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81.
Despite being under challenge for the past 50 years, null hypothesis significance testing (NHST) remains dominant in the scientific field for want of viable alternatives. NHST, along with its significance level p, is inadequate for most of the uses to which it is put, a flaw that is of particular interest to educational practitioners who too often must use it to sanctify their research. In this article, we review the failure of NHST and propose prep, the probability of replicating an effect, as a more useful statistic for evaluating research and aiding practical decision making. © 2007 Wiley Periodicals, Inc. Psychol Schs 44: 471–481, 2007. 相似文献
82.
Wu SS Ma CX Carter RL Ariet M Feaver EA Resnick MB Roth J 《Child abuse & neglect》2004,28(12):1253-1264
CONTEXT: Of the approximately 900,000 children who were determined to be victims of abuse or neglect by US child protective services in 2002, the birth-to-3 age group had the highest rate of victimization (1.6%) and children younger than 1 accounted for the largest percentage of victims (9.6%). OBJECTIVE: To identify perinatal and sociodemographic risk factors associated with maltreatment of infants up to 1 year of age. DESIGN AND SETTING: Observational cohort study. PARTICIPANTS: 189,055 children born in 1996 in Florida. MAIN OUTCOME MEASURE: Infant maltreatment, defined as a verified report of abuse, neglect, or threatened harm that occurred between day 3 of life and 1 year. RESULTS: 1,602 children (.85%) of the 1996 birth cohort had verified instances of maltreatment by age 1. Of 15 perinatal and sociodemographic variables studied, 11 were found to be significantly related to infant maltreatment. Five factors had adjusted relative risks (RR) of two or greater: Mother smoked during pregnancy (RR 2.8); more than two siblings (RR 2.7); Medicaid beneficiary (RR 2.1); unmarried marital status (RR 2.0); low birth weight infant (RR 2.0). Infants who had four of these five risk factors had a maltreatment rate seven times higher than the population average. CONCLUSIONS: Data on nearly all risk factors found to be significantly associated with infant maltreatment are available on the birth certificate. Such information can be incorporated into a population-based risk-assessment tool that could identify subpopulations at highest risk for infant maltreatment. Because resources are limited, these groups should be given priority for enrollment in child abuse prevention programs. 相似文献
83.
Relations Among Cultural Learning Beliefs,Self‐Regulated Learning,and Academic Achievement for Low‐Income Chinese American Adolescents 下载免费PDF全文
This mixed‐methods study of urban low‐income, English‐proficient Chinese American, second‐generation 15‐year‐olds (conducted in 2004; N = 32) examined the relation among the virtue model of learning communicated by parents and adolescents’ learning beliefs, self‐regulated learning (SRL) behaviors, and academic achievement. Analysis of in‐depth individual interviews revealed that for these adolescents, perceptions of family educational socialization predicted students’ endorsement of their culture's virtue‐oriented learning beliefs and that adolescents’ endorsement of these learning beliefs predicted their academic achievement. Importantly, adolescents’ reported that use of SRL strategies mediated the relationship between their endorsement of virtue‐oriented learning beliefs and their academic achievement. Findings are discussed in the context of further research linking cultural learning beliefs, SRL, and children's academic achievement. 相似文献
84.
Plastid atpB/rbcL intergenic spacer sequences were obtained from 21 selected taxa and
one hybrid of Anemoninae (Anemone, Pulsatilla, Hepatica) and compared with Ficaria (Ranun-
culinae) as an outgroup. From the resulting matrix (1226 bp) a single most parsimonious tree was
obtained (Fig. 1 ). The branching of this tree is confirmed by many informative indels and appears
largely congruent with past plastid restriction analyses. Several new taxa are added. The monophyly
of the Anemoninae and their early split into two major clades is supported: clade I with the chromo-
some base number x = 8, clade Ⅱ with the reduced x = 7. Clade Ⅰ is made up of the basal Pulsatilla
and the Rivularis + Vitifolia groups. The Multifida group links to the crown groups Coronaria,
Blanda and Nemorosa. Clade Ⅱ consists of the basal Dichotoma group, followed by Hepatica, and
finally by the N. Hemisphere Narcissiflora and the S. Hemisphere Antucensis groups as sisters. The
problems of the Anemoninae ancestry, phylogenetic differentiation, and recent attempts for systemat-
ic classification are critically discussed. In view of the still incomplete sampling of DNA data, aconservative and informal approach to classification problems is recommended. 相似文献
85.
