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   7301篇
  免费   297篇
  国内免费   5篇
  2023年   63篇
  2022年   74篇
  2021年   100篇
  2020年   151篇
  2019年   154篇
  2018年   242篇
  2017年   258篇
  2016年   253篇
  2015年   190篇
  2014年   231篇
  2013年   885篇
  2012年   411篇
  2011年   359篇
  2010年   221篇
  2009年   235篇
  2008年   292篇
  2007年   327篇
  2006年   256篇
  2005年   207篇
  2004年   221篇
  2003年   200篇
  2002年   155篇
  2001年   129篇
  2000年   127篇
  1999年   114篇
  1998年   75篇
  1997年   61篇
  1996年   51篇
  1995年   54篇
  1994年   55篇
  1993年   54篇
  1992年   56篇
  1991年   47篇
  1990年   70篇
  1989年   52篇
  1988年   51篇
  1987年   57篇
  1986年   62篇
  1985年   60篇
  1984年   63篇
  1983年   57篇
  1982年   40篇
  1981年   46篇
  1980年   48篇
  1979年   59篇
  1978年   49篇
  1976年   51篇
  1975年   60篇
  1974年   63篇
  1973年   46篇
排序方式: 共有7603条查询结果,搜索用时 15 毫秒
81.
82.
The investigation of enzyme activity in cerebrospinal fluid has been without relevant results for laboratories analysing spinal fluid. For neurochemical purposes, it is interesting that the Substance P is convered by Depeptidyl-aminopeptidase IV (DP IV), liberating dipeptides. The hydrolysis of nitroanilids of the form Xaa-Pro-NHNp in cerebrospinal fluid was analysed using them as peptidases substrates. Finally a method for measuring the activity was proposed.  相似文献   
83.
The somatic and psychosocial development of 80 subjects with manifest affective-phasic psychoses is studied retrospectively and compared with that of an identically sized control group consisting of neuropsychiatrically healthy subjects. Statistically significant differences were found particularly in the answers to questions dealing with social situation and social adaptability. Achievement at school and vocational qualifications were lower among the parents of the patients than among those of the healthy subjects. Characteristic features of the patients' childhood and adolescence were transient depression, often for no apparent cause, and maladaption, and vocational wishes were fulfilled less often than among the controls. The patients experienced greater difficulty in settling in to a new group due to their contact difficulties.  相似文献   
84.
This project explores what dreams might reveal about the collective psyche’s response to the COVID-19 pandemic in its first year, before the development of vaccines. A brief survey, distributed to Jungian colleagues and organizations, and to various social media sites, invited people to submit online a dream related to the COVID-19 pandemic. Four hundred and thirty-six dreams were submitted. Forty additional Russian dreams were collected and submitted by Russian colleagues. Using qualitative research methods based on phenomenological hermeneutics, the researchers categorized and counted the range of COVID imagery. In addition, the researchers describe a range of psychic responses to the pandemic, including horror, grief, sickness, social discord, and violence, but also images of healing and transformation, increased sense of community, and spiritual renewal. Several healing nightmares are presented. Healing alchemical and anima/animus imagery is described. Twelve dreams are introduced and presented. It is concluded that the collective psyche, rooted in the Self, is a healing resource for social and cultural trauma. This project supports Beradt’s (1968) inspirational study of dreaming in Nazi Germany, as well as recent studies of COVID-related dreams and recent publications on the social nature of dreaming.  相似文献   
85.
This article analyzes the relationship between competition and justice in Adam Smith in order to determine to what extent competition can promote and undermine justice. I examine how competition features in two basic motivations for human action, “the propensity to truck barter and exchange,” and “the desire of bettering our condition.” Both can be traced back to the desire for recognition, but they operate in very different ways. The former manifests itself in social cooperation, chiefly commercial exchange and the division of labor, and while it can take a competitive form, competitive success produces benefits for everyone. In contrast, the latter may manifest itself in win-lose social competition. Commercial society harnesses both motivations, and both have negative as well as positive effects. However, while Smith explicitly addresses the negative effects of excessive specialization in the division of labor, it is less clear how he thinks the negative effects of social competition can be addressed. I argue that competition can undermine justice when (i) it pits people against each other and (ii) leads to psychological corruption. I conclude with some reflections on what a focus on competition adds to our understanding of Smith's work.  相似文献   
86.
