首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   27921篇
  免费   909篇
  国内免费   14篇
  2020年   268篇
  2019年   282篇
  2018年   332篇
  2017年   397篇
  2016年   436篇
  2015年   340篇
  2014年   387篇
  2013年   2026篇
  2012年   705篇
  2011年   724篇
  2010年   467篇
  2009年   471篇
  2008年   680篇
  2007年   632篇
  2006年   569篇
  2005年   564篇
  2004年   533篇
  2003年   529篇
  2002年   526篇
  2001年   728篇
  2000年   712篇
  1999年   518篇
  1998年   287篇
  1992年   495篇
  1991年   471篇
  1990年   479篇
  1989年   473篇
  1988年   434篇
  1987年   444篇
  1986年   467篇
  1985年   511篇
  1984年   449篇
  1983年   407篇
  1982年   307篇
  1981年   353篇
  1980年   267篇
  1979年   471篇
  1978年   344篇
  1977年   307篇
  1976年   299篇
  1975年   423篇
  1974年   481篇
  1973年   500篇
  1972年   418篇
  1971年   410篇
  1970年   385篇
  1969年   405篇
  1968年   496篇
  1967年   479篇
  1966年   454篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
Two students were alternately presented with interspersed high-compliance requests and social comments as antecedents to low-compliance requests. An initial comparison demonstrated similar positive effects on compliance for interspersed requests and social comments. A second analysis indicated that the effectiveness of social comments for increasing compliance was related to the time interval between social comments and low-compliance requests.  相似文献   
972.
The purpose of this study was both to determine if the Impostor Phenomenon (IP) can be reliably and validly assessed in a Korean context and if so, evaluate the construct within the context of Jungian typology and the 5-factor model of personality. A sample of 654 Korean men and women were selected from 4 major Korean cities and administered the Clance Impostor Phenomenon Scale (CIPS; Clance & Imes, 1978) along with the Myers-Briggs Type Indicator (MBTI, Form G; Myers & McCaulley, 1985) and NEO Personality Inventory-Revised (NEO-PI-R; Costa & McCrae, 1992). Results indicated that the CIPS was very reliable, and the pattern of correlates suggested impostors to be introverted types on the MBTI. Results with the NEO-PI-R showed impostors to be very high on neuroticism and low on conscientiousness. This pattern of correlates is similar to other performance-inhibiting constructs such as fear of success and fear of failure. It was argued that IP be construed more as a motivational style than as a distinct clinical syndrome. The IP seems to be less pervasive in Korea than America and these cross-cultural implications were discussed.  相似文献   
973.
Recent evidence suggests a larger role for personality determinants of the coping response than has been traditionally held. In the two studies presented here, we examined the influence of personality on the use of social support and other coping strategies in samples of undergraduate students. The first study surveyed a range of coping responses to naturally occurring stressors and found that Extraversion was related to social support seeking, optimism (identified as germane to coping in prior research) was related to problem solving, and both dispositions were negatively related to avoidance. The second study used an experimental approach and multiple personality measures to correct for possible methodological problems in the first. Extraversion again proved to be associated with help seeking; moreover, this relationship accounted for that of another disposition, self-esteem—a construct considered crucial in the literature. The utility of personality variables, particularly Extraversion, in predicting and explaining the choice of a coping strategy is discussed.  相似文献   
974.
Predicting Intentions of AIDS-Preventive Behavior Among Adolescents   总被引:3,自引:0,他引:3  
The aim was to predict adolescents' i]ntentions of regular condom use on the basis of an extended version of Ajzen and Fishbein's (1980) theory of reasoned action. Attitude and subjective norm concerning regular condom use were measured along with their antecedent beliefs and evaluations, with fear of AIDS and knowledge about AIDS included as additional variables. A mixed-gender sample comprising both sexually active and sexually inexperienced adolescents was studied. The results strongly support the impact of attitude toward regular condom use as a determinant of a corresponding behavioral intention. Normative pressures failed to predict intentions of regular condom use, as did fear of AIDS and knowledge about AIDS. The findings are discussed with respect to intervention campaigns aimed at promoting condom use among adolescents as an AIDS-preventive measure.  相似文献   
975.
The control of the ground reaction force vector relative to the center of gravity (CoG) was examined while subjects performed a back-lifting task. Six male subjects (aged 24.0 +/- 2.5 years) repeatedly lifted a barbell. A biomechanical analysis that used a linked segment model revealed that the summed rotations of body segments during lifting yielded a specific rate of change of the angular momentum of the entire body. This equaled the external moment provided by Fsubg; relative to CoG. This implies that multisegment movements involve control of the angular momentum of the entire body through an appropriately directed Fsubg;. Thus, in dynamic tasks Fsubg; is pointed away from rather than lined up with the CoG, as is the case in static tasks.  相似文献   
976.
