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   3729篇
  免费   244篇
  国内免费   1篇
  3974篇
  2023年   37篇
  2022年   42篇
  2021年   55篇
  2020年   107篇
  2019年   140篇
  2018年   165篇
  2017年   176篇
  2016年   174篇
  2015年   126篇
  2014年   150篇
  2013年   506篇
  2012年   229篇
  2011年   222篇
  2010年   135篇
  2009年   128篇
  2008年   175篇
  2007年   171篇
  2006年   167篇
  2005年   149篇
  2004年   126篇
  2003年   97篇
  2002年   121篇
  2001年   41篇
  2000年   41篇
  1999年   40篇
  1998年   40篇
  1997年   34篇
  1996年   22篇
  1995年   18篇
  1994年   21篇
  1993年   21篇
  1992年   19篇
  1991年   13篇
  1990年   13篇
  1989年   16篇
  1988年   9篇
  1987年   18篇
  1986年   11篇
  1985年   13篇
  1984年   16篇
  1983年   8篇
  1982年   13篇
  1981年   13篇
  1980年   8篇
  1979年   9篇
  1978年   8篇
  1977年   12篇
  1976年   13篇
  1975年   11篇
  1974年   8篇
排序方式: 共有3974条查询结果,搜索用时 0 毫秒
981.
This article explores the ethical concept of neutrality through use of a psychiatric clinical vignette. In this case a psychiatry resident is faced with the treatment of a patient who was found by the FBI to be in possession of child pornography. Although not accused of any other crimes, the patient was a fugitive from the law and requesting treatment for pedophilia. Faced with the pressures of limited resources and anxiety about the patient's dangerousness to others, the resident and his supervisor tried to strike a balance between the ethical principles of neutrality and beneficence. Through this vignette, the importance of neutrality, as well as how it can be compromised by other pressures such as expediency and anxiety, is explored.  相似文献   
982.
983.
The demand for genetic counseling services is increasing worldwide. This paper highlights the Australian experience of genetic counselor education and the history of the profession. The relevance of local factors, including the healthcare system, the education system and the small population in the evolution of the 1-year training programs are considered as an alternative model for emerging programs. The development of the education and training processes compared to that of other countries namely the United States of America (USA), the United Kingdom (UK) and Canada is discussed. The importance of international collaborations between the programs, to facilitate academic discussion and possible curriculum innovations, and to maintain professional understanding between genetic counselors is emphasized. Core genetic counseling competencies have been published for the UK and USA and an Australian set is proposed. In conclusion future directions are considered, including international issues around genetic counseling certification, reciprocity, and the potential for an Australian role in training genetic counselors in South East Asia.  相似文献   
984.
Recognition memory is usually regarded as a judgment based on trace strength or familiarity. But recognition may also be accomplished by constraining retrieval so that only sought after information comes to mind (source-constrained retrieval). We introduce amemory-for-foils paradigm that provides evidence for source-constrained retrieval in recognition memory (Experiment 1) and source memory (Experiment 2). In this paradigm, subjects studied words under deep or shallow encoding conditions and were given a memory test (recognition or source) that required them to discriminate between new items (foils) and either deep or shallow targets. A final recognition test was used to examine memory for the foils. In both experiments, foil memory was superior when subjects attempted to retrieve deep rather than shallow targets on the earlier test. These findings support a sourceconstrained retrieval view of cognitive control by demonstrating qualitative differences in the basis for memory performance.  相似文献   
985.
Evidence collected from rodent models of memory storage suggests that rapid forms of learning engage the involvement of multiple brain regions each of which may participate in a different component of information processing. The present study used temporary inactivation of the amygdala and hippocampus during different phases of information processing on a one-trial appetitive-conditioning task to examine how these two regions might participate in the storage of appetitive memories. Male Long Evans rats were chronically implanted into the amygdala or dorsal hippocampus and food deprived. Rats were trained on a radial maze conditioned cue preference task where training occurred in one 40-min session and testing took place 24 h later. The amygdala or hippocampus was inactivated separately with muscimol (50 ng/microl) injected immediately before or after training, or immediately before testing. Saline-injected rats displayed a conditioned preference by spending more time in the arm that previously contained food than in the arm that did not contain food. Muscimol injected into the amygdala before training or testing blocked the conditioned preference. Muscimol injected into the hippocampus immediately after training blocked the conditioned preference. These results suggest that the processing of memories may require multiple contributions from separate brain systems for at least short-term (24 h) storage. The resulting output from each system may converge on a similar downstream target to influence behavior.  相似文献   
986.
