全文获取类型
收费全文 | 49688篇 |
免费 | 2090篇 |
国内免费 | 34篇 |
出版年
2020年 | 561篇 |
2019年 | 626篇 |
2018年 | 961篇 |
2017年 | 876篇 |
2016年 | 986篇 |
2015年 | 645篇 |
2014年 | 840篇 |
2013年 | 3761篇 |
2012年 | 1532篇 |
2011年 | 1580篇 |
2010年 | 897篇 |
2009年 | 1028篇 |
2008年 | 1354篇 |
2007年 | 1370篇 |
2006年 | 1234篇 |
2005年 | 1085篇 |
2004年 | 1041篇 |
2003年 | 991篇 |
2002年 | 962篇 |
2001年 | 1702篇 |
2000年 | 1671篇 |
1999年 | 1257篇 |
1998年 | 523篇 |
1997年 | 496篇 |
1995年 | 471篇 |
1992年 | 1019篇 |
1991年 | 930篇 |
1990年 | 972篇 |
1989年 | 889篇 |
1988年 | 863篇 |
1987年 | 796篇 |
1986年 | 818篇 |
1985年 | 902篇 |
1984年 | 725篇 |
1983年 | 639篇 |
1982年 | 503篇 |
1979年 | 749篇 |
1978年 | 554篇 |
1977年 | 483篇 |
1976年 | 491篇 |
1975年 | 618篇 |
1974年 | 738篇 |
1973年 | 770篇 |
1972年 | 643篇 |
1971年 | 541篇 |
1970年 | 492篇 |
1969年 | 532篇 |
1968年 | 667篇 |
1967年 | 585篇 |
1966年 | 591篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
A sample of delinquent and nondelinquent male adolescents was assessed with respect to locus of control and intellectual achievement responsibility. Data were also gathered concerning age, family size, birth order, socioeconomic status, race, and school grade. Results were subjected to a multivariate analysis and showed support for a multidimensional model of locus of control. There was no difference in expectancy of control for negative academic events between delinquents and nondelinquents. In general, birth order and delinquency were the two most important determinants of locus of control. Results are discussed in terms of previous literature on locus of control with particular consideration paid to expectations of control. 相似文献
992.
The present study examined some previously reported relationships between drug use by adolescents and perceived attitudes and behaviors of their parents. An anonymous questionnaire was administered to the student body of an inner-city secondary school for difficult students. Relationships between parental use of drugs and adolescent use of the same drugs were moderate and roughly equivalent across drugs. However, parental use of marijuana was strongly related to the adolescent's use of other, harder drugs such as opiates, cocaine, amphetamines, and barbiturates. This finding is explained within the framework of Kandel's postulated stages of drug initiation. It points to a need for further study of parental influences, which may be increasingly problematic as more individuals who have grown up in our marijuana-accepting society become parents of adolescents. 相似文献
993.
Richard A. Schmidt Stan C.A.M. Gielen Pieter J.M. Van Den Heuvel 《Acta psychologica》1984,57(2):145-164
When an imperative visual stimulus is paired with an auditory (accessory) stimulus, RT is generally faster than with the imperative stimulus alone. Three experiments using additive-factors logic tested an energy-summation view of the accessory, where effects are due to increased rate of information build-up in sensory stages, and a preparation-enhancement view which holds that the accessory serves an alerting function. Experiment 1 found no interaction between the accessory presence and (visual) stimulus brightness, suggesting no role of the accessory in stimulus identification. Experiment 2 found no interaction between accessory presence and spatial S-R compatibility, arguing that the accessory operated in stage(s) other than response selection. Experiment 3 produced an interaction between the accessory and movement complexity, arguing for accessory effects in a response-programming stage. The data generally favored preparation-enhancement, and offered no support for an energy-summation view. 相似文献
994.
Several inherent limitations to secondary school sex education program evaluations are: limited generalizability, lack of longitudinal research, and no clear consensus of program outcomes. With a Bureau of Health Education, Center for Disease Control study as the criterion for program outcomes, a study was undertaken to examine the immediate and long-term impact of sex education upon program participants. Two of the 20 schools in the CDC study identified as having exemplary sex education programs provided access to their students and alumni. Inventories which measured perceived achievement of 33 sex education outcomes were piloted for reliability and validity. Each inventory examined participant changes in knowledge, understanding of self, values, interaction skills, self-esteem, and fear of sex-related activities. Students were surveyed in school; alumni were surveyed through the mail. Response rates ranged from 30 to 100 percent for students and alumni at both schools. Overall there was no statistically significant difference between the perceptions of students and alumni as to achievement of investigated outcomes. Alumni responses at one school did, however, indicate some potentially weak areas of their school's program with respect to values and interaction skills outcomes. It appears that program impact may decrease with time. Thus, isolating and addressing the factors involved may be necessary. This would assist program planners and instructors to strengthen curricula and program activities in order to enhance the overall impact of sex education. The present study supports the notion that positive gains are achieved as a result of each school's sex education program, and these gains remained over time. 相似文献
995.
The authors recently proposed that adverse effects of material rewards on Wechsler subscale performance may be the result of a reward-produced developmental regression. The present study further explores that idea through an attempt to replicate earlier findings with adults and to extend the inquiry to children. Selected Wechsler subscales were administered to 32 subjects at each of three ages (5, 10, and 18 years) under either reward or nonreward conditions. Subscales were chosen to represent both algorithmic and heuristic types of tasks. Reward and nonreward groups (8 males and 8 females per group at each age) were matched initially on age and ability. For adults, consistent with earlier findings, reward had an adverse effect on performance on the heuristic subscales and tended to facilitate performance on the algorithmic subscales. However, rewards generally had no effect at the fourth-grade level and had a reverse effect at the nursery school level, i.e., rewards facilitated heuristic and hampered algorithmic performance. These findings appear to be more consistent with an explanation based on developmental regression than on any available alternative mechanism. 相似文献
996.
997.
998.
A comparison of the WISC-R and the Woodcock-Johnson Psycho-Educational Educational Battery (W-J) was made for children with regular and learning-disabled (LD) class placement. The W-J and Wechsler Intelligence Scale for Children-Revised (WISC-R) evidence low to moderate correlations and significant mean differences, indicating that the two tests are measuring somewhat different abilities to somewhat differing degrees. W-J—WISC-R correlations for the regular students exceed those of the LD students in the greater majority of the cases. Rank ordering of the WISC-R subtests and the W-J clusters indicate, as might be expected, that the LD students fare the worst in the WISC-R academic subtests (Arithmetic, Information and Vocabulary) and in the W-J academic clusters. More research needs to be conducted with the W-J before it should be adopted for use in the placement of exceptional children. 相似文献
999.
David P. Lindeman Henry A. Goodstein Arlene Sachs Clifford C. Young 《Journal of School Psychology》1984,22(1):111-117
The purpose of the present study was to evaluate the predictive validity of the Yellow Brick Road Test (YBRT) relative to performance in reading as measured by the Metropolitan Achievement Test (MAT). A full prediction-performance comparison matrix was employed to compare three different cutoff scores for the YBRT for the identification of “at-risk” children. Four hundred and fourteen kindergarten-aged children were administered the YBRT, 214 of whom were followed to the end of second grade. It was concluded that the YBRT is a moderately valid instrument for predicting the level of reading achievement in a population with a different average performance level from the normative sample. However, the results of this study failed to support the utility of the test author's suggested use of a score of 120 as the cutoff score. Finally, it is recommended that a prediction-performance comparison study be considered standard methodology for the evaluation of the validity and efficiency of screening instruments. 相似文献
1000.