全文获取类型
收费全文 | 2125篇 |
免费 | 30篇 |
专业分类
电工技术 | 37篇 |
综合类 | 2篇 |
化学工业 | 184篇 |
金属工艺 | 29篇 |
机械仪表 | 49篇 |
建筑科学 | 104篇 |
矿业工程 | 5篇 |
能源动力 | 44篇 |
轻工业 | 151篇 |
水利工程 | 32篇 |
石油天然气 | 9篇 |
无线电 | 152篇 |
一般工业技术 | 267篇 |
冶金工业 | 810篇 |
原子能技术 | 22篇 |
自动化技术 | 258篇 |
出版年
2021年 | 17篇 |
2020年 | 12篇 |
2019年 | 16篇 |
2018年 | 17篇 |
2017年 | 16篇 |
2016年 | 17篇 |
2015年 | 21篇 |
2014年 | 37篇 |
2013年 | 119篇 |
2012年 | 43篇 |
2011年 | 60篇 |
2010年 | 44篇 |
2009年 | 42篇 |
2008年 | 53篇 |
2007年 | 71篇 |
2006年 | 66篇 |
2005年 | 60篇 |
2004年 | 56篇 |
2003年 | 41篇 |
2002年 | 62篇 |
2001年 | 36篇 |
2000年 | 38篇 |
1999年 | 53篇 |
1998年 | 184篇 |
1997年 | 134篇 |
1996年 | 102篇 |
1995年 | 69篇 |
1994年 | 54篇 |
1993年 | 50篇 |
1992年 | 38篇 |
1991年 | 30篇 |
1990年 | 30篇 |
1989年 | 41篇 |
1988年 | 34篇 |
1987年 | 23篇 |
1986年 | 25篇 |
1985年 | 35篇 |
1984年 | 16篇 |
1983年 | 20篇 |
1982年 | 25篇 |
1981年 | 30篇 |
1980年 | 18篇 |
1979年 | 15篇 |
1978年 | 14篇 |
1977年 | 37篇 |
1976年 | 37篇 |
1974年 | 9篇 |
1973年 | 15篇 |
1972年 | 14篇 |
1971年 | 9篇 |
排序方式: 共有2155条查询结果,搜索用时 46 毫秒
61.
62.
Information systems (IS) research has drawn heavily on social and cognitive psychology to explain technology adoption. Indeed, the many variations of the technology acceptance model all share these same theoretical foundations. Focusing exclusively on the socio-cognitive lens can lead to overlooking enhanced explanations of technology acceptance, such that new theoretical perspectives may be warranted. In this qualitative grounded theory study, we discovered how the lens of evolutionary psychology, as embodied in the Four-Drive model, was helpful in understanding technology acceptance across three organizational sites. We contend that evolutionary psychology is an important addition to the theoretical repertoire of IS researchers, and propose including ‘evolved psychological mechanisms’ within traditional models of technology acceptance. 相似文献
63.
64.
Jane M. Watson Ben A. Kelly 《Canadian Journal of Science, Mathematics, & Technology Education》2013,13(2):145-166
Abstract: A task adapted from one used by Tversky and Kahneman (1971) was used in an interview or questionnaire context with 122 students from Grade 3 to Grade 13. Two questions assessed student understanding of the relationship of a sample to a population and of the expected value of the arithmetic mean, with and without information on a single value from the sample. Combining responses to the two questions, increasingly complex hierarchical sequences were identified in the observed responses in relation to the expected value of the means, an expectation variable, and in relation to the degree that ideas about variation were used to support judgements, a variation variable. Using data from another task performed by 68 of the students, responses were associated with the observed development of understanding of sampling more generally, a basic sampling variable. Overall, the associations of levels of response among the variables was not strong, suggesting more explicit discussion of sampling issues is required in classrooms. 相似文献
65.
Ventilation system analysis for underground mines has remained mostly unchanged since the Atkinson method was made popular by Mc Elroy in 1935. Data available to ventilation technicians and engineers is typically limited to the quantity of air moving through any given heading. Because computer-aided modelling, simulation, and ventilation system design tools have improved, it is now important to ensure that developed models have the most accurate information possible. This paper presents a new technique for estimating underground drift friction factors that works by processing 3 D point cloud data obtained by using a mobile Li DAR. Presented are field results that compare the proposed approach with previously published algorithms, as well as with manually acquired measurements. 相似文献
66.
67.
68.
R.N. Watson 《成像科学杂志》2013,61(6):304-310
The construction of a computational model representing a masked negative film is described. Model negative tripacks are then used in the context of a complete negative-positive system to demonstrate the changes in colour reproduction which result from increasing the degree of masking of the magenta dye. 相似文献
69.
Donald Watson 《Journal of Architectural Education》2013,67(4):41-42
Summary of some of the topics covered by the author under the ACSA-AMAX Research Fellowship, which he won in 1967. 相似文献
70.