The threat of bioterrorism, the emergence of the SARS epidemic, and a recent focus on professionalism among physicians, present a timely opportunity for a review of, and renewed commitment to, physician obligations to care for patients during epidemics. The professional obligation to care for contagious patients is part of a larger "duty to treat," which historically became accepted when 1) a risk of nosocomial infection was perceived, 2) an organized professional body existed to promote the duty, and 3) the public came to rely on the duty. Physicians' responses to epidemics from the Hippocratic era to the present suggests an evolving acceptance of the professional duty to treat contagious patients, reaching a long-held peak between 1847 and the 1950's. There has been some professional retrenchment against this duty to treat in the last 40 years but, we argue, conditions favoring acceptance of the duty are met today. A renewed embrace of physicians' duty to treat patients during epidemics, despite conditions of personal risk, might strengthen medicine's relationship with society, improve society's capacity to prepare for threats such as bioterrorism and new epidemics, and contribute to the development of a more robust and meaningful medical professionalism.  相似文献   
987.
Mechanisms of belief-desire reasoning. Inhibition and bias   总被引:4,自引:0,他引:4  
Biases in reasoning can provide insight into underlying processing mechanisms. We demonstrate a new bias in children's belief-desire reasoning. Children between 4 and 8 years of age were told a story in which a character was mistaken about which of three boxes contained some object. The character wanted to go to one of the boxes, but only if it did not contain the object. In this scenario, the character would be expected to avoid the box where she falsely believed the object to be, but might go to either of the remaining boxes. Though the character was equally likely to go to either box, children were biased to predict that the character would go to the box that contained the object. In a control task, the character had the same desire but did not have a false belief; in this case, children showed no bias, choosing the two correct answers equally often. The observed pattern of bias was predicted by a developmental model of belief-desire reasoning. Competent belief-desire reasoning depends on a process of selection by inhibition in which the best belief content emerges from a set of candidates.  相似文献   
988.
989.
Auditory trace fear conditioning is a hippocampus-dependent learning task that requires animals to associate an auditory conditioned stimulus (CS) and a fear-producing shock-unconditioned stimulus (US) that are separated by an empty 20-s trace interval. Previous studies have shown that aging impairs learning performance on hippocampus-dependent tasks. This study measured heart rate (HR) and freezing fear responses to determine if aging impairs hippocampus-dependent auditory trace fear conditioning in freely moving rats. Aging and Young rats received one long-trace fear conditioning session (10 trials). Each trial consisted of a tone-CS (5 s) and a shock-US separated by an empty 20-s trace interval. The next day rats received CS-alone retention trials. Young rats showed significantly larger HR and freezing responses on the initial CS-alone retention trials compared to the Aging rats. A control group of aging rats received fear conditioning trials with a short 1-s trace interval separating the CS and US. The Aging Short-Trace Group showed HR and freezing responses on the initial CS alone retention trials that were similar to the Young Long-Trace Group, but greater than the Aging Long-Trace Group. A second aging control group received unpaired CSs and USs, and showed no HR or freezing responses on CS-alone retention trials. These data show that HR and freezing are effective measures for detecting aging-related deficits in trace fear conditioning.  相似文献   
990.
Unconscious processes, by whatever name they may be known (e.g., "subliminal," "implicit"), are invariably operationalized by the dissociation paradigm, any situation involving the dissociation between two indicators (or sets of indicators), one of availability (epsilon) and the other, of accessibility (alpha), such that, epsilon>alpha. Subliminal perception has been traditionally defined by a special case of the dissociation paradigm in which availability exceeds accessibility when accessibility is null (epsilon>alpha/alpha=0). Construct validity issues bedevil all dissociation paradigms since it is not clear what might constitute appropriate indicators that, moreover, are pure and exhaustive. Semantic and theoretic drifts in the recent literature--e.g., the confusion of different versions of the dissociation paradigm, the equation of conscious-unconscious with direct-indirect tests, and the foisting of the criterion of qualitative differences--have tended to undermine emerging theoretic parsimony. On the other hand, a crucial factor has been left out of theory development: time. Both epsilon and alpha can rise and fall over time, often asynchronously, and so dissociations may wax and wane and, even, reverse over time. Some laboratory evidence suggests that accessibility measures (e.g., d'), as they approach chance, may actually dip below chance (subchance perception). If so, d'=0 (the chance-limen or objective threshold), could be an averaging artifact of positive and negative d's. Conscious accessibility is not either-or but more or less, and variable over time.  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