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   4571篇
  免费   716篇
  国内免费   344篇
  2024年   31篇
  2023年   189篇
  2022年   115篇
  2021年   123篇
  2020年   274篇
  2019年   265篇
  2018年   302篇
  2017年   280篇
  2016年   289篇
  2015年   172篇
  2014年   188篇
  2013年   831篇
  2012年   137篇
  2011年   124篇
  2010年   95篇
  2009年   159篇
  2008年   176篇
  2007年   205篇
  2006年   220篇
  2005年   208篇
  2004年   149篇
  2003年   130篇
  2002年   129篇
  2001年   104篇
  2000年   96篇
  1999年   81篇
  1998年   53篇
  1997年   72篇
  1996年   54篇
  1995年   46篇
  1994年   50篇
  1993年   38篇
  1992年   34篇
  1991年   22篇
  1990年   12篇
  1989年   18篇
  1988年   14篇
  1987年   13篇
  1986年   6篇
  1985年   12篇
  1984年   16篇
  1983年   9篇
  1982年   17篇
  1981年   6篇
  1980年   11篇
  1979年   19篇
  1978年   11篇
  1977年   11篇
  1976年   6篇
  1975年   9篇
排序方式: 共有5631条查询结果,搜索用时 15 毫秒
21.
In a conditional discrimination procedure, pigeons' observing responses were analyzed to examine whether two color stimuli (blue or red), conditionally related to whether each of two line stimuli (vertical or horizontal) accompanied reinforcement or nonreinforcement, functioned as conditioned reinforcers. If a variable-interval (VI) 10-s requirement was fulfilled, an observing response produced onset of a color stimulus. A little later, a line stimulus was presented independently of responding, added to the color stimulus to form a compound stimulus. If 55 s elapsed with a response not having occurred either through 55 s or after the variable-interval 10-s had timed out, one of the color-line compound stimuli was presented independently of responding. To control for sensory reinforcement effects and for earlier entrance to the later link, a simple discrimination procedure also was conducted in which reinforcement was not correlated with the color stimuli but with the line stimuli only. As in the conditional discrimination, the observing response also could produce earlier presentation of blue or red. The observing response occurred more frequently during the conditional discrimination than during the simple discrimination. The results were related to different theoretical accounts of conditioned reinforcement, particularly the information hypothesis.  相似文献   
22.
A within-subjects comparison was made of pigeons' performance on two temporal discrimination procedures that were signaled by differently colored keylight samples. During stimulus trials, a peck on the key displaying a slanted line was reinforced following short keylight samples, and a peck on the key displaying a horizontal line was reinforced following long keylight samples, regardless of the location of the stimuli on those two choice keys. During position trials, a peck on the left key was reinforced following short keylight samples and a peck on the right key was reinforced following long keylight samples, regardless of which line stimulus appeared on the correct key. Thus, on stimulus trials, the correct choice key could not be discriminated prior to the presentation of the test stimuli, whereas on position trials, the correct choice key could be discriminated during the presentation of the sample stimulus. During Phase 1, with a 0-s delay between sample and choice stimuli, discrimination learning was faster on position trials than on stimulus trials for all 4 birds. During Phase 2, 0-, 0.5-, and 1.0-s delays produced differential loss of stimulus control under the two tasks for 2 birds. Response patterns during the delay intervals provided some evidence for differential mediation of the two delayed discriminations. These between-task differences suggest that the same processes may not mediate performance in each.  相似文献   
23.
Two cynomolgous macaques categorized six colors into two groups of three after conditional discrimination training (zero-delay symbolic match-to-sample). The procedures resulted in the establishment of relations among the elements of each set-relations that were not specifically trained and that can be characterized by the properties of reflexivity, symmetry, and transitivity. Each set of colors was related to a characteristic pattern of responding: One response pattern involved temporal duration (press and hold the response keys); the second response pattern entailed repeated pressing and releasing of the response keys (fixed ratio 8). Six combinations of two colors were trained, three combinations from each set. After discriminative performance stabilized for each monkey, they were tested with 10 additional color combinations, all of which differed from the training combinations. The conditional relations established between test combinations can be characterized as stimulus equivalence. The training procedures were analogous to the procedure of using category names, and have implications for understanding the function of language in the formation of equivalence classes.  相似文献   
24.
25.
We examined the effect of reducing the interval between a patient's call for an appointment and the appointment itself. In Experiment 1, patients calling a family planning unit of a public health department were assigned appointments within either 1 or 3 weeks of their call. Data on patient “shows” and “no-shows” were recorded weekly for 6 weeks. Show rates for those in the 1-week appointment group were significantly higher than those in the 3-week group. In Experiment 2, patients were assigned to appointment dates either the next operating clinic day (next-day group) or 2 weeks from the call date (2-week group). Show rates for those in the next-day group were significantly better than show rates for patients in the 2-week group. Clinic productivity, time spent with patients, and consumer satisfaction were also assessed. Implications for appointment scheduling are discussed.  相似文献   
26.
