全文获取类型
收费全文 | 3804篇 |
免费 | 40篇 |
国内免费 | 10篇 |
专业分类
教育 | 2709篇 |
科学研究 | 334篇 |
各国文化 | 57篇 |
体育 | 274篇 |
综合类 | 3篇 |
文化理论 | 29篇 |
信息传播 | 448篇 |
出版年
2022年 | 35篇 |
2021年 | 54篇 |
2020年 | 105篇 |
2019年 | 132篇 |
2018年 | 162篇 |
2017年 | 161篇 |
2016年 | 152篇 |
2015年 | 106篇 |
2014年 | 146篇 |
2013年 | 935篇 |
2012年 | 124篇 |
2011年 | 112篇 |
2010年 | 116篇 |
2009年 | 101篇 |
2008年 | 104篇 |
2007年 | 99篇 |
2006年 | 81篇 |
2005年 | 47篇 |
2004年 | 46篇 |
2003年 | 59篇 |
2002年 | 53篇 |
2001年 | 54篇 |
2000年 | 44篇 |
1999年 | 32篇 |
1998年 | 29篇 |
1997年 | 31篇 |
1996年 | 39篇 |
1995年 | 29篇 |
1994年 | 30篇 |
1993年 | 43篇 |
1992年 | 27篇 |
1991年 | 42篇 |
1990年 | 21篇 |
1989年 | 36篇 |
1988年 | 21篇 |
1987年 | 31篇 |
1986年 | 16篇 |
1985年 | 30篇 |
1984年 | 25篇 |
1983年 | 25篇 |
1982年 | 33篇 |
1981年 | 19篇 |
1980年 | 22篇 |
1979年 | 27篇 |
1978年 | 23篇 |
1977年 | 17篇 |
1975年 | 15篇 |
1974年 | 15篇 |
1973年 | 19篇 |
1971年 | 16篇 |
排序方式: 共有3854条查询结果,搜索用时 15 毫秒
91.
In the KL divergence framework, the extended language modeling approach has a critical problem of estimating a query model, which is the probabilistic model that encodes the user’s information need. For query expansion in initial retrieval, the translation model had been proposed to involve term co-occurrence statistics. However, the translation model was difficult to apply, because the term co-occurrence statistics must be constructed in the offline time. Especially in a large collection, constructing such a large matrix of term co-occurrences statistics prohibitively increases time and space complexity. In addition, reliable retrieval performance cannot be guaranteed because the translation model may comprise noisy non-topical terms in documents. To resolve these problems, this paper investigates an effective method to construct co-occurrence statistics and eliminate noisy terms by employing a parsimonious translation model. The parsimonious translation model is a compact version of a translation model that can reduce the number of terms containing non-zero probabilities by eliminating non-topical terms in documents. Through experimentation on seven different test collections, we show that the query model estimated from the parsimonious translation model significantly outperforms not only the baseline language modeling, but also the non-parsimonious models. 相似文献
92.
The term mismatch problem in information retrieval is a critical problem, and several techniques have been developed, such as query expansion, cluster-based retrieval and dimensionality reduction to resolve this issue. Of these techniques, this paper performs an empirical study on query expansion and cluster-based retrieval. We examine the effect of using parsimony in query expansion and the effect of clustering algorithms in cluster-based retrieval. In addition, query expansion and cluster-based retrieval are compared, and their combinations are evaluated in terms of retrieval performance by performing experimentations on seven test collections of NTCIR and TREC. 相似文献
93.
Berent GP Kelly RR Aldersley S Schmitz KL Khalsa BK Panara J Keenan S 《Journal of deaf studies and deaf education》2007,12(1):8-24
Focus-on-form English teaching methods are designed to facilitate second-language learners' noticing of target language input, where "noticing" is an acquisitional prerequisite for the comprehension, processing, and eventual integration of new grammatical knowledge. While primarily designed for teaching hearing second-language learners, many focus-on-form methods lend themselves to visual presentation. This article reports the results of classroom research on the visually based implementation of focus-on-form methods with deaf college students learning English. Two of 3 groups of deaf students received focus-on-form instruction during a 10-week remedial grammar course; a third control group received grammatical instruction that did not involve focus-on-form methods. The 2 experimental groups exhibited significantly greater improvement in English grammatical knowledge relative to the control group. These results validate the efficacy of visually based focus-on-form English instruction for deaf students of English and set the stage for the continual search for innovative and effective English teaching methodologies. 相似文献
94.
