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   1207篇
  免费   103篇
  国内免费   97篇
  2024年   2篇
  2023年   32篇
  2022年   21篇
  2021年   19篇
  2020年   61篇
  2019年   57篇
  2018年   46篇
  2017年   50篇
  2016年   34篇
  2015年   38篇
  2014年   71篇
  2013年   148篇
  2012年   49篇
  2011年   53篇
  2010年   45篇
  2009年   62篇
  2008年   66篇
  2007年   60篇
  2006年   72篇
  2005年   66篇
  2004年   62篇
  2003年   40篇
  2002年   53篇
  2001年   38篇
  2000年   33篇
  1999年   20篇
  1998年   16篇
  1997年   16篇
  1996年   9篇
  1995年   13篇
  1994年   3篇
  1993年   7篇
  1992年   10篇
  1991年   7篇
  1990年   1篇
  1989年   4篇
  1988年   1篇
  1987年   4篇
  1986年   1篇
  1985年   4篇
  1984年   3篇
  1983年   2篇
  1982年   1篇
  1980年   1篇
  1978年   1篇
  1977年   3篇
  1976年   2篇
排序方式: 共有1407条查询结果,搜索用时 46 毫秒
31.
许多行业的决策者必须在睡眠不足的状态下做出选择与判断。睡眠剥夺是睡眠不足的实验室模型, 被证明能显著影响风险决策, 但内在机制不明。基于前人研究基础提出假设模型, 即睡眠剥夺通过影响个体的反馈加工、风险感知、抑制控制、决策理性, 进而影响风险决策。拟通过实验室研究与现场研究, 采用简单赌博任务、概率折扣任务、双选择Oddball任务等研究范式, 对比睡眠剥夺前后被试在执行上述实验任务时的行为差异, 同时比较执行控制网络、奖赏网络等脑功能网络连接强度, 以及任务诱发的FRN等脑电成分在睡眠剥夺前后的变化, 进而论证上述反应被试反馈加工等心理过程的行为-脑电-脑成像指标的变化与睡眠剥夺后被试风险决策变化的关系。研究结果将科学地解释睡眠剥夺影响风险决策的内在机制, 为进一步探讨如何规避睡眠不足导致的决策失误提供理论与实证依据。  相似文献   
32.
为考察视觉空间工作记忆(working memory, WM)维持和操作的组间差异及其神经机制,本研究记录了高、低WM组完成延迟再认(维持)任务和心理旋转(操作)任务时的行为和事件相关电位数据。结果发现,在操作任务中,高WM组比低WM组的反应时显著更短;高WM组的中前额叶慢波显著更正、双侧后顶区慢波显著更负,并且两者的波幅显著负相关。在维持任务中,两组被试的反应时无显著差异;高WM组的中前额叶慢波显著更正。结果表明,高WM组的执行注意能力可能更强,能通过有效调节和分配加工资源来表征视觉信息。  相似文献   
33.
Forty male undergraduates were provoked following their ingestion of high or low doses of either alcohol or delta-9-tetrahydrocannabinol (THC). The expression of physical aggression was related to the quantity of alcohol ingested. The high dose of alcohol instigated more intense aggression than the low dose. The high dose of THC, on the other hand, did not increase aggressive behavior. In fact, it tended to produce a weak suppression effect.  相似文献   
34.
Aggression is defined as a mechanism of spacing by means of force or displays. It has evolved independently in different animal groups. The mechanisms underlying it are therefore not homologous throughout the animal kingdom. The phenomenon of aggression is so widespread, however, that strong selection pressures must be responsible for its development along analogous lines. Its most obvious functions are in competition for mates, natural resources, and territories, and in the preservation of group identity in many gregarious species. Aggression is often ritualized so that no damage is done to conspecifics. This ritualization may appear as modification of fighting into a tournament, or as the development of submissive postures which block further aggression in the opponent shortly after the onset of a potentially damaging fight. Animal aggression is preprogrammed by phylogenetic adaptation in well-defined ways, but can be modified by experience. The inborn programs involve motor patterns, innate releasing mechanisms, releasers, motivating mechanisms, and learning dispositions specific for the species. Aggression on this biological level can be observed in humans as intragroup aggression. Certain motor patterns and signals which lead to the release of aggression are universal. Some can even be found in deaf- and blind-born people, proving their innateness. A number of patterns of aggression in man are highly ritualized and - in a way analogous to that found in many animals - mechanisms of control have evolved inhibiting the killing of a conspecific. There are strong indications of the existence of motivating mechanisms within the brain, e.g., in the form of neuronal circuits, that show a degree of spontaneity. The type of destructive aggression which we call war, is a product of cultural evolution. War takes advantage of the given motivational structure of man, including his fear of strangers, which develops in every baby independently of experience and makes men inclined to form closed groups and causes them to be wary of or hostile to strangers. Based on these tendencies, man underwent a process of cultural subspeciation. Groups demarcated themselves from others by custom, erecting communication barriers. The development of languages demonstrates how fast and efficient this process is. Members of the same group, during this process, were defined as the “real man,” outsiders often were to be valued less -or even considered nonhuman. On the basis of this self-indoctrination, cultural codes of conduct developed, which allowed members of other groups to be killed when groups competed for resources. A cultural fiiter of norms was established which demanded killing under defined conditions, and was superimposed upon the biological filter of norms which inhibits the killing of a human being. This results in a conflict of norms, which is universally felt as guilt, since the biological filter of norms, though superimposed, is nonetheless working, particularly in the circumstance of a personal encounter. The more advanced the technique of armament, which allows fast and distant killing, the less the inhibitions are activated. Nonetheless, ritualizations occur on the cultural level. Warfare is sometimes ritualized and conventions are developed to prevent escalation into massacres, or the wholesale destruction of the subjugated enemy. To a great extent, this is certainly a result of our inborn moral code, If nothing like this were given to man our situation would be disastrous indeed. Whether cultural evolution will, in the future, be guided by moral maxims in accord with our human nature is a deeision men must make rationally. Although a ruthless ethnocentrism may bring advantage to a warring group, this may eventually prove fatal to mankind as a whole. In the escalating competition mankind runs the danger not only of exhausting its resources, but of destroying itself with its new weapons. If the outcome were not selfdestruction but domination by one group it would impoverish the diversity of human cultures, and thus seriously cut down man's spectrum of adaptability. War fulfills certain functions, similar to those found in animals. It is mainly a mechanism for preserving and extending one's territory, and a means of getting access to scarce resources. It is therefore dangerous to consider war merely as a pathological form of human behavior because this may distract our attention from the fact that, h order to overcome war, the functions of war have to be fulfilled by nonviolent means. Cultural evolution phenocopies biological evolution, due to similarities in the selection pressures shaping its course. This allows us to define the point of the evolutionary spiral we are at currently and to predict our future course.  相似文献   
35.
