全文获取类型
收费全文 | 30210篇 |
免费 | 906篇 |
国内免费 | 13篇 |
专业分类
31129篇 |
出版年
2020年 | 251篇 |
2019年 | 245篇 |
2018年 | 1806篇 |
2017年 | 1614篇 |
2016年 | 1287篇 |
2015年 | 278篇 |
2014年 | 364篇 |
2013年 | 1559篇 |
2012年 | 860篇 |
2011年 | 1684篇 |
2010年 | 1422篇 |
2009年 | 1015篇 |
2008年 | 1348篇 |
2007年 | 1591篇 |
2006年 | 556篇 |
2005年 | 571篇 |
2004年 | 519篇 |
2003年 | 485篇 |
2002年 | 438篇 |
2001年 | 812篇 |
2000年 | 816篇 |
1999年 | 589篇 |
1998年 | 237篇 |
1997年 | 218篇 |
1996年 | 196篇 |
1992年 | 483篇 |
1991年 | 424篇 |
1990年 | 490篇 |
1989年 | 408篇 |
1988年 | 384篇 |
1987年 | 366篇 |
1986年 | 388篇 |
1985年 | 441篇 |
1984年 | 341篇 |
1983年 | 287篇 |
1982年 | 224篇 |
1979年 | 322篇 |
1978年 | 260篇 |
1977年 | 207篇 |
1976年 | 200篇 |
1975年 | 300篇 |
1974年 | 346篇 |
1973年 | 354篇 |
1972年 | 274篇 |
1971年 | 242篇 |
1970年 | 208篇 |
1969年 | 228篇 |
1968年 | 289篇 |
1967年 | 252篇 |
1966年 | 272篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
801.
Discrimination of methadone and cocaine by pigeons without explicit discrimination training. 下载免费PDF全文
D W Schaal M P McDonald M A Miller M P Reilly 《Journal of the experimental analysis of behavior》1996,66(2):193-203
Pigeons were trained to peck a key on a variable-interval 2-min schedule of food reinforcement. Prior to each session, either 2.0 mg/kg methadone (n = 3), 3.0 mg/kg cocaine (n = 4), or 5.6 mg/kg cocaine (n = 2) was administered. When each pigeon's rate of pecking was stable, a range of doses of the training drug and saline were administered prior to 20-min extinction sessions separated by at least four training sessions. Rate of pecking during these extinction tests was generally an increasing function of dose, with the lowest rates obtained following saline and low doses and the highest rates obtained following doses near the training doses. Dose functions from pigeons trained with 5.6 mg/kg cocaine were steeper than those from pigeons trained with 3.0 mg/kg cocaine. Pigeons trained with methadone or 3.0 mg/kg cocaine were then given discrimination training, in which food reinforcement followed drug administration and 20-min extinction sessions followed saline administration. Rates of pecking under these conditions quickly diverged until near-zero rates were obtained following saline and high rates were obtained following drug. Discrimination training steepened dose functions for the training drugs, and the effects of several other substituted drugs depended on the pharmacology of the training drug. The pigeons trained with 5.6 mg/kg cocaine were tested with d-amphetamine, methadone, and morphine prior to discrimination training. d-Amphetamine increased rates dose dependently, and methadone and morphine did not. The results suggest that discriminative control by methadone and cocaine was established without explicit discrimination training. 相似文献
802.
ITEM GENERATION PROCEDURES AND BACKGROUND DATA SCALES: IMPLICATIONS FOR CONSTRUCT AND CRITERION-RELATED VALIDITY 总被引:1,自引:0,他引:1
MICHAEL D. MUMFORD DAVID P. COSTANZA MARY SHANE CONNELLY JULIE F. JOHNSON 《Personnel Psychology》1996,49(2):361-398
Background data measures are one of the best predictors of job performance. Nonetheless, questions have been raised about their content and construct validity. The present effort describes a set of procedures for developing construct and content valid background data items. Data gathered in seven field studies and six laboratory studies are presented bearing on the reliability and validity of the measures constructed using these item generation procedures. Findings in these studies indicate that construct-based item generation procedures yield reliable scales evidencing both content and construct validity. Furthermore, these scales are capable of predicting performance in a variety of settings. Theoretical and practical implications of these findings for the development and validation of background data measures are discussed. 相似文献
803.
The purpose of this study was to learn more about the role of religious beliefs and practices in bereavement. Subjects were 312 adults each bereaved approximately one year. They were interviewed at the rate of about 50 per year over a 6 year period. Conclusions include: a) The opportunity to say goodbye to the deceased was significantly related to positive coping and outlook; (b) 47% of our subjects reported contact with the deceased following the death but such contact was not related to coping or outlook; c) grieving people are much more likely to turn to women than men for help; d) 77% said their religious beliefs were of considerable help in their grief. 相似文献
804.
805.
