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131.
ABSTRACT

One of the main needs of Latin America, besides education coverage, is to reduce learning gaps in higher education. In order to respond to such need, many strategies have been designed, worldwide, to impact the demand and provision of higher education programs. Among these strategies we can find grants and scholarships, financial aids, and others. Many have been the options that have been proposed to raise the provision of higher education programs, such as offering technology-supported education modalities like blended-learning, Massive Open Online Courses (MOOCs), and distance and online education. This paper aims to explore the potential of the provision of distance education programs to close learning gaps in Colombia’s higher education. In order to do so, we present an estimatation of the effects that students and programs characteristics can have on the results of the test “Saber PRO” (a Colombian standardized test that measures the level of competences developed by students in different higher education programs). This estimation was done applying a mixed model (Hierarchical Linear Modeling-HLM) based on the information of 451,358 students who were assessed in their last phase of their university major. Data were collected from 2016 to 2018.

The econometrics estimations show that controlling individuals’ backgrounds and the characteristics of different academic programs, the variables that were highly associated with the reduction of learning gaps among individuals registered in distance programs compared to face-to-face programs are the students’ age and their cognitive backgrounds (grades in standardized tests taken before their undergraduate studies). The results show that we could expect distance education to become an efficient mechanism to contribute to the reduction of learning gaps in higher education. The quantitative findings suggest a series of research questions that invite to reflect about the potential of distance education in medium-income countries.  相似文献   
132.
133.
The effectiveness of query expansion methods depends essentially on identifying good candidates, or prospects, semantically related to query terms. Word embeddings have been used recently in an attempt to address this problem. Nevertheless query disambiguation is still necessary as the semantic relatedness of each word in the corpus is modeled, but choosing the right terms for expansion from the standpoint of the un-modeled query semantics remains an open issue. In this paper we propose a novel query expansion method using word embeddings that models the global query semantics from the standpoint of prospect vocabulary terms. The proposed method allows to explore query-vocabulary semantic closeness in such a way that new terms, semantically related to more relevant topics, are elicited and added in function of the query as a whole. The method includes candidates pooling strategies that address disambiguation issues without using exogenous resources. We tested our method with three topic sets over CLEF corpora and compared it across different Information Retrieval models and against another expansion technique using word embeddings as well. Our experiments indicate that our method achieves significant results that outperform the baselines, improving both recall and precision metrics without relevance feedback.  相似文献   
134.
In this study, we assessed the pre-game hydration status and fluid balance of elite young soccer players competing in a match played in the heat (temperature 31.0 ± 2.0 ° C, relative humidity 48.0 ± 5.0%) for an official Brazilian soccer competition. Fluid intake was measured during the match, as were urine specific gravity and body mass before and after the game to estimate hydration status. Data were obtained from 15 male players (age 17.0 ± 0.6 years, height 1.78 ± 0.06 m, mass 65.3 ± 3.8 kg); however, data are only analysed for 10 players who completed the full game. The mean (± s) sweat loss of players amounted to 2.24 ± 0.63 L, and mean fluid intake was 1.12 ± 0.39 L. Pre-game urine specific gravity was 1.021 ± 0.004, ranging from 1.010 to 1.025. There was no significant correlation between sweat loss and fluid intake (r = 0.504, P = 0.137) or between urine specific gravity and fluid intake (r = -0.276, P = 0.440). We conclude that young, native tropical soccer players started the match hypohydrated and replaced about 50% of the sweat lost. Thus, effective strategies to improve fluid replacement are needed for players competing in the heat.  相似文献   
135.
There is not a unique attitude towards the implementation of digital technology in educational sceneries. This paper aims to validate an adaptation of the DeLone and McLean information systems success model in the context of a learning management system. Furthermore, this study means to prove (1) the necessity of segmenting students in order to fit the model more accurately and (2) the impact of other new Internet tools on students’ perceptions with regard to learning management systems. Partial least squares has been used to analyse the measurement and the structural model. Subsequently, the Finite Mixture Partial Least Squarestechnique has been employed to examine unobserved heterogeneity and to find users’ segments. The results of this research indicate that to segment between two groups of students is especially useful in order to improve the understanding of the success of a learning management system. This segmentation is made according to the importance which the students attribute to the new Internet tools to support their learning.  相似文献   
136.
This paper reports the main findings of a study that sought to understand how teachers and department heads perceived and experienced the implementation of a classroom observation system in a teacher evaluation context. The data was collected through a teacher and department head survey and interviews with department heads who were responsible for classroom observation. The findings show that respondents regarded classroom observation as an inadequate teacher evaluation instrument. It was also viewed as one of the features of the teacher evaluation system that least contributed to the teachers’ professional development. Department heads felt torn between their intermediate management role as teacher observers and their professional role as teacher peers. Cultural norms of individual professional autonomy that regulated relations among colleagues prevented department heads from using information, gathered through classroom observation, to nourish in-depth professional discussions about concrete educational practices.  相似文献   
137.
