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21.
FLOSSWorld调查的主体由5部分构成,包括:个人(Private sector)、政府(Government sector)、开源社区参与者(Open Source participants community)、高校管理者(Heigher Education Institutes——Administrators)、高校信息部门主管(Heigher Education Institute——ITManagers) 相似文献
22.
Objective: A natural cyclic peptide previously isolated from Citrus medica was synthesized by coupling oftetrapep-tide units Boc-Leu-Pro-Trp-Leu-Ome and Boc-Ile-Ala-Ala-Gly-Ome after proper deprotection at carboxyl and amino terminals followed by cyclization of linear octapeptide segment.Methods: Solution phase technique was adopted for the synthesis of cyclooctapeptide--sarcodactylamide.Required tetrapeptide units were prepared by coupling of Boc-protected dipeptides viz.Boc-Leu-Pro-OH and Boc-Ile-Ala-OH with respective dipeptide methyl esters Trp-Leu-Ome and Ala-Gly-Ome.Cyclization of linear octapeptide unit was done by p-nitrophenyl ester method.The structure of synthesized cyclopolypeptide was elucidated by FTIR,1H NMR,13C NMR,FABMS spectral data and elemental analysis.The newly synthesized peptide was evaluated for dif-ferent pharmacological activities including antimicrobial,anthelmintic and cytotoxic activities.Results: Synthesis of sarcodac-tylamide was accomplished with >78% yield utilizing dicyclohexylcarbodiimide (DCC) as coupling agent.Newly synthesized peptide possessed potent cytotoxic activity against Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines,in addition to moderate anthelmintic activity against earthworms Megascoplex konkanensis,Pontoscotex corethruses and Eudrilus sp.Moreover,cyclopolypeptide displayed good antimicrobial activity against pathogenic fungi Candida albicans and Gram-negative bacteria Pseudomonas aeruginosa,in comparison to standard drugs griseofulvin and ciprofloxacin.Conclusion: Solution phase technique employing DCC and triethylamine (TEA) as base proved to be effective for the synthesis of natural cyclooctapeptide.N-methyl morpholine (NMM) was found to be a better base for the cyclization of linear octapeptide unit in comparison to TEA and pyridine. 相似文献
23.
Puolakanaho A Ahonen T Aro M Eklund K Leppänen PH Poikkeus AM Tolvanen A Torppa M Lyytinen H 《Journal of learning disabilities》2008,41(4):353-370
The authors examined second grade reading accuracy and fluency and their associations via letter knowledge to phonological and language predictors assessed at 3.5, 4.5, and 5.5 years in children in the Jyv?skyl? Longitudinal Study of Dyslexia. Structural equation modeling showed that a developmentally highly stable factor (early phonological and language processing [EPLP]) behind key dyslexia predictors (i.e., phonological awareness, short-term memory, rapid naming, vocabulary, and pseudoword repetition) could already be identified at 3.5 years. EPLP was significantly associated with reading and spelling accuracy and by age with letter knowledge. However, EPLP had only a minor link with reading fluency, which was additionally explained by early letter knowledge. The results show that reading accuracy is well predicted by early phonological and language skills. Variation in fluent reading skills is not well explained by early skills, suggesting factors other than phonological core skills. Future research is suggested to explore the factors behind the development of fast and accurate decoding skills. 相似文献
24.
基于国家教育标准的地理教材 总被引:1,自引:0,他引:1
为进一步增强美国地理教育。我们要做的许多事情之一就是改进教材的质量。其中最主要的三个方面的任务是:(1)开发优良的教材,(2)利用教师联盟的在职培训网络和职前教育计划培训教师使用这种新教材,(3)通过提供强有力的课程指导,特别是将教材与师资培训和基于国家 相似文献
25.
We review a series of studies that evaluate the role of developing language skills as a prerequisite to spontaneous rehearsal use in deaf populations. We propose a theoretical model that summarizes the contribution of language skills by highlighting the interrelations among age, language proficiency, and automatized language skills. In an initial test of the model, an index of deaf children's language experience was found to be an almost complete mediator of strategy use. Increasing language proficiency, therefore, was implicated as a critical variable in predicting children's spontaneous rehearsal use, minimizing any direct contribution from age per se. In a more direct assessment of the link between general language proficiency and rehearsal use, pragmatic language skills (as measured by the Language Proficiency Profile: LPP-I) were found to be a nearly complete mediator of rehearsal use, with the remaining contributions of age and language experience being nonsignificant. Language proficiency, therefore, was identified as a strong and necessary prerequisite for rehearsal to be used spontaneously as a memory strategy. The additional hypothesis that the automatization of these general language skills, measured by a rapid automatized naming task (RAN), contributes to spontaneous rehearsal was also evaluated. Automatized language emerged as a partial mediator of the language proficiency → rehearsal use relation but additional language-processing variables were implicated. We discuss these findings as they relate to issues around the nature of language proficiency and the identification of those automatized language skills involved in rehearsal. 相似文献
26.
