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   27100篇
  免费   900篇
  国内免费   13篇
  2019年   270篇
  2018年   500篇
  2017年   497篇
  2016年   602篇
  2015年   418篇
  2014年   385篇
  2013年   1871篇
  2012年   879篇
  2011年   913篇
  2010年   413篇
  2009年   405篇
  2008年   555篇
  2007年   608篇
  2006年   526篇
  2005年   1786篇
  2004年   1082篇
  2003年   887篇
  2002年   608篇
  2001年   780篇
  2000年   736篇
  1999年   581篇
  1998年   229篇
  1996年   233篇
  1995年   212篇
  1992年   477篇
  1991年   487篇
  1990年   487篇
  1989年   442篇
  1988年   447篇
  1987年   417篇
  1986年   428篇
  1985年   424篇
  1984年   346篇
  1983年   305篇
  1982年   227篇
  1981年   211篇
  1979年   395篇
  1978年   284篇
  1977年   237篇
  1976年   225篇
  1975年   320篇
  1974年   406篇
  1973年   416篇
  1972年   321篇
  1971年   328篇
  1970年   309篇
  1969年   279篇
  1968年   378篇
  1967年   345篇
  1966年   307篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
941.
The effects of embedding a constant time delay procedure into an independent seat work activity and using instructive feedback were evaluated in this study. Seven students with mild disabilities participated in the study that occurred in their special education classroom. A multiple probe design across sets of target behaviors was used, and students' responses to instructive feedback stimuli were evaluated during each probe condition. The procedures were implemented with a high degree of fidelity, and the results indicate that (a) the students acquired the target behaviors taught with the constant time delay procedure that was embedded into independent seat work, and (b) the students acquired some but not all of the responses to the instructive feedback stimuli. These findings are discussed in terms of using instructive feedback in classrooms and future research on instructive feedback.  相似文献   
942.
We investigated offense characteristics for a national sample of 38,749 homicide arrestees identified in the FBI Supplemental Homicide Reports for 1984 and 1993. Analyses indicated little change from 1984 to 1993 in the circumstances of homicides committed by adolescent girls; however, there were consistent offense differences between girls and boys, and between girls and women. Homicides by adolescent girls were more likely than those committed by boys to involve interpersonal conflict rather than a criminal motive such as robbery. Girls were more likely than boys to use a knife rather than a firearm and their victims were more likely to be under the age of 13 years. Compared to women (18 years or older), girls were more likely to act with an accomplice and their victims were more likely to be female and between 13 and 20 years of age. Results were inconsistent with a stereotypic masculinization theory of the increase in female violence, but provide indirect support for the importance of domestic stress and relational conflict experienced by adolescent girls. Overall, this study supports the need for differentiated study of violence by juvenile girls, and for preventive interventions which target domestic and interpersonal stress.  相似文献   
943.
New York State's initial attempt at individualizing services occurred within the context of an experiment. We randomly assigned children 5–12 years old who were referred for out-of-home placement in treatment foster care to either treatment foster care, Family-Based Treatment (n=15), or to Family-Centered Intensive Case Management (FCICM) (n=27). FCICM used teams of case managers and parent advocates to provide in-home services. Flexible service dollars, respite care, and behavior management skills training were available to assist teams in individualizing care. Preliminary outcomes indicate that children in FCICM are doing as well or better than children assigned to FBT in their functioning and symptom reduction. Parents of children in FCICM have made gains, although not at a statistically significant level, in behavior management skills and family strengths that allow them to provide care for their children at home.  相似文献   
944.
