全文获取类型
收费全文 | 8712篇 |
免费 | 844篇 |
国内免费 | 439篇 |
出版年
2024年 | 21篇 |
2023年 | 192篇 |
2022年 | 136篇 |
2021年 | 181篇 |
2020年 | 400篇 |
2019年 | 443篇 |
2018年 | 442篇 |
2017年 | 471篇 |
2016年 | 400篇 |
2015年 | 287篇 |
2014年 | 351篇 |
2013年 | 1209篇 |
2012年 | 169篇 |
2011年 | 305篇 |
2010年 | 263篇 |
2009年 | 349篇 |
2008年 | 400篇 |
2007年 | 438篇 |
2006年 | 431篇 |
2005年 | 361篇 |
2004年 | 334篇 |
2003年 | 250篇 |
2002年 | 212篇 |
2001年 | 161篇 |
2000年 | 118篇 |
1999年 | 136篇 |
1998年 | 113篇 |
1997年 | 89篇 |
1996年 | 65篇 |
1995年 | 67篇 |
1994年 | 49篇 |
1993年 | 48篇 |
1992年 | 42篇 |
1991年 | 20篇 |
1990年 | 20篇 |
1989年 | 28篇 |
1987年 | 20篇 |
1985年 | 139篇 |
1984年 | 128篇 |
1983年 | 104篇 |
1982年 | 90篇 |
1981年 | 70篇 |
1980年 | 75篇 |
1979年 | 67篇 |
1978年 | 96篇 |
1977年 | 56篇 |
1976年 | 42篇 |
1975年 | 31篇 |
1974年 | 24篇 |
1973年 | 28篇 |
排序方式: 共有9995条查询结果,搜索用时 15 毫秒
101.
Kevin J. Sharpe 《Zygon》1990,25(1):105-122
Abstract. David Bohm's thinking has become widely publicized since the 1982 performance of a form of the Einstein-Podolsky- Rosen (EPR) experiment. Bohm's holomovement theory, in particular, tries to explain the nonlocality that the experiment supports. Moreover, his theories are close to his metaphysical and religious thinking. Fritjof Capra's writings try something similar: supporting a theory (the bootstrap theory) because it is close to his religious beliefs. Both Bohm and Capra appear to use their religious ideas in their physics. Religion, their source for physical hypotheses, provides the motivation to develop and uphold them. 相似文献
102.
To examine whether having self-related personal goals, or rather whether positive or negative appraisal of them, is associated with subjective well-being, 311 students were asked to complete the Personal Project Analysis (PPA) and revised Beck Depression Inventory, first at the beginning of their studies, and then 2 years later. After 3 years they were asked about the use of mental health services. Two groups of students were identified: (1) those with positive self-projects and (2) those with negative self-projects. The results showed that both positive and negative self-related projects showed stability across a 2-year period, but only negative ones were prospectively predicted by earlier depressive symptomatology. Although neither positive nor negative projects predicted depressive symptomatology, both predicted the use of mental health services. 相似文献
103.
A multidisciplinary group of genetic and other professionals discuss a complex case of familial conflict over access to genetic information. One twin wishes to know the results of her deceased mother's tests for BRCA1 mutations; a second twin objects to researchers making this information available. As the case discussion unfolds, the apparent facts of this case are called into question and the lines of ethical certainty become less clear. 相似文献
104.
105.
自由回忆和线索回忆测验中的系列位置效应 总被引:3,自引:1,他引:2
本文以96个中国汉字为材料,使用自由回忆和线索回忆测验方法,对20名被试进行6组分测验和最后所有汉字的总测验。发现自由回忆分测验中存在明显的系列位置效应,总测验出现负近因现象;线索回忆分测验也表现出明显的系列位置效应,但最后的总测验没有出现负近因现象。上述结果验证了Bjork和Whitten(1974)提出的顺序或情景理论。 相似文献
106.
大学生解决物理问题的表征层次的实验研究 总被引:12,自引:1,他引:11
设计了两个实验,探讨优、差生物理问题表征层次的特点。结果表明,优、差生物理问题表征层次有差异。优生侧重于科学理论表征,表现为以物理原理分类,在科学理论表征层次上多为正向推理:差生则受初始表征的影响,以表面特征分类,在科学理论表征层次上多为逆向推理。 相似文献
107.
Shrinkage estimation of linear combinations of true scores 总被引:1,自引:0,他引:1
Nicholas T. Longford 《Psychometrika》1997,62(2):237-244
This paper is concerned with combining observed scores from sections of tests. It is demonstrated that in the presence of population information a linear combination of true scores can be estimated more efficiently than by the same linear combination of the observed scores. Three criteria for optimality are discussed, but they yield the same solution which can be described and motivated as a multivariate shrinkage estimator.Input from Eric Bradlow, Charles Lewis, and Linda Zeger is acknowledged. Research for this paper was funded by the Program Research Council (ETS). Suggestions of the Editor and of anonymous referees were instrumental in several improvements of the paper. 相似文献
108.
A similarity relation is a reflexive and symmetric binary relation between objects. Similarity is relative: it depends on the set of properties of objects used in determining their similarity or dissimilarity. A multi-modal logical language for reasoning about relative similarities is presented. The modalities correspond semantically to the upper and lower approximations of a set of objects by similarity relations corresponding to all subsets of a given set of properties of objects. A complete deduction system for the language is presented. 相似文献
109.
Cheryl A. King Steven H. Katz Neera Ghaziuddin Elena Brand Elizabeth Hill Laurie McGovern 《Journal of abnormal child psychology》1997,25(3):173-181
The Diagnostic Interview Schedule for Children (DISC-2.3) was studied in a sample of 265 adolescent inpatients to determine type and concurrent validity of depressive symptoms and depressive disorder diagnoses for different DISC-2.3 informants (parent, adolescent, both). The Children's Depression Rating Scale — Revised, Reynolds Adolescent Depression Scale (RADS), Suicide Ideation Questionnaire — Junior, Spectrum of Suicide Behavior Scale, and clinical consensus diagnoses were used to assess concurrent validity. Results indicated that (1) parents, compared to adolescents, reported a higher prevalence of all depressive symptoms with the exception of weight change; (2) DISC-2.3 depressive and suicidality symptoms were related positively to independent validating criteria for all informant conditions, suggesting good concurrent validity; (3) the DISC-2.3 both informant condition correctly identified the most depressive disorders; and (4) the parent, but not the adolescent, DISC-2.3 Informant condition contributed to the prediction of clinical consensus diagnoses of depression after taking into account RADS scores. 相似文献
110.
Craig R. Colder John E. Lochman Karen C. Wells 《Journal of abnormal child psychology》1997,25(3):251-263
Parenting practices have been previously linked to childhood symptomatology. However, little consideration has been given to the potential effect of individual differences within the child on this relation. The current study assessed the moderating effects of children's activity level and fear on relations between parenting practices and childhood aggression and depressive symptoms using a sample of 64 fourth-, and fifth-grade boys. The findings showed that poorly monitored active boys and fearful boys who were exposed to harsh discipline exhibited high levels of aggression. Boys characterized by high fear who were exposed to harsh discipline or whose parents were extremely overinvolved showed elevated levels of depressive symptoms. These findings suggest that integrating children's individual differences with parenting models enhances our understanding of the etiology of childhood symptomatology. The intervention implications of such an integration are discussed. 相似文献