Although religiosity promotes resilient outcomes in African American (AA) adolescents, there is a lack of research that examines the protective role of religious development in the context of stressful life events (SLEs). In 1,595 AA adolescents, a cohort-sequential design was used from ages 12 to 18 to examine subtypes of religiosity, as well as distinct developmental patterns within subtypes. The protective role of religious development was also examined in the context of SLEs. The study findings indicated two subtypes of religiosity—extrinsic and intrinsic religiosity—as well as low and high developmental patterns in the identified subtypes. Furthermore, the protective influence of extrinsic and intrinsic religiosity gradually diminished from age 12 to 18 in the context of SLEs. 相似文献
95.
Hae Yeon Lee Jeremy P. Jamieson Adriana S. Miu Robert A. Josephs David S. Yeager 《Child development》2019,90(6):e849-e867
Grades often decline during the high school transition, creating stress. The present research integrates the biopsychosocial model of challenge and threat with the implicit theories model to understand who shows maladaptive stress responses. A diary study measured declines in grades in the first few months of high school: salivary cortisol (N = 360 students, N = 3,045 observations) and daily stress appraisals (N = 499 students, N = 3,854 observations). Students who reported an entity theory of intelligence (i.e., the belief that intelligence is fixed) showed higher cortisol when grades were declining. Moreover, daily academic stressors showed a different lingering effect on the next day's cortisol for those with different implicit theories. Findings support a process model through which beliefs affect biological stress responses during difficult adolescent transitions. 相似文献
96.
Yoo Sung-Sang Mosrur Ridwanul Lee Eunhye Andrea Diego Toca 《Asia Pacific Education Review》2019,20(2):259-272
Asia Pacific Education Review - The correlation between education and development, with time, went through many changes along with the changes of perspectives. Since both of these concepts... 相似文献
97.
Action learning differentiates itself from other inquiry‐based learning approaches in that it requires learners to take actions based on project outcomes. While implementing their plans and reflecting on consequences of their actions, learners are given more and varied learning opportunities. Despite the apparent benefits of action learning, it entails a more complex process and a higher level of involvement from top management than do ordinary training programs. This article seeks to identify benefits and limitations of action learning and proposes a process model that enhances its benefits and helps to overcome its limitations. Thirty‐one research studies from academic journals were reviewed to identify espoused benefits and limitations of action learning. Those findings were used as the foundation for development of the PAIR model. 相似文献
98.
99.
Using a sample of 100 behavior disordered male adolescents, correlations between the Wechsler Intelligence Scale for Children-Revised (WISC-R) and the Woodcock-Johnson Tests of Cognitive Abilities (WJTCA) were computed. All WISC-R subtests correlated with the W-J Broad Cognitive Ability score at the .0001 level. Analysis of the forward selection multiple regression procedure resulted in the inclusion of only WISC-R Verbal subtests for the first six steps. Implications of such results were discussed and a predictive equation reported. 相似文献
100.
O'Connor H Olds T Maughan RJ;International Association of Athletics Federations 《Journal of sports sciences》2007,25(Z1):S49-S60
Evidence of the importance of physique in the athletics disciplines is supported by the persistence of certain characteristics over long periods, despite marked secular changes in the source population. These characteristics may also result in physiological benefits such as effective thermoregulation or a greater power-to-weight ratio. Coaches and athletes are often convinced of weight or fat loss benefits based on personal or anecdotal experience, intuition, and "trained eye" observation of successful competitors. This may entice athletes into adopting unbalanced, erratic or highly restrictive eating patterns that increase the risk for nutrient deficiencies, and disordered eating. Despite heavy training loads and often extreme diets, some athletes fall short of their physique goals as ultimately phenotype is under genetic control. Professionals assisting athletes with physique management need to be highly skilled in anthropometry and require a thorough understanding of sports-specific nutrition requirements. Careful assessment of the risks and benefits of various approaches to weight and fat loss is required before they are recommended to athletes. 相似文献