Groups of rats were administered either DSP4 (50 mg/kg, ip), xylamine (50 mg/kg, ip), or p-chloroamphetamine (2 X 10 mg/kg, ip), either 2 weeks or 1 week before the testing of two-way active avoidance. DSP4 and xylamine, the selective noradrenaline (NA) neurotoxins, caused a two-way avoidance impairment but p-chloroamphetamine, the selective 5-hydroxytryptamine (5-HT) neurotoxin, did not do so. Pretreatment with desipramine (20 mg/kg, ip) blocked the avoidance impairment caused by DSP4 and xylamine treatment. Neither DSP4 nor xylamine caused any alteration of passive avoidance retention. The biochemical analyses indicated severe NA, but not 5-HT, depletions in the DSP4 and xylamine conditions and drastic 5-HT, but not NA, depletions in the p-chloroamphetamine conditions. These results confirm and extend earlier findings concerning the role of NA in avoidance behavior.  相似文献   
945.
Long-term retention of fixed-interval curvature as an index of recall memory which is relatively free of retrieval cues was examined in younger and older rats. Previous research on free-operant behavior in younger and older rats showing within-session decrements in behavior of older rats and within-session increments in younger rats suggested that the results of recall memory tests would depend upon the duration of the test session and the point within the session where data were collected. Consistent with such expectations, recall of fixed-interval curvature was poorer in older rats when data from late in the test session or data averaged over the entire 45-min session were used, but the opposite finding, numerically better retention in the older rats, occurred when data from the earliest part of the test session were used. The results suggest that age-related performance differences from which age-related memory differences are inferred may be confounded by other age-related effects upon performance which have nothing to do with memory.  相似文献   
946.
Psychiatric inpatients in special units designed for the treatment/management of violence (secure care) are compared with inpatients in three forensic programs. Although program designers anticipated that secure care and forensic patients would be similar, they were not. Principally, secure care patients were lower functioning in the psychiatric areas and were more likely to have engaged in a physical assault in the last 30 days.  相似文献   
947.
Previous studies have identified three categories of variables which influence decisions of mock jurors: type of crime, defendant characteristics, and personal characteristics of jurors. This study manipulated the following variables towards the ends of assessing their influence on mock jurors' sentencing severity: premeditated vs. unpremeditated murder, black vs. white defendant, low SES vs. high SES defendant. Only defendant SES predicted sentencing severity: low SES defendants were assigned significantly longer sentences than high SES defendants. None of the measures of juror characteristics correlated with sentencing severity. Failure to replicate significant relationships with most of these variables and sentencing severity suggest that results of studies which manipulate only one variable dimension may overestimate the influence of these variable dimensions in mock jurors' decisions.  相似文献   
948.
The question addressed in this study is whether experts are better calibrated than lay people. We investigated how well people are calibrated when they assess the probabilities of card combinations in the game of blackjack. Three groups of subjects were used: professional dealers, statistical experts, and control subjects. The results showed that experience and statistical expertise do not make people better calibrated in this task. It is argued that the concept of calibration is not wholly appropriate to describe the obtained deviations from the normatively correct responses. This is illustrated by a discriminant analysis performed on the signed deviation scores, which resulted in an almost perfect separation of the three groups, although they were overlapping with respect to calibration.  相似文献   
949.
Inhibition of protein synthesis by anisomycin for a short duration impairs memory of a one-trial inhibitory avoidance task in rats. Memory of escape conditioning involving eight trials is disrupted only if the duration of protein synthesis is prolonged by repeated injections. In marked contrast, olfactory memory of rats trained on two odor discriminations is not affected by anisomycin even if the duration of inhibition is prolonged and the number of trials is reduced to a minimum. In previous work, leupeptin, a thiol proteinase inhibitor, was shown to impair olfactory discrimination learning, but left inhibitory and avoidance conditioning intact. Together, these results provide a pharmacological double dissociation of memory, and suggest that the same chemistries, or mixtures of chemistries, may not be involved in all types of memory.  相似文献   
950.
Life situations often seem to require dualistic, either or decision making, but this common method does not always clarify moral decisions. To show this, standard arguments on why to choose or not to choose the sex or ones child are presented. Then, our feminist thinking, which regards clusters of values, and which reframes questions rather than choosing between desirable alternatives, suggests another possibility, in a gynandrous world vision.  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