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   4141篇
  免费   225篇
  国内免费   85篇
  4451篇
  2024年   13篇
  2023年   52篇
  2022年   77篇
  2021年   105篇
  2020年   122篇
  2019年   156篇
  2018年   192篇
  2017年   204篇
  2016年   160篇
  2015年   128篇
  2014年   137篇
  2013年   501篇
  2012年   304篇
  2011年   312篇
  2010年   225篇
  2009年   122篇
  2008年   275篇
  2007年   210篇
  2006年   202篇
  2005年   137篇
  2004年   126篇
  2003年   84篇
  2002年   75篇
  2001年   43篇
  2000年   52篇
  1999年   39篇
  1998年   32篇
  1997年   17篇
  1996年   20篇
  1995年   19篇
  1994年   24篇
  1993年   17篇
  1992年   20篇
  1991年   14篇
  1990年   14篇
  1989年   19篇
  1988年   12篇
  1987年   16篇
  1986年   11篇
  1985年   13篇
  1983年   8篇
  1982年   9篇
  1981年   11篇
  1979年   10篇
  1974年   8篇
  1973年   9篇
  1972年   7篇
  1971年   10篇
  1968年   15篇
  1965年   7篇
排序方式: 共有4451条查询结果,搜索用时 62 毫秒
21.
The increasing use of digital technology-based retail services provides new opportunities for digital marketing. In this paper, we investigate how augmented reality (AR) technology can be leveraged as part of the firm's strategy. We explore the online purchase intention through AR smart glasses (ARSG), considering consumers' value assessment through a cost–benefit analysis and the influence of technical, experiential and social AR value drivers. We develop an augmented value-based adoption model addressing four main objectives: (1) Evaluate the effect of the perceived value of ARSG, (2) Evaluate the effect of immersion (experiential dimension), (3) Evaluate the effect of AR devices and technical complexity (technical dimension) and (4) Evaluate the importance of subjective norms (social dimension) on the online purchase intention through AR technology. Based on an ESIC Tech Lab experiment with two types of ARSG from market leaders and AR retail apps, the study uses survey data from 253 participants. The results suggest that the technical dimension has an ambiguous effect, with tech-complexity enhancing directly the perceived value of ARSG for online purchase while reducing the net value of consumers' economic cost–benefit analysis. We find strong evidence that the experiential and social AR dimensions (in the form of immersion and subjective norm) have a significant positive influence on consumers' purchase intention online, which are better predictors than the pure economic cost–benefit assessment (through usefulness and difficulty). Furthermore, the technical innovativeness of consumers is found to increase directly the online purchase intention through ARSG.  相似文献   
22.
自闭症谱系障碍(Autism Spectrum Disorder, ASD)表现为社会交往困难以及重复刻板兴趣或行为。社交动机理论提出ASD个体是由于社交动机缺乏导致的社交障碍。目前该理论缺乏理论元素及结构关系的系统论证, 及基于此理论的低龄ASD儿童群体的研究证据。本研究拟采用心理实验法、眼动及近红外脑成像技术, 探索低龄ASD儿童早期社交奖赏、社交定向异常眼动标记及眶额叶脑区活动的神经机制。此外, 通过音乐奖赏强化学习的干预方式改善该理论的核心元素(社交奖赏), 观测能否改善ASD儿童的社交动机。本研究的开展有望对该理论进行系统验证, 并形成改善社交行为的潜在干预方案。  相似文献   
23.
Stroke is the main cause of acquired disability in adults, and specific deficits in working memory (WM) are among the most common cognitive consequences. In neuropsychological routine, WM is most of the time investigated in the framework of the multicomponent model (Baddeley & Hitch, 1974, The psychology of learning and motivation, 47). Using a more recent theoretical WM model, the time-based resource-sharing (TBRS) model (Barrouillet et al., 2011, Psychol. Rev., 118, 175), the aim of the present study was to investigate in young post-stroke patients to which extent attentional maintenance is impaired in WM. To address this question, we discarded other factors known to directly influence WM performance, that is processing speed and short-term memory span. We proposed to 53 post-stroke patients and to 63 healthy controls a complex span paradigm in which participants were asked to alternate between the memorization of a series of images and a concurrent parity judgement task of a series of digits. To investigate the attentional maintenance processes, we manipulated the cognitive load (CL) of the concurrent task. CL effect is typically interpreted as the involvement of attentional maintenance processes. The task was adapted to each participant according to their processing speed and memory span. As expected, the results showed higher recall performance in healthy controls compared with post-stroke patients. Consistent with the literature, we also observed higher performance when the CL was low compared with high. However, the improvement in recall at low CL was smaller for post-stroke patients compared with controls, suggesting that post-stroke WM deficit could be in part due to a deficit of the attentional maintenance processes.  相似文献   
24.
S mith G. J. W., R uuth E., F ranzén G. & S jöholm L. Intermittent regressions in a serial afterimage experiment as signs of schizophrenia. Scand. J. Psychol ., 1972 , 13 , 27 33.—A group of 35 young patients suspected of schizophrenia were tested in a serial afterimage (AI) experiment and were also rated on the Rockland-Pollin scale. Subjects with high psychotic scores showed one or more regressions to immature (size-constant, positive, physiognomic) images in their Al serials, images typical of children who cannot clearly distinguish their Ails as subjective phenomena distinct from the outside world. The Al test thus indicates schizophrenics to be characterized by intermittent withdrawal into a world of experiencing the self and non-self as not clearly distinguished. Regressions were rare in two control groups.  相似文献   
25.
