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   201686篇
  免费   8644篇
  国内免费   163篇
  210493篇
  2020年   2808篇
  2019年   3468篇
  2018年   3876篇
  2017年   4298篇
  2016年   4861篇
  2015年   3952篇
  2014年   4829篇
  2013年   23527篇
  2012年   5595篇
  2011年   4991篇
  2010年   4377篇
  2009年   4997篇
  2008年   4990篇
  2007年   4708篇
  2006年   4983篇
  2005年   4836篇
  2004年   4275篇
  2003年   3855篇
  2002年   3719篇
  2001年   4569篇
  2000年   4378篇
  1999年   3981篇
  1998年   2946篇
  1997年   2754篇
  1996年   2666篇
  1995年   2496篇
  1994年   2443篇
  1993年   2418篇
  1992年   3350篇
  1991年   3107篇
  1990年   2994篇
  1989年   2800篇
  1988年   2797篇
  1987年   2774篇
  1986年   2794篇
  1985年   2963篇
  1984年   2917篇
  1983年   2640篇
  1982年   2501篇
  1981年   2467篇
  1980年   2306篇
  1979年   2765篇
  1978年   2448篇
  1977年   2320篇
  1976年   2159篇
  1975年   2415篇
  1974年   2529篇
  1973年   2513篇
  1972年   2036篇
  1968年   1966篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
921.
Are changes over time in the quality of a woman's job associated with changes in her psychological distress? Do family roles moderate these relationships? We addressed these questions using longitudinal data from a 2-year 3-wave study of a stratified random sample of 403 employed women who varied in occupation, race, partnership, and parental status. After estimating individual rates of change for each woman on each of the predictors and the outcome, we modeled the relationships between family role occupancy and change in job-role quality on the one hand, and change in psychological distress on the other. Among single women and women without children, as job-role quality declined, levels of psychological distress increased. Among partnered women and women with children, change in job-role quality was unrelated to change in psychological distress.  相似文献   
922.
Two experiments examined the influence of anger and retaliatory motivation on memory for negative material. In the 1st study, 60 male undergraduates memorized words with positive, negative, and neutral semantic connotations. It was found that angered men who expected to retaliate against their provocateur recalled more negative words than other words, and more than Ss in all other affect and evaluation conditions. Angered men in the nonretaliation condition displayed no differences in negative word recall. The 2nd experiment investigated memory for details of a provoking experience. Angered men who expected to retaliate more accurately recalled the details of their provocation, but whether they were given the retaliation information before or after provocation had no bearing on memory for these details. Results are discussed in terms of a motivation-based selective generation hypothesis for the relationship between anger and memory.  相似文献   
923.
This article describes the different reactions to emergency warning messages among residents living within a 3-km radius of a hazardous chemical complex and by people living at least 10 km from an industrial site in France, Greece, and the Netherlands. Belief in warning, primary and secondary appraisal, emotional response, and adherence to normal routine were assessed by conducting face-to-face interviews in which a four-phase scenario simulating a credible industrial accident was presented. The results showed that respondents who did not reside in the neighborhood of the hazardous site were, in general, more inclined to trust the warning messages than respondents who resided in the neighborhood were. With the exception of primary appraisal, the warning phases evoked very distinct reactions in the respondents from all three countries with regard to warning belief, secondary appraisal, emotional response, and adherence to normal routine.  相似文献   
924.
In a discrete-trials procedure with pigeons, a response on a green key led to a 4-s delay (during which green houselights were lit) and then a reinforcer might or might not be delivered. A response on a red key led to a delay of adjustable duration (during which red houselights were lit) and then a certain reinforcer. The delay was adjusted so as to estimate an indifference point--a duration for which the two alternatives were equally preferred. Once the green key was chosen, a subject had to continue to respond on the green key until a reinforcer was delivered. Each response on the green key, plus the 4-s delay that followed every response, was called one "link" of the green-key schedule. Subjects showed much greater preference for the green key when the number of links before reinforcement was variable (averaging four) than when it was fixed (always exactly four). These findings are consistent with the view that probabilistic reinforcers are analogous to reinforcers delivered after variable delays. When successive links were separated by 4-s or 8-s "interlink intervals" with white houselights, preference for the probabilistic alternative decreased somewhat for 2 subjects but was unaffected for the other 2 subjects. When the interlink intervals had the same green houselights that were present during the 4-s delays, preference for the green key decreased substantially for all subjects. These results provided mixed support for the view that preference for a probabilistic reinforcer is inversely related to the duration of conditioned reinforcers that precede the delivery of food.  相似文献   
925.
