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   3269篇
  免费   165篇
  国内免费   1篇
  2024年   8篇
  2023年   43篇
  2022年   33篇
  2021年   60篇
  2020年   70篇
  2019年   119篇
  2018年   131篇
  2017年   136篇
  2016年   151篇
  2015年   112篇
  2014年   103篇
  2013年   366篇
  2012年   206篇
  2011年   197篇
  2010年   113篇
  2009年   93篇
  2008年   149篇
  2007年   136篇
  2006年   101篇
  2005年   133篇
  2004年   120篇
  2003年   111篇
  2002年   81篇
  2001年   55篇
  2000年   59篇
  1999年   41篇
  1998年   30篇
  1997年   19篇
  1996年   28篇
  1995年   19篇
  1994年   10篇
  1993年   23篇
  1992年   22篇
  1991年   27篇
  1990年   33篇
  1989年   18篇
  1988年   26篇
  1987年   20篇
  1986年   25篇
  1985年   20篇
  1984年   24篇
  1983年   19篇
  1982年   10篇
  1979年   12篇
  1978年   12篇
  1977年   13篇
  1974年   8篇
  1973年   7篇
  1971年   7篇
  1968年   7篇
排序方式: 共有3435条查询结果,搜索用时 15 毫秒
121.
Twenty-four detoxified opiate addicts were randomized to an experimental group and a control group to evaluate efficacy of a group cue-exposure treatment to reduce or extinguish classically conditioned responses to drug-related stimuli. Assessment included psychophysiological responses (skin temperature, skin conductance level--SCL--, and heart rate) to a videotape and subjective measures (subjective craving, positive and negative affect) before and after the videotape. The experimental group received a group cue-exposure program to drug-related stimuli that comprised twelve treatment sessions administered three times weekly. The treatment program significantly reduced conditioned responses to drug-related stimuli, as measured by SCL and positive affect.  相似文献   
122.
Over the last years several European patents were opposed for protecting technology violating the morality requirement under Article 53(a) EPC. Attempts have been made by the Appeal Boards of the European Patent Office (EPO), as well as by amendments introduced into the Implementing Regulations of the European Patent Convention (EPC), to address this sensitive patentability requirement more precisely. The most recent hot topic coming up in this context is the patentability of stem cells. It is to be expected that this discussion will still go on in the field of biotechnological inventions for the next several years. An earlier version of this paper was presented at an international conference, “The Ethics of Intellectual Property Rights and Patents,” held in Warsaw, Poland on 23–24 April, 2004.  相似文献   
123.
Nanotechnology — A new field of ethical inquiry?   总被引:2,自引:0,他引:2  
Parallel to the public discussion on the benefits and risks of nanotechnology, a debate on the ethics of nanotechnology has begun. It has been postulated that a new “nano-ethics” is necessary. In this debate, the — positive as well as negative — visionary and speculative innovations which are brought into connection with nanotechnology stand in the foreground. In this contribution, an attempt is made to discover new ethical aspects of nanotechnology in a more systematic manner than has been the case. It turns out that there are hardly any completely new ethical aspects raised by nanotechnology. It is much rather primarily a case of gradual shifts of emphasis and of relevance in questions which, in principle, are already known and which give reason for ethical discussions on nanotechnology. In a certain manner, structurally novel ethical aspects arise through the important role played by visions in the public discourse. New questions are also posed by the fact that previously separate lines of ethical reflection converge in the field of nanotechnology. The proposal of an independent “nano-ethics”, however, seems exaggerated.  相似文献   
124.
125.
Weak phantasmata have a decisive and specifically transcendental function in our everyday perception. This paper provides several different arguments for this claim based on evidence from both empirical psychology and phenomenology.I would like to express my gratitude to Bill McKenna for his help with the English text and his critical remarks. This paper was presented in the Cork Roundtable for Philosophy in March 2003, at University College, Cork, and I would like to thank Julia Jansen, Tony O’Connor and the other participants for their constructive critique.  相似文献   
126.
