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   3794篇
  免费   185篇
  国内免费   3篇
  2020年   54篇
  2019年   63篇
  2018年   100篇
  2017年   118篇
  2016年   110篇
  2015年   66篇
  2014年   94篇
  2013年   478篇
  2012年   128篇
  2011年   128篇
  2010年   85篇
  2009年   89篇
  2008年   157篇
  2007年   137篇
  2006年   104篇
  2005年   121篇
  2004年   94篇
  2003年   95篇
  2002年   85篇
  2001年   38篇
  2000年   52篇
  1999年   47篇
  1998年   63篇
  1997年   42篇
  1996年   44篇
  1995年   41篇
  1994年   45篇
  1992年   52篇
  1990年   37篇
  1989年   40篇
  1988年   41篇
  1987年   32篇
  1986年   45篇
  1985年   38篇
  1984年   55篇
  1983年   41篇
  1982年   38篇
  1981年   46篇
  1980年   50篇
  1979年   39篇
  1978年   48篇
  1977年   52篇
  1976年   50篇
  1975年   57篇
  1974年   48篇
  1973年   56篇
  1972年   37篇
  1971年   35篇
  1970年   39篇
  1968年   42篇
排序方式: 共有3982条查询结果,搜索用时 15 毫秒
951.
952.
We describe an ecological momentary assessment (EMA) protocol designed to measure daily life experiences along several psychosocial dimensions (Social Conflict, Task Demand, Decisional Control, Negative Affect, and Arousal) hypothesized to be relevant for cardiovascular disease risk. In a large community sample, these assessments have been administered in conjunction with ambulatory blood pressure (ABP) monitoring and measures of subclinical cardiovascular disease. Several results have emerged that support the promise of this approach. First of all, each of these dimensions of experience appears to be a trigger for cardiovascular activation, with movement on each scale being associated with significant within-person changes in heart rate and blood pressure in the natural environment. Second, there appear to be individual differences in physiological responsiveness to these dimensions of daily experience, with such differences being associated in some cases with laboratory-based assessments of cardiovascular reactivity, as might be expected. Third, EMA ratings are associated in several instances with (between-person) stable individual differences in ABP readings. And finally, we have found that some of the characteristics defined by our EMA ratings are related to measures of subclinical atherosclerosis. Such effects appear to be mediated, in part, by ABP. The advantages of using EMA measures for capturing the effects of psychosocial stressors are highlighted by comparing the predictive validity of these daily life assessments to traditional global self-reports. We conclude by describing future plans for use of this type of assessment protocol for helping us to characterize psychosocial characteristics relevant to cardiovascular disease risk. Personality and social processes during daily living may have an important impact not only on psychological functioning but also on physical health and disease. In this article we review our recent work involving the assessment of daily experience as a means of better understanding the role of psychosocial stress in cardiovascular disease risk. First, we outline the rationale for our interest in daily experience sampling for examining these processes, and we describe the methods we have adopted for this purpose. Next, we review findings from a recent study in which we have used these approaches to examine the role of psychosocial stress on ABP and atherosclerosis in a community-dwelling sample. We compare our approach to more traditional (global self-report and laboratory-observation) methods for examining these relationships in humans, and we discuss potential future directions for use of daily experience sampling in studies of health and behavior.  相似文献   
953.
Crewmember performance before, during, and after spaceflight   总被引:1,自引:0,他引:1  
The development of technologies for monitoring the welfare of crewmembers is a critical requirement for extended spaceflight. Behavior analytic methodologies provide a framework for studying the performance of individuals and groups, and brief computerized tests have been used successfully to examine the impairing effects of sleep, drug, and nutrition manipulations on human behavior. The purpose of the present study was to evaluate the feasibility and sensitivity of repeated performance testing during spaceflight. Four National Aeronautics and Space Administration crewmembers were trained to complete computerized questionnaires and performance tasks at repeated regular intervals before and after a 10-day shuttle mission and at times that interfered minimally with other mission activities during spaceflight. Two types of performance, Digit-Symbol Substitution trial completion rates and response times during the most complex Number Recognition trials, were altered slightly during spaceflight. All other dimensions of the performance tasks remained essentially unchanged over the course of the study. Verbal ratings of Fatigue increased slightly during spaceflight and decreased during the postflight test sessions. Arousal ratings increased during spaceflight and decreased postflight. No other consistent changes in rating-scale measures were observed over the course of the study. Crewmembers completed all mission requirements in an efficient manner with no indication of clinically significant behavioral impairment during the 10-day spaceflight. These results support the feasibility and utility of computerized task performances and questionnaire rating scales for repeated measurement of behavior during spaceflight.  相似文献   
954.