Eight rats' lever presses were reinforced after an interruption in a tone, provided the lever had not been pressed before the tone interruption. After a few sessions, long before the animals reliably refrained from lever pressing before the interruption, the latencies of postinterruption presses (time from the termination of the interruption to the moment of the lever press) dissociated into two classes: short ones for to-be-rewarded presses, and long ones for presses in the other trials, which contained no reward because one or more lever presses had occurred before the interruption. Thus discrimination of impending reinforcement in the current trial occurred before there was evidence of sensitivity to reinforcement in the reinforcement-producing aspect of behavior. This finding is related to Shimp's (1981) contention that the temporal properties of recent behavior are reinforceable, if remembered. The present finding shows that learning to discriminate whether one's behavior has met a contingency, and learning to carry out this behavior, need not go together, implying that memory of temporal properties is probably a necessary but not a sufficient condition for learning the latter.  相似文献   
27.
African Americans are at significantly greater risk of hypertension and worse cardiovascular outcomes than other racialized groups, yet hypertension intervention effects remain limited. Thus, it is necessary to understand the potential mechanisms whereby interventions may be more effectively targeted to improve health. Supported by prior research evidence and guided by the Biobehavioral Family Model, this study examined associations between family relationship quality, psychological wellbeing, and self-management behaviors for African Americans with hypertension. Data were pooled from three Midlife Development in the U.S. projects, resulting in a sample of 317 African Americans (63.4% female, Mage = 53.32) with self-reported high blood pressure in the past 12 months. We tested four cross-sectional multiple mediator models, with depressed mood and environmental mastery mediating associations between family strain and exercise, smoking, problematic alcohol use, and stress-eating. Environmental mastery mediated the association between greater family strain and decreased odds of achieving recommended exercise levels; greater odds of reporting problematic alcohol use; and greater stress-eating. Though family strain was associated with depressed mood in each model, this variable did not serve as an indirect pathway to self-management behaviors. Family strain, and the potential pathway identified via environmental mastery, may be a meaningful predictor of disease self-management for African Americans with hypertension. Longitudinal studies are needed to examine directionality and to support intervention trials for improving self-management and hypertension outcomes.  相似文献   
28.
29.
Nancy Suchman's work highlighted the fundamental role of maternal mentalization in maternal addiction, mental health, and caregiving challenges. In this study, we aimed to examine the role of mental-state language (MSL) as a measure of mentalization in prenatal and postnatal narratives and their sentiment in a sample of 91 primarily White mothers from the western United States, followed from the second trimester of pregnancy, through the third trimester, to 4 months postpartum. Specifically, we investigated the use of affective and cognitive MSL in prenatal narratives when mothers visualized caring for their baby and postnatal narratives when mothers compared their prenatal visualization to the current caregiving reality. Results indicated moderate consistency in MSL between the second and third trimesters, but prenatal and postnatal MSL was not significantly correlated. Across all time points, higher use of MSL was related to more positive sentiment, indicating an association between mentalization and positive caregiving representations across the perinatal period. Women used more affective than cognitive MSL in prenatal imagination of caregiving, but this pattern was reversed in their postpartum reflection. Implications on assessing parental mentalization prenatally and considering the relative dominance of affective and cognitive mentalizing are discussed while considering study limitations.  相似文献   
30.
The mental health field now possesses clinical trials attesting to the efficacy of affirmative practice with sexual minority individuals. With the goal of efficiently moving the results of these clinical trials into real-world clinical practice, this paper offers a model for adapting existing evidence-based practices originally developed for the general population to be lesbian, gay, bisexual, and queer (LGBQ)-affirmative. The adaptation model presented here guides clinicians to incorporate six LGBQ-affirmative transtheoretical principles of change into practice. These principles facilitate raising awareness of the impact of minority stress on sexual minority clients’ mental health and on client self-evaluation while drawing upon sexual minority resilience and intersectional experiences to build empowering coping skills and validating relationships. The adaptation model also provides a transtheoretical approach to case conceptualization that directs clinicians to consider the role of early and ongoing minority stress on sexual minority clients’ cognitive, affective, motivational, behavioral, and self-evaluative experiences that maintain current distress. This case conceptualization approach highlights common associations among these experiences, suggesting clear routes of interventions for many sexual minority client presentations. Case examples from recent clinical trials of LGBQ-affirmative cognitive-behavioral therapy illustrate how these principles and this case conceptualization can be effectively utilized in practice. While the principles and case conceptualization are meant to be transtheoretical and therefore applicable across therapeutic techniques, to date they have been tested only in clinical trials for cognitive-behavioral treatments. Therefore, this paper concludes with a call for future research to determine the effectiveness of implementing this adaptation model across diverse therapeutic modalities and client presentations.  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