The aims of the present review are to apply a recent risk factor approach (H. C. Kraemer et al., 1997) to putative risk factors for eating disorders, to order these along a timeline, and to deduce general taxonomic questions. Putative risk factors were classified according to risk factor type, outcome (anorexia nervosa, bulimia nervosa, binge-eating disorder, full vs. partial syndromes), and additional factor characteristics (specificity, potency, need for replication). Few of the putative risk factors were reported to precede the onset of the disorder. Many factors were general risk factors; only few differentiated between the 3 eating disorder syndromes. Common risk factors from longitudinal and cross-sectional studies were gender, ethnicity, early childhood eating and gastrointestinal problems, elevated weight and shape concerns, negative self-evaluation, sexual abuse and other adverse experiences, and general psychiatric morbidity. Suggestions are made for the conceptualization of future risk factor studies.  相似文献   
127.
High cognitive effort has been frequently related to better indices of motor learning through the study of many different paradigms. However, automaticity presumably invokes minimal cognitive processing but has often been related to high-level motor performance, which suggests a paradox. The objective of this study was to approach this paradox by examining the viability of the use of different cognitive strategies during practice and performance which promote the benefits of high cognitive effort and automaticity. Members of the university community (14 men and 15 women) divided into 3 groups practiced a discrete precision task. All participants completed four sessions totaling 320 trials and were tested on retention and transfer seven days later. Findings suggest that it is indeed possible to benefit from both effortful and minimal cognitive processing strategies and that they should be used complementarily.  相似文献   
128.
129.
The binding problem requires a solution at the level of individual neurons, but no definite mechanism has yet be given. Therefore, the neuronal level is as yet inadequate for modeling cognitive processes in which binding plays a crucial role. Moreover, the neuronal level involves too many details that are unlikely to be essential for understanding cognition. A general model of cognitive brain functioning is described in which cognitive tasks are represented in a network of cell assemblies. In the network, binding is functionally defined in a way that is compatible with the neuronal level. A computer simulation of the model clarifies how the binding of location and identity of a set of simultaneously presented letters takes place and how questions about the location and identity of the letters are answered. From the simulation of the task three predictions on the logistics of neural processes are derived: 1. When the cell assembly representing a letter participates in more than one temporary excitation loop, it will reach its critical threshold faster. At the behavioral level this means that as the number of identical letters in the display increases, responses will be faster. 2. In order to answer questions about the location and identity of presented letters cell assemblies representing the target location and the target identity have to become bound to their appropriate values. As a consequence the facilitatory effect of identical letters will be stronger if they involve the target location or the target identity than when identical non-targets are involved. 3. Negative identifications are more dependent on the presentation time of the letters than positive identifications because the excitation loops involved take more time to reach the critical threshold. Therefore, the facilitatory effect of identical letters is stronger when the external activation is relatively strong, i.e., when presentation time of the letters is sufficiently long. The reaction times obtained in three behavioral experiments support these hypotheses. Effects of binding can therefore be predicted on the basis of the general logistics of neural processes, without assumptions about a specific binding mechanism at the neuronal level.  相似文献   
130.
Participants are worse at identifying spatial symbols (arrowheads) while performing spatially compatible manual key presses. The present experiments investigated the generality of this blindness effect to response-compatible stimuli. In Experiment 1 a left key press deteriorated the identification of left-pointing arrows, and a right key press deteriorated the perception of right-pointing arrows, independent of the hands used to press the key. Thus the blindness effect is based on codes of the distal response location rather than on the body-intrinsic anatomical connection of the hands. Experiment 2 extended the blindness effect to verbal responses and written position words (left, right, up, down). Vocalizing a position word blinded to directly compatible position words (e.g., left-left), but not to orthogonally compatible position words (e.g., left-down). This result suggests that the use of identical stimulus-response codes, and not the use of saliency-matching but distinct codes, suffices to produce blindness effects. Finally, Experiment 3 extended the blindness phenomenon beyond the spatial domain by demonstrating blindness between saying color words and perceiving color patches. Altogether, the experiments revealed action-induced blindness to be a phenomenon of broad empirical validity occurring whenever action and perception afford simultaneous access to the same conceptual codes.  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