H. Nicholas Nagel Lewis P. Shapiro Betty Tuller Rebecca Nawy 《Journal of psycholinguistic research》1996,25(2):319-344
We present three experiments designed to investigate the role of prosody during sentence processing. The first investigated the question of whether an utterance's prosodic contour influences its comprehension on-line. We spliced the beginning and end portions of direct object and embedded clause sentences and observed the consequent effects on comprehension using a dual-task procedure to measure processing load. Our second experiment sought to determine-whether the constituent structure of these sentences could be reliably predicted using prosodic information. We found that the duration and F0 contour associated with the main-clause verb and the following NP reliably distinguished between the direct object and embedded clause constructions. In the final experiment, we manipulated the duration of the main-clause verb and found that subjects used this information to guide their initial parse during on-line sentence comprehension. The need for a model of sentence processing that addresses the use of prosodic information is discussed.The work reported in this paper was supported in part by NTH grant DC00494. 相似文献
806.
Gregory M. Herek J. Roy Gillis Eric K. Glunt Jeffrey Lewis David Welton John P. Capitanio 《American journal of community psychology》1998,26(5):705-743
The importance of using culturally sensitive educational materials in HIV-related interventions with racial and ethnic minority groups is widely recognized. However, little empirical research has been conducted to assess the relative effectiveness of different techniques for creating culturally sensitive AIDS educational videos. Two field experiments with three samples of African American adults (N = 174, 173, and 143) were conducted to assess how source characteristics (race of communicator), message characteristics (multicultural message vs. culturally specific message), and audience characteristics (racial distrust and AIDS-related distrust) influence proximate (perceptions of the message's credibility and attractiveness) and distal (AIDS-related attitudes, beliefs, and behavioral intentions) output variables for AIDS educational videos. In Study 1, an AIDS video with a culturally specific message was rated as more credible, more attractive, and of higher quality than was a video with a multicultural message. The multicultural message was rated less favorably when delivered by a White announcer than when the announcer was Black. In Study 2, the same pattern was replicated with a second community sample and a campus-based sample. Study 2 also indicated that a multicultural message might be more effective if delivered in a culturally specific context, namely, after audience members watch a culturally specific video. Minimal changes were observed in distal outcome variables. It is argued that influencing proximate output variables is necessary, though not sufficient, for effecting long-term change in AIDS-related attitudes, beliefs, and behaviors. 相似文献
807.
Although few guidelines exist, many therapists use prayer as a part of psychotherapy. The immense variance inherent in prayer behaviors and the paucity of literature on its use beckons the profession to develop a model for its use in therapy, examine the ethical implications for such use, and prepare guidelines for practice. A tripartite model for the conceptualization and localization of prayer in therapy is presented, ethical issues of therapist bias and competence and clients' right to autonomous decision making are considered, and guidelines for employing prayer in psychotherapy are developed. 相似文献
808.
Sunaina Assanand John P. J. Pinel Darrin R. Lehman 《Journal of applied social psychology》1998,28(11):998-1015
Recent research on hunger and eating has shown that (a) among individuals with adlibitum access to food, hunger and eating are not regulated by deviations in the body's energy resources from set-points, and (b) it is healthier for people to consume their daily caloric intake as several small snacks than as 3 large meals. People's beliefs about hunger and eating were assessed in 2 questionnaire studies. In Study 1, a large sample of undergraduates was surveyed; in Study 2, dietetics students, nursing students, medical students, dietitians, nurses, and doctors were surveyed. Both studies revealed that people's personal theories of hunger and eating were inconsistent with research findings in ways that could promote overconsumption. These results suggest that educational programs designed to modify the beliefs about hunger and eating of people suffering from problems of overconsumption and of health professionals who treat problems of overconsumption may increase the effectiveness of current treatment regimens. 相似文献
809.
P. A. Lamal 《Journal of applied behavior analysis》1998,31(4):705-706
The proposal of Friman, Hayes, and Wilson (1998) that the concept of emotion be incorporated into behavior analysis is questioned. Their proposal is undermined by the problem of the verification of private events by others. A focus on private events, as exemplified by the proposal of Friman et al., can lead to a reversion to notions of agency and the autonomous individual. Also, the anchoring of hypothetical constructs to the behavioral data language is ill advised. 相似文献
810.
Donna K. Wood Alan R. Frank David P. Wacker 《Journal of applied behavior analysis》1998,31(3):323-338
Multiple baseline designs were used to examine the effects of an instructional package on accuracy of performance in solving multiplication facts by 3 students with learning disabilities. The instructional package included the following components: (a) a modified instructional sequence in which multiplication facts were grouped into the zeros, ones, doubles, fives, and nines categories, and those remaining; (b) identification of the category in which each fact belonged; (c) mnemonic strategies associated with solving facts in each category; and (d) steps to be completed for solving facts in each category. Results indicated that the instructional package produced substantial and immediate effects. After receiving instruction, a participant's accuracy was often 100%, and this was maintained throughout the evaluation even as other strategies were introduced. Comparable results occurred across students, demonstrating replication of the effects of the instructional package. 相似文献