic form must be processed before its meaning becomes available. Some interpret the (null) finding of equal facilitation after semantically transparent and opaque morphologically related primes in early stages of morphological processing as consistent with this view. Recent literature suggests that morphological facilitation tends to be greater after transparent than after opaque primes, however. To determine whether the degree of semantic transparency influences parsing into a stem and a suffix (morphological decomposition) in the forward masked priming variant of the lexical decision paradigm, we compared patterns of facilitation between semantically transparent (e.g., coolantcool) and opaque (e.g., rampantramp) prime—target pairs. Form properties of the stem (frequency, neighborhood size, and prime—target letter overlap), as well as related—unrelated and transparent—opaque affixes, were matched. Morphological facilitation was significantly greater for semantically transparent pairs than for opaque pairs. Ratings of prime—target relatedness predicted the magnitude of facilitation. The results limit the scope of form-then-meaning models of word recognition and demonstrate that semantic similarity can influence even early stages of morphological processing. The research reported here was supported by National Institute of Child Health and Development Grant HD-01994 to Haskins Laboratories.  相似文献   
935.
The ‘Wrong Kind of Reason’ problem for buck-passing theories (theories which hold that the normative is explanatorily or conceptually prior to the evaluative) is to explain why the existence of pragmatic or strategic reasons for some response to an object does not suffice to ground evaluative claims about that object. The only workable reply seems to be to deny that there are reasons of the ‘wrong kind’ for responses, and to argue that these are really reasons for wanting, trying, or intending to have that response. In support of this, it is pointed out that awareness of pragmatic or strategic considerations, unlike awareness of reasons of the ‘right kind’, are never sufficient by themselves to produce the responses for which they are reasons. I argue that this phenomenon cannot be used as a criterion for distinguishing reasons-for-a-response from reasons-for-wanting-to-have-a-response. I subsequently investigate the possibility of basing this distinction on a claim that the responses in question (e.g. admiration or desire) are themselves inherently normative; I conclude that this approach is also unsuccessful. Hence, the ‘direct response’ phenomenon cannot be used to rule out the possibility of pragmatic or strategic reasons for responses; and the rejection of such reasons therefore cannot be used to circumvent the Wrong Kind of Reason Problem.
Jennie LouiseEmail:
  相似文献   
936.
In this paper, we present an approach to transfer that involves analogical mapping of symbols across different domains. We relate this mechanism to Icarus, a theory of the human cognitive architecture. Our system can transfer skills across domains hypothesizing maps between representations, improving performance in novel domains. Unlike previous approaches to analogical transfer, our method uses an explanatory analysis that compares how well a new domain theory explains previous solutions under different mapping hypotheses. We present experimental evidence that the new mechanism improves transfer over Icarus’ basic learning processes. Moreover, we argue that the same features which distinguish Icarus from other architectures support representation mapping in a natural way and operate synergistically with it. These features enable our analogy system to translate a map among concepts into a map between skills, and to support transfer even if two domains are only partially analogous. We also discuss our system’s relation to other work on analogy and outline directions for future research.  相似文献   
937.
Computer-based diagnostic assessment systems hold potential to help teachers identify sources of poor performance and to connect teachers and students to learning activities designed to help advance students’ conceptual understandings. The present article presents findings from a study that examined how students’ performance in algebra and their overcoming of common algebraic misconceptions were affected by the use of a diagnostic assessment system that focused on important algebra concepts. This study used a four-group randomized cluster trial design in which teachers were assigned randomly to one of four groups: a “business as usual” control group, a partial intervention group that was provided with access to diagnostic tests results, a partial intervention group that was provided with access to the learning activities, and a full intervention group that was given access to the test results and learning activities. Data were collected from 905 students (6th–12th grade) nested within 44 teachers. We used hierarchical linear modeling techniques to compare the effects of full, partial, and no (control) intervention on students’ algebraic ability and misconceptions. The analyses indicate that full intervention had a net positive effect on ability and misconception measures.  相似文献   
938.
Research Ethics Boards (REBs) provide oversight for Canadians that research projects will comply with standards of ethics if the studies are carried out as described in the documents that have been approved. While REBs have traditionally been affiliated with institutions such as universities and hospitals, a number of factors - including the increased volume of research being conducted outside academic centres - have resulted in the establishment of some private or independent REBs. This, in turn, has raised concerns about the credibility of REBs in the private sector and their capacity to handle issues around conflict of interest. This Breakout Session was an opportunity to hear the perspectives of people associated with institutional and private REBs and examine perceived problems with boards in the private sector, scrutinize theoretical and structural differences between types of REBs, and look at whether or not there is room for both institutional and private boards in the Canadian research review landscape.  相似文献   
939.
This paper focuses on some of the ethical issues which may arise when conducting research in the context of homelessness. These issues are considered from the viewpoints of researchers, research coordinators and interviewers, drawing from their extensive real world experience. In addition to negotiating the complex context of homelessness, community-based homelessness researchers need to address a number of ethical issues in research conception, design, implementation and dissemination. Although these issues are commonly considered in community-engaged research, research with people who are homeless may raise exceptional challenges. Such challenges include determining the nature of informed consent; protecting research participants and researchers, and determining appropriate compensation for participation. Understanding the context of homelessness to conduct ethical research will require sharing information and joint decision-making, processes that must include members of communities within which the research participants live. Furthermore, researchers should be sensitive to the changing context of homelessness, and vigilant for new ethical challenges.  相似文献   
940.
In this article, an automated and accurate mouse observation method, based on a conventional test for motor function evaluation, is outlined. The proposed measurement technique was integrated in a regular open-field test, where the trajectory and locomotion of a free-moving mouse were measured simultaneously. The system setup consisted of a transparent cage and a camera placed below it with its lens pointing upward, allowing for images to be captured from underneath the cage while the mouse was walking on the transparent cage floor. Thus, additional information was obtained about the position of the limbs of the mice for gait reconstruction. In a first step, the camera was calibrated as soon as it was fixed in place. A linear calibration factor, relating distances in image coordinates to real-world dimensions, was determined. In a second step, the mouse was located and its body contour segmented from the image by subtracting a previously taken “background” image of the empty cage from the camera image. In a third step, the movement of the mouse was analyzed and its speed estimated from its location in the past few images. If the speed was above a 1-sec threshold, the mouse was recognized to be running, and the image was further processed for footprint recognition. In a fourth step, color filtering was applied within the recovered mouse region to measure the position of the mouse’s paws, which were visible in the image as small pink spots. Paws that were detected at the same location in a number of subsequent images were kept as footprints—that is, paws in contact with the cage floor. The footprints were classified by their position relative to the mouse’s outline as corresponding to the front left or right paw or the hind left or right paw. Finally, eight parameters were calculated from the footprint pattern to describe the locomotion of the mouse: right/left overlap, front/hind base, right/left front limb stride, and right/left hind limb stride. As an application, the system was tested using normal mice and mice displaying pentobarbital-induced ataxia. The footprint parameters measured using the proposed system showed differences of 10% to 20% between normal and ataxic mice.  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