36.
An ethical conflict arises when we must performresearch in the interest of future patients,but that this may occasionally injure theinterests of today's patients.In the case of cognitively impaired persons, thequestion arises whether it is compatible withhumane healthcare not only to treat, but alsoto use these patients for research purposes.Some bioethicists and theologians haveformulated a general duty of solidarity, alsopertaining to cognitively impaired persons, as ajustification for research on these persons. Ifone examines this thesis from the theory ofjustice according to John Rawls, it is revealedthat such a duty of solidarity cannotnecessarily be extrapolated from Rawls'conception of justice. This is at least true ofRawls' difference principle, because accordingto the difference principle only those measuresare justifiable which serve the interest of therespective least well off. Those measures whichwould engender additional injury for the leastwell off could not be balanced by any utilityaccording to Rawls.However, John Rawls' difference principleis subordinate to the first principle,which is that each person has an equalright to the most extensive basic libertycompatible with the same liberty for others.These primary goods are determined by thefreedom and integrity of the person.This integrity of decisionally impaired personswould be in danger if one would abstain fromresearch and thus forego the increase inknowledge related to their disease. Thus onecould conclude, at least from Rawls' firstprinciple, that society must take on a duty toguarantee the degrees of freedom forcognitively impaired persons and thus alsosupport the efforts for their healing.  相似文献   
37.
A wide variety of forms of domination hasresulted in a highly heterogeneous health riskcategory, ``the vulnerable.' The study of healthinequities sheds light on forces thatgenerate, sustain, and alter vulnerabilities toillness, injury, suffering and death. Thispaper analyzes the case of a high-risk teenfrom a Boston ghetto that illuminatesintersections between ``race' and class in theconstruction of vulnerability in the US.Exploration of his ``wounds' helps specify howlarge-scale social and cultural forces becomeembodied as individual experience of disparatehealth risk. The case demonstrates that healthinequities would not occur if resources –employment, income, wealth, education, housing,profiling in the legal system, and health care– were more justly managed in keeping withstandards outlined in the Universal Declarationof Human Rights. Professional responses to the``wounds of vulnerability' may reveal importantaspects of who we are and what our work asscholars, practitioners, and advocates mustbecome.  相似文献   
38.
人类基因组计划之我见   总被引:5,自引:0,他引:5  
人类基因组计划是全人类一项宏伟的生物科学工程,它使人类从分子水平认识自我、认识生命、健康和疾病的本质;它极大地推动了DNA芯片技术、生物信息技术、生命科学工业的兴起与发展;开辟了后基因组时代的新纪元。生命科学研究的模式和层次正经历一场深刻的变革,同时它带给我们的影响也是史无前的,我们面临严峻的挑战。我们要把握历史机遇和民族命运。  相似文献   
39.
Not only do the writings of Nietzsche – early and late – fail to support the pedagogy of self-reformulation, this doctrine embodies what for him is worst in man and would destroy that which is higher. The pedagogy of self-reformulation is also incoherent. In contrast, Nietzsche offers a fruitful and comprehensive theory of education that, while non-democratic and contemptuous of egalitarian aspirations, emerges consistently from his metaphysics and philosophical anthropology. Whatever, then, we might think of his premises, Nietzsche’s philosophy of education represents an attractive model for those who would develop a meaningful, distinctive, and persuasive educational theory. It defines a domain of the possible and then straightforwardly states what is and is not to be done within it – and why.  相似文献   
40.
McArthur and Bishop (2004) found that people with specific language impairment (SLI) up to 14 years of age have poor behavioural frequency discrimination (FD) thresholds for 25-ms pure tones, while people with SLI upto 20 years of age have abnormal auditory N1--P2--N2 event-related potential (ERP) responses to the same tones. In the present study, we extended these findings to more complex non-speech and speech sounds by comparing younger (around 13 years) and older (around 17 years) teenagers with SLI and controls for their behavioural FD thresholds and N1-P2 ERPs to 25 and 250-ms pure tones, vowels, and non-harmonic complex tones. We found that a subgroup of people with SLI had abnormal responses to tones and vowels at the level of behaviour and the brain, and that poor processing was associated with the spectral complexity of auditory stimuli rather than their phonetic significance. We suggest that both the age of listeners and the sensitivity of psychoacoustic tasks to age-related changes in auditory skills may be crucial factors in studies of sound processing in SLI.  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