Hungry, unrestrained rats (N = 7) were rewarded for pressing a response beam in excess of 11 different force requirements. Changes in peak force production as a function of peak force requirement were examined by analyses of the first four moments of distributions of peak response forces: constant error, the within-subject standard deviation, skewness, and kurtosis. Results were similar to those previously obtained with human subjects: Constant error was positive at low and negative at high force requirements, the within-subject standard deviation increased as a negatively accelerating function of force requirement, and skewness and kurtosis were positive at low force requirements and decreased to negative values at the highest increments. Additional analyses of response kinetics indicated that rats, like humans, meet increasing force requirements by altering the rate of rise of force. The performance similarities suggest that common processes are engaged by the human and rat motor control systems to solve the problem of generating forces that are appropriate to the prevailing environmental constraints.  相似文献   
977.
The paper addresses three neglected questions from IRT. In section 1, the properties of the “measurement” of ability or trait parameters and item difficulty parameters in the Rasch model are discussed. It is shown that the solution to this problem is rather complex and depends both on general assumptions about properties of the item response functions and on assumptions about the available item universe. Section 2 deals with the measurement of individual change or “modifiability” based on a Rasch test. A conditional likelihood approach is presented that yields (a) an ML estimator of modifiability for given item parameters, (b) allows one to test hypotheses about change by means of a Clopper-Pearson confidence interval for the modifiability parameter, or (c) to estimate modifiability jointly with the item parameters. Uniqueness results for all three methods are also presented. In section 3, the Mantel-Haenszel method for detecting DIF is discussed under a novel perspective: What is the most general framework within which the Mantel-Haenszel method correctly detects DIF of a studied item? The answer is that this is a 2PL model where, however, all discrimination parameters are known and the studied item has the same discrimination in both populations. Since these requirements would hardly be satisfied in practical applications, the case of constant discrimination parameters, that is, the Rasch model, is the only realistic framework. A simple Pearsonx 2 test for DIF of one studied item is proposed as an alternative to the Mantel-Haenszel test; moreover, this test is generalized to the case of two items simultaneously studied for DIF.  相似文献   
978.
Event-related potentials were used to study how parsing of German relative clauses is influenced by semantic information. Subjects read well-formed sentences containing either a subject or an object relative clause and answered questions concerning the thematic roles expressed in those sentences. Half of the sentences contained past participles that on grounds of semantic plausibility biased either a subject or an object relative reading; the other half contained past participles that provided no semantic information favoring either reading. The past participle elicited an N400 component, larger in amplitude for neutral than for semantically biased verbs, but this occurred only in the case of subject relative clauses. More specific effects were obtained only for a subgroup of subjects, when these were grouped into fast and slow comprehenders on the basis of their questionanswering reaction times. Fast comprehenders showed larger N400 amplitudes for neutral than for semantically biased past participles in general and larger N400s for the latter when there was a bias for an object relative reading as opposed to a subject relative reading. Syntactic ambiguity resolution, indicated by an auxiliary in sentence final position, was associated in this subgroup with a positive component (P345), larger in amplitude for auxiliaries indicating an object relative reading than for those indicating a subject relative reading. The latter component was independent of semantically biasing information given by a preceding past participle. Implications of these findings for models of language comprehension are considered.  相似文献   
979.
Stimulus-independent thoughts (SITs) are streams of thoughts and images unrelated to immediate sensory input. Four experiments examined the contribution of aspects of working memory to production of SITs. In Experiments 1 and 2, interventions that were targeted on, respectively, phonological and visuospatial components of working memory both interfered with production of SITs, but there was evidence that these tasks also made demands on central executive resources. Experiments 3 and 4 specifically examined the hypothesis that production of SITs and control of nonproceduralized tasks both depend on central executive resources, and so should show mutual interference. In Experiment 3, prior practice on pursuit rotor and memory tasks reduced the interference with SITs from concurrent task performance. In Experiment 4, randomness within a task involving random-number generation was less when SITs were being produced concurrently than it was when they were not. The results suggest that production of SITs depends on central executive resources.  相似文献   
980.
Top-of-the-head worries were elicited from young people, grades 4 to 8, both before and after they completed quantitative risk assessments of specific health and environmental problems. Results revealed that many students carry a substantial worry burden that includes not only personal matters such as grades and social relations, but also concerns about death and about global issues such as homelessness and environmental degradation. The gender and grade differences that emerged were consistent with a developmental extension from self to societal perspectives. Differences in worry profiles from before to after the risk assessment interviews revealed some impact of recent exposure, as illustrated by a pre—post increase from 7% to 30% in students spontaneously expressing AIDS-related concerns. Implications of the breadth and severity of young people's concerns are discussed, as are the ambiguities inherent in standard assessment approaches.This research was supported by grants from the National Institute of Child Health and Human Development (HD27035) and the University of California Universitywide AIDS Research Program (R901040). We very much appreciate the cooperation of Sally Snyder and the Irvine Unified School District, Amy Watson and the Corinne A. Seeds University Elementary School, Trina Panaqua and the Bruin Kids of UCLA, and the Fernald Child Study Center. Special thanks are due to the 4th- through 8th-grade student participants. We are also grateful to Ellen Dellis, Virginia Elderkin-Thompson, Judy Hollingshead, Alison Holman, Judy Koch-Jones, and Kim Witte for their help with the interviews and to Tammy Merlo, Shealen Nash, and Beth Twambley for competent coding assistance. Finally, we thank the anonymous editorial reviewers for constructive comments on the nature of fear and worry.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号