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   7405篇
  免费   1549篇
  国内免费   6篇
  2024年   11篇
  2023年   66篇
  2022年   72篇
  2021年   176篇
  2020年   218篇
  2019年   516篇
  2018年   478篇
  2017年   589篇
  2016年   532篇
  2015年   442篇
  2014年   418篇
  2013年   1017篇
  2012年   583篇
  2011年   518篇
  2010年   427篇
  2009年   312篇
  2008年   456篇
  2007年   323篇
  2006年   325篇
  2005年   243篇
  2004年   189篇
  2003年   178篇
  2002年   173篇
  2001年   127篇
  2000年   126篇
  1999年   68篇
  1998年   28篇
  1997年   35篇
  1996年   23篇
  1995年   20篇
  1994年   21篇
  1993年   21篇
  1992年   23篇
  1991年   22篇
  1990年   24篇
  1989年   19篇
  1988年   12篇
  1987年   16篇
  1986年   12篇
  1985年   11篇
  1984年   6篇
  1982年   8篇
  1981年   9篇
  1979年   6篇
  1975年   4篇
  1974年   4篇
  1972年   5篇
  1971年   4篇
  1969年   4篇
  1966年   4篇
排序方式: 共有8960条查询结果,搜索用时 15 毫秒
101.
Growing efforts have been made to pool coronavirus data and control measures from countries and regions to compare the effectiveness of government policies. We examine whether these strategies can explain East Asia’s effective control of the COVID‐19 pandemic based on time‐series data with cross‐correlations between the Stringency Index and number of confirmed cases during the early period of outbreaks. We suggest that multidisciplinary empirical research in healthcare and social sciences, personality, and social psychology is needed for a clear understanding of how cultural values, social norms, and individual predispositions interact with policy to affect life‐saving behavioural changes in different societies.  相似文献   
102.
103.
Mixed methods refers to the use of both qualitative and quantitative approaches and methods in one study or sequentially in two or more studies. Without a mixed methods approach there is – to our minds ‐ a risk that only part of a phenomenon or experience is being explored. Our own involvement in mixed methods research has grown out of a shared interest in the concept ‘research‐practitioner’. Psychotherapy is a notoriously complex and ever‐developing field, and our growing sense has been that mixed methods research can contribute to a more complete – both broad and deep ‐ sense of knowledge and understanding.  相似文献   
104.
Background/ObjectiveThe main aim of this study was to compare coping strategies in obsessive-compulsive disorder (OCD) patients and a healthy control group during COVID-19 lockdown and to analyze the relationship with some variables which may influence results (depression, anxiety, comorbidity, subtype of obsession-compulsion). Method: There were 237 participants, 122 OCD and 115 healthy controls, aged 17-61 years old (M = 33.48, SD = 11.13). Results: Groups showed differences in the use of some adaptive strategies (positive reinterpretation, acceptance, humor) and maladaptive (denial, self-blame). Within obsessive-compulsive group, comorbidity affected the greater use of inappropriate strategies (denial, substance abuse and self-blame) while type of obsession-compulsion did not influence use. Anxiety and depression levels were related to the use of less adaptive strategies. Conclusions: These findings strengthen the need for training in the use of effective and adaptive coping strategies, making it necessary to improve clinical follow-up of these patients. It is relevant to be in contact with healthcare professionals, review medication and observe the anxiety and depression levels.  相似文献   
105.
106.
There is currently much interest in the potential impact of psychological factors on immune responses. An attempt was made to assess the effects of dominant/subordinate polarity in male mice on the cytotoxic activities of their natural-killer (NK) cells. On the basis of repeated agonistic encounters, categories of subordinate and dominat animals were selected. These animals were compared with manipulated controls (introduced to a novel test cage without an opponent on each occasion) and undisturbed controls (who remained in isolation without manipulation). In terms of NK activity, immunosuppression was observed in both dominant and subordinate categories when compared to undisturbed controls. There were, however, no differences between the fighting exposed subjects and the manipulated controls, suggesting that stress accounts for any changes. © 1994 Wiley-Liss, Inc.  相似文献   
107.
Effects of timing of social isolation on play fighting and serious fighting were studied at different ages in male golden hamsters. Litters were isolated at 21, 35, and 65 days of age, and tested in a resident-intruder paradigm. Behaviors were compared within grous and with a fourth group of socially reared conspecifics. The earlier the pups were isolated, the more they engaged in play activities. Later, in adulthood, the aggression level of the same animals was retested using the same paradigm. The three isolated groups showed a high level of aggression, with significant differences among them. When compared with socially reared subjects, a reliable difference in the level of aggression was also found. These results support the view that early social experience is important, suggesting that isolation during early critical periods of socialization has a significant impact on play fighting, whereas short periods of isolation may be enough to trigger adult agonistic behavior. © 1994 Wiley-Liss, Inc.  相似文献   
108.
This study assessed whether two types of non-aggressive “standard opponents” (“intact” and “anosmic” group-housed males) produced similar behavioral changes in isolated OF1 male mice given several experiences of victory. Experimental groups confronted either intact or anosmic opponents every two days until they had completed four encounters. The behavioral changes were recorded using a detailed ethologically inspired analysis. These changes were clearly different depending on the opponent type. When intact opponents were used, experimental subjects increased the time spent in digging, non-social exploration, explore from a distance, and attack over encounters, but showed decreased time spent in threat and a decreased latency to the first attack. In encounters with anosmic opponents, only declines in the latencies to threat and attack were noted. Moreover, the experimental groups differed in their behaviors over encounters. Those confronting intact opponents spent less time in social investigation, more time in explore from a distance and threat, and showed a shorter latencies to threat and attack than counterparts confronting anosmics. These results suggest that, although both types of “standard opponents” are similar in their non-aggressiveness, they elicit rather different behavioral responses in their adversaries. These findings provide additional support for the view that the type of opponent used in studies on intermale aggression is of paramount importance. Indeed, the use of different types of “standardized non-aggressive opponents” appears to be an important source of variability between studies. © 1994 Wiley-Liss, Inc.  相似文献   
109.
There is a frequent need to measure the degree of agreement among R observers who independently classify n subjects within K nominal or ordinal categories. The most popular methods are usually kappa-type measurements. When = 2, Cohen's kappa coefficient (weighted or not) is well known. When defined in the ordinal case while assuming quadratic weights, Cohen's kappa has the advantage of coinciding with the intraclass and concordance correlation coefficients. When > 2, there are more discrepancies because the definition of the kappa coefficient depends on how the phrase ‘an agreement has occurred’ is interpreted. In this paper, Hubert's interpretation, that ‘an agreement occurs if and only if all raters agree on the categorization of an object’, is used, which leads to Hubert's (nominal) and Schuster and Smith's (ordinal) kappa coefficients. Formulae for the large-sample variances for the estimators of all these coefficients are given, allowing the latter to illustrate the different ways of carrying out inference and, with the use of simulation, to select the optimal procedure. In addition, it is shown that Schuster and Smith's kappa coefficient coincides with the intraclass and concordance correlation coefficients if the first coefficient is also defined assuming quadratic weights.  相似文献   
110.
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