全文获取类型
收费全文 | 1454篇 |
免费 | 25篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 5篇 |
综合类 | 1篇 |
化学工业 | 197篇 |
金属工艺 | 7篇 |
机械仪表 | 11篇 |
建筑科学 | 42篇 |
矿业工程 | 7篇 |
能源动力 | 21篇 |
轻工业 | 275篇 |
水利工程 | 5篇 |
石油天然气 | 8篇 |
无线电 | 62篇 |
一般工业技术 | 106篇 |
冶金工业 | 580篇 |
原子能技术 | 1篇 |
自动化技术 | 153篇 |
出版年
2022年 | 7篇 |
2021年 | 22篇 |
2020年 | 17篇 |
2019年 | 17篇 |
2018年 | 13篇 |
2017年 | 14篇 |
2016年 | 16篇 |
2015年 | 15篇 |
2014年 | 18篇 |
2013年 | 58篇 |
2012年 | 37篇 |
2011年 | 56篇 |
2010年 | 56篇 |
2009年 | 36篇 |
2008年 | 60篇 |
2007年 | 72篇 |
2006年 | 62篇 |
2005年 | 62篇 |
2004年 | 44篇 |
2003年 | 50篇 |
2002年 | 42篇 |
2001年 | 31篇 |
2000年 | 30篇 |
1999年 | 32篇 |
1998年 | 35篇 |
1997年 | 36篇 |
1996年 | 36篇 |
1995年 | 30篇 |
1994年 | 32篇 |
1993年 | 27篇 |
1992年 | 25篇 |
1991年 | 9篇 |
1990年 | 31篇 |
1989年 | 32篇 |
1988年 | 25篇 |
1987年 | 25篇 |
1986年 | 37篇 |
1985年 | 22篇 |
1984年 | 19篇 |
1983年 | 30篇 |
1982年 | 23篇 |
1981年 | 22篇 |
1980年 | 14篇 |
1979年 | 21篇 |
1978年 | 19篇 |
1977年 | 5篇 |
1976年 | 11篇 |
1975年 | 6篇 |
1974年 | 7篇 |
1964年 | 4篇 |
排序方式: 共有1481条查询结果,搜索用时 0 毫秒
101.
Janet M. Ferguson Jeffrey P. Dorman 《Canadian Journal of Science, Mathematics, & Technology Education》2013,13(3):323-331
Abstract The strongest tradition of classroom‐environment research has focused on empirically testing the relationship between the classroom environment and student outcomes. This paper reports a study conducted within this general framework. Specifically, this research investigated the relationship between the classroom environment and self‐handicapping by students in Canadian high school mathematics classes. Results showed that the classroom environment accounted for appreciable proportions of variance in self‐handicapping, beyond that attributable to academic efficacy. Enhanced affective dimensions of the classroom environment were associated with reduced levels of self‐handicapping. 相似文献
102.
Typical audible pedestrian signals indicate when the pedestrian walk interval is in effect but provide little, or even misleading information for directional alignment. In three experiments, blind and blindfolded sighted adults crossed a simulated crossing with recorded traffic noise to approximate street sounds. This was done to investigate how characteristics of signal presentation affected usefulness of the auditory signal for guiding crossing behaviour. Crossing was more accurate when signals came only from the far end of the crossing rather than the typical practice of presenting signals simultaneously from both ends. Alternating the signal between ends of the crossing was not helpful. Also, the customary practice of signalling two parallel crossings at the same time drew participants somewhat toward the opposite crossing. Providing a locator tone at the end of the crossing during the pedestrian clearance interval improved crossing accuracy. These findings provide a basis for designing audible pedestrian signals to enhance directional guidance. The principal findings were the same for blind and sighted participants and applied across a range of specific signals (e.g. chirps, clicks, voices). 相似文献
103.
Janet Soler 《Pedagogy, Culture & Society》1999,7(3):523-540
The late 1990s have seen a resurgence of the arguments for a skills-focused literacy instruction programme. This article explores the New Zealand-based public and professional debates surrounding the promotion of a technocratic approach to literacy instruction during the 1940s and 1950s, and the reoccurrence of the reading debate in late 1990s. In the early stages of both literacy crises, the professional competency of education officials and primary teachers was attacked by business interests and their political allies. The aftermath of the earlier crisis highlights the failure of this mechanistic and 'culture neutral' view of literacy instruction to cater for Maori children. The outcomes of the earlier debate signals a need avoid a similar conclusion to the current debate by adopting a broader approach to literacy instruction in the new millennium if language and literacy instruction programmes are to cater for complex cultural contexts, and the changing technological environments 相似文献
104.
