全文获取类型
收费全文 | 827篇 |
免费 | 44篇 |
国内免费 | 8篇 |
专业分类
879篇 |
出版年
2025年 | 1篇 |
2024年 | 4篇 |
2023年 | 7篇 |
2022年 | 5篇 |
2021年 | 19篇 |
2020年 | 24篇 |
2019年 | 22篇 |
2018年 | 18篇 |
2017年 | 33篇 |
2016年 | 42篇 |
2015年 | 14篇 |
2014年 | 29篇 |
2013年 | 156篇 |
2012年 | 26篇 |
2011年 | 51篇 |
2010年 | 20篇 |
2009年 | 56篇 |
2008年 | 78篇 |
2007年 | 57篇 |
2006年 | 41篇 |
2005年 | 38篇 |
2004年 | 34篇 |
2003年 | 28篇 |
2002年 | 13篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 12篇 |
1998年 | 5篇 |
1997年 | 7篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
排序方式: 共有879条查询结果,搜索用时 0 毫秒
11.
Minimally-invasive surgery (MIS) offers many benefits to patients, but is considerably more difficult to learn and perform than is open surgery. One main reason for the observed difficulty is attributable to the visuo-spatial challenges that arise in MIS, taxing the surgeons’ cognitive skills. In this contribution, we present a new approach that combines training and assistance as well as the visual and the auditory modality to help surgeons to overcome these challenges. To achieve this, our approach assumes two main components: An adaptive, individualized training component as well as a component that conveys spatial information through sound. The training component (a) specifically targets the visuo-spatial processes crucial for successful MIS performance and (b) trains surgeons in the use of the sound component. The second component is an auditory display based on a psychoacoustic sonification, which reduces and avoids some of the commonly experienced MIS challenges. Implementations of both components are described and their integration is discussed. Our approach and both of its components go beyond the current state of the art in important ways. The training component has been explicitly designed to target MIS-specific visuo-spatial skills and to allow for adaptive testing, promoting individualized learning. The auditory display is conveying spatial information in 3-D space. Our approach is the first that encompasses both training for improved mastery and reduction of cognitive challenges in MIS. This promises better tailoring of surgical skills and assistance to the needs and the capabilities of the surgeons and, thus, ultimately, increased patient safety and health. 相似文献
12.
13.
This is a quantitative study of an 11-year-old boy diagnosed with major depression who in all but one session made a sandplay. A computerized system was used to analyse the written verbalizations on four dimensions of positive and negative: emotions, contracts (psychosocial agreements, relationships, etc.), performance (behaviour) and rewards. It was hypothesized that the verbalizations made by the patient (recorded by the therapist) would become more positive and less negative during the course of therapy. The positive and negative values of the four dimensions were correlated with the session number. This was supported on two (performance & contract) of the four positive dimensions (statistically significant). The hypothesis that the negative dimensions would become less negative was supported on all four dimensions (statistically significant). Thus, six of the eight hypotheses were supported. This uninvestigated area of research illustrates verbal interactions between patient and therapist were an important aspect of sandplay therapy. Through reanalysing the sessions for quantitative content, written recording of direct quotes and observation of behaviour, data was entered into a valid and reliable coding system to quantitatively analyze the verbalizations. This analysis of verbalizations of the patient and observations made by the therapist indicates sandplay therapy is multifaceted. 相似文献
14.
Lister hooded rats were trained on a forced-sample T-maze alternation task in an environment lacking spatial landmarks. An
early study of spontaneous alternation on the T-maze had shown that rats use a "spatial sense" to select alternate maze arms
across mazes. As this phenomenon may provide a useful tool for studying the neural substrates of a directional sense, we wished
to confirm this finding on a different version of the T-maze task, with well-trained animals. We found that rats successfully
selected the appropriate maze arm when the choice phase of the task was presented on a second maze, oriented in the same direction,
and located in an adjacent room. However, choice performance fell to chance level when the second maze was oriented 90° relative
to the first. This result suggests that the rats do not simply alternate turns across the two environments, but rather that
they rely on a sense of direction that is carried across environments.