27.
Silva KM Spinrad TL Eisenberg N Sulik MJ Valiente C Huerta S Edwards A Eggum ND Kupfer AS Lonigan CJ Phillips BM Wilson SB Clancy-Menchetti J Landry SH Swank PR Assel MA Taylor HB;School Readiness Consortium 《Early education and development》2011,22(3):434-460
RESEARCH FINDINGS: The purpose of this study was to examine the relations of children's effortful control and quality of relationships with teachers to school attitudes longitudinally in an ethnically diverse and economically disadvantaged sample. Data were collected as part of a larger intervention project during mid-fall, winter, and late spring (ns = 823, 722, and 758, respectively) for 2 cohorts of 3- to 5-year-olds (collected during 2 different school years). Children's effortful control was assessed in the fall with parents' and teachers' reports and 2 behavioral measures. Teacher-child relationship quality was assessed mid-year with teachers' reports of closeness and conflict. Attitudes toward school were assessed in late spring using teachers' and students' reports of school avoidance and liking. Effortful control, in general, was positively correlated with teacher-child closeness and school liking and negatively correlated with conflict and school avoidance. Using structural equation modeling and controlling for sex and ethnicity, we found that effortful control was positively related to teacher-child relationship quality, which in turn was positively related to school attitudes. Furthermore, the relation of effortful control to school attitudes was mediated by teacher-child relationship quality. PRACTICE OR POLICY: Results provide evidence for the importance of relational processes that take place within the classroom context and have implications for teachers and clinicians working to increase school success in ethnic minority and low-income children. 相似文献
28.
Difrisco E Goodman KE Budin WC Lilienthal MW Kleinman A Holmes B 《The Journal of perinatal education》2011,20(1):28-35
Substantial evidence documents the superiority of breastfeeding for mothers and breastmilk for babies. Although the American Academy of Pediatrics and the U.S. Healthy People 2010 initiative promote breastfeeding, current breastfeeding rates often fall short of recommendations. This study determined factors associated with exclusive breastfeeding 2 to 4 weeks following discharge from a large, urban, academic medical center striving for Baby-Friendly designation. Results indicated that mothers who breastfed within the first hour of birth (61%) were significantly more likely to be exclusively breastfeeding 2 to 4 weeks after discharge. Incorporating care practices that include a number of the "Ten Steps to Successful Breastfeeding," as recommended by the Baby-Friendly Hospital Initiative, may increase the duration of exclusive breastfeeding after discharge. 相似文献
29.
Horowitz A 《Learning & behavior》2011,39(4):314-317
In line with other research, Udell, Dorey, and Wynne’s (in press) finding that dogs and wolves pass on some trials of a putative
theory-of-mind test and fail on others is as informative about the methods and concepts of the research as about the subjects.
This commentary expands on these points. The intertrial differences in the target article demonstrate how critical the choice
of cues is in experimental design; the intersubject-group differences demonstrate how life histories can interact with experimental
design. Even the best-designed theory-of-mind tests have intractable logical problems. Finally, these and previous research
results call for the introduction of an intermediate stage of ability, a rudimentary theory of mind, to describe subjects’ performance. 相似文献
30.
Preschool children (3–4 years old) were trained to perform two actions to gain different outcomes, in the form of video clips
from different cartoons, before one of these outcomes was devalued by noncontingent exposure. The effect of outcome devaluation
was subsequently assessed in an extinction test by giving children the opportunity to perform both actions in the absence
of any outcomes. When the two actions were trained concurrently, performance during the test was modulated by outcome value
and children showed a preference for the action trained with the currently valued outcome. By contrast, when each action was
trained separately on different trials, test performance was insensitive to outcome devaluation. These effects of the training
schedules are interpreted in terms of dual-process theories of action control. 相似文献