86.
The “channeling hypothesis” of DNA electrophoresis in sparse, ordered arrays of posts predicts that the DNA will move through the array relatively unhindered if (i) the spacing between the posts is larger than the DNA coil and (ii) the electric field lines are straight. We tested this hypothesis by studying the electrophoretic separation of a small plasmid DNA (pUC19, 2686 base pairs) and a large, linear DNA (λ-DNA, 48 500 base pairs) in a hexagonal array of 1 μm diameter posts with a pitch of 7 μm. At low electric field strengths, these DNAs are separated due to the long-lived, rope-over-pulley collisions of λ-DNA with the posts. The resolution is lost as the electric field increases due to the onset of channeling by the λ-DNA. Using a diffusive model, we show that channeling arises at low electric fields due to the finite size of the array. This channeling is not intrinsic to the system and is attenuated by increasing the size of the array. Higher electric fields lead to intrinsic channeling, which is attributed to the disparate time scales for a rope-over-pulley collision and transverse diffusion between collisions. The onset of channeling is a gradual process, in agreement with extant Brownian dynamics simulation data. Even at weak electric fields, the electrophoretic mobility of λ-DNA in the array is considerably higher than would be expected if the DNA frequently collided with the posts. 相似文献
87.
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89.
John Fantuzzo Jill Stoltzfus Megan Noone Lutz Helen Hamlet Vijaykumar Balraj Colleen Turner Samuel Mosca 《Early childhood research quarterly》1999,14(4):465
The present study is an evaluation of the special needs referral system in a large urban Head Start program. To assess the validity of this system, two assessments were conducted. The first examined a representative sample of 105 children who were formally referred for special needs services. The Early Intervention Screening Profile (EISP) was used to indicate the distribution of problem behaviors of these special needs children. Two independent raters evaluated all cases. Reliable evaluations revealed that all of the referred children displayed speech and language problems, with 70% showing only speech problems and 30% showing speech plus emotional and behavioral problems. The second assessment examined reports of teachers’ concerns about children program-wide by obtaining a representative sample of 203 children nominated by teachers as most likely to be identified as having special needs. Teachers completed a modified EISP. Results indicated that over 70% of the children evidenced emotional and behavioral problems with no accompanying speech difficulties and 30% displayed emotional and behavioral problems plus speech problems. Implications of referral biases were discussed. 相似文献
90.
Shannon O’Donnell Francisco Tavares Daniel McMaster Samuel Chambers Matthew Driller 《Measurement in physical education and exercise science》2018,22(1):101-107
The current study aimed to assess the validity and test–retest reliability of a linear position transducer when compared to a force plate through a counter-movement jump in female participants. Twenty-seven female recreational athletes (19 ± 2 years) performed three counter-movement jumps simultaneously using the linear position transducer and force plate for validity. In addition, 11 elite female athletes (23 ± 6 years) performed 3 counter-movement jumps with the linear position transducer on three separate days for test–retest reliability. Pearson correlations for jump height between the devices were at a high level (r = .90), with the linear position transducer overestimating jump height by 7.0 ± 2.8 cm. The reliability measured by the linear position transducer resulted in a mean intraclass correlation of .70 for jump height, .90 for peak velocity, and .91 for mean velocity. The linear position transducer was reliable for measuring counter-movement jumps in elite female athletes; however, caution should be taken for one-off jump measures as it may over-estimate jump height. 相似文献