Electronic Publication 相似文献
15.
This work is divided in two papers (Part I and Part II). In Part I, we study a class of polymodal logics (herein called the class of "Rare-logics") for which the set of terms indexing the modal operators are hierarchized in two levels: the set of Boolean terms and the set of terms built upon the set of Boolean terms. By investigating different algebraic properties satisfied by the models of the Rare-logics, reductions for decidability are established by faithfully translating the Rare-logics into more standard modal logics. The main idea of the translation consists in eliminating the Boolean terms by taking advantage of the components construction and in using various properties of the classes of semilattices involved in the semantics. The novelty of our approach allows us to prove new decidability results (presented in Part II), in particular for information logics derived from rough set theory and we open new perspectives to define proof systems for such logics (presented also in Part II). 相似文献
16.
We used a spatial negative priming (SNP) paradigm to examine visual selective attention in infants and adults using eye movements as the motor selection measure. In SNP, when a previously ignored location becomes the target to be selected, responses to it are impaired, providing a measure of inhibitory selection. Each trial consisted of a prime and a probe, separated by 67, 200, or 550 ms interstimulus intervals (ISIs). In the prime, a target was accompanied by a distractor. In the probe, the target appeared either in the location formerly occupied by the distractor (ignored repetition) or in another location (control). Adults exhibited the SNP effect in all three ISI conditions, producing slower saccade latencies on ignored repetition versus control trials. The SNP effect obtained for infants only under 550 and 200 ms ISI conditions. These results suggest that important developments in visual selection are rooted in emerging inhibitory mechanisms. 相似文献
17.
Summary In spite of several attempts to explicate the relationship between a scientific hypothesis and evidence, the issue still cries for a satisfactory solution. Logical approaches to confirmation, such as the hypothetico-deductive method and the positive instance account of confirmation, are problematic because of their neglect of the semantic dimension of hypothesis confirmation. Probabilistic accounts of confirmation are no better than logical approaches in this regard. An outstanding probabilistic account of confirmation, the Bayesian approach, for instance, is found to be defective in that it treats evidence as a formal entity and this creates the problem of relevance of evidence to the hypothesis at issue, in addition to the difficulties arising from the subjective interpretation of probabilities. This essay purports to satisfy the need for a successful account of hypothesis confirmation by offering an original formulation based on the notion of instantiation of the relation urged by an hypothesis. 相似文献
18.
Orientational manoeuvres in the dark: dissociating allocentric and egocentric influences on spatial memory 总被引:2,自引:0,他引:2
Subjects in a darkroom saw an array of five phosphorescent objects on a circular table and, after a short delay, indicated which object had been moved. During the delay the subject, the table or a phosphorescent landmark external to the array was moved (a rotation about the centre of the table) either alone or together. The subject then had to indicate which one of the five objects had been moved. A fully factorial design was used to detect the use of three types of representations of object location: (i) visual snapshots; (ii) egocentric representations updated by self-motion; and (iii) representations relative to the external cue. Improved performance was seen whenever the test array was oriented consistently with any of these stored representations. The influence of representations (i) and (ii) replicates previous work. The influence of representation (iii) is a novel finding which implies that allocentric representations play a role in spatial memory, even over short distances and times. The effect of the external cue was greater when initially experienced as stable. Females out-performed males except when the array was consistent with self-motion but not visual snapshots. These results enable a simple egocentric model of spatial memory to be extended to address large-scale navigation, including the effects of allocentric knowledge, landmark stability and gender. 相似文献
19.
This study tested Annett's right-shift theory on spatial ability with two samples from China. The Vandenberg Mental Rotation Test (MRT), Edinburgh Handedness Inventory, and Family Handedness Questionnaire were administered to 266 high school students and 297 undergraduates. We found very few r++ or r-- among Chinese students. Most Chinese are either moderately right-handed or ambidextrous. Consistent with Casey's finding, we found using different methods to classify handedness leads to different conclusions. However, we did not find the effect of familial handedness that Casey found. Visual strategy is related to success on the MRT but handedness is not. 相似文献
20.