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   4211篇
  免费   224篇
  国内免费   2篇
  4437篇
  2024年   8篇
  2023年   52篇
  2022年   84篇
  2021年   108篇
  2020年   146篇
  2019年   149篇
  2018年   218篇
  2017年   233篇
  2016年   180篇
  2015年   122篇
  2014年   133篇
  2013年   549篇
  2012年   307篇
  2011年   309篇
  2010年   193篇
  2009年   113篇
  2008年   263篇
  2007年   204篇
  2006年   184篇
  2005年   119篇
  2004年   97篇
  2003年   95篇
  2002年   72篇
  2001年   42篇
  2000年   54篇
  1999年   36篇
  1998年   21篇
  1997年   20篇
  1996年   13篇
  1995年   15篇
  1994年   14篇
  1993年   13篇
  1992年   15篇
  1991年   22篇
  1990年   18篇
  1989年   18篇
  1988年   17篇
  1987年   16篇
  1986年   13篇
  1985年   14篇
  1984年   7篇
  1982年   8篇
  1981年   12篇
  1980年   8篇
  1979年   10篇
  1972年   10篇
  1971年   8篇
  1968年   9篇
  1966年   8篇
  1965年   10篇
排序方式: 共有4437条查询结果,搜索用时 0 毫秒
931.

A new density matrix renormalization group (DMRG) algorithm is presented which conserves the total spin. This is the first time that standard DMRG is extended to exploit fully the symmetries of the Hamiltonian. The obtained general procedure works for any operator, even operators that do not commute with the Hamiltonian. The new method gives substantial improvements over the standard DMRG.  相似文献   
932.
Kuba Krys  Colin A. Capaldi  Wijnand van Tilburg  Ottmar V. Lipp  Michael Harris Bond  C.‐Melanie Vauclair  L. Sam S. Manickam  Alejandra Domínguez‐Espinosa  Claudio Torres  Vivian Miu‐Chi Lun  Julien Teyssier  Lynden K. Miles  Karolina Hansen  Joonha Park  Wolfgang Wagner  Angela Arriola Yu  Cai Xing  Ryan Wise  Chien‐Ru Sun  Razi Sultan Siddiqui  Radwa Salem  Muhammad Rizwan  Vassilis Pavlopoulos  Martin Nader  Fridanna Maricchiolo  María Malbran  Gwatirera Javangwe  İdil Işık  David O. Igbokwe  Taekyun Hur  Arif Hassan  Ana Gonzalez  Márta Fülöp  Patrick Denoux  Enila Cenko  Ana Chkhaidze  Eleonora Shmeleva  Radka Antalíková  Ramadan A. Ahmed 《International journal of psychology》2018,53(Z1):21-26
Inequalities between men and women are common and well‐documented. Objective indexes show that men are better positioned than women in societal hierarchies—there is no single country in the world without a gender gap. In contrast, researchers have found that the women‐are‐wonderful effect—that women are evaluated more positively than men overall—is also common. Cross‐cultural studies on gender equality reveal that the more gender egalitarian the society is, the less prevalent explicit gender stereotypes are. Yet, because self‐reported gender stereotypes may differ from implicit attitudes towards each gender, we reanalysed data collected across 44 cultures, and (a) confirmed that societal gender egalitarianism reduces the women‐are‐wonderful effect when it is measured more implicitly (i.e. rating the personality of men and women presented in images) and (b) documented that the social perception of men benefits more from gender egalitarianism than that of women.  相似文献   
933.
The question of how mothers' and fathers' representations of attachment correlate ten years later with children's perceptions of attachment relationships was examined in a longitudinal study on Finnish families (= 42). The parents completed the Adult Attachment Interview (AAI) during the child's first year of life. At 11 years, the children filled out three scales on how secure they perceive the relationship with each parent. Parents' AAI classifications and AAI dimensions based on continuous scales were used as predictors of the preadolescents' attachment security. Regression analyses demonstrated that fathers' but not mothers' State‐of‐Mind and Experience dimensions predicted preadolescents' security of attachment to father. The discussion focuses on the predictive validity of the classical categorical versus the recently proposed continuous approach and the different roles of parents in transmitting security from one generation to another.  相似文献   
934.
The clinical presentation of multiple sclerosis (MS) with psychiatric symptoms is uncommon but it is believed that MS patients are twice as likely to be afflicted with bipolar disorder as the general population. We report two cases (mother and daughter) of MS presenting with bipolar disorder in the form of recurrent manic psychosis and whose outcome was favourable with neuroleptics and corticosteroids. In both cases we found multiple hypersignal lesions on brain magnetic resonance imaging (MRI), especially in the right frontal lobe where we observed signs of activity. Apart from clinical and radiological concordance, the patients exhibited similar class I HLA alleles and identical class II HLA alleles. We focused discussion on whether there may be a common genetic susceptibility to both illnesses or whether MS caused psychiatric manifestations. The coincidence of psychiatric and neurological symptoms in most relapses supports the second hypothesis.  相似文献   
935.
ABSTRACT. Motor disorders may occur in mild cognitive impairment (MCI) and at early stages of Alzheimer's disease (AD), particularly under divided attention conditions. We examined functional mobility in 104 older adults (42 with MCI, 26 with mild AD, and 36 cognitively healthy) using the Timed Up and Go test (TUG) under 4 experimental conditions: TUG single task, TUG plus a cognitive task, TUG plus a manual task, and TUG plus a cognitive and a manual task. Statistically significant differences in mean time of execution were found in all four experimental conditions when comparing MCI and controls (p < .001), and when comparing MCI and AD patients (p < .05). Receiver-operating characteristic curve analyses showed that all four testing conditions could differentiate the three groups (area under the curve > .8, p < .001 for MCI vs. controls; area under the curve > .7, p < .001 for MCI vs. AD). The authors conclude that functional motor deficits occurring in MCI can be assessed by the TUG test, in single or dual task modality.  相似文献   
936.
Decision making has been found to be altered in suicide attempters, but little is known of their performance in social contexts. Twenty‐seven depressed suicide attempters (DSA), 25 nonsuicidal depressed patients (DP), and 60 healthy participants (HC) were evaluated by a decision‐making task in social context . Results indicated DSA and DP obtained lower gains and invested more money with angry partners. DSA were found to invest less money than DP and HC with happy partners. DSA showed insensitivity toward rewards/punishment contingency, and they did not use the socioemotional stimuli to guide their decisions.  相似文献   
937.
938.
939.
940.
This article examines how emotional reactions to political events shape public opinion. We analyze political discussions in which people voluntarily engage online to approximate the public agenda: Online discussions offer a natural approach to the salience of political issues and the means to analyze emotional reactions as political events take place in real time. We measure shifts in emotions of the public over a period that includes 2 U.S. presidential elections, the 9/11 attacks, and the start of military action in Afghanistan and Iraq. Our findings show that emotional reactions to political events help explain approval rates for the same period, which casts novel light on the mechanisms that mediate the association between agenda setting and political evaluations.  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