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151.
This study uses panel data to examine the relationship between faculty employment and external R&D expenditures at Research and Doctoral institutions over a 15-year period of time. On average, a 1% increase in the number of full-time faculty is associated with about 0.2% increase in total R&D expenditure. Further, a one percentage point increase in the share of full-time faculty members that are not on tenure-track lines is associated with a decrease in total external R&D expenditure by about 0.6%, suggesting that full-time faculty that are tenured or on tenure-tracks are the main category of faculty that generate external R&D funding. Further, our results suggest that an increasing usage of part-time faculty, holding constant the institution's full-time faculty size, boosts an institution's external R&D expenditures. On average, a one percentage point increase in the share of part-time faculty members is associated with a 0.44% increase in the total external R&D expenditures. Increases in graduate student enrollments are associated with increases in external R&D expenditures. Finally, an institution's external R&D expenditures are significantly influenced by both the amount of its own institutionally financed research expenditures and the level of federal funding for research.  相似文献   
152.
Current definitions of retention and graduation rates distort the picture of student success by limiting it to completion of a degree at the institution of entry. By incorporating data from the National Student Clearinghouse (NSC), a clearer picture emerges. The NSC data captures retention and graduation at both entry and transfer institutions. To accommodate this polychotomous definition of success, more sophisticated methods of modeling limited dependent variables are needed. Though multinomial logit is often considered the most accessible method, the strict assumptions it imposes may be inappropriate. We therefore compare multinomial regression techniques to assess their utility in modeling multi-institutional student success.  相似文献   
153.
This study investigated the effect of non-traditional guided inquiry instruction on middle school students’ conceptual understandings of lunar concepts. Multiple data sources were used to describe participants’ conceptions of lunar phases and their cause, including drawings, interviews, and a lunar shapes card sort. The data were analyzed via a constant comparative method to produce profiles of each participant’s conceptual understandings and nonparametric tests also were used. Results revealed very positive performance for observable moon phases and patterns of change, as well as the cause of moon phases. Results indicated that significantly more participants shifted from drawing nonscientific shapes on the pretest to drawing scientific shapes on the post-test. Results for the drawings of moon phase sequences were similar in that significantly more participants shifted from drawing alternative waxing and waning sequences on the pretest to drawing scientific sequences on the post-test. Also, significantly more participants shifted from alternative understanding of the cause of the moon phases on the pretest to scientific understanding on the post-test. Implications of these findings and recommendations for further research are provided.  相似文献   
154.
Narrating Characters: The Making of a School Bully   总被引:1,自引:0,他引:1  
Jake was a popular sixth-grader at a local public school. He had plenty of friends and admirers, made good grades, and had adequate social skills. Jake was also a bully. Over the course of that sixth grade year Jake recruited a couple of friends, and then a much larger groups of peers, to target a classmate: Matthew. The school was quick to respond, but despite clear training, strong reprimand, and relentless surveillance the bullying of Matthew only stopped when he finally transferred to a new school. The next year Jake picked a new target: Trent. To date bullying research has largely employed empirical methodologies, including qualitative and quantitative approaches. This paper offers a fresh perspective, employing a missing philosophical lens toward the instantiation of bullying on the school campus. How might a bully – or a group of bullying participants – be narrated in such a way that he or she chooses violence or domination as a means through which to secure status? More specifically, what forces bear upon the experience of bullying, what cultures might its dominance mirror, and from where is its meaning derived? In considering these questions I employ the voices of two disparate philosophers; John Dewey and Michel Foucault.  相似文献   
155.
In this article, we analyze the variation in math achievement trajectories of Black male students to understand the different ways these students successfully or unsuccessfully navigate schools and the school characteristics that are associated with their trajectories. Using longitudinal student-level data from a large urban US city (n = 7,039), we analyze Black male students from one cohort to identify trajectories. We find a lack of growth in standardized math scores, suggesting that, on average, math proficiency among Black male students in our sample is declining over time. We found that the 4th-grade standardized math scores of subsidized-lunch students were somewhat lower than those of nonsubsidized students and those of retained students were substantially lower than their counterparts. The average math score of a Black male student's cohort appears to be the only variable amenable to policy manipulation that has a sizeable association with the growth of their standardized math scores, suggesting that putting Black male students in more challenging learning environments may be the best way to increase math proficiency over time. By themselves, other policy decisions (reducing student mobility, teacher turnover, or special education classification; increasing attendance or spending on after-school programming; or hiring more qualified or experienced teachers) all appear to have no or negligible associations with growth in math scores.  相似文献   
156.
157.
