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Bioecological systems theory provides a framework to understand how factors in the child's environment contribute to parent-child differences in estimations of how often children are helped by their Internet use. A national sample survey of 456 matched parent-child pairs investigated how parents-child relational factors, parental attitudes toward the Internet, and the bio-ecology of the child, are related to differing perceptions of the frequency of using the Internet to seek help with homework assignments, to aid in identity development, and to find health information. While previous research shows that parents underestimate risky online behaviors, we investigate whether parent-child differences will emerge in regards to how often the child engages in the behaviors under investigation here. The findings show that parents overestimate these online activities, suggesting they are biased in their estimations. Parent-child relational factors emerged as predictors of parental overestimation for each of these online activities, with trust perceptions as the most consistent predictor. Parental attitudes toward the Internet predicted parent-child differences in perceptions of how frequently the child used the Internet for help with homework and identity development, while the bioecology of the child was only predictive in the case of using the Internet for help with homework. 相似文献
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A. Zaher S. Li K. T. Wolf F. N. Pirmoradi O. Yassine L. Lin N. M. Khashab J. Kosel 《Biomicrofluidics》2015,9(5)
Implantable drug delivery systems can provide long-term reliability, controllability, and biocompatibility, and have been used in many applications, including cancer pain and non-malignant pain treatment. However, many of the available systems are limited to zero-order, inconsistent, or single burst event drug release. To address these limitations, we demonstrate prototypes of a remotely operated drug delivery device that offers controllability of drug release profiles, using osmotic pumping as a pressure source and magnetically triggered membranes as switchable on-demand valves. The membranes are made of either ethyl cellulose, or the proposed stronger cellulose acetate polymer, mixed with thermosensitive poly(N-isopropylacrylamide) hydrogel and superparamagnetic iron oxide particles. The prototype devices'' drug diffusion rates are on the order of 0.5–2 μg/h for higher release rate designs, and 12–40 ng/h for lower release rates, with maximum release ratios of 4.2 and 3.2, respectively. The devices exhibit increased drug delivery rates with higher osmotic pumping rates or with magnetically increased membrane porosity. Furthermore, by vapor deposition of a cyanoacrylate layer, a drastic reduction of the drug delivery rate from micrograms down to tens of nanograms per hour is achieved. By utilizing magnetic membranes as the valve-control mechanism, triggered remotely by means of induction heating, the demonstrated drug delivery devices benefit from having the power source external to the system, eliminating the need for a battery. These designs multiply the potential approaches towards increasing the on-demand controllability and customizability of drug delivery profiles in the expanding field of implantable drug delivery systems, with the future possibility of remotely controlling the pressure source. 相似文献
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Martine Poirier Michle Dry Jean Toupin Pierrette Verlaan Jean‐Pascal Lemelin Jadzia Jagiellowicz 《Psychology in the schools》2015,52(4):403-418
There is limited empirical research on the correlates of conduct problems (CP) and depression comorbidity during childhood. This study investigated 479 elementary school children (48.2% girls). It compared children with comorbidity to children with CP only, depression only, and control children on individual, academic, social, and family characteristics. The study also analyzed gender differences in the associations between correlates and comorbidity. Multinomial logistic regression results revealed that children with CP and depression had higher levels of anxiety and more school difficulties than children with CP only, more social difficulties and more severe attention deficit and hyperactivity disorder (ADHD) symptoms than children with depression only, and more difficulties in all domains than control children. Girls with CP and depression presented a particularly negative profile, including lower school abilities than CP and control girls, and lower social skills and more severe ADHD symptoms than control girls. Implications for evaluation and intervention planning are discussed. 相似文献
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Jean Saint-Aubin Marie-Claire Losier Macha Roy Mike Lawrence 《Scientific Studies of Reading》2015,19(2):145-165
When readers search for misspellings in a proofreading task or for a letter in a letter detection task, they are more likely to omit function words than content words. However, with misspelled words, previous findings for the letter detection task were mixed. In two experiments, the authors tested the functional equivalence of both tasks. Results reveal similar patterns of omissions for both search tasks when misspellings were produced by substituting one letter for another: There were more omissions for function words than for content words. However, when two letters were transposed, differences between the two tasks emerged. It is possible to conclude that letter detection and proofreading are based on common cognitive processes but the nature of the target can modulate the effects. Results are interpreted in light of the attentional disengagement model and the guidance organization model of the missing-letter effect. 相似文献
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Jean Kayira 《Environmental Education Research》2015,21(1):106-128
Colonialism goes beyond territorial conquest: it affects one’s epistemological stance, worldviews and perceptions. Although most African countries gained independence in the 1960s, the impacts of colonialism continue to be present through modern-day globalization as a form of neocolonialism. Education systems in many countries in southern Africa continue to be grounded in Western viewpoints, marginalizing local Indigenous ways of knowing and being (I capitalize the word ‘Indigenous’ because it is a proper noun referring to particular people, their knowledges, ways of living, etc.). An increased number of scholars in southern Africa are engaging with counter-hegemonic strategies as frames of analysis to counter the impacts of neocolonialism. This paper reviews environmental education studies in southern Africa that have applied postcolonial theory as a frame of analysis either explicitly or implicitly. Postcolonial theory provides a platform to challenge the dominant truths espoused by Western thought. In doing so, it paves the way for other truths to have space in the knowledge discourses, including the sub-Saharan African worldview of Ubuntu/uMunthu. While many scholars are engaging with counter-hegemonic strategies, the review calls for the need for further research from postcolonial frames not only in southern Africa but also other parts of the world as well. 相似文献