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   35584篇
  免费   1541篇
  国内免费   25篇
  2020年   409篇
  2019年   483篇
  2018年   704篇
  2017年   681篇
  2016年   810篇
  2015年   511篇
  2014年   658篇
  2013年   2992篇
  2012年   1169篇
  2011年   1194篇
  2010年   697篇
  2009年   812篇
  2008年   1022篇
  2007年   1045篇
  2006年   941篇
  2005年   779篇
  2004年   806篇
  2003年   739篇
  2002年   751篇
  2001年   1125篇
  2000年   1122篇
  1999年   847篇
  1998年   393篇
  1997年   365篇
  1995年   366篇
  1993年   349篇
  1992年   675篇
  1991年   634篇
  1990年   608篇
  1989年   587篇
  1988年   589篇
  1987年   527篇
  1986年   518篇
  1985年   584篇
  1984年   481篇
  1983年   435篇
  1982年   364篇
  1979年   514篇
  1978年   374篇
  1977年   352篇
  1976年   365篇
  1975年   403篇
  1974年   464篇
  1973年   489篇
  1972年   423篇
  1971年   363篇
  1969年   349篇
  1968年   427篇
  1967年   381篇
  1966年   364篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
In this article the perspective shifts to the “upstream” end of the agricultural knowledge and information system (AKIS). Because knowledge policy and strategic decision-making are not the prerogative of the public sector, organizations such as cooperative unions and multinational companies are included. After considering the influence of the changing environment on the nature of the AKIS, the role of knowledge management and policy in the emerging knowledge and information market is examined. Special attention is given to public and private R&D. The article then looks where information technology (IT) fits in and what considerations determine strategic investment in IT projects and sustained services. Some of the European experiences with this strategic investment are evaluated.  相似文献   
972.
Despite demonstrations of the utility and cost effectiveness of behavioral programming, such techniques are not commonly employed in psychiatric inpatient settings. Several explanations for this have been proposed, including inadequate levels of training and competence in behavioral programming among prevalent treatment staff. This study employed a multiple choice inventory to assess behavioral knowledge among subjects representing several direct care disciplines commonly found in inpatient psychiatric settings. The results support assertions of relatively low levels of behavioral knowledge among disciplines that are most prevalent in such settings. The implications of these results for initiatives to enhance behavioral knowledge and skills are discussed.  相似文献   
973.
Three inexpensive text-to-speech synthesizers are described, intelligibility data from a pilot experiment are reported, and software is offered that has been written to facilitate the phonemic programming of the Heathkit-Votrax synthesizer.  相似文献   
974.
975.
976.
977.
A system of interfaces for the Commodore 64 (C-64) microcomputer for use in the operant laboratory is described. This system frees the experimenter from limitations on the number of I/O lines available on the user port of the C-64 and offers the control of operant chambers for a low cost. Subroutines in machine code to control the interfaces, offering millisecond timing of external events, are presented. A sample BASIC program demonstrates how the subroutines are called from BASIC to run a simple discrimination experiment.  相似文献   
978.
The orienting response (OR) is a specific behavioral act directed towards extraction of information from the environment. Head and eye movements represent only the tip of the iceberg of internal responses, which includes vascular modifications, EEG changes, and event-related potentials. Two mechanisms of the OR have to be differentiated: voluntary and involuntary. In the event-related potential, such a differentiation is expressed in mismatch negativity (involuntary effect) and processing negativity (voluntary effect). Single unit studies have shown that hippocampal neurones are simulating specific features of the OR as a response to novelty. Repeated presentation of stimuli results in a selective habituation of novelty detectors in hippocampus and of the OR. The trace of a standard stimulus formed at the level of hippocampal neurones matches the features of the standard stimulus and can be called a “neuronal model of the stimulus.” The OR is triggered by mismatch between the test stimulus and the elaborated neuronal model, and is activated by verbal instruction, by reinforcement during the initial stage of conditioned reflex elaboration, and by differentiation of signal and non-signal stimuli. A promising new area of practical application of the OR lies in the evaluation of a corridor of optimal functional state for efficient computer-based learning. Registration of the OR and defensive responses can be used for an objective evaluation of the functional state of the student, or, in a wider sense, of the industrial operator. New avenues of OR research are opened by recent techniques that isolate single-trial event related potentials, and their correlation with autonomic and behavioral manifestations of the OR. The combination of single unit recording with such isolated event related potentials can elucidate the neuronal basis of OR generation. Intracellular recording combined with dye injection can be used for analysis of the synaptic contacts involved in generation of the OR. Integration of macro and micro levels of OR organization can be achieved in a computerized model that can be used for simulation and planning of experiments. A step-by-step improvement of the model will accumulate knowledge about the OR as an important mechanism of information processing.  相似文献   
979.
A structured interviewing system was developed which included an item bank of pre-written past-behaviour questions. Scoring anchors for each of 168 questions in the item bank were created from analysis of protocols from individual assessments. A concurrent validation study was conducted, focusing on the job of highway patrol sergeant. Job knowledge experts used a job analysis tool to select a subset of twelve questions from the item bank. Panel interviews were conducted with 32 highway patrol sergeants as subjects. Average inter-rater reliability was 0.65 and interview validity was 0.42 for group consensus scores and 0.44 for panel average scores. Discussion focused on practical issues affecting the interviewing system.  相似文献   
980.
This paper examines the effects of person-centered theory on contemporary psychological testing. Seven basic ideas or assumptions, which are integral to and guide the testing process, are identified and briefly discussed. Each idea is considered to have been affected either directly or indirectly by person-centered philosophy. Some of the ways in which these ideas are reflected in contemporary testing practice are indicated.  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