全文获取类型
收费全文 | 2461篇 |
免费 | 91篇 |
国内免费 | 2篇 |
出版年
2020年 | 27篇 |
2019年 | 59篇 |
2018年 | 51篇 |
2017年 | 57篇 |
2016年 | 65篇 |
2015年 | 54篇 |
2014年 | 57篇 |
2013年 | 268篇 |
2012年 | 96篇 |
2011年 | 106篇 |
2010年 | 83篇 |
2009年 | 63篇 |
2008年 | 91篇 |
2007年 | 99篇 |
2006年 | 96篇 |
2005年 | 96篇 |
2004年 | 78篇 |
2003年 | 77篇 |
2002年 | 74篇 |
2001年 | 45篇 |
2000年 | 37篇 |
1999年 | 32篇 |
1998年 | 26篇 |
1997年 | 32篇 |
1996年 | 27篇 |
1995年 | 36篇 |
1994年 | 22篇 |
1993年 | 27篇 |
1992年 | 25篇 |
1991年 | 24篇 |
1990年 | 24篇 |
1989年 | 23篇 |
1988年 | 29篇 |
1987年 | 25篇 |
1986年 | 16篇 |
1985年 | 36篇 |
1984年 | 35篇 |
1983年 | 19篇 |
1982年 | 25篇 |
1981年 | 17篇 |
1980年 | 32篇 |
1979年 | 32篇 |
1978年 | 24篇 |
1977年 | 24篇 |
1976年 | 28篇 |
1975年 | 27篇 |
1974年 | 29篇 |
1973年 | 20篇 |
1971年 | 16篇 |
1967年 | 18篇 |
排序方式: 共有2554条查询结果,搜索用时 15 毫秒
171.
The base units of the SI include six units of continuous quantities and the mole, which is defined as proportional to the number of specified elementary entities in a sample. The existence of the mole as a unit has prompted comment in Metrologia that units of all enumerable entities should be defined though not listed as base units. In a similar vein, the BIPM defines numbers of entities as quantities of dimension one, although without admitting these entities as base units. However, there is a basic ontological distinction between continuous quantities and enumerable aggregates. The distinction is the basis of the difference between real and natural numbers. This paper clarifies the nature of the distinction: (i) in terms of a set of measurement axioms stated by H?lder; and (ii) using the formalism known in metrology as quantity calculus. We argue that a clear and unambiguous scientific distinction should be made between measurement and enumeration. We examine confusion in metrological definitions and nomenclature concerning this distinction, and discuss the implications of this distinction for ontology and epistemology in all scientific disciplines. 相似文献
172.
The misinformation effect is a well-established phenomenon in the false memory literature, although the mechanisms that underlie it are debated. In the present study, we explored one aspect of the controversy, the fate of the original memory. We began from an activation-based view of memory, capitalizing on the well-understood processes of associative priming and spreading activation, to test the hypothesis that true and suggested information can coexist in memory. After exposure to misinformation, participants were unknowingly primed with associates of either the true or a suggested item. Misled participants who were primed for the true item performed better on a final memory test than did misled participants primed for neutral information. The results indicated that true and suggested information coexist and that retrieval is influenced by each concept's activation level at test. Implications for theories of the misinformation effect were discussed. 相似文献
173.
174.
175.
176.
177.
Roxborough HM Hewitt PL Kaldas J Flett GL Caelian CM Sherry S Sherry DL 《Suicide & life-threatening behavior》2012,42(2):217-233
The role of interpersonal components of perfectionism in suicide outcomes among youth was assessed and the Perfectionism Social Disconnection Model (PSDM) was tested by determining whether the links between socially prescribed perfectionism (SPP) and perfectionistic self-presentation (PSP) and suicide outcomes are mediated by experiences of social disconnection, as indicated by social hopelessness and being bullied. PSP, trait perfectionism, suicide outcomes, and experiences of being bullied and social hopelessness were measured in 152 psychiatric outpatient children and adolescents. Correlational tests confirmed that PSP and SPP were associated with suicide outcomes and these interpersonal perfectionism components were associated significantly with bullying and social hopelessness. Support was also obtained for the PSDM. The relationship between the PSP facets, particularly nondisplay of imperfections, and suicide outcomes were mediated by being bullied. Additionally, the relationship between all interpersonal components of perfectionism and suicide risk was mediated by social hopelessness. Theoretical and clinical implications of interpersonal components of perfectionism and social disconnection in suicide outcomes for youth are discussed. 相似文献
178.
Shayna D. Cunningham Deanna L. Kerrigan Clea A. McNeely Jonathan M. Ellen 《Journal of religion and health》2011,50(2):407-421
This paper examines the activities of churches in Baltimore, Maryland, concerning the issues of sexuality, whether they potentially stigmatize persons with or at risk for HIV/AIDS, and to what extent individual agency versus institutional forces influence churches in this regard. In-depth interviews were conducted with 20 leaders from 16 churches and analyzed using a grounded theory methodology. Although many churches were involved in HIV/AIDS-related activities, the content of such initiatives was sometimes limited due to organizational constraints. Church leaders varied, however, in the extent to which they responded in accordance with or resisted these constraints, highlighting the importance of individual agency influencing churches?? responses to HIV/AIDS. 相似文献
179.
Blood GW Blood IM Tramontana GM Sylvia AJ Boyle MP Motzko GR 《Perceptual and motor skills》2011,113(2):353-364
Self-reported self-esteem, life orientation, satisfaction with life, and bullying were examined in relation to victimization experiences among 54 students who stuttered and 54 students who did not stutter. Those who stuttered reported greater, i.e., clinically significant, victimization (44.4%) than students who did not stutter (9.2%). Significant differences were found between means for self-esteem and life orientation, with students who stuttered reporting lower self-esteem and less optimistic life orientation than those who did not stutter. In both groups of students, high victimization scores had statistically significant negative correlations with optimistic life orientation, high self-esteem, and high satisfaction with life scores. Given the increased likelihood of students who stuttered being bullied, the negative relation of adjustment variables and bullying, and the potentially negative long-term effects of bullying, increased vigilance and early intervention are discussed. 相似文献
180.
Two child groups (5-6 and 8-9 years of age) participated in a challenging rule-following task while they were (a) told that they were in the presence of a watchful invisible person (“Princess Alice”), (b) observed by a real adult, or (c) unsupervised. Children were covertly videotaped performing the task in the experimenter’s absence. Older children had an easier time at following the rules but engaged in equal levels of purposeful cheating as the younger children. Importantly, children’s expressed belief in the invisible person significantly determined their cheating latency, and this was true even after controlling for individual differences in temperament. When “skeptical” children were omitted from the analysis, the inhibitory effects of being told about Princess Alice were equivalent to having a real adult present. Furthermore, skeptical children cheated only after having first behaviorally disconfirmed the “presence” of Princess Alice. The findings suggest that children’s belief in a watchful invisible person tends to deter cheating. 相似文献