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   1140篇
  免费   249篇
  国内免费   54篇
  2024年   3篇
  2023年   22篇
  2022年   15篇
  2021年   21篇
  2020年   35篇
  2019年   49篇
  2018年   56篇
  2017年   49篇
  2016年   45篇
  2015年   29篇
  2014年   47篇
  2013年   185篇
  2012年   25篇
  2011年   55篇
  2010年   29篇
  2009年   50篇
  2008年   55篇
  2007年   54篇
  2006年   62篇
  2005年   41篇
  2004年   39篇
  2003年   47篇
  2002年   22篇
  2001年   30篇
  2000年   14篇
  1999年   20篇
  1998年   17篇
  1997年   21篇
  1996年   20篇
  1995年   11篇
  1994年   12篇
  1993年   17篇
  1992年   17篇
  1991年   15篇
  1990年   10篇
  1989年   6篇
  1988年   7篇
  1987年   6篇
  1986年   16篇
  1985年   9篇
  1984年   12篇
  1983年   8篇
  1982年   9篇
  1981年   15篇
  1980年   14篇
  1979年   13篇
  1978年   25篇
  1977年   24篇
  1976年   29篇
  1975年   11篇
排序方式: 共有1443条查询结果,搜索用时 15 毫秒
71.
There are three primary purposes of this review. First, the review distinguishes among three types of reliability and describes the importance of evaluating the reliability of child psychopathology assessment instruments for clinical practice and research. Second, parent-child reliability findings from 5 of the more carefully studied and frequently used Structured (semi and highly) diagnostic interviews (The Schedule for Affective Disorders and Schizophrenia for School-age Children, The Child Assessment Scale, The Anxiety Disorders Interview Schedule for Children. The Diagnostic Interview for Children and Adolescents, and the Diagnostic Interview Schedule for Children) are examined. Finally, this review explores factors that have been implicated in terms of their potential effect on parent-child agreement. In addition, future directions for research and clinical practice within this area are identified and potential resolutions to the conundrum of parent-child discordance are discussed.  相似文献   
72.
The article addresses the issue of rationing health care services, a topic currently being hotly debated in many countries. The author argues that the aspect of causal responsibility ought to play a decisive role in the allocation of limited medical resources. Starting out from Ronald Dworkin's distinction between option luck and brute luck, the appropriate and meaningful uses of the term causal responsibility are clarified first. A discussion of the conditions which might justify giving lower priority to patients whose illnesses are the result of unhealthy behavior, like e.g. alcohol abuse, follows. Causal responsibility is then viewed in the context of private health insurance and the club model of organ donation. It is argued that individuals themselves are basically responsible for their decisions regarding insurance coverage and membership in organ donors' clubs. Causal responsibility is shown to be a more suitable criterion for rationing scarce medical resources than other criteria which might alternatively be considered, such as patients' age.  相似文献   
73.
Covert food stealing is common among individuals with Prader-Willi syndrome. We found that verbal reprimands, delivered contingent upon eating prohibited foods, were sufficient to decrease the food stealing of a girl with Prader-Willi syndrome. Warning stimuli were then used to help her discriminate between permitted and prohibited foods during sessions in which food stealing was not directly observed. This procedure resulted in decreases in food stealing from containers labeled with the warning stimuli.  相似文献   
74.
Four rats were studied with variants of a progressive-ratio schedule with a step size of 6 in which different terminal components followed completion of the 20th ratio: (a) a reversal of the progression, (b) a fixed-ratio 6 schedule, or (c) extinction. Responding in the progressive-ratio components of these schedules was compared to performances under conventional progressive-ratio baselines. Under baseline conditions, postreinforcement pauses increased exponentially as a function of increasing ratio size, whereas running rates showed modest declines. The procedure of linking the progressive-ratio schedule to the reversed progression or to the fixed-ratio component resulted in decreased pausing. Linking the progressive-ratio schedule to the extinction component had the opposite effect, that of producing weakened progressive-ratio performances as evidenced by increased pausing. Subjects whose responses were reinforced on half of the ratios also showed exponential increases; however, pauses were substantially shorter following ratios on which the reinforcer was omitted. The results suggested that progressive-ratio pausing reflects the influence of remote as well as local contingencies.  相似文献   
75.
