全文获取类型
收费全文 | 44770篇 |
免费 | 1939篇 |
国内免费 | 31篇 |
出版年
2020年 | 496篇 |
2019年 | 583篇 |
2018年 | 832篇 |
2017年 | 786篇 |
2016年 | 885篇 |
2015年 | 610篇 |
2014年 | 763篇 |
2013年 | 3429篇 |
2012年 | 1437篇 |
2011年 | 1387篇 |
2010年 | 868篇 |
2009年 | 907篇 |
2008年 | 1199篇 |
2007年 | 1233篇 |
2006年 | 1096篇 |
2005年 | 983篇 |
2004年 | 935篇 |
2003年 | 837篇 |
2002年 | 885篇 |
2001年 | 1598篇 |
2000年 | 1598篇 |
1999年 | 1163篇 |
1998年 | 473篇 |
1997年 | 450篇 |
1995年 | 435篇 |
1992年 | 931篇 |
1991年 | 876篇 |
1990年 | 877篇 |
1989年 | 797篇 |
1988年 | 777篇 |
1987年 | 724篇 |
1986年 | 701篇 |
1985年 | 751篇 |
1984年 | 635篇 |
1983年 | 583篇 |
1982年 | 448篇 |
1979年 | 667篇 |
1978年 | 481篇 |
1977年 | 439篇 |
1976年 | 435篇 |
1975年 | 530篇 |
1974年 | 644篇 |
1973年 | 671篇 |
1972年 | 554篇 |
1971年 | 506篇 |
1970年 | 448篇 |
1969年 | 491篇 |
1968年 | 597篇 |
1967年 | 536篇 |
1966年 | 491篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
William C. Rein 《Behavioral sciences & the law》1984,2(2):179-193
In September 1981, a symposium of distinguished mental health practitioners from various clinical, administrative, research, and legal disciplines was conducted on the topic of “Behavioral Science and the Secret Service,” under the sponsorship of the National Academy of Sciences, Institute of Medicine. The article combines a study of the symposium's written conference summary, the author's experience as legal counsel to a state security hospital, and research into federal cases that have interpreted the so-called “Presidential Threat Statute” (18 USC 871) in order to discuss the role of the Secret Service in protecting elected federal officials from physical harm. The potential for increasing practical cooperation between the Service and state mental health systems is also discussed. 相似文献
962.
不同时相日光下颜色的恒常性 总被引:1,自引:0,他引:1
一、前言 在光源光谱成份改变的条件下,我们周围物体的颜色在眼睛看来保持相对不变,称为颜色恒常性。1807年Thomas Young首先描述了颜色恒常性现象,他指出室内不管是由蜡烛的黄光或火焰的红光来照明的,书页纸仍然看来是白色的。Young认为,外界某一表面的颜色外观,并不完全决定于网膜的红、绿、蓝三种感受器的吸收特性,而也依赖于周围其它物体射入眼睛的光通量。此后,E.Hering对颜色恒常性做了实验表演。一般认为颜色恒常性是对环境照明感受性的降低。视觉通道只传递由物体表面所反射的光谱成 相似文献
963.
964.
965.
JAMES T. KEMP 《Journal of counseling and development : JCD》1984,62(5):270-272
Each counseling experience with a frail or dying client is a learning opportunity. In these circumstances if is the counselor who is the student. 相似文献
966.
Bonnie B. Vermilyea David H. Barlow Gerald T. O'Brien 《Journal of psychopathology and behavioral assessment》1984,6(1):1-11
One purpose of this investigation was to examine the importance of assessing treatment integrity in a study evaluating a treatment for specific anxiety disorders. Three subjects, two social phobics and one simple phobic, received self-instruction training (Phase I) followed by exposure and self-instruction training (Phase II) in a multiple baseline across subjects design. All subjects were assessed during a pretreatment baseline and throughout treatment using measures of treatment integrity and measures of change in phobic severity. Improvement took place at different times for different subjects. Measures of treatment integrity, which consisted of monitoring of self-statements as well as practice outside the session, indicated that treatment was not always received as intended and that improvement was correlated with practice. The usefulness of measures of treatment integrity in both clinical and research settings is highlighted. 相似文献
967.
