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991.
Philip Hallinger Ronald H. Heck Joseph Murphy 《Educational Assessment, Evaluation and Accountability》2014,26(1):5-28
In recent years, substantial investments have been made in reengineering systems of teacher evaluation. The new generation models of teacher evaluation typically adopt a standards-based view of teaching quality and include a value-added measure of growth in student learning. With more than a decade of experience and research, it is timely to assess empirical evidence bearing on the efficacy of this school improvement strategy. This paper examines the new generation of teacher evaluation along three lines of analysis: evidence on the magnitude, consistency, and stability of teacher effects on student learning, evidence on the impact of teacher evaluation on growth in student learning, and literature from the sociology of organizations on how schools function. Although the trend towards focusing on teacher evaluation is increasingly evident internationally, most of the empirical research evaluated in this paper is from the USA. This critical evaluation of the empirical literature yields two key conclusions. First, we conclude that the policy logic supporting this reform remains considerably stronger than the empirical evidence. Second, we suggest that alternative improvement strategies may yield more positive results and at a lower cost in terms of staff time and district funds. 相似文献
992.
First‐Generation Students' Sense of Belonging,Mental Health,and Use of Counseling Services at Public Research Universities 下载免费PDF全文
Michael J. Stebleton Krista M. Soria Ronald L. Huesman Jr. 《Journal of College Counseling》2014,17(1):6-20
This study explored 1st‐generation students' sense of belonging, mental health status, and use of mental health services in comparison to non‐1st‐generation students. Using the Student Experience in the Research University multi‐institutional survey, the authors found that 1st‐generation students tended to report lower ratings of belonging, greater levels of depression/stress, and lower use of services compared to non‐1st‐generation students. Implications for college counselors and suggestions for future inquiry are provided. 相似文献
993.
Rahim Esfandyarpour Mehdi Javanmard Zahra Koochak Hesaam Esfandyarpour James S. Harris Ronald W. Davis 《Biomicrofluidics》2013,7(4)
Detection of proteins and nucleic acids is dominantly performed using optical fluorescence based techniques, which are more costly and timely than electrical detection due to the need for expensive and bulky optical equipment and the process of fluorescent tagging. In this paper, we discuss our study of the electrical properties of nucleic acids and proteins at the nanoscale using a nanoelectronic probe we have developed, which we refer to as the Nanoneedle biosensor. The nanoneedle consists of four thin film layers: a conductive layer at the bottom acting as an electrode, an oxide layer on top, and another conductive layer on top of that, with a protective oxide above. The presence of proteins and nucleic acids near the tip results in a decrease in impedance across the sensing electrodes. There are three basic mechanisms behind the electrical response of DNA and protein molecules in solution under an applied alternating electrical field. The first change stems from modulation of the relative permittivity at the interface. The second mechanism is the formation and relaxation of the induced dipole moment. The third mechanism is the tunneling of electrons through the biomolecules. The results presented in this paper can be extended to develop low cost point-of-care diagnostic assays for the clinical setting. 相似文献
994.
Abstract Both radiant and forced convective heat flow were measured for a prototype rowing headgear and white and black cotton caps. The measurements were performed on a thermal manikin headform at a wind speed of 4.0 m · s?1 (s = 0.1) in a climate chamber at 22.0°C (s = 0.05), with and without radiant heat flow from a heat lamp, coming from either directly above (90°) or from above at an angle of 55°. The effects of hair were studied by repeating selected measurements with a wig. All headgear reduced the radiant heat gain compared with the nude headform: about 80% for the caps and 95% for the prototype rowing headgear (P < 0.01). Forced convective heat loss was reduced more by the caps (36%) than by the prototype rowing headgear (9%) (P < 0.01). The radiant heat gain contributed maximally 13% to the net heat transfer, with or without headgear, showing that forced convective heat loss is the dominant heat transfer parameter under the chosen conditions. The results of the headgear – wig combinations were qualitatively similar, with lower absolute heat transfer. 相似文献
995.