A high ambient temperature reduces the capacity to perform prolonged exercise. Total carbohydrate oxidation is less, and thus glycogen depletion is not limiting. Fluid ingestion in the heat should, therefore, focus on maintenance of hydration status rather than on substrate provision. Six healthy males cycled to exhaustion at 60% of maximum oxygen consumption (VO 2max ) with no drink, ingestion of a 15% carbohydrate-electrolyte drink (1.45 - 0.29 litres) or ingestion of a 2% carbohydrate-electrolyte drink (3.12 - 0.47 litres). The ambient temperature was 30.2 - 0.6°C (mean - s ), with a relative humidity of 71 - 1% and an air speed of approximately 0.7 m.s -1 on all trials. Weighted mean skin temperature, rectal temperature and heart rate were recorded and venous samples drawn for determination of plasma volume changes, blood metabolites, serum electrolytes and osmolality. Expired gas was collected to estimate rates of fuel oxidation. Exercise capacity was significantly ( P ? 0.05) different in all trials. The median (range) time to exhaustion was 70.9 min (39.4-97.4 min) in the no-drink trial, 84.0 min (62.7-145 min) in the 15% carbohydrate trial and 118 min (82.6-168 min) in the 2% carbohydrate trial. The 15% carbohydrate drink resulted in significantly ( P ? 0.05) elevated blood glucose and total carbohydrate oxidation compared with the no-drink trial. The 2% carbohydrate drink restored plasma volume to pre-exercise values by the end of exercise. No differences were observed in other thermoregulatory or cardiorespiratory responses between trials. These results suggest that fluid replacement with a large volume of a dilute carbohydrate drink is beneficial during exercise in the heat, but the precise mechanisms for the improved exercise capacity are unclear.  相似文献   
158.
This study investigated the construct and concurrent validity of a 12-minute crawl stroke swim as a field test of swimming endurance. A sample of 42 male college students who ranged from certified life savers to competitive swimmers were administered three tests. The first, a multistage swimming endurance test, required that a tethered subject swim to exhaustion under a linear progressive increase in workload. The second measure was the crawl stroke count for two lengths of a 25-yard pool. The third test was a 12-minute crawl stroke swim for distance with total distance and distance covered each minute recorded for each subject. Alpha factor analysis of the 12 minute intervals of the crawl stroke swim produced one factor which demonstrated that swimming performance was internally consistent during the 12-minute swim. There was a correlation of .898 (p < .01) between the 12-minute swim and the tethered swim test. Cross validity procedures demonstrated a high degree of stability for the correlation between the 12-minute swim and the tethered swim and for resulting regression statistics. The construct validity was established for both the multistage test and the 12-minute swim using the known groups approach. On the basis of the data the 12-minute swim is a valid field test for swimming endurance for the population studied.  相似文献   
159.
Abstract

Hydration status is not easily measured, but acute changes in hydration status are often estimated from body mass change. Changes in body mass are also often used as a proxy measure for sweat losses. There are, however, several sources of error that may give rise to misleading results, and our aim in this paper is to quantify these potential errors. Respiratory water losses can be substantial during hard work in dry environments. Mass loss also results from substrate oxidation, but this generates water of oxidation which is added to the body water pool, thus dissociating changes in body mass and hydration status: fat oxidation actually results in a net gain in body mass as the mass of carbon dioxide generated is less than the mass of oxygen consumed. Water stored with muscle glycogen is presumed to be made available as endogenous carbohydrate stores are oxidized. Fluid ingestion and sweat loss complicate the picture by altering body water distribution. Loss of hypotonic sweat results in increased osmolality of body fluids. Urine and faecal losses can be measured easily, but changes in the water content of the bladder and the gastrointestinal tract cannot. Body mass change is not always a reliable measure of changes in hydration status and substantial loss of mass may occur without an effective net negative fluid balance.  相似文献   
160.
Abstract

The main aim of this study was to determine the test–retest reliability of existing tests of health-related fitness. Participants (mean age 14.8 years, s = 0.4) were 42 boys and 26 girls who completed the study assessments on two occasions separated by one week. The following tests were conducted: bioelectrical impedance analysis (BIA) to calculate percent body fat, leg dynamometer, 90° push-up, 7-stage sit-up, and wall squat tests. Intra-class correlation (ICC), paired samples t-tests, and typical error expressed as a coefficient of variation were calculated. The mean percent body fat intra-class correlation coefficient was similar for boys (ICC = 0.95) and girls (ICC = 0.93), but the mean coefficient of variation was considerably higher for boys than girls (22.2% vs. 12.2%). The boys' coefficients of variation for the tests of muscular fitness ranged from 9.0% for the leg dynamometer test to 26.5% for the timed wall squat test. The girls' coefficients of variation ranged from 17.1% for the sit-up test to 21.4% for the push-up test. Although the BIA machine produced reliable estimates of percent body fat, the tests of muscular fitness resulted in high systematic error, suggesting that these measures may require an extensive familiarization phase before the results can be considered reliable.  相似文献   
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