Helen L. Evans Russell T. Jones 《Journal of psychopathology and behavioral assessment》1984,6(3):207-218
This investigation was designed to ascertain the effects of instructions, criterion setting, and the presence of tangible rewards on the self-reinforcement process. Fifty-two third- and fourth-grade subjects were assigned to one of four treatment groups: (a) stringent instructions/criterion setting/tangible reward, (b) stringent instructions/criterion setting/no tangible reward, (c) nonstringent instructions/criterion setting/tangible reward, and (d) nonstringent instructions/no tangible reward. In the stringent-instruction conditions, subjects received social reinforcement for selecting stringent performance criteria, whereas in the non-stringent-instruction conditions, social reinforcement was withheld. Subjects in the tangible-reward groups were allowed to select a prize following the successful completion of their self-selected work performance. Subjects in the no-tangible-reward groups received no prizes for their work. All subjects performed an arithmetic task in which the number of correct problems completed, number of problems attempted, and time at task served as dependent variables across five reinforcement and two extinction trials. The results suggest that the condition of stringent instructions, criterion setting, and tangible reward was more effective in producing behavior change than the other three conditions. Perceived task difficulty and previous achievement on arithmetic task performance were shown to affect criteria selected and mathematical performance. The results are discussed in light of the contributory role of instructions, criterion setting, and tangible rewards on the self-reinforcement procedure.This study is based on a doctoral dissertation submitted to the Faculty of Arts and Sciences at the University of Pittsburgh by Helen L. Evans. Dr. Russell T. Jones was the dissertation committee chairperson. It was partially funded by an American Psychological Association Minority Fellowship awarded to the first author. Special thanks are extended to the committee members, Drs. Lloyd Bond, Robert Glaser, Johnny Matson, and Samuel M. Turner, for their assistance. The authors would like to thank Thomas DeVoge, Paul Karoly, and Samuel M. Turner for reading and commenting on an early draft of this study. Portions of this paper were presented at the 1982 APA convention. 相似文献
968.
SCOTT T. MEIER 《Journal of Occupational & Organizational Psychology》1984,57(3):211-219
Considerable confusion exists in the burnout literature about the similarities and separateness among the constructs of burnout, depression and job satisfaction. This study examined the construct validity of burnout using Campbell & Fiske's multitrait-multimethod approach. The constructs of burnout, depression and orderliness (chosen as a discriminant construct) were assessed by three types of self-report instruments. Data were analysed for 181 females and 139 male faculty members who spent at least 50 per cent of their time in teaching. Results indicated that measures of burnout largely met Campbell & Fiske's criteria for construct validity: burnout measures possessed adequate to good internal reliability and convergent validity. However, burnout measures also correlated substantially with measures of depression. Results are discussed in terms of possible explanations for the substantial overlap that has been demonstrated among measures of burnout, depression and job satisfaction. 相似文献
969.
Myron Charles Baker Diana F. Tomback Daniel B. Thompson Tad C. Theimer Dana C. Bradley 《Learning and motivation》1984,15(4):428-440
The functional significance of learned population differences in male song in the white-crowned sparrow was explored in natural populations using playback tests. Laboratory results have shown that learning of the population-specific song seems to take place in early life and is strongly dependent upon the nature of the auditory experience at that time. However, the varied results of recent studies make it difficult to reach a confident conclusion about the ecological functions of song learning. The present research took advantage of naturally occurring variation in the differences between songs of adjacent populations to determine a function relating degree of difference in song to intensity of territorial singing elicited. Applying a typological evaluation of syllable structure to the four segments of the song allowed a crude quantitative ranking of the differences between local songs and playback stimuli. These results, together with those of other studies, suggest a unimodal aggressive response function of males to songs of other males. A maximum response to songs slightly different from the local song environment suggests that male exclusion based upon acquired song components may contribute to the maintenance of discrete and stable song dialects. 相似文献
970.
Three experiments are described which elaborate some of the conditions under which rats will contact and manipulate a periodically presented retractable lever. Experiment 1 demonstrated that (i) initial manipulative oral and manual contact with the lever was facilitated if the rat had previous experience of food delivery in the experimental chamber; (ii) persistence in contacting the lever on successive presentations was a function of whether food continued to be presented in the experimental environment; and (iii) food satiation significantly reduced the tendency of the rat to contact the lever even though an expectancy of food had previously been established under conditions of food deprivation. Experiment 2 suggested that the tendency to approach and contact the lever was in part a function of the local moment-to-moment conditional probability of food delivery. Experiment 3 found that the probability of contacting the lever was higher during presentation of an auditory CS signaling a high rate of food delivery than during stimuli signaling no food at all. These results are interpreted as suggesting that the food-signaling aspects of an appetitive CS and that CS's ability to generate signal-directed behaviors are experimentall separable properties. 相似文献