Valerie Fayt Reinoud J. Bootsma Ronald G. Marteniuk Christine L. Mackenzie Michel Laurent 《Journal of sports sciences》2013,31(6):581-586
In the light of the intensity coupling effects reported in the literature, subjects' capacities for independently controlling the absolute velocity of their movement at the point of interception was evaluated by asking them to learn to propel orthogonally approaching balls, varying in their speed of approach, into target boxes placed at various distances from the interception point. As required for successful accomplishment of the task, movement velocity was found to be adapted to the distance to be covered, with the near target giving rise to lower velocities and the far target giving rise to higher velocities even when the conditions were presented in random order. Nevertheless, even though target distance accounted for a substantial proportion of the total variance, a small but significant effect of ball approach speed on movement velocity was found, suggesting that intensity coupling is a persistent but modulable phenomenon in interception tasks. 相似文献
996.
997.
Deborah L. Dewar Ronald C. Plotnikoff Philip J. Morgan Anthony D. Okely Sarah A. Costigan 《Research quarterly for exercise and sport》2013,84(4):483-491
Purpose The aim of this study was to test the hypothesized structural paths in Bandura's social-cognitive theory (SCT) model on adolescent girls' physical activity following a 12-month physical activity and dietary intervention to prevent obesity. Method We conducted a 12-month follow-up study of 235 adolescent girls (M age = 13.2 years, SD = 0.4) from 12 secondary schools located in low-income communities. At baseline, participants completed SCT scales related to physical activity (i.e., self-efficacy, intention, parental support, and outcome expectations). At baseline and 12-month follow-up (postintervention), participants wore accelerometers for 7 days. Structural equation modeling was used to determine if Time 1 measures predicted physical activity at 12-month follow-up after adjusting for baseline activity. Results The model explained 28% and 34% of the variance in physical activity and intention, respectively. Model fit indexes indicated the data were a good fit to the model; however, only self-efficacy was associated with physical activity at 12 months. There was no support for intention or outcome expectations as proximal determinants of behavior. Self-efficacy was associated with outcome expectations and parental support; however, only outcome expectations predicted intention. Conclusions Current findings indicate a large proportion of the variance for physical activity and intention remains unexplained and that the proposed pathways in the SCT model were not fully supported. Future model testing may need to consider augmentation or integration of theoretical models, which may include ecological components if we are to advance our understanding of physical activity behavior in this subgroup of the adolescent population. 相似文献
998.
Hui-ying Wang Zhong-shan Gao Zhao-wei Yang Jing-xin Shao Xiu-zhen Zhao Yu Dai Ronald Van Ree 《Journal of Zhejiang University. Science. B》2012,13(10):851-854
Chinese bayberry Myrica rubra is a very popular fruit in southeastern China. In spite of its wide consumption, no allergies to this fruit have been reported previously. Here we report on a 40-year-old woman suffering from anaphylaxis to Chinese bayberry fruit. Prick-prick skin tests revealed strong reactions to fresh Chinese bayberry fruits as well as to peach, and weaker reactions to some other fruits including apple, melon, and banana. ImmunoCAP analysis revealed identical titers of specific IgE (4.3 kUA/L) to peach extract and its lipid transfer protein (LTP, rPru p 3), which was confirmed by detection of a 9 kD band following immunoblotting. Immunoblot analysis with Chinese bayberry extract gave bands of 22, 45, and 90 kD, but no 9 kD band was recognized. There was also no evidence of LTP recognition for loquat (36 kD) or melon (24 kD). This first report of a severe allergic reaction to Chinese bayberry fruit in a patient with LTP-mediated peach allergy indicates that other as yet unidentified non-pollen related fruit allergens are involved in this new severe fruit allergy. 相似文献
999.
1000.
This research consists of a longitudinal study of 12 female elementary preservice teachers' conceptual understanding over the course of several months. The context in which the participants received instruction was in an inquiry‐based physics course, and the targeted science content was the cause of moon phases. Qualitative research methods, including observations and interviews, were used to investigate and describe participants' conceptual understanding over time. Participants were interviewed on their understanding of the cause of moon phases before instruction, 3 weeks after instruction, and again in delayed post‐interviews several months after instruction. Patterns and themes in the participants' conceptual understanding were identified through constant‐comparative data analysis. Consistent with results reported earlier, participants who had instruction that included recording and analyzing moon observations over time and psychomotor modeling of changes in moon phases were very likely to hold a scientific conceptual understanding shortly after instruction. The present study indicates a majority of participants continued to hold a scientific understanding six months or more after instruction. However, some participants reverted to alternative conceptions they had shown during the pre‐interview. These results are interpreted utilizing contemporary conceptual change theory. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 44: 303–326, 2007 相似文献