Stimulus effects on concurrent performance in transition   总被引:2,自引:2,他引:0       下载免费PDF全文
Six experimentally naive pigeons were exposed to concurrent variable-interval variable-interval schedules in a three-key procedure in which food reinforcement followed pecks on the side keys and pecks on the center key served as changeover responses. In Phase 1, 3 birds were exposed to 20 combinations of five variable-interval values, with each variable-interval value consistently associated with a different color on the side keys. Another 3 pigeons were exposed to the same 20 conditions, but with a more standard procedure that used a nondifferential discriminative stimulus on the two side keys throughout all conditions. In Phase 2, the differential and nondifferential stimulus conditions were reversed for each pigeon. Each condition lasted for one 5-hr session and one subsequent 1-hr session. In the last 14 conditions of each phase, the presence of differential discriminative stimuli decreased the time necessary for differential responding to develop and increased the sensitivity of behavior to reinforcement distribution in the 1st hr of training; during the last hours of training in each condition, however, the effects of the differential discriminative stimuli could not be distinguished from the effects of reinforcement distribution per se. These results show the importance of studying transitions in behavior as well as final performance. They may also be relevant to discrepancies in the results of previous experiments that have used nonhuman and human subjects.  相似文献   
926.
In two experiments, key pecking of pigeons was maintained by a variable-interval 180-s schedule of food presentation. Conjointly, a second schedule delivered response-dependent electric shock. In the first experiment, shocks were presented according to either a variable-interval or a nondifferential interval-percentile schedule. The variable-interval shock schedule differentially delivered shocks following long interresponse times. Although the nondifferential shock schedules delivered shocks less differentially with respect to interresponse times, the two shock schedules equally reduced the relative frequency of long interresponse times. The second experiment differentially shocked long or short interresponse times in different conditions, with resulting decreases in the relative frequency of the targeted interresponse times. These experiments highlight the importance of selecting the appropriate level of analysis for the interaction of behavior and environment. Orderly relations present at one level of analysis (e.g., interresponse times) may not be revealed at other levels of analysis (e.g., overall response rate).  相似文献   
927.
Inelastic supply: An economic approach to simple interval schedules   总被引:1,自引:1,他引:0       下载免费PDF全文
Economic theory predicts an inverse relationship between the quantity of a commodity supplied to the marketplace and the equilibrium market price of that commodity. This prediction was tested in three experiments. Pigeons responded on simple variable-interval schedules, and quantity of reinforcement supplied was varied in a different way in each experiment. In Experiment 1, quantity supplied was varied by manipulating reinforcement rate while keeping session length constant. In Experiment 2, quantity supplied was varied by manipulating reinforcement rate while keeping reinforcers per session constant. In Experiment 3, quantity supplied was varied by manipulating reinforcer magnitude while keeping number of reinforcers constant. As predicted by economic theory, the obtained behavioral cost (responses per reinforcer) increased as supply decreased. The results could not be explained by simple artifacts such as satiation and time available to respond. In addition, the function relating response rate to reinforcement rate was bitonic in 7 of 9 animals in Experiments 1 and 2, which supports economic and regulatory theories over more traditional reinforcement theories.  相似文献   
928.
We evaluated the efficacy of the Addiction Potential Scale (APS) and the Addiction Acknowledgement Scale (AAS), two new scales designed to assess substance abuse problems with the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), in samples from settings different from those used in their development. Results replicate earlier findings that both scales discriminate between psychiatric and substance abuse samples and do so more effectively than other substance abuse scales designed for use with the MMPI and carried over to the MMPI-2. Results also suggest that APS may be more resistant than AAS to response distortion.  相似文献   
929.
The Rorschach Inkblot Test has been the source of long-standing controversies as to its nature and its psychometric properties. Consistent with behavioral science research in general, the concept of statistical power has been entirely ignored by Rorschach researchers. The concept of power is introduced and discussed, and a power survey of the Rorschach literature published between 1975 and 1991 in the Journal of Personality Assessment, Journal of Consulting and Clinical Psychology, Journal of Abnormal Psychology, Journal of Clinical Psychology, Journal of Personality, Psychological Bulletin, American Journal of Psychiatry, and Journal of Personality and Social Psychology was undertaken. Power was calculated for 2,300 statistical tests in 158 journal articles. Power to detect small, medium, and large effect sizes was .13, .56, and .85, respectively. Similar to the findings in other power surveys conducted on behavioral science research, we concluded that Rorschach research is underpowered to detect the differences under investigation. This undoubtedly contributes to the inconsistency of research findings which has been a source of controversy and criticism over the decades. It appears that research conducted according to the Comprehensive System for the Rorschach is more powerful. Recommendations are offered for improving power and strengthening the design sensitivity of Rorschach research, including increasing sample sizes, use of parametric statistics, reduction of error variance, more accurate reporting of findings, and editorial policies reflecting concern about the magnitude of relationships beyond an exclusive focus on levels of statistical significance.  相似文献   
930.
Mental health practitioners continually struggle to find a simple framework for describing the characteristics of the psychologically healthy individual. Hillel's often quoted saying provides relevant insight into the healthy personality and a convenient framework against which to examine psychological health.  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