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   394篇
  免费   16篇
化学工业   104篇
金属工艺   3篇
机械仪表   3篇
建筑科学   30篇
能源动力   8篇
轻工业   68篇
水利工程   1篇
无线电   8篇
一般工业技术   56篇
冶金工业   59篇
自动化技术   70篇
  2023年   3篇
  2022年   9篇
  2021年   19篇
  2020年   10篇
  2019年   10篇
  2018年   8篇
  2017年   10篇
  2016年   11篇
  2015年   9篇
  2014年   19篇
  2013年   28篇
  2012年   19篇
  2011年   33篇
  2010年   16篇
  2009年   22篇
  2008年   18篇
  2007年   19篇
  2006年   15篇
  2005年   12篇
  2004年   8篇
  2003年   15篇
  2002年   5篇
  2001年   4篇
  2000年   7篇
  1999年   7篇
  1998年   7篇
  1997年   3篇
  1996年   5篇
  1995年   5篇
  1994年   4篇
  1993年   4篇
  1992年   5篇
  1990年   3篇
  1988年   5篇
  1985年   5篇
  1983年   1篇
  1982年   2篇
  1981年   1篇
  1980年   2篇
  1979年   3篇
  1978年   1篇
  1977年   3篇
  1976年   3篇
  1974年   1篇
  1970年   1篇
  1965年   2篇
  1964年   1篇
  1962年   1篇
  1960年   1篇
  1957年   1篇
排序方式: 共有410条查询结果,搜索用时 15 毫秒
71.
Hispanic children are the fastest growing segment of the population. Numerous factors place them at-risk for school success. This study examined the effects of Child-Centered Play Therapy (CCPT) compared to a curriculum-based small group intervention with 29 Hispanic children referred for school counseling due to behavior problems. Children were assigned to treatment groups by random drawing within grade levels. Treatment was provided by Hispanic bilingual counselors. Statistical analysis revealed that, according to parent report, children receiving CCPT showed statistically significant decreases in externalizing behavior problems, compared to the curriculum-based treatment group. Effect size calculations revealed that CCPT demonstrated a large treatment effect on externalizing behavior problems and a moderate treatment effect on internalizing behavior problems. Cultural considerations and recommendations for practice and future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
72.
Blind and blindfolded sighted observers were presented with auditory stimuli specifying target locations. The stimulus was either sound from a loudspeaker or spatial language (e.g., "2 o'clock, 16 ft"). On each trial, an observer attempted to walk to the target location along a direct or indirect path. The ability to mentally keep track of the target location without concurrent perceptual information about it (spatial updating) was assessed in terms of the separation between the stopping points for the 2 paths. Updating performance was very nearly the same for the 2 modalities, indicating that once an internal representation of a location has been determined, subsequent updating performance is nearly independent of the modality used to specify the representation. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
73.
74.
The dehydroalkylation of toluene with ethane to the isomeric ethyltoluenes was studied on 0.4Pt/H-ZSM-5 at varying contact times (1/WHSV). At a high contact time of 1.0 h, toluene disproportionation and hydrogenolysis reactions dominate, resulting in low selectivity to the desired ethyltoluenes via the alkylation reaction. However, at a low contact time of 0.12 h side reactions are eliminated, resulting in maximum selectivities to the kinetically favored ethyltoluenes and hydrogen. Results at high selectivities to ethyltoluenes provide significant insight into reaction pathways.  相似文献   
75.
The 5-HTTLPR is an insertion/deletion polymorphism in the promoter region of the serotonin transporter gene. Prior research has revealed associations between the short-allele variant of this polymorphism, enhanced self-reported negative emotionality, and hypersensitivity of fear relevant neural circuits. In a sample of 50 healthy women we examined the role of 5-HTTLPR for cognitive-affective processing of phylogenetical fear-relevant stimuli (spiders) in a dot probe task. In contrast to homozygote long-allele carriers (ll), participants carrying at least 1 short allele (ss and sl) selectively shifted attention toward pictures of spiders, when these were presented for a duration of 2,000 ms. These results argue for an involvement of 5-HTTLPR in cognitive processing of threatening stimuli and thus, underpin its general role for individual differences in negative affect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
76.
77.
. The development of a representational framework, based on Moran's Command Language Grammar, for constructing adaptive computer systems is the main topic of this paper. A model of the user interface is developed of which two aspects are discussed: the mental model in the mind of the user and the perceptual model on the side of the machine. Cognitive style and personality factors are considered in their relation to the development of the mental model. The concept of metacommunication is analysed and discussed on all levels of Moran's CLG.  相似文献   
78.
79.
Eleven surfactants representing pure cationic anionic and nonionic detergents, four commercial detergents, sodium pyrophosphate, sodium tripolyphosphate, a soap and nitrilotriacetic acid were investigated for their effect on the spectrophotometric and specific ion electrode determinations of fluoride in water. Cationic, anionic and nonionic detergents at concentrations up to 50, 400 and 1000 mg l−1, respectively, gave 5% error or less in the determination of fluoride. Sodium tripolyphosphate interfered badly above 1.5 mg l−1, and therefore the interference by formulated detergents containing tripolyphosphate was large. The fluoride ion activity electrode method is the most suitable procedure for the determination of fluoride in polluted waters containing surfactants.  相似文献   
80.
As the use of computers increases, the cost of educating computer users rises. Therefore the need for extensive education of users should be avoided as much as possible. Instead computer systems should be adapted to the requirements and characteristics of computer users. Hereby the need to identify user characteristics arises. The less computer educated the users, the more their requirements of the systems will differ. Where user characteristics are difficult to change, it will be worthwhile to attend to user differences in the design of systems. The implications of user differences may vary depending upon the type of task to be performed. The present paper presents an analysis of different user characteristics and their possible interactions with different task requirements. Hereby some recommendations regarding the need to educate users or adapt systems to the user were derived.  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