This study investigated (1) whether attention deficit/hyperactivity disorder (AD/HD) is associated with executive functioning (EF) deficits while controlling for oppositional defiant disorder/conduct disorder (ODD/CD), (2) whether ODD/CD is associated with EF deficits while controlling for AD/HD, and (3)~whether a combination of AD/HD and ODD/CD is associated with EF deficits (and the possibility that there is no association between EF deficits and AD/HD or ODD/CD in isolation). Subjects were 99~children ages 6–12 years. Three putative domains of EF were investigated using well-validated tests: verbal fluency, working memory, and planning. Independent of ODD/CD, AD/HD was associated with deficits in planning and working memory, but not in verbal fluency. Only teacher rated AD/HD, but not parent rated AD/HD, significantly contributed to the prediction of EF task performance. No EF deficits were associated with ODD/CD. The presence of comorbid AD/HD accounts for the EF deficits in children with comorbid AD/HD+ODD/CD. These results suggest that EF deficits are unique to AD/HD and support the model proposed by R. A. Barkley (1997).  相似文献   
955.
The authors highlight the utility of distribution-analytical techniques in the study of individual differences and clinical disorders. Cognitive deficits associated with attention-deficit/hyperactivity disorder (AD/HD) were examined by using delta-plot analyses of performance data (reaction time and accuracy) obtained through the use of a prototypical conflict task, the Eriksen flanker task. In 20 children with AD/HD (compared with matched control participants), overall performance measures indicated a marginal performance deficit. Delta-plot analyses indicated that performance deficits associated with AD/HD involve response inhibition but not automatic response activation. In a within-subjects titration study, the response inhibition deficit was eliminated by methylphenidate treatment, but these effects were highly dose specific. The beneficial effect of methylphenidate was clarified further after correcting for inter-individual variation in sensitivity to medicine dosage.  相似文献   
956.
This paper describes a hypothesis of Tronick's (2002) that positive and negative affect activation waves with changing amplitudes based on positive and negative lived experiences are the sources of persistent or regularly recurrent moods of feeling upbeat or downbeat. The characteristics of discrete affects, moods, and affect states are discussed in the light of a previous study based on clinical observation (Lichtenberg, Lachmann, and Fosshage 1996). The clinical experience theory underpinning that study is then compared with Tronick's Sanderian activation wave theory. A case example is presented, and the overall relevance of Tronick's theory to clinical work is discussed.  相似文献   
957.
Viewing a distorted face induces large aftereffects in the appearance of an undistorted face. The authors examined the processes underlying this adaptation by comparing how selective the aftereffects are for different dimensions of the images including size, spatial frequency content, contrast, and color. Face aftereffects had weaker selectivity for changes in the size, contrast, or color of the images and stronger selectivity for changes in contrast polarity or spatial frequency. This pattern could arise if the adaptation is contingent on the perceived similarity of the stimuli as faces. Consistent with this, changing contrast polarity or spatial frequency had larger effects on the perceived identity of a face, and aftereffects were also selective for different individual faces. These results suggest that part of the sensitivity changes underlying the adaptation may arise at visual levels closely associated with the representation of faces.  相似文献   
958.
Preference orderings among a set of options may depend on the elicitation method (e.g., choice or pricing); these preference reversals challenge traditional decision theories. Previous attempts to explain these reversals have relied on allowing utility of the options to change across elicitation methods by changing the decision weights, the attribute values, or the combination of this information--still, no theory has successfully accounted for all the phenomena. In this article, the authors present a new computational model that accounts for the empirical trends without changing decision weights, values, or combination rules. Rather, the current model specifies a dynamic evaluation and response process that correctly predicts preference orderings across 6 elicitation methods, retains stable evaluations across methods, and makes novel predictions regarding response distributions and response times.  相似文献   
959.
Criminal justice, mental health, and social service professionals face a myriad of role expectations in working with prisoners with mental illness to facilitate community re-entry. These expectations include those related to law enforcement, social welfare, and administrative efficiency. The challenge for front line workers and the multiple systems that employ them is to integrate all these expectations effectively on behalf of the individual as well as the community. Current models of re-entry for individuals leaving prison with mental illness focus on the management and interaction of service systems. This paper presents a model of prisoner re-entry that incorporates a larger social context, illustrating dynamics related to both individuals with mental illness leaving prison and their interaction with the community setting. This model was generated through an interdisciplinary team effort. It was refined through a focus group process that included advocates, community members and other informants from mental health and criminal justice systems in five states. The model is designed to generate new questions for research that address both individual and community level issues.  相似文献   
960.
Lightness, the perceived gray shade of a surface, and the perception of self-luminous surfaces—that is, surfaces that appear to glow—have most often been studied with paper displays and computer-generated stimuli presented on CRT monitors. Although both methods are often effective, experiments that require a wide range of luminance values in the same display are often difficult to conduct with paper and computer displays alone. Also, color mode appearance is often an issue when surface color perception is the topic of research; CRT monitors are essentially light sources themselves and often appear in the luminous mode of color appearance. Here, we describe an apparatus in which the target is an undetected aperture whose luminance is adjustable. Whereas a typical CRT monitor offers a luminance range of about 100:1, much broader luminance ranges are possible with the described apparatus. Unlike a CRT monitor, the stimulus background will always appear in the surface mode of color perception, and the target(s) can appear as either surface colors or luminous colors. Apparatus modifications are possible, including the addition of a stereoscope or an embedded CRT for creating an adjustable region that is computer controlled.  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