The problem of adaptive stabilization of a class of continuous-time and time-varying nonlinear plants is treated in this paper. The control scheme guarantees that the state of the plant, with bounded time-varying parameters, asymptotically converges to zero. For the nonlinear case with n2+n unknown parameters (n time-varying and n2 constant), when the control matrix B is unknown the controller has to adjust n2+1 parameters providing only local stability results. On the contrary, when the control matrix B is known only one parameter has to be adjusted and the proposed scheme provides global stability results. The general methodology is particularized for the linear case with 2n2 unknown parameters (n2 time-varying and n2 constant), adjusting n2+1 parameters when the control matrix B is unknown and guarantees only local stability results, whereas in the case when the control matrix B is known only one parameter has to be adjusted and the proposed scheme provides global stability results.  相似文献   
138.
One of the proposals of the North American educational reform movement is that teachers should stress scientific argumentation more than the manipulation of symbols and algorithms in their mathematics instruction. The aim of this article is to apply some theoretical concepts, drawn from the fields of sociolinguistics and rhetoric, to the analysis of argumentation in a lesson conducted in an urban middle school classroom. Our analysis focuses on the implementation of the classroom teacher's instructional goals during a lesson on area measurement. As a result of our analyses, we found that she achieved her instructional goals of being nondirective in her teaching and getting students actively involved in arguing about mathematical concepts. The teacher was able to orchestrate discussion by recruiting attention and participation from her class, aligning students with argumentative positions through reported speech, highlighting positions through repetition, and pointing out important aspects of their arguments through expansion. In addition, we also found that her students differed in the way they framed the mathematical content of the lesson in terms of the facts or grounds, algorithms or warrants, premises or backings, as well as solutions or claims. Their arguments also varied in terms of explicitness and ability to integrate their classmates' arguments. In conclusion, we feel that discourse analysis, based on sociolinguistic and rhetorical theoretical frameworks, can be a valuable tool for the evaluation of educational reform in mathematics.  相似文献   
139.
This study tested whether maternal responsiveness moderated or mediated pathways from iron deficiency (ID) at 12–18 months to adolescent behavior problems. Participants were part of a large Chilean cohort (N = 933). Iron status was assessed at 12 and 18 months. Maternal responsiveness was assessed at 9 months and 5 years. Parents reported their child’s symptomology at 5 years, 10 years, and adolescence (11–17 years; M = 14.4). Structural equation modeling identified a previously unrecognized pathway by which child externalizing problems and negative maternal responsiveness at 5 years mediated associations between ID at 12–18 months and adolescent internalizing, externalizing, and social problems. Positive maternal responsiveness in infancy did not buffer those with ID anemia from developing 5-year internalizing problems.  相似文献   
140.
Plyometric training composed by unilateral exercises with horizontal jumping direction seems to be an effective way to improve physical performance in athletes. The present study aimed to compare the influence of a combined jumping direction and force application (horizontal-unilateral vs. vertical-bilateral) plyometric training on linear sprinting, jumping, change of direction (COD) and dynamic balance in young elite basketball players. Twenty young (U-13 to U-14) male basketball players (age: 13.2?±?0.7 years, body mass: 59.5?±?12.7?kg, height: 172.9?±?7.9?cm) were randomly assigned either to a unilateral-horizontal (UH, n?=?10) or bilateral-vertical (BV, n?=?10) plyometric group, twice a week for 6-wk. Both groups performed between 60 and 100 jumps/session. UH executed all jumps unilaterally with horizontal direction, while jumps in the BV were bilaterally with vertical direction. Performance was assessed by a linear sprinting test, vertical and horizontal jumping tests, COD tests (V-cut and 5+5?m with a 180°COD test), an ankle dorsiflexion test and dynamic balance tests (anterior and postero-lateral directions). Within-group differences showed substantial improvements (Effect size (ES):0.31–1.01) in unilateral vertical and horizontal jumping, V-cut test and postero-lateral direction with right leg after both training interventions. Furthermore, UH group also substantially improved (ES:0.33–0.78) all sprinting times and postero-lateral direction with left leg, while BV enhanced anterior direction with left leg (ES:0.25). Between-group analyses showed substantially greater improvements (ES:0.33) in 10-m and V-cut test in UH than in BV. The likely beneficial effect (small ES) achieved in sprinting abilities suggests the combination of unilateral-horizontal jumps to improve such abilities.  相似文献   
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