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241.
The acquisition, extinction, and subsequent recovery of conditioned fear can be influenced by the nature of the conditional stimulus (CS) and the context in which the CS is presented. The combined effects of these factors were examined in a differential fear-conditioning procedure with humans. Fear-relevant or fear-irrelevant CSs were followed by a shock unconditional stimulus (US) during acquisition and presented alone during extinction. The CSs were images presented upon different background contexts. Half the participants received the same context during acquisition and extinction and the remaining received different contexts. All participants received test trials in the same context as acquisition. In Experiment 1 (N=64), a renewal of shock expectancy and skin conductance responses was found during test for fear-relevant and fear-irrelevant CSs when extinction was given in a different context. In Experiment 2 (N=72), renewal for fear-relevant stimuli was enhanced when acquisition and test was given in an indoor office context and extinction in an outdoor bush context. The opposite context configuration produced the strongest renewal for fear-irrelevant stimuli. The return of extinguished conditioned fear can occur to fear-relevant stimuli that are commonly associated with clinical fears and its strength may be enhanced when the stimuli are encountered in certain contexts after extinction.  相似文献   
242.
Risk analysis and regulatory systems are usually evaluated according to utilitarian frameworks, as they are viewed to operate “objectively” by considering the health, environmental, and economic impacts of technological applications. Yet, the estimation of impacts during risk analysis and the decisions in regulatory review are affected by value choices of actors and stakeholders; attention to principles such as autonomy, justice, and integrity; and power relationships. In this article, case studies of biotechnology are used to illustrate how non-utilitarian principles are prominent in risk analysis and regulatory review and to argue that these relationships should be carefully considered as we consider nanotechnology oversight systems for its products. We argue that there are not distinct separations between “science-based” review systems, in which evaluations of the consequences of technological products are primarily considered, and principles of integrity, justice, non-maleficence, and autonomy. It should further be expected that, given research into fair treatment during decision-making processes, attention to ethics will affect how citizens assess emerging technologies. Finally, a more holistic approach for evaluating oversight systems for the products of nanotechnology is suggested, one which does not draw a sharp distinction between risk analysis, regulation, and respect for non-utilitarian values.
John C. BesleyEmail:
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243.
The purpose of the present study was to assess the navigational behaviour of adult humans following a disorientation procedure that perturbed their egocentric frame of reference. The assessment was carried out in a virtual reality (VR) environment by manipulating the disorientation procedure, the retention interval, the relative positions of target and landmark. The results of experiment I demonstrated that adding a physical rotation to a virtual disorientation procedure did not yield an additional decrease in searching performance. The results of experiment II showed that shortening the delay between study and test phase decreased the errors more markedly for geometric than landmark ones. An orientation specificity effect due to the manipulation of the relative position between target and landmark was discussed across the experiments. In conclusion, VR seemed to be a valuable method for studying human reorientation. Moreover, the virtual experimental setting involved here promoted knowledge of the relationship between working memory and spatial reorientation paradigm.  相似文献   
244.
A number of philosophers defend naturalistic moral realism by appeal to an externalist semantics for moral predicates. The application of semantic externalism to moral predicates has been attacked by Terence Horgan and Mark Timmons in a series of papers that make use of their “Moral Twin Earth” thought experiment. In response, several defenders of naturalistic moral realism have claimed that the Moral Twin Earth thought experiment is misleading and yields distorted and inaccurate semantic intuitions. If they are right, the intuitions generated by Moral Twin Earth cannot be appealed to in arguments against externalist moral semantics. The most developed case against the Moral Twin Earth argument that follows this strategy is found in a paper by Stephen Laurence, Eric Margolis and Angus Dawson. Here I argue that their attack on the Moral Twin Earth thought experiment fails. Laurence, Margolis and Dawson have not shown that we have reason to distrust the semantic intuitions it generates
Michael RubinEmail:
  相似文献   
245.