Western scholarship has underlined the relevance of social identity, perceived efficacy, emotions, and cost–benefit assessments as central catalysts of collective action. Little has been done to understand the context-sensitivity of these catalysts by means of cross-culturally comparative designs. The current study explores their context-sensitivity. It aims to find out whether existing opportunity structures in a democratic, nonrepressive country like Germany produce catalysts of collective action different from those produced in an autocratic, repressive country like Turkey. It also aims to understand the role of social media in mobilizing people in these two contexts. Semistandardized interviews with activists were carried out in both countries (n = 18 in Germany and n = 15 in Turkey) and analyzed by means of a cross-culturally comparative inductive coding procedure including initial and focused coding. Results show that collective action is related to different configurations of collective-action catalysts in the two countries. Solidarity concerns at the face of existential risks are more pronounced in Turkey, whereas political-change concerns are more important in Germany. The role of social media accordingly differs, adhering to the different activist goals. Theoretical implications for the role of context in studying collective action are discussed.  相似文献   
87.
We conducted a systematic review of research on relational sacrifices in romantic relationships from 2002 to 2021 [N = 115 studies] to answer three questions: Q1: Whose voices and vantage points are represented in the research?; Q2: What types of questions are valued?; Q3: What are the reflections and connections about relational sacrifices that were learned during the review? To address Q1, we coded sample demographics of study participants on geographical location, race/ethnicity, education/income/SES, gender (i.e., gender differences explored and beyond gender binaries), sexual orientation, age, and disability, using a coding system of 1 (exclusion/absence) to 5 (focus on context-relevant experiences for underrepresented samples). Results for Q1 showed that the most frequent codes were 1 (exclusion/absence) for information about the samples' disability status, education/income/SES, and both codes for gender (i.e., gender differences explored and beyond gender binaries); when demographic information was reported, the most frequent codes were 2 (compensatory addition) for age, sexual orientation, geographical location, and race/ethnicity. To address Q2, we coded for aspects of the study designs and conceptual dimensions of sacrifice. Results for Q2 showed that a majority of the studies in our review used quantitative and close-ended measures emphasizing behavioral frequency of sacrifice. For Q3, we include our own reflections and connections about relational sacrifices, questioning research methods, and challenging assumptions drawn from existing research to move toward a more inclusive science.  相似文献   
88.
Visual context processing was investigated in both action video game players and nonplayers using the Ebbinghaus illusion task (N = 312, 39.4% female) in a cross-sectional study design. When presented in context, players showed markedly poorer target size discrimination accuracy compared with nonplayers in the 6-, 7-, 8-, and 9-years old age groups, but this difference was reduced in 10-years old group and diminished in adults. When presented in isolation (no-context), the two groups displayed similar performance in all age groups. Furthermore, nonplayers (linear) and players (bell curve) showed profoundly different age-related differences in context processing. These findings provide evidence that players might have enhanced perceptual bias to process visual context in the transition from early childhood to early adolescence, and the differences between the two groups start at early ages and continue with distinct developmental profiles.  相似文献   
89.
Animal Cognition - The alarm calls of nonhuman primates are occasionally cited as functionally equivalent to lexical word meaning in human language. Recently, however, it has become increasingly...  相似文献   
90.
Categorical moderators are often included in mixed-effects meta-analysis to explain heterogeneity in effect sizes. An assumption in tests of categorical moderator effects is that of a constant between-study variance across all levels of the moderator. Although it rarely receives serious thought, there can be statistical ramifications to upholding this assumption. We propose that researchers should instead default to assuming unequal between-study variances when analysing categorical moderators. To achieve this, we suggest using a mixed-effects location-scale model (MELSM) to allow group-specific estimates for the between-study variance. In two extensive simulation studies, we show that in terms of Type I error and statistical power, little is lost by using the MELSM for moderator tests, but there can be serious costs when an equal variance mixed-effects model (MEM) is used. Most notably, in scenarios with balanced sample sizes or equal between-study variance, the Type I error and power rates are nearly identical between the MEM and the MELSM. On the other hand, with imbalanced sample sizes and unequal variances, the Type I error rate under the MEM can be grossly inflated or overly conservative, whereas the MELSM does comparatively well in controlling the Type I error across the majority of cases. A notable exception where the MELSM did not clearly outperform the MEM was in the case of few studies (e.g., 5). With respect to power, the MELSM had similar or higher power than the MEM in conditions where the latter produced non-inflated Type 1 error rates. Together, our results support the idea that assuming unequal between-study variances is preferred as a default strategy when testing categorical moderators.  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