Summary This paper expands a new hypothesis on the causal mechanisms underlying irrelevant behaviour. It begins with a critical summary of earlier theories which attempted to explain displacement activities, but failed to predict the consistency with which certain types of behaviour are shown in stressful situations by a variety of species. Behavioural and physiological studies suggest that these behaviour patterns are closely associated with the incipient activation of sleep. The functional significance of this link and some of the causal processes which may be responsible for it are discussed. Paradoxically, however, displacement activities occur when animals are in a state of high arousal. The concept of arousal is reconsidered in the light of information theory and assumed to be closely correlated with the information processing rate in the nervous system. The relationships between neural and autonomic arousal are considered in this context. It is argued that over-arousal may occur when information handling exceeds the limited channel capacity of the system, with a consequent loss of efficiency. It is pointed out that there are mechanisms capable of controlling the information influx into the brain, and it is hypothesized that they are tied up in a feedback mechanism which regulates arousal and which involves the activation of a de-arousal system, corresponding to the neurological sleep mechanism. Displacement activities are viewed as consequences of this regulatory activation of the sleep system. This hypothesis is then compared with existing theories of displacement and its relationship with them is discussed.
Zusammenfassung Die Arbeit erweitert eine neue Hypothese über die kausalen Mechanismen, die dem übersprungverhalten zugrunde liegen. Sie beginnt mit einer kritischen Übersicht der früher vorgeschlagenen Theorien und zeigt auf, daß diese nicht die Beständigkeit, mit der gewisse Verhaltensweisen von einer Anzahl von Tierarten in Stress-Situationen gezeigt werden, erklären. Verhaltens- und physiologische Studien deuten an, daß diese Verhaltensweisen in einem engen Zusammenhang mit einer partiellen Schlafaktivierung stehen. Die funktionelle Bedeutung dieses Zusammenhanges und die möglichen physiologischen Mechanismen, die dafür verantwortlich sein könnten, werden diskutiert. Paradoxerweise werden aber Übersprungsverhalten dann gezeigt, wenn sich Tiere in einem gesteigerten Wachzustand befinden. In diesem Zusammenhang wird das Arousal-Konzept im Lichte der Informationstheorie neu beleuchtet und es wird angenommen, daß der Arousal-Zustand eines Tieres im engen Zusammenhang mit der jeweiligen Informationsverarbeitungsrate im Nervensystem steht. Die Verhältnisse zwischen neuralem und autonomischen Arousal werden diskutiert. Es wird vorgeschlagen, daß sich Überarousal dann einstellt, wenn die Informationsverarbeitungsrate die Kanalkapazität des Systems übersteigt mit einem sich daraus ergebenen Wirkungsgradverlust. Es wird darauf hingewiesen, daß es Mechanismen gibt, die den Informationsfluß in das Gehirn regeln und angenommen, daß diese innerhalb eines Rückkopplungssystems funktionieren, welches Arousal reguliert. Diese Regelung benötigt die Aktivierung eines Arousal herabsetzenden Systems, das in den neurologischen Schlafmechanismen besteht. Das Auftreten von Übersprungsverhalten wird als eine Konsequenz dieser regulatorischen Aktivierung des Schlafsystems angesehen. Die Hypothese wird dann mit den vorhandenen Übersprungsverhaltenstheorien verglichen.


The research underlying this paper has been supported by grants from the U.S. Air Force Office of Scientific Research through the European Office of Aerospace Research, the Science Research Council and the Royal Society to Professor N. Tinbergen, F. R. S. and myself. It was partly carried out at the Department of Zoology, Oxford. I am grateful to Dr. S. A. Hillyard who by revising an earlier version contributed much to whatever merits this paper has.  相似文献   
26.
27.
The direct methods of ratio estimation and magnitude estimation and the indirect method of pair comparison were used to construct scales of liberalism and conservatism. It was found ( a ) that the scales of conservatism are linearly related to each other and ( b ) those of liberalism are also linearly related to each other but with a discontinuity in the middle of the range; one linear function for the conservative statements and another for the liberal statements, with the discontinuity occurring in the middle of the subjective scale. Liberalism vs. conservatism was found to be reverse. The linear function between all kinds of scales as well as the reverse relation between liberalism vs. conservatism suggest that the continuum of political preferences is metathetic.  相似文献   
28.
This paper describes a possible near-death experience (NDE) among the Mapuche people of Chile. The individual reporting the experience was in a cataleptic-like state for two days, the experience itself occurring at the end of this period. Some common features of NDEs, such as encounters with deceased people and being sent back, are present, together with clear evidence that past and present cultural environment shape in part the content of mental experiences.This work was funded in part by the University of Chile (DTI Project Q-3064).The author thanks Editorial Andrés Bello for permissionto translate the near death account into English.  相似文献   
29.
The purpose of this study was to evaluate the role of maternal and paternal alcohol consumption as independent risk factors in postneonatal mortality. Questions on the frequency and quantity of alcoholic drinks consumed were included in a questionnaire used as part of a case-control study. Over a period of 11 months the families of 157 cases and 468 controls, matched for age and locality, were interviewed. Odds ratios and 95% confidence intervals were obtained by matched univariate analysis and by multiple conditional logistic regression. Maternal consumption during pregnancy, maternal consumption during breastfeeding and maternal consumption in the past year were not risk factors for postneonatal mortality. A multiple matched analysis did not alter these results. Matched univariate analysis of paternal alcohol consumption gave several positive results, including variables pertaining to the father's consumption in a multiple logistic regression model with traditional risk factors, which revealed that the frequency of paternal consumption in the last year, as estimated by the mother, was found to have a significant effect on postneonatal mortality.  相似文献   
30.
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