Using barpress conditioned suppression, we studied the renewal of conditioned fear in rats, an animal model for the relapse of human fears and phobias. We demonstrated ABA renewal when the only differences between Contexts A and B included (1) their odor, (2) their location (i.e., side of room), and (3) unintended differences between copies of the same box at the two sites. Removing either the odor or location cues abolished the renewal effect. We then directly compared the effects of ABA and AAB procedures under two levels of context similarity. Although AAB renewal occurred, ABA renewal was stronger. Adding multiple context distinctions to the three listed above did not significantly enhance either form of renewal. Finally, we directly compared the strengths of AAB, ABC, and ABA renewal. AAB renewal, though again significant, was weaker than ABA and ABC renewal, which did not differ significantly. Fear renewal (relapse) can thus be reduced by extinguishing the fear in the acquisition context, regardless of the nature of the test context.  相似文献   
246.
本研究通过变化计算机屏幕呈现的物理特性(前景和背景颜色)控制场合因素,操纵词对的呈现次数(实验一)及双字词的加工水平(实验二)控制项目强度,考察了线索相对强度与再认场合效应的关系。结果发现:(1)项目呈现次数对再认场合效应无显著影响;(2)项目加工水平对再认场合效应有显著影响,深加工项目的激活对场合效应发生了掩蔽。最后,在回顾实验设计的基础上,对上述结果的成因及潜在变量的影响进行了简要探讨。  相似文献   
247.
采用理想点方法检验生活取向测验及其修订版的单维性   总被引:2,自引:1,他引:1  
该文从项目反应过程出发,认为可能是由于原有的维度分析方法将生活取向测验(LOT)及其修订版(LOT-R)这两个测验的项目反应理想点过程错误地限定为优势过程,导致两个测验违背单维性的结论;进而采用主成分分析的未旋转成分负荷散点图和对应分析的维度分数散点图,并结合项目相关矩阵法验证LOT和LOT-R的维度。结果显示LOT-R的单维性得到了验证,LOT由于包含两个测量应对的项目而导致违背单维性。最后作者提出应该与理想点过程相一致的心理计量学模型对LOT-R的数据进行分析。  相似文献   
248.
Habituation, a decrement in response to a stimulus that is presented repeatedly without ill effect, can be identified in almost all animals. It can also be used in machine learning to provide a variety of different applications, such as novelty detection, recency encoding, and temporal signal pre-processing. This paper examines how habituation can be mathematically modelled, and discusses how well these models fit the revised characteristics of habituation. It then demonstrates how the models can be combined with neural networks in order to realise the various applications. Finally, some simple experimental results are presented that demonstrate the effectiveness of the methods.  相似文献   
249.
It is not unusual for researchers in ethnography (and sometimes Institutional Review Boards) to assume that research of “public” behavior is morally unproblematic. I examine an historical case of ethnographic research and the sustained moral outrage to the research expressed by the subjects of that research. I suggest that the moral outrage was legitimate and articulate some of the ethical issues underlying that outrage. I argue that morally problematic Ethnographic research of public behavior can derive from research practice that includes a tendency to collapse the distinction between harm and moral wrong, a failure to take account of recent work on ethical issues in privacy; failure to appreciate the deception involved in ethnographers’ failure to reveal their role as researchers to subjects and finally a failure to appropriately weigh the moral significance of issues of invasion of privacy and inflicted insight in both the research process and subsequent publication of research.
Brian SchragEmail:
  相似文献   
250.
We have two aims in this paper. The first is negative: to demonstrate the problems in Bernard Gert’s account of common morality, in particular as it applies to professional morality. The second is positive: to suggest a more satisfactory explanation of the moral basis of professional role morality, albeit one that is broadly consistent with Gert’s notion of common morality, but corrects and supplements Gert’s theory. The paper is in three sections. In the first, we sketch the main features of Gert’s account of common morality in general. In the second, we outline Gert’s explanation of the source of professional moral rules and demonstrate its inadequacy. In the third section, we provide an account of our own collectivist needs-based view of the source of the role-moral obligations of many professional roles, including those of health care professionals.
Andrew AlexandraEmail:
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