Previous research on preference between variable-interval terminal links in concurrent chains has most often used variable-duration terminal links ending with a single reinforcer. By contrast, most research on resistance to change in multiple schedules has used constant-duration components that include variable numbers of reinforcers in each presentation. Grace and Nevin (1997) examined both preference and resistance in variable-duration components; here, preference and resistance were examined in constant-duration components. Reinforcer rates were varied across eight conditions, and a generalized-matching-law analysis showed that initial-link preference strongly over-matched terminal-link reinforcer ratios. In multiple schedules, baseline response rates were unaffected by reinforcer rates, but resistance to intercomponent food, to extinction, and to intercomponent food plus extinction was greater in the richer component. The between-component difference in resistance to change exhibited additive effects for the three resistance tests, and was systematically related to reinforcer ratios. However, resistance was less sensitive to reinforcer ratios than was preference. Resistance to intercomponent food and to intercomponent food plus extinction was more sensitive to reinforcer ratios in the present study than in Grace and Nevin (1997). Thus, relative to variable-duration components, constant-duration components increased the sensitivity of both preference and relative resistance, supporting the proposition that these are independent and convergent measures of the effects of a history of reinforcement.  相似文献   
76.
Brief multiple-stimulus-without-replacement (MSWO) preference assessments were conducted with 3 adolescent boys with emotional-behavioral disorders in the context of their public school educational program. The reinforcing effects of stimuli identified as high, medium, and low preference were then evaluated using an alternating treatments design in which, following an initial baseline, stimuli were delivered contingent on on-task behavior. High-preference stimuli produced the highest percentages of on-task behavior for all 3 participants.  相似文献   
77.
The fixed point combinator (Y) is an important non-proper combinator, which is defhable from a combinatorially complete base. This combinator guarantees that recursive equations have a solution. Structurally free logics (LC) turn combinators into formulas and replace structural rules by combinatory ones. This paper introduces the fixed point and the dual fixed point combinator into structurally free logics. The admissibility of (multiple) cut in the resulting calculus is not provable by a simple adaptation of the similar proof for LC with proper combinators. The novelty of our proof—beyond proving the cut for a newly extended calculus–is that we add a fourth induction to the by-and-large Gentzen-style proof. Presented by Robert Goldblatt  相似文献   
78.
79.
Chronic fatigue syndrome (CFS) is an important condition confronting patients, clinicians, and researchers. This article provides information concerning the need for appropriate diagnosis of CFS subtypes. We first review findings suggesting that CFS is best conceptualized as a separate diagnostic entity rather than as part of a unitary model of functional somatic distress. Next, research involving the case definitions of CFS is reviewed. Findings suggest that whether a broad or more conservative case definition is employed, and whether clinic or community samples are recruited, these decisions will have a major influence in the types of patients selected. Review of further findings suggests that subtyping individuals with CFS on sociodemographic, functional disability, viral, immune, neuroendocrine, neurology, autonomic, and genetic biomarkers can provide clarification for researchers and clinicians who encounter CFS characteristically confusing heterogeneous symptom profiles. Treatment studies that incorporate subtypes might be particularly helpful in better understanding the pathophysiology of CFS. This review suggests that there is a need for greater diagnostic clarity, and this might be accomplished by subgroups that integrate multiple variables including those in cognitive, emotional, and biological domains.  相似文献   
80.
These recommendations describe the minimum standard criteria for genetic counseling and testing of individuals and families with fragile X syndrome, as well as carriers and potential carriers of a fragile X mutation. The original guidelines (published in 2000) have been revised, replacing a stratified pre- and full mutation model of fragile X syndrome with one based on a continuum of gene effects across the full spectrum of FMR1 CGG trinucleotide repeat expansion. This document reviews the molecular genetics of fragile X syndrome, clinical phenotype (including the spectrum of premature ovarian failure and fragile X-associated tremor-ataxia syndrome), indications for genetic testing and interpretation of results, risks of transmission, family planning options, psychosocial issues, and references for professional and patient resources. These recommendations are the opinions of a multicenter working group of genetic counselors with expertise in fragile X syndrome genetic counseling, and they are based on clinical experience, review of pertinent English language articles, and reports of expert committees. These recommendations should not be construed as dictating an exclusive course of management, nor does use of such recommendations guarantee a particular outcome. The professional judgment of a health care provider, familiar with the facts and circumstances of a specific case, will always supersede these recommendations.  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