Examined the power–dependency relationships between "whistle blowers" and their employers through the regression analyses of survey data from 636 employees of federal agencies who had reported evidence of official wrongdoing. Ss reported that they were more likely to suffer retaliation if they lacked the support of their supervisors and managers. Retaliation was also more severe if the wrongdoing was serious and if the S used channels outside the organization to report the incident. Following severe retaliation, Ss were likely to file official complaints about the retaliation and to leave their jobs involuntarily. Other predictors of reactions to retaliatory action are discussed. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
105.
Maylor Elizabeth A.; Vousden Janet I.; Brown Gordon D. A. 《Canadian Metallurgical Quarterly》1999,14(4):572
Age-related deficits in short-term memory have been widely reported, but reduced overall scores could reflect increased order errors, increased omissions, or increased intrusions. Different explanations for reduced short-term memory with aging lead to different predictions. In this study, young (n?=?68; M age?=?20 years) and older (n?=?99; M age?=?65 years) adults were presented with lists of letters and were asked to recall each list immediately in the correct order. Age differences in error patterns were similar for auditory and visual presentation. For example, older adults made more errors of every type, and a greater proportion of the older adults' errors were omissions. An additional condition, in which older adults were encouraged to guess, ruled out an age increase in response threshold as a full explanation for the results. The data were modeled by an oscillator-based computational model of memory for serial order. A good fit to the aging data was achieved by simultaneously altering two parameters that were interpreted as corresponding to frontal decline and response slowing. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
106.
Fifty-nine 3-year-olds were tested 3 times over a period of 7 months in order to assess the contribution of theory of mind to language development and of language to theory-of-mind development (including the independent contributions of syntax and semantics). Language competence was assessed with a standardized measure of reception and production of syntax and semantics (the Test of Early Language Development). Theory of mind was assessed with false-belief tasks and appearance–reality tasks. Earlier language abilities predicted later theory-of-mind test performance (controlling for earlier theory of mind), but earlier theory of mind did not predict later language test performance (controlling for earlier language). These findings are consistent with the argument that language is fundamental to theory-of mind development. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
107.
Sanders Raymond E.; Wise Janet L.; Liddle Cherie L.; Murphy Martin D. 《Canadian Metallurgical Quarterly》1990,5(2):172
The usual superiority in frequency-of-occurrence judgments of younger vs older subjects was hypothesized to result from greater strategic encoding of the materials conveying frequency information. A subject-paced, visual search task was designed to control nontarget word encoding. Relative frequency judgments for the nontarget word pairs were equally accurate for younger and older subjects, and performance of both groups was above chance. Results suggest that strategic cover-task encoding can induce age differences in incidental frequency processing. Consistent with a nonoptimal as opposed to an optimal view, automatic processes require only minimal capacity for above-chance performance, but additional strategic resources can increase performance. When such additional resources are used more by younger than by older subjects, the former are better in frequency performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
108.
Professors in 6 matched pure and applied fields of study were interviewed to determine the validation processes and truth criteria used in their disciplines. Differences across disciplines were found in the validation processes and in the importance placed on conceptual frameworks or models. Use of empirical evidence was more important in the natural and social sciences; peer review was more important in the humanities. Professors in pure fields of study were more likely to use conflicting evidence or counterexamples in validating their work than were professors in applied fields. The results suggest that different fields of study operate according to different sets of rules. An important part of university instruction is to provide students with a sense of what these rules are and how they affect learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
109.
110.
This study investigated the thoughts and feelings that young adults from violent (VPA) and nonviolent (NPA) interparental-conflict backgrounds reported while listening to simulated marital conflicts and after a delay for reflection. While listening to conflicts, VPAs were more likely than NPAs to predict negative outcomes and to place blame. No between–groups differences regarding negative outcomes emerged after a delay. VPAs also reported perpetrating and experiencing more aggressive conflict in their dating relationships. Post hoc probes revealed that the negative-outcome-prediction and blaming variables played no significant mediating role in participants' intergenerational patterns of intimate-relationship aggression; however, methodological limitations likely compromised the statistical power for examining this mediational model. Results are discussed in light of research regarding intergenerational patterns of violence within families. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献